Measuring pulse rate variability using long-range, non-contact imaging photoplethysmography.

Area of Science:

• Biomedical Engineering
• Physiological Measurement
• Remote Sensing

Background:

• Non-contact, camera-based photoplethysmography (IP) is popular for remote pulse rate measurement.
• Less research exists on IP for pulse rate variability (PRV) and accuracy at long distances.

Purpose of the Study:

• To assess the accuracy of camera-based IP for measuring PRV at a distance of 25 meters.
• To compare time-domain and periodogram approaches for PRV analysis using remote video data.

Main Methods:

• Recorded video of 19 participants at rest from 25 meters using a digital camera.
• Acquired concurrent ground truth cardiovascular data (electrical and optical).
• Analyzed recovered blood volume pulse morphology for inter-pulse interval (IPI) time series extraction.

Main Results:

• Time-domain analysis reduced pulse rate error from 1.6 to 0.2 beats per minute compared to the periodogram approach.
• Correlation (r2) for PRV measures ranged from 0.779 to 0.973, comparable to short-distance results.
• Accurate PRV estimation is achievable with sufficient blood volume pulse morphology quality.

Conclusions:

• Camera-based IP can accurately measure PRV at long distances (25m) with minimal error (<1 bpm).
• This non-contact method shows promise for remote cardiovascular health monitoring.
• The quality of recovered blood volume pulse morphology is crucial for accurate PRV analysis.