PTAB

IPR2025-01391

Terumo BCT Inc v. Haemonetics Corp

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Petition
petition

1. Case Identification

2. Patent Overview

  • Title: System and Method for Collecting Plasma
  • Brief Description: The ’652 patent relates to systems and methods for collecting plasma in blood apheresis procedures. The invention purports to more accurately determine the volume of pure plasma collected by calculating, in real-time, the volume of anticoagulant mixed with the plasma and subtracting it from the total collected fluid volume.

3. Grounds for Unpatentability

Ground 1: Claims 1, 5, 6, 8, 10, 11, 16, 17, and 19 are anticipated or rendered obvious by Takagi

  • Prior Art Relied Upon: Takagi (Japanese Patent Publication No. JP 2002-282352 A).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Takagi disclosed a blood component collection device that performs all steps of the challenged method and contains all elements of the challenged system. Takagi’s system used a control unit and a weight sensor to monitor the plasma collection bag during a procedure. Petitioner asserted that as the bag fills with a mixture of plasma and anticoagulant, Takagi’s controller calculated in real-time the "apparent plasma collection amount" (the total volume) and the "anticoagulant admixture amount." It then calculated the "true current plasma collection amount" (pure plasma) by subtracting the calculated anticoagulant volume from the total volume. This calculation was performed repeatedly as the collection bag’s weight increased, directly mapping to the ’652 patent’s core limitations of calculating anticoagulant and pure plasma volumes while the plasma component is being collected.

Ground 2: Claims 1, 3, 5, 6, 8, 10-12, 14, 16-17, and 19 are anticipated or rendered obvious by Lavender

  • Prior Art Relied Upon: Lavender (Patent 4,898,675).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner contended that Lavender disclosed an automated blood fractionation system that performed real-time calculations to accurately determine plasma volume. Lavender’s microprocessor repeatedly performed weight measurements of the plasma collection bag and, using a predefined anticoagulant-to-plasma ratio based on donor hematocrit, calculated the total volume of pure plasma (termed "total plasma filtered" or TPF) and the total volume of anticoagulant ("total citrate filtered" or TCF). Petitioner argued that because the calculation of pure plasma volume (TPF) was mathematically dependent on the anticoagulant ratio, it was inherently based on the calculated anticoagulant volume (TCF). These calculations were updated approximately every two seconds, satisfying the real-time calculation limitations of the challenged claims. Lavender also disclosed determining anticoagulant volume based on the number of rotations of an anticoagulant pump, mapping to claim 3.

Ground 3: Claims 2, 9, 13, and 20 are obvious over Takagi in view of Min

  • Prior Art Relied Upon: Takagi (Japanese Patent Publication No. JP 2002-282352 A) and Min (Patent 8,075,468).

  • Core Argument for this Ground:

    • Prior Art Mapping: This ground addressed claims requiring the calculation of anticoagulant volume based on a change in volume within the anticoagulant source container and accounting for anticoagulant added during a priming step. Petitioner argued that while Takagi disclosed the foundational apheresis system, Min explicitly taught using weigh sensors to track weight changes in an anticoagulant source container to derive the volume of fluid dispensed. Min also disclosed adding a predetermined volume of anticoagulant during a system priming step.
    • Motivation to Combine: A POSITA would combine Min’s teachings with Takagi’s system to improve the accuracy of determining the added anticoagulant volume. Directly measuring the dispensed anticoagulant from its source, as taught by Min, was a known technique to improve similar systems and would have been an obvious alternative or addition to Takagi's method of calculating anticoagulant volume based on measurements of the final collection bag. Including the priming volume, as taught by Min, would further reduce errors.
    • Expectation of Success: A POSITA would have a high expectation of success, as both references relate to blood separation technology and employ standard components like weigh sensors and controllers. Integrating Min’s weight sensor for the anticoagulant source into Takagi’s control system, which already processed weight data from the plasma collection bag, would have been a straightforward modification.

  • Additional Grounds: Petitioner asserted additional obviousness challenges, including that claims 7 and 18 are obvious over Lavender in view of Takagi, Headley, and Barrett, and that claims 4 and 15 are obvious over Lavender in view of Takagi, Min, and Turgut. These grounds relied on combining teachings for real-time hematocrit monitoring and measuring anticoagulant remaining in the separation device to further improve accuracy.

4. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 1-20 of Patent 10,758,652 as unpatentable.