Operative Line of Resection Determination Method for Emphysema Surgery using High-Speed Laser Scanner and Non-Rigid Registration

A successful image-to-physical space overlay method is necessary to provide reliable guidance information to surgeons and accurate surface displacement data for use in compensation algorithm of soft tissue deformation. In this paper we outline a novel approach to relate preoperative images to intraoperative space in a lung volume reduction surgery. The protocol requires intraoperative geometric data to measure and compensate for tissue deformation in the organ. We use 3D laser scanner to accomplish these tasks intraoperatively. A laser scanner based on the optical principle of triangulation acquires a dense set of three-dimensional point data in a very short time. The non-rigid registration is then performed via robust point matching algorithm between control points identifiable in both the preoperative tomograms and the intraoperatively acquired point cloud data provided by a laser scanner. Using the obtained warping field, preoperative region of interest is determined in a physical space. Phantom studies using commercial pig’s lung were performed to test the ability to link 3D laser scanner with preoperative modality data through non-rigid registration. The experiments demonstrate that the proposed protocol is capable of achieving non-overlapping ratio of less than 1.41 %. Surface deformation studies were performed in order to determine if the non-rigid registration is capable of compensate soft tissue deformation. In the deformation studies, the laser scanner with non-rigid registration method was able to track changes in preoperative region of interest less than 3.13 % non-overlapping ratio. The experiments were also performed different field of vision data: the non-overlapping error was below 4.14 % with 84 % of the organ visible and below 1.66 % with 96 % of the organ visible. Copyright © 2016 IFSA Publishing, S. L.