ELECTRICAL MUSCLE CONTROLLER AND PACING WITH HEMODYNAMIC ENHANCEMENT

• US 20080140142A1
• Filed: 10/31/2007
• Published: 06/12/2008
• Est. Priority Date: 01/08/1996
• Status: Active Grant

• Current Assignee: Impulse Dynamics NV
• Original Assignee: Impulse Dynamics NV
• Inventors: Ben-Haim, Shlomo, Darvish, Nissim, Mika, Yuval, Felsen, Bella, Fenster, Maier, Kornfield, Judith, Shemer, Itzik
• Granted Patent: US 8,321,013 B2
• Time in Patent Office: Days
• US Class Current: 607/11
• CPC Class Codes: A61N 1/05 for implantation or insertion into the body, e.g. heart electrode A61N1/06 takes precedence
• CPC Class Codes: A61N 1/0587 Epicardial electrode systems; Endocardial electrodes piercing the pericardium
• CPC Class Codes: A61N 1/3627 for treating a mechanical deficiency of the heart, e.g. congestive heart failure or cardiomyopathy
• CPC Class Codes: A61N 1/36514 controlled by a physiological quantity other than heart potential, e.g. blood pressure controlled by two or more physical parameters A61N1/36585
• CPC Class Codes: A61N 1/36564 controlled by blood pressure

Abstract

A method of modifying the force of contraction of at least a portion of a heart chamber is provided. A non-excitatory electric field of given duration is applied, at a delay after an activation of the heart, which increase the force of contraction by at least 5%. Apparatus is also provided for pacing with hemodynamic improvement. Circuitry applies an extended pacing signal to electrodes to pace the heart, the extended pacing signal having an overall duration greater than 8 ms from a time of initiation of application of that portion of the signal that initiates action potential propagation. The signal includes a train of biphasic pulses having pulse durations of at least 1 ms, and the signal has an amplitude that is at least three times as great as a threshold for pacing the heart and that is sufficient neither for cardioversion nor for defibrillation. Other embodiments are also described.

Claims

1. Heart control apparatus for modifying the activity of at least part of a heart, comprising:

(a) a sensor adapted for sensing a parameter characterizing the activity of at least part of the heart;

(b) circuitry adapted to determine at least one of the parameters of a stimulus,

wherein said parameters are selected from the group consisting of a magnitude, shape, duty cycle, phase, frequency, duration, and time of application of said stimulus,

wherein said determining is responsive to said sensed characterizing parameter, and

wherein said circuitry is adapted to generate a stimulus comprising at least one non-excitatory portion, which is applied after an essentially 0 ms delay from the activation time of the portion at which said stimulus is applied, and is unable to generate a propagating action potential or prevent propagation of a propagating action potential and is adapted to modify contraction of said heart; and

(c) at least one stimulus applying element adapted to apply said stimulus,

wherein the stimulus further comprises at least one excitatory portion, which is able to propagate, generate or prevent a propagating action potential.

2. The heart control apparatus according to claim 1, wherein the delay is calculated from sensing of the activation at the stimulus application site.

3. The heart control apparatus according to claim 1, wherein the delay is calculated from sensing activation at a different site of the heart.

4. The heart control apparatus according to claim 1, wherein the delay is calculated from a time of pacing of at least one of the heart chambers.

5. The heart control apparatus according to claim 1, wherein the circuitry for generating the non-excitatory portion of the stimulus comprises circuitry for generating an electric current.

6. The heart control apparatus according to claim 5, wherein the amplitude of said electric current is less than 20 mA.

7. The heart control apparatus according to claim 5, wherein the amplitude of the electric current is greater than 3 mA and less than 20 mA.

8. The heart control apparatus according to claim 1, wherein the circuitry for generating the non-excitatory portion of the stimulus comprises circuitry for generation of a stimulus characterized in that the width of said stimulus is in the range of 10 to 100 msec.

9. The heart control apparatus according to claim 1, wherein the circuitry for generating the non-excitatory portion of the stimulus comprises circuitry for the generation of a stimulus characterized in that the width of said stimulus is in the range of 1 to 20 msec.

10. The heart control apparatus according to claim 1, wherein the stimulus is comprised of at least one biphasic pulse.

11. The heart control apparatus according to claim 1, wherein the stimulus is comprised of at least one monophasic pulse.

12. The heart control apparatus according to claim 1, wherein the stimulus application devices comprise one or more electrodes mounted on a lead that is configured to be introduced into the heart intravenously, passing through coronary vessels of the heart to locate said electrodes on a left ventricle of the heart.

13. The heart control apparatus according to claim 1, wherein the stimulus application devices comprise one or more electrodes mounted on at least one lead that is configured to be introduced into a right ventricle of the heart.

14. The heart control apparatus according to claim 13, wherein the one or more electrodes are configured to deliver the stimulus to a septum muscle of the heart.

15. Apparatus for human heart pacing with hemodynamic improvement, comprising:

one or more implantable electrodes, which are adapted to convey electrical signals to respective cardiac muscle segments; and

signal generation circuitry, which is adapted to apply an extended pacing signal to the one or more electrodes so as to pace the human heart, the extended pacing signal having an overall duration greater than 8 ms from a time of initiation of application of that portion of the signal that initiates action potential propagation,

wherein the extended pacing signal comprises a train of pulses,

wherein the signal has an amplitude that is at least three times as great as a threshold for pacing the heart and that is sufficient neither for cardioversion nor for defibrillation, and

wherein each of the pulses in the train has a pulse duration of at least 1 ms, and

wherein the train of pulses comprises a plurality of biphasic pulses.

16. The apparatus according to claim 15, wherein each of the pulses in the train has a pulse duration of at least 1 ms.

17. The apparatus according to claim 15, wherein the pulse train has a period of at least 5 ms.

18. The apparatus according to claim 17, wherein the pulse train has a period of at least 20 ms.

19. The apparatus according to claim 15, wherein the train of pulses has a duty cycle between about 10% and 50%.