Abstract: A voluntary opening prehension device is constructed with a pivot member having a pair of fingers mounted thereon and extending distally from the pivot member. The fingers may be pivoted individually or simultaneously so as to selectively separate or converge at their distal ends. An electric motor is used to separate the fingers. A closing mechanism biases the fingers into contact with each other when the motor is not in operation. A battery supplies electrical power to the motor. A field effect transistor driver serves as a switch for actuating the electric motor when it is supplied with a myopulse of a specified threshold strength or greater. This reduces the amount of electrical power utilized to operate the device since the motor is actuated only when a clear signal is sent from the user. A control mechanism supplies the myopulse to the field effect transistor driver in response to a myoelectric signal generated by the user.

Abstract: A myoelectrically controlled artificial hand is provided having a pair of fingers extending distally from a pivot and mounted thereon for selective separation and conversions by means of a pair of electrical motors. The first electric motor has high speed and low torque with a drive train connected to one of the fingers so as to affect rapid separation and conversion of the fingers. The second motor has low speed and high torque, and has a drive train connected to the second finger to effect pinch force between the fingers. A field effect transistor driver actuates the electric motor to operate the artificial hand. The control mechanism for the motors is actuated by myoelectric signals from the user, so as to supply myoelectric pulses to the field effect transistor driver. As a result, the user can selectively separate or converge the fingers based on his own muscular movement.