SCAVENGED ENERGY FOR ELECTRIC FIELD GENERATION TO PREVENT BONE LOSS AND ENCOURAGE BONE GROWTH FOR ORTHOPEDIC APPLICATIONS

• US 20080077193A1
• Filed: 09/25/2007
• Published: 03/27/2008
• Est. Priority Date: 09/26/2006
• Status: Abandoned Application

• Current Assignee: Jennifer Bow
• Original Assignee: Jennifer Bow
• Inventors: Pearce, Joshua M., Bow, Jennifer K.
• Application Number:
  US11/861,256
• Publication Number:
  US 20080077193A1
• Time in Patent Office: Days
• US Class Current: 607/51
• CPC Class Codes: A61N 1/326 for promoting growth of cells, e.g. bone cells
• CPC Class Codes: A61N 1/40 Applying electric fields by inductive or capacitive coupling microwave apparatus A61N5/00; Applying radio-frequency signals

Abstract

In this invention, stress shielding effects seen in total joint arthroplasty patients and trauma patients is prevented by causing the bone above the press fit of the implant to continue to act as if it were under stress by inducing an electric field in the surrounding bone that simulates the electric field generated when bone is under mechanical stress. This same effect is used to stimulate bone union in fractures and surgical arthrodesis, as well as to encourage increased bone mass and consolidation of bone during limb lengthening procedures. The electric field can be generated by a number of methods utilizing scavenged energy, with the preferred embodiment being the generation of electricity using arrays of thousands of thermoelectric generators built into an implantable chip. These generators exploit the well-known thermocouple effect, in which a small voltage is generated when two of the junctions between two dissimilar materials are kept at different temperatures. The temperature gradient is produced between the underside of the skin and the interior of the body.

Claims

1. An internal medical device for stimulating bone comprising:

(a) a means of converting scavenged energy to electricity,

(b) a plurality of electrically conductive wires,

(c) at least one electrode with the ability to create an electric field,

(d) said means of converting scavenged energy to electricity connected by said wires to said electrode to create an electric field in the bone.

2. The device in claim 1 wherein the means of converting scavenged energy to electricity makes use of a thermocouple.

3. The device in claim 1 wherein the means of converting scavenged energy to electricity uses the Dorn Effect.

4. The device in claim 1 wherein the means of converting scavenged energy to electricity uses an inertial energy converter.

5. The device in claim 1 wherein the means of converting kinetic energy of motion to electrical energy.

6. The device in claim 1 wherein the means of producing electricity makes use of a thermophotovoltaic device.

7. The device in claim 1 wherein the means of producing electricity uses a plurality of energy conversion methods.

8. The device in claim 1 wherein the bone stimulation is used to improve bone mass.

9. The device in claim 1 wherein the bone stimulation is used to prevent stress shielding in orthopedic implants.

10. The device in claim 1 wherein the bone stimulation is used to induce bone healing.

11. The device in claim 1 wherein the bone stimulation is used to induce bone consolidation.

12. The device in claim 1 wherein said wire acts as the electrode by locating near the targeted bone.

13. An orthopedic implant containing a means of stimulating bone comprising:

(a) a means of converting scavenged energy to electricity,

(b) at least one electrically conductive wire,

(c) at least one electrode with the ability to create an electric field,

(d) said means of converting scavenged energy to electricity connected by said wires to said electrode to create an electric field at the site of stress shielding.

14. The device in claim 13 wherein the means of converting scavenged energy to electricity uses the Dorn Effect.

15. The device in claim 13 wherein the means of converting scavenged energy to electricity uses an inertial energy converter.

16. The device in claim 13 wherein the means of converting kinetic energy of motion to electrical energy.

17. The device in claim 13 wherein the bone stimulation is used to improve bone mass.

18. The device in claim 13 wherein the bone stimulation is used to prevent stress shielding in orthopedic implants.

19. The device in claim 13 wherein the bone stimulation is used to induce bone healing.

20. The device in claim 13 wherein the bone stimulation is used to induce bone consolidation.