Robotic bronchoscopy system with variable-stiffness catheter for pulmonary lesion biopsy

Abstract

Bronchoscopy is a minimally invasive and effective method for early lung cancer diagnosis. Traditional bronchoscopy faces challenges such as limited dexterity, operator fatigue, and difficulty in maintaining steady manipulation. Existing robot-assisted methods have deficiencies, such as tool instability due to the dynamic respiratory environment. This paper presents a teleoperated robotic bronchoscopy system, featuring a controllable variable-stiffness catheter that enhances stability and flexibility during transbronchial biopsies. The 7 DoF robotic system allows for translation, rotation, and bending of the bronchoscope; delivery and bending of the catheter; delivery and control of biopsy tools; as well as stiffness adjustment of the catheter, which adapts to the dynamic pulmonary environment to provide stable support during tissue sampling. Key contributions include the robotic platform integrated with the variable-stiffness catheter and the implementation of a novel three-stage procedure for tissue sampling. The robotic system has been thoroughly evaluated through a series of tests, including the system accuracy, characterization of the variable-stiffness catheter's flexibility, force exertion, safety during operation, temperature control, and in-vivo experiment. The results demonstrated the system's feasibility and effectiveness, with metrics such as safe force limits, system flexibility, and positioning accuracy, showing its potential to improve the accuracy and safety of traditional bronchoscopy procedures.