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 .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 25 February 2026 has been entered.
Response to Arguments
Applicant’s arguments, see Remarks page 7, filed 25 February 2026, with respect to the rejections of claims 1, 5-10, 14, 15, and 19 under 35 U.S.C. 103 have been fully considered and are persuasive. Therefore, the rejection has been withdrawn. However, upon further consideration, a new ground(s) of rejection is made in view of Hauser et al 2019 in view of Wyzgol et al.
Applicant’s arguments for the novelty of amended claim 1 hinge on the unique properties of the dimensional changes in the metering channel. Applicant correctly identifies a deficiency in Wyzgol, that the reduction in width occurs as a cross-section of the channel, not as a longitudinal reduction. Accordingly, a new rejection is made in view of Wyzgol et al, which teaches the structure of the metering channel in amended claim 1.
Status of Claims
Applicant's amendments to the claims filed 25 February 2026 have been entered. Applicant's remarks filed 25 February 2026 are acknowledged.
Claims 1 and 6 are in status “currently amended.” Claims 5 and 7 – 19 are in status “Original” or “Previously Presented.” Claim 21 is new. Claims 2 – 4 are cancelled. Claim 20 is withdrawn.
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.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 1, 5-10, 14, 15, 19, and 21 are rejected under 35 U.S.C. 103 as being unpatentable over Houser et al 2019 (Hauser J., Lenk G., Ullah S., Beck O., Stemme G., Roxhed N., “An Autonomous Microfluidic Device for Generating Volume-Define Dried Plasma Spots,” Anal. Chem. 2019; 91: 7125-7130, cited on the IDS submitted 01 September 2022) in view of Wyzgol et al (US 20020114738 A1).
With regards to claim 1, Hauser et al 2019 teaches;
The claimed “a microfluidic device configured to sample, meter and collect a metered volume of body fluid for analysis by means of capillary transport” has been read on the taught (Conclusions, paragraph 1, “A novel capillary-driven sampling device for autonomous generation of volumetric DPS was presented. The volume defining concept is based on capillary-driven filtration through a porous filtration membrane into a microchannel and absorption of a channel geometry-defined volume by an absorbent sample pad.”);
The claimed “an inlet section, for receiving a sample of body fluid, the inlet section comprising an inlet port” has been read on the taught (Results and Discussion, Device Operation, paragraph 2, “…blood is applied to the filtration membrane and plasma starts filling the metering channel by capillary action.”; The area where blood is applied reads on the inlet section. Please see annotated figure 1);
The claimed “a metering section configured to receive body fluid from the inlet section and comprising a metering channel, wherein the metering section is arranged to separate a metered volume of body fluid filled in the metering channel” has been read on the taught (Results and Discussion, Device Operation, paragraph 2, “…plasma starts filling the metering channel by capillary action... Thereby, the plasma volume is defined by the channel dimensions.”; The metering channel reads on the metering section comprising a metering channel.);
The claimed “an outlet section configured to receive and transport the separated metered volume of body fluid from the metering channel to a capillary means arranged in the outlet section for collection of the metered volume of body fluid, the capillary means having a predetermined surface geometry” has been read on the taught (Results and Discussion, Device Operation, paragraph 2, “The metering channel is emptied once the DPS paper absorbs the plasma volume.”; The DPS paper which absorbs the plasma volume reads on the capillary means having a predetermined surface geometry. It will be understood by one of ordinary skill in the art that all objects have a surface geometry. The space where the capillary means is located reads on the outlet section. Please see annotated figure 1, provided below.)
PNG
media_image1.png
285
757
media_image1.png
Greyscale
Hauser et al 2019 additionally teaches that the geometry of the metering channel has a predictable effect on the volume of fluid absorbed by the capillary means (Conclusions, paragraph 1, “The volume-defining concept is based on capillary-driven filtration through a porous filtration membrane into a microchannel and absorption of a channel geometry-defined volume by an absorbent sample pad.”; emphasis added by examiner).
However, Hauser et al 2019 does not explicitly disclose wherein a distal end of the metering channel is connected to the outlet section and has a first part having a gradual reduction in width and a second part having a constant width which is smaller than a width of the metering channel.
In the analogous art of microfluidic devices with channel structures, Wyzgol et al teaches;
The claimed “wherein a distal end of the metering channel is connected to the outlet section and has a first part having a gradual reduction in width and a second part having a constant width which is smaller than a width of the metering channel” has been read on the taught ([0078], “The comparatively wide connecting capillary 911 turns into a short microchannel 912 having a narrow orifice…”; [0079], “The elements 912, 913 and 914 can serve as flow restrictors or "flow gates" and capillary stop structures for gating of fluids.”);
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the device of Hauser et al 2019 with the capillary flow structures as taught by Wyzgol et al, for the predictable benefit of allowing effective transport of liquids in bio-arrays ([0007], “Therefore, it would be desirable to provide an improved device which is available for a variety of miniaturized analytical purposes including analytical chips, and allowing for effective transport, delivery, and removal of liquids for efficient experimentation using bio-arrays.”).
With regards to claim 5, the device of claim 1 is obvious over Hauser et al 2019 in view of Wyzgol et al.
Hauser et al 2019 additionally teaches;
The claimed “wherein the surface geometry of the capillary means at an interface surface with the fluid front meniscus is curved or substantially planar” has been read on the taught (Experimental Section, Device Fabrication, paragraph 1, “The DPS paper with an initial thickness of 830 μm was cut to 5 × 10 mm2 and partially laser ablated to fit the channel height of 170 μm.”; A rectangular prism shaped block of paper reads on a substantially planar surface geometry at an interface surface with the fluid front meniscus.).
With regards to claim 6, the device of claim 1 is obvious over Hauser et al 2019 in view of Wyzgol et al.
Hauser et al 2019 additionally teaches;
The claimed “a bridge element arranged in fluid communication with the outlet section and a paper substrate connected to the bridge element” has been read on the taught (Figure 1, Porous plug, Absorbent Paper; Device Design, Paragraph 1, “Excessive plasma volume […] is removed through an excess drainage valve. This valve consists of a porous plug in the metering channel, a water-soluble poly(vinyl alcohol) (PVA) film, and an absorbent paper.”; The porous plug in the metering channel reads on a bridge element arranged in communication with thou outlet part of the metering channel. The absorbent paper reads on a paper substrate connected to the bridge element. See annotated figure 1, below).
PNG
media_image2.png
604
948
media_image2.png
Greyscale
With regards to claim 7, the device of claim 6 is obvious over Hauser et al 2019 in view of Wyzgol et al.
Hauser et al 2019 additionally teaches;
The claimed “wherein the bridge element is a hydrophilic porous element with an average pore size smaller than the smallest dimension of the metering channel” has been read on the taught (Experimental section, Materials, paragraph 1, “The porous plug is cut from Ahlstrom grade 319 paper (Ahlstrom Filtration LLC).”; Device Design, paragraph 2, teaches the use of the porosity in the bridge element, “The filled cavities around the porous plug, filled during the first filling cycle, dissolve the PVA in the excess drainage, thereby opening the excess drainage valve (Figure 1b, step 3).”; One of ordinary skill in the art would recognize that the average pore size must be smaller than the smallest diameter of the metering channel, as a substance with a pore larger than the smallest dimension of the metering channel would not be able to fit inside the channel).
With regards to claim 8, the device of claim 7 is obvious over Hauser et al 2019 in view of Wyzgol et al.
Hauser et al 2019 additionally teaches;
The claimed “wherein the bridge element, is made from a material selected from at least one of micro paper pulp, micro fibrillated cellulose, an open cell hydrophilic polymer or a highly compressible glass fiber web” has been read on the taught (Experimental section, Materials, paragraph 1, “The porous plug is cut from Ahlstrom grade 319 paper (Ahlstrom Filtration LLC).”; Filter paper reads on micro paper pulp).
With regards to claim 9, the device of claim 6 is obvious over Hauser et al 2019 in view of Wyzgol et al.
Hauser et al 2019 additionally teaches;
The claimed “wherein the surface geometry of the bridge element at an interface surface with the fluid front meniscus is curved or substantially planar” has been read on the taught (Experimental Section, Device Fabrication, paragraph 1, “The porous plug was laser-cut to a disc with a diameter of 1.6 mm to fit the opening in the metering channel.”; A disc reads to fit an opening in a stacked device reads on a surface geometry of the bridge element being substantially planar; Figure 2 of Hauser shows the porous plug as a flat disk placed in the bottom of the metering channel, substantially planar to the fluid front meniscus).
With regards to claim 10, the device of claim 1 is obvious over Hauser et al 2019 in view of Wyzgol et al.
Hauser et al 2019 additionally teaches;
The claimed “a filtration membrane configured to separate selected cells from the body fluid” has been read on the taught (Device Design, paragraph 1, “…a filtration membrane in connection to a metering channel…”; Device Design, paragraph 2, “Blood plasma is passively filtered, using our previously demonstrated plasma filtration principle, when blood is applied to the filtration membrane…”; The filtration membrane for blood plasma reads on a filtration membrane configured to separate cells from the body fluid.)
The claimed “wherein the inlet section is configured to transport the sample of body fluid to, and to distribute it across the filtration membrane and wherein the metering section comprises an extraction chamber configured to receive body fluid from the filtration membrane and to transport the received body fluid to the metering channel” has been read on the taught (Device Design, paragraph 2, “Blood plasma is passively filtered, using our previously demonstrated plasma filtration principle, when blood is applied to the filtration membrane and fills the metering channel, driven by capillary forces”; Blood being applied to the filtration membrane and filling the metering channel reads on the inlet section being configured to transport the sample of fluid to and distribute it across the filtration membrane. The fluid filling the metering channel by capillary forces reads on the extraction chamber configured to receive and transport the fluid; See also annotated figure 1).
PNG
media_image3.png
220
400
media_image3.png
Greyscale
With regards to claim 14, the device of claim 10 is obvious over Hauser et al 2019 in view of Wyzgol et al.
Hauser et al 2019 additionally teaches;
The claimed “wherein the metering section comprises a fluid connector extending between the extraction chamber and the metering channel, and an air vent” has been read on the taught (Figure 1 shows the fluid connector located between the space labeled “air pinch-off structure”, see annotated figure 1, below);
PNG
media_image4.png
183
442
media_image4.png
Greyscale
The claimed wherein the metering section comprises “an air vent” has been read on the taught (Device Design, paragraph 1, “A precise and user-independent volume-metering is enabled by an air pinch-off structure, which is realized as a vented geometrical constriction below the filtration membrane, providing a controlled air inflow when the high capillary force of the DPS paper matrix acts on plasma in the metering channel..”; A vented geometrical constriction reads on an air vent).
With regards to claim 15, the device of claim 14 is obvious over Hauser et al 2019 in view of Wyzgol et al.
Hauser et al 2019 additionally teaches;
The claimed “wherein the air vent is arranged adjacent to, or at the position where the fluid connector meets the metering channel” has been read on the taught (Figure 1 shows the fluid connector located between the space labeled “air pinch-off structure”, see annotated figure 1 above).
With regards to claim 19, the device of claim 14 is obvious over Hauser et al 2019 in view of Wyzgol et al.
Hauser et al 2019 in view of Wyzgol et al does not explicitly disclose wherein the maximum height of the extraction chamber is lower than the height of the metering channel.
However, Hauser et al 2019 teaches that the dimensions of the metering channel define the volume of plasma transferred by the metering channel, as read on the taught (Device Design, paragraph 2, “The volume of the transferred plasma is defined by the dimensions of the metering channel and the controlled air inflow at the inlet of the metering channel enabled by the air pinch-off structure.”).
Likewise, Wyzgol et al teaches that varying the size of capillary channels modifies the properties of fluids moving through those structures, as read on the taught (Column 20, line 44, “Therefore, by combining capillary channels of two or more significantly differing widths, fluid handling properties of divergent character can be accomplished by a single structure. For example, certain of the channels could be of relatively small size to facilitate capillary transport to a particular distant location from the region of initial absorption, whereas other channels could be of relatively large size to facilitate rapid acquisition of the fluid.").
As such, the height of metering channel in reference to the extraction chamber is a result-effective variable for fluid transport through the metering channel.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the height of the metering channel with regard to the maximum height of the extraction chamber as optimization of a results effective variable to achieve the well-known and effective result of modifying the fluid flow properties and capillary forces acting within the metering channel.
With regards to claim 21, the device of claim 1 is obvious over Hauser et al 2019 in view of Wyzgol et al.
Hauser et al additionally teaches the claimed “wherein the outlet section comprises a porous plug” as read on the taught (Device Design, paragraph 1, “This valve consists of a porous plug in the metering channel…”).
Claims 11-13, and 16-18 are rejected under 35 U.S.C. 103 as being unpatentable over Houser et al 2019 (Hauser J., Lenk G., Ullah S., Beck O., Stemme G., Roxhed N., “An Autonomous Microfluidic Device for Generating Volume-Define Dried Plasma Spots,” Anal. Chem. 2019; 91: 7125-7130, cited on the IDS submitted 01 September 2022) in view of Wyzgol et al (US 20020114738 A1) as applied to claim 10, and as evidenced by Hauser et al 2018 (Hauser J., Lenk G., Hansson J., Beck O., Stemme G., Roxhed N., “High-Yield Passive Plasma Filtration from Human Finger Prick Blood,” Anal. Chem. 2018; 90: 13393-13399, cited on the IDS submitted 01 September 2022).
With regards to claim 11, the device of claim 10 is obvious over Hauser et al 2019 in view of Wyzgol et al.
Hauser et al 2019 additionally teaches;
The claimed device “further comprising a pinch-off means configured to separate the metered volume of body fluid” has been read on the taught (Device Design, paragraph 1, “A precise and user-independent volume-metering is enabled by an air pinch-off structure...”; The air pinch-off structure reads on a pinch-off means.);
The claimed “wherein the pinch-off means comprises at least one air vent” has been read on the taught (Device Design, paragraph 1, “A precise and user-independent volume-metering is enabled by an air pinch-off structure, which is realized as a vented geometrical constriction below the filtration membrane, providing a controlled air inflow when the high capillary force of the DPS paper matrix acts on plasma in the metering channel..”; A vented geometrical constriction reads on at least one air vent).
Regarding the limitation of “at least one air vent arranged in a part of the extraction chamber with a maximum height”;
Hauser et al 2019 relies on a reference to earlier work, Hauser et al 2018, to teach the arrangement of the separation membrane and the extraction chamber within the device (Device Design, paragraph 2, “Blood plasma is passively filtered, using our previously demonstrated plasma filtration principle [Ref 21]…”; Reference 21 is Hauser et al 2018).
Hauser et al 2018 teaches that the filtration membrane is designed in a “wedge configuration”, with the highest end of the membrane located on the side facing the entrance to the capillary channel (Materials and Methods, Device Design, paragraph 1, “The device consists of a blood separation filter in a wedge configuration with the hydrophilic bottom surface of a capillary channel unit.”; Figure 1 caption, “The wedge configuration is formed by the acute angle between the filtration membrane and the hydrophilic bottom surface of a capillary channel.”).
Hauser et al 2018 additionally reports that the wedge configuration serves the purpose of initiating the filling of the capillary channel (Materials and Methods, Device Design, paragraph 2, “The wedge configuration provides a high capillary force along the contact line between the filtration membrane and the bottom surface of the capillary channel, which reliably initiates gradual filling of the filtration chamber and the capillary channel.”)
Figure 1 of Hauser et al 2019 is consistent with this disclosure, showing a wedge configuration of the filter membrane, with the air pinch-off structure located on the end of the filtration membrane closest to the metering channel. As such, the claimed “wherein the pinch-off means comprises at least one air vent arranged in a part of the extraction chamber with a maximum height” has been read on the taught (Figure 1, filter membrane, air pinch-off structure; see annotated figure 1).
PNG
media_image5.png
202
756
media_image5.png
Greyscale
No motivation is required to combine the teachings of the primary reference Hauser et al 2019 with that of Hauser et al 2018, as Hauser et al already teaches incorporating the structures of Hauser et al 2018 into the device design and fabrication. Accordingly, the device of claim 11 is obvious over Hauser et al 2019 in view of Wyzgol et al as evidenced by Hauser et al 2018.
With regards to claim 12, the device of claim 11 is obvious over Hauser et al 2019 in view of Wyzgol et al as evidenced by Hauser et al 2018.
Hauser et al 2019 additionally teaches;
The claimed “wherein the pinch-off means comprises a pinch-off region in fluid communication with the at least one air vent” has been read on the taught (Device Design, paragraph 1, “A precise and user-independent volume-metering is enabled by an air pinch-off structure, which is realized as a vented geometrical constriction below the filtration membrane, providing a controlled air inflow when the high capillary force of the DPS paper matrix acts on plasma in the metering channel..”; A vented geometrical constriction reads on at least one air vent).;
The claimed “pinch-off region being arranged in the part of the extraction chamber with the maximum height and surrounded by areas with lower height” has been read on the taught (Figure 1, filter membrane, air pinch-off structure; see annotated figure);
Hauser et al 2018 further evidences the pinch-off region being surrounded by areas with lower height, teaching (Materials and Methods, Device Design, paragraph 2, “The capillary channel is designed to have a much smaller channel height than width in order for the capillary force to be determined by the channel height and the hydrophilicity of the channel surface.”).
No motivation is required to combine the teachings of the primary reference Hauser et al 2019 with that of Hauser et al 2018, as Hauser et al already teaches incorporating the structures of Hauser et al 2018 into the device design and fabrication. Accordingly, the device of claim 12 is obvious over Hauser et al 2019 in view of Wyzgol et al as evidenced by Hauser et al 2018.
With regards to claim 13, the device of claim 12 is obvious over Hauser et al 2019 in view of Wyzgol et al as evidenced by Hauser et al 2018.
Hauser et al 2019 additionally teaches;
The claimed “wherein at least one part of the extraction chamber surrounding the pinch-off region has a height lower than the height of the metering channel” has been read on the taught (Figure 1, filter membrane, air pinch-off structure; see annotated figure);
Hauser et al 2018 further evidences the pinch-off region being surrounded by areas with lower height, teaching (Materials and Methods, Device Design, paragraph 2, “The capillary channel is designed to have a much smaller channel height than width in order for the capillary force to be determined by the channel height and the hydrophilicity of the channel surface.”).
No motivation is required to combine the teachings of the primary reference Hauser et al 2019 with that of Hauser et al 2018, as Hauser et al already teaches incorporating the structures of Hauser et al 2018 into the device design and fabrication. Accordingly, the device of claim 12 is obvious over Hauser et al 2019 in view of Wyzgol et al as evidenced by Hauser et al 2018.
With regards to claim 16, the device of claim 15 is obvious over Hauser et al 2019 in view of Wyzgol et al.
Hauser et al 2019 additionally teaches;
The claimed “wherein the air vent is arranged at the entrance of the metering channel and is configured as an orifice to ambient air” has been read on the taught (Device Design, paragraph 1, “A precise and user-independent volume-metering is enabled by an air pinch-off structure, which is realized as a vented geometrical constriction below the filtration membrane, providing a controlled air inflow when the high capillary force of the DPS paper matrix acts on plasma in the metering channel.”; a vented geometrical constriction reads on an orifice to ambient air.).
Hauser et al 2019 relies on a reference to earlier work, Hauser et al 2018, to teach the arrangement of the inlet of the device (Device Design, paragraph 2, “Blood plasma is passively filtered, using our previously demonstrated plasma filtration principle [Ref 21]…”; Reference 21 is Hauser et al 2018).
Hauser et al 2018 teaches that the filtration membrane is designed in a “wedge configuration”, with the highest end of the membrane located on the side facing the entrance to the capillary channel (Materials and Methods, Device Design, paragraph 1, “The device consists of a blood separation filter in a wedge configuration with the hydrophilic bottom surface of a capillary channel unit.”; Figure 1 caption, “The wedge configuration is formed by the acute angle between the filtration membrane and the hydrophilic bottom surface of a capillary channel.”).
Hauser et al 2018 supports the air vent having a larger cross-sectional area than the metering channel, as the small size of metering channel is what causes the capillary filling, as read on the taught (Materials and Methods, Device Design, paragraph 2, “The wedge configuration provides a high capillary force along the contact line between the filtration membrane and the bottom surface of the capillary channel, which reliably initiates gradual filling of the filtration chamber and the capillary channel. The capillary channel is designed to have a much smaller channel height than width in order for the capillary force to be determined by the channel height and the hydrophilicity of the channel surface.”).
Figure 1 of Hauser et al 2019 is consistent with this disclosure, showing a wedge configuration of the filter membrane, with the air pinch-off structure located on the end of the filtration membrane closest to the metering channel, at the highest point of the wedge.
Accordingly, the claimed wherein the air vent has “a cross-sectional area equal to or greater than the size of the cross-sectional area of the metering channel” has been read on the taught (Figure 1, air pinch-off structure; see annotated figure 1).
No motivation is required to combine the teachings of the primary reference Hauser et al 2019 with that of Hauser et al 2018, as Hauser et al already teaches incorporating the structures of Hauser et al 2018 into the device design and fabrication. Accordingly, the device of claim 16 is obvious over Hauser et al 2019 in view of Wyzgol et al as evidenced by Hauser et al 2018.
With regards to claim 17, the device of claim 14 is obvious over Hauser et al 2019 in view of Wyzgol et al.
Hauser et al 2019 relies on a reference to earlier work, Hauser et al 2018, to teach the arrangement of the inlet of the device (Device Design, paragraph 2, “Blood plasma is passively filtered, using our previously demonstrated plasma filtration principle [Ref 21]…”; Reference 21 is Hauser et al 2018).
Hauser et al 2018 teaches that the filtration membrane is designed in a “wedge configuration”, with the highest end of the membrane (and thus the fluid connector) located on the side facing the entrance to the metering channel (Materials and Methods, Device Design, paragraph 1, “The device consists of a blood separation filter in a wedge configuration with the hydrophilic bottom surface of a capillary channel unit.”; Figure 1 caption, “The wedge configuration is formed by the acute angle between the filtration membrane and the hydrophilic bottom surface of a capillary channel.”).
Hauser et al 2018 supports the fluid connector having a smaller cross-sectional area than the metering channel, as the small size of metering channel is what causes capillary filling, as read on the taught (Materials and Methods, Device Design, paragraph 2, “The wedge configuration provides a high capillary force along the contact line between the filtration membrane and the bottom surface of the capillary channel, which reliably initiates gradual filling of the filtration chamber and the capillary channel. The capillary channel is designed to have a much smaller channel height than width in order for the capillary force to be determined by the channel height and the hydrophilicity of the channel surface.”).
Accordingly, the claimed “wherein the fluid connector has a different dimension than the metering channel, the dimension being selected from one or more of height, width and length” has been read on the taught (Figure 1, air pinch-off structure. See also marked fluid connector on annotated figure 1).
No motivation is required to combine the teachings of the primary reference Hauser et al 2019 with that of Hauser et al 2018, as Hauser et al already teaches incorporating the structures of Hauser et al 2018 into the device design and fabrication. Accordingly, the device of claim 16 is obvious over Hauser et al 2019 in view of Wyzgol et al as evidenced by Hauser et al 2018.
With regards to claim 18, the device of claim 17 is obvious over Hauser et al 2019 in view of Wyzgol et al as evidenced by Hauser et al 2018.
Hauser et al 2018 teaches that the filtration membrane is designed in a “wedge configuration”, with the highest end of the membrane (and thus the fluid connector) located on the side facing the entrance to the metering channel (Materials and Methods, Device Design, paragraph 1, “The device consists of a blood separation filter in a wedge configuration with the hydrophilic bottom surface of a capillary channel unit.”; Figure 1 caption, “The wedge configuration is formed by the acute angle between the filtration membrane and the hydrophilic bottom surface of a capillary channel.”).
Accordingly, the claimed “wherein the fluid connector has a gradually increasing height towards the entrance of the metering channel” has been read on the taught (Figure 1, air pinch-off structure, filter membrane. See also marked “fluid connector” on annotated figure 1).
No motivation is required to combine the teachings of the primary reference Hauser et al 2019 with that of Hauser et al 2018, as Hauser et al already teaches incorporating the structures of Hauser et al 2018 into the device design and fabrication. Accordingly, the device of claim 16 is obvious over Hauser et al 2019 in view of Wyzgol et al as evidenced by Hauser et al 2018.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Dothie et al (US 20150147777 A1, cited on the IDS provided 17 July 2025) describes methods of designing microfluidic metering channels.
Karlsen et al (US 20120196280 A1) teaches capillary valves with channel constrictions.
Patel et al (US 20090148858 A1) teaches gradually tapering microfluidic channels as a means of avoiding bubble formation
Marshall et al (US 20190071661 A1) teaches the use of capillary barriers to prevent bubble formation and to provide flow control features.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to ALISON CLAIRE GERHARD whose telephone number is (571)270-0945. The examiner can normally be reached M-F, 9:00 - 5:30pm EST.
Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Lyle Alexander can be reached at (571) 272-1254. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/ALISON CLAIRE GERHARD/Examiner, Art Unit 1797 /LYLE ALEXANDER/Supervisory Patent Examiner, Art Unit 1797
Prosecution Insights