BodyTechnic: New funding for brain implants

The implants, hoped to one day allow paralysis victims to operate artificial limbs, are made of cone shaped glass and contain an electrode that picks up impulses from the nerve endings. Before they are implanted, the cones are coated with chemicals - taken from tissue inside the patients' own knees - to encourage nerve growth. The implants are then placed in the brain's motor cortex - which controls body movement - and over the course of the next few months the chemicals encourage nerve cells to grow and attach to the electrodes.

A transmitter just inside the skull picks up signals from the cones and translates these into cursor commands on the computer. Using the cursor the patient is able to communicate by pointing at different icons. So far only two patients have received the implants - a woman with Lou Gehrig's disease (a fatal neuromuscular disease) who has since died of her illness and a 57-year-old man who is almost paralysed by a stroke.

By listening to a buzzer that became louder if they were thinking along the right lines, the patients were trained to use the implants to activate simple computer voice phrases such as: "I'm thirsty." Although the research is still at an early stage, the new funding will help one more patient who has yet to be named.

"It will be several years before we see a practical application, but the hope is that in the future it will enable paralysed patients to move limbs" a spokeswoman at Emory University claimed.