Charge recovery bi-phasic control for tissue stimulation

• US 9,415,223 B2
• Filed: 11/02/2010
• Issued: 08/16/2016
• Est. Priority Date: 11/02/2009
• Status: Active Grant

• Current Assignee: Boston Scientific Neuromodulation Corporation (Boston Scientific Corporation)
• Original Assignee: Boston Scientific Neuromodulation Corporation (Boston Scientific Corporation)
• Inventors: Carbunaru, Rafael, Bradley, Kerry
• Primary Examiner(s): Koharski, Christopher D
• Assistant Examiner(s): Bays, Pamela M
• Application Number:
  US12/938,202
• Publication Number:
  US 20110106214A1
• Time in Patent Office: 2,114 Days
• Field of Search: 607/2, 607/45, 607/46, 607/62, 607/63, 607/72, 607/74
• US Class Current: 1/1
• CPC Class Codes: A61N 1/0551 Spinal or peripheral nerve electrodes
• CPC Class Codes: A61N 1/36071 Pain
• CPC Class Codes: A61N 1/36125 Details of circuitry or electric components
• CPC Class Codes: A61N 1/36128 Control systems
• CPC Class Codes: A61N 1/36178 Burst or pulse train parameters
• CPC Class Codes: A61N 1/36185 Selection of the electrode configuration

Abstract

A method and external control device for providing therapy to a patient using first and second electrodes implanted within the patient is provided. A train of electrical multi-phasic pulses is generated. A first electrical current is sourced from the second electrode and at least a portion of the first electrical current is sunk to the first electrode during a stimulation phase of each multi-phasic pulse, thereby therapeutically stimulating a first tissue region adjacent the first electrode. A second electrical current is sourced from the first electrode and at least a portion of the second electrical current is sunk to the second electrode during a charge recovery phase of each multi-phasic pulse, thereby recovering at least a portion of the charge that had been injected into the patient during the stimulation phase of each multi-phasic pulse, and therapeutically stimulating a second tissue region adjacent the second electrode.

Claims

1. An external control device for controlling a neurostimulator and associated first and second electrodes respectively implanted adjacent first and second tissue regions of a patient, wherein the first and second electrodes respectively have first and second tissue stimulation thresholds for stimulating tissue in the first and second tissue regions respectively, comprising:

a user interface configured for receiving an input from a user;

telemetry circuitry configured for wirelessly communicating with the neurostimulator; and

a processor configured for, in response to the user input, generating and transmitting instructions to the neurostimulator via the telemetry circuitry to (a) generate a train of electrical multi-phasic pulses, (b) source a first electrical current from the second electrode into tissue in the second tissue region and sink at least a portion of the first electrical current from tissue in the first tissue region to the first electrode to stimulate tissue in the first tissue region during a stimulation phase of each multi-phasic pulse, and (c) to source a second electrical current from the first electrode into tissue in the first tissue region and sink at least a portion of the second electrical current from tissue in the second tissue region to the second electrode to stimulate tissue in the second tissue region during a charge recovery phase of each multi-phasic pulse, wherein the processor is further configured for setting the amplitude of the portion of the first sunk electrical current below the amplitude of the portion of the second sunk electrical current if the first tissue stimulation threshold to stimulate the first tissue region is less than the second tissue stimulation threshold to stimulate the second tissue region, and setting the amplitude of the portion of the first sunk electrical current above the amplitude of the portion of the second sunk electrical current if the first tissue stimulation threshold to stimulate the first tissue region is greater than the second tissue stimulation threshold to stimulate the second tissue region.

2. The external control device of claim 1, wherein the processor is configured for generating and transmitting instructions to the neurostimulator via the telemetry circuitry to adjust an interphase between the stimulation phase and the charge recovery phase of each multi-phasic pulse.

3. The external control device of claim 2, wherein the interphase is at least one-half of the stimulation phase.

4. The external control device of claim 1, wherein each multi-phasic pulse is a bi-phasic pulse.

5. The external control device of claim 4, wherein each bi-phasic pulse is symmetrical.

6. The external control device of claim 4, wherein each bi-phasic pulse is asymmetrical.

7. The external control device of claim 1, wherein the processor is configured for generating and transmitting instructions to the neurostimulator via the telemetry circuitry to sink a first test electrical current to the first electrode from the first tissue region, and to sink a second test electrical current to the second electrode from the second tissue region, and the processor is further configured for determining the first stimulation threshold of the first electrode based on the first test electrical current, and determining the second stimulation threshold of the second electrode based on the second test electrical current.

8. The external control device of claim 1,

wherein the amplitude of the portion of the first sunk electrical current is set below the amplitude of the portion of the second sunk electrical current by sinking another portion of the first electrical current to a third electrode implanted within the patient during the stimulation phase of each multi-phasic pulse;

and

wherein the amplitude of the portion of the first sunk electrical current is set above the amplitude of the portion of the second sunk electrical current by sinking another portion of the second electrical current to the third electrode during the charge recovery phase of each multi-phasic pulse.

9. The external control device of claim 1,

wherein the amplitude of the portion of the first sunk electrical current is set below the amplitude of the portion of the second sunk electrical current by adjusting the duration of the stimulation phase of each multi-phasic pulse to be longer than the duration of the charge recovery phase of each multi-phasic pulse;

and

wherein the amplitude of the portion of the first sunk electrical current is set above the amplitude of the portion of the second sunk electrical current sunk by adjusting the duration of the charge recovery phase of each multi-phasic pulse to be longer than the duration of the stimulation phase of each multi-phasic pulse.

10. A neurostimulation system, comprising:

first and second electrodes configured for being respectively implanted adjacent first and second tissue regions of a patient, wherein the first and second electrodes respectively have first and second tissue stimulation thresholds for stimulating tissue in the first and second tissue regions respectively;

a neurostimulator configured for (a) generating a train of electrical multi-phasic pulses, therapeutically stimulating the first tissue region by sourcing a first electrical current from the second electrode into tissue in the second tissue region and sinking at least a portion of the first electrical current from tissue in the first tissue region to the first electrode during a stimulation phase of each multi-phasic pulse, and (b) therapeutically stimulating the second tissue region by sourcing a second electrical current from the first electrode into tissue in the first tissue region and sinking at least a portion of the second electrical current from tissue in the second tissue region to the second electrode during a charge recovery phase of each multi-phasic pulse; and

an external control device configured for (a) instructing the neurostimulator to set the amplitude of the portion of the first sunk electrical current below the amplitude of the portion of the second sunk electrical current if the first tissue stimulation threshold to stimulate the first tissue region is less than the second tissue stimulation threshold to stimulate the second tissue region, and (b) to set the amplitude of the portion of the first sunk electrical current above the amplitude of the portion of the second sunk electrical current if the first tissue stimulation threshold to stimulate the first tissue region is greater than the second tissue stimulation threshold to stimulate the second tissue region.

11. The neurostimulation system of claim 10, wherein the external control device is configured for instructing the neurostimulator to sink a first test electrical current to the first electrode from the first tissue region, and sink a second test electrical current to the second electrode from the second tissue region, and wherein the external control device is further configured for determining the first tissue stimulation threshold of the first electrode based on the first test electrical current, and determining the second tissue stimulation threshold of the second electrode based on the second test electrical current.

12. The neurostimulation system of claim 10, wherein the external control device is configured for instructing the neurostimulator to set the amplitude of the portion of the first sunk electrical current below the amplitude of the portion of the second sunk electrical current sunk by sinking another portion of the first electrical current to a third electrode implanted within the patient during the stimulation phase of each multi-phasic pulse, and instructing the neurostimulator to set the amplitude of the portion of the first sunk electrical current above the amplitude of the portion of the second sunk electrical current by sinking another portion of the second electrical current to the third electrode during the charge recovery phase of each multi-phasic pulse.

13. The neurostimulation system of claim 10, wherein the external control device is configured for instructing the neurostimulator to set the amplitude of the portion of the first sunk electrical current below the amplitude of the portion of the second sunk electrical current sunk by adjusting the duration of the stimulation phase of each multi-phasic pulse to be longer than the duration of the charge recovery phase of each multi-phasic pulse, and instructing the neurostimulator to set the amplitude of the portion of the first sunk electrical current above the amplitude of the portion of the second sunk electrical current by adjusting the duration of the charge recovery phase of each multi-phasic pulse to be longer than the duration of the stimulation phase of each multi-phasic pulse.

14. An external control device for controlling a neurostimulator and associated first and second electrodes respectively implanted adjacent first and second tissue regions of a patient, wherein the first and second electrodes respectively have first and second stimulation thresholds with respect to the first and second tissue regions, comprising:

a user interface configured for receiving an input from a user;

telemetry circuitry configured for wirelessly communicating with the neurostimulator; and

a processor configured for, in response to the user input, generating and transmitting instructions to the neurostimulator via the telemetry circuitry to (a) generate a train of electrical multi-phasic pulses, (b) source a first electrical current from the second electrode and sink at least a portion of the first electrical current to the first electrode during a stimulation phase of each multi-phasic pulse, and (c) to source a second electrical current from the first electrode and sink at least a portion of the second electrical current to the second electrode during a charge recovery phase of each multi-phasic pulse, wherein the processor is further configured for setting the amplitude of the portion of the first sunk electrical current below the amplitude of the portion of the second sunk electrical current if the first stimulation threshold to stimulate the first tissue region is less than the second stimulation threshold to stimulate the second tissue region, and setting the amplitude of the portion of the first sunk electrical current above the amplitude of the portion of the second sunk electrical current if the first stimulation threshold to stimulate the first tissue region is greater than the second stimulation threshold to stimulate the second tissue region,

wherein the amplitude of the portion of the first sunk electrical current is set below the amplitude of the portion of the second sunk electrical current by sinking another portion of the first electrical current to a third electrode implanted within the patient during the stimulation phase of each multi-phasic pulse; and

wherein the amplitude of the portion of the first sunk electrical current is set above the amplitude of the portion of the second sunk electrical current by sinking another portion of the second electrical current to the third electrode during the charge recovery phase of each multi-phasic pulse.