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 .
Priority
Applicant’s claim for the benefit of a prior-filed application (371 of PCT/CN2021/112498, filed 08/13/2021) under 35 U.S.C. 119(e) or under 35 U.S.C. 120, 121, 365(c), or 386(c) is acknowledged.
Acknowledgment is made of applicant’s claim for foreign priority (CN202010827754.X, filed 08/17/2020) under 35 U.S.C. 119 (a)-(d). Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55.
Drawings
The drawings were received on 21 October 2025. These drawings are acceptable.
Claim Interpretation
The claims recite that “the hollow fiber membrane comprises an outer surface having a surface energy of 10-45 mN/m”. Surface energy is commonly accepted to be considered the amount of available free energy on a surface to interact with other surfaces or substances, e.g., a measure of inertness or capacity for interaction. As indicated in the Specification, p0010, a surface energy less than 72.8 mN/m indicates the surface is hydrophobic (p00140); such a disclosure is directed toward an inherent property of the claimed outer surface.
Similarly, the claims recite “the hollow fiber membrane has a tensile strength of at least 100 cN and an elongation at break of at least 150%”. Tensile strength and elongation-at-break are commonly accepted as inherent properties or material properties of a material or substance.
The claims recite “a second direction of the outer surface… the second direction of the outer surface is parallel to a circumferential direction of the hollow fiber membrane” with respect to a “pore size” of “first pores”. This “second direction” is interpreted as explained by the Applicant in the Remarks filed 21 October 2025. While Applicant contends that a pore dimension on an “outer surface” cannot have a depth, the Examiner respectfully disagrees; pores by definition must have a depth otherwise they would not exist. Applicant defines the second direction to be “a circumferential direction” in that controlling pore dimensions along the axial direction and circumferential direction results in an elongated oval shape on the outer surface of the hollow fiber membrane.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
Claims 1 and 3-10 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Regarding Claim 1, a broad range or limitation together with a narrow range or limitation that falls within the broad range or limitation (in the same claim) may be considered indefinite if the resulting claim does not clearly set forth the metes and bounds of the patent protection desired. See MPEP § 2173.05(c). In the present instance, Claim 1 recites the broad recitation “the first pores having a pore size of 10nm to 300nm in a first direction of the outer surface and a pore size of 10nm to 300nm in a second direction of the outer surface”, and the claim also recites “the first pores have a pore size of 150nm to 300nm in the first direction of the outer surface, the first pores have a pore size of 10nm to 90nm in the second direction of the outer surface” which is the narrower statement of the range/limitation. The claim(s) are considered indefinite because there is a question or doubt as to whether the feature introduced by such narrower language is (a) merely exemplary of the remainder of the claim, and therefore not required, or (b) a required feature of the claims. The Examiner will interpret the claim by the broadest reasonable interpretation, i.e., the broad recitation that “the first pores having a pore size of 10nm to 300nm in a first direction of the outer surface and a pore size of 10nm to 300nm in a second direction of the outer surface”. Claims 3-10 are also rejected due to their dependence on Claim 1.
Regarding Claim 1, the claim introduces “an outer surface” of a separation layer of a hydrophobic hollow fiber membrane, i.e., “the separation layer comprising an outer surface…”, and subsequently introduces another “outer surface” of the hollow fiber membrane, i.e., “the hollow fiber membrane comprises an outer surface having a surface energy of 10-45 mN/m”. It is unclear whether Applicant is introducing two unique “outer surface” or referencing the same “outer surface”. Based on the prosecution history, the Examiner will interpret this as a single “outer surface” being referenced.
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.
Claim(s) 1 and 3-10 is/are rejected under 35 U.S.C. 103 as being unpatentable over MULLER et al. (US 6,409,921 B1).
Regarding Claim 1, MULLER ‘921 discloses an asymmetric hydrophobic polyolefin membrane (abstract; c1/7-10); such a membrane is a hollow fiber membrane (i.e., [a]n asymmetric hydrophobic polyolefin hollow fiber membrane; c13/50-51). The membrane comprises an integrally asymmetric membrane with a separation layer and a support layer (i.e., comprising a support layer and a separation layer; the support layer comprising an inner surface facing a lumen of the hollow fiber membrane; c5/24-30); the separation layer further includes an exterior layer having a denser structure (i.e., the separation layer comprising an outer surface, the outer surface being located at the side of the separation layer opposite the support layer; c8/20-39).
MULLER ‘921 further discloses the exterior layer comprises pores smaller than 100 nm (i.e., the outer surface comprises a plurality of first pores; c8/28-33), which overlaps with the claimed range of having a pore size of 10nm to 300nm in a first direction of the outer surface and a pore size of 10nm to 300nm in a second direction of the outer surface and therefore, establishes a case of prima facie obviousness (MPEP 2144.05). Finally, as shown in FIGs. 1, 2, 4, 6, and 7, the number of pores in the exterior surface is shown to range from a few pores (FIG. 7) to tens of pores (FIG. 6) per square micron, which at least makes obvious the claimed range of a pore density of 4 to 35 pores/ 1µm2 and therefore, establishes a case of prima facie obviousness (MPEP 2144.05).
Regarding the limitations that “the hollow fiber membrane comprises an outer surface having a surface energy of 10-45 mN/m” and “the hollow fiber membrane has a tensile strength of at least 100 cN and an elongation at break of at least 150%”, as explained in §Claim Interpretation, such limitations are considered inherent properties of the claimed outer surface and of the hollow fiber membrane, respectively. The discovery of properties of a known material does not make it novel, the identification and characterization of a prior art material also does not make it novel (In re Crish, 393 F.3d 1253, 1258, 73 USPQ2d 1364, 1368, Fed. Cir. 2004; MPEP §2112 I).
Regarding Claim 3, MULLER ‘921 makes obvious the membrane of Claim 1. MULLER ‘921 discloses the separation layer has a thickness between 0.1 and 0.6 µm (c12/40-42) and an overall hollow fiber membrane thickness of between 10 and 100 µm (c13/55-60), which reads on the claimed range of the separation layer [having] a thickness of 0.1 µm to 2 µm and overlaps with the claimed range of 0.5 to 5% of total thickness of the hollow fiber membrane and therefore, establishes a case of prima facie obviousness (MPEP 2144.05).
Regarding Claim 4, MULLER ‘921 makes obvious the membrane of Claim 1. MULLER ‘921 discloses the separation layer has an average pore diameter between 10 nm and 100 nm (c12/22-26), which overlaps the claimed range of a mean pore size of the separation layer [being] 10 nm to 60 nm and therefore, establishes a case of prima facie obviousness (MPEP 2144.05).
Regarding Claims 5-8, MULLER ‘921 makes obvious the membrane of Claim 1. The instant claim limitations directed to an O2 permeation rate, a gas separation factor alpha between CO2 and O2, a gas separation factor alpha between O2 and an anesthetic gas—the anesthetic gas being sevoflurane, xenon, remifentanil, and/or propofol, a CO2 permeation rate, and a plasma permeation duration are all directed toward materials and articles worked upon by the claimed membrane and manners or methods of use of the claimed membrane and thus, have no patentable weight. The inclusion of material or article worked upon by a structure being claimed does not impart patentability to the claims (In re Young, 75 F.2d 996, 25 USPQ 69 (CCPA 1935); MPEP §2115). The manner or method in which an apparatus is to be utilized is not subject to the issue of patentability of the apparatus itself (In re Casey, 370 F.2d 576, 152 USPQ 235 (CCPA 1967); MPEP §2115).
Regarding Claim 9, MULLER ‘921 makes obvious the membrane of Claim 1. MULLER ‘921 discloses the separation layer has a thickness between 0.1 and 0.6 µm (c12/40-42) and an overall hollow fiber membrane thickness of between 10 and 100 µm (c13/55-60). MULLER ‘921 further discloses the support layer has pores which can be of any geometry but are essentially isotropic (c11/51-60). As shown in FIG. 12 of a cross-section of an exemplary hollow fiber membrane, the open-pored microporous interior surface and support structure comprises a dense exterior skin layer on the right, and pores ranging from a few tens of nanometers to a few hundreds of nanometers in the underlying support structure apart from the separation layer (approximately left half of the membrane). Thus, there is at least a thickness of membrane not part of the separation layer and part of an arbitrary “transition layer” disposed between the separation layer and support layer. Because the claim does not distinguish any specificity as to what is considered the “transition layer”, the claimed thickness of a 10 nm to 50 nm thick transition layer having a mean pore size of 100 nm to 300 nm can be selected from any region in FIG. 12 within the support layer.
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Regarding Claim 10, MULLER ‘921 makes obvious the membrane of Claim 1. MULLER ‘921 discloses the overall hollow fiber membrane thickness of between 10 and 100 µm, which overlaps with the claimed range of 30 µm to 50 µm and therefore, establishes a case of prima facie obviousness (MPEP 2144.5), and an outer diameter of 100 to 300 µm (c13/55-60), i.e., which indicates an inner diameter of 100 µm to 280 µm, reading on the claimed range of an inner diameter of 100 µm to 300 µm. MULLER ‘921 further discloses a volumetric porosity of 50-75% (c5/29-30), which overlaps with the claimed range of 30% to 60% and therefore establishes a case of prima facie obviousness (MPEP 2144.05).
Response to Amendments/Arguments
Applicant’s amendments and arguments filed 21 October 2025 have been fully considered.
Applicant’s amendments to Claim 1 have addressed the 35 USC 112(b) rejections of Claims 1-10; these rejections have been withdrawn. However, please note the added rejections of Claims 1-10 as being indefinite under 35 USC 112(b).
Applicant’s cancelation of Claim 2 has been considered; the rejection of Claim 2 under 35 U.S.C. 103 as being unpatentable over MULLER et al. (US 6,409,921 B1) in view of MULLER et al (US 2007/0157812 A1) has been withdrawn.
Applicant’s amendments and arguments with respect to the rejections of Claim(s) 1 and 3-10 under 35 U.S.C. 103 as being unpatentable over MULLER et al. (US 6,409,921 B1) have been fully considered but are not persuasive.
Applicant argues that the prior art references fail to teach/suggest the limitation that the claimed outer surface has a surface energy of 10-45 mN/m and that such a limitation is not considered a product-by-process limitation (pg. 9-10). Applicant argues that “surface energy is a property and a structural limitation, just as ‘thickness’ is a property and a structural limitation” (pg. 9, bottom).
The Examiner respectfully disagrees.
The as-amended claim has removed the limitation of measuring surface tension at 20°C; this renders such a limitation not a product-by-process limitation. However, surface tension is considered an intrinsic/inherent property by those of ordinary skill in the art. Surface tension, as admitted by Applicant in their disclosure, is a measure of hydrophobicity (see p00140), whereby a lower surface tension value indicates higher hydrophobicity. The prior art discloses the same membrane property, i.e., a hydrophobic polyolefin membrane. If arguendo surface tension is not considered an inherent property, while the prior art may not have explicitly specified a degree of hydrophobicity, such a measure is recumbent on the Applicant to disprove. Because the prior art has disclosed all structural limitations of the claimed product except for this specific claimed product property, which the Examiner cannot determine whether the prior art inherently possesses, a case of prima facie obviousness has been established. The burden of proof shifts to the Applicant to show that the prior art reference does not teach or suggest the claimed inherent properties (In re Fitzgerald, 619 F.2d 67, 205 USPQ 594 (CCPA 1980)).
Applicant similarly argues that “tensile strength” and “elongation at break” are structural limitations that claim a physical property and “must be given patentable weight”; Applicant argues the asserted reference does not teach or suggest these features (pg. 10, middle).
The Examiner respectfully disagrees.
It is acknowledged that tensile strength and elongation at break are indeed properties of a material; however, these are intrinsic/inherent properties. However, the prior art discloses or makes obvious all other limitations of the hydrophobic membrane. The claiming of a new use, new function or unknown property which is inherently present in the prior art does not necessarily make the claim patentable (In re Best, 562 F.2d 1252, 1254, 195 USPQ 430, 433 (CCPA 1977)). Even if arguendo tensile strength and elongation at break were not considered inherent, the prior art membrane would nonetheless possess such characteristics because these properties (whether inherent or not) are due to composition and makeup of the membrane itself (which Applicant has only claimed a pore size and a pore density). So long as the prior art discloses or makes obvious the other cited limitations, these instant limitations of tensile strength and elongation-at-break are also necessarily present. Because the prior art has disclosed all structural limitations of the claimed product except for these specific claimed product properties, which the Examiner cannot determine whether the prior art inherently possesses, a case of prima facie obviousness has been established. The burden of proof shifts to the Applicant to show that the prior art reference does not teach or suggest the claimed inherent properties (In re Fitzgerald, 619 F.2d 67, 205 USPQ 594 (CCPA 1980)).
Applicant’s arguments with respect to MULLER ‘812 (pg. 11-13) have been considered but are not persuasive. MULLER ‘812 was recited for the rejection of Claim 2; however, Claim 2 has been canceled, and the rejection has been withdrawn. Thus, Applicant’s arguments are not persuasive because they are directed to grounds of rejection that have been withdrawn. Therefore, the arguments are not commensurate in scope with the presently pending claims.
Conclusion
THIS ACTION IS MADE FINAL. 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.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to RYAN B HUANG whose telephone number is (571)270-0327. The examiner can normally be reached 9 am-5 pm 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, In Suk Bullock can be reached at 571-272-5954. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/Ryan B Huang/Primary Examiner, Art Unit 1777