A Magnetic Catheter With Force Sensing Capability Toward Interventional Surgery

Abstract

Magnetically actuated medical instruments could greatly facilitate minimally invasive surgery (MIS). For example, onboard magnetic materials help catheters travel across tortuous lumens and reach difficult-to-access sites inside human bodies, guided by a controlled magnetic field (MF). However, permanent magnets inside the human body could cause mechanical hazards when controlled in attraction mode with a small actuation distance. Moreover, current magnetic catheters lose some dexterity when the MF source is spatially hindered by surgical facilities or the patient's body. We propose a magnetically guided catheter tipped with a solenoid and a soft force sensor. The catheter's bending direction and angle could be controlled conveniently via reversing the current direction and tuning the strength of the current, respectively. The thermal safety and operation safety in attraction mode is demonstrated in experiments. Passing through a bifurcation model and an aortic arch phantom proves its superiority in navigating efficiency and demonstrates its agility in 3D compact space. Additionally, the magnetic catheter exerts desired forces at predetermined sites and guides the laser beam spot along stable paths on the heart chamber phantom's interior wall, showing great potential in radiofrequency ablation (RFA).