New photoplethysmogram indicators for improving cuffless and continuous blood pressure estimation accuracy

Area of Science:

• Biomedical Engineering
• Physiological Monitoring
• Cardiovascular Health

Background:

• Cuffless and continuous blood pressure (BP) estimation accuracy remains a challenge for clinical utility.
• Existing methods require further refinement to meet clinical standards.

Purpose of the Study:

• To enhance the accuracy of cuffless and continuous BP estimation.
• To develop improved BP estimation models using novel physiological indicators.

Main Methods:

• Extraction of new indicators from photoplethysmogram (PPG) recordings.
• Development of BP estimation models using linear regression with PPG indicators and pulse transit time (PTT).
• Evaluation of model performance during induced BP fluctuations (mental arithmetic stress, Valsalva's manoeuvre) in 22 subjects.

Main Results:

• The best PPG-based model reduced estimation errors (GAM & GSD) by 0.31±0.08 mmHg (SBP) and 0.33±0.01 mmHg (DBP) compared to prior PPG methods.
• The combined PPG and PTT model achieved superior error reduction (GAM & GSD) of 0.81±0.95 mmHg (SBP) and 0.75±0.54 mmHg (DBP) over PTT-based methods.

Conclusions:

• Newly proposed PPG indicators show significant promise for improving continuous and cuffless BP estimation.
• The developed models offer a potential advancement for non-invasive BP monitoring.