MXPA97003910A - Magnetic stimulator for nerve to excitate peripheral nervous - Google Patents

Abstract

The present invention relates to a magnetic stabilizing system for the ribs, which comprises a core (2) of a highly saturable material with a coil winding (4). A capacitor thyristor discharges circuit pulses to the device. A magnetic field of rapid changes is guided by the core (2), which is preferably constructed of vanadium premendur. For specific excitation tasks of several nerve groups, the specially constructed cores allow the excitation of the nerves, at deeper levels with greater efficiency, than is possible with an air core stimulator. Among the possible applications with the present invention, are the treatment of incontinence, the rehabilitation of large muscle groups of the leg and arm, and the excitation of the muscle groups of the abdominal wall, to assist in the loss of breasts and the increase of the metabolic amount. To focus the stimulation as desired, a form of "

Description

MAGNETIC STIMULATOR FOR NERVES TO EXCITATE THE PERIPHERAL NERVOUS BACKGROUND OF THE INVENTION BACKGROUND OF THE INVENTION v Description of the Prior Art A nerve cell can be excited in many ways, but a direct method is to increase the electrical charge within the nerve, thereby increasing the potential of the membrane within the nerve, with with respect to the extracellular fluid that surrounds it. A type of device that is within the coverage of the Functional Electrical Stimulation (FES), performs the excitation of the nerves by directly injecting charges into the nerves by means of electrodes, which are placed either on the skin or in I live next to the nervous group of interest. The electric fields necessary for the transfer of the charge are impressed simply by means of the wires of the electrodes. The FES is achieved through a mechanism, which comprises a half cell reaction. The flow of electrons in the cables and the flow of ions in the body, At the electro-electrolytic interface, a cell-mediated reaction occurs to perform the electron-ion exchange, Unless this half-cell reaction is maintained in the reversible regimen, necrosis will result-partly due to the oxidation of the half-cell reaction and partly due to the chemical deficit that accompanies it.

The advantage of FES is that the stimulation can be performed generally, from extremely small electrodes with very modest levels of current and voltage. The disadvantage, however, is that it comprises half-cell reactions. Most rehabilitation programs that use FES place the electrodes directly on the skin. On the site there should be a conductive gel or a buffer between the electrodes and the surface of the skin. Excitement of the nerve or long-term muscle tissue is often accompanied by skin irritation, due to the concentration of the current at the electrode / skin interface. This problem is aggravated, especially when large levels of arousal are required for more complete stimulation or recruitment of the nervous group. In contrast, the magnetic stimulation performs the electric fields necessary for the transfer of the charge, by means of induction. The rapidly changing magnetic fields induce the electric fields in the biological tissue, when the stimulation is oriented in a correct way and when the appropriate magnitude is achieved, the magnetic field induced magnetically achieves the same result as that achieved by the FES, that of the transfer charge directly inside the nerve that is going to be excited. When the potential of the membrane is located within the nerve, it rises with respect to its negative normal environmental level of approximately -90 millivolts (this level being sensitive to the type of nerve and the local pH of the surrounding tissue), the nerve "lights".

The present invention is especially focused on applications that are not suitable for the use of implanted electrodes. It is preferable to use the present invention in those situations in which stimulation can be achieved in a non-invasive manner. In those applications that include incontinence and muscle group rehabilitation, as well as potential weight loss treatments, the levels of arousal desired using the FES are often outside those that could be considered as comfortable limits, ie, The electric current that would be ideally injected, through the skin to excite the muscle groups of interest, often leads to some kind of skin irritation over time. Even in applications where this is not the case, the mandatory use of gels and the direct placement of the electrode on the skin is inconvenient, and frequently, the patient resists this application. Magnetic excitation, on the other hand, has the attractive feature of not requiring contact of the electrodes with the skin. Thus, the stimulation can be achieved through the clothing that is being used. This overcomes the objection of the inconvenience and the preservation of the patient's dignity. Second, because there is no direct contact, stronger levels of arousal can be made, without the additional, undue irritation of the skin. A contribution offered by the present invention is the ability to achieve higher levels of magnetic field focusing and thus, stimulation within the patient. Attached to this larger level of approaches, comes the flexibility in the number of possible applications, which could be programmed. Also, accompanying this higher level of focus, it is at the highest level of power efficiency. Generally, the methods that are being designed by the methods established in the present invention, reduce the magnetic path of the reluctance by a factor of two. This reduction in reluctance results in a decrease in current for the same factor and a fourfold reduction in power loss. Magnetic stimulation of neurons has been investigated deeply in recent decades. Almost all of the magnetic stimulation work has been done in vivo. Most of the work of magnetic stimulation has been in the area of brain stimulation. Cohen has been a major contributor to this field of research (see for example, the article by T. Kujirai, M. Sato, J. Rothwell and LG Cohen: "The Effects of Transcranial Magnetic Stimulation on Median Nerve Somatosensory Evoked Potentials", in Journal of Clinical Neurophysiology and Electro Encephalography, Volume 89, No. 4, 1993, pages 227 to 234). This work has been carried out through several research efforts including that of Davey and associates (See, the article by KR Davey, CH Cheng, CM Epstein: "An Alloy - Core Electromagnet for Transcranial Brain Stimulation" in the Journal of Clinical Neurophysiology, Volume 6, Number 4, 1989, page 354), and that of Epstein and associates, (see the article by Charles Epstein, Daniel. Schwartzberg, Kent Davey and David Sudderth, "Localizing the Site of Magnetic Brain Stimulation in Humane, in Neurology, Volume 40, April 1990, pages 666 to 670). Most attempts of magnetic stimulation research, to load the nerves, focus on the central nervous system. The present invention differs in several aspects from previous investigations and efforts. First, the present invention focuses primarily on the application to the peripheral nervous system, although it can also be employed to stimulate the nerves in the central nervous system. Second, and more importantly, the earlier work of nerve stimulation is dominated, almost exclusively by air core coils of different shapes and sizes. The present invention, as will be explained below, refers to the use of a core of a highly saturable material, preferably vanadium permendur. Among the air core stimulators, there are coils of circular, oval, eight-figure and D-shaped shapes. The coils are normally excited by a discharge of the capacitor inside the winding of the core of these coils. This field of exponential decay has a constant time generally in the vicinity of 100 microseconds. The typical programmed values for the peak of the magnetic field, happen near two tesla. J. A. Cadwell is perhaps the leader among those who are now using and marketing these air core stimulators. Among its main patents is US Patent No. 4,940,453, entitled "Method and Apparatus for Magnetically Stimulating Neurons" of July 10, 1990. There is a quantity of energy supplies, of which, all operate with a basic discharge of the capacitor type, within a number of air core coils, which are sold with their units. At the same time, several forms of coils are being explored. One of these coils is an apparatus in the form of a lid, which is placed on the cortex of the m otor, (see the article by K. Krus, L. Gugino, W. Levy, J. Cadwell and B. Roth " The use of a cap-shaped coil for transcranial stimulation of the motor cortex ", in Journal of Neurophysiology, Volume 10, Number 3, 1992, pages 353 to 362).

Several efforts have been directed to several circuits used to power these air core coils. H. Eton and R. Fisher offer one such alternative in their patent "Nervous Magnetic Stimulator, US Patent No. 5, 066,272, November 19, 199 1. They suggest the use of two capacitors, one to discharge capacitor within the coil of interest, and the second, to recover the charge of the inducing energy resident in the coil The circuit used in the present invention achieves the same objective with a simple capacitor Some stimulation investigations are being carried out on the peripheral nervous system (see, for example, the article by Paul Maccabee, and V. Amassi na, L. Eberle and R. Cracco, "Magnetic Coil Stimulation of Straight and Bent Amphivian and Mammalian Peripheral Nerve in vitro: Locus of Excitation, in the Journal of Physiology , Volume 460, January 1993, pages 201 to 219). However, most of Maccabee's work is programmed for cranial excitation. The applications of the present invention focus on the peripheral nervous system, although they can also be used in the central nervous system.

SUMMARY OF INVENTION Magnetic stimulation of peripheral nerves has the advantages of convenience and threshold variability over competing FES systems. An advance of the present invention on magnetic stimulators for competitive nerves is in the use of a magnetic core of a highly saturable material, and in the design of the magnetic core stimulator itself. An object of the present invention is to "turn on" a coil having a decay characteristic time of 100 microseconds, fifteen times per second. The system can be efficient and reasonably reliable, to turn on a high amount of repetition. This amount is necessary to keep the muscle groups more or less stimulated continuously. The exact frequency of stimulation would be somewhat varied, depending on the requirements of the application. Sometimes, muscle groups will need to be aroused for a period of five seconds, followed by a rest for a period of five seconds and then, being stimulated continuously for another five seconds and then resting again. While these muscle groups are being stimulated, it is desirable to have the muscle groups continuously excited. This requirement determines the need for the continuous pulse of the cores in a repetition range of 15 Hz. Due to the large currents included during any ignition of the determined coil, it is necessary to make the coils as efficient as possible. It is desirable to focus the magnetic field towards the region programmed for the stimulus for the exclusion of the regions that surround it. The specially designed coils offered by the present invention perform this approach, while the air core coils used by the prior art do not. The simplest nucleus that could be selected, would be the nucleus in the form of "C". The span of the "C" must be chosen carefully; the span affects both the depth of penetration and the magnitude of the field. Possibly what is of greater importance, is the construction of the nucleus. The best cores are constructed of thin, highly saturable sheet metal. A typical core could be wound using two thousandths of an inch vanadium permendur material. A long strip of said material is wound on a mandrel (for example, a wooden or plastic mandrel) to obtain the desired radius, thickness and depth. Each side of the batten is covered with a thin insulating coating to isolate it electrically from the surrounding environment. A generic nucleus that could be used in several locations around the body could cross an angle of approximately 210 °. Once the strip of material has been wound on the mandrel in the desired dimensions, it is immersed in epoxy material to fix its position. 'Once the epoxy material has dried, the mandrel is removed and the core can be cut to the desired angle dimensions. The cut can destroy the electrical insulation of adjacent laminations. Each of the cuts must be finely ground so that it is smooth and then a deep etching is carried out. Etching to deep water is carried out by immersing each of the cut ends in an acid bath. This causes the cutting ends to delaminate slightly, but the electrical insulation of the laminations is preserved. The lack of realization of this deep engraving apparently results in a considerable loss of countercurrent and heating at the cutting ends of the core. After deep engraving, the ends are brushed with epoxy material to preserve the shape and structural integrity of the core. The final step of the construction is to wind an insulated cable coil around the core. A typical inductance for a core of this type is approximately 20 μH. However, the present invention can also be practiced in other inductances or powers, of the magnetic field. In the simplest configuration, each core has only one winding. The winding is excited by a pulse that decreases exponentially with the characteristic time of approximately 20 μs. The real signal has a sound period of about that time, inside a shell, which is decreasing exponentially, so that only two to three cycles are ever witnessed, by the current of the coil. The excitation is repeated in a period of approximately 15 to 20 Hz. As stated above, the repetition cycle of these patterns may be varied according to the desired application. The circuit usually consists of a transformer, which is fed into a full wave rectifier bridge. The bridge voltage charges the capacitor; The charge of the capacitor is detonated with a silicon control rectifier to drive the current inside the coil. The return charge that is returning through the coil the second time, is fed again, through a diode inside the capacitor to prepare the circuit for the second phase of excitation. There are three main application objectives for the present invention, the treatment of incontinence, muscle rehabilitation and weight control. For the treatment of incontinence, it is necessary to stimulate the pelvic floor muscles. This stimulation is achieved by concentrating and focusing the magnetic flux, directly above the vaginal cavity. A suitable core, with the capacity to achieve this objective, is constructed by combining two individual "C" shaped nuclei, each one encompassing an angle of approximately 210 °. The legs of the nuclei meet in the central region. The common central leg of the two "C" shaped cores is wound by a coil and the return flow path is divided between the two "C" s. The nuclei themselves are fixed close and distally, on top of a chair, on which the patient sits during the treatment. The second area of potential application is the rehabilitation of the muscles. The muscle groups that focus mainly are the thigh, the calf, the biceps and the triceps. The geometry is similar for all these applications and therefore, a cylindrical extension is used around the muscle. Although a solution to this problem is a coil and a simple C-shaped core, which is moved around, at the discretion of the patient, a more suitable stimulator, resembles tubular-shaped motors used in electromechanics to drive a limb. In this case, the geometry would necessarily require an articulated form that has steps or grooves, which run azimuthally, around the muscle group that is to be stimulated.The stimulator coils are fixed in these steps or If the structures were adapted with two or three coils, they could be stimulated in a phase distribution.This excitation would have the effect of a massage of the muscle group tissue. , along its longitudinal axis, this particular excitation pattern can be instrumental in the larger muscle groups, which They are completely recruited such as the hamstring group of the leg. The complete recruitment or stimulation of the nervous group would be advantageous for long-term rehabilitation. Preliminary experiments with the apparatus indicate that the excitations at the frequencies mentioned, perform the exercise of the muscles in a range and efficiency higher than those that could be achieved through normal means. Another area of potential application is to help in the management of weight loss. In a way similar to muscle rehabilitation, an alternative is to simply use a manual unit that moves over multiple areas of the body. A particularly difficult group to stimulate could be the abdominal wall. A possible method to carry out the excitation of this group would resemble a pectoral plate that could be held by means of hinges, next to a chair in which the patient sits. The chest plate would contain a two or three phase distribution of coils supported by laminated vanadium cores constructed in the manner indicated above. The nuclei would be separated to drive the flow, deep within the abdominal muscle group. Both in muscle rehabilitation and in the management of weight loss, the programming of the phases of the coils can be alternated, with time, to give the effect of the "massage" stimulation pattern backwards and forwards. The reasoning in the management of the weight, is that the ignition of these muscular groups, requires the administration of adenosine triphosphate; but this expenditure of energy is being induced artificially by the magnetic stimulator. In summary, it has been observed that there are a number of methods to stimulate in a more efficient way, several muscle groups within the body. The key to these more efficient techniques revolves around the use of high saturation thin laminate material to build these cores and through them drive and focus the flow to the desired regions. A simple core of type "C" achieves a reluctance advantage, of at least a factor of two, over conventional cores. By using multiple cores connected to a central leg, a single focusing site can be achieved, with the return path being spent in two or more areas, so that the excitation is discouraged when the field is returned. In other applications, the multi-phase coils that actually enclose the tissue of interest can be excited to rotate or massage the muscle groups directionally, over time. Certain wrapping applications may be more instrumental for the superior recruitment of injured muscle groups.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a plan view of a stimulator with a "C" shaped core with a winding toroidal coil field wrapped around the core. These field lines (dotted lines) indicate the depth of penetration and the focus of the stimulation. Figure 2 is a schematic view of the circuit used to stimulate the winding of the coil. Figure 3 is a planar top view of a configuration of the core stimulator used in the treatment of incontinence; The core is designed to be fixed under a mattress-shaped chair, in which the patient sits during treatments. Figure 4 is a perspective view of a core stimulator (wound around a patient's leg) used to massage the muscles of the leg for rehabilitation purposes. The tubular core is articulated on one side and is designed to bend around the leg. Figure 5 is a perspective view of a section of a half of the core stimulator used for the rehabilitation of the arm or leg muscles; the windings of different phases are placed in the adjacent steps or slots, cut inside the core. Figure 6 is an end view of the stimulator of the leg or arm. The winding that goes from one section to the next, is stuck in a long fold to allow easy opening of the core units, in order to facilitate its placement around the leg or arm. Figure 7 is a schematic perspective view of a multi-phase stimulator, hinged to place it around the torso of a patient.

DETAILED DESCRIPTION OF THE INVENTION As illustrated in Figure 1, a "C" shaped nucleus is capable of stimulating various peripheral nerve groups throughout the body. The core 2 is constructed by winding two to four millisecond laminations of a highly saturable material in a mandrel; The required number of laminations will be dictated by the desired thickness and depth of the core. This spool of tightly rolled laminations is removed from the mandrel and covered with an epoxy material to give the unit structural integrity. This tight winding is then cut to provide the length and angle of the "C" shape, as desired. Then the deep etching operation is carried out at the cutting ends. The cutting ends are submerged in an acid bath, which causes the epoxy to dissolve, resulting in a light delamination of the core in the vicinity of the cut. Then the epoxy material is brushed on the etched ends to avoid additional delamination. This procedure is necessary to prevent cross-currents from flowing in the core. This would decrease the effective B field, which can be produced by the core. The characteristic magnetic fields in the nuclei, have powers in a range of two Tesla. The laminated material must be constructed of a highly saturable material. Preferably, vanadium permendur is used. The material carries a high density of the field. In this application, high saturation is more important than high permeability. A winding or coil 4 is then wound around the core in such a way that the flow is conducted through the cutting ends 5. The lines 6 of the field provide an indication of the depth of penetration and the degree of focus expected from that core. Figure 2 shows an electrical circuit used for "turn on" the core and coil of Figure 1. A normal signal of 120 volts, 60 Hz, excites the circuit in 7. A transformer 8 amplifies the voltage to approximately 1 to 3 kV. This High Voltage Alternating Current (AC) signal is then fed into the full wave rectifier bridge 10- The signal from the rectifier bridge, it is subsequently passed through a diode 12 to charge a capacitor 14. The purpose of all electrical components to the left or above the capacitor, is simply to charge the capacitor. The energy that resides in the circuit, which will be pumped into the stimulator core, is one half of the C value (capacitance value) multiplied by the voltage squared. When the thyristor 16 is detonated with a small pulse of control voltage, the current flow passes through the thyristor and into the core 2. Most of the energy goes back to the capacitor 14, recharging it in the polarity opposite to that of its initial charge. The capacitor with the reverse load 14 immediately re-discharges through the stimulator coil 2, through the diode 18, connected in parallel. Theoretically, all this energy must pass inside the capacitor to recharge it according to its initial polarity. In practice, of course, this LC circuit has some loss and the thyristor 16 is not cut immediately. In practice, two or three cycles of exponentially decreasing sound of this circuit L are attested, before the core 2 current is cut off. After cutting, the capacitor is charged through diode 12 as it did initially. It continues charging until the thyristor 16 is detonated again. For different tasks, different stimulation / rest cycles are used. In the treatment of incontinence, one of these stimulation cycles could be turned on for five seconds, and off five seconds. During the five seconds that are characterized as "on", the thyristor 16 would be pulsed continuously, 15 times per second. These stimulation schedules can be altered according to the requirements and the goal of the stimulation protocol. The circuit shown is a preferred embodiment for practicing the present invention, but other circuit designs (such as a dual capacitor distribution, etc.) can also be used to turn on the coil, as will be appreciated by those skilled in the art. . In addition, whenever the magnetic field is produced using this modality, pulses can also be practiced with variations in that frequency, of approximately 20 to 50 kHz. In Figure 3 a dual distribution of the type of core in the form of "C" is illustrated. for the treatment of incontinence. The individual "C" s comprising this core each comprise an angle of approximately 220 °. The cores 20 are placed end to end in a type W distribution. The winding 4 is wound around the common central leg of the two cores. The cutting ends of these cores are designed to be washed with the lower end of the mattress of the chair 21, in which the patient sits. The primary flow is conducted upward from the common central nucleus within the vaginal cavity. This flow is returned through the posterior and anterior arms of the T, because the return flow is smaller in magnitude, no stimulation occurs elsewhere, except in the vaginal floor near the central leg of the "W". Figure 4 shows a core stimulator suitable for exciting the muscle groups of the leg or arm, in this configuration, the nuclei 22 would constitute a tubular-type mantle, inside which a leg 24 or an arm would be inserted. The "C" shaped core of Figure 1 would be suitable for this task, it is difficult for its geometry to achieve a homogeneous and controlled stimulus of this muscle group As illustrated in Figure 5, each of the sections of the stimulator 22 comprises two halves of a shell 26. The steps or slots 27 are cut inside the shell halves to allow the placement of the coils, which will be preferably wound, within the shells.

The individual windings of the shell 26 are aligned in such a way as to create a magnetic field, which is preferably along the axis of the arm or the leg. The adjacent steps or grooves of the stimulator 22 will contain different phases. To excite a magnetic field trip, which moves down and up the axis of the arm or leg, a two- or three-phase distribution is used. This distribution of the winding is likely to be used in tubular motors, to perform an axial travel wave. One end of the two common halves that constitute the stimulator 22 must act as a joint. The winding electrically connecting the two halves is achieved by simply lowering the cable as an extension 28 as suggested in Figure 6. The extra length of the winding associated with the extension 28 ensures the flexibility the stimulator needs to move and wrap. around the patient's arm or leg. Figure 7 suggests yet another suitable alternative modality for the stimulation of the abdominal muscles. In this mode, the stimulator 30 is articulated to a chair within which the patient sits. The stimulator then bends around the patient's abdomen during treatment. The stimulator 30 is constructed again of highly permeable and saturable laminate material. Multiple windings lie on the step or slots that are cut into the core. The windings are designed to drive the flow within the abdomen and cause a contraction of the muscle group of the abdominal wall. Again, the windings can be activated in phases in order to cause a directional massage of the muscle group. Although the present invention has been described with respect to certain specific embodiments, it should be understood that the description should not be taken as a limitation thereof, since those skilled in the art may suggest additional modifications to the present invention, and that it is intended to cover such modifications within the scope of the appended claims.

Claims (27)

1. R E I V I N D I C A C I O N S 1. A magnetic stimulator for the nerves, which comprises: a) a core of a highly saturable material b) a stimulating coil, said coil having its longitudinal axis located within the outer geometrical limits defined by said core; and c) electrical current means connected to said stimulating coil to create a current flow in said stimulating coil, which causes said stimulating coil and said core to generate a magnetic field.
2. 2. A magnetic stimulator for the nerves, as described in Claim 1, further characterized in that said core is constructed of vanadium permendur.
3. 3. A magnetic stimulator for the nerves, as described in Claim 1, further characterized in that said core has approximately a "C" shape.
4. 4. A magnetic stimulator for the nerves, as described in Claim 1, further characterized in that the shape of said core focuses and / or concentrates the magnetic field produced by said coil and said core.
5. 5. A magnetic stimulator for the nerves, as described in Claim 1, further characterized in that said core is substantially tubular.
6. 6. A magnetic stimulator for the nerves, as described in Claim 5, further characterized in that said core comprises at least one step for holding said coil.
7. 7. A magnetic stimulator for the nerves, as described in Claim 1, further characterized in that said electrical current means comprise: a) a supply of electrical energy; b) a transformer connected to said power supply; c) a full wave rectifier bridge connected to said transformer d) a diode connected to said full wave rectifier bridge; e) capacitor means connected to said diode; f) a thyristor connected to said capacitor, said thyristor being connected to said stimulating coil; and g) a second diode connected to said capacitor, said second diode also being connected to said stimulation coil.
8. 8. A magnetic stimulator for the nerves, as described in Claim 7, further characterized in that said capacitor means comprises a single capacitor.
9. 9. A magnetic stimulator for the nerves, as described in Claim 1, further characterized in that the decay time of said coil is approximately one hundred (100) microseconds.
10. 10. A magnetic stimulator for the nerves, as described in Claim 1, further characterized in that said coil generates a magnetic field at least about fifteen (15) times per second. 1.
11. A magnetic stimulator for the nerves, as described in Claim 1, further characterized in that said core defines an arc of approximately two hundred and ten (210) degrees.
12. 12. A magnetic stimulator for the nerves, as described in Claim 1, further characterized in that said core comprises a strip of said saturable material covered with a thin insulating coating.
13. 13. A magnetic stimulator for the nerves, as described in Claim 12, further characterized in that said strip of saturable material is additionally provided with an epoxy coating.
14. 14. A magnetic stimulator for the nerves, as described in Claim 3, further characterized in that the ends of said core are finely ground.
15. 15. A magnetic stimulator for the nerves, as described in claim 1, further characterized in that it additionally comprises at least about two "C" shaped cores that are provided with a single coil around the adjacent legs.
16. A magnetic stimulator for the nerves, as described in Claim 1, further characterized in that two of said cores are provided, said cores being in the form of "C", and next to a seat to sit in.
17. 17. A magnetic stimulator for the nerves, as described in Claim 16, further characterized in that said generated magnetic fields, produced by said coils and said cores interact to produce an aggregate magnetic field of a desired direction, power and frequency.
18. 18. A magnetic stimulator for the nerves, as described in Claim 1, further characterized in that said coil and said core are an integral part of a chest plate.
19. 19. A method to magnetically stimulate the nerves of an organism, which comprises the steps of: a) charging a capacitor with an electric charge; b) discharging said capacitor through a stimulating coil that is in communication with a core of a highly saturable material; and c) exposing the neurons of said organism to the magnetic field generated by said stimulator and said coil.
20. 20. A method as described in Claim 19, further characterized in that said highly saturable material comprises vanadium permendur.
21. 21. A method as described in Claim 19, further characterized in that said neurons comprise the peripheral nervous system of said organism.
22. 22. A method as described in Claim 19, further characterized in that it further comprises the step of stimulating said nerves for the treatment of incontinence.
23. 23. A method as set forth in Claim 19, further characterized in that it further comprises the step of stimulating said ribs for the purpose of weight control.
24. 24. A method as described in Claim 19, further characterized in that it further comprises the step of stimulating said nerves for the purpose of muscular rehabilitation.
25. 25. A method as described in Claim 19, further characterized in that it further comprises the step of stimulating said nerves in cycles, said cycles comprising periods of stimulation of said nerves and periods of rest of said nerves.
26. 26. A method as described in Claim 19, further characterized in that it further comprises the step of focusing and / or concentrating said magnetic field in the desired region.
27. 27. A method of constructing an apparatus for use as a magnetic stimulator for the nerves, which comprises the steps of: a) covering a strip of highly saturable material with a thin insulating coating; b) winding said strip of material in a tight chuck in a desired radius, thickness and depth; c) covering said strip of material with epoxy material to form a core; d) cutting said core at a desired span angle thereby forming the ends of said core; e) grinding said ends of said core until a smooth surface is obtained; f) immersing said ends of said core in an acid bath; g) covering said ends of said core with epoxy material; and h) winding an insulated cable coil around said core. EXTRACT OF THE INVENTION A magnetic stimulation system for the nerves, which comprises a core (2) of a highly saturable material with a coil winding (4). A capacitor thyristor discharges circuit pulses to the device. A magnetic field of rapid changes is guided by the core (2), which is preferably constructed of vanadium permendur. For specific excitation tasks of several nerve groups, the specially constructed cores allow the excitation of the nerves, at deeper levels with greater efficiency, than is possible with an air core stimulator. Among the possible applications with the present invention, are the treatment of incontinence, the rehabilitation of large muscle groups of the leg and arm, and the excitation of the muscle groups of the abdominal wall, to aid in weight loss and the increase of the metabolic amount. To focus the stimulation as desired, a "C" shape is used.