Neurostimulator

• US 8,369,956 B2
• Filed: 08/19/2011
• Issued: 02/05/2013
• Est. Priority Date: 08/19/2002
• Status: Expired due to Fees

• Current Assignee: Arizona Board of Regents (University of Arizona)
• Original Assignee: Arizona Board of Regents (University of Arizona)
• Inventors: Towe, Bruce C., Crisp, William E.
• Primary Examiner(s): MANUEL, GEORGE C
• Application Number:
  US13/214,077
• Publication Number:
  US 20120041499A1
• Time in Patent Office: 536 Days
• Field of Search: 607/48
• US Class Current: 607/48
• CPC Class Codes: A61N 1/05 for implantation or insertion into the body, e.g. heart electrode A61N1/06 takes precedence
• CPC Class Codes: A61N 1/32 alternating or intermittent currents applying electric fields by inductive or capacitive coupling A61N1/40; microwave apparatus A61N5/02
• CPC Class Codes: A61N 1/36071 Pain
• CPC Class Codes: A61N 1/36125 Details of circuitry or electric components
• CPC Class Codes: A61N 1/37205 Microstimulators, e.g. implantable through a cannula
• CPC Class Codes: A61N 1/3787 from an external energy source
• CPC Class Codes: A61N 7/00 Ultrasound therapy lithotripsy A61B17/22, A61B17/225; massage using supersonic vibration A61H23/00 ; using ultrasound for introducing media into the body A61M37/0092

Abstract

Methods and devices for stimulating nerves are disclosed. In one embodiment adapted for stimulating excitable tissue, the invention includes drive circuitry, an acoustic transducer and a pair of electrodes.

Claims

1. A neurostimulator, comprising:

drive circuitry;

an acoustic transducer connected to the drive circuitry; and

an implantable stimulator having a piezoelectric chip and a pair of electrodes;

where the drive circuitry is configured to drive the acoustic transducer to generate a pressure wave;

where the acoustic transducer is positioned to direct the pressure wave at the implantable stimulator and generate a current between the pair of electrodes;

where the piezoelectric chip comprises

a piezoelectric element having at least two opposite surfaces;

a diode; and

a biocompatible coating surrounding the piezoelectric element and the diode.

2. The neurostimulator of claim 1, wherein the piezoelectric chip includes lead zirconate titanate (PZT).

3. The neurostimulator of claim 1, where in the piezoelectric chip includes polyvinylidene fluoride (PVDF).

4. The neurostimulator of claim 1, wherein the drive circuitry further comprises:

a pulse generator;

a function generator connected to the pulse generator; and

amplifier circuitry connected to the function generator.

5. The neurostimulator of claim 4, wherein the amplifier circuitry comprises:

a drive amplifier; and

a RF amplifier.

6. A neurostimulator, comprising:

drive circuitry;

an acoustic transducer connected to the drive circuitry; and

an implantable stimulator having a piezoelectric chip and a pair of electrodes;

where the drive circuitry is configured to drive the acoustic transducer to generate a pressure wave;

where the acoustic transducer is positioned to direct the pressure wave at the implantable stimulator and generate a current between the pair of electrodes; and

further comprising additional piezoelectric chips,

where each of the piezoelectric chips has a different resonant frequency; and

where the drive circuitry is configured to drive the acoustic transducer at the resonant frequency of one of the piezoelectric chips.

7. A method of stimulating tissue, comprising:

applying high frequency ultrasound signals to body tissue;

applying electrical stimulation to the body tissue using a pair of electrodes; and

where the high frequency ultrasound signal inhibits the generation of a compound action potential in a nerve fiber.

8. The method of claim 7, where the electrodes are located external to a subject.

9. The method of claim 7, where the electrodes are internal to a subject and where applying electrical stimulation to the body tissue using a pair of electrodes comprises:

producing drive electrical signals in a drive circuitry;

emitting pressure waves with an acoustic transducer in response to the drive electrical signals; and

converting the pressure waves into stimulation electrical signals in an implantable stimulator, where the implantable stimulator includes a piezoelectric chip and a pair of electrodes.

10. The method of claim 9, where one of the drive electrical signals is a pulse.

11. The method of claim 9, where the high-frequency ultrasound signal occurs before converting the pressure waves into stimulation electrical signals.

12. The method of claim 9, where the high frequency ultrasound signal is a pulse having a length of between 300 μ

s and 10 ms.

13. The method of claim 9, where the high frequency ultrasound signal is a series of pulses with a repetition rate between 1 pulse per second and 10 pulses per second.

14. The method of claim 9, where the implantable stimulator is placed in close proximity to a nerve in a patient.

15. The method of claim 7, where the high frequency ultrasound signal provides stimulation to a tissue.

16. The method of claim 7, further comprising stimulating a pudental nerve with the electrical stimulation.