RADIO FREQUENCY ANTENNA FOR A WIRELESS INTRAVASCULAR MEDICAL DEVICE

• US 20080046040A1
• Filed: 10/24/2007
• Published: 02/21/2008
• Est. Priority Date: 10/05/2005
• Status: Active Grant

• Current Assignee: Kenergy, Inc.
• Original Assignee: Kenergy, Inc.
• Inventors: Denker, Stephen, Bulkes, Cherik, Beutler, Arthur J.
• Granted Patent: US 7,826,903 B2
• Time in Patent Office: Days
• US Class Current: 607/60
• CPC Class Codes: A61N 1/37205 Microstimulators, e.g. implantable through a cannula
• CPC Class Codes: A61N 1/37229 Shape or location of the implanted or external antenna
• CPC Class Codes: A61N 1/3787 from an external energy source
• CPC Class Codes: H01Q 1/273 Adaptation for carrying or wearing by persons or animals
• CPC Class Codes: H01Q 1/40 Radiating elements coated with or embedded in protective material
• CPC Class Codes: H01Q 7/00 Loop antennas with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop

Abstract

A radio frequency antenna is provided for use with a medical device for implantation into an animal. The antenna comprises a coil formed by a wire that includes a core formed of a shape-memory material with an electrically conductive first layer applied to an outer surface of the core. A second layer, of an electrically insulating and biologically compatible material, extends around the first layer. If necessary to reduce friction, a lubricant is placed between the first and second layers. If second layer is formed of a porous material or a non-biological compatible material, a biological compatible outer layer surrounds the second layer thereby providing a barrier that is impermeable to body fluids of the animal.

Claims

1. A radio frequency antenna for a medical device that is implanted into an animal, wherein radio frequency antenna comprises a collapsible coil formed by a wire comprising:

an elongated electrical conductor;

an insulator layer of an electrically insulating and biologically compatible material extending around the elongated electrical conductor; and

a lubricating layer between the elongated electrical conductor and the insulator layer and permitting movement of the elongated electrical conductor and the insulator layer with respect to each other.

2. The radio frequency antenna as recited in claim 1 wherein the elongated electrical conductor comprises a core formed of a material selected from the group consisting of silver, a silver alloy, gold, a gold alloy, copper, aluminum, steel, and a shape-memory material.

3. The radio frequency antenna as recited in claim 1 wherein the elongated electrical conductor comprises a core of a shape-memory material having an outer surface coated with an electrically conductive material.

4. The radio frequency antenna as recited in claim 3 wherein the electrically conductive material is selected from the group consisting of silver, gold, copper, aluminum, and alloys of one or more of those elements.

5. The radio frequency antenna as recited in claim 1 wherein the insulator layer has an exterior surface that is coated with a material that provides a barrier which is impermeable to body fluids of the animal.

6. The radio frequency antenna as recited in claim 1 wherein the elongated electrical conductor comprises a shape-memory material.

7. The radio frequency antenna as recited in claim 6 wherein the shape-memory material is a metal alloy.

8. The radio frequency antenna as recited in claim 6 wherein the shape-memory material is an alloy selected from the group consisting of titanium-palladium-nickel, nickel-titanium, gold-cadmium, silver-cadmium, titanium-niobium-aluminum, uranium-niobium, hafnium-titanium-nickel, nickel-titanium, nickel-iron-zinc-aluminum, titanium-niobium, nickel-zirconium-titanium, copper-zinc-aluminum, iron-manganese-silicon, iron-manganese-silicon-chromium-nickel, nickel-titanium-copper, iron-platinum, iron-nickel-carbon, iron-palladium, iron-nickel-tin-cobalt, iron-zinc-copper-aluminum, copper-tin, copper-zinc, copper-aluminum-iron, copper-aluminum-nickel, indium-titanium, nickel-aluminum, manganese-copper, zirconium-copper-zinc, zirconium-aluminum-nickel-copper.

9. The radio frequency antenna as recited in claim 6 wherein the shape-memory material comprises a polymer selected from the group consisting of polynorborene, polyisoprene, styrene butadiene, polyurethane, vinyl acetate, polyester, and an oligo (ε

-caprolactone)diol and crystallisable oligo(ρ

-dioxanone)diol compound.

10. The radio frequency antenna as recited in claim 1 wherein the elongated electrical conductor is hollow.

11. The radio frequency antenna as recited in claim 1 wherein the lubricating layer is formed of polytetrafluoroethylene.

12. The radio frequency antenna as recited in claim 1 wherein the insulator layer is formed of expanded polytetrafluoroethylene.

13. The radio frequency antenna as recited in claim 1 further comprising an outer layer extending around the insulator layer and providing a barrier that is impermeable to body fluids of the animal.

14. The radio frequency antenna as recited in claim 13 wherein the outer layer is formed of polytetrafluoroethylene.