Miftakhov R, Wingate D
Gastrointestinal Science Research Unit, Royal London Hospital Medical College, University of London, UK.
Biorheology. 1994 Jul-Aug;31(4):309-25. doi: 10.3233/bir-1994-31402.
A mathematical model and results of numerical simulation of the peristaltic reflex development of the small bowel are presented. The organ is modeled as a soft orthotropic cylindrical biological shell, reinforced by the smooth muscle elements. Their mechanical activity is under the control of a simple reflex arc represented by a single cholinergic neurone. The dynamical reaction starts as a response to the depolarization wave propagating along the smooth muscle layers. The muscle layers contract independently but in a coordinated way with the generation of active forces. The mechanical properties of the wall are supposed to be nonlinear. Deformations of the bioshell are finite. The governing system of equations is obtained and solved numerically. The finite-difference method of second-order accuracy over the time and space variables has been used. The dynamics of stress-strain distribution in the biological shell and shape changes are analyzed. It is shown that there is no axial symmetry in the organ's deformation during the first (preliminary) stage of motor reaction. Only with the development of propulsive contractions is the symmetry observed.
本文介绍了小肠蠕动反射发育的数学模型及数值模拟结果。该器官被建模为一个由平滑肌元件加强的软正交各向异性圆柱形生物壳。它们的机械活动受单个胆碱能神经元代表的简单反射弧控制。动力反应始于对沿平滑肌层传播的去极化波的响应。肌肉层独立收缩，但在产生作用力时相互协调。假定壁的力学性能是非线性的。生物壳的变形是有限的。得到了控制方程组并进行了数值求解。采用了在时间和空间变量上具有二阶精度的有限差分法。分析了生物壳中应力应变分布的动力学和形状变化。结果表明，在运动反应的第一（初始）阶段，器官变形不存在轴对称性。只有随着推进性收缩的发展才观察到对称性。
