Modeling and Design of a Tandem Axial-flow Left Ventricular Assist System

Over the years, the number of deaths caused by cardiovascular diseases has been increasing. As a type of cardiovas-cular disease, heart failure also shows a rapid growth trend worldwide. China has a huge population of heart failure patients, and the number of new heart failure patients is also increasing year by year. At present, heart transplantation is the best treatment for end-stage heart failure when drug control is ineffective. However, due to many intractable problems, this surgical treatment has been difficult to carry out widely. Ventricular assist device (VAD), as the second-best alternative therapy for heart failure patients, has been identified as an important tool in the management of end-stage heart failure. Parallel ventricular assist devices have been becoming the main devices on the market, which increases the survival rate of patients to a certain degree. However, after the installation of this parallel ventricular assist device, the patient's quality of life has not been significantly improved. The patients are prone to many complications after receiving treatment, and the function of the heart is difficult to recover. Therefore, we propose a tandem left ventricular assist device (LVAD), which minimizes surgical trauma and postoperative complications. The life expectancy of patients with end-stage heart failure can be extended and the quality of life can be greatly improved. We model and simulate this device using a lumped parameter model of the cardiovascular system. According to the simulation results, the combination of LVAD and left heart is successful in this model, which enables the blood pressure and cardiac output of patients with end-stage heart failure to be increased to normal levels.