A novel method for non-invasive blood pressure estimation based on continuous pulse transit time: An observational...

Area of Science:

• Biomedical Engineering
• Cardiovascular Physiology

Background:

• Traditional pulse transit time (PTT) methods have limitations in continuous blood pressure (BP) estimation.
• Continuous PTT (CPTT) allows for PTT calculation across the entire cardiac cycle, offering potential for real-time BP monitoring.

Purpose of the Study:

• To evaluate the feasibility of CPTT as a non-invasive, consecutive blood pressure estimation method.
• To compare the accuracy of CPTT-based BP estimation against traditional PTT methods and a gold standard device.

Main Methods:

• CPTT was calculated using time delays from photoplethysmograms at two body sites in 20 volunteers.
• Blood pressure (BP) parameters including systolic (SBP), diastolic (DBP), mean arterial pressure (MAP), and pulse pressure (PP) were estimated using both PTT and CPTT.
• BP estimation performance was evaluated using correlation coefficients and root-mean-squared-error (RMSE) against a non-invasive volume clamp BP monitoring device.

Main Results:

• CPTT-based BP estimation showed slightly improved correlations for SBP (.436 vs .407), DBP (.446 vs .373), and PP (.506 vs .410) compared to PTT.
• RMSE values for CPTT were comparable or slightly better than PTT for SBP (5.36±1.39 vs 5.44±1.56 mmHg), DBP (3.02±0.49 vs 3.14±0.46 mmHg), and MAP (3.44±0.63 vs 3.66±0.70 mmHg).
• CPTT demonstrated a correlation of .097 for MAP, while PTT showed .286, indicating potential areas for further investigation.

Conclusions:

• CPTT is a feasible non-invasive method for continuous blood pressure estimation.
• CPTT shows comparable and in some parameters, improved accuracy over traditional PTT for BP monitoring.
• Further research may optimize CPTT algorithms for enhanced accuracy in all BP parameters, particularly MAP.