Hospital-Clean Hands, Without All the Scrubbing

HOSPITAL workers often have to wash their hands dozens of times a day — and may need a minute or more to do the process right, by scrubbing with soap and water. But new devices could reduce the task to just four seconds, cleaning even hard-to-reach areas under fingernails.

Instead of scrubbing, the workers would put their hands into a small box that bathes them with plasma — the same sort of luminous gas found in neon signs, fluorescent tubes and TV displays. This plasma, though, is at room temperature and pressure, and is engineered to zap germs, including the drug-resistant supergerm MRSA.

The technology is being developed in several laboratories. Gregor Morfill, who created several prototypes using the technology at the Max Planck Institute for Extraterrestrial Physics in Garching, Germany, says the plasma quickly inactivates not only bacteria but also viruses and fungi.

Dr. Morfill and his colleagues have tested their devices on hands and feet. “It works on athlete’s foot,” he said. “And the nice thing is, you don’t have to take your socks off. They are disinfected, too.” (The cleaning takes a bit longer when socks are added to the job, he said — about 25 seconds. “And it doesn’t yet work through shoes,” he added.)

Plasmas engineered to zap microorganisms aren’t new. During the last decade, they have come into use to sterilize some medical instruments. But using them on human tissue is another matter, said Mark Kushner, director of the Michigan Institute for Plasma Science and Engineering and a professor at the University of Michigan in Ann Arbor. “Many thousands of volts drive the generation of plasma,” he said, “and normally one doesn’t want to touch thousands of volts.” But the design of the new hand sanitizers, he said, protects people from doing so. Reassured by that design, about five years ago he put his naked thumb into a jet of microbe-destroying plasma at the lab of another plasma researcher.

“It was just one of those leaps of faith,” he said. (His thumb survived just fine.)

Research in the field of plasma medicine has grown quickly in the last decade, with at least 50 groups worldwide working on medical uses, Professor Kushner estimated.

He said that there were many documented cases of plasmas being applied for sanitizing skin or other body parts, and “for speeding the rate of blood clotting in wound healing.”

“Plasmas turn out to have beneficial effects,” he said.

Dr. Morfill, who has a plasma research laboratory inside the international space station, took an unusual route to studying medical uses of plasmas. He was researching the natural plasmas of space, including the charged dust in Saturn’s rings, and decided to develop plasmas for health on earth.

He has developed several prototypes of hand-cleaning devices that can be mounted on walls, as well as a portable, battery-operated model the size of a large electric toothbrush. Companies are interested in manufacturing the devices, he said, which may one day be particularly useful in developing countries where medical services can be scarce.

The devices can probably be built for $100 or less, as no expensive parts are used, he said.

The plasma cleaners make their antibacterial cocktails by running electrical current through air, said David B. Graves, a professor of chemical engineering at the University of California, Berkeley, who has worked on low-temperature plasma applications for 25 years.

Professor Graves is doing computer simulations of the chemical reactions that occur in the Morfill plasmas. The electric current ionizes the oxygen, nitrogen and water vapor in the air, he said, eventually creating the nitric oxide, hydrogen peroxide and particles that are so effective against bacteria, viruses and fungi.

Many other cleaning applications of plasma are being researched. In addition to hand sanitizers, Michael G. Kong, a professor of bioelectrics engineering at Loughborough University in Leicestershire, England, has developed a prototype for plasma jets that can be built into air-conditioning systems. As air is transmitted through the system from one hospital room to another, for example, the jets inactivate microorganisms, fungi and viruses in the air.

IN the Netherlands, Gerrit M. W. Kroesen, a professor of plasma physics at the Eindhoven University of Technology, is focusing on the treatment of burn wounds. “We have seen that plasmas help with disinfection,” he said. “They also stimulate regeneration of tissue.”

The first products to reach hospitals, after surface cleaners and instrument disinfectants, will probably be hand sanitizers, said Alexander Fridman, a professor and director of the Drexel Plasma Institute at Drexel University in Philadelphia.

“Hand sanitizers are the low-hanging fruit here,” he said, as their safety can be demonstrated relatively easily.

But other potential applications, including treatment of burns or cancers, are further away. “We are able to do miracles with this technology,” he said, “but we have to make sure the treatments are not toxic.”

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