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We apply a look-up table technique to calibrate both position and orientation readings from a magnetic tracker for use in virtual environments within a defined working volume. In a test volume of 2.4 cubic meters, the method reduced the tracker's average position error by 79% and its average orientation error by 40%. We test the correction table against the(More)
We present a real-time stereoscopic video-see-through augmented reality (AR) system applied to the medical procedure known as ultrasound-guided needle biopsy of the breast. The AR system was used by a physician during procedures on breast models and during non-invasive examinations of human subjects. The system merges rendered live ultrasound data and(More)
We present the design and a prototype implementation of a three-dimensional visualization system to assist with laparoscopic surgical procedures. The system uses 3D visualization, depth extraction from laparoscopic images, and six degree-of-freedom head and laparoscope tracking to display a merged real and synthetic image in the surgeon's video-see-through(More)
We report the results of a randomized, controlled trial to compare the accuracy of standard ultrasound-guided needle biopsy to biopsies performed using a 3D Augmented Reality (AR) guidance system. Fifty core biopsies of breast phantoms were conducted by a board-certified radiologist, with each set of five biopsies randomly assigned to one of the methods.(More)
Figure 1: Left to right: A) Without lighting control, virtual imagery shown through a conventional optical see-through display appears transparent and low contrast in a normally lit room. B-C) Remote user appears inside local environment from different tracked viewing positions with projector-based lighting control. D) Remote user and his environment(More)
Accurate registration between real and virtual objects is crucial for augmented reality applications. Existing tracking methods are individually inadequate: magnetic trackers are inaccurate, mechanical trackers are cumbersome, and vision-based trackers are computationally problematic. We present a hybrid tracking method that combines the accuracy of(More)
We present a new approach for establishing correspondence between two homeomorphic 3D polyhedral models. The user can specify corresponding feature pairs on the polyhedra with a simple and intuitive interface. Based on these features, our algorithm decomposes the boundary of each polyhedron into the same number of morphing patches. A 2D mapping for each(More)
Augmented reality systems with see-through head-mounted displays have been used primarily for applications that are possible with today's computational capabilities. We explore possibilities for a particular application---in-place, real-time 3D ultrasound visualization---without concern for such limitations. The question is not "How well could we currently(More)
Applications such as telepresence and training involve the display of real or synthetic humans to multiple viewers. When attempting to render the humans with conventional displays, non-verbal cues such as head pose, gaze direction, body posture, and facial expression are difficult to convey correctly to all viewers. In addition, a framed image of a human(More)