Replenishing urease in dialysis systems using urease pouches
An apparatus and method for replenishing urease in a sorbent cartridge for use in sorbent dialysis using urease pouches. The sorbent cartridge is configured to allow insertion of a urease pouch or injection of a urease solution into the sorbent cartridge containing a urease pouch. The sorbent module can also comprise other, rechargeable, sorbent materials for removing toxins other than urea from spent dialysate.
1. A method, comprising the steps of:
adding urease to a sorbent cartridge adapted to replenish urease in the sorbent cartridge via a urease introducer;
wherein the urease introducer comprises a urease door; a urease tray or a urease injection port;
wherein the step of adding urease to the sorbent cartridge comprises either:
i) removing a urease pouch having a reduced amount of urease, if present, and then adding a fresh urease pouch into the sorbent cartridge using the urease door or the urease tray; or
ii) adding a urease solution to the sorbent cartridge; wherein the sorbent cartridge contains a urease pouch containing alumina, silica, or a combination thereof.
2. The method of claim 1 , wherein the step of adding urease to the sorbent cartridge comprises adding the urease solution to the sorbent cartridge; and wherein adding the urease solution comprises introducing a urease solution into the sorbent cartridge having 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.
3. The method of claim 1 , further comprising the step of:
recharging an amount of one or more sorbent materials contained in the sorbent cartridge by passing a solution containing an appropriate amount of solutes for recharging the one or more sorbent materials through the sorbent cartridge.
4. The method of claim 1 , further comprising the step of recharging an amount of one or more sorbent materials by replacing one or more modules of a modular regeneration assembly containing an amount of the one or more of sorbent materials.
5. The method of claim 1 , wherein the step of adding urease to the sorbent cartridge comprises removing the urease pouch having a reduced amount of urease, if present, and then adding the fresh urease pouch into the sorbent cartridge using the urease door or the urease tray; wherein the fresh urease pouch further contains alumina, silica, or a combination thereof.
6. The method of claim 1 , wherein the step of adding urease to the sorbent cartridge comprises removing the urease pouch having a reduced amount of urease, if present, and then adding the fresh urease pouch into the sorbent cartridge using the urease door or the urease tray; wherein the fresh urease pouch is formed from a porous material, the porous material allowing fluid to pass through the urease pouch and substantially retaining the urease in the urease pouch.
7. The method of claim 1 , wherein the step of adding urease to the sorbent cartridge comprises removing the urease pouch having a reduced amount of urease, if present, and then adding the fresh urease pouch into the sorbent cartridge using the urease door or the urease tray; wherein a top of the fresh urease pouch has a pore size small enough to prevent urease from passing through and a bottom of the urease pouch has a pore size to allow urease to pass through.
8. The method of claim 1 , wherein the step of adding urease to the sorbent cartridge comprises removing the urease pouch having a reduced amount of urease, if present, and then adding the fresh urease pouch into the sorbent cartridge using the urease door or the urease tray; wherein a top of the fresh urease pouch has a pore size to allow urease to pass through and a bottom portion of the fresh urease pouch has a pore size small enough to prevent urease from passing through.
9. The method of claim 1 , wherein the step of adding urease to the sorbent cartridge comprises removing the urease pouch having a reduced amount of urease, if present, and then adding the fresh urease pouch into the sorbent cartridge using the urease door or the urease tray; wherein a top and a bottom of the fresh urease pouch has a pore size to allow urease to pass through.
10. The method of claim 1 , wherein the step of adding urease to the sorbent cartridge comprises adding the urease solution to the sorbent cartridge; wherein the urease pouch has a top with a pore size small enough to prevent urease from flowing through and a bottom with a pore size to allow urease to flow through.
11. The method of claim 1 , wherein the urease introducer is a urease door.
12. The method of claim 1 , wherein the urease introducer is a urease tray.
13. The method of claim 1 , wherein the urease introducer is a urease injection port.
14. The method of claim 13 , wherein the step of adding urease to the sorbent cartridge comprises adding the urease solution to the sorbent cartridge; and wherein the urease is solution is added by injecting the urease solution through the urease injection port.
15. The method of claim 14 , wherein the urease solution further comprises buffer or priming solution.
16. The method of claim 1 , further comprising the step of detecting an amount of urea converted to ammonia by urease in a prior dialysis session.
17. The method of claim 1 , further comprising the step determining an amount of urease to introduce to the sorbent cartridge.
18. The method of claim 17 , wherein the amount of urease to introduce is based on one or more of patient size, patient weight, and/or patient BUN.