Patent attributes
Biological fluid filtration systems including biological fluid filtration devices capable of filtering blood or blood products, including the removal of leukocytes from the blood or blood product. Each system includes a mechanism to automatically drain the biological fluid upstream of the biological fluid filtration media disposed in the biological fluid filtration device. Both single sided and double sided biological fluid filtration devices are disclosed, including double sided biological fluid filtration devices with a solid partition wall with a first independent fluid flow path on one side of the partition wall, and a second independent fluid flow path on the other side of the partition wall. Draining mechanisms include vent filtration devices, diaphragm draining devices, and biological fluid filtration devices that include an integral diaphragm. The biological fluid filtration devices include low hold-up volume filter underdrains that purge in excess of 95% of the initial air in the device before liquid begins to flow from the outlet, thereby allowing the devices to be used in bed side applications. Variable surface area biological fluid filtration devices are disclosed that further reduce hold-up volume.