Heart Monitoring Systems, Apparatus and Methods Adapted to Detect Myocardial Ischemia

• US 20080228094A1
• Filed: 03/12/2007
• Published: 09/18/2008
• Est. Priority Date: 03/12/2007
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Combs, William J., Carney, James K., Audet, Sarah A.
• Granted Patent: US 9,179,852 B2
• Time in Patent Office: Days
• US Class Current: 600/513
• CPC Class Codes: A61B 5/0006 ECG or EEG signals
• CPC Class Codes: A61B 5/0031 Implanted circuitry
• CPC Class Codes: A61B 5/318 Heart-related electrical modalities, e.g. electrocardiography [ECG]
• CPC Class Codes: A61B 5/349 Detecting specific parameters of the electrocardiograph cycle
• CPC Class Codes: A61B 5/721 using a separate sensor to detect motion or using motion information derived from signals other than the physiological signal to be measured
• CPC Class Codes: A61B 5/7475 User input or interface means, e.g. keyboard, pointing device, joystick

Abstract

Embodiments include heart monitoring systems, apparatus, and methods adapted to detect myocardial ischemia. An apparatus includes at least one first-tier sensor/analyzer adapted to sense a first input related to cardiac function, and to produce a first-tier trigger signal when the first input indicates myocardial ischemia. In an embodiment, a first-tier sensor/analyzer includes an ECG sensor/analyzer. In another embodiment, a first-tier sensor/analyzer includes a patient activator. An apparatus further includes at least one second-tier sensor/analyzer adapted to sense a second input related to cardiac function, and to produce a second-tier trigger signal when the second input indicates myocardial ischemia. In an embodiment, a second-tier sensor-analyzer includes a heart sound sensor/analyzer. A triggering element is adapted to produce a response-invoking signal in response to the first-tier trigger signal and the second-tier trigger signal. The response-invoking signal may invoke a patient alert, a message to an external system, and/or a cardiac stimulus.

Claims

1. A heart monitoring apparatus adapted to detect myocardial ischemia, the apparatus comprising:

at least one first-tier sensor/analyzer adapted to sense a first input related to cardiac function, and to produce a first-tier trigger signal when the first input indicates myocardial ischemia; and

at least one second-tier sensor/analyzer adapted to sense a second input related to cardiac function, and to produce a second-tier trigger signal when the second input indicates myocardial ischemia; and

a triggering element adapted to produce a response-invoking signal in response to the first-tier trigger signal and the second-tier trigger signal.

2. The heart monitoring apparatus of claim 1, further comprising:

a patient alert element adapted to produce an alert in response to the response-invoking signal.

3. The heart monitoring apparatus of claim 1, further comprising:

an external system notification element adapted to send a message to an external system in response to the response-invoking signal.

4. The heart monitoring apparatus of claim 1, further comprising:

a cardiac stimulus element adapted to produce a stimulus to heart tissue in response to the response-invoking signal.

5. The heart monitoring apparatus of claim 1, wherein the at least one first-tier sensor/analyzer includes an electrocardiogram (ECG) sensor/analyzer.

6. The heart monitoring apparatus of claim 1, wherein the at least one first-tier sensor/analyzer includes at least one patient activator with which a patient may indicate a presence of a symptom.

7. The heart monitoring apparatus of claim 1, wherein the at least one first-tier sensor/analyzer includes a heart sound sensor/analyzer.

8. The heart monitoring apparatus of claim 1, further comprising:

a second-tier initiation control element adapted to activate inactivated ones of the at least one second-tier sensor/analyzer when the first-tier trigger signal is produced.

9. The heart monitoring apparatus of claim 1, further comprising:

a control element adapted to adjust at least one threshold for at least one first-tier sensor/analyzer.

10. The heart monitoring apparatus of claim 1, further comprising:

a control element adapted to adjust at least one threshold for at least one second-tier sensor/analyzer when the first-tier trigger signal is produced.

11. The heart monitoring apparatus of claim 1, wherein the at least one first-tier sensor/analyzer includes a plurality of sensors/analyzers selected from a group of sensors/analyzers that includes an ECG sensor/analyzer, a heart sound sensor/analyzer, a vibration sensor/analyzer, a pressure sensor/analyzer, a change in pressure with time (dp/dt) sensor/analyzer, a magnetic sensor/analyzer, a hall sensor/analyzer, a biomarker level sensor/analyzer, an oxygen level sensor/analyzer, a carbon dioxide level sensor/analyzer, a glucose sensor/analyzer, a pH sensor/analyzer, a temperature sensor/analyzer, a heart rate sensor/analyzer, a heart rate variability sensor/analyzer, a heart wall motion sensor/analyzer, an impedance sensor/analyzer, an optical sensor/analyzer, a respiration sensor/analyzer, and a patient activator.

12. The heart monitoring apparatus of claim 1, wherein the at least one second-tier sensor/analyzer includes a heart sound sensor/analyzer.

13. The heart monitoring apparatus of claim 1, wherein the at least one second-tier sensor/analyzer includes a plurality of sensors/analyzers selected from a group of sensors/analyzers that includes an ECG sensor/analyzer, a heart sound sensor/analyzer, a vibration sensor/analyzer, a pressure sensor/analyzer, a change in pressure with time (dp/dt) sensor/analyzer, a magnetic sensor/analyzer, a hall sensor/analyzer, a biomarker level sensor/analyzer, an oxygen level sensor/analyzer, a carbon dioxide level sensor/analyzer, a glucose sensor/analyzer, a pH sensor/analyzer, a temperature sensor/analyzer, a heart rate sensor/analyzer, a heart rate variability sensor/analyzer, a heart wall motion sensor/analyzer, an impedance sensor/analyzer, an optical sensor/analyzer, a respiration sensor/analyzer, and a patient activator.

14. A heart monitoring apparatus adapted to detect myocardial ischemia, the apparatus comprising:

an electrocardiogram (ECG) sensor/analyzer adapted to sense bioelectrical activity, to produce a current ECG waveform, and to produce an ECG trigger signal when at least a portion of the current ECG waveform indicates myocardial ischemia;

a heart sound sensor/analyzer adapted to sense heart sounds, to produce a current heart sound waveform, and to produce a heart sound trigger signal when at least a portion of the current heart sound waveform indicates myocardial ischemia; and

a triggering element adapted to produce a response-invoking signal in response to the ECG trigger signal and the heart sound trigger signal.

15. The heart monitoring apparatus of claim 14, wherein the ECG sensor/analyzer is adapted to produce the ECG trigger signal when a difference between an ST segment of the current ECG waveform and an ST segment of a baseline ECG waveform meets or exceeds a threshold value.

16. The heart monitoring apparatus of claim 14, wherein the ECG sensor/analyzer is adapted to produce the ECG trigger signal when an ST segment of the current ECG waveform exceeds a threshold value.

17. The heart monitoring apparatus of claim 14, wherein the heart sound sensor/analyzer is adapted to produce the heart sound trigger signal when a difference between a portion of the current heart sound waveform corresponding to a fourth heart sound and a portion of a baseline heart sound waveform corresponding to the fourth heart sound meets or exceeds a threshold value.

18. The heart monitoring apparatus of claim 14, wherein the heart sound sensor/analyzer is adapted to produce the heart sound trigger signal when a difference between a portion of the current heart sound waveform corresponding to a third heart sound and a portion of a baseline heart sound waveform corresponding to the third heart sound meets or exceeds a threshold value.

19. The heart monitoring apparatus of claim 14, wherein the heart sound sensor/analyzer is adapted to produce the heart sound trigger signal when a portion of the heart sound waveform that corresponds to a fourth heart sound exceeds a threshold value.

20. The heart monitoring apparatus of claim 14, wherein the heart sound sensor/analyzer is adapted to produce the heart sound trigger signal when a portion of the heart sound waveform that corresponds to a third heart sound exceeds a threshold value.

21. The heart monitoring apparatus of claim 14, further comprising an initiation control element adapted to activate the heart sound sensor/analyzer in response to the ECG trigger signal.

22. The heart monitoring apparatus of claim 14, further comprising:

a patient alert element adapted to produce an alert in response to the response-invoking signal.

23. The heart monitoring apparatus of claim 14, further comprising:

an external system notification element adapted to send a message to an external system in response to the response-invoking signal.

24. The heart monitoring apparatus of claim 14, further comprising:

a cardiac stimulus element adapted to produce a stimulus to heart tissue in response to the response-invoking signal.

25. The heart monitoring apparatus of claim 14, further comprising at least one additional sensor/analyzer selected from a group of sensors/analyzers that includes an ECG sensor/analyzer, a heart sound sensor/analyzer, a vibration sensor/analyzer, a pressure sensor/analyzer, a change in pressure with time (dp/dt) sensor/analyzer, a magnetic sensor/analyzer, a hall sensor/analyzer, a biomarker level sensor/analyzer, an oxygen level sensor/analyzer, a carbon dioxide level sensor/analyzer, a glucose sensor/analyzer, a pH sensor/analyzer, a temperature sensor/analyzer, a heart rate sensor/analyzer, a heart rate variability sensor/analyzer, a heart wall motion sensor/analyzer, an impedance sensor/analyzer, an optical sensor/analyzer, a respiration sensor/analyzer, and a patient activator.

26. A method for heart monitoring adapted to detect myocardial ischemia, the method comprising the steps of:

sensing at least one first input related to cardiac function;

sensing at least one second input related to cardiac function when at least one first input indicates myocardial ischemia; and

producing a patient alert when the at least one second input also indicates the myocardial ischemia.

27. The method of claim 26, wherein sensing the at least one first input comprises the steps of:

sensing bioelectrical activity of a heart;

producing a current ECG waveform; and

producing an ECG trigger signal when at least a portion of the current ECG waveform indicates the myocardial ischemia.

28. The method of claim 26, wherein sensing the at least one first input comprises the steps of:

sensing heart sounds;

producing a current heart sound waveform; and

producing a heart sound trigger signal when at least a portion of the current heart sound waveform indicates the myocardial ischemia.

29. The method of claim 26, further comprising the steps of:

the patient feeling symptoms that are associated with cardiac ischemia; and

the patient activating a patient activator in response to the symptoms.

30. The method of claim 26, wherein sensing the at least one second input comprises the steps of:

sensing bioelectrical activity of a heart;

producing a current ECG waveform; and

producing an ECG trigger signal when at least a portion of the current ECG waveform indicates the myocardial ischemia.

31. The method of claim 26, wherein sensing the at least one second input comprises the steps of:

sensing heart sounds;

producing a current heart sound waveform; and

producing a heart sound trigger signal when at least a portion of the current heart sound waveform indicates the myocardial ischemia.

32. The method of claim 26, further comprising the step of:

establishing baseline information for the at least one first input.

33. The method of claim 32, further comprising the step of:

determining that the at least one first input indicates the myocardial ischemia when a difference between the at least one first input and the baseline information exceeds a threshold.

34. The method of claim 26, further comprising the step of:

determining that the at least one first input indicates the myocardial ischemia when a portion of the at least one first input exceeds a threshold.

35. The method of claim 26, further comprising the step of:

adjusting at least one threshold used to determine whether the at least one second input indicates the myocardial ischemia.

36. The method of claim 26, further comprising the step of:

sending a message to an external notification system when the at least one second input also indicates the myocardial ischemia.

37. The method of claim 26, further comprising the step of:

initiating cardiac stimulus when the at least one second input also indicates the myocardial ischemia.