Signal Ring measures your blood pressure without a cuff. Ever. Not even for calibration. This avoids the inherent accuracy drift problem and offers more convenience than any calibration based approach. A unique, ultra-fast sensor measures blood flow in higher resolution, showing previously undiscovered details.

Assuming it works as advertised, this is an incredible piece of tech. I am convinced Apple will release a ring wearable device at some point because there is so much potential in this category.