https://blog.hackster.io/these-glasses-from-microsoft-monitor-blood-pressure-without-the-cuff-7ee972ed8397

Many medical conditions, particularly those related to heart problems and hypertension, require at-home blood pressure monitoring. If high blood pressure is an especially big concern, you may even need to constantly monitor your blood pressure. Unfortunately, the devices on the market, such as blood pressure cuffs, are uncomfortable and cumbersome. Microsoft Research’s Glabella Project glasses continuously monitor blood pressure without the need for a bulky cuff.

The Glabella Project glasses look mostly like regular eyeglasses, albeit with a thick frame. That large frame is used to house a processor and a 3-axis IMU (Inertial Measurement Unit). Those are used in conjunction with optical pulse sensors in order to indirectly check the wearer’s blood pressure. They’ve tested prototypes with the optical sensor located on the bridge of the nose, and with with it located on the side of the head. The first is more accurate, but the latter is less noticeable.