Magnetic beads in muscle could improve prosthetic leg control

Researchers at MIT have shown they can track muscle length, velocity and activation with tiny magnetic beads implanted in the muscle. The study appears in the peer-reviewed journal Nature Sensors.
Professor Hugh Herr and graduate student Christopher Shallal tested the method in three people with below-knee amputations. Today's prostheses rely on skin electrodes, which Herr's team says have not proved reliable enough for safe walking. Shallal says the method is minimally invasive, because only two beads go into the muscle. The study was small, and the team's hope of commercial development has not yet been met.