Magnetic Needle Steering in Soft Phantom Tissue

Mahdi Ilami,Reza James Ahmed,Borhan Beigzadeh,Hamid Marvi,Alex Petras

doi:10.1038/s41598-020-59275-x

Abstract

Needle steering is a technology for guiding needles around sensitive internal obstacles in minimally invasive surgery. Traditional techniques apply rotation at the base of a needle with an asymmetric tip, enabling steering through the redirection of radial forces. Magnetic steering of catheters and continuum manipulators is another technology that allows steering of a shaft in the body. Both of these techniques rely on mechanical or manual shaft advancement methods. Needle steering has not achieved widespread clinical use due to several limitations: 1- buckling and compression effects in the shaft and needle rotation cause excessive tissue damage; 2- torsion effects on the shaft and needle deflection at tissue boundaries lead to difficulty in control; and 3- restricted radius of curvature results in limited workspace. Magnetically steered catheters and continuum manipulators also suffer from limited curvature and the possibility of buckling. This paper proposes a novel needle steering method empowered by electromagnetic actuation that overcomes all of the aforementioned limitations, making it a promising option for further study toward healthcare applications.

Highlights

Needles are among the least invasive surgical tools available to doctors and surgeons
In radiofrequency ablation (RFA), a tumor or other target tissue is thermally destroyed by heat induced by high frequency alternating current, applied at the end effector of a small electrode[3]
It was found that 94% of respondents agree that needle steering would be helpful to correct unwanted needle bending; 84% of respondents find needle steering to be a useful tool for steering around anatomical obstacles; and only 2% of respondents do not believe that steerable needles would make new interventions possible[6,7,8,9]

Summary

Introduction

Needles are among the least invasive surgical tools available to doctors and surgeons. The benefits of the ability to tightly steer around sensitive or protective internal obstacles can be seen in several medical applications This ability is especially significant during treatment of glioblastoma, where tumors can develop and extend into sensitive tissues such as venous sinuses, the brain stem, or deep cerebellar nuclei. This technique uses a pressure gradient to deliver pharmaceuticals more successfully across the blood-brain barrier[2] Another application where tight needle steering would provide clinical benefits is in radiofrequency ablation (RFA) of liver tumors. In RFA, a tumor or other target tissue is thermally destroyed by heat induced by high frequency alternating current, applied at the end effector of a small electrode[3] This technique is often hindered by the maneuverability of the ablation needle; Adebar et al pointed out the need for tighter needle steering in order to target the highest number of points per entry wound as possible, reducing the risk of hemorrhaging[4]. This asymmetric tip may be beveled, complex, active, inactive, programmable, composite, or articulated[4,10,11]

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Results

Conclusion