Fig. 1From: Combined cumulative sum (CUSUM) and chronological environmental analysis as a tool to improve the learning environment for linear-probe endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) trainees: a pilot study a CUSUM Graphs of learning curves for operator A. b CUSUM Graphs of learning curves for operator B. c CUSUM Graphs of learning curves for operator CBack to article page