Magnetic coil for pulsed electromagnetic field

• US 6,186,941 B1
• Filed: 05/12/1999
• Issued: 02/13/2001
• Est. Priority Date: 08/29/1997
• Status: Expired due to Fees

• Current Assignee: Orthosoft LLC (Zimmer Biomet Holdings, Inc.)
• Original Assignee: Orthosoft LLC (Zimmer Biomet Holdings, Inc.)
• Inventors: Blackwell, Lyman L.
• Primary Examiner(s): Lacyk, John P.
• Application Number:
  US09/310,373
• Time in Patent Office: 643 Days
• Field of Search: 600/9-15
• US Class Current: 600/13
• CPC Class Codes: A61F 7/007 characterised by electric heating
• CPC Class Codes: A61F 7/034 Flameless
• CPC Class Codes: A61N 2/02 using magnetic fields produced by coils, including single turn loops or electromagnets A61N2/12 takes precedence

Abstract

A portable electronic PEMF apparatus comprises a PEMF coil, power supply, and electronic switching means contained therein. The power supply along with the switching means provide periodic electric power to the PEMF coil. The PEMF coil comprises multiple turns of a conductive wire around a core with an elongated cross section. The core comprises a magnetic shield layer of materials such as mu metal or soft iron. The power supply comprises a battery, a regulated voltage source and unregulated voltage source from the battery and electronic switching circuit, powered by the regulated voltage, for electrically connecting the unregulated voltage source to the coil. The electronic switching circuit is tuned to periodically provide power to the coil at a frequency to generate a non-inverting, varying electromagnetic field from the coil.

Claims

1. A method for applying an electromagnetic field to a patient comprising the steps of,

a) applying one or more therapeutic coil to an injured area of a patient'"'"'s body;

and

b) conducting a periodic electric current to the one or more therapeutic coil to generate an electromagnetic field, wherein said one or more therapeutic coil comprises a core with an bottom surface and an top surface defining a thickness, a first side edge portion and a second side edge portion defining a height, a first end portion and second end portion defining a width and an electrically conductive wire wound a plurality of turns around the first end portion, the bottom surface, the second end portion and the top surface, to form a coil comprising a plurality of loops, each loop having at least two dimensions wherein a first dimension is at least about 5 times as great as a second dimension.

2. The method of claim 1 wherein the periodic electric current is a non-inverting current.

3. The method of claim 1 wherein the periodic electric current is selected from the group consisting of square waves, sawtooth waves, triangle waves, sinusoidal waves, and rectified sinusoidal waves.

4. The method of claim 1 wherein the periodic electric current is of a frequency which provides a non-inverting electromagnetic field.

5. The method of claim 1 wherein the periodic electric current comprise a plurality of pulses, each pulse comprising a half sine wave current with a duration of about 0.5 to about 2 milliseconds.

6. The method of claim 5, wherein the plurality of pulses is delivered at a rate of about 100 pulses to about 4000 pulses per second.

7. The method of claim 5, wherein the plurality of pulses is delivered at the cyclotron resonance frequency of a pre-selected ion.

8. The method of claim 7, wherein the ion is selected from the group consisting of copper, silver, gadolinium, potassium, chloride, zinc, cobalt, iron, manganese, sodium, calcium, magnesium and lithium ions.

9. The method of claim 1 wherein the injured area is a soft tissue injury.

10. The method of claim 1 wherein the step of applying further comprises the step of placing a plurality of electrically connected coils to the injury to optimize the magnetic field between coils at the injury.

11. The method of claim 1 further comprising the step of applying a static magnetic field to the injured area.

12. The method of claim 11 wherein the static magnetic field is supplied a permanently magnetized core or a constant current through the one or more therapeutic coil.

13. The method of claim 1, wherein a North pole of said electromagnetic field is positioned next to the injured area of a patient'"'"'s body.

14. The method of claim 1, fisher comprising the step of:

applying heat in proximity to said injured area of a patient'"'"'s body.

15. The method of claim 14 wherein said step of applying heat is accomplished using an electrical resistance heater.

16. The method of claim 14 wherein said step of applying heat is accomplished using a chemical heater.