Active lower limb orthosis with one degree of freedom for people with paraplegia.

The main challenges of designing devices for paraplegic walking can be summarized into three groups, stability and comfort, high efficiency or low energy consumption, dimensions and weight. A new economical device for people with paraplegia which tackles all problems of the three groups is introduced in this paper. The main idea of this device is based on HALO mechanism.

Vision-based fluid-type tactile sensor for measurements on biological tissues.

Hardness, dimensions, and location of biological tissues are important parameters for electronic palpation protocols with standardized performance. This study presents a novel fluid-type tactile sensor able to measure size and depth of heterogeneous substances in elastic bodies. The new sensor is very simple and can be easily fabricated.

Gait generation for powered Hip-Ankle-Linkage-Orthosis.

A hip-knee-ankle-foot orthotic system called `HALO'(Hip and Ankle Linked Orthosis) for paraplegic walking has been developed in our previous study. Each ankle joint of the HALO system is linked with a medial single joint via a wire which allows both feet of the orthosis to stay always parallel to the floor during walking and assists swinging the leg. The tests of the HALO system demonstrated that it allows smoother walking and easy don/doff.

Contact region estimation based on a vision-based tactile sensor using a deformable touchpad.

A new method is proposed to estimate the contact region between a sensor and an object using a deformable tactile sensor. The sensor consists of a charge-coupled device (CCD) camera, light-emitting diode (LED) lights and a deformable touchpad. The sensor can obtain a variety of tactile information, such as the contact region, multi-axis contact force, slippage, shape, position and orientation of an object in contact with the touchpad.

A new powered orthosis with hip and ankle linkage for paraplegics walking.

Several types of hip-knee-ankle-foot orthotic systems have been proposed for paraplegic walking during these decades. Hip and ankle linked orthosis (HALO) is compact one in those orthoses, which seeks to achieve a smoother-movement and user-easiness on its don/doff in paraplegic walking. The idea of HALO is to link two ankle joints with medial single joint via wires so that the orthosis keeps both feet always parallel to the floor while walking and assist the swinging of the leg.

Simulation of human walking with powered orthosis for designing practical assistive device.

To design a powered assistive orthosis for human walking, we have simulated walking motion with an orthosis. The model dynamics of the coupled human-orthosis is represented by a 10-rigid-link system. In this model there exist rotational joints at lumbar, both thighs and both legs for orthosis, and each joints are controlled by a couple of central pattern generators (CPG) which imitates neuronal system in the spinal cord of mammals.

Estimation of mental workload using saccadic eye movements in a free-viewing task.

This study proposes a new method to automatically estimate a person's mental workload (MWL) using a specific type of eye movements called saccadic intrusions (SI). Previously, the most accurate existing method to estimate MWL was the pupil diameter measure [1]. However, pupil diameter is not practical in a vehicle driving environment because it is overly sensitive to brightness changes.

Bilateral transfer in active and passive guidance-reproduction based bimanual tasks: effect of proprioception and handedness.

Recently, bilateral movement training based on robot-assisted rehabilitation systems has been attracting a lot of attention as a post-stroke motor rehabilitation protocol. Since humans generate coordinated motions based on their motor and sensory systems, investigation of the innate properties of human motor or sensory systems may provide insight into planning of effective bilateral movement training. In this study, we investigate the effects of proprioception and handedness on the movement of the contra-lateral upper limb, under both active and passive guidance conditions of the robot manipulators.

Robust control of CPG-based 3D neuromusculoskeletal walking model.

This paper proposes a method for enhancing the robustness of the central pattern generator (CPG)-based three-dimensional (3D) neuromusculoskeletal walking controller. The CPG has been successfully applied to walking controllers and controllers for walking robots. However, the robustness of walking motion with the CPG-based controller is not sufficient, especially when subjected to external forces or environmental variations.

State estimation of walking phase and functional electrical stimulation by wearable device.

Functional electrical stimulation (FES) is useful to improve the gait of patients with peroneal nerve palsy or spastic hemiparesis after stroke. So as to apply FES to such patients, we have to have estimators for detecting the timing of phase switching in walking motion. We designed a wearable device for state estimating of walking and functional electrical stimulation.

Relationship between adaptation of motor control and cognition of environmental dynamics.

This paper considers the analysis of dynamics of human operators when the environmental dynamics changes. When an operator conducts a task with his arm, the adaptation on his manipulating dynamics occurs according to the dynamics of environment. We assume that the adaptation has a certain relation to the cognition of the change of environmental dynamics.

Design of lower limb prosthesis with contact pressure adjustment by MR fluid.

This paper reports on the development of a new lower limb prosthesis that can change its volume and hardness based on the users requirements. The size and viscosity of several Magneto-Rheological fluid filled bags, fixed on the inner side of the socket is changed, in order to vary the socket properties. TSB (total surface bearing) sockets have been most selling ones during these two decades.

Hybrid control of powered orthosis and functional neuromuscular stimulation for restoring gait.

The restoration of motor functions of patients with spinal cord injury (SCI) is one of important subjects for study. For this purpose, methods of functional neuromuscular stimulation (FNS) have been investigated in medical science and practice during these three decades. However, we have not achieved complete restoration of motor functions in SCI patients.

Development of FES-rowing machine.

As per present social needs, assisting machines are very much needed for persons of advanced age. We analyzed and developed a fitness apparatus suitable for meeting the requirement of elderly people. The proposed apparatus consists of a rowing machine and Functional Electrical Stimulation (FES), that can be used to exercise every muscle of a person of advanced age.

A computer simulation of human walking in persons with joint contractures.

Joint contractures decrease the patient's ability to walk, but usually other parts of the body compensate the affected joint contractures. When we restore the gait performance in paraplegic patients by means of functional electrical stimulation, however, we cannot expect complications of compensation. A computer simulation was done to clarify how the contractures affect the gait pattern when no complications of compensation were expected.