Diffuse correlation spectroscopy towards dynamic topography of blood flow index in deep tissues: A multi-channel system and experiment validation

Abstract

Near-infrared (NIR) diffusion correlation spectroscopy (DCS) provides a novel tool for clinical monitoring of blood flow in deep tissues. While DCS has the advantages of non-invasiveness, high sensitivity and large penetration depth, accelerating its data acquisition process to realize real-time imaging is still an on-going task. We have proposed herein a 10-detection-channel DCS system for dynamic topography of the blood flow index. In the design, an imaging speed up to 1 frame/s can be achieved by taking the advantage of the concurrency of a multi-channel multi-delay designed hardware correlator, the improved NIR-sensitivity of a single photon avalanche photodiode detector and the high efficiency of the prior-guided fitting procedure for the blood flow index extraction. We firstly evaluated the flow-rate resolution, measurement fidelity and imaging depth of the system using phantom experiments, and then performed in-vivo experiments on human arm to demonstrate the ability of the proposed methodology to capture blood flow changes in terms of their shapes and positions.