This study presents the development and validation of a fibre Bragg gratings (FBGs)-based sensor system for the assessment of strain in the midpalatal suture in subjects using rapid palatal expanders (RPEs). The ex-vivo experiments were made by means of positioning two RPEs in a porcine palatal region. The RPEs used were the Hyrax, a tooth-borne expander and MARPE (microimplant-assisted rapid palatal expansion), a bone-borne expander. In order to define the regions in the palatal region for the sensors positioning, a finite-element analysis was performed in a porcine head subjected to the loadings caused by an RPE. In addition, a strain transfer model was used to obtain a correction coefficient that approximates the strain estimated by the FBG to the actual strain in the structure under shear and normal stress. Results show high linearity in the sensors characterisation tests with the advantages of compactness, intrinsic safe operation and multiplexing capabilities of FBGs. In the RPE analysis, a higher strain was estimated in the anterior region, which is in accordance with the simulation and previously reported results, where MARPE showed a higher strain (with an exponential pattern) than Hyrax as the number of activations increase.

中文翻译：

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光纤布拉格光栅传感器，用于快速pa扩展器中的缝合扩展评估：体外验证

这项研究提出了基于光纤布拉格光栅（FBGs）的传感器系统的开发和验证，该系统用于评估使用快速pa骨扩张器（RPE）的subjects骨中缝缝合线的应变。通过将两个RPE定位在猪的region区域进行离体实验。所用的RPE是Hyrax（一种牙齿传播的扩张器）和MARPE（微植入物辅助的快速pa扩展）（一种骨骼传播的扩张器）。为了定义传感器定位的the区域中的区域，在受到RPE载荷的猪头中进行了有限元分析。另外，使用应变传递模型来获得校正系数，该校正系数使FBG估算的应变近似于结构在剪切和正应力下的实际应变。结果表明，在传感器特性测试中，FBG具有紧凑，固有的安全操作和多路复用功能等优点，因此具有很高的线性度。在RPE分析中，与模拟和先前报道的结果一致，在前部区域估计有更高的应变，其中随着激活次数的增加，MARPE显示出比Hyrax更高的应变（具有指数模式）。