Phones could become diagnostic tools

Phones could become diagnostic tools

URBANA — Are there allergens in your food? Could you be developing heart disease?

One day, a smartphone could be used to help find out.

Researchers at the University of Illinois have developed a cradle and app that converts an iPhone into a portable — and much more affordable — version of lab equipment to run tests for food safety and environmental toxins and even help diagnose medical conditions.

Ah, but your phone runs on the Android operating system? A cradle for phones that use that operating system is already in the pipeline.

Research team leader Brian Cunningham, a UI professor of electrical and computer engineering and bioengineering, said he and his team started out with the idea for a special cradle that would allow them to use the camera in a smartphone as a biosensor instrument.

There are many uses for a portable smartphone biosensor that can go where larger lab equipment can't, Cunningham told The News-Gazette recently, and such a tool could make a big difference in developing areas of the world where there aren't labs nearby.

The researchers are already developing tests to detect iron deficiency and vitamin A deficiency in children and expectant mothers, and to detect toxins in harvested corn and soybeans and pathogens in food and water.

Other uses could include tests for detecting allergens in food — for example, peanuts for people with nut allergies — and monitoring disease conditions and treatments, Cunningham said.

There are medical tests planned for use by doctors and eventually patients in their own homes, he said.

"It's important to catch problems before they become acute problems," Cunningham said.

How the process basically works: The user mixes a substance, such as blood, with a test liquid; the mixture is placed on a slide that is inserted into a slot into the cradle; and the app walks the user through the testing steps.

The wedge-shaped cradle, which contains lenses and filters, is attached to the phone and uses the phone's camera and processing power.

The instrument is then held up to a light bulb or other light source and light passes through the biosensor and into the phone, Cunningham said.

"The light that goes in is white light with all the wavelengths, and then the biosensor subtracts out some of the wavelength, and then we can measure with the phone what wavelengths were removed," he said.

That wavelength information shows how much of the molecule is present in the sample.

These are existing tests that are being adapted for the iPhone, said Kenny Long, a graduate student on the research team along with graduate student Hojeong Yu.

The cradle was built with $200 worth of components, but it performs as accurately as a $50,000 spectrophotometer in a lab, the researchers found.

The cradle weighs about 3 pounds, but cradles for commercial use would be lighter, Cunningham said.

It's going to be a few years before anyone can likely buy one of these smartphone cradles, and the first commercial ones are likely to be for professionals who need this kind of portable equipment out in the field, he said.

To see a smartphone biosensor demonstration, visit

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