Registration Tasks for a Hybrid Tracking System for Medical Augmented Reality

Abstract

Tracking technologies for medical Virtual or Augmented Reality (VR/AR) applications have to fulfill demanding\nrequirements. A hybrid tracking system can merge positive attributes of different tracking technologies, for example\noptical and electromagnetic, and try to compensate the bad ones. The alignment of two or more tracking\nsystems by means of transforming all measured data from different systems into one common coordinate system\nis a fundamental precondition. Usage and processing of time stamps assigned to each measurement is a very effective\nelement in order to achieve a higher accuracy in the alignment procedure and during later use. The algorithms\nfor the alignment of tracking systems can also be used for the registration of the patient, another typical task in\nmedical VR/AR applications. This paper describes both procedures in detail, including algorithms and results\nfrom test sequences. The representative tests illustrate, that the proposed algorithms provide satisfying results. An\noverview of the integration of the hybrid tracking system in a medical AR system is given. Adverse conditions\nlike environmental influences on the tracking systems and the identification of corresponding measurements of two\ntracking systems are discussed.