Cardiac Stimulation Using Leadless Electrode Assemblies

• US 20090018599A1
• Filed: 09/13/2007
• Published: 01/15/2009
• Est. Priority Date: 09/13/2006
• Status: Active Grant

• Current Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Original Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Inventors: Pikus, Michael J., Hastings, Roger N., Lafontaine, Daniel M., Willard, Martin R.
• Granted Patent: US 8,644,934 B2
• Time in Patent Office: Days
• US Class Current: 607/32
• CPC Class Codes: A61N 1/059 Anchoring means
• CPC Class Codes: A61N 1/365 controlled by a physiological parameter, e.g. heart potential evoked response A61N1/371
• CPC Class Codes: A61N 1/372 Arrangements in connection with the implantation of stimulators
• CPC Class Codes: A61N 1/37205 Microstimulators, e.g. implantable through a cannula
• CPC Class Codes: A61N 1/37288 Communication to several implantable medical devices within one patient
• CPC Class Codes: A61N 1/375 Constructional arrangements, e.g. casings
• CPC Class Codes: A61N 1/37512 Pacemakers
• CPC Class Codes: A61N 1/37518 Anchoring of the implants, e.g. fixation
• CPC Class Codes: A61N 1/3756 Casings with electrodes thereon, e.g. leadless stimulators

Abstract

An implantable cardiac tissue excitation system includes an implantable pacing controller unit with a pulse generation circuit. The system also includes a lead with a lead body extending between a proximal lead end attachable to the pacing controller unit and a distal lead end configured to be implanted within a heart. A lead conductor extends within the lead body. The system also includes a transmitter assembly located near the distal lead end that is electrically connected to the pulse generation circuit through the lead conductor to wirelessly transmit pacing control information and pacing energy. The system also includes a leadless electrode assembly configured to be implanted within the heart that includes a receiver to receive the wireless transmission, a charge storage unit to store the charge energy, and an electrical stimulation circuit to deliver an electrical stimulus to cardiac tissue using the pacing control information and the charge energy.

Claims

1. A cardiac tissue excitation lead, comprising:

a flexible elongate lead body having a proximal end adapted to be inserted into an implantable pulse generator assembly and having a distal end adapted to be positioned within a heart;

a lead conductor extending within the lead body; and

a transmitter assembly located near the distal end of the lead body and electrically connected to the pulse generator assembly via the lead conductor to wirelessly transmit pacing control information and pacing energy from the transmitter assembly to an implanted leadless electrode assembly.

2. The cardiac tissue excitation lead of claim 1, wherein the transmitter assembly comprises a coil wound around a ferrite core

3. The cardiac tissue excitation lead of claim 2, wherein the wireless transmission of pacing control information and pacing energy occurs when the pulse generator assembly supplies a time-varying current to the coil through the lead conductor to emit a magnetic field.

4. The cardiac tissue excitation lead of claim 1, wherein the transmitter assembly comprises an ultrasonic transducer.

5. The cardiac tissue excitation lead of claim 4, wherein the wireless transmission of pacing control information and pacing energy occurs when the pulse generator assembly supplies an electrical current to the ultrasonic transducer through the lead conductor to emit an ultrasonic beam.

6. The cardiac tissue excitation lead of claim 1, wherein the transmitter assembly comprises a pair of separated electrodes.

7. The cardiac tissue excitation lead of claim 6, wherein the wireless transmission of pacing control information and pacing energy occurs when the pulse generator assembly supplies a time-varying current through the lead conductor across the pair of separated electrodes to emit an electric field.

8. The cardiac tissue excitation lead of claim 1, further comprising a first magnet positioned near the transmitter assembly that magnetically attracts a second magnet included with the leadless electrode assembly to orient the transmitter assembly and the leadless electrode assembly.

9. The cardiac tissue excitation lead of claim 1, wherein the pacing control information includes pace timing information and a pace trigger signal.

10. The cardiac tissue excitation lead of claim 1, wherein the transmitter assembly comprises a plurality of transmitter assemblies located near the distal end of the lead body and electrically connected to the pulse generator assembly via the one or more lead conductors to wirelessly transmit pacing control information and pacing energy to a plurality of implanted leadless electrode assemblies.

11. The cardiac tissue excitation lead of claim 10, wherein each of the transmitter assemblies in the plurality of transmitter assemblies transmits pacing control information and pacing energy to a different implanted leadless electrode assembly in the plurality of implanted leadless electrode assemblies.

12. An implantable cardiac tissue excitation system, comprising:

an implantable pacing controller unit comprising a pulse generation circuit;

a lead comprising a lead body extending between a proximal lead end attachable to the pacing controller unit and a distal lead end configured to be implanted within a heart, a lead conductor extending within the lead body, and a transmitter assembly located near the distal lead end, the transmitter assembly electrically connected to the pulse generation circuit through the lead conductor to wirelessly transmit pacing control information and charge energy from the transmitter assembly when the pulse generation circuit provides an electrical current to the transmitter assembly through the lead conductor; and

a leadless electrode assembly configured to be implanted within the heart and comprising a receiver to receive the wireless transmission from the lead transmitter assembly, a charge storage unit to store the charge energy, and an electrical stimulation circuit to deliver an electrical stimulus to cardiac tissue using the pacing control information and the charge energy.

13. The implantable cardiac tissue excitation system of claim 12, further comprising one or more implanted remote pacing stimulators in communicable contact with the leadless electrode assembly, each of the one or more remote pacing stimulators located in the heart and configured to apply pacing stimuli to surrounding heart tissue at the direction of the leadless pacing module.

14. The implantable cardiac tissue excitation system of claim 13, wherein each of the one or more remote pacing stimulators communicates with the leadless electrode assembly wirelessly.

15. The implantable cardiac tissue excitation system of claim 13, wherein each of the one or more remote pacing stimulators communicates with the leadless electrode assembly over a wire between the leadless electrode assembly and the remote pacing stimulator.

16. The implantable cardiac tissue excitation system of claim 12, wherein the leadless electrode assembly further comprises a sense circuit for sensing electrical cardiac activity and a transmitter for wirelessly transmitting information associated with the sensed electrical cardiac activity.

17. The implantable cardiac tissue excitation system of claim 12, wherein the pacing controller passes a time-varying current through the transmitter to generate an electric field to transmit the pacing control information and charge energy.

18. The implantable cardiac tissue excitation system of claim 12, wherein the transmitter comprises a coil enclosing at least a portion of a ferrite core.

19. The implantable cardiac tissue excitation system of claim 18, wherein the pacing controller passes a time-varying current through the coil to generate a magnetic field to transmit the pacing control information and charge energy.

20. The implantable cardiac tissue excitation system of claim 12, wherein the transmitter comprises a magnetic coil.

21. The implantable cardiac tissue excitation system of claim 20, wherein the leadless electrode assembly includes a magnet, and wherein a magnetic force between the magnetic coil and the magnet assists in orienting the leadless electrode assembly.

22. The implantable cardiac tissue excitation system of claim 12, further comprising a magnet assembly configured to be affixed to a heart wall and including a magnet that attracts a magnet included in the leadless assembly to position the leadless electrode assembly.

23. A method of operating a cardiac pacing system, the method comprising:

transmitting an energy signal wirelessly from a wired lead whose distal end is positioned within a heart;

receiving the transmitted energy signal at a wireless pacing electrode assembly positioned within the heart; and

issuing a pacing pulse from the wireless pacing electrode assembly.

24. The method of claim 23, wherein the energy transmission comprises charging energy and pacing information.

25. The method of claim 23, wherein transmitting the energy signal wirelessly from a wired lead comprises generating an electric field created at the wired lead positioned in the first chamber of the heart.

26. The method of claim 23, wherein transmitting the energy signal wirelessly from a wired lead comprises generating a magnetic field created at the wired lead positioned in the first chamber of the heart.

27. The method of claim 23, wherein transmitting the energy signal wirelessly from a wired lead comprises generating an ultrasonic beam at the wired lead positioned in the first chamber of the heart.

28. The method of claim 23, wherein a plurality of wireless pacing electrode assemblies receive the transmitted energy signal.

29. The method of claim 23, wherein the distal end of the wired lead is positioned in a first chamber of the heart and the wireless pacing electrode is positioned in a second, different chamber of the heart.

30. The method of claim 29, wherein the first chamber is a right ventricle of the heart and the second chamber is a left ventricle of the heart.

31. A method of operating a cardiac pacing system, the method comprising:

transmitting an energy signal wirelessly from a wired lead whose distal end is positioned in first chamber of a heart;

receiving the transmitted energy signal at a wireless pacing electrode assembly positioned within a second chamber of the heart; and

issuing, in response to receiving the transmitted energy signal, a pacing pulse from the wireless pacing electrode assembly to surrounding cardiac tissue unless a native cardiac electrical signal is sensed by the wireless pacing electrode assembly within a specified time period from the receipt of the transmitted signal.

32. The method of claim 31, wherein the energy transmission comprises charging energy and pacing information.

33. The method of claim 31, wherein the wireless pacing electrode assembly includes sense circuitry to sense the native cardiac electrical signal.

34. The method of claim 31, wherein transmitting the energy signal wirelessly from a wired lead comprises generating an electric field created at the wired lead implanted in the first chamber of the heart.

35. The method of claim 31, wherein transmitting the energy signal wirelessly from a wired lead comprises generating a magnetic field created at the wired lead implanted in the first chamber of the heart.

36. The method of claim 31, wherein transmitting the energy signal wirelessly from a wired lead comprises generating an ultrasonic beam at the wired lead implanted in the first chamber of the heart.

37. The method of claim 31, wherein the native cardiac electrical signal originates at a sino-atrial node of the heart.