Engineers adapt smartphone for blood-sugar screening

Researchers modified a commercially available test strip into a prototype that enables people to self-test for prediabetes. 

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Researchers at the University of Washington and UW Medicine might have found a sweet spot for increasing early detection of prediabetes. The team developed a new system that employs the capacitive touch-sensing capabilities of any smartphone to measure blood-glucose levels without the need for a separate reader.

The researchers describe the technology in a paper published March 28 in the Proceedings of the Association for Computing Machinery on Interactive, Mobile, Wearable and Ubiquitous Technologies.

According to the Centers for Disease Control and Prevention, 1 in 3 U.S. adults has prediabetes, a condition marked by elevated blood sugar that can presage type 2 diabetes. The good news? If detected early, prediabetes can be reversed with lifestyle changes to diet and exercise. The bad news? Eight out of 10 Americans with prediabetes don’t know they have it.

Current screening methods typically involve a visit to a healthcare facility for lab testing and/or the use of a portable glucometer for at-home testing. Access and cost pose barriers to widespread screening.

"One of the barriers I see in my clinical practice is that many patients can't afford to test themselves, as glucometers and their test strips are too expensive. And it's usually the people who most need their glucose tested who face the biggest barriers," said co-author Dr. Matthew Thompson, a professor of family medicine at the UW School of Medicine. "Given how many of my patients use smartphones now, a system like GlucoScreen could really transform our ability to screen and monitor people with prediabetes and even diabetes."

In conventional screening, a person applies a drop of blood to a test strip, on which the blood reacts chemically with the enzymes on the strip. A glucometer analyzes that reaction and delivers a blood glucose reading, said lead author Anandghan Waghmare, a doctoral student in the Paul G. Allen School of Computer Science & Engineering.

"We took the same test strip and added inexpensive circuitry that communicates data generated by that reaction to any smartphone through simulated tapping on the screen," Waghmare said. 

GlucoScreen then processes the data and displays the result on the phone, alerting the person if a reading is high so they can follow up with their physician.

The researchers' study results suggest GlucoScreen's accuracy is comparable to that of standard glucometer testing. The team found the system accurate at the crucial threshold between a normal blood-glucose level, at or below 99 mg/dL, and prediabetes, defined as a blood glucose between 100 and 125 mg/dL.

Employing smartphones in lieu of another device to process data helps to minimize the cost to manufacture the strip and the power required for it to operate, compared with more conventional communication device methods such as Bluetooth and Wi-Fi.  The test strip also doesn't need batteries; instead, it draws power from the phone's flash.

This approach could make glucose testing less costly and more accessible — particularly for onetime screening of members of a large population.

GlucoScreen is a research prototype. Additional user-focused and clinical studies, along with alterations to how test strips are manufactured and packaged, would be required before the system could be made widely available, the team said. 

Read the original, longer version of this news release.

Related: Video of GlucoScreen system

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Tags:diabeteshealth technologyblood sugarprediabetes

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