The Experts below are selected from a list of 77676 Experts worldwide ranked by ideXlab platform

Kohji Koshiji - One of the best experts on this subject based on the ideXlab platform.

  • Position detection for transcutaneous Energy Transmission System for capsule endoscope
    2013 IEEE Wireless Power Transfer (WPT), 2013
    Co-Authors: Takahiko Yamamoto, Kohji Koshiji
    Abstract:

    This paper describes a method for detecting the position of a capsule endoscope by using small, flat arrayed coils and discusses the improvement of this position detection and the Energy Transmission efficiency. The position of the capsule endoscope was detectable by measuring the terminal voltage variation in each small, flat coil connected in parallel. The coil that is utilized as an arrayed connection should have no crevice. Such coils can broaden the domain of high Energy Transmission efficiency.

  • Improvement in magnetic field immunity of externally-coupled transcutaneous Energy Transmission System for a totally implantable artificial heart
    Journal of Artificial Organs, 2008
    Co-Authors: Takahiko Yamamoto, Kohji Koshiji, Eisuke Tatsumi, Akihiko Homma, Yoshiyuki Taenaka
    Abstract:

    Transcutaneous Energy Transmission (TET) that uses electromagnetic induction between the external and internal coils of a transformer is the most promising method to supply driving Energy to a totally implantable artificial heart without invasion. Induction-heating (IH) cookers generate magnetic flux, and if a cooker is operated near a transcutaneous transformer, the magnetic flux generated will link with the external and internal coils of the transcutaneous transformer. This will affect the performance of the TET and the artificial heart System. Hence, it is necessary to improve the magnetic field immunity of the TET System. During operation of the System, if the transcutaneous transformer is in close proximity to an IH cooker, the electric power generated by the cooker and coupled to the transformer can drive the artificial heart System. To prevent this coupling, the external coil was shielded with a conductive shield that had a slit in it. This reduces the coupling between the transformer and the magnetic field generated by the induction cooker. However, the temperature of the shield increased due to heating by eddy currents. The temperature of the shield can be reduced by separating the IH cooker and the shield.

  • Energy Transmission transformer for a wireless capsule endoscope analysis of specific absorption rate and current density in biological tissue
    IEEE Transactions on Biomedical Engineering, 2008
    Co-Authors: Kenji Shiba, Tomohiro Nagato, Toshio Tsuji, Kohji Koshiji
    Abstract:

    This paper reports on the electromagnetic influences on the analysis of biological tissue surrounding a prototype Energy Transmission System for a wireless capsule endoscope. Specific absorption rate (SAR) and current density were analyzed by electromagnetic simulator in a model consisting of primary coil and a human trunk including the skin, fat, muscle, small intestine, backbone, and blood. First, electric and magnetic strength in the same conditions as the analytical model were measured and compared to the analytical values to confirm the validity of the analysis. Then, SAR and current density as a function of frequency and output power were analyzed. The validity of the analysis was confirmed by comparing the analytical values with the measured ones. The SAR was below the basic restrictions of the International Commission on Nonionizing Radiation Protection (ICNIRP). At the same time, the results for current density show that the influence on biological tissue was lowest in the 300-400 kHz range, indicating that it was possible to transmit Energy safely up to 160 mW. In addition, we confirmed that the current density has decreased by reducing the primary coil's current.

  • analysis of specific absorption rate and current density in an Energy Transmission System for a wireless capsule endoscope
    International Conference of the IEEE Engineering in Medicine and Biology Society, 2007
    Co-Authors: Kenji Shiba, Tomohiro Nagato, Toshio Tsuji, Kohji Koshiji
    Abstract:

    This paper reports on the electromagnetic influences on the analysis of biological tissue surrounding a prototype Energy Transmission System for a wireless capsule endoscope. Specific absorption rate (SAR) and current density were analyzed by electromagnetic simulator in a model consisting of primary coil and a human trunk including the skin, fat, muscle, small intestine, blood and backbone. SAR and current density as a function of frequency and output power were analyzed. The SAR was below the basic restrictions of the International Commission on Non-Ionizing Radiation Protection (ICNIRP). At the same time, the results for current density show that the influence on biological tissue was lowest in the 300-400 kHz range, indicating that it was possible to transmit Energy safely up to 100 mW.

  • Transcutaneous Energy Transmission System for a Totally-Implantable Artificial Heart in case Using External Battery
    World Congress on Medical Physics and Biomedical Engineering 2006, 2007
    Co-Authors: Takahiko Yamamoto, Yukinari Nawa, Yoshinori Ikeda, Mitsue Yanagi, Kohji Koshiji, Eisuke Tatsumi, Akihiko Homma, Yoshiyuki Taenaka
    Abstract:

    We have been developing the externally-coupled transcutaneous Energy Transmission System (ECTETS) for a totally-implantable artificial heart (TIAH). The transcutaneous Energy Transmission (TET) System enables the TIAH to supply the driving Energy without infectious disease and reduction of patient’s QOL (quality of life). Since the TET System uses the electromagnetic induction between the external (primary) and the internal (secondary) coils, it is necessary for the TET System to be compatible electromagnetically. In the practical use of artificial heart, such as a patient going out, the artificial heart is driven by the Energy from the portable rechargeable battery outside of the body. In this paper, the drive performance and the electromagnetic compatibility of the TET System were investigated in case of using the external rechargeable battery. As a result, the ECTETS, driven by the external rechargeable battery consisting of the Lithium ion battery pack with a weight of 430 g, was able to drive the TIAH actuator for 4 hours and 9 minutes. The radiated emission from the ECTETS was suppressed within the regulation of class-B and group-1 in CISPR (international special committee on radio interference) Pub.11, and the ECTETS satisfied the electrostatic discharge immunity test based on IEC61000-4-2 (International Electrotechnical Commission), the radiation immunity test based on IEC61000-4-3, and the power supply frequency magnetic field immunity test based on IEC61000-4-8. Therefore, it was concluded that the ECTETS investigated had satisfactory characteristics in the drive performance and the electromagnetic compatibility.

Kenji Shiba - One of the best experts on this subject based on the ideXlab platform.

  • Energy Transmission transformer for a wireless capsule endoscope analysis of specific absorption rate and current density in biological tissue
    IEEE Transactions on Biomedical Engineering, 2008
    Co-Authors: Kenji Shiba, Tomohiro Nagato, Toshio Tsuji, Kohji Koshiji
    Abstract:

    This paper reports on the electromagnetic influences on the analysis of biological tissue surrounding a prototype Energy Transmission System for a wireless capsule endoscope. Specific absorption rate (SAR) and current density were analyzed by electromagnetic simulator in a model consisting of primary coil and a human trunk including the skin, fat, muscle, small intestine, backbone, and blood. First, electric and magnetic strength in the same conditions as the analytical model were measured and compared to the analytical values to confirm the validity of the analysis. Then, SAR and current density as a function of frequency and output power were analyzed. The validity of the analysis was confirmed by comparing the analytical values with the measured ones. The SAR was below the basic restrictions of the International Commission on Nonionizing Radiation Protection (ICNIRP). At the same time, the results for current density show that the influence on biological tissue was lowest in the 300-400 kHz range, indicating that it was possible to transmit Energy safely up to 160 mW. In addition, we confirmed that the current density has decreased by reducing the primary coil's current.

  • analysis of specific absorption rate and current density in an Energy Transmission System for a wireless capsule endoscope
    International Conference of the IEEE Engineering in Medicine and Biology Society, 2007
    Co-Authors: Kenji Shiba, Tomohiro Nagato, Toshio Tsuji, Kohji Koshiji
    Abstract:

    This paper reports on the electromagnetic influences on the analysis of biological tissue surrounding a prototype Energy Transmission System for a wireless capsule endoscope. Specific absorption rate (SAR) and current density were analyzed by electromagnetic simulator in a model consisting of primary coil and a human trunk including the skin, fat, muscle, small intestine, blood and backbone. SAR and current density as a function of frequency and output power were analyzed. The SAR was below the basic restrictions of the International Commission on Non-Ionizing Radiation Protection (ICNIRP). At the same time, the results for current density show that the influence on biological tissue was lowest in the 300-400 kHz range, indicating that it was possible to transmit Energy safely up to 100 mW.

  • Evaluation of Conducted Emission from Transcutaneous Energy Transmission System for a Totally-Implantable Artificial Heart
    IEEJ Transactions on Industry Applications, 1999
    Co-Authors: Kenji Shiba, Eimei Shu, Kohji Koshiji
    Abstract:

    This paper reports on evaluation of radiated emission from transcutaneous Energy Transmission System for a totally implantable artificial heart. The radiated emission from the coreless type (transformer A) and the externally-coupled type (transformer B) of the transcutaneous transformers are measured, respectively, and compared with German regulation of VDE-0871 for medical electric equipment. From the measurement, the radiated electric field intensities at 100kHz from the transformers A and B are 67.7dBμV/m and 38.7dBμV/m, respectively. As a result, it is found that the radiated emission from the transformer B is sufficiently small compared with the level regulated in VDE-0871.

  • A transcutaneous Energy Transmission System with rechargeable internal back-up battery for a totally implantable total artificial heart.
    ASAIO journal (American Society for Artificial Internal Organs : 1992), 1999
    Co-Authors: Kenji Shiba, Kohji Koshiji, Eisuke Tatsumi, Yoshiyuki Taenaka, Eimei Shu, Kinji Tsukahara, T. Nakamura, Toru Masuzawa, Hisateru Takano
    Abstract:

    We have been developing an externally coupled transcutaneous Energy Transmission System (ECTETS) for a totally implantable total artificial heart (TITAH). When the ECTETS is unable to supply the Energy to drive the TITAH from outside the body, a rechargeable internal back-up battery (RIBB) implanted inside the body is used as a back-up to supply the required Energy. This paper reports on the performance characteristics of our ECTETS with an RIBB. In this study, a lithium-ion (Li+) secondary battery was used as the RIBB. The transcutaneous Energy Transmission and the charging control characteristics of the ECTETS, while simultaneously supplying Energy to the TITAH and the RIBB, were evaluated in an in vitro experiment. The output power and Transmission efficiency of the ECTETS operating in this mode were found to vary from 20 W to 34 W and from 84% to 71%, respectively. It was also found that a sufficient power of more than 20 W could be supplied to the TITAH. The time needed to fully charge the RIBB was 117 minutes, and a fully charged RIBB could drive the TITAH, consuming 20 W for 62 minutes. It may, therefore, reasonably be concluded that the ECTETS with the RIBB is sufficient to drive the TITAH.

  • Efficiency improvement and in vivo estimation of externally-coupled transcutaneous Energy Transmission System for a totally implantable artificial heart
    Proceedings of the 19th Annual International Conference of the IEEE Engineering in Medicine and Biology Society. 'Magnificent Milestones and Emerging , 1
    Co-Authors: Kenji Shiba, Kohji Koshiji, Eimei Shu, Kinji Tsukahara, Toru Masuzawa, K. Tsuchimoto, T. Ohu-mi, Takao Nakamura, S. Endo, Eisuke Tatsumi
    Abstract:

    In order to enhance the implantability of the externally-coupled transcutaneous Energy Transmission System (ECTETS), efficiencies in various parts of the circuit System were improved to reduce heat dissipation. As a result, a DC-to-DC Energy Transmission efficiency of 85% or more was obtained in an in vitro experiment conducted at a power output of 19 W. In the in vivo measurement of this improved ECTETS with the internal coil and the rectifier circuit implanted under the skin of a living goad, a DC-to-DC Energy Transmission efficiency of 82% or more was obtained. Fluctuation of efficiency due to movement of the body was found to be less than 0.5%. When this improved ECTETS is used with the totally implantable electrohydraulic artificial heart with an overflow mock circulatory System connected as a load, the pump output flow at a changing heart rate was found to be 4.4-7.0 L/min (50-110 bpm). For continuous operation at 70 bpm, the DC-to-DC Energy Transmission efficiency was 81% or more, the pump output flow was 6.2 L/min, and the temperature in the part of implantation was lower than 41/spl deg/C, a temperature that can hardly affect a living body.

Tomohiro Nagato - One of the best experts on this subject based on the ideXlab platform.

  • Energy Transmission transformer for a wireless capsule endoscope analysis of specific absorption rate and current density in biological tissue
    IEEE Transactions on Biomedical Engineering, 2008
    Co-Authors: Kenji Shiba, Tomohiro Nagato, Toshio Tsuji, Kohji Koshiji
    Abstract:

    This paper reports on the electromagnetic influences on the analysis of biological tissue surrounding a prototype Energy Transmission System for a wireless capsule endoscope. Specific absorption rate (SAR) and current density were analyzed by electromagnetic simulator in a model consisting of primary coil and a human trunk including the skin, fat, muscle, small intestine, backbone, and blood. First, electric and magnetic strength in the same conditions as the analytical model were measured and compared to the analytical values to confirm the validity of the analysis. Then, SAR and current density as a function of frequency and output power were analyzed. The validity of the analysis was confirmed by comparing the analytical values with the measured ones. The SAR was below the basic restrictions of the International Commission on Nonionizing Radiation Protection (ICNIRP). At the same time, the results for current density show that the influence on biological tissue was lowest in the 300-400 kHz range, indicating that it was possible to transmit Energy safely up to 160 mW. In addition, we confirmed that the current density has decreased by reducing the primary coil's current.

  • analysis of specific absorption rate and current density in an Energy Transmission System for a wireless capsule endoscope
    International Conference of the IEEE Engineering in Medicine and Biology Society, 2007
    Co-Authors: Kenji Shiba, Tomohiro Nagato, Toshio Tsuji, Kohji Koshiji
    Abstract:

    This paper reports on the electromagnetic influences on the analysis of biological tissue surrounding a prototype Energy Transmission System for a wireless capsule endoscope. Specific absorption rate (SAR) and current density were analyzed by electromagnetic simulator in a model consisting of primary coil and a human trunk including the skin, fat, muscle, small intestine, blood and backbone. SAR and current density as a function of frequency and output power were analyzed. The SAR was below the basic restrictions of the International Commission on Non-Ionizing Radiation Protection (ICNIRP). At the same time, the results for current density show that the influence on biological tissue was lowest in the 300-400 kHz range, indicating that it was possible to transmit Energy safely up to 100 mW.

Toshio Tsuji - One of the best experts on this subject based on the ideXlab platform.

  • Energy Transmission transformer for a wireless capsule endoscope analysis of specific absorption rate and current density in biological tissue
    IEEE Transactions on Biomedical Engineering, 2008
    Co-Authors: Kenji Shiba, Tomohiro Nagato, Toshio Tsuji, Kohji Koshiji
    Abstract:

    This paper reports on the electromagnetic influences on the analysis of biological tissue surrounding a prototype Energy Transmission System for a wireless capsule endoscope. Specific absorption rate (SAR) and current density were analyzed by electromagnetic simulator in a model consisting of primary coil and a human trunk including the skin, fat, muscle, small intestine, backbone, and blood. First, electric and magnetic strength in the same conditions as the analytical model were measured and compared to the analytical values to confirm the validity of the analysis. Then, SAR and current density as a function of frequency and output power were analyzed. The validity of the analysis was confirmed by comparing the analytical values with the measured ones. The SAR was below the basic restrictions of the International Commission on Nonionizing Radiation Protection (ICNIRP). At the same time, the results for current density show that the influence on biological tissue was lowest in the 300-400 kHz range, indicating that it was possible to transmit Energy safely up to 160 mW. In addition, we confirmed that the current density has decreased by reducing the primary coil's current.

  • analysis of specific absorption rate and current density in an Energy Transmission System for a wireless capsule endoscope
    International Conference of the IEEE Engineering in Medicine and Biology Society, 2007
    Co-Authors: Kenji Shiba, Tomohiro Nagato, Toshio Tsuji, Kohji Koshiji
    Abstract:

    This paper reports on the electromagnetic influences on the analysis of biological tissue surrounding a prototype Energy Transmission System for a wireless capsule endoscope. Specific absorption rate (SAR) and current density were analyzed by electromagnetic simulator in a model consisting of primary coil and a human trunk including the skin, fat, muscle, small intestine, blood and backbone. SAR and current density as a function of frequency and output power were analyzed. The SAR was below the basic restrictions of the International Commission on Non-Ionizing Radiation Protection (ICNIRP). At the same time, the results for current density show that the influence on biological tissue was lowest in the 300-400 kHz range, indicating that it was possible to transmit Energy safely up to 100 mW.

Setsuo Takatani - One of the best experts on this subject based on the ideXlab platform.

  • The Re-design at the Transformer Portion of Transcutaneous Energy Transmission System for All Implantable Devices
    Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual Inte, 2007
    Co-Authors: Masaya Watada, R. Saisho, Yong-jae Kim, Katsuhiro Ohuchi, Setsuo Takatani
    Abstract:

    All implantable devices, such as an artificial heart, an artificial lung, a pacemaker, a defibrillator, need electric power. So the electric power supply through the skin is requested. Then, it is transcutaneous Energy Transmission System (TETS) that has been studied and used a lot. TETS is the System which performs an electric power supply by non-contact transcutaneously using the electromagnetic induction phenomenon of an external primary side coil and a secondary side coil in human body. In this research, we are developing the core type TETS which applied for the implantable devices. In this paper, corresponding to various conditions, such as a difference in required electric power and Transmission distance change, the core type transformer which can hold high Transmission efficiency is designed.

  • The development of core-type Transcutaneous Energy Transmission System for artificial heart.
    Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and, 2005
    Co-Authors: Masaya Watada, Kenji Iwawaki, Tomoyuki Tamada, Katsuhiro Ouchi, Setsuo Takatani
    Abstract:

    Recently, Artificial Heart (AH) is recognized as the alternate method of the heart graft. Though there are many problems and defect on AH, long term durability, miniaturization and weight saving interfaced with flow rate performance, efficiency of device. Considering rehabilitation into the society and advancement of QOL (Quality of Life), the construction of power source which supplies electric power to the device is important and has many problems. Especially, the electric feeder line restricts behavior of the transplant recipient and disturbs rehabilitation into the society. For solving these problems, Transcutaneous Energy Transmission System (TETS) is noticed and studied. This study proposes core-type TETS. It achieves high magnetic coupling compared with air-core-type TETS which is carried out on clinical study. Because core-type TETS has high magnetic coupling, it is possible to reduce the input current and to miniaturize transformer size. This paper mentions the characteristic of core-type TETS.

  • The re-design of Transformer portion in Transcutaneous Energy Transmission System for Left Ventricle Assist Device
    World Congress on Medical Physics and Biomedical Engineering 2006, 1
    Co-Authors: R. Saisho, Masaya Watada, Yong-jae Kim, Katsuhiro Ohuchi, Takuya Ohsugi, Setsuo Takatani
    Abstract:

    Recently, Artificial Heart (AH) is recognized as the alternate method of the heart graft. Though there are many problems and defect on AH, long term durability, miniaturization and weight saving interfaced with flow rate performance, efficiency of device. Considering rehabilitation into the society and advancement of QOL (Quality of Life), the construction of power source which supplies electric power to the device is important and has many problems. Especially, the electric feeder line restricts behavior of the transplant recipient and disturbs rehabilitation into the society. For solving these problems, Transcutaneous Energy Transmission System (TETS) is noticed and studied. This study proposes core-type TETS. It achieves high magnetic coupling compared with aircore- type TETS which is carried out on clinical study. Because core-type TETS has high magnetic coupling, it is possible to reduce the input current and to miniaturize trans size. This paper mentions the characteristic of core-type TETS.

  • The design of core-type transcutaneous Energy Transmission Systems for artificial heart
    30th Annual Conference of IEEE Industrial Electronics Society 2004. IECON 2004, 1
    Co-Authors: Kenji Iwawaki, Masaya Watada, Setsuo Takatani
    Abstract:

    Recently, artificial heart (AH) is noticed as the alternate method of the heart graft. Though there are many problems and defect on AH, long term durability, miniaturization and weight saving interfaced with flow rate performance, efficiency of device. Considering rehabilitation into the society and advancement of QOL (quality of life), the construction of power source, which supplies electric power to the device, is important and has many problems. Especially, the electric feeder line restricts behavior of the transplant recipient and disturbs rehabilitation into the society. For solving these problems, transcutaneous Energy Transmission System (TETS) is noticed and studied. This study proposes core-type TETS. It achieves high magnetic coupling and position stability compared with air-core-type TETS which is carried out on clinical study. Because core-type TETS has high magnetic coupling, it is possible to reduce the input current and to miniaturize trans size. This paper mentions the design of core-type TETS.