メニエール病患者の身体動揺の特徴*

In order for the navigator to handle the ship for safe navigation, he/she judges the navigational information through the five senses. Here, we think that visual information is the most important because it is said to occupy eighty percent of the whole information. We research on the relationship between the visual environment and its influence on the ship's bridge simulator. It is used to train and educate the handling of ships as well as the handling of some navigational instruments. The purpose of this paper is to find characteristics of the body sway of the navigators and inexperienced persons for rolling created through the picture of ship's bridge simulator not physically or mechanically. The four kinds of visual field (210/spl deg/, 150/spl deg/, 90/spl deg/, and 30/spl deg/) are also carried out. The results show that the characteristic of body sway is different among navigators, inexperienced persons and seasick subjects, and the body sway tunes with the period of rolling while subjects feel the true rolling.

Body sway in patients standing with eyes closed was observed by tilting the plate toward the front, back, left, and right. Patients with equilibrium dysfunction produced a specific body sway under these conditions. It is shown that merely standing on the flat plate does not always show a specific pattern even in patients with equilibrium dysfunction. However, for subjects standing on the tilting plate, it is possible to discriminate equilibrium disorders from normals. Eight directional display and a power spectrum of body sway are useful for the diagnosis of equilibrium dysfunction. Abnormal subjects show a peculiar pattern in the radar chart display of displacement, and the power spectrum of body movement does not obey the rule of 1/f fluctuation. >

〔目的〕パーキンソン病患者における立位時足圧中心の前後移動量と足圧分布の関連について調べた．〔対象〕パーキンソン病患者8名と健常高齢者8名が参加した．〔方法〕足圧分布計上で体幹前後動揺を行った．足趾部・中足骨部・踵部の荷重圧変化を独立変数，足圧中心の移動変化を従属変数とした重回帰分析を行い，偏回帰係数を算出した．〔結果〕パーキンソン病患者は健常群と比較して足長に対する足圧中心の移動比率が前後共に低下し，偏回帰係数は足趾部で有意に低く，中足骨部で有意に高かった．〔結語〕パーキンソン病患者における立位時の随意的な前方への足圧中心移動量の低下は，足趾部への荷重量低下に起因する．

Following a lesion in the vestibular system visual, proprioceptive and residual vestibular information is integrated by the brain, to enable a patient to attain equilibrium. The basis of vestibular rehabilitation is to encourage these adaptive and compensatory mechanisms. Another form of rehabilitation is to provide some form of mechanical aid, and walking sticks are often used for this purpose in patients with balance disorders. There are no reported studies objectively assessing the use of walking sticks in patients with balance disorders. In this study we used the Sway Weigh balance platform (Raymar) to determine the efficacy of a walking stick in 25 patients with peripheral vestibular balance disorders. Patients were tested with their eyes opened and eyes closed whilst they were standing on a flat surface and on an air-filled bed (to alter limb proprioception) on the Sway Weigh balance platform. All the tests were carried out with, and without, a walking stick. The results demonstrate that a walking stick significantly reduces lateral body sway in patients with peripheral vestibular balance disorders.

This study was done to examine age-stage (preschool children, young adults, and elderly people) differences in the center-of-pressure sway using body-sway factors (unit-time sway, front-back sway, left-right sway, and high frequency-band power), power-spectrum distribution, and relative accumulation of power frequency (25%, 50%, and 75% RAPF) of the center-of-pressure spectrum. The center-of-pressure movement for 1 min. was measured twice using Anima's stabilometer. Data-sampling frequency was set at 20 Hz. Significant age-stage differences were found for 3 factors except for left-right sway, which was larger for preschool children and elderly than for young adults. The power spectrum of body sway in any age-stage was noted mainly in low frequency bands. A marked age-stage difference was found at 75% RAPF. Body-sway characteristics in each age-stage differ, and differences of postural-sway frequency are marked in the low frequency bands.

Human quiet standing is accompanied by body sway. The amplitude of this body sway is known to be larger than would be predicted from simple noise effects, and sway characteristics are changed by neurological disorders. This large sway is thought to arise from nonlinear control with prolonged periods of no control (intermittent control), and a nonlinear control system of this kind has been predicted to exhibit bifurcation. The presence of stability-dependent transition enables dynamic reaction that depends on the stability of the environment, and can explain the change in sway characteristics that accompanies some neurological disorders. This research analyses the characteristics of a system model that induces transition, and discusses whether human standing reflects such a mechanism. In mathematical analysis of system models, (intermittent control-like) nonlinear control with integral control is shown to exhibit Hopf bifurcation. Moreover, from the analytical solution of the system model with noise, noise is shown to work to smooth the enlargement of sway around the bifurcation point. This solution is compared with measured human standing sway on floors with different stabilities. By quantitatively comparing the control parameters between human observation and model prediction, enlargement of sway is shown to appear as predicted by the model analysis.

Today, because of spread of large-scale indoor environment (e.g. shopping male, university and airport), personal vehicle to expand our mobility is needed. In this research, we especially focused on psychological status of driver and body sway to estimate driver's psychological status using body sway of drivers. In this paper, we investigate relationship between trans-velocity of vehicle and body sway. And its result shows that there is non-liner characteristics between transit velocity and RMS area of body sway. Using this characteristics, there is possibility to establish personal vehicle control system including driver's state anxiety.

The control of the human body sway by the central nervous system, muscles, and conscious brain is of interest since body sway carries information about the physiological status of a person. Several models have been proposed to describe body sway in an upright standing position, however, due to the statistical intractability of the more realistic models, no formal parameter inference has previously been conducted and the expressive power of such models for real human subjects remains unknown. Using the latest advances in Bayesian statistical inference for intractable models, we fitted a nonlinear control model to posturographic measurements, and we showed that it can accurately predict the sway characteristics of both simulated and real subjects. Our method provides a full statistical characterization of the uncertainty related to all model parameters as quantified by posterior probability density functions, which is useful for comparisons across subjects and test settings. The ability to infer intractable control models from sensor data opens new possibilities for monitoring and predicting body status in health applications.