Method and device for monitoring the supply of substitution fluid during an extracorporeal blood treatment

• US 20050065459A1
• Filed: 11/22/2002
• Published: 03/24/2005
• Est. Priority Date: 12/05/2001
• Status: Active Grant

• Current Assignee: Fresenius Medical Care Deutschland GmbH (Fresenius Medical Care AG)
• Original Assignee: Fresenius Medical Care Deutschland GmbH (Fresenius Medical Care AG)
• Inventors: Zhang, Wei, Wamsiedler, Ralf
• Granted Patent: US 7,850,856 B2
• Time in Patent Office: Days
• US Class Current: 604/4.10
• CPC Class Codes: A61M 1/342 Adding solutions to the blood, e.g. substitution solutions for preventing coagulation A61M1/3672
• CPC Class Codes: A61M 1/3434 with pre-dilution and post-dilution
• CPC Class Codes: A61M 1/3437 downstream of the filter, e.g. post-dilution with filtrate
• CPC Class Codes: A61M 1/3465 using dialysate as substitution fluid
• CPC Class Codes: A61M 1/3639 Blood pressure control, pressure transducers specially adapted therefor
• CPC Class Codes: A61M 1/3656 Monitoring patency or flow at connection sites; Detecting disconnections
• CPC Class Codes: A61M 5/16859 Evaluation of pressure response, e.g. to an applied pulse
• CPC Class Codes: Y10S 210/929 Hemoultrafiltrate volume measurement or control processes

Abstract

The invention relates to a method for monitoring the supply of substitution liquid during an extracorporeal blood treatment and to an extracorporeal blood treatment unit equipped with a device for monitoring the supply of substitution liquid. The monitoring of the supply of substitution liquid is based on the measurement of pressure waves, which are generated by the substitution liquid pump, in the extracorporeal blood circulation system. A disturbance in the supply of substitution liquid is inferred when the amplitude of the pressure waves exceeds a predetermined limit value. The amplitude of the pressure waves is preferably monitored in the venous blood line.

Claims

1-16. -16. (canceled).

17. A method for monitoring the supply of a substitution fluid during an extracorporeal blood treatment with an extracorporeal blood circuit, wherein the extracorporeal blood circuit includes a first chamber of a dialyser or a filter, wherein the dialyser or the filter is subdivided by a semipermeable membrane into the first chamber and a second chamber, and with a fluid system which includes the second chamber of the dialyser or the filter, the method comprising:

feeding the substitution fluid from the fluid system to the extracorporeal blood circuit upstream or downstream of the dialyser or the filter by operation of a substituate pump which generates pressure waves; and

monitoring the amplitude of the pressure waves in the fluid system or in the extracorporeal blood circuit generated by the substituate pump, wherein a malfunction of the supply of the substitution fluid is indicated by the amplitude of the pressure waves exceeding a preset limiting value.

18. The method according to claim 17, wherein the substitution fluid is fed downstream of the dialyser or the filter, and the amplitude of the pressure waves is monitored in the extracorporeal blood circuit.

19. The method according to claim 17, wherein the substitution fluid is fed upstream of the dialyser or the filter, and the amplitude of the pressure waves is monitored in the fluid system.

20. The method according to claim 17, further comprising:

monitoring a pumping rate of the substituate pump, wherein a malfunction of the supply of the substitution fluid is indicated by the amplitude of the pressure waves exceeding a preset limiting value only if the pumping rate lies between a second preset limiting value and a third preset limiting value.

21. The method according to claim 17, further comprising:

measuring a pressure signal in the extracorporeal blood circuit; and

filtering the pressure signal with a bandpass, wherein the amplitude of the filtered pressure signal is compared with the preset limiting value.

22. The method according to claim 17, further comprising:

emitting at least one of an acoustic alarm and an optical alarm when the preset limiting value is exceeded.

23. The method according to claim 17, wherein the substituate pump is a roller pump.

24. The method according to claim 17, wherein the monitoring of the supply of the substitution fluid occurs continuously during the extracorporeal blood treatment.

25. The method according to claim 17, wherein the monitoring of the supply of the substitution fluid takes place continuously during the operation of the substituate pump.

26. An apparatus for extracorporeal blood treatment comprising:

an extracorporeal blood circuit including a first chamber of a dialyser or a filter, wherein the dialyser or the filter is subdivided by a semipermeable membrane into the first chamber and a second chamber;

a fluid system including the second chamber of the dialyser or the filter;

a substitution fluid line leading from the fluid system to the extracorporeal blood circuit upstream or downstream of the dialyser or the filter, wherein a substituate pump generating pressure waves is arranged in the substitution fluid line; and

a monitoring device for monitoring a supply of substitution fluid from the fluid system into the extracorporeal blood circuit, wherein the monitoring device includes means for monitoring the amplitude of the pressure waves in the fluid system or in the extracorporeal blood circuit generated by the substituate pump, and means for evaluating the amplitude of the pressure waves, wherein the monitoring device is designed such that a malfunction of the supply of substitution fluid is indicated by the amplitude of the pressure waves exceeding a preset limiting value.

27. The apparatus according to claim 26, wherein the means for monitoring the amplitude of the pressure waves generated by the substituate pump are arranged in the extracorporeal blood circuit downstream of the dialyser or the filter.

28. The apparatus according to claim 26, wherein the means for monitoring the amplitude of the pressure waves generated by the substituate pump are arranged in the-fluid system upstream of the dialyser or the filter.

29. The apparatus according to claim 26, further comprising:

means for monitoring a pumping rate of the substituate pump, wherein a malfunction of the supply of the substitution fluid is indicated by the amplitude of the pressure waves exceeding a preset limiting value only if the pumping rate lies between a second preset limiting value and a third preset limiting value.

30. The apparatus according to claim 27, further comprising:

means for monitoring a pumping rate of the substituate pump, wherein a malfunction of the supply of the substitution fluid is indicated by the amplitude of the pressure waves exceeding a preset limiting value only if the pumping rate lies between a second preset limiting value and a third preset limiting value.

31. The apparatus according to claim 28, further comprising:

means for monitoring a pumping rate of the substituate pump, wherein a malfunction of the supply of the substitution fluid is indicated by the amplitude of the pressure waves exceeding a preset limiting value only if the pumping rate lies between a second preset limiting value and a third preset limiting value.

32. The apparatus according to claim 26, wherein the means for monitoring the amplitude of the pressure waves generated by the substituate pump include a pressure sensor for measuring a pressure in the extracorporeal blood circuit downstream of the dialyser or the filter, a pressure signal sensor for generating a pressure signal dependent on the measured pressure, and a bandpass filter for filtering the pressure signal.

33. The apparatus according to claim 27, wherein the means for monitoring the amplitude of the pressure waves generated by the substituate pump include a pressure sensor for measuring a pressure in the extracorporeal blood circuit downstream of the dialyser or the filter, a pressure signal sensor for generating a pressure signal dependent on the measured pressure, and a bandpass filter for filtering the pressure signal.

34. The apparatus according to claim 28, wherein the means for monitoring the amplitude of the pressure waves generated by the substituate pump include a pressure sensor for measuring a pressure in the extracorporeal blood circuit downstream of the dialyser or the filter, a pressure signal sensor for generating a pressure signal dependent on the measured pressure, and a bandpass filter for filtering the pressure signal.

35. The apparatus according to claim 26, further comprising:

an alarm unit for generating at least one of an acoustic alarm and an optical alarm when the preset limiting value is exceeded.

36. The apparatus according to claim 26, wherein the substituate pump is a roller pump.