Camera-based assessment of arterial stiffness and wave reflection parameters from neck micro-motion

Area of Science:

• Biomedical Engineering
• Medical Imaging
• Cardiovascular Physiology

Background:

• Traditional methods for assessing carotid distension waveforms, such as laser Doppler velocimetry (LDV) and accelerometry, can be user-unfriendly.
• Applanation tonometry is another method for extracting central pulse pressure waveform features, but may be improved with alternative techniques.
• Camera-based approaches offer a potential user-friendly alternative for non-invasive cardiovascular assessment.

Purpose of the Study:

• To describe the application of camera-based micro-motion imaging for extracting health-related features from carotid displacement waveforms.
• To evaluate the feasibility of this novel imaging technique for cardiovascular health assessment.

Main Methods:

• Developed a camera-based system to acquire skin motion (sMOT) waveforms near the carotid artery under uneven illumination.
• Assumed dominant contribution of carotid wall displacement to the sMOT waveform's cardiac-related frequency components.
• Employed a two-step approach: querying sMOT signals based on remote-photoplethysmography sensor amplitude and ensemble-averaging for analysis.

Main Results:

• Demonstrated the feasibility of camera-based micro-motion imaging for assessing cardiovascular parameters.
• Successfully evaluated stiffness index, augmentation pressure, augmentation index, and reflection magnitude.
• Results were validated on a dataset of 28 participants aged 23-62 years.

Conclusions:

• Camera-based micro-motion imaging is a feasible technique for extracting key cardiovascular features from carotid distension waveforms.
• This method presents a user-friendly alternative to existing technologies like LDV and applanation tonometry.
• Micro-motion imaging can serve as an auxiliary tool to enhance sensor placement and signal quality in other cardiovascular monitoring systems.