A modular multisensory prosthetic hand

This paper presents a multi-DOF and multisensory prosthetic hand (HIT V prosthetic hand) with five modular fingers. The hand has a total of 11 joints, which are actuated by 6 intrinsic DC motors. Each digit (2 joints, DIP and MCP, coupled) is driven separately by a motor within the proximal phalange, while the trapeziometacarpal (TM) joint of the thumb is specially devised with an additional actuation in the palm to accomplish adduction/abduction. A type of worm-and-wheel is applied to the metacarpophalangeal (MCP) joints of the five fingers and the TM joint, which can provide a self-locking ability when no motion is internally actuated. Multiple sensors integrated in the distal phalanxes can measure the current position and applied forces of the fingers. The hand control system is composed of two subsystems separately in the finger and in the palm. The finger, integrated with the actuator, the transmission mechanism, the sensory system and the control system as a whole, can obtain abilities to perceive and control all by itself, which provides a technical possibility for partial upper-limb amputees. The hand configuration is specially designed to provide versatile grasps in human's activities of daily living (ADLs). According to the primary experimental results, the technical specifications of the newly-developed prosthetic hand, including the output force and motion velocity, are given in detail. It is validated that the hand can accomplish most of the grasping patterns in our daily lives.