NEURO-STIMULATION

• US 20120161945A1
• Filed: 07/19/2010
• Published: 06/28/2012
• Est. Priority Date: 07/20/2009
• Status: Active Grant

• Current Assignee: Saluda Medical Pty Ltd.
• Original Assignee: National ICT Australia Limited
• Inventors: Single, Peter, Robinson, David, Parker, John, Ayre, Peter, Karantonis, Dean
• Granted Patent: US 9,566,439 B2
• Time in Patent Office: Days
• US Class Current: 340/12.1
• CPC Class Codes: A61N 1/05 for implantation or insertion into the body, e.g. heart electrode A61N1/06 takes precedence
• CPC Class Codes: A61N 1/36146 specified by the stimulation parameters
• CPC Class Codes: A61N 1/36189 using modulation techniques

Abstract

The invention is a distributed implantable neuro-stimulation system, comprising an implant controller including control logic to transmit two time-varying power signals, varying between two levels and out of phase with the other, and a command signal modulated onto at least one of the power signals. One or more electrode cells, each having control logic to extract charge from the power signals and recover commands from the command signal. A two-wire bus interconnecting the implant controller and all the electrode cells, to carry one of the time varying signals in each of the two wires, and to carry the command signal.

Claims

1. A distributed implantable neuro-stimulation system, comprising:

an implant controller including control logic to transmit two time-varying power signals, varying between two levels and out of phase with the other, and a command signal modulated onto at least one of the power signals;

one or more electrode cells, each having control logic to extract charge from the power signals and recover commands from the command signal; and

a two-wire bus interconnecting the implant controller and all the electrode cells, to carry one of the time varying signal in each of the two wires, and to carry the command signal.

2. The system according to claim 1, wherein, in operation, when recovered commands select an electrode of at least one of the electrode cells to deliver a stimulus, the control logic within the selected cell uses the commands to control the selected electrode to deliver extracted charge, in cooperation with at least one other electrode.

3. The system according to claim 2, a stimulus is delivered in the form of a biphasic pulse which have an anodic and a cathodic phase, with matched charge in each phase.

4. The system according to claims 3, wherein the control logic of each electrode cell is further operable to recover timing information from at least one of the power signals to coordinate a selected electrode to step through anodic and cathodic phases of the biphasic pulse in cooperation with at least one other electrode.

5. The system according to claim 4, wherein the timing information is in the form of crossovers in the power signals.

6. The system according to claim 4, wherein the timing information is in the form of crossovers with fixed frequency in the power signals.

7. The system according to claim 3 wherein the commands define the amplitude of each phase the biphasic pulse and whether the biphasic pulse is cathodic or anodic in the first phase.

8. The system according to claim 1, wherein, in operation, recovered commands select plural electrodes to make telemetry measurements.

9. The system according to claim 8, wherein the selected electrodes make measurements in sequence and deliver telemetry measurements to the implant controller.

10. The system according to claim 1, wherein commands are modulated onto at least one of the power signals using phase modulated pulse pairs.

11. The system according to claim 1, wherein the implant controller and electrode cells each comprise a switch to selectively allow the flow of stimulus current from the implant controller to the electrode cell, and vice versa, and to control the direction of stimulus current.

12. The system according to claim 1, wherein the control logic in both the implant controller or electrode cells, or both, are provided by a processor or programmable logic array.

13. The system according to claim 1, wherein at least one of the electrode cells stores commands for more than one stimulation.

14. The system according to claim 1, wherein more than two electrode cells take part in generating a stimulus.

15. An implantable implant controller for delivering neuro-stimulation, including:

control logic to transmit two time-varying power signals, varying between two levels and out of phase with the other, and to modulate a command signal onto at least one of the power signals;

wherein, in operation, the implant controller is connectable to plural electrode cells via a two-wire bus, the bus being operable to carry a respective one of the time varying signals in each of the two wires, and to carry the command signal, and each electrode cell having control logic to extract charge from the power signals and recover commands from the command signal.

16. The controller according to claim 15, wherein, in operation, when recovered commands select an electrode of the electrode cell to deliver a stimulus, the control logic within the selected cell uses the commands to control the selected electrode to deliver extracted charge, in cooperation with at least one other electrode.

17. The controller according to claim 15, further comprising a reference electrode and a multi-pole switch to selectively connect the reference electrode to a voltage source, a current source or an open circuit to coordinate delivery of the stimulus.

18. The controller according to claim 15, further comprising control logic and an alternator to deliver the two time varying power signals, each varying between two levels and each being out of phase with the other, and a clock and data transmitter to modulate the power signals with clock and data signals.

19. An implantable electrode cell for delivering neuro-stimulation, including:

at least one electrode; and

control logic to extract charge from two time-varying power signals, varying between two levels and out of phase with the other, to recover commands from a command signal modulated onto at least one of the power signals, and to deliver extracted charge to the electrode;

wherein the electrode cell is connectable to an implant controller and at least one other electrode cell via a two-wire bus, the implant controller having control logic to transmit the two time time-varying power signals and the command signal, and the bus is operable to carry a respective one of the time varying signals in each of the two wires, and to carry the command signal.

20. The electrode cell according to claim 19, wherein, in operation, when recovered commands select an electrode of the electrode cell to deliver a stimulus, the control logic within the selected cell uses the commands to control the selected electrode to deliver extracted charge, in cooperation with at least one other electrode.

21. The electrode cell according to claim 20, wherein the stimulus is a biphasic pulse having anodic and cathodic phases.

22. The electrode cell according to claim 21, wherein the control logic is further operable to recover timing information from at least one of the time-varying power signals coordinate a selected electrode to step through anodic and cathodic phases of the biphasic pulse in cooperation with at least one other electrode.

23. The electrode cell according to claim 22, further comprising a multi-pole switch to selectively connect an electrode to a voltage source, a current source or an open circuit to coordinate delivery of a stimulus.

24. The electrode cell according to claim 23, wherein the control logic in the electrode cell is housed in a chip.

25. The electrode cell according to claim 24, wherein the chip provides a substrate for mounting the following components:

a rectifier and storage capacitor to extract charge from the power signals;

a clock and data receiver to recover clock and data signals; and

a current source to deliver extracted charge to an electrode.

26. A method of operating an implantable electrode cell for delivering neuro-stimulation, comprising the steps of:

receiving two time-varying power signals varying between two levels and out of phase with the other, and a command signal modulated onto at least one of the power signals;

determining whether the signals are addressed to the electrode cell;

if the electrode cell has more than one electrode, determining which electrode is selected;

directing electrical charge from the signals to an on-board current source,

then recovering commands from the command signal, and;

setting the current of the current source to the value defined by the recovered commands,

connecting the electrode to the on-board current source at a first time prescribed by the recovered commands, and,

disconnecting the electrode from the current source at a second time prescribed by the recovered commands.

28. The signals according to claim 26, wherein commands are modulated using differential pulse phase modulation.

27. A pair of signals for transmission between an implant controller and an electrode cell, comprising:

two time-varying power signals, each varying between two levels and each being out of phase with the other;

wherein at least one of the power signals is modulated with commands;

wherein, the command selects an electrode of at least one of the electrode cells to deliver a stimulus; and

wherein, the control logic within the selected cell uses the command to control the selected electrode to deliver charge extracted from the power signals, in cooperation with at least one other electrode.

29. A distributed implantable neuro-stimulation system, comprising:

an implant controller;

one or more electrode cells;

and a bus interconnecting the implant controller and the electrode cells, to carry power and command signals;

wherein there are ‘

n’

wires in the bus and ‘

m’

electrodes and 1<

n<

m.