Yasunori Hashimoto

Development of Shear Type Compact MR Brake for the Intelligent Ankle-Foot Orthosis and Its Control; Research and Development in NEDO for Practical Application of Human Support Robot

A brake in which the magnetorheologic fluid (MRF) is used has a simple structure and good responsibility. Therefore, MR brake is expected to perform a good adaptability for human-coexistence system. Being applied in an ankle-foot orthosis, however, conventional MR brake is too large to fit. Then, in this study we developed a shear-type MR brake with multi layer disks and minute gaps (50 micrometers) to realize compactness and high performance. This paper describes the development of a shear type compact MR brake and a new controllable ankle-foot orthosis with this brake. Furthermore, we design algorithm to control an ankle. We assist gait of a patient by changing a brake force.

Intelligently controllable Ankle Foot Orthosis (I-AFO) and its application for a patient of Guillain-Barre syndrome

Ankle-Foot Orthoses (AFOs) are orthotic devices supporting movements of ankles for disabled people for example hemiplegia, peroneal nerve palsy, etc. In our research, we have developed the intelligently controllable AFO (I-AFO) which can control its ankle torque by using compact Magneto-rheological fluid (MRF) brakes. In this paper, we describe the gait-control tests with I-AFO for a patient of the Guillain-Barre syndrome. The subject has difficulty in his voluntary movement of the peripheral part of the inferior limb, and there are physical limitations on his ankle. By applying the I-AFO, his gait control was improved by the prevention of drop-foot in the swing-phase and the forward promotion in the stance-phase.

Development of an Intelligent Prosthetic Ankle Joint (3rd Report, Development of the 2nd Prototype with an Intelligent Prosthetic Ankle Joint and Experimental Evaluations)

It is very important to test the intelligent prosthetic ankle joint in various conditions to ensure the usability of the equipment, however, there are some difficulties to evaluate the performance of the first prototype which is controlled by a bulky system adequately for the inferior mobility of the controlling system. In this paper, a prototype with an intelligent prosthetic ankle joint controlled by a mobile system constructed from a notebook computer and a compact and light control unit was developed to enable testing experiments in various environments. Walking experiments with the prototype was carried out and the usability of the intelligent prosthetic ankle joint was confirmed.