An experimental system for robotic needle biopsy of lung nodules with respiratory motion

CT-guided needle biopsy is a dominant method of obtaining tissue samples from lung nodules for lung cancer diagnosis. Current practice requires patients to hold their breath during the procedure, which is not applicable to those who have difficulty in holding breath. This paper introduces a CT-guided robotic needle biopsy technique, which adapts to the patient respiratory motion pattern and uses a robot manipulator to drive the biopsy needle towards a target lung nodule with respiratory motion. It enables biopsies on patients who have difficulty in holding breath. An experimental system has been created to facilitate the development and evaluation of the robotic needle placement technique. It consists of three subsystems coordinated by a computer, i.e. a lung nodule phantom subsystem which mimics a lung nodule with respiratory motion, a robotic needle manipulation subsystem which drives the biopsy needle to hit the moving target, and a vision feedback subsystem which tracks the moving lung nodule phantom in real time for controlling the needle placement. The results from a sequence of needle placement tests based on clinically-obtained lung nodule motion paths show that the robotic needle placement technique can provide quick and highly accurate needle placement on moving nodules.