A prototype smart ring developed by engineers at the University of California appears to have cracked one of the holy grails of health wearables: non-invasive blood sugar measurement. The data is sent to a companion app on a paired iPhone.
Source: [9to5Mac](https://9to5mac.com/2026/07/29/prototype-smart-ring-cracks-the-holy-grail-of-non-invasive-blood-sugar-measurement/)