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. A method of modifying an activity of a heart or of a portion thereof, the method comprising: applying to cardiac neural tissue which is nervous tissue contacting heart muscle an electric field of a magnitude, shape, duty cycle, phase, frequency, and duration suitable to obtain a desired change, to modify an activity of the heart or a portion thereof, wherein said field is applied at a time at which it is non-excitatory and thereof unable to generate a propagating action potential in the heart muscle, wherein said field has a strength insufficient for defibrillation the heart by synchronization of refractory and non-refractory cells to which it is applied and wherein said field is applied during an absolute refractory phase of cardiac muscle cells in tissue adjacent said cardiac neural tissue an in synchrony with activation thereof.
2. A method according to claim 1 , wherein the non-excitatory electric field dampens excitability of neural tissue.
3. A method according to claim 1 , wherein the non-excitatory electric field blocks conduction of stimuli along a neural pathway.
4. A method according to claim 1 , wherein the non-excitatory electric field enhances conduction of stimuli along a neural pathway.
5. A method according to claim 1 , wherein the non-excitatory electric field reduces an excitability of the cardiac neural tissue.
6. A method according to claim 5 , the excitability of the cardiac neural tissue is reduced by reducing an amount of available calcium.
7. A method according to claim 1 , comprising:
monitoring an activity of the heart or a portion thereof; and
adjusting the applying responsive to the monitoring.
8. A method according to claim 7 , wherein the non-excitatory electric field dampens excitability of neural tissue.
9. A method according to claim 7 , wherein the non-excitatory electric field blocks conduction of stimuli along a neural pathway.
10. A method according to claim 7 , wherein the non-excitatory electric field enhances conduction of stimuli along a neural pathway.
11. A method according to claim 7 , wherein the non-excitatory electric field reduces an excitability of the cardiac neural tissue.
12. A method according to claim 11 , the excitability of the cardiac neural tissue is reduced by reducing an amount of available calcium.
13. A method according to claim 1 , comprising applying said non- excitatory electric field as a continuation of a pacing field.
14. A method according to claim 1 , comprising also pacing said heart.
15. A method according to claim 1 , wherein said applying comprises applying for a plurality of non-contiguous beats with a plurality of non-applied beats between.
16. A method according to claim 1 , wherein said applying comprises applying with a magnitude greater than needed for pacing of said heart.
17. A method according to claim 1 , wherein said applying comprises applying in a manner suitable for a desired effect of increasing stroke volume of said heart.
18. A method according to claim 1 , wherein said applying comprises applying in a manner suitable for a desired effect of increasing cardiac output of said heart.
19. A method according to claim 1 , wherein said applying comprises applying in a manner suitable for a desired effect of controlling heart rate.
20. A method according to claim 19 , wherein said applying comprises applying in a manner suitable for a desired effect of reducing heart rate.
21. A method according to claim 19 , wherein said applying comprises applying in a manner suitable for a desired effect of one or both of stopping arrhythmia and preventing arrhythmia.
22. A method according to claim 1 , wherein said applying comprises applying said field at least 100 beats out of 50,000 consecutive beats.
23. A method according to claim 1 , wherein said applying comprises applying said field at least 1000 beats out of 50,000 consecutive beats.
24. A method according to claim 1 , wherein said applying comprises applying said field at least 4000 beats out of 50,000 consecutive beats.
25. A method according to claim 1 , wherein said applying causes an increase in flow volume of at least 5%.
26. A method according to claim 1 , wherein said applying comprises determining a state of reduced cardiac output and applying said field in response to said determining.
27. A method according to claim 1 , comprising, as part of an ongoing schedule of applying to a paced heart or a heart in a non-arrhythmic state, modifying said applying in response to feedback indicating cardiac output.
28. A method according to claim 1 , wherein said applying comprises applying said field for between 3 and 5000 consecutive beats.
29. A method according to claim 1 , wherein said applying comprises applying said field periodically according to a therapy schedule.
30. A method according to claim 29 , wherein said applying comprises applying said field on a daily basis.
31. A method according to claim 1 , wherein said applying causes an increase in cardiac output.
32. A method according to claim 1 , wherein said applying causes an increase in contractility of at least 5%.
33. A method according to claim 1 , wherein said electric field has a frequency selected to open some ion channels and not others.