In Depth: China’s Blood Sugar Tracking Device-Makers Come Down Off a High

A coin-sized sensor that can be stuck on the upper arm is transforming how people monitor their blood sugar.

Secured with an adhesive patch, the device uses a micro needle to penetrate the skin, allowing continuous wear for up to 14 days without interfering with daily activities like bathing or exercise. A smartphone app can display the wearer’s real-time glucose levels and trend curves, giving them insights into how certain foods change their blood sugar levels.