A Doppler and B-Mode Hybrid Ultrasound Tracking Method for Microcatheter Navigation in Noisy Environments

Robot-assisted ultrasound imaging provides a promising microrobot tracking method for biomedical tasks. However, noise artifacts such as interfaces or acoustic shadows have a direct influence on localization accuracy. This paper introduces a novel ultrasound tracking method that uses an ultrasound Doppler image-based noise filter and a template matching algorithm to accurately localize the microcatheter in Brightness mode(B-mode) images. We also propose a robot-assisted ultrasound imaging system that can switch between in-plane and out-of-plane tracking and provides 3D localization of the microcatheter in noisy environments. A magnetic microcatheter design that can generate strong Doppler signals and perform drug delivery is also presented. The tracking performance of the proposed system is experimentally verified both in a tissue-mimicking agarose phantom and an ex vivo phantom made of chicken breast. The proposed method can robustly navigate the microcatheter to the desired position in noisy environments. A blood clot clearance experiment is also demonstrated to verify the effectiveness of the microcatheter.