Prosecution Insights
Last updated: April 19, 2026
Application No. 17/594,156

SORBENT FOR USE IN RENAL THERAPY

Non-Final OA §103
Filed
Oct 04, 2021
Examiner
YANG, CHENG FONG
Art Unit
3781
Tech Center
3700 — Mechanical Engineering & Manufacturing
Assignee
Qidni Labs Inc.
OA Round
3 (Non-Final)
64%
Grant Probability
Moderate
3-4
OA Rounds
3y 2m
To Grant
87%
With Interview

Examiner Intelligence

Grants 64% of resolved cases
64%
Career Allow Rate
91 granted / 142 resolved
-5.9% vs TC avg
Strong +23% interview lift
Without
With
+23.0%
Interview Lift
resolved cases with interview
Typical timeline
3y 2m
Avg Prosecution
33 currently pending
Career history
175
Total Applications
across all art units

Statute-Specific Performance

§101
1.2%
-38.8% vs TC avg
§103
48.1%
+8.1% vs TC avg
§102
23.7%
-16.3% vs TC avg
§112
20.0%
-20.0% vs TC avg
Black line = Tech Center average estimate • Based on career data from 142 resolved cases

Office Action

§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 . 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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 July 2025 has been entered. Priority As directed by the amendment filed on 25 July 2025: claim(s) 1 & 26 have been amended, claim(s) 15 has been cancelled. Thus, claims 1, 3, 6-8, 10, 13-14, 16-18, 21, 23-24, 26, 28-29, and 31-32 are pending. Response to Arguments Applicant's arguments filed 25 July 2025 have been fully considered but they are not persuasive. Regarding the argument on pg. 6 of Remarks that “the Nosrati reference does mention temperature and temperature gradient. However, Nosrati does so in the context of microfluidics, and not bulk systems like is discussed on the specification” & “The physics of temperature gradients and its effects are much different in such a system than in microfluidics systems such as Nosrati”, both Nanko and Nosrati’s device comprises of microfluidic elements (Nanko: “particles having an average size of not more than 300 μm” [0135]) (Nosrati: “hollow fibers of the hollow fiber membrane have a thickness of less than 0.5 mm. In another embodiment, the hollow fibers of the hollow fiber membrane have a thickness of less than 200 microns” Specifications [0083]). Nosrati’s device is designed to approximate “various medical devices, various forms of dialysis devices including albumin and lipid dialysis, water purification, bioreactors, bio-artificial organ support systems” (see Abstract). Thus, Nosrati’s sensor and heater/cooler elements are relevant for any fluid purification circuits since they operate like a thermostat-controlled heater ([0048]-[0059]). Furthermore, applicant has not shown how the alleged difference in the effect of temperature gradient physics would result in a patentably distinct structure or teach away from the combination of the cited references. 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, 6, 7, 17, 21, 23-24, 26, and 31-32 is/are rejected under 35 U.S.C. 103 as being unpatentable over Nanko et al. (US 20040226874 A1) in view of Nosrati (US 20170252701 A1). Regarding Claim 1, Nanko discloses a sorbent cartridge for use in a portable wearable renal therapy system ([0148], [0170]), the sorbent cartridge comprising: an inlet 1 and an outlet 2 ("1 denotes an inlet for body fluid, 2 denotes an outlet for body fluid"; [0149]; FIG. 1), the inlet configured to receive process fluid from the renal therapy system and the outlet configured to discharge treated process fluid ([0146]; FIG. 1); a hydrogel 3 ("hydrogel of C-cellulose as adsorbent"; [0149] & [0153]; FIG. 1) configured to absorb and adsorb a toxin from the process fluid ([0069]) without use of a dialysate to purify the process fluid ("does not need an additional fluid replacement"; [0170]); wherein the inlet and the outlet are each configured to couple to the renal therapy system (see FIG. 3); said sorbent cartridge further comprising: a temperature sensor ([0283]), and at least one of a heating element and/or a cooling element ([0044]), the temperature sensor configured to send a temperature signal to a controller ("sensor control board"; [0270]), and the at least one of a heating element and/or a cooling element configured to receive an output signal from a controller ([0048]-[0059]). Nanko fails to specify that the inlet and the outlet are each configured to releasably couple to the renal therapy system for removing the sorbent cartridge. However, the court has held that it would be obvious to make an element removable “if it were considered desirable for any reason”. In re Dulberg, 289 F.2d 522, 523, 129 USPQ 348, 349 (CCPA 1961). Furthermore, Nanko shows the inlet 13 and outlet 15 as friction-fit spikes (FIG. 2). Therefore, it would have been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to modify Nanko’s device as a matter of obvious engineering choice, such that the inlet and the outlet are each configured to releasably couple to the renal therapy system for removing the sorbent cartridge, to switch out a cartridge for another containing a different sorbent to suitably adjust the absorbing ability of the renal therapy system ([0078]). Nanko fails to specify said sorbent cartridge further comprising: a temperature sensor, and at least one of a heating element and/or a cooling element, the temperature sensor configured to send a temperature signal to a controller, and the at least one of a heating element and/or a cooling element configured to receive an output signal from a controller. However, Nosrati teaches a modular biomimetic microfluidic modules for combining into “medical devices such as dialysis, bioreactors and organ support devices” (see Abstract) with a sorbent cartridge ([0264]) comprising: a temperature sensor ("enables operation of the device and monitoring of blood temperature" [0147]), and at least one of a heating element and/or a cooling element ("heating and cooling elements" [0044]), the temperature sensor configured to send a temperature signal to a controller ("sensor control board"; [0270]), and the at least one of a heating element and/or a cooling element configured to receive an output signal from a controller ([0048]-[0059]). Therefore, it would have been obvious to modify Nanko’s device to incorporate the claimed features as taught by Nosrati "to motivate faster permeation, diffusion and convection" and improve device operation efficiency ([0048]-[0073]). Regarding Claim 6, Nanko discloses the hydrogel is formed as a plurality of beads ("shape of hydrogel particles contained in a device for blood purification is spherical"; [0134]), the plurality of beads position in a reservoir of the sorbent cartridge configured to receive process fluid flowing through the sorbent cartridge ([0149]-[0150]; FIG. 1), the sorbent cartridge comprising a filter 5 to prevent passage of the plurality of beads into circulation of the process fluid ("5 denote a filter through which body fluid and ingredients contained in body fluid can pass but the adsorbent cannot pass"; [0149]; FIG. 1). Regarding Claim 7, Nanko discloses the sorbent cartridge is configured such that the hydrogel is in direct contact with the process fluid ([0167]). Regarding Claim 21, Nanko discloses a renal therapy system comprising the sorbent cartridge of claim 1 (see rejection for Claim 1), wherein the renal therapy system is at least one of a hemodialysis system ([0168]) or a hemoperfusion system ([0167]). Regarding Claim 26, Nanko discloses a method for removing toxic substances from process fluid, the method comprising: providing the sorbent cartridge of claim 1 ([0002]); moving process fluid through the sorbent cartridge in communication with the hydrogel ("body fluid is flowed through the container"; [0146]), the process fluid comprising toxins ("substances related to malady, especially β2-microglobulin or chemokines"; [0144]); and absorbing or adsorbing the toxins from the process fluid into the hydrogel to provide treated process fluid ([0076]); Nanko fails to specify receiving a temperature input from a temperature sensor on the sorbent cartridge and determining that a temperature gradient must be created across a portion of the sorbent cartridge; andcausing a cooling element to create the temperature gradient. However, Nosrati teaches a modular biomimetic microfluidic modules for combining into “medical devices such as dialysis, bioreactors and organ support devices” (see Abstract) with a sorbent cartridge ([0264]) comprising receiving a temperature input from a temperature sensor on the sorbent cartridge ("enables operation of the device and monitoring of blood temperature" [0147]) and determining that a temperature gradient must be created across a portion of the sorbent cartridge ([0048] & [0269] & [0373]); and causing a cooling element to create the temperature gradient ([0269]). Therefore, it would have been obvious to modify Nanko’s device to incorporate the claimed features as taught by Nosrati "to motivate faster permeation, diffusion and convection" and improve device operation efficiency ([0048]-[0073]). Regarding Claims 17, 23-24, and 31-32, Nanko discloses the hydrogel as a sorbent but fails to specify a vibration element configured to vibrate the hydrogel; a cooling element to create a temperature gradient along a length of the hydrogel; vibrating the hydrogel; and cooling the hydrogel to create a temperature gradient along a length of the hydrogel. However, Nosrati teaches modular biomimetic microfluidic modules for combining into “medical devices such as dialysis, bioreactors and organ support devices” (see Abstract); a vibration element configured to vibrate the hydrogel ([0060]); a cooling element to create a temperature gradient along a length of the hydrogel ([0048]-[0059]); vibrating the hydrogel ([0060]); and cooling the hydrogel to create a temperature gradient along a length of the hydrogel ([0048]-[0059]). Therefore, it would have been obvious to modify Nanko’s device to incorporate the claimed features "to motivate faster permeation, diffusion and convection" and improve device operation efficiency ([0048]-[0073]). Claim(s) 3 and 29 is/are rejected under 35 U.S.C. 103 as being unpatentable over Nanko/Nosrati in view of Tanabe et al. (US 4734097 A). Regarding Claim 3, Nanko discloses the hydrogel as the sorbent but fails to specify that the hydrogel is configured to release to the process fluid at least one of an electrolyte, a buffer, a mineral, a vitamin, or an anti-coagulant. However, Tanabe teaches “a medical material comprising a molded hydrogel” (see Abstract) wherein the hydrogel is configured to release to the process fluid an anti-coagulant (col. 3 ln. 19-27). Therefore, it would have been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to modify Nanko/Nosrati’s device to incorporate the claimed features "to improve the antithrombosis" ability of the medical device (col. 2 ln. 18-21). Regarding Claim 29, Nanko discloses the hydrogel as the sorbent but fails to specify releasing at least one of an electrolyte, a buffer, a mineral, a vitamin, or anti-coagulant from the hydrogel to the process fluid. However, Tanabe teaches “a medical material comprising a molded hydrogel” (see Abstract) that releases anti-coagulant from the hydrogel to the process fluid (col. 3 ln. 19-27). Therefore, it would have been obvious to modify Nanko/Nosrati’s device to incorporate the claimed features "to improve the antithrombosis" ability of the medical device (col. 2 ln. 18-21). Claim(s) 8, 14, and 16 is/are rejected under 35 U.S.C. 103 as being unpatentable over Nanko/Nosrati in view of Shettigar et al. (US 5211850 A). Regarding Claim 8, Nanko discloses the sorbent cartridge but fails to specify the sorbent cartridge is configured such that the hydrogel is in indirect communication with the process fluid across a membrane. However, Shettigar teaches a system for “selective removal of plasma components using sorbents” (col. 3 ln. 3-4) wherein the sorbent cartridge ("container 31"; col. 7 ln. 2-3; FIG. 3) is configured such that the hydrogel ("sorbents 33"; col. 7 ln. 4; FIG. 3) is in indirect communication with the process fluid across a membrane ("filter 30"; col. 7 ln. 1-14; FIG. 3). Therefore, it would have been obvious to modify Nanko/Nosrati’s device to incorporate the claimed features to achieve extracorporeal blood filtration without using any plasma pump or transmembrane pressure controls (col. 1 ln. 7-14). Regarding Claim 14, Nanko discloses the hydrogel and the sorbent cartridge but fails to specify the hydrogel is cast in place over the membrane in said sorption cartridge, and wherein the membrane is a hollow fiber membrane. However, Shettigar teaches a system for “selective removal of plasma components using sorbents” (col. 3 ln. 3-4) wherein the hydrogel (“sorbent 14”) is cast in place over the membrane in said sorption cartridge (col. 4 ln. 65 thru col. 5 ln. 25; FIG. 1), and wherein the membrane is a hollow fiber membrane ("hollow fiber membrane 10"; col. 4 ln. 66; FIG. 1). Therefore, it would have been obvious to modify Nanko/Nosrati’s device to incorporate the claimed features to achieve extracorporeal blood filtration without using any plasma pump or transmembrane pressure controls (col. 1 ln. 7-14). Regarding Claim 16, Nanko/Shettigar discloses the membrane but fails to specify a conductive member configured to couple with a cooling element to create a temperature gradient along a distance between the conductive member and the membrane. However, Nosrati teaches modular biomimetic microfluidic modules for combining into “medical devices such as dialysis, bioreactors and organ support devices” (see Abstract) comprising a conductive member ("heatsink"; [0044]) configured to couple with a cooling element (“cooling elements”; [0048]) to create a temperature gradient along a distance between the conductive member and the membrane ([0048]-[0059]). Therefore, it would have been obvious to modify Nanko/Shettigar’s device to incorporate the claimed features "to motivate faster permeation, diffusion and convection" and improve device operation efficiency ([0048]-[0073]). Claim(s) 13 is/are rejected under 35 U.S.C. 103 as being unpatentable over Nanko/Nosrati in view of Shettigar et al. and further in view of Grossman (US 3742946 A). Regarding Claim 13, Nanko/Nosrati/Shettigar discloses the sorbent cartridge but fails to specify the sorbent cartridge comprises a first compartment and a second compartment, the first compartment comprising the membrane configured to remove water from the process fluid, and the second compartment comprising the membrane configured to toxin removal. However, Grossman teaches an “apparatus for the in vivo treatment of blood containing harmful components” (col. 1 ln. 5-6) comprising a sorbent cartridge ("blood treating unit indicated generally by the numeral 12"; col. 2 ln. 43; FIG. 1) wherein the sorbent cartridge 12 comprises a first compartment and a second compartment (see FIG. 2), the first compartment comprising the membrane ("semi-permeable membrane 14"; col. 3 ln. 41; FIG. 2) configured to remove water from the process fluid (col. 4 ln. 14-20), and the second compartment comprising the membrane configured to toxin removal ("migration of the undesirable small molecules from tube 14 into the solid packing surrounding the tube"; col. 4 ln. 31-33; FIG. 2). Therefore, it would have been obvious to modify Nanko/Nosrati/Shettigar’s device to incorporate the claimed features to provide “a lightweight, portable, blood-purifying apparatus which does not involve hemo-dialysis, which does not require attachment to plumbing, which is relatively inexpensive and which may be made widely available to persons afflicted with kidney disease” (col. 1 ln. 33-37). Claim(s) 10 is/are rejected under 35 U.S.C. 103 as being unpatentable over Nanko/Nosrati in view of O'Loughlin et al. (US 20050123529 A1). Regarding Claim 10, Nanko discloses the hydrogel as a sorbent but fails to specify the hydrogel is configured to absorb 1 gram to 100 grams of urea in 24 hours from the process fluid without altering electrolyte levels outside of a physiological range that would cause harm a user of the renal therapy system. However, O'Loughlin teaches a system for “the treatment of uremic toxins” with a sorbent (see Abstract) wherein the treatment is designed to eliminate toxins similarly to the kidney, which is configured to absorb 1 gram to 100 grams of urea in 24 hours from the process fluid without altering electrolyte levels outside of a physiological range that would cause harm a user of the renal therapy system ([0002]). Therefore, it would have been obvious to modify Nanko/Nosrati’s device to incorporate the claimed features to avoid uremia or uremic toxicity ([0002]). Claim(s) 18 is/are rejected under 35 U.S.C. 103 as being unpatentable over Nanko/Nosrati in view of Kudo et al. (US 20160272806 A1). Regarding Claim 18, Nanko discloses the hydrogel as a sorbent but fails to specify the hydrogel forms a hydrogel layer having a thickness of greater than or equal to about 1 mm. However, Kudo teaches an organic/inorganic composite hydrogel (see Abstract) for medical use ([0117]) wherein the hydrogel forms a hydrogel layer having a thickness of greater than or equal to about 1 mm. Therefore, it would have been obvious to modify Nanko/Nosrati’s device to suitably form a self-supporting hydrogel having high modulus of elasticity that allows a shape to be retained in water (see Abstract). Claim(s) 28 is/are rejected under 35 U.S.C. 103 as being unpatentable over Nanko/Nosrati in view of Grossman. Regarding Claim 28, Nanko discloses the method of Claim 26 but fails to specify absorbing water from the process fluid into the hydrogel. However, Grossman teaches an “apparatus for the in vivo treatment of blood containing harmful components” (col. 1 ln. 5-6) comprising absorbing water from the process fluid into the hydrogel (“a proportion of the water is removed by the desiccant”; col. 2 ln. 7-8). Therefore, it would have been obvious to modify Nanko/Nosrati’s device to incorporate the claimed features to “to extend the time between treatments” (col. 4 ln. 58). Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to Cheng Fong "Ted" Yang whose telephone number is (571)272-8846. The examiner can normally be reached 10am - 6pm (EST) M-F. 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, Rebecca E. Eisenberg can be reached at (571) 270-5879. 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. /Adam Marcetich/Primary Examiner, Art Unit 3781 Cheng Fong "Ted" Yang Examiner Art Unit 3781
Read full office action

Prosecution Timeline

Oct 04, 2021
Application Filed
Jul 18, 2024
Non-Final Rejection — §103
Oct 26, 2024
Response Filed
Nov 07, 2024
Final Rejection — §103
May 22, 2025
Response after Non-Final Action
Jul 25, 2025
Request for Continued Examination
Jul 28, 2025
Response after Non-Final Action
Oct 14, 2025
Non-Final Rejection — §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

3-4
Expected OA Rounds
64%
Grant Probability
87%
With Interview (+23.0%)
3y 2m
Median Time to Grant
High
PTA Risk
Based on 142 resolved cases by this examiner. Grant probability derived from career allow rate.

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