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Carlos Serrao
The world's first computer-controlled artificial leg recently got an upgrade: a knee that changes its range of motion on demand. Triathletes like John Siciliano of Los Angeles, shown here wearing the C-Leg, can now compete in events such as September's Nautica Malibu Triathlon without having to change prosthetics midstream. By tapping his prosthetic toes three times, Siciliano tells the microprocessor to switch the knee's settings to correspond with his sport. A strain sensor in the pylon, or shin, detects how much pressure is being put on different parts of the foot. That data goes to the battery-powered chip in the knee, which then adjusts the flow of fluid to the damping mechanism in the joints during movement, up to 50 times per second. The more fluid, the less resistance. This latest tweak to the C-Leg also allows Siciliano to move with less effort down stairs and on uneven terrain, so he can expand his repertoire to include activities like in-line skating. Distributed by Otto Bock Health Care of Minneapolis, a top-of-the-line C-Leg sells for $55,000 – a fraction of what bionic limbs cost the Six Million Dollar Man.
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| The Bionic Triathlete
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