MXPA00006350A - Magnetic nerve stimulator for exciting peripheral nerves - Google Patents

Abstract

A magnetic nerve stimulator system is comprised of a core (2) constructed from a material having a high field saturation with a coil winding (4). A thyrister capacitive discharge circuit pulses the device. A rapidly changing magnetic field is guided by the core (2), preferably vanadium permendur. For task specific excitation of various nerve groups, specially constructed cores allow for excitation of nerves at deeper levels with higher efficiency than is possible with aircore stimulators. Among the applications possible with this invention are treatment of incontinence, rehabilitation of large muscle groups in the leg, the arm, and excitation of abdominal wall muscles groups to aid in weight loss, and metabolic rate increase. A C shape is employed for focussing the stimulation as desired.

Description

MAGNETIC NERVOUS STIMULATOR TO EXCITATE THE PERIPHERAL NERVOUS RELATED APPLICATIONS The present application is a continuation in part of the United States Patent Application Serial No. 08 / 345,572, filed on November 28, 1994 (pending) and claims all rights of priority thereof.

BACKGROUND OF THE INVENTION A nerve cell can be excited in several different ways, but a direct method is to increase the electrical charge within the nerve, thereby increasing the membrane potential within the nerve with respect to the surrounding extracellular fluid. A class of devices that is covered by functional electrical stimulation (FES) performs excitation of the nerves by directly injecting charges into the nerves by means of electrodes, which either are placed on the skin or in I live next to the group of nerves of interest. The electric fields necessary for load transfer are printed simply by means of the electrode wires. The FES is achieved through a mechanism that includes a half-cell or half-cell reaction. The electrons flow in the wires and the ions flow in the body. At the electro-electrolytic interface, a half-cell reaction occurs to achieve electron-ion exchange. Unless this half-cell reaction is maintained in the reversible regimen, necrosis will occur-partly due to the oxidation of the half-cell reaction and partly due to the chemical imbalance that accompanies it. The advantage of FES is that stimulation can usually be achieved from extremely small electrodes with very modest current and voltage levels. However, the disadvantage is that it includes half-cell reactions. Most of the rehabilitation programs that use FES place the electrodes directly on the skin. A conductive gel or a buffer solution should be placed between the electrodes and the surface of the skin. The long-term excitation of nerve or muscle tissue is often accompanied by skin irritation, due to the concentration of current at the electrode / skin interface. This problem is especially aggravated when higher levels of arousal are required for more complete stimulation or for the recruitment of the nervous group. By contrast, magnetic stimulation achieves. by induction, the electric fields necessary for the transfer of charge. The rapidly changing magnetic fields induce electric fields in biological tissue; when they are properly oriented and when the appropriate magnitude is reached, the magnetic field induced in magnetic form achieves the same result as that achieved by the FES, which is the load transfer directly in the nerve that will be excited. When the membrane potential located within the nerve increases with respect to its normal negative environmental level of approximately -90 milli olts (this level is sensitive to the type of nerve and the local pH of the surrounding tissue), the nerve "lights up". The present invention is especially focused on applications that are not suitable for the use of implanted electrodes. The invention is designed for the non-invasive external stimulation of the selected nerve or nerve groups, particularly in certain applications. In these applications, which include incontinence and muscle group rehabilitation, as well as the treatment of potential weight loss, the desired levels of arousal using the FES are often outside of what can be considered comfortable limits. That is, the electric current that would ideally be injected to through the skin to excite the muscle groups of interest, often leads to some skin irritation over time. The invention can also be used even in applications where this is not the case, since the use of gels and direct electrode / skin placement is inconvenient and there is often resistance on the part of the patient. In opposition to the FES, the magnetic excitation has the attractive peculiarity of not requiring an electrode-skin contact. In this way, stimulation can be achieved through the clothing that is being used. This overcomes the objection of inconvenience and preserves the dignity of the patient. Secondly, because there is no direct contact, more intense levels of arousal can be achieved without the undue additional irritation on the skin. A contribution offered by the present invention is the ability to obtain higher levels of focus of the magnetic field and, thus, of the stimulation within the patient. In proportion to this higher level of focus comes some flexibility in the number of possible applications to which it may be directed. Accompanying the approach also, there is a higher level of power efficiency. Typically, devices that are designed by the methods described in this invention reduce by a factor of two the magnetic reluctance trajectory. This reduction in reluctance results in a decrease, in the same factor, in the current and in a reduction to a quarter in the power loss. Magnetic stimulation of neurons has been investigated in depth in the last decade. Almost all of the magnetic stimulation work has been done in vivo. The volume of magnetic stimulation work has been in the area of stimulation to the brain. Cohen has been a very important contributor in this field of research (see, for example, T. Kujirai, M. Sato, J. Rothwell and LG Cohen, "The Effects of Transcranial Magnetic Stimulation on Median Nerve Somatosensory Evoked Potentials", Journal of Clinical Neurophysiology and Electro Encephalography, Vol. 89, No. 4, 1993, pages 227 2. 3. 4) . This work has been accompanied by several other research efforts that include the Davey et al. (See, K. R. Davey, C. H. Cheng, C. M.

Epstein "An Alloy - Core Electromagnet for Transcranial Brain Stimulation", Journal of Clinical Neurophysiology, Volume 6, Number 4, 1989, page 354); and that of Epstein et al. (see, Charles Epstein, Daniel Schwartzberg, Kent Davey and David Sudderth, "Localizing the Site of Magnetic Brain Stimulation in Humans," Neurology, Volume 40, April 1990, pages 666-670). The volume of all the Research in magnetic stimulation attempts to ignite the nerves of the central nervous system. The present invention differs in several aspects from previous research efforts. First, the present invention has primary applicability to the peripheral nervous system, although it can also be used to stimulate the nerves of the central nervous system. Second, and most importantly, previous work on nerve stimulation is dominated almost exclusively by coils with air cores of various shapes and sizes. The present invention is directed to the use of a magnetic core, more specifically, a permeable core having a high field saturation, wherein the most preferred material is vanadium permendur. Among the stimulators with an air nucleus are coils in the shape of circles, ovals, with figures of eights and letters D. The coils are normally excited by a capacitive discharge in the winding of the core of these coils. This field with exponential extinction has a time constant normally in the vicinity of 100 microseconds. Typical white values for the magnetic field peak occur near two Tesla. J.A. Cadwell is perhaps the leader among those who are currently using and marketing these air core stimulators. Among his patents P1084 primary is United States Patent Number 4,940,453, entitled "Method and Apparatus for Magnetically Stimulating Neurons", July 10, 1990. There are several sources or supplies of power, of which all operate in a basic capacitive type discharge in several coils with air core that are sold with their units. At this moment, coils with varied forms are being explored. One of these coils is a lid-shaped device that fits over the motor cortex (K. Krus, L. Gugino, W. Levy, J. Cadwell and B. Roth "The use of a cap shaped coil for transcranial stimulation the motor cortex ", Journal of Neurophysiology, Volume 10, Number 3, 1993, pages 353-362). Some studies are being done on the various circuits used to turn on these coils with air core. H. Eton and R. Fisher offer one of these alternatives in their United States Patent Number 5,066,272, "Magnetic Nerve Stimulator", dated November 19, 1991. They suggest the use of two capacitors-one to capacitively discharge to the coil of interest and the second to recover the charge of the inductive energy resident in the coil. The circuit used in the present invention achieves the same objective with a single capacitor. Some research is being carried out in the stimulation of the peripheral nervous system (see, for example, Paul Maccabee, V. Amassian, L. Eberie and R. Cracco, "Magnetic Coil Stimulation of Straight and Bent Amphibian and Mammalian Peripheral Nerve in vi tro: Locus of Excitation," Journal of Physiology, Volume 460, January 1993, pages 201-219). However, most of Maccabee's work is focused on cranial excitement. The applications of the present invention are focused on the peripheral nervous system, although it can also be used in the central nervous system.

SUMMARY OF THE INVENTION An object of the present invention is to provide a magnetic nerve stimulator to excite the nerves of the peripheral nervous system. A further object of the present invention is to provide a magnetic nerve stimulator for the non-invasive stimulation of nerves within the peripheral nervous system. A further object of the present invention is to provide a nerve stimulator for the production of magnetic fields having a significant depth and ease of focus to stimulate the deep nerves in a human being. A further object of the present invention is provide a magnetic nervous stimulator that can produce magnetic fields, which can be focused on the internal peripheral nerves to perform a non-invasive nerve stimulation. A further object of the present invention is to provide a magnetic nerve stimulator for the treatment of bladder and urinary disorders. A further object of the present invention is to provide magnetic nerve stimulators for the treatment of incontinence. A further object of the present invention is to provide a magnetic nerve stimulator for rehabilitation and / or muscle conditioning. A further object of the present invention is to provide a magnetic nerve stimulator for use as an aid in weight loss. Further objects of the invention will be apparent in connection with the disclosure that is provided herein. To achieve the objectives of the present invention, a magnetic nerve stimulator that can be used to stimulate the nerves without the need for surgery is provided herein. Magnetic stimulation of peripheral nerves has the advantages of convenience and threshold variability over and above competing FES systems. An advantage of the present invention over competing magnetic nerve stimulators is in the use of a highly saturable magnetic core, ie, a permeable core of high field saturation and, in the design of the same magnetic core stimulator. In the preferred embodiment, the magnetic nerve stimulator is preferably constructed using a core of a magnetic or magnetizable material. A permeable material having a high field saturation is used, wherein the preferred core has a field saturation of at least 1.5 Tesla. Some materials suitable for the nucleus include vanadium permendur, ortinol, metallic glasses (metglass), by its contraction of the terms in English, permalloy, supermalloy, iron powder and the silicon irons or the silicon steels, in particular, the grain steel oriented at 3% (magnesil). Ferrite can also be used, although it is not preferred, due to the fact that it is saturated at 0.5 T. According to the present invention, what is most preferred is that an open core be used. Toroidal cores are not preferred, since it has been found that an open core can be used more effectively to focus the magnetic field produced by the P1084 stimulator and, since it has been found that the suitability of the toroidal nuclei is limited to invasive applications. With the term "open core", reference is made to an arc-shaped core extending at an angle less than 360 degrees. A 180 degree core is very convenient to use the material efficiently, since two cores can be constructed from each mandrel. A core having a greater angle (eg, 210-220 degrees) can also be used. These nuclei are more focused, although they have a lower depth of penetration. Alternatively, cores with smaller or larger angles may be used in non-preferred embodiments. In the present embodiments of the invention, it is an objective to "turn on" a coil having a characteristic extinguishing time of approximately 100 microseconds, from five (5) to fifty (50) times per second. The system must be reasonably efficient and reliable to turn on at this high repetition rate. It is known that ignition speeds of 5 to 10 Hz are effective for treating urinary tension incontinence using the FES. Higher stimulation velocities (eg, fifty (50) Hz) have been shown to be useful for the treatment of irritative symptoms of urinary frequency and urgency. HE present sustained contractions above fifteen (15) Hz. As medical knowledge advances, as well as varied and additional investigations are conducted, other firing speeds of higher or lower frequencies or with particular excitation patterns may prove useful in specific applications. The exact stimulation frequency will vary somewhat, depending on the requirements of the application, as needed. Sometimes, muscle groups will need to be excited for a period of five seconds, followed by a rest period of five seconds and then stimulated continuously for another five seconds and then again another rest. While these are being stimulated, it is often desirable to have muscle groups in a sustained contraction. This requirement dictates the need to continue sending pulses to the cores at a repetition rate of 15 Hz. Due to the large currents involved during any given ignition of the nucleus, it is necessary that the nuclei be as efficient-as possible. It is desirable to focus the magnetic field on the target region of the stimulus for the exclusion of the surrounding regions. The specially designed cores, offered by this invention, achieve such ease of focus, also called focusability, in P1084 so much that the coils with air core used in the prior art do not achieve it. With respect to the configuration of the core, the simplest configuration of the core of the present invention is that of a core with a "C" shape. The extension of the "C" must be chosen carefully; the extension affects both the depth of penetration and the magnitude of the field. The construction of the nucleus has an additional importance. The best cores are constructed from thin laminated materials that have a high field saturation. A typical core can be wound using two thousandths of an inch vanadium permendur material. A long ribbon of this material is wound or wound on a mandrel (for example, a wooden or plastic mandrel) for the desired radius, thickness and depth. Each side of the tape is covered with a thin insulating coating to electrically isolate it from its vicinity. A generic core that can be used in various places around the body can extend at an angle of approximately 180-220 °. Once the tape has been wound or wound on the mandrel to the desired dimensions, it is immersed in epoxy resin to fix its position. Once the epoxy has cured, the mandrel is removed and the core is cut to the desired angle extension. The cut P1084 it will destroy the electrical insulation of adjacent laminations. Each cut must be finely ground, so that it is smooth and, afterwards, a deep or deep etching is carried out. The deep etching is done by immersing each of the ends of the cut in an acid bath. This causes the ends of the cut to delaminate slightly, although they maintain the electrical isolation of the laminations. Failure to perform this deep etching results in considerable loss by parasitic currents and heating at the ends of the core cut. After deep etching, the ends are varnished with epoxy resin to maintain the shape and structural integrity of the core. The final step of the construction is to wind an insulated wire coil around the core. The typical inductance of a core of this type is approximately 30μH. However, the present invention can also be practiced at other inductances or magnetic field strengths. In the simplest configuration, each core has only one winding. The winding is excited by an impulse that expires exponentially with a characteristic time of approximately 100 μS. The actual signal has a period of oscillation of about that time within an envelope that is extinguished exponentially, so that only two or three cycles P1084 they are attested by the current of the coil. The excitation is repeated in a period of about 5-50 Hz. As stated above, the repetition cycle of these patterns will vary according to the application. The circuit usually consists of a transformer that feeds a full wave rectifier bridge. The bridge voltage charges the capacitor; The charge in the capacitor is triggered with a silicon control rectifier to drive or excite the current in the coil. The return charge that returns through the coil the second time is fed through the diode back to the capacitor to prepare the circuit for the second phase of the excitation. There are at least three important white applications 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 into the vaginal cavity. A suitable core that has the ability to achieve this goal is constructed by combining two individual "C" cores each extending at an angle of approximately 180 °. The branches of the nuclei are put together in the central region. The common central branch of the two cores "C" is wound P1084 by a coil and the return path for the flow is divided between the two "C" s. The same nuclei are adjusted or accommodated proximally and distally under a chair in which the patient sits during the treatment. A second area of application is in the rehabilitation of muscles. The primary target muscle groups are the thigh, the calf, the biceps and the triceps. The geometry is similar in all these applications and, in this way, a cylindrical extension is used around the muscle. Although a solution to this problem is a simple "C" core and a coil that moves around at the discretion of the patient, an alternative stimulator resembles the tubular-shaped motors used in electromechanics to propel a secondary member through a tube. Here, geometry would necessarily require an articulated tubular shape that has recesses or grooves, which would run azimuthally around the muscle group that will be stimulated. The stimulator coils fit into these recesses or grooves and the surrounding structure again would be a laminated vanadium composite. If the structure had two or three coils adapted, these could be stimulated in a phase arrangement. This excitement would have the effect of kneading the muscle tissue group along its longitudinal axis.

P1084 This particular pattern of excitement can be instrumented in more fully restored muscle groups, such as the hamstring group in the leg. Complete restoration or stimulation of the nerve group would be advantageous for long-term rehabilitation. Preliminary experiments with this device indicate that excitations at the mentioned frequencies manage to exercise the muscles at a greater efficiency and speed than could be achieved through normal means. Another area of application is to help in the management of weight loss. As with muscle rehabilitation, an alternative is to simply use a displaced hand unit on multiple areas of the body. One group that may be particularly difficult to stimulate is the abdominal wall. An alternative method to achieve excitement of this group resembles a chest plate that can be secured to a patient or articulated next to a chair in which the patient sits. The chest plate contains a two- or three-phase arrangement of coils supported by high saturation field cores, constructed in the manner indicated above. The nuclei are separated to drive or excite the flow to depth within the muscular group of the abdomen. Both in the rehabilitation P1084 As in the management of weight loss, the phasing of the coils can alternate with time to provide the effect of a "kneading" stimulation pattern back and forth. The reasoning behind weight management is that the ignition of these muscle groups requires the absorption of adenosine triphosphate; This energy expenditure is artificially induced by the magnetic stimulator. In summary, it is observed that there are several ways to more efficiently stimulate the various muscle groups of the body. The key to these more efficient techniques revolves around the use of a thin laminated material with high magnetic field saturation to build these cores and, thus, to drive and focus the flow within the desired regions. A simple "C" type core achieves an advantage in reluctance by a factor of at least two above conventional cores. By using multiple cores connected in a central branch, a single focus site can be achieved with the return path worn in two or more areas, so that it discourages excitation when the field is returned. In other applications, multi-phase coils that enclose or actually envelop the tissue of interest can be excited, so that they knead muscle groups directionally with the P1084 weather. Certain wrapping or covering applications may be more instrumental for the superior restoration of injured muscle groups.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a plan view of a "C" shaped core stimulator, where the field winding of the toroidal coil is wound around the core. The field lines between (broken lines) indicate the depth of penetration and the focus of the stimulation. Figure 2 is a schematic of the electrical circuit used to stimulate the winding of the coil. Figure 3 is a side view of a core stimulator configuration used in the treatment of incontinence; The core is designed to fit under a seat in which the patient sits during treatments. Figure 4 is a perspective view of a core stimulator (placed around the 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 or fold around the leg. Figure 5 is a perspective view of the P1084 half the section of the core stimulator used for muscle rehabilitation of the arm or leg; the windings of different phases are placed in recesses or adjacent grooves, cut in the core. Figure 6 is an end view of the leg or arm stimulator. The winding that goes from one section to the next is removed in a long fold to allow easy opening of the core units and facilitate placement around the leg or arm. Figure 7 is a schematic perspective view of a multi-stage articulated stimulator, designed to conform around the torso of a patient.

DETAILED DESCRIPTION OF THE PREFERRED MODALITIES In accordance with the present invention, a magnetic nerve stimulator is provided which can be used for the non-invasive stimulation of the nerves of the peripheral nervous system. The advantage of non-invasive stimulation is a significant one, since nerves can be stimulated deep below the surface of the skin without the need for surgery, body incisions or the use of uncomfortable electrodes. However, to obtain an effective non-invasive stimulator, the stimulator must be carefully designed to achieve sufficient depth and penetration within the body, so as to effectively stimulate the nerves or groups of nerves of interest. The present inventors have recognized the objective of a very effective non-invasive stimulation by providing a magnetic nerve stimulator that can achieve significant depth and penetration, so that groups of internal human nerves can be stimulated to treat incontinence, achieve muscle rehabilitation (or conditioning) or help weight loss. In the preferred embodiment, the core is constructed of a permeable magnetic material having a high field saturation. For high field saturation, the inventors refer to the use of a magnetizable material, which is saturated at 1.5 Tesla or higher. The magnetic nerve stimulator is preferably manufactured with a magnetizable material. Since the desired magnetic fields normally reach 1.5 Tesla or higher, it is desirable to use materials that saturate at or above 1.5 Tesla. For example, a suitable material is vanadium permendur. Other suitable materials include metallic glasses (ie, metglass), per alloy, supermalloy, iron in P1084 powder and silicon irons or silicon steels, in particular, grain-oriented steel at 3% (magnesil). Ferrite can also be used, although this is not what is preferred, due to the fact that it is saturated at 0.5 T. These materials can be obtained from, for example, Magnetics, Inc. of Butler, Pennsylvania. It has been found that 3% oriented grain silicon steel is a particularly useful core material. This material has the advantage of providing a very good performance at a relatively low cost. Oriented grain steel is also useful as it can be wound on a coil. A higher field can be reached when the magnetic grains are azimuthally oriented (around the coil) in the direction in which the field will travel. A summary of some materials that can be used for the core and its characteristic properties is as follows: Table 1: Materials for the Magnetic Core P1084 Thus, in general, the use of a magnetizable material for the core is preferred, since this helps to focus and increase the magnetic field used for nerve stimulation. In accordance with this, materials with a high field saturation are recommended, that is, materials that saturate at 1.5 Tesla or higher. With some materials a saturation of 2.0 Tesla can be achieved. Although, in accordance with the disclosure herein, magnetic nerve stimulators can also be constructed using materials that saturate to smaller fields, for example, materials that saturate at 1.0 Tesla or higher or even at 0.5 Tesla or higher, such as the ferrite. However, these stimulators are not preferred, as they have been found to be less effective. In accordance with the present invention, the use of an open core is also desirable. By the term "open core", the inventors refer to the fact that the core is curved in an arc, such that there is a gap or gap between the ends of the core. This allows the magnetic field generated by the core to focus in a more intense and precise way beyond the opening and, therefore, below the surface of the skin. In this way, uses an open core to provide a desirable degree of penetration and focus and thus improve the effectiveness of the stimulator. The open core is not toroidal, that is, it extends in an arc less than 360 degrees, and between the ends of the core there is a separation. In preferred embodiments, the open core is C-shaped. A preferred angle for extending the arch of the core is approximately 180-220 degrees. In preferred embodiments, a suitable core may extend at an angle from about 205 to about 215 or 220 degrees. In other embodiments, cores with approximately 190-230 degrees may be used. Alternatively, a core extending in an arc of about 180-270 degrees is also possible. The greater the angle of the arc, the better the focus of the field, however, the depth of penetration is less. Unless geometry demands it, it is believed that there is no advantage in a core extending at an angle less than 180 degrees. A large radius is also recommended for the nucleus to stimulate the deep nerves. The magnetic field extinguishes exponentially according to the inverse of the distance between the heads of the poles. A nucleus with a small radius has a very high field between the heads P1084 but the field decreases rapidly. A large nucleus has a smaller field between the heads although the field decreases less quickly. In this way, a nucleus with a greater radius will have a larger field a few centimeters inside body. For the treatment of incontinence, it is desired to stimulate the pelvic floor muscles. A depth of penetration of at least 5 centimeters is recommended for this task and, in this way, a core with a larger radius is preferred. The placement of two (2) cores together has the advantage of concentrating the field at one point. The field is cut in half at the return points. This discourages secondary stimulation sites. For a handheld device, an external diameter of approximately 5"and an internal diameter of approximately 4" is recommended. For the device for incontinence, an external diameter of approximately 6"and an internal diameter of approximately 3" is recommended. For the coil, No. 6 AWG 15 kVolts wire with 15 kV insulation can be used. The present device produces a much greater stimulus for the same current as the devices of the prior art, which is a significant improvement in performance. A device test demonstrated, for example, almost twice the stimulus with respect to a well-known prior art device, for the P1084 same amount of current. Another important advantage of the present invention is that the design of the stimulator allows the magnetic treatment to be external. By "external", the present inventors refer to the fact that stimulation can be achieved without the implantation of any element within the body or engaging in any surgery or surgical incision. In this way, it is not necessary to use an internal element of any type within the human body, such as, for example, an implanted electrode. The high saturation field material used in the stimulator provides a magnetic field of depth and ease of focus sufficient to effectively penetrate the body and stimulate the internal nerves within the body without the need for any invasive surgery. This is a particularly great advantage in the treatment of incontinence. It is also potentially useful in other applications. As shown in Figure 1, a "C" shaped nucleus is presented, which has the ability to stimulate several peripheral nerve groups throughout the body. The core 2 is constructed by winding in a mandrel laminations of two to four thousandths of an inch of a material having a high saturation field P1084 magnetic; The number of laminations required will be dictated by the desired thickness and depth of the core. This closed-loop lamination reel is removed from the mandrel and coated with epoxy resin to provide unitary structural integrity. The closed curve is then cut to provide the length and angle of the "C" shape as desired. Then, deep etching with acid takes place on the cut edges. The cut edges are immersed in an acid bath, which causes the epoxy resin to dissolve, resulting in a slight delamination of the core in the vicinity of the cut. Then, the epoxy resin is varnished at the etched ends to prevent subsequent delamination. This procedure is necessary to prevent parasitic currents from flowing in the nucleus. This would reduce the effective B field that can be produced by the core. The laminate material must be constructed of a saturable material and, preferably, of a material having a high field saturation. As previously described, characteristic magnetic fields in the cores have preferred intensities of at least 1.5 Tesla. With the appropriate materials, characteristic fields can be obtained in the range of at least two P1084 Teslas. Preferably, vanadium permendur or 3% grain oriented steel is used, since these materials carry a high field density, although the present invention is not limited to these preferred embodiments. In the present stimulators, high field saturation is more important than high permeability. In addition to the high saturation factor, it may also be desirable in preferred embodiments to choose the core that minimizes heat production and / or minimizes noise levels. In particular, minimization of hysteresis losses is desirable. Hysteresis is internal loss due to a change in the orientation of the molecular structure of the core material. This is related to the way the BH curve is open. Hysteresis is probably the main contributor to core warming. When an applied field changes the length of the material, reference is made to the material showing magnetostriction. This can result in noise during the operation of the stimulator. Stray current losses can be addressed using a thin material or even powder. A useful material to achieve low losses by hysteresis and low magnetorestriction, are permalloy products. These materials have a high content of P1084 nickel (50% - 80%). The 80% nickel variant has very low "hysteresis losses, although the material saturates to only 0.7 T. These nickel alloys can be obtained in thicknesses of one thousandth of an inch." Another material that can be used is metglass. A metal-plated glass material with low internal resistance The normal material has the trade name of NAMGLASS1 or SAI This material can be annealed in cross-sectional field This process orients the grain structure at right angles to the use of the field flow. annealing significantly reduces hysteresis loss, it also reduces permeability, although this effect is not significant for the purposes of the present stimulator.The material also has very low magnetostriction.Other material, pure iron, is very soft and has a rounded curve, it is believed that this ductility reduces noise, saturates at 1.7 T and is often found in dust cores. As before, another useful material for the core is, in general, grain steel oriented at 3%. A generic name for this material, which is used by some manufacturers, is magnesil. The material is essentially steel with 3% silicon and is saturated at 1.75 T. Another suitable material for the core is P1084 the supermendur This material includes iron and cobalt and saturates to 2.2 T. However, these two materials are very magnetorestrictive, changing their length when exposed to a magnetic field. Both materials also have a square BH curve. After the choice of the core, a winding or coil 4 is then wound around the core in such a way as to drive the flow through the cut ends 5. The field lines 6 provide an indication of the depth of penetration and the degree of expected focus with this nucleus. Figure 2 shows an electrical circuit used to "turn on" the core and coil of Figure 1. A normal signal of 120 volts and 60 Hz excites the circuit at 7. A transformer 8 amplifies the voltage to approximately 1-3 kV. This high-voltage AC signal is then fed to a full-wave rectifier bridge 10. The rectifier bridge signal is then passed through a diode 12 to charge the capacitor 14. The purpose of all electrical components to the left or upstream of the capacitor is simply to load the capacitor. The energy resident in the circuit, which will be pumped into the stimulator core, is half C (the value of the capacitance) for the voltage squared. When the P1084 Thyristor 16 is activated with a small control voltage pulse, current flows through the thyristor to the core 2. Most of this energy goes back to capacitor 14, recharging it in the polarity opposite its initial charge. The capacitor 14 charged inversely again is immediately discharged through the coil 2 of the stimulator through the diode 18, connected in parallel. Theoretically, all this energy must pass to the capacitor 14 to recharge it according to its initial polarity. In practice, this LC circuit of course has some losses and thyristor 16 does not turn off immediately. In practice, two to three resonance cycles of exponential extinction of this circuit L are witnessed before the current of the core 2 is interrupted. After the interruption, the capacitor is charged through diode 12, as it did initially. And it continues charging it until the thyristor 16 is activated again. Different stimulation / rest cycles are used for different tasks. For the treatment of incontinence, one of these stimulation cycles can be five seconds on, five seconds off. During the five seconds that are characterized as "on", the thyristor 16 could be continuously pulsing 15 times per second. These montages of P1084 Stimulation can be altered in accordance with the requirements and with the goal of the stimulation protocol. The circuit shown is a preferred embodiment for the practice of this invention although other circuit designs (such as a dual capacitor array, etc.) can also be used to turn on the coil, as will be apparent to those skilled in the art. . In addition, while the magnetic field produced by this mode oscillates at approximately 20-50 kHz, variants can also be practiced at that frequency. This frequency is simply: (Equation 1) \ LC-LC Figure 3 shows a double-core type "C" arrangement, suitable for the treatment of incontinence. The individual "C" s comprising this core each extend at an angle of approximately 220 °. The cores 20 are placed end to end in a type arrangement. The winding 4 is wound around the common central branch of the two cores. The cut ends of these cores are designed to be flush with the underside of a seat cushion 21, in which the patient sits. The primary flow is driven by the common central nucleus in the vaginal cavity. This flow is returned through the P1084 rear and front arms of the "W". Because the return flow is much lower, no stimulation occurs except for the vaginal floor near the central branch of the "W". Figure 4 shows a core stimulator suitable to excite the muscle groups of the leg and arm. In this configuration, the cores 22 would constitute a tubular-type sheath in which a leg 24 or an arm would be inserted. Although the "C" core of Figure 1 would be suitable for this task, due to its geometry it is difficult to achieve a homogeneous and controlled stimulation of this muscle group. As shown in Figure 5, each section of the stimulator 22 is comprised of two half-shells 26. The recesses or slots 27 are cut in the half-shells to allow the placement of coils that would be wound, preferably, within the shells. The individual windings of the shell 26 are aligned in such a way as to generate a magnetic field that is preferably along the axis of the arm or the leg. The adjacent recesses or slots of the stimulator 22 will contain different phases. A two- or three-phase arrangement is used to excite a traveling magnetic field that moves up and down the arm / leg axis. This arrangement of windings is not different from that used in tubular motors for P1084 achieve an axial traveling wave. An edge of the two common halves constituting the stimulator 22 must act as a joint. The winding electrically connecting the two halves is achieved simply by extending the wire as an extension 28, as suggested in Figure 6. The additional length of the winding associated with the extension 28 guarantees the necessary flexibility of the stimulator to articulate and to wind or be placed around the patient's arm or leg. Figure 7 suggests another suitable alternative modality for the stimulation of abdominal muscles. Here, the stimulator 30 is articulated to a chair in which the patient sits. The stimulator is then folded around the patient's abdomen during the treatment. The stimulator 30 is again constructed of laminated permeable material having a high magnetic field saturation. The multiple windings are placed in the recesses or grooves that are cut in the core. The windings are designed to drive the flow in the abdomen and cause a contraction of the muscle group of the abdominal wall. Again, the windings can be phased to cause the directional massage of this muscle group. Having described this invention with respect to certain specific embodiments, it will be understood that the P1084 The description does not have the meaning of a limitation, since additional modifications can now be suggested by themselves to those skilled in the art and it is intended to cover these modifications as they fall within the scope of the appended claims.

P1084

Claims (51)

1. CLAIMS 1. A method for the treatment of incontinence in a human being by magnetically stimulating the nerves of the person, comprising the steps of: (a) providing a magnetic nerve stimulator; (b) providing energy to the magnetic nerve stimulator to generate a magnetic field; (c) stimulating the nerves of the person to treat urinary incontinence. A method according to claim 1, wherein the method comprises external stimulation, external stimulation comprises the stimulation of the person's nerves, to treat incontinence, while the magnetic nervous stimulator remains external to the body of the person . 3. A method according to claim 2, wherein the magnetic nerve stimulator comprises a stimulator capable of providing a magnetic field with sufficient depth and focus, so that the magnetic field can penetrate the person to stimulate the nerves of said person, to treat incontinence, while the magnetic nervous stimulator remains external to the body of the person. 4. A method for the treatment of P1084 incontinence in a human being by magnetically stimulating the nerves of the person, comprising the steps of: (a) providing a magnetic nerve stimulator, the magnetic nerve stimulator comprising a core of magnetic material; (b) providing energy to the magnetic nerve stimulator to generate a magnetic field; and (c) externally stimulating the nerves of the person to treat urinary incontinence, external stimulation comprises the stimulation of the person's nerves, to treat incontinence, while the magnetic nervous stimulator remains external to the body of the person . A method according to claim 4, wherein the magnetic nerve stimulator comprises a core of highly saturable material, the highly saturable magnetic material is a magnetic material that is saturated at a magnetic field strength of at least 1.5 Tesla. 6. A method according to claim 5, wherein the highly saturable magnetic material is saturated to magnetic fields of at least 2.0 Tesla. 7. A method according to claim 5, wherein the highly saturable magnetic material is saturated to magnetic fields greater than 2.0 Tesla. 8. A method according to claim 5, in P1084 where the highly saturable magnetic material comprises a silicon steel. 9. A method according to claim 5, wherein the highly saturable magnetic material comprises grain-oriented steel with 3% silicon. 10. A method according to claim 8, wherein the silicon steel has magnetic grains, the magnetic grains are oriented azimuthally in the direction that the magnetic field will travel. A method according to claim 9, wherein the grain steel oriented with 3% silicon has magnetic grains, the magnetic grains are azimutially oriented in the direction that the magnetic field will travel. 12. A method according to claim 5, wherein the highly saturable magnetic material comprises a metallic glass. 13. A method according to claim 5, wherein the highly saturable magnetic material comprises ortinol. 14. A method according to claim 5, wherein the highly saturable magnetic material comprises permalloy. 15. A method according to claim 5, wherein the highly saturable magnetic material comprises P1084 Vanadium permendur. 16. A magnetic nerve stimulator comprising: (a) a core of highly saturable magnetic material, the highly saturable material comprises a magnetizable material that saturates magnetic fields of at least 1.5 Tesla; (b) a stimulating coil for transporting electric current in proximity to the core; and (c) a means for the electric current, connected to the stimulating coil to generate an electric current flow in the stimulating coil and cause the stimulating coil and the core to generate a magnetic field. 17. A magnetic nerve stimulator according to claim 16, wherein the core comprises a highly saturable magnetic material, in which the highly saturable magnetic material is saturated to magnetic fields of at least 2.0 Tesla. 18. A magnetic nerve stimulator according to claim 16, wherein the highly saturable magnetic material is saturated to magnetic fields of more than 2.0 Tesla. 19. A magnetic nerve stimulator according to claim 16, wherein the magnetic material is very P1084 saturable comprises silicon steel. 20. A magnetic nerve stimulator according to claim 16, wherein the highly saturable magnetic material comprises grain-oriented steel with 3% silicon. 21. A magnetic nerve stimulator according to claim 19, wherein the silicon steel is wound on a coil. 22. A magnetic nerve stimulator according to claim 21, wherein the silicon steel comprises magnetic grains and, where the silicon steel is wound on the coil, such that the magnetic grains are azimuthally oriented in the direction it will travel. the magnetic field. 23. A magnetic nerve stimulator according to claim 20, wherein the grain-oriented steel with 3% silicon is wound on a coil. 24. A magnetic nerve stimulator according to claim 20, wherein the grain-oriented steel with 3% silicon comprises magnetic grains and, where the grain-oriented steel with 3% silicon is wound on the coil, in such a way that the magnetic grains are azimuthally oriented in the direction that the magnetic field will travel. 25. A magnetic nerve stimulator according to P1084 claim 16, wherein the highly saturable magnetic material comprises a metallic glass. 26. A magnetic nerve stimulator according to claim 16, wherein the highly saturable magnetic material comprises ortinol. .27. A magnetic nerve stimulator according to claim 16, wherein the highly saturable magnetic material comprises permalloy. 28. A magnetic nerve stimulator according to claim 16, wherein the highly saturable magnetic material comprises vanadium permendur. 29. A magnetic nerve stimulator comprising: (a) an open core of highly saturable magnetic material, the highly saturable material comprises a material that saturates magnetic fields of at least 1.5 Tesla; (b) a stimulating coil for transporting electric current in proximity to the core; and (c) a means for the electric current connected to the stimulating coil to generate an electric current flow in the stimulating coil and cause the stimulating coil and the core to generate a magnetic field. 30. A magnetic nerve stimulator according to claim 29, wherein the open core extends P1084 at an angle of approximately 180 to 270 degrees. 31. A magnetic nerve stimulator according to claim 29, wherein the open core extends at an angle of about 190 to 230 degrees. 32. A magnetic nerve stimulator according to claim 29, wherein the open core extends at an angle of about 205 to 220 degrees. 33. A magnetic nerve stimulator according to claim 31, wherein the core comprises a highly saturable magnetic material, wherein the highly saturable magnetic material is saturated to magnetic fields of at least 2.0 Tesla. 34. A magnetic nerve stimulator according to claim 31, wherein the highly saturable magnetic material is saturated to magnetic fields of more than 2.0 Tesla. 35. A magnetic nerve stimulator according to claim 29, wherein the highly saturable magnetic material comprises silicon steel. 36. A magnetic nerve stimulator according to claim 30, wherein the highly saturable magnetic material comprises silicon steel. 37. A magnetic nerve stimulator according to claim 31, wherein the highly saturable magnetic material comprises silicon steel. P1084 38. A magnetic nerve stimulator according to claim 32, wherein the highly saturable magnetic material comprises silicon steel. 39. A magnetic nerve stimulator according to claim 29, wherein the highly saturable magnetic material comprises grain-oriented steel with 3% silicon. 40. A magnetic nerve stimulator according to claim 30, wherein the highly saturable magnetic material comprises grain-oriented steel with 3% silicon. 41. A magnetic nerve stimulator according to claim 31, wherein the highly saturable magnetic material comprises grain-oriented steel with 3% silicon. 42. A magnetic nerve stimulator according to claim 32, wherein the highly saturable magnetic material comprises grain-oriented steel with 3% silicon. 43. A magnetic nerve stimulator according to claim 35, wherein the silicon steel comprises magnetic grains, the magnetic grains are azimutially oriented in the direction that the magnetic field will travel. 44. A magnetic nerve stimulator according to claim 39, wherein the grain steel oriented with 3% silicon comprises magnetic grains, such that the magnetic grains are azimutially oriented in the direction that the magnetic field will travel. 45. A magnetic nerve stimulator according to claim 29, wherein the highly saturable magnetic material comprises a metallic glass. 46. A magnetic nerve stimulation according to claim 29, wherein the highly saturable magnetic material comprises ortinol. 47. A magnetic nerve stimulator according to claim 29, wherein the highly saturable magnetic material comprises permalloy. 48. A method according to claim 12, wherein the metallic glass is annealed with a transverse field. 49. A magnetic nerve stimulator according to claim 25, wherein the metallic glass is annealed with a transverse field. 50. A magnetic nerve stimulator according to claim 45, wherein the metallic glass is annealed with a transverse field. 51. A method for constructing a device for use as a magnetic nerve stimulator, comprising the steps of: (a) coating a tape of highly saturable material P1084 with a thin insulating coating; (b) winding the coil on a closed curve mandrel for the desired radius, thickness and depth; (c) coating the tape with epoxy resin to form a core; (d) cutting the core at a desired extension angle, thereby forming the ends of the core; (e) grind the ends of the core to smoothness; (f) immersing the ends of the core in an acid bath; (g) cover the ends of the core with epoxy resin; and (h) winding an insulated wire coil around the core. P1084