Measurement of the Bicycle Driving Time Using a Triaxial Accelerometer System

摘要

〔目的 〕3軸加速度計システムを用いて自転車駆動を判別し，その駆動時聞を測定することを目的とした. 〔対象〕実験1では健常学生11名，実験2では健常学生9名を対象とした. 〔方法〕実験1では，対象者に2つの3軸加速度計を装着させ，自転車を含む日常生活動作を行わせた. 3紬加速度計が記録した加速度から変動値を算出し，総時聞における判別された時聞の割合から判別闘値を検討した.実験2では，対象者に3軸加速度計を装着させ実験1と同様の活動を行わせ，その様子をビデオカメラで撮影した.次に，加速度計とピデオカメラから各動作の総時聞を求めBland-Altman解析を用い比較した. 〔結果〕実験1の結果，判別された時聞の割合が90%以上である闘値を自転車の判別闘値と決定した.実験2の結果， 3紬加速度計とビデオカメラから求めた測定時聞は全ての活動において強い相闘がみられた.また，加算誤差，比例誤差は認められなかった. 〔結語〕これらの実験結果から， 3軸加速度計システムを用いた自転車駆動の判定と駆動時間測定方法の信頼性が示唆された.[Purpose] The purpose of this study was to . discriminate the movement of bicycle drive and measure the time spent operating a bicycle using a new triaxial accelerometer system. [Suhjects] Eleven healthy students participated in the first experiment and nine healthy students participated in the second experiment. [Methods] Subjects wearing two accelerometers carried out the activities of daily living, including a bicycle drive, in the first experiment. We evaluated the variation values from the data obtained from the acceleration accelerometer system and determined the discriminating threshold from the percentages of times analyzed to be during the bicycle drive in the total times. Subjects wearing two accelerometers carried out the activities of daily living, including a bicycle drive, and were videotaped in the second experiment. The times obtained by these two methods were compared using the Bland-Altman method. [Results] The discriminating threshold was capable of distinguishing the bicycle operating time at a ratio of 90% or more in the first experiment. There was a strong and significant correlation among all the activity times measured by the video camera and the accelerometer, and no flxed or proportional errors were observed in the second experiment. [Conclusion] These data suggest the reliability of using the new triaxial accelerometer system to measure the time spent operating a bicycle.