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The purpose of this study is to develop a precise-loss circuit simulation model for ferrite inductors and transformers used in power converters. The power loss in ferrite is mainly due to the magnetic losses of hysteresis and dynamic magnetic losses. The B-H loop becomes narrower with decreasing excitation frequency. However, even at frequencies lower than 1 kHz, the B-H loop exhibits a certain minimum width. This loop is referred to as the DC hysteresis loop or simply the hysteresis loop. The dynamic magnetic loss is obtained by subtracting the hysteresis loss from the B-H loop area measured at a frequency above 1–10 kHz. Magnetic field intensity, Hf, causing the dynamic magnetic loss is defined as (dB/dt)A, f, where kf is the dynamic magnetic loss parameter. Hf is obtained as a function of B and dB/dt from the measured B-H loops under rectangular waveform voltage excitation. Using the Hf data, we simulated B- H loops under sinusoidal waveform voltage excitation where the instantaneous value of dB/dt changes at every moment in time. The simulated and experimental results were in good agreement. The results of the present study contribute to the development of a precise-loss nonlinear simulation circuit model for ferrite-applied magnetic devices. The model can be used in the design of power electronics.

A transformer possesses several functions, such as insulation, voltage transformation, impedance transformation, and so forth. Similarly, an inductor or a reactor is used for current ripple reduction, resonance, energy storage, and so on. Those magnetic power devices are separately placed and connected to circuitries so far. On the other hand, cost reduction is strongly required in designing power supplies. Therefore, power circuit engineers always consider the ways to reduce the number of circuitries.In this article, we introduce recently developed technologies that reduce the number of circuitries in DC-DC converters by synthesizing the functions of a transformer and an inductor.

The ability to predict anti-tumor immune responses at local tumor growing sites using only peripheral blood specimens would be helpful in determining therapeutic options for patients with solid tumors. Here, we show that the glutathione intracellular content (icGSH) of peripheral monocytes (Mo) correlates positively with T cell infiltration within tumor islets and overall survival in patients with colorectal carcinoma. IcGSH redox status was determined in CD14(+) Mo prior to surgery by staining with monochlorobimane. The tumor-infiltrating T cells (TIL) were quantified as CD45RO(+) T cells in resected tumors using paraffin sections. A positive association was found between the GSH index and TIL in tumor islets (P0.001). The 50% cut-off value for the GSH index, that is the determinant between TIL presence or absence in tumor islets, was calculated to be almost 0.7 through logistic regression analysis. Mo with a GSH index ofor =0.7 were termed reductive (R)-Mo, and those with0.7 were designated as oxidative (O)-Mo. Cox's proportional hazards regression analysis of patients with R-Mo or O-Mo prior to surgery, and the presence or absence of TIL, was found to correlate significantly with the overall survival rate of stage II and III patients. Kaplan-Meier analysis also showed a significant correlation. These results indicate that the Mo icGSH index is a useful biomarker parameter for better understanding the host/tumor relationship prior to surgery, thereby enabling the development of an individual patient-oriented therapeutic strategy.

The B-H loop of ferrite becomes narrower with a decrease in the excitation frequency. However, even at frequencies lower than 1 kHz, the B-H loop exhibits a certain minimum width, which is referred to as the (DC) hysteresis loop, and its area corresponds to the hysteresis loss. The dynamic magnetic loss is obtained by subtracting the hysteresis loss from the B-H loop area measured at a frequency above 1–10 kHz. The temperature characteristics of the hysteresis and dynamic magnetic losses are determined to be experimentally different, which suggests that the mechanism for the generation of dynamic magnetic loss is not exactly the same as that for the hysteresis loss. The dynamic magnetic loss is expressed using the dynamic magnetic loss parameter, which is a function of B and its time derivative, dB/dt. The dynamic magnetic loss parameter is measured under excitation with a rectangular waveform voltage. A ferrite core of TDK PC47 was used and the maximum magnetic flux density Bm, was set to 350 mT. The measured dynamic magnetic loss parameter was experimentally verified to be one of the intrinsic characteristics of ferrite and was also validated for cases of excitation with sinusoidal waveform voltages.

An integration of an output choke with a transformer has been attempted to miniaturization of forward converter. For example, a forward active clamp topology using a four-legged core has been proposed. This paper proposes a design methodology for this four-legged transformer. By means of an analysis, it was found that the magnetic flux in the leg, which acts as a output choke, has both dc and ac component. When the core of a transformer was designed using the proposed method, it was possible to reduce the footprint of the magnetic device in comparing with that of a conventional converter.

Efficiency improvement and cost reduction are important requirements for the design of DC-DC converters. Zero voltage switching is one good solution for increasing efficiency, and an active clamp circuit is useful for implementing it effectively. A cost reduction could be achieved by devising a new transformer that functions not only as a conventional transformer but also as a DC reactor that reduces the switching device peak current. However, no design methodology for such a transformer has yet been established. This paper proposes a novel method that simulates the operations of a DC-DC converter and estimates the magnetic flux distribution in the new transformer. The magnetic circuit of the transformer is transformed into its equivalent electric circuit with two ideal transformers. Circuit simulation results agree fairly well with experimental ones.

Ferrite cores are used for power electronics circuits operating under excitation conditions of frequency ranging from hundreds of kilohertz to several tens of megahertz. Development of a mathematical model enabling the estimation of the power loss of ferrites in high-frequency regions, contributes to the designing of power circuits. The power loss in high-frequency regions consists of hysteresis and dynamic magnetic losses. Although hysteresis loss does not depend on the excitation frequency, the dynamic magnetic loss increases with increasing excitation frequency. The dynamic magnetic loss parameter, λf, has been introduced for identifying the power loss in high-frequency regions. In this study, λf − dB/dt characteristics are experimentally obtained by a newly introduced hysteresis model that uses a normal distribution function. It is found that the λf − dB/dt characteristics do not depend on the size of B − H loops. The instantaneous power loss of a ferrite core in the high-frequency region can be calculated using the λf − dB/dt characteristics. Copyright © 2007 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.

The measurement of the iron loss in ferrites is important for developing high-efficiency switching power supplies. The authors have proposed the dynamic magnetic loss parameter, λf, for evaluating the iron loss in ferrites. In previous studies, the parameter was assumed to be a constant value for an individual ferrite material and defined for one period of a small B–H loop. In this paper, assuming that λf is a function of the time derivative of the magnetic flux density, dB/dt, a novel measurement method of λf of a Ni-Zn ferrite is proposed using rectangular wave voltage excitation and the Fourier expansion of the exciting current. In order to realize an iron loss measurement system with the rectangular wave voltage excitation, a high-frequency FET inverter has been developed. The results of measuring λf show that it is uniquely determined by dB/dt regardless of the B–H loop size. The measured dB/dt characteristics of λf are applied to practical examples for switching power supplies and sinusoidal wave voltage excitations. Their experimental and computational results coincide and it is clarified that the measured dB/dt characteristics are effective and useful. © 2006 Wiley Periodicals, Inc. Electr Eng Jpn, 156(1): 1–6, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20101

The induction of interleukin-12 (IL-12) responsiveness in T cells depends on T cell receptor (TCR) triggering, and is regarded as a parameter of recently TCR-sensitized T cells. Here, we investigated whether IL-12 responsiveness could be detected in freshly prepared T cells from tumor-bearing patients, and if so whether such patients exhibited additional immunological parameters related to IL-12 responsiveness. CD4(+) and CD8(+) T cell populations from an appreciable proportion of tumor-bearing patients exhibited high levels of IL-12 responsiveness as evaluated by IL-12-stimulated interferon-gamma (IFN-gamma) production. T cell populations with high IL-12 responsiveness were observed in the group of patients with moderate to large tumor mass or tumor metastases rather than in patients with small tumors. The frequency of such a T cell population was also lower in post-surgery tumor-free patients, showing the correlation between IL-12 responsiveness and the presence of a certain extent of tumor burden. More importantly, a higher incidence of IL-12 responsiveness was observed in tumor-bearing patients exhibiting detectable plasma IL-12 levels, and correlated with IL-18 responsiveness. T cell IL-12 and IL-18 responsiveness is induced by TCR triggering and subsequent IL-12 stimulation respectively. Furthermore, TCR-triggered T cells stimulate antigen-presenting cells (APC) to produce IL-12. Therefore, the present observations suggest that an immune response loop from TCR sensitization to the induction of IL-12/IL-18 responsiveness via IL-12 production operates in tumor-bearing patients, particularly in those with relatively large tumor burdens.

In this paper, we propose the power supply and the bi-directional information transmission system using ultrasonic. Ultrasonic does not interfere with the electronic circuits of implanted devices and is safe for a living body. Previously, we have clarified experimentally that ultrasonic is applicable to power and information transmission. This study deals with improving information transmission speed from the inside to the outside of the body. The new system uses two transmission paths, Path 1 and Path 2. Each path consists of a pair of piezo oscillators. Path 1 transmits a carrier wave and Path 2 echoes back the inside information. As a result, the transmission speed increases to 9.6 Kbps from 600 bps without errors. Additionally, several types of information, such as text, static and motion image files can be transmitted. The proposed system can be applied to various medical applications.

A novel method for the contactless sheet resistance measurement is presented. The sheet resistance of a silicon wafer has been conventionally measured using the four-point probe technique. However, the high mechanical pressure of the probe causes pitting and structural damage in semiconductor wafers. Therefore, to prevent such damage, a contactless measurement technique was devised that employs electromagnetic induction. The conventional contactless method is implemented using high frequency sinusoidal magnetic excitation with a Robinson marginal oscillator as an excitation current supply. However, the oscillator gain drifts due to an increase in temperature during continuous scanning of the wafer, which causes an error in the resistance measurement. The proposed method does not require an analogue electronic circuit; therefore, more precise measurement is expected. This novel method utilizes an impulse voltage to generate an eddy current in the sheet under test. However, no high voltage source is required, because the impulse voltage is generated by cutting off the DC current flowing through the winding of a ferrite core facing the sheet.

A novel contactless method for measurement of the sheet resistance of a semiconductor wafer, that utilizes pulse voltage excitation, has been proposed by one of the authors. This novel method was applied and a prototype instrument was developed that can measure sheet resistance under 5 mQ/sq, which is the same as the smallest value for the conventional contactless method.

In order to compensate for the reactive power and to eliminate harmonic components of the current in single phase power lines, an active power filter with an FIR (finite impulse response) digital filter technique is worked out. The validity of the proposed method is studied by computer simulations and model experiments. In the experiments, the active power filter which consists of a single-phase full-bridge power MOS-FET inverter is used. The inverter is controlled by a DSP (digital signal processor). The active power filter is connected in parallel between the voltage source and the full-bridge diode rectifier as a load. Digital filtering operation done by the DSP provides the load current of the fundamental frequency. The voltage-in-phase load current of the fundamental frequency is computed with the phase signal of the line voltage. Subtracting the voltage-in-phase load current from the total load current, the reference of the compensation current is obtained. Comparing the reference and measured compensation currents, the voltage pulse width pattern of the inverter is generated.The digital filter used in this study was designed as a band-pass filter of 50Hz. Its filter length and the sampling frequency are 200 and 10kHz, respectively. Therefore, the time length of the sampling data of the measured load current required for the digital filtering operation is 20ms, i.e. one period for 50Hz. In other words, the transient response time for the reactive power compensation including harmonic current elimination is 20ms.With the active power filter, both of the third and fifth harmonics of the source current were reduced by 1/7.

The complex permeability of ferrites is frequency dependent. The real part of the complex permeability deteriorates in a high frequency range and the imaginary part has a peak after starting the deterioration. This paper examines the possibility that the frequency characteristics for some ferrites can be approximately derived from a first-order linear differential equation for the magnetic field intensity and magnetic flux density. The first-order differential equation is expressed by the reciprocal of the complex permeability and provides first-order magnetic and electric circuits for ferrite cores. In contrast with the commonly used series Rs-Ls, circuit for the cores, obtained from B = (μ′ − jμ′)H, the first-order electric circuit derived consists of an inductance (L) and resistance connected in parallel. In this paper, it is demonstrated that the inductance L remains constant, whereas Ls decrease with the increase in frequency. In other words, the real part of the reciprocal of the complex permeability remains constant for an increase in frequency. In addition, it is found that the imaginary part of the reciprocal of the complex permeability is approximately proportional to the frequency. © 1998 Scripta Technica, Electr Eng Jpn, 123(2): 1–7, 1998

Iron loss measurement of ferrite cores up to MHz range is carried out. Taking the DC magnetic hysteresis, the eddy and displacement currents into account, the electromagnetic fields and iron losses in the cores are computed. As a result, increasing the exciting frequency, the computed iron loss becomes considerably smaller than the experimented one. In order to explain the deference between them, a new magnetic field component yielding a dynamic magnetic loss is assumed and added to the magnetic field of the DC magnetic hysteresis. This assumption is verified by evaluating the iron loss frequency characteristics for different size cores of the same ferrite material.

This paper describes the power loss characteristics of Mn-Zn and Ni-Zn ferrite cores in the high-frequency range. Two kinds of Mn-Zn and an Ni-Zn ferrite material were used to verify the proposed magnetization model. To analyze the iron loss, we propose an equivalent circuit of ferrite cores, whose circuit elements are derived from measured material constants. Analysis of the power loss, showed that the dielectric loss and magnetic loss are dominant in the high-frequency region. Ferrite cores having a large relative permittivity have a considerable skin effect, which accounts for the complex frequency characteristics of the iron loss in Mn-Zn ferrites.

Iron loss measurements of Mn-Zn ferrite cores up to the megahertz range are reported. Taking the dc magnetic hysteresis, the eddy, and displacement currents into account, magnetic and electric field distributions in the cores are computed with the cylindrical coordinates and Bessel functions. The computed iron loss due to the magnetic and electric fields is compared with the experimental value at different exciting frequencies. It is noted that the computed iron loss becomes considerably smaller than the experimental at high frequencies. In order to explain the difference between the computed and experimental iron losses, a new magnetic field component yielding a dynamic magnetic loss is assumed and added to the magnetic field intensity of the dc magnetic hysteresis. This assumption is verified by evaluating the iron losses in different size cores composed of the same ferrite material. Displacement current distribution in a ferrite core depends on the cross-sectional area of the magnetic flux path, which brings about the dependence of the frequency characteristics of the iron loss upon core size.

BACKGROUND We studied on the anti-tumour effects of recently cloned cytokine interleukin-12 (IL-12) for murine renal cell carcinoma (RC-2) with special reference to the difference of its activity based upon the different method of administration. MATERIALS AND METHODS Ten days after RC-2 inoculation to subcutaneous of BALB/C mice, the recombinant murine IL-12 (rMu-IL-12 was administered (0.5 microgram/mouse, 1.0 microgram/mouse and 2.0 micrograms/mouse) 5 times per week for 3 weeks. Two administration methods were applied: intraperitoneal administration (i.p.) and subcutaneous administration near grown tumour (s.c.). We evaluated the efficacy of IL-12 for the RC-2 by means of the ratio of relative mean tumour weight (TRW/CRW), the degree of histological degeneration and the survival time of tumour-bearing mice. Furthermore, the serial body weight of mice excluding the tumour weight was monitored in order to evaluate the side effect of IL-12. RESULTS 1) The ratio of TRW/CRW: As to the experiment of IL-12 injected at 0.5 microgram/mouse, the anti-growth effect was more potent in the i.p. group than in the s.c. group. On the other hand, as to the higher dose groups including 1.0 microgram/mouse and 2.0 micrograms/ mouse groups, the s.c. groups showed more potent anti-tumour growth effects than the i.p. groups. 2) The histological effect: All examined groups showed the degree of grade II degeneration which meant the existence of viable tumour cells after the treatment had been finished. Furthermore, we found out the different pattern of degeneration between the two administration groups (i.p. and s.c.). Namely, there observed sporadicaly degeneration in the i.p. groups, and also observed uniform degeneration close to the injected area in the s.c. groups. 3) Survival time: All treated groups showed a significant prolongation of survival compared with the control, but no significant difference was observed between these two different injected groups. 4) Side effects: Through monitoring serial changes of body weight of treated mice, no significant decrease of body weight due to the administration of IL-12 was observed in all experiments. CONCLUSION The anti-tumour effects of IL-12 for murine renal cell carcinoma with special reference to the difference of anti-tumour effect based upon the different method of administration shows that more potent anti-tumor growth effects are observed in the i.p. group dosed at 0.5 microgram/mouse than in the s.c. group. On the other hand, as to the escalating doses, more potent anti-tumour effects are observed in the s.c. groups than in the i.p. groups. Through all treatment groups, no complete regression of the tumour is observed. Therefore, further precise study to clarify the immunological reaction between tumour and its host derived from the administration of IL-12 must be needed in order to establish more effective treatment with IL-12 in the future.

With the goal of developing an artificial heart, a linear motion magnetic actuator has been produced and applied to a pump. The actuator is composed of two ring-shaped Nd-Fe-B magnets that face each other, the outer and inner diameters and thickness of which are 63mm, 17mm and 3mm, respectively. Rotating one of the magnets circumferentially via a motor produces reciprocating forces on the other magnet. The pumping motion is performed using the power of the reciprocating magnet. Because the actuator uses no windings, no copper loss, which causes heat generation in the body, is generated. The output powers of the actuator and the pump reached 1.03W and 0.65W, respectively.

This paper presents a novel objective function in order to design electromagnetic devices. The finite element method taking the open boundary condition into account is used for magnetic field computation. Comparison of the results obtained with the novel objective function and the least squares shows that the former is superior to the latter. >

This paper proposes an innovative electric power supply system for medical devices implanted deeply, using a low-frequency magnetic field. It is composed of a permanent-magnet coupling and a small generator. The system provides sufficient power at deep positions, adopting two kinds of acceleration. A prototype experiment is carried out and it is verified that the system is able to provide power at deep positions in the human body.

Using two small Nd-Fe-B magnets (0.7 mm/spl times/0.7 mm/spl times/2 mm), a novel magnetic actuator, the length of which is 20 mm, has been developed. The actuator swims in water in parallel to the magnetic field applied. Its swimming velocity performance was experimentally evaluated with three parameters: dc bias magnetic field intensity, and the amplitude and the frequency of the ac magnetic field. A maximum velocity of 37 mm/s was obtained.

Background/Aims Interleukin-12 (IL-12), a cytokine with antitumor activity, was examined for the suppressive effect on hepatocellular carcinoma (HCC) in mouse model, and its mechanism of antitumor activity was analyzed. Methods Mice implanted with MIH-2 HCC cells were treated with recombinant mouse IL-12 (500ng/mouse). Involvement of CD4 + , CD8 + , NK cells and interferon (IFN)-gamma on tumor suppression by IL-12 was examined by treatment of mice with each antibody. Interferon-gamma (IFN-gamma) production by tumor infiltrating cells was analyzed by immunofluorescence microscopy and flow cytometric analysis. Signal transduction for apoptosis induction was examined by immunoblot analysis. Results The growth of implanted MIH-2 tumors was significantly suppressed by IL-12 and the suppression was inhibited by depletion of CD8 + T cells. IL-12 treatment caused numerous IFN-gamma-producing CD8 + T cells to infiltrate into MIH-2 tumors. Antitumor activity of IL-12 was blocked by treating mice with anti-IFN-gamma mAb. CD8 + T cells from IL-12-treated mice attached to MIH-2 cells and produced IFN-gamma in vitro. Cell attachment might be associated with intercellular adhesion molecule-1 induced by IFN-gamma. In vitro treatment with IFN-gamma induced apoptosis of MIH-2 cells via a mitochondria-dependent pathway. Conclusions IL-12 suppressed HCC growth in mouse model. IFN-gamma produced by IL-12-activated tumor-infiltrating CD8 + T cells directly induced apoptosis of HCC cells.

Despite aggressive treatment, the median survival of patients with high-grade malignant astrocytoma is about 1 year. The authors investigated the safety and clinical response to immunotherapy using fusions of dendritic and glioma cells combined with recombinant human interleukin 12 (rhIL-12) for the treatment of malignant glioma. Fifteen patients with malignant glioma participated in this study. Dendritic cells were generated from peripheral blood. Cultured autologous glioma cells were established from surgical specimens in each case. Fusion cells were prepared from dendritic and glioma cells using polyethylene glycol. All patients received fusion cells intradermally on day 1. rhIL-12 was injected subcutaneously at the same site on days 3 and 7. Response to the treatment was evaluated by clinical observations and radiologic findings. No serious adverse effects were observed. In four patients, magnetic resonance imaging showed a greater than 50% reduction in tumor size. One patient had a mixed response. These results show that administration of fusion cells and rhIL-12 safely induces clinical antitumor effects in some patients with malignant glioma.

Summary form only given. Safe electric power provision to medical implants, such as pacemakers and artificial hearts, is much needed, because those medical devices are becoming more sophisticated. Up to the present, several noninvasive methods of transmitting power to a rechargeable battery for implanted medical devices have been reported. In this paper, we propose a novel electric power provision system to a medical implant at a deep position in the body. A permanent magnet rotor is set up outside the body. Another permanent magnet rotor, in which a generator has been installed, is implanted. The magnets of the rotors have magnetic coupling each other. When the rotor outside the body rotates, the other rotor in the body synchronously rotates and the electric power is generated from the mechanical power.

Summary form only given. In reporting the developments of various kinds of magnetic actuators with metal magnets, we have proposed a small (cm-size) magnetic actuator swimming toward the magnetic field. In this paper, an improved actuator is proposed and its measured velocity characteristics are shown.

Interleukin (IL)-11 has anti-inflammatory activity in animal models of gut inflammation, endotoxemia, and radiation-induced thoracic injury. The aim of the present study was to investigate the protective role of IL-11 in a model of acute necrotizing pancreatitis in mice. Acute pancreatitis was induced by administration of seven intraperitoneal injections of cerulein (50 microg/kg) at hourly intervals. Lipopolysaccharide (LPS) was injected 5 hours after the first cerulein injection. Treatment with recombinant human IL-11 (rhIL-11) was started 30 minutes before the first cerulein injection and repeated 4 hours later. Serum levels of amylase, lipase, and tumor necrosis factor (TNF)-alpha were measured at the end of the experiments. The severity of pancreatitis was evaluated by histological scoring using a semiquantitative analysis of hematoxylin and eosin-stained sections of the pancreas. Competitive reverse transcription-polymerase chain reaction (RT-PCR) was performed to quantify the intrapancreatic TNF-alpha mRNA levels. Serum amylase and lipase levels progressively increased with a maximum reached between 8 and 11 hours. Treatment with rhIL-11 significantly decreased amylase and lipase levels at 6 and 8 hours. Serum TNF-alpha peaked at 6 hours and rapidly decreased thereafter. The elevation of serum TNF-alpha was markedly inhibited by treatment with rhIL-11. Histologically, treatment of rhIL-11 reduced the severity of pancreatic injury including edema, inflammatory cell infiltration, and hemorrhage at 6 hours. Intrapancreatic TNF-alpha mRNA levels were reduced by >50% in the rhIL-11-treated group at 6 hours. In conclusion, rhIL-11 decreased the severity of experimental pancreatitis early on but not later and inhibited the intrapancreatic TNF mRNA expression in vivo, suggesting that the protective effect of IL-11 during the early stage of acute pancreatitis may be mediated, at least in part, through modulation of TNF production.

A circuit model was developed to analyze the electromagnetic field in ferrites, for contribution to the design of power circuits by taking into account the power loss in the high-frequency region. The ferrite power loss in the high-frequency region consists of the hysteresis loss and the dynamic magnetic loss. This paper proposes a novel model for electromagnetic field analysis, which is able to compute the magnetic, eddy current and displacement current losses, based on the spatial network method. The validity of the method is verified by comparing the computed power losses with those obtained by the finite element method.

This paper proposes a simple mathematical B-H loop model capable of quantitatively representing B-H loops of various sizes, using only 11 parameters. In the proposed model, the differential permeability is represented as a normal distribution function for the magnetic flux density. The coefficients of the function are approximated as quadratic and cubic curves with respect to the applied maximum magnetic flux density. The B-H loops of a sample Ni-Zn ferrite core, in sizes ranging from small to large, are successfully demonstrated by using the proposed model with a circuit simulator.

With the goal of developing an artificial heart, the authors fabricated a prototype pump employing a linear motion magnetic actuator, and carried out performance tests. The actuator is composed of two disk-shaped Nd–Fe–B magnets having a diameter of 80 mm and a thickness of 7 mm. The disks are magnetized in the direction normal to the circular surface, and are formed by semicircular pieces; one semicircle serves as a N pole and the other as a S pole. The magnets face each other in the actuator. One magnet is limited to spin around its axis while the second magnet is limited to move in linear motion along its axis. In this way, the circumferential rotation of one of the magnets produces reciprocating forces on the other magnet, causing it to move back and forth. This coupled action produces a pumping motion. Because the two magnets are magnetically coupled without any mechanical contact, the rotating magnet does not have to be implanted and should be placed outside the body. The rotating magnet is driven b...

Using ultrasonic, we propose here a novel method of transmitting power and information to implanted medical equipment. The proposed system is composed of two piezo oscillators and has the following functions: transmission of power and control information to an implanted device, and transmission of the information acquired by an implanted device to the outside of a living body. With amplitude shift keying (ASK), 9.5 Kbps is obtained for the proposed information transmission system.