Assessing cardiac activity
View Patent ↗A method of assessing contractility of a cardiac muscle which has at least one activation parameter, the method comprising: (a) utilizing time correlated data pertaining to at least one activation parameter to produce a profile of said parameter; (b) identifying from measurement of said at least one parameter a time interval during which interference from an artificial signal occurs; (c) ameliorating effects of said interference; and (d) analyzing changes in said profile to generate an indication of contractility, as a function of time to generate a cardiac activation profile.
1. A method of assessing efficacy of a treatment on cardiac contractility, the method comprising:
(a) utilizing time correlated data pertaining to an activation parameter, to produce a first profile of said parameter, comprising:
(i) measuring at least one parameter as a function of time to generate a cardiac activation profile;
(ii) identifying from the measurement of said at least one parameter a time interval during which interference from an artificial signal occurs; and
(iii) ameliorating effects of said interference;
(b) analyzing changes in said first profile to generate an indication of contractility;
(c) applying a treatment and re-performing steps (a) and (b) to generate a second profile; and
(d) comparing said first profile and said second profile to ascertain an efficacy of the treatment.
2. A method according to claim 1 , wherein said activation parameter includes a mechanical activation parameter.
3. A method according to claim 2 , wherein said mechanical activation parameter includes at least one of impedance and acoustic output.
4. A method according to claim 1 , wherein said analyzing changes includes analyzing changes in a first derivative of the profile.
5. A method according to claim 1 , wherein said time correlated data is acquired without any intra-corporeal measuring device.
6. The method of claim 1 , wherein said treatment includes administration of a cardiac contractility modulation (CCM) input.
7. A method according to claim 1 , additionally comprising analyzing said activation parameter correlated to time and said corresponding CCM input.
8. A method according to claim 7 , wherein said analyzing further comprises providing an output in the form of a desired change in activation profile.
9. A method according to claim 7 , wherein said analyzing further comprises providing an output in the form of a recommended change in CCM delivery.
10. A method according to claim 9 , wherein said a controller implements the recommended change in CCM delivery.
11. A method according to claim 1 , wherein said ameliorating includes data deletion followed by interpolation to reconstruct a missing portion of said profile.
12. A method according to claim 1 , wherein said ameliorating includes data deletion followed by data regeneration to reconstruct a missing portion of said profile.
13. A method according to claim 1 , wherein said amelioration includes application of a band pass filter.
14. The method of claim 1 , wherein said treatment includes administration of an electric signal.
15. A method according to claim 1 , wherein said ameliorating comprises modifying an application of said artificial signal during said measuring.
16. A method according to claim 15 , wherein said modifying comprises changing one or more of a time, application electrodes, amplitude and frequency of said artificial signal.
17. A method according to claim 16 , wherein ameliorating comprises changing application electrodes and wherein said application electrodes are selected to be distanced from a measuring location of said measuring.
18. A method according to claim 16 , wherein application electrodes are changed between beats to allow measurement at multiple locations.
19. A method according to claim 1 , wherein ameliorating comprises ameliorating using data from other beats.
20. A method according to claim 19 , wherein ameliorating comprises averaging for different artificial signal applications.
21. A method according to claim 1 , wherein ameliorating comprises measuring an effect of the signal in a beat after the artificial signal is applied and stopped.
22. A method according to claim 1 , further comprising turning off a measuring system during an application or expected application of said artificial signal.
23. A method according to claim 1 , wherein ameliorating comprises reconstructing missing peak data.
24. A method according to claim 23 , wherein the missing data is reconstructed based on a slope of the peak.
25. A method according to claim 23 , wherein the missing data is reconstructed based on a relaxation time of the peak.
26. A method according to claim 23 , wherein a peak decay is reconstructed based on a peak rise or a peak rise is reconstructed based on a peak decay.
27. A method according to claim 1 , wherein ameliorating comprises reconstructing missing data using data from times outside the time of application of the artificial signal, using fitting or interpolation.
28. A method according to claim 1 , wherein said artificial signal is applied during a refractory period of said the heart being measured.
29. A method according to claim 1 , wherein said artificial signal is applied for a period of at least 10 milliseconds long during which said measurement is compromised and later ameliorated.
30. A method according to claim 1 , wherein said artificial signal is applied for a period of at least 20 milliseconds long during which said measurement is compromised and later ameliorated.
31. A method according to claim 1 , further comprising identifying a sharp change in said at least one parameter.
32. A method according to claim 1 , further comprising identifying a slope above a certain threshold in said at least one parameter.
33. A method according to claim 1 , further comprising identifying a value over a certain threshold in said at least one parameter.
34. A method according to claim 1 , wherein said identifying comprises identifying an interference which occurred.
35. A method according to claim 1 , wherein said measurement of said at least one parameter is used to predict when an interference will occur.
36. A method according to claim 1 , additionally comprising displaying the values of said activation parameters correlated to time as an activation profile.
37. The method of claim 1 , wherein said artificial signal results from pacing.
38. The method of claim 1 , wherein said artificial signal results from a CCM delivery.
39. A method of positioning a lead, the method comprising,
(a) utilizing time correlated data pertaining to an activation parameter, to produce a first profile of said parameter, comprising:
(i) measuring at least one parameter as a function of time to generate a cardiac activation profile;
(ii) identifying from the measurement of said at least one parameter a time interval during which interference from an artificial signal occurs; and
(iii) ameliorating effects of said interference;
(b) analyzing changes in said first profile to generate an indication of contractility;
(c) applying a therapeutic signal through a lead at a position in said heart at a known time;
(d) performing a method according to steps (a) and (b) to generate a second profile;
(e) comparing said first and second profile; and
(f) adjusting the positioning of the lead responsive to said comparison results.
40. A method according to claim 39 , wherein adjusting the positioning of the lead responsive to comparison results comprises adjusting if a selected portion of said first profile is not significantly narrower in said second profile.
41. A method according to claim 39 , wherein said therapeutic signal is a pacing signal.
42. A method according to claim 39 , wherein said applying a signal comprises applying a non excitatory signal.
43. A method according to claim 42 wherein the non-excitatory electric therapy includes CCM.
44. A method according to claim 39 , wherein a significant narrowing in said profile indicates that said position is said desired position.
45. A method of generating a profile of the heart, the method comprising:
(a) measuring at least one parameter as a function of time to generate a cardiac activation profile;
(b) identifying from the measurement of said at least one parameter a time interval during which interference from an artificial signal occurs; and
(c) ameliorating effects of said interference;
wherein:
said amelioration includes calculation of a first derivative of said function.
46. A method of assessing efficacy of a non-excitatory electric treatment, the method comprising:
(a) performing a method to generate a first profile, said method comprising:
(i) utilizing time correlated data pertaining to an activation parameter measured by:
(A) measuring at least one parameter as a function of time to generate a cardiac activation profile;
(B) identifying from the measurement of said at least one parameter a time interval during which interference from an artificial signal occurs; and
(C) ameliorating effects of said interference;
to produce a profile of said parameter; and
(ii) analyzing changes in said profile to generate an indication of therapy efficacy;
(b) applying a treatment and re-performing a method according to step (a) to generate a second profile;
(c) comparing said first profile and said second profile to ascertain an efficacy of the treatment.
47. A method according to claim 46 , wherein said activation parameter includes a mechanical activation parameter.
48. A method according to claim 46 wherein the non-excitatory electric treatment includes CCM.
49. A method of assessing cardiac disease progression in a subject, the method comprising:
(a) generating a first profile by:
(i) utilizing time correlated data pertaining to an activation parameter measured by:
(A) measuring at least one parameter as a function of time to generate a cardiac activation profile;
(B) identifying from the measurement of said at least one parameter a time interval during which interference from an artificial signal occurs; and
(C) ameliorating effects of said interference;
to produce a profile of said parameter; and
(ii) analyzing changes in said profile to generate an indication of therapy efficacy;
(b) allowing an increment of time to elapse and re-performing a method according to step (a) to generate a second profile;
(c) comparing said first profile and said second profile to ascertain a degree of disease progression.