A Novel 3D-Printed Gravity-Independent Air-Eliminating Filter for Rapid Intravenous Infusions

INTRODUCTION: The absence of a consistent downward G vector can make separation of gases from liquids challenging, such as in field medicine without stable upright equipment or during spaceflight. This limits the use of medical equipment and procedures like administration of intravenous (IV) fluids in microgravity and can make field medicine hazardous. Administering IV fluids and medications in microgravity requires a technique to separate air from the liquid phase. Current commercial filters for separation of gases are incompatible with high flow and blood. We present a novel filter designed to provide adequate air clearance without a consistent downward G vector.METHODS: Inline air-eliminating filters were designed for use with IV fluid tubing in microgravity using computer-aided design software and printed using nylon 12 on an EOS Selective Laser Sintering 3D printer. A 0.2-μm membrane filter was adhered around a central, hollow pillar with external spiral baffles allowing separation and venting of air from the fluid. Results were compared against commercially available inline air-eliminating filters.RESULTS: The 3D-printed filters outperformed the commercial filters in both percentage of air removed and flow rates. The centrifugal, baffled filter had flow rates that far exceeded the commercial filters during rapid transfusion.DISCUSSION: IV fluid administration is an often underappreciated and a necessary basic requirement for medical treatment. An air-eliminating filter compatible with blood and rapid transfusion was developed and validated with crystalloid solutions to allow the successful administration of IV fluid and medication without a consistent downward G vector.Formanek A, Townsend J, Ottensmeyer MP, Kamine TH.