Prosecution Insights
Last updated: April 19, 2026
Application No. 18/683,040

MULTI-PART DIALYZER

Non-Final OA §102§103
Filed
Feb 12, 2024
Examiner
ARBLE, JESSICA R
Art Unit
3781
Tech Center
3700 — Mechanical Engineering & Manufacturing
Assignee
B. Braun Avitum AG
OA Round
1 (Non-Final)
66%
Grant Probability
Favorable
1-2
OA Rounds
3y 5m
To Grant
92%
With Interview

Examiner Intelligence

Grants 66% — above average
66%
Career Allow Rate
256 granted / 390 resolved
-4.4% vs TC avg
Strong +26% interview lift
Without
With
+26.2%
Interview Lift
resolved cases with interview
Typical timeline
3y 5m
Avg Prosecution
48 currently pending
Career history
438
Total Applications
across all art units

Statute-Specific Performance

§101
0.6%
-39.4% vs TC avg
§103
47.9%
+7.9% vs TC avg
§102
20.8%
-19.2% vs TC avg
§112
23.0%
-17.0% vs TC avg
Black line = Tech Center average estimate • Based on career data from 390 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 Applicant’s election without traverse of Group I in the reply filed on 02/26/2026 is acknowledged. Claims 14 and 15 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on 02/26/2026. 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) 5-9 and 13 is/are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Baurmeister et al (US 4724900). Regarding Claim 5, Baurmeister discloses a second dialyzer element with housing (2, Figs. 1, 5, 10, and 14), which is formed as, or comprises, a closable, openable, and reusable housing (Col. 1 lines 49-56, Col. 7 lines 3-21), the second dialyzer comprising: a first housing part (left half, Fig. 14) and a second housing part (right half, Fig. 14) which are configured to be brought in an open state and in a closed state (Fig. 14; Col. 7 lines 3-21), wherein; the first housing part (left half, Fig. 14) and the second housing part (right half, Fig. 14) are configured in the open state to receive a first dialyzer element without housing (bundle of hollow fibers 16, Fig. 1, 5, 10, and 14; Col. 7 lines 3-21); the first housing part (left half, Fig. 14) and the second housing part (right half, Fig. 14) are lockable to each other in the closed state (Figs. 14-17; Col. 7 lines 3-37); and the housing (2, Figs. 1, 5, 10, and 15) is connectable to a dialysis fluid circuit (abstract, Fig. 7). Regarding Claim 6, Baurmeister discloses the second dialyzer element with housing is configured to be firmly and permanently attached to a blood treatment device (abstract; the device is fully capable of being permanently attached to the blood treatment device; for example, the blood treatment device could be an entirely disposable device itself and the dialyzer would not need to be changed in that instance). Regarding Claim 7, Baurmeister discloses a hinge (groove-like indentions 13, Fig. 14) about which the first housing part (left half, Fig. 14) and/or the second housing part (right half, Fig. 15) is pivotable in order to move the first housing part (left half, Fig. 14) and the second housing part (right half, Fig. 14) into the open state and into the closed state (Fig. 14; Col. 7 lines 3-21). Regarding Claim 8, Baurmeister discloses at least one closure element (clasp 14, Fig. 14-15) which is arranged on the first housing part (left half, Fig. 14-15) and/or on the second housing part (right half, Fig. 14-15) and via which the first housing part (left half, Fig. 14-15) and the second housing part (right half, Fig. 14-15) are lockable to each other (Col. 7 lines 3-37). Regarding Claim 9, Baurmeister discloses a third sealing element or a third sealing surface (bulges 8, Fig. 1; Col. 4 lines 4-40) at or near a first axial end of the housing (2, Fig. 1) and a fourth sealing element or a fourth sealing surface (bulges 8, Fig. 1; Col. 4 lines 4-40) at or near a second axial end of the housing (Col. 4 lines 4-40). Regarding Claim 13, Baurmeister discloses a blood treatment device comprising: a second dialyzer element with housing (2, Figs. 1, 5, 10, and 14), which is formed as, or comprises, a closable, openable, and reusable housing (Col. 1 lines 49-56, Col. 7 lines 3-21), the second dialyzer comprising: a first housing part (left half, Fig. 14) and a second housing part (right half, Fig. 14) which are configured to be brought in an open state and in a closed state (Fig. 14; Col. 7 lines 3-21), wherein; the first housing part (left half, Fig. 14) and the second housing part (right half, Fig. 14) are configured in the open state to receive a first dialyzer element without housing (bundle of hollow fibers 16, Fig. 1, 5, 10, and 14; Col. 7 lines 3-21); the first housing part (left half, Fig. 14) and the second housing part (right half, Fig. 14) are lockable to each other in the closed state (Figs. 14-17; Col. 7 lines 3-37); and the housing (2, Figs. 1, 5, 10, and 15) is connectable to a dialysis fluid circuit (abstract, Fig. 7); and a machine front (Fig. 7, Col. 5 lines 36-56), wherein the second dialyzer element with housing (2, Figs. 1 and 5) is firmly attached or installed on the machine front (Fig. 7, Col. 1 line 49-56, Col. 5 lines 36-56). 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. Claim(s) 1, 2, 4, 11, and 12 is/are rejected under 35 U.S.C. 103 as being unpatentable over Baurmeister et al (US 4724900) in view of Wollbeck et al (US 5032269). Regarding Claim 1, Baurmeister discloses a first dialyzer element (16, Figs. 1 and 5) without housing (Figs. 1 and 5) comprising: a hollow fiber bundle (16, Figs. 1 and 5) comprising a first axial end and a second axial end (Figs. 1 and 5); a first cast element (3, Figs. 1 and 5; Col. 4 lines 4-40) provided at the first axial end of the hollow fiber bundle (16, Figs. 1 and 5) and a second cast element (3, Figs. 1 and 5; Col. 4 lines 4-40) provided at the second axial end of the hollow fiber bundle (16, Figs. 1 and 5; Col. 4 lines 4-40); and a first end cap (1, Figs. 1 and 5) attached to the first cast element (3, Figs. 1 and 5) and a second end cap (1’, Fig. 5) attached to the second cast element (3, Figs. 1 and 5; Col. 4 lines 4-40), wherein the first dialyzer element without housing (Figs. 1 and 5) is connectable to an extracorporeal blood circuit (abstract, Fig. 7). Baurmeister is silent whether the first dialyzer element without housing comprises a liquid-permeable sheathing circumferentially wrapped around the hollow fiber bundle. Wollbeck teaches a hollow fiber module, thus being in the same field of endeavor, where the hollow fiber bundle (1, Fig. 4) is enclosed in a sheath (envelope 6, Fig. 4) which can serve as a pre-filter prior to the fluid coming into contact with the hollow fibers of the hollow fiber bundle (Col. 2 line 63 – Col. 3 line 3). Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the first dialyzer element without housing of Baurmeister to include a liquid-permeable sheathing circumferentially wrapped around the hollow fiber bundle, as taught by Wollbeck, to serve as a pre-filter prior to fluid coming into contact with the hollow fibers of the hollow fiber bundle (as motivated by Wollbeck Col. 2 line 63 – Col. 3 line 3). Regarding Claim 2, the combination of Baurmeister/Wollbeck discloses the claimed invention substantially as claimed as set forth above for Claim 1. The combination of Baurmeister/Wollbeck further discloses the liquid-permeable sheathing (Wollbeck 6, Fig. 4) is formed as a textile surface structure (Wollbeck Col. 2 line 63 – Col. 3 line 3, Col. 4 lines 51-56). Regarding Claim 4, Baurmeister further discloses the first end cap (1, Figs. 1 and 5) has a first sealing surface or a first sealing element on an outer surface of the first end cap (1, Figs. 1 and 5), and the second end cap (1’, Figs. 1 and 5) has a second sealing surface or a second sealing element on an outer circumference of the second end cap (1’, Figs. 1 and 5; the exterior surface of both caps can be considered the first and second sealing surfaces). Regarding Claim 11, Baurmeister discloses a first dialyzer element (16, Fig. 1) without housing (Figs. 1 and 5) comprising: a hollow fiber bundle (16, Figs. 1 and 5) comprising a first axial end and a second axial end (Figs. 1 and 5); a first cast element (3, Figs. 1 and 5; Col. 4 lines 4-40) provided at the first axial end of the hollow fiber bundle (16, Figs. 1 and 5) and a second cast element (3, Figs. 1 and 5; Col. 4 lines 4-40) provided at the second axial end of the hollow fiber bundle (16, Figs. 1 and 5; Col. 4 lines 4-40); and a first end cap (1, Figs. 1 and 5) attached to the first cast element (3, Figs. 1 and 5) and a second end cap (1’, Fig. 5) attached to the second cast element (3, Figs. 1 and 5; Col. 4 lines 4-40), wherein the first dialyzer element without housing (Figs. 1 and 5) is connectable to an extracorporeal blood circuit (abstract, Fig. 7); and a second dialyzer element with housing (2, Figs. 1, 5, 10, and 14), which is formed as, or comprises, a closable, openable, and reusable housing (Col. 1 lines 49-56, Col. 7 lines 3-21), the second dialyzer comprising: a first housing part (left half, Fig. 14) and a second housing part (right half, Fig. 14) which are configured to be brought in an open state and in a closed state (Fig. 14; Col. 7 lines 3-21), wherein; the first housing part (left half, Fig. 14) and the second housing part (right half, Fig. 14) are configured in the open state to receive the first dialyzer element without housing (Fig. 1, 5, 10, and 14; Col. 7 lines 3-21); the first housing part (left half, Fig. 14) and the second housing part (right half, Fig. 14) are lockable to each other in the closed state (Figs. 14-17; Col. 7 lines 3-37); and the housing (2, Figs. 1, 5, 10, and 15) is connectable to a dialysis fluid circuit (abstract, Fig. 7). Baurmeister is silent whether the first dialyzer element without housing comprises a liquid-permeable sheathing circumferentially wrapped around the hollow fiber bundle. Wollbeck teaches a hollow fiber module, thus being in the same field of endeavor, where the hollow fiber bundle (1, Fig. 4) is enclosed in a sheath (envelope 6, Fig. 4) which can serve as a pre-filter prior to the fluid coming into contact with the hollow fibers of the hollow fiber bundle (Col. 2 line 63 – Col. 3 line 3). Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the first dialyzer element without housing of Baurmeister to include a liquid-permeable sheathing circumferentially wrapped around the hollow fiber bundle, as taught by Wollbeck, to serve as a pre-filter prior to fluid coming into contact with the hollow fibers of the hollow fiber bundle (as motivated by Wollbeck Col. 2 line 63 – Col. 3 line 3). Regarding Claim 12, Baurmeister further discloses the first dialyzer element (16, Figs. 1 and 5) without housing is inlaid into the second dialyzer element with housing (2, Figs. 1 and 5), in the closed state of the second dialyzer element with housing (2, Figs. 1 and 5), the second dialyzer element with housing (2, Figs. 1 and 5) completely surrounds the first dialyzer element without housing (16, Figs. 1 and 5), and the second dialyzer element with housing (2, Figs. 1 and 5) and the first dialyzer element without housing (16, Figs. 1 and 5) are sealed to each other via corresponding sealing elements and sealing surfaces (as seen in Fig. 1, sealing elements such as bulges 8 and sealing surfaces such as exterior surfaces of fiber bundle 16 and interior surfaces of housing 2 are involved in sealing the fiber bundle within the housing). Claim(s) 3 is/are rejected under 35 U.S.C. 103 as being unpatentable over Baurmeister et al (US 4724900) in view of Wollbeck et al (US 5032269) further in view of Hornung et al (US 2016/0129172). Regarding Claim 3, Baurmeister/Wollbeck is silent whether the first dialyzer element without housing is packaged sterile in a sterile packaging. Hornung teaches a dialyzer, thus being in the same field of endeavor, that is packaged sterile in sterile packaging (¶ [0037]). This ensures the dialyzer is sterile prior to unpackaging, limiting the risk of infection to the user. Therefore, it would have been obvious to modify the first dialyzer element without housing of Baurmeister/Wollbeck to be packaged sterile in a sterile packaging, as taught by Hornung, to ensure the dialyzer is sterile prior to unpackaging, limiting the risk of infection to the user. Claim(s) 10 is/are rejected under 35 U.S.C. 103 as being unpatentable over Baurmeister et al (US 4724900) in view of Strohhofer et al (US 2016/0058934). Regarding Claim 10, Baurmeister is silent whether the second dialyzer element with housing further comprises a housing insert separate from the housing and/or a sensor installed on the housing. Strohhofer teaches a dialyzer (100, Fig. 2A), thus being in the same field of endeavor, with a sensor (200, Fig. 2A) installed on the housing (110, Fig. 2A), to allow information about the substances within the dialyzer to be obtained (¶ [0013, 0084]). Therefore, it would have been obvious to modify the second dialyzer element with housing to comprise a sensor installed on the housing, as taught by Strohhofer, to allow information about the substances within the dialyzer to be obtained by the system (as motivated by Strohhofer ¶ [0013, 0084]). Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to Jessica Arble whose telephone number is (571)272-0544. The examiner can normally be reached Mon - Fri 9 AM - 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, Sarah Al-Hashimi can be reached at 571-272-7159. 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. /JESSICA ARBLE/ Primary Examiner, Art Unit 3781
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Prosecution Timeline

Feb 12, 2024
Application Filed
Mar 02, 2026
Non-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

1-2
Expected OA Rounds
66%
Grant Probability
92%
With Interview (+26.2%)
3y 5m
Median Time to Grant
Low
PTA Risk
Based on 390 resolved cases by this examiner. Grant probability derived from career allow rate.

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