Needle Selection in a Miniature Robotic Penetration System for Biomedical Applications

Needles are indispensable tools in surgical sce-narios for advancing minimally invasive healthcare. Taking advantage of their ability to access small and constrained spaces, a large variety of miniature robotic systems have been designed to deliver needles for tissue penetration inside human bodies. However, there has yet to be a theoretical guideline and systematic analysis on needle selection for these novel robotic systems, leading to poor reliability and safety. Here, we propose a simplified mathematical framework to estimate the interaction forces during a needle penetrating a multi-layer substrate. Quantitative analysis and comparisons are conducted on the effects of different parameters on the penetration and buckling forces. The results suggest that needle diameter and length are the most significant impact factors of penetration force and buckling force, respectively. In addition, we demonstrate the needle penetration assisted by a teleoperated miniature robotic system, which integrates the needle into a customized magnetic robot. The results in this paper could serve as a general guide-line for needle selection in a robot-assisted penetration process inside human bodies, bridging the gap between theoretical research and real-world biomedical applications.