DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Applicant' s arguments, filed 2/13/2026, have been fully considered. The following rejections and/or objections are either reiterated or newly applied. They constitute the complete set presently being applied to the instant application.
Applicants have amended their claims, filed 2/13/2026, and therefore rejections newly made in the instant office action have been necessitated by amendment.
Claims 1-17 and 19-21 are the currently pending claims hereby under examination. Claim 18 has been canceled. Claim 21 has been newly added.
Claim Interpretation
The following is a quotation of 35 U.S.C. 112(f):
(f) Element in Claim for a Combination. – An element in a claim for a combination may be expressed as a means or step for performing a specified function without the recital of structure, material, or acts in support thereof, and such claim shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof.
The following is a quotation of pre-AIA 35 U.S.C. 112, sixth paragraph:
An element in a claim for a combination may be expressed as a means or step for performing a specified function without the recital of structure, material, or acts in support thereof, and such claim shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof.
The claims in this application are given their broadest reasonable interpretation using the plain meaning of the claim language in light of the specification as it would be understood by one of ordinary skill in the art. The broadest reasonable interpretation of a claim element (also commonly referred to as a claim limitation) is limited by the description in the specification when 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, is invoked.
As explained in MPEP § 2181, subsection I, claim limitations that meet the following three-prong test will be interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph:
(A) the claim limitation uses the term “means” or “step” or a term used as a substitute for “means” that is a generic placeholder (also called a nonce term or a non-structural term having no specific structural meaning) for performing the claimed function;
(B) the term “means” or “step” or the generic placeholder is modified by functional language, typically, but not always linked by the transition word “for” (e.g., “means for”) or another linking word or phrase, such as “configured to” or “so that”; and
(C) the term “means” or “step” or the generic placeholder is not modified by sufficient structure, material, or acts for performing the claimed function.
Use of the word “means” (or “step”) in a claim with functional language creates a rebuttable presumption that the claim limitation is to be treated in accordance with 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph. The presumption that the claim limitation is interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, is rebutted when the claim limitation recites sufficient structure, material, or acts to entirely perform the recited function.
Absence of the word “means” (or “step”) in a claim creates a rebuttable presumption that the claim limitation is not to be treated in accordance with 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph. The presumption that the claim limitation is not interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, is rebutted when the claim limitation recites function without reciting sufficient structure, material or acts to entirely perform the recited function.
Claim limitations in this application that use the word “means” (or “step”) are being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, except as otherwise indicated in an Office action. Conversely, claim limitations in this application that do not use the word “means” (or “step”) are not being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, except as otherwise indicated in an Office action.
This application includes one or more claim limitations that do not use the word “means,” but are nonetheless being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, because the claim limitation(s) uses a generic placeholder that is coupled with functional language without reciting sufficient structure to perform the recited function and the generic placeholder is not preceded by a structural modifier. Such claim limitation(s) is/are:
Claim 16 recites “rotating mechanism configured to rotate” (line 3) and “position adjusting mechanism configured to move” (line 5). The term “mechanism”, when used in combination with purely functional language, is a nonspecific nonce word that does not recite sufficient structure to perform the claimed functions under Williamson v. Citrix. Accordingly, the limitations are construed to cover the corresponding structures disclosed in the specification and statutory equivalents (see Specification ¶[0055]–[0061], for details of the driving device D, rotating mechanism R, and position adjusting mechanism T.
Because this/these claim limitation(s) is/are being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, it/they is/are being interpreted to cover the corresponding structure described in the specification as performing the claimed function, and equivalents thereof.
If applicant does not intend to have this/these limitation(s) interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, applicant may: (1) amend the claim limitation(s) to avoid it/them being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph (e.g., by reciting sufficient structure to perform the claimed function); or (2) present a sufficient showing that the claim limitation(s) recite(s) sufficient structure to perform the claimed function so as to avoid it/them being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph.
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claims 1 and 8-9 are rejected under 35 U.S.C. 103 as being unpatentable over Tang et al. (Tang et al. “Design of Novel End-Effectors for Robot-Assisted Swab Sampling to Combat Respiratory Infectious Diseases.” 2021 43rd Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC). vol. 2021. United States: IEEE, 2021. 4757–47), hereto referred as Tang, and further in view of Chen et al. (CN-201039231-Y), hereto referred as Chen.
Regarding claim 1, Tang teaches that a robot pressing mechanism (Tang, Title: "Design of Novel End-effectors for Robot-assisted Swab Sampling to Combat Respiratory Infectious Diseases"; Abstract: "...end-effector designs that can be equipped at the distal end of a robot to passively regulate or actively sense the force exerted onto patients. One way is to introduce passive compliant mechanisms with soft material to increase the flexibility of the swabbing system... It is identified that the passive compliant mechanisms can increase the flexibility of the swabbing system when subjected to the lateral force and mitigate the vertical force resulted from buckling", demonstrating a robot pressing mechanism) comprises:
pressing device extending in a first direction (Tang, FIG. 1-2; p. 4757-4758, II.A: "The design consists of a fixture to hold the swab in place and a passive mechanism with different configurations to introduce extra compliance (Fig. 2). The base of the compliant mechanism is mounted to a connector, which can be further attached to a robot... When the tip of the swab touches upon the nasal or the oral cavity, there will be force acting upon the swab and as a result the swab will bend... additional compliance is introduced with bending motions generated by the mechanism through body deformation to adaptively adjust the posture of the swab, avoiding excessive force", Tang teaches an end-effector subassembly in which an elongated swab functions as the pressing device that is advanced into the nasal or oral cavity along the direction of the swab's elongated body, and thereby corresponds to a pressing device extending in a first direction, where the swab tip applies force to the patient when advanced into the nasal or oral cavity); a support device connected to the pressing device and moving in the first direction relative to the pressing device (Tang, FIG. 2; p. 4757-4758, II.A: “The base of the compliant mechanism is mounted to a connector, which can be further attached to a robot… When the tip of the swab touches upon the nasal or the oral cavity, there will be force acting upon the swab and as a result the swab will bend”, FIG. 2 depicts the connector (support device) coupled to the compliant mechanism and the fixture holding the swab (pressing device). As the robot advances or withdraws the end-effector, the connector is driven in the insertion direction, and the compliant mechanism introduces bending and deformation that cause the position of the swab to shift relative to the connector along that same direction. Thus, even though the connector and fixture are carried forward together by the robot arm, the compliant mechanism’s deformation produces relative displacement in the first direction between the support device and pressing device under swabbing loads); and the support device comprises a guide member that is spaced apart from the pressing device in a direction crossing the first direction (Tang, FIG. 2: depicts the connector (i.e. support device) as coupling with the compliant mechanism via a disk (i.e. guide member) which is orientated in a direction crossing the first direction and acts to support and guide a portion of the compliant mechanism. The disk is also spaced apart from the pressing device).
Also regarding claim 1, Tang does not fully teach that a flat spring is configured to connect the pressing device to the support device. Rather, Tang teaches a compliant mechanism that functions as a spring and figure 2 depicts several configurations including sets of elongated bars which are the equivalent of flat springs (Tang, FIG. 2; p. 4757-4758, II.A: "The compliant mechanism was 3D printed using Thermoplastic polyurethane (TPU), with a Young’s Modulus of 8 MPa and a Poisson's ratio of 0.45... Because of the soft structure is made of TPU that has a Young’s Modulus smaller than the material of the swab stick, additional compliance is introduced with bending motions generated by the mechanism through body deformation to adaptively adjust the posture of the swab, avoiding excessive force"). These disclosures show that Tang provides a compliant spring-like connection between the swab (pressing device) and the connector (support device), but Tang does not describe that compliant mechanism as a flat spring or characterize it as a band-type or plate-type spring configured in a defined flat-spring geometry.
Chen fills this gap by expressly disclosing a constant-force spring mechanism in which a band or flat-type "coil spring" connects two structural members: an elongated rod for pushing and a guide-type member. Chen explains that the coil spring is fixed in the supporting member and that one end portion of the spring is anchored in a positioning groove and held by a positioning piece while the opposite end is connected to a sliding push rod, so that the flat spring ends are fixed relative to the respective members they connect (Chen, FIG. 1, 4; Abstract; [0029]).
It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified Tang in view of Chen to implement Tang’s compliant connection between the swab fixture (pressing device) and the connector (support device) as a flat spring having its ends connected to those components, by adopting Chen’s band-type spring configuration in which a flat spring is fixed within a supporting member and has its opposite ends coupled and fixed to members that move relative to one another along defined directions. Such a modification would have been feasible because both Tang and Chen address controlling force transmission between components using compliant spring structures, and one of ordinary skill in the art would have recognized that reshaping Tang’s compliant body as a Chen-type flat band spring with fixed end portions at the pressing-device side and support-device side would preserve the compliant function while providing a more predictable constant-force response. The benefit would be improved consistency and repeatability of the compliant behavior during insertion and pressing, helping to avoid excessive or sudden forces on the patient and thereby improving safety and comfort in robot-assisted nasopharyngeal sampling.
Also regarding claim 1, the modified Tang does not teach that the flat spring comprises: a first plate coupled to the pressing device and extending in the first direction; a second plate coupled to the guide member and extending in a direction in which the guide member extends; and a third plate bent [once and directly coupled to the first plate and the second plate] to connect one end of the first plate and one end of the second plate. Rather, it teaches a robot swab end-effector that uses a passive compliant mechanism between a fixture holding the swab and a connector mounted to the robot, where the compliant mechanism is 3D-printed from a soft material and bends to introduce additional compliance and regulate force on the patient (Tang, II.A); however, Tang does not disclose that the compliant mechanism is implemented as a flat spring that is explicitly divided into a first plate coupled to the pressing device extending in a first direction, a second plate coupled to a guide member extending in the guide direction, and a third bent plate connecting the ends of the first and second plates.
Chen teaches a constant-force spring mechanism including coil spring (4) fixed within a supporting member and connected to a push rod that moves relative to the supporting member (Chen, ¶[0008]–[0010]; Figs. 1–6). As illustrated in Chen’s figures, the coil spring is formed from a continuous spring strip having straight end portions that are respectively coupled to structural members and a curved intermediate portion forming the spring body between those end portions. The inner end of the spring is anchored within a positioning groove of positioning block 8 inside supporting member 1, while the opposite end portion extends outward and connects to the sliding push rod (Chen, Figs. 1 and 4; ¶[0008]–[0010]; [0029]). Because the push rod moves along its guide direction within the supporting member, the straight end portion coupled to the push rod extends along that rod direction, while the opposite end portion is fixed relative to the supporting member and oriented along the direction defined by the guide structure of the support member. Accordingly, Chen discloses a flat spring structure having (1) a first plate-like end portion coupled to a first structural member and extending along that member’s direction of motion, (2) a second plate-like end portion coupled to a different structural member and extending along the direction defined by the guide structure of the support member, and (3) a bent intermediate portion connecting the end portions.
It would have been prima facie obvious before the effective filing date of the claimed invention to implement Tang’s compliant connection between the pressing device and the support device using a flat spring configuration of the type taught by Chen. Tang teaches the desirability of providing compliance between the swab fixture and the supporting connector to regulate force and avoid excessive force during swab insertion (Tang, Sec. II.A; Fig. 2), while Chen teaches a coil spring configuration having end portions coupled to respective structural members and an intermediate bent spring body that regulates relative displacement between those members (Chen, ¶[0008]–[0010]; Figs. 1–6). In view of these teachings, one of ordinary skill in the art would have recognized that Chen’s spring configuration could be implemented when designing the compliant element of Tang’s mechanism such that one plate-like portion of the spring extends along the pressing-device direction and another plate-like portion extends along the guide-member direction, with a bent intermediate region connecting those plate portions to permit controlled relative movement between the components. In such an implementation, the spring would be positioned between the swab fixture and the connector of Tang’s end-effector with opposite end portions secured to those respective structures, allowing the spring to deform between them during swab insertion while maintaining guided relative motion between the components.
With respect to the limitation that the third plate is “bent once,” the claim requires that the third plate be a bent portion that connects one end of the first plate and one end of the second plate. The claim does not require that the spring body exclude additional curvature beyond that bent connection, nor does it require that a continuous curved spring region be treated as “bent more than once” merely because it continues through multiple turns. Under a broad, reasonable interpretation, Chen’s coil spring formed from a continuous spring strip includes an intermediate curved region that directly connects the two end portions, and therefore already reads on the third plate being “bent once” and directly coupled to the first and second plates, because the end portions are connected through the continuous spring body without any intervening linkage or separate component (Chen, Figs. 2–5; ¶[0008]–[0010]).
Alternatively, “bent once” may simply refer to a formation process in which the third plate is formed in a one-time bending process. That is, “bent once” can also be interpreted as the physical action of forming that occurs at a single time, regardless of how many bends or turns are formed. With this interpretation, the method of formation does not distinguish the claimed structure form the combination.
Alternatively, even assuming, arguendo, that Applicant advances a narrower interpretation of “bent once” to require a single bend without additional turns, Chen still supports the Office position because Chen illustrates coil spring (4) with different winding configurations (i.e. number of windings) across embodiments (Chen, Figs. 2, 4, and 6), demonstrating that the winding configuration is a selectable spring-geometry parameter used to meet packaging and force-response objectives. Springs are well known mechanical elements used to regulate force between relatively movable components, and selecting a particular spring geometry or bend configuration to achieve a desired compliance profile constitutes routine engineering design within the level of ordinary skill in the art.
The benefit of this combination would be to improve Tang’s swabbing end-effector by providing a more predictable and substantially constant force response during swab insertion and pressing. Because Tang already seeks to introduce compliance to avoid excessive force applied to the patient (Tang, Sec. II.A), implementing the compliant element using the spring configuration taught by Chen would enhance the ability of the mechanism to regulate insertion forces in a controlled and repeatable manner while maintaining the compliant behavior described by Tang, thereby improving safety and comfort during robot-assisted nasopharyngeal or oropharyngeal sampling.
Regarding claim 8, the modified Tang does not expressly state that the first plate is fixed to the outer surface of the pressing device, and the second plate is fixed to the inner surface of the guide member. As established in the mapping of claim 1, the modified Tang structure in view of Chen already teaches a flat spring having a first plate region on the pressing-device side and a second plate region on the guide-member side, each arranged along the corresponding outer and inner surfaces so that the pressing device and guide member are elastically linked. However, the combined art does not explicitly state that the first plate is fixed to the outer surface of the pressing device and that the second plate is fixed to the inner surface of the guide member, in the sense that the plate ends are non-slidingly anchored to those surfaces.
Chen teaches that the band-type wind spring is fixed at its ends to structural members of a sliding mechanism. Chen explains that a “first pushrod 2 and second pushrod 3 are inserted into the two slots 5 respectively. The first pushrod 2 and the second pushrod 3 can slide relatively parallel to each other. One end of the first pushrod 2 and the second pushrod 3 are respectively connected to a coil spring 4, which is fixed in support number 1” and that the “rear cover 7 is provided with a positioning groove corresponding to the position of the coil spring 4. The coil spring 4 is locked in the positioning groove and secured by the positioning block 8 of the front cover 6.” (Chen, [0027]-[0032]). These passages show that the flat, band-like spring is fixed in the supporting member and its end is stuck in a positioning groove and chucked by a positioning block, i.e., the spring ends are rigidly anchored to defined surfaces of the structural members rather than loosely coupled or sliding along them (see also FIG. 4).
It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the combined Tang and Chen in view of Chen so that the first plate of the flat spring is fixed to the outer surface of the pressing device and the second plate is fixed to the inner surface of the guide member. In such a modification, the first plate region at the pressing-device side would be fixed to the outer surface of the pressing device, and the second plate region at the guide-member side would be fixed to the inner surface of the guide member, implementing Chen’s fixed and chucked spring-end attachment scheme at the specific surfaces defined in the robot pressing mechanism.
Such a modification would have been feasible because the combined Tang and Chen structure already positions the flat spring between the pressing device and the guide member and requires stable transmission of elastic force between these components. Chen demonstrates that a band-like flat spring can be fixed in a supporting member and stuck in a positioning groove using a positioning block, providing a straightforward, well-known way to rigidly anchor flat spring ends to surrounding structural surfaces. One of ordinary skill in the art would have recognized that the same fixed anchoring technique can be applied to the plate portions of the flat spring at the outer surface of the pressing device and the inner surface of the guide member in the robot pressing mechanism without altering the overall geometry or function of the compliant linkage.
The benefit of this combination would be to ensure that the flat spring plates remain in precise, repeatable alignment with the outer surface of the pressing device and the inner surface of the guide member, improving the predictability of the elastic restoring force, maintaining a stable relationship between the spring deformation and the pressing motion, and avoiding unintended slip or shifting at the interfaces. This is consistent with Chen’s teaching that, under the effect of the fixed wind spring, “the force on each segment is almost constant, making the sliding cover smooth and easy to use” (Chen, [0034]), and would similarly provide smooth, consistent operation of the robot pressing mechanism while preserving the compact flat-spring configuration established in the claim 1 combination.
Regarding claim 9, the modified Tang does not disclose that the guide member and the flat spring are each provided in plurality, and the plurality of guide members and the plurality of flat springs are equally spaced apart from each other around the pressing device. As established in claim 1, the modified Tang structure in view of Chen already teaches a robot pressing mechanism having a pressing device, a support device, a guide member spaced from the pressing device, and a flat spring connecting the pressing device and the guide member so that the pressing force applied by the swab is elastically regulated. However, the combined art does not disclose that the guide member and the flat spring are each provided in plurality, or that a plurality of guide members and a plurality of flat springs are equally spaced apart from each other around the pressing device.
Tang further demonstrates that compliant elements may be arranged symmetrically around the axis of the swab/pressing device. In particular, Tang’s Fig. 2 illustrates three different passive compliant mechanism configurations in which spring-like members are distributed about the central axis of the end-effector so that deformation of the compliant structure can adjust the posture of the swab while accommodating forces from different directions. These schematic configurations show that it is design-routine to place multiple compliant members in symmetric positions around the pressing axis in order to obtain balanced compliance.
Chen, for its part, teaches a specific single flat-spring arrangement connecting a pressing-related member (push rod) to a supporting member via a band-type wind spring that is fixed at its ends, providing a compact and well-defined constant-force linkage between one moving rod and its structural support. Although Chen also discloses a second spring and rod, each spring in Chen is associated with its own rod; Chen is therefore relied upon here only for the structure and attachment of one flat-spring system to its corresponding pressing-related member, not for any teaching of multiple springs around a single pressing device.
It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the combined Tang and Chen structure in view of Tang’s multi-configuration compliant mechanism to provide the guide member and the flat spring in plurality and to arrange the plurality of guide members and plurality of flat springs at equal angular intervals around the pressing device. In such a modification, the designer would replicate Chen’s single flat-spring linkage (pressing device–guide member connection) at multiple circumferential positions suggested by the symmetric layouts in Tang’s Fig. 2, so that each guide member around the pressing device is connected by its own flat spring in the same manner as the original linkage.
Such a modification would have been feasible because the combined Tang and Chen structure already employs a known flat-spring linkage between one guide member and the pressing device, and Tang explicitly presents end-effector designs in which compliant elements are symmetrically placed about the central axis. One of ordinary skill in the art would have recognized that duplicating the same Chen-type flat-spring linkage at several equally spaced angular positions around the pressing device is a straightforward geometric replication of a known connection, consistent with Tang’s teaching of symmetric compliant layouts, and would not change the basic compliant function or force-regulation principle of the mechanism.
The benefit of this combination would be to distribute the compliant support more uniformly around the pressing device, thereby reducing asymmetric forces that could cause tilting or binding and providing a more stable and centrally directed pressing force. By equally spacing multiple guide members and flat springs around the pressing device, a robot pressing mechanism based on Tang and Chen would minimize lopsided force application from a single off-axis spring and would produce a more uniform pressing resistance that is not skewed to one side, improving alignment, comfort, and reliability during nasopharyngeal swabbing while preserving the advantages of Tang’s compliant design and Chen’s constant-force flat-spring connection.
Claims 2-5 are rejected under 35 U.S.C. 103 as being unpatentable over Tang et al. (Tang et al. “Design of Novel End-Effectors for Robot-Assisted Swab Sampling to Combat Respiratory Infectious Diseases.” 2021 43rd Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC). vol. 2021. United States: IEEE, 2021. 4757–47), hereto referred as Tang, and further in view of Chen et al. (CN-201039231-Y), hereto referred as Chen, and further in view of Mineshita et al. (Mineshita, Hiroki et al. “Development of a Trapezoidal Leaf Spring for a Small and Light Variable Joint Stiffness Mechanism.” ROMANSY 23 - Robot Design, Dynamics and Control. Ed. by Gentiane Venture et al. Cham: Springer International Publishing, 2020. 355–363. Web. (Year: 2020)), hereto referred as Mineshita.
The combined Tang and Chen teaches claim 1 as described above.
Regarding claim 2, the modified Tang does not teach that the width of the third plate is not constant. Rather, it teaches a robot pressing mechanism in which a flat spring connects a pressing device (swab fixture) and a support device (connector with guide member), and the flat spring includes plate-like end regions respectively coupled to the pressing device and the guide member, with a bent intermediate region joining those plates, allowing relative displacement and compliant force regulation along the insertion direction; however, it does not disclose that the bent plate segment has a non-constant width along its length.
Mineshita fills this gap by teaching that a leaf spring used in a joint-stiffness mechanism may have its width varied along its length and formed into a trapezoidal profile to maintain strength while reducing stiffness and size. Specifically, Mineshita explains that “with respect to the shape of the leaf spring, we considered the necessary requirements to maintain strength and reduce stiffness” and that “Therefore, sufficient strength could be secured at the fixed point where the maximum stress was applied, and the strength could be reduced at the tip. Therefore, alternation of the width was considered, and a trapezoidal shape was adopted” (Mineshita, Sec. 2.1, Techniques for Shortening Leaf Springs; see also FIG. 5). Mineshita further teaches that changing the leaf spring from a rectangular shape to a trapezoidal shape allows the mechanism to be downsized while maintaining strength and elasticity, stating that “Therefore, to make the mechanism smaller and lighter, we shorten the length of the leaf spring. We succeeded in downsizing the mechanism by changing its rectangular shape to trapezoidal, while maintaining strength and elasticity” (Mineshita, Abstract).
It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the combined Tang and Chen in view of Mineshita to configure the third plate of the flat spring with a non-constant width, such as a trapezoidal width profile along the bent intermediate region, so that the third plate’s width increases or otherwise varies along its length in order to tailor stiffness and strength characteristics of the flat spring while maintaining the overall three-plate geometry and compliant connection between the pressing device and support device.
Such a modification would have been feasible because the modified Tang already provides a flat spring structure connecting the pressing device and support device with a plate-like bent intermediate segment, and Mineshita shows that varying the width of such a spring segment along its length (forming a trapezoidal leaf spring) is a straightforward and well-understood design choice to reduce size and adjust stiffness while preserving strength at critical regions. One of ordinary skill in the art would have recognized that the third plate of the flat spring in Tang’s modified mechanism could be formed with a non-constant width as in Mineshita, for example by tapering or widening the plate segment between its ends, without changing the basic function of the spring or the three-plate connection between the pressing device and the guide member.
The benefit of this combination would be to provide a robot pressing mechanism whose flat-spring intermediate plate region not only allows compliant relative motion between the pressing device and support device but also offers improved control over stiffness distribution and strength, enabling the mechanism to be made smaller and lighter while maintaining adequate strength, as demonstrated by Mineshita’s trapezoidal leaf spring design. This would allow finer tuning of the force profile and mechanical response of the robot pressing mechanism during nasopharyngeal swabbing, improving safety and comfort while also reducing the size and mass of the compliant mechanism assembly.
Regarding claim 3, the modified Tang does not teach that the width of the third plate increases in a direction from the first plate to the second plate. As discussed for claim 2, Mineshita suggests that the bent intermediate region (third plate) may be formed with a non-constant width such as a trapezoidal profile to tailor stiffness and strength. However, the combined Tang, Chen, and Mineshita do not explicitly state that the width of the third plate increases in a direction from the first plate to the second plate.
Mineshita explains that, for a leaf spring used in a variable joint stiffness mechanism, it is advantageous to vary the width along the length of the spring, stating that “With respect to the shape of the leaf spring, we considered the necessary requirements to maintain strength and reduce stiffness… Therefore, sufficient strength could be secured at the fixed point where the maximum stress was applied, and the strength could be reduced at the tip. Therefore, alternation of the width was considered, and a trapezoidal shape was adopted” and further that “the calculation of a trapezoidal leaf spring should have nb as the width of the root and as the width of the tip… The calculations confirmed that the same stiffness can be achieved even if the length is shorter than the rectangular shape. This reduces the leaf spring while maintaining strength” (Mineshita, Sec. 2.1, Techniques for Shortening Leaf Springs). This teaches that a trapezoidal leaf spring is intentionally designed so that its width is greater at one end (root) than at the other (tip), thereby establishing a direction of increasing width along the length of the spring from its most distal tip to proximal base.
It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the combined Tang, Chen, and Mineshita in view of Mineshita to orient the third plate of the flat spring such that its width increases in a direction from the first plate toward the second plate, analogous to the way Mineshita’s trapezoidal leaf spring has a larger width at the root and a smaller width at the tip, thereby providing a defined direction of increasing width along the spring segment.
Such a modification would have been feasible because the modified Tang already provides a flat spring with a bent intermediate segment connecting two end plates associated with distinct structural members (pressing device and guide member), and Mineshita shows that designing a trapezoidal leaf spring with different widths at the root and tip is a straightforward way to distribute strength and stiffness along the spring’s length. One of ordinary skill in the art would have recognized that, by selecting which end of the third plate corresponds to the first plate (swab-side plate) and which corresponds to the second plate (guide-member-side plate), the designer could readily arrange the geometry so that the width of the third plate increases along the path from the first plate to the second plate, implementing the same root-to-tip width variation that Mineshita uses, without altering the basic three-plate configuration or the compliant function of the mechanism.
The benefit of this combination would be to provide a robot pressing mechanism whose flat spring not only has a non-constant width third plate (as in claim 2) but also has a directional width increase from the first plate to the second plate, allowing strength to be concentrated near the plate associated with higher stress (analogous to the root in Mineshita) and reduced toward the opposite plate, thereby enabling finer control of stiffness distribution, potential downsizing of the spring, and improved mechanical performance during nasopharyngeal swabbing while maintaining adequate strength where needed.
Regarding claim 4, the modified Tang does not expressly teach that the third plate has a trapezoidal shape so that the width of the third plate increases constantly in the direction from the first plate to the second plate. As discussed for claims 2 and 3, the combination demonstrates that the third plate may have a non-constant width profile and that a trapezoidal shape may be adopted to vary width along the length of a leaf spring, thereby tailoring strength and stiffness distribution. However, the combined Tang, Chen, and Mineshita do not literally disclose that the trapezoidal third plate is arranged such that its width increases constantly in the direction from the first plate to the second plate.
Mineshita explains that the shape of the leaf spring is deliberately modified from a rectangular to a trapezoidal profile to achieve downsizing while maintaining strength and elasticity, stating that “We succeeded in downsizing the mechanism by changing its rectangular shape to trapezoidal, while maintaining strength and elasticity” (Mineshita, Abstract), and further that “With respect to the shape of the leaf spring, we considered the necessary requirements to maintain strength and reduce stiffness… Therefore, sufficient strength could be secured at the fixed point where the maximum stress was applied, and the strength could be reduced at the tip. Therefore, alternation of the width was considered, and a trapezoidal shape was adopted” (Mineshita, Sec. 2.1, Techniques for Shortening Leaf Springs). Mineshita also describes analysis of a trapezoidal leaf spring in which the width at the root and width at the tip are different and the trapezoidal shape is treated as a linear variation in width along the length of the spring, explaining that “the calculation of a trapezoidal leaf spring should have nb as the width of the root and as the width of the tip… The calculations confirmed that the same stiffness can be achieved even if the length is shorter than the rectangular shape. This reduces the leaf spring while maintaining strength” (Mineshita, Sec. 2.1, Techniques for Shortening Leaf Springs). Collectively, along with figure 5, these disclosures teach that a trapezoidal leaf spring is formed so that the width varies in a monotonic, effectively linear manner between a smaller width at one end and a larger width at the other, embodying a constant rate of width change over the spring’s length.
It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the combined Tang, Chen, and Mineshita in view of Mineshita to configure the third plate of the flat spring so that it not only has a trapezoidal shape but also is oriented such that its width increases constantly in the direction from the first plate to the second plate, analogous to orienting the smaller-width end of the trapezoidal leaf spring toward the first plate and the larger-width end toward the second plate so that the width varies at a constant rate along the bent third plate between those plates.
Such a modification would have been feasible because the modified Tang already provides a flat spring with a third plate segment connecting a first plate (associated with the pressing device) and a second plate (associated with the guide member), and Mineshita shows that forming a leaf spring with a trapezoidal profile (i.e., different widths at its root and tip with a linear transition between them) is a straightforward design choice to adjust stiffness and strength while shortening the spring. One of ordinary skill in the art would have recognized that by selecting which end of the third plate corresponds to the narrower and wider sides of the trapezoidal profile and aligning those ends, respectively, with the first and second plates, the geometry could readily be arranged so that the width of the third plate increases constantly from the first plate to the second plate, without changing the overall three-plate configuration or the basic compliant function of the mechanism.
The benefit of this combination would be to provide a robot pressing mechanism whose third plate is not only of trapezoidal shape but is also directionally graded so that its width increases constantly from the first plate toward the second plate, concentrating strength and stiffness nearer the higher-stress region while allowing reduced cross-section toward the opposite end. This enables further downsizing and weight reduction of the flat spring, finer control of stiffness distribution, and more predictable, uniform elastic response during nasopharyngeal swabbing, thereby enhancing safety and comfort for the patient while maintaining sufficient structural robustness in the spring-supported mechanism.
Also regarding claim 4, with respect to the limitation that the third plate has a U-shaped structure bent about 180 degrees and generates a constant elastic restoring force regardless of a bent position, the modified Tang, teaches a bent structure but does not expressly teach that it has a 180 degree bend making a U-shaped structure and generates a constant elastic restoring force regardless of a bent position.
Chen teaches that its coil spring provides substantially constant force behavior, stating: “Under the action of the coil spring 4, the force on each segment is almost constant”. (Chen, [0034]). Chen further discloses that the coil spring (4) is fixed in the support member and coupled to the push rod so that relative motion is regulated by the elastic action of the coil spring (Chen, ¶[0027]–[0029]; ¶[0033]–[0034]; Figs. 5–7). Further, Chen expressly presents multiple embodiments (e.g., Embodiment 1 and Embodiment 2) with corresponding drawings, and the drawings depict different spring-strip configurations and winding extents for coil spring (4), evidencing that the spring-strip geometry is not limited to a single fixed implementation and may be selected among disclosed configurations to meet design objectives (Chen, ¶[0018]–[0024]; ¶[0030]–[0032]; FIG. 2, 4, and 6).
It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the combined Tang, Chen, and Mineshita so that the third plate has a U-shaped structure bent about 180 degrees and the flat spring generates a substantially constant elastic restoring force regardless of the bent position of the third plate, including by selecting a spring geometry (including a partial-turn/approximately 180-degree bend) to meet the claimed third-plate shape while maintaining the substantially constant-force behavior taught by Chen as the design objective. Because the claim requires only that the third plate be bent about 180 degrees to form a U-shaped structure, selecting an approximately 180-degree curvature segment (i.e., a partial turn) of Chen’s spring strip between the plate-like end portions would have satisfied this limitation. Tang teaches providing compliance to “avoid[] excessive force due to the bending of the swab stick” and further indicates that “Different configurations would result in different bending stiffnesses”. (Tang, p. 4757, Sec. II.A; Tang, p. 4758, Sec. IV). Chen expressly teaches that its coil spring provides substantially constant-force behavior, stating: “Under the action of the coil spring 4, the force on each segment is almost constant”. (Chen, ¶[0034]). Thus, one of ordinary skill in the art would have been motivated to select and configure the spring-strip geometry (including an approximately 180-degree U-shaped bend for the third plate) so that the resulting spring exhibits the substantially constant restoring-force characteristic taught by Chen while meeting the claimed shape requirement. Springs are well known mechanical elements used to regulate force between relatively movable components, and selecting a particular spring geometry or bend configuration (including a U-shaped approximately 180-degree bend) to achieve a desired compliance profile constitutes routine engineering design within the level of ordinary skill in the art.
Such a modification would have been feasible because Chen already uses a spring strip coupled at its ends to respective members to regulate relative motion, and selecting a partial-turn (about 180-degree) curvature for the intermediate bent region between the end portions is a straightforward spring-geometry selection while consistent with Chen’s taught constant-force behavior (Chen, ¶[0033]–[0034]; FIG. 2, 4, and 6).
The benefit of this combination would be improved predictability and repeatability of the elastic restoring force during swab insertion and pressing, thereby enhancing Tang’s stated objective of reducing excessive force on the patient and providing a safe and smooth sampling experience, while also allowing stiffness and strength tailoring via the trapezoidal third-plate profile. (Tang, Sec. II.A; Chen, ¶[0034]; Mineshita, Sec. 2.1).
Regarding claim 5, the modified Tang does not teach that the guide member has a plate shape, wherein the guide member extends in the first direction, and the inner surface of the guide member is parallel to the pressing device. Rather, it discloses a robot-assisted swab sampling end-effector with a guide member for guiding the second flat spring plate, but it does not describe the guide member as a plate-shaped and its inner surface extending parallel to the pressing/swab direction (Tang, Sec. II-A, Fig. 2).
By contrast, Chen discloses a constant-force spring mechanism in which a guide member, positioning block 8, has inner surfaces forming a retaining groove for accepting the end of the straightened end of the spring (i.e. second plate)(Chen, FIG. 4, [0029]). Thus, the retaining groove has a plate-like shape since it is formed to accept the plate-like flat spring. Additionally, these inner surfaces run parallel to and along the direction of the sliding rod, functioning as structural guides to the end portion of the spring.
It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the combined Tang, Chen, and Mineshita configuration in view of Chen so that the guide member adopts a plate shape extending in the first (swab) direction with an inner surface parallel to the pressing device. The combined art already provides: (1) a flat-spring connection between the pressing device and guide member; (2) the plate-like straightened spring end oriented along the guide direction; and (3) a functional guiding interface at the spring-to-guide junction. Chen further teaches that the spring-coupling guide component (positioning block 8) defines planar inner faces forming a retaining groove for the straightened spring end, which function as guiding surfaces parallel to the direction of motion. One of ordinary skill would have recognized that configuring the modified Tang’s guide member with similar planar, plate-like inner surfaces oriented along the swab direction would preserve the spring alignment function already present in the combined mechanism while improving the geometric definition and function of the guide.
Such a modification would have been feasible because the combined art already employs a flat spring whose straight end portion cooperates with a guide member to constrain movement along a defined direction, and Chen provides a clear instructional example of forming the guide’s internal surfaces as plate-like, parallel faces that maintain alignment of the spring end. Adapting the existing guide member into a plate-shaped component with parallel inner surfaces would not alter the compliant function, the three-plate geometry, or the relative-motion behavior established in the combined Tang, Chen, and Mineshita mechanism.
The benefit of the modification would be improved stability and more consistent translational alignment of the flat spring’s second plate against a planar guide surface, resulting in smoother, more predictable deformation and force transmission during swab insertion. This would enhance the robustness and precision of the pressing mechanism while maintaining the compact, compliant, and force-regulated characteristics derived from the base combination of Tang, Chen, and Mineshita.
Claims 6-7, 10, and 14-15 are rejected under 35 U.S.C. 103 as being unpatentable over Tang et al. (Tang et al. “Design of Novel End-Effectors for Robot-Assisted Swab Sampling to Combat Respiratory Infectious Diseases.” 2021 43rd Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC). vol. 2021. United States: IEEE, 2021. 4757–47), hereto referred as Tang, and further in view of Chen et al. (CN-201039231-Y), hereto referred as Chen, and further in view of Homner et al. (US-20200332579-A1), hereto referred as Homner.
The combined Tang and Chen teaches claim 1 as described above.
Regarding claim 6, the modified Tang does not fully teach that the first plate is coupled to the outer surface of the pressing device, and the second plate is coupled to the inner surface of the guide member, wherein the inner surface of the guide member is not parallel to the outer surface of the pressing device, and the first plate is not parallel to the second plate. As established in claim 1, the combined Tang and Chen teaches a robot pressing mechanism a three part flat spring that connects a pressing device to a guide member. However, the it does not explicitly disclose that the first plate is coupled to an outer surface of the pressing device and the second plate is coupled to an inner surface of the guide member such that the inner surface of the guide member is not parallel to the outer surface of the pressing device and the first and second plates themselves are arranged non-parallel.
Chen demonstrates that the spring is coupled to the outer surface of the rod (i.e. pressing device) and the inner surface of the positioning block (i.e. guide member) called the positioning groove. Specifically, Chen teaches that the band-type wind spring is fixed at its ends to structural members of a sliding mechanism. Chen explains that a “first pushrod 2 and second pushrod 3 are inserted into the two slots 5 respectively. The first pushrod 2 and the second pushrod 3 can slide relatively parallel to each other. One end of the first pushrod 2 and the second pushrod 3 are respectively connected to a coil spring 4, which is fixed in support number 1” and that the “rear cover 7 is provided with a positioning groove corresponding to the position of the coil spring 4. The coil spring 4 is locked in the positioning groove and secured by the positioning block 8 of the front cover 6.” (Chen, [0027]-[0032]). These passages show that the flat, band-like spring is fixed in the supporting member and its end is stuck in a locating groove and chucked by a locating piece, i.e., the spring ends are rigidly anchored to defined surfaces of the structural members rather than loosely coupled or sliding along them (see also FIG. 4).
Homner teaches that the end of a flat spiral spring may be anchored in a groove formed in a torque adjustment unit and that this unit is rotatably adjustable relative to a fixed hinge part by an adjusting screw, allowing the angular position and pretension of the spring to be selectively set and then maintained. Specifically, Homner explains that “the flat spiral spring 18 is anchored in a groove of the torque adjustment unit 28” and that “the torque adjustment unit 28 allows the flat spiral spring 18 to be pretensioned to the required torque. The pretension of the flat spiral spring 18 can be varied by means of an adjusting screw 30 located on the fixed hinge part 14, with the screw shaft meshing with a toothed portion 32 of the torque adjustment unit 28. Varying the adjusting screw 30 results in a corresponding rotation of the torque adjustment unit 28, which in turn pretensions the flat spiral spring 18 that is firmly anchored at both its ends 24, 26. The pretension set in this way is maintained by means of the adjusting screw 30” (Homner, FIG. 1, ¶[0031]). This teaches that a flat spring end can be held in a groove of a carrier part whose angular position is adjustably set and fixed relative to a supporting structure, thereby defining a selectable angular relationship between the spring end and that structure.
It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the combined Tang and Chen in view of Homner and Chen to arrange the guide member and pressing device so that their respective surfaces and the first and second plates are non-parallel, by providing the guide member (or a guide-supporting block) with a groove or mounting interface for the second plate whose angular position is adjustable and then fixed, analogous to Homner’s torque adjustment unit. In such a modification, the first plate would remain coupled to an outer surface of the pressing device, while the second plate would be coupled to an inner surface of the guide member set at an oblique angle to the pressing device, thereby establishing the claimed non-parallel relationships between the outer and inner surfaces and between the first and second plates.
Such a modification would have been feasible because the existing combined mechanism already employs a flat spring with defined plate regions connecting the pressing device and guide member, and Homner demonstrates that it is straightforward to anchor a spring end in a groove of an angularly adjustable carrier that can be rotated and then locked by an adjusting screw to set the desired angular relationship and torque. One of ordinary skill in the art would have recognized that the guide member or an intermediate guide block in the combined Tang and Chen structure could similarly be mounted or formed on an adjustable carrier so that, after the angular position is set, the guide’s inner surface and the second plate are oriented at a non-parallel angle relative to the pressing device and first plate without altering the fundamental compliant function of the mechanism.
The benefit of this combination would be to allow the designer to deliberately set and maintain a specific force with an oblique, non-parallel relationship between the pressing device and guide member (and their respective spring plates), enabling control over the direction of compliance and the way contact forces are redirected through the flat spring. This can optimize force vectors during insertion and pressing, and provide a more predictable and tunable mechanical response, while preserving the compact, flat-spring-based compliant behavior already achieved by the combination of Tang and Chen.
Regarding claim 7, the modified Tang does not fully disclose that the support device further comprises a support body configured to support the guide member, wherein the pressing device passes through the support body in the first direction, and the guide member is connected to the support body and rotates relative to the support body, and an acute angle formed between the guide member and the first direction is variable. As established in claim 6, the modified Tang structure demonstrates a torque adjustment unit that supports the guide member and allows adjustable rotation of the guide member with respect to the torque adjustment unit such that the angle between the pressing device and guide member is variable (as the guide member is rotated to adjust the spring force). However, the combined art does not disclose that the torque adjustment unit is a support body comprised as part of the support structure and that the pressing device passes through the support body in the first direction.
Homner teaches the missing aspects of the support body by disclosing that the flat spiral spring 18 is anchored in a groove of a torque adjustment unit 28 that is mounted to a fixed hinge part 14 and rotated by an adjusting screw 30, with the screw shaft meshing with a toothed portion 32 of the torque adjustment unit so that turning the screw rotates the unit and changes the pretension of the spring, and the set pretension (and corresponding angular position) is then maintained (Homner, ¶[0031]). Where the torque adjustment unit is coupled to a supporting structure such that the spring is coupled to the support structure via the adjustment unit (Homner, FIG. 1). This demonstrates a torque-adjustment-type support body (the torque adjustment unit and its mounting to the fixed hinge part) that forms part of the support device and carries the spring-related member while allowing the guide members angular orientation to be varied and fixed.
Chen complements this by teaching that an elongated member (push rod) passes through a supporting member 1 along its length via a slot or passage, so that the supporting member surrounds and guides the rod while the rod extends through it in the direction of sliding (Chen, [0030], FIG. 4: showing a supporting member with slots that receive the rods such that the rods pass through and along the support device equivalent in the sliding direction).
It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the combined Tang, Chen, and Homner in view of Homner and Chen so that the torque-adjustment-type unit functions as the claimed support body that is integrated into the support device and the pressing device traverses though the support device in the first direction via an opening or slot. In such a modification, the guide member (already connected to the flat spring and support structure) would be mounted to or formed on the torque adjustment unit-type support body so that rotation of this support body relative to the rest of the support device is adjustable to any angle, including acute angles, between the guide member and the first direction, while the pressing device continues to extend through the support device along that first direction.
Such a modification would have been feasible because the modified Tang mechanism already includes a pressing device extending through an associated structural member along the first direction (as in Chen’s rod passing through supporting member 1) and a guide member connected via a flat spring, and Homner shows that a spring-coupling component can be mounted on a rotatable torque-adjustment-type unit that is part of the support structure and whose angular position can be set and held. One of ordinary skill in the art would have recognized that implementing the guide member on such a torque-adjustment-type support body, with the pressing device passing through the support body, would yield a support body configured to support the guide member, allow the guide member to rotate relative to the support body, and maintain a selected acute angle between the guide member and the first direction while preserving the established flat-spring connection and overall geometry.
This would enhance control over the alignment and directional compliance of the flat spring during swab insertion, improving safety and comfort for the patient while maintaining the compact and functionally robust structure derived from the combined Tang, Chen, and Homner teachings.
Regarding claim 10, Tang teaches that a nasopharyngeal swab sampling apparatus comprises: a pressing device; (Tang, Title: "Design of Novel End-effectors for Robot-assisted Swab Sampling to Combat Respiratory Infectious Diseases"; Abstract: "...end-effector designs that can be equipped at the distal end of a robot to passively regulate or actively sense the force exerted onto patients. One way is to introduce passive compliant mechanisms with soft material to increase the flexibility of the swabbing system... It is identified that the passive compliant mechanisms can increase the flexibility of the swabbing system when subjected to the lateral force and mitigate the vertical force resulted from buckling", demonstrating a robot pressing mechanism in which the swab assembly functions as the pressing device); a support device that moves in a first direction relative to the pressing device (Tang, FIG. 1–2; p. 4757–4758, II.A: "The design consists of a fixture to hold the swab in place and a passive mechanism with different configurations to introduce extra compliance (Fig. 2). The base of the compliant mechanism is mounted to a connector, which can be further attached to a robot... When the tip of the swab touches upon the nasal or the oral cavity, there will be force acting upon the swab and as a result the swab will bend... additional compliance is introduced with bending motions generated by the mechanism through body deformation to adaptively adjust the posture of the swab, avoiding excessive force", Tang teaches an end-effector subassembly in which the connector and compliant mechanism act as a support device coupled to the swab/pressing device; as the robot advances or withdraws the end-effector, the connector is driven in the insertion direction and the compliant mechanism deforms so that the position of the swab shifts relative to the connector along that same first direction, thereby providing movement of the support device in the first direction relative to the pressing device); wherein the pressing device comprises: a swab coupling member; and a swab which is coupled to the swab coupling member and extends from the swab coupling member in the first direction (Tang, FIG. 1–2; p. 4757–4758, II.A: "The design consists of a fixture to hold the swab in place and a passive mechanism with different configurations to introduce extra compliance (Fig. 2)", Tang teaches that the swab is held by a fixture at the distal end of the end-effector; the fixture functions as a swab coupling member, and the swab extends from this coupling member along its elongated axis in the insertion (first) direction into the nasal or oral cavity); wherein the support device comprises a guide member that is spaced apart from the swab coupling member in a direction crossing the first direction, (Tang, FIG. 2: depicts the connector (support device) as coupling with the compliant mechanism via a disk-like intermediate structure that is oriented in a plane crossing the first direction and is spaced from the swab fixture; this disk-like portion supports and guides a portion of the compliant mechanism and corresponds to a guide member that is spaced apart from the swab coupling member in a direction crossing the first direction)
Also regarding claim 10, Tang does not fully teach that a flat spring has one end fixed to the pressing device and the other end fixed to the support device. Rather, Tang teaches a compliant mechanism that functions as a spring and figure 2 depicts several configurations including sets of elongated bars which are the equivalent of flat springs (Tang, FIG. 2; p. 4757-4758, II.A: "The compliant mechanism was 3D printed using Thermoplastic polyurethane (TPU), with a Young’s Modulus of 8 MPa and a Poisson's ratio of 0.45... Because of the soft structure is made of TPU that has a Young’s Modulus smaller than the material of the swab stick, additional compliance is introduced with bending motions generated by the mechanism through body deformation to adaptively adjust the posture of the swab, avoiding excessive force"). These disclosures show that Tang provides a compliant spring-like connection between the swab (pressing device) and the connector (support device), but Tang does not describe that compliant mechanism as a flat spring or characterize it as a band-type or plate-type spring configured in a defined flat-spring geometry.
Chen fills this gap by expressly disclosing a constant-force spring mechanism in which a band or flat-type "coil spring" connects two structural members: an elongated rod for pushing and a guide-type member. Chen explains that the coil spring is fixed in the supporting member and that one end portion of the spring is anchored in a positioning groove and held by a positioning piece while the opposite end is connected to a sliding push rod, so that the flat spring ends are fixed relative to the respective members they connect (Chen, FIG. 1, 4; Abstract; [0029]).
It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified Tang in view of Chen to implement Tang’s compliant connection between the swab fixture (pressing device) and the connector (support device) as a flat spring having its ends fixed to those components, by adopting Chen’s band-type spring configuration in which a flat spring is fixed within a supporting member and has its opposite ends coupled and fixed to members that move relative to one another along defined directions. Such a modification would have been feasible because both Tang and Chen address controlling force transmission between components using compliant spring structures, and one of ordinary skill in the art would have recognized that reshaping Tang’s compliant body as a Chen-type flat band spring with fixed end portions at the pressing-device side and support-device side would preserve the compliant function while providing a more predictable constant-force response; the benefit would be improved consistency and repeatability of the compliant behavior during insertion and pressing, helping to avoid excessive or sudden forces on the patient and thereby improving safety and comfort in robot-assisted nasopharyngeal sampling.
Also regarding claim 10, Tang does not fully teach that the flat spring is coupled to the pressing device and the support device and includes a first plate, a second plate, and a third plate, the first plate extending from one end of the third plate in an opposite direction to the first direction, the second plate extending from the other end of the third plate in the opposite direction to the first direction, the third plate bent once and directly coupled to the first plate and the second plate so as to make the flat spring generate a constant elastic restoring force regardless of a bent position of the third plate. Rather, as modified in the preceding limitation, Tang in view of Chen provides a flat band-type spring connecting the pressing device and support device, but Chen anchors the two straight end regions of the spring so that they extend in generally opposite directions. Thus, it does not disclose that the compliant mechanism is implemented as a flat spring that is explicitly divided into a first plate, a second plate, and a third plate bent once between them so as to generate a constant elastic restoring force regardless of the bent position of the third plate, where the first plate and the second plate extend from opposite sides of the third plate toward the swab coupling member and the guide member in a direction opposite the first direction.
Chen teaches a constant-force spring mechanism including coil spring (4) fixed within a supporting member and connected to a push rod that moves relative to the supporting member (Chen, ¶[0008]–[0010]; FIG. 1–6). As illustrated in Chen’s figures, the coil spring is formed from a continuous spring strip having straight end portions that are respectively coupled to structural members and a curved intermediate portion forming the spring body between those end portions. The inner end of the spring is anchored within a positioning groove of positioning block 8 inside supporting member 1, while the opposite end portion extends outward and connects to the sliding push rod (Chen, FIG. 1 and 4; ¶[0008]–[0010]; [0029]). Because the push rod moves along its guide direction within the supporting member, the straight end portion coupled to the push rod extends along that rod direction, while the opposite end portion is fixed relative to the supporting member and oriented along the direction defined by the guide structure of the support member. The figures depict that end of the plate is faced away from the tip of the rod (Chen, FIG. 1-7). Accordingly, Chen discloses a flat spring structure having (1) a first plate-like end portion coupled to one structural member, (2) a second plate-like end portion coupled to another structural member, and (3) a bent intermediate portion connecting the end portions, corresponding to the claimed first plate, second plate, and third plate. Further, Chen teaches that the coil spring produces a substantially constant force response during operation, explaining that “under the action of the coil spring 4, the force on each segment is almost constant” (Chen, ¶[0034]), thereby corresponding to the claimed feature that the flat spring generates a constant elastic restoring force regardless of the bent position of the third plate. However, Chen anchors the two straight end regions of the spring so that they extend in generally opposite directions. Thus, it does not disclose a configuration in which both spring end segments extend generally rearward from the swab tip in the same direction.
Homner teaches that the angular orientation and pretension of a flat spiral spring end relative to its supporting structure can be selected and adjusted by rotating the mounting element to which the spring end is anchored, thereby allowing the orientation of the spring end to be set according to design requirements and then fixed in place (Homner, ¶[0031]). Because Tang’s swab is advanced along a defined insertion direction, a person of ordinary skill in the art would have recognized that orienting both spring end segments in the same rearward direction opposite the insertion direction would align the spring geometry with the insertion axis and provide a compact spring arrangement behind the swab fixture.
It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the combined Tang and Chen in view of Chen and Homner by configuring the flat spring to include a first plate, a second plate, and a third plate, the first plate extending from one end of the third plate in an opposite direction to the first direction, the second plate extending from the other end of the third plate in the opposite direction to the first direction, the third plate bent once and directly coupled to the first plate and the second plate so as to make the flat spring generate a constant elastic restoring force regardless of a bent position of the third plate. Tang teaches the desirability of providing compliance between the swab fixture and the supporting connector in order to regulate force and avoid excessive force during swab insertion (Tang, Sec. II.A; Fig. 2), while Chen teaches a flat spring configuration having end portions coupled to respective structural members and an intermediate bent spring body that regulates relative displacement between those members (Chen, ¶[0008]–[0010]; FIGS. 1–6). Homner further teaches that the angular orientation and pretension of a flat spiral spring end relative to its supporting structure can be selected and adjusted by rotating the mounting element to which the spring end is anchored, thereby allowing the orientation of the spring end to be set according to design requirements and then fixed in place (Homner, ¶[0031]). In view of these teachings, one of ordinary skill in the art would have recognized that the orientation of the end segments of the flat spring used in Tang’s compliant mechanism could be selected and fixed using the type of adjustable anchoring arrangement taught by Homner so that both spring end portions extend generally rearward from the swab tip in the same direction opposite the insertion direction. In such an implementation, the spring would include two plate-like end segments extending in the same rearward direction from a bent intermediate portion, thereby corresponding to the claimed first plate and second plate extending from the third plate, while the bent intermediate portion provides the compliant deformation that generates a substantially constant restoring force as taught by Chen. The benefit of such a configuration would be to maintain the predictable constant-force spring behavior described by Chen while arranging the spring geometry in a compact orientation compatible with the swab insertion direction in Tang’s device, thereby improving packaging and providing consistent force regulation during robot-assisted nasopharyngeal sampling.
With respect to the limitation that the third plate is “bent once,” the claim requires that the third plate be a bent portion that connects one end of the first plate and one end of the second plate. The claim does not require that the spring body exclude additional curvature beyond that bent connection, nor does it require that a continuous curved spring region be treated as “bent more than once” merely because it continues through multiple turns. Under a broad, reasonable interpretation, Chen’s coil spring formed from a continuous spring strip includes an intermediate curved region that directly connects the two end portions, and therefore already reads on the third plate being “bent once” and directly coupled to the first and second plates, because the end portions are connected through the continuous spring body without any intervening linkage or separate component (Chen, Figs. 2–5; ¶[0008]–[0010]).
Alternatively, “bent once” may simply refer to a formation process in which the third plate is formed in a one-time bending process. That is, “bent once” can also be interpreted as the physical action of forming that occurs at a single time, regardless of how many bends or turns are formed. With this interpretation, the method of formation does not distinguish the claimed structure form the combination.
Alternatively, even assuming, arguendo, that Applicant advances a narrower interpretation of “bent once” to require a single bend without additional turns, Chen still supports the Office position because Chen illustrates coil spring (4) with different winding configurations across embodiments (Chen, Figs. 2, 4, and 6), demonstrating that the winding configuration is a selectable spring-geometry parameter used to meet packaging and force-response objectives. Springs are well known mechanical elements used to regulate force between relatively movable components, and selecting a particular spring geometry or bend configuration to achieve a desired compliance profile constitutes routine engineering design within the level of ordinary skill in the art.
The benefit of this combination would be to improve Tang’s swabbing end-effector by providing a more predictable and substantially constant force response during swab insertion and pressing. Because Tang already seeks to introduce compliance to avoid excessive force applied to the patient (Tang, Sec. II.A), implementing the compliant element using the spring configuration taught by Chen would enhance the ability of the mechanism to regulate insertion forces in a controlled and repeatable manner while maintaining the compliant behavior described by Tang, thereby improving safety and comfort during robot-assisted nasopharyngeal or oropharyngeal sampling.
Regarding claim 14, the modified Tang does not fully teach that the guide member has a plate shape, wherein the guide member is inclined to form an acute angle relative to the first direction, and thus the inner surface of the guide member is not parallel to the swab coupling member. Rather, the modified Tang demonstrates a compliant mechanism in which a flat spring connects a swab-side pressing device to a guide-side structure, but it does not disclose that the guide member itself has a plate-shape that is inclined to form an acute angle relative to the first direction of swab insertion, nor that the inclination causes its inner surface to be non-parallel to the swab coupling member.
By contrast, Chen discloses a constant-force spring mechanism in which a guide member, positioning block 8, has inner surfaces forming a retaining groove for accepting the end of the straightened end of the spring (i.e. second plate)(Chen, FIG. 4, [0029]). Thus, the retaining groove has a plate-like shape since it is formed to accept the plate-like flat spring. Additionally, these inner surfaces run parallel to and along the direction of the sliding rod, functioning as structural guides to the end portion of the spring.
Homner teaches that the angular orientation of a spring-carrying member relative to a fixed support can be adjusted and maintained by mounting the spring end in a torque adjustment unit that is rotated by an adjusting screw. Specifically, Homner explains that “a torque adjustment unit 28 is arranged on the flat spiral spring 18, and the radially inner end 24 of the flat spiral spring 18 is connected to the torque adjustment unit 28. In this embodiment, the flat spiral spring 18 is anchored in a groove of the torque adjustment unit 28. The torque adjustment unit 28 allows the flat spiral spring 18 to be pretensioned to the required torque. The pretension of the flat spiral spring 18 can be varied by means of an adjusting screw 30 located on the fixed hinge part 14, with the screw shaft meshing with a toothed portion 32 of the torque adjustment unit 28. Varying the adjusting screw 30 results in a corresponding rotation of the torque adjustment unit 28, which in turn pretensions the flat spiral spring 18 that is firmly anchored at both its ends 24, 26. The pretension set in this way is maintained by means of the adjusting screw 30” (Homner, ¶[0031]). This teaches that a spring-related member can be mounted on a carrier, guide member, whose angular position relative to a reference structure is adjustable and then fixed.
It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the combined Tang, Chen, and Homner in view of Chen and Homner to configure the guide member of the nasopharyngeal swab sampling apparatus to have a plate-shaped that is mounted so that it is inclined at an acute angle relative to the first direction, thereby making the inner surface of the guide member non-parallel to the swab coupling member. In such a modification, the guide member (or a guide-supporting block functioning as the guide member) would be oriented at a selected acute angle relative to the insertion direction by mounting it on an angularly adjustable carrier analogous to Homner’s torque adjustment unit, so that once the desired inclination is set, the inner surface of the guide member is consistently oblique relative to the swab coupling member.
Such a modification would have been feasible because the modified Tang structure already employs a guide-side component interacting with a spring and swab-side element and requires a defined geometry between these members, while Homner demonstrates that it is straightforward to implement an angularly adjustable, spring-carrying unit whose orientation relative to a fixed part can be changed and then maintained. One of ordinary skill in the art would have recognized that shaping the guide member as a plate and mounting it at a selected acute angle relative to the insertion direction using an arrangement analogous to Homner’s torque adjustment unit would not alter the basic compliant function of Tang’s mechanism but would simply set the guide at a controlled oblique orientation.
The benefit of this combination would be to provide a nasopharyngeal swab sampling apparatus in which the guide member is a plate-shaped component deliberately inclined at an acute angle relative to the insertion direction so that its inner surface is non-parallel to the swab coupling member, allowing the designer to control the direction of compliance and contact forces between the swab and surrounding anatomy. This yields improved control over how the flat spring deflects and how forces are redirected during swab insertion and pressing, enhancing safety, comfort, and mechanical robustness while preserving the compact compliant mechanism derived from the combination of Tang and Chen.
Regarding claim 15, the modified Tang teaches that the sampling apparatus of claim 10 further comprises a driving device which is coupled to the support device and moves the support device (Tang, FIG. 1, Abstract: "In this study, we proposed two detachable, recyclable, and cost-efficient end-effectors that can be equipped at the distal end of a robot to passively regulate or actively sense the force exerted onto patients", Tang explains that the compliant swab-holding mechanism is specifically designed as a robot end-effector that is mounted at the distal end of a robot so that the robot serves as the driving device that actuates the connected end-effector structure, including the connector and compliant mechanism corresponding to the support device, and thereby moves the support device during robot-assisted nasopharyngeal swab sampling, see also figure 1; p. 4758, II.A: "The design consists of a fixture to hold the swab in place and a passive mechanism with different configurations to introduce extra compliance (Fig. 2). The base of the compliant mechanism is mounted to a connector, which can be further attached to a robot", this passage shows that the compliant mechanism and connector (support device) are structurally arranged to be attached to a robot so that, when the robot drives the end-effector, the connector/support device is moved by the robot, thus corresponding to a driving device coupled to the support device that moves the support device as recited in the claim).
Claims 11-13 are rejected under 35 U.S.C. 103 as being unpatentable over Tang et al. (Tang et al. “Design of Novel End-Effectors for Robot-Assisted Swab Sampling to Combat Respiratory Infectious Diseases.” 2021 43rd Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC). vol. 2021. United States: IEEE, 2021. 4757–47), hereto referred as Tang, and further in view of Chen et al. (CN-201039231-Y), hereto referred as Chen, and further in view of Homner et al. (US-20200332579-A1), hereto referred as Homner, and further in view of Mineshita et al. (Mineshita, Hiroki et al. “Development of a Trapezoidal Leaf Spring for a Small and Light Variable Joint Stiffness Mechanism.” ROMANSY 23 - Robot Design, Dynamics and Control. Ed. by Gentiane Venture et al. Cham: Springer International Publishing, 2020. 355–363. Web. (Year: 2020)), hereto referred as Mineshita.
The combined Tang, Chen, and Homner teaches claim 10 as described above.
Regarding claim 11, the modified Tang does not teach that a width of the third plate is not constant. Rather, it teaches a nasopharyngeal swab sampling apparatus in which a flat spring connects a pressing device (swab fixture) and a support device (connector with guide member), and the flat spring includes plate-like end regions respectively coupled to the pressing device and the guide member, with a bent intermediate region joining those plates, allowing relative displacement and compliant force regulation along the insertion direction; however, it does not disclose that the flat spring is formed as a “variable flat spring” whose width is not constant along its length.
Mineshita fills this gap by teaching that a leaf spring used in a joint-stiffness mechanism may have its width varied along its length and formed into a trapezoidal profile to maintain strength while reducing stiffness and size. Specifically, Mineshita explains that “with respect to the shape of the leaf spring, we considered the necessary requirements to maintain strength and reduce stiffness” and that “Therefore, sufficient strength could be secured at the fixed point where the maximum stress was applied, and the strength could be reduced at the tip. Therefore, alternation of the width was considered, and a trapezoidal shape was adopted” (Mineshita, Sec. 2.1, Techniques for Shortening Leaf Springs; see also FIG. 5). Mineshita further teaches that changing the leaf spring from a rectangular shape to a trapezoidal shape allows the mechanism to be downsized while maintaining strength and elasticity, stating that “Therefore, to make the mechanism smaller and lighter, we shorten the length of the leaf spring. We succeeded in downsizing the mechanism by changing its rectangular shape to trapezoidal, while maintaining strength and elasticity” (Mineshita, Abstract).
It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the combined Tang, Chen, and Homner in view of Mineshita to configure the flat spring of the nasopharyngeal swab sampling apparatus as a variable flat spring with a non-constant width, such as a trapezoidal width profile along the bent intermediate region, so that the flat spring’s width increases or otherwise varies along its length in order to tailor stiffness and strength characteristics of the flat spring while maintaining the overall three-plate geometry and compliant connection between the swab coupling member and support device. Such a modification would have been feasible because the modified Tang already provides a flat spring structure connecting the pressing device and support device with a plate-like bent intermediate segment, and Mineshita shows that varying the width of such a spring segment along its length (forming a trapezoidal leaf spring) is a straightforward and well-understood design choice to reduce size and adjust stiffness while preserving strength at critical regions. One of ordinary skill in the art would have recognized that the flat spring in Tang’s modified swab sampling mechanism could be formed with a non-constant width as in Mineshita, for example by tapering or widening the plate segment between its ends, without changing the basic function of the spring or the three-plate connection between the swab coupling member and the guide member. The benefit of this combination would be to provide a nasopharyngeal swab sampling apparatus whose flat-spring intermediate region not only allows compliant relative motion between the swab coupling member and support device but also offers improved control over stiffness distribution and strength, enabling the mechanism to be made smaller and lighter while maintaining adequate strength, as demonstrated by Mineshita’s trapezoidal leaf spring design. This would allow finer tuning of the force profile and mechanical response of the nasopharyngeal swab sampling mechanism during nasopharyngeal swabbing, improving safety and comfort while also reducing the size and mass of the compliant mechanism assembly.
Regarding claim 12, the modified Tang does not teach that the width of the third plate increases in a direction from the one end to the other end. As discussed for claim 11, Mineshita suggests that a flat spring (leaf spring) used in a joint-stiffness mechanism may be formed with a non-constant width such as a trapezoidal profile to tailor stiffness and strength. However, the combined Tang, Chen, and Mineshita do not explicitly state that the width of the variable flat spring increases in a direction from the one end to the other end.
Mineshita explains that, for a leaf spring used in a variable joint stiffness mechanism, it is advantageous to vary the width along the length of the spring, stating that “With respect to the shape of the leaf spring, we considered the necessary requirements to maintain strength and reduce stiffness… Therefore, sufficient strength could be secured at the fixed point where the maximum stress was applied, and the strength could be reduced at the tip. Therefore, alternation of the width was considered, and a trapezoidal shape was adopted” and further that “the calculation of a trapezoidal leaf spring should have nb as the width of the root and as the width of the tip… The calculations confirmed that the same stiffness can be achieved even if the length is shorter than the rectangular shape. This reduces the leaf spring while maintaining strength” (Mineshita, Sec. 2.1, Techniques for Shortening Leaf Springs). This teaches that a trapezoidal leaf spring is intentionally designed so that its width is greater at one end (root) than at the other (tip), thereby establishing a direction of increasing width along the length of the spring from its most distal tip to proximal base.
It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the combined Tang, Chen, Homner, and Mineshita in view of Mineshita to orient the variable flat spring in the nasopharyngeal swab sampling apparatus such that its width increases in a direction from the one end toward the other end, analogous to the way Mineshita’s trapezoidal leaf spring has a larger width at the root and a smaller width at the tip, thereby providing a defined direction of increasing width along the spring segment.
Such a modification would have been feasible because the modified Tang already provides a flat spring structure in the swab sampling mechanism and, as explained for claim 11, Mineshita shows that designing a trapezoidal leaf spring with different widths at the root and tip is a straightforward way to distribute strength and stiffness along the spring’s length. One of ordinary skill in the art would have recognized that, by selecting which end of the variable flat spring corresponds to the “one end” and which corresponds to “the other end”, the designer could readily arrange the geometry so that the width of the variable flat spring increases along the path from the one end to the other end, implementing the same root-to-tip width variation that Mineshita uses, without altering the basic flat-spring configuration or the compliant function of the mechanism.
The benefit of this combination would be to provide a nasopharyngeal swab sampling apparatus whose variable flat spring not only has a non-constant width (as in claim 11) but also has a directional width increase from one end to the other, allowing strength to be concentrated near the higher-stress region (analogous to the root in Mineshita) and reduced toward the opposite end. This enables finer control of stiffness distribution, potential downsizing of the spring, and improved mechanical performance during nasopharyngeal swabbing while maintaining adequate strength where needed.
Regarding claim 13, the modified Tang mostly teaches that the third plate has a trapezoidal shape, and thus the width of the third plate increases constantly in the direction from the one end to the other end. As discussed for claims 11 and 12, the combination demonstrates that the flat spring used between the swab coupling member and support device may have a non-constant width profile and that a trapezoidal shape may be adopted to vary width along the length of a leaf spring, thereby tailoring strength and stiffness distribution. However, it does not literally disclose that the variable flat spring of the nasopharyngeal swab sampling apparatus is arranged such that it both has a trapezoidal shape and has a width that increases constantly in the direction from the one end to the other end.
Mineshita explains that the shape of the leaf spring is deliberately modified from a rectangular to a trapezoidal profile to achieve downsizing while maintaining strength and elasticity, stating that “We succeeded in downsizing the mechanism by changing its rectangular shape to trapezoidal, while maintaining strength and elasticity” (Mineshita, Abstract), and further that “With respect to the shape of the leaf spring, we considered the necessary requirements to maintain strength and reduce stiffness… Therefore, sufficient strength could be secured at the fixed point where the maximum stress was applied, and the strength could be reduced at the tip. Therefore, alternation of the width was considered, and a trapezoidal shape was adopted” (Mineshita, Sec. 2.1, Techniques for Shortening Leaf Springs). Mineshita also describes analysis of a trapezoidal leaf spring in which the width at the root and width at the tip are different and the trapezoidal shape is treated as a linear variation in width along the length of the spring, explaining that “the calculation of a trapezoidal leaf spring should have nb as the width of the root and as the width of the tip… The calculations confirmed that the same stiffness can be achieved even if the length is shorter than the rectangular shape. This reduces the leaf spring while maintaining strength” (Mineshita, Sec. 2.1, Techniques for Shortening Leaf Springs). Collectively, along with Figure 5, these disclosures teach that a trapezoidal leaf spring is formed so that the width varies in a monotonic, effectively linear manner between a smaller width at one end and a larger width at the other, embodying a constant rate of width change over the spring’s length.
It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the combined Tang, Chen, Homner, and Mineshita in view of Mineshita to configure the variable flat spring of the nasopharyngeal swab sampling apparatus so that it not only has a trapezoidal shape but also is oriented such that its width increases constantly in the direction from the one end to the other end, analogous to orienting the smaller-width end of the trapezoidal leaf spring toward the “one end” of the variable flat spring and the larger-width end toward the “other end” so that the width varies at a constant rate along the variable flat spring between those ends.
Such a modification would have been feasible because the modified Tang already provides a flat spring connecting two structural members (the swab coupling member and the support device), and Mineshita shows that forming a leaf spring with a trapezoidal profile (i.e., different widths at its root and tip with a linear transition between them) is a straightforward design choice to adjust stiffness and strength while shortening the spring. One of ordinary skill in the art would have recognized that by selecting which end of the variable flat spring corresponds to the narrower and wider sides of the trapezoidal profile and aligning those ends, respectively, with the “one end” and “other end” of the spring, the geometry could readily be arranged so that the width of the variable flat spring increases constantly from the one end to the other end, without changing the overall configuration or the basic compliant function of the mechanism.
The benefit of this combination would be to provide a nasopharyngeal swab sampling apparatus whose variable flat spring not only has a non-constant width (as in claim 11) and a directional increase in width from one end to the other (as in claim 12), but also has a trapezoidal profile that embodies a substantially constant rate of width increase along its length. This allows strength to be concentrated near the higher-stress end (analogous to the root in Mineshita) and reduced toward the opposite end, thereby enabling finer control of stiffness distribution, potential downsizing of the spring, and improved mechanical performance during nasopharyngeal swabbing while maintaining adequate strength where needed.
Claims 16 is rejected under 35 U.S.C. 103 as being unpatentable over Tang et al. (Tang et al. “Design of Novel End-Effectors for Robot-Assisted Swab Sampling to Combat Respiratory Infectious Diseases.” 2021 43rd Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC). vol. 2021. United States: IEEE, 2021. 4757–47), hereto referred as Tang, and further in view of Chen et al. (CN-201039231-Y), hereto referred as Chen, and further in view of Homner et al. (US-20200332579-A1), hereto referred as Homner, and further in view of Wang et al. (Wang, Shuangyi et al. “Design of a Low-Cost Miniature Robot to Assist the COVID-19 Nasopharyngeal Swab Sampling.” IEEE transactions on medical robotics and bionics 3.1 (2021): 289–293. Web.), hereto referred as Wang.
The combined Tang, Chen, and Homner teaches claims 10 and 15 as described above.
Regarding claim 16, the modified Tang does not explicitly teach that the driving device comprises: a rotating mechanism configured to rotate the support device around an axis parallel to the first direction; and a position adjusting mechanism configured to move the support device in the first direction. As established in claim 15, the modified Tang structure already teaches a nasopharyngeal swab sampling apparatus in which a robot acts as a driving device coupled to the support device (connector and compliant mechanism) and moves the support device and attached swab assembly during robot-assisted sampling (Tang, Abstract: "In this study, we proposed two detachable, recyclable, and cost-efficient end-effectors that can be equipped at the distal end of a robot to passively regulate or actively sense the force exerted onto patients", Fig. 1). However, Tang does not describe the internal composition of the driving device in terms of distinct mechanisms that respectively rotate the support device about an axis parallel to the insertion direction and adjust the position of the support device along that same axis, although figure 1 connotes these mechanisms and driving orientations (Tang, FIG, 1).
Wang fills this gap by teaching a nasopharyngeal swab robot whose end-effector incorporates both a linear position-adjusting mechanism and a rotation mechanism for the swab. Specifically, Wang explains that "The proposed robot includes an active 2-degree of freedom (DOF) end-effector for actuating the swab and a generic 6-DOF passive arm for the global positioning... Within the supporting case, a leadscrew driven linear stage actuated by a stepper motor was mounted. A small geared stepper motor is attached to the front end of the linear stage, controlling the following rotation link" and that "with the 2-axis joystick actuated diagonally, the swab can be translated and rotated simultaneously, in both directions of each axis" (Wang, Sec. II.A, Design Concepts; Sec. II.B, Hardware and Software Implementation, Fig. 2–3). In context, Wang teaches an active 2-DOF end-effector in which a leadscrew-driven linear stage actuated by a stepper motor provides controlled insertion and retraction of the swab along its axis, while a separate geared stepper motor drives a rotation link that rotates the swab gripper about that same axis, thereby providing coordinated translation and rotation of the swab.
It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the combined Tang, Chen, Homner robot-assisted swab sampling apparatus in view of Wang to configure the driving device so that it comprises a rotating mechanism configured to rotate the support device around an axis parallel to the first direction and a position adjusting mechanism configured to move the support device in the first direction. Such a modification would have been feasible because Tang already discloses an end-effector assembly attached to a robot for NP swabbing, and Wang demonstrates that it is a straightforward design choice to realize the robot’s driving function with a leadscrew-driven linear stage for axial insertion/retraction and a separate geared motor and rotation link for rotation about the insertion axis, all housed within a compact supporting case and coupled to a swab gripper. One of ordinary skill in the art would have recognized that implementing Tang’s driving device using Wang’s two-degree-of-freedom end-effector methodology, with or without its architecture, would be a simple scheme for Tang’s robot actuation which has more degrees of freedom, without changing the overall purpose of robot-assisted NP swab sampling.
The benefit of this combination would be to provide a nasopharyngeal swab sampling apparatus in which the driving device not only moves the support device and swab along the insertion direction but also actively rotates the support device about that axis, enabling controlled insertion, dwell, and rotational retraction profiles as described by Wang. This would improve the precision and repeatability of the swabbing motion, allow fine tuning of insertion depth and rotational speed, and enhance patient safety and comfort while maintaining the compliant force-regulation features provided by Tang’s end-effector design.
Claims 17 and 21 are rejected under 35 U.S.C. 103 as being unpatentable over Tang et al. (Tang et al. “Design of Novel End-Effectors for Robot-Assisted Swab Sampling to Combat Respiratory Infectious Diseases.” 2021 43rd Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC). vol. 2021. United States: IEEE, 2021. 4757–47), hereto referred as Tang, and further in view of Wang et al. (Wang, Shuangyi et al. “Design of a Low-Cost Miniature Robot to Assist the COVID-19 Nasopharyngeal Swab Sampling.” IEEE transactions on medical robotics and bionics 3.1 (2021): 289–293. Web.), hereto referred as Wang, and further in view of Chen et al. (CN-201039231-Y), hereto referred as Chen.
Regarding claim 17, Tang teaches that a nasopharyngeal swab sampling method comprises: pressing the human body by using the swab in a state in which the swab is inserted into the nasal cavity (Tang, p. 4758, II.A: “When the tip of the swab touches upon the nasal or the oral cavity, there will be force acting upon the swab and as a result the swab will bend. Because of the soft structure is made of TPU that has a Young’s Modulus smaller than the material of the swab stick, additional compliance is introduced with bending motions generated by the mechanism through body deformation to adaptively adjust the posture of the swab, avoiding excessive force due to the bending of the swab stick”, Tang teaches that, once the robot has advanced the swab so that its tip touches the nasal or oral cavity, the swab exerts force on the patient’s tissues and the compliant mechanism bends to adjust posture and avoid excessive force, corresponding to pressing the human body by using the swab while it is inserted into the nasal cavity; Fig. 1, p. 4757, I: “In this study, we proposed two detachable, recyclable, and cost-efficient end-effectors that can be equipped at the distal end of a robot to passively regulate or actively sense the force exerted onto patients (Fig. 1): (1) passive compliant mechanisms with soft materials to increase the flexibility of the swabbing system, so as to decrease the force that acts upon the patient”, these passages show that the end-effector is specifically designed to interact with patient anatomy during swabbing and to regulate the force exerted onto patients, reinforcing that Tang’s swab is intended to press against the nasal/oral cavity while inserted); the robot pressing mechanism comprises (Tang, Title: "Design of Novel End-effectors for Robot-assisted Swab Sampling to Combat Respiratory Infectious Diseases"; Abstract: "...end-effector designs that can be equipped at the distal end of a robot to passively regulate or actively sense the force exerted onto patients. One way is to introduce passive compliant mechanisms with soft material to increase the flexibility of the swabbing system... It is identified that the passive compliant mechanisms can increase the flexibility of the swabbing system when subjected to the lateral force and mitigate the vertical force resulted from buckling", demonstrating a robot pressing mechanism): a swab coupling member which extends in the first direction and to which the swab is fixed (Tang, FIG. 1-2; p. 4757-4758, II.A: "The design consists of a fixture to hold the swab in place and a passive mechanism with different configurations to introduce extra compliance (Fig. 2). The base of the compliant mechanism is mounted to a connector, which can be further attached to a robot... When the tip of the swab touches upon the nasal or the oral cavity, there will be force acting upon the swab and as a result the swab will bend... additional compliance is introduced with bending motions generated by the mechanism through body deformation to adaptively adjust the posture of the swab, avoiding excessive force", Tang teaches an end-effector subassembly in which an elongated swab, is held by a fixture that extends in the direction of the swab, and functions as the pressing device that is advanced into the nasal or oral cavity along the direction of the swab's elongated body, and thereby corresponds to a pressing device and swab coupling member extending in a first direction, where the swab tip applies force to the patient when advanced into the nasal or oral cavity); a support device that moves in the first direction relative to the swab coupling member (Tang, FIG. 2; p. 4757-4758, II.A: “The base of the compliant mechanism is mounted to a connector, which can be further attached to a robot… When the tip of the swab touches upon the nasal or the oral cavity, there will be force acting upon the swab and as a result the swab will bend”, FIG. 2 depicts the connector (support device) coupled to the compliant mechanism and the fixture holding the swab (pressing device). As the robot advances or withdraws the end-effector, the connector is driven in the insertion direction, and the compliant mechanism introduces bending and deformation that cause the position of the swab to shift relative to the connector along that same direction. Thus, even though the connector and fixture are carried forward together by the robot arm, the compliant mechanism’s deformation produces relative displacement in the first direction between the support device and pressing device under swabbing loads); and wherein the support device further comprises a guide member that is spaced apart from the swab coupling member in a direction crossing the first direction (Tang, FIG. 2: depicts the connector (i.e. support device) as coupling with the compliant mechanism via a disk (i.e. guide member) which is orientated in a direction crossing the first direction and acts to support and guide a portion of the compliant mechanism. The disk is also spaced apart from the pressing device).
Also regarding claim 17, the modified Tang partially teaches aligning a swab of a robot pressing mechanism in front of the nasal cavity of the human body and moving the swab, which is aligned in front of the nasal cavity, in a first direction to insert the swab into the nasal cavity. The modified Tang establishes a robot-assisted OP/NP swab sampling context in which compliant end-effector mechanisms attached to a robot regulate the force exerted onto patients during swabbing, but it does not explicitly articulate separate steps of (i) aligning the swab “in front of the nasal cavity” before insertion and (ii) moving the aligned swab in a first direction to insert it into the nasal cavity, instead assuming the general swabbing procedure is known (Tang, p. 4757, “oropharyngeal (OP) or nasopharyngeal (NP) swab samplings are common approaches of collecting the specimens for screening and diagnosis”; p. 4759, “we proposed two detachable, recyclable, and cost-efficient end-effectors that can be equipped at the distal end of a robot to passively regulate or actively sense the force exerted onto patients”; Fig. 1–2; see also Abstract).
Wang fills both the alignment and insertion details by expressly describing the nasopharyngeal swab sampling procedure, including positioning of the patient’s head and the subsequent insertion of the swab through the nostril into the nasal cavity and nasopharynx along a defined trajectory, which implicitly requires that the swab be aligned with the nasal opening beforehand and then moved along the nasal passage (Wang, Fig. 1, 3; p. 1, I. INTRODUCTION: “The NP swab collections involve inserting a specifically manufactured swab into a patient’s nasal cavity [8]. The head of the patient is expected to be tilted back (at approximate 70°) so the nasal passage becomes straight and accessible. The swab is then inserted through the nostril parallel to the palate, all the way to the nasopharynx. After left in place for several seconds for secretion absorptions, the swab is then rotationally retracted from the nasal cavity slowly”; see also p. 2–3, II.B. Hardware and Software Implementation). In context, Wang is teaching the standard sequence of patient positioning, swab alignment at the nostril, and insertion along the nasal passage for NP collections, in the same clinical setting as Tang’s robot-assisted swab sampling.
It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified Tang’s robot-assisted swab sampling system in view of Wang to include the combined steps of aligning the robot-mounted swab in front of the patient’s nasal cavity and, once aligned, moving the swab in a first direction through the nostril into the nasal cavity along the NP insertion path described by Wang. Such a modification would have been feasible because Tang’s end-effector is already designed to be mounted at the distal end of a robot for OP/NP swabbing, and Wang shows that the standard NP procedure involves positioning the patient’s head, bringing the swab into alignment at the nostril, and inserting it parallel to the palate to the nasopharynx. One of ordinary skill in the art would have recognized that, when implementing Tang’s robot in the specific NP swab procedure described by Wang, the operator would necessarily place the robot’s swab tip in front of the nostril opening and then drive it along the nasal passage, so explicitly reciting these alignment and insertion steps merely formalizes routine operational actions already implicit in the combined teachings. The benefit of this combination would be to provide a robot-assisted nasopharyngeal swab sampling method that closely tracks the established clinical protocol for NP sampling, improving repeatability, insertion accuracy, and patient safety while preserving Tang’s compliant force-regulation features and the NP trajectory described by Wang.
Also regarding claim 17, the modified Tang does not teach a flat spring is configured to connect the swab coupling member to the support device. The modified Tang teaches an end-effector in which a swab-holding fixture (swab coupling member) extends along the swab axis and is joined to a connector that can be attached to a robot, with a compliant mechanism between them that bends under load when the swab tip contacts the nasal/oral cavity (Tang, p. 4758–4759, II.A; Fig. 2). However, Tang does not explicitly describe this compliant mechanism as a “flat spring” connecting the swab coupling member to a “support device that moves in the first direction relative to the swab coupling member” as claimed.
Chen fills this structural gap by teaching a constant-force spring mechanism where a spring element links a movable push rod to a supporting member so that the push rod slides relative to the support while the spring deforms (Chen, ¶[0029]-[0032]). In context, Chen shows how to implement a bent flat spring as an explicit mechanical element connecting a moving member to a support, rather than as a monolithic compliant body.
It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the combined Tang and Wang in view of Chen to realize the compliant connection between the swab coupling member and the support device using a flat spring element that connects the swab-side fixture to the robot-side support and allows relative motion along the insertion axis. Such a modification would have been feasible because Tang already requires a compliant connection between the swab holder and a robot-mounted connector, and Chen demonstrates a straightforward way to implement a spring-based linkage between a moving component and a support. One of ordinary skill in the art would have recognized that using a flat spring to connect Tang’s swab fixture to the connector would preserve the desired compliance while providing a compact, tunable spring geometry analogous to Chen’s wind spring mechanism. The benefit of this combination would be to provide a robot pressing mechanism in which the swab coupling member is linked to the support device through a defined flat spring structure, facilitating predictable elastic response, easier manufacturing, and consistent force characteristics during NP swab insertion and pressing.
Also regarding claim 17, the modified Tang partially teaches that the pressing of the human body by using the swab comprises: moving the support device in the first direction; and elastically deforming the flat spring by using the support device that moves in the first direction. The modified Tang discloses that the swab-holding fixture and compliant mechanism are mounted on a connector attached to a robot, and that when the swab tip touches the nasal or oral cavity the compliant mechanism deforms to adjust posture and avoid excessive force, but it does not explicitly decompose the pressing step into (a) moving a “support device” in the first direction and (b) elastically deforming a specific “flat spring” by using that support-device motion (Tang, p. 4758–4759, II.A, “The design consists of a fixture to hold the swab in place and a passive mechanism with different configurations to introduce extra compliance (Fig. 2). The base of the compliant mechanism is mounted to a connector, which can be further attached to a robot… When the tip of the swab touches upon the nasal or the oral cavity, there will be force acting upon the swab and as a result the swab will bend… additional compliance is introduced with bending motions generated by the mechanism through body deformation to adaptively adjust the posture of the swab, avoiding excessive force”).
Chen demonstrates that when a member linked by a spring is driven in a particular direction relative to a supporting member, the spring elastically deforms, storing and releasing energy and providing a controlled force profile (Chen, [0033]: “When the sliding cover is pushed upward, the first pushrod 2 moves upward with the sliding cover... since one end of the coil spring 4 is constrained, the pushrod drives the coil spring 4 to slide upward to the top of the support member 1. Under the action of the contraction force of the coil spring 4, the pushrod naturally slides upward into the determined stroke, thereby making the sliding cover automatically enter the position”). Wang, in turn, provides the explicit robot actuation scheme in which a leadscrew-driven linear stage translates the swab end-effector along the insertion axis so that the support structure is actively moved during NP sampling (Wang, p. 2–3, II.A–II.B, “Within the supporting case, a leadscrew driven linear stage actuated by a stepper motor was mounted… with the 2-axis joystick actuated diagonally, the swab can be translated and rotated simultaneously, in both directions of each axis”). In context, Chen teaches the mechanical principle that motion of a support-linked member produces elastic spring deformation, while Wang shows the concrete implementation of support motion along the NP insertion direction for the swab robot.
It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the combined Tang, Wang, and Chen in view of Wang and Chen to perform the pressing step by driving the support device (connector and associated end-effector structure) along the insertion axis using a linear stage while allowing the flat spring that connects the swab coupling member to that support device to elastically deform as the swab contacts the nasal cavity. Such a modification would have been feasible because Tang already attaches the compliant swab holder to a robot-mounted connector, Chen shows that moving a support-linked member naturally deforms the connecting spring, and Wang provides a practical method (and if needed, mechanism) for moving the swab-support structure along the insertion axis during NP sampling. One of ordinary skill in the art would have recognized that combining these teachings means that when the robot advances the support device along the first direction, the flat spring between the support and the swab coupling member will elastically deform under contact forces, thereby defining the pressing step in terms of support motion and spring deformation as recited. The benefit of this combination would be to implement a robot-assisted NP swab method in which pressing is realized through controlled motion of the support device and predictable elastic deformation of a flat spring, yielding more controlled force application, improved patient comfort, and safer, repeatable sampling while maintaining the low-cost, compliant design motivations of Tang and Wang.
Also regarding claim 17, the modified Tang does not explicitly teach that the flat spring comprises: a first plate that has one end fixed to the swab coupling member and extends in the first direction; a second plate that has one end fixed to the guide member and extends in the first direction; and a third plate that has a curved shape and is bent once and directly connected to the other end of the first plate and the other end of the second plate. Rather, the modified Tang teaches a robot swab end-effector that uses a passive compliant mechanism between a fixture holding the swab and a connector mounted to the robot, and is implemented as a flat spring as shown above. However, it does not explicitly divide the spring into a first plate fixed to the swab coupling member, a second plate fixed to the guide member, and a third plate having a curved shape that is bent once and directly connects the other ends of the first and second plates, where the first plate and the second plate extend in the first direction from their respective fixed ends toward the third plate, such that the third plate bridges and connects the extending ends of the first and second plates.
Chen teaches a constant-force spring mechanism including coil spring (4) fixed within a supporting member and connected to a push rod that moves relative to the supporting member (Chen, ¶[0008]–[0010]; FIG. 1–6). As illustrated in Chen’s figures, the coil spring is formed from a continuous spring strip having straight end portions that are respectively coupled to structural members and a curved intermediate portion forming the spring body between those end portions. The inner end of the spring is anchored within a positioning groove of positioning block 8 inside supporting member 1, while the opposite end portion extends outward and connects to the sliding push rod (Chen, FIG. 1 and 4; ¶[0008]–[0010]; [0029]). Because the push rod moves along its guide direction within the supporting member, the straight end portion coupled to the push rod extends along that rod direction, while the opposite end portion is fixed relative to the supporting member and oriented along the direction defined by the guide structure of the support member. The figures depict that end of the plate is faced away from the tip of the rod (Chen, FIG. 1-7). Accordingly, Chen discloses a flat spring structure having (1) a first plate-like end portion coupled to one structural member, (2) a second plate-like end portion coupled to another structural member, and (3) a bent intermediate portion connecting the end portions, corresponding to the claimed first plate, second plate, and third plate. Further, Chen teaches that the coil spring produces a substantially constant force response during operation, explaining that “under the action of the coil spring 4, the force on each segment is almost constant” (Chen, ¶[0034]), thereby corresponding to the claimed feature that the flat spring generates a constant elastic restoring force regardless of the bent position of the third plate. However, Chen anchors the two straight end regions of the spring so that they extend in generally opposite directions. Thus, it does not disclose a configuration in which the second plate extends in the same direction as the first plate.
Homner teaches that the angular orientation and pretension of a flat spiral spring end relative to its supporting structure can be selected and adjusted by rotating the mounting element to which the spring end is anchored, thereby allowing the orientation of the spring end to be set according to design requirements and then fixed in place (Homner, ¶[0031]). Because Tang’s swab is advanced along a defined insertion direction, a person of ordinary skill in the art would have recognized that setting the angular orientation of the spring ends so that both plate-like end portions extend in the first direction toward the curved third plate would provide a compact spring geometry aligned with the insertion axis while retaining the constant-force behavior taught by Chen.
It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the combined Tang and Chen in view of Chen and Homner by configuring the flat spring to include a first plate, a second plate, and a third plate, wherein the first plate has one end fixed to the swab coupling member and extends in the first direction toward the third plate, the second plate has one end fixed to the guide member and extends in the first direction toward the third plate, and the third plate has a curved shape bent once and directly connects the other ends of the first plate and the second plate so as to generate a constant elastic restoring force regardless of the bent position of the third plate. Tang teaches the desirability of providing compliance between the swab fixture and the supporting connector in order to regulate force and avoid excessive force during swab insertion (Tang, Sec. II.A; Fig. 2), while Chen teaches a flat spring configuration having end portions coupled to respective structural members and an intermediate bent spring body that regulates relative displacement between those members (Chen, ¶[0008]–[0010]; FIGS. 1–6). Homner further teaches that the angular orientation and pretension of a flat spiral spring end relative to its supporting structure can be selected and adjusted by rotating the mounting element to which the spring end is anchored, thereby allowing the orientation of the spring end to be set according to design requirements and then fixed in place (Homner, ¶[0031]). In view of these teachings, one of ordinary skill in the art would have recognized that the orientation of the end segments of the flat spring used in Tang’s compliant mechanism could be selected and fixed using the type of adjustable anchoring arrangement taught by Homner so that both spring end portions extend generally towards the third plate in the same insertion direction. In such an implementation, the spring would include two plate-like end segments extending in the same direction from a bent intermediate portion, thereby corresponding to the claimed first plate and second plate extending from the third plate, while the bent intermediate portion provides the compliant deformation that generates a substantially constant restoring force as taught by Chen. The benefit of such a configuration would be to maintain the predictable constant-force spring behavior described by Chen while arranging the spring geometry in a compact orientation compatible with the swab insertion direction in Tang’s device, thereby improving packaging and providing consistent force regulation during robot-assisted nasopharyngeal sampling.
With respect to the limitation that the third plate is “bent once,” the claim requires that the third plate be a bent portion that connects one end of the first plate and one end of the second plate. The claim does not require that the spring body exclude additional curvature beyond that bent connection, nor does it require that a continuous curved spring region be treated as “bent more than once” merely because it continues through multiple turns. Under a broad, reasonable interpretation, Chen’s coil spring formed from a continuous spring strip includes an intermediate curved region that directly connects the two end portions, and therefore already reads on the third plate being “bent once” and directly coupled to the first and second plates, because the end portions are connected through the continuous spring body without any intervening linkage or separate component (Chen, Figs. 2–5; ¶[0008]–[0010]).
Alternatively, “bent once” may simply refer to a formation process in which the third plate is formed in a one-time bending process. That is, “bent once” can also be interpreted as the physical action of forming that occurs at a single time, regardless of how many bends or turns are formed. With this interpretation, the method of formation does not distinguish the claimed structure form the combination.
Alternatively, even assuming, arguendo, that Applicant advances a narrower interpretation of “bent once” to require a single bend without additional turns, Chen still supports the Office position because Chen illustrates coil spring (4) with different winding configurations across embodiments (Chen, Figs. 2, 4, and 6), demonstrating that the winding configuration is a selectable spring-geometry parameter used to meet packaging and force-response objectives. Springs are well known mechanical elements used to regulate force between relatively movable components, and selecting a particular spring geometry or bend configuration to achieve a desired compliance profile constitutes routine engineering design within the level of ordinary skill in the art.
The benefit of this combination would be to improve Tang’s swabbing end-effector by providing a more predictable and substantially constant force response during swab insertion and pressing. Because Tang already seeks to introduce compliance to avoid excessive force applied to the patient (Tang, Sec. II.A), implementing the compliant element using the spring configuration taught by Chen would enhance the ability of the mechanism to regulate insertion forces in a controlled and repeatable manner while maintaining the compliant behavior described by Tang, thereby improving safety and comfort during robot-assisted nasopharyngeal or oropharyngeal sampling.
Regarding claim 21, the modified Tang does not explicitly teach that the third plate has a U-shaped structure bent about 180 degrees so as to make the flat spring generate a constant elastic restoring force regardless of a bent position of the third plate. Rather, the modified Tang teaches a bent structure but does not expressly teach that it has a 180 degree bend making a U-shaped structure and generates a constant elastic restoring force regardless of a bent position.
Chen teaches that its coil spring provides substantially constant force behavior, stating: “Under the action of the coil spring 4, the force on each segment is almost constant”. (Chen, ¶[0034]). Chen further discloses that the coil spring (4) is fixed in the support member and coupled to the push rod so that relative motion is regulated by the elastic action of the coil spring (Chen, ¶[0027]–[0029]; ¶[0033]–[0034]; Figs. 5–7). Further, Chen expressly presents multiple embodiments (e.g., Embodiment 1 and Embodiment 2) with corresponding drawings, and the drawings depict different spring-strip configurations and winding extents for coil spring (4), evidencing that the spring-strip geometry is not limited to a single fixed implementation and may be selected among disclosed configurations to meet design objectives (Chen, ¶[0018]–[0024]; ¶[0030]–[0032]; FIG. 2, 4, and 6).
It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the combined Tang, Chen, and Wang so that the third plate has a U-shaped structure bent about 180 degrees and the flat spring generates a substantially constant elastic restoring force regardless of the bent position of the third plate, including by selecting a spring geometry (including a partial-turn/approximately 180-degree bend) to meet the claimed third-plate shape while maintaining the substantially constant-force behavior taught by Chen as the design objective. Because the claim requires only that the third plate be bent about 180 degrees to form a U-shaped structure, selecting an approximately 180-degree curvature segment (i.e., a partial turn) of Chen’s spring strip between the plate-like end portions would have satisfied this limitation. Tang teaches providing compliance to “avoid[] excessive force due to the bending of the swab stick” and further indicates that “Different configurations would result in different bending stiffnesses”. (Tang, p. 4757, Sec. II.A; Tang, p. 4758, Sec. IV). Chen expressly teaches that its coil spring provides substantially constant-force behavior, stating: “Under the action of the coil spring 4, the force on each segment is almost constant”. (Chen, ¶[0034]). Thus, one of ordinary skill in the art would have been motivated to select and configure the spring-strip geometry (including an approximately 180-degree U-shaped bend for the third plate) so that the resulting spring exhibits the substantially constant restoring-force characteristic taught by Chen while meeting the claimed shape requirement. Springs are well known mechanical elements used to regulate force between relatively movable components, and selecting a particular spring geometry or bend configuration (including a U-shaped approximately 180-degree bend) to achieve a desired compliance profile constitutes routine engineering design within the level of ordinary skill in the art.
Such a modification would have been feasible because Chen already uses a spring strip coupled at its ends to respective members to regulate relative motion, and selecting a partial-turn (about 180-degree) curvature for the intermediate bent region between the end portions is a straightforward spring-geometry selection while consistent with Chen’s taught constant-force behavior (Chen, ¶[0033]–[0034]; FIG. 2, 4, and 6).
The benefit of this combination would be improved predictability and repeatability of the elastic restoring force during swab insertion and pressing, thereby enhancing Tang’s stated objective of reducing excessive force on the patient and providing a safe and smooth sampling experience (Tang, Sec. II.A; Chen, ¶[0034]).
Claim 19 is rejected under 35 U.S.C. 103 as being unpatentable over Tang et al. (Tang et al. “Design of Novel End-Effectors for Robot-Assisted Swab Sampling to Combat Respiratory Infectious Diseases.” 2021 43rd Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC). vol. 2021. United States: IEEE, 2021. 4757–47), hereto referred as Tang, and further in view of Wang et al. (Wang, Shuangyi et al. “Design of a Low-Cost Miniature Robot to Assist the COVID-19 Nasopharyngeal Swab Sampling.” IEEE transactions on medical robotics and bionics 3.1 (2021): 289–293. Web.), hereto referred as Wang, and further in view of Chen et al. (CN-201039231-Y), hereto referred as Chen, and further in view of Mineshita et al. (Mineshita, Hiroki et al. “Development of a Trapezoidal Leaf Spring for a Small and Light Variable Joint Stiffness Mechanism.” ROMANSY 23 - Robot Design, Dynamics and Control. Ed. by Gentiane Venture et al. Cham: Springer International Publishing, 2020. 355–363. Web. (Year: 2020)), hereto referred as Mineshita.
The combined Tang, Wang, and Chen teaches claim 17 and 18 as described above.
Regarding claim 19, the modified Tang does not teach that the width of the third plate is not constant. Rather, the modified Tang teaches a nasopharyngeal swab sampling method using a robot pressing mechanism in which a flat spring connects a pressing device (swab fixture) and a support device (connector with guide member), and the flat spring includes plate-like end regions respectively coupled to the pressing device and the guide member, with a bent intermediate region joining those plates, allowing relative displacement and compliant force regulation along the insertion direction; however, it does not disclose that the bent plate segment has a non-constant width along its length.
Mineshita fills this gap by teaching that a leaf spring used in a joint-stiffness mechanism may have its width varied along its length and formed into a trapezoidal profile to maintain strength while reducing stiffness and size. Specifically, Mineshita explains that “with respect to the shape of the leaf spring, we considered the necessary requirements to maintain strength and reduce stiffness” and that “Therefore, sufficient strength could be secured at the fixed point where the maximum stress was applied, and the strength could be reduced at the tip. Therefore, alternation of the width was considered, and a trapezoidal shape was adopted” (Mineshita, Sec. 2.1, Techniques for Shortening Leaf Springs; see also FIG. 5). Mineshita further teaches that changing the leaf spring from a rectangular shape to a trapezoidal shape allows the mechanism to be downsized while maintaining strength and elasticity, stating that “Therefore, to make the mechanism smaller and lighter, we shorten the length of the leaf spring. We succeeded in downsizing the mechanism by changing its rectangular shape to trapezoidal, while maintaining strength and elasticity” (Mineshita, Abstract).
It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the combined Tang, Wang, and Chen in view of Mineshita to configure the third plate of the flat spring in the nasopharyngeal swab sampling method with a non-constant width, such as a trapezoidal width profile along the bent intermediate region, so that the third plate’s width increases or otherwise varies along its length in order to tailor stiffness and strength characteristics of the flat spring while maintaining the overall three-plate geometry and compliant connection between the swab coupling member and support device. Such a modification would have been feasible because the combined Tang, Wang, and Chen already provides a flat spring structure with a bent intermediate segment connecting the swab-side and support-side plates, and Mineshita shows that varying the width of such a spring segment along its length (forming a trapezoidal leaf spring) is a straightforward and well-understood design choice to reduce size and adjust stiffness while preserving strength at critical regions. One of ordinary skill in the art would have recognized that the third plate of the flat spring in the modified robot swab mechanism could be formed with a non-constant width as in Mineshita, for example by tapering or widening the plate segment between its ends, without changing the basic function of the spring or the three-plate connection between the swab coupling member and the guide member.
The benefit of this combination would be to provide a nasopharyngeal swab sampling method whose robot end-effector uses a flat-spring intermediate plate region that not only allows compliant relative motion between the swab coupling member and support device but also offers improved control over stiffness distribution and strength, enabling the mechanism to be made smaller and lighter while maintaining adequate strength, as demonstrated by Mineshita’s trapezoidal leaf spring design. This would allow finer tuning of the force profile and mechanical response of the robot pressing mechanism during nasopharyngeal swabbing, improving safety and comfort while also reducing the size and mass of the compliant mechanism assembly.
Claim 20 is rejected under 35 U.S.C. 103 as being unpatentable over Tang et al. (Tang et al. “Design of Novel End-Effectors for Robot-Assisted Swab Sampling to Combat Respiratory Infectious Diseases.” 2021 43rd Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC). vol. 2021. United States: IEEE, 2021. 4757–47), hereto referred as Tang, and further in view of Wang et al. (Wang, Shuangyi et al. “Design of a Low-Cost Miniature Robot to Assist the COVID-19 Nasopharyngeal Swab Sampling.” IEEE transactions on medical robotics and bionics 3.1 (2021): 289–293. Web.), hereto referred as Wang, and further in view of Chen et al. (CN-201039231-Y), hereto referred as Chen, and further in view of Homner et al. (US-20200332579-A1), hereto referred as Homner.
The combined Tang, Wang, and Chen teaches claim 17 and 18 as described above.
Regarding claim 20, the modified Tang does not fully teach that the guide member is inclined to form an acute angle relative to the first direction, and thus is not parallel to the swab coupling member, and the support device further comprises a support body configured to support the guide member, wherein the swab coupling member passes through the support body in the first direction, and the guide member is connected to the support body and rotates relative to the support body. As established in the rejection of claim 17, the combined Tang, Wang, and Chen teaches a nasopharyngeal swab sampling method in which a robot pressing mechanism uses a flat spring between a swab coupling member and a support device to provide compliant motion during insertion and pressing in the first direction, and a guide-side structure is provided to orient and support the second plate of the flat spring relative to the swab direction; however, this combination does not disclose that the guide member itself is formed and arranged so that it is inclined at an acute angle relative to the first direction and is therefore non-parallel to the swab coupling member, nor that the support device includes a support body that both supports the guide member and allows the guide member to rotate relative to the support body while the swab coupling member passes through that support body in the first direction.
Homner teaches the missing aspects of a support body that allows rotation and angular adjustment by disclosing a hinge in which a flat spiral spring is connected to a torque adjustment unit mounted on a support part, and in which the torque adjustment unit can be rotated relative to the support part to set and maintain a desired spring pretension and corresponding angular orientation. Specifically, Homner explains that “a torque adjustment unit 28 is arranged on the flat spiral spring 18, and the radially inner end 24 of the flat spiral spring 18 is connected to the torque adjustment unit 28. In this embodiment, the flat spiral spring 18 is anchored in a groove of the torque adjustment unit 28. The torque adjustment unit 28 allows the flat spiral spring 18 to be pretensioned to the required torque. The pretension of the flat spiral spring 18 can be varied by means of an adjusting screw 30 located on the fixed hinge part 14, with the screw shaft meshing with a toothed portion 32 of the torque adjustment unit 28. Varying the adjusting screw 30 results in a corresponding rotation of the torque adjustment unit 28, which in turn pretensions the flat spiral spring 18 that is firmly anchored at both its ends 24, 26. The pretension set in this way is maintained by means of the adjusting screw 30” (Homner, ¶[0031]).
It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the combined Tang, Wang, and Chen in view of Homner to implement the support device in the nasopharyngeal swab sampling method with a support body that supports a guide member for rotation and allows the angular orientation of the guide member relative to the swab coupling member and first direction to be adjusted, so that the guide member can be inclined to form an acute angle relative to the first direction and thus be non-parallel to the swab coupling member while the swab coupling member passes through the support body in the first direction. In such a modification, the support body in the robot pressing mechanism would correspond functionally to Homner’s fixed hinge part and housing that support the torque adjustment unit, while the rotatable guide member would correspond to the torque adjustment unit or an attached member whose angular position is adjusted and then maintained relative to the support body by an adjustment feature analogous to Homner’s adjusting screw.
Such a modification would have been feasible because both the combined Tang, Wang, and Chen structure and Homner’s hinge mechanism involve spring-based compliant elements whose relative angular orientation with respect to a supporting structure influences force transmission and motion. One of ordinary skill in the art would have recognized that mounting Tang’s guide-side structure or an intermediate guide block on a support body in a manner similar to Homner’s torque adjustment unit would allow the angle between the guide member and the swab direction to be set and varied while preserving the compliant flat-spring connection between the swab coupling member and the support device.
The benefit of this combination would be to provide a nasopharyngeal swab sampling method in which the robot end-effector not only has compliant motion and force regulation via the flat spring but also offers an adjustable, plate-like guide member whose inclination relative to the swab direction can be tuned and maintained by the support body. This allows deliberate control of the acute angle between the guide member and the swab coupling member and thus control over the direction and distribution of contact forces during insertion and pressing, improving the predictability and tunability of the mechanical response and enabling better alignment with anatomical pathways and patient comfort during robot-assisted swab sampling.
Response to Arguments
35 U.S.C. §112(b)
Applicant's arguments filed 2/13/2026, page 8, regarding the previous 112(b) Rejections of claims 10-16 have been fully considered and are persuasive. The previous 112(b) rejections have been withdrawn.
35 U.S.C. §103
Applicant's arguments filed 2/13/2026, pages 8-11, regarding the previous 103 Rejections of claims 1-17 and 19-21 have been fully considered but are not persuasive as shown below.
Applicant’s Argument: Applicant contends that amended claim 1 is not obvious because none of the cited references disclose a flat spring comprising a first plate, a second plate, and a third plate bent once and directly coupled to the first plate and the second plate. Applicant argues that Chen discloses a multi-turn coiled spring and therefore cannot correspond to a third plate that is bent once and directly coupled to the first and second plates. Applicant further asserts that neither Tang nor Chen discloses a flat spring configured to connect the pressing device to the support device having the specific three plate configuration recited in claim 1.
Examiner’s Response: The arguments are not persuasive.
As set forth in the prior Office Action, Tang teaches a compliant connection between the swab fixture, which corresponds to the claimed pressing device, and the connector, which corresponds to the claimed support device. Tang expressly discloses a passive compliant mechanism positioned between these components that bends under load to regulate force during swab insertion (Tang, Fig. 2; Sec. II.A "Passive Compliant Mechanisms"). Tang further explains that “by changing the configuration of the mechanism, different bending stiffness can be obtained”, while still increasing flexibility under lateral force and avoiding excessive force (Tang, p. 4, Sec. IV). Although Tang does not expressly describe the compliant mechanism as a flat spring, the rejection relies on Chen for the flat spring configuration.
Chen discloses a constant-force spring mechanism in which a coil spring (4) connects a movable push rod within a supporting member/device body (Chen, ¶[0030]; Figs. 2–6). One end of the push rod is connected to the coil spring, while the opposite end is connected to the device body, such that relative movement of the components is regulated by the spring (Chen, ¶[0030]). The drawings illustrate that the coil spring is implemented as a spiral band spring wound from a flat strip, which is fixed at one end within the support member via a flat section of the strip and connected at the other end to the movable push rod via flat section of the strip (Chen, Figs. 2–5). This configuration provides a spring element that stores bending energy in the wound strip while allowing controlled relative movement between connected components. Further, Chen’s drawings depict the coil spring with different winding configurations across embodiments (for example, Chen illustrates coil spring 4 with a different number and arrangement of windings in Figs. 2, 4, 6). This variation confirms that the number of windings is a design consideration selected to satisfy packaging and performance requirements rather than a fixed, essential design.
The limitation that the third plate is "bent once" requires that the third plate include a bend that directly connects the first plate and the second plate. The claim language does not require that the overall spring body contain only a single curvature feature or exclude additional curvature elsewhere along the strip. The spiral band spring shown in Chen is formed from a continuous strip element that includes end portions and a curved intermediate portion that forms the spiral spring. As illustrated in Chen’s drawings (Figs. 2–5), the strip spring includes two substantially straight end portions used to connect to the push rod and the device body, and a curved intermediate portion between those end portions that forms the spring body. Thus, the curved region directly connects the two straight regions and therefore corresponds to the claimed third plate bent between and directly connecting the first plate and the second plate. Because the flat strip spring is continuous, the end regions are directly coupled through the intermediate bent region without any intervening linkage or separate component.
Alternatively, “bent once” may simply refer to a formation process in which the third plate is formed in a one-time bending process. That is, “bent once” can also be interpreted as the physical action of forming that occurs at a single time, regardless of how many bends or turns are formed. With this interpretation, the method of formation does not distinguish the claimed structure form the combination.
Alternatively, even assuming, arguendo, that Chen’s straight end portions correspond to the claimed first plate and second plate, the region between those straight portions still constitutes a bent portion of the flat strip spring that directly connects the end portions. The presence of additional winding or curvature in Chen’s illustrated embodiment does not negate the existence of such a bent region directly connecting the end portions, nor does the claim language require the exclusion of additional curvature beyond a single bend. However, even if Applicant’s narrow reading of “bent once” were adopted for purposes of argument, it would have been prima facie obvious to a person of ordinary skill in the art to modify Chen’s flat strip spring by selecting a reduced-turn configuration, including a configuration having only a single curved bend between the two straight end regions, in order to meet a desired force response and size constraint while retaining Chen’s taught constant-force spring functionality. Such selection of the number of windings or turns is a routine spring-design optimization within the level of ordinary skill in the art, especially in view of Chen’s different winding configurations across embodiments.
Applicant’s assertion that the remaining cited references also fail to disclose the amended features of claim 1 is not persuasive. The rejection of claim 1 relies on Tang in view of Chen for the flat spring configuration, and Applicant has not identified reversible error in the findings regarding those references or in the articulated rationale for their combination.
It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to implement the compliant connection between Tang’s pressing device and support device using a flat strip spring structure of the type taught by Chen in order to provide a predictable and controlled force response between the relatively movable components. Tang teaches the desirability of introducing compliance to regulate contact force and avoid excessive force during swab insertion, while Chen teaches a flat strip spring configuration capable of providing controlled and substantially constant force behavior. In view of these teachings, a person of ordinary skill in the art would have recognized that Chen’s spring concept could be applied when designing the compliant element of Tang’s mechanism to achieve a desired compliance and force profile. As discussed above, Chen further illustrates that the winding configuration of the spring is a design parameter, and selecting an appropriate winding count or reduced-turn bend geometry for the spring in the compliant mechanism implemented in accordance with Tang would have been a routine engineering optimization to achieve the desired force response and packaging constraints.
Accordingly, claim 1 remains unpatentable over Tang in view of Chen.
Applicant’s further assertion that dependent claims are allowable because claim 1 is allowable is not persuasive, as claim 1 remains unpatentable for the reasons set forth above.
Applicant’s Argument: Applicant argues that claim 4 recites that the third plate has a U shaped structure bent about 180 degrees so as to make the flat spring generate a constant elastic restoring force regardless of a bent position of the third plate. Applicant contends that modifying Tang to provide a constant elastic restoring force would render Tang unsatisfactory for its intended purpose of adjusting posture and avoiding excessive force by changing the generated restoring force. Applicant relies on MPEP 2143.01.V and asserts that there is no motivation to make such a modification.
Examiner’s Response: The argument is not persuasive.
Applicant’s asserted “intended purpose” for Tang is not supported by Tang’s disclosure. Tang describes that, when the swab contacts the nasal or oral cavity, the swab bends and the passive compliant mechanism introduces “additional compliance” via “bending motions generated by the mechanism through body deformation” to “adaptively adjust the posture of the swab” and “avoid[] excessive force due to the bending of the swab stick” (Tang, p. 4757-4758, Sec. II.A; Fig. 2). Tang further explains that “by changing the configuration of the mechanism, different bending stiffness can be obtained”, while still increasing flexibility under lateral force and avoiding excessive force (Tang, p. 4760, Sec. IV). Tang does not state that its compliant mechanism avoids excessive force 'by changing the generated elastic restoring force' as a function of bend position, as Applicant asserts. Rather, Tang’s stated objective is safe force reduction and posture adjustment via added compliance and bending stiffness selection (Tang, Abstract; Sec. I; Sec. II.A; Fig. 2). Accordingly, providing a constant force spring does not render Tang unsatisfactory for its intended purpose of reducing force on the patient during swabbing.
Chen expressly teaches a constant force spring mechanism in which “the force on each segment is almost constant”, providing smooth operation (Chen, ¶[0034]; see also ¶[0030] and ¶[0031]). Additionally, Chen’s drawings illustrate the coil spring with different winding configurations across embodiments, evidencing that the number of windings is a design parameter used to tune the spring’s constant-force behavior and accommodate packaging constraints. Accordingly, a person of ordinary skill in the art implementing Tang’s compliant mechanism would have found it obvious to employ a spring configuration based on Chen’s constant-force spring concept in order to provide predictable and controlled force regulation. Selecting a spring geometry that provides a U-shaped bend about approximately 180 degrees, or otherwise selecting a reduced-turn bend geometry that achieves the desired constant-force response, would have been a routine design optimization within the level of ordinary skill in the art. Tang’s purpose of reducing excessive force on the patient remains satisfied by such an implementation.
Accordingly, claim 4 remains unpatentable over Tang in view of Chen
Applicant’s Argument: Applicant asserts that amended claim 10 and method claim 17 include limitations similar to those discussed for claim 1 and therefore are allowable for at least the same reasons (as well as their dependents).
Examiner’s Response: Applicant does not present separate arguments for claims 10 through 17 beyond those addressed for claim 1. The arguments are therefore not persuasive for the reasons discussed above with respect to claim 1. The structural flat spring configuration relied upon by Applicant is taught or suggested by the combination of Tang and Chen, and the additional cited references for the dependent claims.
Because the apparatus and method claims rely on the same flat spring structural features already addressed, and because the cited references collectively teach or suggest those features, claims 10, 17 and their dependent claims remain unpatentable for the reasons set forth in the prior Office Action and as clarified herein.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
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/AARON MERRIAM/Examiner, Art Unit 3791
/MATTHEW KREMER/Primary Examiner, Art Unit 3791
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