Time domain reflectometer-integrity testing system and method for medical device electrode

• US 5,233,986 A
• Filed: 11/04/1992
• Issued: 08/10/1993
• Est. Priority Date: 04/10/1992
• Status: Expired due to Fees

• Current Assignee: Random Technologies LLC
• Original Assignee: Random Technologies LLC
• Inventors: Robson, Jack R.
• Primary Examiner(s): Kamm, William E.
• Application Number:
  US07/971,415
• Time in Patent Office: 279 Days
• Field of Search: 128/419.046
• US Class Current: 607/28
• CPC Class Codes: A61N 1/3706 Pacemaker parameters stimulation threshold A61N1/371
• CPC Class Codes: G01R 31/11 using pulse reflection methods

Abstract

A device and method for testing the integrity of an electrode/wire, such as a pacemaker electrode, and electrical wires connected thereto has a receptacle for an electrode and includes a time domain reflectometer comprising an output signal mechanism operatively connected to the electrode receptacle. The method of analyzing the integrity of an electrode comprises the steps of generating a time domain reflectometer (TDR) reading (output signal) from the electrode, and transmitting the signal to an output device. The output signal may be analyzed to determined whether it varies by a predetermined threshold, or it may be displayed so that differences in the electrical characteristics of the electrode may be identified. The present invention allows a cardiologist or technician to ensure that the electrode is properly engaged and to determine the integrity of the electrode.

Claims

1. An electrical medical device comprising:

means for receiving a first electrode,

means for transmitting a first electrical signal to the electrode receiving means,

time domain reflectometer means operatively connected to the electrode receiving means such that at a time domain reflectometer pulse may be transmitted to the electrode receiving means, the time domain reflectometer means comprising output signal means, and

anti-coincidence means preventing a time domain reflectometer pulse from being transmitted to the electrode receiving means when a first electrical signal is being transmitted to the electrode receiving means.

2. The device of claim 1 wherein the device comprises a pacemaker.

3. The device of claim 1 wherein the device comprises a defibrillator.

4. The device of claim 1 wherein the output signal of the means comprises a TDR reading from the time domain reflectometer.

5. The device of claim 1, wherein the output signal means comprises means for graphically displaying a TDR output signal.

6. The device of claim 1, further comprising:

means for storing a reference TDR signal representative of a TDR signal from a working electrode connected to the electrode receiving means,

means for comparing a TDR output signal to a stored reference TDR signal,

means for indicating whether the TDR output signal varies from the stored reference TDR signal by a predefined threshold.

7. The device of claim 6 wherein the means for indicating comprises a graphical display of an electrode.

8. The device of claim 7 further comprising means for graphically displaying the relative point on the graphically displayed electrode where the TDR output signals varies from the stored reference TDR signal by the predefined threshold.

9. The device of claim 1, further comprising means for receiving at least one additional electrode, the time domain reflectometer means being operatively connected to the at least one additional electrode receiving means such that at a time domain reflectometer pulse may be transmitted to the at least one additional electrode receiving means.

10. The device of claim 9, further comprising at least one ECG reading electrode connected to at least one of the electrode receiving means.

11. The device of claim 9, further comprising means for automatically causing a TDR reading to be taken on each electrode receiving means.

12. A method of analyzing the integrity of a first medical electrode for transmitting an electrical signal, comprising the steps of:

providing means for transmitting an electrical signal on the first electrode, the transmitting means being capable of being selectively enabled and disabled,

providing a time domain reflectometer (TDR) operatively connected to the first electrode,

disabling the transmission of electrical signals on the first electrode,

generating a first TDR reading from the first electrode and outputting the TDR reading,

reenabling the transmission of electrical signals on the first electrode.

13. The method of claim 12 wherein the means for transmitting comprises a means for transmitting pacemaker pulses.

14. The method of claim 12 wherein the means for transmitting comprises a means for transmitting a defibrillator pulse.

15. The method of claim 12 wherein the means for transmitting comprises a means for transmitting an ECG reading signal.

16. The method of claim 12, wherein the disabling of the transmission of electrical signals on the first electrode occurs based on the timing of heartbeats of a patient to whom the electrode is connected.

17. The method of claim 12, further comprising the steps of:

storing a reference TDR signal representative of a TDR signal from a working electrode connected to the electrode receiving means,

comparing the outputted TDR signal to the stored reference TDR signal, and

indicating whether the outputted TDR signal varies from the stored reference TDR signal by a predefined threshold.

18. The method of claim 17 wherein the indicating step includes graphically displaying an electrode.

19. The method of claim 17 wherein the indicating step further includes, if the outputted TDR signal varies from the stored reference TDR signal by a predefined threshold, graphically displaying the relative point on the graphically displayed electrode where the TDR output signals varies from the stored reference TDR signal by the predefined threshold.

20. The method of claim 12, further comprising the steps of:

providing at least one second medical electrode, and providing means for operatively connecting the TDR to the at least one second medical electrode such that a time domain reflectometer pulse may be transmitted thereto, and

providing means for selecting which of the electrodes the TDR may be operatively connected to.

21. The method of claim 20, wherein the means for selecting comprises automatic means for automatically causing a TDR reading to be taken on each medical electrode.

22. The method of claim 12, further comprising the step of graphically displaying the outputted TDR reading.

23. The method of claim 12, further comprising the steps of:

selecting a portion of the generated TDR reading, and

graphically displaying the selected portion of the TDR reading.