Computational modeling and validation of a pediatric intra-aortic balloon pump

Abstract

The Intra-Aortic Balloon Pump (IABP) is the most widely used mechanical circulatory assist device in adult patients with heart failure. This has resulted from the fact it can be deployed and removed with a minimally invasive approach compared to others assist devices. The IAB works in counterpulsation with diastole insufflation, increasing significantly the blood flow towards the ascending aorta, which improves coronary, cerebral and renal blood flow. The balloon inflation is generated by pressurized helium gas with low density facilitating a rapid pneumatic response. The presence of the balloon reduces the aortic impedance contributing to a reduced cardiac work, and therefore myocardial oxygen requirements. However, the use of IABP in pediatric patients under the age of five is technically ineffective, mainly due to the high elasticity of the aorta that prevents increased diastolic pressure. In these patients, there is also difficulty in adjusting and synchronizing to the cardiac cycle the balloon inflation and deflation, given the high heart rates compared to adults. This research aims to develop a pediatric intra-aortic device based on the concept of jointless mechanisms that rely on elastic deformation to transmit forces and motion using metamaterials, designed via Topology Optimization Method (MOT). The hypothesis is based on the possibility of designing an elastic structure to equalize the high compliance of the pediatric aorta. To solve the aimed scope of this project that has a high complexity, it is proposed to develop the computational model of the intra-aortic balloon based on the Finite Element Method (FEM) considering the Fluid-Structure interaction (FSI) of non-turbulent flows, the optimization problem definition and the use of MOT to identify the design concept of new actuation mechanism of the device. The numerical solution via MEF will be evaluated with in-vitro study using a simulator of the human cardiovascular system intended for testing the designed IABP. (AU)