System for and method of power efficient electrical tissue stimulation

• US 7,295,872 B2
• Filed: 10/09/2002
• Issued: 11/13/2007
• Est. Priority Date: 10/10/2001
• Status: Active Grant

• Current Assignee: Massachusetts Institute of Technology
• Original Assignee: Massachusetts Institute of Technology
• Inventors: Wyatt, John, Kelly, Shawn, Rizzo, Joseph
• Primary Examiner(s): Pezzuto; Robert
• Assistant Examiner(s): JOHNSON, SHEVON ELIZABETH
• Application Number:
  US10/267,764
• Publication Number:
  US 20030130699A1
• Time in Patent Office: 1,861 Days
• Field of Search: 607/34, 607/36, 607/33, 607/61, 607/2, 607 4- 5, 607/9, 607/13, 607/53
• US Class Current: 607/2
• CPC Class Codes: A61N 1/0541 Cochlear electrodes
• CPC Class Codes: A61N 1/0543 Retinal electrodes
• CPC Class Codes: A61N 1/08 Arrangements or circuits for monitoring, protecting, controlling or indicating for external stimulators A61N1/3603; for implantable neurostimulators A61N1/36128; for heart stimulators A61N1/37; for defibrillators A61N1/3925
• CPC Class Codes: A61N 1/3787 from an external energy source

Abstract

Circuitry for and method of power efficient operation of, and energy recovery from, tissue-stimulating electrodes having high charge capacities. Post-stimulation energy is recovered from the electrodes through a variety of techniques into circuit elements such as other electrodes, an intermediate distribution system, a power supply or any other elements, through the use of sequential switching. Energy is also recoverable from the intermediate distribution system, which preferably is comprised of one or more storage capacitors operating a different voltages. Efficient power transfer among circuit elements is effected by transferring energy while limiting element-element voltage differences and/or voltage differences between the elements and the capacitances of the electrodes.

Claims

1. A system for power recovery in a tissue stimulator, comprising:

one or more tissue stimulating electrodes, each having a capacitance; and

means for recovering post-stimulation energy from the electrodes and further comprising;

a power supply; and

power transfer circuitry coupled to the power supply and the electrodes that provides energy to the electrodes directly from the power supply while limiting voltage differences between the power supply and the capacitance of the electrodes to which the power supply is to be connected, wherein the power transfer circuitry further comprises a synchronous switching rectifier for directly recovering power from the one or more storage capacitors, wherein the power transfer circuitry is responsive to timing intervals from a timing control unit.

2. A system for power-recovery in a tissue stimulator, comprising:

one or more tissue stimulating electrodes, each having a capacitance; and

means for recovering post-stimulation energy from the electrodes and further comprising;

a power supply;

an intermediate distribution network including one or more storage capacitors;

a switching network coupled to the one or more electrodes and the intermediate distribution system, that provides energy to the electrodes from the one or more storage capacitors while limiting voltage differences between the storage capacitors and the capacitance of the electrodes to which the storage capacitors are to be connected; and

power transfer circuitry coupled to the power supply and the intermediate distribution system, that provides energy to the storage capacitors from the power supply while limiting voltage differences between to power supply and the storage capacitors to which the power supply is to be connected, wherein the power transfer circuitry further comprises a synchronous switching rectifier for directly recovering power from the one or more storage capacitors wherein the power transfer circuitry is responsive to timing intervals, from a timing control unit.

3. A system for power-recovery in a tissue stimulator, comprising:

a power supply;

an intermediate distribution system including one or more storage capacitors;

power transfer circuitry, coupled to the power supply and the intermediate distribution system that recovers energy from the storage capacitors to the power supply while limiting voltage differences between the power supply and the storage capacitors to which the power supply is to be connected;

one or more tissue stimulating electrodes, each having a capacitance; and

a switching network, coupled to the one or more electrodes and the intermediate distribution system, that provides sequential connections for the one or more storage capacitors to one or more of the electrodes while limiting voltage differences between the storage capacitors and the capacitances of the one or more electrodes to which the one or more storage capacitors are to be connected wherein the power transfer circuitry further comprises a synchronous switching rectifier for directly recovering power from the one or more storage capacitors wherein the power transfer circuitry is responsive to timing intervals from a timing control unit.