Investigation of the dynamic body balance by tracking a moving target on CRT using visual-guided stimulation.

1994 Fiscal Year Final Research Report Summary

• Project/Area Number: 05671447
• Research Category: Grant-in-Aid for General Scientific Research (C)
• Allocation Type: Single-year Grants
• Research Field: Otorhinolaryngology
• Research Institution: Toho University School of Medicine
• Principal Investigator: YAMAMOTO Masahiko Toho University School of Medicine, Dept.Otorhinolaryngology, Associate Professor, 医学部, 助教授 (40112916)
• Project Period (FY): 1993 – 1994
• Keywords: visual-guided stimulation / gravic body sway / body equilibrium / tracking ability / body tracking test / BTT

Research Abstract

In order to evaluate the function of the dynamic postural equilibrium, a computer-assisted evaluation system was constructed utilizing a gravicorder and a computer-controlled, dynamic target displayd on CRT.The system is constructed in such a way that the moving target on CRT is tracked by the volitional bodily movements, the gravitational center of which is simultaneously displayd on the same CRT.One is asked to attempt tracking the moving target by the center of body movement.This system is thus named the Body Tracking Test (BTT).
System : Gravicorder is a G5500 model of ANIMA Co.and a PC 9801 personal computer (NEC) and a A/D converter (Analog-pro and ADX-98 model of Canopus C). A display stand was specially made by Hata Electric Co. ; i.e., the display stand can bring the moving target up to an appropriate height at the level of examinee's eyes.
Method : The display stand was set in front of gravicorder and the eye level of the examinee.The moving target was displayd according to the BTT program.The examinee was to track the moving target on display by voluntary motions of the body. BTT programs contain several patterns, that include laterally moving, anterior-posterior moving, circling (clock-wise and counterclock-wise), and random stimulation.In this investigation, the stimulation used was in most case that of lateral movements.
Analysis method : For evaluation of BTT,I have developed programs for data analysis.For this trial, the BTT was evaluated by comparing the moving distances of the target with that of bodily gravic movements for tracking the moving target. The test parameters. THE distance between the CRT and examinee, laterally moving target speed on CRT and the gain of displayd gravitational center as an output data from the gravicorder. The output power of gravicorder was 100mv/10Kg・cm.
Results : Analysis of many BTT data of normal subjects revealed the following results.
The most appropriate moving speed of target was 0.125Hz on the span of 15cm.2. The gain of the displayd target for tracking against a moving target was twice larger than that of moving target.3. Distance of the target from the gravicorder was 100 cm.According to the setup of these parameters, the test has been performed without major difficulty either of the examinee or the machine side and the results thus obtained were rather consistent.
In the future, the BTT will be used to evaluate the quality and magnitude of disability brought about by the disorders of equilibrium, its rehabilitational functions and so forth.It will be utilized also to evaluate the equilibrium functions of an individual, when one's proficiency for specific sports is to be evaluated.