# US 10,245,365 B2 · Replenisihing urease in dialysis systems using a urease introducer > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,245,365 B2 - Document ID: US10245365B2 - Status: Granted - Kind: B2 - Application number: 16/003,245 - Filed: 2018-06-08 - Published: 2018-10-11 - Granted: 2019-04-02 - Earliest claimed: 2014-06-24 - Assignees: Medtronic, Inc. - Applicants: Medtronic, Inc. - Inventors: Martin T. Gerber; Christopher M. Hobot - Web page: https://patentgrep.com/patent/US10245365B2 ## CPC - A61M 1/1696: {with dialysate regeneration} - A61M: DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY (introducing media into or onto the bodies of animals A61D7/00; means for inserting tampons A61F13/26; devices for administering food or medicines orally A61J; containers for collecting, storing or administering blood or medical fluids A61J1/05); DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY (surgery A61B; chemical aspects of surgical articles A61L); DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR {(Electrotherapy, e.g. producing anaesthesia by the use of alternating or intermittent currents A61N1/36021)} ## Abstract An apparatus and method for replenishing urease in a sorbent cartridge for use in sorbent dialysis. The sorbent cartridge is configured to allow an amount of urease to be added to the sorbent cartridge. A urease solution can be injected into the sorbent cartridge to replenish the urease containing module, or solid urease can be added to the sorbent cartridge. The sorbent module can also comprise other, rechargeable, sorbent materials for removing toxins other than urea from spent dialysate. ## Claims ### Claim 1 A method, comprising the steps of: detecting an amount of urea directly or indirectly by measuring products proportional to an amount of urea in a sample in a dialysate downstream of a sorbent cartridge; wherein the sorbent cartridge contains urease and at least one or more other sorbent materials; and supplying urease to the sorbent cartridge by a urease introducer if the amount of urea downstream of the sorbent cartridge is above a threshold, wherein the sorbent cartridge is adapted to receive an adjustable amount of urease, wherein the urease introducer comprises any one of a slideable tray and a door. ### Claim 2 (depends on 1) The method of claim 1, wherein the step of detecting the amount of urea in the dialysate downstream of the sorbent cartridge is performed by any one of the means selected from the group consisting of an optical sensor, a chemical sensor, a blood urea nitrogen assay, and combinations thereof. ### Claim 3 (depends on 1) The method of claim 1, wherein the step of supplying urease is performed by introducing a urease solution with a concentration between any of 1 mg/mL to 250 mg/mL, 15 mg/mL to 150 mg/mL, 10 mg/mL to 100 mg/mL, or 75 mg/mL to 250 mg/mL of urease into the sorbent cartridge. ### Claim 4 (depends on 1) The method of claim 1, wherein the step of supplying urease is performed by introducing between any of 1.3 mL to 13.3 mL, 1.5 mL to 3.5 mL, 2.3 mL to 10.3 mL, or 5.0 mL to 12.3 mL at an activity of 300 unit/mg of urease activity of a urease solution into the sorbent cartridge. ### Claim 5 (depends on 1) The method of claim 1, further comprising the step of: recharging the at least one or more other sorbent materials housed inside the sorbent cartridge by passing a solution containing appropriate solutes for recharging the at least one or more other sorbent materials through the sorbent cartridge. ### Claim 6 (depends on 1) The method of claim 1, further comprising the step of: recharging the at least one or more sorbent materials housed inside the sorbent cartridge by replacing one or more modules of a modular regeneration assembly that make up the sorbent cartridge containing an amount of the at least one or more other sorbent materials. ### Claim 7 (depends on 5) The method of claim 5, wherein the step of supplying urease to the sorbent cartridge is performed after the step of recharging the at least one or more other sorbent materials. ### Claim 8 (depends on 1) The method of claim 1, wherein the step of supplying urease to the sorbent cartridge is performed during dialysis treatment. ### Claim 9 (depends on 1) The method of claim 1, wherein the step of supplying urease to the sorbent cartridge is performed prior to dialysis treatment. ### Claim 10 (depends on 1) The method of claim 1, wherein the step of supplying urease to the sorbent cartridge is performed after dialysis treatment. ### Claim 11 (depends on 1) The method of claim 1, wherein the step of supplying urease to the sorbent cartridge is performed by a dialysis system based on detection of urea in the dialysate downstream of the sorbent cartridge. ### Claim 12 (depends on 1) The method of claim 1, wherein an amount of urease introduced to the sorbent cartridge is based on one or more patient parameters. ### Claim 13 (depends on 12) The method of claim 12, wherein at least one of the one or more patient parameters is selected from the group consisting of: patient weight, a blood urea nitrogen content of the patient's blood, dialysis time, and urea load. ### Claim 14 (depends on 1) The method of claim 1, further comprising the step of injecting urease into the sorbent cartridge via a urease injection port. ### Claim 15 (depends on 14) The method of claim 14, wherein the urease injection port is located upstream of the sorbent cartridge. ### Claim 16 (depends on 14) The method of claim 14, wherein the urease injection port is located on the sorbent cartridge. ### Claim 17 (depends on 1) The method of claim 1, wherein the step of supplying urease to the sorbent cartridge further comprises the step of supplying alumina, silica, or a combination thereof by the slideable tray or door. ### Claim 18 (depends on 17) The method of claim 17, wherein the alumina, silica, or combination thereof includes urease adsorbed onto the alumina silica, or combination thereof. ### Claim 19 (depends on 1) The method of claim 1, wherein the step of supplying urease to the sorbent cartridge comprise supplying solid urease to the sorbent cartridge by the slideable tray or door. ### Claim 20 (depends on 19) The method of claim 19, wherein the sorbent cartridge comprises alumina, silica, or a combination thereof downstream of the slideable tray or door. ### Claim 21 (depends on 1) The method of claim 1, wherein the step of detecting an amount of urea indirectly is performed by measuring ammonia using an ammonia detector located downstream of a urease layer and upstream of a zirconium phosphate layer. ### Claim 22 (depends on 1) The method of claim 1, wherein the step of detecting an amount of urea indirectly is performed by measuring carbonic acid using a conductivity sensor measuring conductivity. ### Claim 23 (depends on 1) The method of claim 1, wherein the step of detecting an amount of urea indirectly is performed by measuring ammonia using photometry.