Blood Shot

Useful, but barbaric. That's how San Leandro, CA-based EndoBionics' CEO Lynn Barr describes balloon angioplasty-the use of a balloon-tipped catheter to open clogged arteries. The procedure itself causes artery-narrowing scarring in about 20 percent of the roughly 600,000 people in the U.S. who undergo it each year. To stop this scarring, mechanical engineer and EndoBionics founder Kirk Seward created a retractable polymer sheath for a steel needle one millimeter long and roughly the diameter of two hairs. After an angioplasty, a surgeon could guide the sheathed needle through an artery in the patient's leg or neck to the coronary artery. Once the device was in place, a microscale hydraulic system would allow the surgeon to retract the sheath while simultaneously pushing the needle into the artery wall. This way, the device could inject a tiny amount of a blockage-preventing drug directly into the site where scarring and blockage could occur. The technique would deliver the drug much further into the artery walls than other methods being developed for this purpose, Barr says. EndoBionics plans to partner with a yet unnamed medical device company to bring the technology to market in late 2004. Eventually, Barr says, the microneedle could be used to deliver tumor-killing drugs or genes to the brain.

Body Power

Our bodies ooze energy in the form of heat. Infineon Technologies, a microelectronics company in Munich, Germany, has developed a dime-sized chip that converts this heat into enough electricity to power a small electronic gadget, which would otherwise rely on tiny and expensive batteries. One side of the "thermogenerator" faces the body, and the other faces the air; the temperature difference between the two sides produces a current. Unlike other heat-to-electricity devices, which are made out of expensive and toxic metals, Infineon's chips are silicon-a cheaper and more benign material.

Given a typical temperature difference at the wrist of 5 C, prototype devices can generate enough power for a wristwatch-around one microwatt per square centimeter-says Werner Weber, head of Infineon's Laboratory for Emerging Technologies. Infineon is working with a watchmaker to incorporate the thermogenerator into the firm's products. The chips, says Weber, could find their way onto the market in two years in watches or wearable medical devices; a thermogenerator embedded in a jogging suit, for instance, could power a heart sensor.