Automatic and fast registration method for image-guided surgery

In this paper, we propose a dynamic coordinate registration method. This method simplifies and automates the registration procedure between image space coordinates and patient space coordinates with a high accuracy. Compared with paired-point registration, three-dimensional registration can be performed with only one Navpass model instead of three or more points. The Navpass is a real-world model designed by our group, which can be easily detected in Computed Tomography (CT) images. First, the pose information such as position and orientation of the Navpass is detected automatically on the images by our Dynamic Region Growing (DRG) algorithm. Then, we calculate the registration transformation when the corresponding location in the patient coordinates obtained by electromagnetic tracking device in real time. In the navigation procedure, the method is capable of computing the registration error in real-time during the respiratory cycle and assisting the surgeon to insert needles within the minimal error. When the target registration error is beyond a certain threshold, the registration matrix would be updated automatically. Our method has been tested on a real-world navigation system with a specially designed phantom. Based on the practical and extensive experiments, we conclude that our method can provide fast and accurate registration with a 1.7 ± 0.03 mm target registration error, and that it helps reduce the operation time dramatically for the surgeons as well as the patients.