Prosecution Insights
Last updated: April 19, 2026
Application No. 17/343,190

METHOD OF CLEANING USED DIALYSIS FLUID USING ELECTRODIALYSIS AND UREA OXIDATION

Non-Final OA §103
Filed
Jun 09, 2021
Examiner
KEELING, ALEXANDER W
Art Unit
1795
Tech Center
1700 — Chemical & Materials Engineering
Assignee
BAXTER HEALTHCARE SA
OA Round
8 (Non-Final)
56%
Grant Probability
Moderate
8-9
OA Rounds
3y 4m
To Grant
95%
With Interview

Examiner Intelligence

Grants 56% of resolved cases
56%
Career Allow Rate
320 granted / 570 resolved
-8.9% vs TC avg
Strong +39% interview lift
Without
With
+38.8%
Interview Lift
resolved cases with interview
Typical timeline
3y 4m
Avg Prosecution
56 currently pending
Career history
626
Total Applications
across all art units

Statute-Specific Performance

§101
0.8%
-39.2% vs TC avg
§103
53.2%
+13.2% vs TC avg
§102
19.1%
-20.9% vs TC avg
§112
20.1%
-19.9% vs TC avg
Black line = Tech Center average estimate • Based on career data from 570 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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 11/18/2025 has been entered. Status of Rejections All previous rejections are maintained. The rejections of claims 1 and 22 are updated in response to the Applicant’s amendments. No new art is cited. Claims 1, 9-13, 17, 18, 22, and 23 are pending and under consideration for this Office Action. Claim Rejections - 35 USC § 103 The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action. Claim(s) 1, 9, 10, 12, 13, 18, 22, and 23 is/are rejected under 35 U.S.C. 103 as being unpatentable over Ding et al (US 20110048949 A1) in view of Myron (“Hemodialysis”, 2010, pages 1-6) and Botte (US 20160251765 A1). BBC (“Revise: Acids and bases”, 2019) cited as evidentiary reference for claims 1 and 22. Liao et al (“Insights into mechanisms on electrochemical oxygen evolution substitution reactions”, Journal of Catalysis, 428 (2023) 115161) cited as an evidentiary reference for claim 18. Claim 1: Ding discloses an electrodialysis cell and urea treatment device (see e.g. abstract) comprising: a first set of electrodes (see e.g. #22 and #24 on Fig 1) that are electrically charged to separate the dialysis fluid having urea into an acid stream and a basic stream (see e.g. [0030], [0036], and [0042]), wherein the first set of electrodes includes an anode (see e.g. #24 on Fig 1) and a cathode (see e.g. #22 on Fig 1); at least two of a cation exchange membrane (see e.g. #14 on Fig 1) and an anion exchange membrane (see e.g. #16 on Fig 1) between the anode and the cathode of the first set of electrodes; a urea treatment device positioned to contact the basic stream (anode stream #66) for decomposition of urea (see e.g. #30 on Fig 1), wherein the acid stream is configured to bypass the urea treatment device (see e.g. acid stream #64 flow path and urea treatment device #30 on Fig 1), and wherein the acid stream (see e.g. #72 on Fig 1) is placed in fluid communication (see e.g. #78 on Fig 1) with the basic stream after the basic stream passes through the second set of electrodes (see e.g. #70 on Fig 1). Ding discloses that the acid stream is added directly to the regenerated dialysis flow (see e.g. #64 and #78 on Fig 1). Myron teaches dialysate pH would be between 6.5 and 7.5 (see e.g. page 2, paragraph starting with “All dialysis”). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date that the acid stream would have a pH suitable for the dialysate as taught in Myron so that the regenerated dialysate can be used for hemodialysis. MPEP § 2144.05 I states “In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990)”. The limitation claiming that the acid stream is placed in fluid communication with the basic stream after the basic stream passes through the second set of electrodes to lower the pH of the combined solution is a functional limitation describing what the two streams do when they are combined but does not structurally limit the electrodialysis cell and urea treatment device. Adding a stream, such as the acid stream, to a basic stream would reduce the pH (as evidenced by the BBC). Ding does not explicitly teach at least one power source configured to electrically charge the first and a second sets of electrodes. However, Ding discloses that the device has two sets of electrodes (see e.g. cell #10 and cell #40). These cells require an electric potential to function (see e.g. [0030]). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the instant invention that the device of Ding would require at least one power source to electrically charge the first and a second sets of electrodes so that the device can properly function. Ding does not explicitly teach that the urea treatment device is an urea electrooxidation device comprising one or more second set of electrodes positioned to contact the basic stream with an electrocatalytic surface for decomposition of urea via electrooxidation, wherein the one or more second set of electrodes include an anode and a cathode, and wherein the electrocatalytic surface is electrically charged for activation and is present on the anode of the one or more second set of electrodes. Ding does teach that device treats urea in the stream via hydrolysis (see e.g. [0031]) and that the device can comprise multiple electrolytic cells (see e.g. #20 and #40 on Fig 1). Botte discloses an electrolytic treatment device (see e.g. [0069]) comprising one or more second set of electrodes (see e.g. #13 and #15 on Fig 1) positioned to contact a stream containing urea with an electrocatalytic surface for decomposition of urea via electrooxidation (see e.g. [0069]), wherein the one or more second set of electrodes include an anode and a cathode (see e.g. [0072]), and wherein the electrocatalytic surface is electrically charged for activation and is present on the anode of the one or more second set of electrodes (see e.g. [0028]), wherein the anode of the one or more second set of electrodes comprises nickel hydroxide or nickel oxide hydroxide (NiOOH) (see e.g. [0028] and [0061]). The device of Botte can consume urea via hydrolysis into ammonia (see e.g. [0052]) or oxidization (see e.g. [0068]). It would have been obvious to a person having ordinary skill in the art before the effective filing date of the instant invention to modify the device of Ding by substituting the urea treatment device with the urea device taught in Botte because the device of Botte can remove urea from the dialysate using hydrolysis or oxidation and KSR rationale B states that “[s]imple substitution of one known element for another to obtain predictable results” is a suitable rationale for a conclusion of obviousness. Furthermore, Botte teaches that urea treatment device uses a pH between 7 and 10 (see e.g. [0039]). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date that the base stream entering the urea treatment device should have a suitable pH (between 7 and 10) so that urea treatment device can function properly. Claim 9: Ding in view of Myron and Botte discloses that the device is configured to operate with the dialysis fluid being a salt solution (see e.g. [0030] of Ding). Claim 10: Ding in view of Myron and Botte discloses that the device is configured to operate with the dialysis fluid having at least one of a sodium salt, a magnesium salt, and a calcium salt (see e.g. [0060] of Ding). Claim 12: Ding in view of Myron and Botte discloses that the device is configured to operate with the basic stream having NaOH (see e.g. [0042]). Claim 13: Ding in view of Myron and Botte discloses that the device is configured to operate with the acid stream having HCl (see e.g. [0042]). Claim 18: Ding in view of Myron and Botte discloses the oxidation of urea (see e.g. [0068] of Botte). As evidenced by Liao, the oxidation of urea at the second set of electrodes would produce nitrogen gas, carbon dioxide gas, and water (see e.g. page 4, col 2, equation 3). Claim 22: Ding discloses a hemodialysis system (see e.g. abstract) comprising: a blood circuit and a dialysis fluid circuit (see e.g. [0011]), wherein the dialysis fluid circuit is in fluid communication with a combination electrodialysis cell and urea treatment device (see e.g. abstract), the combination electrodialysis and urea oxidation cell comprising: a first set of electrodes (see e.g. #22 and #24 on Fig 1) that are electrically charged to separate the dialysis fluid having urea into an acid stream and a basic stream (see e.g. [0030], [0036], and [0042]), wherein the first set of electrodes includes an anode (see e.g. #24 on Fig 1) and a cathode (see e.g. #22 on Fig 1); at least two of a cation exchange membrane (see e.g. #14 on Fig 1) and an anion exchange membrane (see e.g. #16 on Fig 1) between the anode and the cathode of the first set of electrodes; a urea treatment device positioned to contact the basic stream (anode stream #66) for decomposition of urea (see e.g. #30 on Fig 1), wherein the acid stream is configured to bypass the urea treatment device (see e.g. acid stream #64 flow path and urea treatment device #30 on Fig 1), wherein the acid stream (see e.g. #72 on Fig 1) is placed in fluid communication (see e.g. #78 on Fig 1) with the basic stream after the basic stream passes through the second set of electrodes (see e.g. #70 on Fig 1). Ding discloses that the acid stream is added directly to the regenerated dialysis flow (see e.g. #64 and #78 on Fig 1). Myron teaches dialysate pH would be between 6.5 and 7.5 (see e.g. page 2, paragraph starting with “All dialysis”). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date that the acid stream would have a pH suitable for the dialysate as taught in Myron so that the regenerated dialysate can be used for hemodialysis. MPEP § 2144.05 I states “In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990)”. The limitation claiming that the acid stream is placed in fluid communication with the basic stream after the basic stream passes through the second set of electrodes to lower the pH of the combined solution is a functional limitation describing what the two streams do when they are combined but does not structurally limit the electrodialysis cell and urea treatment device. Adding a stream, such as the acid stream, to a basic stream would reduce the pH (as evidenced by the BBC). Ding does not explicitly teach at least one power source configured to electrically charge the first and a second sets of electrodes. However, Ding discloses that the device has two sets of electrodes (see e.g. cell #10 and cell #40). These cells require an electric potential to function (see e.g. [0030]). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the instant invention that the device of Ding would require at least one power source to electrically charge the first and a second sets of electrodes so that the device can properly function. Ding does not explicitly teach that the urea treatment device is an urea electrooxidation device comprising one or more second set of electrodes positioned to contact the basic stream with an electrocatalytic surface for decomposition of urea via electrooxidation, wherein the one or more second set of electrodes include an anode and a cathode, and wherein the electrocatalytic surface is electrically charged for activation and is present on the anode of the one or more second set of electrodes. Ding does teach that device treats urea in the stream via hydrolysis (see e.g. [0031]) and that the device can comprise multiple electrolytic cells (see e.g. #20 and #40 on Fig 1). Botte discloses an electrolytic treatment device (see e.g. [0069]) comprising one or more second set of electrodes (see e.g. #13 and #15 on Fig 1) positioned to contact a stream containing urea with an electrocatalytic surface for decomposition of urea via electrooxidation (see e.g. [0069]), wherein the one or more second set of electrodes include an anode and a cathode (see e.g. [0072]), and wherein the electrocatalytic surface is electrically charged for activation and is present on the anode of the one or more second set of electrodes (see e.g. [0028]), wherein the anode of the one or more second set of electrodes comprises nickel hydroxide or nickel oxide hydroxide (NiOOH) (see e.g. [0028] and [0061]). The device of Botte can consume urea via hydrolysis into ammonia (see e.g. [0052]) or oxidization (see e.g. [0068]). It would have been obvious to a person having ordinary skill in the art before the effective filing date of the instant invention to modify the device of Ding by substituting the urea treatment device with the urea device taught in Botte because the device of Botte can remove urea from the dialysate using hydrolysis or oxidation and KSR rationale B states that “[s]imple substitution of one known element for another to obtain predictable results” is a suitable rationale for a conclusion of obviousness. Furthermore, Botte teaches that urea treatment device uses a pH between 7 and 10 (see e.g. [0039]). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date that the base stream entering the urea treatment device should have a suitable pH (between 7 and 10) so that urea treatment device can function properly. Claim 23: Ding in view of Myron and Botte discloses at least a pump (see e.g. [0041]). Claim(s) 11 is/are rejected under 35 U.S.C. 103 as being unpatentable over Ding in view of Myron and Botte as applied to claim 1 above, and in further view of Ofshtun et al (US 20110060273 A1). Claim 11: Ding in view of Myron and Botte does not explicitly teach a tank for the dialysis fluid containing urea. Instead, Ding teaches a system where the dialysis fluid containing urea is taken directly from the patient and fed to the device (see e.g. [0046] of Ding). Ofshtun teaches that storage tanks for the dialysis fluids can be included in a dialysis system so that the fluid can be treated when the patient is not connected (see e.g. [0058]). It would have been obvious to a person having ordinary skill in the art before the effective filing date of the instant invention to modify the device of Ding by including a tank for the dialysis fluid containing urea as taught in Ofshtun so that the fluid can be treated when the patient is not connected. Claim(s) 17 is/are rejected under 35 U.S.C. 103 as being unpatentable over Ding in view of Myron and Botte as applied to claim 1 above, and in further view of Kreymann et al (US 8377308 B2). Claim 17: Ding in view of Myron and Botte does not explicitly teach a tank for cleansed dialysis fluid. Instead, Ding teaches a system where the cleansed (regenerated) dialysis fluid is taken directly from the device and is returned to the patient (see e.g. [0046] of Ding). Kreymann teaches a system for regenerating dialysate (see e.g. abstract) wherein the cleansed dialysis fluid is stored in a reservoir (see e.g. col 11, lines 1-5) which can help provide efficient protection of the patient’s blood (see e.g. col 6, lines 19-38). It would have been obvious to a person having ordinary skill in the art before the effective filing date of the instant invention to modify the device of Ding by a tank for cleansed dialysis fluid as taught in Kreymann to provide efficient protection of the patient’s blood. Response to Arguments Applicant's arguments filed 11/18/2025 have been fully considered but they are not persuasive. On page(s) 7-8, the Applicant argues that “Therefore, Ding teaches that the combined solution comprises a basic stream following through flow path 70, an acidic stream following through flow path 72, and a neutral stream following flow path 78. However, the present claims recite that the combined solution comprises only a basic stream and an acidic stream, without the neutral stream taught by Ding”. This is not considered persuasive. The claim uses the transitional phrase “comprising”, which “is inclusive or open-ended and does not exclude additional, unrecited elements or method steps” (see MPEP § 2111.03 I). Therefore, even if Ding does teach an additional stream, the claim language would not exclude the presence of that additional stream. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to ALEXANDER W KEELING whose telephone number is (571)272-9961. The examiner can normally be reached 7:30 AM - 4:00 PM. 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, Luan Van can be reached at 571-272-8521. 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. /ALEXANDER W KEELING/Primary Examiner, Art Unit 1795
Read full office action

Prosecution Timeline

Jun 09, 2021
Application Filed
Mar 24, 2023
Non-Final Rejection — §103
Jun 30, 2023
Response Filed
Jul 12, 2023
Final Rejection — §103
Oct 18, 2023
Response after Non-Final Action
Oct 23, 2023
Response after Non-Final Action
Nov 17, 2023
Request for Continued Examination
Nov 20, 2023
Response after Non-Final Action
Dec 03, 2023
Non-Final Rejection — §103
Mar 06, 2024
Response Filed
Apr 11, 2024
Final Rejection — §103
Jun 18, 2024
Response after Non-Final Action
Jun 24, 2024
Response after Non-Final Action
Jul 02, 2024
Request for Continued Examination
Jul 03, 2024
Response after Non-Final Action
Oct 26, 2024
Non-Final Rejection — §103
Jan 30, 2025
Response Filed
Mar 25, 2025
Non-Final Rejection — §103
Jul 28, 2025
Response Filed
Aug 14, 2025
Final Rejection — §103
Nov 18, 2025
Request for Continued Examination
Nov 20, 2025
Response after Non-Final Action
Jan 14, 2026
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

8-9
Expected OA Rounds
56%
Grant Probability
95%
With Interview (+38.8%)
3y 4m
Median Time to Grant
High
PTA Risk
Based on 570 resolved cases by this examiner. Grant probability derived from career allow rate.

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