PTAB

IPR2017-02091

Inogen Inc v. CAire Inc

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Key Events
Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Compact and Lightweight Oxygen Concentrator
  • Brief Description: The ’133 patent discloses a compact, portable oxygen concentrator (POC) for use in respiratory therapy. The apparatus uses a pressure swing adsorption (PSA) system to generate oxygen-rich gas from ambient air and incorporates an integrated "conserver" system to deliver the gas to a user only during inhalation, thereby improving efficiency.

3. Grounds for Unpatentability

Ground 1: Claims 1-4, 6-10, and 12-14 are obvious over Hill in view of Rotariu.

  • Prior Art Relied Upon: Hill (Patent 6,651,658) and Rotariu (Patent 4,971,049).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Hill discloses the fundamental elements of the challenged claims, including a portable, lightweight POC that uses a multi-bed PSA system to generate concentrated oxygen and an integrated conserver to supply oxygen only during inhalation. Hill discloses a device weighing less than ten pounds, capable of delivering up to 3 LPM, and controlled by a microprocessor. However, Petitioner contended that Hill describes its conserver system at a high level without detailing its specific electronic components. Rotariu, which discloses a stand-alone oxygen conserving device, was asserted to supply these missing details. Specifically, Rotariu was argued to teach the structures corresponding to the "integrated conserving means" of claim 1: a pressure sensor, operational amplifiers for signal gain and comparison, an averaging circuit using a resistor and capacitor to establish a baseline breathing pressure, a transistor to correct for pressure spikes from gas delivery, and a valve with a driver controlled by a microprocessor. Petitioner further argued that making a device with a volume under 820 cubic inches (limitation 1.c) would have been an obvious design choice for a POSITA motivated by Hill’s emphasis on portability and market trends toward smaller devices.
    • Motivation to Combine: A POSITA, starting with Hill’s high-level description of a POC with an integrated conserver, would be motivated to look to a reference like Rotariu for a known, detailed, and proven implementation of conserver circuitry. Rotariu was presented as a solution to common problems like sensor drift and baseline pressure inaccuracies, providing a clear reason to incorporate its specific electronic components (amplifiers, averaging circuit, transistor) into Hill’s system to achieve a predictably functioning and improved device.
    • Expectation of Success: Petitioner asserted that a POSITA would have a reasonable expectation of success because combining the known conserver circuitry from Rotariu with the POC system of Hill would involve standard electrical engineering principles and the integration of well-understood components to perform their known functions.

Ground 2: Claims 5 and 11 are obvious over Hill and Rotariu in further view of Sanyo.

  • Prior Art Relied Upon: Hill (Patent 6,651,658), Rotariu (Patent 4,971,049), and Sanyo (Japanese Patent Application No. JP 2000-37458).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground built upon the combination of Hill and Rotariu from Ground 1 to establish the base POC apparatus. Claims 5 and 11 add the limitation of an alarm that activates if the oxygen concentration falls below about 80%. Petitioner argued that while Hill and Rotariu mention alarms, they do not disclose one tied specifically to oxygen concentration. Sanyo was asserted to teach this missing element. Sanyo discloses a POC with an oxygen sensor and an alarm designed to "issue a warning if the concentration of the oxygen gas... falls to or below 82%." This, Petitioner contended, would necessarily be activated if the concentration fell below the claimed 80% threshold.
    • Motivation to Combine: A POSITA would be motivated to add Sanyo’s oxygen concentration alarm to the Hill/Rotariu POC for the important and well-known purpose of ensuring patient safety. An insufficient oxygen level could pose a health risk, making the inclusion of such a safety feature a desirable and obvious improvement. Petitioner also noted that a 1996 ISO standard recommended alarms for oxygen purity drops below 82%, further motivating the combination.
    • Expectation of Success: Integrating a known type of alarm circuit into a POC was argued to be a straightforward modification for a POSITA, yielding the predictable result of enhanced patient safety without undue experimentation.

4. Key Claim Construction Positions

Petitioner dedicated significant argument to several means-plus-function limitations, accepting for the purpose of the inter partes review (IPR) the Patent Owner's constructions from co-pending litigation but arguing the prior art disclosed the required structures.

  • "Integrated conserving means" (Claim 1): The function is "sensing the inhalation of the user and delivering product gas only during the initial inhalation of the user." Petitioner accepted the corresponding structure as a pressure sensor, quad amplifier, averaging circuit (resistor and capacitor), transistor, valve with driver, and a microcontroller with an algorithm. Petitioner’s core contention was that Hill teaches the function and some structures, while Rotariu explicitly teaches all the detailed electronic components (amplifier, averaging circuit, transistor) required by the construction.
  • "Means for producing the product gas" (Claim 4): The function is "producing O2 rich gas." The corresponding structure includes adsorber sieve beds, a compressor, valves, valve drivers, and a microcontroller with an algorithm. Petitioner argued that Hill discloses all these structures, which are fundamental components of a PSA-based POC.
  • Contention on Algorithms: For multiple means-plus-function terms, the proposed construction included an "algorithm." Petitioner argued that while the ’133 patent does not expressly disclose any algorithm or source code, an algorithm would be inherent in the prior art's microprocessors (e.g., in Hill). Furthermore, Petitioner contended that generating such an algorithm for controlling valves and transistors would have been obvious to a POSITA with basic software skills.

5. Relief Requested

  • Petitioner requested the institution of an IPR and the cancellation of claims 1-14 of the ’133 patent as unpatentable.