Prior art — US Patent 10758652

Analysis of Prior Art for U.S. Patent 10,758,652

Based on a review of the prosecution history and the face of the patent, the following patents were cited as prior art during the examination of US 10,758,652. This analysis evaluates their potential relevance to the claims of the '652 patent.

Key Challenge of the Invention

The core novelty asserted in US 10,758,652 is the method and system for collecting a target volume of pure plasma by dynamically calculating and subtracting the volume of anticoagulant mixed with the collected plasma. This addresses the variability in collected "pure plasma" that arises from differences in donor hematocrit when collection is based on total fluid volume. Prior art systems, as described in the '652 patent's background, were "unable to determine the total volume of plasma that has been collected (e.g., because the product collected is a mixture of plasma and anticoagulant)" and therefore collected based on total volume, leading to inconsistent pure plasma yields (US 10,758,652, Col. 1, lines 60-67).

Analysis of Cited Prior Art

The following prior art was cited by the examiner.

1. US Patent 4,086,924 A - "Plasmapheresis apparatus"

Full Citation: US 4,086,924 A
Publication Date: May 2, 1978
Assignee: Haemonetics Corporation
Brief Description: This patent describes an early automated plasmapheresis system. It controls the collection of anticoagulated plasma into a container and measures the collected volume. The system uses a weigh scale to monitor the amount of collected fluid and automatically controls draw and return cycles. It also controls the ratio of anticoagulant to whole blood.
Potential Anticipation of Claims:
- This reference discloses many foundational elements of a plasmapheresis system, such as withdrawing blood, adding anticoagulant, separating components, and collecting plasma into a container that is weighed (relevant to claims 1(d-g), 6, 11, and 17).
- However, US 4,086,924 does not appear to anticipate the key steps of claims 1 and 11. It does not teach or suggest calculating a volume of pure plasma by determining the volume of anticoagulant in the collected product and subtracting it from the total collected volume. The system in the '924 patent stops collection based on the total weight/volume of the plasma-anticoagulant mixture. Therefore, it does not disclose the novel elements of claim 1(h), 1(i), and the corresponding functions of the controller in claim 11.

2. US Patent 5,316,540 A - "Apparatus and method for separating microscopic units in a substantially continuous density gradient solution"

Full Citation: US 5,316,540 A
Publication Date: May 31, 1994
Assignee: Cobe Laboratories, Inc.
Brief Description: This patent details a centrifugal system for separating blood components. A significant feature is its use of an optical sensor to monitor the location of the interface between different blood components (e.g., the "buffy coat") within the centrifuge. This allows for more precise control over which component is being harvested.
Potential Anticipation of Claims:
- The '540 patent discloses the use of an optical sensor to monitor blood components within a separation device. This is directly relevant to dependent claims 7 and 18, which describe determining the donor's hematocrit by "monitoring a volume of red blood cells collected within the blood component separation device" using an optical sensor.
- While this patent provides a mechanism for determining hematocrit during the procedure, it does not appear to anticipate the core inventive concept of independent claims 1 and 11. The '540 patent does not disclose using this hematocrit value to then calculate the volume of anticoagulant in the final collected plasma product and stop the collection based on a target volume of pure plasma. Its focus is on the precision of the separation process itself.

3. US Patent 5,651,766 A - "System for controlling a blood processing apparatus"

Full Citation: US 5,651,766 A
Publication Date: July 29, 1997
Assignee: Baxter International Inc.
Brief Description: This patent describes a sophisticated control system for an apheresis device. The system can estimate or determine various donor-specific physiological parameters (like total blood volume, plasma volume) and use these parameters to optimize the collection procedure, for example, by controlling pump rates to minimize procedure time. It can also estimate the volume of plasma available for collection from a donor.
Potential Anticipation of Claims:
- The '766 patent teaches determining donor parameters (like weight, hematocrit) and using them to control the apheresis process. This is relevant to the preliminary steps of claim 1(a-b) and the system's ability in claim 11 to use this information.
- Crucially, the '766 patent discusses optimizing the procedure based on donor data, but it does not appear to explicitly teach the calculation of pure plasma in the final collection bag in real-time. It does not disclose the steps of calculating the anticoagulant volume within the collected product as it is being collected and using that to determine the pure plasma volume to meet a specific pure plasma target. The control described is more focused on the rate and efficiency of the collection process rather than the precise composition of the final product.

4. US Patent 6,053,856 A - "Method of and apparatus for controlling a fluid separation process"

Full Citation: US 6,053,856 A
Publication Date: April 25, 2000
Assignee: Baxter International Inc.
Brief Description: This patent describes a control system for apheresis that predicts the volume of a blood component to be collected based on donor data and process parameters. It can adjust the collection procedure in real-time. The system calculates a target volume of anticoagulated plasma (AC plasma) based on a desired pure plasma yield and the donor's hematocrit.
Potential Anticipation of Claims:
- This is a highly relevant prior art reference. The system in the '856 patent calculates a target volume for the anticoagulated mixture before the procedure begins, based on a desired pure plasma target and donor hematocrit. For example, it states, "the desired plasma yield... and the donor HCT are used to calculate the target AC plasma volume" (Col. 14, lines 52-54).
- However, there is a subtle but important distinction from the claims of the '652 patent. Claims 1 and 11 of the '652 patent specify calculating the volume of pure plasma as the plasma component is being collected and continuing until a target volume of pure plasma is reached. The '856 patent appears to set a target for the total mixture volume at the outset and collects to that volume. It does not describe a dynamic, real-time calculation and subtraction of the anticoagulant volume from the currently collected fluid to determine the current pure plasma volume. The '652 patent claims a method of real-time monitoring of the pure plasma volume itself, rather than collecting to a pre-calculated mixture volume. This distinction, focusing on the dynamic calculation during collection, appears to be what separates the '652 patent from this prior art.