UC San Diego Engineers Develop Smartphone-Based Glucose Monitoring System for Diabetes Patients

Engineers at the University of California San Diego (UCSD) have created a groundbreaking smartphone case and app that simplifies blood glucose monitoring for diabetes patients, whether at home or on the move.

Currently, managing diabetes often requires carrying bulky glucose monitoring kits. The new system, called GPhone, integrates glucose sensing directly into a smartphone setup, eliminating the need for separate devices. According to Patrick Mercier, professor of electrical and computer engineering at UCSD, the solution also allows automatic storage, processing, and transmission of readings to healthcare providers or cloud platforms.

How GPhone Works

The GPhone system features two main components: a slim, 3D-printed smartphone case with a reusable sensor on one corner, and a stylus containing one-time-use enzyme pellets that attach magnetically to the sensor. To perform a test, users dispense a pellet onto the sensor, apply a blood sample, and the device measures glucose levels. Data is then sent wirelessly via Bluetooth to a dedicated Android app, displaying results within about 20 seconds. Each stylus holds enough pellets for 30 tests.

The enzyme pellets use glucose oxidase to generate an electrical signal proportional to glucose concentration. Unlike previous sensors that wore out after repeated use, the pellet-based design ensures the reusable sensor remains functional over time.

Future Potential and Benefits

The GPhone platform is highly versatile and could be adapted to detect other substances for healthcare, environmental, or defense applications. It also stores extensive historical data, enabling long-term tracking of glucose trends. While the refill pellets may cost slightly more than traditional test strips, the reusable sensor and 3D-printed components are low-cost.

The research team envisions integrating glucose monitoring directly into smartphones in the future. Next steps include testing with actual blood samples, reducing the sample volume required, and adding app notifications to remind users to check their blood sugar.

The study, titled “Re-usable electrochemical glucose sensors integrated into a smartphone platform”, was led by Amay J. Bandodkar, Somayeh Imani, Rogelio Nuñez-Flores, Rajan Kumar, Chiyi Wang, A.M. Vinu Mohan, Joseph Wang, and Patrick P. Mercier, and published in Biosensors and Bioelectronics. Funding support came in part from the National Institute of Biomedical Imaging and Bioengineering (NIH, award no. R21EB019698).