Université Laval, CERVO Brain Research Center, Neuroscience, Quebec City, Québec, G1V 0A6, Canada.
Université Laval, Center for optics, photonics and lasers (COPL), Physics Engineering, Quebec City, Québec, G1V 0A6, Canada.
Sci Rep. 2019 Aug 6;9(1):11387. doi: 10.1038/s41598-019-47621-7.
Retinal oximetry is a non-invasive technique to investigate the hemodynamics, vasculature and health of the eye. Current techniques for retinal oximetry have been plagued by quantitatively inconsistent measurements and this has greatly limited their adoption in clinical environments. To become clinically relevant oximetry measurements must become reliable and reproducible across studies and locations. To this end, we have developed a convolutional neural network algorithm for multi-wavelength oximetry, showing a greatly improved calculation performance in comparison to previously reported techniques. The algorithm is calibration free, performs sensing of the four main hemoglobin conformations with no prior knowledge of their characteristic absorption spectra and, due to the convolution-based calculation, is invariable to spectral shifting. We show, herein, the dramatic performance improvements in using this algorithm to deduce effective oxygenation (SO), as well as the added functionality to accurately measure fractional oxygenation ([Formula: see text]). Furthermore, this report compares, for the first time, the relative performance of several previously reported multi-wavelength oximetry algorithms in the face of controlled spectral variations. The improved ability of the algorithm to accurately and independently measure hemoglobin concentrations offers a high potential tool for disease diagnosis and monitoring when applied to retinal spectroscopy.
视网膜血氧计是一种非侵入性技术,用于研究眼睛的血液动力学、血管和健康状况。目前的视网膜血氧计技术受到定量不一致测量的困扰,这极大地限制了它们在临床环境中的应用。为了具有临床相关性,血氧计测量必须在研究和地点之间变得可靠且可重复。为此,我们开发了一种用于多波长血氧计的卷积神经网络算法,与之前报道的技术相比,该算法在计算性能方面有了很大的提高。该算法无需校准,能够在没有其特征吸收光谱先验知识的情况下感知四种主要的血红蛋白构象,并且由于基于卷积的计算,它不受光谱移动的影响。在此,我们展示了使用该算法推断有效氧合(SO)的显著性能改进,以及准确测量分氧饱和度 ([Formula: see text]) 的附加功能。此外,本报告首次比较了几种以前报道的多波长血氧计算法在面对受控光谱变化时的相对性能。该算法能够准确和独立地测量血红蛋白浓度的能力为应用于视网膜光谱学的疾病诊断和监测提供了一个高潜力的工具。