Tiny implants that act as artificial nerves could help reduce potentially dangerous muscle wastage in stroke patients, researchers say. The implants, called BIONs, can be injected directly into muscle tissue and stimulate them from within to prevent them wasting away through lack of use. The muscle wasting that afflicts many stroke patients can lead to serious complications such as thrombosis in bedridden patients.
Unused muscles can also become so weak and flaccid that the arm dislocates from the shoulder.
Once in place they are activated by a radio signal from a coil worn by the patient. This controls the frequency and intensity of the electrical stimuli produced by each implant. Doctors can then download a set of exercise programs into a portable controller for the patient to take home. The muscles can be stimulated in other ways, but these require surgery or leave wires sticking out from the skin, increasing the risk of infection. Attaching electrodes to the skin can work, but makes targeting of specific muscle groups difficult, and can burn the skin.