Asynchronous Rectification-Based Fast Local Imaging and Estimation Scheme for High-Speed Rotating States Observation of MM

Abstract

Magnetic microrobots (MMs) have emerged as promising tools for targeted therapies, including non-invasive in vivo treatments and precise drug delivery, owing to their untethered controllability and biocompatibility. Current actuation strategies for MMs primarily rely on two magnetic field (MF) generation approaches: gradient-based and rotational methods. Unlike the gradient method, rotational actuation enables efficient manipulation of MMs under significantly weaker magnetic fields. To fully leverage the potential of rotationally driven MMs, a comprehensive understanding of their fundamental spin motility is essential. Achieving accurate characterization of these MMs necessitates the development of an MF generation system equipped with rapid motion-tracking and broad-range measurement capabilities. This study proposes a high-speed rotating states observation scheme by developing a tracking-based optimal local imaging and estimation scheme, simultaneously meeting the broad-range observation capability and the high imaging speed requirement. Specifically, the CSR-DCF tracking method is adopted to detect the MM’s location, and based on this, the observation system adjusts the imaging region optimally. An estimation scheme based on the asynchronous rectification method is derived to measure the MM rotating states consistently using measured MF data and local optical images of the target. Experimental studies are carried out to validate the effectiveness of the proposed scheme.