Method for inhibiting decrease or promoting increase of at least one among bone density and bone strength, and vector potential generating device

Abstract

[Problem] To provide a method for inhibiting the decrease or promoting the increase of at least one among bone density (bone mass) and bone strength. [Solution] A method for inhibiting the decrease or promoting the increase of at least one among bone density and bone strength in the tissue of a living body, the method including a step for applying electrical stimulation to the tissue using a vector potential generating device 1, wherein controlling the electrical stimulation by adjusting the alternating current frequency applied to the vector potential generating device 1 inhibits the decrease or promotes the increase of at least one among bone density and bone strength.

Description

Method for inhibiting the decrease or promoting the increase of at least one of bone density and bone strength, and vector potential generation device Cross Reference

[0001] The contents of the patents, patent applications and publications cited throughout this application are hereby incorporated by reference.

[0002] The present invention relates to a method and a vector potential generation device for inhibiting a decrease in or promoting an increase in at least one of bone density and bone strength.

[0003] Traditionally, medication and exercise therapy have been used to treat osteoporosis. However, some medications have side effects. For example, denosumab and bisphosphonates have high therapeutic effects, but they have also been pointed out as potentially causing serious conditions such as osteonecrosis of the jaw. Exercise therapy cannot be performed by people with impaired physical function.

[0004] Physical therapy using electrical stimulation is also being performed. For example, Patent Document 1 discloses a method and device for treating fibromyalgia and other neurological disorders involving central pain, central hypersensitivity, and abnormal brain neural network connectivity using electrical stimulation. Transcutaneous electrical stimulation does not provide ideal therapeutic effects because the current cannot reach deep into the affected area due to the influence of the skin, subcutaneous fat, body fluids, etc.

[0005] Meanwhile, a non-contact spatial electric field generator has been disclosed that can generate a linear electric field and perform work externally by generating a vector potential without generating a magnetic field (see, for example, Patent Document 2).It has also been reported that an electrical stimulation device created using this principle can be used to treat bone fractures, osteoporosis, and other injuries to the body, as well as tumors, with a shorter healing time and less strain on the living body and easy to install (see, for example, Patent Document 3).

[0006] Patent Publication No. 2017-503612 International Publication WO2015 / 099147 Pamphlet Japanese Patent Application Laid-Open No. 2020-58523

[0007] The electrical stimulation device disclosed in Patent Document 3 is indeed capable of electrically stimulating specific body parts, such as bones, using a device that is easy to attach and places little strain on the body, and it is suggested that this could hasten the recovery of fractures and inhibit the progression of osteoporosis and other conditions. However, the specific operating method of this electrical stimulation device and the other diseases that it can treat are not necessarily clear.

[0008] Therefore, an objective of the present disclosure is to clarify how electrical stimulation by a vector potential generation device affects bone sites, and to provide a method for inhibiting a decrease or promoting an increase in at least one of bone density (bone mass) and bone strength using this device, or a method for promoting an increase, and a vector potential generation device.

[0009] The present disclosure has been made to solve the above-mentioned problems, and has discovered that electrical stimulation caused by the generation of vector potentials can improve various functions in a living body, and in particular can suppress a decrease in at least one of bone density (bone mass) and bone strength. That is, the present disclosure includes the following embodiments.

[0010] [1] A method for inhibiting (controlling) a decrease or promoting an increase in at least one of bone density (bone mass) and bone strength in the tissue of a living body, comprising a step of applying electrical stimulation (VP coil output voltage) to the tissue using a vector potential generation device, and controlling the frequency of the alternating current applied to the vector potential generation device and the output voltage of the VP coil while adjusting the electric field (macro level) generated within the VP coil to control the electrical stimulation, thereby inhibiting a decrease or promoting an increase in at least one of bone density (bone mass) and bone strength. [2] The vector potential generation device includes a solenoid coil (basic wire) made of a core wire with an insulating coating and a conductor wound tightly around the core wire as a winding axis, and further includes a tubular portion formed by winding the solenoid coil in a loop, one end of the core wire being electrically connected to one end of the conductor, the other end of the core wire being connected to one end of a drive circuit (including an amplifier), and the other conductor being connected to the other end of the drive circuit, the tubular portion including the steps of holding a living body or part of a living body inside the tubular portion, and the drive circuit passing an alternating current of a frequency of 2 kHz to 650 kHz through the solenoid coil for a predetermined therapeutically effective period of time. [3] The method according to [2], wherein the drive circuit preferably passes an alternating current of a frequency of 20 kHz to 350 kHz through the solenoid coil for a predetermined therapeutically effective period of time. [4] The method according to [2], wherein the part of the living body is a bone, joint, ligament, or tendon of the living body. [5] The method according to [2], wherein the frequency of the alternating current is more preferably 100 kHz to 350 kHz. [6] The method according to [1], wherein the therapeutically effective time is at least 30 minutes per day. [7] A vector potential generation device configured by winding a solenoid coil around an insulating cylindrical base, the solenoid coil being formed by winding a conductor connected in series to a core wire around a winding axis, the vector potential being generated in the internal space by passing an alternating current from a drive circuit including an amplifier connected to the solenoid coil to the core wire and conductor of the vector potential coil, and controlling the frequency of the alternating current to suppress a decrease in or promote an increase in at least one of bone density (bone mass) and bone strength.[8] The vector potential generation device described in [7] includes a solenoid coil (basic wire) made of a core wire with an insulating coating and a conductor wound tightly around the core wire, with the core wire as a winding axis, and further includes a tubular portion formed by winding the solenoid coil in a loop shape, one end of the core wire is electrically connected to one end of the conductor, the other end of the core wire is connected to one end of a drive circuit (including an amplifier), and the other end of the conductor is connected to the other end of the drive circuit, and the drive circuit passes an alternating current of a frequency of 2 kHz to 650 kHz through the solenoid coil for a predetermined therapeutically effective period of time. [9] The vector potential generation device described in [8], wherein the drive circuit preferably passes an alternating current of a frequency of 20 kHz to 350 kHz through the solenoid coil for a predetermined therapeutically effective period of time.

[10] The vector potential generation device described in [8], wherein the frequency of the alternating current is more preferably 100 kHz to 350 kHz.

[0011] According to the present invention, it is possible to inhibit a decrease in or promote an increase in at least one of bone density (bone mass) and bone strength.

[0012] FIG. 1 is a schematic diagram illustrating a solenoid coil that constitutes a vector potential generation device used in the method of the present disclosure. FIG. 2 is a schematic diagram illustrating a vector potential generation device to which the solenoid coil shown in FIG. 1 is applied. FIG. 3 is a diagram showing thinly sliced ​​trabecular bone specimens from the CO group, HS group, and VP group. FIG. 4 is a diagram showing the bone mass structure in the secondary spongiosa of the CO group, HS group, and VP group after 3 weeks. FIG. 5 is a graph showing the bone mineral density (BV) in the secondary spongiosa of the CO group, HS group, and VP group after 3 weeks. FIG. 6 is a graph showing the bone strength in a fracture test of femurs extracted from the CO group, HS group, and VP group after 3 weeks.

[0013] 1 Vector potential device, 5 Living body or part of a living body, 8 Drive circuit, 9 AC power supply, 10 Solenoid coil (basic wire), 20 Cylinder portion, 21 Core wire, 22 Conductor wire.

[0014] Next, each embodiment of the present disclosure will be described with reference to the drawings. Note that each embodiment described below does not limit the invention according to the claims, and not all of the elements and combinations thereof described in each embodiment are necessarily essential to the solution of the present invention.

[0015] <Vector Potential Device> A vector potential device (hereafter referred to as the "VP device") 1 used in the method disclosed herein, as shown generally in FIG. 1, includes a solenoid coil (basic wire) 10 made up of a core wire 21 with an insulating coating, and a conductor 22 wound tightly around the core wire 21 as a winding axis, and further includes a cylindrical portion 20 formed by winding this solenoid coil 10 in a loop shape, with one end of the core wire 21 electrically connected to one end of the conductor 22, the other end of the core wire 21 connected to one end of a drive circuit 8, and the other end of the conductor 22 connected to the other end of the drive circuit 8. The drive circuit 8 is composed of an oscillator 9 and an amplifier (not shown).

[0016] The solenoid coil 10 includes a core wire 21 and a conductor wire 22 wound helically around the core wire 21. The core wire 21 and the conductor wire 22 are separate conductors, with their respective ends p1 and p2 connected at point P. The end p3 of the core wire 21, which is opposite end p1, and the end p4 of the conductor wire 22, which is opposite end p2, are, for example, the ends of a first lead wire 212 and a second lead wire 222, which connect to an external circuit 8. The drive circuit 8 is a circuit for transmitting an electrical signal (e.g., current) input to the core wire 21 and the conductor wire 22, and such a drive circuit 8 functions as a power supply device that supplies current. The electrical stimulation device 1 generates an electric field inside the tubular portion 20 formed by winding the solenoid coil 10. The core wire 21 and the conductor wire 22 are not limited to separate conductors, but may also be a single conductor that is folded back at point P.

[0017] FIG. 2 is a schematic diagram explaining a vector potential device 1 that uses the solenoid coil 10 shown in FIG. 1. The solenoid coil 10 is wound around the vector potential device 1 in a loop shape with one or more turns, and a tubular section 20 (inner diameter D1 = 8 cm, outer diameter D2 = 26 cm) is formed inside it to hold a living organism or part of a living organism (a rat 5 in FIG. 2). Note that the inner diameter D1 and outer diameter D2 are not limited to these values ​​and can be freely set depending on the object to be held. In the example of FIG. 2, a rat 5 is held, and a holding member 7 (such as a sheath with a semicircular cross section) that can be inserted into the tubular section 20 is prepared, and the rat is held inside the holding member 7. At this time, it is preferable that the outer peripheral surfaces of adjacent solenoid coils 10 in this tubular section 20 are aligned with no gaps between them. A predetermined part of the human body (e.g., thigh, lower leg, rib, upper limb, lower limb, knee, elbow, ankle, wrist, etc.) is held within the tube portion 20, and a current of a predetermined frequency is passed through the solenoid coil 10 from an AC power supply (not shown) connected to the drive circuit 8. This generates an electric field along the axial direction of the tube portion 20 without contact and without generating a magnetic field within the tube portion 20. Furthermore, within this electric field, current flows from the strong point of the electric field to the weak point of a human body part, such as a lower limb or knee joint. This makes it possible to apply a predetermined electrical stimulation to a predetermined human body part, such as a lower limb or knee joint.

[0018] The drive circuit 8 also includes a control unit (not shown) that controls parameters such as the magnitude, time, and frequency of the current flowing through the core wire 21 and the conductor wire 22 of the cylindrical portion 20. Furthermore, the control unit preferably further includes a function to change the parameters such as the current and frequency based on data fed back from other sensors, such as a body temperature sensor or a bioelectric current sensor.

[0019] <Method for Inhibiting Loss of Bone Density (Bone Mass) and Bone Strength> The method for inhibiting loss of bone density (bone mass) and bone strength according to the present disclosure includes adjusting the frequency of an alternating current applied to the VP device to apply electrical stimulation to tissue of a living organism. Here, the term "living organism" refers to a living thing, such as an animal, such as a mammal, including but not limited to, primates (e.g., humans), cattle, sheep, goats, horses, dogs, cats, rabbits, rats, and mice; an animal, such as a bird, including but not limited to, chickens, ducks, and turkeys; or an animal, such as a fish, including but not limited to, eels, salmon, and horse mackerel. In a preferred embodiment, the subject is a human. In one embodiment, the electrical stimulation is applied by holding the living organism or a portion of its tissue within the tubular portion 20 of the VP device 1 and generating an alternating current in the drive circuit for a predetermined period of time. Here, "holding" refers to maintaining the position of a living organism or a part thereof by fixing it within the tubular portion using a jig or the like. It also includes, for example, maintaining the position of a living organism or a part thereof within the tubular portion 20 by fitting it into a concave or concavely curved surface, or maintaining the position of a living organism or a part thereof by placing it on a flat surface. In a preferred embodiment, a planar mounting base (not shown) may be provided within the tubular portion 20. Regarding the material of the mounting base, an insulating material that does not allow electrical current to flow is preferred, such as a resin material such as rubber, polyethylene, or polyvinyl chloride. Furthermore, from a heat-resistant perspective, ceramics and other materials are also acceptable. A sheet-like VP device can also be attached to a living organism or a part of its tissue and electrically stimulated by applying an alternating current from an AC power source. A part of a living organism refers to a bone, joint, ligament, tendon, etc.

[0020] To provide electrical stimulation to the restrained living body or a part thereof, the current generated by the drive circuit 8 may be a continuous or pulsed alternating current. Furthermore, the frequency used may be from several Hz to several kHz depending on individual differences, the condition of the disease, etc. For example, for the treatment of articular cartilage, the frequency of the alternating current is preferably 2 kHz to 650 kHz, more preferably 20 kHz to 350 kHz, and even more preferably 100 kHz to 350 kHz.

[0021] In some examples, a therapeutically effective time is the time during which the electrical stimulation device of the present embodiment is operated to inhibit loss of at least one of bone mineral density (bone mass) and bone strength and treat osteoporosis as described herein. For example, the therapeutically effective time is at least 30, 60, or 90 minutes per day, preferably operated once a day, continuously or non-continuously every day, preferably five or more days per week, for one to three weeks or more. This example of operating time is not limiting. Additional treatment plans may include other therapies based on the symptoms or lifestyle of the subject being treated.

[0022] In the treatment method of the present disclosure, the disease to be treated is not particularly limited, but preferred treatment targets include diseases related to bones or joints. For example, the method may be used to treat conditions involving widespread overactive or inappropriate bone growth, such as rheumatoid arthritis, fibrodysplasia ossificans progressiva (FOP), diffuse idiopathic osteophytosis (DISH), ankylosing spondylitis, and heterotopic ossification. Some treatment targets may be used for removing bone masses in conditions involving neoplastic bone formation or bone tumors, such as osteosarcoma, chondrosarcoma, Ewing's sarcoma, osteoblastoma, and osteoid osteoma.

[0023] Similarly, it may be used to remove bone spurs (i.e., "osteophytes") that form in the legs, shoulders, neck, spine, etc. as a result of chronic osteoarthritis, rheumatoid arthritis, reactive arthritis, rotator cuff injuries, plantar fasciitis, spondylosis, and / or spinal stenosis.

[0024] Another preferred treatment target is ligament injury. The joints of the body are supported by ligaments. Ligaments are tough bands of connective tissue that connect bones to other bones. A sprain is a simple stretch or tear of a ligament. The areas most susceptible to sprains are the ankle, knee, and wrist. The mildest sprains can be cured with rest, ice, compression, elevating, and exercise and / or physical therapy. Moderate sprains may also require a period of immobilization. Severe sprains may require surgery to repair the torn ligament.

[0025] In still other embodiments, it may also be used for similar purposes in non-human mammals, such as companion animals such as dogs and cats, and horses, particularly race horses, in the veterinary field.

[0026] The present invention will now be described in more detail with reference to the following examples, but the present invention is not limited to these examples in any way.

[0027] <Experimental Apparatus> A schematic diagram of the vector potential generation device (hereinafter referred to as the "VP device") used in the following examples is shown in Figure 2. As shown in Figure 2, a solenoid coil (VP wire) 10 is wound around a cylindrical portion 20. The cylindrical portion 20 is a cylindrical space that is formed after the solenoid coil 10 is wound.

[0028] (Example 1) In this example, the trabecular structure of the secondary cancellous bone was observed when electrical stimulation was given to the following rat groups using the VP device 1 using AC power sources of different frequencies, and the bone mineral density (BV) and trabecular width (Tb.Th) of the cancellous bone were measured, as well as bone strength.

[0029] <Experimental Method and Materials> Six 7-week-old male Wistar rats were used in each group and classified as follows: CO group: group of rats kept normally HS group: group of rats kept with hind limb suspension (group of rats with weight restriction and no VP irradiation) VP group: group of rats kept with electricity applied using a vector potential generator (group of rats with weight restriction and VP irradiation)

[0030] Here, the above-mentioned hindlimb-suspended rat group (HS group) will be described. This rat group refers to a group of rats bred with their hindlimb suspended. To provide the height necessary for tail suspension in a standard cage, a wooden frame was attached to the standard cage, providing sufficient height for tail suspension. For tail suspension, the hindlimb was suspended so that the angle between the rat's head and the cage bottom was 30 degrees, and no weight was applied to the hindlimb. Care was taken to allow free movement so that food and water could be freely accessed.

[0031] In the following description and in Figures 5 and 6, VP2 indicates a group of domestic rats irradiated with VP at a frequency of 2 kHz, VP20 indicates a group of domestic rats irradiated with VP at a frequency of 20 kHz, VP200 indicates a group of domestic rats irradiated with VP at a frequency of 200 kHz, VP350 indicates a group of domestic rats irradiated with VP at a frequency of 350 kHz, VP500 indicates a group of domestic rats irradiated with VP at a frequency of 500 kHz, and VP600 indicates a group of domestic rats irradiated with VP at a frequency of 600 kHz.

[0032] The above-mentioned VP-irradiated rat groups (hereinafter, sometimes referred to as the "VP-irradiated group" when no particular distinction is made) were subjected to electrical current at each of the above frequencies for 30 minutes per day, 5 days per week, for 3 weeks under anesthesia. A voltage of approximately 67 mV was generated across the VP device, and assuming the impedance of the rats held inside was 500 Ω, a current of 0.12 mA was estimated to flow. After the 3-week experimental period, all groups were euthanized, and the femurs were removed and histologically analyzed using the following measurement method.

[0033] <Measurement Method> [Method for Bone Morphometry] The excised femurs from each group were sliced ​​to a thickness of 4 μm, and the sliced ​​trabecular bone specimens were stained with toluidine blue. The completed trabecular bone specimens were photographed using an optical microscope (BX53F, Olympus, Tokyo, Japan) combined with a camera (DP74, Olympus, Tokyo, Japan) and imaging software (Cell Sens Standard 4.1, Olympus, Tokyo, Japan) to measure bone morphology. The results are shown in Figures 3 to 5. Figure 3 shows images of the sliced ​​trabecular bone specimens from each group. For example, the trabecular width of the epiphyseal trabecular bone in the HS group was shorter than that of the CO group. On the other hand, the trabecular width of the trabecular bone in the VP group was similar to that of the CO group, particularly in VP2, VP20, and VP200. From the above, it can be seen that the decrease due to the load restriction was suppressed in the VP irradiation group.

[0034] Figure 4 shows images of the bone mass structure in the secondary trabecular bone after 3 weeks in each group. The epiphyseal trabeculae of the CO group were dense, whereas the HS group had thin trabeculae and an overall decrease in density. This difference between the two groups became more pronounced as the experimental period progressed. On the other hand, the thickness and density of the epiphyseal trabeculae of the VP group remained close to those of the CO group throughout the experimental period, indicating that the loss of trabeculae (bone density) due to load restriction was suppressed.

[0035] Figure 5 is a graph showing bone mineral density (BV) in the secondary trabecular bone of each group after 3 weeks. Images are shown. Bone mass was significantly higher at 20 and 200 kHz VP than at HS, with bone mass increasing in that order. It was also found to be higher than at HS at 350, 500, and 650 kHz (**p<0.01, *p<0.05). This indicates that frequencies between 20 and 650 kHz are effective for maintaining trabecular bone, and frequencies between 20 and 200 kHz are even more effective for maintaining trabecular bone. All data obtained through statistical processing were analyzed using SPSS ver. 26 (SPSS Inc., Chicago, IL, USA), one-way analysis of variance was performed using Tukey's test, with a rejection rate of 1% or less (**p<0.01) (same as in Figure 6). For VP2 and VP20 in Figure 5 and Hs, VP2, and VP20 in Figure 6, one-way analysis of variance was performed using Tukey's test, with a rejection rate of 5% or less (*p<0.05).

[0036] As shown in Figure 5, for example, with regard to bone density, bone mass at VP frequencies of 2 kHz, 20 kHz, and 200 kHz was significantly higher than that at HS, and bone mass increased without decreasing in that order. It was also found that bone mass at frequencies of 350, 500, and 650 kHz was higher than that at HS. This indicates that frequencies between 20 and 650 kHz can inhibit bone density loss or promote bone density increase. It is also clear that frequencies between 20 and 650 kHz are effective for maintaining trabecular bone, and frequencies between 20 and 200 kHz are even more effective for maintaining trabecular bone.

[0037] [Bone Fracture Test] The excised femur was wrapped in saline-soaked Kimwipes to prevent drying until the fracture test was performed. The fracture test was performed on the day of sampling (Olli et al., 2009). To fracture the central femoral shaft from the anterior, the femoral shaft was marked and placed on the support table of a fracture testing machine (TK-252C, Muromachi Kikai, Tokyo, Japan). The crosshead was adjusted to contact the marked area, and then the fracture test was performed. Bone strength was measured under the fracture conditions of three-point bending, a crosshead speed of 10 mm / min, and a support distance of 10 mm. The results are shown in Figure 6.

[0038] Figure 6 is a graph showing bone strength in a fracture test of femurs removed from each group after 3 weeks. As shown in Figure 6, the bone strength of the HS group was lower than that of the CO group. On the other hand, the bone strength of the VP group was higher than that of the HS group, and the bone strength of VP at 20 kHz and 200 kHz was close to that of the CO group.

[0039] As shown in Figure 6, for example, with regard to bone strength, the bone strength of VP at 20 kHz and 200 kHz was close to that of the CO group and significantly higher than that of HS. The bone mass increased without any decrease, and was also higher than that of HS at 350, 500, and 650 kHz. The bone mass of VP at 20 and 200 kHz was significantly higher than that of HS. The bone mass increased without any decrease, and was also higher than that of HS at 350, 500, and 650 kHz. This indicates that frequencies between 20 and 650 kHz inhibit the decrease in bone strength due to load restriction and promote the increase in bone strength. It is also clear that frequencies between 20 and 650 kHz are effective for maintaining trabecular bone, and frequencies between 20 and 200 kHz are even more effective for maintaining trabecular bone. Therefore, it can be seen that by using a VP device to pass an alternating current of 20 kHz to 650 kHz through bone sites in a non-contact manner, it is possible to suppress a decrease in bone density (bone mass) and bone strength, and to promote an increase in bone density (bone mass) and bone strength.

[0040] The disclosed method of operating an electrical stimulation device is useful for treating a variety of disorders, particularly disorders associated with osteoporosis.

Claims

1. A method for suppressing a decrease or promoting an increase in at least one of bone density and bone strength in a living body tissue, comprising a step of applying an electrical stimulus to the tissue using a vector potential generator, and controlling the electrical stimulus by adjusting an electric field generated in a VP coil while controlling a frequency of an alternating current applied to the vector potential generator and an output voltage of the VP coil, thereby suppressing a decrease or promoting an increase in at least one of bone density and bone strength.

2. The vector potential generator includes a solenoid coil composed of a core wire having an insulating film and a conducting wire wound around the core wire without a gap with the core wire as a spool, and further has a cylindrical portion formed by winding the solenoid coil in a loop shape. One end of the core wire is electrically connected to one end of the conducting wire, the other end of the core wire is connected to one end of a drive circuit, and the other end of the conducting wire is connected to the other end of the drive circuit. The method according to claim 1, characterized in that the cylindrical portion includes a step of holding a living body or a part of the living body therein, and the drive circuit includes a step of passing an alternating current having a frequency of 2 kHz to 650 kHz through the solenoid coil for a predetermined therapeutically effective time.

3. The method according to claim 2, characterized in that the drive circuit preferably includes a step of passing an alternating current having a frequency of 20 kHz to 350 kHz through the solenoid coil for a predetermined therapeutically effective time.

4. The method according to claim 2, characterized in that the part of the living body is a bone, joint, ligament, or tendon of the living body.

5. The method according to claim 2, wherein the frequency of the alternating current is more preferably 100 kHz to 350 kHz.

6. The method according to claim 1, wherein the therapeutically effective time is at least 30 minutes per day.

7. A vector potential generating device, characterized in that a solenoid coil in which a conductor serially connected to the core wire is wound around the core wire as a spool is wound along an insulating cylindrical base body, and an alternating current is passed through the core wire and the conductor of the vector potential coil from a drive circuit including an amplifier connected to the solenoid coil to generate a vector potential in the internal space, and by controlling the frequency of the alternating current, at least one of bone density and bone strength is suppressed from decreasing or promoted to increase.

8. The vector potential generating device according to claim 7, comprising a solenoid coil composed of a core wire having an insulating film and a conducting wire wound around the core wire as a spool without a gap, further having a cylindrical portion formed by winding the solenoid coil in a loop shape, one end of the core wire being electrically connected to one end of the conducting wire, the other end of the core wire being connected to one end of the drive circuit, and the other end of the conducting wire being connected to the other end of the drive circuit, wherein the drive circuit passes an alternating current having a frequency of 2 kHz to 650 kHz through the solenoid coil for a predetermined therapeutically effective time.

9. The vector potential generating device according to claim 8, wherein the drive circuit preferably passes an alternating current having a frequency of 20 kHz to 350 kHz through the solenoid coil for a predetermined therapeutically effective time.

10. The vector potential generating device according to claim 8, wherein the frequency of the alternating current is more preferably 100 kHz to 350 kHz.

Images