Lomonosov Moscow State University, Faculty of Physics, Moscow, Russia.
First Moscow State Medical University, Biomedical Science and Technology Park, Laboratory of Clinical Biophotonics, Moscow, Russia.
J Biomed Opt. 2023 May;28(5):057002. doi: 10.1117/1.JBO.28.5.057002. Epub 2023 May 13.
Edema occurs in the course of various skin diseases. It manifests itself in changes in water concentrations in skin layers: dermis and hypodermis and their thicknesses. In medicine and cosmetology, objective tools are required to assess the skin's physiological parameters. The dynamics of edema and the skin of healthy volunteers were studied using spatially resolved diffuse reflectance spectroscopy (DRS) in conjunction with ultrasound (US).
In this work, we have developed a method based on DRS with a spatial resolution (SR DRS), allowing us to simultaneously assess water content in the dermis, dermal thickness, and hypodermal thickness.
An experimental investigation of histamine included edema using SR DRS under the control of US was conducted. An approach for skin parameter determination was studied and confirmed using Monte-Carlo simulation of diffuse reflectance spectra for a three-layered system with the varying dermis and hypodermis parameters.
It was shown that an interfiber distance of 1 mm yields a minimal relative error of water content determination in the dermis equal to 9.3%. The lowest error of hypodermal thickness estimation was achieved with the interfiber distance of 10 mm. Dermal thickness for a group of volunteers (7 participants, 21 measurement sites) was determined using SR DRS technique with an 8.3% error using machine learning approaches, taking measurements at multiple interfiber distances into account. Hypodermis thickness was determined with root mean squared error of 0.56 mm for the same group.
This study demonstrates that measurement of the skin diffuse reflectance response at multiple distances makes it possible to determine the main parameters of the skin and will serve as the basis for the development and verification of an approach that works in a wide range of skin structure parameters.
水肿发生在各种皮肤病的过程中。它表现为皮肤层（真皮和皮下组织）中的水分浓度变化及其厚度变化。在医学和美容领域，需要客观的工具来评估皮肤的生理参数。本研究采用空间分辨漫反射光谱（DRS）与超声（US）相结合的方法，对水肿和健康志愿者的皮肤进行了研究。
本工作基于具有空间分辨率（SR DRS）的 DRS 方法，开发了一种同时评估真皮含水量、真皮厚度和皮下组织厚度的方法。
在 US 控制下，采用 SR DRS 对组织胺诱导的水肿进行了实验研究。研究并验证了一种皮肤参数确定方法，该方法通过对具有不同真皮和皮下组织参数的三层系统漫反射光谱进行 Monte-Carlo 模拟。
结果表明，纤维间距离为 1mm 时，真皮中水分含量的相对误差最小，为 9.3%。纤维间距离为 10mm 时，皮下组织厚度的估计误差最小。利用机器学习方法，对 7 名志愿者（21 个测量部位）的皮肤进行了 SR DRS 技术测量，其真皮厚度的误差为 8.3%，同时考虑了在多个纤维间距离处进行测量。对于同一组志愿者，使用均方根误差为 0.56mm 确定了皮下组织厚度。
本研究表明，在多个距离处测量皮肤漫反射响应，可确定皮肤的主要参数，并为开发和验证适用于广泛皮肤结构参数范围的方法提供依据。
