研究者詳細 - 和田　親宗

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Automatic classification method using machine learning with a single inertial measurement unit for trunk posture category of OWAS 査読有り国際誌

Kodai Kitagawa, Sai-Wei Yang, Fan-Chih Kuo, Chikamune Wada

World Congress on Medical Physics and Biomedical Engineering 2018 (WC2018) ID 1660 2018年06月

An estimation method for lower-limb joint angles during the motion of standing up using an inertial measurement unit 査読有り国際誌

Chikamune Wada, Fan Jin, Takayuki Nagasaki

World Congress on Medical Physics and Biomedical Engineering 2018 (WC2018) ID 1695 2018年06月

1D4-2　鏡映描写課題遂行時の自律神経系指標と主観的メンタルワークロード

倉岡宏幸, 和田親宗, 三宅晋司

人間工学 ( 一般社団法人日本人間工学会 ) 54 ( Supplement ) 1D4-2 - 1D4-2 2018年06月

Force feedback training system to hold axillary crutch stably 査読有り国際誌

Wada C., Nagasaki T.

Proceeding - 2017 5th International Conference on Electrical, Electronics and Information Engineering: Smart Innovations for Bridging Future Technologies, ICEEIE 2017 2018-January 71 - 76 2018年03月

担当区分：筆頭著者記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）

© 2017 IEEE. This study aimed to decrease risk of falls via displacement of the axilla during crutch walking. An axillary force feedback system is developed for providing a visual information to crutch users. An imbalance point is existed between the force of the upper arm on the axillary pad and the force of the chest wall on the axillary pad. Moreover, the system also provides real-time information on force placed on axillary pads during crutch walking and evaluated the effectiveness of our training system. Results suggested that this feedback system was effective for beginners.

DOI： 10.1109/ICEEIE.2017.8328765

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Novel method for evaluation of hindfoot alignment in weight-bearing position using laser beam 査読有り

Ohnishi Tadasuke, Hida Mitsumasa, Nakamura Yukio, Wada Chikamune

Journal of Physical Therapy Science ( 理学療法科学学会 ) 30 ( 3 ) 474 - 478 2018年01月

担当区分：責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

[Purpose] It is clinically important to accurately evaluate the alignment of hindfoot alignment from the body surface in weight-bearing position. In general, measurement is carried out using a goniometer, but the measurement with goniometer requires experience, and the reliability in this measurement is also in question. Therefore, it is necessary to establish a clinical measurement method to replace the goniometer. As a solution, we devised a hindfoot alignment measurement method with laser beam (HAML), which measures hindfoot alignment along the body surface using a laser beam. This study aimed to study the correlation between the measurement result along the body surface with laser or goniometer and that of radiography with regard to hindfoot alignment. [Subjects and Methods] Subjects included 23 individuals with knee osteoarthritis. Their hindfoot alignment using radiography and goniometry were measured. The correlation between the measurement result along the body surface with or without laser and radiography was investigated. [Results] The correlation between HAML and radiography was better than that between HAML and goniometry. [Conclusion] The correlation between radiography and HAML for measuring hindfoot alignment was good. This finding implies that HAML can be used as a screening test or epidemiological survey in regional medicine.

DOI： 10.1589/jpts.30.474

その他リンク： https://ci.nii.ac.jp/naid/130006413901

New estimation model of the initial lower limb angle to improve angle estimation during the extension phase of standing-up movement 査読有り

Jin Fang, Nagasaki Takayuki, Wada Chikamune

Journal of Physical Therapy Science ( 理学療法科学学会 ) 30 ( 5 ) 669 - 674 2018年01月

担当区分：責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

[Purpose] An estimation model of the knee and ankle joint angles during the extension phase was proposed in the previous study. However, it had limited use because of the fixed initial lower limb angle before standing up. This study aimed to propose a new estimation model of the initial lower limb angle to improve the angle estimation during extension phase. [Subjects and Methods] Seven healthy male volunteers were enrolled. The new estimation model approximated the initial lower limb angle using a force sensor plate that measured the plantar pressure of the subjects. The estimated angle and force were compared to those obtained by a motion capture system and force plate. [Results] The new estimation model of initial lower limb angle showed no significant difference compared with the true values obtained by motion capture, except for the subject who had a greater foot-pressure measurement error compared with the force plate measurement, with maximum errors of 5.98° and 6.31°, respectively. [Conclusion] The proposed model in this study can estimate the initial lower limb angle before standing and can be applied to the angle estimation model during the extension phase of the standing-up movement.

DOI： 10.1589/jpts.30.669

その他リンク： https://ci.nii.ac.jp/naid/130006732364

Novel method for evaluation of frontal plane knee alignment using bony prominences in patients with osteoarthritis 査読有り

Ohnishi Tadasuke, Hida Mitsumasa, Nagasaki Takayuki, Wada Chikamune

Journal of Physical Therapy Science ( 理学療法科学学会 ) 30 ( 9 ) 1168 - 1172 2018年01月

担当区分：責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

[Purpose] Angle measurement using images of bony prominences (AMI) determines frontal plane knee alignment from the skin surface without using radiation. The purpose of this study was to assess the validity and reliability of images obtained with the AMI method. [Participants and Methods] The study included 21 patients with osteoarthritis. We measured the functional axis of the lower limb, obtained via full-leg radiography and correlated the findings with the angle of dissection and the angle measured with the AMI method. Additionally, we assessed the reliability of the AMI method. [Results] The angle obtained using the AMI method and the radiographic anatomic axis (the full-leg radiograph)/the mechanical axis were well correlated. The AMI method also showed high reliability. [Conclusion] The AMI method is a valid and reliable alternative to full-leg radiography for imaging of functional and anatomical knee axes. As AMI does not use special equipment or involve radiation exposure, the method can be used in outside medical facilities and can be repeated over time without increased risk to patients.

DOI： 10.1589/jpts.30.1168

その他リンク： https://ci.nii.ac.jp/naid/130007481316

Estimation of the frequency response of body-conducted sound sensors via the equivalent circuit model 査読有り

Joyashiki T., Wada C.

Transactions of Japanese Society for Medical and Biological Engineering ( 公益社団法人日本生体医工学会 ) 56 ( 2 ) 44 - 51 2018年01月

担当区分：最終著者記述言語：英語掲載種別：研究論文（学術雑誌）

Body-conducted sound sensors have an electret condenser microphone with an exposed diaphragm. By covering the sensor with a urethane elastomer, the sensor can be used as a bioacoustic sensor with high sensitivity and resistance to external noise. The body-conducted sound sensors constructed in the past had different parameters such as contact area, thickness of the propagation layer and mass, and the extent of their influence on frequency characteristics is unclear. This study aimed to investigate the influence of the mass and shape of body-conducted sound sensor on pressure sensitivity. The methods comprised ( 1 ) simulation using the equivalent circuit model, ( 2 ) production of body-conducted sound sensors and measurement systems, and ( 3 ) sensitivity measurements and analyses. The simulation results demonstrated that the sensitivity increased when the body-conducted sound sensor had a small mass and a large contact area. In the sensitivity measurement system, a compact acceleration sensor was used as a reference sensor, and the sensitivity to pressure was calculated. The results obtained from the sensitivity measurement system correlated strongly with the frequency characteristics of the simulations, with a correlation coefficient of 0.90-0.95 in the frequency range of 100-2,000 Hz. In the statistical analysis, by varying the mass and contact area, significant differences were observed in the frequency range of 700-2,000 Hz while no significant differences were observed in the frequency range of 100-600 Hz. Moreover, as a result of reducing the housing mass, sensitivity was increased. In conclusion, body-conducted sound sensors with a small mass and large contact area exhibit high pressure sensitivity in the frequency range of 700-2,000 Hz, and their frequency characteristics can be estimated by simulation.

DOI： 10.11239/jsmbe.56.44

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Design of a wireless surface EMG acquisition system 査読有り国際誌

Ishak A., Ahmad S., Soh A., Naraina N., Jusoh R., Chikamune W.

2017 24th International Conference on Mechatronics and Machine Vision in Practice, M2VIP 2017 2017-December 1 - 6 2017年12月

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）

© 2017 IEEE. Wireless Technology plays a significant role in current world. Many applications use wireless sensor network for health monitoring. One of the examples is the application to measure muscle response or electrical activity in response to a nerve's stimulation of the muscle. The development of wireless Electromyography (EMG) for remote monitoring of muscle activities is one of many vital parts in the biomedical technology. This wireless EMG is able to transmit signals through wireless transmission to computer for monitoring. By employing this technology, doctors treating patients with muscle complication can monitor their patients from the comfort of their office while the patients roam freely in their own room or therapy room. This technology is essential for patients with needs of home-based monitoring and economical medical services. The design of wireless EMG system comprises of a preamplifier and an electrode for the measurement of EMG signal, main amplifier for signal processing, DSP processor for A/D conversion and X-Bee module for wireless transmission. During power spectral density, EMG signal is distributed between 10 to 500Hz. Thus, EMG signals become consistent with the application of wireless transmission.

DOI： 10.1109/M2VIP.2017.8211481

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New Combination Method for Road Features Extraction 査読有り

Watcharin Tangsuksant, Chikamune Wada

International Conference on ICT Robotics 2017 Paper ID:104A4 2017年11月

An estimation method of knee and ankle joint angles during standing up motion using an inertial sensor 査読有り国際誌

Chikamune Wada, Fang Jin, Takayuki Nagasaki

Fifth International Symposium on Applied Engineering and Sciences 2017年11月

Development of Axillary Pressure Feedback System for Crutch Walking 査読有り国際誌

Chikamune Wada, Takayuki Nagasaki

39th Annual International Conference of the IEEE Engineering in Medicine and Biology Society Paper FrBT16.2 2017年07月

Auto-grasping algorithm of robot gripper based on pressure sensor measurement 査読有り国際誌

Almassri A., Wada C., Wan Hasan W., Ahmad S.

Pertanika Journal of Science and Technology 25 ( S ) 113 - 122 2017年02月

担当区分：責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

© 2017 Universiti Putra Malaysia Press. This paper presents an auto grasping algorithm of a proposed robotic gripper. The purpose is to enhance the grasping mechanism of the gripper. Earlier studies have introduced various methods to enhance the grasping mechanism, but most of the works have not looked at the weight measurement method. Thus, with this algorithm, the weight of the object is calculated based on modified Wheatstone Bridge Circuit (WBC) which is controlled by programmable interface controller (PIC) method. Having this approach introduces and improves the grasping mechanism through an auto grasping algorithm. Experimental results show that an auto grasping algorithm based on pressure sensor measurements leads to a more precise grasping measurement and consequently enhance the sensitivity measurement as well as accurate movement calibration. Furthermore, several different grasping objects based on the proposed method are examined to demonstrate the performance and robustness of our approach.

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Artificial Neural Network Based Step-Length Prediction Using Ultrasonic Sensors from Simulation to Implementation in Shoe-Type Measurement Device 査読有り

Romy Budhi Widodo, Chikamune Wada

Journal of Advanced Computational Intelligence and Intelligent Informatics 21 ( 2 ) 321 - 329 2017年02月

Study of the Relationship Between Sit-to-Stand Activity and Seat Orientation 査読有り

Chikamune Wada, Shuichi Ino

Journal of Advanced Computational Intelligence and Intelligent Informatics 21 ( 2 ) 337 - 341 2017年02月

Real-time human motion analysis and grasping force using the OptiTrack system and flexi-force sensor 査読有り国際誌

Saidon N., Wada C., Ahmad S., Rahman R., Eguchi K., Tomiyama Y., Rahman F.

Pertanika Journal of Science and Technology 25 ( S ) 69 - 76 2017年01月

記述言語：英語掲載種別：研究論文（学術雑誌）

© 2017 Universiti Putra Malaysia Press. Biologically inspired robotic hands have important applications in industry and biomedical robotics. The grasping capacity of robotic hands is crucial for a robotic system. This paper presents an experimental study on the finger force and movements of a human hand during the grasping operation in real-time. It focuses on two topics; measuring grasping force using Flexi-force sensors and analysing human hand action during grasping operation. The findings show that lifting required higher forces compared with grasp force in the static phase.

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An estimation of knee and ankle joint angles during extension phase of standing up motion performed using an inertial sensor 査読有り

Jin F., Nagasaki T., Wada C.

Journal of Physical Therapy Science ( 理学療法科学学会 ) 29 ( 7 ) 1171 - 1175 2017年01月

担当区分：責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

© 2017 The Society of Physical Therapy Science. Published by IPEC Inc. [Purpose] Motion capture system is difficult to use in daily life. The aim of this study was to propose an estimation model for knee and ankle joint angle measurements and locate body center of gravity (COG) of the extension phase during standing-up motion. [Subjects and Methods] Seven healthy male volunteers were enrolled. An estimation model was proposed for the knee and ankle joint angle measurements by combining the angle and acceleration of the trunk, based on readings from the inertial sensor attachment on the subject’s chest, during the extension phase. Joint angles and COG position were compared to those obtained by a motion capture system. [Results] The joint angles and COG position demonstrated high correlation coefficients which represent strong correlation between the proposed model and the motion capture system. The proposed model could estimate the joint angle during extension phase, with a maximum error of 4.58 degrees, as well as COG position in the horizontal and vertical directions with maximum errors of 4.48 cm and 3.19 cm, respectively. [Conclusion] The proposed system could be used instead of motion capture system to estimate knee and ankle joint angles; however, the estimation of the COG position was insufficient because of lacked accuracy.

DOI： 10.1589/jpts.29.1171

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Attitude Estimation using Kalman Filtering: External Acceleration Compensation Considerations 査読有り国際誌

Romy B. Widodo, C. Wada

Journal of Sensors 2016 Article ID 6943040 2016年12月

担当区分：最終著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）

Attitude estimation is often inaccurate during highly dynamic motion due to the external acceleration. This paper proposes extended Kalman filter-based attitude estimation using a new algorithm to overcome the external acceleration. This algorithm is based on an external acceleration compensation model to be used as a modifying parameter in adjusting the measurement noise covariance matrix of the extended Kalman filter. The experiment was conducted to verify the estimation accuracy, that is, one-axis and multiple axes sensor movement. Five approaches were used to test the estimation of the attitude: (1) the KF-based model without compensating for external acceleration, (2) the proposed KF-based model which employs the external acceleration compensation model, (3) the two-step KF using weighted-based switching approach, (4) the KF-based model which uses the threshold-based approach, and (5) the KF-based model which uses the threshold-based approach combined with a softened part approach. The proposed algorithm showed high effectiveness during the one-axis test. When the testing conditions employed multiple axes, the estimation accuracy increased using the proposed approach and exhibited external acceleration rejection at the right timing. The proposed algorithm has fewer parameters that need to be set at the expense of the sharpness of signal edge transition.

DOI： 10.1155/2016/6943040