Numerical modelling of blood flow behaviour in the valved catheter of the PUCA-pump, a LVAD

Mechanical heart assistance, performed by the PUlsatile CAtheter (PUCA) pump, chronologically takes place by sucking blood from the left ventricle and ejecting it into the ascending aorta. Within the pump activity the problem of hemolysis and clotting is encountered. In this study the influence of valve geometry on blood cell damage and stagnant zones has been investigated. A variable valve length coupled to a catheter ejection gap and a Variable valve angle have been studied. In case of the studied valve, optimal parameter values have been determined. Compared to small catheter ejection gaps with a corresponding valve length, blood damage is found to be less for large ejection gaps with corresponding valve dimensions. In systole a valve positioned in a 0 degrees angle proves to be best, whereas in diastole a +20 degrees angle is preferable. Because the system is operating in both systole and diastole, a 0 degrees angle valve is applied.