Device for generating a very-low-frequency pulsed magnetic field carried by a very-low-frequency alternating magnetic field

Abstract

The invention relates to a device for generating a very-low-frequency pulsed magnetic field carried by a very-low-frequency alternating magnetic field and intended to be applied to a region of the human body, the device is provided with a plurality of pairs of angular magnet sectors of opposite polarity, the pairs of angular magnet sectors being centered on one same axis of rotation, angularly spaced apart from one another, and set in rotation at a predetermined speed about the axis of rotation so as to generate an alternating magnetic field at a predefined frequency, and at least one conductive wire coil centered on the axis of rotation of the angular magnet sectors and supplied with a pulsed electric current so as to generate a pulsed magnetic field superimposed over the alternating magnetic field generated by the setting in rotation of the angular magnet sectors.

Claims

1. A device for generating a very-low-frequency, pulsed magnetic field carried by a very-low-frequency alternating magnetic field, and intended to be applied to a region of a human body, the device comprising: a plurality of pairs of angular magnet sectors of opposite polarity, the pairs of angular magnet sectors being centered on one same axis of rotation, angularly spaced apart from one another, and set in rotation at a predetermined speed about the axis of rotation so as to generate an alternating magnetic field at a predefined frequency; and at least one conductive wire coil centered on the axis of rotation of the angular magnet sectors and supplied with a pulsed electric current so as to generate a pulsed magnetic field superimposed over the alternating magnetic field generated by the setting in rotation of the angular magnet sectors.

2. The device according to claim 1, wherein the conductive wire coil is supplied with a pulsed electric voltage in a form of regular pulses of less than 1 ms duration, frequency of 20 Hz and generating sufficient intensity to generate a magnetic field of 1 to 2 mT.

3. The device according to claim 2, further comprising a microcontroller to cause the pulse frequency of the pulsed electric current to vary during a cycle of use.

4. The device according to claim 1, further comprising a microcontroller to cause a rotation frequency of the pairs of magnet sectors to vary during a cycle of use.

5. The device according to claim 1, wherein a rotation frequency of the pairs of magnet sectors is less than or equal to 10 Hz.

6. The device according to claim 1, wherein the conductive wire coil is a circular coil centered on the axis of rotation of the angular magnet sectors.

7. The device according to claim 1, wherein the conductive wire coil is a figure-of-eight coil.

8. The device according to claim 1, wherein each said angular magnet sector has one same geometric shape with an inner angular opening (a) of 90° at the axis of rotation, an outer angular opening (β) of between 20° and 50° at a free end opposite the axis of rotation, and two side edges defining a radius extending over a distance of between one third and two thirds of a distance separating the axis of rotation from the free end of the angular magnet sectors.

9. The device according to claim 1 further comprising a magnetic circuit layer arranged on a back of the pairs of angular magnet sectors.

10. The device according to claim 1 further comprising a magnetic shielding layer arranged around the pairs of angular magnet sectors.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Other characteristics and advantages of the present invention will become apparent from the description given below, with reference to the appended drawings illustrating an example of embodiment that is in no way limiting. In the Figures:

(2) FIG. 1 is a schematic view of a device according to one embodiment of the invention;

(3) FIG. 2 is a cross-sectional view along II-II in FIG. 1;

(4) FIGS. 3A and 3B are examples of pulsed magnetic fields generated by the device of the invention; and

(5) FIG. 4 gives curves showing the blood microcirculation obtained with the device of the invention, with a device having rotating magnets, and with a device having a conductive wire coil.

DETAILED DESCRIPTION OF THE INVENTION

(6) FIGS. 1 and 2 schematically illustrate a portable device 2 of the invention to generate a low-frequency pulsed magnetic field carried by an alternating magnetic field, and intended to be applied to a region of the human body.

(7) This device 2 comprises a casing 4 inside which there are assembled two pairs of angular magnet sectors 6-1 to 6-4 as described in patent application FR 17 60443 filed by the Applicant.

(8) As described in this patent application FR 17 60443, the angular magnet sectors 6-1 to 6-4 have one same geometric shape, are centred on one same axis of rotation X-X, and are contained within a circle C of diameter D and centre O.

(9) More specifically, the angular magnet sectors 6-1 to 6-4 are angularly spaced apart from one another about the axis of rotation X-X and are arranged so that two adjacent angular magnet sectors have opposite polarity (North or South).

(10) The device 2 also comprise means to set the pairs of angular magnet sectors in rotation about the axis of rotation X-X. In one embodiment, these means are in the form of an electric motor and belt transmission. Evidently any other means could be envisaged to ensure this setting in rotation.

(11) Preferably, the four angular magnet sectors 6-1 to 6-4 are each of symmetrical shape relative to a radius of symmetry, R-1 to R-4 respectively, of the circle C within which they are contained.

(12) Each angular magnet sector 6-1 to 6-4 comprises two side edges 8-1 to 8-4 which are symmetrical relative to the radius of symmetry of the angular magnet sector and they face or are in direct contact with the corresponding side edges of two adjacent angular magnet sectors.

(13) In addition, the two side edges 8-1 to 8-4 of each angular magnet sector define a joining radius (delimited between the centre O of circle C and point 10-1 to 10-4 of the side edge the furthest distant from the centre O) which extends over a distanced corresponding to two thirds of the radius D/2 of circle C (i.e. two thirds of the distance separating the axis of rotation X-X from the free end of the angular magnet sectors). For practicality reasons, only points 10-1 of the angular magnet sector 6-1 are shown in FIG. 1.

(14) In addition, the side edges 8-1 to 8-4 of each angular magnet sector together form an angle α of 90° (it can also be said that the inner angular opening α of each angular magnet sector at the axis of rotation X-X is 90°).

(15) Also preferably, each angular magnet sector further comprises an outer angular opening β at a free end opposite the axis of rotation X-X which is between 20° and 50°, and is preferably 45°.

(16) In other words, the free end of each angular magnet sector 6-1 to 6-4 is preferably delimited between two points 12a, 12b positioned on circle C within which the angular magnet sectors are contained. These points are symmetrical and the radii formed by points O and 12a, and by O and 12b, together form an angle β of between 20° and 50°, and preferably of 45°.

(17) The angular magnet sectors 6-1 to 6-4 of the device of the invention are set in rotation about the axis of rotation X-X preferably at a speed of 300 rpm, which generates an induced sinusoidal electric current at a frequency preferably lower than or equal to 10 Hz. This setting in rotation of the angular magnet sectors 6-1 to 6-4 of the device generates an alternating magnetic field.

(18) As illustrated in FIG. 2, the device 2 of the invention further comprises at least one conductive wire coil 14 centred on the axis of rotation X-X of the angular magnet sectors and supplied with a pulsed electric current.

(19) This coil 14 is for example a circular coil centred on the axis of rotation of the angular magnet sectors. It can be made of copper wire having a diameter of less than 0.5 mm, with a single layer of turns, the outer diameter thereof covering the outer diameter of the magnets.

(20) Also, this coil is supplied with pulsed electric voltage. By «pulsed electric voltage» it is meant a variation in electric voltage in the form of regular, uniform pulses over time, of which the pulse duration (or generation time) and pulse recurrence time (or frequency) can be determined. They may also be irregular pulses that are known however and known how to reproduce.

(21) Preferably, the pulsed electric voltage supplying the conductive wire coil 14 is in the form of regular pulses of less than 1 ms duration, frequency of 20 Hz and generating sufficient intensity to generate a maximum magnetic field of 1 to 2 mT.

(22) In this manner, the conductive wire coil 14 generates a pulsed magnetic field superimposed over the alternating magnetic field generated by the setting in rotation of the angular magnet sectors 6-1 to 6-4.

(23) It will be noted that the conductive wire coil can be a figure-of-eight coil («butterfly» type coil) centred on the axis of rotation X-X of the angular magnet sectors.

(24) It will also be noted that the device 2 of the invention may further comprise means (of microcontroller type 15) to cause the pulse frequency of the pulsed electric current supplying the conductive wire coil 14 and/or the rotation frequency of the pairs of magnet sectors 6-1 to 6-4 to vary during a cycle of use.

(25) This characteristic is particularly advantageous for varying the magnetic field generated by the device during a cycle of use.

(26) It will be further noted that the angular magnet sectors 6-1 to 6-4 are driven in rotation about the axis of rotation X-X by an electric motor (not illustrated) independent of the electric supply to the coil 14. Also, when the coil 14 is powered the polarity thereof remains unchanged. In particular, the coil does not undergo any polarity reversal when the device of the invention is in operation.

(27) FIGS. 3A and 3B illustrate examples of a magnetic field (as a function of time) generated by superimposition of these two fields.

(28) In particular, FIG. 3A gives an example of a curve showing the induced current C1 generated by the device of the invention in the centre thereof i.e. at the axis of rotation X-X of the angular magnet sectors. FIG. 3B gives an example of a curve showing the alternating induced current C2 at a distance of one centimetre from the centre of the device.

(29) These two curves of induced current C1, C2 clearly show each of the pulses carried by a sine wave. In particular, it is ascertained that the intensity of the pulses carried by the sine-wave is greater in the centre of the device and decreases on moving away from the centre. Therefore, the conductive wire coil when supplied with pulsed electric current creates a strong induced current at the centre of the device and of lesser intensity on the periphery thereof.

(30) FIG. 4 illustrates a test example of the device of the invention and the results obtained on blood microcirculation in a region of the human body exposed to the device over several cycles of application.

(31) More specifically, the test of the device was conducted on a person's hand with the following operating mode: a rest period P1 (lasting 5 mn), a first cycle of application of the device P2 (lasting 3 mn), a second cycle of application of the device P3 (lasting 3 mn), and a period of return to normal P4 (lasting 15 mn).

(32) Using a blood perfusion imaging system, it was possible directly to measure the level of skin perfusion (i.e. blood microcirculation) throughout the test. The data given by the imager were normalised in relation to the mean of the values of the last minute of the rest period P1 to express the percentage increase in microcirculation during the test.

(33) FIG. 4 gives three different curves corresponding to three different tests: a curve C3 corresponding to a test using a device of the invention; a curve C4 corresponding to a test using a magnetotherapy device having a conductive wire coil but without rotating magnets, and a curve C5 corresponding to a test using a device having rotating magnets but without a conductive wire coil.

(34) It is ascertained that the effect on blood microcirculation obtained by applying the device of the invention during the application cycles P2, P3 (curve C3) is largely greater than the simple addition of the effects obtained with the two other devices (curves C4 and C5). An increase of 100% is found in global blood perfusion of the hand at the start of the two application cycles P2, P3, whereas this increase is only 50% for the device without conductive wire coil (curve C5). For the device without rotating magnets (curve 4) there is very little effect on microcirculation.

(35) In addition, as for the device described in patent application FR 17 60443, it will be noted that the device of the invention can have angular magnet sectors of varying thicknesses and can be provided with a magnetic circuit layer arranged on the back of the pairs of angular magnet sectors and with a magnetic shielding layer arranged around the pairs of magnetic angular sectors (not illustrated in the Figures). In this case, the antenna is positioned on the side opposite the magnetic circuit so that the magnetic field of the circular antenna is not attenuated by the magnetic circuit.