The study of the hydrodynamic structure of Tornado-like swirling viscous flows has proved that these flows possess a strictly organized laminar structure which can be exhaustively described using the exact solution of nonstationary Navier-Stocks and Continuity equations [6]. The flows of this type belong to the class of quasi-potential self-organizing swirling flows that serve the restoration of equilibrium in nature. These flows are characterized by a high efficiency of medium transportation while the energy losses are minimized. This is manifested in a significant decrease of hydrodynamic resistance and special organization of the boundary layer. Recent studies performed in Bakulev Research Center for Cardiovascular Surgery (Moscow, RF) have proved that the structure of blood flow corresponds to the class of Tornado-like swirling flows. This allows modeling the optimum geometry of the surgically reconstructed flow channel of the heart and major arteries in order to exclude excessive flow disturbances. Most currently used substituting implantable devices contacting with the blood do not take into account the peculiar hydrodynamic properties of blood flow in the heart and great vessels. This leads to the formation of undesirable disturbance of the hydrodynamic flow structure, i.e. stagnant or separation zones, which can create conditions for thrombus formation and hyperplasia. Therefore, the exact solution can serve as a basis for the design of implantable devices contacting with blood flow without significant distortion of its structure. The following devices have been proposed.
- The aortic valve prosthesis, whose flowing surface has a convergent circular cross-section in the open position. Use of this prosthesis should provide significant reduction in the intensity of anticoagulant therapy after implantation.
- Blood vessel prosthesis with radial elasticity and convergent shape in accordance with the replaced section of artery.
- Circulatory assist device, whose working chamber contains directing profile on the inner surface corresponding to the Tornado-like flow streamlines.
- Hydrodynamic bench for physical modeling of the Tornado-like flow with specified characteristics, allowing testing of implantable devices contacting with blood flow under physiological conditions. The implantable devices for cardiovascular surgery designed on the basis of exact solutions of nonstationary hydrodynamics equations for the Tornado-like swirling flows will be more effective and safe, will reduce the rehabilitation time, and improve the quality of life of patients after surgery.
