IMPLANTABLE WIRELESS ACCOUSTIC STIMULATORS WITH HIGH ENERGY CONVERSION EFFICIENCIES

• US 20140046420A1
• Filed: 10/21/2013
• Published: 02/13/2014
• Est. Priority Date: 03/25/2008
• Status: Active Grant

• Current Assignee: EBR Systems, Inc.
• Original Assignee: EBR Systems, Inc.
• Inventors: Moore, David F., Mohr, Paul, Willis, N. Parker, Brisken, Axel F.
• Granted Patent: US 9,180,285 B2
• Time in Patent Office: Days
• US Class Current: 607/119
• CPC Class Codes: A61B 2560/0214 of power generation or supply
• CPC Class Codes: A61N 1/02 Details
• 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 1/362 Heart stimulators heart defibrillators A61N1/39
• CPC Class Codes: A61N 1/37205 Microstimulators, e.g. implantable through a cannula
• CPC Class Codes: A61N 1/3756 Casings with electrodes thereon, e.g. leadless stimulators
• CPC Class Codes: A61N 1/3758 Packaging of the components within the casing
• CPC Class Codes: A61N 1/3787 from an external energy source
• CPC Class Codes: H02N 2/181 Circuits; Control arrangements or methods
• CPC Class Codes: H02N 2/186 Vibration harvesters
• CPC Class Codes: H02N 2/188 adapted for resonant operation
• CPC Class Codes: H10N 30/03 Assembling devices that include piezoelectric or electrostrictive parts
• CPC Class Codes: H10N 30/30 with mechanical input and electrical output, e.g. functioning as generators or sensors
• CPC Class Codes: Y10T 29/42 Piezoelectric device making

Abstract

Receiver-stimulator with folded or rolled up assembly of piezoelectric components, causing the receiver-stimulator to operate with a high degree of isotropy are disclosed. The receiver-stimulator comprises piezoelectric components, rectifier circuitry, and at least two stimulation electrodes. Isotropy allows the receiver-stimulator to be implanted with less concern regarding the orientation relative the transmitted acoustic field from an acoustic energy source.

Claims

1. A method for manufacturing an implantable receiver-stimulator for converting an acoustic field to electrical power comprising the steps of:

forming an insulating layer on an electrically conductive sheet;

forming a circuit pattern on the insulating layer;

electrically connecting a first plurality of acoustic piezoelectric components to the circuit pattern on the sheet;

electrically connecting a plurality of individual rectifier circuits to the circuit pattern on the sheet, the rectifier circuits configured to convert electrical power output from the piezoelectric components to a biologically stimulating electrical output;

electrically connecting the biologically stimulating electrical output to a pair of stimulation electrodes; and

folding the sheet into an octagonal or otherwise substantially cylindrical can structure, thereby arranging the acoustic piezoelectric components such that acoustic energy is harvested efficiently from any direction of the propagating acoustic field.

2. The method of claim 1, wherein the acoustic piezoelectric components are composed of a piezoelectric material, optionally wherein the piezoelectric material is one of a poly crystalline ceramic piezoelectric material or a single crystal piezoelectric material.

3. The method of claim 2, wherein the piezoelectric components are in the shape of a cuboid, wherein one of the faces of the cuboid is mounted to the circuit pattern on the sheet.

4. The method of claim 1, wherein the rectifier circuitry comprises one or more rectifiers connected in parallel and protection circuitry to protect the rectifiers from damage due to voltages above approximately 4V.

5. The method of claim 4, wherein the protection circuitry comprises a Zener diode or a series of GaAs Schottky diodes.

6. The method of claim 1, further comprising:

affixing an end cap to the can structure, the end cap having a second plurality of acoustic piezoelectric components composed of a piezoelectric material, wherein the second plurality of piezoelectric components has a piezoelectric axis that is substantially perpendicular to that of the first plurality of piezoelectric components.

7. An implantable stimulator for harvesting acoustic power from an acoustic field, comprising:

a hermetically sealed enclosure with an inner and outer surface, wherein the inner or outer surface is etched to form a plurality of apertures each defined by a width and length; and

a plurality of acoustic piezoelectric components each affixed to the inner surface at a location of an etched acoustic aperture, wherein one or more of the etched acoustic apertures is larger than the widths and/or lengths of the piezoelectric components affixed to the aperture location.

8. The implantable stimulator of claim 7, wherein each piezoelectric component is configured to convert the impinging acoustic field into electrical power.

9. The implantable stimulator of claim 8, comprising a plurality of rectifiers electrically connected to each of the plurality of acoustic piezoelectric components, wherein the output from each piezoelectric component is rectified independently.