The Medical Device Research Institute, College of Science and Engineering, Flinders University, Adelaide, Australia.
Department of Gastroenterology and Surgery, Flinders Medical Centre, Adelaide, Australia.
Neurogastroenterol Motil. 2018 Jun;30(6):e13274. doi: 10.1111/nmo.13274. Epub 2018 Jan 8.
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).
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.
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.
腔内阻抗是一种用于研究人体食管中食团运动的常用诊断工具。然而，在人类结肠中使用时，由于内容物无法控制，且可能随时包含液体、气体、固体或它们的混合物，因此受到限制。本文研究了使用复阻抗谱来研究不同管腔内容物（液体和气体）的方法。
将豚鼠近端结肠的一段离体部分置于 37°C 的 Krebs 溶液器官浴中，并将定制的生物阻抗导管放置在管腔中。通过管腔泵入液体（Krebs）和气体（空气），并以每秒 10 个样本的速度在五个不同频率（1、5.6、31.6、177.18 kHz 和 1 MHz）下测量腔内阻抗。创建了一个数值模型来模拟具有不同内容物的食团通过，并将其与实验数据进行比较。
对于不同的内容物，在不同的频率下（从 1 到 177.18 kHz），发现了平均阻抗幅度和相位角的差异。数值结果与实验研究定性一致。食团的电导率对检测其通过有影响。
复阻抗谱可以在一定的测量频率范围内区分不同的管腔内容物。数值模型表明，对于那些可以控制食团的研究中，食团电导率对于食团转运研究非常重要。
