SAN DIEGO—The machine–human connection ran like a titanium thread through several of today’s TEDMED sessions.

* Hugh Herr of the Massachusetts Institute of Technology’s Media Lab captivated the audience with his work on prosthetics. In 1982 both his legs were amputated below the knee after a mountain-climbing accident left him with severe frostbite. “I designed my body from the ground up,” he said. “I reasoned that there’s no such thing as a disabled person; there are only disabled technologies.” Now he can stand on coin-size footholds when climbing. “You could not with a straight face label me ‘disabled.’ I climb mountains, for God’s sake.” Herr said he wouldn’t trade his prostheses for his biological legs. “My artificial limbs are part of me,” he said. “Besides, I can upgrade.”

“In a decade or so, my bionic limbs will be linked to my nervous system.” So when he walks on a beach, he’ll be able to sense the sand underfoot. His lab is developing biophysical models of muscles, tendons, spinal reflexes, to improve prostheses. They are looking at exoskeletons that can span a biological leg. With it, if you have a bad hip or knee, you can still run.

* Segway inventor Dean Kamen of Deka Research shared three technologies for “arms, water, power.” He developed a prosthesis for soldiers who’ve lost an arm. The prosthetic hand has movable digits, which enabled an amputee soldier to build a model of a wooden boat.

To prevent limb loss in gold mining, where workers use dynamite to extract the metal, Kamen developed an exoskeleton that lets a man control a mining robot. The robot's “hands” mimic the movements of the operator, letting the miner stay out of potential harm's way.

Other inventions Kamen discussed were a water purifier and an electricity generator that could be used in developing nations. “More than a billion people lack safe drinking water.” His vapor-compression distiller can treat 1,000 liters a day.

* Stephen Oesterle, senior vice president for medicine and technology for Medtronic, traced pacemakers from their origins in 1958 as palm-sized devices to a coin-size unit today. He said the next-generation pacemaker, available in three or four years, will be leadless and the size of an antibiotic capsule. The programmable device will include battery, memory and radio, and will be implanted without surgery—through a catheter directly into a heart chamber. It would have “hooks” on it to stay in place once inserted.

Pacemakers aren’t only for hearts. "Everything in your body is electrically active," says Oesterle. He showed a slide with 15 areas that might be paced for therapies. In the brain, pacing electrodes applied to basal ganglia can ease Parkinsonian tremors, for instance. Similar therapies might also ease obsessive-compulsive disorders, drug addiction and depression. The same capsule form factor could hold injectable sensors as well. What’s after that? Medtronic is working to develop a pacemaker that gets energy from ambient area; a mock up was about the size of Lincoln's beard on a penny.

Image: A future pacemaker, the size of a capsule pill, could be inserted into a heart chamber via a catheter. Credit: Medtronic