Wolfgang Matthias, Weißensteiner Michael, Clarke Phillip, Hsiao Wen-Kai, Khinast Johannes G
Research Center Pharmaceutical Engineering GmbH, Graz, Austria.
Institute for Process and Particle Engineering, Graz University of Technology, Graz, Austria.
Int J Pharm X. 2020 Nov 11;2:100058. doi: 10.1016/j.ijpx.2020.100058. eCollection 2020 Dec.
This paper presents a novel evaluation approach for optical coherence tomography (OCT) image analysis of pharmaceutical solid dosage forms based on deep convolutional neural networks (CNNs). As a proof of concept, CNNs were applied to image data from both, in- and at-line OCT implementations, monitoring film-coated tablets as well as single- and multi-layered pellets. CNN results were compared against results from established algorithms based on ellipse-fitting, as well as to human-annotated ground truth data. Performance benchmarks used include, efficiency (computation speed), sensitivity (number of detections from a defined test set) and accuracy (deviation from the reference method). The results were validated by comparing the output of several algorithms to data manually annotated by human experts and microscopy images of cross-sectional cuts of the same dosage forms as a reference method. In order to guarantee comparability for all results, the algorithms were executed on the same hardware. Since modern OCT systems must operate under real-time conditions in order to be implemented in-line into manufacturing lines, the necessary steps are discussed on how to achieve this goal without sacrificing the algorithmic performance and how to tailor a deep CNN to cope with the high amount of image noise and alterations in object appearance. The developed deep learning approach outperforms static algorithms currently available in pharma applications with respect to performance benchmarks, and represents the next level in real time evaluation of challenging industrial OCT image data.
本文提出了一种基于深度卷积神经网络(CNN)的药物固体剂型光学相干断层扫描(OCT)图像分析新评估方法。作为概念验证,CNN被应用于在线和离线OCT成像的图像数据,监测薄膜包衣片以及单层和多层微丸。将CNN的结果与基于椭圆拟合的既定算法的结果以及人工标注的地面真值数据进行比较。使用的性能基准包括效率(计算速度)、灵敏度(从定义的测试集中检测到的数量)和准确性(与参考方法的偏差)。通过将几种算法的输出与人类专家手动标注的数据以及相同剂型横截面的显微镜图像作为参考方法进行比较,对结果进行了验证。为了确保所有结果的可比性,算法在同一硬件上执行。由于现代OCT系统必须在实时条件下运行才能在线实施到生产线中,因此讨论了如何在不牺牲算法性能的情况下实现这一目标,以及如何调整深度CNN以应对大量图像噪声和物体外观变化的必要步骤。所开发的深度学习方法在性能基准方面优于目前制药应用中可用的静态算法,代表了对具有挑战性的工业OCT图像数据进行实时评估的下一个水平。