A study of 196 individuals published in *Nature* by Google researchers and medical collaborators shows that hypertension can be screened without cuff calibration using optical pulse wave and accelerometer signals from standard smartwatches. The AI system identified 65.8% of participants with hypertension (sensitivity) and achieved a 90% identification rate for those without hypertension (specificity), though approximately 33% of hypertension cases still went undetected.