Prosecution Insights
Last updated: April 19, 2026
Application No. 17/053,848

Membrane for Capillary Microfiltration

Final Rejection §102§103
Filed
Nov 09, 2020
Examiner
KURTZ, BENJAMIN M
Art Unit
1779
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Solventum Intellectual Properties Company
OA Round
8 (Final)
57%
Grant Probability
Moderate
9-10
OA Rounds
3y 1m
To Grant
74%
With Interview

Examiner Intelligence

Grants 57% of resolved cases
57%
Career Allow Rate
627 granted / 1104 resolved
-8.2% vs TC avg
Strong +17% interview lift
Without
With
+17.4%
Interview Lift
resolved cases with interview
Typical timeline
3y 1m
Avg Prosecution
50 currently pending
Career history
1154
Total Applications
across all art units

Statute-Specific Performance

§101
0.2%
-39.8% vs TC avg
§103
43.0%
+3.0% vs TC avg
§102
23.9%
-16.1% vs TC avg
§112
25.1%
-14.9% vs TC avg
Black line = Tech Center average estimate • Based on career data from 1104 resolved cases

Office Action

§102 §103
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 . Election/Restrictions Claims 14-15 are withdrawn from further consideration pursuant to 37 CFR 1.142(b), as being drawn to a nonelected invention, there being no allowable generic or linking claim. Claim Rejections - 35 USC § 102 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 the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action: A person shall be entitled to a patent unless – (a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention. Claim(s) 1, 3-6, 9 and 11-13 is/are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Ansorge et al. US 2010/0224553. Claim 1, Ansorge teaches a hydrophilic, integrally asymmetric, semi-permeable hollow fiber membrane made from a hydrophobic aromatic sulfone polymer and at least one hydrophilic polymer (abstract), the membrane comprising an inner surface facing towards its lumen, an outer surface facing outward and an intermediate wall having a wall thickness, and comprising an open-pore separating layer having a minimum pore size and a supporting layer having an asymmetric, sponge like structure without finger pores, the hollow fiber membrane comprises an essentially isotropic area adjoining to a wall of the inner surface (the separating layer), after which the membrane comprises an area wherein the pore size abruptly increases up to a maximum pore size, after which the membrane comprises an area wherein the pore size decreases, after which the membrane comprises an essentially isotropic supporting layer (the outer layer) which then is adjoined by the outer surface, wherein the pore sizes of the essentially isotropic supporting layer remain constant, the separating layer has a cut off of greater than 300,000 Daltons (Ansorge teaches a cutoff of larger than 200,000 Daltons which will inherently also cutoff anything larger than 300,000 Daltons), the membrane exhibits a nominal pore size in the separating layer of 10-100 nm and therefore incorporates the recited 45-150 nm, and the size of the pores in a zone with maximum pore sizes is in the range of from 15-50 microns (par 1-2, 13, 29). Claims 3-6, 9, Ansorge further teaches the essentially isotropic area adjoining the wall of the inner surface comprises the separating layer and has a proportion in the range of less than 10% of the total thickness of the membrane and thus incorporates the 1-8% recited range (par 13); the wall thickness is in the range of 150-350 microns which falls within the recited 140-400 micron range (par 36); the inner diameter of the membrane is 500-1500 micron which significantly overlaps with the recited range of 700-2000 micron (par 36); the area where the pore size abruptly increases up to a maximum pore size is located at a distance from the inner surface in the range between 15-40% of the wall thickness (par 29); Claims 11-13 recite operating parameters of the membrane and certain mechanical characteristics of the membrane. Ansorge teaches all of the claimed structural characteristics of the membrane of claim 1, namely, the same material having the recited layers and cutoff. Therefore, the operating parameters and mechanical characteristics are considered inherent to the membrane meeting the structural requirements of the membrane of claim 1. Claim Rejections - 35 USC § 103 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. Claim(s) 7 and 8 is/are rejected under 35 U.S.C. 103 as being unpatentable over Ansorge et al. US 2010/0224553. Claim 7, Ansorge teaches the membrane of claim 1 and teaches the mean pore size of the outer surface is larger than the separating layer (0.01 micron) and less than the mean pore size of the supporting layer (5 micron) (par 13), but does not teach the maximum diameters being less than 1.5 micron. Ansorge teaches that a significant influence can be exerted on the permeability of the membrane by modifying the pore size of the outer layer (par 27). Thus, Ansorge recognized the pore size of the outer layer as a result effective variable. The recitation of a maximum diameter of the pore size of the outer surface being less than 1.5 micron falls within the range taught by Ansorge and it would have been obvious to adjust the sizes of the pores to achieve a desired permeability. [W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation, In re Aller, 105 USPQ 233 (1955). Claim 8, Ansorge does not teach the recited range of maximum pores sizes of less than 3 micron for the inner surface. Ansorge teaches the mean pore size would be 10-100 nm or 0.01-0.1 micron which is orders of magnitude smaller than 3 microns. While it is possible to have a mean pore size within the range taught by Ansorge and have maximum pores be larger than 3 microns, such conditions would require a very large distribution of pores which one of ordinary skill in the art would recognize as undesirable as larger pores would not be able to achieve the desired cutoff. Therefore, it would have been obvious to optimize the maximum diameters of the pores of the inner surface to ensure the membrane is capable of meeting the desired cutoff. [W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation, In re Aller, 105 USPQ 233 (1955). Response to Arguments Applicant's arguments filed 2/26/26 have been fully considered but they are not persuasive. Applicant argues that Ansorge does not teach a cut off of greater than 300,000 Daltons. The cut off is a property of the membrane that is determined by the pore sizes of the separating layer, i.e. a smaller pore size will have a smaller cut off. Smaller pores will also be able to cut off larger molecules as the smaller pore size will be able to retain anything that is larger than the pore size. The cut off of larger than 200,000 of Ansorge will likewise also cut off anything 300,000 Daltons or larger. Applicant pointed out the previous office action had a typo and should have said that Ansorge teaches a pore size in the range of 10-100 nm. In paragraph 1 Ansorge teaches that ultrafiltration membranes cover the size range of pores of 10-100nm. Ansorge paragraph 13, then states the invention is a membrane for ultrafiltration. Ansorge teaches the definition of what pore sizes are included for ultrafiltration and then says the invention is an ultrafiltration membrane. Therefore, one of ordinary skill in the art would recognize that the pore sizes of the invention of Ansorge would have pore sizes in the range of 10-100 nm. Applicant argues Ansorge does not teach the recited pore size of the maximum pores. Ansorge teaches a range of 5-15 microns and the claimed invention is 15-50 microns and the claimed invention share the size of 15 microns and therefore the prior art meets the limitations of the claim. 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 BENJAMIN M KURTZ whose telephone number is (571)272-8211. The examiner can normally be reached Monday-Friday 8:30-5. 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, Bobby Ramdhanie can be reached on 571-270-3240. 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. /BENJAMIN M KURTZ/Primary Examiner, Art Unit 1778
Read full office action

Prosecution Timeline

Nov 09, 2020
Application Filed
Sep 21, 2023
Non-Final Rejection — §102, §103
Jan 02, 2024
Response Filed
Jan 30, 2024
Final Rejection — §102, §103
Apr 16, 2024
Request for Continued Examination
Apr 17, 2024
Response after Non-Final Action
May 31, 2024
Non-Final Rejection — §102, §103
Nov 05, 2024
Response Filed
Nov 22, 2024
Final Rejection — §102, §103
Feb 12, 2025
Examiner Interview Summary
Mar 25, 2025
Request for Continued Examination
Mar 25, 2025
Response after Non-Final Action
Mar 26, 2025
Response after Non-Final Action
Apr 09, 2025
Final Rejection — §102, §103
Jun 04, 2025
Applicant Interview (Telephonic)
Jun 04, 2025
Examiner Interview Summary
Jul 14, 2025
Request for Continued Examination
Jul 16, 2025
Response after Non-Final Action
Jul 28, 2025
Non-Final Rejection — §102, §103
Aug 27, 2025
Examiner Interview Summary
Oct 30, 2025
Response Filed
Nov 21, 2025
Non-Final Rejection — §102, §103
Feb 26, 2026
Response Filed
Mar 04, 2026
Examiner Interview Summary
Mar 25, 2026
Final Rejection — §102, §103 (current)

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Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

9-10
Expected OA Rounds
57%
Grant Probability
74%
With Interview (+17.4%)
3y 1m
Median Time to Grant
High
PTA Risk
Based on 1104 resolved cases by this examiner. Grant probability derived from career allow rate.

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