Implantable stimulator with replenishable, high value capacitive power source and method therefor

• US 5,591,217 A
• Filed: 01/04/1995
• Issued: 01/07/1997
• Est. Priority Date: 01/04/1995
• Status: Expired due to Term

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Plexus Corporation
• Inventors: Barreras, Francisco J.
• Primary Examiner(s): Kamm, William E.
• Assistant Examiner(s): Getzow, Scott M.
• Application Number:
  US08/368,326
• Time in Patent Office: 734 Days
• Field of Search: 607/5, 607/9, 607/32, 607/34, 607/65, 607/2, 607/33, 607/61
• US Class Current: 607/61
• CPC Class Codes: A61N 1/37223 Circuits for electromagnetic coupling
• CPC Class Codes: A61N 1/3787 from an external energy source
• CPC Class Codes: H02J 2310/23 The load being a medical device, a medical implant, or a life supporting device
• CPC Class Codes: H02J 50/10 using inductive coupling
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 7/00034 Charger exchanging data with an electronic device, i.e. telephone, whose internal battery is under charge

Abstract

The implantable stimulator in accordance with the principles of the present invention utilizes a high value, small sized capacitor having at least a capacitive rating of 0.1 farads which is completely contained within the implantable stimulator. This high value, small size capacitor or series of capacitors enables the implantable stimulator to deliver, on a controlled and continual basis, electric stimulation pulses to targeted tissues over at least a 8 period. Further, the capacitive power source is recharged or replenished via an external, RF coupled device on a daily or other long term periodic basis. The method includes providing, on an exclusive basis, power to an implantable stimulator via a high value capacitive source during at least a twenty-four cycle of substantially continual delivery of electric stimulation pulses to targeted tissue. The method includes incorporating and containing a capacitive device in the implantable stimulator wherein the capacitive device has a capacitive rating of at least 0.1 farads. The capacitive device captures and stores a pre-determined amount of coulombs of electrical energy. This electrical energy is utilized to power the implantable stimulator during the 8 hour cycle during substantial continual delivery of electric stimulation pulses, all based upon energy stored by the capacitive device.

Claims

1. A system for delivering, in a controlled manner, one or more electric stimulation pulses to targeted tissue comprising:

an implantable stimulator, said stimulator capable of delivering, in a controlled manner, one or more electric stimulation pulses to targeted tissue;

a power source, contained within said implantable stimulator, sufficient to supply power to said implantable stimulator on an exclusive basis over at least an 8 hour period, said power source including a high value, small size capacitive energy storage unit having a capacitive rating of at least 0.1 farads; and

an inductor coil adapted to gather emf power transmissions, a rectifier and a voltage regulator, all electrically coupled to said capacitive energy storage unit and incorporated into said implantable stimulator, for supplying replenishing current to said capacitive energy storage unit.

2. A system as claimed in claim 1 wherein said capacitive energy storage unit has a large enough capacitive rating to exclusively and solely provide power to all portions of said implantable stimulator during at least an 8 hour period while said stimulator delivers the controlled electric stimulation pulses to targeted tissue.

3. A system as claimed in claim 1 including an external means for replenishing said capacitive power source up to its maximum rated voltage by generating said emf power transmissions near said inductor coil.

4. A system as claimed in claim 3 wherein said external means for replenishing said capacitive energy storage unit up to its maximum rated voltage replenishes said capacitive energy storage unit within two hours or less in the presence of said EMF power transmission near said inductor coil.

5. A system as claimed in claim 3 including means, coupled to said capacitive energy storage unit, for detecting when a voltage, representative of the replenishing current fed to said capacitive energy storage unit, has exceeded a threshold level indicative of a full capacitive power source.

6. A system as claimed in claim 5, said implantable stimulator including means, coupled to said means for detecting, for signaling to said external means for replenishing via specific telemetry code, the completion of the replenishing cycle.

7. A system as claimed in claim 6 including means disposed in said external means for replenishing for detecting said telemetry signal generated by said implantable stimulator to indicate completion of the replenishing cycle.

8. A system as claimed in claim 6 including one of an audible and visual indicator for alerting the user of completion of the replenishing cycle as part of said means for replenishing.

9. A system as claimed in claim 3 wherein said external means for replenishing is powered by one of a primary or rechargeable battery, and is capable of non-invasively transferring the energy from its battery to the capacitive power source within said implanted stimulator utilizing EMF power transmissions within a frequency spectrum from 50 Hertz to 500 KiloHertz.

10. A system as claimed in claim 1 wherein said capacitive energy storage unit is a high value, small size capacitor having a capacitive rating of at least 0.1 farads contained within said implantable stimulator.

11. A system as claimed in claim 10 wherein said capacitor is a single, high value, small size capacitor.

12. A system as claimed in claim 10 wherein said capacitor is a plurality of high value, small size capacitors electrically coupled together in parallel wherein said plurality of capacitors, as a single electronic unit have a capacitive rating of at least 0.1 farads or higher.

13. A system as claimed in claim 1 wherein said small size capacitive energy storage unit has a volumetric size less than 4.0 cubic centimeters, and is contained within said implantable stimulator.

14. A system as claimed in claim 1 wherein said capacitive energy storage unit has an energy storage capacity sufficient to supply power to said implantable stimulator on an exclusive basis over at least an 8 hour period during the continual delivery of stimulation pulses to the targeted tissue.

15. A method of providing, on an exclusive basis, power to an implantable stimulator during at least an 8 hour cycle of substantially continual delivery of one or more electric stimulation pulses to targeted tissue in a controlled manner comprising the steps of:

incorporating and containing a capacitive device in said implantable stimulator, said capacitive device having a capacitive rating of at least 0.1 farads;

capturing at least 5 coulombs of electrical energy in said capacitive device prior to said 8 hour period; and

,

powering said implantable stimulator, during said 8 hour cycle for the substantially continual delivery of electric stimulation pulses, solely from said capacitive device.

16. A system for delivering electric stimulation pulses, in a controlled manner, to targeted tissue comprising:

an implantable stimulator capable of delivering, in a controlled manner, one or more electric stimulation pulses to targeted tissue;

a power source, contained within said implantable stimulator, sufficient to supply power to said implantable stimulator on an exclusive basis over at least an 8 hour period, said power source including a high value, small size capacitive energy storage unit having a capacitive rating of at least 0.1 farads;

an inductor coil adapted to gather emf power transmissions, a rectifier and a voltage regulator, all electrically coupled to said capacitive energy storage unit and incorporated into said implantable stimulator; and

,

means, external to said implantable stimulator and not adapted for implantation, for replenishing said capacitive energy storage unit up to its maximum rated voltage by generating said emf power transmission near said inductor coil.

17. A system for delivering electric stimulation pulses as claimed in claim 16 wherein said external means for replenishing is portable and is powered by one of a rechargeable battery and a non-rechargeable battery.

18. A system for delivering electric stimulation pulses as claimed in claim 17 wherein said external means for replenishing includes a transmitting coil which generates emf power transmissions within a frequency spectrum from 50 hertz to 500 kilohertz towards said inductor coil in said implantable stimulator.

19. A system for delivering electric stimulation pulses as claimed in claim 18 wherein said implantable stimulator includes means, coupled to said capacitive energy source, for detecting when a voltage, representative of a replenishing current, fed to said capacitive energy source via said inductor coil, rectifier and regulator, exceeds a threshold level.

20. A system for delivering electric stimulation pulses as claimed in claim 19 wherein said implantable stimulator includes means, coupled to the threshold detector means, for determining and signaling to the external means for replenishing, a completion of a replenishment cycle for said capacitive energy unit.

21. A system for delivering electric stimulation pulses as claimed in claim 20 wherein said external means for replenishing includes means for sensing the completion of replenishment signal from said implant and means, coupled to said sensing means, for alerting the user via one of an audible and a visual indicator of the completion of said replenishing cycle.

22. A system for delivering electric stimulation pulses as claimed in claim 21 wherein said implantable stimulator includes an emf sensitive ON/OFF switch, and means, coupled to said emf sensitive switch, for activating and deactivating said stimulation pulses developed by said implant, and the system includes a user controlled emf source, matched to said emf sensitive switch, which enables the user to non-invasively turn ON and OFF the implant.

23. A system for delivering electric stimulation pulses as claimed in claim 19 wherein said implantable stimulator includes means, coupled to said capacitive energy source, for detecting a low charge voltage when a voltage, present at said capacitive energy source, falls below a low threshold level, and said stimulator includes means, coupled to the low charge voltage means, for reducing the power consumption of said stimulator upon detection of said low charge voltage.

24. A system for delivering electric stimulation pulses as claimed in claim 16 wherein said implantable stimulator includes an emf sensitive ON/OFF switch, and means, coupled to said emf sensitive switch, for activating and deactivating said stimulation pulses developed by said implant, and the system includes a user controlled emf source, matched to said emf sensitive switch, which enables the user to non-invasively turn ON and OFF the implant.

25. A system for delivering electric stimulation pulses as claimed in claim 16 wherein said external means for replenishing includes means for programming said implantable stimulator such that said stimulator delivers electric stimulation pulses to said targeted tissue in a manner dependent upon the stimulation program.