High-resolution and high-speed 3D tracking of microrobots using a fluorescent light field microscope

Quantitative Imaging in Medicine and Surgery

article

Jiahang Lv¹  Yao Hu¹  Hongyu Zhao²  Min Ye²  Ning Ding²  Jingshan Zhong²  Xiaopu Wang² 

[1] Beijing Key Lab for Precision Optoelectronic Measurement Instrument and Technology, School of Optics and Photonics , Beijing Institute of Technology;Shenzhen Institute of Artificial Intelligence and Robotics for Society ,(AIRS) , The Chinese University of Hong Kong;Research Center for Humanoid Sensing , Zhejiang Lab

关键词: Microrobot;    3D tracking;    light field microscope (LFM);    digital refocusing;   

DOI  :  10.21037/qims-22-430

学科分类：外科医学

来源: AME Publications

【 摘 要 】

Background: Imaging and tracking are crucial for microrobots which navigate through complex 3D environments. Fluorescent imaging (FI) by microscope offers a high-resolution and high-sensitive imaging method to study the property of microrobots. However, conventional microscope suffers from shallow depth of field (DOF) and lacks 3D imaging capability. Methods: We proposed a high-resolution and high-speed 3D tracking method for microrobots based on a fluorescent light field microscope (FLFM). We designed the FLFM system according to the size of a representative helical microrobot (150 μm body length, 50 μm screw diameter), and studied the system’s performance. We also proposed a 3D tracking algorithm for microrobots using digital refocusing. Results: We validated the method by simulations and built an FLFM system to perform the tracking experiments of microrobots with representative size. Our 3D tracking method achieves a 30 fps data acquisition rate, 10 μm lateral resolution and approximately 40 μm axial resolution over a volume of 1,200×1,200×326 μm3. Results indicate that the accuracy of the method can reach about 9 μm. Conclusions: Compared with the FI by a conventional microscope, the FLFM-based method gains wider DOF and 3D imaging capability with a single-shot image. The tracking method succeeds in providing the trajectory of the microrobot with a good lateral resolution.

【 授权许可】

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