2009 年 4 巻 2 号 p. 212-220
Surface electromyography (sEMG) is commonly used to measure muscle activity because of easy application. Advantages of sEMG measurements include noninvasiveness and no pain. However, there are also problems with the sEMG technique when the activities of individual muscles are measured. The measurement of activity of individual muscles in the forearm with sEMG must be analyzed further because of superimposition of sEMG signals. In this work, a cylindrical phantom-forearm model filled with ground specimens of muscle was developed containing source and surface electrode pairs. A weak alternating current was applied to a source electrode pair immersed in the model, and the sEMG signals were measured with surface electrodes around the surface of the model. The attenuation characteristics of muscle action potential (MAP) were estimated from the measured sEMG, and the source position of the MAP was reverse-estimated. The reverse-estimated depth was accurate for less than 30mm of source depth. A 10% difference in the power exponent of attenuation caused errors in the reverse-estimation of less than 3mm.