Design and performance analysis of magnetic helical robot used for vascular interventions

Abstract

During minimally invasive vascular interventions, the maneuverability of guidewires is usually limited by narrow blood vessels. In this study, we designed a magnetic helical robot capable of overcoming spatial constraints within narrow blood vessels and precisely navigating guidewires to target regions. The structure of the magnetic helical robot consists of a front-end permanent magnet and helical structure, a flexible body structure, and a trailing guidewire. By considering resistance theory in low Reynolds number environments, we developed a dynamic model for the magnetic helical robot and analyzed the relationship between its motion velocity and helical structure parameters. Based on a guidewire deflection cantilever model, we investigated the relationship between guidewire deflections and flexible body structure parameters. Dynamic experiments were conducted on the magnetic helical robot to verify its active locomotion capability and confirm the optimal helical structure parameters. Additionally, guidewire deflection experiments demonstrated that increasing the length of the flexible body structure resulted in a maximum bending gain of up to 30 %, confirming the enhanced deformability of the carried guidewire and determining the optimal length of the flexible body structure. Furthermore, successful navigation experiments of the magnetic helical robot carrying a guidewire were performed in a three-dimensional vascular model, with a navigation error of 0.80 mm, thereby validating the locomotion and capability of enhancing guidewire deflections of the magnetic helical robot. The designed magnetic helical robot in this study provides experimental evidence for minimally invasive vascular interventions and holds promise for application in vascular intervention procedures.