Test-Retest Reliability and Concurrent Validity of Photoplethysmography Finger Sensor to Collect Measures of Heart...

Area of Science:

• Physiological monitoring
• Biomedical engineering
• Cardiovascular research

Background:

• Heart rate variability (HRV) is a key indicator of autonomic nervous system function.
• Accurate HRV measurement is crucial for various health and performance applications.
• Electrocardiography (ECG) is the gold standard, but other methods are sought for convenience.

Purpose of the Study:

• To evaluate the test-retest reliability of a photoplethysmography (PPG) finger sensor for HRV metrics.
• To assess the concurrent validity of the PPG sensor against ECG and heart rate monitor (HRM) devices.
• To determine the accuracy and consistency of PPG-based HRV data in different positions.

Main Methods:

• Collected R-R interval data from 45 participants over two sessions 48 hours apart.
• Measured HRV using a PPG finger sensor, ECG, and HRM in supine and seated positions.
• Analyzed data for test-retest reliability (ICC) and concurrent validity (correlation, agreement, effect size).

Main Results:

• The PPG sensor demonstrated moderate-to-excellent test-retest reliability (ICC = 0.60-0.93).
• Near-perfect relationships (r = 0.91-1.00) and very large-to-near-perfect agreement (CCC = 0.81-1.00) were found between PPG and reference devices.
• Statistically significant but trivial-to-small differences were observed between PPG and ECG/HRM.

Conclusions:

• The PPG finger sensor exhibits adequate test-retest reliability and concurrent validity for HRV assessment.
• PPG is a reliable and valid tool for measuring HRV in both supine and seated resting conditions.
• This validates PPG as a practical alternative for HRV monitoring.