研究者業績

藤田 孝之

フジタ タカユキ  (Takayuki Fujita)

基本情報

所属
兵庫県立大学 先端医療工学研究所 教授 (副所長)
学位
博士(工学)(2000年3月 姫路工業大学)

J-GLOBAL ID
201801005909816068
researchmap会員ID
B000310193

論文

 176
  • 室井 大和, 藤田 大輔, 小橋 昌司, 藤田 孝之
    バイオメディカル・ファジィ・システム学会年次大会講演論文集 36回 5-8 2023年12月  
  • Takahito Yokota, Kensuke Kanda, Takayuki Fujita, Kazusuke Maenaka
    IEEJ Transactions on Sensors and Micromachines 143(8) 256-261 2023年8月1日  査読有り
  • 神田健介, 梶山佳敬, 平田善明, 島倉泰久, 藤田孝之, 前中 一介
    143(6) 137-142 2023年6月1日  査読有り
  • Noriyasu Kondo, Daisuke Fujita, Syoji Kobashi, Takayuki Fujita
    Conference Proceedings - IEEE International Conference on Systems, Man and Cybernetics 1652-1657 2023年  
    The incidence of falls in hospital facilities is high and can lead to a decrease in patients' quality of life and an increase in medical expenses. Therefore, the development of a system that can predict getting-up from a bed is necessary. This study proposes a get-up detecting sensor using 6-axis inertial sensor. This system can detect getting-up from a bed in real-time using machine learning with Edge AI. To evaluate the basic performance of the proposed system, a protocol was applied for four subjects, and data were collected. Alert accuracy rate and false alert rate were used as evaluation metrics, and a model was built using data from three of the subjects and evaluated with the remaining subject, which was repeated for all four subjects. For high-risk bed-leaving behavior, medium-risk pre-bed-leaving behavior, and low-risk get-up behavior, the alert accuracy rate (i.e., Recall) was 89.4%, 97.5%, and 86.3%, respectively, and the false alert rate (1-Precision) was 6.3%, 10.2%, and 0.0%, respectively. This confirmed the possibility of predicting rising behavior with high accuracy. Furthermore, as a proof of concept, a real-time get-up detection system was developed, and its practicality was demonstrated. Future challenges include reevaluating feature extraction and evaluating the performance of the proposed system with a diverse range of subjects of different ages, genders, and health statuses.
  • Noriyasu Kondo, Daisuke Fujita, Syoji Kobashi, Takayuki Fujita
    SMC 1652-1657 2023年  

MISC

 133
  • 藤田孝之, 小橋昌司
    障害福祉サービス等報酬における医療的ケア児の判定基準確立のための研究 令和元年度 総括・分担研究報告書(Web) 2020年  
  • 奈倉道明, 藤田孝之, 小橋昌司
    障害福祉サービス等報酬における医療的ケア児の判定基準確立のための研究 令和元年度 総括・分担研究報告書(Web) 2020年  
  • 藤本 匠, 福永 彬人, 前中 一介, 神田 健介, 藤田 孝之
    36 3p 2019年11月19日  
  • 杉野 裕輝, 福永 彬人, 藤田 孝之, 神田 健介, 前中 一介
    36 3p 2019年11月19日  
  • 平井 翔太, 神田 健介, 藤田 孝之, 前中 一介
    35 4p 2018年10月30日  
  • 本郷 裕之, 月山 元貴, 神田 健介, 藤田 孝之, 前中 一介
    35 4p 2018年10月30日  
  • 髙原 光將, 神田 健介, 遠山 蒼, 藤田 孝之, 前中 一介
    35 5p 2018年10月30日  
  • 遠山 蒼, 髙原 光將, 神田 健介, 藤田 孝之, 前中 一介
    35 3p 2018年10月30日  
  • 月山 元貴, 本郷 裕之, 廣田 朝地, 氏家 朱理, 神田 健介, 藤田 孝之, 前中 一介
    2018(28) 23-25 2018年8月8日  
  • 本郷 裕之, 月山 元貴, 氏家 朱理, 神田 健介, 藤田 孝之, 前中 一介
    2018(21) 1-4 2018年7月13日  
  • Kensuke Kanda, Taiki Ushiia, Takayuki Fujita, Kazusuke Maenaka
    2018 IEEE MICRO ELECTRO MECHANICAL SYSTEMS (MEMS) 2018-January 1032-1035 2018年  
    For the first time, it is experimentally validated that the output voltage from series-connected piezoelectric elements on MEMS structure can be multiplied without degradation. The output voltage has been degraded for conventional devices (piezoelectric voltage-output sensors) based on the series-connected piezoelectric elements because of parasitic capacitances. The elimination of the parasitic capacitance by using not Si but polymer for structural material achieves output voltage multiplication.
  • 遠山蒼, 高原光將, 神田健介, 藤田孝之, 前中一介
    センサ・マイクロマシンと応用システムシンポジウム(CD-ROM) 35th 2018年  
  • 本郷裕之, 月山元貴, 神田健介, 藤田孝之, 前中一介
    センサ・マイクロマシンと応用システムシンポジウム(CD-ROM) 35th 2018年  
  • 高原光將, 神田健介, 遠山蒼, 藤田孝之, 前中一介
    センサ・マイクロマシンと応用システムシンポジウム(CD-ROM) 35th 2018年  
  • 平井翔太, 神田健介, 藤田孝之, 前中一介
    センサ・マイクロマシンと応用システムシンポジウム(CD-ROM) 35th 2018年  
  • 藤田 孝之, 横川 隆司, 神田 岳文, 峯田 貴
    電気学会論文誌E(センサ・マイクロマシン部門誌) 137(4) NL4_2-NL4_9 2017年  
  • 藤田 孝之
    電気学会論文誌E(センサ・マイクロマシン部門誌) 137(12) NL12_3-NL12_6 2017年  
  • Shinya Toda, Kensuke Kanda, Takayuki Fujita, Kazusuke Maenaka
    INTERNATIONAL JOURNAL OF INNOVATIVE COMPUTING INFORMATION AND CONTROL 12(4) 1365-1373 2016年8月  
    This paper describes flexible and stretchable wiring for wearable healthcare systems. The stretchable wiring was fabricated by filling magnetic and conductive powder in hollow silicone tubes. The powder consists of magnetic particles coated with conductive metal. The stretchability and stable conductivity are attributed to the magnetic force of the particles. To realize the wiring, the magnetic powder was coated with Au/Cu metal. The electrical and mechanical performance of the wiring was evaluated. The evaluation demonstrates that the wiring has conductivity of 4.92 S/cm and axial strain limit of 60%. The 1000 cycles of repetitive tensile tests revealed deterioration in the conductivity of the wiring. However, it is found that the deteriorated performance of the wiring can be retrieved by remagnetization.
  • S. Toda, K. Kanda, T. Fujita, K. Maenaka
    2016 International Conference on Electronics Packaging, ICEP 2016 329-332 2016年6月7日  査読有り
    © 2016 The Japan Institute of Electronics Packaging. We report a novel stretchable wiring that has selfhealing property. The wiring was fabricated by filling conductive magnetic powder into a hollow tube of silicone material. This stretchable wiring has good performance, which is conductivity of 1715 S/cm under nonstretch status and stretchability of 150% with conductivity. In addition, this wiring has good credibility, i.e. enduring 1000 cycles tensile test under strain of 100%. Furthermore, to confirm self-healing property, we applied excessive strain of 250% intentionally. The experiment result shows a fine self-healing property, that the wiring retrieved conductivity at any time by releasing wiring.
  • Ryo Sano, Kensuke Kanda, Junichi Inoue, Takayuki Fujita, Kazusuke Maenaka
    2016 IEEE 29TH INTERNATIONAL CONFERENCE ON MICRO ELECTRO MECHANICAL SYSTEMS (MEMS) 2016-February 1173-1176 2016年  
    Multimorph structure of Pb(Zr,Ti)O-3 (PZT) thin films by using sputtering deposition, which is compatible with batch-fabrication, was realized for the applications of low voltage driving and large generative force actuators. Test microcantilevers with four layers of PZT thin film were fabricated by dry etching of PZT with metal thin films on a four inch wafer, without deterioration of piezoelectric performance. All PZT layers worked well as piezoelectric material and an actuation test revealed a four-fold displacement per voltage compared with single layer actuations. In addition, a limit of the number of laminated layer for PZT multimorph was also evaluated from point of the view of total stress index.
  • 秦 誠一, 安部 隆, 藤田 孝之, 横川 隆司
    電気学会論文誌E(センサ・マイクロマシン部門誌) 136(3) NL3_3-NL3_8 2016年  
  • 藤田 孝之
    電気学会論文誌E(センサ・マイクロマシン部門誌) 136(3) 43-43 2016年  
    センサ・マイクロマシン部門誌(論文誌E)では,英語の論文・レターのみを集めた「英文特集号」を試みており,2014年3月号および2015年3月号に引き続き本年3月号にも特集号を発行する運びとなりました。電気学会には和文誌とは別に共通英文誌が存在しますが,本企画は和文誌
  • 林 健司, 藤田 孝之
    電気学会論文誌E(センサ・マイクロマシン部門誌) 136(5) 133-133 2016年  
    センサ・マイクロマシン部門誌(論文誌E)では,平成25年度より,総合研究会で講演された論文に関する特集号を企画しています。今回は本誌2016年5月号にて刊行されることになりました。掲載されている論文は「平成27年度センサ・マイクロマシン部門総合研究会」(平成26年7月
  • 南 啓大, 三輪谷 直輝, 神田 健介, 藤田 孝之, 前中 一介
    マイクロ・ナノ工学シンポジウム 2015(7) "28pm3-F-1-1"-"28pm3-F-1-2" 2015年10月21日  
    In this paper, we present a design approach for electrostatic energy harvester under low acceleration. In electrostatic energy harvester, the electrostatic force that prevents mass movement or causes pull-in is occurred due to the charged electret. We propose a dual-phase electrode arrangement and bipolar charged electret to reduce the electrostatic force. Utilizing dual-phase electrode arrangement or bipolar charged electret, the electrostatic energy harvester can reduce electrostatic force both vertical and horizon directions in a static condition from FEM analysis. It is found that the approached electrostatic energy harvester can generate more power than conventional structure in a low acceleration from SPICE equivalent circuit model. In addition, the air-gap can be smaller and the limited output power can be higher by reducing vertical electrostatic force.
  • Takashi Okubo, Ryo Sano, Kensuke Kanda, Takayuki Fujita, Kazusuke Maenaka
    2015 JOINT IEEE INTERNATIONAL SYMPOSIUM ON THE APPLICATIONS OF FERROELECTRIC, INTERNATIONAL SYMPOSIUM ON INTEGRATED FUNCTIONALITIES AND PIEZOELECTRIC FORCE MICROSCOPY WORKSHOP (ISAF/ISIF/PFM) 178-181 2015年  
    This paper reports a batch fabrication process combining piezoelectric Pb(Zr, Ti)O-3 (PZT) thin films with photosensitive polymer SU-8. Fabricated PZT/SU-8 structure shows small stiffness and less brittleness. In addition, the piezoelectric characteristics are equivalent to conventional PZT thin films on Si substrates. From the result of actuation experiments of cantilevers, the PZT/SU-8 structures show excellent flexibility. This allows 1-mm long cantilever to actuate at bending angle over 90 degrees without breaking.
  • 藤田 孝之
    電気学会論文誌E(センサ・マイクロマシン部門誌) 135(12) NL12_4-NL12_4 2015年  
  • 藤田 孝之
    システム/制御/情報 59(11) 429 2015年  
  • 藤田 孝之
    電気学会論文誌E(センサ・マイクロマシン部門誌) 134(5) NL5_8-NL5_8 2014年  
  • 池原 毅, 秦 誠一, 安部 隆, 藤田 孝之
    電気学会論文誌E(センサ・マイクロマシン部門誌) 134(5) NL5_1-NL5_7 2014年  
  • 山口 晃平, 藤田 孝之, 田中 祐至, 小峠 竜也, 園田 晃司, 神田 健介, 前中 一介
    マイクロ・ナノ工学シンポジウム 2013 3-4 2013年  
    This paper shows the optimization of the structure of the electromagnetic energy harvester consisting of the sputtered NdFeB film on high aspect ratio Si trench and the Au serpentine coil. The magnetic flux density change is caused by distance change between coil and magnet film on the corrugated Si. In order to maximize the harvesting energy, the optimum parameters such as width, depth of Si trench, and coil size are investigated by FEM analysis and theoretical calculation. Assuming the trench depth of 400 μm the vibration amplitude of 400 μm_<p-p> and the frequency of 100 Hz the maximum output power of 12 nW and the maximum electromotive force of 4 mV are obtained by 60 μm and 80 μm, respectively.
  • Jun-ichi Inoue, Kensuke Kanda, Takayuki Fujita, Kazusuke Maenaka
    2013 IEEE INTERNATIONAL SYMPOSIUM ON THE APPLICATIONS OF FERROELECTRIC AND WORKSHOP ON THE PIEZORESPONSE FORCE MICROSCOPY (ISAF/PFM) 257-260 2013年  
    This paper reports depositions of double layers of thick Pb(Zr, Ti)O-3 films in order to realize piezoelectric bimorph structures for MEMS(micro electro-mechanical systems) applications. The PZT/PZT bimorph with the total thickness of 5.4 mu m, deposited by magnetron sputtering system, is much thicker than conventionally reported ones. The optimization of the sputtering conditions and electrode structures results in preferable electric and ferroelectric characteristics for both top and bottom PZT layers. In addition, the characteristics of the two layers are consistent with each other.
  • Tomoya Tanaka, Takayuki Fujita, Koji Sonoda, Manabu Nii, Kensuke Kanda, Kazusuke Maenaka, Alex Chan Chun Kit, Sayaka Okochi, Kohei Higuchi
    World Automation Congress Proceedings 2012年12月14日  
    Continuous human monitoring is substantially useful to realize a high QoL (quality of life) society. In the previous work, we fabricated a prototype system for monitoring an electrocardiograph (ECG), heart rate (HR), 3 axes human body acceleration, temperature for human body and human circumstances, simultaneously. These data are transmitted to the host PC and used for analyzing the human activities and conditions such as a heart rate variability (HRV). The HRV that calculated from HR is valuable for recognizing a mental or physical stress of human subjects. In this study, we demonstrate a fuzzy logic HR extraction algorithm on the prototype system to realize an autonomous HRV monitoring system. On-board fuzzy algorithm will reduce the communication traffic and improve an accuracy of the HR extraction. From the implementation result, the error ratio of the HR extraction is improved from 0.9 % to 0.4 %. © 2012 TSI Press.
  • Takayuki Fujita, Toshikazu Onishi, Kohei Fujii, Kensuke Kanda, Kazusuke Maenaka, Kohei Higuchi
    2012 WORLD AUTOMATION CONGRESS (WAC) 2012年  
    This paper reports an evaluation of a human vibration for autonomous power source that generate an electrical power from human vibration. The actual energy harvesting results from the MEMS (micro electromechanical systems) electret based energy harvester on the human body is also described. The harvester consists of the silicon grid structure, stripe-pattern charged electret material and support spring structures. Using a multipurpose data-logging device that can gather the 3-axis acceleration, pressure, humidity temperature and also harvesting voltage simultaneously investigate an actual harvested power from the human movement.
  • S. Miki, T. Fujita, T. Kotoge, Y. G. Jiang, M. Uehara, K. Kanda, K. Higuchi, K. Maenaka
    Proceedings of the IEEE International Conference on Micro Electro Mechanical Systems (MEMS) 1221-1224 2012年  査読有り
    This study describes the fabrication and measurement of an electromagnetic-type energy harvester by using buried NdFeB/Ta multilayer films. The energy harvester is fabricated by bonding a vibratory mass with buried micro-magnets and a stator with integrated micro-coils together. The performance of the micro-magnets was enhanced by new methods of a mechanical polishing process of buried NdFeB. The output power of the energy harvester was improved to 760 pW with an applied vibration amplitude of 48 μm p-p at 94.9 Hz. © 2012 IEEE.
  • Toshikazu Onishi, Takayuki Fujita, Kohei Fujii, Kensuke Kanda, Kazusuke Maenaka, Kohei Higuchi
    World Automation Congress Proceedings 2012年  査読有り
    Electret materials are useful for electrostatic type energy harvesters. Since the power generated from the electret energy harvester is proportional to the surface charge concentration, i.e. charged voltage on the electret, frequency and dynamic range of the capacitance change. To fabricate the electret, the corona discharge is a very popular charging method, which consists of a high voltage needle for corona ions generation and a grid electrode applying a bias voltage that implants the electrons from corona ions to the electret material. We have established the charging method with finely patterned charging area by using the buried grid electrodes (BGE) applied with a bias voltage for organic material CYTOP. However, CYTOP has slightly poor characteristics in terms of the thermal robustness. In this study we report a fabrication technique of the selectively charged SiN/SiO2 as electret material alternative to the CYTOP. By using the BGE method to SiN/SiO 2 film, a fine patterned electret with highly thermal robustness was obtained. © 2012 TSI Press.
  • 松木 勇介, 藤田 孝之, 神田 健介, 前中 一介
    電気学会研究会資料. PHS, フィジカルセンサ研究会 2011(1) 1-4 2011年1月13日  
  • 永田 和幸, 山川 隆洋, 伊賀 友樹, 神田 健介, 藤田 孝之, 樋口 行平, 前中 一介
    電気学会研究会資料. PHS, フィジカルセンサ研究会 2011(1) 5-10 2011年1月13日  
  • 保毛津 林太郎, 村井 康二, 林 祐司, 才木 常正, 樋口 行平, 藤田 孝之, 前中 一介
    自動制御連合講演会講演論文集 54 302-302 2011年  
    水先業務において、海上における水先要請船舶と水先艇間における移乗による乗下船は、水先人にとって身体的危険を伴う労働環境の一つである。そして、死亡事故に至ることが全国発生件数から見れば3年に1人の頻度で生じている。本研究では、伊勢三河湾水先区の三級水先修業生を対象に、乗下船時の身体運動を小型加速度センサーにより測定し、得られた身体運動の知見から乗下船時における安心・安全について検討、考察する。
  • S. Tanaka, K. Sonoda, K. Kasai, K. Kanda, T. Fujita, K. Higuchi, K. Maenaka
    Proceedings of the IEEE International Conference on Micro Electro Mechanical Systems (MEMS) 217-220 2011年  査読有り
    We found that an appropriate mixture of SF6, C4F 8 and O2 gases in a standard Inductively Coupled Plasma Reactive Ion Etching (ICP-RIE) apparatus achieves crystal orientation dependent etching. The etched shapes after the RIE of silicon wafers with (100), (110), and (111) surface orientation are investigated by the masks with circular openings and isolated pattern. The results of the etching process show (111) terraces; i.e., the etching rate of the (111) plane is slower than that of other planes similar to the alkaline-based wet etching. The etching rate in the horizontal direction in each crystallographic orientation is examined by etching a wagon wheel pattern. We also demonstrate an application, Through-Silicon Via (TSV) holes with horn-shaped openings using this process.
  • K. Fujii, T. Toyonaga, T. Fujita, Y. G. Jiang, K. Higuchi, K. Maenaka
    2011 16th International Solid-State Sensors, Actuators and Microsystems Conference, TRANSDUCERS'11 2634-2637 2011年  査読有り
    In this study, an electret based energy harvester with a single silicon structure that shares harvesting counter electrodes and charging grid is demonstrated. The shared electrode provide the batch fabrication process that can avoid the charge leakage from the charged electret. The mass structure supported by the thin Si spring has resonant frequency of 40 Hz. The harvesting demonstration showed the 0.23 μW at 10 Hz, 0.1 G with load resistance of 1 Mω. © 2011 IEEE.
  • X. C. Hao, Y. G. Jiang, H. Takao, K. Maenaka, T. Fujita, K. Higuchi
    2011 16th International Solid-State Sensors, Actuators and Microsystems Conference, TRANSDUCERS'11 116-119 2011年  査読有り
    A novel gas sealed capacitive pressure sensor with a self-temperature compensated structure is reported. The pressure sensor is sealed by Au-Au diffusion bonding in nitrogen with a pressure of 100 kPa and integrated with a platinum resistor based temperature sensor for human activity monitoring. A ring-shaped structure on the diaphragm of the pressure sensor is used for temperature compensation. The pressure sensor with the temperature compensation structure can mechanically suppress the thermal expansion effect of the sealed gas in cavity. Using the compensation structure, measured temperature coefficient was much reduced as compared to that of the pressure sensor without compensation. The sensitivities of the pressure sensor before and after compensation are almost same in a pressure range from 80 kPa to 100 kPa. © 2011 IEEE.
  • Hamada Hiroyuki, Fujita Takayuki, Jiang Yonggang, Aono Yutaka, Okada Jun, Higuchi Kohei, Maenaka Kazusuke
    SCIS & ISIS 2010 1475-1479 2010年  
    In this study, we developed a waterproof cardiography/accelerogram device for human health and activity monitoring. The sensor system consists of a cardiograhy sensor, a tri-axial accelerometer, sensor interface, microcontroller and a RF module. It was coated with Poly dimethyl siloxane ( PDMS ) to achieve a waterproof and patch-type device. The RF module with low power consumption was utilized to transfer the cardiography/accelerogram data from the device to the base station. Static postures and long-term human activity were estimated from the data of cardiography sensor, triaxial accelerometer and other integrated sensors. The details of the system configuration and some measurement examples for human health monitoring are described in this paper.
  • Xiuchun Hao, Yonggang Jiang, Shohei Shiono, Takayuki Fujita, Kohei Higuchi, Kazusuke Maenaka
    2010 World Automation Congress, WAC 2010 2010年  査読有り
    This paper reports a capacitive pressure sensor for human activity monitoring application, which is fabricated by Au-Au diffusion bonding in ambient pressure. The optimized condition for the Au-Au bonding was investigated. A maximum bonding strength of 26.7 MPa is achieved with a bonding temperature of 400°C and bonding pressure of 5.5 MPa. By measuring the pressure-capacitance characteristics of the atmospheric pressure sensor, its sensitivity is found to be 7fF/kPa with a good linearity in the ambient pressure range from 60 kPa to 100kPa.
  • Takayuki Fujita, Kensuke Kanda, Kazusuke Maenaka, Jun Okada, Sayaka Okochi, Kohei Higuchi
    4th International Symposium on Computational Intelligence and Industrial Applications, ISCIIA 2010 65-69 2010年  査読有り
    Continuous observation of human activities and circumstances are quite important for healthcare apprications that collect a lot of data from the various MEMS (Micro ElectroMechanical Systems) sensors. This study demonstrates the multi-environmental sensing device for human applications that can measure the time-based three-axes acceleration (three-axes shock), barometric pressure, temperature and relative humidity, simultaneously. The measured data are stored in a flash memory via an onboard microcontroller. The detailed configurations of the prototype device and some experimental results are also shown.
  • Yuki Iga, Kensuke Kanda, Takayuki Fujita, Kohei Higuchi, Kazusuke Maenaka
    2010 World Automation Congress, WAC 2010 2010年  査読有り
    In this paper, we describe about design and fabrication of a piezoelectric gyroscope with a trident tuning fork structure for MEMS processes. The PZT thin film on the silicon beam was used for driving source and detection. We obtained the PZT thin film with thickness of 3um by the sputtered. The report describes a design of the gyroscope and characteristics of the PZT thin film. © 2010 TSI Press.

書籍等出版物

 5

講演・口頭発表等

 365

所属学協会

 6

共同研究・競争的資金等の研究課題

 15

産業財産権

 19