Objective: To develop a series of small-sized membrane oxygenators for experimental studies on small animals. Develop a hydrodynamic stand to evaluate the performance characteristics of oxygenators.
Materials and methods: The external design of the mini oxygenator consists of a housing that includes two disposable ¼ × ¼ inch polystyrene connectors. Each connector has one Luer port, which are oriented in the same directions. A 14 × 5 (+/-2) cm microporous polypropylene hollow fiber sheet was rolled and placed inside the outer structure. Both ends were then sealed: a 13 cm long tube was sealed at both ends (inner diameter: 4mm; outer diameter: 6mm) with epoxy resin (Figure 1).


We determined the main dimensions of the mini-oxygenator (total length, diameter), the effective length of the fibers (the average length of the fibers exposed to the perfusate) and the “dry” weight of the mini-oxygenator. The efficiency of oxygen transfer was tested using a recirculating hydrodynamic test bench in vitro. At all given time points, one sample was taken before and immediately after the mini-oxygenator. The samples were used to determine PO2 in buffer and blood samples, and SatO2, hemoglobin, and hematocrit levels in blood perfusate samples. Temperature and pressure in the perfusion circuit at the inlet and outlet of the oxygenator were also recorded.
Results: For this study, a series of 10 low-volume oxygenators was manufactured. Basic physical characteristics were measured: total length - 13 cm, dry weight 12.7 ± 1.12 g, average number of fibers 100 ± 8, total effective working surface area 78 ± 6 cm, perfusate flow ≤70 ml/min. It should be especially noted that miniature oxygenators have an average filling volume of 1.5±0.5 ml. The performance of oxygenators remains constant for at least 2 hours.