Method and device for detecting a fault condition

Patent metadata

Field	Value
Publication number	US-9612182-B2
Application number	US-201013519248-A
Country	US
Kind code	B2
Filing date	Dec 22, 2010
Priority date	Dec 28, 2009
Publication date	Apr 4, 2017
Grant date	Apr 4, 2017

Abstract

A device and method for detecting fault conditions in a fluid connection system between a first fluid containing system including a first pulse generator (e.g., an extracorporeal blood circuit) and a second fluid containing system including a second pulse generator (e.g., a human or animal vascular system). A pressure sensor detects first pulses from the first pulse generator and second pulses from the second pulse generator. A time-dependent monitoring signal based on data obtained from said pressure sensor is generated and processed to calculate a parameter value indicative of the shape of at least part of a first pulse in the monitoring signal. The parameter value is evaluated to detect the fault condition. The fault condition may involve disconnection of an access device; reversed connection of access devices; occlusion of the fluid path through an access device; or infiltration in tissue surrounding an access point in the vascular system.

First claim

The invention claimed is:

1. A method for detecting and responding to a fault condition in a pumping device included in an extracorporeal blood treatment system, said method comprising:
obtaining measurement data by detecting pulses in the extracorporeal blood treatment system using at least one pressure sensor arranged in the extracorporeal blood treatment system, wherein the pulses comprises first pulses originating from the pumping device of the extracorporeal blood treatment system and second pulses originating from a physiological pumping device in a subject connected to the extracorporeal blood treatment system;
generating a time-dependent monitoring signal based on the measurement data obtained from the at least one pressure sensor, wherein the monitoring signal comprises one or more of the first pulses and none of the second pulses;
processing the monitoring signal to calculate a parameter value which is indicative of the shape of at least part of a first pulse in the monitoring signal;
evaluating the parameter value for detection of a fault condition in the pumping device; and
activate an alarm and/or stop the pumping device if a fault condition is detected.

2. The method of claim 1 , wherein generating the monitoring signal comprises filtering the measurement data for removal of the second pulses.

3. The method of claim 2 , wherein the filtering comprises:
obtaining a second pulse profile which is a predicted temporal signal profile of at least one second pulse, and
filtering the measurement data in the time-domain, using the second pulse profile, to essentially eliminate the second pulses while retaining the first pulses.

4. The method of claim 1 , wherein generating the monitoring signal comprises operating the extracorporeal blood treatment system such that the second pulses are prevented from reaching said at least one pressure sensor.

5. The method of claim 1 , wherein the fault condition comprises a loss of occlusion of a tube by rollers in the pumping device.

6. The method of claim 1 , wherein the pumping device comprises a peristaltic pump and each first pulse is generated while a rotating roller of the peristaltic pump engages a tubing segment to displace blood through the extracorporeal blood treatment system.

7. The method of claim 6 , wherein the parameter value is calculated as a dispersion measure based on signal values in the measurement data obtained from the at least one pressure sensor in the monitoring signal.

8. The method of claim 6 , wherein the parameter value is calculated to represent the symmetry between consecutive first pulses in the monitoring signal.

9. The method of claim 6 , wherein the parameter value is calculated by extracting shape-indicative data from the monitoring signal and comparing the shape-indicative data to reference data.

10. The method of claim 9 , wherein the shape-indicative data comprises signal values in the monitoring signal, and the reference data comprises a temporal reference profile.

11. The method of claim 9 , wherein the shape-indicative data is extracted by an analysis of the frequency content of the monitoring signal, and wherein the reference data is indicative of an amplitude spectrum.

12. The method of claim 9 , further comprising obtaining a current value of one or more system parameters of the extracorporeal blood treatment system, and obtaining the reference data as a function of the current value.

13. The method of claim 12 , wherein obtaining the reference data comprises: identifying, based on the current value, one or more reference profiles in a reference database; and obtaining the reference data based on the one or more reference profiles.

14. The method of claim 12 , wherein the one or more system parameters is indicative of the rate of first pulses in the extracorporeal blood treatment system.

15. A non-transitory computer-readable medium containing computer instructions stored therein for causing a processor to detect a fault condition in a pumping device included in an extracorporeal blood treatment system, the processor detecting and responding to the fault condition by:
generating a time-dependent monitoring signal based on measurement data obtained from said at least one pressure sensor arranged in an extracorporeal blood treatment system configured for connection to a vascular system of a subject, wherein the at least one pressure sensor detects first pulses originating from the pumping device of the extracorporeal blood treatment system pumping blood from the vascular system through a blood treatment device and back to the vascular system, wherein the at least one pressure sensor also detects second pulses originating from a physiological pulse generator in the subject, wherein the monitoring signal comprises one or more first pulses and no second pulses;
processing the monitoring signal to calculate a parameter value which is indicative of the shape of at least part of a first pulse in the monitoring signal;
evaluating the parameter value for detection of a fault condition in the pumping device; and
activating an alarm and/or stopping the pumping device if a fault condition is detected.

16. A device for detecting and responding to a fault condition in a pumping device included in an extracorporeal blood treatment system, wherein the extracorporeal blood treatment system is configured for connection to a vascular system of a subject such that the pumping device pumps blood from the vascular system through a blood treatment device back to the vascular system, and wherein at least one pressure sensor is arranged in the extracorporeal blood treatment system and configured to detect first pulses originating from the pumping device-and second pulses originating from a physiological pulse generator in the subject, said device comprising:
means for generating a time-dependent monitoring signal based on measurement data obtained from said at least one pressure sensor, wherein the monitoring signal comprises one or more first pulses and no second pulses;
means for processing the monitoring signal to calculate a parameter value which is indicative of the shape of at least part of a first pulse in the monitoring signal;
means for evaluating the parameter value for detection of a fault condition in the pumping device; and
means for activating an alarm and/or stopping the pumping device if a fault condition is detected.

17. A device for detecting and responding to a fault condition in a pumping device included in an extracorporeal blood treatment system, wherein the extracorporeal blood treatment system is configured for connection to a vascular system of a subject such that the pumping device pumps blood from the vascular system through a blood treatment device back to the vascular system, and wherein at least one pressure sensor is arranged in the extracorporeal blood treatment system and configured to detect first pulses originating from the pumping device and second pulses originating from a physiological pulse generator in the subject, said device comprising:
an input configured to obtain measurement data from said at least one pressure sensor, and
a signal processor connected to said input and being configured to:
generate a time-dependent monitoring signal based on measurement data obtained from said at least one pressure sensor, wherein the monitoring signal comprises one or more first pulses and no second pulses,
process the monitoring signal to calculate a parameter value which is indicative of the shape of at least part of a first pulse in the monitoring signal, and
evaluate the

Assignees

• Olde Bo
• Solem Kristian
• Gambro Lundia Ab

Inventors

• Olde Bo
• Solem Kristian

Classifications

• A61M2230/04

  Heartbeat characteristics, e.g. ECG, blood pressure modulation · CPC title

• A61M2205/13

  with means for the detection of operative contact with patient, e.g. lip sensor · CPC title

• A61M5/16859

  Evaluation of pressure response, e.g. to an applied pulse · CPC title

• A61M2205/15

  Detection of leaks · CPC title

• A61M1/3656

  Monitoring patency or flow at connection sites; Detecting disconnections · CPC title