記述言語：英語   出版者・発行元：The Magnetics Society of Japan  

Research and development is actively underway on contactless power transmissions as methods of charging electric vehicles (EVs). Coils with the same structure for both primary and secondary sides have generally been investigated for contactless charging of EVs. When contactless power transmission becomes more common, it may be apparent that the coil structure may differ according to the model of EVs. Therefore, developing primary coils that can respond to a variety of secondary coils in contactless charging of EVs would be beneficial. We previously reported that magnetic couple exists between heterogeneous coils by dislocation. We studied the coupling coefficient and efficiency between heterogeneous coils depending on the position in this research.

DOI： 10.3379/msjmag.1402R003

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記述言語：英語   出版者・発行元：公益社団法人 日本磁気学会  

  Technology for wireless power transmission via electromagnetic induction is expected to be useful for many kinds of electric equipment. In this technology, an alternating magnetic field shared between the primary and secondary coils is necessary. However, the leakage magnetic field caused by this linkage may negatively affect electronic circuits and other devices near the wireless power transmission unit. This paper describes a wireless power transmission coil shape that has high efficiency and a restraining leakage magnetic field. The main result is that a figure-8 coil with a ferrite plate reduces leakage magnetic field strength while maintaining efficiency of wireless power transmission.

DOI： 10.3379/msjmag.1312R003

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記述言語：日本語   出版者・発行元：The Magnetics Society of Japan  

Many engineers have recently been developing battery chargers that have employed contactless power transmission techniques for consumer products. These have contributed to improving the convenience of charging batteries. We investigated methods of electromagnetic induction for transmission from several different types. The efficiency of power transmission was dependent on the quality factors of two coils and the coupling coefficient between them. Previous reports indicated that copper clad aluminum wire (CCAW) and magnetic-plated wire (MPW) can improve quality factors. We need to select these materials appropriately according to our individual needs in order to achieve highly efficient power transmission systems. Therefore, we examined the performance of three materials for power transmission coils in this research and found a method of selecting materials to construct a highly efficient system of transmission with a broad range of coupling coefficients.

DOI： 10.3379/msjmag.1305R001

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1109/TMAG.2013.2242858

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記述言語：日本語   出版者・発行元：The Magnetics Society of Japan  

Technology to achieve, contactless power transmission that can improve the utility of power feeding has recently attracted a great deal of attention. We researched electromagnetic induction as a method of contactless power transmission. This method is based on simple and standard technology. We propose a method that uses two coils on the secondary side, which we called the LC-Booster method. This method consists of using an LC-resonator and pick-up coil connected to the load, and it has the advantage of sequential matching by changing the coupling coefficient between the LC-resonator and pick-up coil. This paper reports the effect of additional capacitance connected to the pick-up coil to aim for a more effective LC-Booster method.

DOI： 10.3379/msjmag.1305R002

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1063/1.3676046

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）  

DOI： 10.1109/IMWS.2012.6215779

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記述言語：日本語   出版者・発行元：The Magnetics Society of Japan  

Electric vehicle (EVs) have been attracting a lot of attention as part of the proactive approach to global environment problems being taken around the world. However, existing EV batteries have not yet achieved high enough energy density of and thsu, EVs are not very common. The construction of the EV charging infrastructure is a key factor in solving this problem. Our objective is to construct charging system for a contactless power station for moving EVs, focusing on of safe handling of the high-power equipment and reducing the stop time required for charging. The electric power needed to operate this system is transmitted from the power transmission coil, which is located on the road, to receiving coil, which is installed on the underside of the EV. We designed and constructed a one-fifth of an actual vehicle scale model coil, and we used it to investigate the coupling factor and efficiency between coils when the gap between the power transmission coil and a receiving coil was changed.

DOI： 10.3379/msjmag.1205R014

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記述言語：日本語   出版者・発行元：The Magnetics Society of Japan  

Functional electrical stimulation (FES) is a therapy used to rehabilitate patients with lost movement functions, and to apply stimulations. We adapted a method of implanted direct feeding method to apply stimulation as part of this therapy. Stimulus energy and signals for controlling devices are applied to devices by utilizing a mounted system using magnetic coupling. Power feeding is presently carried out with a serial resonance circuit in the method of direct feeding. Two feeding coils are used for the upper and lower arms individually in order not to disturb the movement in the joint of the elbow. Declination of resonance from variations in coupling interference from the movement of feeding coils is a problem. To solve it, we used a method that reduced variations in coupling interference by using a short coil between feeding coils. We report here the result of experiments conducted on this method.

DOI： 10.3379/msjmag.1205R017

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記述言語：日本語   出版者・発行元：The Magnetics Society of Japan  

Mobile devices are not sufficiently convenient yet because they need to be charged frequently. It is especially inconvenient when their battery power has slightly discharged. We have researched a contactless power transmission system (CLPS) for a station-type charger in mobile devices. This system can be installed in many types of mobile devices. We tested the transmission system of the station-type charger using a coil within a mobile device and confirmed that the system was effective and provided steady transmission of electrical power.

DOI： 10.3379/msjmag.1201R003

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1109/TMAG.2011.2157961

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1109/TMAG.2011.2156399

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記述言語：日本語   出版者・発行元：The Magnetics Society of Japan  

Functional electrical stimulation (FES) is the therapy used in the rehabilitation of lost movement functions, and to apply stimulation, the implanted direct feeding method was adapted. In this method, stimulus energy and signals for controlling devices are applied to the devices by a mounted system using magnetic coupling. In a previous study, the mounted coil was developed to be able to generate the magnetic flux for supplying energy and communication with the time-division exciting method. However, this exciting method reduces the communication speed to half of the specified speed of the mounted communication coil. In addition, the previous driving method requires an equal number of inverters as communication coils, which consumes a lot of energy. To address these problems, a new driving and exciting method have been proposed, in which the communication speed is not reduced and it needs a single inverter to excite coils. In this report, these new methods are introduced, and the experimental results show that the possibility of the whole area communication for the direct feeding method and the single source driving method.

DOI： 10.3379/msjmag.1102R009

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記述言語：日本語   出版者・発行元：The Magnetics Society of Japan  

Hyperthermia is a cancer therapy that necrotizes cancerous tumors with heat. Functional Hyperthermia (soft-heating hyperthermia) is one type that implants small elongated elements inside the body. The element generates heat induced by a high-frequency magnetic field produced by exciting coils and is therefore a less-invasive method.</br>  The most heat is generated when the element's major axis is parallel to the direction of the incoming magnetic field. However, a single coil can be excited in a constant direction. Therefore, an exciting system to generate multidirectional magnetic fields is needed. We developed this exciting system using two coils and two frequencies. The combination of two frequencies and an easy way of estimating the heating value were examined. The profiles of various combinations of these two frequencies were measured and as a result, we found the heating value was much the same, if the sum of the two frequencies was the same. Using a single solenoid coil and the magnetic field of strain waveform enabled us to successfully of and easily estimate the heating value.

DOI： 10.3379/msjmag.10R055zH

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記述言語：日本語   出版者・発行元：The Magnetics Society of Japan  

Radiation is one treatment for cancer, and it is used together with other therapies. The accuracy of irradiation has recently improved due to advances in image diagnosis processors such as CT, MRI, and external irradiation machines. However, real-time data on internal doses near the focus are required to treat cancers effectively. Therefore, an implantable dosimeter with a wireless signal transmission system is needed. The dosimeter also needs a wireless power feeding system to drive the internal circuit. However, depending on where the internal elements are placed, there may be cases when power feeding cannot be achieved with conventional solenoid or spiral coils. To solve this problem, we suggest a new model for the feeding coil that can generate multi-directional excitation. If the feeding coil can generate multi-directional excitation, we can supply sufficient power to drive the internal circuit to the internal element. We studied an external feeding circuit and measured the feeding area where we could supply power to the internal element regardless of the position or direction of the internal elements that had been installed.

DOI： 10.3379/msjmag.1106R013

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記述言語：英語  

DOI： 10.3191/thermalmed.27.41

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記述言語：日本語   出版者・発行元：公益社団法人 日本磁気学会  

&nbsp;&nbsp;The technology to transfer power wirelessly in a variety of fields has attracted people's attention recently because it increases the convenience of many devices. There are many methods of wireless power transfer including microwaves, magnetic resonance, electric resonance, and electromagnetic induction. The method we applied is that of electromagnetic induction. We can more easily supply devices with large reserves of power by means of this method than with other techniques of power transfer. We discuss here the relationship between efficiency and the figure-of-merit in a secondary-side resonance circuit and propose a matching technique to achieve maximum efficiency.

DOI： 10.3379/msjmag.1102R012

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記述言語：日本語   出版者・発行元：The Magnetics Society of Japan  

Functional electrical stimulation (FES) is a therapy used in the rehabilitation of lost-movement functions by applying electrical stimulation to paralyzed extremities. We adapted the implanted direct-feeding method to apply stimulation, in which small implanted stimulators were placed under the skin at a depth of 20 mm, and stimulus energy and signals to control the devices were applied to them with a mounted system using magnetic coupling. This method had two main advantages in that it had no percutaneous points and it provided highly precise stimulation. The sizes of the mounted coil and the implanted coil were quite different so that the coupling between each was extremely low. To retain this disadvantage, the implant coil had a high-aspect ratio ferrite core, which gave the implant coil a magnetic direction for easy feeding and communication. Therefore, the magnetic fluxes from the mounted coil for feeding and communication had to be generated in the same direction inside the mounted coil. We propose a mounted coil that is able to generate such a magnetic flux, and tested and verified the possibility of whole area feeding and communication with it.

DOI： 10.3379/msjmag.1002R0011

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記述言語：日本語   出版者・発行元：The Magnetics Society of Japan  

Hyperthermia is a cancer therapy that necrotizes cancerous tumors with heat. The soft-heating method is one type of hyperthermia implanting small elongated elements inside the body. The heat element consists of thermosensitive ferrite with a metallic ring. The element generates heat induced by a high-frequency magnetic field produced by the exciting coils. The most heat is generated when the element's major axis is parallel to the direction of the magnetic field, but the solenoidal and spiral coils may be excited in a nearly constant direction. It is difficult to heat the elements efficiently with these coils. Therefore, we need a coil construction that can excite the elements efficiently without having to depend on the direction of the heat elements. In this paper, we discuss a multicoil construction we examined to generate multidirectional magnetic fields. Our group advanced a method of reducing induced current that could drive safely even if it was electromagnetically-coupled. We also examined a therapeutic coil model with this method that had strong electromagnetic coupling. As a result, multidirectional magnetic fields could be generated by using the therapeutic model.

DOI： 10.3379/msjmag.1003R003

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記述言語：日本語   出版者・発行元：The Magnetics Society of Japan  

Therapeutic electrical stimulation (TES) is electrical stimulation to treat disorders caused by abnormalities in nerves. We have been researching implanted TES that stimulates objective nerves directly inside the body. Prior to this, separate coils were used in implanted TES to transmit power and signals. However, the two-coil system presents several problems. For example, it is necessary to carefully design both coils because the one for power transmission is more powerful than the one for signal transmission, and the power magnetic field interferes with the signal magnetic field. That makes it extremely difficult to design these coils flexibly. To solve this problem, we have begun research on establishing a different method that would increase the flexibility with which coils could be designed. The concept underlying this new approach was to transmit power and signals simultaneously with the same magnetic field. To achieve this, we superimposed the signal on the power. In the first step in this research, we ascertained that this superimposed system of transmission could drive the system for implanted TES.

DOI： 10.3379/msjmag.1003R009

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記述言語：日本語   出版者・発行元：The Magnetics Society of Japan  

In radiation therapy, excessive exposure to radiation occurs because the dose actually delivered to the tumor is not known. As a result, a patient suffers from side effects. To solve this problem, a system is needed in which the delivered dose is measured inside the body and the dose data are transmitted from inside to outside of the body during radiation therapy. If such a system is realized, it will be possible to treat cancer safely and effectively. The proposed real-time internal radiation dose measurement system consists of an implantable dosimeter, a wireless communication system, and a wireless feeding system. In this study, a wireless communication system that uses magnetic fields was investigated. As a result, a communication distance of 200 mm was obtained. It was confirmed that radiation dose data could be transmitted outside the body when the communication distance is the required 200 mm.

DOI： 10.3379/msjmag.0903RH8039

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1063/1.3075566

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記述言語：日本語   出版者・発行元：The Magnetics Society of Japan  

Hyperthermia is a cancer therapy that necrotizes cancerous tumors by means of heat. The soft-heating method is one type of hyperthermia in which a small elongated element is implanted inside the body. The element generates heat induced by high frequency magnetic field produced by an exciting coil allows the element to generate heat. The most heat is generated when the element's major axis is parallel to the direction of the magnetic field, but solenoid and spiral coils may be excited in a nearly constant direction. It is therefore difficult to heat efficiently using these coils. What is required is a coil that can excite the element efficiently without depending on the position and direction of the heat element. In this paper, we examine a multidirectional exciting coil. We have concluded that, in case of using orthogonal type coil, multidirectional magnetic fields can be generated by being driven each coil with current phase difference or with different frequencies.

DOI： 10.3379/msjmag.0903RH8038

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記述言語：日本語   出版者・発行元：公益社団法人日本磁気学会  

Some therapeutic methods of cancer therapy have been developed. Of these, we tried soft-heating hyperthermia. We created a thermosensitive magnetic powder coated with Ag as a heater for cancer therapy. This powder can generate more heat due to losses through hysteresis and inductive current than magnetic powder alone. We could also control the temperature of the heater by using the Curie point. Consequently, we used thermosensitive magnetic powder coated with Ag. This powder composed of Ni-Cu-Zn ferrite granules and Ag was used as the heater for hyperthermia. The Ag coating was achieved by baking Ag paste on the powder. We examined what effect the metallic thickness had in relation to the thermosensitive magnetic powder coated with Ag for cancer therapy. We confirmed that we could increase the heating properties of the powder by selecting the metallic thickness.

DOI： 10.3379/msjmag.0901RH8041

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1109/TMAG.2008.2003011

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1063/1.2832612

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記述言語：日本語   出版者・発行元：公益社団法人日本磁気学会  

Hyperthermia is a method of treating cancer that uses heat to destroy tumors. Soft heating has been proposed as one method of treating hyperthermia. This is where the thermosensitive ferrite inserted into the tumor as a heating element produces heat in a high-frequency magnetic field. We applied soft heating in this study. Heat element developed can control temperature automatically, referring the Curie-point of the thermosensitive ferrite. The heat element consists of a thermosensitive ferrite and metal ring coated on it. The purpose of the metal ring wrapped to ferrite is to increase heat quantity compared with that of ferrite alone. The effect of the heat element in murine B-16 Melanoma model is examined. As a result, the tumors of mice were locally heated to the point at which tumor is necrotized.

DOI： 10.3379/msjmag.32.439

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1109/TMAG.2007.893861

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記述言語：日本語   出版者・発行元：The Magnetics Society of Japan  

Hyperthermia is a method of treating cancer that uses heat to destroy tumors. Soft heating has been proposed as one method of treating hyperthermia. This is where the thermosensitive ferrite inserted into the tumor as a heating element produces heat in a high-frequency magnetic field. Although the heater needs to be implanted the heater in the tumor tissue, there are various advantages to soft heating, such as easy retreatment, localized heating of the tumor, and a low degree of invasiveness. We applied soft heating in this study. We created a complex heater composed of thermosensitive ferrite wound on a metallic ring. It produced a greater amount of heat due to losses through hysteresis and inductive current than thermosensitive ferrite alone. We could also control the temperature of the heater by using the Curie-point. To use this technique, it is necessary to miniaturize the element and achieve optimal performance. We demonstrated that the proposed heater has superior performance and operation at high power.

DOI： 10.3379/jmsjmag.31.288

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記述言語：日本語   出版者・発行元：The Magnetics Society of Japan  

Hyperthermia is a therapeutic method that necrotizes cancer tumora by heating. We developed an implantable heat element for tumors, which is excited by applying an external magnetic field. The previously proposed soft-heating method of hyperthermia features the use of thermosensitive ferrite as the heat element. This means that the heat element can control the temperature automatically by referring to the Curie temperature of the thermosensitive ferrite. The heat element consists of a thermosensitive ferrite and a metal ring. For wrapped around the ferrite to increase the heat quantity. For application to superficial tumors, the utility of a plane-type spiral coil was examined. As a result, it was confirmed that the influence of the magnetic gradient in excitation does not greatly influence the temperature characteristic. Moreover, arranging the magnetic ferrite in a plane-type coil is effective in easing the excitation current value and the directivity of the magnetic flux.

DOI： 10.3379/jmsjmag.31.389

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記述言語：日本語   出版者・発行元：The Magnetics Society of Japan  

The energy source of the artificial heart is located outside body. Moreover, signal transmission system is important to control the implanted device and to monitor inside body environment. Transcutaneous power and signal transmission system is useful, because it doesn't penetrate through the skin. The signal transmission coil, which is called figure-eight coil, is set in power transmission coil. Induced voltage from power transmission in signal transmission coil can be canceled by this signal transmission coil, because the direction of figure-eight coil is opposite in each loop. We design signal transmission circuit by using PIC (Peripheral Interface Controller), so we examine character of signal transmission in power transmission system.

DOI： 10.3379/jmsjmag.31.385

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1063/1.2177424

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1109/TMAG.2005.854861

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