The omniTRAX active patient tracker provides clinicians automatic image registration of fused images for uninterrupted navigation when using real-time ultrasound with previously acquired CT volume data sets. The two-part system consists of omniTRAX, a disposable locating device, and a reusable general-purpose electromagnetic sensor. Compatible with imaging systems with navigation technology, the device allows physicians to quickly and accurately register patient anatomy, eliminating tedious manual image registration.