A basic study of new sensory feedback system for postural control by use of a mixed reality technology

[目的]分析振动反馈系统对维持良好站立平衡的作用。[方法]实验对象为青年人和老年人。所有受试者的日常生活活动都是独立的。振动反馈系统由振动装置单元、测力板单元和反馈控制单元三部分组成。振动装置单元由八个振动器组成，分别带有海绵脚垫和腰部带。该系统需要被试的反馈，以告知他们的站立平衡状况。测力板单元真实的实时记录压力中心（COP）数据。如果COP的轨迹到达由检查者确定的前足位置、前足下方的振动器和他们的腰部，则激活反馈控制单元。前瞻性目标位置定义为每例受试者COP最大位移的50%和110%，这是从改良的交叉检验中获得的。受试者在测力板上站立7s作为起始位置，然后在每个方向上尝试达到目标位置6s，最后在最大位置保持7s。[结果]受试者COP运动对振动呈现距离的准确性较高，超过80%。这意味着这种振动刺激似乎有效地提供姿势信息。[结论]振动反馈对人体在支撑基础内的姿势平衡有积极的影响。可以假设，该系统可能能够作为用于平衡训练或姿势稳定性意识注意的特殊装置来帮助控制身体摇摆。

[PURPOSE] The purpose of this study was to analyze the effects of the vibratory feedback system between the force plate and vibratory stimulation for maintaining good standing balance. [METHODS] The young adult and the elderly were participated in the experiment. All subjects were independent in their activities of daily living. The vibratory feedback system has three units, vibratory device unit, and force plate unit, feedback control unit. The vibratory device unit was composed of eight vibrators with sponge foot mats and the belt at their waist, respectively.. The system needs the feedback for the subjects to inform from of their condition of standing balance. The force plate unit recorded the center of pressure (COP) data in real time. The feedback control unit was activated if the trajectory of the COP reaches a position of forefeet, which has been determined by the examiner, the vibrators under the forefeet and their waist. The prospective target position was defined as 50 % and 110 % of the maximal displacement of the COP in each subject, which was obtained from the modified Cross-test. The subjects stood on the force plate for 7 seconds as the start position and then they tried to reach the target position in each direction for 6 seconds and finally maintain at the maximal position for 7 seconds. [RESULT] The accuracy of the COP movement to the vibratory presentation distance showed a high accuracy that exceeded 80% in the subjects. It means that this vibratory stimulation seems effective as providing posture information. [CONCLUSION] The results suggest that the vibratory feedback may positively affect postural balance within the base of support. It might be hypothesized that this system may be able to help in the control of body sway as a special device for balance training or postural stability awareness attention.