It is difficult to fully understand why the prosthetics field has taken so long to respond to the advances in electronics and materials science. It is true that the market is price sensitive and it has to wait for advances in the consumer goods markets for batteries and electronics before these devices can be incorporated into newer systems. Therefore the individual elements must regulate themselves and leave only the central processing to the brain. Paradoxically, the control of exo-prosthetic systems, is still one of direct control of each joint by the operator. This results in a slow and arduous actions and limits their range of use.
Humans manipulate objects by adapting the shape of the hand to that of the target object.
They maximise the contact area and so minimise the contact forces required for stable manipulation. The reconfigurable nature of the human hand means the shape it adopts can reflect the task enabling the hand to impart larger forces through a power grip, or finer control using a precision grip. If a microprocessor is given information concerning the shape, orientation and stability of the held object within the grasp of a prosthesis, the processor can control more of the functions of the hand itself. The operator gives simple commands and the controller co-ordinates multiple degrees of freedom to shape the hand to maximise the contact area between the hand and the object and so minimise contact forces. If the object slips this is detected and the controller responds.