We developed a gas-spring-powered device for assisting activities of sit-to-stand and stand-to-sit for the elderly andpersons with disability. The assistive device is fitted to both normal chair and wheelchairs, and is comprised of three mainparts; a seat, two support frames and two gas-springs. The assistive device was evaluated in comparison experimentswith or without this assistive device and commercially available assistive chair. Ten young healthy subjects aged from 21 to 24 yr-old had measurements of joint torque of knee and elbow using a force plate, load-cell attached on an armrest andposition of joint marker in video. In addition electromyography of upper arm and thigh were also measured. From theresults, maximum values of joint torque decreased by 29%-78%in both activities of sit-to-stand and stand-to-sit by usingthe assistive device. In addition, maximum and integrated values of electromyography output of upper arm and thighdecreased by50%-74%in both activities of sit-to-stand and stand-to-sit. In contrast, percentage decrease of commerciallyavailable device(joint torque: -7%-40%, EMG: -24-43%)was lower than the present device. We suggest that thenewly developed device could be a useful means for assisting sit-to-stand and stand-to-sit activities.

抄録全体を表示

In this study, we evaluated relationship between artificial lung(AL)design and gas exchange performance(GEP)for long-term use. Velocity and pressure distribution was calculated by Computational Fluid Dynamics(CFD)analysis. Standard deviation of flow rate in fiber bundle(SDhfb)was calculated from velocity distribution as the evaluation index uniformity of flow velocity. Three AL designs were used in order to evaluate design. Design1was characterized by arc extrusion shape and inlet and outlet port set up the fiber bundle in parallel. Design2had taper shape by changing Design1.Design 3 imitated a CUBE6000(Dainippon Ink&Chemicals CO.). In Design2, SDhfb showed minimum value1.57× 10-4and GEP was increased by 52.3%when compared with Design3that showed maximum value of SDhfb7.19× 10-4. In the results of CFD, flow velocity attenuated with the taper wall in the inflow part. High pressure was caused in the taper wall and the pressure was decreased by almost constant value. In conclusion, it was important for L design that the fluid kinetic energy was converted into the pressure by the taper wall in neighborhood of inlet port, and the fluid was uniformly diffused to the fiber bundle at low flow velocity by the uniform pressure.

抄録全体を表示

A monopivot magnetic suspension blood pump is a centrifugal blood pump in which an impeller is supported with a single pivot and a magnetic bearing. The pump impellers of the monopivot pumps were designed to have three configurations of washout holes for blood recirculation, and four female pivot shapes to reduce blood stagnation and to enhance the antithrombogenicity. The hemolytic properties of monopivot pumps were not changed when the impeller design was not changed, but were changed when the female pivot shape was changed. This indicates that hemolysis in monopivot pumps is mainly caused by shear stress between the male and female pivots.

抄録全体を表示

This paper describes a straight and circular road driving control scheme for power assisted wheelchair. Power assisted wheelchair which assists the driving force by electric motors is expected to be widely used asa mobility support system for elderly people and disabled people, however, the performance of the straightand circular road driving must be further improved because the two wheels are driven independently. Thisaper proposes a straight and circular road driving control scheme based on the balanced assisted torquebetween the two wheels. The balanced assisted torque is determined from the proportion of the human inputtorque to the right and left wheels. Some experiments and performance evaluation from trial subjects showthe effectiveness of the proposed control system.

抄録全体を表示