Automated In Vivo Navigation of Magnetic-Driven Microrobots Using OCT Imaging Feedback

Objective: The application of in vivo microrobot navigation has received considerable attention from the field of precision therapy, which uses microrobots in living organisms. Methods: This study investigates the navigation of microrobots in vivo using optical coherence tomography (OCT) imaging feedback. The electromagnetic gradient field generated by a home-made electromagnetic manipulation system is magnetically modeled. With this model, the magnetic force acting on the microrobot is calculated, and the relationship between this force and the velocity of the microrobot is characterized. Results: Results are verified through in vitro experiments wherein microrobots are driven in three types of fluid, namely, normal saline, gastric juice, and mouse urine. In vivo experiments are performed to navigate the microrobot in a mouse portal vein in which the OCT imaging system tracks the microrobot in vivo. Conclusions: Experimental results demonstrate the effectiveness of the proposed approach. The microrobots can be magnetically driven in the in vivo environment using the OCT imaging feedback. Significance: The significance of this study lies in providing a new method of driving microrobots in vivo.