ACOUSTICALLY-POWERED WIRELESS DEFIBRILLATOR

• US 20070293895A1
• Filed: 06/18/2007
• Published: 12/20/2007
• Est. Priority Date: 06/20/2006
• Status: Active Grant

• Current Assignee: EBR Systems, Inc.
• Original Assignee: EBR Systems, Inc.
• Inventors: Cowan, Mark W., Brisken, Axel F.
• Granted Patent: US 7,751,881 B2
• Time in Patent Office: Days
• US Class Current: 607/5
• CPC Class Codes: A61N 1/3787 from an external energy source
• CPC Class Codes: A61N 1/39622 Pacing therapy
• CPC Class Codes: A61N 1/3968 Constructional arrangements, e.g. casings A61N1/375 takes precedence
• CPC Class Codes: A61N 1/3975 Power supply A61N1/378 takes precedence

Abstract

An acoustic transmitter produces a pulsed ultrasound waveform which is transmitted through body tissues to an implanted receiver-stimulator device. The waveform has an acoustic amplitude, pulse width, and pulse repetition period, which corresponds to a pacing pulse electrical amplitude, pacing pulse width, and pacing cycle length, respectively. The receiver-stimulator device intercepts at least a portion of the transmitted acoustic energy and coverts that acoustic energy into electrical energy using piezoelectric or other devices. This electrical energy is applied to circuitry, which produces a desired stimulating pulse waveform, which is then applied to tissue-contacting electrodes.

Claims

1. A method for terminating undesirable cardiac arrhythmias including ventricular fibrillation, said method comprising:

generating acoustic energy at a first implantation site; and

receiving said acoustic energy at a second implantation site;

wherein said acoustic energy is converted to electrical energy and stored at a level to produce appropriate amplitude and waveform sufficient to treat the cardiac arrhythmia.

2. A system for terminating undesirable cardiac arrhythmias including ventricular fibrillation, said system comprising:

an implantable acoustic controller-transmitter; and

an implantable acoustic receiver-defibrillator having electrode assemblies adapted to deliver defibrillation energy to the cardiac muscle tissue;

wherein the controller-transmitter and receiver-defibrillator are adapted to transmit and receive acoustic energy which provides both defibrillation energy and signal information to the receiver-defibrillator sufficient to provide defibrillation or termination of other cardiac arrhythmias.

3. The system as in claim 2, wherein the receiver-defibrillator comprises an acoustic receiver which receives acoustic energy and generates an alternating current signal, means for converting the alternating current signal to a direct current signal, means for accumulating and storing energy from the direct current signal, means to generate an appropriate waveform from the stored energy to defibrillate the cardiac tissue, and defibrillation electrodes adapted to deliver the defibrillation waveform to myocardial tissue.

4. The system of claim 3, wherein the receiver-defibrillator has distal and proximal ends, where the distal end of the receiver-defibrillator is adapted to be secured in the right ventricular apex of the heart, and the proximal end is located above the heart.

5. The system of claim 4, wherein one defibrillation electrode is located near the right ventricular apex of the heart, another defibrillation electrode is located within brachiocephalic, subclavian, or a vein generally superior to the heart.

6. The system of claim 3, wherein the controller-transmitter comprises a power source, means for sensing physiologic variables, control and timing circuitry to detect undesirable cardiac arrhythmias and provide a defibrillation output signal, means for converting the defibrillation output signal to an acoustic energy signal, and means for transmitting the acoustic energy signal to the receiver-defibrillator.

7. The system of claim 6, wherein means for sensing physiologic variables includes processing a surface ECG signal from electrodes located on the exterior surface of the controller-transmitter and in contact with body tissue.

8. A method for terminating undesirable cardiac arrhythmias including ventricular fibrillation and stimulating cardiac muscle, said method comprising:

generating acoustic energy at a first implantation site; and

receiving said acoustic energy at a second implantation site;

wherein said acoustic energy is converted to electrical energy suitable for either cardiac defibrillation or cardiac muscle stimulation based on both energy and signal information encoded in the generated acoustic energy.

9. The method of claim 8, wherein receiving stimulating energy comprises receiving the acoustic energy at at least two different cardiac sites.

10. The method of claim 8, wherein a predetermined configuration causes stimulation of at least two different sites simultaneously.

11. The method of claim 8, wherein a predetermined configuration causes stimulation of at least two different sites sequentially.

12. The method of claim 8, wherein the encoded signal information causes stimulation of at least two different sites simultaneously.

13. The method as in claim 8, wherein the encoded signal information causes stimulation of at least two different sites sequentially.

14. A system for terminating undesirable cardiac arrhythmias including ventricular fibrillation and for stimulating cardiac muscle, said system comprising:

an implantable acoustic controller-transmitter; and

an implantable acoustic receiver-defibrillator-stimulator having electrode assemblies adapted to deliver defibrillation energy or stimulation energy to the cardiac muscle tissue;

wherein the controller-transmitter and receiver-defibrillator-stimulator are adapted to transmit and receive acoustic energy which provides energy to the receiver-defibrillator-stimulator sufficient for accomplishing one of either stimulation or defibrillation, and which also provides signal information sufficient to perform one of either stimulation or defibrillation.

15. The system of claim 14, wherein the receiver-defibrillator-stimulator with proximal and distal ends comprises an acoustic receiver which receives acoustic energy and generates an alternating current signal, means for converting the alternating current signal to a direct current signal and further converting the direct current signal into stimulation energy or defibrillation energy, means for detecting whether the acoustic energy is intended to stimulate or defibrillate, means for applying stimulation energy to stimulation electrodes adapted to deliver the stimulation energy to myocardial tissue, means for accumulating and storing defibrillation energy, means to generate an appropriate waveform to defibrillate the cardiac tissue utilizing the stored defibrillation energy, and defibrillation electrodes adapted to deliver the defibrillation waveform to myocardial tissue.

16. The system of claim 15, wherein the distal end of the receiver-defibrillator-stimulator is adapted to be secured in the right ventricular apex of the heart, and wherein the proximal end is located above the heart in the superior vena cava.

17. The system of claim 15, wherein the distal end of the receiver-defibrillator-stimulator is adapted to be secured in the right ventricular apex of the heart, and wherein the proximal end is located above the heart.

18. The system of claim 15, wherein one defibrillation electrode is located near the right ventricular apex of the heart, a second defibrillation electrode is located within the superior vena cava, brachiocephalic vein or left subclavian vein, and one stimulation electrode is located near the right ventricular apex of the heart in contact with right ventricular tissue.

19. The system of claim 18, wherein a second stimulation electrode is located within the right atrium of the heart and disposed on the surface of the receiver-defibrillator-stimulator in such a manner to be in contact with right atrial tissue.

20. The system of claim 18, wherein a second stimulation electrode is located within the right atrium of the heart and connected to the receiver-defibrillator-stimulator in such a manner to be in contact with right atrial tissue.

21. The system of claim 18, wherein a second stimulation electrode provides stimulation to the right atrium sequentially with respect to the stimulation of the right ventricle.

22. The system of any one of the claims 14 through 21, wherein at least one independent receiver-stimulator is secured within the left ventricle and provides stimulation synchronous with the stimulation of the right ventricle.

23. The system of any one of the claims 14 through 21, wherein at least one independent receiver-stimulator is secured within the left ventricle and provides stimulation sequentially with the stimulation of the right ventricle.

24. The system of claim 14, wherein the controller-transmitter comprises a power source, control circuitry and timing circuitry to provide a pacing signal and to detect undesirable cardiac arrhythmias and provide a pacing or defibrillating output signal, means for converting the output signal to an acoustic energy signal, and means for transmitting the acoustic energy signal to the receiver-defibrillator-stimulator.

25. The system of claim 24, wherein control circuitry includes one or more means for sensing physiologic variables in order to adjust timing of stimulation or to detect undesirable cardiac arrhythmias.

26. The system of claim 25, wherein the sensed physiologic variables determine the appropriate pacing or defibrillation therapy.

27. The system of claims 25 or 26, wherein means for sensing physiologic variables includes processing a surface ECG signal from electrodes located on the exterior surface of the controller-transmitter and in contact with body tissue.

28. The system of claims 25 or 26, wherein means for sensing physiologic variables includes a blood pressure sensor.

29. The system of claims 25 or 26, wherein means for sensing physiologic variables includes an accelerometer for sensing body movement activity.

30. The system of claims 25 or 26, wherein means for sensing physiologic variables includes processing heart sounds.

31. The system of claims 25 or 26, wherein means for sensing physiologic variables includes processing impedance changes in the body related to respiration cycles.