Researchers at the
Sensors in the arm will send signals to nerves in the remainder of the amputated arm and then to the brain, allowing the user to sense the arm’s motion and location, and to feel objects with the mechanical hand and fingers, invoking perception and feeling.
Key to this interface will be the Utah Slanted Electrode Array — a wireless device that will be able to interpret signals from residual nerves, translate them and send them wirelessly to the bionic arm. Greg Clark, principal investigator at
‘At the same time, we can have sensors on fingertips or to measure the joint angle to establish sensory, perceptive information and send it back the other way.’
This technique differs from conventional prosthetics in two ways. traditional prosthetics are controlled by signals from an intact muscle, for example a shoulder shrug which must be learned by the user and can be challenging.
Second, only one movement can occur at a time, whereas the new prosthesis will tap into signals going to all the muscle groups. This means the arm could merge various movements simultaneously to produce a more realistic movement. As
Despite being involved in this field for the past 15 years,
Worth potentially $10.3m (£5.5m) the project is just part of a larger DARPA-funded initiative called Revolutionising Prosthetics which involves the John Hopkins University Applied Physics Laboratory and a number of sub-contractors, including two branches of the Fraunhofer Institute; the Institute of Reliability and Microintegration and Institute for Biomedical Technology who will assist in the manufacture of the array and components.
The Pentagon announced the project earlier in the year when it awarded John Hopkins $30.4m over two years, with additional funding that could bring the total to $54.8m over four years. The university is sub-contracting work to 28 other universities, labs, hospitals and companies who will be involved in making the rest of the arm, such as sensors, power supply and attachments.
But whether, after just four years, this project will have produced a fully-fledged realistic prosthetic limb remains to be seen.