GB2485201A

GB2485201A - Apparatus for generating an oscillating magnetic field

Info

Publication number: GB2485201A
Application number: GB1018676.5A
Authority: GB
Inventors: Mafaq Abdul Razak
Original assignee: Individual
Current assignee: Individual
Priority date: 2010-11-05
Filing date: 2010-11-05
Publication date: 2012-05-09
Also published as: GB201018676D0

Abstract

An apparatus for generating an oscillating magnetic field having a magnetic transducer 110 with a support structure 120 and a coil 140 attached to the support structure 120. The coil 140 has terminals 142a, 142b for receiving input electrical signals and the transducer 110 also has a magnet 152 movably mounted to the support structure 120 proximal the coil 140. A headset (260, Fig 2) for generating an oscillating magnetic field is also disclosed. The device can be used to provide massage and/or simulation of parts of the body especially the cranial.

Description

Compact Apparatus for Generating an Oscillating Magnetic Field

Field of Use:

The present invention relates to an apparatus for providing a locally oscillating

magnetic field.

Description of the Related Art:

A range of applications exist for devices producing oscillating magnetic fields in science and technology and particularly in the fields of physics and electronics. Such applications include, analysis and measurements of material properties, plasma physics, low frequency communications, experimental tests on atomic particles, and read! record heads for the storage of data on magnetic media.

In recent years, devices producing oscillating magnetic fields have been used to provide massage and! or stimulation of parts of the body. In particular, oscillating magnetic fields have been used for cranial massage and! or stimulation. This type of massage and! or stimulation has been shown to provide relief from the effects of a range of ailments and conditions.

Typically, an apparatus for generating a locally oscillating magnetic field comprises one or more coils of wire, through which an oscillating electrical current is passed.

Since a current flowing in a coil of wire produces a magnetic field in the vicinity around the coil of wire, passing an oscillating electrical current through a coil of wire produces a corresponding oscillating magnetic field in the vicinity of the coil. This type of apparatus can also be used as a device for cranial massage and! or stimulation. In such use, the current carrying coil is brought near a subject's head, the current is switched on, and the user is exposed to the resulting oscillating magnetic field. However, in the area of cranial massage or stimulation, an apparatus employing coils of wire for generating an oscillating magnetic field has several limitations.

Problems associated with providing cranial massage and! or stimulation using an apparatus employing an oscillating current passing through one or more coils of wire are manifold. Firstly, in order to produce a large peak magnetic field strength, a very large current must flow through the coil; this produces a requirement for coil formed of a wire having a heavy gauge, which necessarily makes the coil bulky. Secondly, the magnetic field induced by a coil of wire falls off with the cube of the distance from the coil, so that the coil must be placed near the head of the subject to provide a sufficient peak level of the oscillating magnetic field and in order to achieve the maximum effect from the apparatus. To overcome these problems, some devices for cranial magnetic stimulation and! or massage employ coils which completely surround the head of the subject being treated. However, such devices are unsightly and produce a substantial fear factor in the subject. Moreover, devices employing coils of wire for magnetic massage and! or stimulation of the head are not portable and cannot provide a localized region within which the magnetic massage and! or stimulation is confined.

An apparatus to provide a locally oscillating magnetic field, for magnetic cranial massage and! or stimulation would be highly advantageous. Moreover, a compact and portable device for magnetic cranial massage and! or stimulation would be highly beneficial.

Statement of the Invention

Accordingly, the present invention provides an apparatus for generating an oscillating

magnetic field comprising:

a magnetic transducer having a support structure and a coil attached to the support structure, the coil having terminals for receiving input electrical signals; the transducer further comprising a magnet movably mounted to the support structure proximal the coil.

Ideally, the magnet is suspended by a diaphragm which is attached to the support structure.

During operation, the input electrical signals are fed to the coil via the terminals thereby causing the magnet to vibrate and producing oscillating magnetic signals in vicinity of the transducer.

In one embodiment the coil is attached to an inner portion of the support structure. In another embodiment, the diaphragm is attached to an outer portion of the support structure.

Preferably, the magnet is formed of a metal alloy comprising one or more rare earth elements.

Preferably, the magnet is a neodymium magnet.

Preferably, the electrical signals have a frequency in a range from 20 Hz to 3500Hz.

Preferably, the electrical signals vary sinusoidally.

Preferably, the oscillating magnetic field generated in the vicinity of the transducer oscillates in a range from zero to 1 Tesla.

Preferably, the strength of the magnetic field generated in the vicinity of the transducer is adjustable by adjusting the amplitude of the input electrical signals.

In some embodiments, the input electrical signals are generated by an audio player.

The generated input electrical signals may further be amplified by a low frequency amplifier.

In some embodiments, at least a portion of the support structure is formed of ferrite.

In other embodiments, at least a portion of the support structure is formed of a material having a high relative magnetic permeability.

Preferably, the inner core of the support structure is formed of a material having a high relative magnetic permeability.

According to a second aspect, the present invention provides a headset for generating an oscillating magnetic field comprising at least one magnetic transducer attached to a headband: the at least one magnetic transducer comprising a support structure and a coil attached to the support structure, the coil having terminals for receiving input electrical signals; the at least one transducer further comprising a magnet movably mounted to the support structure proximal the coil.

Ideally, the magnet is suspended by a diaphragm also attached to the support structure.

During operation, the input electrical signals are fed to the coil via the terminals thereby causing the magnet to vibrate producing oscillating magnetic signals in vicinity of the at least one transducer.

Embodiments of the present invention will now be described in detail with reference to the accompanying figures in which:

Brief Description of Drawings

Fig. IA shows a sectional view of a compact apparatus for generating a locally oscillating magnetic field according to an embodiment of the present invention.

Fig. 1 B shows a front sectional view of transducer 110 of Fig. IA in the plane defined byAA'of Fig. 1 A. Fig. 2 shows a picture of a headphone unit comprising a pair of transducers for generating a locally oscillating magnetic field according to a second embodiment of the present invention.

Detailed Description

Fig. IA shows a sectional view of a compact apparatus for generating a locally oscillating magnetic field according to an embodiment of the present invention. The apparatus of Fig. 1A comprises a transducer 110. Transducer 110 comprises a support structure 120 formed of three sections, an outer section 122, a bridging section 124 and an inner core 126. The outer section 122 of support structure 120 is axially symmetric and is generally ring shaped; the inner core 126 is also axially symmetric, and is generally cylindrically shaped. In the embodiment of the present invention depicted in Fig. IA, both outer section 122 and inner core 122 share a common axis of symmetry, AX. Bridging section 124 of support structure 120 connects one end of outer section 122 to one end of inner core 126, so that a cross section of support structure 120 through the common axis generally resembles the form of the letter E'. A coil 140 formed of an electrically conductive wire is wound around inner core 126 of support structure 120. The coil of wire 140 has input terminals 142A, 142B for receiving input electrical signals. The pair of input terminals 142A, 142B is collectively defined as input port P1.

The transducer 110 further comprises a magnet 152 positioned proximal the coil 140.

The magnet 152 is suspended by a diaphragm 154 which is attached to the outer section 122 of support structure 120. In the embodiment of the present invention depicted in Fig. 1A, magnet 152 is cylindrically shaped and shares the same common axis AX as outer section 122 and inner core 126 of support structure 120.

Diaphragm 154 is formed of a flexible material, and is stretched over an end of outer section 126 of support structure 120 opposing the end to which bridging section 124 is attached. Diaphragm 154 is attached to outer section 122 of support structure 120 via one or more fixing means 128. One or more fixing means 128 may comprise mechanical attachment means such as screws, bolts, flanges, etc, or may alternatively be an adhesive, or a bonding process.

Diaphragm 154 is stretched over outer section 122 of support structure 120 so that a cavity 155 is formed in the region inside. Magnet 152 is free to move within a range x along the axis AX of inner core 126.

Magnet 152 is typically formed of an alloy or compound comprising one or more rare earth elements producing a material having a very high level of magnetization.

Examples of suitable materials for magnet 154 include, but are not limited to: an alloy of samarium and cobalt; an alloy of neodymium comprising neodymium, iron, and boron forming the compound Nd2Fe14B. A block of material formed of the latter alloy is generally referred to as a Neodymium magnet.

During operation of transducer 110, input electrical signals are fed to the fixed coil via terminals 142A, 142B; the oscillating signals passing through coil 140 generates a weakly oscillating magnetic field in the vicinity around coil 140. The weakly oscillating magnetic field in the vicinity of coil 140 produces a time varying force acting on magnet 152, thereby causing magnet 152 to vibrate forwards and backwards in the X direction as shown in Fig. IA.

The use of a strong permanent magnet such as a Neodymium magnet for magnet 152 of Fig. 1A causes the magnet to oscillate violently in the presence of even a small oscillating magnetic field. Thus, the apparatus of Fig. IA has an amplifying effect on the locally oscillating magnetic field produced by the current passing through coil alone. Vibrating magnet 152 produces strongly oscillating magnetic signals in vicinity of magnet 152, and consequently in the vicinity of transducer 110 due to the fact that the distance of the magnet changes with time as it moves backwards and forwards in the x direction, and because of the rapid fall off of field strength with distance.

Moreover, the strongly oscillating magnetic field in the vicinity of transducer 110 decays rapidly with distance from the transducer, so that the oscillating field is localized to the region around transducer 110.

In use, the apparatus of Fig. 1A is positioned adjacent to the head of a subject for cranial massage and! or stimulation (not shown). The apparatus is orientated so that magnet 152 is located between support structure 120 and the user's head. This orientation places the magnet 152 closest to the user's head, so that any vibrations of the magnet will produce the largest variation in the magnetic field. Electrical signals are fed to input terminals 142A, 142B, at an appropriate frequency. The oscillating input electrical cause the neodymium magnet to vibrate at the same frequency as that of the input signal. The vibrating magnet 152 produces a powerful oscillating magnetic field in the region surrounding the magnet 152.

Suitable frequencies of operation of the apparatus of the present invention range from 0.001 Hz to 3500Hz. The oscillation of the magnetic field can produce a magnetic field strength varying in a range from zero to 1 Tesla. The available range of magnetic field strength for a given embodiment depends on the type of magnet used, and also depends on the range of movement of magnet 152 allowed by diaphragm 154.

In the embodiment of the present invention depicted in Fig. 1A, support structure 120 is formed of a material having a high relative magnetic permeability. For example, a suitable material for support structure 120 is ferrite which has a relative magnetic permeability of several hundred. Nonetheless, the operation of transducer 110 is improved if at least inner core 126 of support structure 120 is formed of a material having a high relative magnetic permeability. The use of a high relative magnetic permeability material for inner core 126 of support structure 120 has the effect of concentrating the magnetic field lines in the centre of coil 150, so that an increased force acts on magnet 152 when an alternating input electrical signal is fed to the coil via terminals 142A, 142B. Support structure 120, comprising outer section 122, inner core 126 and bridging section 124 may be formed as a single piece of material, or may be formed in sections, joined together by an appropriate joining or bonding process.

Fig. I B shows a front sectional view of transducer 110 of Fig. 1A in the plane defined by AN of Fig. 1 A. For clarity, the same reference numerals are used to represent the various elements which appear in both Fig. 1A and Fig. I B. Transducer 110 of Fig. lB comprises a support structure 120 formed of three sections, an outer section 122, a bridging section 124 and an inner core 126. The outer section 122 of support structure 120 is axially symmetric and is generally ring shaped. Inner core 126 is axially symmetric and generally cylindrically shaped. Both outer section 122 and inner core 126 share the same axis. A coil or wire 140 is wound around inner core 126 of support structure 120. The coil of wire 140 has input terminals 142A, 142B for receiving input electrical signals. The pair of input terminals 142A, 142B collectively comprising an input port P1.

Transducer 110 further comprises a magnet 152 positioned so that it is inside the area defined by coil 140. The magnet 152 is suspended by a diaphragm (not shown, see numeral 158 in Fig. 1A) which is attached to the outer section 122 of support structure 120 via fixing means 128. Diaphragm 154 is stretched over outer section 122 of support structure 120 so that a cavity (not shown) is formed in the region inside allowing free movement of magnet 152 along the axes of outer section 122, and inner core 126.

Fig. 2 shows a picture of a headphone unit 260 for generating a locally oscillating magnetic field according to the present invention. The headphone unit 260 of Fig. 2 comprises a pair of magnetic field producing transducers 210A, 210B attached to an adjustable headband 262. In use, the headphone unit 260 of Fig. 2 is worn by a user for cranial magnetic massage and! or stimulation. Respective transducer 210A, 210B produces a locally oscillating magnetic field in the vicinity of the transducer.

Respective transducer 210A, 21DB is mounted in a respective outer casing 266A, 266B. The position of respective outer casing 266A, 266B is adjustable inside a sliding mount 264A, 264B forming part of the headband 260. Thus, the position of respective transducer 21 OA, 21 OB is adjustable, so that the area of the head which is to be magnetically massaged and! or stimulated can be adjusted as required.

Respective sliding mount 264A, 264B may be pivotally attached to headband 262, thereby providing an extra degree of freedom for the position of respective transducer 210A, 210B on the head of the user (not shown).

A feed wire 242 is provided to feed input electrical signals to respective transducer 210A, 210B. A single feed wire 242 may be provided to supply the electrical signal to both transducers 210A, 210B; alternatively, a pair of feed wires (not shown) may be provided. The headphone unit 260 of Fig. 2 comprises respective transducer 210A, 210B, and thus provides an apparatus for cranial magnetic massage and! or stimulation of two sides of a treatment subject's head. Nonetheless, a headphone unit comprising a single transducer might alternatively be provided, so that cranial magnetic massage and! or stimulation can be applied to one portion of the head of a subject for treatment.

A range of alternative mounting devices may be deployed for holding one or more transducers against the head of a subject. The present invention is by no means limited to a transducer mounted on an adjustable headband as shown in Fig. 2.

The descriptions of the specific embodiments contained herein are made by way of example only and are not for the purposes of limitation. It will be obvious to a person skilled in the art that in order to achieve some or most of the advantages of the present invention, practical implementations may not necessarily be exactly as exemplified and can include variations within the scope of the present invention.

Claims

Claims 1. An apparatus for generating an oscillating magnetic field comprising: a magnetic transducer having a support structure and a coil attached to the support structure, the coil having terminals for receiving input electrical signals; the transducer further comprising a magnet movably mounted to the support structure proximal the coil.
2. An apparatus as claimed in claim 1, wherein the magnet is suspended by a diaphragm which is attached to the support structure.
3. An apparatus as claimed in claim 1 or claim 2, wherein the coil is attached to an inner portion of the support structure.
4. An apparatus as claimed in claim 2 or 3, wherein the diaphragm is attached to an outer portion of the support structure.
5. An apparatus as claimed in any one of the preceding claims, wherein the magnet is formed of a metal alloy comprising one or more rare earth elements.
6. An apparatus as claimed in any one of the preceding claims, wherein the magnet is aNo neodymium magnet.
7. An apparatus as claimed in any one of the preceding claims, wherein the input electrical signals have a frequency in a range from 20 Hz to 3500 Hz.
8. An apparatus as claimed in any one of the preceding claims, wherein the input electrical signals vary sinusoidally.
9. An apparatus as claimed in any one of the preceding claims, wherein a magnetic field generated in the vicinity of the transducer oscillates in a range from zero to I Tesla.
10. An apparatus as claimed in any one of the preceding claims, wherein the strength of the magnetic field generated in the vicinity of the transducer is adjustable by adjusting the amplitude of the input electrical signals.
11. An apparatus as claimed in any one of the preceding claims, wherein the input electrical signal is generated by an audio player.
12. An apparatus as claimed in claim 11, wherein the generated input electrical signal is amplified by a low frequency amplifier.
13. An apparatus as claimed in any one of the preceding claims, wherein at least a portion of the support structure is formed of ferrite.
14. An apparatus as claimed in any one of the preceding claims, wherein at least a portion of the support structure is formed of a material having a high relative magnetic permeability.
15. An apparatus as claimed in any one of the preceding claims, wherein the inner core of the support structure is formed of a material having a high relative magnetic permeability.
16. An apparatus as claimed in any one of the preceding claims, wherein the transducer comprises a support structure formed of three sections, an outer section, a bridging section and an inner core. r
17. An apparatus as claimed in claim 16, wherein the outer section of support structure is axially symmetric and is generally ring shaped.r.
18. An apparatus as claimed in claim 16 or claim 17, wherein the inner core is also axially symmetric, and is generally cylindrically shaped.
19. An apparatus as claimed in any one of claims 16 to 18, wherein both outer section and inner core share a common axis of symmetry, AX.
20. An apparatus as claimed in any one of claims 16 to 19, wherein the bridging section of the support structure connects one end of outer section to one end of inner core, so that a cross section of support structure through the common axis generally resembles the form of the letter E'
21. A headset for generating an oscillating magnetic field comprising at least one magnetic transducer attached to a headband: the at least one magnetic transducer comprising a support structure and a coil attached to the support structure, the coil having terminals for receiving input electrical signals; the at least one transducer further comprising a magnet movably mounted to the support structure proximal the coil.
22. A headset as claimed in claim 21, wherein the magnet is suspended by a diaphragm also attached to the support structure.
23. An apparatus substantially as herein before described with reference to and/or as shown in the accompanying Figures IA and I B.
24. A headset substantially as herein before described with reference to and/or as shown in the accompanying Figure 2. rN