Abstract. Conventional clinical evaluation of spontaneous movements in early infants is a subjective evaluation based on visual observation. To clarify the parameters for these complicated movements, chaos analysis was conducted using angular acceleration of elbow extension–flexion movements. Neurologically normal premature infants were measured every 4 weeks at 36–56 weeks post menstrual age using a three-dimensional motion analyzer. The data were used for chaos analysis (the largest Lyapunov exponent, the correlation dimension). All data had chaos dynamics. The largest Lyapunov exponent were decreased and the correlation dimension were increased. Significant difference was found among the outcomes. The parameters used to quantify complicated movements were clarified. (初期乳児期の自発運動に対する従来からの評価法は視覚認知を用いて行われてきた。本研究の目的は、自発運動中の肘の屈曲伸展運動の角加速度に対してカオス解析を行い、カオス解析の値が複雑さを表すパラメータになり得るかを明らかにすることである。在胎週数36週から56週の乳児の肘の運動を4週毎に3次元動作分析装置で計測し最大リアプノフ指数と相関次元を算出した。結果、全でーたにおいてカオス性を有しており、最大リアプノフ指数は有意に減少し、相関次元は有意に増加していった。これらのパラメータは運動の複雑さの変化を表すことがわかった。)
Mamoru IGARASHI, Hideki OYAMA, Shin-ichi IZUMI
