Implantable Electroacupuncture System and Method for Treating Parkinson's Disease and Essential Tremor

• US 20140214119A1
• Filed: 02/12/2013
• Published: 07/31/2014
• Est. Priority Date: 03/06/2012
• Status: Active Grant

• Current Assignee: Valencia Bioscience, Inc.
• Original Assignee: Valencia Technologies Corporation
• Inventors: Greiner, Jeffrey H., Peterson, David K. L., Thenuwara, Chuladatta, Greiner, Stacy O.
• Granted Patent: US 9,433,786 B2
• Time in Patent Office: Days
• US Class Current: 607/45
• CPC Class Codes: A61N 1/36067 Movement disorders, e.g. tremor or Parkinson disease stimulating motor muscle A61N1/36003
• CPC Class Codes: A61N 1/36125 Details of circuitry or electric components
• CPC Class Codes: A61N 1/36153 Voltage A61N1/3616 takes precedence
• CPC Class Codes: A61N 1/36157 Current A61N1/3616 takes precedence
• CPC Class Codes: A61N 1/36175 Pulse width or duty cycle
• CPC Class Codes: A61N 1/37205 Microstimulators, e.g. implantable through a cannula
• CPC Class Codes: A61N 1/3756 Casings with electrodes thereon, e.g. leadless stimulators
• CPC Class Codes: A61N 1/3782 producing a voltage above the power source level

Abstract

An implantable electroacupuncture device (IEAD) treats Parkinson'"'"'s disease or Essential Tremor through application of stimulation pulses applied at at least one of acupoints GB34 and GV20. The IEAD includes an hermetically-sealed implantable electroacupuncture (EA) device having at least two electrodes located outside of its housing. The housing contains a primary power source, pulse generation circuitry, and a sensor that wirelessly senses externally-generated operating commands. The pulse generation circuitry generates stimulation pulses as controlled, at least in part, by the operating commands sensed through the sensor. The stimulation pulses are applied to the specified acupoint or nerve through the electrodes in accordance with a specified stimulation regimen. Such stimulation regimen requires that the stimulation session be applied at a very low duty cycle not greater than 0.05.

Claims

1. An Implantable ElectroAcupuncture System (IEAS) for treating Parkinson'"'"'s disease or Essential Tremor through application of electroacupuncture (EA) stimulation pulses applied at a specified tissue location of a patient, comprising:

an implantable electroacupuncture (EA) device comprising a small, hermetically-sealed housing containing a primary power source, pulse generation circuitry powered by the primary power source, and a sensor that wirelessly senses operating commands generated external to the housing, wherein the pulse generation circuitry generates stimulation pulses in accordance with a specified stimulation regimen as controlled at least in part by the operating commands sensed through the sensor;

a plurality of electrode arrays, where at least one electrode array of the plurality of electrode arrays functions as a cathodic electrode array and at least one electrode array of the plurality of electrode arrays functions as an anodic electrode array, wherein an electrode array comprises an array of n conductive contacts electrically joined together to function jointly as one electrode, where n is an integer of from 1 to 24, on the outside of the EA device housing electrically coupled to the pulse generation circuitry on the inside of the EA device housing through at least one feed-through terminal passing through a wall of the hermetically-sealed housing, whereby the stimulation pulses generated by the pulse generation circuitry are directed to flow through the patient'"'"'s tissue at the specified tissue location as such pulses flow between the anodic and cathodic electrode arrays on the outside of the EA device housing in accordance with the specified stimulation regimen;

wherein the specified stimulation regimen defines how often a stimulation session comprising a stream of stimulation pulses is applied to the patient, the stimulation regimen requiring that the stimulation session have a duration of T3 minutes and a rate of occurrence of once every T4 minutes, wherein the ratio of T3/T4 is no greater than 0.05; and

wherein the specified tissue location whereat EA stimulation pulses are applied comprises a target tissue location defined by at least one of acupoints GV20 or GB34.

2. The IEAS of claim 1 wherein the plurality of electrode arrays are located on an outside surface of the case of the implantable EA device.

3. The IEAS of claim 2 wherein the plurality of electrode arrays are located on a bottom surface of the case of the implantable EA device.

4. The IEAS of claim 3 wherein a first one of the plurality of electrode arrays is centrally located on the bottom surface of the case of the implantable EA device and a second one of the plurality of electrode arrays surrounds the first array.

5. The IEAS of claim 1 wherein the dimensions of the EA device are L×

W×

H, where L is the longest linear dimension, W is the shortest linear dimension measured in substantially the same plane as L, and H is the maximum height or thickness of the housing measured in a plane orthogonal with the plane where L and W are measured, and wherein L is no greater than about 25 mm, W is no less than about 15 mm and H is no greater than about 2.5 mm.

6. The IEAS of claim 1 wherein the primary power source of the EA device comprises a battery having a nominal output voltage of no more than 3.0 volts and an internal impedance of no less than about 5 ohms.

7. The IEAS of claim 6 wherein the pulse generation circuitry includes:

a boost converter circuit that boosts the nominal voltage of the primary battery to an output voltage V_OUT that is at least three times the nominal battery voltage;

a control circuit that selectively turns the boost converter circuit OFF and ON to limit the amount of current that may be drawn from the primary battery; and

an output circuit powered by V_OUT and controlled by the control circuit that generates the stimulation pulses as defined by the specified stimulation regimen.

8. The IEAS of claim 7 wherein the stimulation pulses generated by the pulse generation circuit and delivered through the plurality of electrode arrays into a load at the specified tissue location comprise voltage pulses having a voltage amplitude of no less than about 1V and no greater than about 15 V.

9. The IEAS of claim 7 wherein the stimulation pulses generated by the pulse generation circuit and delivered through the plurality of electrode arrays into a load at the specified tissue location comprise current pulses having a current amplitude of no less than about 1 milliampere (mA) and no greater than about 25 mA.

10. The IEAS of claim 7 wherein the primary battery has sufficient capacity to power the pulse generation circuitry in accordance with the specified stimulation regimen for a minimum of 2 years.

11. The IEAS of claim 1 further including an external control device adapted to selectively generate operating commands that are sensed by the sensor within the implantable EA device.

12. The IEAS of claim 11 wherein the sensor within the implantable EA device comprises a magnetic field sensor, and wherein the external control device comprises a magnet.

13. An Implantable ElectroAcupuncture Device (IEAD) for treating a Parkinson'"'"'s or Essential Tremor condition of a patient, comprising

a) an implantable electroacupuncture (EA) device housing having a maximum linear dimension of no more than 25 mm in a first plane, and a maximum height of no more 2.5 mm in a second plane orthogonal to the first plane;

b) a primary battery within the EA housing having an internal impedance of no less than about 5 ohms;

c) pulse generation circuitry within the EA housing and powered by the primary battery that generates stimulation pulses during a stimulation session;

d) control circuitry within the EA housing and powered by the primary battery that controls the frequency of the stimulation sessions to occur no more than once every T4 minutes, and that further controls the duration of each stimulation session to last no longer than T3 minutes, where the ratio of T3/T4 is no greater than 0.05;

e) sensor circuitry within the EA housing and coupled to the control circuitry that is responsive to the presence of a control command generated external to the EA device housing, which control command when received by the control circuitry sets the times T3 and T4 to appropriate values; and

f) a plurality of electrodes located outside of the EA device housing that are electrically coupled to the pulse generation circuitry within the EA device housing, wherein stimulation pulses of the stimulation sessions are applied to body tissue located in the vicinity of the plurality of electrodes; and

g) wherein the plurality of electrodes are positioned to lie at or near a target tissue location belonging to the group of target tissue locations comprising acupoints GV20 or GB34.

14. The IEAD of claim 13 wherein the sensor circuitry within the EA housing comprise magnetic field sensing circuitry, and wherein the control command is derived from the timing associated with when a magnetic field is present or absent.

15. A method for treating Parkinson'"'"'s disease or Essential Tremor of a patient, comprising the steps of:

(a) implanting an electroacupuncture (EA) device in the patient below the patient'"'"'s skin at or near at least one specified target tissue location;

(b) enabling the EA device to generate stimulation sessions at a duty cycle that is less than or equal to 0.05, wherein each stimulation session comprises a series of stimulation pulses, wherein the duty cycle is the ratio of T3/T4, where T3 is the duration of each stimulation session, and T4 is the duration between stimulation sessions; and

(c) delivering the stimulation pulses of each stimulation session to the at least one specified target tissue location through a plurality of electrode arrays electrically connected to the EA device, where an electrode array comprises an array of n conductive contacts electrically joined together to function jointly as one electrode, where n is an integer.

16. The method of treating Parkinson'"'"'s disease or Essential Tremor of claim 15 wherein the at least one specified target tissue location at which the stimulation pulses are applied is selected from the group of target tissue locations comprising acupoints GV20 or GB34.

17. The method of treating Parkinson'"'"'s Disease or Essential Tremor of claim 16 further comprising attaching the plurality of electrode arrays to an outside surface of the EA device, with one electrode array of the plurality of electrode arrays comprising a central electrode array, and with another electrode array of the plurality of electrode arrays comprising an annular electrode array that surrounds the central electrode array, and wherein the spacing between the center of the central electrode array and the closest electrode contact within the annular electrode array comprises at least 5 mm.

18. The method of treating Parkinson'"'"'s disease or Essential Tremor of claim 17 further including setting the time T4, the time between stimulation sessions, to be at least 1440 minutes [1 day] but no longer than 20,160 minutes [14 days].

19. A method of treating Parkinson'"'"'s disease or Essential Tremor of a patient using a small implantable electroacupuncture device (IEAD) powered by a small disc primary battery having a specified nominal output voltage of about 3 volts, and having an internal impedance of at least 5 ohms, the IEAD being configured, using electronic circuitry within the IEAD, to generate stimulation pulses in accordance with a specified stimulation regimen and apply the stimulation pulses through at least two electrodes located outside of the housing of the IEAD at a selected tissue location, said at least two electrodes comprising at least one cathode electrode and at least one anode electrode, said method comprising:

(a) implanting the IEAD below the skin surface of the patient at or near a target tissue location selected from the group of target tissue locations comprising acupoints GV20 or GB34, and

(b) enabling the IEAD to provide EA stimulation pulses in accordance with a stimulation regimen that provides a stimulation session having a duration of T3 minutes at a rate of once every T4 minutes, where the ratio of T3/T4 is no greater than 0.05, and wherein T3 is at least 10 minutes and no greater than 60 minutes.

20. The method of claim 19 further including setting the stimulation pulses during a stimulation session to have a duration of T1 seconds, that occur at a rate of once every T2 seconds, wherein T1 is 0.1 to 2.0 milliseconds, and T2 is 67 to 1000 milliseconds.

21. The method of claim 19 further including setting the stimulation pulses during a stimulation session to have a duration of T1 seconds, that occur at a rate of once every T2 seconds, wherein T1 is 0.1 to 2.0 milliseconds, and T2 is 8.3 to 10 milliseconds.

22. The method of claim 19 further including controlling the electronic circuits within the IEAD to limit the instantaneous current drawn from the small disc primary battery so that the output voltage of the primary battery does not drop more than about 11% below the output voltage of the primary battery when current is being drawn from the primary battery, where the output voltage of the primary battery is equal to the specified nominal output voltage of the primary battery less the voltage drop caused by the instantaneous current flowing through the internal impedance of the primary battery.

23. The method of claim 22 wherein the electronic circuitry within the IEAD includes a boost converter circuit, and wherein the method of controlling the electronic circuits within the IEAD to limit the instantaneous current drawn from the battery comprises modulating the operation of the boost converter circuit between an ON state and an OFF state.

24. A method of assembling an implantable electroacupuncture device (IEAD) in a small, thin, hermetically-sealed, housing having a maximum linear dimension in a first plane of no more than 25 mm and a maximum linear dimension in a second plane orthogonal to the first plane of no more than 2.5 mm, the housing having at least one feed-through pin assembly radially passing through a wall of the thin housing that isolates the feed-through pin assembly from high temperatures and residual weld stresses that occur when the thin housing is welded shut to hermetically-seal its contents, the IEAD being adapted for use in treating Parkinson'"'"'s disease or Essential Tremor of a patient, the method comprising the steps of:

(a) forming a thin housing having a bottom case and a top cover plate, the top cover plate being adapted to fit over the bottom case, the bottom case having a maximum linear dimension of no more than 25 mm;

(b) forming a recess in a wall of the housing;

(c) placing a feed-through assembly within the recess so that a feed-through pin of the feed-through assembly electrically passes through a wall of the recess at a location that is separated from where the wall of the housing is designed to contact the top cover plate; and

(d) welding the top cover plate to the bottom case around a perimeter of the bottom case, thereby hermetically sealing the bottom case and top case together.