4. Bionic arm controlled by thought
It can restore a sense of touch to those missing limbs – and could revolutionise prosthetics.Researchers have revealed two patients fitted with radical new artificial limbs that interface directly with their skeleton and nervous system. They were able to identify objects that touched their skin, and do everything from chop wood to drive trucks. To provide more natural sensations the researchers have developed algorithms that convert the input from the sensors taped to a patient’s hand into varying patterns and intensities of electrical signals. The sensors themselves aren’t sophisticated enough to discern textures – they detect only pressure. The different signal patterns – passed through the electrodes – are read as different stimuli by the brain.
The artificial arm is directly attached to the skeleton, thus providing mechanical stability. Then the human’s biological control system, that is nerves and muscles, is also interfaced to the machine’s control system via neuromuscular electrodes. This creates an intimate union between the body and the machine; between biology and mechatronics. The patient’s arm was amputated over 10 years ago. Before the surgery, his prosthesis was controlled via electrodes placed over the skin. Beyond that the neural interfacing and new stimulation techniques may be useful in controlling tremors, deep brain stimulation and more.
