Minimally invasive implantable neurostimulation system
Various embodiments of a minimally invasive implantable medical device (IMD) system are described. In one embodiment, the implantable medical device system includes an external device for transmitting a communication signal and an implantable device for receiving the communication signal by inductive coupling. The implantable device is configured to harvest power from the inductively coupled communication signal and power a signal generator from the harvested power to generate a therapeutic electrical stimulation signal.
1. A medical device system, comprising:
an external medical device comprising an inductive communication initiating device coupled to an external antenna; and
an implantable medical device comprising:
a control unit;
a signal generator for generating a therapeutic electrical stimulation signal;
a plurality of electrodes coupled to the signal generator for delivering the electrical stimulation signal to a neurostimulation site of a patient;
an inductive communication target device;
an implantable antenna coupled to the target device for receiving a communication signal inductively coupled between the external antenna and the implantable antenna;
a rectifier coupled to the implantable antenna for receiving the inductively coupled communication signal and having a voltage output providing a voltage output signal in response to receiving the inductively coupled communication signal; and
a sampling circuit coupled to the control unit and to a signal line for measuring a voltage signal correlated to the voltage output, and for providing the control unit with a feedback control signal based on the voltage signal,
the voltage output being a sole power source coupled to the signal generator to provide the voltage output signal to the signal generator for generating the therapeutic electrical stimulation signal delivered by the plurality of electrodes, the control unit configured to alter control of the signal generator based on the feedback control signal.
2. The system of claim 1 , wherein the voltage output is further coupled to at least one of the control unit and the target device to provide the voltage output signal to power the at least one of the control unit and the target device.
3. The system of claim 2 , wherein the voltage output signal being a sole signal for powering functions of the implantable medical device.
4. The system of claim 1 , wherein the rectifier comprises a rectifier included in the target device.
5. The system of claim 1 , wherein the implantable device further comprises a rechargeable energy storage device, the voltage output being further coupled to the rechargeable energy storage device for recharging the energy storage device.
6. The system of claim 1 , wherein the communication signal comprises a carrier signal, the external medical device enabled to apply the carrier signal to the external antenna for inductively coupling the carrier signal between the external antenna and the implantable antenna for generating the voltage output signal for a full duration of a neurostimulation therapy session.
7. The system of claim 6 , wherein the external medical device is further enabled to modulate the carrier signal to transmit the communication signal comprising an interval of communication data during the therapy session, the rectifier configured to receive the inductively coupled signal during the interval of communication data to provide the voltage output signal in response to the inductively coupled signal.
8. The system of claim 1 , wherein the implantable medical device is configured to start generating and delivering the electrical stimulation signal in response to receiving the communication signal from the external device upon the external device being within a communication range of the implantable medical device.
9. The system of claim 1 , wherein the rectifier comprises a rectifier coupled to the implantable antenna in parallel to the target device.
10. The system of claim 1 , wherein the implantable antenna extends from the implantable medical device as a fixation member for stabilizing an implant position of the implantable medical device.
11. A method, comprising:
enabling an external medical device comprising an inductive communication initiating device and an external antenna to apply a communication signal to the external antenna;
receiving on an implantable antenna of an implantable medical device the communication signal inductively coupled between the external antenna and the implantable antenna, the implantable medical device comprising an inductive communication target device coupled to an implantable antenna, a control unit, a signal generator, a plurality of electrodes coupled to the signal generator, and a rectifier coupled to the implantable antenna;
generating a voltage output signal at a voltage output of the rectifier in response to the inductively coupled communication signal;
measuring, by a sampling circuit, a voltage signal correlated to one of the inductively coupled signal and the voltage output signal for providing the control unit with a feedback control signal;
providing the voltage output signal to the signal generator as a sole power source for powering generation of a therapeutic electrical stimulation signal delivered by the plurality of electrodes to a neurostimulation site of a patient; and
altering control of the signal generator based on the feedback control signal.
12. The method of claim 11 , further comprising powering at least one of the implantable medical device control unit and the target device by providing the voltage output signal to the at least one of the control unit and the target device.
13. The method of claim 12 , further comprising solely powering the functions of the implantable medical device from the voltage output signal.
14. The method of claim 11 , further comprising generating the voltage output signal from a rectifier included in the target device.
15. The method of claim 11 , further comprising coupling the voltage output signal to a rechargeable energy storage device included in the implantable medical device; and
recharging the energy storage device from the voltage output signal.
16. The method of claim 11 , further comprising inductively coupling a communication carrier signal between the external antenna and the implantable antenna for generating the voltage output signal for a full duration of a neurostimulation therapy session.
17. The method of claim 16 , further comprising:
modulating the carrier signal to encode communication data in the communication signal;
inductively coupling the communication signal comprising an interval of communication data during the therapy session; and
enabling the rectifier to generate the voltage output signal in response to the communication signal during the interval of communication data.
18. The method of claim 11 , further comprising generating and delivering the electrical stimulation signal in response to receiving the communication signal from the external device upon the external device being within a communication range of the implantable medical device.
19. The method of claim 11 , further comprising coupling the rectifier to the implantable antenna in parallel to the target device.
20. The method of claim 11 , further comprising stabilizing an implant position of the implantable medical device using the implantable antenna extending from the implantable medical device as a fixation member.
21. An implantable medical device system, comprising:
an external device for transmitting a communication signal; and
an implantable device for receiving the communication signal by inductive coupling and configured to:
harvest power from the inductively coupled communication signal; and
power a signal generator from the harvested power to generate a therapeutic electrical stimulation signal;
the implantable device comprising a sealed housing enclosing electronic circuitry and an implantable antenna extending from the sealed housing, the implantable antenna having at least a portion electrically coupled to the electronic circuitry and having a bend in the portion of the implantable antenna for anchoring the implantable medical device at a target implant site of a patient,
the implantable antenna configured to receive the inductively coupled communication signal, wherein the power harvested from the inductively coupled communication signal comprises the sole source of power for the implantable device,
and wherein the implantable antenna is configured to be held in an undeployed position aligned with the sealed housing to allow the implantable device and the implantable antenna to be implanted through a skin incision.
22. The system of claim 21 , wherein the implantable antenna comprises a dipole antenna.
23. The system of claim 21 , wherein the implantable antenna comprises a magnetically-coupled loop antenna.
24. The system of claim 21 , wherein the implantable antenna comprises a stent-like woven portion.
25. The system of claim 21 , wherein the external device comprises a wearable external coupling device.