NEW YORK — They sweep. They swab. They sterilize. And still the germs persist.

In U.S. hospitals, an estimated 1 in 20 patients pick up infections they didn’t have when they arrived, some caused by dangerous ‘superbugs’ that are hard to treat.

The rise of these superbugs, along with increased pressure from the government and insurers, is driving hospitals to try all sorts of new approaches to stop their spread:

Machines that resemble “Star Wars” robots and emit ultraviolet light or hydrogen peroxide vapors. Germ-resistant copper bed rails, call buttons and IV poles. Antimicrobial linens, curtains and wall paint.

While these products can help get a room clean, their true impact is still debatable. There is no widely-accepted evidence that these inventions have prevented infections or deaths.

“We’re seeing a culture change” in hospitals, said Jennie Mayfield, who tracks infections at Barnes-Jewish Hospital in St. Louis.

Those hospital infections are tied to an estimated 100,000 deaths each year and add as much as $30 billion a year in medical costs, according to the Centers for Disease Control and Prevention.