Precise angle estimation of capsule robot in ultrasound using heatmap guided two-stage network

Fang Chen; Lingyu Chen; Tianze Xu; Haoran Ye; Hongen Liao; Daoqiang Zhang

doi:10.1016/j.cmpb.2023.107605

Precise angle estimation of capsule robot in ultrasound using heatmap guided two-stage network

Comput Methods Programs Biomed. 2023 Oct:240:107605. doi: 10.1016/j.cmpb.2023.107605. Epub 2023 May 18.

Authors

Fang Chen¹, Lingyu Chen², Tianze Xu², Haoran Ye², Hongen Liao³, Daoqiang Zhang²

Affiliations

¹ Key Laboratory of Brain-Machine Intelligence Technology, Ministry of Education, Nanjing University of Aeronautics and Astronautics, Nanjing, China; College of Computer Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing, China. Electronic address: chenfang@nuaa.edu.cn.
² Key Laboratory of Brain-Machine Intelligence Technology, Ministry of Education, Nanjing University of Aeronautics and Astronautics, Nanjing, China; College of Computer Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing, China.
³ Department of Biomedical Engineering, School of Medicine, Tsinghua University, China.

PMID: 37390795
DOI: 10.1016/j.cmpb.2023.107605

Abstract

Purpose: A capsule robot can be controlled inside gastrointestinal (GI) tract by an external permanent magnet outside of human body for finishing non-invasive diagnosis and treatment. Locomotion control of capsule robot relies on the precise angle feedback that can be achieved by ultrasound imaging. However, ultrasound-based angle estimation of capsule robot is interfered by gastric wall tissue and the mixture of air, water, and digestive matter existing in the stomach.

Methods: To tackle these issues, we introduce a heatmap guided two-stage network to detect the position and estimate the angle of the capsule robot in ultrasound images. Specifically, this network proposes the probability distribution module and skeleton extraction-based angle calculation to obtain accurate capsule robot position and angle estimation.

Results: Extensive experiments were finished on the ultrasound image dataset of capsule robot within porcine stomach. Empirical results showed that our method obtained small position center error of 0.48 mm and high angle estimation accuracy of 96.32%.

Conclusion: Our method can provide precise angle feedback for locomotion control of capsule robot.

Keywords: Angle estimation; Capsule robot; Heatmap guidance; Ultrasound.

MeSH terms

Animals
Humans
Robotics* / methods
Swine
Ultrasonography