Automated peritoneal dialysis cycler and methods of use
Automated peritoneal dialysis (APD) cycler systems and methods are disclosed. The APD cycler can include a heater tray with load cells configured to measure the weight of fluid contained within a heater bag and/or a drain bag. The load cells can be toggleable between enabled and disabled configurations. The APD cycler can include a pressure-based volume measurement system, which can be used to confirm measurements made by the load cells. In some embodiments, the APD cycler can have algorithms for tracking an estimated patient volume to prevent overfilling the patient.
1. A method of performing a dialysis treatment comprising:
infusing an infusion volume of dialysis solution into a patient;
draining fluid from a patient;
identifying an indicator that the draining may be complete;
measuring the volume of drained fluid;
calculating a minimum drain volume, wherein the minimum drain volume is a predetermined percentage of an expected drain volume, wherein the expected drain volume comprises the infusion volume and an estimated residual patient volume; and
determining, using one or more computing devices, if the measured volume of drained fluid is less than the minimum drain volume.
2. The method of claim 1 , further comprising posting an alarm if the measured volume of drained fluid is less than the minimum drain volume.
3. The method of claim 1 , further comprising continuing the dialysis treatment if the measured volume of drained fluid is not less than the minimum drain volume.
4. The method of claim 3 , further comprising updating the estimated residual patient volume to be the difference between the expected drain volume and the measured volume of drained fluid.
5. The method of claim 4 , further comprising performing a subsequent infusion stage and a subsequent drain stage, and using the updated estimated residual patient volume to calculate the minimum drain volume for the subsequent drain stage.
6. The method of claim 3 , further comprising reducing a volume of a subsequent infusion stage if the measured volume of drained fluid is less than the expected drain volume.
7. The method of claim 6 , further comprising:
adding an additional infusion cycle to a treatment session schedule;
determining an amount of infusion fluid remaining to be infused during the dialysis treatment;
calculating an adjusted infusion volume by dividing the amount of infusion fluid remaining by a number of scheduled infusion cycles; and
infusing the adjusted infusion volume of dialysis solution to the patient.
8. The method of claim 1 , wherein the expected drain volume further comprises an expected ultrafiltration volume.
9. The method of claim 1 , further comprising:
infusing a second infusion volume of dialysis solution into the patient;
draining fluid from the patient a second time;
measuring a second volume of drained fluid;
calculating a second minimum drain volume larger than the minimum drain volume,
wherein the second minimum drain volume is the predetermined percentage of a second expected drain volume, wherein the second expected drain volume comprises the second infusion volume and a second estimated residual patient volume, wherein the second estimated residual patient volume is based at least in part on the difference between the expected drain volume and the measured volume of drained fluid; and
determining if the second measured volume of drained fluid is less than the second minimum drain volume.
10. The method of claim 1 , wherein the predetermined percentage is determined using a formula that comprises A=(B+C)/(D), wherein:
A comprises the predetermined percentage;
B comprises the infusion volume;
C comprises an expected per cycle ultrafiltration; and
D comprises a fill limit.
11. A dialysis system comprising:
an infusion system configured to infuse an infusion volume of dialysis solution into a patient;
a drainage system configured to drain fluid from the patient into a drain container;
a controller configured to:
identify an indicator that a drain may be complete;
determine a drain volume of the fluid in the drain container;
determine a minimum drain volume, wherein the minimum drain volume is a predetermined percentage of an expected drain volume, wherein the expected drain volume comprises the infusion volume and an estimated residual patient volume; and
determine if the drain volume is less than the minimum drain volume.
12. The dialysis system of claim 11 , wherein the controller is configured to post an alarm if the drain volume is less than the minimum drain volume.
13. The dialysis system of claim 11 , wherein the controller is configured to continue dialysis treatment if the drain volume is not less than the minimum drain volume.
14. The dialysis system of claim 13 , wherein the controller is configured to update the estimated residual patient volume to be the difference between the expected drain volume and the drain volume.
15. The dialysis system of claim 14 , wherein the controller is configured to perform a subsequent infusion stage and a subsequent drain stage, and to use the updated estimated residual patient volume to calculate an updated minimum drain volume for the subsequent drain stage.
16. The dialysis system of claim 13 , wherein the controller is configured to reduce a volume of a subsequent infusion stage if the drain volume is less than the expected drain volume.
17. The dialysis system of claim 16 , where in the controller is configured to:
add an additional infusion cycle to a treatment session schedule;
determine an amount of infusion fluid remaining to be infused during a dialysis treatment; and
determine an adjusted infusion volume by dividing the amount of infusion fluid remaining by the number of scheduled infusion cycles.
18. The dialysis system of claim 11 , wherein the expected drain volume further comprises an expected ultrafiltration volume.
19. The dialysis system of claim 11 , wherein:
the infusion system is configured to infuse a second infusion volume of dialysis solution into the patient;
the drainage system is configured to drain fluid from the patient into the drain container a second time; and
the controller is configured to:
determine a second drain volume of the fluid drained into the drain container a second time;
determine a second minimum drain volume larger than the minimum drain volume, wherein the second minimum drain volume is the predetermined percentage of a second expected drain volume, wherein the second expected drain volume comprises the second infusion volume and a second estimated residual patient volume, wherein the second estimated residual patient volume is based at least in part on the difference between the expected drain volume and the drain volume; and
determining if the second drain volume is less than the second minimum drain volume.
20. The dialysis system of claim 11 , wherein the predetermined percentage is determined using a formula that comprises A=(B+C)/(D), wherein:
A comprises the predetermined percentage;
B comprises the infusion volume;
C comprises an expected per cycle ultrafiltration; and
D comprises a fill limit.