PTAB

IPR2024-01076

Medela LLC v. Meac Engineering Ltd

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1. Case Identification

2. Patent Overview

  • Title: Wound Closure and Drainage System
  • Brief Description: The ’534 patent relates to a negative pressure wound therapy (NPWT) vacuum system for draining an open wound. The system includes a wound enclosure, pump, waste container, and tubing, and utilizes a "venting arrangement" with "flow restrictors" to control ambient air flow into the system to regulate negative pressure.

3. Grounds for Unpatentability

Ground 1: Obviousness of Claims 1-5, 9, 10, 19, and 22 over Risk in view of Watson

  • Prior Art Relied Upon: Risk (Patent 6,764,462) and Watson (Patent 7,790,945).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Risk, a portable NPWT system, taught all elements of the base claims, including an enclosure (bandage), a tube, a vacuum source, and a controller. Risk’s bandage included a vent to the atmosphere, satisfying the “venting arrangement” limitation. However, Petitioner contended that Risk’s vent lacked the claimed “flow restrictor.” This missing element was supplied by Watson, which taught a wound dressing with a “semi-permeable” cover. Petitioner asserted a POSITA would understand this semi-permeable material, which allows air to pass but restricts its flow, to be a flow restrictor as claimed.
    • Motivation to Combine: A POSITA would combine Risk and Watson to gain better control over the negative pressure applied to the wound while still allowing the wound to breathe and protecting it from environmental contaminants. Both references operate in the same NPWT field, and using semi-permeable covers was a well-known technique for managing airflow and preventing contamination. Risk itself suggested using a "semi-occlusive" cover, further motivating a POSITA to look to references like Watson that detailed such covers.
    • Expectation of Success: A POSITA would have expected success in applying Watson’s semi-permeable cover to Risk’s bandage vent. The combination involved applying a known material to an existing system to achieve the predictable result of a controlled, restricted flow of ambient air, which was a common objective in NPWT system design.

Ground 2: Obviousness of Claims 6-8, 20, and 21 over Risk in view of Watson and Lina

  • Prior Art Relied Upon: Risk (Patent 6,764,462), Watson (Patent 7,790,945), and Lina (Patent 6,695,823).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground builds upon the Risk and Watson combination to address dependent claims requiring the controller to operate the pump’s electric motor to achieve a desired pressure level. Petitioner argued that while Risk taught a controller, it modulated pressure by adjusting a proportional valve, not by directly controlling the motor's speed, voltage, or torque. Lina taught this missing feature, disclosing a microcontroller that directly controls the speed of the pump motor by varying its voltage to adjust the negative pressure.
    • Motivation to Combine: A POSITA would combine Lina’s motor control method with the Risk/Watson system because it was one of a limited number of known, alternative ways to regulate pressure in NPWT systems. It would have been obvious to try substituting Lina’s direct motor control for Risk’s proportional valve control to create a potentially simpler or more efficient system. Both were well-established techniques for achieving the same goal.
    • Expectation of Success: Success was expected because controlling pump motor speed to regulate pressure was a common and well-understood principle. Modifying Risk’s controller to implement Lina’s voltage-based control strategy was a straightforward engineering task that would predictably result in the claimed functionality.

Ground 3: Anticipation of Claims 1-6, 9-15, 17-20, and 22 by Hunt

  • Prior Art Relied Upon: Hunt (Patent 6,142,982).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Hunt, a single prior art reference, disclosed every element of the challenged claims. Hunt taught a portable wound treatment apparatus with an enclosure (dressing and drape), a vacuum pump, a multi-lumen tube, and a controller. Crucially, Petitioner asserted that Hunt’s “venting arrangement”—consisting of a pressure relief valve connected to a tube that admits ambient air into the system—inherently performed the function of the claimed “flow restrictor.” The valve could be opened, closed, or set to intermediate positions, thereby restricting and controlling airflow. This venting arrangement was located outside the wound enclosure and introduced air upstream of the vacuum source, directly corresponding to limitations added during the prosecution of the ’534 patent.
  • Additional Grounds: Petitioner asserted additional obviousness challenges based on combinations of Hunt, Lina, and Dolliver (Application # 2005/0192548), relying on similar theories of substituting known elements and combining known features to achieve predictable results.

4. Arguments Regarding Discretionary Denial

  • Petitioner argued against discretionary denial under Fintiv because the co-pending district court litigation is in its early stages, with no trial date set and only initial disclosures exchanged. Petitioner asserted that it filed the IPR expeditiously and stipulated that it will not pursue in district court any invalidity grounds raised or that reasonably could have been raised in the IPR. Finally, Petitioner contended that the petition presents a compelling case for unpatentability, which weighs in favor of institution per Director Vidal’s guidance.

5. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 1-22 of Patent 8,858,534 as unpatentable.