Motivation: Present day cardiac and respiratory gating require cabled sensors that impede patient workflow. A non-contact sensing method is needed. Goal(s): Our goal is to determine whether non-contact mm-wave radar neck vessel motion sensing can distinguish the cardiac cycle from respiratory motion with a long term aim of non-contact gating. Approach: We updated a 4 channel 24GHz CW radar system using dual Analog Discovery Pros for chest/neck data capture and integrated ECG monitoring with Python scripting. Results: Respiratory motion remains easily detected with high SNR. Neck vessel motion creates unique waveforms with carotid notch and jugular venous pulse contributions variably mixed. Impact: MM-wave radar is a promising candidate for non-contact sensing of cardiac and respiratory cycles, with potential applications in non-contact motion gating in pediatric MRI and synchronizing on pulsatile motion of the cerebrum in neuroimaging.
Arora et al. (Tue,) studied this question.