Physiologic stimulator tuning apparatus and method

• US 20040243192A1
• Filed: 06/02/2003
• Published: 12/02/2004
• Est. Priority Date: 06/02/2003
• Status: Abandoned Application

• Current Assignee: Cardiodynamics International Corporation (Fujifilm Holdings Corporation)
• Original Assignee: Cardiodynamics International Corporation (Fujifilm Holdings Corporation)
• Inventors: Hepp, Dennis G., Baura, Gail D., Malecha, Jeremy R.
• Application Number:
  US10/453,820
• Publication Number:
  US 20040243192A1
• Time in Patent Office: Days
• US Class Current: 607/17
• CPC Class Codes: A61N 1/36585 controlled by two or more physical parameters
• CPC Class Codes: A61N 1/37211 Means for communicating with stimulators
• CPC Class Codes: A61N 1/37254 Pacemaker or defibrillator security, e.g. to prevent or inhibit programming alterations by hackers or unauthorised individuals
• CPC Class Codes: A61N 1/37264 Changing the program; Upgrading firmware

Abstract

An improved apparatus and method for evaluating, tuning and operating a physiologic stimulator such as an implantable pacemaker or defibrillator. In one exemplary embodiment, an impedance cardiography system is used to measure one or more cardiac functions such as stroke volume or mitral regurgitation as the parameters determining the operation of the pacemaker are varied, such as via a non-invasive pacemaker programming device. After a plurality of the parameters have been programmed in and corresponding measurements of stroke volume or mitral regurgitation obtained, the data is evaluated to determine one or more optimized parameter values.

Claims

1. Evaluation apparatus for use with a cardiac stimulation device, comprising impedance cardiography apparatus adapted for determining at least one aspect of cardiac function under varied conditions of stimulation produced by said device.

2. The apparatus of claim 1, further comprising control apparatus adapted to control said conditions of said stimulation device.

3. The apparatus of claim 2, wherein said control apparatus comprises a programming device adapted to vary one or more settings of said stimulation device in situ.

4. The apparatus of claim 3, wherein said act of varying comprises transmitting data from said programming device to said stimulation device via electromagnetic energy.

5. The apparatus of claim 2, wherein said control apparatus is adapted to iterate said conditions through at least two different settings, said impedance cardiography apparatus measuring said at least one aspect for each of said at least two iterations.

6. The apparatus of claim 1, wherein said at least one aspect is selected from stroke volume.

7. The apparatus of claim 1, wherein said impedance cardiography apparatus comprises at least one set of electrodes having predetermined inter-electrode spacing.

8. The apparatus of claim 1, wherein said impedance cardiography apparatus comprises wavelet transform signal processing.

9. The apparatus of claim 8, wherein said wavelet transform signal processing is used to identify at least one fiducial point within an impedance waveform.

10. The apparatus of claim 8, wherein said wavelet transform signal processing is used to identify at least one fiducial point within an ECG waveform.

11. The apparatus of claim 1, wherein said impedance cardiography apparatus comprises pacing spike detection.

12. The apparatus of claim 11, wherein said pacing spike detection is accomplished at least in part via a fuzzy model.

13. The apparatus of claim 2, wherein said impedance cardiography apparatus comprises a discrete ICG module in data communication with said control apparatus.

14. The apparatus of claim 1, wherein said impedance cardiography apparatus and said control apparatus operate according to a substantially time divided or multiplexed scheme.

15. The apparatus of claim 1, wherein said cardiography apparatus comprises substantially automated ECG lead selection.

16. The apparatus of claim 1, wherein said varied conditions of stimulation comprise at least one condition selected from the group consisting of (i) AV delay, and (ii) VV skew.

17. The apparatus of claim 1, wherein determining under varied conditions is initiated through a single user action.

18. A method of tuning a stimulation device, comprising:

evaluating at least one aspect of cardiac function under varied conditions of stimulation produced by said stimulation device; and

tuning said stimulation device based at least in part on said act of evaluating.

19. The method of claim 18, wherein said acts of evaluating and tuning are initiated through a single user action.

20. The method of claim 18, wherein said act of evaluating is accomplished at least in part through use of impedance cardiography.

21. The method of claim 20, wherein said acts of evaluating and tuning are initiated through a single user action.

22. The method of claim 20, wherein said act of evaluating comprises iterating through at least two different settings of at least one parameter associated with said stimulation device.

23. The method of claim 22, wherein said act of iterating comprises iterating through at least two AV timing values.

24. The method of claim 22, wherein said act of iterating comprises iterating through at least two VV timing values.

25. The method of claim 20, wherein said act of evaluating further comprises placing electrodes with a predetermined spacing on the thorax of a subject associated with said stimulation device.

26. The method of claim 20, wherein said act of evaluating further comprises generating at least one wavelet transform of impedance signals.

27. The method of claim 20, wherein said act of evaluating further comprises utilizing a fuzzy model to identify the noise threshold for least one cardiac pacing spike.

28. A method of treating a patient having a cardiac stimulation device, comprising:

evaluating at least one aspect of cardiac function under varied stimulation device settings, said act of evaluating being performed at least in part using impedance cardiography; and

tuning said stimulation device based at least in part on said act of evaluating.

29. The method of claim 28, wherein said act of evaluating further comprises placing electrodes with a predetermined spacing on the thorax of said patient.

30. The method of claim 28, wherein said act of evaluating further comprises generating at least one wavelet transform of impedance signals obtained from said patient as a result of the application of a stimulation current.

31. The method of claim 28, wherein said act of evaluating further comprises utilizing a fuzzy model to identify the noise threshold for at least one pacing spike within ECG signals obtained from said patient.

32. The method of claim 28, wherein said act of evaluating further comprises iterating through a plurality of different settings for at least one parameter of said stimulation device, and measuring said at least one aspect during each said iteration.

33. The method of claim 32, wherein said acts of iterating and measuring are initiated through a single user action.

34. A method of operating a cardiac pacemaker implanted within a living subject, comprising:

operating said pacemaker in a first operating condition;

measuring a first cardiac parameter using ICG to produce a first value;

operating said pacemaker in a second operating condition;

measuring said first cardiac parameter using ICG to produce a second value; and

evaluating said first and second values for use in subsequent operation.

35. The method of claim 34, wherein said acts of operating, measuring, and evaluating are initiated through a single user action.

36. The method of claim 35, further comprising:

selecting one of said first and second operating conditions based at least in part on said act of evaluating; and

subsequently operating said device according to said selected condition, said act of selecting also being performed through said single user action.

37. A method of operating a cardiac pacemaker implanted within a living subject, comprising:

operating said pacemaker with a first AV delay;

measuring a first cardiac parameter using ICG to produce a first value;

operating said pacemaker with a second AV delay;

measuring said first cardiac parameter using ICG to produce a second value; and

selecting on of said first and second values for use in subsequent operation.

38. A method of operating a cardiac pacemaker implanted within a living subject, comprising:

automatically iterating at least one parameter associated with the operation of said pacemaker across a plurality of different values, and measuring the value of at least one cardiac parameter using ICG during each iteration; and

selectively utilizing at least one of said plurality of different values for subsequent operation of said pacemaker.

39. The method of claim 38, wherein said acts of automatically iterating and selectively utilizing are accomplished as a result of a single user action.

40. The method of claim 38, wherein said act of measuring comprises using a plurality of electrodes to sense the impedance of at least a portion of the thoracic cavity of said subject, at least two of said electrodes having a predetermined spacing.

41. The method of claim 38, wherein said act of measuring comprises identifying at least one fiducial point within either of an impedance or ECG waveform obtained from said subject using at least one wavelet transform.

42. The method of claim 38, wherein said act of measuring comprises identifying at least one pacing spike within an ECG waveform obtained from said subject using a fuzzy model.

43. Cardiac apparatus, comprising:

a stimulation source adapted to produce a stimulation current;

a plurality of electrodes adapted for use on a living subject, at least a portion of said electrodes being further adapted to apply said stimulation current to said subject;

a pacemaker controller adapted to control at least one parameter associated with a pacemaker; and

processing means operatively coupled to at least a portion of said electrodes and said pacemaker controller, said processing means adapted to coordinate evaluation of signals obtained from said at least portion of electrodes with changes in said at least one parameter of said pacemaker in order to identify an optimal value thereof.

44. Cardiac apparatus, comprising:

a stimulation source adapted to produce a stimulation current;

a plurality of electrodes adapted for use on a living subject, at least a portion of said electrodes being further adapted to apply said stimulation current to said subject; and

a data interface adapted to transmit data between said apparatus and a pacemaker controller configured to control at least one parameter associated with a pacemaker; and

signal processing apparatus operatively coupled to at least a portion of said electrodes and said data interface, said signal processing apparatus adapted to coordinate evaluation of signals obtained from said at least portion of electrodes with changes in said at least one parameter of said pacemaker in order to identify an optimal value thereof.

45. A method of operating a cardiac stimulation device, comprising:

evaluating at least one aspect of cardiac function under varied stimulation device settings, said act of evaluating being substantially continuous and performed at least in part using impedance cardiography; and

tuning said stimulation device based at least in part on said act of evaluating.

46. The method of claim 45, wherein said stimulation device settings are varied in substantially continuous fashion during said act of evaluating.

47. Biomedical apparatus, comprising:

a stimulation source adapted to produce a stimulation current;

at least one electrode interface adapted to communicate electrical signals with a plurality of electrodes used on a living subject, at least a portion of said electrodes being adapted to apply said stimulation current to said subject; and

a data interface adapted to transmit data between said apparatus and a controller configured to control at least one parameter associated with a cardiovertor-defibrillator; and

signal processing apparatus operatively coupled to at least a portion of said electrode and data interfaces, said signal processing apparatus adapted to coordinate evaluation of signals obtained from said at least portion of electrodes with changes in said at least one parameter of said defibrillator in order to identify an optimal value thereof.

48. A method of optimizing stimulation device lead placement, comprising:

disposing at least one lead of said device in physical communication with a portion of a subject'"'"'s anatomy;

stimulating at least a portion of said anatomy using said lead;

measuring at least one parameter from said anatomy related to the functioning thereof; and

evaluating said act of disposing based at least in part on said act of measuring.

49. The method of claim 48, wherein said act of measuring comprises measuring said at least one parameter using ICG.

50. The method of claim 49, wherein said at least one parameter comprises stroke volume (SV).

51. The method of claim 48, wherein said act of evaluating comprises evaluating the suitability of a specific location where said lead is placed in said physical communication.

52. The method of claim 48, wherein said acts of stimulating and measuring are performed contemporaneously.

53. The method of claim 48, wherein said acts of disposing, stimulating and measuring are performed in substantially iterative fashion.

54. The method of claim 53, wherein said acts of stimulating and measuring are performed during surgical implantation of said device.