title: Catheter-based acoustic interrogation device for real-time monitoring of the dynamics of the lower esophageal sphincter: in vitro and pilot canine studies.
abstract: This paper presents a novel minimally-invasive catheter-based acoustic interrogation device for real-time monitoring the dynamics of the lower esophageal sphincter (LES). Dysfunction of the LES could result gastrointestinal (GI) diseases, such as gastroesophageal reflux disease (GERD). A micro-oscillator actively emitting sound wave at 16 kHz is located at one side of the LES, and a miniature microphone is located at the other side of the LES to capture the sound generated from the oscillator. Thus, the dynamics of the opening and closing of the LES can be monitored. The device was tested in vitro by utilizing a custom-designed LES simulator, as well as in vivo in a pilot canine model. In the in vitro test, the sound was captured by the microphone and its strength was correlated with the level of LES opening and closing which was controlled by the simulator. The measurements showed statistically significant (p  <  0.05) Pearson correlation coefficients (0.905 on the average in quiet environment and 0.736 on the average in noisy environment, DOF  =  9). In the in vivo test, the LES was forced open and closed by a transoral endoscope, which was monitored in real-time by a transpyloric endoscope inserted from the duodenum and positioned into the distal stomach. Frame-by-frame video analysis validated the interrelation between the sound strength and the LES opening and closing. The LES dynamics monitored by the proposed device has the potential to become a valuable minimally-invasive technique for understanding LES dysfunction.
authors.affiliation: Department of Electrical and Computer Engineering, University of Calgary, 2500 University Drive, N.W., Calgary, Alberta, T2N1N4, Canada.
authors.forename: Qian
authors.initials: Q
authors.lastname: Lu
authors.forename: Lili
authors.initials: L
authors.lastname: Zhang
authors.forename: Chunshan
authors.initials: C
authors.lastname: Zhao
authors.forename: Hong
authors.initials: H
authors.lastname: Jin
authors.forename: Bangmao
authors.initials: B
authors.lastname: Wang
authors.forename: Orly
authors.initials: O
authors.lastname: Yadid-Pecht
authors.forename: Daniel C
authors.initials: DC
authors.lastname: Sadowski
authors.forename: Martin P
authors.initials: MP
authors.lastname: Mintchev
mesh_terms: D000818:Animals; D057785:Catheters; D004285:Dogs; D004867:Equipment Design; D049630:Esophageal Sphincter, Lower / Q000502:physiology*; D050782:Esophageal pH Monitoring / Q000295:instrumentation*; D008297:Male; D013997:Time Factors