Augmented reality simulator for training in two-dimensional echocardiography

In two-dimensional echocardiography the sonographer must synthesize multipl e tomographic slices into a mental three-dimensional (3D) model of the hear t. Computer graphics and virtual reality environments are ideal to visualiz e complex 3D spatial relationships. In augmented reality (AR) applications, real and virtual image data are linked, to increase the information conten t. In the presented AR simulator a 3D surface model of the human heart is l inked with echocardiographic volume data sets. The 3D echocardiographic dat a sets are registered with the heart model to establish spatial and tempora l congruence. The heart model, together with an animated ultrasound sector represents a reference scenario, which displays the currently selected two- dimensional echocardiographic cutting plane calculated from the volume data set. Modifications of the cutting plane within the echocardiographic data are transferred and visualized simultaneously and in real time within the r eference scenario. The trainee can interactively explore the 3D heart model and the registered 3D echocardiographic data sets by an animated ultrasoun d probe, whose position is controlled by an electromagnetic tracking system . The tracking system is attached to a dummy transducer and placed on a pla stic puppet to give a realistic impression of a two-dimensional echocardiog raphic examination. (C) 2000 Academic Press.