For patients recovering from open-heart surgery, blood tests can mean the difference between staying on a respirator or breathing on their own.

So when cost-cutting measures two years ago left the University of Virginia Health Sciences Center's new hospital without a 24-hour emergency lab near intensive-care units, doctors sought a new way of maintaining quality care.

The solution? A robot stationed near the cardiac intensive-care unit that now analyzes blood tests in less than five minutes--a quarter of the time it takes an aide to race a vial of blood to the main laboratory for testing. The robot looks like an automated bank-teller machine, but a mechanical arm inside uncaps vials of blood, performs blood tests, reports results to a central hospital computer and stores leftover samples.

In short, it does "all the chores that a medical technologist does," said Robin Felder, associate director of the clinical chemistry, toxicology and robotics labs at UVA's Health Sciences Center.

"It has been a very good answer," said heart surgeon Stanton Peelle Nolan, director of the hospital's thoracic cardiovascular postoperative unit. Robots are playing a small but growing role throughout medicine. From the laboratory to the operating room, these high-tech--and still largely experimental--devices hold the promise of improved efficiency and greater precision.

They can also save money. At UVA, for example, the $90,000 laboratory robot is expected to last for about five years and has eliminated the need for roughly four full-time technologists, each earning about $25,000 per year plus benefits. In Danbury, Conn., a mobile robot delivers meal trays and saves the local hospital roughly the cost of one full-time employee.

Most of these new robots, however, are stationary mechanical extensions of computers, not quite R2D2 clones. They grew out of the Detroit assembly line, where robots have been helping to make cars for nearly a decade.

Robots excel at performing repetitive tasks. The advantage of using robots instead of regular machines is that they can be programmed to perform a range of often-complicated duties. "Medicine is a rapidly evolving field," said Felder. Because robots are hooked to computer programs, "robots can change more rapidly (than machines can) as our needs change," he said.

At the same time, robots still require human supervision. At Virginia, a human technologist stationed two floors away reviews robot blood analyses by computer.