Optical Hemodynamic Imaging of Jugular Venous Dynamics During Altered Central Venous Pressure.

An optical imaging system is proposed for quantitatively assessing jugular venous response to altered central venous pressure. The proposed system assesses sub-surface optical absorption changes from jugular venous waveforms with a spatial calibration procedure to normalize incident tissue illumination. Widefield frames of the right lateral neck were captured and calibrated using a novel flexible surface calibration method. Jugular venous optical attenuation (JVA) signals were computed using an optical model for quantifying hemodynamic changes, and a jugular venous pulsatility map was computed using a time-synchronized arterial waveform. JVA was assessed in three cardiovascular protocols that altered central venous pressure by inducing acute central hypovolemia (lower body negative pressure), venous congestion (head-down tilt), and impaired cardiac filling (Valsalva maneuver). JVA waveforms exhibited biphasic properties and sub-wave timing consistent with jugular venous pulse dynamics with time-synchronized electrocardiogram waves. JVA correlated strongly (median, interquartile range) with invasive central venous pressure during graded central hypovolemia (r=0.85, [0.72, 0.95]), graded venous congestion (r=0.94, [0.84, 0.99]), and impaired cardiac filling (r=0.94, [0.85, 0.99]). Reduced JVA during graded acute hypovolemia was strongly correlated with reductions in stroke volume (SV) (r=0.85, [0.76, 0.92]) from baseline (SV: 79$\pm$15 mL, JVA: 0.56$\pm$0.10 a.u.) to -40 mmHg suction (SV: 59$\pm$18 mL, JVA: 0.47$\pm$0.05 a.u.; p$<$0.01). The proposed non-contact optical imaging system demonstrated jugular venous dynamics consistent with invasive central venous monitoring during three protocols that altered central venous pressure.