A novel pulsatile blood pump design for cardiothoracic surgery - proof-of-concept in a mock circulation

Pulsatile perfusion during extracorporeal circulation is a promising concept to improve perfusion of critical organs. Clinical benefits are limited by the amount of pulsatile energy provided by standard pumps. We investigated the properties of a novel positive displacement blood pump in a mock circulation containing an aortic model with a human-like geometry and compliance as a pseudo patient. Using a regular oxygenator, maximum flow was 2.6 L/min at a pressure of 27 mmHg and a frequency (F) of 90 bpm. Pulse pressure (PP; 28.9 mmHg) and surplus hemodynamic energy (SHE; 26.1% of mean arterial pressure) were highest at F=40 bpm. Flow and pressure profiles appeared sinusoid. Using a low-resistance membrane ventilator to assess the impact of back pressure, maximum flow was 4.0 L/min at a pressure of 58.6 mmHg and F=40 bpm. At F=40 bpm, PP was 58.7 mmHg with an SHE of 33.4%. SHE decreased with increasing flow, heart rate, and systolic percentage but surpassed 10% with reasonable settings. The present prototype achieved sufficient flow and pressure ranges only in the presence of a low-resistance membrane ventilator. It delivered supraphysiologic levels of pulse pressure and SHE. Further modifications will help to establish this concept for adult pulsatile perfusion.