Information Filtering for Ultrasound-Based Real-Time Registration

This paper presents methods based on information filters for solving matching problems with emphasis on real time, or effectively real-time applications. Both applications discussed in this paper deal with ultrasound-based rigid registration in computer-assisted orthopedic surgery. In the first application, the usual workflow of rigid registration is reformulated such that registration algorithms would iterate while the surgeon is acquiring ultrasound images of the anatomy to be operated. Using this effectively real-time approach to registration, the surgeon would then receive feedback in order to better gauge the quality of the final registration outcome. The second application considered in this paper circumvents the need to attach physical markers to bones for anatomical referencing. Experiments using anatomical objects immersed in water are performed in order to evaluate and compare the different methods presented herein, using both 2-D as well as real-time 3-D ultrasound.