Ultrasound-Powered Prosthetic Hand
Image credit: Fraunhofer IBMT
Development of a powered prosthetic hand is underway which engages an array of ultrasonic sensors to create movement – an advance in technology which researchers called a significant improvement from conventionally-used electrodes.
The research comes from a team from the Fraunhofer Institute for Biomedical Engineering (IBMT), working as part of the five-country SOMA Project, who are working to improve control of prosthetic hands.
Typically, powered prosthetic hands rely on electrodes placed on the skin, detecting signals from muscle contractions and converting them to movement in the prosthesis.
In contract, the technique developed by Fraunhofer IBMT researchers uses ultrasonic sensors which send a continual stream of sound pulses into the forearm muscle. As sound waves are reflected by tissue, data can be collected around the depth of the muscle strand reflecting the wave – enabling a far greater degree of intricacy when identifying patterns of movement.
Researchers said they would ultimately look to software powered by artificial intelligence to handle the process of identification, which could then enable movement of the prosthetic fingers in real time.
The current version of the system is a wearable bracelet, positioned on the forearm to send dozens of ultrasound pulses per second into the muscles below.
“The ultrasonic-based control acts with greater sensitivity and accuracy than would be possible with electrodes,” said Fraunhofer IBMT researcher, Dr Marc Fournelle in a statement.
“The sensors are able to detect varying degrees of freedom such as flexing, extending or rotating,”
Fellow Fraunhofer IBMT researcher, Andreas Schneider-Ickert added: “When someone who hasn’t lost their hand picks up a glass of water and holds it to their mouth, they get constant feedback from their fingers on how tight to hold the glass, so that on the one hand it doesn’t slip and fall, and on the other so it doesn’t shatter from being squeezed too tightly.
“Such functionality is also being investigated within Soma, and could one day be integrated into prosthetic hands.”
Check out the full story via Fraunhofer IBMT.
