Medicine in the Mist

The fight against infection takes to the air.

Roughly 1 in 25 hospital patients have to prolong their stay because of healthcare-related infections developed within the hospital. But a novel idea out of the labs of UC San Diego may well bring that number down to zero.

Engineers and physicians are currently working together to create a device that can diffuse potent disinfectants into the air to effectively eliminate bacteria that commonly cause hospital-acquired infections. It may even work against drug-resistant strains of bacteria, a growing concern in modern healthcare.

“Cleaning and disinfecting environmental surfaces in medical facilities is a critical infection prevention and control practice,” said Dr. Monika Kumaraswamy, a physician scientist at UC San Diego and hospital epidemiologist at the VA San Diego Healthcare System. “This device will make it much easier to keep hospital rooms clean.”

The technology has broader potential applications as well. Atomization could be used to deliver many new classes of medicines to patients via inhalers. “Our goal is to make injectable treatments inhalable,” says James Friend, professor of mechanical engineering at the UC San Diego Jacobs School of Engineering and lead researcher on the project.

What’s more, researchers have built the device using inexpensive, off-the-shelf smartphone components. In phones, these parts produce acoustic waves that mainly filter wireless cellular signals and identify voice and data information. In the diffuser, however, these smartphone components generate sound waves at extremely high frequencies—ranging from 100 million to 10 billion hertz—and create what’s known as a fluid capillary wave, which emits droplets and generates a mist. This method is energy efficient and can atomize even the most viscous fluids into a fine mist able to stay in the air for more than an hour.

A truly interdisciplinary endeavor, the device was built by Friend’s team and tested in the laboratory of Dr. Victor Nizet at the UC San Diego School of Medicine, in experiments led by Kumaraswamy. Together, the group plans to have an updated prototype for use in hospital settings within two years—but they don’t intend to stop there. The device also could be used in airports, airplanes and other forms of public transportation during flu season or epidemic outbreaks.