One possible application of Near Infrared techniques is to analyze human brain metabolic activity. Currently used models take into account the layered structure of the human head but, usually, they do not consider the non-planar surface of some of the boundaries, i.e. gray matter, which results in a much more complex structure, thus leading to more sophisticated models and longer calculation times. The main objective of this work is to determine if it is worth to replace a planar layered structure by a non-planar one. To this end we implement a Bayesian-based quantitative methodology for choosing between two competitive models describing light propagation in layered turbid media. Experiments of time-resolved diffuse reflectance measurements are performed in layered phantoms and complemented with numerical calculations. The resulting Distributions of Time of Flight of both models are compared using Bayesian model selection analysis. The non-planar interface was introduced in the simulations by a simple surface parametrization. Results suggest that, under certain conditions, a multilayer model with planar boundaries is good enough.

中文翻译：

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应用贝叶斯选择标准的几何变化分层混浊介质中的似是而非模型之间的比较

近红外技术的一种可能应用是分析人脑代谢活动。当前使用的模型考虑了人头的分层结构，但通常它们不考虑某些边界的非平面表面，即灰质，这导致结构更加复杂，从而导致更复杂模型和更长的计算时间。这项工作的主要目的是确定是否值得用非平面结构代替平面分层结构。为此，我们实施了一种基于贝叶斯的定量方法，用于在描述分层混浊介质中光传播的两个竞争模型之间进行选择。时间分辨漫反射测量实验在分层模型中进行，并辅以数值计算。使用贝叶斯模型选择分析来比较两种模型的飞行时间分布。通过简单的表面参数化在模拟中引入了非平面界面。结果表明，在某些条件下，具有平面边界的多层模型就足够了。