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Hiroshi Mizoguchi - One of the best experts on this subject based on the ideXlab platform.

  • EMBC - Measurement of the passive stiffness of ankle joint in 3 DOF using stewart Platform Type ankle foot device
    Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual Inte, 2016
    Co-Authors: Kenta Nomura, Teru Yonezawa, Hiroshi Mizoguchi, Hiroshi Takemura
    Abstract:

    This paper presents a method to measure the passive stiffness of an ankle joint in three degrees of freedom (DOF) under two motion speeds (1 Hz and 5 degree/s) using a developed Stewart Platform-Type device. The developed device can reproduce input motions of the foot in 6 DOF by controlling six pneumatic linear motion actuators. We used the device to measure the passive stiffness of an ankle joint undergoing three kinds of motion, namely dorsi-plantar flexion, inversion-eversion, and adduction-abduction. The measured values of the passive stiffness of the ankle joint in dorsiflexion that we obtained agreed well with that obtained in a previous study, indicating that the developed device is useful for measuring the passive stiffness of ankle joint. In addition, the developed device can be used to measure the stiffness in inversion-eversion and adduction-abduction motions as well, parameters that have never been measured. The results we obtained demonstrated certain interesting features as we varied both the direction and pace of motion (e.g., there were significant differences in the stiffness not only between adduction and abduction during the faster pace, but also between these and the other motions).

  • EMBC - Development of Stewart Platform Type ankle-foot device for trip prevention support
    Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and, 2015
    Co-Authors: Kenta Nomura, Takeki Ogitsu, Teru Yonezawa, Hiroshi Mizoguchi, Hiroshi Takemura
    Abstract:

    This paper presents an ankle-foot device using a Stewart Platform, which is a Type of parallel-link mechanism, for trip prevention support. The developed device can reproduce the input motions of the ankle joint in six degrees of freedom by controlling six pneumatic cylinders at the same time. The root mean square errors of the 3-D position and rotation angle of the reproduced motions with the input motions (dorsiflexion and plantar flexion) were 6.3 mm and 3.0°, respectively. Verification experiments for trip prevention support performance were conducted by comparing motions in each walking condition measured using a motion capture system. The experimental results showed that the minimum foot clearance during mid-swing and initial swing increased significantly by the trip prevention support offered by the developed device. The developed device can perform passive exercises for ankle rehabilitation and support walking for trip prevention.

  • Position, Force and Stiffness Control of a Stewart-Platform-Type Ankle-Foot Assist Device
    Volume 2: Legged Locomotion; Mechatronic Systems; Mechatronics; Mechatronics for Aquatic Environments; MEMS Control; Model Predictive Control; Modelin, 2012
    Co-Authors: Ming Ding, Takayuki Onodera, Hiroshi Takemura, Ryojun Ikeura, Hiroshi Mizoguchi
    Abstract:

    In this research, we developed an ankle-foot assist device for foot rehabilitation and walking assistant purpose. In order to support all 6 DOFs human foot motion (the rotations of human foot and the displacement of rotation axes), a six air cylinders drive Stewart Platform Mechanism was used. In our previous work, we have proposed a measuring and calculating method to get the posture of human foot and estimate the instantaneous rotation axis of ankle joint [1]. In this paper, we further propose a new method to control the position, force and stiffness of this device. The position can be controlled even if the potentiometers do not measure the length of air cylinders directly. The force can be controlled by changing the air pressures in two chambers of each cylinder, without using any force sensors. The stiffness can also be controlled which is controlled by changing the stiffness of all cylinders, by changing the pressures in chambers. These control methods are tested in experiments for one cylinder and for developed assist device. The results show the accuracy and validity of the device and the method in the control of position, force and stiffness.Copyright © 2012 by ASME

  • Design and Control of a Wearable Stewart Platform-Type Ankle-Foot Assistive Device
    International Journal of Advanced Robotic Systems, 2012
    Co-Authors: Hiroshi Takemura, Takayuki Onodera, Ding Ming, Hiroshi Mizoguchi
    Abstract:

    The design and control of an active ankle-foot rehabilitation orthotic system that was designed as a wearable and portable rehabilitation and walking assistive tool is presented. This device can measure and assist the six degree of freedoms (DOFs) movement of the human ankle joint by using a Stewart Platform mechanism, which can adapt to the displacement of the rotation axis during the movement of a human foot. The estimation method of an instantaneous rotation axis of ankle-foot motion is also proposed. In this paper, the motion measurement and motion control performance of the developed assistive device is evaluated. Static and dynamic motion measurement and motion reproduction performance verification experiments are conducted. The experimental results showed that the developed assistive device is enough for measuring and controlling the human ankle-foot motion.

  • Design and development of Stewart Platform-Type assist device for ankle-foot rehabilitation
    2012 First International Conference on Innovative Engineering Systems, 2012
    Co-Authors: Takayuki Onodera, Hiroshi Takemura, Ming Ding, Hiroshi Mizoguchi
    Abstract:

    In this research, we propose a novel ankle-foot assist device for rehabilitation. This device uses a Stewart Platform mechanism to measure and assist the movements of a human ankle joint in six DOF. The Stewart Platform mechanism adapts to the displacement of the rotation axis of a human ankle joint during the movement of a human foot. In this study, check the accuracy of motion measurement of this device and the performance of motion control of this assist device by conducting static measurement and motion reproduction experiments. The translation error and The rotation error were less than 0.5 [mm] and 0.6 [deg] respectively. The mean reproducibility of all subjects was 0.98 These experimental results show the validity of our proposed assist device.

Hiroshi Takemura - One of the best experts on this subject based on the ideXlab platform.

  • EMBC - Measurement of the passive stiffness of ankle joint in 3 DOF using stewart Platform Type ankle foot device
    Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual Inte, 2016
    Co-Authors: Kenta Nomura, Teru Yonezawa, Hiroshi Mizoguchi, Hiroshi Takemura
    Abstract:

    This paper presents a method to measure the passive stiffness of an ankle joint in three degrees of freedom (DOF) under two motion speeds (1 Hz and 5 degree/s) using a developed Stewart Platform-Type device. The developed device can reproduce input motions of the foot in 6 DOF by controlling six pneumatic linear motion actuators. We used the device to measure the passive stiffness of an ankle joint undergoing three kinds of motion, namely dorsi-plantar flexion, inversion-eversion, and adduction-abduction. The measured values of the passive stiffness of the ankle joint in dorsiflexion that we obtained agreed well with that obtained in a previous study, indicating that the developed device is useful for measuring the passive stiffness of ankle joint. In addition, the developed device can be used to measure the stiffness in inversion-eversion and adduction-abduction motions as well, parameters that have never been measured. The results we obtained demonstrated certain interesting features as we varied both the direction and pace of motion (e.g., there were significant differences in the stiffness not only between adduction and abduction during the faster pace, but also between these and the other motions).

  • EMBC - Development of Stewart Platform Type ankle-foot device for trip prevention support
    Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and, 2015
    Co-Authors: Kenta Nomura, Takeki Ogitsu, Teru Yonezawa, Hiroshi Mizoguchi, Hiroshi Takemura
    Abstract:

    This paper presents an ankle-foot device using a Stewart Platform, which is a Type of parallel-link mechanism, for trip prevention support. The developed device can reproduce the input motions of the ankle joint in six degrees of freedom by controlling six pneumatic cylinders at the same time. The root mean square errors of the 3-D position and rotation angle of the reproduced motions with the input motions (dorsiflexion and plantar flexion) were 6.3 mm and 3.0°, respectively. Verification experiments for trip prevention support performance were conducted by comparing motions in each walking condition measured using a motion capture system. The experimental results showed that the minimum foot clearance during mid-swing and initial swing increased significantly by the trip prevention support offered by the developed device. The developed device can perform passive exercises for ankle rehabilitation and support walking for trip prevention.

  • Position, Force and Stiffness Control of a Stewart-Platform-Type Ankle-Foot Assist Device
    Volume 2: Legged Locomotion; Mechatronic Systems; Mechatronics; Mechatronics for Aquatic Environments; MEMS Control; Model Predictive Control; Modelin, 2012
    Co-Authors: Ming Ding, Takayuki Onodera, Hiroshi Takemura, Ryojun Ikeura, Hiroshi Mizoguchi
    Abstract:

    In this research, we developed an ankle-foot assist device for foot rehabilitation and walking assistant purpose. In order to support all 6 DOFs human foot motion (the rotations of human foot and the displacement of rotation axes), a six air cylinders drive Stewart Platform Mechanism was used. In our previous work, we have proposed a measuring and calculating method to get the posture of human foot and estimate the instantaneous rotation axis of ankle joint [1]. In this paper, we further propose a new method to control the position, force and stiffness of this device. The position can be controlled even if the potentiometers do not measure the length of air cylinders directly. The force can be controlled by changing the air pressures in two chambers of each cylinder, without using any force sensors. The stiffness can also be controlled which is controlled by changing the stiffness of all cylinders, by changing the pressures in chambers. These control methods are tested in experiments for one cylinder and for developed assist device. The results show the accuracy and validity of the device and the method in the control of position, force and stiffness.Copyright © 2012 by ASME

  • Design and Control of a Wearable Stewart Platform-Type Ankle-Foot Assistive Device
    International Journal of Advanced Robotic Systems, 2012
    Co-Authors: Hiroshi Takemura, Takayuki Onodera, Ding Ming, Hiroshi Mizoguchi
    Abstract:

    The design and control of an active ankle-foot rehabilitation orthotic system that was designed as a wearable and portable rehabilitation and walking assistive tool is presented. This device can measure and assist the six degree of freedoms (DOFs) movement of the human ankle joint by using a Stewart Platform mechanism, which can adapt to the displacement of the rotation axis during the movement of a human foot. The estimation method of an instantaneous rotation axis of ankle-foot motion is also proposed. In this paper, the motion measurement and motion control performance of the developed assistive device is evaluated. Static and dynamic motion measurement and motion reproduction performance verification experiments are conducted. The experimental results showed that the developed assistive device is enough for measuring and controlling the human ankle-foot motion.

  • Design and development of Stewart Platform-Type assist device for ankle-foot rehabilitation
    2012 First International Conference on Innovative Engineering Systems, 2012
    Co-Authors: Takayuki Onodera, Hiroshi Takemura, Ming Ding, Hiroshi Mizoguchi
    Abstract:

    In this research, we propose a novel ankle-foot assist device for rehabilitation. This device uses a Stewart Platform mechanism to measure and assist the movements of a human ankle joint in six DOF. The Stewart Platform mechanism adapts to the displacement of the rotation axis of a human ankle joint during the movement of a human foot. In this study, check the accuracy of motion measurement of this device and the performance of motion control of this assist device by conducting static measurement and motion reproduction experiments. The translation error and The rotation error were less than 0.5 [mm] and 0.6 [deg] respectively. The mean reproducibility of all subjects was 0.98 These experimental results show the validity of our proposed assist device.

Jiqing Qiu - One of the best experts on this subject based on the ideXlab platform.

  • Platform Type fuzzy number and separability of fuzzy number space
    Fuzzy Sets and Systems, 2001
    Co-Authors: Jiqing Qiu
    Abstract:

    Abstract In this paper, we introduce the notions of the rectangular fuzzy set and step Type fuzzy number. It is shown that the family of all Platform Type fuzzy numbers E T 1 is dense in fuzzy numbers space E 1 about L p -metric D p , and the family of all rational Type step fuzzy numbers E QG 1 (E QG 1 ⊂E T 1 and E QG 1 is a countable set) is dense in (E T 1 ,D p ) . Further, as corollaries, we obtain that (E 1 ,D p ) is a separable metric space and several separable metric spaces about p -mean symmetric difference metric d Δ p .

N. Siva Prasad - One of the best experts on this subject based on the ideXlab platform.

Judith E Deutsch - One of the best experts on this subject based on the ideXlab platform.

  • a stewart Platform based system for ankle telerehabilitation
    Autonomous Robots, 2001
    Co-Authors: M Girone, Grigore C Burdea, Mourad Bouzit, V Popescu, Judith E Deutsch
    Abstract:

    The “Rutgers Ankle” is a Stewart Platform-Type haptic interface designed for use in rehabilitation. The system supplies six-DOF resistive forces in response to virtual reality-based exercises running on a host PC. The Stewart Platform uses double-acting pneumatic cylinders, linear potentiometers as position sensors, and a six-DOF force sensor. The Rutgers Ankle controller contains an embedded Pentium board, pneumatic solenoid valves, valve controllers, and associated signal conditioning electronics. Communication with the host PC is over a standard RS232 line. The Platform movement and output forces are transparently recorded by the host PC in a database. This database can be accessed remotely over the Internet. Thus, the Rutgers Ankle Orthopedic Rehabilitation Interface will allow patients to exercise at home while being monitored remotely by therapists. A protoType was constructed, and proof-of-concept trials were conducted at the University of Medicine and Dentistry of New Jersey. The results indicate that the system works well as a diagnostic tool. The subjective evaluation by patients was very positive. Further medical trials are needed before the system clinical efficacy in rehabilitation can be established.