Emitter Seed Localization using Movable Sensor Barriers

We present a novel method for precise, non-optical 3D localization of a seed particle which emits a wave or particles which can be sensed by a detector and blocked by a barrier. A primary application of this method is the localization of radioactive seeds implanted into the body for cancer treatments. We have currently implemented an initial prototype demonstration system using an infrared LED as the emitter, photodetectors, and metal sheet barriers actuated by stepmotors to simulate radioactive seed localization. A geometric analysis of the concept is given and our prototype implementation is presented. Experimental results of the system demonstrate submillimeter localization accuracy.