筋電信号差動増幅における信号誘導範囲の検討

摘要

手指の動作において表面筋電図（s EMG）を計測するとき，前腕部の筋は大腿部の筋などに比べ小さいためクロストークを無視出来ない．そこで，ダブル差動（Double Differential：DD）増幅という方法を用いることでクロストークの影響を抑えることが出来る．また，双極誘導における電極中心間距離（以下，電極間隔）を広くとると，得られる筋電信皆の振幅は大きくなる．本研究では，差動（Single Differential:SD）増幅とDDを比較し，各電極間隔で得られる積分筋電図（IEMG）の変化量から深さ方向における誘導範囲を調べた.実験の結果，DDとり得られるIEMGはSDに比べ明らかに減衰していた.また，電極間隔が広がるにつれIEMGは増加していき，表層の被験筋の厚みとほぼ同じ電極間隔においてIEMGに変化がみられた．%When we measure surface electromyogram in the movement of fingers or hand, the target muscle lies on forearm. A muscle of forearm is small in comparison with a muscle of femoral regions. When we measure electromyogram of a small muscle, we must consider the cross talk of defluvium signal from adjacent muscles. Therefore we use the Double Differential (DD) amplification that can suppress affect of cross talk.rnGenerally amplitude of myoelectrie signal is related to the interelectrode distance. We compared DD amplification with Single Differential (SD) amplification and used the change of integration electromyogram (IEMG) provided from the change of electrode interval and examined a derivation range. A result of an experiment shows that IEMG from DD amplification is clearly small in comparison with IEMG from SD amplification and DD amplification suppresses cross talk. Additionally, as electrode interval broadened, IEMG increased, and the alteration was watched in IEMG in electrode interval almost the same as thickness of a surface muscle.