Tactile Imaging System for Localizing Lung Nodules during Video Assisted Thoracoscopic Surgery

Early detection and removal of small pulmonary nodules significantly improves long term survival rates for patients with lung cancer. To aid in the localization of these tumors during video assisted thoracoscopic surgery (VATS), a tactile imaging system (TIS) is presented. The system consists of a capacitive array sensor mounted on a minimally invasive surgical probe that is integrated with the thoracoscopic imaging. A vision-based algorithm localizes the probe in the live video and overlays a registered pseudo-color map of the measured pressure distribution on the streaming images. The surgeon can locate the hard nodules by scanning the tactile sensor head across the surface of the lung and observing the spatial variation in contact pressures caused by the elasticity differences in the underlying tissue. A validation experiment was conducted to compare the system to a current localization technique using a rigid rod. Results indicate that subjects could localize stiff lumps in lung phantoms more quickly and accurately using the TIS.