Contact Person

Patrick Borchers

Project Description

Nowadays, heart failure is one of the main causes of mortality in the developed world. Due to donor heart scarcity, end-stage heart failure patients are frequently treated with a left ventricular assist device (LVAD), which assists the heart by pumping an additional amount of blood from the left ventricle into the aorta. In this project, we focus on the Sputnik LVAD (c. f. Figure 1), which is an axial-flow rotational blood pump (RBP). This pump was recently developed by our Russian project partners and has already been implanted in more than 50 patients in Russia.
In clinical practice, RBPs are typically operated with a constant rotational speed level. However, if the conditions of the patient’s cardiovascular system (CSV) change, this may cause dangerous over-pumping or under-pumping situations. Therefore, physiological control strategies that adapt the pump speed to the time-variant demand of the CVS and the changing performance of the remaining heart activity will be investigated in this project.
One of the main technical issues in building an LVAD is the minimization of hemolysis, the destruction of blood cells due to the exposure of blood to the artificial pumping mechanism. Much work has been dedicated in the past to optimize the pump geometry in this respect. Within this research project, we want to investigate if hemocompatibility can be improved by optimizing the dynamic control of the RBP. To achieve this, a hemolysis model will be determined based on literature and data from hemolysis experiments. Using this model, we aim to develop optimized physiological control strategies for the Sputnik LVAD, which cannot only provide the required hemodynamics but also minimize blood damage (c. f. Figure 1).
To generate data for the hemolysis model and to assess optimized control strategies a hemolysis mock circulatory loop will be developed, which should also allow for the generation of remaining heart activity (c. f. Figure 2). Porcine blood from a slaughterhouse will be circulated for about 6 hours in the loop and sampled once per hour. To increase the sample rate and reduce the risk of blood processing errors, we also aim to develop real-time hemolysis measurement methods based on bioimpedance and optics.

Project Goals

• Development and control of a hemolysis test loop with generation of remaining heart activity

• Hemolysis experiments under several LVAD operating conditions

• Modeling of LVAD-induced hemolysis

• Physiological and hemolysis minimizing control strategies for LVADs

• Real-time hemolysis measurement methods in whole blood based on bioimpedance and optics

Project Partner

National Research University for Electronic Technology, Moscow, Russia