Abstract No. 512 Augmented reality for transperineal prostate procedures with smart-glasses or smartphone needle planning and guidance

Abstract

The grid template based guidance method in transperineal prostate procedure is associated with limited positioning resolution and lack of needle angulation options. To overcome the limitations, and to free the operator from the constraints of a grid, a novel augmented reality system was developed that uses smart see-through glasses, a smartphone, or a tablet for needle planning and guidance in transperineal prostate procedures. The custom IR AR system was developed to display the planned needle path on the smartphone and smart-glasses’ screens, in real-time, superimposed over the patient’s anatomy. A special designed image marker registration frame with fiducial markers embedded was attached to a phantom patient perineum, and was used to orient and track the pre-procedural volumetric image with the AR system. The displayed needle plan was always referenced to the patient and independent from the physical pose of the devices. The AR feature allows the operator to continuously compare the actual needle location with the plan as well as with the superimposed anatomy and target. Multiple devices can be used simultaneously and communicate via a local network. The AR app’s on-the-spot planning function allow defining needle path at the bedside. The system was evaluated using interventional prostate phantoms with iPhone and ODG R-7 glasses. The overlay accuracy was defined as the 2D angular difference between the actual needle inserted into the phantom and the derived virtual needle on the AR device. After free-hand insertion with AR assistance, the guidance accuracy was measured by the distance between the needle tip and the target in the post CT. The overlay accuracy was 0.58±0.43º and 1.62±1.52º in iPhone and R-7 respectively. The iPhone guidance accuracy was 1.9±0.97 mm (lateral) and 1.0±0.5 mm (in-direction), the R-7 guidance accuracy was 2.8±1.4 mm (lateral) and 2.3±1.5 mm (in-direction). A custom AR system using smart-glasses and smartphone can provide accurate needle guidance and see-through-the-skin display of anatomy, needle, and targets for transperineal prostate interventions. How such devices might assist or augment standard procedures remains to be defined.