SYSTEMS AND METHODS FOR PUMPING SALINE THROUGH A STERILIZING FILTER

A method is provided for controlling fluid flow through a tubing segment is provided in which a pump draws fluid through the tubing segment using negative pressure P. The method includes the steps of: a) operating the pump at an initial commanded fluid flow rate to draw fluid through the tubing segment; b) measuring on a continuous basis the P in the tubing segment; c) determining into which of four zones the measured P falls, a first zone being where P>X1, a second zone being where X1>P>X2, a third zone where X2>P>X3, and a fourth zone where X3>P; d) if P is in the first zone for greater than a first pre-established time period, then increasing the commanded flow rate of the pump and returning to step b); e) if P is in the second zone, then continuing to operate the pump at the flow rate at which the pump is currently operated and returning to step b); f) if P is in the third zone, for greater than a second pre-established time period, then decreasing the commanded flow rate of the pump and returning to step b); and g) if P is in the fourth zone, then commanding the pump to stop. A system including a programmable controller configured to automatically perform the method is also disclosed