Prosthetic Limbs with a Sense of Touch

The Defense Advanced Research Projects Agency (DARPA) has always been at the forefront of ground breaking research. The fact that we can all communicate via the Internet today is partly down to their research projects with the development of ARPANET back in the sixties leading the field of computer networking.

It’s always interesting to keep abreast of what research they’re funding because, although they are essentially a research branch of the American DOD, much of their work has civilian applications. The latest innovative project that has caught my attention is their work with prosthetic limbs. Since 2000 over two thousand US Service Men have suffered amputated limbs so there is a very prescient reason for DARPA to be interested in prostheses.

Working in cooperation with Case Western Reserve University in Cleveland DARPA has created a prosthetic limb that interfaces directly with the patients neural system. In practical terms this means that these new prosthetic limbs can do two startling things; they can be entirely controlled by thought and they impart a sense of touch to the user. This makes activities we take for granted such as turning a light switch on in the dark, close to impossible with a normal prosthetic, far simpler.

How is this achieved? The new prostheses integrate directly with the remaining nerves in a patients limb. The Flat Interface Nerve Electrode (FINE) developed under DARPA’s RE-NET program is the technology that makes this human/machine interface possible. Essentially a nerve is flattened to allow more of it to come into contact with an electrode which allows for much more efficient transmission of information from the machine directly to the patient’s nervous system. This means that the patient can actually feel what the prosthetic is touching allowing far better coordination of the limb. As touch sensor technology improves it should be possible to create limbs with a near native sense of touch. The video above shows a patient conducting a blind task and gives an idea of what this technology will be able to deliver to victims of amputation.