Detection of cutaneous oxygen saturation using a novel snapshot hyperspectral camera: a feasibility study

Abstract

Background: Tissue necrosis, a consequence of inadequate tissue oxygenation, is a common post-operative complication. As current surgical assessments are often limited to visual and tactile feedback, additional techniques that can aid in the interrogation of tissue viability are needed to improve patient outcomes. In this bi-institutional pilot study, the performance of a novel snapshot hyperspectral imaging camera to detect superficial cutaneous oxygen saturation (StO 2 ) was evaluated.Methods: Healthy human volunteers were recruited at two participating centers. Cutaneous StO 2 of the forearm was determined by a snapshot hyperspectral camera on two separate study days during occlusionreperfusion of the brachial artery and after induction of local vasodilation. To calculate the blood StO 2 at each pixel in the multispectral image, spectra were selected, and fitting was performed over wavelengths ranging from 470 to 950 nm. Results: Quantitative detection of physiological changes in cutaneous StO 2 levels was feasible in all sixteen volunteers. A significant (P<0.001) decrease in cutaneous StO 2 levels from 78.3% (SD: 15.3) at baseline to 60.6% (SD: 19.8) at the end of occlusion phase was observed, although StO 2 levels returned to baseline after five minutes. Mean cutaneous StO 2 values were similar in the same subjects on separate study days (Pearson R2: 0.92 and 0.77, respectively) at both centers. Local vasodilation did not yield significant changes in cutaneous StO 2 values.Conclusions: This pilot study demonstrated the feasibility of a snapshot hyperspectral camera for detecting quantitative physiological changes in cutaneous StO 2 in normal human volunteers, and serves as a precursor for further validation in perioperative studies.

A comparative study of analytical tissue reflectance models using simulated and experimental data

“…The measured NIST skin dataset is analysed using the inverse problem of the Yudovsky 2009 double-layer model, which results in a mean (± standard deviation) extracted StO 2 of 39.6% (± 11.1%). This shows significantly different results from previous literature analysis, such as 78.3% (± 12.9%) 8 or 71% (± 16), 9 suggesting that this model should be used with caution when encountering experimental data.…”

Multiexposure laser speckle contrast analysis system calibration limited by perfusion-dependent scattering on the skin

“…While cooling usually leads to vasoconstriction, local cooling of the skin can result is vasodilation and increased perfusion, 36 which is in agreement with our observations. Capsaicin also causes local vasodilation 37 . The RBC enrichment in the subcutaneous region seems to strongly influence the scattering properties of the tissue, resulting in a decrease of the overall decorrelation factor.…”

“…Capsaicin also causes local vasodilation. 37 The RBC enrichment in the subcutaneous region seems to strongly influence the scattering properties of the tissue, resulting in a decrease of the overall decorrelation factor.…”

LIBRA: Low spectral resolution brain tumor classifier for medical hyperspectral imaging

“…This fact led to a recent shift in HSI in medical contexts by using HS snapshot cameras. For example, Van et al [49] show the feasibility of using HS snapshot cameras to detect cutaneous oxygen saturation with a multi-camera system that acquires information ranging between 470 and 950 nm in 41 spectral bands. Khouj et al [19] present a study evaluating the performance of a snapshot HS system to determine whether detectable changes in spectral characteristics between healthy and breast tissues can be found.…”