Cardiac Motion Characterization by Strain Measurement

• US 20080255629A1
• Filed: 10/31/2005
• Published: 10/16/2008
• Est. Priority Date: 11/01/2004
• Status: Active Grant

• Current Assignee: Proteus Digital Health, Inc. (Otsuka Holdings Company Limited)
• Original Assignee: Proteus Biomedical, Inc. (Otsuka Holdings Company Limited)
• Inventors: Zdeblick, Mark J., Thompson, Todd, Colliou, Olivier, Arne, Lawrence W., Savage, George M., White, Robert, Frank, Jeremy, Jenson, Marc
• Granted Patent: US 8,121,687 B2
• Time in Patent Office: Days
• US Class Current: 607/19
• CPC Class Codes: A61B 2562/0266 Optical strain gauges
• CPC Class Codes: A61B 5/1107 Measuring contraction of parts of the body, e.g. organ, muscle apparatus for measuring work or force in general G01L
• CPC Class Codes: A61B 5/6851 Guide wires
• CPC Class Codes: A61B 5/6857 with a distal pigtail shape
• CPC Class Codes: A61B 5/6858 with a distal basket, e.g. expandable basket
• CPC Class Codes: A61B 5/686 Permanently implanted devices, e.g. pacemakers, other stimulators, biochips A61B5/6861 takes precedence
• CPC Class Codes: A61N 1/056 Transvascular endocardial electrode systems
• CPC Class Codes: A61N 1/3627 for treating a mechanical deficiency of the heart, e.g. congestive heart failure or cardiomyopathy

Abstract

Methods for evaluating motion of a cardiac tissue location, e.g., heart wall, are provided. In the subject methods, timing of a signal obtain from a strain gauge stably associated with the tissue location of interest is employed to evaluate movement of the cardiac tissue location. Also provided are systems, devices and related compositions for practicing the subject methods. The subject methods and devices find use in a variety of different applications, including cardiac resynchronization therapy.

Claims

1. A method for evaluating movement of a cardiac tissue location in a subject, said method comprising:

(a) determining timing of a signal obtained from a strain gauge stably associated with said cardiac location; and

(b) using said determined timing to evaluate movement of said cardiac tissue location.

2. The method according to claim 1, wherein said method comprises using timing of signals produced by two or more strain gauges each stably associated with a different cardiac tissue location.

3. The method according to claim 2, wherein said strain gauge is present on a lead.

4. The method according to claim 3, wherein said lead comprises two or more strain gauges positioned at different locations at a distal end of said lead.

5. The method according to claim 1, wherein said strain gauge comprises a single strain transducer.

6. The method according to claim 1, wherein said strain gauge comprises multiple strain transducers.

7. The method according to claim 1, wherein said strain gauge comprises at least one strain transducer present on a substrate.

8. The method according to claim 7, wherein said substrate is compliant.

9. The method according to claim 1, wherein said strain gauge does not include a substrate.

10. The method according to claim 1, wherein said strain gauge comprises a transducer that is hermetically sealed.

11. The method according to claim 1, wherein said strain gauge comprises a transducer that is not hermetically sealed.

12. The method according to claim 1, wherein said strain gauge comprises a transducer in which strain induces an electrical signal.

13. The method according to claim 7, wherein said transducer is a fabricated from a resistive material.

14. The method according to claim 13, wherein said resistive material is platinum.

15. The method according to claim 7, wherein said strain transducer is fabricated from a piezoelectric material.

16. The method according to claim 1, wherein said strain gauge comprises a resonant marker band structure.

17. The method according to claim 3, wherein said strain gauge is coupled to a signal conductive element present in said lead.

18. The method according to claim 17, wherein said signal conductive element is an electrically conductive element.

19. The method according to claim 17, wherein said signal conductive element is an optically conductive element.

20. The method according to claim 3, wherein said lead comprises a tissue securing element for stably associating said strain gauge with said cardiac tissue location.

21. The method according to claim 3, wherein said lead is configured so that said strain gauge is stably associated with said cardiac location by a compressive force.

22. The method according to claim 1, wherein said strain gauge is present on an acute device.

23. The method according to claim 1, wherein said strain gauge is present on a permanently implantable device.

24. The method according to claim 1, wherein said method comprises further obtaining a second motion timing signal from a second cardiac location.

25. The method according to claim 24, wherein said second motion timing signal is obtained using a magnetic induction sensing element.

26. The method according to claim 25, wherein said second cardiac location is a septal wall location.

27. The method according to claim 26, wherein said cardiac location is a heart wall location.

28. The method according to claim 27, wherein said heart wall is a chamber wall.

29. The method according to claim 28, wherein said chamber wall is a ventricular wall.

30. The method according to claim 28, wherein said chamber wall is a septal wall.

31. The method according to claim 1, wherein said method is a method of determining timing of cardiac wall motion.

32. The method according to claim 31, wherein said method is a method of determining cardiac wall motion of a first cardiac wall relative to a second cardiac wall.

33. The method according to claim 32, wherein said method is a method of determining timing of cardiac wall motion of a first cardiac wall relative to a second cardiac wall.

34. The method according to claim 33, wherein said method is a method of detecting ventricular mechanical dyssynchrony.

35. The method according to claim 34, wherein said ventricular mechanical dyssynchrony is interventricular.

36. The method according to claim 34, wherein said ventricular mechanical dyssynchrony is intraventricular.

37. The method according to claim 34, wherein said method further comprises performing cardiac resynchronization therapy based on said detected dyssynchrony.

39. A computer readable storage medium having a processing program stored thereon, wherein said processing program operates a processor to operate a system according to claim 38 to perform a method according to claim 1.

40. A processor comprising a computer readable medium according to claim 39.

41. A kit comprising:

a computer readable storage medium according to claim 39.

42. The kit according to claim 41, wherein said computer readable storage medium is present in a processor according to claim 40.

43. The kit according to claim 41, wherein said processor is present in a cardiac pacing device.

38. A system for evaluating movement of a cardiac tissue location, said system comprising:

(a) a strain gauge stably associated with said cardiac tissue location; and

(b) a signal processing element configured to employ timing of a signal obtained from said strain gauge that is induced by movement of said cardiac tissue location to evaluate movement of said tissue location.

44. A device for evaluating movement of a cardiac location, said device comprising:

(a) a strain gauge stably associated with said cardiac tissue location; and

(b) a signal processing element configured to employ timing of a signal obtained from said strain gauge that is induced by movement of said cardiac tissue location to evaluate movement of said tissue location.

45. The device according to claim 44, wherein said device further comprises a cardiac electrical stimulation element.

46. The device according to claim 45, wherein said device is a cardiac resynchronization therapy device.