Electrical muscle controller
View Patent ↗A method of modifying the force of contraction of at least a portion of a heart chamber, including providing a subject having a heart, comprising at least a portion having an activation, and applying a non-excitatory electric field having a given duration, at a delay after the activation, to the portion, which causes the force of contraction to be increased by a least 5%.
1. Apparatus for treatment of reduced cardiac output, the apparatus comprising:
(a) a signal generator adapted to apply an electric signal to a cardiac tissue; and
(b) a controller adapted to operate the signal generator so as to selectively apply the signal during a period of absolute refractory of said cardiac tissue,
wherein the electric signal increases a contractility of cardiac muscle and wherein said controller is adapted to apply said signal often enough to provide a clinically meaningful improvement in cardiac function.
2. Apparatus according to claim 1 , wherein the contractility of cardiac muscle comprises cellular contractility.
3. Apparatus according to claim 1 , wherein contractility of cardiac muscle comprises increased local contractility.
4. Apparatus according to claim 1 , wherein the increased contractility has a residual effect on at least one subsequent heartbeat.
5. Apparatus according to claim 4 , wherein the residual effect persists through subsequent heart beats in the absence of the electric signal.
6. Apparatus according to claim 1 , wherein the signal comprises a pacing pulse and at least one additional pulse applied during a refractory period.
7. Apparatus according to claim 1 , wherein said controller is adapted to operate the signal generator according to a control sequence which specifies a first number of beats in which a first control logic is applied and a second number of beats in which a second control logic is applied.
8. Apparatus according to claim 1 , wherein the electric signal comprises a non-excitatory signal.
9. Apparatus according to claim 1 , wherein the controller applies the signal also during a relative refractory period.
10. Apparatus according to claim 1 , wherein said apparatus is adapted for treating congestive heart failure.
11. Apparatus according to claim 1 , wherein said controller is adapted to apply said signal at least 100 beats out of 50,000 consecutive beats.
12. Apparatus according to claim 1 , wherein said improvement comprises an increase in flow volume of at least 5%.
13. Apparatus according to claim 1 , wherein said controller applies said signal in response to an indication of reduced cardiac output.
14. Apparatus according to claim 1 , wherein said controller is configured to modify said application in response to feedback indicating cardiac output.
15. Apparatus according to claim 1 , wherein said controller is adapted to apply said signal at least 4000 beats out of 50,000 consecutive beats.
16. Apparatus according to claim 1 , wherein said controller is configured to apply said signal periodically according to a therapy.
17. Apparatus according to claim 16 , wherein said controller is configured to apply said signal on a daily basis.
18. Apparatus according to claim 1 , wherein said controller is adapted to apply said signal for between 3 and 5000 consecutive beats.
19. A method of treating reduced cardiac output, the method comprising applying an electric signal to cardiac tissue to increase a contractility of cardiac muscle, said applying being during an absolute refractory period of said muscle and said applying being sufficient to provide a clinically significant improvement in cardiac function.
20. A method according to claim 19 , wherein the applying is conducted according to a control sequence which specifies a first number of beats in which a first control logic is applied and a second number of beats in which a second control logic is applied.
21. A method according to claim 19 , wherein the electric signal comprises a non-excitatory signal.
22. A method according to claim 19 , wherein the applying occurs during a refractory period.
23. A method according to claim 19 , wherein the applying comprises applying only during an absolute refractory period.
24. A method according to claim 19 , wherein said treating comprises treating congestive heart failure.
25. A method according to claim 19 , wherein said applying comprises applying said signal at least 100 beats out of 50,000 consecutive beats.
26. A method according to claim 19 , wherein said improvement comprises an increase in flow volume of at least 5%.
27. A method according to claim 19 , wherein said applying comprises determining a state of reduced cardiac output and applying said signal in response to said determining.
28. A method according to claim 19 , comprising modifying said applying in response to feedback indicating cardiac output.
29. A method of long term treatment of reduced cardiac output, the method comprising:
implanting an electrode to contact cardiac tissue; and
applying electric pulses to the cardiac tissue via the implanted electrode, said applying being during an absolute refractory period of said tissue, said applying being sufficient to clinically improve cardiac function.
30. A method according to claim 29 , wherein the electric pulses are applied via electrodes in a single heart chamber.
31. A method according to claim 29 , wherein the electric pulses are applied through a vein.
32. A method according to claim 29 , wherein the electric pulses increase contractility of cardiac muscle.
33. A method according to claim 29 , wherein the electric pulses are non-excitatory.
34. A method according to claim 29 , wherein the applying improves a condition of a patient with said congestive heart failure.
35. A method according to claim 29 , wherein said treating comprises treating congestive heart failure.
36. A method according to claim 29 , wherein said applying comprises applying said signal at least 100 beats out of 50,000 consecutive beats.
37. A method according to claim 29 , wherein said improvement comprises an increase in flow volume of at least 5%.
38. A method according to claim 29 , wherein said applying comprises determining a state of reduced cardiac output and applying said signal in response to said determining.
39. A method according to claim 29 , comprising modifying said applying in response to feedback indicating cardiac output.
40. A method according to claim 29 , wherein applying comprises applying over a period of at least 1 month.
41. A method according to claim 29 , wherein said applying comprises applying in response to one or both of a time of day and an accelerometer input.
42. A method of treating reduced cardiac output, the method comprising applying an electric signal to cardiac tissue to increase a contractility of cardiac muscle, said applying being during a non-paced cardiac cycle, said applying being repeated for sufficient cardiac cycles to provide a clinically significant improvement in cardiac function.
43. A method according to claim 42 , wherein said electric signal is applied to a series of consecutive non-paced cardiac cycles.
44. A method according to claim 42 , wherein said treating comprises treating congestive heart failure.
45. A method according to claim 42 , wherein said applying comprises applying said signal at least 100 beats out of 50,000 consecutive beats.
46. A method according to claim 42 , wherein said applying comprises applying said signal at least 1000 beats out of 50,000 consecutive beats.
47. A method according to claim 42 , wherein said applying comprises applying said signal at least 4000 beats out of 50,000 consecutive beats.
48. A method according to claim 42 , wherein said improvement comprises an increase in flow volume of at least 5%.
49. A method according to claim 42 , wherein said applying comprises determining a state of reduced cardiac output and applying said signal in response to said determining.
50. A method according to claim 42 , comprising modifying said applying in response to feedback indicating cardiac output.
51. A method according to claim 42 , wherein said applying comprises applying said signal for between 3 and 5000 consecutive beats.
52. A method according to claim 42 , wherein said applying comprises applying said signal periodically according to a therapy schedule.
53. A method according to claim 50 , wherein said applying comprises applying said signal on a daily basis.
54. A method according to claim 42 , wherein said improvement comprises an increase in cardiac output.
55. A method according to claim 42 , wherein said increase in contractility comprises an increase of at least 5%.
56. Apparatus according to claim 1 , wherein said controller is adapted to apply said signal at least 1000 beats out of 50,000 consecutive beats.