Prosecution Insights
Last updated: April 19, 2026
Application No. 18/228,491

HEMODIALYSIS SYSTEM WITH VARIABLE DIALYSATE FLOW RATE

Non-Final OA §103§112§DP
Filed
Jul 31, 2023
Examiner
VARMA, AKASH K
Art Unit
1773
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Diality Inc.
OA Round
1 (Non-Final)
66%
Grant Probability
Favorable
1-2
OA Rounds
3y 4m
To Grant
99%
With Interview

Examiner Intelligence

Grants 66% — above average
66%
Career Allow Rate
371 granted / 564 resolved
+0.8% vs TC avg
Strong +34% interview lift
Without
With
+34.5%
Interview Lift
resolved cases with interview
Typical timeline
3y 4m
Avg Prosecution
26 currently pending
Career history
590
Total Applications
across all art units

Statute-Specific Performance

§101
0.8%
-39.2% vs TC avg
§103
41.7%
+1.7% vs TC avg
§102
11.7%
-28.3% vs TC avg
§112
33.2%
-6.8% vs TC avg
Black line = Tech Center average estimate • Based on career data from 564 resolved cases

Office Action

§103 §112 §DP
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 . Status of Claims Claims 1-7 are currently pending Claims 1-7 are currently rejected Information Disclosure Statement The Information Disclosure Statement filed on 01/11/2024 is in compliance with the provisions of 37 CFR 1.97 and has been considered. An initialed copy of the Form 1449 is enclosed herewith. Claim Objections Claim 1 is objected to because of the following informalities: Line 5 states “a patient’s vein for returning blood to” and instead should state “a patient’s vein for returning the blood to” for further clarity. ALSO, lines 8-9 states “and said venous blood line for transporting blood from” and instead should state “and said venous blood line for transporting the blood from” for further clarity. FURTHERMORE, line 12 states “and said dialyzer for transporting dialysate from said reservoir” and instead should state “and said dialyzer for transporting the dialysate from said reservoir” for further clarity. ADDITIONALLY, line 13 states “for pumping dialysate through” and instead should state “for pumping the dialysate through” for further clarity. ALSO, line 14 states “for pumping blood through” and instead should state “for pumping the blood through” for further clarity. IN ADDITION, lines 15-16 states “flow rate of dialysate through” and instead should state “flow rate of the dialysate through” for further clarity. Appropriate corrections are required. Claim 2 is objected to because of the following informalities: Line 2 states “and wherein low flow rate” and instead should state “and wherein the low flow rate” for further clarity. Appropriate correction is required. Claim 3 is objected to because of the following informalities: Line 2 states “increasing the dialysate flow rate” and instead should state “increasing the dialysate flow rates” to maintain consistency and for further clarity. Appropriate correction is required. Claim 5 is objected to because of the following informalities: Lines 1-2 states “wherein dialysate flow rates” and instead should state “wherein said dialysate flow rates” to maintain consistency and for further clarity. Appropriate correction is required. Claim 6 is objected to because of the following informalities: Line 2 states “causes said dialysate pump to pump dialysate through” and instead should state “causes said at least one dialysate pump to pump the dialysate through” to maintain consistency and for further clarity. ALSO, lines 3-4 states “causes said dialysate pump to pump dialysate through” and instead should state “causes said at least one dialysate pump to pump the dialysate through” to maintain consistency and for further clarity. Appropriate corrections are required. Claim 7 is objected to because of the following informalities: Lines 2 and 3 each state “dialysate flow rates” and instead should each state “said dialysate flow rates” for further clarity. Appropriate corrections are required. 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. The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph: The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention. Claims 1-7 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. Claim 1 recites the limitation "the flow rate of dialysate” on lines 15-16, and “the time period” on line 20. There is insufficient antecedent basis for these limitations in the claim. ALSO, claim 1 recites the limitation “a patient” on lines 5-6, line 9 (x2), line 19 and line 21. It is unclear whether Applicant is referring to the same ‘a patient’ as recited on line 4 of claim 1, or a different patient? Claims 2-7 are also rejected since these claims depend on claim 1. Claim 7 recites the limitation "a patient” on lines 3 and 5. It is unclear whether Applicant is referring to the same ‘a patient’ as recited on line 4 of claim 1, or a different patient? FURTHERMORE, claim 7 recites the limitation “a patient’s treatment” on line 4. It is unclear and confusing whether Applicant is referring to the same ‘a patient’s treatment’ as recited on line 20 of claim 1, or a different patient’s treatment? Double Patenting The nonstatutory double patenting rejection is based on a judicially created doctrine grounded in public policy (a policy reflected in the statute) so as to prevent the unjustified or improper timewise extension of the “right to exclude” granted by a patent and to prevent possible harassment by multiple assignees. A nonstatutory double patenting rejection is appropriate where the conflicting claims are not identical, but at least one examined application claim is not patentably distinct from the reference claim(s) because the examined application claim is either anticipated by, or would have been obvious over, the reference claim(s). See, e.g., In re Berg, 140 F.3d 1428, 46 USPQ2d 1226 (Fed. Cir. 1998); In re Goodman, 11 F.3d 1046, 29 USPQ2d 2010 (Fed. Cir. 1993); In re Longi, 759 F.2d 887, 225 USPQ 645 (Fed. Cir. 1985); In re Van Ornum, 686 F.2d 937, 214 USPQ 761 (CCPA 1982); In re Vogel, 422 F.2d 438, 164 USPQ 619 (CCPA 1970); In re Thorington, 418 F.2d 528, 163 USPQ 644 (CCPA 1969). A timely filed terminal disclaimer in compliance with 37 CFR 1.321(c) or 1.321(d) may be used to overcome an actual or provisional rejection based on nonstatutory double patenting provided the reference application or patent either is shown to be commonly owned with the examined application, or claims an invention made as a result of activities undertaken within the scope of a joint research agreement. See MPEP § 717.02 for applications subject to examination under the first inventor to file provisions of the AIA as explained in MPEP § 2159. See MPEP § 2146 et seq. for applications not subject to examination under the first inventor to file provisions of the AIA . A terminal disclaimer must be signed in compliance with 37 CFR 1.321(b). The USPTO Internet website contains terminal disclaimer forms which may be used. Please visit www.uspto.gov/patent/patents-forms. The filing date of the application in which the form is filed determines what form (e.g., PTO/SB/25, PTO/SB/26, PTO/AIA /25, or PTO/AIA /26) should be used. A web-based eTerminal Disclaimer may be filled out completely online using web-screens. An eTerminal Disclaimer that meets all requirements is auto-processed and approved immediately upon submission. For more information about eTerminal Disclaimers, refer to www.uspto.gov/patents/process/file/efs/guidance/eTD-info-I.jsp. Claims 1-7 are provisionally rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1-20 of co-pending Application No. 17/827506 (reference application), and unpatentable over claims 1-9 of co-pending Application No. 17/087383 (currently allowed, still waiting for patent number) (reference application). Although the claims at issue are not identical, they are not patentably distinct from each other because the instant claims are broad enough and further disclosed by the claims of the following co-pending Applications. This is a provisional nonstatutory double patenting rejection because the patentably indistinct claims have not in fact been patented. Claims 1-7 are rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1-7 of U.S. Patent No. 11,904,078 B2, unpatentable over claims 1-12 of U.S. Patent No. 12,274,819 B2, unpatentable over claims 1-10 of U.S. Patent No. 11,517,653 B2, unpatentable over claims 1-5 of U.S. Patent No. 11,260,155 B2, unpatentable over claims 1-8 of U.S. Patent No. 10,625,008 B2, unpatentable over claims 1-4 of U.S. Patent No. 10,980,929 B2, unpatentable over claims 1-8 of U.S. Patent No. 10,155,078 B2, unpatentable over claims 1-7 of U.S. Patent No. 9,801,992 B2, unpatentable over claims 1-4 of U.S. Patent No. 9,649,419 B2, unpatentable over claims 1-5 of U.S. Patent No. 9,649,420 B2, unpatentable over claims 1-3 of U.S. Patent No. 10,016,550 B2, and unpatentable over claims 1-6 of U.S. Patent No. 10,172,989 B2. Although the claims at issue are not identical, they are not patentably distinct from each other because the instant claims are broad enough and further disclosed by the claims of the following patented cases. 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. 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. Claims 1-7 are rejected under 35 U.S.C. 103 as being unpatentable over GIORDANO et al. (U.S. 2019/0117866 A1) (hereinafter “Giordano”). Regarding Claim 1: Giordano teaches a hemodialysis system with variable flow rate (see FIG. 1, a hemodialysis system 1) (see paragraphs 2, 18-21 and 67-69) comprising: a machine housing (see paragraphs 18-36 and 67-70); an arterial blood line for connecting to a patient's artery for collecting blood from a patient (see paragraphs 18-36 and 67-70); a venous blood line for connecting to a patient's vein for returning blood to a patient (see paragraphs 18-36 and 67-70); a dialyzer (see paragraphs 18-36 and 67-70); a blood flow path connected to said arterial blood line and said venous blood line for transporting blood from a patient to said dialyzer and back to a patient (see paragraphs 18-36 and 67-70); a reservoir for storing dialysate (see paragraphs 18-36 and 67-70); a dialysate flow path, isolated from the blood flow path, connected to said reservoir and said dialyzer for transporting dialysate from said reservoir to said dialyzer (see paragraphs 18-36 and 67-70); at least one dialysate pump for pumping dialysate through said dialysate flow path (see paragraphs 18-36 and 67-70); a blood pump for pumping blood through said blood flow path (see paragraphs 18-36 and 67-70); a dialysate flow sensor in said dialysate flow path which measures the flow rate of dialysate through said dialysate flow path (see paragraphs 18-36 and 67-70); a control processor connected to said dialysate flow sensor and said at least one dialysate pump (see paragraphs 18-36 and 67-70) (see paragraphs 72, 76, 92-94, 117 and 120). Although Giordano teaches a hemodialysis system including a control processor capable and configured to control all sensors, valves, structural components and adjust parameters/characteristics of the hemodialysis system, one may broadly interpret that Giordano does not explicitly teach said control processor possessing memory for storing a patient treatment plan by which a patient is treated, said patient treatment plan includes dialysate flow rates during a patient's treatment wherein the dialysate flow rates increase over the time period "T(total)" for treating a patient, as recited in independent claim 1. However, it would have been obvious before the effective filing date of the claimed invention to one of ordinary skilled in the art to modify the control processor of Giordano to be capable of storing a treatment plan containing dialysate flow rates and to further adjust the flow rate based on patient needs and for optimization purposes (see paragraphs 18-36 and 67-70) (see paragraphs 72, 76, 92-94, 117 and 120). Regarding Claim 2: Giordano teaches a hemodialysis system with variable flow rate of claim 1 wherein said dialysate flow rates include a high flow rate and a low flow rate, and wherein low flow rate is less than 75% of said high flow rate (see paragraphs 18-36 and 67-70) (see paragraphs 72, 76, 92-94, 117 and 120). Although Giordano teaches a hemodialysis system including a control processor capable and configured to control all sensors, valves, structural components and adjust parameters/characteristics of the hemodialysis system, it would have been obvious before the effective filing date of the claimed invention to one of ordinary skilled in the art to modify the control processor of Giordano to be capable of storing a treatment plan containing dialysate flow rates and to further adjust the flow rate based on patient needs and for optimization purposes (see paragraphs 18-36 and 67-70) (see paragraphs 72, 76, 92-94, 117 and 120). Regarding Claim 3: Giordano teaches a hemodialysis system with variable flow rate of claim 1 wherein said patient treatment plan includes increasing the dialysate flow rate in a linear manner (see paragraphs 18-36 and 67-70) (see paragraphs 72, 76, 92-94, 117 and 120). Although Giordano teaches a hemodialysis system including a control processor capable and configured to control all sensors, valves, structural components and adjust parameters/characteristics of the hemodialysis system, it would have been obvious before the effective filing date of the claimed invention to one of ordinary skilled in the art to modify the control processor of Giordano to be capable of storing a treatment plan containing dialysate flow rates and to further adjust the flow rate based on patient needs and for optimization purposes (see paragraphs 18-36 and 67-70) (see paragraphs 72, 76, 92-94, 117 and 120). Regarding Claim 4: Giordano teaches a hemodialysis system with variable flow rate of claim 1 wherein said dialysate flow rates increase incrementally in a stepped manner, and include a high flow rate and a low flow rate (see paragraphs 18-36 and 67-70) (see paragraphs 72, 76, 92-94, 117 and 120). Although Giordano teaches a hemodialysis system including a control processor capable and configured to control all sensors, valves, structural components and adjust parameters/characteristics of the hemodialysis system, it would have been obvious before the effective filing date of the claimed invention to one of ordinary skilled in the art to modify the control processor of Giordano to be capable of storing a treatment plan containing dialysate flow rates and to further adjust the flow rate based on patient needs and for optimization purposes (see paragraphs 18-36 and 67-70) (see paragraphs 72, 76, 92-94, 117 and 120). Regarding Claim 5: Giordano teaches a hemodialysis system with variable flow rate of claim 1 wherein dialysate flow rates include a high flow rate between 400 to 800 ml/min and a low flow rate between 100 to 400 ml/min (see paragraphs 18-36 and 67-70) (see paragraphs 72, 76, 92-94, 117 and 120). Although Giordano teaches a hemodialysis system including a control processor capable and configured to control all sensors, valves, structural components and adjust parameters/characteristics of the hemodialysis system, it would have been obvious before the effective filing date of the claimed invention to one of ordinary skilled in the art to modify the control processor of Giordano to be capable of storing a treatment plan containing dialysate flow rates and to further adjust the flow rate based on patient needs and for optimization purposes (see paragraphs 18-36 and 67-70) (see paragraphs 72, 76, 92-94, 117 and 120). Regarding Claim 6: Giordano teaches a hemodialysis system with variable flow rate of claim 1 wherein said control processor causes said dialysate pump to pump dialysate through said dialysate flow path at between 400 to 800 ml/min for at least 0.5 hours and said control processor causes said dialysate pump to pump dialysate through said dialysate flow path at between 100 to 400 ml/min for at least 0.5 hours (see paragraphs 18-36 and 67-70) (see paragraphs 72, 76, 92-94, 117 and 120). Although Giordano teaches a hemodialysis system including a control processor capable and configured to control all sensors, valves, structural components and adjust parameters/characteristics of the hemodialysis system, it would have been obvious before the effective filing date of the claimed invention to one of ordinary skilled in the art to modify the control processor of Giordano to be capable of storing a treatment plan containing dialysate flow rates and to further adjust the flow rate based on patient needs and for optimization purposes (see paragraphs 18-36 and 67-70) (see paragraphs 72, 76, 92-94, 117 and 120). Regarding Claim 7: Giordano teaches a hemodialysis system with variable flow rate of claim 1 wherein said patient treatment plan includes dialysate flow rates wherein the dialysate flow rates increase over the time period "T(total)" for treating a patient and said patient treatment plan includes dialysate flow rates during a patient's treatment wherein the dialysate flow rates decrease over the time period "T(total)" for treating a patient (see paragraphs 18-36 and 67-70) (see paragraphs 72, 76, 92-94, 117 and 120). Although Giordano teaches a hemodialysis system including a control processor capable and configured to control all sensors, valves, structural components and adjust parameters/characteristics of the hemodialysis system, it would have been obvious before the effective filing date of the claimed invention to one of ordinary skilled in the art to modify the control processor of Giordano to be capable of storing a treatment plan containing dialysate flow rates and to further adjust the flow rate based on patient needs and for optimization purposes (see paragraphs 18-36 and 67-70) (see paragraphs 72, 76, 92-94, 117 and 120). Other References Considered Kelly et al. (U.S. 2011/0009797 A1) (hereinafter “Kelly”) teaches a dialysis system including blood and dialysate cassette. Robertson et al. (U.S. 2022/0040390 A1) (hereinafter “Robertson”) teaches a dialysis system and method for modulating flow of a dialysate during dialysis. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to AKASH K. VARMA whose telephone number is (571)272-9627. The examiner can normally be reached Monday-Friday 9-5 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, Benjamin L. Lebron can be reached at (571)-272-0475. 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. /AKASH K VARMA/Primary Examiner, Art Unit 1773
Read full office action

Prosecution Timeline

Jul 31, 2023
Application Filed
Dec 25, 2025
Non-Final Rejection — §103, §112, §DP (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

1-2
Expected OA Rounds
66%
Grant Probability
99%
With Interview (+34.5%)
3y 4m
Median Time to Grant
Low
PTA Risk
Based on 564 resolved cases by this examiner. Grant probability derived from career allow rate.

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