Masimo has received FDA De Novo clearance for its W1 Health Watch for continuous cuffless blood pressure monitoring, making it the first consumer wearable device cleared for this indication and potentially transforming hypertension management.
Masimo has received FDA De Novo clearance for the W1 Health Watch for continuous cuffless blood pressure monitoring, a landmark regulatory decision that makes the W1 the first consumer wearable device cleared for this medical indication in the United States.
The W1 uses Masimo's adaptive algorithm combining photoplethysmography (PPG), accelerometry and a proprietary pulse transit time calculation to estimate systolic and diastolic blood pressure without an inflatable cuff, taking readings every 15 minutes throughout the day and night.
Clinical Validation
The FDA De Novo decision was supported by a 2,200-subject validation study that demonstrated the W1 meets IEEE 1708-2014 and ISO 81060-2 standards for ambulatory BP monitoring:
- Systolic BP mean error: 1.2 ± 6.8 mmHg
- Diastolic BP mean error: 0.8 ± 5.4 mmHg
- Compliance: 93% of participants wore device >20 hours/day
- Battery life: 72 hours continuous monitoring
Hypertension affects 1.28 billion adults worldwide and is the leading risk factor for stroke and heart disease. Ambulatory BP monitoring is currently underused due to patient inconvenience with traditional cuff-based systems.
The Masimo W1 will retail at $399, with a prescription required for the cleared BP monitoring feature. It is expected in US pharmacies and direct-to-consumer from May 2026.