System And Method For Collecting Plasma

What is this patent about?

’124 is related to the field of blood apheresis, specifically systems and methods for collecting plasma from a donor. Traditional apheresis procedures involve withdrawing whole blood, separating it into components, collecting the desired component (e.g., plasma), and returning the remaining components to the donor. Existing systems often struggle with precisely determining the volume of pure plasma collected due to the presence of anticoagulant, leading to potential under- or over-collection relative to regulatory limits.

The underlying idea behind ’124 is to accurately determine the pure plasma volume collected during apheresis by accounting for the anticoagulant mixed with the plasma. This is achieved by calculating the volume of anticoagulant present in the collected plasma based on the donor's hematocrit and the amount of anticoagulant introduced. By subtracting the calculated anticoagulant volume from the total collected volume, the system can precisely determine the volume of pure plasma.

The claims of ’124 focus on a method and system for collecting plasma that includes determining a donor's weight and hematocrit, withdrawing whole blood and introducing anticoagulant, separating the blood into components, collecting the plasma, calculating the volume of anticoagulant in the collected plasma based on the donor's hematocrit, calculating the volume of pure plasma, and continuing the process until a target volume of pure plasma is collected. The system includes a controller that performs these calculations and controls the blood draw pump.

In practice, the system uses a centrifugal bowl to separate blood components. A controller monitors the amount of anticoagulant added, either by tracking pump rotations or measuring the weight change of the anticoagulant source. The donor's hematocrit, either pre-determined or measured during the process using an optical sensor, is then used to calculate the anticoagulant volume in the collected plasma. This allows for a more accurate determination of the pure plasma volume, ensuring compliance with regulatory limits and maximizing plasma collection.

Unlike prior approaches that rely on total volume (plasma + anticoagulant) for collection, ’124 adjusts for variations in donor hematocrit. This ensures that a consistent volume of pure plasma is collected from each donor, regardless of their hematocrit level. By precisely controlling the collection process based on pure plasma volume, the system can potentially collect a greater volume of plasma compared to prior art systems, while still adhering to regulatory guidelines.