Stanford Medicine

S T A N F O R D M D

Volume 18 Number 2 Fall 2001

Alumni Profile: Gregory Kovacs
The realm of the engineer
by Krista Conger

The works of this Stanford medical alum bridges the worlds of medicine and engineering

Not many Stanford MDs have their own personal set of camouflage. Fewer still might arrange for a group of students to fly to an active Marine base for a test of their research project. But Gregory Kovacs, MD, PhD, class of 1992 is not a normal MD.

“I’m really a geek,” Kovacs says, with a wide grin. He obviously enjoys the announcement, which seems to be supported by his academic pedigree, peppered with degrees in both electrical engineering and medicine.

But a little digging proves that his proclamation demands at least a modifier: He’s a renaissance geek. He flies planes, files patents, scuba dives and tirelessly champions his students while holding down two faculty appointments — engineering and medicine.

Currently Kovacs is an associate professor at Stanford in electrical engineering and medicine (by courtesy). His most recent research project — to develop a cell-based system to detect toxins used in chemical or biological warfare — continues a tradition of melding the two disciplines. Last October, he and his students — appropriately decked out in regulation camouflage — traveled to Twentynine Palms Marine Corps Combat Center in California to test their prototype in the field. The project is sponsored by the Defense Advanced Projects Agency, or DARPA.

At first blush, medicine and engineering may not seem like they have much in common. But Kovacs, who received his PhD in electrical engineering at Stanford in 1990, began to work the two together as a medical student. During his clinical rotations, he worked with fellow student and future Stanford faculty member Michael Stephanides, MD, to develop miniscule arrays of electrodes capable of recording signals from nerves.

During his medical school clinical rotations, Kovacs was invited to speak to the electrical engineering faculty about his research. “At the time I didn’t realize that it was a job talk,” says Kovacs. Although he soon ended up as a faculty member in the electrical engineering department, he did not relinquish his love of biology and medicine, or of a good challenge.

The challenges of Kovacs’ latest project are many. Toxins in the air or water must be quickly detected and identified, with a minimum of fuss, by military personnel in the field. The results must be reliable, and the system must be portable.

“Ideally we’d have a simple ‘red light, green light’ detection system for chemical or biological toxins,” says Kovacs. He and his students have been working to develop a flexible, rugged system using living cells that can be deployed by someone without specialized biological training.

The idea of using living cells as a detection system is similar to the canaries used by coal miners in the 19th century; because birds are especially sensitive to toxic gases, the miners would use a caged canary as a gauge of the air purity in the mine shaft. When the bird fell off its perch, the miners knew they should retreat to fresher air.

Cells have many of the same advantages as canaries. Although tiny, they are very complicated living systems, and it’s reasonable to assume that their response to toxins will at least mimic that of a whole organism like a human. And, as with a canary, it’s not necessary to know exactly what type of toxin you’re looking for — anything that causes an untoward effect on the cells’ activity raises a red flag.

Unfortunately, though, it’s not possible to just toss a batch of cells into your pocket and tromp out to the battlefield, taking a peek now and then to see if they’re doing all right. They require carefully controlled, sterile conditions and sensitive monitoring to gauge their responses to potential toxins.

Scientists trying to develop a cell-based detection system have to balance the cells’ needs with those of the real world: a portable, low-maintenance, self-contained and rugged detector that gives accurate, reliable results every time.

In response to these conflicting demands, Kovacs and his students have developed a way to grow several thousand cardiac or nerve cells in fluid-filled channels on a surface about the size of a microscope slide. At the right temperature, with enough food and oxygen, the cells can survive for several days on the “chip.” Minute electrodes monitor electrical currents produced by the cells in the presence of various chemical or biologic agents. Some compounds alter the pattern of the cells’ firing, and some can stop it altogether — something to be concerned about if the chemical is in your food or drinking water.

The team is also experimenting with cells that have been genetically engineered to detect individual types or classes of toxins. They’ve found that by comparing the responses of cells missing certain genes and those of unaltered cells, they can specifically detect chemicals that target the missing gene.

Designing the chip and a traveling case to protect the cells from rough treatment and extremes in temperature fell to Kristin Gilchrist and Valerie Barker, graduate students in Kovacs’ lab. Another graduate student, Derek DeBusschere, has focused his attention on incorporating the chip into a hand-held biosensor.

Kovacs has nothing but praise for Gilchrist, Barker, DeBusschere and the other students and staff involved in the project. “We get the very best students here at Stanford,” he says. “They’re willing to take this on because they haven’t stopped to think that none of this has been done before. It’s really a privilege to hang out with them.”

The detection system performed beautifully during the simulated deployment at Twentynine Palms, reaching the desert testing site without incident and responding to simulated toxins just as it had in the lab. The next hurdle is a bit more realistic. Kovacs and his students plan to return to the testing site this fall to deploy their system while the Marines conduct a live-fire exercise.

“I’d like the students to see how things get really dirty,” says Kovacs, adding that the students will stay well out of harm’s way. “When things are exploding, the military personnel have a lot of things to deal with. They don’t want to have to drive around a PhD in a van just to operate the detection system.”

Point well taken. But the gleam in Kovacs’ eye gives him away again: He’s at least as excited just to see things blow up.

“I realized after nine or 10 years at Stanford that it’s important to pick something that’s fun to work on,” says Kovacs. “This is a blast.”