Pilot study of longitudinal ultrasonic sensor for dynamic volumetric assessment of gastroesophageal reflux

In patients with gastroesophageal reflux disease (GERD), esophageal symptoms are traditionally diagnosed by monitoring the contact time between the reflux content and the esophagus using multichannel intraluminal impedance and pH (MII-pH) catheters. However, esophageal catheter for quantifying the volume of reflux content is still lacking. The present work proposes an innovative method to develop a longitudinal ultrasonic catheter and an information extraction system for reflux event detection and reflux volume estimation. Gastroesophageal model that mimics reflux events was developed to test the proposed catheter. Ultrasonic sensing was evaluated by simulating different volumes of reflux. The obtained signals showed good consistency in detecting reflux events and measuring reflux volume. During an in vivo human testing, a MII-pH catheter was used simultaneously to compare the ultrasonic output. Both in vitro and in vivo human testing results demonstrated the feasibility of utilizing the proposed method for gastroesophageal reflux (GER) detection and reflux volume estimation.