Extracorporeal Circuit

Within the last two years, four pre-bypass filters of relatively the same design and performance characteristics were introduced into the cardiopulmonary bypass market. Two, the Harvey H-600 and the Delta Medical PB-005t pre-bypass filters were previously studied by this author 1• A determination was made of the type and number of particles released from different oxygenation systems. Additionally, pressure gradients generated across the pre-bypass filters at predetermined flow rates were measured. The particles removed by these filters indicated that particles were released from the extracorporeal circuit and that pre-bypass filtration could be advantageous in eliminating this source of microemboli. The present research project was designed to determine particulate size filtration limitations in a prebypass application and to propose the question of where we should set our pre-bypass filtration limits. The filter investigated in this study is the Gelman 0.45 ~m minicapsule filter*, which is, at this time, not a medical device. The present applications of this filter include clarification of aqueous and biological solutions and determination of coliform concentrations in water. A comparison of the design characteristics between the Gelman 0.45 ~m minicapsule filter and the