Implantable electroacupuncture device and method for treating depression, bipolar disorder and anxiety

• US 9,198,828 B2
• Filed: 09/28/2012
• Issued: 12/01/2015
• Est. Priority Date: 09/29/2011
• 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.
• Primary Examiner(s): Lavert, Nicole F.
• Assistant Examiner(s): KIMBALL, JEREMIAH T
• Application Number:
  US13/630,322
• Publication Number:
  US 20140214117A1
• Time in Patent Office: 1,159 Days
• Field of Search: 607/2, 607 44- 46, 607/72, 128/907
• US Class Current: 1/1
• CPC Class Codes: A61H 39/002 Using electric currents electrotherapy A61N1/32
• CPC Class Codes: A61N 1/36096 Mood disorders, e.g. depression, anxiety or panic disorder
• CPC Class Codes: A61N 1/36117 for treating hypertension
• CPC Class Codes: A61N 1/36125 Details of circuitry or electric components
• 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
• CPC Class Codes: Y10T 29/49002 Electrical device making

Abstract

An implantable electroacupuncture device (IEAD) treats depression, bipolar disorder or Anxiety through application of stimulation pulses applied at acupoints GV20 and/or EXHN3. The IEAD comprises an implantable, coin-sized, self-contained, leadless electroacupuncture device having at least two electrodes attached to an outside surface of its housing. The device generates stimulation pulses in accordance with a specified stimulation regimen. Power management circuitry within the device allows a primary battery, having a high internal impedance, to be used to power the device. The stimulation regimen generates stimulation pulses during a stimulation session of duration T3 minutes applied every T4 minutes. The duty cycle, or ratio T3/T4, is very low, no greater than 0.05. The low duty cycle and careful power management allow the IEAD to perform its intended function for several years.

Claims

1. An Implantable ElectroAcupuncture Device (IEAD) for treating depression, bipolar disorder, or anxiety, adapted for application of electroacupuncture (EA) stimulation pulses substantially at or near at least one of acupoints GV20 and EXHN3 of a patient, comprising:

a small, thin, leadless coin-sized and coin-shaped IEAD housing having a symmetrical electrode configuration thereon that includes at least two electrodes/arrays, a longest linear dimension of the IEAD housing being no greater than about 25 mm, wherein at least one of said at least two electrodes/arrays comprises a central electrode/array located substantially in a center of a first surface of the IEAD housing, and wherein at least another of said at least two electrodes/arrays comprises a circumferential electrode/array located substantially around and at least 5 mm distant from the center of the central electrode/array, wherein the first surface of the IEAD housing when implanted is adapted to face selected target tissue at or near at least one of acupoints GV20 and EXHN3;

pulse generation circuitry located within the IEAD housing and electrically coupled to the at least two electrodes/arrays, wherein said pulse generation circuitry, once turned on, is adapted to continuously deliver stimulation sessions in accordance with a specified stimulation regimen to the at least two electrodes/arrays adapted for placement at or near the patient'"'"'s body tissue near at least one of acupoints GV20 and EXHN3, said stimulation regimen defining the duration and rate at which a stimulation session is applied to the patient, said stimulation regimen requiring that the stimulation session have a duration of T3 minutes, where T3 is at least 10 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 during each stimulation session EA stimulation pulses having one or more specified widths and amplitudes are generated at one or more specified rates;

a primary battery contained within the IEAD housing and electrically coupled to the pulse generation circuitry, said primary battery having a nominal output voltage of 3 volts, and an internal impedance greater than 5 ohms; and

a magnetic sensor contained within the IEAD housing responsive to a presence or absence of a magnetic field placed near the IEAD housing, the sensed presence/absence of the magnetic field in a prescribed sequence allowing the pulse generation circuitry to be turned on, thereby allowing limited external control of the IEAD.

2. The IEAD of claim 1 wherein the central electrode/array comprises an electrode array having no more than 4 segments, the central electrode array having a maximum linear dimension of no greater than about 7 mm.

3. The IEAD of claim 2 wherein the circumferential electrode/array comprises an electrode array having no more than 4 electrode segments positioned around the central electrode/array.

4. The IEAD of claim 3 wherein the circumferential electrode/array comprises an anode electrode/array and the central electrode/array comprises a cathode electrode/array.

5. The IEAD of claim 3 wherein the circumferential electrode/array comprises a cathode electrode/array and the central electrode/array comprises an anode electrode/array.

6. The IEAD of claim 1 wherein the IEAD housing is coin-shaped having a diameter no greater than about 25 mm and a thickness of no greater than about 2.5 mm.

7. The IEAD of claim 1 wherein the IEAD housing is oval shaped having a maximum linear dimension of no greater than about 25 mm and a thickness of no greater than about 2.5 mm.

8. The IEAD of claim 1 wherein the duration of the stimulation session T3 varies between 10 minutes and 70 minutes and the rate of occurrence of the stimulation session T4 is set to a value between 1440 minutes [1 day] and 20,160 minutes [14 days].

9. The IEAD of claim 1 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 EA stimulation pulses as defined by the specified stimulation regimen.

10. The IEAD of claim 9 wherein the EA stimulation pulses generated by the pulse generation circuit are delivered through the at least two electrodes/arrays into a load at the specified acupoint comprise voltage pulses having a voltage amplitude of no less than about 1 V and no greater than about 15 V.

11. The IEAD of claim 9 wherein the EA stimulation pulses generated by the pulse generation circuit are delivered through the at least two electrodes/arrays into a load at the specified acupoint comprise current pulses having a current amplitude of no less than about 1 milliampere (mA) and no greater than about 15 mA.

12. The IEAD of claim 9 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.

13. A method of treating depression, bipolar disorder, or anxiety in a patient using a small, leadless, coin-sized and coin shaped implantable electroacupuncture device (IEAD) powered by a small disc primary battery having a specified nominal output voltage of 3 volts, and having an internal impedance of at least 5 ohms, the IEAD being configured, using self-contained electronic circuitry within the IEAD, to generate electroacupuncture (EA) stimulation pulses in accordance with a specified stimulation regimen and apply the EA stimulation pulses to at least two electrodes/arrays located on an outside surface of a housing of the IEAD and configured in a symmetrical pattern, said at least two electrodes/arrays comprising at least one central electrode/array of a first polarity, having a maximum width of no more 7 mm, centrally located on a first surface of the IEAD housing, and at least one annular electrode/array of a second polarity spaced apart from the central electrode/array by at least 5 mm measured from the edge of the annular electrode/array closest to the central electrode/array to the center of the central electrode/array, said method comprising:

(a) implanting the IEAD below the skin surface of the patient at at least one acupoint selected from acupoints GV20 and EXHN3, with the first surface of the IEAD facing a target tissue location associated with the selected acupoint;

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

14. The method of claim 13 further including setting the time T4 to be at least 720 minutes [½

day], but no more than about 20,160 minutes [14 days].

15. The method of claim 14 further setting T3, the duration of the stimulation session, to a value between 20 minutes and 72 minutes if T4, the rate of occurrence of the stimulation session, is set to a value between 1,440 minutes and 20,160 minutes [14 days];

and setting T3 to a value between 10 minutes and a maximum T3 value, T3(max), if T4 is set to a value between 720 minutes and 1,440 minutes, wherein T3(max) varies as a function of T4 as defined by the equation;

T3(max)=0.05*T4.

16. The method of claim 14 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, where the ratio of T1/T2 is no greater than 0.01.

17. The method of claim 16 further including setting the time T1 to be 0.1 to 1.0 millisecond and the time T2 to be 250 to 1000 milliseconds.

18. The method of claim 13 further including controlling the electronic circuits within the IEAD to limit 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.

19. The method of claim 18 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.

20. A method for treating depression, bipolar disorder or anxiety in a patient comprising the steps of:

(a) implanting a small, thin, coin-sized and coin-shaped, leadless, electroacupuncture (EA) device in the patient below the patient'"'"'s skin at at least one specified acupoint;

(b) enabling the EA device to generate stimulation sessions at a duty cycle that is less than or equal to 0.05, each stimulation session comprising a series of stimulation pulses, wherein the duty cycle is the ratio of T3/T4, where T3 is the duration in minutes of each stimulation session, wherein T3 is at least 10 minutes, and T4 is the time in minutes between stimulation sessions; and

(c) continuously delivering the stimulation pulses of each stimulation session to the at least one specified acupoint through at least two electrodes/arrays attached to an outside surface of the EA device in a slow and methodical manner that is adapted to gradually condition and remodel the patient'"'"'s central nervous system so as to produce a sustained therapeutic benefit for patient.

21. The method of treating depression, bipolar disorder, or anxiety of claim 20 wherein the at least one specified acupoint at which the stimulation pulses are applied is selected from the group of acupoints that includes acupoints GV20 and EXHN3.

22. The method of treating depression, bipolar disorder or anxiety of claim 20 further comprising forming the at least two electrodes/arrays attached to the outside surface of the EA device in a concentric pattern, with one electrode/array of the at least two electrodes/arrays comprising a central electrode/array, and with another electrode of the at least two electrodes/arrays comprising an annular electrode/array that surrounds the central electrode/array, wherein the spacing between the center of the central electrode/array and an edge of the annular electrode/array closest to the central electrode/array comprises at least 5 mm.

23. The method of treating depression, bipolar disorder or anxiety of claim 22 further including forming the annular electrode/array as a ring electrode/array attached around a perimeter edge of the coin-sized EA device.

24. The method of treating depression, bipolar disorder or anxiety of claim 23 further including configuring the central electrode/array as a cathode electrode and the perimeter-edge ring electrode/array as an anode electrode.

25. The method of treating depression, bipolar disorder or anxiety of claim 20 wherein enabling the EA device to generate stimulation sessions includes generating the series of stimulation pulses within each stimulation session so that each stimulation pulse has a duration of between 0.1 and 1.0 millisecond and occurs at a rate of between 1 and 3 Hz.

26. The method of treating depression, bipolar disorder or anxiety of claim 20 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].

27. The method of treating depression, bipolar disorder or anxiety of claim 26 further setting T3, the duration of the stimulation session, to a value between 10 minutes and 72 minutes.

28. A method of assembling an implantable electroacupuncture device (IEAD) for use in treating depression, bipolar disorder or anxiety in a thin, hermetically-sealed, coin-sized housing having at least one feed-through pin assembly radially passing through a wall of the coin-sized housing that isolates the feed-through pin assembly from high temperature damage that could occur when the coin-sized housing is welded shut to hermetically-seal its contents, the method comprising the steps of:

(a) forming a coin-sized 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 longest linear dimension D2 of no more than about 25 mm and a perimeter side wall extending all the way around the perimeter of the bottom case, the perimeter side wall having a height W2, wherein the ratio of W2 to D2 is no greater than about 0.13;

(b) forming a recess in one segment of the side wall, said recess extending radially inwardly from the side wall to a depth D3, said recess having an opening in a bottom wall portion thereof;

(c) hermetically sealing a feed-through assembly in the opening in the bottom of the recess, the feed-through assembly having a feed-through pin that passes through the opening without contacting the edges of the opening, a distal end of the pin extending radially outward beyond the side wall of the bottom case, and a proximal end of the feed-through pin extending radially inward toward a center of the bottom case, whereby the feed-through assembly is hermetically bonded to the opening in the side wall at a location in the bottom of the recess that is located a distance D3 from the perimeter side wall, thereby thermally and mechanically isolating the feed-through assembly from high temperatures and residual weld stresses that occur at the perimeter side wall when the cover plate is welded to the edge of the perimeter side wall in step (e);

(d) attaching a central electrode to the thin coin-sized housing at a central location on a bottom outside surface of the housing;

(e) inserting an electronic circuit assembly, including a battery, inside of the bottom case, and connecting the proximal end of the feed-though pin to an output terminal of the electronic circuit assembly, and electrically connecting the bottom case to a reference terminal of the battery;

(f) welding the top cover plate to the edges of the side wall of the bottom case, thereby hermetically sealing the electronic circuit assembly, including the battery, inside of the IEAD housing, the IEAD housing comprising the assembly resulting from welding the top cover plate to the bottom case, the top cover plate forming a top surface of the IEAD housing, and a surface of the IEAD housing opposite the top surface comprising a bottom surface of the IEAD housing;

(g) placing an insulating layer of non-conductive material around the perimeter edge of the IEAD housing;

(h) placing a circumscribing electrode over the insulating layer of non-conductive material around the perimeter edge of the IEAD housing, and then electrically connecting the distal end of the feed-through pin to circumscribing electrode; and

(i) covering all external surface areas of the IEAD housing with a layer of non-conductive material except for the circumscribing electrode around the perimeter of the IEAD housing and the central electrode centrally located on the bottom surface of the IEAD housing.