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The artificial muscle works on the same principle as the Chinese finger trap, a helically woven webbing that contracts as it thickens. When the CO2 gas goes into the muscle, the sides expand and the ends come closer together. The muscle is made up of four parts: the webbing which contracts in length when the middle of it expands, a bladder made of rubber which fits inside the webbing, and the two metal end piece to hold the bladder and webbing together.

On the side of the chair there is a flask with the gas in it. A plastic tube runs from that to the valves under my left foot. Here there are four valves: two underneath the front of the foot, one to the top right, and one under the heel. (FOOTPEDAL PICTURE). It takes about six ounces of push to operate a valve. The footpedal sits on the pedal of my chair. It has a universal joint under it which enables my foot to move left, right and up and down. With this range, I'm able to hit the four valves. The only muscles of my own by which I work this setup are: a good peronaeus bogus, weak toe extensors, and weak toe flexors.

From the foot pedal the tubes coming from the valves are wrapped together with larger tubing and go up to the ball-bearing feeder. The feeder is an ordinary feeder with a few adjustments on the trough. It has four muscles on it: two for horizontal movement, one for vertical movement and one for a pinch. One of the horizontal muscles is attached from the side of the chair to a spot just behind the feeder's elbow joint. (ARM PICTURE). The muscle on the right side of the arm is for vertical movement. The fourth muscle on the left is for pinch. With this setup I feed myself, play chess and hope to have a switchboard with micro-switches for telephone, tape recorder, etc.

All the braces and muscles were made at the Rancho Los Amigos Orthotic Department under the supervision of Roy Snelson. Working with the orthotists are a P.T., Jan Paterson, and an O.T., Lois Barber who train patients in the use of their new devices. This program is being sponsored by the National Foundation. (Photographs courtesy of Warren and Barbara Transue).