Detection of thermal gradients through fiber-optic Chirped Fiber Bragg Grating (CFBG): Medical thermal ablation scenario
Detection of thermal gradients through fiber-optic Chirped Fiber Bragg Grating (CFBG): Medical thermal ablation scenario
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DOI：
10.1016/j.yofte.2017.12.017
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发表时间：
2018-03-01
影响因子：
2.7
通讯作者：
Tosi, Daniele
中科院分区：
文献类型：
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作者：
Korganbayev, Sanzhar;Orazayev, Yerzhan;Tosi, Daniele
在本文中，我们描述了一种使用啁啾光纤布拉格光栅（CFBG）光纤传感器进行空间分布式温度测量的新方法。所提出的方法通过解调 CFBG 光谱来确定 CFBG 区域的热分布。该方法基于迭代优化，旨在最大限度地减少测量的 CFBG 光谱与基于耦合模式理论 (CMT) 且受温度梯度扰动的 CFBG 模型之间的不匹配。在解调部分，我们利用蒙特卡罗方法在模拟CFBG频谱上模拟不同的温度分布模式。然后，我们获得成本函数，最小化测量光谱和模拟光谱之间的差异，并得出最终的温度曲线。首先用线性梯度进行了实验和模拟，证明了正确的操作（误差2.9摄氏度）；然后，安排了一个装置来测量暴露于医用激光热消融的 5 厘米长部分的温度模式。总体而言，所提出的方法可以作为 1.5-5 cm 区域内热梯度的实时检测技术，并成为生物医学应用中微尺度热梯度估计的关键资产。
In this paper, we describe a novel method for spatially distributed temperature measurement with Chirped Fiber Bragg Grating (CFBG) fiber-optic sensors. The proposed method determines the thermal profile in the CFBG region from demodulation of the CFBG optical spectrum. The method is based on an iterative optimization that aims at minimizing the mismatch between the measured CFBG spectrum and a CFBG model based on coupled-mode theory (CMT), perturbed by a temperature gradient. In the demodulation part, we simulate different temperature distribution patterns with Monte-Carlo approach on simulated CFBG spectra. Afterwards, we obtain cost function that minimizes difference between measured and simulated spectra, and results in final temperature profile. Experiments and simulations have been carried out first with a linear gradient, demonstrating a correct operation (error 2.9 degrees C); then, a setup has been arranged to measure the temperature pattern on a 5-cm long section exposed to medical laser thermal ablation. Overall, the proposed method can operate as a real-time detection technique for thermal gradients over 1.5-5 cm regions, and turns as a key asset for the estimation of thermal gradients at the micro-scale in biomedical applications.