Danish scientists say they have found a way to help paralyzed people perform simple tasks. Morten Haugland and Andreas Inmann at the Center for Sensory-Motor Interaction at Aalborg University have developed a portable system that monitors bundles of nerves from the index finger of a patient to detect overexertion and compensate by adjusting their grip. The system has been designed to work with commercial neural prostheses that work by electrically stimulating particular muscles, causing them to contract and making it possible to achieve coordinated movements. The new add-on system helps to refine the motions provided by the prosthetic devices. Haugland’s add-on device consists of three electrodes wrapped around a nerve bundle implanted into the palm of the hand. Information on the strength of grip is fed back to the muscle stimulator, located externally on a wrist cuff. The stimulator is controlled by two buttons pressed by a head-mounted prodder: one turns the system on and increases the power, the other decreases the power and turns it off.
The team’s ultimate goal is to restore a patient’s sensation, but for now they are planning to exploit the new approach. Haugland is using similar electrodes to help paraplegics balance when standing. Haugland’s system uses the hand as an extension to a machine–with muscles instead of motors, and nerves replacing touch sensors.
SOURCE/REFERENCE: Reported by New Scientist, 6/10/00
