A computer-controlled experimental set-up enabling the quantification of motor performance in man, applied to mastication.

This paper describes a computer-controlled experimental set-up, which enables the simulation and manipulation of the resistance of food, the bolus size and reflex evoking events during chewing in man. Food resistance was simulated by an external downward directed force on the mandible during the closing phase. The force was supplied by a magnet-coil system. A coil, rigidly attached to the subject's mandible, was located in a permanent magnetic field. By varying the current through the coil, the force on the coil and thus on the mandible could be adjusted. The current was on line computed as a function of the jaw gape. Food resistance and bolus size could be simulated and manipulated by varying the amplitude of the force and the jaw gape at which the force started, respectively. The possibility of varying these parameters could be used simultaneously and independently. Reflex evoking events were simulated by an additional loading or unloading force pulse, superimposed on the food-simulating force. The set-up has been tested during experiments in which food resistance, bolus size and reflex evoking events were simulated. Examples of these experiments are presented in this paper.