Particulate Removal Efficiency in Arterial Screen Filters

___ ____________ _ Six types of commercially available arterial screen filters ranging from 20 to 40 microns pore size were evaluated for their efficiency in removing particulate matter. Five filters of each of these six commercial types were tested, for a total of thirty filters. Three sizes of polystryene microspheres ranging from 25 to 53 microns in diameter were used to simulate particulate contamination. For each determination, approximately 124,000 microspheres were introduced proximal to each filter in a circuit flowing at 6L/min. An ultrasonic microemboli detector was positioned distal to each filter to monitor the presence of microspheres. Filtration efficiency ranged from 20.6% to 99.6% with 25 micron spheres, 13.9% to 99.5% with 35 micron spheres, and 94.4% to 99.4% with 53 micron spheres. IntroductioiL ___________ _ Microemboli have long been incriminated as a cause of multi-organ dysfunction during and after cardiopulmonary bypass. 14 Several sources of emboli can be cited: platelet aggregation induced Direct communications to: Ronald J. Massimino, 106 Moorefield St.. Providence, RI 02909.