Application of Computer Vision in Pharmaceutical Crystallization Processes

In-situ Image Tracking Crystal Size, Shape, and Polymorphic Transformation Kinetics

Program Overview

  • Accelerate the crystallization processes R&D
  • Deepen the understanding of crystallization processes

Deep learning-based image segmentation and classification had been proposed for the in-situ measurement of microcrystal size and shape, which showed great potential to expand as a process analytical technology (PAT) to chemical multi-phase flow processes.

In this talk, an open-access chemical microparticle image database (open-CMD) was established containing particle agglomerations (A), bubbles (B), crystals (C), and droplets (D) in various chemical multi-phase flow scenarios. The advanced neural network, Mask R-CNN, coupled with 2,500 labeled images containing more than 50,000 labeled particles in open-CMD, was trained to build the ability of target particle segmentation and classification.

The training results indicated that a data augmentation strategy could significantly improve the accuracy of the trained models, which were named MicropNet+ and MicropNet according to whether the augmented data was used for training or not. Based on the superior capability of MicropNet+, multidimensional particle descriptors were extracted, and further, the degree of agglomeration and agglomeration distribution were defined and quantified. Then, two classical multi-phase flow processes, crystallization, and emulsification were analyzed using the MicropNet+ model, in which the agglomeration degree and distribution (Cin A) of succinic acid crystals and the relative number and diameter (Deq) of droplets were analyzed quantitatively under different operations conditions.

It was concluded that the well-trained MicropNet+ model has high accuracy and efficiency in microparticle segmentation and classification. At last, the undergoing research on computer vision-assisted high-throughput screening and high-density slurry scenarios analysis will be introduced.   


Zhenguo Gao, Ph.D.,

Associate Professor, School of Chemical Engineering and Technology, Tianjin University

Dr. Zhenguo Gao is currently an associate professor at the School of chemical engineering and technology, Tianjin University (TJU). He worked at the University of Western Ontario (UWO) as a research assistant before joining TJU. Zhenguo received a dual-PhD degree from the University of Western Ontario, Canada, and Tianjin University, China in 2019, and then joined the National Engineering Research Center of Industrial Crystallization Technology (NERCICT) in TJU. Zhenguo’s research interests include i) crystallization process design and control, especially in continuous crystallization intensification and control, novel crystallizer design; ii) melt crystallization including layer crystallization and suspension crystallization especially for ultrapure wet electronic chemicals; iii) smart Process Analytical Technology, for example, AI-based process imaging analysis, etc. He has published more than 60 papers in top-tier international conferences and journals, including Chemical Engineering Journal, Chemical Engineering Science, Crystal Growth & Design, Engineering, CrystEngComm, Industrial & Engineering Chemistry Research, Separation and Purification Technology, Ultrasonics Sonochemistry, etc. He served as a guest editor for the journal Crystals, and the reviewer of multiple international journals e.g., IECR, Crystal Growth & Design, Org. Process. Res. Dev., Pharmaceuticals etc.