Prosecution Insights
Last updated: April 19, 2026
Application No. 17/706,304

OXYGENATOR WITH WOUND FILTER MEMBRANE AND FLOW DIFFUSER

Non-Final OA §103
Filed
Mar 28, 2022
Examiner
CHATRATHI, ARJUNA P
Art Unit
3781
Tech Center
3700 — Mechanical Engineering & Manufacturing
Assignee
Cardiacassist Inc.
OA Round
5 (Non-Final)
64%
Grant Probability
Moderate
5-6
OA Rounds
2y 11m
To Grant
87%
With Interview

Examiner Intelligence

Grants 64% of resolved cases
64%
Career Allow Rate
127 granted / 200 resolved
-6.5% vs TC avg
Strong +23% interview lift
Without
With
+23.4%
Interview Lift
resolved cases with interview
Typical timeline
2y 11m
Avg Prosecution
55 currently pending
Career history
255
Total Applications
across all art units

Statute-Specific Performance

§101
0.6%
-39.4% vs TC avg
§103
59.0%
+19.0% vs TC avg
§102
14.0%
-26.0% vs TC avg
§112
16.4%
-23.6% vs TC avg
Black line = Tech Center average estimate • Based on career data from 200 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 . Response to Amendment Applicant amended claim 1 and canceled claim 25. Claims 1, 3-4, and 18-24 are currently pending. Response to Arguments Applicant’s arguments, see pages 4-5 of Applicant’s Remarks, filed 09/18/25, with respect to the rejections of claims 1, 3, 4, 18-20, 24, and 25 under 35 U.S.C. 103 as being unpatentable over Chambers in view of Prasad and in further view of Peticca and of claims 21-23 in further view of Tuval have been fully considered and are not persuasive. While the amendment to require that the spiral shaped flow diverter has a diameter that is 90% to 95% of a diameter of the inner cavity of the gas exchange medium along a majority of the length of the flow diverter distinguishes over the disclosure of Chambers, the combination of Chambers, Prasad, and Peticca renders claim 1 obvious because the device suggested by Chambers in view of Prasad and in further view of Peticca only differs from the claimed device by the relative dimensions of the flow diverter and does not perform differently from the claimed device, as discussed in more detail below. 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. Claims 1, 3-4, 18-20, and 24 are rejected under 35 U.S.C. 103 as being unpatentable over Chambers et al. (US 6,682,698 B2) in view of Prasad et al. (US 5,352,361 A) and in further view of Peticca et al. (US 2017/0007755 A1). Regarding claims 1, 20, and 24, Chambers discloses a blood oxygenator (Figs. 1-4, feat. 10; Col. 3, line 51 – Col. 4, line 53) comprising: a housing (12) having a first end opposite a second end with a sidewall extending between the first end and the second end along a longitudinal axis (26 and 28 are the inner and outer surface of the sidewall), the housing defining an interior chamber (34) having a fluid inlet (14; Col. 5, lines 21-32) and a fluid outlet (20; Col. 6, lines 15-45); a gas exchange medium (16) positioned within the interior chamber (34), the gas exchange medium having a plurality of hollow fibers (Col. 4, line 46 – Col. 5, line 20), the gas exchange medium defining an inner cavity extending longitudinally through its center (Figs. 2-3: gas exchange medium 16 has a hollow inner cavity); and a flow diverter (Fig. 3, feat. 18) positioned within the inner cavity of the gas exchange medium (Figs. 2-3: flow diverter 18 is in the center of the inner cavity of the gas exchange medium 16) and configured for guiding fluid flow through the gas exchange medium (Col. 5, line 21 – Col. 6, line 14), wherein the flow diverter has a fixed end fixedly connected to a central portion of the housing (Col. 5, lines 33-50: separator 18 is attached to the second end 32 of the housing 12) and a free end extending from the first end along the longitudinal axis (Col. 5, lines 51-65), and a length extending therebetween (Fig. 3, feat. 18; Col. 5, lines 33-50). Chambers does not disclose that the hollow fibers are in a single continuous woven fiber mat rolled into a spiral shape around the longitudinal axis, that the flow diverter has a spiral shape between the fixed end and the free end, or that the spiral shaped flow diverter has a diameter that is 90% to 95% of a diameter of the inner cavity of the gas exchange medium along a majority of the length of the flow diverter. Prasad teaches hollow fiber filter membrane bundles comprising a spirally wound hollow fiber bundle (Col. 2, line 46 – Col. 3, line 68) comprising a plurality of hollow fibers fabricated into a fabric-like array in which the hollow fibers constitute weft filaments held in place by warp filaments, which may be either solid or additional hollow fibers (Col. 6, line 45 – Col. 7, line 10). Because the fabric-like array of hollow fibers comprises warp and weft filaments, the fabric-like array is a continuous woven fiber mat. The fiber bundle is then formed by winding the fabric-like array around a core mandrel in a spiral pattern (Col. 7, line 11 – Col. 8, line 8). Prasad teaches that forming the fibers into a woven fabric-like array advantageously promotes regularity of the fiber bundle and therefore uniform fluid flow dynamics (Col. 6, lines 45-52). Therefore, it would have been prima facie obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to modify the oxygenator disclosed by Chambers so that the hollow fibers are in a single continuous woven fiber mat rolled into a spiral shape around the longitudinal axis in order to promote regularity of the fiber bundle and therefore uniform fluid flow dynamics of the blood in the oxygenator as taught by Prasad. Chambers in view of Prasad does not disclose that the flow diverter has a spiral shape between the fixed end and the free end or that the spiral shaped flow diverter has a diameter that is 90% to 95% of a diameter of the inner cavity of the gas exchange medium along a majority of the length of the flow diverter Peticca teaches a blood oxygenator (Fig. 2, feat. 200; ¶0028) comprising a pump module (230; ¶0041) for pumping blood from the inlet (242) to the outlet (244) through the oxygenator module (240), which includes a heat exchanger (248; ¶0033) and oxygenator fiber bundle (250). . Peticca also discloses that the outer profile of the pump module (Figs. 2 and 4, feat. 230), which includes the rotary vane member (232) may be cylindrical (¶0053), and would therefore have a substantially uniform diameter along its length. Peticca teaches that the pump module (230) comprises a tapering rotary vane member (Figs. 2 and 4, feat. 232; ¶0041) in the center of the heat exchanger (248) and oxygenator (250) fiber bundles and which includes vanes (that necessarily create grooves) which may be attached in curved spirals to the rotary vane member (232a-d; ¶0055-0060). Peticca teaches that the rotary vane member and vanes help to ensure a uniform radial flow distribution in the oxygenator (¶0041). The rotary vane member of Peticca redirects or diverts flow from the axial direction from the inlet (Fig. 2, feat. 242) to the radial direction to the outlet (Fig. 2, feat. 244), and therefore the rotary vane member of Peticca is a flow diverter. Therefore, it would have been prima facie obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to modify the oxygenator suggested by Chambers in view of Prasad so that the flow diverter has a spiral shape between the fixed end and the free end, with respect to claim 1, so that the spiral shaped flow diverter has at least one spiral groove extending the length of the flow diverter, the at least one groove creating at least one spiral ridge extending the length of the flow diverter, with respect to claim 20, and so that a diameter of the flow diverter is uniform along its length, with respect to claim 24, in order to help ensure a uniform radial flow distribution in the oxygenator as taught by Peticca. Chambers in view of Prasad and in further view of Peticca does not disclose the diameter of the flow diverter along the majority of the length of the flow diverter as claimed. However, the Federal Circuit held that, where the only difference between the prior art and the claims was a recitation of relative dimensions of the claimed device and a device having the claimed relative dimensions would not perform differently than the prior art device, the claimed device was not patentably distinct from the prior art device. Please see MPEP §2144.04(IV)(A) with respect to the discussion of Gardner v. TEC Syst., Inc., 725 F.2d 1338, 220 USPQ 777 (Fed. Cir. 1984), cert. denied, 469 U.S. 830, 225 USPQ 232 (1984). In the current case, modifying the flow diverter of Chambers to include spiral shaped vanes would provide a uniform radial flow distribution of the blood through the gas exchange medium, as taught by Peticca (Peticca: ¶0041), in the same manner as the flow diverter of the claimed invention (Please see ¶0051 of the present specification. Therefore, the flow diverter of the oxygenator suggested by Chambers in view of Prasad and in further view of Peticca having the claimed relative dimensions would not perform differently than the claimed oxygenator, and therefore the spiral shaped flow diverter having a diameter that is 90% to 95% of a diameter of the inner cavity of the gas exchange medium along a majority of the length of the flow diverter does not render the claimed device patently distinct from the prior art of record. Regarding claim 3, Chambers in view of Prasad and in further view of Peticca suggests the blood oxygenator of claim 1, and Chambers further discloses that a diameter of the flow diverter increases or decreases between the fixed end and the free end (Fig. 3, feat. 18; Col. 5, line 51 – Col. 6, line 6). Regarding claim 4, Chambers in view of Prasad and in further view of Peticca suggests the blood oxygenator of claim 1, and Chambers further discloses that the flow diverter (Fig. 3, feat. 18) extends along 25% to 100% of the longitudinal length of the gas exchange medium (16; Col. 5, lines 33-50). Regarding claim 18, Chambers in view of Prasad and in further view of Peticca suggests the blood oxygenator of claim 1, and Chambers further discloses that the flow diverter (Fig. 3, feat. 18) extends along 50% or more of the length of the gas exchange medium (16; Col. 5, lines 33-50). Regarding claim 19, Chambers in view of Prasad and in further view of Peticca suggests the blood oxygenator of claim 1, and Chambers further discloses that the flow diverter (Fig. 3, feat. 18) extends along 75% or more of the length of the gas exchange medium (16; Col. 5, lines 33-50). Claims 21-23 are rejected under 35 U.S.C. 103 as being unpatentable over Chambers et al. (US 6,682,698 B2) in view of Prasad et al. (US 5,352,361 A), in further view of Peticca et al. (US 2017/0007755 A1), and in further view of Tuval et al. (WO 2018/078615 A1). Regarding claims 21-23, Chambers in view of Prasad and in further view of Peticca suggests the blood oxygenator of claim 1, but does not disclose that the flow diverter has 0.5 to 10 twists per inch along its length, with respect to claim 21, that the flow diverter has 0.5 to 5 twists per inch along its length, with respect to claim 22, or that the flow diverter has 2 to 8 twists per inch along its length, with respect to claim 23. Tuval teaches an impeller (Fig. 2, feat. 42; Figs. 4A-5D, feat. 50; Page 8, line 21 – Page. 9, line 9), or flow diverter, for a blood pump (Figs. 2 and 4, feat. 40; Page 7, line 16 – Page 8, line 3) comprising a helical, or spiral shaped, element (52, 56). Tuval teaches that the pitch of the helical element controls the blood flow created by the impeller, and that the pitch should be between 1 mm (about 25.4 twists per inch) and 20 mm (about 1.27 twists per inch) to produce sufficient flow (Page 12, lines 16-28). The prior art range of 1.27 to 25.4 twists per inch overlaps the range of 0.5 to 10 twists per inch of claim 21, the range of 0.5 to 5 twists per inch of claim 22, and the range of 2 to 8 twists per inch of claim 23, and therefore a prima facie case exists for the claimed ranges. Please see MPEP §2144.05(I). Therefore, it would have been prima facie obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to modify the oxygenator suggested by Chambers in view of Prasad and in further view of Peticca so that the flow diverter has 0.5 to 10 twists per inch along its length, with respect to claim 21, so that the flow diverter has 0.5 to 5 twists per inch along its length, with respect to claim 22, or so that the flow diverter has 2 to 8 twists per inch along its length, with respect to claim 23, in order to produce sufficient flow as taught by Tuval. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to ARJUNA P CHATRATHI whose telephone number is (571)272-8063. The examiner can normally be reached M-F 8:30-5:00. 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, Sarah Al-Hashimi can be reached at 5712727159. 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. /ARJUNA P CHATRATHI/Examiner, Art Unit 3781 /LESLIE R DEAK/Primary Examiner, Art Unit 3799 12 December 2025
Read full office action

Prosecution Timeline

Mar 28, 2022
Application Filed
Aug 06, 2024
Non-Final Rejection — §103
Nov 15, 2024
Response Filed
Nov 18, 2024
Final Rejection — §103
Jan 24, 2025
Response after Non-Final Action
Feb 28, 2025
Request for Continued Examination
Mar 04, 2025
Response after Non-Final Action
Apr 18, 2025
Non-Final Rejection — §103
Jul 28, 2025
Response Filed
Aug 13, 2025
Final Rejection — §103
Sep 18, 2025
Response after Non-Final Action
Oct 27, 2025
Request for Continued Examination
Nov 03, 2025
Response after Non-Final Action
Dec 11, 2025
Non-Final Rejection — §103 (current)

Precedent Cases

Applications granted by this same examiner with similar technology

Patent 12594372
METHODS AND SYSTEMS FOR CONTROLLING ASPIRATION FLOW RATE
2y 5m to grant Granted Apr 07, 2026
Patent 12576007
FLEXIBLE BAG FOR THE PREPARATION OF ADIPOSE TISSUE GRAFTS AND RELATIVE KIT
2y 5m to grant Granted Mar 17, 2026
Patent 12533459
FLUIDIC CONNECTORS FOR NEGATIVE PRESSURE WOUND THERAPY
2y 5m to grant Granted Jan 27, 2026
Patent 12409083
PATIENT INCONTINENCE PAD WITH INTEGRATED SUPPORT AND LIFTING MEMBER
2y 5m to grant Granted Sep 09, 2025
Patent 12376985
Waste Management Appliance
2y 5m to grant Granted Aug 05, 2025
Study what changed to get past this examiner. Based on 5 most recent grants.

AI Strategy Recommendation

Get an AI-powered prosecution strategy using examiner precedents, rejection analysis, and claim mapping.
Powered by AI — typically takes 5-10 seconds

Prosecution Projections

5-6
Expected OA Rounds
64%
Grant Probability
87%
With Interview (+23.4%)
2y 11m
Median Time to Grant
High
PTA Risk
Based on 200 resolved cases by this examiner. Grant probability derived from career allow rate.

Sign in with your work email

Enter your email to receive a magic link. No password needed.

Personal email addresses (Gmail, Yahoo, etc.) are not accepted.

Free tier: 3 strategy analyses per month