Hand Prosthesis Control Via Myoelectric Patterns

It is well known that many orthopaedic appliances do not receive the immediate appreciation hoped for.In fact, they are frequently put away on the shelf or in the drawer, and the patient manages without them.This is to some extent true also for myoelectrically controlled artificial hands.Undoubtedly the mechanism of rejection of such a hand prosthesis by an amputee is a complicated one, involving various psychological components.However, it is reasonable to believe that the patient's attitude toward his new device is a result of a cost-benefit analysis in which the cost is made up of technical breakdowns, unsatisfactory function and training time demands.The benefit is calculated on the functional assistance and cosmesis.Provided a hand prosthesis is well designed, technical breakdowns should be a minor source of trouble.The unsatisfactory function, on the other hand, is a consequence of failure to solve a basic problem: how to provide the patient with some of the vital hand functions he has lost.The ultimate answer cannot be the simple device of today, supplied with active hand opening and closing only.The multifunctional hand concept has been introduced to enhance prosthetic hand function, and to make the patient more likely to accept and draw full advantage of the prosthesis.So far, multifunctional hands have not been very successful: none is commercially available as of now, despite efforts in many countries (Rakit 1967, Kato et al. 1970, Germans et al. 1970, Voskoboinikova 1970, Schmidl 1971, Lymark 62 Mohl 1967).In addition to certain engineering problems, this fact is due to the problem of how to leani to operate a complicated device quickly and efficiently.