Until 1992, Philip Kithil didn't know much about cars or the intricacies of air bag systems. He had been a lobbyist for a hotel association in New Mexico and had worked in advertising and promotions. He had even tried manufacturing skiing and camping gear.

But in March of that year, his 17-year-old daughter had a car accident that changed his life, even though she wasn't seriously injured. The wreck - in his 1980s Plymouth Reliant station wagon - got him thinking about a way to retrofit air bags into older model vehicles.

With the end of the cold war, Mr. Kithil knew he could get some help from his neighborhood government laboratory, where sharp minds no longer had to be quite as focused on the concept of global annihilation. He lived in Santa Fe, within an hour of Los Alamos and Sandia national laboratories, which were beginning to provide technical assistance to small and large businesses.

Mr. Kithil started at Los Alamos, where scientists already knew a lot about air bags and helped him build some prototype retrofit systems.

But within a year it became painfully clear to him that the retrofit market was going nowhere; he changed gears.

At Sandia, Mr. Kithil discovered a capacitive sensing system the government was using on a robotic arm to inspect tanks holding high-level radioactive material. The sensor could determine if the arm was near the side of the tank and could prevent it from punching a hole in it.

Why then, he thought, couldn't the same sensor technology be applied to air bags? Capacitive sensors, when positioned in the windshield or instrument panel, could create three-dimensional hemispheric fields to determine instantly if a person is too close to the air bag unit. The air bag then could inflate at lower power or be disabled.

"You have a 3D electric field that can't be fooled. It will always detect an object approaching it," Mr. Kithil says. He considers capacitive sensors faster and more reliable than ultrasound or infrared sensors, which use reflective beams to gather information about the occupant's position.

In 1993, he created Advanced Safety Concepts Inc. (ASCI) to continue developing the technology as safety advocates were identifying the need for "smart" air bags. The company has licensed the technology to automotive glass supplier PPG Industries Inc. and interior supplier Lear Corp.

PPG and ASCI recently displayed their Sungate Occupant Sensing Windshield at Convergence '98 electronics conference in Dearborn, MI, and at the Air Bag 2000 symposium in Germany. The tiny electrodes were embedded in the glass and appeared much like a radio antenna. Mr. Kithil says they can be made practically invisible to the naked eye.

Lear has demonstrated the technology in recent years on vehicles at the SAE Congress in Detroit. With Lear, the electrodes are embedded in the instrument panel. The technology is not only for front passengers: ASCI has developed a "drowsy driver" application using sensors in the headliner to prevent a driver from nodding off.

Mr. Kithil expects his technology to appear on a production vehicle by 2003, and he says the cost could be between $10 and $20 per air bag system, depending on how many sensors are used.

With only four employees (including himself), Mr. Kithil isn't interested in manufacturing his product. Besides PPG or Lear, ASCI could license an air bag or electronic control unit supplier to produce the sensors.

Mr. Kithil realizes the stark contrast between his tiny venture and the mega-suppliers hot on the trail of smart air bags. But he sees a distinct advantage in being agile enough to respond quickly as the auto industry waits for the government to decide whether to require such features.

He is not deterred by questions about the safety of air bags and believes technology such as his will alleviate those concerns. From a business perspective, it's just another bump in the road. "I guess I'm an entrepreneur at heart like many people," Mr. Kithil says. "It's always a struggle."