Retinal Pulse Wave Estimation Through Near-Infrared Fundus Video Analysis

Area of Science:

• Ophthalmology
• Biomedical Engineering
• Medical Imaging

Background:

• Non-contact physiological monitoring is crucial for patient comfort and continuous data acquisition.
• Estimating pulse wave signals noninvasively can aid in cardiovascular health assessment.
• Retinal imaging offers a unique window into the microvasculature for physiological measurements.

Purpose of the Study:

• To develop and evaluate a non-contact method for estimating pulse wave-like signals using retinal vessel diameter changes.
• To assess the feasibility of using near-infrared (NIR) fundus videos for continuous physiological signal monitoring.
• To compare signals obtained from NIR fundus imaging with traditional photoplethysmography.

Main Methods:

• A compact imaging system with a commercial camera and NIR LED was used to capture continuous fundus videos.
• Temporal changes in retinal vessel diameter were analyzed from the acquired videos.
• Signals extracted from NIR fundus imaging were compared with those from fingertip photoplethysmography.

Main Results:

• Periodic waveforms, indicative of pulse signals, were successfully extracted from NIR fundus videos.
• The extracted signals exhibited similarities to photoplethysmography signals, with minor discrepancies in peak intervals.
• The method demonstrated potential for noninvasive physiological signal monitoring without mydriatic agents.

Conclusions:

• NIR fundus imaging is a promising non-contact technique for estimating pulse wave-like signals.
• Further research with larger cohorts and enhanced imaging precision is required to confirm statistical validity and clinical applicability.
• This approach may offer a comfortable and effective alternative for long-term physiological monitoring.