PTAB

IPR2014-00551

Apex Medical Corp. v. ResMed Limited

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1. Case Identification

2. Patent Overview

  • Title: Humidifier with Structure to Prevent Backflow of Liquid Through the Humidifier Inlet
  • Brief Description: The ’453 patent describes a humidifier assembly for a continuous positive airway pressure (CPAP) apparatus. The assembly features a humidifier with a base configured to hold liquid, a top cover, and a seal, along with a connecting structure that physically and pneumatically interfaces with the CPAP apparatus and includes a heating element to warm the liquid in the humidifier's base.

3. Grounds for Unpatentability

Ground 1: Obviousness over Mayer - Claims 1, 2, and 4-7 are obvious over Mayer.

  • Prior Art Relied Upon: Mayer (Patent 7,096,864).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Mayer, which discloses a modular "humidifying apparatus" for a "CPAP-unit," teaches all limitations of independent claim 1. Mayer’s system was asserted to show a humidifier with a base for liquid ("trough element"), a top cover ("cup portion"), a seal between them, and a connecting structure. This structure includes a housing to support the humidifier, a retaining mechanism for securing it to the CPAP unit, and a heating element in contact with a heat-conducting part of the base. Petitioner further contended that Mayer discloses the dependent claim features, including an inlet and outlet communicated with the base (claim 2), electrical contact elements for power (claim 4), a configuration for removable attachment (claim 5), a metallic heat-conducting material (claim 6), and the overall CPAP apparatus incorporating the assembly (claim 7).
    • Motivation to Combine: Not applicable as this ground relies on a single reference.
    • Expectation of Success: Not applicable as this ground relies on a single reference.

Ground 2: Obviousness over Mayer and Lipscombe - Claim 3 is obvious over Mayer in view of Lipscombe.

  • Prior Art Relied Upon: Mayer (Patent 7,096,864), Lipscombe (Patent 6,554,260).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner asserted that Mayer teaches all elements of the base invention as recited in claim 1, but does not explicitly disclose the limitation of dependent claim 3: "a control knob to control a heat setting of the heating element." To supply this missing element, Petitioner pointed to Lipscombe, which is directed to a similar humidifier assembly. Lipscombe was alleged to explicitly teach a "control knob 32 which can be rotated in order to vary the amount of humidification," directly corresponding to the claim 3 limitation.
    • Motivation to Combine: A person of ordinary skill in the art (POSITA) would combine the references because both are analogous art addressing the common problem of delivering humidified respiratory gas. Petitioner argued a POSITA would find it obvious and desirable to incorporate Lipscombe’s well-known control knob into Mayer’s humidifier to provide user control over the heat setting, which is a simple and conventional feature for such devices.
    • Expectation of Success: The petition asserted a high expectation of success, as the combination involved the straightforward integration of a known control feature into an existing system, with predictable results.

Ground 3: Obviousness over Dobson - Claims 1, 2, 5, and 7 are obvious over Dobson.

  • Prior Art Relied Upon: Dobson (Patent 5,673,687).

  • Core Argument for this Ground:

    • Prior Art Mapping: Petitioner presented Dobson as an alternative primary reference, contending it discloses a humidifier assembly for a "ventilator," a term Petitioner argued a POSITA would understand to encompass a CPAP apparatus. Dobson was said to teach a humidifier with a base reservoir, a separable top cover, and a resilient seal. It also allegedly shows a connecting structure (air inlet) for removably attaching the ventilator (claim 5) and the entire apparatus (claim 7). While Dobson does not explicitly show a heating element in contact with a heat-conducting base, Petitioner argued that for a device to "add humidity" to air as Dobson describes, a POSITA would have known that a heating element and a thermally conductive base are necessary and inherent components for efficient operation.
    • Motivation to Combine: Not applicable as this ground relies primarily on a single reference, supplemented by the general knowledge of a POSITA.
    • Key Aspects: This ground’s strength depended on the argument that a POSITA’s common knowledge would supply the heating element and heat-conducting material limitations, viewing them as obvious or inherent requirements for achieving the stated purpose of Dobson's invention.

  • Additional Grounds: Petitioner asserted additional obviousness challenges, including that claim 3 is obvious over Dobson in view of Lipscombe, and that claims 4 and 6 are obvious over Dobson in view of Mayer. These grounds relied on similar rationales, using Lipscombe to supply a control knob and Mayer to add electrical power contacts and specify a metallic heat-conducting material to the base system described in Dobson.

4. Key Claim Construction Positions

  • Petitioner requested that all challenged claim terms be given their plain and ordinary meaning consistent with the "broadest reasonable interpretation" standard. Key constructions proposed, which Petitioner asserted were supported by the ’453 patent's specification, included:
    • "seal": Construed as "a sealing engagement."
    • "connecting structure": Construed as being "configured to connect between the CPAP apparatus and humidifier."
    • "control knob": Construed as "a controller such as a knob or other selecting device... to control a heat setting."
  • These proposed constructions were foundational to Petitioner's arguments for mapping the prior art references onto the claim limitations.

5. Relief Requested

  • Petitioner requested institution of an inter partes review of claims 1-7 of the ’453 patent and cancellation of all challenged claims as unpatentable under 35 U.S.C. § 103.