Medical instrument i.e. file, fatigue measuring method, involves evaluating integral of value correlated with electrical power that is applied for operating instrument on electric motor at time of employment of instrument

摘要

The method involves evaluating an integral of a value correlated with an electrical power that is applied for operating an instrument on an electric motor at the time of employment of the instrument. The electrical power applied for a cutting operation of the instrument is maintained smaller during the evaluation of the integral of the value. A weighting factor is entered corresponding to the degree of the curvature of a root channel.