Extending the Sonic Flashlight to Real Time Tomographic Holography

Abstract

Real Time Tomographic Reflection (RTTR) permits in situ visualization of tomographic images, enabling natural hand-eye coordination to guide invasive procedures. The method as originally developed uses a half-silvered mirror to merge the visual outer surface of the patient with a simultaneous scan of the patient's interior. A viewpoint-independent virtual image is reflected precisely into the correct location within the patient. When applied to ultrasound, we call the resulting device the sonic flashlight. In this paper we present the first published description of a derivative method that replaces the half-silvered mirror with a Holographic Optical Element (HOE). The new technique, called Real Time Tomographic Holography (RTTH), has the advantage over the mirror-based system that the virtual image is no longer required to match the size and shape of the actual display. We are currently in the first year of an NSF grant from the Robotics and Human Augmentation Program (CISE/IIS) to develop prototype RTTH systems. Although at the time of this writing our systems are not yet functional, we consider the concept itself of potential importance, and wish to report it, along with our current progress towards implementation, to the Augmented Reality community.