Device and method for collecting blood plasma

An improved device for forcing segregated plasma from a flexible bag containing a layer of plasma over a layer of red blood cells, comprising:

• a base;
• a fixed member secured normal to the base;
• a movable member connected to the base by a hinge and rotatable about the hinge to substantially close against the fixed member;
• spring means for urging the movable member toward the fixed member;
• support means attached to the fixed member for supporting the bag in a vertical orientation on the fixed member between the fixed member and the movable member;
• a finger pivotaly secured to one of the members and pointing generally toward the other member so that it will contact the other member to prevent further movement of the movable member;
• the length and positioning of the finger being selected to cause cessation of movement of the movable member when a large portion of the plasma has been forced from the bag, the finger being pivotal into a noninterfering position to allow further closing movement of the movable member while being monitored by an operator.

In a method of removing plasma from a flexible bag containing a layer of plasma over a layer of red blood cells, the method including the steps of placing the bag between a fixed member and a movable member, and urging the movable member toward the fixed member to squeeze the bag and force fluid from the top, the improvement comprising:

• positioning a stop member between the fixed and movable members to automatically stop closing movement at a point selected to occur when a large portion of the plasma has been forced from the bag;
• then
• releasing the stop member to allow further closing movement of the movable member;
• and
• monitoring the movement after the stop member has been released to manually stop movement of the movable member when substantially all of the plasma has flowed from the bag and prior to any red cells flowing from the bag.