Cardiac rhythm management systems and methods using acoustic contractility indicator

• US 20030216620A1
• Filed: 05/15/2002
• Published: 11/20/2003
• Est. Priority Date: 05/15/2002
• Status: Active Grant

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Meyer, Scott A., Jain, Mudit, Higgins, Steven L.
• Granted Patent: US 7,228,175 B2
• Time in Patent Office: Days
• US Class Current: 600/300
• CPC Class Codes: A61N 1/36528 the parameter being measured by means of ultrasound

Abstract

This document describes systems, devices, and methods that measure a distance between ultrasound or other acoustic transducers to provide a contractility or other therapy efficacy indication. In one example, the indication is communicated to a caregiver for assisting in the caregiver'"'"'s determination of particular therapy settings. In another example, the indication is used in a feedback controller to automatically adjust one or more therapy parameters based at least in part on the indication.

Claims

1. A system comprising:

first and second acoustic transducer interfaces, the first acoustic transducer interface configured to be coupled to a first acoustic transducer located in or about a heart, the second acoustic transducer interface configured to be coupled to a second acoustic transducer; and

a controller circuit, coupled to the first and second acoustic transducer interfaces to measure a distance, between the first and second acoustic transducers, that varies during a heart contraction, the controller configured to provide an indication based on a variation of the distance during at least one heart contraction.

2. The system of claim 1, further comprising the first and second acoustic transducers.

3. The system of claim 2, in which the first transducer is disposed on a first intracardiac lead.

4. The system of claim 3, in which the second transducer is disposed on a second intracardiac lead.

5. The system of claim 4, in which the first and second intracardiac leads are the same intracardiac lead.

6. The system of claim 4, in which the first and second intracardiac leads are different intracardiac leads.

7. The system of claim 4, in which one of the first and second intracardiac leads is sized and shaped to be introduced into a coronary sinus of the heart.

8. The system of claim 7, in which the other of the first and second intracardiac leads is sized and shaped to be introduced into a right ventricle of the heart.

9. The system of claim 2, in which the first and second transducers are ultrasound transducers.

10. The system of claim 1, in which the controller is configured to measure the distance using a transit time of a signal between the first and second acoustic transducers.

11. The system of claim 1, in which the controller is configured to measure the variation of the distance during the at least one heart contraction with respect to a reference distance.

12. The system of claim 11, in which the controller is configured to measure the reference distance using triangulation.

13. The system of claim 1, further comprising:

a therapy circuit to deliver therapy to the heart; and

a memory location, coupled to the controller, to store at least one parameter to control operation of the therapy circuit, the at least one parameter based at least in part on the variation of the distance during at least one heart contraction.

14. The system of claim 13, further comprising a feedback circuit, coupled to the controller and the memory location, to store a value of the at least one parameter based at least in part on the variation of the distance during the at least one heart contraction.

15. The system of claim 1, further comprising an implantable device, comprising the first and second acoustic transducer interfaces and the controller, the implantable device comprising a first communication circuit configured for communicating to a remote external interface the indication based on the variation of the distance during at least one heart contraction.

16. The system of claim 15, further comprising the remote external interface comprising a second communication circuit to communicate with the implantable device for receiving the indication based on the variation of the distance during at least one heart contraction.

17. The system of claim 15, in which the remote external interface includes the second communication circuit to further communicate with the implantable device to store in the memory location the value of the at least one parameter that is based at least in part on the variation of the distance during the at least one heart contraction.

18. The system of claim 1, further comprising an implantable device, comprising the first and second acoustic transducer interfaces and the controller, the implantable device comprising a power interface to receive power from an external power source to compensate for power consumed by at least one of the first and second transducer interfaces.

19. A system comprising:

first and second acoustic transducer interfaces, the first acoustic transducer interface configured to be coupled to a first acoustic transducer located in or about a heart, the second acoustic transducer interface configured to be coupled to a second acoustic transducer;

means for measuring a distance, between the first and second acoustic transducers, that varies during a heart contraction; and

means for providing a contractility indication based on a variation of the distance during at least one heart contraction.

20. The system of claim 19, further comprising the first and second acoustic transducers.

21. The system of claim 19, further comprising:

a therapy circuit to deliver therapy to the heart; and

a memory location, coupled to a controller, to store at least one parameter to control operation of the therapy circuit, the at least one parameter based at least in part on the variation of the distance during at least one heart contraction.

22. The system of claim 19, further comprising an implantable device, comprising the first and second acoustic transducer interfaces, the means for measuring the distance, and the means for providing the contractility indication, the implantable device further comprising a first communication circuit configured for communicating to a remote external interface the indication based on the variation of the distance during at least one heart contraction.

23. The system of claim 22, further comprising a remote external interface comprising a second communication circuit to communicate with the implantable device for receiving the indication based on the variation of the distance during at least one heart contraction.

24. A system comprising:

an elongate first catheter, comprising a distal portion sized and shaped to be intravascularly introduced into a right ventricle of a heart, the distal portion of the first catheter comprising an ultrasonic first transducer;

an elongate second catheter, comprising a distal portion sized and shaped to be intravascularly introduced into a coronary sinus of the heart, the distal portion of the second catheter comprising an ultrasonic second transducer; and

an implantable cardiac rhythm management device, comprising;

first and second acoustic transducer interfaces, configured to be respectively coupled to the first and second transducers; and

a controller circuit, coupled to the first and second acoustic transducer interfaces to measure a distance, between the first and second acoustic transducers, that varies during a heart contraction, the controller configured to provide an indication based on a variation of the distance during at least one heart contraction.

25. The system of claim 24, in which the implantable device further includes:

a therapy circuit to deliver therapy to the heart; and

a memory location, coupled to the controller, to store at least one parameter to control operation of the therapy circuit, the at least one parameter based at least in part on the variation of the distance during at least one heart contraction.

26. The system of claim 25, in which the implantable device further includes a first communication circuit configured for communicating to a remote external interface the indication based on the variation of the distance during at least one heart contraction.

27. The system of claim 26, further comprising a remote external interface comprising a second communication circuit to communicate with the implantable device for receiving the indication based on the variation of the distance during at least one heart contraction.

28. A system comprising:

a hermetically-sealed implantable cardiac rhythm management device housing comprising;

first and second acoustic transducer interfaces, the first acoustic transducer interface configured to be coupled to a first acoustic transducer located in or about a heart, the second acoustic transducer interface configured to be coupled to a second acoustic transducer;

a controller circuit, coupled to the first and second acoustic transducer interfaces to measure a distance, between the first and second acoustic transducers, that varies during a heart contraction, the controller configured to provide an indication based on a variation of the distance during at least one heart contraction;

a therapy circuit to deliver therapy to the heart; and

a memory location, coupled to the controller, to store at least one parameter to control operation of the therapy circuit, the at least one parameter based at least in part on the variation of the distance during at least one heart contraction.

29. The system of claim 28, in which the memory location includes a parameter to select at least one particular electrode for delivering therapy.

30. The system of claim 28, in which the memory location includes a parameter to determine a delay between at least one pair of electrodes in delivering stimuli associated with a single ventricular heart contraction.

31. The system of claim 28, further comprising an elongate first catheter, comprising a distal portion sized and shaped to be intravascularly introduced into a heart, the distal portion of the first catheter comprising an ultrasonic first transducer.

32. The system of claim 31, further comprising an elongate second catheter, comprising a distal portion sized and shaped to be intravascularly introduced into the heart, the distal portion of the second catheter comprising an ultrasonic second transducer.

33. A method comprising:

transmitting, at a first location, an acoustic signal through a portion of a pump;

receiving, at a second location, the acoustic signal;

determining a change in a distance between the first and second locations during at least one pump contraction; and

providing a contractility indication that is based at least in part on a degree of the change in the distance between the first and second locations during the at least one pump contraction.

34. The method of claim 33, further comprising communicating the contractility indication from within a body to a remote interface external to the body.

35. The method of claim 34, further comprising receiving from the external interface a pump control parameter that is based at least in part on the contractility indication.

36. The method of claim 34, further comprising displaying the contractility indication.

37. The method of claim 33, further comprising adjusting a pump control parameter based at least in part on the contractility indication.

38. The method of claim 33, in which the determining the change in the distance includes:

determining a reference distance using triangulation; and

determining the change in the distance, between the first and second locations during at least one pump contraction, with respect to the reference distance.

39. The method of claim 33, in which the determining the change in the distance includes using a transit time of the acoustic signal to determine a distance between transmitting and receiving acoustic transducers.

40. The method of claim 33, further comprising wirelessly receiving power from a remote power source to compensate for at least a portion of power used in the transmitting and receiving acoustic signals.

41. A method comprising:

transceiving an ultrasound signal between a first location in a right ventricle and a second location in a coronary sinus;

determining a distance between the first and second locations based on a transit time of the ultrasound signal;

determining a change in the distance between the first and second locations during at least one pump contraction; and

providing a contractility indication that is based at least in part on a degree of the change in the distance between the first and second locations during the at least one pump contraction.

42. The method of claim 41, further comprising adjusting a therapy parameter based at least in part on the contractility indication.

43. The method of claim 42, further comprising providing therapy based on the adjusted therapy parameter.