PTAB

IPR2025-01374

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 ’124 patent discloses systems and methods for collecting plasma in blood apheresis procedures. The purported invention involves accurately determining the volume of pure plasma collected by calculating the volume of anticoagulant in the collected plasma product, based at least in part on the donor’s hematocrit.

3. Grounds for Unpatentability

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

  • Prior Art Relied Upon: Lavender (Patent 4,898,675).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued Lavender, an automated system for fractionating blood, discloses all limitations of the challenged claims. Lavender’s system determines a donor’s weight and hematocrit and uses these inputs in a series of interrelated equations to control the plasma collection process. Petitioner asserted that Lavender’s calculation of the total citrate (anticoagulant) volume in the collection bag (TCF) is necessarily “based, at least in part, upon the hematocrit of the donor” because it depends on the total plasma flow volume (TQP), which is itself calculated directly from the donor’s hematocrit. Furthermore, Lavender calculates the total pure plasma volume (TPF) based on the total dilute plasma filtered (TDPF), which is determined by the weight of the collected fluid. Petitioner contended that because the calculated volumes of pure plasma (TPF) and anticoagulant (TCF) share a direct mathematical relationship via a conversion factor, calculating one is inherently based on the other, thus meeting the limitations of claims 1 and 11.
    • Key Aspects: The core of this ground rested on the argument that the mathematical interdependencies within Lavender's disclosed algorithms meet the "based, at least in part, on" claim limitations, even if not stated in the exact manner as the ’124 patent.

Ground 2: Claims 1, 3, 5, 6, 8, 10-12, 14, 16-17, and 19 are obvious over Lavender in view of Fletcher-Haynes.

  • Prior Art Relied Upon: Lavender (Patent 4,898,675), Fletcher-Haynes (Patent 7,072,769).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Lavender provides the primary apheresis system, while Fletcher-Haynes provides teachings to optimize it. If the Board were to find Lavender does not inherently teach calculating pure plasma volume based on the anticoagulant volume, Fletcher-Haynes explicitly discloses this method. Fletcher-Haynes teaches determining "Product Plasma" as the "total plasma volume less anticoagulant volume." Petitioner asserted that a person of ordinary skill in the art (POSITA) would have found it obvious to substitute Fletcher-Haynes’s explicit formula for calculating pure plasma into Lavender’s main algorithm. The petition demonstrated how Fletcher-Haynes's equations for anticoagulant ratio and total volume are functionally equivalent to Lavender's, making the integration straightforward and predictable.
    • Motivation to Combine: A POSITA would combine Lavender and Fletcher-Haynes to more accurately track and optimize the amount of plasma collected from a donor. Both references relate to plasma apheresis and use substantially similar algorithms based on donor parameters, making the combination a predictable application of known techniques for a known purpose.
    • Expectation of Success: A POSITA would have a high expectation of success because the references address the same technical problem with similar, mathematically compatible solutions. The combination would involve substituting one known calculation method for another to achieve the predictable result of improved accuracy.

Ground 3: Claims 2, 9, 13, and 20 are obvious over Lavender in view of Fletcher-Haynes and Min.

  • Prior Art Relied Upon: Lavender (Patent 4,898,675), Fletcher-Haynes (Patent 7,072,769), and Min (Patent 8,075,468).

  • Core Argument for this Ground:

    • Prior Art Mapping: This ground built upon the Lavender/Fletcher-Haynes combination by adding Min to address dependent claims. For claim 2, which required determining a change in volume within an anticoagulant container, Min taught using weigh sensors to track weight changes and derive fluid volumes from an anticoagulant source container. For claim 9, which required including anticoagulant added during a priming step, Min taught conveying a predetermined volume of anticoagulant during a pre-collection priming cycle. Petitioner argued it would be obvious to incorporate these features from Min into the base system.
    • Motivation to Combine: A POSITA would add Min’s teachings to the Lavender/Fletcher-Haynes system to improve accuracy. Using Min's weigh sensor on the anticoagulant source would provide a direct measurement of the anticoagulant used, reducing potential errors from relying solely on pump rate calculations. Including the priming volume, as taught by Min, would further correct for errors by accounting for all anticoagulant introduced into the system.
    • Expectation of Success: Success would be expected, as incorporating weigh sensors and accounting for priming volumes were well-known techniques for improving accuracy in fluid management systems like those used in apheresis. The functionality would be complementary and result in a more robust system.

  • Additional Grounds: Petitioner asserted additional obviousness challenges. Ground 4 argued claims 7 and 18 are obvious over Lavender, Fletcher-Haynes, Headley, and Barrett, primarily to add teachings of real-time hematocrit monitoring. Ground 5 argued claims 4 and 15 are obvious over Lavender, Fletcher-Haynes, Min, and Turgut to add teachings for determining the volume of anticoagulant remaining within the blood separation device itself.

4. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 1-20 of Patent 11,738,124 as unpatentable.