Xing Shengqiang, Zhang Jiaming, Luo Yifeng, Yang Yang, Fu Xiaping
School of Information Science and Engineering, Zhejiang Sci-Tech University, Hangzhou 310018, China.
Key Laboratory of Transplanting Equipment and Technology of Zhejiang Province, Hangzhou 310018, China.
Foods. 2023 Jan 4;12(2):238. doi: 10.3390/foods12020238.
Recently, Spatial Frequency Domain Imaging (SFDI) has gradually become an alternative method to extract tissue optical properties (OPs), as it provides a wide-field, no-contact acquisition. SFDI extracts OPs by least-square fitting (LSF) based on the diffuse approximation equation, but there are shortcomings in the speed and accuracy of extracting OPs. This study proposed a Long Short-term Memory Regressor (LSTMR) solution to extract tissue OPs. This method allows for fast and accurate extraction of tissue OPs. Firstly, the imaging system was developed, which is more compact and portable than conventional SFDI systems. Next, numerical simulation was performed using the Monte Carlo forward model to obtain the dataset, and then the mapping model was established using the dataset. Finally, the model was applied to detect the bruised tissue of 'crown' pears. The results show that the mean absolute errors of the absorption coefficient and the reduced scattering coefficient are no more than 0.32% and 0.21%, and the bruised tissue of 'crown' pears can be highlighted by the change of OPs. Compared with the LSF, the speed of extracting tissue OPs is improved by two orders of magnitude, and the accuracy is greatly improved. The study contributes to the rapid and accurate extraction of tissue OPs based on SFDI and has great potential in food safety assessment.
最近，空间频域成像（SFDI）逐渐成为一种提取组织光学特性（OPs）的替代方法，因为它提供了一种宽视野、非接触式采集方式。SFDI基于扩散近似方程通过最小二乘拟合（LSF）来提取OPs，但在提取OPs的速度和准确性方面存在不足。本研究提出了一种长短期记忆回归器（LSTMR）解决方案来提取组织OPs。该方法能够快速、准确地提取组织OPs。首先，开发了成像系统，该系统比传统的SFDI系统更紧凑、更便携。接下来，使用蒙特卡罗正向模型进行数值模拟以获得数据集，然后使用该数据集建立映射模型。最后，将该模型应用于检测‘皇冠’梨的 bruised 组织。结果表明，吸收系数和约化散射系数的平均绝对误差分别不超过0.32%和0.21%，并且‘皇冠’梨的 bruised 组织可以通过OPs的变化凸显出来。与LSF相比，提取组织OPs的速度提高了两个数量级，准确性也大大提高。该研究有助于基于SFDI快速、准确地提取组织OPs，在食品安全评估方面具有巨大潜力。
