Active Lubrication of Transluminal Medical Instruments

TL;DR

This paper introduces an ultrasonic vibration-based active lubrication system for transluminal medical instruments, significantly reducing friction and buckling risks during minimally invasive procedures, thereby improving safety and procedural stability.

Contribution

The study presents a novel ultrasonic vibration technique to actively lubricate medical instruments, validated through prototypes and ex-vivo tests demonstrating substantial friction reduction and safety.

Findings

Friction reduced by up to 42% on porcine tissue and 82% on rigid surfaces.

Temperature at contact interface remained within safe limits.

Effective prevention of catheter buckling during insertion.

Abstract

Transluminal minimally invasive surgery uses natural orifices and small incisions to access internal anatomical structures, promoting quicker recovery and reduced morbidity. However, navigating instruments--catheters and endoscopes--through anatomical pathways creates frictional interactions with luminal walls, risking complications such as perforation, poor haptic feedback, and instrument buckling. In this paper, we present a new approach to actively lubricate transluminal instruments and dynamically reduce friction with surrounding tissues. This approach employs ultrasonic vibrations, at the instrument surface, to generate a pressurized fluid layer at the contact interface, lubricating the interface and thereby reducing friction. We implemented this approach in a prototype catheter, which we validated under dry and liquid-lubricated conditions, across rigid and soft interfaces, and along varied anatomical curvatures. In a cardiac catheter use case, active lubrication reduced friction by up to 42% on ex-vivo porcine aorta tissue and 82% on rigid substrates, denoting its potential performance on healthy and calcified tissue, respectively. Thermal imaging confirmed that temperature at the tissue-catheter interface remained within safe limits. Additionally, the system effectively prevented buckling during catheter insertion experiment, further showcasing its potential. By minimizing injury risk and enhancing procedural stability, active lubrication can drastically enhance the safety and efficacy of transluminal interventions.