VERIFICATION OF PRESSURE METRICS

• US 20120283580A1
• Filed: 05/03/2011
• Published: 11/08/2012
• Est. Priority Date: 05/03/2011
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Havel, William J., Bennett, Tommy D., Cho, Yong Kyun, Taepke, Robert T. II
• Granted Patent: US 8,827,913 B2
• Time in Patent Office: Days
• US Class Current: 600/485
• CPC Class Codes: A61B 5/0215 by means inserted into the body catheters A61M25/00
• CPC Class Codes: A61B 5/686 Permanently implanted devices, e.g. pacemakers, other stimulators, biochips A61B5/6861 takes precedence
• CPC Class Codes: A61B 5/7207 of noise induced by motion artifacts
• CPC Class Codes: A61B 5/7239 using differentiation including higher order derivatives
• CPC Class Codes: A61N 1/36564 controlled by blood pressure
• CPC Class Codes: A61N 1/3702 Physiological parameters A61N1/365 takes precedence; evoked response A61N1/371

Abstract

An example system may include at least one pressure sensor configured to measure a cardiovascular pressure signal and another medical device configured to measure an electrical depolarization signal of the heart. The system determines a plurality of cardiovascular pressure metrics based on the measured cardiovascular pressure signal, including at least one cardiovascular pressure metric indicative of a timing of at least one cardiac pulse. The system also determines a metric indicative of a timing of at least one heart depolarization within the measured electrical depolarization signal. The system compares the timing of the at least one cardiac pulse to the timing of the at least one depolarization, and determines whether to discard the plurality of cardiovascular pressure metrics based on whether the timings substantially agree.

Claims

1. A method comprising:

measuring, by a pressure sensor, a cardiovascular pressure signal;

determining a plurality of cardiovascular pressure metrics based on the measured cardiovascular pressure signal, wherein the plurality of cardiovascular metrics includes at least one cardiovascular pressure metric indicative of a timing of at least one cardiac pulse;

measuring, by a medical device that is coupled to the pressure sensor, an electrical depolarization signal of the heart;

determining a metric indicative of a timing of at least one heart depolarization based on the measured electrical depolarization signal;

comparing the timing of the at least one cardiac pulse to the timing of the at least one heart depolarization; and

determining whether to discard the plurality of cardiovascular pressure metrics based on whether the timings substantially agree.

2. The method of claim 1, wherein the metric indicative of a timing of at least one heart depolarization comprises a heart rate and the at least one cardiovascular pressure metric indicative of a timing of at least one cardiac pulse comprises a pulse rate.

3. The method of claim 1, wherein the pressure sensor is wirelessly coupled to the medical device.

4. The method of claim 1, further comprising:

transmitting the plurality of cardiovascular pressure metrics from the pressure sensor to the medical device.

5. The method of claim 1, further comprising:

transmitting the metric indicative of a timing of at least one heart depolarization from the medical device to the pressure sensor.

6. The method of claim 5, wherein the metric indicative of a timing of at least one heart depolarization is transmitted wirelessly.

7. The method of claim 1, further comprising:

re-measuring, by the pressure sensor, the cardiovascular pressure signal in response to discarding the plurality of cardiovascular pressure metrics;

determining plurality of cardiovascular pressure metrics based on the re-measured cardiovascular pressure signal, wherein the plurality of cardiovascular metrics includes the at least one cardiovascular pressure metric indicative of the timing of at least one cardiac pulse;

re-measuring, by the medical device that is coupled to the pressure sensor, the electrical depolarization signal of the heart;

determining the metric indicative of a timing of at least one heart depolarization based on the re-measured electrical depolarization signal;

comparing the timing of the at least one cardiac pulse to the timing of the at least one heart depolarization; and

determining whether to discard the plurality of cardiovascular pressure metrics based on whether the timings substantially agree.

8. The method of claim 7, further comprising:

determining a number of times that the cardiovascular pressure signal has been re-measured in response to discarding the plurality of cardiovascular pressure metrics;

comparing the number of times that the cardiovascular pressure signal has been re-measured to a predetermined threshold; and

determining whether to re-measure the cardiovascular pressure signal based on the comparison.

9. The method of claim 1, wherein, in addition to the cardiovascular pressure metric indicative of a timing of at least one cardiac pulse, the plurality of cardiovascular pressure metrics include at least one of a systolic pressure and a diastolic pressure.

10. The method of claim 1, wherein the medical device is an external monitoring device.

11. The method of claim 1, wherein the medical device is an implantable medical device.

12. The method of claim 11, wherein the medical device is implanted subcutaneously.

13. A system comprising:

at least one pressure sensor configured to measure a cardiovascular pressure signal;

an medical device configured to measure an electrical depolarization signal of the heart;

at least one analysis module configured to;

determine a plurality of cardiovascular pressure metrics based on the measured cardiovascular pressure signal, wherein the plurality of cardiovascular metrics includes at least one cardiovascular pressure metric indicative of a timing of at least one cardiac pulse; and

determine a metric indicative of a timing of at least one heart depolarization based on the measured electrical depolarization signal; and

at least one processor configured to;

compare the timing of the at least one cardiac pulse to the timing of the at least one heart depolarization; and

determine whether to discard the plurality of cardiovascular pressure metrics based on whether the timings substantially agree.

14. The system of claim 13, wherein the metric indicative of a timing of at least one heart depolarization comprises a heart rate and the at least one cardiovascular pressure metric indicative of a timing of at least one cardiac pulse comprises a pulse rate.

15. The system of claim 13, wherein the at least one pressure sensor is a wirelessly coupled to the medical device.

16. The system of claim 15, wherein the pressure sensor is configured to wirelessly transmit the plurality of cardiovascular metrics to the medical device.

17. The system of claim 13, wherein the processor is configured to control the pressure sensor to re-measure the cardiovascular pressure signal if the plurality of cardiovascular pressure metrics is discarded.

18. The system of claim 17, wherein the processor is configured to:

determine a number of times that the cardiovascular pressure signal has been re-measured in response to discarding the plurality of cardiovascular pressure metrics;

compare the number of times that the cardiovascular pressure signal has been re-measured to a predetermined threshold; and

determine whether to control the pressure sensor to re-measure the cardiovascular pressure signal based on the comparison.

19. The system of claim 13, wherein, in addition to the cardiovascular pressure metric indicative of a timing of at least one cardiac pulse, the plurality of cardiovascular pressure metrics include at least one of a systolic pressure and a diastolic pressure.

20. The system of claim 13, wherein the medical device comprises the processor.

21. The system of claim 13, wherein the medical device is configured for subcutaneous implantation within a patient.

22. A system comprising:

means for measuring a cardiovascular pressure signal;

means for measuring an electrical depolarization signal of the heart;

means for determining a plurality of cardiovascular pressure metrics based on the measured cardiovascular pressure signal, wherein the plurality of cardiovascular metrics includes at least one cardiovascular pressure metric indicative of a timing of at least one cardiac pulse;

means for determining a metric indicative of a timing of at least one heart depolarization within the measured electrical depolarization signal;

means for comparing the timing of the at least one cardiac pulse to the timing of the at least one depolarization signal; and

means for determining whether to discard the plurality of cardiovascular pressure metrics based on whether the timings substantially agree.

23. The system of claim 22, wherein the metric indicative of a timing of at least one heart depolarization comprises a heart rate and the at least one cardiovascular pressure metric indicative of a timing of at least one cardiac pulse comprises a pulse rate.

24. A method comprising:

measuring, by a first pressure sensor, a first cardiovascular pressure signal;

determining a plurality of first cardiovascular pressure metrics based on the measured first cardiovascular pressure signal, wherein the plurality of first cardiovascular metrics includes at least one first cardiovascular pressure metric indicative of a timing of at least one cardiac pulse;

measuring, by a second pressure sensor that is coupled to the first pressure sensor, a second cardiovascular pressure signal;

determining at least one second cardiovascular pressure metric based on the measured second cardiovascular pressure signal, wherein the at least one second cardiovascular pressure metric is indicative of a timing of at least one cardiac pulse;

comparing the timing of the at least one cardiac pulse indicated by the first cardiovascular pressure metric to the timing of the at least one cardiac pulse indicated by the second cardiovascular pressure metric; and

determining whether to discard the plurality of first cardiovascular pressure metrics based on whether the timings substantially agree.

25. The method of claim 24, wherein the first pressure sensor is located outside of the heart and the second pressure sensor is located within the heart.

26. A system comprising:

a first pressure sensor configured to measure a first cardiovascular pressure signal;

a second pressure sensor configured to measure a second cardiovascular pressure signal, wherein the first and second pressure sensors communicate with each other; and

one or more analysis modules implemented in one or more of the first and second pressure sensors configured to;

determine a plurality of first cardiovascular pressure metrics based on the measured first cardiovascular pressure signal, wherein the plurality of first cardiovascular metrics includes at least one first cardiovascular pressure metric indicative of a timing of at least one cardiac pulse;

determine at least one second cardiovascular pressure metric based on the measured second cardiovascular pressure signal, wherein the at least one second cardiovascular pressure metric is indicative of a timing of at least one cardiac pulse;

compare the timing of the at least one cardiac pulse indicated by the first cardiovascular pressure metric to the timing of the at least one cardiac pulse indicated by the second cardiovascular pressure metric; and

determine whether to discard the plurality of first cardiovascular pressure metrics based on whether the timings substantially agree.

27. A method comprising:

measuring, by a medical device that is coupled to a pressure sensor, an electrical depolarization signal of the heart;

detecting asystole based on the electrical depolarization signal of the heart; and

in response to the detection of asystole, directing the pressure sensor to measure a cardiovascular pressure signal.

28. A system comprising:

a pressure sensor; and

a medical device configured to;

measure an electrical depolarization signal of the heart;

detect asystole based on the electrical depolarization signal of the heart; and

in response to the detection of asystole, directing the pressure sensor to measure a cardiovascular pressure signal.