Using a motorized prosthetic hand can be difficult, as users have to continuously concentrate on controlling the thing. That's why scientists from Switzerland's EPFL research institute are developing new technology, in which a computer takes over certain functions.
Known as a shared control system, the setup incorporates muscular-activity-detecting electrodes which are placed on the amputee user's residual arm stump.
After an initial training period, an integrated computer system learns to associate specific patterns of activity with the movement of specific fingers on the prosthetic hand. This means that in order to open or close a given finger or set of fingers, the user purposefully contracts or relaxes their stump muscles in a given way.
Doing so could get mentally and physically taxing after a while, though, which is where the computer system comes in. Utilizing feedback from pressure sensors on the inside of the hand, it automatically tightens the fingers around objects that they're touching, effectively grasping those items.
And should the sensors subsequently detect that an object is slipping from the hand, the computer system responds within 400 milliseconds by further tightening the grip. Of course, users can still manually release grasped items, whenever they want.
For now, the shared control system is being tested on a third-party robotic arm. Once developed further, though, it is hoped that the technology could make its way into commercially-available prostheses.
The system is described in a paper that was recently published in the journal Nature Machine Intelligence, and can be seen in the following video.
Source: EPFL