Apparatus and Method for Detecting Cardiac Events

• US 20100030034A1
• Filed: 07/31/2008
• Published: 02/04/2010
• Est. Priority Date: 07/31/2008
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Day, John K., Huynh, Tho V., Cope, William, Lee, Brian Bruce, York, Jeffrey O., Haskin, Scott Wayne, Kallmyer, Todd A., Schulhauser, Randal C.
• Granted Patent: US 9,545,215 B2
• Time in Patent Office: Days
• US Class Current: 600/301
• CPC Class Codes: A61B 5/0205 Simultaneously evaluating both cardiovascular conditions and different types of body conditions, e.g. heart and respiratory condition
• CPC Class Codes: A61B 5/02055 Simultaneously evaluating both cardiovascular condition and temperature
• CPC Class Codes: A61B 5/021 Measuring pressure in heart or blood vessels A61B5/0205 takes precedence
• CPC Class Codes: A61B 5/024 Detecting, measuring or recording pulse rate or heart rate A61B5/0205, A61B5/021 take precedence
• CPC Class Codes: A61B 5/0816 Measuring devices for examining respiratory frequency measuring frequency of electric signals G01R23/00
• CPC Class Codes: A61B 5/11 Measuring movement of the entire body or parts thereof, e.g. head or hand tremor, mobility of a limb for measuring pulse A61B5/02 ;A61B5/1038 takes precedence; motion detection to correct for motion artifacts in physiological signals A61B5/721
• CPC Class Codes: A61B 5/14539 for measuring pH
• CPC Class Codes: A61B 5/349 Detecting specific parameters of the electrocardiograph cycle
• CPC Class Codes: A61B 5/4839 combined with drug delivery
• CPC Class Codes: A61B 7/00 Instruments for auscultation
• CPC Class Codes: A61N 1/37 Monitoring; Protecting

Abstract

A method and system which includes a minimally invasive, implantable device with a sensor configured for collecting electrical data associated with cardiac performance, a sensor configured for collecting mechanical data associated with cardiac performance, a sensor for collecting optical data associated with cardiac performance, a sensor for collecting biochemical data associated with cardiac performance, and a processor for deriving cardiac conditions and actuating an alarm upon identifying a cardiac event.

Claims

1. A method for monitoring of cardiac conditions incorporating an implantable medical device in a subject, the method comprising the steps of:

collecting physiological data associated with the subject from the implantable device, wherein the collected data includes real-time electrocardiac signal data, heart sound data, activity level data and tissue perfusion data;

comparing the electrocardiac signal data with a threshold electrocardiac criteria for indicating a strong likelihood of a cardiac event;

triggering an alarm state if the electrocardiac signal data is not within the threshold electrocardiac criteria;

determining the current activity level of the subject from the activity level data if the electrocardiac signal data is within the threshold electrocardiac criteria;

comparing the tissue perfusion data with a threshold tissue perfusion criteria for indicating a strong likelihood of a cardiac event if the current activity level is below a threshold activity level;

triggering an alarm state if the threshold tissue perfusion data is not within the threshold tissue perfusion criteria; and

triggering an alarm state if the threshold tissue perfusion data is within the threshold tissue perfusion criteria and the heart sound data indicates that S3 and S4 heart sounds are detected,

wherein if an alarm state is not triggered, the physiological data associated with the subject is collected at the expiration of a preset period of time.

2. The method according to claim 1, wherein the threshold electrocardiac criteria relates to ST segment deviation from preset values.

3. The method according to claim 1, wherein the current activity level is measured as a state relating to at least one of physical exertion and body posture.

4. The method according to claim 1, wherein the step of tissue perfusion data comparing includes comparing the tissue perfusion data with a threshold tissue perfusion criteria for indicating a strong likelihood of a cardiac event if the current activity level indicates the subject is engaged in a minimal amount of activity.

5. The method according to claim 1, wherein the threshold tissue perfusion criteria relates to an acceptable level of oxygenation in adjacent body tissue.

6. The method according to claim 5, wherein the acceptable level of oxygenation is determined based on the color of the adjacent body tissue.

7. The method according to claim 1, further comprising the steps of:

collecting biomarker data relating to biochemical indicators of a cardiac event; and

triggering an alarm state if the biochemical indicators are detected.

8. The method according to claim 1, further comprising the steps of:

collecting respiration data relating to the subject'"'"'s respiration;

comparing the respiration data with a threshold respiration criteria for indicating a strong likelihood of a cardiac event if the current activity level is below a threshold activity level; and

triggering an alarm state if either the threshold tissue perfusion data is not within the threshold tissue perfusion criteria or the respiration data is not within the threshold respiration criteria.

9. The method according to claim 1, further comprising the steps of

collecting systolic pressure data;

and

triggering an alarm state if the activity level is below a threshold activity level, the threshold tissue perfusion data is within the threshold tissue perfusion criteria, the heart sound data does not indicate that S3 and S4 heart sounds are detected and the systolic pressure data indicates a systolic pressure change greater than a threshold criteria for systolic pressure.

10. The method of claim 1, wherein one or more threshold values are changed based on the determined activity level of the subject.

11. A system for monitoring of cardiac conditions incorporating an implantable medical device in a subject, comprising:

means for collecting physiological data associated with the subject from the implantable device, wherein the collected data includes real-time electrocardiac signal data, heart sound data, activity level data and tissue perfusion data;

means for comparing the electrocardiac signal data with a threshold electrocardiac criteria for indicating a strong likelihood of a cardiac event,

means for triggering an alarm state if the electrocardiac signal data is not within the threshold electrocardiac criteria;

means for determining the current activity level of the subject from the activity level data if the electrocardiac signal data is within the threshold electrocardiac criteria;

means for comparing the tissue perfusion data with a threshold tissue perfusion criteria for indicating a strong likelihood of a cardiac event if the current activity level is below a threshold activity level;

means for triggering an alarm state if the threshold tissue perfusion data is not within the threshold tissue perfusion criteria; and

means for triggering an alarm state if the threshold tissue perfusion data is within the threshold tissue perfusion criteria and the heart sound data indicates that S3 and S4 heart sounds are detected,

wherein if an alarm state is not triggered, means for collecting the physiological data associated with the subject is at the expiration of a preset period of time.

12. An implantable system for the monitoring of cardiac conditions in a subject, comprising

a support housing;

a sensor disposed in the support housing and configured for collecting electrical data associated with cardiac performance;

a sensor disposed in the support housing and configured for collecting mechanical data associated with cardiac performance;

a sensor disposed in the support housing and configured for collecting optical data associated with cardiac performance;

a sensor disposed in the support housing and configured for collecting biochemical data associated with cardiac performance; and

a processor disposed in the support housing, the processor being in communication with the sensors and configured for collecting and processing sensor data to assess cardiac conditions and actuate an alarm upon identifying a cardiac event.

13. An implantable device as recited in claim 12, wherein the sensor disposed in the support housing and configured for collecting electrical data associated with cardiac performance further comprises a sensor for monitoring electrocardiac signals.

14. An implantable device as recited in claim 12, wherein the sensor disposed in the support housing and configured for collecting mechanical data associated with cardiac performance further comprises a sensor configured for monitoring sounds made by the heart functioning.

15. An implantable device as recited in claim 12, wherein the sensor disposed in the support housing and configured for collecting optical data associated with cardiac performance further comprises a sensor configured for detecting tissue perfusion.

16. An implantable device as recited in claim 12, wherein the sensor disposed in the support housing and configured for collecting biochemical data associated with cardiac performance further comprises a sensor configured to detect the presence of a cardiac enzyme.

17. An implantable device as recited in claim 12, wherein the sensor disposed in the support housing and configured for collecting mechanical data associated with cardiac performance further comprises a sensor for detecting systolic pressure.

18. An implantable device as recited in claim 12, further comprising a sensor disposed in the support housing and configured for collecting activity level data associated with the level of activity engaged in by the subject.

19. An implantable device as recited in claim 18, wherein the sensor disposed in the support housing and configured for collecting activity level data associated with the level of activity engaged in by the subject further comprises an accelerometer for measuring the activity of the subject and a sensor configured for measuring the rate of respiration of the subject.