Αρχειοθήκη ιστολογίου

Δευτέρα 8 Ιανουαρίου 2018

Impedance spectroscopy measurements as a tool for distinguishing different luminal content during bolus transit studies

Abstract

Background

Intraluminal electrical impedance is a well-known diagnostic tool used to study bolus movement in the human esophagus. However, it is use in the human colon it is hindered by the fact that the content cannot be controlled and may include liquid, gas, solid, or a mixture of these at any one time. This article investigates the use of complex impedance spectroscopy to study different luminal content (liquid and gas).

Methods

An excised section of guinea pig proximal colon was placed in an organ bath with Krebs solution at 37°C and a custom built bioimpedance catheter was placed in the lumen. Liquid (Krebs) and gas (air) content was pumped through the lumen and the intraluminal impedance was measured at five different frequencies (1, 5.6, 31.6, 177.18 kHz and 1 MHz) at 10 samples per second. A numerical model was created to model the passage of bolus with different content and compared to the experimental data.

Key Results

Differences in mean impedance magnitude and phase angle were found (from 1 to 177.18 kHz) for different contents. The numerical results qualitatively agreed with those in the experimental study. Conductivities of bolus had an effect on detecting its passage.

Conclusions & Inferences

Complex impedance spectroscopy can distinguish between different luminal content within a range of measuring frequencies. The numerical model showed the importance of bolus conductivities for bolus transit studies in those where the bolus is controlled.

Thumbnail image of graphical abstract

This article investigates the use of complex impedance spectroscopy to study different luminal content. The numerical model of the lumen qualitatively agreed with those in the experimental study. This work will allow clinical GI researchers to gain insight into the mechanism of electrical impedance and achieve greater quantitation in future bolus transit studies.



from #ORL-AlexandrosSfakianakis via ola Kala on Inoreader http://ift.tt/2m5IGL2

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