Working With PCs Made Simpler for People With Severe Disabilities

Thanks to high-performance sensors, developed by the IPCA project, people with severe motor or speech disabilities can now operate a PC.

The original idea behind the IPCA project was to adapt biofeedback sensors used for rehabilitation purposes, so that they can be used as part of a computer interface. Biofeedback training enables people who no longer have full muscular control to ‘teach’ their bodies how to operate the muscles appropriately. The sensors measure parameters such as electromyographic response (EMG, i.e. minute electrical signals that control muscles), respiration rate, heart rate, skin conductivity and other factors.

“We had determined that people with severe motor and speech disabilities were not being adequately served by existing computer input devices,” says Dr. Carlos Velasco of Fraunhofer-Institut für Angewandte Informationstechnik (FIT), and IPCA coordinator. “So we formed a project team to look at the problem which included a Dutch company with expertise in hardware and sensor technology, the Asociación Instituto de Biomecánica de Valencia (IBV), and ISdAC (Information Society disAbilities Challenge) as the user group.”

Three types of sensor were developed within the project: EMG, inertia/gravity and skin conductivity. “With the EMG sensor, all we need to do is to find a muscle in the body over which the person can exert control, and this can be used to operate the computer,” says Velasco. “For people who have sufficient movement, an inertia/gravity sensor can be placed on their wrist or head. Even if they have only a few degrees of movement, this is sufficient to control a PC with this assistive technology device. The skin conductivity sensor can be used to detect changes in emotional state when the user is engaged in some activity, and this, too, can be used as a computer input.”

Once the signals from the various sensors have been processed, the output is applied to the PC via the standard PS/2 keyboard interface cable. Special interface software runs on the computer, optimizing the interaction between the sensors and the PC applications.

“Last summer, the prototype was tested in a pilot trial involving 60 people,” adds Velasco, “and the level of acceptance was very high. Before we can commercialize it, however, some more design work is needed to miniaturize the sensor and processor electronics, and adding a USB interface. We may be looking at alternative funding.”

Source: IST Results