A device for penetrating tissue is provided that has a driving actuator with a body and motor shaft that is reciprocated. A coupler is attached to the motor shaft, and a key engages the driving actuator and coupler and limits rotational motion of the motor shaft and permits linear motion of the motor shaft, A penetrating member is carried by the coupler, and linear motion of the motor shaft is translated to the penetrating member to linearly reciprocate the penetrating member.
