The market niche is expected to grow from $30 million to $80 million in the next three years, according to Frost & Sullivan, a market research firm.
Mark Stibich, Xenex's chief scientific officer, said client hospitals sometimes call them robots and report improved satisfaction scores from patients who seem impressed that the medical center is trotting out that kind of technology.
At Westchester, workers still clean rooms, but the staff appreciates the high-tech backup, said housekeeping manager Carolyn Bevans.
"We all like it," she said of the Xenex.
At Cooley Dickinson Hospital, a 140-bed facility in Northampton, Mass., the staff calls their machines Thing One, Thing Two, Thing Three and Thing Four, borrowing from the children's book "The Cat in the Hat."
But while the things in the Dr. Seuss tale were house-wrecking imps, Cooley Dickinson officials said the ultraviolet has done a terrific job at cleaning their hospital of the difficult C-diff.
"We did all the recommended things. We used bleach. We monitored the quality of cleaning," but C-diff rates wouldn't budge, said nurse Linda Riley, who's in charge of infection prevention at Cooley Dickinson.
A small observational study at the hospital showed C-diff infection rates fell by half and C-diff deaths fell from 14 to 2 during the last two years, compared to the two years before the machines.
Some experts say there's not enough evidence to show the machines are worth it. No national study has shown that these products have led to reduced deaths or infection rates, noted Dr. L. Clifford McDonald of the Centers for Disease Control and Prevention.
His point: It only takes a minute for a nurse or visitor with dirty hands to walk into a room, touch a vulnerable patient with germy hands, and undo the benefits of a recent space-age cleaning.
"Environments get dirty again," McDonald said, and thorough cleaning with conventional disinfectants ought to do the job.
Beyond products to disinfect a room, there are tools to make sure doctors, nurses and other hospital staff are properly cleaning their hands when they come into a patient's room. Among them are scanners that monitor how many times a health care worker uses a sink or hand sanitizer dispenser.
Still, "technology only takes us so far," said Christian Lillis, who runs a small foundation named after his mother who died from a C-diff infection.
Lillis said the hospitals he is most impressed with include Swedish Covenant Hospital in Chicago, where thorough cleanings are confirmed with spot checks. Fluorescent powder is dabbed around a room before it's cleaned and a special light shows if the powder was removed. That strategy was followed by a 28 percent decline in C-diff, he said.
He also cites Advocate Christ Medical Center in Oak Lawn, Ill., where the focus is on elbow grease and bleach wipes. What's different, he said, is the merger of the housekeeping and infection prevention staff. That emphasizes that cleaning is less about being a maid's service than about saving patients from superbugs.
"If your hospital's not clean, you're creating more problems than you're solving," Lillis said.