METHOD FOR DETECTING THE DISCONNECTION OF AN EXTRACORPOREAL DEVICE USING A PATIENT'S ENDOGENOUS ELECTRICAL VOLTAGES

• US 20070000847A1
• Filed: 06/08/2006
• Published: 01/04/2007
• Est. Priority Date: 06/16/2005
• Status: Active Grant

• Current Assignee: Edward Ross, Rosalind Sadleir
• Original Assignee: Edward Ross, Rosalind Sadleir
• Inventors: Sadleir, Rosalind, Ross, Edward
• Granted Patent: US 7,530,962 B2
• Time in Patent Office: Days
• US Class Current: 210/781
• CPC Class Codes: A61M 1/3621 Extra-corporeal blood circuits single-needle circuits A61M1/30
• CPC Class Codes: A61M 1/3656 Monitoring patency or flow at connection sites; Detecting disconnections
• CPC Class Codes: A61M 1/3669 Electrical impedance measurement of body fluids; transducers specially adapted therefor
• CPC Class Codes: A61M 2205/13 with means for the detection of operative contact with patient, e.g. lip sensor

Abstract

The present invention describes a system, apparatus, and method for detection of disconnection of a device from a patient, such as dislodgment of a device during medical treatments or therapies, using a patient'"'"'s electrical voltages.

Claims

1. A method of detecting the disconnection of an extracorporeal device, wherein blood from proximate vascular access points of a patient travels through an extracorporeal blood path comprising an arterial line in fluid communication with a first vascular access point, a blood treatment device, and a venous line in fluid communication with a second vascular access point, comprising:

(a) obtaining a value based on endogenous electrical signals of a patient along the extracorporeal blood path; and

(b) comparing the obtained value to a predetermined threshold value; and

(c) triggering a safety response when the obtained value substantially meets or exceeds the threshold value, thereby indicating disconnection.

2. The method of claim 1 wherein the value is obtained by measuring the difference between endogenous voltages at two points along the blood path.

3. The method of claim 1 wherein the value is obtained by measuring impedance between two points along the blood path.

4. The method of claim 1, wherein sensors are placed remote from the patient to obtain the value, such that a first sensor is in communication with blood in the arterial line and a second sensor is in communication with blood in the venous line.

5. The method of claim 1, wherein sensors are placed to obtain the value, such that a first sensor is in communication with an arterial access needle and a second sensor is in communication with a venous access needle.

6. The method of claim 1, wherein sensors are placed to obtain the value, such that a first sensor is in communication with an arterial drip chamber and a second sensor is in communication with a venous injection port to obtain the value.

7. The method of claim 1, wherein sensors are placed to obtain the value, such that a first sensor is in communication with an arterial drip chamber and a second sensor is in communication with a venous drip chamber to obtain the value.

8. The method of claim 1 wherein the blood path comprises tubing that is electrically conductive at the point of attachment of one or more sensors placed to obtain the value.

9. The method of claim 1 wherein the blood path comprises tubing that is electrically conductive along part of its length.

10. The method of claim 1 wherein the blood path comprises tubing that is electrically conductive along its entire length.

11. The method of claim 1 wherein the blood path comprises tubing having an electrically conductive element along its entire length.

13. The method of claim 1 further comprising indicating a safe connection when the obtained value does not exceed the threshold value.

14. The method of claim 1, wherein the safety response comprises an alarm selected from the group consisting of visual and audible alarms.

15. The method of claim 1, wherein the safety response comprises closing a cutoff clamp in the venous line.

16. The method of claim 1, wherein the safety response comprises interrupting the provision of blood to the extracorporeal blood path.

17. The method of claim 1, wherein the safety response comprises stopping a blood pump provided in the arterial line.

18. The method of claim 1 wherein the step of obtaining a value based on endogenous electrical signals of a patient along the extracorporeal blood path comprises obtaining the value when the tubing in the blood path is periodically occluded during blood pump operation.

12. The method of claim I further comprising a separate conductive element connected between the vascular access and a remote sensor used to obtain the value.

19. A method of detecting the disconnection of an extracorporeal blood treatment device, wherein blood of a patient travels through an extracorporeal blood path comprising an arterial line in fluid communication with a first vascular access, a blood treatment device, and a venous line in fluid communication with a second remote vascular access, comprising:

(a) obtaining cardiac signals of a patient along the extracorporeal blood path;

(b) triggering a safety response when the cardiac signal is lost, thereby indicating disconnection.

20. A device for detecting the disconnection of an extracorporeal device, wherein blood from proximate vascular access points of a patient travels through an extracorporeal blood path comprising an arterial line in fluid communication with a first vascular access point, a blood treatment device, and a venous line in fluid communication with a second vascular access point, comprising:

(a) circuitry for obtaining a value based on endogenous electrical signals of a patient along the extracorporeal blood path, and comparing the obtained value to a predetermined threshold value; and

(b) one or more safety response devices triggered when the obtained value substantially meets or exceeds the threshold value, thereby indicating disconnection.

21. A system for detecting the disconnection of an extracorporeal device, wherein blood from proximate vascular access points of a patient travels through an extracorporeal blood path comprising an arterial line in fluid communication with a first vascular access point, a blood treatment device, and a venous line in fluid communication with a second vascular access point, comprising:

(a) means for obtaining a value based on endogenous electrical signals of a patient along the extracorporeal blood path; and

(b) means for comparing the obtained value to a predetermined threshold value; and

(c) means for triggering a safety response when the obtained value substantially meets or exceeds the threshold value, thereby indicating disconnection.

22. A blood tubing set for use between an extracorporeal device and a patient comprising tubing having electrically conductive properties.

23. The blood tubing set of claim 22 comprising an arterial set component comprising arterial tubing having electrical conductive properties;

and a venous set component comprising venous tubing having electrical conductive properties.

24. The blood tubing set of claim 22 wherein the tubing is co-extruded with a biocompatible conductive substance.

25. The blood tubing set of claim 22 wherein the tubing comprises a conductive metallic wire intergrated with the tubing to provide electrically conductive properties.