US 4151844

US Patent 4151844: Automated Blood Component Separation

Title: Method and apparatus for separating whole blood into its components and for automatically collecting one component.

Assignee: The current assignee is Baxter International Inc., with the original assignee being Baxter Travenol Laboratories Inc.

Inventors: Herbert M. Cullis, Anthony L. Almond, Michael B. Uffer, Mirza A. Kohja, and Rodolfo R. Rodgriguez.

Filing Date: November 11, 1977.

Issue Date: May 1, 1979.

Abstract: The patent describes a method and apparatus for centrifugally separating whole blood into at least three components. Whole blood is withdrawn from a donor, passed through a fluid system, and centrifuged. One component, typically white blood cells (buffy coat), is withdrawn at a fixed volumetric rate for collection, while the other two components (red blood cells and plasma containing platelets) are withdrawn at variable rates. An optical sensing device monitors the collected component to detect contamination from the other two. If contamination is sensed, the system automatically adjusts the withdrawal rates of the other two components (red blood cells and plasma) to maintain the desired composition and minimize contamination of the collected component. The other two components are then recombined and returned to the donor.

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Independent Claims Overview:

Independent Claim 1 (Method):
This claim outlines a method for separating whole blood into at least three components. It involves drawing whole blood from a donor, centrifuging it within a fluid system to achieve separation, and then withdrawing each component during centrifugation. A key aspect is the withdrawal of one specific component (e.g., white blood cells) at a constant, fixed rate, while the other two components (e.g., red blood cells and plasma) are withdrawn at adjustable rates. These other two components are then recombined and returned to the donor. The method further includes sensing the composition of the component being collected at a fixed rate to detect any mixing with the other two components. If such mixing is detected, the withdrawal rates of one or both of the other two components are adjusted to ensure the collected component has minimal contamination, and a specified amount of this desired component is collected.

Independent Claim 7 (Apparatus):
This claim describes an apparatus designed to perform the blood separation method. It includes mechanisms for drawing whole blood from a donor and supplying it to a centrifuge for separation. The apparatus features a first withdrawing means for a first blood component, a second withdrawing means for a second blood component (the one to be collected), and a third withdrawing means for a third blood component. Crucially, it includes a means for recombining the first and third blood components for return to the donor. The apparatus also comprises a sensing means to determine the composition of the second blood component being withdrawn. In response to sensing a mixing of the first or third components with the second component, an adjusting means modifies the withdrawal rates of the first and third withdrawing means. Finally, there is a means for collecting the second blood component.

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CAFC 2026 Dockets:
A direct search of the CAFC 2026 dockets for specific patent number US4151844 through available search tools did not yield specific case information for the year 2026. The provided search results offer general access to Federal Circuit case information, filings, records, and opinions, but do not allow for a direct query by patent number for current dockets. Therefore, I cannot definitively report on any ongoing legal challenges related to this patent in the CAFC for 2026 with the current information.