Pulse Transit Time Based Continuous Cuffless Blood Pressure Estimation: A New Extension and A Comprehensive...

Area of Science:

• Biomedical Engineering
• Cardiovascular Technology
• Wearable Health Devices

Background:

• Continuous blood pressure (BP) monitoring is crucial for cardiovascular health management.
• Conventional cuff-based BP measurement is obtrusive and intermittent.
• Cuffless BP monitoring offers a promising alternative for unobtrusive, continuous measurement.

Purpose of the Study:

• To introduce and evaluate a novel cuffless BP measurement method incorporating the photoplethysmogram (PPG) intensity ratio (PIR) combined with pulse transit time (PTT).
• To compare the accuracy of the PTT-PIR model against sole PTT models across various conditions.
• To assess the performance of cuffless BP monitoring over extended calibration intervals and during dynamic BP changes.

Main Methods:

• Developed and validated BP estimation models using PTT and a novel indicator, PIR.
• Compared the performance of PTT-PIR models with six PTT-only models.
• Conducted validation on 33 subjects (hypertensive and normotensive) at rest, during maneuvers, and over 24-hour calibration intervals.

Main Results:

• The PTT-PIR methods demonstrated superior accuracy compared to PTT-only models at rest and over a 24-hour calibration interval.
• While all methods showed increased errors during dynamic maneuvers, the PTT-PIR methods still outperformed others over extended calibration.
• The inclusion of PIR as an additional indicator significantly enhanced the accuracy of cuffless BP measurement.

Conclusions:

• The integration of PIR with PTT provides added value for improving the accuracy of cuffless BP measurement.
• The proposed method shows potential for revolutionizing continuous and unobtrusive BP monitoring.
• Further research is warranted for tracking dynamic BP changes and long-term monitoring using cuffless techniques.