Cancer treatment apparatus and cancer treatment system

Abstract

A cancer treatment apparatus for applying a magnetic field to a living body is disclosed. The cancer treatment apparatus includes a magnetic field generator configured to generate a magnetic field; a power supply unit configured to supply a drive current to the magnetic field generator; and a controller configured to control the drive current supplied from the power supply unit, based on information on a cross section of a portion of a living body to which the magnetic field generated by the magnetic field generator is applied.

Description

DescriptionTitle of Invention: CANCER TREATMENT APPARATUS AND CANCER TREATMENT SYSTEMTechnical Field

[0001] The present disclosure relates to a cancer treatment apparatus and a cancer treatment system.Background Art

[0002] Cancer treatment apparatuses using various types of therapies have been proposed in the related art.

[0003] For example, a cancer treatment apparatus has been proposed to provide a low-cost cancer treatment apparatus suitable for remission treatment (for example, see Patent Document 1). The cancer treatment apparatus disclosed in Patent Document 1 includes a magnetic field generator configured to generate an alternating magnetic field to be applied to tissues of a cancer-affected area.Citation ListPatent Literature

[0004] PTL 1: Japanese Patent No. 6603812Summary of InventionTechnical Problem

[0005] However, in the cancer treatment apparatus disclosed in Patent Document 1, the temperature of a portion of the living body to which the magnetic field is applied may rise in accordance with an eddy current generated in that portion. Such a temperature rise may adversely affect the living body to be treated for cancer, for example, by changing the physical condition.Thus, it is desirable to provide a cancer treatment apparatus capable of inhibiting the temperature rise in a portion of a living body to which a magnetic field is applied.Solution to Problem

[0006] According to an aspect of the present disclosure, a cancer treatment apparatus for applying a magnetic field to a living body is provided. The cancer treatment apparatus includes:

[0007] a magnetic field generator configured to generate a magnetic field;

[0008] a power supply unit configured to supply a drive current to the magnetic field generator; and

[0009] a controller configured to control the drive current supplied from the power supply unit, based on information on a cross section of a portion of a living body to which themagnetic field generated by the magnetic field generator is applied.Effects of the Invention

[0010] According to the present disclosure, a cancer treatment apparatus capable of inhibiting a temperature rise in a portion of a living body to which a magnetic field is applied can be provided.Brief Description of Drawings

[0011] [Fig.l]FIG. 1 is a schematic top view illustrating a use state of a cancer treatment apparatus according to a first embodiment of the present disclosure.[Fig.2]FIG. 2 is a schematic front view illustrating a use state of the cancer treatment apparatus according to the first embodiment of the present disclosure.[Fig.3]FIG. 3 is a schematic side view illustrating a use state of the cancer treatment apparatus according to the first embodiment of the present disclosure.[Fig.4]FIG. 4 is a schematic perspective view illustrating a magnetic field generator in the cancer treatment apparatus according to the first embodiment of the present disclosure.[Fig.5]FIG. 5 is a cutaway perspective view illustrating the magnetic field generator in the cancer treatment apparatus according to the first embodiment of the present disclosure.[Fig.6]FIG. 6 is a block diagram illustrating a hardware configuration of a controller in the cancer treatment apparatus according to the first embodiment of the present disclosure.[Fig.7]FIG. 7 is a block diagram illustrating a functional configuration of a controller in the cancer treatment apparatus according to the first embodiment of the present disclosure.[Fig.8]FIG. 8 is a diagram illustrating a waveform of a drive current supplied by the cancer treatment apparatus according to the first embodiment of the present disclosure.[Fig.9]FIG. 9 is a flowchart illustrating an operation of the cancer treatment apparatus according to the first embodiment of the present disclosure.[Fig.l0]FIG. 10 is a photograph illustrating a pseudo living body.[Fig.11]FIG. 11 is a diagram illustrating a sectional temperature distribution of a pseudo living body when a magnetic field is applied.[Fig.12]FIG. 12 is a diagram illustrating a relationship between the size of a first example of a pseudo living body and the size of a coil.[Fig.l3]FIG. 13 is a diagram illustrating a relationship between the size of a second example of a pseudo living body and the size of a coil.[Fig.14]FIG. 14 is a diagram illustrating a relationship between the size of a third example of a pseudo living body and the size of a coil.[Fig.15]FIG. 15 is a diagram illustrating a first example of a relationship between the distance from the center of a pseudo living body and the temperature.[Fig.l6]FIG. 16 is a diagram illustrating a second example of a relationship between the distance from the center of the pseudo living body and the temperature.[Fig.l7]FIG. 17 is a diagram illustrating a third example of a relationship between the distance from the center of the pseudo living body and the temperature.[Fig.l8]FIG. 18 is a schematic side view illustrating a use state of a cancer treatment apparatus according to a second embodiment of the present disclosure.[Fig.l9]FIG. 19 is a block diagram illustrating a functional configuration of a controller in the cancer treatment apparatus according to the second embodiment of the present disclosure.[Fig.20]FIG. 20 is a flowchart illustrating the operation of the cancer treatment apparatus according to the first embodiment of the present disclosure.[Fig.21]FIG. 21 is a schematic top view illustrating a first example of a use state of a cancer treatment apparatus according to a third embodiment of the present disclosure. [Fig.22]FIG. 22 is a schematic top view illustrating a second example of a use state of the cancer treatment apparatus according to the third embodiment of the present disclosure.[Fig.23]FIG. 23 is a flowchart illustrating an operation of the cancer treatment apparatus according to the third embodiment of the present disclosure.[Fig.24]FIG. 24 is a schematic diagram illustrating a method of obtaining the size and position of an artifact from a plurality of continuous pieces of cross-sectional information.Description of Embodiments

[0012] Hereinafter, embodiments for implementing the present disclosure will be described with reference to the accompanying drawings. In the present specification and drawings, components having substantially the same functional configurations are denoted by the same reference numerals, and redundant description will be appropriately omitted. In addition, for facilitating the understanding of the description, the scale of each portion in the drawings may be different from the actual scale.

[0013] In directions such as parallel, perpendicular, orthogonal, horizontal, vertical, up and down, and left and right, a deviation is allowed to the extent that the effects of the embodiment of the present disclosure are not impaired. The shape of the corner portion is not limited to a right angle, and may be rounded in an arch shape. Parallel, perpendicular, orthogonal, horizontal, and vertical may include substantially parallel, substantially perpendicular, substantially orthogonal, substantially horizontal, and substantially vertical.First Embodiment of the Present Disclosure

[0014] Configuration of Cancer Treatment Apparatus According to First Embodiment of the Present Disclosure>(Overall Configuration Example)

[0015] An overall configuration of a cancer treatment apparatus according to a first embodiment of the present disclosure will be described with reference to FIGS. 1 to 3. FIGS. 1 to 3 are views illustrating an example of an overall configuration of a cancer treatment apparatus 10 according to the first embodiment of the present disclosure. FIG. 1 is a schematic top view illustrating the cancer treatment apparatus 10. FIG. 2 is a schematic front view illustrating the cancer treatment apparatus 10. FIG. 3 is a schematic side view illustrating the cancer treatment apparatus 10. Each of FIGS. 1 to 3 illustrates the cancer treatment apparatus 10 in a use state.

[0016] The cancer treatment apparatus 10 is an apparatus that treats cancer by applying a magnetic field to a living body P. For example, the cancer treatment apparatus 10 can treat cancer by applying a magnetic field generated by a coil included in a magnetic field generator 100 to the living body P to at least inhibit the growth of cancer cells or shrink cancer cells in cancer-affected areas of a living body.

[0017] The cancer treatment apparatus 10 can treat cancer without using a heat generating medium. The cancer treatment apparatus 10 can treat cancer by directly applying the magnetic field to a cancer- affected area by the magnetic field generator 100, instead of treating cancer by a thermal effect using a heating action by the magnetic field. In another viewpoint, the cancer treatment apparatus 10 can treat cancer by disposing a cancer-affected area in a magnetic field space formed by the magnetic field from the magnetic field generator 100 without using a heat generating medium and without relying on a thermal effect using a heat generating action by the magnetic field.

[0018] Examples of the living body P include, in addition to a person who suffers from cancer, a pet such as a dog or a cat, and domestic animals such as livestock, which suffer from cancer. The expression “apply a magnetic field to the living body P” may be replaced with the expression “interlink a magnetic flux with the living body P”.

[0019] As illustrated in FIGS. 1 to 3, the cancer treatment apparatus 10 includes the magnetic field generator 100 configured to generate a magnetic field, and a powersupply unit 101 configured to supply a drive current to the magnetic field generator 100. The cancer treatment apparatus 10 includes a controller 102 configured to control the drive current supplied from the power supply unit 101, based on the information on a cross section of a portion of the living body P to which the magnetic field generated by the magnetic field generator 100 is applied. Further, in the examples illustrated in FIGS. 1 to 3, the cancer treatment apparatus 10 includes a treatment table 106 on which the living body P is placed, a non-conductive buffer material 109 disposed onthe treatment table 106, and a coil cooling unit 103 configured to supply a cooling liquid to a manifold 104 through a hose 105.

[0020] The controller 102 can control the drive current supplied from the power supply unit 101 so as not to allow a surface temperature of the living body P to exceed a predetermined temperature upper limit value, based on information on an amount of heat produced by the living body P due to the application of the magnetic field, which is obtained based on information on the cross section of the living body P to which the magnetic field is applied. Here, “controlling the drive current” means controlling the amount of drive current supplied from the power supply unit 101 per unit time.

[0021] For example, a temperature of the portion of the living body to which the magnetic field is applied may rise in accordance with an eddy current generated in that portion. Such a temperature rise may adversely affect a living body to be treated for cancer, for example, by changing the physical condition. The cancer treatment apparatus 10 can reduce the eddy current generated in the portion of the living body P to which the magnetic field is applied by controlling the drive current supplied from the power supply unit 101, based on the information on the cross section of the portion of the living body P to which the magnetic field generated by the magnetic field generator 100 is applied. Thus, the cancer treatment apparatus 10 can inhibit the temperature rise of the portion of the living body P to which the magnetic field is applied. In addition, in the cancer treatment apparatus 10 an adverse effect on the living body P to which the cancer treatment is applied by the cancer treatment apparatus 10 may be reduced. Such an adverse effect includes a change in the physical condition of the living body P or the like due to the temperature rise.

[0022] The predetermined temperature upper limit value of the surface temperature of the living body P can be set to, for example, 40°C or higher and 45°C or lower. By setting the predetermined temperature upper limit value to 45°C or lower, the difference from the allowable body temperature range of the living body P does not become too large, thereby reducing the adverse effect on the living body P. The allowable body temperature range is a range of body temperatures that do not pose a risk to life. Some of the proteins that make up the human body denature (coagulate) at temperatures above 42°C, and the respective proteins cease to function, resulting in human death. Above 42°C, the risk of death increases within a dozen hours, and above 44°C, irreversible changes in the oxygen system occur and recovery is impossible, even for short periods of time. The core temperature, which is the temperature in the depths of the body such as the cranium, the thoracic cavity, and the abdominal cavity, is on average 37.2°C in the rectum, 36.8°C in the oral cavity, and 36.4°C in the axilla, and the limit temperature when these temperatures increase is considered to be 42°C. At this temperature, irreversible biochemical reactions in the cells occur, leading to death. Furthermore, at45°C, there is a risk of death even within a short period of time. When the predetermined temperature upper limit value is lower than 40°C, the time for applying the magnetic field will not be increased to inhibit the temperature rise, and thus a sufficient therapeutic effect on cancer may not be obtained. By setting the predetermined temperature upper limit value to 40°C or higher, the time of application of the magnetic field can be made longer than when the predetermined temperature upper limit value is lower than 40°C, and thus, the therapeutic effect on cancer can be enhanced.

[0023] The cancer to be treated by the cancer treatment apparatus 10 may be at least one of malignant glioma, malignant melanoma, malignant mesothelioma, or oral cancer. However, the cancer to be treated by the cancer treatment apparatus 10 is not limited thereto, and may be breast cancer, pancreatic cancer, or the like. When a portion having a relatively small volume such as a head portion including a face or a head, an arm portion, or a leg portion, from among various portions of the living body P is a cancer-affected area, treatment can be performed in a state where the cancer-affected area is disposed inside a cylindrical portion formed by the coil included in the magnetic field generator 100. In addition, when a portion having a relatively large volume such as the chest or the trunk is the cancer-affected area, treatment can be performed in a state where the plurality of coils included in the magnetic field generator 100 are arranged around the chest or the trunk.

[0024] Hereinafter, each configuration of the cancer treatment apparatus 10 will be described in detail.

[0025] The magnetic field generator 100 generates a magnetic field. The magnetic field generator 100 converts a current supplied from the power supply unit 101 into a magnetic flux by electromagnetic induction. The magnetic field generator 100 is configured to include, for example, a coil. In the examples illustrated in FIGS. 1 to 3, the magnetic field generator 100 generates a magnetic field to be applied to the living body P in accordance with the drive current supplied from the power supply unit 101 via the controller 102. The magnetic field generator 100 generates a magnetic field having a magnetic flux density of 10 mT to 30 mT at a position where the cancer- affected area of the living body P is disposed. The position where the cancer-affected area of the living body P is disposed is the center position of the coil included in the magnetic field generator 100 or the like. The intensity of the magnetic field generated by the magnetic field generator 100 varies according to the drive current supplied from the power supply unit 101 under the control of the controller 102.

[0026] The power supply unit 101 supphes a drive current to the magnetic field generator 100. The power supply unit 101 is connected to a power supply PS which is, for example, a commercial power supply. The power supply unit 101 generates a drive current at any supply frequency of supply frequencies from 100 kHz to 300 kHz, forexample, using supply of power from the power supply PS. The power supply unit 101 supplies the generated drive current to the magnetic field generator 100 via the controller 102. The power supply unit 101 adjusts the power such that the magnetic field generator 100 generates a magnetic field having a desired magnetic flux density.

[0027] The controller 102 can perform impedance matching between the power supply unit 101 and the magnetic field generator 100 in addition to control of the drive current supplied from the power supply unit 101 to the magnetic field generator 100. The controller 102 can supply power stable at a target resonance frequency (for example, 230 kHz) to the magnetic field generator 100. In view of performing impedance matching, the controller 102 may be referred to as a matching unit. The hardware configuration and the functional configuration of the controller 102 will be described in detail later with reference to FIGS. 6 and 7.

[0028] The coil cooling unit 103 supplies a cooling liquid to the magnetic field generator 100 to cool the magnetic field generator 100. The magnetic field generator 100 generates heat when receiving the power from the power supply unit 101. The cancer treatment apparatus 10 can inhibit a temperature rise of the magnetic field generator 100 by cooling the magnetic field generator 100 with the cooling liquid supplied from the coil cooling unit 103.

[0029] The coil cooling unit 103 is, for example, a chiller. The coil cooling unit 103 is connected to a power supply PS which is, for example, a commercial power supply. The coil cooling unit 103 cools the cooling liquid by using the electric power’ from the power supply PS. The cooling liquid is, for example, water. However, the cooling liquid may be water with an antifreeze added thereto, or an inert liquid such as a fluorine-based liquid or the like.

[0030] The coil cooling unit 103 can collect the cooling liquid that has cooled the magnetic field generator 100. The coil cooling unit 103 can circulate the cooling liquid while maintaining a constant water temperature by repeating supply and collection of the cooling liquid.

[0031] The coil cooling unit 103 supplies the cooling liquid to the manifold 104 through the hose 105. The manifold 104 supplies the cooling liquid supplied by the coil cooling unit 103 to the magnetic field generator 100. The manifold 104 collects the supplied cooling liquid from the magnetic field generator 100.

[0032] The cancer treatment apparatus 10 may branch the cooling liquid supplied from the coil cooling unit 103 at the manifold 104 and supply the cooling liquid to both the power supply unit 101 and the controller 102. That is, the cancer treatment apparatus 10 may cool at least one of the power supply unit 101 or the controller 102 using the cooling liquid supplied from the coil cooling unit 103.

[0033] The cancer treatment apparatus 10 includes the non-conductive buffer material 109on the treatment table 106. When the treatment table 106 contains metal, the magnetic flux generated by the magnetic field generator 100 is interlinked to generate an eddy current, and the treatment table 106 may generate heat. In order to prevent the treatment table 106 from generating heat, the cancer treatment apparatus 10 includes the non-conductive buffer material 109 such that the treatment table 106 can be separated from the magnetic field generator 100 by a sufficient distance.

[0034] The living body P is placed on the non-conductive buffer material 109 when the cancer treatment apparatus 10 performs treatment. For example, the living body P lies on the non-conductive buffer material 109 in a supine posture. For example, when the cancer of the living body P is a brain tumor such as a malignant glioma of the head, the head of the living body P is inserted into the magnetic field generator 100, and thus the head is disposed inside the magnetic field generator 100. The magnetic field generator 100 is formed such that the head of the living body P can be placed inside. The magnetic field generator 100 can apply the magnetic field to the head of the living body P placed inside.(Configuration Example of Magnetic Field Generator 100)

[0035] FIG. 4 is a perspective view illustrating the magnetic field generator 100. As illustrated in FIG. 4, the magnetic field generator 100 includes a coil 100a and a pipe 100b. As a material constituting each of the coil 100a and the pipe 100b, a material having conductivity can be used. Each of the coil 100a and the pipe 100b is made of a hollow tubular member. The coil 100a and the pipe 100b have substantially the same cross-sectional shape. Each of the coil 100a and the pipe 100b is not limited to a cylindrical shape, and may be an elliptic cylindrical shape, a square cylindrical shape, or the like. FIG. 4 illustrates the coil 100a having a cylindrical shape.

[0036] The coil 100a has a spiral shape. The living body P has a portion to which a magnetic field is applied (i.e., a cancer-affected area) disposed on the inside lOOai of the coil 100a. The pipe 100b includes pipes 100b respectively connected to two ends of the coil 100a.

[0037] The temperature-controlled cooling liquid supplied by the coil cooling unit 103 flows through the coil 100a and the pipes 100b. Further, a current flows through each of the coil 100a and the pipes 100b from the power supply unit 101 via the controller 102. Heat generated by the current flowing through the coil 100a and the pipes 100b is cooled by the cooling liquid flowing through the coil 100a and the pipes 100b. The coil 100a and the pipes 100b are kept at a constant temperature by cooling with the cooling liquid.

[0038] Next, an insulating structure included in the coil 100a will be described. FIG. 5 is a cutaway perspective view illustrating the magnetic field generator 100. FIG. 5 illustrates the coil 100a having a rectangular tube shape. If the living body were to comeinto contact with the coil 100a, there would be a possibility of electric shock. Therefore, the coil 100a has an insulating structure to prevent electric shock.

[0039] The coil 100a includes a metallic pipe lOOal, an insulating sheet 100a2, and a protective sheet 100a3. The metallic pipe 100a! is made of a metallic material such as copper. The insulating sheet 100a2 is an insulating tape such as a polyimide tape. The protective sheet 100a3 is an insulating sheet such as a glass sheet. The coil 100a can protect the metallic pipe 100a! by providing the insulating sheet 100a2 and the protective sheet 100a3 around the metallic pipe lOOal . The insulating sheet 100a2 and the protective sheet 100a3 can insulate the metallic pipe lOOal from the living body P and the like.

[0040] Note that a protective material such as cloth or rubber may be further provided on the outside of the protective sheet 100a3 provided on the coil 100a. By further providing a protective material such as cloth or rubber on the outside of the protective sheet 100a3 provided on the coil 100a, insulation from the human body can be reliably maintained.(Configuration Example of Controller 102)

[0041] FIG. 6 is a block diagram illustrating an example of a hardware configuration of the controller 102. The controller 102 includes a central processing unit (CPU) 121, a read only memory (ROM) 122, a random access memory (RAM) 123, an interface (I / F) 125, and a matching circuit 126. These components are connected to each other via a system bus A so as to be able to communicate with each other.

[0042] The CPU 121 executes control processing including various kinds of arithmetic processing. The ROM 122 stores a program used for driving the CPU 121, such as an initial program loader (IPL). The RAM 123 is used as a work area of the CPU 121.

[0043] A Hard Disk Drive / Solid State Drive (HDD / SSD) 124 stores various kinds of information such as a program, correspondence information on a relationship between information on a cross section and information on the temperature of the living body P according to the application time of the magnetic field, and the like.

[0044] The I / F 125 is an interface for connecting a processor to various devices. The devices herein include the magnetic field generator 100 and the like. The I / F 125 may have a capability of communicating with an external device via a communication network or the like. For example, the controller 102 may be connected to the Internet via the I / F125 and may be able to communicate with an external device via the Internet.

[0045] The matching circuit 126 is an electric circuit for matching the impedance between the power supply unit 101 and the magnetic field generator 100. The matching circuit126 includes a known resonant circuit such as a series circuit or a parallel circuit that includes an inductor, a capacitor, and a resistor. In the cancer treatment apparatus 10, the inductance and resistance of the coil 100a included in the magnetic field generator 100, with the capacitor in the matching circuit 126, constitute a parallel LCR resonancecircuit. The power supply unit 101 has a function of controlling the peak frequency of the parallel LCR resonance circuit to follow the peak frequency of the parallel LCR resonance circuit even if the peak frequency of the parallel LCR resonance circuit were to be shifted due to variation of the LCR caused by a parasitic element.

[0046] The matching circuit 126 may be connected to the power supply unit 101 and may not be connected to the system bus A of the controller 102. In this case, the cun-ent value may be set using the operation unit of the power supply unit 101, or the power supply unit 101 may be turned on or off. For example, the power supply unit 101 may be connected to the controller 102 via an interface such as a RS485, separately from the system bus A. All operations such as current setting and on / off that can be performed on the operation panel may be performed by instructions from the controller 102 via this interface.

[0047] Next, a functional configuration of the controller 102 will be described with reference to FIGS. 7 and 8. First, FIG. 7 is a block diagram illustrating an example of a functional configuration of the controller 102. The controller 102 includes an input unit 21, a drive current controller 22, a storage unit 23, a matching unit 24, and a frequency controller 25.

[0048] The function of the input unit 21 is implemented by the I / F 125 or the like. The functions of the drive current controller 22 and the frequency-controller 25 are implemented by a processor such as the CPU 121 executing processing defined in a program stored in a nonvolatile memory such as a ROM 122. The function of the storage unit 23 is implemented by the HDD / SSD 124 or the like. The function of the matching unit 24 is implemented by the matching circuit 126 and the like.

[0049] Some of the functions of the controller 102 may be implemented by an external device such as an external personal computer (PC) or an external server, or may be implemented by distributed processing between the controller 102 and the external device. The matching unit 24 may be a separate component independent of the controller 102.

[0050] The input unit 21 inputs information Pr on a cross section of a portion of the living body P to which the magnetic field generated by the magnetic field generator 100 is applied. For example, the input unit 21 can input the information Pr on the cross section from a measurement device by controlling communication with the measurement device configured to acquire the information Pr on the cross section by measurement. Alternatively, the input unit 21 can input the information Pr on the cross section via an input device such as a keyboard or a touch panel by controlling communication with the input device. The information Pr on the cross section may be input to the cancer treatment apparatus 10 via a portable memory such as a universal serial bus (USB) memory.

[0051] The information Pr on the cross section can include information on a cross-sectional area of the portion of the living body P to which the magnetic field is applied. Alternatively, the information Pr on the cross section may be information on a largest cross- sectional area of the portion of the living body P to which the magnetic field is applied. The information on the cross-sectional area and the information on the largest cross- sectional area of the portion of the living body P can be acquired from an imaging result obtained by using a computed tomography (CT) apparatus, a magnetic resonance imaging (MRI) apparatus, or the like. The cancer treatment apparatus 10 uses these imaging results as the information Pr on the cross section. However, the information Pr on the cross section is not limited to the information on the cross-sectional area or the information on the largest cross-sectional area of the portion of the living body P, and may be a measurement value of the outer circumferential length of the portion of the living body P by a tape measure or the like.

[0052] The information on the cross-sectional area may be standardized using a circle having the same cross-sectional area as the portion of the living body P to which the magnetic field is applied, and the predetermined temperature upper limit value corresponding to one of an area, a radius, or a diameter of the circle may be associated with a magnetic flux density of the magnetic field to be applied. The information on the cross-sectional area may be standardized using an ellipse having the same cross- sectional area as the portion of the living body P to which the magnetic field is applied, and the predetermined temperature upper limit value corresponding to one of the area, the major axis, and the minor axis of the ellipse may be associated with the magnetic flux density of the magnetic field to be applied. Thus, the information on the cross- sectional area can be easily acquired from the imaging results by the CT apparatus or the MRI apparatus. The cancer treatment apparatus 10 can use the acquired information on the cross-sectional area as the information Pr on the cross section.

[0053] The drive current controller 22 controls the drive current supplied from the power supply unit 101 based on the information Pr on the cross section. For example, the drive current controller 22 can acquire information Tm on the amount of heat produced by the living body P based on correspondence information 230 on the relationship between the information Pr on the cross section and the information Tm on the temperature of the living body P according to the application time of the magnetic field. More specifically, the storage unit 23 stores the correspondence information 230 acquired in advance by an experiment or a simulation. The drive current controller 22 can acquire the information Tm on the amount of heat produced by the living body P with reference to the correspondence information 230 stored in the storage unit 23 based on the information Pr on the cross section input via the input unit 21. Thus, the controller 102 can easily acquire the information on the amount of heat produced bythe living body P, based on the information on the cross section without performing arithmetic and logic operations using complicated mathematical expressions.

[0054] The drive current controller 22 can control the drive current supplied from the power supply unit 101 based on the information Tm on the amount of heat produced by the living body P so as not to allow the surface temperature of the living body P to exceed the predetermined temperature upper limit value.

[0055] The power supply unit 101 supplies the drive current by outputting a predetermined waveform at a predetermined supply frequency, and the drive current controller 22 can control the drive current by varying at least one of the shape of the waveform and the supply frequency. For example, the power supply unit 101 supplies the drive current by outputting a rectangular wave at a predetermined supply frequency, and the controller 102 can control the drive current by varying the duty ratio of the rectangular wave. Thus, the controller 102 can control the drive current supplied from the powersupply unit 101 so as not to allow the surface temperature of the living body P to exceed the predetermined temperature upper limit value.

[0056] FIG. 8 is a diagram illustrating an example of a waveform of the drive current supplied by the cancer treatment apparatus 10. FIG. 8 illustrates a drive current having a rectangular wave SW supplied from the power supply unit 101 to the magnetic field generator 100 at a supply frequency f. The rectangular wave SW is an example of the waveform of the drive current. The rectangular- wave SW is constituted by a period H in which the current value is high and a period L in which the current value is low. In the period H in which the current value is high, a larger amount of drive current is supplied to the magnetic field generator 100 than in the period L in which the cun-ent value is low. The duty ratio corresponds to a value calculated by H x f.

[0057] The drive current controller 22 can control the drive current supplied from the power supply unit 101 to the magnetic field generator 100 by varying the duty ratio, for example. However, the drive cun-ent controller 22 may control the drive current by varying the current value or varying the supply frequency f. The waveform of the drive current is not limited to the rectangular wave, and may be a sine wave, a triangular wave, any given waveform, or the like.

[0058] For example, a plurality of waveforms that differ from each other in at least one of a duty ratio, a current value, a supply frequency, a waveform shape, and the like are stored in the storage unit 23 or the like. The drive current controller 22 can vary at least one of the duty ratio, the cun-ent value, the supply frequency, the waveform shape, and the like by selecting a corresponding waveform based on the information Tm on the generated amount of heat corresponding to the information Pr on the cross section. However, the drive current controller 22 may continuously vary at least one of the duty ratio, the current value, the supply frequency, the waveform shape, and the like basedon the information Pr on the cross section which is continuously input.

[0059] The waveform of the drive current may be associated with an allowable magnetic flux density obtained by multiplying an upper limit magnetic flux density, which is associated in advance with the predetermined temperature upper limit value relating to the surface temperature of the living body P, by an application time of the magnetic field applied by the magnetic field generator 100.

[0060] For example, information on the relationship between the allowable magnetic flux density and the waveform of the drive current is acquired in advance by an experiment, a simulation, or the like, and is stored in the storage unit 23. The drive current controller 22 selects a waveform based on the allowable magnetic flux density by referring to the information on the relationship between the allowable magnetic flux density and the waveform of the drive current stored in the storage unit 23. The drive current controller 22 can control the drive current by changing the waveform of the drive current output from the power supply unit 101 to the selected waveform. Thus, the controller 102 can accurately control tire drive current supplied from the power supply unit 101 so as not to allow the surface temperature of the living body P to exceed the predetermined temperature upper limit value.

[0061] In the rectangular wave SW of the drive current, a large current (High) and a small current (Low) alternately change in accordance with the supply frequency f. For example, the controller 102 may control the change of the current according to the supply frequency f through a RS485 interface or the like. Note that the power supply unit 101 has a function of supplying a constant current. The current value of the current supplied from the power supply unit 101 is changed by an operation by an operator using the operation unit of the power supply unit 101 or instructions from the controller 102.

[0062] The resonance frequency of the parallel LCR resonance circuit is, for example, 230 kHz. On the other hand, the supply frequency f is 1 Hz at the fastest because the time required for the power supply unit 101 to switch the current value, which is not affected even if the supply frequency f is made faster. The High period in the rectangular wave SW of the drive current is 10 seconds, and the Low period is 20 seconds. The period is 30 seconds.

[0063] In FIG. 7, the matching unit 24 performs impedance matching between the power supply unit 101 and the magnetic field generator 100.

[0064] The frequency controller 25 controls the supply frequency of the drive current from the power supply unit 101 to the magnetic field generator 100 such that the magnetic field generator 100 can always output the maximum current value. The controller 102 may control the frequency controller 25 to supply a stable drive current to the magnetic field generator 100. The drive current controller 22 can also control the drive currentby controlling the supply frequency in coordination with the frequency controller 25. cOperation Example of Cancer treatment apparatus 10>

[0065] Next, the operation of the cancer treatment apparatus 10 will be described. FIG. 9 is a flowchart illustrating an example of an operation of the cancer treatment apparatus 10.

[0066] As a preparation for the operation of the cancer treatment apparatus 10, the cancer treatment apparatus 10 acquires information on a largest cross-sectional area of the portion of the living body P to which the magnetic field is applied by the magnetic field generator 100 as information Pr on the cross section from the imaging result by the CT apparatus or the MRI apparatus. Alternatively, the cancer treatment apparatus 10 may acquire, as the information Pr on the cross section, information on a cross- sectional area of the approximate ellipse from the major axis and the minor axis of the maximum cross section of the portion of the living body P to which the magnetic field is applied. The cancer treatment apparatus 10 may acquire diameter information of a circle having the same area from the acquired information on the cross-sectional area as the information Pr on the cross section. Further, the cancer treatment apparatus 10 may measure the outer circumferential length of the portion of the living body P by a tape measure or the like, and calculate the diameter of a circle having the same outer circumferential length as the outer circumferential length or the major axis and minor axis of an ellipse having the same outer circumferential length as the outer circumferential length, thereby acquiring the information Pr on the cross section. In this case, the ratio of the major axis to the minor axis is predetermined. In the following, a case where the diameter of a circle is used as a numerical value representing the maximum cross-sectional area (hereinafter, referred to as a cross-sectional shape representative value) will be described as an example.

[0067] For example, the living body P is placed on the treatment table 106 of the cancer treatment apparatus 10. In the example illustrated in FIG. 9, the living body P is a person having a malignant glioma of the brain in the head. The living body P lies on the back on the treatment table 106 such that the head is arranged inside the coil 100a of the magnetic field generator 100. The timing at which the living body P is placed on the treatment table 106 of the cancer treatment apparatus 10 may be any timing as long as it is a timing before the magnetic field is applied in the cancer treatment apparatus 10 illustrated in FIG. 9.

[0068] The optical fiber thermometer is fixed to one or more places on the epidermis of the living body P arranged on the treatment table 106. The surface temperature of the head is monitored by the optical fiber thermometer. However, the surface temperature of the head of the living body P may be monitored in a non-contact manner by imaging the head with a thermocamera, or both the optical fiber thermometer and the thermocamera may be used in combination. The thermometer continuously or inter-mittently measures the temperature from before the start of treatment to after the end of treatment, and transmits the measurement results or the imaging results to the controller 102 of the cancer treatment apparatus 10 in a wired or wireless manner.

[0069] The cancer treatment apparatus 10 starts the operation of FIG. 9 on the condition that an operator of the cancer treatment apparatus 10 (hereinafter, simply referred to as the operator) turns on the power button of the operation unit and supply of power from the commercial power supply to the cancer treatment apparatus 10 is started. The start condition of the operation of the cancer treatment apparatus 10 can be changed as appropriate.

[0070] First, in step SI 1, the cancer treatment apparatus 10 inputs a cross-sectional shape representative value of the living body P by the input unit 21. For example, the controller 102 inputs the cross-sectional shape representative value of the living body P by the operator manually inputting the cross-sectional shape representative value using an operation unit such as a touch panel included in the cancer treatment apparatus 10.

[0071] Subsequently, in step S12, the cancer treatment apparatus 10 calculates, by the drive current controller 22, the application time of the magnetic field in minutes when the magnitude of the flux density is set as a reference value, based on the cross-sectional shape representative value input via the input unit 21.

[0072] Subsequently, in step S 13, when the calculated application time of the magnetic field is not sufficient for the time required for the treatment, the cancer treatment apparatus 10 selects the magnitude of the magnetic flux density and the waveform for supplying the drive current from a plurality of options prepared in advance by the drive current controller 22. However, an operator such as a medical practitioner, a doctor, or a veterinarian may select the magnitude of the magnetic flux density and the waveform for supplying the drive current from the plurality of options prepared in advance using the operation unit of the cancer treatment apparatus 10 or the power supply unit 101, and the cancer treatment apparatus 10 may receive the selection result. For example, the options of the waveform include a plurality of rectangular waves SW as illustrated in FIG. 8, which have different duty ratios or the like. When the application time of tire magnetic field is sufficient for the time required for the treatment, the cancer treatment apparatus 10 can use the waveform determined in advance as the initial value as it is.

[0073] Subsequently, in step S14, the cancer treatment apparatus 10 controls communication with the power supply unit 101 by the drive current controller 22 to input the selected waveform to the power supply unit 101. However, the operator may input the selected waveform to the power supply unit 101 by operating the touch panel.

[0074] Subsequently, in step S15, the cancer treatment apparatus 10 starts the operation of the coil cooling unit 103. For example, the coil cooling unit 103 starts operating when the operator turns on the power button of the coil cooling unit 103. Thereafter, thecooling liquid whose temperature is adjusted by the coil cooling unit 103 circulates between the coil cooling unit 103 and the coil 100a of the magnetic field generator 100 until the operation of the coil cooling unit 103 is stopped.

[0075] Subsequently, in step S 16, the cancer treatment apparatus 10 starts supplying a drive current to the coil 100a included in the magnetic field generator 100 by the power supply unit 101. For example, the power supply unit 101 starts supplying the drive current to the coil 100a when the operator turns on a current supplying switch included in the power supply unit 101. The power supply unit 101 continues to supply the drive current to the coil 100a until the operator turns off the current supplying switch.

[0076] When the supply of the drive current from the power supply unit 101 to the coil 100a is started, the magnetic field generator 100 applies the magnetic field to the living body P in accordance with the waveform selected in step S13, and thus the cancer treatment is performed.

[0077] It is preferable that the living body P does not move while the magnetic field generator 100 applies the magnetic field to the living body P. The surface temperature information of the living body P acquired by the optical fiber thermometer, the thermocamera, or the like during the application of the magnetic field to the living body P may be displayed on a display unit such as a liquid crystal display included in the cancer treatment apparatus 10.

[0078] Subsequently, in step S17, the cancer treatment apparatus 10 determines whether a predetermined treatment time has elapsed by the controller 102. The treatment time is, for example, 30 minutes.

[0079] In step S17, when the cancer treatment apparatus 10 determines that the predetermined treatment time has not elapsed (step S17, NO), the operation of step S17 is performed again and repeated until the predetermined treatment time elapses.

[0080] On the other hand, when the cancer treatment apparatus 10 determines in step S17 that the predetermined treatment time has elapsed (YES in step S17), the controller 102 stops the supply of the drive current from the power supply unit 101 to the magnetic field generator 100 in step SI 8.

[0081] After the application of the magnetic field to the living body P is stopped, the living body P rises on the treatment table 106, and descends from the treatment table 106 to be away from the cancer treatment apparatus 10. The living body P away from the cancer treatment apparatus 10 can move to a waiting room or the like.

[0082] Subsequently, in step S19, the cancer treatment apparatus 10 stops the operation of the coil cooling unit 103. For example, when the operator turns off the power button of the coil cooling unit 103, the coil cooling unit 103 stops operating.

[0083] Subsequently, in step S20, the operator turns off the power button of the operation unit, and thus supply of power from the commercial power supply to the cancertreatment apparatus 10 is stopped. The cancer treatment apparatus 10 is thus turned off.

[0084] As described above, the cancer treatment apparatus 10 can treat cancer of the living body P.

[0085] When the surface temperature of the living body P exceeds the predetermined temperature upper limit value, for example, 42°C while the surface temperature of the living body P is monitored, the cancer treatment apparatus 10 temporarily interrupts the application of the magnetic field, or changes the waveform of the drive current such that the magnetic field to be applied is weakened. Thus, the surface temperature of the living body P is made to be lower than the predetermined temperature upper limit value. After the value falls below the predetermined temperature upper limit value, whether to change the waveform again is appropriately determined asking of the feeling of the living body P or examining the state of the living body P.Experimental Results on Temperature Rise of Living body with Application of Magnetic Field>

[0086] In the cancer treatment apparatus, for example, when a magnetic field having a supply frequency of 230 kHz and a magnetic flux density of about 20 mT is applied to a living body, the temperature of a liquid in tissues of a human or a medium-sized animal such as a dog increases little by little, and the body temperature increases. The increase in the body temperature may affect the living body P, for example, by changing the physical condition. Therefore, the relationship between the application of the magnetic field and the temperature of the living body was examined by an experiment. FIGS. 10 to 17 are diagrams illustrating an experiment of a relationship between application of the magnetic field and the temperature of a living body and results thereof.

[0087] In the experiment, a pseudo living body Q which is a columnar member simulating a human head and made of agar impregnated with physiological saline was used. The pseudo living body Q was arranged inside the coil 100a in the magnetic field generator 100, and temperature information relating to the temperature distribution and the temperature change of the pseudo living body Q when the magnetic field generator 100 applied the magnetic field was acquired. A thermocamera was used to acquire the temperature information. The temperature information at each position of the pseudo living body Q was acquired from an image captured by the thermocamera.

[0088] FIG. 10 is a photograph illustrating the pseudo living body Q used in the experiment. FIG. 11 is a diagram illustrating an example of a cross-sectional temperature distribution of the pseudo living body Q when the magnetic field is applied. The cross section illustrated in FIG. 11 is a cross section substantially orthogonal to the cylinderaxis of the cylindrical pseudo living body Q. FIGS. 10 and 11 indicate the pseudo living body Q viewed from the same direction. The cross-sectional temperature dis-tribution of the pseudo living body Q illustrated in FIG. 11 is based on the image captured by the thermocamera. The temperature information at the position of each pixel can be acquired from the luminance value of each pixel of the image captured by the thermocamera. Note that in thermal imaging, colors represent different temperature ranges. Generally, cooler temperatures are depicted in darker or cooler colors like black or blue, while warmer temperatures are depicted in lighter or warmer colors like red, orange, or yellow. In FIG. 11, temperatures are depicted from blue, yellow, red, and then to white as the temperature increases from low to high.

[0089] In the experiment, three kinds of pseudo living bodies Q having different diameters were prepared, and temperature information of the pseudo living body Q when the magnetic field was applied was acquired for each of the three kinds of pseudo living bodies Q. FIGS. 12 to 14 are diagrams illustrating a relationship between the size of each of the three types of pseudo living bodies QI to Q3 and the size of the magnetic field generator. A diameter dl in FIG. 12 is a diameter of the pseudo living body QI. A diameter d2 in FIG. 13 is a diameter of the pseudo living body Q2. A diameter d3 in FIG. 14 is a diameter of the pseudo living body Q3. The relationship between the sizes of the diameters dl to d3 is represented by dl > d2 > d3.

[0090] FIGS. 15 to 17 are diagrams illustrating a relationship between a distance from the center of the pseudo living body Q and a temperature. In FIGS. 15 to 17, “0” on the horizontal axis represents the center of the pseudo living body Q, and the larger the distance, the closer to the outside of the pseudo living body Q the position is. In FIGS. 15 to 17, the solid line curve illustrates the case where the drive current is 651.1 A, the broken line curve illustrates the case where the drive current is 569.5 A, the one dotted line curve illustrates the case where the drive current is 487.9 A, and the two dotted line curve illustrates the case where the drive current is 406.3 A.

[0091] As illustrated in FIG. 11, in the cross section of the pseudo living body Q, a remarkable temperature rise was observed at a position close to the outer circumference. As illustrated in FIGS. 15 to 17, in each of the pseudo living bodies QI to Q3, the temperature increased from the center toward the outside. The temperature rise varies according to the diameter of the pseudo living body Q, and the temperature rise increases as the diameter of the pseudo living body Q increases.

[0092] The above experimental results indicate that in the cancer treatment apparatus 10, the larger the cross-sectional area of the living body P to which the magnetic field is applied, the more easily the temperature rises. The reason why the temperature is more likely to rise as the cross-sectional area of the living body P to which the magnetic field is applied in the cancer treatment apparatus 10 is larger is considered to be that an eddy current is generated by electromagnetic induction since water occupying about 70% of the living body P is an electrolytic solution having electric conductivity. It isconsidered that the temperature rise is increased as a result of the increase in heat generated due to the eddy current in the vicinity of the outer circumference where a large eddy current is generated when the magnetic flux of the magnetic field generated by the magnetic field generator 100 is interlinked.

[0093] Since the temperature of the outer circumference of the living body P is the maximum value of the temperature due to the application of the magnetic field, the temperature information of the outer circumference of the living body P may be acquired as the information Tm on the temperature of the living body P. For example, the correspondence information 230 indicating a relationship between the maximum cross-sectional area of the living body P in which magnetic flux is interlinked and to which a magnetic field is applied and the maximum value of the temperature of the living body P when the magnetic field is applied is acquired in advance. The cancer treatment apparatus 10 can acquire, with reference to the correspondence information 230, the information Tm on the temperature which is the maximum value of the temperature of the living body P, based on the information on the largest cross-sectional area of the living body P to which the magnetic field is applied.

[0094] For example, the maximum temperature rise value within the treatment time can be estimated with reference to FIGS. 15 to 17 and the like, based on the diameter, the applied magnetic flux density, and the application time in the pseudo living body acquired in advance, and the applied magnetic flux density or the application time can be determined.

[0095] More specifically, a case where the sectional area of the living body P is such that the radius of the equivalent circle corresponds to 110 mm is considered. In this case, even when the temperature rises from 38°C (in the case of a dog) which is a normal temperature, the temperature rise needs to be kept to 4°C or lower in order to lower the body temperature to 42°C or lower. FIG. 16 indicates that the current value of the supplied drive current may be set to 569.5 A for the application time of the magnetic field of 30 minutes. The magnetic flux density generated by the applied current can be estimated by electromagnetic simulation.

[0096] Instead of FIGS. 15 to 17, curves of experimental results in which the horizontal axis represents the application time of the magnetic field may be prepared and used. When the current value of the supplied drive current is set to 569.1 A, and a sufficient treatment effect is not obtained, the treatment time can be shortened while increasing the supplied drive current.Second Embodiment of the Disclosure

[0097] Next, a cancer treatment apparatus according to a second embodiment of the present disclosure will be described. The same names and reference numerals as those in the above-described embodiment of the present disclosure denote the same or similarmembers or components, and a detailed description thereof will be appropriately omitted. The same can apply the embodiments described below.■Configuration Example of Cancer Treatment Apparatus According to Second Embodiment of the Present Disclosure>

[0098] FIG. 18 is a diagram illustrating an example of a configuration of a cancer treatment apparatus 10a according to a second embodiment of the present disclosure. FIG. 18 illustrates the cancer treatment apparatus 10a in a use state. The second embodiment of the present disclosure is different from the first embodiment of the present disclosure in that the second embodiment further includes a living body cooling unit 120 configured to cool the portion of the living body P to which a magnetic field is applied, and the controller 102 can further control an operation of the living body cooling unit 120 based on the information Pr on the cross section. Er the cancer treatment apparatus 10a, the portion of the living body P to which the magnetic field is applied is cooled by the living body cooling unit 120, and thus it is possible to further inhibit a temperature rise of the portion of the living body to which the magnetic field is applied.

[0099] The living body cooling unit 120 includes at least one of a blower or a cooler. The blower can cool the portion of the living body P by supplying air to the poilion of the living body P to which the magnetic field is applied. The cooler can cool the portion of the living body P by supplying cold air to the portion of the living body P to which the magnetic field is applied. However, the living body cooling unit 120 may be a cooling material disposed around a portion having the largest cross-sectional area among portions of the living body P to which the magnetic field is applied.

[0100] FIG. 19 is a block diagram illustrating an example of a functional configuration of a controller 102a included in the cancer treatment apparatus 10a. As illustrated in FIG. 19, the controller 102a includes a cooling controller 26. The function of tire cooling controller 26 is implemented by a processor of the CPU 121 or the like illustrated in FIG. 6 executing processing defined in a program stored in the nonvolatile memory such as the ROM 122 or the like.

[0101] The cooling controller 26 controls the operation of the living body cooling unit 120 based on the information Pr on the cross section. For example, the cooling controller 26 can acquire the information Tm on the amount of heat produced by the living body P based on the correspondence information 230 on the relationship between the information Pr on the cross section and the information Tm on the temperature of the living body P according to the application time of the magnetic field.

[0102] The cooling controller 26 can control the operation of the living body cooling unit 120 so as not to allow the surface temperature of the living body P to exceed the predetermined temperature upper limit value based on the information Tm on the amount of heat produced by the living body P. For example, the cook ng controller 26 can controlthe amount of air supplied by the living body cooling unit 120 to the portion of the living body P to which the magnetic field is applied. Alternatively, the cooling controller 26 can control the temperature of the air supplied by the living body cooling unit 120 to the portion of the living body P to which the magnetic field is applied. <Operation Example of Cancer Treatment Apparatus 10a>

[0103] FIG. 20 is a flowchart illustrating an example of the operation of the cancer treatment apparatus 10a. The description of the same operation as the operation of the cancer treatment apparatus 10 illustrated in FIG. 9 will be omitted as appropriate. The preparation in the cancer treatment apparatus 10a, the timing at which the living body P is placed on the treatment table 106 of the cancer treatment apparatus 10, the method of measuring the temperature of the portion to which the magnetic field is applied, the operation start condition, and the like are the same as those of the cancer treatment apparatus 10.

[0104] In step S25, the cancer treatment apparatus 10a obtains an application time during which the temperature does not reach the predetermined temperature upper limit value, by using a model created in advance in consideration of both the decrease in a living body-surface temperature corresponding to the cooling capability of the living body cooling unit 120 and the increase in the surface temperature of the portion of the living body P to which the magnetic field is applied. The cancer treatment apparatus 10a cools the portion of the living body P to which the magnetic field is applied by the living body cooling unit 120 during the obtained application time. Further, the head portion, which is the portion of the living body P to which the magnetic field is applied, may be cooled by further placing a cooling material around the head portion. The cooling of the living body P is continuously performed until the operation of the living body cooling unit 120 is stopped in step S31.

[0105] As described above, the cancer treatment apparatus 10a can treat the cancer of the living body P.

[0106] When the surface temperature of the living body P exceeds the predetermined temperature upper limit value during the treatment, the cancer treatment apparatus 10a can perform control such that the surface temperature of the living body P falls below the predetermined temperature upper limit value by temporarily interrupting the application of the magnetic field, changing the waveform of the drive current, or changing the cooling capability of the living body cooling unit 120.

[0107] The living body cooling unit 120 can also cool the artery of the living body P. For example, the living body cooling unit 120 has a cooling material, and can cool the carotid artery or the like by disposing the cooling material around the carotid artery or the like of the living body P. Thus, the temperature of the portion of the living body P to which the magnetic field is applied can be suitably reduced.

[0108] The living body cooling unit 120 can further cool the magnetic field generator 100.That is, the cancer treatment apparatus 10a may have a configuration including one cooling unit having both the function of the living body cooling unit 120 and the function of the coil cooling unit 103. This configuration can simplify the configuration of the cancer treatment apparatus 10a.Third Embodiment of the Disclosure

[0109] Next, a cancer treatment apparatus according to a third embodiment of the present disclosure will be described. The cancer treatment apparatus according to the third embodiment of the present disclosure is different from the cancer treatment apparatus according to the first embodiment in that the information on the cross section is information on an artifact which is included in the cross section of the portion of the living body P to which the magnetic field is applied and which is implanted or indwelled in an acquired manner. The cancer treatment apparatus according to the third embodiment of the present disclosure can suitably treat the living body P in which an artifact is implanted or indwelled inside of or on the body surface of the living body P.

[0110] In the cancer treatment apparatus according to the third embodiment of the present disclosure, the artifact includes a metal. The metal generates heat when a magnetic flux density of the magnetic field applied to the artifact changes. For example, when the metal is included in the artifact implanted or indwelled inside of or on the body surface of the living body P, when the magnetic flux density interlinked in the alternating magnetic field changes, an eddy current is generated in the metal included in the artifact by electromagnetic induction. The generation of the eddy current generates Joule heat in accordance with the electric resistance value of a substance and the eddy current value, and thus the artifact generates heat, which may adversely affect the portion of the living body P located around the artifact.

[0111] The metal included in the artifact refers to a material that generates heat when the magnetic flux density of the applied magnetic field changes. For example, the metal included in the artifact includes a material having an electrical conductivity of 4.0% lACS or higher, a non-ferrous metal such as aluminum, silver, or copper, an iron-based metal, or an alloy of a non-ferrous metal or an iron-based metal. These metalcontaining artifacts include at least one of dental fillings, dental coverings, implants, bridges, dentures, plates placed after craniotomy, medical staples, implantable pacemakers, implantable defibrillators, aneurysm clips, Swan-Ganz catheters, implantable electrocardiographic data recorders, metal threads, gastrointestinal clips, artificial heart valves, shunt valves, cochlear implants (inner implants), middle ear implants, implantable insulin pumps, continuous glucose monitors, ostomies, neurostimulation systems, coronary stents, aortic stents, ocular prostheses, artificial limbs, and internal fixation devices duringbone fracture.

[0112] When a patient has an artifact containing a metal inside the body or on the body surface, the amount of heat generated in the artifact is large, and therefore, it is necessary to predict in advance how much the alternating magnetic field will affect the treatment. When the magnitude and frequency of the magnetic flux density interlinked with the artifact, the application time, the volume of the artifact, the electrical conductivity, or the like are known, existing simulation software can be used to calculate respective values of the generated amount of heat and the surface temperature rise.

[0113] Here, FIG. 21 is a schematic top view illustrating a first example of a use state of a cancer treatment apparatus 10b according to the third embodiment of the present disclosure. In the first example illustrated in FIG. 21, the living body P has a filling or a covering (hereinafter, referred to as a filling 301) for dental treatment.

[0114] In the cancer treatment apparatus 10b, the controller 102 controls the drive current supplied from the power supply unit 101 based on the information on an artifact so as not to allow the temperature of the artifact to exceed a predetermined temperature upper limit value due to heat generated by the artifact induced by the magnetic field applied to the cross section including the artifact. Thus, the cancer treatment apparatus 10b can reduce the adverse effect of the heat generated by the artifact 300 on the portion of the living body P located around the artifact 300.

[0115] In the cancer treatment apparatus 10b, the information on the artifact includes position information of the artifact in the cross section, one of volume information or dimension information of the artifact, and physical property information of the artifact. For example, the physical property information of the artifact includes electric conductivity relating to the magnitude of heat generated when the magnetic field is interlinked. Since the information on the artifact includes these pieces of information, the cancer treatment apparatus 10b can predict the amount of heat generated in the artifact due to the magnetic field applied to the cross section including the artifact.

[0116] In the treatment of a malignant brain tumor, the head of the living body P is inserted into the magnetic field generator 100. In this case, the cancer treatment apparatus 10b obtains the Joule heat from the magnitude of the flux density interlinked with the filling 301 located outside the magnetic field generator 100, the size of the filling 301, and the electrical conductivity. The cancer treatment apparatus 10b calculates the temperature of the filling 301 using the information. When the calculation result of the surface temperature of the filling 301 exceeds a predetermined temperature, for example, 42 degrees, the cancer treatment apparatus 10b inhibits the temperature rise by reducing the magnitude of the magnetic flux density interlinked with the filling 301 or by cooling the filling 301 by bringing the cooling material into contact with the filling 301. When the temperature rises due to the artifact and the magnetic fluxrequired for the treatment cannot be applied, the cancer treatment apparatus 10b stops the treatment.

[0117] When a plurality of artifacts are present inside of or on the body surface of the living body P, the controller 102 acquires information on generated heat of each of the plurality of artifacts from the position information, one of the volume information or the dimension information, and the physical property information, and controls the drive current supplied from the power supply unit 101 such that the maximum value of the surface temperature of each of the plurality of artifacts does not exceed a predetermined temperature upper limit value. Thus, even when a plurality of artifacts are present inside of or on the body surface of the living body P, the cancer treatment apparatus 10b can reduce the adverse effect of heat generated by the artifacts 300 on the portion of the living body P located around the artifacts 300.

[0118] FIG. 22 is a schematic top view illustrating a second example of a use state of the cancer treatment apparatus 10b according to a third embodiment of the present disclosure. In the second example illustrated in FIG. 22, the living body P has two artifacts containing different types of metals. A stent 302 is incorporated in the aorta of the living body P. An implantable pacemaker 303 is disposed in the chest of the living body P.

[0119] In the treatment of a malignant brain tumor, the head of the living body P is inserted into the magnetic field generator 100. In this case, the cancer treatment apparatus 10b obtains the Joule heat from the magnitude of the magnetic flux density interlinked with the stent 302 and the implantable pacemaker 303 located outside the magnetic field generator 100, and the magnitude and the electrical conductivity of each of the stent 302 and the implantable pacemaker 303. The cancer treatment apparatus 10b calculates the respective surface temperatures of the stent 302 and the implantable pacemaker 303 using these pieces of information. When the surface temperature of each of the stent 302 and the implantable pacemaker 303 exceeds a predetermined temperature, for example, 42 degrees, the magnitude of the magnetic flux density interlinked with each of the stent 302 and the implantable pacemaker 303 is reduced, or the stent 302 and the implantable pacemaker 303 are cooled by bringing a cooling material into contact with the stent 302 and the implantable pacemaker 303, thereby inhibiting the temperature rise. The temperature rise of the stent 302 and the implantable pacemaker 303 needs to be estimated not only from the viewpoint of the adverse effect on the living body P in contact with the stent 302 and the implantable pacemaker 303 but also from the viewpoint of not impairing the functions of the stent 302 and the implantable pacemaker 303 themselves.

[0120] Next, an operation of the cancer treatment apparatus 10b according to the third embodiment of the present disclosure will be described with reference to FIGS. 23 and 24.FIG. 23 is a flowchart illustrating an example of an operation of the cancer treatment apparatus 10b according to the third embodiment of the present disclosure. FIG. 24 is a diagram illustrating an example of a method of obtaining a size and a position of an artifact from a plurality of continuous pieces of cross-sectional information.

[0121] When detecting an artifact such as the filling 301, the stent 302, or the implantable pacemaker 303, the cancer treatment apparatus 10b starts the operation illustrated in FIG. 23. For example, the cancer treatment apparatus 10b can detect the presence or absence of the artifact inside of or on the body surface of the living body P from a plurality of continuous pieces of cross-sectional information of the living body P obtained by virtually slicing the living body P. Alternatively, the cancer treatment apparatus 10b may perform an inspection using a metal detector before the start of the treatment to detect the presence or absence of an artifact. Further, the cancer treatment apparatus 10b may detect an artifact when the operator of the cancer treatment apparatus 10b receives, via the operation unit, information indicating that the living body P has an artifact in accordance with a self-report from the living body P or the like.

[0122] In step S41, the cancer treatment apparatus 10b calculates the size and the position of the artifact inside or on the body surface of the living body P from a plurality of continuous pieces of living body cross-sectional information of the living body P obtained by virtually slicing the living body P. The volume information or the dimension information of the artifact is acquired based on a predetermined number of pieces of cross-sectional information obtained by slicing at a thickness given in advance with respect to the living body P to which the magnetic field is applied.

[0123] FIG. 24 illustrates eight pieces of biological cross-sectional information Prl to Pr8 obtained by slicing along the height direction A0 of the living body P from the end portion of the magnetic field generator 100 above in the gravity direction with respect to the chest of the living body P, and pieces of positional information e l to e8 corresponding to the pieces of biological cross-sectional information Prl to Pr8. The cancer treatment apparatus 10b can calculate the shape and dimensions of the artifact 300 from the biological cross-sectional information Prl to the biological cross-sectional information Pr8 of the artifact 300 included in the slice information Sc2 to the slice information Sc8. In other words, the cancer treatment apparatus 10b can calculate the position, the shape, and the dimensions of the artifact 300 with respect to the magnetic field generator 100 using the biological cross-sectional information Prl to Pr8. The biological cross-sectional information Prl to Pr8 may be directly obtained from a cross- sectional image obtained from the CT scanner, or may be obtained from information such as a cross-sectional image obtained by the CT scanner, which is recorded in advance. The artifact 300 includes the filling 301, a stent 302, an implantablepacemaker 303, and the like.

[0124] Returning back to FIG. 23, the description will be continued. In step S42, the cancer treatment apparatus 10b calculates the amount of heat generated in the artifact 300 from the magnitude of the magnetic flux density of the alternating magnetic field interlinked with the artifact 300, and the size and the material of the artifact 300 when the alternating magnetic field application pattern having the flux density of the required magnitude is applied to the cancer-affected area (cancerous lesion) of the living body P for the required time. There are several types of application patterns of the magnetic flux density required for treatment. The type of the application pattern of the magnetic flux density includes, for example, a pattern in which the magnetic flux density is gradually increased from a low magnetic flux density at first. The plurality of application patterns of the magnetic flux density are determined in advance from the viewpoint of treatment effectiveness.

[0125] Subsequently, in step S43, the cancer treatment apparatus 10b calculates the surface temperature of the artifact 300 based on the calculation result of the amount of heat generated in the artifact 300.

[0126] Subsequently, in step S44, the cancer treatment apparatus 10b determines whether both of the following two conditions (a) and (b) are satisfied: (a) the amount of heat generated in the artifact and the temperature rise do not adversely affect the living body P in contact with the artifact, such as causing burns, and (b) the function of the artifact is not impaired.

[0127] When the cancer treatment apparatus 10b determines in step S44 that both the above two conditions are not satisfied (NO in step S44) and when the artifact 300 such as a dental filling is on the body surface, the cancer treatment apparatus 10b cools the artifact 300 by covering the dental filling with a cooling material for cooling the artifact 300 in step S45. When the artifact 300 is inside the body, the cancer treatment apparatus 10b cools the artifact 300 by bringing the cooling material into contact with the body surface near the artifact 300.

[0128] Subsequently, in step S46, the cancer treatment apparatus 10b calculates the amount of heat generated in the artifact using another candidate application pattern of the magnetic flux density. Thereafter, the operations after step S43 are performed again, and the operations are repeated until the cancer treatment apparatus 10b determines in step S44 that the both of the above conditions are satisfied.

[0129] On the other hand, when the cancer treatment apparatus 10b determines in step S44 that the above two conditions are satisfied (YES in step S44), the cancer treatment apparatus 10b determines whether the treatment is effective in step S47. For example, depending on the application pattern of magnetic flux density selected to inhibit the amount of heat generated in the artifact, sufficient magnetic flux density may not beapplied to the living body P and the treatment may not be effective. In step S47, the cancer treatment apparatus 10b estimates the effectiveness of the treatment according to the application pattern of the magnetic flux density and determines whether the treatment is effective.

[0130] When the cancer treatment apparatus 10b determines in step S47 that the treatment is not effective (NO in step S47), the cancer treatment apparatus 10b stops the cancer treatment in step S48, and then ends the operation.

[0131] On the other hand, when the cancer treatment apparatus 10b determines in step S47 that the treatment is effective (YES in step S47), the cancer treatment apparatus 10b performs the cancer treatment in step S49.

[0132] Subsequently, in Step S50, the cancer treatment apparatus 10b determines whether to end the operation. When the cancer treatment apparatus 10b determines in step S50 that the operation is not to be ended (NO in step S50), the cancer treatment apparatus 10b repeatedly performs the operation in step S49 until the cancer treatment apparatus 10b determines in step S50 that the operation is to be ended.

[0133] Note that the operation illustrated in FIG. 23 is included in the operation of step S13 (selecting a waveform) in FIG. 9 in the first embodiment of the present disclosure. In addition, the operation illustrated in FIG. 23 is included in the operation of step S23 (selecting a waveform) of FIG. 20 in the second embodiment of the present disclosure.

[0134] As described above, in the cancer treatment apparatus 10b, it is possible to reduce the adverse effect on the portion of the living body P located around the artifact 300 due to the heat generated by the artifact 300.

[0135] Although the preferred embodiments have been described in detail, the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope of the appended claims.

[0136] Embodiments of the present disclosure also include a cancer treatment system. For example, the cancer treatment system includes the above-described cancer treatment apparatus 10 and a cross-section information acquisition apparatus that acquires information Pr on a cross section of the living body P. The controller 102 controls the drive current supplied by the power supply unit 101 based on the information Pr on the cross section of the living body P acquired by the cross section information acquisition apparatus. A cancer treatment system may include the cancer treatment apparatus 10a, and the controller 102a may control the drive current supplied by the power supply unit 101 based on the information Pr on the cross section of the living body P acquired by the cross section information acquiring apparatus. These cancer treatment systems can also achieve the same effects as those of the above-described cancer treatment apparatus 10 or the cancer treatment apparatus 10a.

[0137] All the numbers such as ordinal numbers and quantities used in the description of the embodiments of the present disclosure are examples for specifically describing the technology of the present disclosure, and the present disclosure is not limited to the exemplified numbers. In addition, the connection relationship between the constituent components is an example for specifically describing the technology of the present disclosure, and the connection relationship for realizing the functions of the present disclosure is not limited thereto.

[0138] The division of the blocks in the functional block diagram is an example, and a plurality of blocks may be implemented as one block, one block may be divided into a plurality of blocks, or some of the functions may be moved to another block. Further, functions of a plurality of blocks having similar functions may be processed in parallel or in a time-division manner by a single piece of hardware or software. Further, some or all of the functions may be distributed to a plurality of computers.

[0139] Each function of the embodiments of the present disclosure can be implemented by one or higher processing circuitries. Here, the “processing circuitry” in the present specification includes a processor programmed to execute each function by software, such as a processor implemented by an electronic circuit, and a device such as an application specific integrated circuit (ASIC), a digital signal processor (DSP), a field programmable gate array (FPGA), or a conventional circuit module designed to execute each function described above.

[0140] The treatment by the cancer treatment apparatus 10, the cancer treatment apparatus 10a, or the cancer treatment apparatus 10b can be performed, for example, three times a week for three weeks, with the above-described treatment as one time. The effect of at least one of the growth inhibition of cancer cells and the inhibition of tumors by the treatment can be checked by a magnetic resonance imaging apparatus, a simple X-ray computer tomography (simple X-ray CT) apparatus, contrast-enhanced computer tomography, positron emission tomography (PET), or the like. Treatment may be performed at a frequency other than three times per week for three weeks, for example, daily treatment.

[0141] Aspects of the present disclosure are as follows, for example.<Aspect 1>

[0142] A cancer treatment apparatus for applying a magnetic field to a living body, the cancer treatment apparatus comprising:

[0143] a magnetic field generator configured to generate a magnetic field;

[0144] a power supply unit configured to supply a drive current to the magnetic field generator; and

[0145] a controller configured to control the drive current supplied from the power supply unit, based on information on a cross section of a portion of a living body to which themagnetic field generated by the magnetic field generator is applied.<Aspect 2>

[0146] The cancer treatment apparatus according to aspect 1, wherein the controller controls the drive current supplied from the power supply unit so as not to allow a surface temperature of the living body to exceed a predetermined temperature upper limit value, based on information on an amount of heat produced by the living body due to the application of the magnetic field, the information on the amount of heat produced by the living body being obtained based on the information on the cross section.<Aspect 3>

[0147] The cancer treatment apparatus according to aspect 2, wherein the controller acquires information on the amount of heat produced by the living body, based on correspondence information on a relationship between the information on the cross section and information on a temperature of the living body according to an application time of the magnetic field.<Aspect 4>

[0148] The cancer treatment apparatus according to aspect 2 or 3, wherein the predetermined temperature upper limit value is 40°C or higher and 45°C or lower.<Aspect 5>

[0149] The cancer treatment apparatus according to any one of aspects 1 to 4,

[0150] wherein the power supply unit supplies the drive current by outputting a predetermined waveform at a predetermined supply frequency, and

[0151] wherein the controller controls the drive current by varying at least one of a shape of the predetermined waveform or the predetermined supply frequency.<Aspect 6>

[0152] The cancer treatment apparatus according to aspect 5,

[0153] wherein the power supply unit supplies the drive current by outputting a rectangular wave at the predetermined supply frequency, and

[0154] wherein the controller controls the drive current by varying a duty ratio of the rectangular wave.< Aspect 7>

[0155] The cancer treatment apparatus according to the above aspect 5 or 6, wherein the predetermined waveform is associated with an allowable magnetic flux density, the allowable magnetic flux density being obtained by multiplying an upper limit magnetic flux density by an application time of the magnetic field applied by the magnetic field generator, and the upper limit magnetic flux density being associated in advance with the predetermined temperature upper- limit value relating to the surface temperature of the living body.<Aspect 8>

[0156] The cancer treatment apparatus according to any one of aspects 1 to 7, wherein the information on the cross section includes information on a cross-sectional area of the portion of the living body to which the magnetic field is applied.<Aspect 9>

[0157] The cancer treatment apparatus according to any one of aspects 1 to 8, wherein the information on the cross section is information on the largest cross-sectional area of the portion of the living body to which the magnetic field is applied.<Aspect 10>

[0158] The cancer treatment apparatus according to aspect 8,

[0159] wherein the information on the cross-sectional area is standardized using a circle having a cross-sectional area equal to that of the portion of the living body to which the magnetic field is applied, and

[0160] wherein a temperature upper limit value corresponding to one of an area, a radius, or a diameter of the circle is associated with a magnetic flux density of the magnetic field to be applied.<Aspect 11>

[0161] The cancer treatment apparatus according to aspect 8,

[0162] wherein the information on the cross-sectional area is standardized using an ellipse having a cross-sectional area equal to that of the portion of the living body to which the magnetic field is applied, and

[0163] wherein a temperature upper limit value corresponding to one of an area, a major axis, or a minor axis of the ellipse is associated with a magnetic flux density of the magnetic field to be applied.<Aspect 12>

[0164] The cancer treatment apparatus according to any one of aspects 1 to 11, wherein the information on the cross section is information on an artifact, the artifact being included in the cross section of the portion of the living body to which the magnetic field is applied and being implanted or indwelled in an acquired manner.<Aspect 13>

[0165] The cancer treatment apparatus according to aspect 12, wherein the information on the artifact includes position information of the artifact in the cross section, one of volume information or dimension information of the artifact, and physical property information of the artifact.<Aspect 14>

[0166] The cancer treatment apparatus according to the above aspect 12 or 13,

[0167] wherein the artifact includes a metal, and

[0168] wherein the metal generates heat when a magnetic flux density of the magnetic field applied to the artifact changes.< Aspect 15>

[0169] The cancer treatment apparatus according to aspect 14, wherein the metal has an electrical conductivity of 4.0% IACS or higher.<Aspect 16>

[0170] The cancer treatment apparatus according to any one of aspects 12 to 15, wherein the artifact includes at least one of a dental filling, a dental covering, an implant, a bridge, a denture, a plate to be placed after craniotomy, a medical stapler, an implantable pacemaker, an implantable defibrillator, an aneurysm clip, a Swan-Ganz catheter, an implantable electrocardiographic data recorder, a metal thread, a gastrointestinal clip, an artificial heart valve, a shunt valve, a cochlear implant, a middle ear implant, an implantable insulin pump, a continuous glucose meter, an artificial anus, a neural stimulation system, a coronary stent, an aortic stent, an artificial eye, an artificial limb, and an internal fixture at fracture.< Aspect 17>

[0171] The cancer treatment apparatus according to any one of aspects 12 to 16, wherein the controller controls the drive current supplied from the power supply unit, based on the information on the artifact, so as not to allow a surface temperature of the artifact to exceed a predetermined temperature upper limit value due to heat generated by the artifact induced by the magnetic field applied to the cross section including the artifact.<Aspect 18>

[0172] The cancer treatment apparatus according to the above aspect 13, wherein the physical property information of the artifact includes an electric conductivity relating to a magnitude of heat generated when the magnetic field is interlinked.<Aspect 19>

[0173] The cancer treatment apparatus according to the above aspect 13, wherein the volume information or the dimension information of the artifact is acquired based on a predetermined number of pieces of cross-sectional information obtained by slicing at a thickness given in advance with respect to the living body to which the magnetic field is applied.<Aspect 20>

[0174] The cancer treatment apparatus according to aspect 13, wherein when a plurality of artifacts are present inside the living body or on a body surface of the living body, the controller acquires information on heat generated by each of the plurality of artifacts from the position information, one of the volume information or the dimension information, and the physical property information, and controls tire drive current supplied from the power supply unit such that a maximum value of a surface temperature of each of the plurality of artifacts does not exceed a predetermined temperature upper limit value.<Aspect 21 >

[0175] The cancer treatment apparatus according to any one of aspect 1 to 20, further including a living body cooling unit configured to cool the portion of the living body to which the magnetic field is applied, wherein the controller is further capable of controlling an operation of the living body cooling unit, based on the information on the cross section.<Aspect 22>

[0176] The cancer treatment apparatus according to the above aspect 21, wherein the living body cooling unit includes at least one of a blower or a cooler.<Aspect 23>

[0177] The cancer treatment apparatus according to the above aspect 21 or 22, wherein the living body cooling unit is a cooling material disposed around a portion having a largest cross-sectional area among portions of the living body to which the magnetic field is applied.<Aspect 24>

[0178] The cancer treatment apparatus according to any one of aspect 21 to 23, wherein the living body cooling unit cools an artery of the living body.<Aspect 25>

[0179] The cancer treatment apparatus according to any one of aspect 21 to 24, wherein the living body cooling unit further cools the magnetic field generator.<Aspect 26>

[0180] The cancer treatment apparatus according to any one of the above aspects 21 to 25, wherein the cancer to be treated by the cancer- treatment apparatus is at least one of malignant glioma, malignant melanoma, malignant mesothelioma, or oral cancer.< Aspect 27 >

[0181] A cancer treatment system includes

[0182] the cancer treatment apparatus according to any one of aspects 1 to 26; and

[0183] a cross-section information acquisition apparatus configured to acquire information on the cross section, wherein the controller controls the drive current supplied by the power supply unit, based on the information on the cross section acquired by the crosssection information acquisition apparatus.

[0184] The present disclosure is not limited to the configurations described in the embodiments of the present disclosure, such as combinations of the configurations with other elements. These points can be changed without departing from the scope of the present disclosure, and can be appropriately determined according to the application form.

[0185] The present application is based on and claims the benefit of priorities of Japanese Patent Application No. 2023-124253 filed on July 31, 2023 and Japanese Patent Ap-plication No. 2024-082373 filed on May 21, 2024. The entire contents of these applications are incorporated herein by reference.Reference Signs List

[0186] 10, 10a, 10b cancer treatment apparatus21 input unit22 drive current controller23 storage unit230 correspondence information24 matching portion25 frequency controller26 cooling controller100 magnetic field generator100a coil lOOal metal piping100a2 insulating sheet100a3 protective sheet100b pipe lOOe end101 power supply102 102a controller103 coil cooling unit104 manifold105 hose106 treatment table109 non-conductive buffer120 living body cooling unit121 CPU122 ROM123 RAM124 HDD / SSD125 I / F126 matching circuit300 artifact301 filling302 stent303 implantable pacemakerA0 height directiondl-d3 diameter el-e8 position information f supply frequencyH period in which current value is highL period in which current value is lowP living bodyPr information on cross sectionPrl-Pr8 biological cross-sectional informationPS commercial powerQ, Q1-Q3 pseudo living bodySc2-Sc8 slice informationSW rectangular waveTm information on temperature

Claims

Claims

1. A cancer treatment apparatus for applying a magnetic field to a living body, the cancer treatment apparatus comprising: a magnetic field generator configured to generate a magnetic field; a power supply unit configured to supply a drive current to the magnetic field generator; and a controller configured to control the drive current supplied from the power supply unit, based on information on a cross section of a portion of a living body to which the magnetic field generated by the magnetic field generator is applied.

2. The cancer treatment apparatus according to claim 1, wherein the controller controls the drive current supplied from the power supply unit so as not to allow a surface temperature of the living body to exceed a predetermined temperature upper limit value, based on information on an amount of heat produced by the living body due to the application of the magnetic field, the information on the amount of heat produced by the living body being obtained based on the information on the cross section.

3. The cancer treatment apparatus according to claim 2, wherein the controller acquires information on the amount of heat produced by the living body, based on correspondence information on a relationship between the information on the cross section and information on a temperature of the living body according to an application time of the magnetic field.

4. The cancer treatment apparatus according to claim 2, wherein the predetermined temperature upper limit value is 40°C or higher and 45°C or lower.

5. The cancer treatment apparatus according to claim 1, wherein the power supply unit supplies the drive current by outputting a predetermined waveform at a predetermined supply frequency, and wherein the controller controls the drive current by varying at least one of a shape of the predetermined waveform or the predetermined supply frequency.

6. The cancer treatment apparatus according to claim 5, wherein the power supply unit supplies the drive current by outputting a rectangular wave at the predetermined supply frequency, and wherein the controller controls the drive current by varying a duty ratioof the rectangular wave.

7. The cancer treatment apparatus according to claim 5, wherein the predetermined waveform is associated with an allowable magnetic flux density, the allowable magnetic flux density being obtained by multiplying an upper limit magnetic flux density by an application time of the magnetic field applied by the magnetic field generator, and the upper limit magnetic flux density being associated in advance with a predetermined temperature upper limit value relating to a surface temperature of the living body.

8. The cancer treatment apparatus according to claim 1, wherein the information on the cross section includes information on a cross-sectional area of the portion of the living body to which the magnetic field is applied.

9. The cancer treatment apparatus according to claim 1, wherein the information on the cross section is information on a largest cross- sectional area of the portion of the living body to which the magnetic field is applied.

10. The cancer treatment apparatus according to claim 8, wherein the information on the cross-sectional area is standardized using a circle having a cross-sectional area equal to that of the portion of the living body to which the magnetic field is applied, and wherein a temperature upper limit value corresponding to one of an area, a radius, or a diameter of the circle is associated with a magnetic flux density of the magnetic field to be applied.

11. The cancer treatment apparatus according to claim 8, wherein the information on the cross-sectional area is standardized using an ellipse having a cross-sectional area equal to that of the portion of the living body to which the magnetic field is applied, and wherein a temperature upper limit value corresponding to one of an area, a major axis, or a minor axis of the ellipse is associated with a magnetic flux density of the magnetic field to be applied.

12. The cancer treatment apparatus according to claim 1, wherein the information on the cross section is information on an artifact, the artifact being included in the cross section of the portion of the living body to which the magnetic field is applied and being implanted or indwelled in an acquired manner.

13. The cancer treatment apparatus according to claim 12, wherein the information on the artifact includes position information of the artifact inthe cross section, one of volume information or dimension information of the artifact, and physical property information of the artifact.

14. The cancer treatment apparatus according to claim 12, wherein the artifact includes a metal, and wherein the metal generates heat when a magnetic flux density of the magnetic field applied to the artifact changes.

15. The cancer treatment apparatus according to claim 14, wherein the metal has an electrical conductivity of 4.0% IACS or higher.

16. The cancer treatment apparatus according to claim 12, wherein the artifact includes at least one of a dental filling, a dental covering, an implant, a bridge, a denture, a plate to be placed after craniotomy, a medical stapler, an implantable pacemaker, an implantable defibrillator, an aneurysm clip, a Swan-Ganz catheter, an implantable electrocardiographic data recorder, a metal thread, a gastrointestinal clip, an artificial heart valve, a shunt valve, a cochlear implant, a middle ear implant, an implantable insulin pump, a continuous glucose meter, an artificial anus, a neural stimulation system, a coronary stent, an aortic stent, an artificial eye, an artificial limb, and an internal fixture at fracture.

17. The cancer treatment apparatus according to claim 12, wherein the controller controls the drive current supplied from the power supply unit, based on the information on the artifact, so as not to allow a surface temperature of the artifact to exceed a predetermined temperature upper limit value due to heat generated by the artifact induced by the magnetic field applied to the cross section including the artifact.

18. The cancer treatment apparatus according to claim 13, wherein the physical property information of the artifact includes an electric conductivity relating to a magnitude of heat generated when the magnetic field is interlinked.

19. The cancer treatment apparatus according to claim 13, wherein the volume information or the dimension information of the artifact is acquired based on a predetermined number of pieces of cross-sectional information obtained by slicing at a thickness given in advance with respect to the living body to which the magnetic field is applied.

20. The cancer treatment apparatus according to claim 13, wherein, when a plurality of artifacts are present inside the living body or on a body surface of the living body, the controller acquires information on heat generated by each of the plurality of artifacts from the position in-formation, one of the volume information or the dimension information, and the physical property information, and controls the drive current supplied from the power supply unit such that a maximum value of a surface temperature of each of the plurality of artifacts does not exceed a predetermined temperature upper limit value.

21. The cancer treatment apparatus according to claim 1, further comprising: a living body cooling unit configured to cool the portion of the living body to which the magnetic field is applied, wherein the controller is further capable of controlling an operation of the living body cooling unit, based on the information on the cross section.

22. The cancer treatment apparatus according to claim 21, wherein the living body cooling unit includes at least one of a blower or a cooler.

23. The cancer treatment apparatus according to claim 21, wherein the living body cooling unit is a cooling material disposed around a portion having a largest cross-sectional area among portions of the living body to which the magnetic field is applied.

24. The cancer treatment apparatus according to claim 21, wherein the living body cooling unit cools an artery of the living body.

25. The cancer treatment apparatus according to claim 21, wherein the living body cooling unit further cools the magnetic field generator.

26. The cancer treatment apparatus according to claim 1, wherein the cancer to be treated by the cancer treatment apparatus is at least one of malignant glioma, malignant melanoma, malignant mesothelioma, or oral cancer.

27. A cancer treatment system comprising: the cancer treatment apparatus according to any one of claims 1 to 26; and a cross-section information acquisition apparatus configured to acquire information on the cross section, wherein the controller controls the drive current supplied by the power supply unit, based on the information on the cross section acquired by the cross-section information acquisition apparatus.

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