Blood Pressure Continuous Measurement through a Wearable Device: Development and Validation of a Cuffless Method

Area of Science:

• Biomedical Engineering
• Cardiovascular Technology
• Wearable Health Devices

Background:

• Continuous blood pressure monitoring is crucial for managing cardiovascular health.
• Existing methods often rely on invasive techniques or infrequent cuff-based measurements.
• Development of cuffless, continuous blood pressure monitoring systems is a significant unmet need.

Purpose of the Study:

• To develop and validate a cuffless method for continuous blood pressure measurement using a wearable device.
• To utilize the time-delay method, based on the transit time of blood volume from the heart to a peripheral site, for blood pressure estimation.
• To assess the performance of the developed method against international standards and a reference sphygmomanometer.

Main Methods:

• A wearable device, comprising a sensorized shirt and wristband, recorded electrocardiographic (ECG) and photoplethysmographic (PPG) signals.
• The time-delay was calculated as the interval between the R peak of the ECG signal and a marker on the PPG wave.
• A linear regression model used the time-delay and PPG features to estimate blood pressure variations.

Main Results:

• The developed time-delay method demonstrated notable performance according to international standards.
• 85% of the estimated blood pressure measurements had errors lower than 10 mmHg.
• The mean absolute error of the estimates was less than 7 mmHg when compared to a certified digital sphygmomanometer.

Conclusions:

• The study successfully developed and validated a cuffless method for continuous blood pressure estimation.
• The time-delay method implemented in the wearable device shows good performance compared to the traditional oscillometric technique.
• This approach offers a promising non-invasive solution for continuous blood pressure monitoring.