Prosecution Insights
Last updated: May 04, 2026
Application No. 17/759,761

MEDICAL SYRINGE AND PISTON STOPPERS FOR A MEDICAL SYRINGE

Non-Final OA §103
Filed
Jul 29, 2022
Priority
Apr 24, 2020 — EU 20171391 +1 more
Examiner
CARPENTER, WILLIAM R
Art Unit
3783
Tech Center
3700 — Mechanical Engineering & Manufacturing
Assignee
Fresenius Kabi Deutschland GmbH
OA Round
3 (Non-Final)
55%
Grant Probability
Moderate
3-4
OA Rounds
0m
Est. Remaining
99%
With Interview

Examiner Intelligence

Grants 55% of resolved cases
55%
Career Allowance Rate
546 granted / 998 resolved
-15.3% vs TC avg
Strong +53% interview lift
Without
With
+53.2%
Interview Lift
resolved cases with interview
Typical timeline
3y 7m
Avg Prosecution
57 currently pending
Career history
1055
Total Applications
across all art units

Statute-Specific Performance

§101
1.2%
-38.8% vs TC avg
§103
48.6%
+8.6% vs TC avg
§102
19.8%
-20.2% vs TC avg
§112
23.7%
-16.3% vs TC avg
Black line = Tech Center average estimate • Based on career data from 998 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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 30 January 2026 has been entered. 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) 1-5, 7-12, 14, 16-20 is/are rejected under 35 U.S.C. 103 as being obvious over WO 2013/033453 (“Gibler”) in view of U.S. Publication No. 2018/0043102 (“Cojocariu”) Regarding Claim 1, Gibler discloses a plunger stopper (110) for a medical syringe (20), the plunger stopper comprising: a main body (inter alia 200, 330) with an end wall (200), a lateral wall (330), and an internal thread (not shown; Par. 72) for securing a plunger rod, wherein the main body is formed of a thermoplastic material (Par. 55); wherein the main body has a plurality of sealing rings (50, 55) made of an elastic material (Par. 51) extending around the main body, the plurality of sealing rings comprises a distally first sealing ring (50) directly adjoining the end wall in an axial direction (see Fig. 4), the distally first sealing ring covered at least partially distally by a circumferential web (220) of the main body, wherein the web protrudes radially from the main body (see Fig. 4), and a second circumferential web (260) protruding radially from the main body and directly adjoining the distally first sealing ring proximally of the distally first sealing ring (see Fig. 4) with the distally first sealing ring directly adjoining the end wall (see Fig. 4), the second web having an outer diameter smaller than an outer diameter of the circumferential web (Par. 57). Gibler discloses the invention substantially as claimed except that that the main body comprises a “cycloolefin” material. However, Cojocariu discloses a related plunger (10) comprising a main body (inter alia 12, 16, 14) which can be made of a polymeric material such as cyclic olefin polymer (i.e. cycloolefin) (Par. 8). It would have been obvious for one having ordinary skill in the art at the time the invention was made to construct the main body of the invention of Gibler of a cycloolefin polymer, as disclosed by Cojocariu, wherein the prior art explicitly recognizes such a material as being a useful alternative, providing predictable and expected results when utilized for such a purpose. It has been held that selecting a known prior art material based upon its recognized utility for such a purpose in the prior art to obtain only a predictable and expected outcome is obvious, see In re Leshin, 277 F.2d 197, 125 USPQ 416 (CCPA 1960). Gibler, as modified, discloses the invention substantially as claimed except that the sealing rings are “connected in a materially-bonded manner to the main body”. However, Cojocariu discloses that in related plunger stoppers it is known to provide related sealing rings (230) to be materially bonded to the plunger body using a “two-shot molding” process by which an annular seal can be overmolded on a molded head portion (Par. 16, 66, 70). It would have been obvious for one having ordinary skill in the art at the time the invention was made to overmold the annular sealing rings of Gibler to the stopper main body, as disclosed by Cojocariu, in order to integrally connect the two components and help prevent accidental separation or displacement of the sealing rings which might compromise the sealing integrity of the stopper causing leakage or exposure to air. Regarding Claim 2, Gibler, as modified by Cojocariu, obviates the sealing rings to be overmolded to the main body (see Par. 16, 66, 70 – Cojocariu). Regarding Claim 3, Gibler discloses the sealing rings are formed in the cross-section of a circular segment (see Fig. 4) with consideration as to modifications by Cojocariu to obviate overmolding the sealing rings creating known, obvious shapes of a circular segment with a polygonal base (see e.g. Fig. 10; see also Fig. 12 - Cojocariu), whereby modification to the shape of the sealing rings of Gibler would have been obvious for the ordinary artisan in order to provide sufficient surface area for bonding the sealing rings to the surface of the main body and such changes in shape being obvious when the affect only predicted and expected results, see In re Dailey, 357 F.2d 669, 149 USPQ 47 (CCPA 1966). Regarding Claim 4, Gibler discloses the sealing rings sit in circumferential grooves (160, 170) of the main body. Regarding Claims 5 and 17, Gibler discloses the invention substantially as claimed except that that the plurality of sealing rings comprises at least three sealing rings, rather Gibler only explicitly discloses two rings. However, Cojocariu discloses, in similar plunger stoppers, that sealing rings may be provided as “at least two” rings (Abstract), whereby the inclusion of such phrasing “at least” implicitly obviates configurations in excess of two inclusive to three, four, or more rings, as desired, as a product of mere, obvious duplication of parts. It has been held that duplication of parts is obvious and requires only routine and customary skill and knowledge in the art, see In re Harza, 274 F.2d 669, 124 USPQ 378 (CCPA 1960). As such, it would have been obvious for one having ordinary skill in the art at the time the invention was made to construct the stopper of Gibler to have three or more sealing rings, as implicitly obviated by Cojocariu, in order to increase the sealing function of the stopper by providing additional sealing surfaces. Regarding Claim 7, Gibler discloses the end wall of the main body of the plunger merges into the circumferential web at an edge (see Fig. 4 – whereby the form a unitary integral, seamless construction) and the circumferential web is rounded at the edge (see Fig. 2 and 4) and the circumferential web rests on an inner wall of the syringe body (see Fig. 4) – and whereby the specifically enumerated dimensions in the instant claim would have been obvious for construction of the syringe in Gibler in order to scale the syringe (and stopper) to an appropriate size for dispensing any particular volume of fluid. Regarding Claim 8, Cojocairu obviates the use of various materials for forming the main body of the invention of Gibler including a cycloolefin polymer or copolymer (Par. 49). Regarding Claims 9 and 20, Gibler discloses the plurality of sealing rings comprise at least one plastic selected from butyl rubber, specifically bromobutyl (Abstract). Regarding Claim 10, Gibler discloses a proximal tip angle of the end wall corresponds substantially to a distal tip angle of the end wall (see Fig. 4). Regarding Claim 11, Gibler discloses a syringe (20) with the claimed plunger stopper (see Fig 4). Regarding Claim 12, Gibler discloses a syringe with a plunger stopper as claimed, wherein the circumferential web rests on an inner wall of a syringe body (Par. 58 – especially when fully depressed). Regarding Claim 14, Gibler discloses a syringe body and the plunger stopper inserted into the syringe body, wherein the outer diameter of the circumferential web corresponds substantially to or is slightly smaller than an inner diameter of the syringe body (Par. 55). Regarding Claim 16, Gibler, as modified in view of Cojocairu, discloses the polygonal base comprises a rectangular base (see Fig. 10, 12 – Cojocairu), such a shape being an obvious design choice for connecting the sealing rings of Gibler to the main body via an overmolding process. Regarding Claim 18, Gibler fails to explicitly disclose that the web may have a heigh of "less than 0.5mm". However, Cojucairu discloses that discloses that the height of the web is a distance (D3) less than the thickness of the annular rings (see Fig. 2), wherein D3 comprises "about one half of the thickness T" of the annular seals, or less than about 30% or less than about 20% of the thickness T of the annular seals (Par. 52), wherein the annular seals may comprise exemplary thicknesses of 0.090 inches (Par. 54), i.e. 2.286mm. As such, in exemplary embodiments Cojucairu discloses the web can be as small as 1.143mm. Cojucairu discloses that variation of thickness is known and expected depending upon the size of the syringe (Par. 54). As such, it would have been obvious for one having ordinary skill in the art at the time the invention was made to construct the piston and seals of the invention of Gibler such that the web comprises a height of less than 0.5mm, since it has been held that mere changes in design and proportion are obvious, particularly where such a change in size constitutes merely carrying forward the stated purpose of the invention, see In re Williams, 36 F.2d 436, 438 (CCPA 1929), Gardner V. TEC Syst., Inc., 725 F.2d 1338, 220 USPQ 777 (Fed. Cir. 1984), In re Rose, 220 F.2d 459, 105 USPQ 23 Regarding Claim 19, Gibler fails to disclose the extend by which the sealing ring protrudes in a plan view. However, Cojucairu discloses the distally first sealing ring protrudes in a plan view of the distal side of the plunger stopper beyond an outer edge of the web (see Fig. 2), but a distance of D3, whereby D3 may be as little as 20% of the thickness of the seal (Par. 52) and wherein the seals may include exemplary values of 0.090 inches (2.286mm), such that D3 can be as small as 457mm. Cojocairu discloses that variation of thickness is known and expected depending upon the size of the syringe (Par. 54). As such, it would have been obvious for one having ordinary skill in the art at the time the invention was made to construct the piston and seals of the invention of Gibler such that the sealing protrudes between 0.08 and 0.2mm beyond the outer edge of the web, since it has been held that mere changes in design and proportion are obvious, particularly where such a change in size constitutes merely carrying forward the stated purpose of the invention, see In re Williams, 36 F.2d 436, 438 (CCPA 1929), Gardner V. TEC Syst., Inc., 725 F.2d 1338, 220 USPQ 777 (Fed. Cir. 1984), In re Rose, 220 F.2d 459, 105 USPQ 237 (CCPA 1955), and In re Rinehart, 531 F.2d 1048, 189 USPQ 143 (CCPA 1976). Claim(s) 13 is/are rejected under 35 U.S.C. 103 as being obvious over WO 2013/033453 (“Gibler”) in view of U.S. Publication No. 2018/0043102 (“Cojocariu”) as applied above, and further in view of WO 2011/125133 (“Yotsutsuji”). Regarding Claim 13, Gibler discloses the syringe to have a plunger rod (not shown – Par. 72), whereby the plunger rod has a distal connection end to which the plunger stopper rests within a corresponding inner side of the plunger stopper. However, Gibler fails to illustrate or particularly expand upon the shape of this interconnection other than indicating that it may be “threaded” (Par. 72). However, Yotsutsuji disclose related syringes (Fig. 2), wherein the syringe has a plunger rod with a conical distal end (see Fig. 2), which, with the plunger rod connected to the plunger stopper, rests on a conical inner side of the end wall of the plunger stopper (see Fig. 2). It would have been obvious for one having ordinary skill in the art at the time the invention was made to construct the push rod of Gibler to comprise a conical end which is configured to be received against the corresponding conical space of the stopper in a threaded connection, as disclosed by Yotsutsuji, in order to ensure that the interior of the stopper is sufficiently filled to provide strength and rigidity to the connection, with such changes in shape being obvious design choices when known to the prior art, see In re Dailey, 357 F.2d 669, 149 USPQ 47 (CCPA 1966). Response to Arguments Applicant’s arguments with respect to the claim(s) have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to WILLIAM R CARPENTER whose telephone number is (571)270-3637. The examiner can normally be reached Mon. to Thus. - 7:00AM to 5:00PM (EST/EDT). 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, KEVIN SIRMONS can be reached at (571) 272-4965. 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. /WILLIAM R CARPENTER/Primary Examiner, Art Unit 3783 04/22/2026
Read full office action

Prosecution Timeline

Show 1 earlier event
May 27, 2025
Non-Final Rejection — §103
Sep 02, 2025
Response Filed
Oct 28, 2025
Final Rejection — §103
Jan 13, 2026
Examiner Interview Summary
Jan 13, 2026
Examiner Interview (Telephonic)
Jan 30, 2026
Request for Continued Examination
Feb 25, 2026
Response after Non-Final Action
Apr 22, 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

3-4
Expected OA Rounds
55%
Grant Probability
99%
With Interview (+53.2%)
3y 7m (~0m remaining)
Median Time to Grant
High
PTA Risk
Based on 998 resolved cases by this examiner. Grant probability derived from career allowance rate.

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