In this article, we set forth a detailed analysis of the mechanical characteristics of anthropomorphic prosthetic hands. We report on an empirical study concerning the perfor- mance of several commercially available myoelectric pros- thetic hands, including the Vincent, iLimb, iLimb Pulse, Bebionic, Bebionic v2, and Michelangelo hands. We investi- gated the finger design and kinematics, mechanical joint cou- pling, and actuation methods of these commercial prosthetic hands. The empirical findings are supplemented with a compi- lation of published data on both commercial and prototype research prosthetic hands. We discuss numerous mechanical design parameters by referencing examples in the literature. Crucial design trade-offs are highlighted, including number of actuators and hand complexity, hand weight, and grasp force. Finally, we offer a set of rules of thumb regarding the mechani- cal design of anthropomorphic prosthetic hands.

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Mechanical design and performance specifications of anthropomorphic prosthetic hands: a review.

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.

The MANUS-HAND Dextrous Robotics Upper Limb Prosthesis: Mechanical and Manipulation Aspects

In this paper we set forth a review of performance characteristics for both common commercial prosthetics as well as anthropomorphic research devices. Based on these specifications as well as surveyed results from prosthetic users, ranges of hand attributes are evaluated and discussed. End user information is used to describe the performance requirements for prosthetic hands for clinical use.

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Performance characteristics of anthropomorphic prosthetic hands

An "ideal" upper limb prosthesis should be perceived as part of the natural body by the amputee and should replicate sensory-motor capabilities of the amputated limb. However, such an ideal "cybernetic" prosthesis is still far from reality: current prosthetic hands are simple grippers with one or two degrees of freedom (DOF), which barely restore the capability of the thumb-index pinch. This paper describes the development of a novel prosthetic hand based on a "biomechatronic" design. The proposed hand is designed to augment the dexterity of traditional prosthetic hands while maintaining approximately the same dimension and weight. Our approach is aimed at providing enhanced grasping capabilities and "natural" sensory-motor coordination to the amputee, by integrating miniature mechanisms, sensors, actuators, and embedded control. A biomechatronic hand prototype with three fingers and a total of six independent DOFs has been designed and fabricated. The paper is focused on the actuators system, which is based on miniature electromagnetic motors.

The development of a novel prosthetic hand-ongoing research and preliminary results

A survey of bio-inspired robotics hands implementation: New directions in dexterous manipulation

The first part of this paper reviews different approaches to define the motion of the fingers and the thumb in order to obtain prehension. The last part presents the design of a hand prosthesis based on a new plane of action for the thumb and on proposed design specifications and functional characteristics. The design methodology consists of two steps: the morphology design of the hand prosthesis and the 4-bar mechanism design for each finger. A 3-D computer-aided design (CAD) interactive program was used as a design tool to obtain the hand morphology. This CAD technique was also used to check the geometry, the relative motions of the fingers, and the possibility of interference for the proposed model with two prehension patterns (tridigital and lateral). It is noted that identical flexion angles of the finger joints were obtained for these two prehension patterns, the difference being in the inclination angle of the thumb's plane of flexion. This finding greatly simplified the design of the internal mechanisms of the fingers. CAD was a powerful tool in the design process of this hand prosthesis and will be more and more useful in the future.

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G Drouin

Papers

Design methodology for a multifunctional hand prosthesis