GB2027594A

GB2027594A - Inductors for high frequency electromagnetic therapy apparatus

Info

Publication number: GB2027594A
Application number: GB7930077A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1978-05-31
Filing date: 1979-08-30
Publication date: 1980-02-27

Abstract

A treatment inductor for high frequency electromagnetic therapy has one or more flexible induction elements 2 and is embodied in a flexible material 8 (such as silicone rubber) whereby it may conform to the body area to be treated. The inductor may be generally planar or have a curved surface complementary to the body area to be treated. The induction element 2 may be a sheathed wire with a centre tap 4, or coaxial cable with a two pole connector connected to the screen and inner conductor or with a three-pole connector 6 connected to the two ends of the inner conductor and to a centre-tap on the screen. The inductor may form part of a timed circuit of a VHF pulse generator, or a crystal oscillator may be used. An alternative pulse generator, (Fig. 3), has a type 555 integrated circuit timer 18 and a BFY50 power output stage giving 100 msec wide 12 volt pulses at intervals of 1 msec to a coiled coax. inductor in a 10 cm diameter circular body, the output power being in the milliwatt range. <IMAGE>

Description

SPECIFICATION Inductors for high frequency electromagnetic therapy apparatus This invention relates to high frequency electromagnetic therapy apparatus and particularly to inductors for use with such apparatus.

For over forty years, high radio frequency electromagnetic radiation has been in regular use in the therapeutic treatment of a number of medical conditions. Many pathological processes have been sucessfully treated, by the direct application to the area under consideration, of an induced electromagnetic field in the VHF band. The Diapulse Corporation (New York, U.S.A.) produces a pulsed VHF electromagnetic field generator suitable for such medical use.

Present equipment is relatively high powered and is consequently large. The Diapulse Corporation equipment, for example, can produce a pulsed peak power of 900 watts and an average power output of 1.5 to 38 watts. The inductor which is placed adjacent the area to be treated is approximately the size of a domestic kettle and consequently the patient is somewhat restricted in movement during treating sessions.

I have recently discovered that the use of such large amounts of power is in fact unnecessary for the treatment of some conditions, and I have developed a smaller, portable, high frequency electromagnetic energy therapy apparatus which employs a relatively small treatment inductor. This may be placed in position to leave the patient generally mobile. Since the patient maintains mobility and can continue with normal activities during treatment, beneficially longer therapeutic treatment periods are possible.

According to the invention I provide a treatment inductor, for use with a high frequency electromagnetic therapy apparatus, having one or more induction elements for connection to said apparatus whereby to enable a high frequency electromagnetic field to be induced, characterised in that said induction elements are flexible and the inductor is embodied in a flexible material whereby it may be conformed to lie against an area of the body to be treated.

By providing the inductor as a flexible body, it may be conveniently attached to the patient by means of surgical tape and will lie naturally against the area to be treated.

Normally the inductor will be generally planar, but for treatment of acutely curved areas of the body, it may be more convenient to form the inductor as a complementary curved surface.

The inductor may be part of a tuned circuit of the high frequency electromagnetic therapy apparatus, in which case the inductor elements will be wound, generally in a circle. The number of turns provided, and any tapping points, will need to be exactly determined to provide the appropriate resonating frequency.

The incorporation of the inductor in the tuned circuit can be avoided by including a crystal oscillator in the pulse generator. This arrangement is preferred since it provides more flexibility to-the design of the inductor.

The inductor elements are generally electrically-conductive wire, for example multifilament wire. Coaxial cable has also proved to be useful. More than one inductor element may be employed if desired.

To form the treatment inductors, the inductor elements can be laid in the pattern required and then provided with a flexible cover, for example, of silicone rubber. Various patterns may be provided for different areas of the body, and if a generally- planar inductor is required then the product will generally be a sheet-like body of resilient material having the inductor elements embedded therein and having connector leads extending from one edge, for connection to the high frequency electromagnetic radiation generator. The latter is generally a miniaturised VHF pulse generator. The power generated by such apparatus (functioning from small batteries) is in the milliwatt region.

Preferred features of the invention will now be described with reference to the accompanying drawings, wherein:~ Figure 1 is a schematic plan view in cross section of a treatment inductor according to the invention, Figure 2 is a view similar to Figure 1 of a further inductor according to the invention, and Figure 3 is a circuit diagram of a miniature VHF pulse generator for use with a treatment inductor of the invention.

Figure 1 illustrates a treatment inductor which is to form part of a tuned circuit with a VHF pulse generator. The inductor comprises a spirally wound, sheathed multifilament eiectrically conductive wire 2 having a centre-tapping 4. This provides a three-pin connection 6 from the two ends and the centre of the wire. The wire is embedded in silicone rubber 8 and the whole inductor is of generally-planar appearance.

Figure 2 illustrates a treatment inductor for use with a self-oscillating VHF pulse generator. Since the inductor does not need to form part of a tuned circuit (as with the Figure 1 inductor), the number of turns of inductor element wire and other parameters are not so critical. The inductor comprises a small coaxial cable 10 providing a two-pin connection 12, one of the connections being to the coaxial cable screen 14 and the other to central conductor 16. The cable is embedded in silicone rubber 8 and the inductor is of generally planar appearance. It is also elongated for use with the treatment of elongated areas of the body, e.g. along the length of a limb or a digit.

Figure 3 is a circuit diagram of a self-oscillating VHF pulse generator for use with a three-pin treatment inductor of the invention. The latter consists of a spirally-wound coaxial cable, similar to the inductor shown in Figure 1, but with the centre-tapping of the cable being taken to the screen and the outer and inner connections being made to the central conductor of the cable. The inductor winding connections are shown to the right of Figure 3.

The pulse generator includes a timing-unit 18 (Type 555 available from Radio Spares, London, U.K.) feeding a power amplifier output stage which itself provides outputs for connection to the three pins of the treatment inductor already mentioned. The circuit illustrated provides 12 volt output pulses from pin 3 of the oscillator, 1 00 #ttsec. in width and at intervals of 1 msec. The inductor coil was formed of coaxial cable with cable lengths: outer connection to screen connection 79 cm, screen connection to inner connection 57 cm. The generally circular electrode produced was approximately 10 cm. in diameter and produced a power output in the milliwatt range.

Claims

1. A treatment inductor, for use with a high frequency electromagnetic therapy apparatus, having one or more induction elements for connection to said apparatus whereby to enable a high frequency electromagnetic field to be induced, characterised in that said induction elements are flexible and the inductor is embodied in a flexible material whereby it may be conformed to lie against an area of the body to be treated.

2. An inductor according to claim 1 wherein said induction elements are electrically-conductive wire.

3. An inductor according to claim 2 wherein said induction elements are coaxial cables.

4. An inductor according to claim 1 or 2 which is generally planar.

5. An inductor according to any of claims 1 to 3 wherein said flexible material overlays said induction elements in the form of a resilient cover.

6. An inductor according to any of claims 1 to 5 wherein said flexible material is silicone rubber.

7. An inductor according to any of claims 1 to 6 having an electrical connector for providing electrical connection between said one or more induction elements and said high frequency electromagnetic therapy apparatus.

8. A high frequency electromagnetic therapy apparatus in combination with a treatment inductor as claimed in any of claims 1 to 7.