Abstract Fiber Bragg grating (FBG) is a promising technology for shape detection in medical surgery robots. Conventional optical fiber is prone to fracture due to bending and torsion, so it needs fiber encapsulation before use. However, the encapsulating materials and bonding materials bring strain transfer loss. For correcting error and improving measurement precision, the thin diameter no-substrate sensor suitable for laryngeal surgery robot detection was proposed to establish the model. The four-layer composite structure of FBG shape sensor, including adhesive layer, fiber optic layer, coating layer and adhesive layer, was established. The theoretical model of strain transmissibility of fiber optic coating was proposed, and the effects of elastic modulus of adhesive, length of adhesive layer and diameter of encapsulation on static strain transfer were analyzed. The correctness of theoretical prediction was verified by finite element numerical analysis. The research results revealed the influence law of strain transmissibility of non-substrate sensor, offered theoretical model for strain analysis, and provided important basis for improving shape perception accuracy of medical devices. The strain transfer rate is introduced into shape reconstruction, and the accuracy of end positioning is improved from 2.71% to 2.45%.

中文翻译：

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无基板薄径传感器应变传递特性分析

摘要 光纤布拉格光栅（FBG）是一种很有前途的医疗手术机器人形状检测技术。传统光纤容易因弯曲和扭转而断裂，因此在使用前需要进行光纤封装。然而，封装材料和键合材料带来了应变传递损失。为修正误差、提高测量精度，提出了适用于喉科手术机器人检测的细径无基板传感器建立模型。建立了FBG形状传感器的四层复合结构，包括粘合层、光纤层、涂层和粘合层。提出了光纤涂层应变传递率的理论模型，以及胶粘剂弹性模量的影响，分析了静态应变传递时粘合层的长度和封装的直径。通过有限元数值分析验证了理论预测的正确性。研究结果揭示了非基板传感器应变传递率的影响规律，为应变分析提供了理论模型，为提高医疗器械形状感知精度提供了重要依据。将应变传递率引入形状重建，端部定位精度由2.71%提高到2.45%。为提高医疗器械形状感知精度提供了重要依据。将应变传递率引入形状重建，端部定位精度由2.71%提高到2.45%。为提高医疗器械形状感知精度提供了重要依据。将应变传递率引入形状重建，端部定位精度由2.71%提高到2.45%。