Pilot Study of Longitudinal Ultrasonic Sensor for Dynamic Volumetric Assessment of Gastroesophageal Reflux

Department of Electrical and Computer Engineering, University of Calgary, AB T2N 1N4, Canada.
Conference proceedings: ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference 01/2010; 2010:899-902. DOI: 10.1109/IEMBS.2010.5627843
Source: PubMed

ABSTRACT 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.

Download full-text


Available from: Martin P Mintchev, May 13, 2015
10 Reads
  • [Show abstract] [Hide abstract]
    ABSTRACT: Catheter-based high-frequency intraluminal ultrasound imaging is a powerful tool to study esophageal sensory and motor function and dysfunction in vivo in humans. It can be combined with manometry, pH, and impedance measurement techniques to determine the relationships between different physiologic parameters. High-frequency intraluminal ultrasound imaging has provided a number of important insights regarding the longitudinal muscle function of the esophagus. On the basis of the ultrasound images and intraluminal pressure recordings, it seems that there is synchrony in the timing and the amplitude of contraction between the circular and longitudinal muscle layers. A sustained contraction of the longitudinal muscle layer is temporally related to esophageal chest pain and heartburn. The biomechanics of the esophageal wall and its relationship to sensory and motor function can be studied in humans in vivo by using high-frequency intraluminal ultrasound much more precisely than has previously been possible. Achalasia, diffuse esophageal spasm, and nutcracker esophagus are associated with hypertrophy of circular and longitudinal muscle layers. Finally, high-frequency intraluminal ultrasound imaging is the only technique that can detect reflux-related distention of the esophagus and its role in esophageal symptoms. Future approaches to display and quantify ultrasound image data are discussed. The principles of high-frequency intraluminal ultrasound described here are also applicable to study of the motor and sensory function of the other regions of the gastrointestinal tract.
    Gastroenterology 03/2005; 128(2):487-97. DOI:10.1053/j.gastro.2004.08.004 · 16.72 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: In patients with gastro-oesophageal reflux disease (GORD), oesophageal and extraoesophageal symptoms are traditionally attributed to increased contact time between the mucosa and refluxates. However, the volume of reflux may be important by increasing the total amount of highly concentrated damaging substances, either by prolonging distal mucosal exposure or by expanding to more proximal areas. To date, it has not been possible to accurately measure the volume of gastro-oesophageal reflux. Determination of the volume of reflux will help to better understand the pathophysiology of GORD and to evaluate the efficacy of antireflux treatments.
    Gut 03/2005; 54(2):175-8. DOI:10.1136/gut.2004.043984 · 14.66 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: A method for the measurement of intraventricular volume by means of an ultrasound echo technique (intraventricular catheter) is described. From two diameters measured and a correction factor the volume is calculated. The correction factor was derived from measurements on excised non beating hearts. In experiments on beating hearts of 6 anesthetized dogs stroke volume was measured simultaneously with the ultrasonic catheter and the dye dilution technique. Under normal physiological conditions there was a good agreement between the two methods. The difference of 4.0±1.7% (N=24) was not significant. When the hearts were enlarged or made smaller, large deviations occurred which were consistent in their direction, while the scattering remained almost as small as under basic conditions. Only further work can show whether the method can be developed to a reliable procedure for routine measurement of stroke volume under a variety of conditions.
    Pflügers Archiv - European Journal of Physiology 02/1974; 349(4):369-76. DOI:10.1007/BF00588422 · 4.10 Impact Factor