Voltage converter for implantable microstimulator using RF-powering coil

• US 6,631,296 B1
• Filed: 03/05/2001
• Issued: 10/07/2003
• Est. Priority Date: 03/17/2000
• Status: Active Grant

• Current Assignee: Boston Scientific Neuromodulation Corporation (Boston Scientific Corporation)
• Original Assignee: Advanced Bionics Corporation (Sonova Holding AG)
• Inventors: Parramon, Jordi, Haller, Matthew I.
• Primary Examiner(s): Hoang, Tu Ba
• Application Number:
  US09/799,467
• Time in Patent Office: 946 Days
• Field of Search: 600/302, 342/50, 455/100, 607/40, 607/42, 607/45, 607/59, 607/60, 607/61, 607/64, 607/50, 607/65, 128/903
• US Class Current: 607/61
• CPC Class Codes: A61N 1/37205 Microstimulators, e.g. implantable through a cannula
• CPC Class Codes: A61N 1/3787 from an external energy source

Abstract

A voltage converter for use within small implantable electrical devices, such as a microstimulator, uses a coil, instead of capacitors, to provide a voltage step up and step down function. The output voltage is controlled, or adjusted, through duty-cycle modulation. Good efficiencies are achieved for virtually any voltage within the compliance range of the converter. In accordance with one aspect of the invention, applicable to implantable devices having an existing RF coil through which primary or charging power is provided, the existing RF coil is used in a time-multiplexing scheme to provide both the receipt of the RF signal and the voltage conversion function. This minimizes the number of components needed within the device, and thus allows the device to be packaged in a smaller housing, or frees up additional space within an existing housing for other circuit components. In accordance with another aspect of the invention, the voltage up/down converter circuit is controlled by a pulse width modulation (PWM) low power control circuit. Such operation allows high efficiencies over a wide range of output voltages and current loads. The invention thus provides a voltage converter circuit for use within an implantable device that is compact, efficient, and provides a wide range of output voltages and currents.

Claims

1. An implantable medical device comprising:

an implantable housing;

electrical circuitry carried within said housing, said electrical circuitry including a coil;

wherein said coil is configured with said electrical circuitry to receive power from an external power source, thereby performing a power receiving function; and

wherein said coil is also configured with said electrical circuitry to convert the power received from the external source to a different voltage level, thereby performing a voltage conversion function;

whereby the same coil is used to perform both power receiving and voltage conversion functions within the implantable medical device.

2. The implantable medical device of claim 1 wherein said coil is further configured with said electrical circuitry to receive command information from an external programming source, thereby performing a command receiving function;

whereby the same coil is used to perform power receiving, command receiving and voltage conversion functions within the implantable medical device.

3. The implantable medical device of claim 2 wherein said coil is still further configured with said electrical circuitry to receive data information from an external data source, thereby performing a data receiving function;

whereby the same coil is used to perform power receiving, command receiving, data receiving and voltage conversion functions within the implantable medical device.

4. An implantable medical device comprising:

an implantable housing;

electrical circuitry carried within said housing, said electrical circuits including a coil;

wherein said coil is configured with said electrical circuitry to receive power from an external power source, thereby performing a power receiving function; and

wherein said coil is also configured with said electrical circuitry to convert the power received from the external source to a different voltage level, thereby performing a voltage conversion function;

wherein said coil is further configured with said electrical circuitry to receive command information from an external programming source, thereby performing a command receiving function; and

wherein said coil is additionally configured with said electrical circuitry to transmit data to an external source, thereby performing a data transmission function;

whereby the same coil is used to perform power receiving, command receiving, data transmission and voltage conversion functions within the implantable medical device.

5. The implantable medical device of claim 4 wherein said coil is additionally configured with said electrical circuitry to receive data information from an external source, thereby performing a data receiving function;

whereby the same coil is used to perform power receiving, command receiving, data receiving, data transmission and voltage conversion functions within the implantable medical device.

6. The implantable medical device of claim 5 wherein the electrical circuitry further includes a multiplicity of switches, and further wherein said switches are configured with said electrical circuitry to define an operating mode for said electrical circuitry as a function of whether said switches are set to be ON or OFF, wherein said electrical circuitry operates in a power receiving mode, command receiving mode, data receiving mode, data transmission mode or voltage conversion mode as a function of the setting of said switches.

7. The implantable medical device of claim 6 wherein each of the multiplicity of switches comprises a transistor switch.

8. The implantable medical device of claim 4 wherein the electrical circuitry further includes a multiplicity of switches, and further wherein said switches are configured with said electrical circuitry to define an operating mode for said electrical circuitry as a function of whether said switches are set to be ON or OFF, wherein said electrical circuitry operates in a power receiving mode, command receiving mode, data transmission or voltage conversion mode as a function of the setting of said switches.

9. The implantable medical device of claim 8 wherein the electrical circuitry operates in the power receiving mode and command receiving mode (power/command receiving mode) simultaneously, and wherein the electrical circuitry operates in the power/command receiving mode, the data transmission mode and the voltage conversion mode in a time-multiplexed manner.

10. An implantable medical device comprising:

an implantable housing;

electrical circuitry carried within said housing, said electrical circuitry including a coil;

wherein said coil is further configured with said electrical circuitry to receive command information from an external programming source, thereby performing a command receiving function; and

wherein said coil is further configured with said electrical circuitry to convert a power received from an external source to a different voltage level, thereby performing a voltage conversion function;

whereby the same coil is used to perform command receiving and voltage conversion functions within the implantable medical device.

11. The implantable medical device of claim 10 wherein the electrical circuitry further includes a plurality of switches, and further wherein said plurality of switches are configured with said electrical circuitry to define an operating mode for said electrical circuitry as a function of whether said switches are set to be ON or OFF, wherein said electrical circuitry operates in a power receiving mode, command receiving mode, or voltage conversion mode as a function of the setting of said switches and wherein each operating mode employs said coil in said electrical circuit.