肠道压力数据的盒维数分形分析

Box Dimension Based Fractal Analysis of Intestinal Pressure Data

结肠测压是广泛使用的评价消化道功能的检查手段,对结肠运动障碍疾病的诊断有较高的价值,是其他检查手段不可替代的。本研究对肠道压力数据进行分形特性的分析。首先对结肠压力数据进行预处理,采用截止频率为0.4Hz的低通滤波器滤除结肠压力信号中的高频干扰成分。采用盒维数计算正常受试者和异常受试者结肠压力数据的分形维数。计算盒维数的基本原理为利用待分析曲线的积分和差分的四分位偏差值来计算分形维数。结果表明,正常的结肠压力信号的分形维数值大且随时间的变化小而异常的结肠压力信号正好相反,采用分形维数可以作为判断肠道动力性能的辅助手段。

Colonic manometry is a widely used method to evaluate functions of alimentary tract and is most valuable to the diagnosis of the colonic functions. In this work the fractal characteristic of colonic pressure data was analyzed through box dimension. In order to eliminate the high-frequency disturbances before fractal analysis of colon pressure data, a low-pass filter with a cut-off frequency of 0.4 Hz is applied to pre-proeess the colonic pressure data. A box based method using quartile deviation of integrated and subtracted fluctuation was applied to calculate the fractal dimensions. Through the fractal dimensions the data were classified into normal and abnormal according to the original diagnosis. Experimental results showed that the fractal dimensions of normal colonic pressure data were greater with less fluctuation compared with abnormal colonic pressure data. The method could serve as an assistant diagnosis of the colonic motility and contribute to further research of colonic motility based on pressure data.