Detection of apex motion for monitoring cardiac dysfunction

• US 20070032749A1
• Filed: 03/30/2006
• Published: 02/08/2007
• Est. Priority Date: 01/31/2003
• Status: Active Grant

• Current Assignee: Board of Trustees of the Leland Stanford Junior University (Stanford University)
• Original Assignee: Board of Trustees of the Leland Stanford Junior University (Stanford University)
• Inventors: Francis, Daniel, Angel, Aimee, Mead, R., Overall, William
• Granted Patent: US 7,445,605 B2
• Time in Patent Office: Days
• US Class Current: 600/595
• CPC Class Codes: A61B 2562/0219 Inertial sensors, e.g. accelerometers, gyroscopes, tilt switches
• CPC Class Codes: A61B 2562/028 Microscale sensors, e.g. electromechanical sensors [MEMS]
• CPC Class Codes: A61B 5/02444 Details of sensor A61B5/02427 takes precedence

Abstract

Systems, devices and methods for detecting and monitoring cardiac dysfunction. The devices include motion sensors for detecting signals representative of the total movement of the heart, and of the apex of the heart in particular.

Claims

1. A system for monitoring cardiac function in a human patient, the system comprising:

at least one motion sensor adapted for positioning at the heart and for sensing total movement of the apex of the heart; and

a motion analysis element in operable communication with the at least one motion sensor, the motion analysis element adapted for receiving signals representative of the overall movement of the heart from the at least one motion sensor and for processing the received signals, wherein the signals are related to at least one predetermined baseline value of the movement of the heart.

2. The system according to claim 1, wherein the sensor is adapted for sensing the direction of motion of the apex.

3. The system according to claim 2, wherein the sensor is adapted to sense the motion of the apex in the perpendicular to the long axis of a heart ventricle.

4. The system according to claim 1, wherein the motion sensor is configured to sense motion within at least one directional axis.

5. The system according to claim 4, wherein the motion sensor is configured to sense motion in two or more directional axes.

6. The system according to claim 4, wherein the motion sensor is configured to sense motion in only one directional axis.

7. The system according to claim 6, wherein the directional axis is the anterior-posterior direction relative to the heart.

8. The system according to claim 1, wherein the motion sensor is an accelerometer.

9. The system according to claim 8, wherein the accelerometer comprises a MEMS.

10. The system according to claim 1, wherein the signals from the motion sensor are multiplexed.

11. The system according to claim 1, wherein the system comprises a single motion sensor.

12. The system according to claim 1, further comprising a reference sensor adapted for implantation in a location distinct from the at least one motion sensor.

13. The system according to claim 1, wherein at least one of the motion sensors is adapted for implantation at the apex of the heart and the sensed motion is apical motion.

14. The system according to claim 13, wherein the motion sensor is adapted for implantation endocardially at the right-ventricular apex, the epicardial apex, or an apical cardiac vein.

15. The system according to claim 1, wherein the processed signals are further analyzed to provide information related to intracardiac pressure.

16. The system according to claim 1, wherein the processed signals are representative of an ischemic condition of the heart.

17. The system according to claim 16, wherein the ischemic condition of the heart is a location of an ischemic area, a location of an occluded coronary artery or the degree of the ischemic condition.

18. The system according to claim 1, wherein the operable connection between the at least one motion sensor and the motion analysis element comprises an electrical lead.

19. The system according to claim 1, wherein the motion analysis element is substantially integrated with another device adapted for implantation in a patient.

20. The system according to claim 19, wherein the other implanted device is a pacemaker, a defibrillator, a cardioverter, a ventricular assist device, an infusion pump, an event monitor, an annuloplasty ring, an atrial appendage occlusion device or a catheter.

21. The system according to claim 1, wherein the motion analysis element is further configured to transmit an alarm signal when the processed signal is determined to be outside a predetermined threshold range.

22. The system according to claim 1, wherein the motion analysis element is further configured to provide therapeutic treatment to the heart when the processed signal is determined to be outside a predetermined threshold range.

23. The system according to claim 22, wherein the therapeutic treatment comprises the delivery of pacing signals.

24. The system according to claim 22, wherein the therapeutic treatment comprises the delivery of an agent.

25. The system of claim 1, further comprising electrocardiogram means.

26. The system of claim 1, wherein the at least one motion sensor is configured to filter out frequencies above about 10 Hz.

27. The system of claim 1, wherein the predetermined baseline value is the normal movement of the apex.

28. A method for monitoring cardiac function in a patient, the method comprising:

sensing the motion of the apex of the heart with at least one motion sensor implanted at the heart;

processing signals generated by the at least one motion sensor; and

producing an output as a result of the processing.

29. The method according to claim 28, wherein the output comprises an indication of an ischemic condition of the heart.

30. The method according to claim 29, wherein the ischemic condition of the heart is a location of an ischemic area, a location of an occluded coronary artery or the degree of the ischemic condition.

31. The method according to claim 28, wherein the processing comprises relating the signals to at least one predetermined baseline value of the movement of the apex of the heart.

32. The method according to claim 30, wherein the predetermined baseline value is the normal movement of the apex.

33. The method according to claim 28, wherein the sensing comprises sensing apical motion within at least one directional axis.

34. The method according to claim 28, wherein the sensing comprises sensing apical motion within two or more directional axes.

35. The method according to claim 28, wherein the motion sensor is configured to sense motion in only one directional axis.

36. The method according to claim 35, wherein the directional axis is the anterior-posterior direction relative to the heart.

37. The method according to claim 38, wherein the sensing is performed with a single motion sensor.

38. The method according to claim 28, wherein the processing comprises interpreting the processed signals as representative of an ischemic condition of the heart.

39. The method according to claim 37, wherein the ischemic condition of the heart is a location of an ischemic area, a location of an occluded coronary artery or the degree of the ischemic condition.

40. The method according to claim 28,:

wherein the output is a cardiac pacing signal.

41. The method according to claim 28, wherein the output is the delivery a therapeutic agent to the heart.

42. The method according to claim 28, wherein the output is an alarm signal when a processed signal is determined to be outside a predetermined threshold range.

43. The method according to claim 28, further comprising performing an electrocardiogram of the heart with another sensor.

44. A method according to claim 28, wherein the at least one sensor is implanted endocardially.

45. A method according to claim 28, wherein the at least one sensor is implanted epicardially.

46. A method according to claim 28, wherein the processing comprises filtering out signals having frequencies above about 10 Hz.