By Cassidy DeStefano, news editor

After four years of research, a Northeastern engineering professor has launched a patented system that may allow people with diabetes to trade in standard finger-prick blood tests for a less invasive saliva-based approach.

“Patients have to track their glucose levels five to six times every day,” Ming Wang, the professor behind the product, said. “With me, I see one blood drop and I’m already afraid.”

The system, which is the first of its kind to hit the market, has patients chew on unsweetened foam to generate saliva, which is then collected through a narrow tube and sent for immediate processing. The resulting measurement indicates the concentration of milligrams (mg) of glucose per deciliter (dL) of saliva, Wang said.

“The blood has 100 times more glucose than the saliva, and so we need to make sure our sensor has fast-response capabilities that can give back results in 30 seconds,” Wang said, naming the ideal concentration at about 1.5 mg/dL.

Freshman history major Maggie Gallagher was diagnosed with Type 1 diabetes in 2007. She has used invasive technologies ever since.

“When you start with Type 1, you move from syringes to pen needles to a pod or a pump, and you take about five shots a day,” she said. “Through that, you get a lot of scar tissue.”

Now, Gallagher uses a Dexcom, a continuous monitoring system that inserts a wire into highly concentrated areas of muscle tissue such as the stomach or legs to track blood sugar.

“The insertion is very painful, but I like that I can just check the system instead of checking my blood sugar,” Gallagher said.

She said that while Wang’s saliva-based system sounds feasible in theory, there may be social issues that arise in practice.

“I think it could be great, but I feel like if you had to chew on something then that would physically show you were different from the rest of the group,” she said. “A handheld system is something you can hide away, but chewing something is visible and hard to do discretely.”

Gallagher also expressed concern about the accuracy and hygienics of saliva testing.

“When you check your blood sugar with a finger prick, you have to have a sterile finger to make sure that the measurement is accurate and not affected by anything you have touched,” she said. “But with saliva, that would be hard to accomplish.”

Still, interdisciplinary engineering Ph.D student Wenjun Zhang, Wang’s partner for the project, said that medical professionals are coming to rely more on saliva for tests.

“Saliva, commonly considered as the ‘mirror of the body’, is very attractive as a biomedium for clinical diagnostics,” she said in an email to The News. “There are a large number of diagnostic analytes present in saliva, enabling various diseases detection and monitoring.”

Wang agreed with the potential of turning to saliva for glucose readings.

“Saliva research has gained some major attention either to replace or complement blood tests because it is convenient and numerically-founded,” he said. “There is an immediate future for this product.”

Photo by Robert Smith

Correction: An earlier version of this article reported that a Dexcom is used to track blood pressure. The device measures blood sugar.