Implantable head located radiofrequency coupled neurostimulation system for head pain
A system is provided for driving an implantable neurostimulator lead, the lead having an associated plurality of electrodes disposed in at least one array on the lead. The system comprises an implantable pulse generator (IPG), the IPG including an electrode driver, a load system for determining load requirements, an IPG power coupler, and an IPG communication system. The system also includes an external unit, which includes an external variable power generator, an external power coupler, an external communication system, and a controller for varying the power level of the variable power generator.
1. A system for driving an implantable neurostimulator lead having a plurality of electrodes disposed in at least one array, comprising:
an implantable pulse generator (IPG), including:
an electrode driver for driving the electrodes,
a current limiting current regulator for limiting the current to the IPG,
a load system for determining a minimum load requirement of the IPG to provide the necessary power to the current regulator,
an IPG power coupler for receiving power across a dermis layer for interface of the power with the electrode driver, and
an IPG communication system for transmitting the determined minimum load requirement of the IPG across the dermis layer; and
an external unit including:
an external variable power generator,
an external power coupler for coupling power across the dermis layer to the IPG power coupler,
an external communication system for receiving from the IPG communication system the determined minimum load requirement of the IPG, and
a controller for varying the power level of the variable power generator as a function of the received determined minimum load requirement of the IPG.
2. The system of claim 1 , wherein the load system comprises:
a detector for detecting the state of the current regulator; and
a processor for determining the necessary power from the external unit required by the electrode driver as the determined minimum load requirement of the IPG to maintain the current regulator in regulation.
3. The system of claim 2 , wherein the current regulator delivers a predetermined constant current.
4. The system of claim 3 , wherein the determined minimum load requirement comprises at least enough power from the external unit to provide the predetermined constant current from the current regulator.
5. The system of claim 1 , wherein the IPG further includes a charge storage device.
6. The system of claim 1 , wherein the IPG is head-located beneath the dermis layer of a patient.
7. The system of claim 1 , wherein the IPG communication system and the external communication system each comprises at least one coil.
8. A system for driving a plurality of implantable neurostimulator leads, each lead having an associated plurality of electrodes disposed in at least one array on the lead, the system comprising:
at least two implantable pulse generators (IPGs), each IPG including:
an electrode driver for driving the electrodes associated with the IPG,
a current limiting current regulator for limiting the current to the IPG,
a load system for determining a minimum load requirement of the IPG to provide the necessary power to the current regulator,
an IPG power coupler for receiving power across a dermis layer for interface of the power with the electrode driver of the IPG, and
an IPG communication system for transmitting the determined minimum load requirement of the IPG across the dermis layer; and
an external unit for providing power to the at least two IPGs, the external unit including:
an external variable power generator,
an external power coupler for coupling power across the dermis layer to the IPG power couplers,
an external communication system for receiving from the IPG communication systems the respective determined minimum load requirements, and
a controller for varying the power level of the variable power generator as a function of the received determined minimum load requirement of the IPG with the greatest minimum load requirement.
9. The system of claim 8 , wherein the communication systems of each IPG is operable to transmit the determined minimum load requirement to the external communication system independently of the communication systems of each of the other IPGs.
10. The system of claim 8 , wherein each of the IPG communication systems transmits its respective determined minimum load requirement to the external unit communication system inductively.
11. The system of claim 8 , wherein each IPG power coupler is for receiving levels of power across a dermis layer that are independent of the levels of power received by the power couplers of each of the other IPGs.
12. The system of claim 8 , wherein at least one of the IPGs further includes a charge storage device.