title: Applied potential tomography in liquid gastric emptying measurement: design, assembling, calibration, and clinical application.
abstract: The present study aimed to validate the accuracy of a homemade applied potential tomography (APT) apparatus for liquid gastric emptying (GE). Twelve electrodes were placed in a circular array around the subjects. Ten electrodes in a rotated order recorded electrical current delivered from a driving pair of electrodes. Based on tomography, averaged signals of changed resistivity were constructed to display area changes. Six beakers were respectively placed into a saline-filled Perspex tank to measure their cross-sections. True beaker cross-sections are 2.01, 15.9, 18.8, 30.19, 38.48, and 63.61 cm2, respectively, whereas APT generated cross-sections were 7.9 +/- 2.9, 16.7 +/- 3.3, 22.4 +/- 4.9, 28 +/- 4.8, 48.7 +/- 7.6, 67 +/- 6.1 cm2, respectively (r = 0.98, P < 0.001). Twenty-four healthy males ingested 500-ml test solution to assess GE using both APT and scintigraphy. Only 20 (83.3%) subjects had a successful measurement. The APT half emptying time was 15.6 +/- 4.8 min, whereas scintigraphy was 21.9 +/- 6.3 min (r = 0.67, P < 0.01). In conclusion, our APT apparatus is a simple, noninvasive, and inexpensive way to assess liquid GE. Its clinical usefulness is confirmed using both phantom and human models.
authors.affiliation: Division of Gastroenterology, Taipei Veterans General Hospital, Taiwan, Republic of China.
authors.forename: F Y
authors.initials: FY
authors.lastname: Chang
authors.forename: C L
authors.initials: CL
authors.lastname: Lu
authors.forename: C Y
authors.initials: CY
authors.lastname: Chen
authors.forename: S D
authors.initials: SD
authors.lastname: Lee
authors.forename: D S
authors.initials: DS
authors.lastname: Tsai
authors.forename: S E
authors.initials: SE
authors.lastname: Fu
mesh_terms: D000328:Adult; D002138:Calibration; D005260:Female; D005746:Gastric Emptying; D006801:Humans; D008297:Male; D008875:Middle Aged; D014054:Tomography