Fiber-based Ultra-High Speed Diffuse Speckle Contrast Analysis System for Deep Blood Flow Sensing Using a Large SPAD Camera

TL;DR

This paper presents a novel fiber-based diffuse speckle contrast analysis system utilizing a large SPAD camera, significantly improving deep blood flow sensing capabilities with high temporal resolution and broad field of view for biomedical applications.

Contribution

It introduces the first large-format SPAD camera application in DSCA, enhancing measurement accuracy and enabling detailed spatiotemporal blood flow analysis.

Findings

High temporal resolution captures rapid blood flow changes.

Broad field of view allows comprehensive tissue monitoring.

Validated through simulations, phantom, and in vivo experiments.

Abstract

Diffuse speckle contrast analysis (DSCA), also called speckle contrast optical spectroscopy(SCOS), has emerged as a groundbreaking optical imaging technique for tracking dynamic biological processes, including blood flow and tissue perfusion. Recent advancements in single-photon avalanche diode (SPAD) cameras have unlocked exceptional capabilities in sensitivity, time resolution, and high frame rate imaging. Despite this, the application of large-format SPAD arrays in speckle contrast analysis is still relatively uncommon. In this study, we introduce a pioneering use of a large format SPAD camera for DSCA. By harnessing the camera's high temporal resolution and photon detection efficiency, we significantly enhance the accuracy and robustness of speckle contrast measurements. Our experimental results demonstrate the system's remarkable ability to capture rapid temporal variations over a broad field of view, enabling detailed spatiotemporal analysis. Through simulations, phantom experiments, and in vivo studies, we validate the approach's potential for a wide range of biomedical applications, such as cuff occlusion tests and functional tissue monitoring. This work highlights the transformative impact of large SPAD cameras on DSCA, paving the way for new breakthroughs in optical imaging.