Fundamental Examination of an Extracapillary Blood Flow Type Oxygenator for Extracorporeal Circulation Model of a Rat

A miniature extracorporeal circulation model for a rat is used to study the mechanism of pathophysiological changes during extracorporeal circulation. The miniature extracorporeal circulation model consists of an extracapillary blood flow type oxygenator, a roller pump and a tubing. In this study, the extracapillary blood flow type oxygenator for the miniature extracorporeal circulation model for a rat was developed and evaluated in in vitro experiments. Three types of oxygenators with different priming volume (Type A: 7ml; Type B: 5ml; Type C: 3ml) were prototyped. The gas exchange performance and pressure drop in each oxygenator were evaluated in in vitro experiments. These oxygenators were installed horizontally and vertically in order to evaluate the influence of blood flow in the oxygenator. As a result, O2 gas transfer rate of the oxygenator Type C with the lowest priming volume of 3ml in vertical installation was higher than the reference value of AAMI. Furthermore, it was confirmed that the change in blood flow by installation direction of the oxygenator affects gas exchange performance. It is considered that the developed oxygenator Type C has the performance that can be used for the miniature extracorporeal circulation model for a rat.