Simulation of Force Changes in the Human Biceps Using a Muscle Model Based on Electromyographic Signals

Abstract

The purpose of this study was to reproduce the force in a voluntary contraction via surface electromyography (SEMG) using a systematic muscle model. We measured the isometric voluntary contractile force and SEMG of the human biceps. We examined the effect of the electrode size on SEMG. A pair of electrodes with a diameter of 1 mm was adopted, because they avoided signal interference from the action potentials of other motor units. We added a converter to the muscle model to obtain an artificial action potential that successively drives an excitation-contraction controller and a motor unit. When the force was less than 30% of the maximum force, EMG signals were obtained from a few motor units. The resultant force coincided well with the experimentally observed force with an accuracy of around 90% when an appropriate threshold level was set up in the converter. This method will increase in performance when we can separately detect the SEMG signals from multipoint measurements.