This paper proposes a regenerative baking control system of handle-type electric wheelchairs for senior citizen. “Electric wheelchair”, which generates the driving force by electric motors according to the human operation, is expected to be widely used as a mobility support system for elderly people. This study focuses on the braking control to realize the safety and smooth stopping motion using the regenerative braking control technique based on fuzzy inference. The ride quality improvement and energy recycling can be expected by the proposed control system with stopping distance estimation and variable duty ratio control on the step-up chopper regenerative circuit. Driving experimental results are provided to verify the effectiveness of the proposed control system.

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The aim of this research was to evaluate the usefulness of anti-electrostatic shoes, developed for the prevention of static electricity in the clothing of medical workers, in medical measurements such as EEG recordings. The shoe was constructed employing a sole with thin conductive rubber and a midsole part made of electro-conductive tape. The shoe sole impedance showed a significant!y lower resistance (5×10⁶Ω), compared with that (8×10¹²Ω) of conventional shoes. Using these impedances, each time constant showed a decay in the current which discharged into the ground through the shoe sole from the electrified hand of a medical worker, being about 1,700 sec. on wearing conventional shoes, and 1.2 sec. on wearing the anti-electrostatic shoes. The electrostatic noise (288.21±66.15μV)in EEG records induced by the electrified hand movement of medical workers wearing conventional shoes with a distance of 5cm from the EEG electrode lead box, showed a signiflcantly higher voltage in comparison to the noise (17.57±3.47μV) on wearing the anti-electrostatic shoes. These results suggest that wearing anti-electrostatic shoes was useful for the elimination of electrostatic noise in the recording data, when biomedical measurements such as EEG and ECG were performed by medical workers.

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The work presented here is about scoliosis measurement. As the ISO16840-1 standard, which is the international standard of seated posture measurement, is a noninvasive measurement method and does not need large-scale devices, it is useful clinically for scoliosis measurement. However, to our knowledge, there has been no clinical attempt that measures scoliosis according to the ISO16840-1 standard. The purpose of this paper is to report our work that evaluates the possibility of application of the ISO16840-1 standard to thoracic scoliosis measurement. First, we measured the gradient angle of the “frontal sternum line” as defined in the ISO16840-1 standard and measured the gradient angle of the thoracic spine from X-ray pictures. Subjects were 29 persons with scoliosis. Next, we compared their gradient angles individually. As a result, it was found that measuring scoliosis according to the ISO16840-1 standard lacks validity for persons with relatively severe scoliosis (larger than 40 degrees of the ”Cobb angle”), but is valid for persons with relatively mild scoliosis (under 40 degrees of the "Cobb angle"). In conclusion, it is indicated that the ISO16840-1 standard can be applied to thoracic scoliosis for persons with mild scoliosis.

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