New Smart Ring Prototype Tracks Glucose Through Sweat: What Users Need to Know

Researchers at UC San Diego have developed a prototype smart ring called CHARM that can track glucose levels through sweat. This technology offers a potential alternative to current methods of glucose monitoring, which often involve wearing a separate device on the body. The CHARM ring uses a soft hydrogel to passively draw small amounts of sweat from the skin and then uses sensors to detect glucose levels. The device sends the data wirelessly to a phone for the user to view.

In early testing, CHARM was compared to commercial continuous glucose monitoring (CGM) systems and blood-glucose meters. The results showed that CHARM accurately captured glucose changes throughout the day, including those related to meals. However, there were some delays between CHARM's readings and the reference measurements, typically around 15 to 20 minutes. Researchers also found that once personalized calibration settings were established, they remained stable for about two months.

While CHARM can monitor glucose levels, it's important to note that sweat-based glucose readings are not the same as blood-glucose readings. Researchers use personalized calibration to estimate corresponding blood-glucose levels. The ring also has the capability to monitor other biomarkers such as ketones, lactate, uric acid, vitamin C, and alcohol. Up to four biomarkers can be monitored simultaneously.

The CHARM prototype currently has a battery life of about 12 hours, and the researchers are working on improving all-day battery life and water resistance to make the device more suitable for everyday use. Currently, CHARM is a research prototype and not yet available for commercial use. The FDA has not authorized any smartwatch or smart ring to independently measure or estimate blood glucose levels without piercing the skin.

As with any new health technology, it's crucial for users to continue using FDA-authorized glucose monitors for treatment decisions. However, CHARM represents an exciting step towards potentially simpler, more discreet glucose monitoring. A ring-based sensor could appeal to individuals who find the current systems of juggling multiple devices cumbersome.