Using imaging photoplethysmography for heart rate estimation in non-human primates

Area of Science:

• Physiological monitoring
• Animal behavior research
• Non-invasive sensing technologies

Background:

• Heart rate is a key indicator of physiological and emotional states in humans and non-human primates.
• Non-contact heart rate estimation in humans uses imaging photoplethysmogram (iPPG) based on skin optical property changes.
• A simple, non-invasive method for pulse rate measurement in awake, behaving animals is lacking.

Purpose of the Study:

• To demonstrate the accurate, non-contact estimation of pulse rate in rhesus monkeys using iPPG from facial videos.
• To validate the iPPG method against established contact pulse-oximetry reference data.
• To establish iPPG as a viable tool for physiological studies and welfare assessment in non-human primates.

Main Methods:

• Computed iPPG signals from eight color facial videos of four awake, head-stabilized rhesus monkeys.
• Compared iPPG-derived pulse rate estimates with simultaneous measurements from a contact pulse-oximeter.
• Analyzed the accuracy and agreement between the non-contact iPPG method and the reference method.

Main Results:

• iPPG-based pulse rate estimation showed good agreement with reference pulse-oximeter data.
• Error in pulse rate estimation was below 5% of the individual average in 83% of recorded epochs.
• Error was below 10% for 98% of epochs, demonstrating high accuracy.

Conclusions:

• iPPG enables accurate, non-invasive, and non-contact pulse rate estimation in non-human primates.
• This technique is valuable for advancing physiological studies in research animals.
• The method supports improved welfare assessment for non-human primates in research settings.