Microstimulator neural prosthesis

• US 20040044380A1
• Filed: 08/29/2002
• Published: 03/04/2004
• Est. Priority Date: 08/29/2002
• Status: Active Grant

• Current Assignee: United States of Government As Represented By The Department of Veterans Affairs
• Original Assignee: United States of Government As Represented By The Department of Veterans Affairs
• Inventors: Bruninga, Keith Walter, Zaszczurynski, Paul Joseph, Riedy, Lisa Wittenkeller
• Granted Patent: US 7,027,860 B2
• Time in Patent Office: Days
• US Class Current: 607/48
• 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 1/36128 Control systems
• CPC Class Codes: A61N 1/36157 Current A61N1/3616 takes precedence
• 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 1/37223 Circuits for electromagnetic coupling
• CPC Class Codes: A61N 1/3787 from an external energy source

Abstract

A microstimulator or neural prosthesis is powered and operative in response to an externally applied RF signal which includes a power component and control component. A slow rise time storage circuit stores RF power during a charging period and a fast rise time triggering circuit responsive to a fast rise time input triggers the device for producing output pulses following a selected delay time. The duration of the delay controls the current level of the output pulses.

Claims

1. An implantable electrical stimulator for neural prosthesis powered by an operative in response to an externally applied radio frequency (RF) signal having a power component and a control component for producing stimulation pulses operative to stimulate function of muscles and organs in a patient comprising:

a power storage circuit responsive to the power component of the RF signal for storing energy to a selected level at least sufficient to power the electrical stimulator;

a control circuit coupled to the power storage circuit for receiving stored energy therefrom and being operative to produce the stimulation pulses at a selectable output level and rate; and

a control circuit coupled between the power storage circuit of the pulse generating circuit being responsive to the energy level stored in the storage circuit for controlling the output level and rate of the stimulator pulses In accordance therewith.

2. The implantable electrical stimulator according to claim 1 wherein the power component has a relatively slow temporal characteristic and the energy storage circuit is responsive to said relatively slow temporal characteristic to store energy over a selected interval.

3. The implantable electrical stimulator of claim 1, wherein the control component has a relatively fast temporal characteristic and the pulse generating circuit is triggerably responsive to said relatively fast temporal characteristic for producing output pulses.

4. The implantable electrical stimulator of claim 1, wherein the power component and the control component of the RF signal are selectively temporally separated for selectively controlling the level of energy stored in the energy storage circuit.

5. The implantable electrical stimulator of claim 1, wherein the control circuit produces an output current of greater than 10 miliamps.

6. The implantable electrical stimulator of claim 5, wherein the control circuit produces an output current of 15 miliamps.

7. The implantable electrical stimulator of claim 1, wherein the control circuit produces output pulses of about 1,000 microseconds.

8. The implantable electrical stimulator of claim 1, wherein the control circuit produces 40 pulses per second.

9. The implantable electrical stimulator of claim 1, being operable for a duration sufficient to stimulate the organ to function.

10. The implantable electrical stimulator of claim 1, including an external transmitter for producing the RF signal.

11. The implantable electrical stimulator of claim 1, wherein the RF generator is operative for producing at least one of a selective charge time and a selected delay time in the RF signal for varying the amplitude and duration of the output signal respectively.

12. A method for operating an implantable electrical stimulator for neural prosthesis comprising the steps of:

providing an externally applied radio frequency (RF) signal having a power component and a control component;

storing energy to a selected level at least sufficient to power the electrical stimulator;

receiving stored energy to produce the stimulation pulses at a selectable rate; and

controlling the output level of the stimulator pulses in accordance with the stored energy level.