Painlevé property, Lax pair and Darboux transformation of the variable-coefficient modified Kortweg-de Vries model in fluid-filled elastic tubes

With the consideration on the artery as a thin walled prestressed elastic tube with variable radius, a variable-coefficient modified Kortweg-de Vries (vc-mKdV) equation is obtained by the long wave approximation for the blood which is assumed as the incompressible non-viscous fluid. In the present paper, we firstly investigate the Painlevé property of the vc-mKdV equation. Furthermore, with the Ablowitz-Kaup-Newell-Segur procedure and symbolic computation, the Lax pair of the vc-mKdV equation is constructed, by virtue of which we construct the Darboux transformation and a new soliton solution. Finally, the features of the new solution are discussed to illustrate the influences of the constant and variable coefficients in the solitonic propagation.