Spatially resolved diffuse optical correlation spectroscopy (SR-DOCS) for quantitative assessment of skin tissue perfusion matrix

TLDR: In this article, the authors presented the fabrication of a perfused tissue physical model that mimic skin tissue and subsequent estimation of perfusion matrix including optical properties, flow, and depth of the microvascular bed.

Abstract: Assessment of skin tissue perfusion is vital for understanding the normal and the pathologic physiology of human body. Diffuse optical methods provide numerous pathways for assessing various static and dynamic perfusion markers such as variations in bulk tissue optical properties, depth dimensions of microvascular bed, rate and volume of blood flow and so on. There have been numerous studies on these aspects ending up with qualitative assessments on various parameters, where separate approaches are explored for individual parametric evaluation. With the introduction of precise optical tissue phantom models, integration of different static and dynamic perfusion markers are possible to facilitate quantitative assessment of such a perfusion matrix. In this work, we present the fabrication of a perfused tissue physical model that mimic skin tissue and subsequent estimation of perfusion matrix including optical properties, flow, and depth of the microvascular bed. Different layers of skin are spin coated onto micron-sized embedded channels, and the model was subjected to optical measurements, inducing different flow levels using a syringe pump. The parameters have been estimated using spatially resolved diffuse correlation optical spectral measurements, using a handheld fiber optic probe with a precise source to target distance sensing mechanism and associated signal processing algorithms. This work is aimed to provide a methodology for quantitative assessment of various perfusion parameters using a versatile physical model that provides flexibility in varying involved parameters accurately. The work performed here, after standardization is expected to have potential in developing non-invasive quantitative optical skin biopsy tools to augment the current histopathological studies.