Leadless cardiac stimulation systems

• US 20060085041A1
• Filed: 03/07/2005
• Published: 04/20/2006
• Est. Priority Date: 10/20/2004
• Status: Active Grant

• Current Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Original Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Inventors: Edmunds, Kevin D., Hastings, Roger N., Sadasiva, Anupama, Pikus, Mike
• Granted Patent: US 7,650,186 B2
• Time in Patent Office: Days
• US Class Current: 607/33
• 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 1/37223 Circuits for electromagnetic coupling
• CPC Class Codes: A61N 1/3756 Casings with electrodes thereon, e.g. leadless stimulators
• CPC Class Codes: A61N 1/3787 from an external energy source

Abstract

Various configurations of systems that employ leadless electrodes to provide pacing therapy are provided. In one example, a system that provides multiple sites for pacing of myocardium of a heart includes wireless pacing electrode assemblies that are implantable at sites proximate the myocardium using a percutaneous, transluminal, catheter delivery system. Also disclosed are various configurations of such systems, wireless electrode assemblies, and delivery catheters for delivering and implanting the electrode assemblies.

Claims

1. A leadless tissue excitation system comprising:

a control unit having an antenna to produce a magnetic field; and

one or more wireless direct activation electrode assemblies operable to receive energy from the magnetic field and to deliver excitation pulses in response to the field.

2. The leadless tissue excitation system of claim 1, wherein the antenna comprises one or more wire loops.

3. The leadless tissue excitation system of claim 1, wherein the control unit is configured to be implanted in a human subject and the antenna is configured to lie under the skin of the subject in proximity to the heart of the subject.

4. The leadless tissue excitation system of claim 1, wherein the control unit comprises a battery, a capacitor in electrical communication with the antenna, and a controllable switch that controls charging and discharging of the capacitor.

5. The leadless tissue excitation system of claim 4, wherein control unit generates a magnetic field having a waveform appropriate to cause the one or more wireless electrode assemblies to generate an excitation voltage sufficient to provide a pacing pulse to heart tissue.

6. The leadless tissue excitation system of claim 1, wherein the one or more wireless electrode assemblies comprise a wire coil surrounding a permeable core.

7. The leadless tissue excitation system of claim 1, wherein the one or more wireless electrode assemblies comprise a pair of electrodes attached to the wire coil.

8. The leadless tissue excitation system of claim 7, wherein the pair of electrodes comprise a pair of circular caps mounted at opposed ends of the permeable core.

9. The leadless tissue excitation system of claim 8, wherein each of the one or more wireless electrode assemblies is approximately 5 millimeters in length and the pair of end caps are approximately 3 millimeters in diameter.

10. A leadless pacing electrode assembly comprising:

a passive wireless receiver; and

two or more electrodes attached to the passive wireless receiver to generate an excitation pulse when the passive wireless receiver receives energy from a magnetic field.

11. The leadless pacing electrode assembly of claim 10, wherein the passive wireless receiver comprises a permeable core and a coil surrounding the permeable core.

12. The leadless pacing electrode assembly of claim 11, wherein the two or more electrodes comprise two ring electrodes located at opposed ends of the permeable core.

13. The leadless pacing electrode assembly of claim 12, wherein the two ring electrodes are mounted around the permeable core at opposed ends of the permeable core.

14. The leadless pacing electrode assembly of claim 13, wherein the pacing electrode assembly is approximately 5 millimeters in length and the two ring electrodes are approximately 3 millimeters in diameter.

15. The leadless pacing electrode assembly of claim 10, wherein the pacing electrode assembly is configured to be introduced through a 9 French delivery catheter.

16. The leadless pacing electrode assembly of claim 10, further comprising an attachment mechanism secured near a first end of the electrode assembly.

17. The leadless pacing electrode assembly of claim 16, wherein the attachment mechanism includes a helical tine.

18. The leadless pacing electrode assembly of claim 16, wherein the attachment mechanism includes a plurality of radially extending tines operable to be extended from a first end of the electrode assembly.

19. The leadless pacing electrode assembly of claim 16, further comprising a detachment mechanism near a second end of the electrode assembly.

20. The leadless pacing electrode assembly of claim 19, wherein the detachment mechanism includes a threaded fitting.

21. A method for providing an excitation pulse via wireless implantable electrode assemblies, comprising:

providing a control unit having an antenna in a first location to produce a magnetic field;

providing one or more wireless direct activation electrode assemblies in a second location to be subjected to the magnetic field; and

energizing the antenna to create a magnetic field around the one or more wireless direct activation electrode assemblies to create an excitation pulse.

22. The method of claim 21, further comprising introducing the one or more wireless direct activation electrode assemblies into one or more chambers of a heart and attaching the wireless electrode assemblies to a wall of the heart so that the excitation pulse is delivered to the heart tissue.

23. The method of claim 22, wherein the electrode assemblies are introduced through an access catheter on the end of a flexible elongate member.

24. The method of claim 23, wherein the electrode assembly is directed to an area of an interior lining of a heart and screwed into the heart tissue.

25. The method of claim 24, wherein multiple electrode assemblies are screwed into multiple distinct areas of the heart tissue though the interior lining of the heart.

26. The method of claim 24, wherein multiple electrode assemblies are screwed into multiple chambers of the heart.

27. The method of claim 21, wherein the antenna is energized to with a critically damped, exponentially decaying current waveform.

28. A leadless pacing electrode assembly comprising:

a passive wireless receiver;

a pair of spaced electrodes; and

means for providing an excitation pulse between the pair of spaced electrodes.