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

• US 5,807,397 A
• Filed: 08/01/1996
• Issued: 09/15/1998
• 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): GETZOW, SCOTT M
• Application Number:
  US08/672,328
• Time in Patent Office: 775 Days
• Field of Search: 607/30, 607/32, 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 an 8 hour period. Further, the capacitive power source is replenished via an external, RF coupled device on a daily or other long term periodic basis. During the replenishing cycle, the energy contained in the battery of the external transmitter is transferred to the internal capacitive power source in the implantable stimulator. The method includes providing, on an exclusive basis, power to an implantable stimulator via a high value capacitive source during at least an 8 hour 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 at least an 8 hour cycle during substantial continual delivery of electric stimulation pulses, all based upon energy stored by the capacitive device. Longer cycles (exceeding 24 hours) may be possible. The replenishment unit can be programmed to interrogate the implant and reprogram the implant upon detection of a lower power status signal. Also, automatic as well as manually commanded replenishment routines are established between the replenishment unit and the implant. Data transmission, error detection routines are established for the programming of the implant.

Claims

1. 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;

said implantable stimulator having in its interior;

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;

a low level voltage detector, electrically coupled to said capacitive energy source, for detecting and issuing a low voltage command when a voltage at said capacitive energy source falls below a predetermined level,

a telemetry circuit coupled to said low voltage detector and receiving said low voltage command, said telemetry circuit transmitting a signal representative of said low voltage command;

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 transmissions near said inductor coil;

said replenishing means having a corresponding telemetry circuit, said corresponding telemetry circuit receiving said signal representative of said low voltage command; and

,

means for controlling said means for replenishing, said means for controlling coupled to said corresponding telemetry circuit and activating said means for replenishing upon receipt of said signal representative of said low voltage command.

2. A system for delivering electric stimulation pulses as claimed in claim 1 wherein said external means for replenishing and said implantable stimulator include means for checking the exchange of telemetry data and commands therebetween.

3. A system for delivering electric stimulation pulses as claimed in claim 1 wherein said implantable stimulator includes a voltage level detection circuit, coupled to said power source, said voltage level detection circuit having means for determining the voltage across said power source.

4. A system for delivering electric stimulation pulses as claimed in claim 3 wherein said implantable stimulator includes means for electrically decoupling said inductor coil from said power source upon detecting a maximum voltage level from said voltage level detection circuit.

5. 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;

said implantable stimulator having in its interior;

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;

a high level voltage detector, electrically coupled to said capacitive energy source, for detecting and issuing a high voltage command when a voltage at said capacitive energy source exceeds a predetermined level,

a telemetry circuit coupled to said high voltage detector and receiving said high voltage command, said telemetry circuit transmitting a signal representative of said high voltage command;

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 transmissions near said inductor coil;

said replenishing means having a corresponding telemetry circuit, said corresponding telemetry circuit receiving said signal representative of said high voltage command; and

,

means for controlling said means for replenishing, said means for controlling coupled to said corresponding telemetry circuit and deactivating said means for replenishing upon receipt of said signal representative of said high voltage command.

6. A system for delivering electric stimulation pulses as claimed in claim 5 wherein said implantable stimulator includes a voltage level detection circuit, coupled to said power source, said voltage level detection circuit having means for determining the voltage across said power source.

7. A system for delivering electric stimulation pulses as claimed in claim 6 wherein said implantable stimulator includes means for electrically decoupling said inductor coil from said power source upon detecting a maximum voltage level from said voltage level detection circuit.

8. 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;

said implantable stimulator having in its interior;

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;

a low level voltage detector, electrically coupled to said capacitive energy source, for detecting and issuing a low voltage command when a voltage at said capacitive energy source falls below a predetermined level;

a telemetry circuit coupled to said low voltage detector and receiving said low voltage command, said telemetry circuit transmitting a signal representative of said low voltage command; and

,

a micro-controller with a memory storing a stimulation program and providing means for controlling the delivery of said stimulation pulses based upon said stored stimulation program;

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 transmissions near said inductor coil;

said replenishing means having;

a corresponding telemetry circuit;

a corresponding micro-controller with a memory storing a primary stimulation program for said implantable stimulator;

said corresponding telemetry circuit receiving said signal representative of said low voltage command and passing said representative low voltage signal to said corresponding micro-controller;

said corresponding micro-controller having means for responding to said representative low voltage signal and up loading said primary stimulation program via said corresponding telemetry circuit, said micro-controller controlling said means for replenishing said capacitive energy storage unit up to its maximum rated voltage and activating the same upon receipt of said representative low voltage signal.

9. A system for delivering electric stimulation pulses as claimed in claim 8 wherein said external means for replenishing includes a user actuable control and means to generate increase or diminish stimulation pulse commands based upon user actuation of said user actuable control, and said corresponding micro-controller having means to transfer said increase or diminish stimulation pulse commands to the implant micro-controller via said telemetry circuits, said implant micro-controller having means for altering said stimulation program based upon said increase or diminish stimulation pulse commands.

10. A system for delivering electric stimulation pulses as claimed in claim 9 wherein said external means for replenishing and said implantable stimulator include means for checking the exchange of telemetry data and commands therebetween, the respective means for checking utilizing said implant micro-controller and memory and said corresponding micro-controller and memory in said means for replenishing.

11. A system for delivering electric stimulation pulses as claimed in claim 8 wherein said external means for replenishing includes, as part of said corresponding micro-controller and memory, means to interrogate said implant micro-controller and memory in order to ascertain the validity of said stimulation program stored therein.

12. A system for delivering electric stimulation pulses as claimed in claim 11 wherein said means to interrogate includes means to re-program said implant micro-controller and memory upon detection of an invalid stimulation program.

13. A system for delivering electric stimulation pulses as claimed in claim 11 wherein,

said implantable stimulator includes:

a high level voltage detector, electrically coupled to said capacitive energy source, for detecting and issuing a high voltage command when a voltage at said capacitive energy source exceeds a predetermined high level; and

,

said telemetry circuit includes means to transmit a signal representative of said high voltage command; and

,

said means for replenishing includes;

means, as part of said means for controlling, for deactivating said means for replenishing upon receipt of said signal representative of said high voltage command.

14. A system for delivering electric stimulation pulses as claimed in claim 8 wherein said implantable stimulator includes a voltage level detection circuit, coupled to said power source, said voltage level detection circuit having means for determining the voltage across said power source.

15. A system for delivering electric stimulation pulses as claimed in claim 14 wherein said implantable stimulator includes means for electrically decoupling said inductor coil from said power source upon detecting a maximum voltage level from said voltage level detection circuit.

16. 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;

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

permitting the automatic re-programming of said implantable stimulator upon detection of a corrupted stimulation program in said stimulator.

17. A method as claimed in claim 16 including the steps of automatically beginning and ending a replenishment cycle for said capacitive device upon detection of low and high voltage levels, respectively.