M. Hinteregger, C. Janeczek, A. Karabegovic, H. Mad, H. Hackl, M. Gföhler, R. Willinger, W. Mohl:
"First results in the development of a pneumatically driven temporary left ventricle assist device";
Poster: 42nd Annual Meeting of the German Society for Cardiovascular and Thoracic Surgery, Freiburg im Breisgau; 2013-02-17 - 2013-02-20; in: "Thorac cardiovasc Surg 2013", Thieme, 61 (2013).
First results in the development of a pneumatically driven temporary left ventricle assist device
Hinteregger M.G.1, Janeczek C.1, Willinger R.1, Karabegovic A.1, Mad H.1, Hackl H.1, Mohl W.˛, Gföhler M.1
1Institute for Engineering Design and Logistics Engineering, Vienna University of Technology
˛Department of Cardiac Surgery, Medical University Vienna
Background: Critically ill patients after a heart attack or before/after heart surgery need temporary circulatory assistance. Intra-aortic counterpulsation and electric heart-assist pumps are clinically used to increase cardiac output and support the failing heart temporarily. Both systems have their limitations in regaining full recovery of myocardial jeopardy. We conceptualized a pneumatic tiny blood pump integrating both benefits (i.e. unloading the left ventricle and increasing coronary circulation).
Methods & Results: A first functional prototype of the pump was developed based on theoretical and experimental research and manufactured on a scale of 2:1 (diameter 10mm) and has shown promising results and proven the feasibility of the concept based on a pneumatic drive. Characteristics of the pump and pneumatic drive unit were determined and improved in an iterative process, considering flow simulation results and optimal material pairings. CFD (computational fluid dynamics) simulation of the flow was done for both pump and drive unit. For the drive unit pneumatic performance was predicted and computationally optimized by design modifications. For the pump unit hydraulic performance was optimized and shear stress distribution determined in order to minimize hemolysis. A mock circulation system was built to obtain further experimental results. After successful testing of the 2:1 prototype the next step is downsizing to original size.(diameter 5mm)
Conclusion: Our prototype has several advantages against the current intravascular support systems. The clinically used electric drive in blood pumps is problematic because of the generated heat, hemolysis and drive lubricants primed into blood. A well-established method to increase myocardial oxygen perfusion is the intra-aortic balloon pump (IABP), but in severe cases efficiency is not sufficient. In our concept we propose to combine both methods - a pneumatic driven pump to increase cardiac output and a balloon catheter to increase myocardial perfusion.