David LaRose

Transgraph: interactive intensity-based 2D/3D registration of x-ray and CT data

This paper presents work towards a system for intra-operative registration of 3D CT data to 2D X-ray radiographs. The registration procedure involves iterative comparison of Digitally Reconstructed Radiographs (DRRs) with X-ray images acquired during surgery. A new data structure called a Transgraph permits rapid generation of DRRS, and greatly speeds up the registration process. The underlying data structures are described, and the registration algorithm is evaluated for application to an existing image guided radiosurgery system.

Post-Operative Measurement of Acetabular Cup Position Using X-Ray/CT Registration

This paper describes a system for measuring acetabular implant orientation following total hip replacement surgery. After a manual initialization procedure, the position of the pelvis is established relative to a pair of nearly orthogonal radiographs by automatically registering to pre-operative pelvic CT data. The pose of the cup is then recovered by projecting a 3D surface model into the two images. A phantom study is presented in which this pose is expressed relative to well defined anatomical landmarks and compared to measurements obtained using an image-guided surgery system.

A robust image mosaicing technique capable of creating integrated panoramas

Existing featureless image mosaicing techniques do not pay enough attention to the robustness of the image registration process, and are not able to combine multiple video sequences into an integrated panoramic view. These problems have certainly restricted applications of the existing methods for large-scale panorama composition, video content overview and information visualization. In this paper we propose a method that is able to create an integrated panoramic view for a virtual camera from multiple video sequences which each records a part of a vast scene. The method further enables the user to visualize the integrated panoramic view from an arbitrary viewpoint and orientation by altering the parameters of the virtual camera. To ensure a robust and accurate panoramic view synthesis from long video sequences, we attach a global positioning system (GPS) to the video camera, and utilize its output data to provide initial estimates for the cameras translational parameters, and to prevent the camera parameter recovery process from falling into spurious local minima. Our proposed method is not only suitable for video content overview but also applicable to the areas of information visualization, team collaborations, disastrous rescues, etc. The experimental results demonstrate the effectiveness of the proposed method.

High performance teleoperation for industrial work robots

We have developed a set of perception and control technologies to support practical and effective teleoperation of industrial work robots for use in a variety of industries and tasks. This system is suitable for control of remote mobile robots and manipulators in industrial settings, contaminated or hazardous areas, and on remote platforms over low-bandwidth communications links and would be especially well suited to a variety of applications in power generation and transmission. Our approach combines high-quality, bandwidth-adaptable, 360 degree video, a persistent virtual 3D view of the workspace which is built on the fly, and a robust operator control system to provide a highly effective teleoperation system. This system provides good operator performance over a wide range of available bandwidths, enhanced operator situational awareness, and is resistant to the adverse effects of communications interruptions and slow-downs.