Tiny devices implanted on the vagus nerve and used for a few minutes a day might be able to reduce the signs and symptoms of rheumatoid arthritis, say the authors of a pilot study.

Researchers have previously used vagus-nerve stimulators, about the size of a coffee bean, as anti-seizure devices.

Since the vagus nerve plays a role in the body’s inflammatory reflex, the team had wondered whether the device could be reprogrammed for autoimmune-disease treatment, said senior author Dr David Chernoff, from the device manufacturer SetPoint Medical in Valencia, California.

Dr Chernoff and colleagues worked with 14 patients at five research sites across the US who had moderate-to-severe rheumatoid arthritis and didn’t respond to two or more anti-rheumatic drugs.