Using your phone to diagnose disease or track your medical condition is the holy grail for remote health monitoring. So far it’s been impractical to combine the two in a single device. Tech companies don’t want the regulatory headaches that would come from labeling phones as medical devices.

But University of Cincinnati engineers have come up with the next best thing. UC professor Chong Ahn has designed a tiny portable lab device that plugs into a phone, connecting it automatically to a doctor’s office through a custom app UC developed. With a single drop of blood or saliva on a custom plastic lab chip, the device smaller than a credit card can diagnose infectious diseases.

And while Ahn’s latest study did not expressly look at coronavirus, he says it would have similar applications in diagnosing infectious diseases or tracking health conditions like depression and anxiety.

The phone provides the power and test protocol to the lab chip. A patient simply puts a single-use plastic lab chip into his or her mouth then plugs that into a slot in the box to test the saliva.

The device automatically transmits results to the patient’s doctor through a custom app UC created for nearly instant results. In his latest study, Ahn and his research team used the smartphone device to test for malaria. But the device could be used for smart point of care testing for countless chronic or infectious diseases or to measure hormones related to stress.

“Everybody has a phone — more than 3 billion people,” Ahn says. “So how can we use that technology to test for infectious diseases such as coronavirus? It’s a rapid diagnostic tool you can use at home. Right now, it takes several hours or even days to diagnose in a lab, even when people are showing symptoms. The disease can spread.”

Ahn’s study on malaria was published in Microsystems & Nanoengineering. The project demonstrates UC’s commitment to research as described in its strategic direction called “Next Lives Here.”

UC engineers developed a smartphone app that can record and transmit test results from a portable lab that people can plug into their phones. The lab uses saliva from plastic test strips that people put in their mouths like a sucker. (Credit: Joseph Fuqua II/UC Creative Services)

Ahn is an electrical and biomedical engineering professor in UC’s College of Engineering and Applied Science. He directs two centers on campus, the Engineering Research Center Clean room and the Ohio Center for Microfluidic Innovation. UC honored him last year as a distinguished research professor.

His research team created a novel lab chip that uses natural capillary action, the tendency for a liquid to adhere to a surface, to draw a sample down two channels called a microchannel capillary flow assay. One channel mixes the sample with freeze-dried detection antibodies. The other contains a freeze-dried luminescent material to read the results when the split samples combine again on three sensors.

Ahn says the device is accurate, simple to use and inexpensive.

“The performance is comparable to laboratory tests. The cost is cheaper. And it’s user-friendly,” Ahn says. “We wanted to make it simple so anyone could use it without training or support.”

Improving Mental Health

UC doctoral student Sthitodhi Ghosh, the study’s lead author, says the biggest advancement in the device is in the novel design of its tiny channels that naturally draw the sample through the sensor arrays using capillary flow. Ahn is Ghosh’s PhD advisor.

“The innovation of this device is using a capillary-driven microfluidic lab chip,”

Chong Ahn is a distinguished research professor in UC’s College of Engineering and Applied Science. (Credit: Joseph Fuqua II/UC Creative Services)

Ghosh says. “So the entire test takes place on the chip automatically. You don’t have to do anything.

“This is the future of personal healthcare,” Ghosh says.

While the device has applications for diagnosing or monitoring viruses or other diseases, Ahn said he sees potential in the field of mental health. Mental health providers already use smartphones to track the wellness of patients through regular surveys. But psychosocial data can be subjective.

Ahn recalls the excruciating stomach ache he felt when he was hospitalized for an infection. He had trouble translating how he felt on a pain scale of 1 to 10 for his doctors. The pain left him feverish and soaked in sweat, but he reasoned it could surely be worse.

“I said, ‘I’m a 2’ so they didn’t give me pain medicine. My wife said, ‘Honey, you almost died! Take the pain medicine.’ So from then on I said I was a 6 or 7 and I got pain medicine and I was good,” he says.

Evidence-Based Treatment

By routinely testing hormones or other biomarkers associated with depression or anxiety, Ahn says he could help doctors correlate how patients feel with actual changes in their biochemistry. This could improve treatment for countless patients, he says.

And the device can use saliva as well as blood, which is less invasive and less stress-inducing than a finger prick.

“If you’re stressed from doing a finger prick, it’s already creating a bias in the testing of stress,” Ghosh says. “That’s why we’re moving to a noninvasive method.”

Ahn is pursuing a patent to commercialize his device. Medical diagnostics company Mico Biomed, which has offices in Cincinnati, is a co-author of the study.

The biggest hurdle could be making people feel confident and comfortable enough to use the unfamiliar device at home, he says.

But the vast amounts of data collected from the tests over time could help psychiatrists better understand the biochemistry underlying mental illness, which could lead to better evidence-based treatments, he says.

“My dream for the rest of my career at UC is to improve public and mental health by providing a new mobile health tool,” he says.

This article was written by Michael Miller, University of Cincinnati. For more information, visit here .