多通道阻抗胃动力测量原理仿真与模拟验证研究

Simulation and model experiment research of multichannel impedance gastric motility measurement

目的研究体表多通道阻抗测量信号与腹内胃收缩、蠕动的时相关系以及空间传导特性。方法以螺旋胃体模型的旋转模拟胃的收缩、蠕动传导，通过三维电特性胃体模型仿真以及盐水槽模拟装置进行多通道阻抗胃动力测量原理模拟实验，验证多通道阻抗胃动力测量的可行性与有效性。结果随着胃体模型的旋转，上腹躯干内电流密度、电势分布的变化，模型外侧边缘（即胃充盈时的膨大位置）从上至下移动及顺序经过检测电极的变化过程相一致，胃体模型连续旋转3周的边界测量电压波形也清晰显示了胃的收缩部位，以及相邻测量通道间的传导时相关系；模拟实验装置连续记录60s的数据，3个测量通道的电压波形与胃体模型运动状况的时相关系相对应。结论体表多通道测量信号反映了胃蠕动的周期性，多道信号间的相位差与蠕动波的传播速度以及测量电极的位置、通道间距等相关。研究结果为定量研究体表多通道阻抗测量与腹内胃收缩、蠕动的时相关系以及空间传导特性提供了仿真与实验基础。

Objective To study the phase correlation of cutaneous muhichannel impedance measurements and the contractions, peristalsis of stomach and the conduction properties in space. Methods A spiral gastric body model was rotated to simulate shrinkage and creep of the stomach. In order to verify the feasibility and validity of the multichannel impedance gastric dynamic measurement, experiments with emulation of muhichannel impedance gastric motility measuring principle were conducted through three-dimensional simulation on the electrical characteristics of gastric body model in saline tank simulator. Results The emulation results showed that the change of epigastric current density and potential distribution is consistent with the course of moving from top to bottom when lateral edge of model （namely the intumescent location when the stomach is full） after detecting electrodes in sequence. Meanwhile, the measurement voltage wave forms clearly showed the contraction location of stomach after the model rotating for three cycles in a row, and the phase relationship between adjacent measurement channels was also measured. The sixty seconds data acquired by the experiment device proved that voltage wave form of three measurement channels corresponded to the phase relationship of movement status of the gastric body model. Conclusions Cutaneous muhichannel wave forms prove a cyclical movement of stomach, and phase difference among the multichannel signals relating to speed of peristaltic wave, position of the measuring electrodes and channel spacing, etc. This study provides simulation and experimental basis for explanation of quantitative study of conduction properties in space and phase relationship between the results of surface multichannel impedance measurements and the contractions, peristalsis of stomach.