Automated deviation and modoling of the pressure-geometry relationship of esophageal body in impedance planimetry studies

This study aimed to develop an automated method to investigate the pressure-geometry relationship of esophageal body in patients with eosinophilic esophagitis (EoE). Esophageal cross-sectional areas (CSAs) and intrabag pressure data were measured in 25 EoE patients with a functional luminal imaging probe (FLIP) and analyzed by a manual reading and by a customized MATLAB program with three functions: minimizing artifacts with a median filter; isolating contraction waves with a nonlinear pulse detector and deriving median values of a minimal pressure segment and corresponding narrowest esophageal CSAs during each distension; and modeling the distensibility of the esophageal body with a polynomial regression technique to derive the distension slope and distension plateau. This regression technique was also applied to manual readings for comparison. Such comparison shows that results of automated method highly correlated with manual reading (R≥0.84) and offered advantages in minimizing the influence of artifacts and inter-observer variability.