(FORTUNE Small Business) – When it comes to impressive résumés, it's hard to one-up Mae Jemison, 48: A Stanford graduate, physician, Peace Corps medical officer in Africa, NASA astronaut, and Ivy League professor, she also speaks Russian, Swahili, and Japanese. As if that weren't enough, Jemison is now president of Houston-based BioSentient, which aims to open up a new area of medical diagnostics.

Jemison's device, MobileMe, monitors the body's autonomic nervous system (ANS), which controls body functions such as breathing, sweating, heart rate, and digestion. In the same way that a lie-detector test monitors slight changes in the ANS to detect falsehoods, MobileMe will pick up on slight changes to help diagnose a broad spectrum of medical and behavioral conditions, including anxiety disorders, neurological complications stemming from diabetes, attention deficit disorder, and even anger-management problems. For example, a patient in anger management therapy could observe his increased heart rate and blood pressure before he actually felt angry, learn to identify the causes of these reactions, and head off a full-blown meltdown.

Jemison first encountered the technology at NASA, where she used it to monitor and control her body's responses to weightlessness in space. In 2001, BioSentient licensed the technology from the government. MobileMe is a half-pound device the size of a cellphone, with sensors incorporated into a skintight shirt or undergarment so that body functions can be measured anywhere, noninvasively. "It's one thing to put people in a static room and measure things," says Jemison. "It's another thing to measure as they walk, talk, and chew bubblegum in real life." Data can be displayed on on a wrist display similar to a watch, or transmitted to a doctor wirelessly or over the Internet. So far BioSentient has been self-financed by Dr. Jemison, along with a government grant. MobileMe should become available in the third quarter of 2005. —J.S.