The research addresses the characterization of the assembly skillfulness for clinical procedures with an analysis of the operator’s mental and behavioral activities. The focal point of this study is to present a method for denoting novice behavioral trends and dispositions with attention or confusion by physio-psychological indices and hand manipulation movements, in the preparation of a hemodialysis blood circuit. Our approach utilized the electrocardiogram (ECG), electrodermal activity (EDA), and inertial measurement units (IMU) on the wrists. Also, synchronized video recording examined the context sequence of the assembly task. Thirteen undergraduates who belong to a clinical engineering course participated in the experiment. They were knowledgeable but in training for hemodialysis procedures. Short-time Fourier transform (STFT) examined frequency features over the time in the RR intervals (RRI), and EDA responses revealed content-specific arousals of the sympathetic nerve during the assembly task. Hand movements through the IMU measurement enumerated degrees of continuities and intensity of movement. Results prospect feasibility of the method for describing the assembly skill characterized by attention or confusion in particular contexts, that expected to contribute to the skill enhancement in practice with useful feedback indicating the trigger factors.