The purpose of this study was to evaluate the workers' skill levels quantitatively by biological measurement during performance of milling work. We evaluated the relationship between the workers' skill levels, the difficulty levels of the tasks, and the workers' nervous system activities, i.e., changes in oxyhemoglobin and deoxyhemoglobin in prefrontal cortex as central nervous system activities and LF/HF as autonomic nervous system activities. Subjects were divided into two groups, i.e., an expert group and an intermediate subject group. As a result, it was shown that there is a certain relationship between workers' skill levels, the difficulty level of the tasks and nervous system activities. In conclusion, there is a possibility that changes in nervous system activities can evaluate the workers' milling skill level quantitatively.
https://ror.org/04jndar25 
