Analysis of Operator's Muscle Fatigue Using Time-Frequency Analysis during Suture Ligation Training

Surgical care affects the musculoskeletal fatigue of surgeons, resulting in a shorter working life span. To prevent this problem, a surgeon fatigue analysis method was introduced to assess muscle fatigue by using mechanomyograms (MMGs) and compared with the use of electromyograms (EMGs). The participants were adult males (eight engineering students). Biometric sensors were attached to the upper trapezius (UT) and anterior deltoid (AD) muscles, and electromyogram (EMG) and mechanomyogram (MMG) were measured during suture ligation training. Subjective evaluation values were measured and compared with the results of fatigue analysis of EMG and MMG. Continuous wavelet transform (CWT) was more effective than short-time Fourier transform (STFT) in detecting remarkable changes in both EMG and MMG. EMG measurement was effective in detecting fatigue in the AD, whereas MMG was effective in detecting it in the UT. Subjective fatigue evaluation values were particularly high not only in the neck, shoulders, and lower back but also in the calves and soles. The CWT of EMG and MMG was effective for fatigue detection. It is necessary to consider the participant and the analysis method that can detect the change more significantly from the viewpoint of myofascial meridians from the result of subjective evaluation value.