System, method, and apparatus for utilizing a pumping cassette

Patent metadata

Field	Value
Publication number	US-9488167-B2
Application number	US-201414290482-A
Country	US
Kind code	B2
Filing date	May 29, 2014
Priority date	Jul 20, 1999
Publication date	Nov 8, 2016
Grant date	Nov 8, 2016

Abstract

The present invention involves, in some embodiments, systems and methods for performing an integrity test on a medical grade cassette that is configured to be used on a medical fluid handling system, wherein the cassette may be disposable and may comprise a membrane therein. The test may be configured to determine an error condition, such as detection of membrane leakage above a threshold value, and may in certain cases be implemented by a medical computer system. In certain cases the integrity test is a dry integrity test and in certain cases, the test is configured to determine a leakage rate of fluid through the membrane.

First claim

What is claimed is:

1. A method for performing a dry integrity test on a medical-grade cassette, the medical-grade cassette being a single-use disposable cassette that can removably mate with a reusable portion of a dialysis machine, the method comprising:
adjusting a pressure of a pressure tank in the reusable portion;
closing a valve in the reusable portion of the dialysis machine connecting the pressure tank to a membrane of a medical-grade disposable cassette;
measuring a first pressure of the pressure tank within the reusable portion;
opening the valve in the reusable portion;
measuring a second pressure of the pressure tank;
determining a difference between the first and second pressures; and
determining whether the membrane of the medical-grade disposable cassette is leaking above a threshold using the difference.

2. The method according to claim 1 , wherein the method is implemented by one or more processors within a medical apparatus.

3. The method according to claim 1 , wherein the cassette is loaded into a dialysis machine, wherein the dialysis machine performs the method.

4. The method according to claim 1 , wherein the act of determining whether the membrane is leaking above the threshold using the difference comprises the act of comparing the difference to a predetermine value to determine if the difference is greater than the predetermined value.

5. The method according to claim 1 , where the acts of opening the value and closing the valve each includes an act of actuating the valve.

6. The method according to claim 1 , further comprising an act of actuating the valve to transition from the open valve position to the closed valve position.

7. The method according to claim 1 , wherein the first pressure measurement is determined by taking a first set of a plurality of measurements of a pressure transducer.

8. The method according to claim 7 , wherein the first set of the plurality of measurements occur at predetermined intervals.

9. The method according to claim 7 , wherein the second pressure measurement is determined by taking a second set of a plurality of measurements of the pressure transducer.

10. The method according to claim 9 , wherein the second set of the plurality of measurements occur at the predetermined intervals.

11. The method according to claim 1 , wherein the first and second measurements are temporally different.

12. The method according to claim 1 , further comprising the act of continuously monitoring the pressure of the pressure tank.

13. The method according to claim 1 , wherein the determining acts are calculating acts performed by at least one processor.

14. The method according to claim 1 , further comprising the act of halting an operation of a dialysis machine when the difference is above the threshold.

15. The method according to claim 1 , wherein the membrane is determined to be leaking if the difference is above the threshold.

16. A method for performing a dry integrity test on a disposable cassette that is configured to be used on a medical fluid handling system, the method comprising:
receiving a pressure on a membrane of the cassette;
measuring a first pressure associated with the membrane;
allowing a predetermined amount of time to pass;
measuring a second pressure associated with the membrane;
determining a difference between the first and second pressures; and
determining whether the difference is above a predetermined threshold.

17. The method according to claim 16 , wherein the method further comprises determining the cassette has a leak if the difference is above the predetermined threshold.

18. The method according claim 16 , wherein the method is configured to have a greater difference as a leak in the membrane is larger.

19. A method for detecting a leakage rate of fluid through a medical grade membrane in a fluid flow control system having a first chamber and a second chamber, the membrane being disposed between the first chamber and the second chamber, the second chamber having a connection to a pressure tank, the pressure tank having a fluid with a pressure, the connection defining a fluid path, the method comprising:
blocking the fluid path;
adjusting the pressure of the fluid in the pressure tank;
measuring a first pressure in the pressure tank to generate a first pressure value while the fluid path is blocked and after the pressure in the pressure tank is adjusted;
unblocking the fluid path;
measuring a second pressure in the pressure tank to generate a second pressure value after the fluid path is unblocked; and
determining whether there is a leak in the membrane based on a difference between the first pressure and the second pressure.

20. A method for detecting a leakage rate of fluid through a medical membrane in a fluid flow control medical system having a first chamber and a second chamber, the membrane being disposed between the first chamber and the second chamber, the second chamber having a medical-grade connection to a pressure tank, the pressure tank having a fluid with a pressure, the connection defining a medical-grade fluid path, the method comprising:
blocking the fluid path;
adjusting the pressure of the fluid in the pressure tank;
measuring a first pressure in the pressure tank to generate a first pressure value while the fluid path is blocked and after the pressure in the pressure tank is adjusted;
unblocking the fluid path;
measuring a second pressure in the pressure tank to generate a second pressure value after the fluid path is unblocked; and
determining a leakage of fluid through the membrane based on the first and second pressure values.

21. The method according to claim 20 , further comprising the act of causing an alarm when the leakage becomes greater than a predetermined threshold value.

22. The method according to claim 21 , wherein the step of causing an alarm occurs in a processor.

23. The method according to claim 21 , wherein the alarm is an auditory alarm.

24. The method according to claim 21 , wherein the alarm is a visual alarm.

25. The method according to claim 20 , wherein in the act of measuring a pressure at a first set of multiple timed intervals and in the act of measuring a pressure at a second set of multiple timed intervals the pressure is measured with a transducer.

26. The method according to claim 20 , wherein in the act of calculating a blocked pressure rate and in the act of calculating an unblocked pressure rate the rates are calculated in a processor.

27. The method according to claim 20 , wherein the fluid is air.

28. The method according to claim 20 , further comprising the acts of:
measuring the pressure at a first set of multiple timed intervals; and
storing each of the pressure measurements in a memory unit; and
providing the pressure measurements in the memory unit to a processor.

29. The method according to claim 20 , further comprising the acts of:
measuring the pressure at a second set of multiple timed intervals;
storing each of the pressure measurements in a memory unit; and
providing the pressure measurements in the memory unit to a processor.

30. A method implemented by a medical computer system for detecting a leakage rate of fluid through a membrane in a fluid flow control system having a first chamber and a second chamber, the membrane disposed

Assignees

• Deka Products Lp

Inventors

• Gray Larry B
• Bryant Jr Robert J
• Spencer Geoffrey P

Classifications

• F04B49/12 Primary

  by varying the length of stroke of the working members · CPC title

• F04B43/02

  having plate-like flexible members, e.g. diaphragms (F04B43/14 takes precedence) · CPC title

• F04B45/06 Primary

  having tubular flexible members (F04B45/02, F04B45/08 take precedence) · CPC title

• G01M3/26

  by measuring rate of loss or gain of fluid, e.g. by pressure-responsive devices, by flow detectors · CPC title

• A61M2205/12

  with interchangeable cassettes forming partially or totally the fluid circuit · CPC title