Autonomous planning and guidance for convex-probe endobronchial ultrasound bronchoscopy

To perform lung cancer staging, the physician uses bronchoscopy to stage the central-chest lymph nodes. Because the lymph nodes lie outside the airways, physicians use convex-probe endobronchial ultrasound (CP-EBUS) as a supplement to videobronchoscopy to help see target nodes situated behind airway walls. Within this context, computer-based image-guided bronchoscopy systems have seen increasing usage in the management of lung- cancer patients. In particular, our group has recently developed an integrated multimodal system for guiding both videobronchoscopy and CP-EBUS. To use this system, a guidance plan, which instructs the physician how to maneuver the device through the airways and locate target nodes for biopsy, is created off-line prior to the live procedure. The planning process, however, involves a time-consuming error prone approach requiring a skilled technician to derive. We propose an efficient automated approach for creating guidance plans for EBUS-based nodal biopsy. We also integrate this methodology into our multimodal guidance system to facilitate technician- free autonomous image-guided EBUS bronchoscopy. Patient studies show that the proposed method enables automatic reproducible computation of procedure plans without errors or dependence on technician skill. The mean planning time was reduced from 40 min per target lymph node to 5 min, with the time-consuming device maneuvers calculations reduced to a few seconds per plan. In addition, the follow-on procedure can be performed fully independent of technician assistance.