The MANUS-HAND dextrous robotics upper limb prosthesis: Mechanical and manipulation aspects

Dextrous artificial hand design and manipulation is an active research topic. A very interesting practical application is the field of upper limb prosthetics. This paper presents the mechanical design and manipulation aspects of the MANUS-HAND project to develop a multifunctional upper limb prosthesis. The kinematics of our design makes use of the so-called underactuated principle and leads to an innovative design that triples the performance of currently existing commercial hand prosthesis. In addition, the thumb design allows its positioning both in flexion and opposition. As a consequence, up to four grasping modes ( cylindrical, precision, hook and lateral) are available with just two actuators. The proposed impedance control approach allows the fingers to behave as virtual springs. Given the difficulty of including the user in the control loop, this approach is based on an autonomous coordination and control of the grasp. As a consequence, the requirements on the Human Machine interface are reduced. At the end of the paper, we briefly describe the clinical trials that were set up for evaluation purposes.