ABSTRACT The long-term goal of this project is to develop and commercialize a navigation system that can accurately determine margins in real-time during surgery for lung cancer. Surgery is currently the standard of care for early stage lung cancer. A critical challenge is to reliably identify small, early-stage tumors and resect them with sufficient margins (distance between the edge of tumor and the line of resection). Too close a margin is associated with a higher incidence of recurrence and death. To address this challenge, this team developed a new surgical procedure called image-guided video thoracoscopic surgery (iVATS), in which the surgeon localizes and resects small lung nodules by marking them percutaneously using a fiducial marker, a small passive metal tag called T-bar, placed under C-arm CT image-guidance. A novel navigation technology, NaviSci™, was developed to aid in identifying and removing lung tumors by using an active sensing nodule marker, called J- Bar, that is placed in the lung just next to the tumor and can track the tumor position in real-time and help assess margins. However, use of the J-Bar requires either intraoperative imaging or approximate visual positioning of very small tumors that may not be visible during surgery from the lung surface. Navigation Sciences is now developing a tumor marker that can be positioned with a bronchoscope and does not require CT imaging during surgery. The objective of this Phase I STTR project is to develop and validate the NaviSci-EndoMarkerTM (called EndoMarker hereafter) to accurately localize small lung tumors. The EndoMarker will be positioned adjacent to the tumor with a bronchoscope based on navigation planned using diagnostic CT images. This will simplify the clinical workflow and make this procedure accessible to hospitals that do not have advanced intra-operative imaging technologies. Aim 1 is to design and develop the bronchoscopic EndoMarker. Aim 2 is to validate the workflow for deploying the EndoMarker, mechanical stability, and electrical isolation of the EndoMarker in a 3D printed lung phantom, ex vivo porcine lungs and 2 live pigs. This STTR project is a collaboration between Navigation Sciences and ongoing collaborators at the Brigham and Women’s Hospital (Boston, MA). The proposed R&D project is significant since it addresses an important problem of accurately localizing and resecting lung nodules while preserving healthy lung function, which could benefit thousands of patients each year. The novelty lies in the design of the EndoMarker, which will allow the J-Bar marker to be placed accurately via a bronchoscope so that it can readily localize small tumors and define their margins during surgery. Successful completion of this project will result in an innovative disruptive product that will provide surgical guidance to ensure sufficient resection of early-stage lung cancer with acceptable margins without any additional imaging equipment at the medical center.