Smartwatch Blood Pressure Monitoring: Current Accuracy and Future Outlook

As of 2024, no consumer smartwatch provides clinically validated, cuff-equivalent blood pressure measurement for medical decision-making.

Current Technology

• Optical PPG (photoplethysmography): Estimates pulse wave analysis; calibrates with occasional cuff. Samsung Galaxy Watch (BP monitor), Aktiia (cuffless, CE-marked), Omron HeartGuide (inflatable cuff in band).
• Limitations: Motion artifact, vascular tone changes, calibration drift, positional variance (wrist vs. brachial).
• Validation: Most lack AAMI/ESH/ISO 81060-2 certification. Studies show mean error 5–8 mmHg, but individual readings can deviate >15 mmHg.

Clinical Role Today

• Trend tracking, lifestyle correlation, white-coat hypertension screening.
• Not for: Diagnosis, medication titration, hypertensive urgency assessment.

Near-Term Advances

• Continuous cuffless BP via PTT (pulse transit time) + AI calibration.
• Radial artery tonometry (Apple patent, research stage).
• Regulatory pathways evolving (FDA De Novo for cuffless).

Recommendation

Use validated upper-arm cuff (Omron, Welch Allyn) for clinical decisions. Smartwatch as adjunct for awareness only.