DETAILED ACTION
Applicant’s request for continued examination filed March 12, 2026 is acknowledged. Claim 24 is amended, claims 1-23 and 31-35 are withdrawn, and claims 45-46 are canceled. Claims 24-25, 28-29, and 40-44 are further considered on the merits.
Response to Amendment
In light of applicant’s amendment, the examiner modifies the grounds of rejection set forth in the office action filed December 9, 2025.
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) 24-25, 28-29, and 40-44 is/are rejected under 35 U.S.C. 103 as being unpatentable over Gerber et al., US 2015/0367052 (Gerber) in view of Thompson, US 6878283 (Thompson, of record) and Labib et al., US 2016/0375188 (Labib).
Regarding claim 24, Gerber discloses a sorbent cartridge (abstract, figs. 12-13) comprising:
A housing (REF 272, see “cartridge”, ¶ 0071) sized and shaped to accept multiple sorbent cartridge casings (see “sorbent pouches”, ¶ 0129) in a desired order, the housing comprising an exit end including an outlet and an inlet end including an inlet (see “fluid is directed through”, ¶ 0092 and “dialysate flows through the sorbent cartridge”, ¶ 0133);
A first zirconium casing including H+ZP (see “zirconium phosphate”, ¶ 0028, 0107, 0120 and “multiple sorbent pouches”, ¶ 0118-0119) located within the housing;
A second zirconium casing including Na+ZP (see “zirconium phosphate”, ¶ 0028, 0107, 0120 and “multiple sorbent pouches”, ¶ 0118-0119) located within the housing;
At least one additional casing located within the housing such as a urease casing (¶ 0028, 0107);
Wherein each of the first and second zirconium casing includes a refurbished zirconium compound (¶ 0121); and
Wherein each casing includes a seal that seals to another one of the casings or to the housing when the housing is closed for treatment, such that fluid travelling through the housing during treatment is prevented from leaking between the casings and between the housing and the casings (¶ 0095);
Wherein the first zirconium casing and the second zirconium casing are configured to be refurbished by flowing a refurbishment fluid through the housing in a reverse flow direction from the outlet to the inlet (via inlet/outlet of cartridge housing).
Gerber does not disclose the housing exit end being closed and the inlet end comprising a removable cap threadedly connected to said inlet end. However, Thompson discloses dialysate sorbent cartridges (abstract, figs. 1-6) having a closed exit end (REF 400, fig. 5) and an inlet end comprising a removable cap (REF 450).
At the time of invention, it would have been obvious to one having ordinary skill in the art to modify the cartridge of Gerber to utilize the cartridge end caps described in Thompson in order to prevent leakage and maintain sufficient fluid pressure during dialysate regeneration.
While Gerber (in view of Thompson) discloses a removable cap (via “physical latch”, Thompson C5/L21-31), Gerber does not disclose the cap being connected via a threaded engagement. However, Labib discloses that it is common for dialysis cartridges to have removable caps secured to a housing by a variety of attachment methods including a threaded seal (¶ 0144).
At the time of invention, it would have been obvious to one having ordinary skill in the art to modify the cartridge of Gerber (in view of Thompson) to have a threadedly connected cap as described in Labib since the examiner notes the equivalence of latches and threads for their use in the dialysis art and the selection of any of these known equivalents to removably secure a cap would be within the level of ordinary skill in the art (MPEP 2144.06).
Lastly, while Gerber discloses using multiple zirconium phosphate casings containing both H+ and Na+, Gerber does not disclose the two separate casings containing different zirconium containing materials such as one casing containing H+ZP and another casing containing Na+ZP. However, Thompson discloses that it is common to include multiple different zirconium containing materials within dialysis sorbent cartridges (C6/L36-42).
At the time of invention, it would have been obvious to one having ordinary skill in the art to modify the cartridge of Gerber to have different zirconium containing materials as described in Thompson since it has been shown that broadly providing multiple different zirconium containing materials within dialysis sorbent cartridges is effective in dialysis treatment and the selection of any of these known materials to include in said cartridge would a matter of obvious design choice absent a showing of criticality or unexpected results (MPEP 2144.07).
Regarding claim 25, Gerber (in view of Thompson and Labib) discloses a sorbent cartridge wherein the housing is conically sized and shaped to accept multiple sorbent cartridge casings in a desired order and orientation (¶ 0110).
Regarding claim 28, Gerber (in view of Thompson and Labib) discloses a sorbent cartridge where the zirconium casings are located in parallel within the housing (¶ 0131).
Regarding claim 29, Gerber (in view of Thompson and Labib) discloses a sorbent cartridge wherein the zirconium casings are located in series within the housing (¶ 0127).
Regarding claim 40, Gerber (in view of Thompson and Labib) discloses a sorbent cartridge wherein the at least one additional casing comprises an anion exchange resin casing (¶ 0008), a mechanical filter casing (¶ 0009), an activated carbon and filter casing (¶ 0008), and a urease casing (¶ 0008).
Regarding claim 41, Gerber (in view of Thompson and Labib) discloses a sorbent cartridge comprising an additional activated carbon and filter casing (¶ 0008, 0118-0119).
Regarding claims 42-43, while Gerber (in view of Thompson and Labib) does not disclose the recited order of casings, Gerber recognizes that the individual casings may be arranged in any preferred order (¶ 0119). Therefore, it would have been obvious to one having ordinary skill in the art at the time the invention was made to provide the recited order of casings since it has been held that rearranging parts of an invention involves only routine skill in the art absent a showing of criticality or unexpected results (MPEP 2144.04, Section VI, Part C).
Regarding claim 44, Gerber (in view of Thompson and Labib) discloses a sorbent cartridge wherein the casings have a conical shape (¶ 0015, 0110).
Response to Arguments
Applicant’s arguments with respect to the rejection(s) of claim(s) 24 under 35 U.S.C. 103 have been fully considered and are persuasive. Therefore, the rejection has been withdrawn. However, upon further consideration, a new ground(s) of rejection is made in view of Thompson and Labib as seen above.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to DIRK R BASS whose telephone number is (571)270-7370. The examiner can normally be reached 8-4:30 EST Monday-Friday.
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DIRK R. BASS
Primary Examiner
Art Unit 1779
/DIRK R BASS/Primary Examiner, Art Unit 1779