Analysis and Clustering of Upper Limb Motion during the Hand Dexterity Pegboard Test using Inertial Sensor Systems.

Maintaining hand and upper limb mobility is important from the viewpoint of freedom in daily life and high performance in work. Few studies on the mobility and dexterity of the upper limb have focused on detailed hand and finger movements. Therefore, we measured the motion of the upper limbs during a general hand dexterity pegboard test using inertial sensor systems and our previous measuring method.

Analysis of Dexterity Motion by Singular Value Decomposition for Hand Movement Measured Using Inertial Sensors.

Finger movements play an important role in many daily human actions. Among the studies on the dexterity of fingers required for various tasks in neurology and simple evaluation tests, few have focused on detailed finger movements themselves. Therefore, in this study, we improved the hand motion measurement system using inertial sensors and the motion analysis method developed in our previous study and measured the motion of the upper limbs (including the fingers) during a general finger dexterity test.

Time-series changes in intramuscular coherence associated with split-belt treadmill adaptation in humans.

Humans can flexibly modify their walking patterns. A split-belt treadmill has been widely used to study locomotor adaptation. Although previous studies have examined in detail the time-series changes in the spatiotemporal characteristics of walking during and after split-belt walking, it is not clear how intramuscular coherence changes during and after split-belt walking.

Hand Motion Measurement using Inertial Sensor System and Accurate Improvement by Extended Kalman Filter.

Analysis of hand motions is crucial in such actual conditions as daily life and traditional work. We developed a measurement system using inertial sensors instead of an optical motion capture system that measures with spatial constraints. However, for these sensors, the posture error caused by the integration of the angular velocity is critical.

Variant and Invariant Spatiotemporal Structures in Kinematic Coordination to Regulate Speed During Walking and Running.

Humans walk, run, and change their speed in accordance with circumstances. These gaits are rhythmic motions generated by multi-articulated movements, which have specific spatiotemporal patterns. The kinematic characteristics depend on the gait and speed.

Modeling of Hand and Forearm Link using Inertial Sensors.

In this paper, we describe our hand and forearm motion measuring system using inertial sensors. Although a sensor axis is often used to measure human body motion, it is prone to attachment and offset error, and, because a hand is made of five parallel links, it is not suitable for hand measurement. Therefore, we propose a method of modeling the hand and forearm link using only sensors.

Estimation of joint center and measurement of finger motion by inertial sensors.

The authors developed a wearable finger motion measurement system using inertial and geomagnetic sensors. Using this system, motion and posture of the hands and fingers can be measured. However, the joint center and segment axis cannot be accurately measured in a previous study using the sensors.

Real-time motion discrimination considering variation of EMG signals associated with lapse of time.

This study proposes a motion discrimination method that considers the variation of electromyogram (EMG) signals associated with a lapse of time. In a previous study, we proposed a real-time discrimination method based on EMG signals of the forearm. Our method uses a hypersphere model as a discriminator.

Measurement of rehabilitation in thumb MP joint subluxation due to rheumatoid arthritis.

As treatment for subluxation due to rheumatoid arthritis (RA), rehabilitation by hand therapy is one option, but the number of therapist is not sufficient. Therefore, a device for rehabilitation of thumb metacarpophalangeal (MP) joint subluxation has been developed. To improve the device, it is necessary to measure in close proximity to the actual rehabilitation.

Quantitative evaluation of unrestrained human gait on change in walking velocity.

In human gait motion analysis, which is one useful method for efficient physical rehabilitation to define various quantitative evaluation indices, ground reaction force, joint angle and joint loads are measured during gait. To obtain these data as unrestrained gait measurement, a novel gait motion analysis system using mobile force plates and attitude sensors has been developed. On the other hand, a human maintains a high correlation among the motion of all joints during gait.

Motion discrimination technique by EMG signals using hyper-sphere model.

This study developed a method of discriminating real-time motion from electromyogram (EMG) signals. We previously proposed a real-time motion discrimination method using hyper-sphere models that discriminated five motions (open, grasp, pinching, wrist extension, and wrist flexion) above 90% and quickly learned EMG signals. Our method prevents elbow motions from interfering with hand motion discrimination.

Gait motion analysis in the unrestrained condition of trans-femoral amputee with a prosthetic limb.

Trans-femoral amputees must regain moving pattern by refined rehabilitation program using ground reaction forces, joint angles and joint moments applied on a prosthetic limb. On the other hand, understanding those loads and kinematic variables is indispensable for gait analysis based on the biomechanical consideration of trans-femoral amputees. However, conventional prosthetic gait training systems cannot measure long continuous walking motions.

Calculation of joint reaction force and joint moments using by wearable walking analysis system.

In gait analysis, which is one useful method for efficient physical rehabilitation, the ground reaction force, the center of pressure, and the body orientation data are measured during walking. In the past, these data were measured by a 3D motion analysis system consisting of high-speed cameras and force plates, which must be installed in the floor. However, a conventional 3D motion analysis system can measure the ground reaction force and the center of pressure just on force plates during a few steps.

Forearm motion discrimination technique using real-time EMG signals.

The objective of this study is to develop a method of discriminating real-time motion from electromyogram (EMG) signals. We previously proposed a motion discrimination method. This method could discriminate five motions (hand opening, hand closing, hand chucking, wrist extension, and wrist flexion) at a rate of above 90 percent from four channel EMG signals in the forearm.

Development of walking analysis system consisting of mobile force plate and motion sensor.

In walking analysis, which is one useful method for efficient physical rehabilitation, the ground reaction force, the center of pressure, and the body orientation data are measured during walking. In the past, these data were measured by a 3D motion analysis system consisting of high-speed cameras and force plates, which must be installed in the floor. However, a conventional 3D motion analysis system can measure the ground reaction force and the center of pressure just on force plates during a few steps.

Development of a novel six-axis force/moment sensor attached to a prosthetic limb for the unrestrained gait measurement.

Since the number of trans-femoral amputees has increased by industrial or traffic accidents in modern society, a prosthetic limb has been required. In this case, those amputees must regain moving pattern by efficient gait training using load conditions on a prosthetic limb as quantitative evaluation indices. However, conventional gait training systems cannot measure long continuous walking motions.

Biomechanical consideration based on the unrestrained gait measurement of trans-femoral amputee with a prosthetic limb.

Trans-femoral amputees must regain moving pattern by refined rehabilitation program using loads applied on a prosthetic limb. On the other hand, understanding those loads is indispensable for biomechanical consideration of trans-femoral amputees. However, conventional prosthetic gait training systems cannot measure long continuous walking motions.

Prosthetic hand control using motion discrimination from EMG signals.

In this report, we improve the motion discrimination method from electromyogram (EMG) for a prosthetic hand and propose prosthetic hand control. In the past, we proved that a motion discrimination method using conic models could discriminate three hand motions without the incorrect discriminations that the elbow motions cause. In this research, to increase discrimination accuracy of motion discrimination using conic models, we propose a feature extraction method using quadratic polynomials.

Development of prosthetic arm with pneumatic prosthetic hand and tendon-driven wrist.

Recently, various prosthetic arms have been developed, but few are both attractive and functional. Considering human coexistence, prosthetic arms must be both safe and flexible. In this research, we developed a novel prosthetic arm with a five-fingered prosthetic hand using our original pneumatic actuators and a slender tendon-driven wrist using a wire drive and two small motors.

Hand motion discrimination by EMG signals without incorrect discriminations that elbow motions cause.

The objective of this research is to develop a hand motion discrimination method that uses electromyogram (EMG) signals for controlling myoelectric prosthetic hands without the incorrect discriminations that elbow motions cause. We proposed a method that can discriminate hand motions using linear multiple regression models in the past. However, this method incorrectly discriminates hand motions when elbow motions are performed.

Development of robot hand with pneumatic actuator and construct of master-slave system.

Recently, research has concentrated on robots that can coexist with people and be of use to them. Such a robot needs to be both safe and flexible. Here, we use a pneumatic actuator as the driving source of a robot hand.

Development of measuring system to measure standing pose of the foot using distributed triaxial force sensor.

The bottom of a person's foot grips the floor for balance, and the action force and action moment work at the foot bottom when he maintains posture and when he moves. They are important indices in the evaluation and the medical attention of standing pose balance and gait disturbances. A lot of equipments to measure the floor reaction force have been researched.

Hand motion estimation by EMG signals using linear multiple regression models.

The purpose of this research is to construct an intelligent upper limb prosthesis control system that uses electromyogram (EMG) signals. The signal processing of EMG signals is performed using a linear multiple regression model that can learn parameters in a short time. Using this model, joint angles are predicted, and the motion pattern discrimination is conducted.