1. Field of the Invention
This invention relates generally to a magnetic field generating apparatus and more specifically to a magnetic field generating apparatus that produces a time-varying angular displacement of magnetic flux density for use in therapeutic applications on humans or on animals.
2. Description of the Related Art
Various devices have been made to create time-varying magnetic fields for use on the human body. Generally, two types of time-varying magnetic fields have be used. The first one used an alternating current (xe2x80x9cACxe2x80x9d) field that is produced when electric current is caused to alternate at any given frequency. In accordance with Maxwell""s equations, a magnetic field is concurrently produced at the same frequency as the electric field. Included in this first type of time-varying magnetic field device are pulsed electromagnetic fields (PEMF) which are generated when a current is caused to move through a conductor in discreet impulses of electric charge moving in the same direction.
A second general type of device for creating time-varying magnetic field involves physically moving a static magnetic field through space. While linear displacement is one way to accomplish this, another common method involves rotating the static magnetic field. The source of the static magnetic field is generally a permanent magnet, since an electromagnet requires considerable expenditure of energy in the form of current generation and the subsequent dissipation of unwanted heat energy.
The therapeutic uses of time-varying magnetic fields have been described and clinically evaluated in numerous literature. The more popular publications written for the general public include xe2x80x9cMagnetic Therapyxe2x80x9d by Dr. Ronald Lawrence and Dr. Paul Rosch, xe2x80x9cThe Pain Relief Breakthroughxe2x80x9d by Dr. Julian Whitaker and Brenda Adderly, and xe2x80x9cMagnetic Therapy in Eastern Europexe2x80x9d by Dr. Jiri Jerabek and Dr. William Pawluk. These books offer numerous references to clinical studies which purport to show the effectiveness of time-varying magnetic fields for the treatment of a multitude of chronic and acute conditions including atherosclerosis, carpal tunnel syndrome, chronic bronchitis, post-ischemic injury, edema, fractures, infected wounds, limb grafts, burns, scars, macular degeneration, etc. The lack of any substantial negative side effects are also purported for most treatments. In recent years, the general public and even the medical community have increasingly accepted magnetic therapy as an alternative treatment worthy of consideration for such conditions.
Patented devices which utilize permanent magnets to produce a time-varying magnetic field for therapeutic purposes include Horl, U.S. Pat. No. 4,727,857; Kleitz U.S. Pat. No. 5,632,720; and Sounder U.S. Pat. No. 6,001,055. All of these devices function by causing permanent magnets to rotate around a fixed axis. The magnetic field generated by each of these devices sweeps out into space in a single direction. Changing the direction of the rotation requires manual manipulation of the entire device since the axis upon which the magnets rotate is stationary. It has been observed that the angle at which magnetic flux lines cut through tissue can influence the degree of beneficial effects. What is needed therefore is a handheld device or a device capable of being attached a part of the body or to clothing, or the like, that will create a sweeping magnetic field in a multitude of directions, thus providing more complete angular coverage to the part of the body being treated with the moving magnetic field.
The present invention provides a magnetic field that varies in intensity and/or in polarity by causing a magnet to rotate about two axes at the same time. This is accomplished by rotating a magnet about a first axis and concurrently or intermittently rotating this first axis around a second axis that is oblique from the first axis.
It is an object of the present invention to provide a handheld device for applying a time-varying magnetic field for use on the body of a human or animal. Another object of the present invention is providing a therapeutic device that causes the magnetic field to vary in time in more than one direction.
It is another object of the present invention to provide a device that can be attachable to a part of a body or to clothing for applying a time-varying magnetic field to the body.
These and other objects and advantages of the present invention will be apparent from a review of the following specification and accompanying drawings.