The objective of the work described in this paper is to develop an artificial hand to replicate the appearance and performance of the natural hand. The ultimate goal of this research is to obtain a complete functional replacement of the natural hand. This means that the user must feel the artificial hand as part of his own body (extended physiological proprioception (EPP)) and must provide the user with the same functions of the natural hand: tactile exploration, grasping and manipulation ("cybernetic" prosthesis).
Prosthetic devices available on the market, as well as multifunctional hand designs, have good (sometimes excellent) reliability and robustness, but their grip capabilities can be improved. It has been demonstrated that the methodologies and knowledge developed for the robotic hands can be apologies and the knowledge developed for the robotic hands can be applied to the prosthesis domain to increase the final performance. The first significant example of an artificial hand designed in accordance with a robotic approach is the Belgrade / USC hand.
Subsequently, several robotic forceps and articulated hands have been developed, such as the Stanford / JPL hand and Utah / MIT hand which have obtained excellent results. An accurate description and a comparative analysis of the state of the art of artificial hands can be found. These hands have performed well in mimicking human capacities, but they are complex devices that require large controllers and their mass and size are not compatible with the strict requirements of prosthetic hands.
In fact, artificial hands for prosthesis applications pose challenging specifications and problems, as is often the case with devices that will be used for functional replacement in clinical practice. These problems have forced the development of simple, robust and reliable commercial prostheses, such as Otto Brock Sensor Hand prostheses, widely implanted and appreciated by users. Otto Bock's hand has only one degree of freedom (DOF), can move the fingers at a proportional speed of 15-130 mm / s and can generate a gripping force of up to 100 N.
Advantages of the biomechanical hand
Handicapt can lead independent living.
Quiet operation so as not to interrupt social interactions, adequate cost to support the health insurance system.
Disadvantages of biomechanical hand
The cost of implementation is very expensive.
Can not withstand a load of more than 40 N.
Causes a problem when controlling the hand precisely.