An electrogastrogram （EGG） is a recording of the electrical activity in the stomach, as measured on the abdominal surface. In this study, the goal is to obtain a mathematical model of an EGG; to achieve this, the EG...An electrogastrogram （EGG） is a recording of the electrical activity in the stomach, as measured on the abdominal surface. In this study, the goal is to obtain a mathematical model of an EGG; to achieve this, the EGG of 14 subjects （seven males and seven females） will be obtained. Initially, the Wayland algorithm to the EGG to measure the degree of determinism is applied. However, it could not be determined whether the EGG could be generated by a chaotic process. In addition, the waveform of the electric potential in the interstitial cells of Cajal is similar to the graphs of the numerical solutions to the Van der Pol equation. Therefore, the Van der Pol equation to a periodic function was added, and random white noise was used to represent the intestinal motility and other biosignals. The EGG and numerical solutions were compared and evaluated on the basis of the translation error （Etrans） in the Wayland algorithm and the maximum Lyapunov exponent （2） in Rosenstein＇s algorithm. By projecting the data from an obtained stationary EGG from the subjects, along with the numerical solutions, onto the Etrans-λ plane, the affinity between them was qualitatively evaluated. The EGG was well described by stochastic resonance from the stochastic differential equations.展开更多
文摘An electrogastrogram （EGG） is a recording of the electrical activity in the stomach, as measured on the abdominal surface. In this study, the goal is to obtain a mathematical model of an EGG; to achieve this, the EGG of 14 subjects （seven males and seven females） will be obtained. Initially, the Wayland algorithm to the EGG to measure the degree of determinism is applied. However, it could not be determined whether the EGG could be generated by a chaotic process. In addition, the waveform of the electric potential in the interstitial cells of Cajal is similar to the graphs of the numerical solutions to the Van der Pol equation. Therefore, the Van der Pol equation to a periodic function was added, and random white noise was used to represent the intestinal motility and other biosignals. The EGG and numerical solutions were compared and evaluated on the basis of the translation error （Etrans） in the Wayland algorithm and the maximum Lyapunov exponent （2） in Rosenstein＇s algorithm. By projecting the data from an obtained stationary EGG from the subjects, along with the numerical solutions, onto the Etrans-λ plane, the affinity between them was qualitatively evaluated. The EGG was well described by stochastic resonance from the stochastic differential equations.
