Fisher Paykel Healthcare Ltd v. ResMed Corp

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Fisher & Paykel Healthcare Ltd (New Zealand)
  • Defendant: ResMed Corp. (Minnesota)
  • Plaintiff’s Counsel: Knobbe, Martens, Olson & Bear, LLP
• Case Identification: 2:16-cv-06099, C.D. Cal., 08/15/2016
• Venue Allegations: Venue is alleged to be proper as Defendant ResMed Corp. resides in California and has committed the alleged acts of infringement within the judicial district.
• Core Dispute: Plaintiff alleges that Defendant’s Continuous Positive Airway Pressure (CPAP) machines, heated tubing, and nasal masks infringe nine patents related to breathing assistance apparatus, humidifiers, and patient interfaces.
• Technical Context: The technology domain is medical devices for treating respiratory conditions such as Obstructive Sleep Apnea (OSA), a market characterized by intense competition and innovation focused on patient comfort and therapeutic efficacy.
• Key Procedural History: The complaint alleges Defendant had pre-suit knowledge of each asserted patent via written communications sent between February 2015 and February 2016. Subsequent to the filing of this complaint, several of the asserted patents were subject to Inter Partes Review (IPR) proceedings, resulting in the cancellation or disclaimer of a number of asserted claims. For example, claim 6 of the '072 patent and claims 24 and 25 of the '547 patent, both asserted in this complaint, were later disclaimed. The status of these post-filing invalidity decisions raises significant questions about the ongoing viability of several infringement counts.

Case Timeline

II. Technology and Patent(s)-in-Suit Analysis

U.S. Patent No. 8,443,807 - "Breathing Assistance Apparatus"

The Invention Explained

• Problem Addressed: The patent’s background describes conventional respiratory masks used for CPAP therapy as potentially "cumbersome and uncomfortable," leading to pressure sores, particularly on the nasal bridge, which can result in poor patient compliance (’807 Patent, col. 2:23-28, 2:60-63).
• The Patented Solution: The invention proposes a headgear and mask interface designed to improve comfort and stability. Its central feature is a "continuous and substantially curved elongate member" that extends below the user’s nose and along the cheeks, to which the mask and headgear straps attach. This structure is intended to transfer the mechanical load of the interface away from the sensitive nasal bridge and onto the user's cheeks (’807 Patent, Abstract; col. 2:66-3:4).
• Technical Importance: This design approach seeks to enhance patient adherence to CPAP therapy by creating a more stable and comfortable interface that minimizes pressure on common points of irritation.

Key Claims at a Glance

• The complaint asserts independent claim 1.
• Essential elements of claim 1 include:
  • A mask assembly with a mask body sized to leave the user's mouth uncovered, and two nasal pillows extending from the mask body.
  • A ring engaging the mask body.
  • An elbow rotatably engaged with the ring, with a tube extending from the elbow.
  • A headgear assembly with two side straps passing down the cheeks, a top strap with a buckle, and an adjustable back strap.
  • A specific connection scheme wherein the side straps connect and disconnect with the mask assembly, and the top strap connects "only with one or more of the side straps and the back strap."
• The complaint reserves the right to assert dependent claims 2, 4, 6, 8, 17, 20, and 21 (Compl. ¶24).

U.S. Patent No. 8,479,741 - "Breathing Assistance Apparatus"

The Invention Explained

• Problem Addressed: The patent addresses the need for patient interfaces that provide an effective seal without compromising user comfort, noting that prior art masks can be uncomfortable (’741 Patent, col. 2:25-28).
• The Patented Solution: The invention describes a patient interface constructed from materials with different flexibility: a "mask body" made of a "substantially flexible plastics material" that includes the nasal pillows, and a separate "mask base" made of a "less flexible" material to which the headgear attaches. The solution also specifies "three-dimensionally molded" side arms with "varying cross-sectional thickness" to provide a combination of stability and adaptability to the user's face (’741 Patent, Abstract; col. 3:10-23).
• Technical Importance: This composite material and structural design aims to balance the need for a soft, pliable seal at the nares with a rigid, stable frame for securing the headgear, thereby improving both comfort and performance.

Key Claims at a Glance

• The complaint asserts independent claim 1.
• Essential elements of claim 1 include:
  • A mask body of a "substantially flexible plastics material" with two angled nasal pillows.
  • A mask base of a "plastics material that is less flexible than" the mask body material, the base having a housing and a recess that receives a tubular portion of the mask body.
  • Two side arms removably connected to the mask base.
  • Each side arm is "three-dimensionally molded and has a varying cross-sectional thickness."
  • Headgear with two side straps.
• The complaint reserves the right to assert dependent claims 2-3, 16, 17, 34, and 35 (Compl. ¶35).

U.S. Patent No. 8,186,345 - "Apparatus for Supplying Gases to a Patient"

• Technology Synopsis: The patent describes an apparatus for identifying a specific type of heated breathing tube connected to a humidifier. The system uses a controller to measure a "characteristic impedance" of an identification element (e.g., a thermistor) in the tube's circuitry to determine the conduit type and apply appropriate power to the heater wire (’345 Patent, Abstract).
• Asserted Claims: Independent claim 1 and dependent claim 3 (Compl. ¶49).
• Accused Features: The accused ResMed AirSense 10, AirCurve 10, and ClimateLineAir products allegedly include a controller that automatically identifies the attached conduit by using the resistance from a thermistor to determine the tube type (Compl. ¶51).

U.S. Patent No. 8,453,641 - "Apparatus For Measuring Properties of Gases Supplied to a Patient"

• Technology Synopsis: The patent discloses an apparatus where the heater wire in a breathing tube is itself part of an electrical circuit used to measure properties of the gas, such as temperature. A controller measures changes in the circuit, which includes a thermistor, to determine these properties (’641 Patent, Abstract).
• Asserted Claims: Independent claims 1 and 6, and dependent claim 5 (Compl. ¶61).
• Accused Features: The AirSense 10 with ClimateLine Air tubing is alleged to use its heater wire as part of a circuit, which is measured by a controller to determine gas properties like temperature, based on changes in current from a thermistor (Compl. ¶63).

U.S. Patent No. 9,265,902 - "Apparatus For Measuring Properties of Gases Supplied to a Patient"

• Technology Synopsis: The patent describes a heated breathing tube with an electrical circuit containing a heater wire and a thermistor positioned within the gas stream. A controller determines gas temperature based on the current flowing through the circuit, which can be enclosed in an overmolding that extends into the tube (’902 Patent, Abstract).
• Asserted Claims: Independent claims 7 and 11, and dependent claim 12 (Compl. ¶74).
• Accused Features: The AirSense 10 with ClimateLine Air is alleged to have a tube with a heater wire and an electrical circuit with a thermistor positioned in the gas stream, where a controller determines temperature based on the current (Compl. ¶76).

U.S. Patent No. 8,550,072 - "Apparatus for Delivering Humidified Gases"

• Technology Synopsis: The patent relates to the physical interface between a humidifier and a water chamber. It describes an apparatus with adjacent outlets and returns for pressurized and humidified gases, allowing both fluid connections to the water chamber to be made in a "single motion" (’072 Patent, Abstract).
• Asserted Claims: Independent claim 6 and dependent claims 12 and 13 (Compl. ¶87).
• Accused Features: The AirSense 10 is alleged to have a pressurized gases outlet and an adjacent humidified gases return, allowing connection to a water chamber to be made in a single motion (Compl. ¶89).

U.S. Patent No. 8,091,547 - "Apparatus for Delivering Humidified Gases"

• Technology Synopsis: This invention also concerns the interface between a humidifier housing and a removable water chamber. It claims a housing adapted to receive the chamber via a "single motion" that simultaneously disposes the chamber base adjacent to a heater and makes or breaks the separable fluid connections between the housing and the chamber (’547 Patent, Abstract).
• Asserted Claims: Independent claim 24 and dependent claim 25 (Compl. ¶100).
• Accused Features: The AirSense 10 is alleged to have a housing that accommodates a removable humidification chamber, where a single motion of engagement places the chamber on a heater and makes the required fluid connections (Compl. ¶102).

U.S. Patent No. 7,111,624 - "Apparatus for Delivering Humidified Gases"

• Technology Synopsis: The patent describes a humidifier apparatus with a housing containing a pressurized gas supply and distinct outlets and returns. The system is adapted to make fluid connections to a humidifier's inlet and outlet ports in a single slide-on motion (’624 Patent, Abstract).
• Asserted Claims: Independent claims 1 and 7, and dependent claims 2-3 (Compl. ¶113).
• Accused Features: The AirSense 10 is alleged to be an apparatus for humidified gas delivery with a housing that has a pressurized gas outlet and a humidified gas return adapted to connect with a humidifier (Compl. ¶116).

U.S. Patent No. 6,398,197 - "Water Chamber"

• Technology Synopsis: The invention is a water chamber for a humidifier featuring a horizontally oriented gas inlet with an "elongate flow tube" extending into the chamber. This tube directs incoming gas away from the chamber wall before it exits, a design intended to reduce noise and prevent water spillage if the chamber is tilted (’197 Patent, Abstract).
• Asserted Claims: Independent claim 1 (Compl. ¶126).
• Accused Features: The AirSense 10 is alleged to include a water chamber with a horizontally oriented inlet and an elongate flow tube that extends into the chamber to direct the flow of gases (Compl. ¶128).

III. The Accused Instrumentality

• Product Identification: The complaint names multiple accused instrumentalities, which can be grouped into three categories: (1) nasal pillow masks, specifically the ResMed Swift FX and Swift LT masks (Compl. ¶22); (2) CPAP and bi-level PAP devices, specifically the ResMed AirSense 10 and AirCurve 10 series (Compl. ¶19-20); and (3) heated air tubing, specifically the ResMed ClimateLineAir (Compl. ¶21).
• Functionality and Market Context:
  • The accused Swift FX and Swift LT masks are patient interfaces designed to create a seal at the user's nares to deliver pressurized air for CPAP therapy (Compl. ¶26, 37).
  • The AirSense 10 and AirCurve 10 devices are flow generators that provide a supply of pressurized air. They are alleged to incorporate humidifiers that connect to water chambers and controllers for managing heated tubing (Compl. ¶51, 89, 102).
  • The ClimateLineAir is a heated breathing tube designed to work with the AirSense/AirCurve 10 devices to deliver warmed, humidified air to the patient while preventing condensation (Compl. ¶51, 63).
  • No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

’807 Patent Infringement Allegations

• Identified Points of Contention:
  • Scope Questions: A potential dispute may arise over the term "ring engaging the mask body." The analysis may question whether the specific mechanical interface in the Swift FX product constitutes "engaging" in the manner disclosed and claimed in the patent, which describes a distinct ring fitting into a channel on the mask body (’807 Patent, col. 6:4-10).
  • Technical Questions: The complaint alleges the accused product meets the specific negative limitation that the "top strap connects only with one or more of the side straps and the back strap." A factual question for the court will be whether the physical construction of the Swift FX headgear adheres to this specific connectivity arrangement or if it connects to other components, such as the mask assembly itself.

’741 Patent Infringement Allegations

• Identified Points of Contention:
  • Scope Questions: The relative terms "substantially flexible" and "less flexible" will be central. The dispute will question whether the specific durometer and performance characteristics of the materials used in the Swift LT mask fall within the scope of these claim terms as understood in light of the patent's specification.
  • Technical Questions: A factual question will be whether the accused side arms have a "varying cross-sectional thickness" that performs the structural function described in the patent (e.g., providing both rigidity and flexibility), or if any observed variations in thickness are incidental or for other purposes.

V. Key Claim Terms for Construction

For the ’807 Patent

• The Term: "ring engaging the mask body"
• Context and Importance: This term defines the core structural connection between the headgear-adjacent components and the patient-sealing components. The nature of this "engagement" is critical to infringement, as a finding that the accused connection is fundamentally different could be dispositive.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The plain meaning of "engaging" suggests a wide range of physical interactions. The specification describes the function as allowing the mask body to be "readily attached to and detached from the mask base" (’807 Patent, col. 6:10-12), which could support any connection achieving that function.
  • Evidence for a Narrower Interpretation: The preferred embodiments consistently depict the "ring" as part of a mask base and the "mask body" as having a lip that fits into a channel on that ring (’807 Patent, Fig. 3-5; col. 6:4-10). This may support a narrower construction limited to a component that fits into or around another.

For the ’741 Patent

• The Term: "a substantially flexible plastics material" (for the mask body) vs. a plastics material that is "less flexible" (for the mask base)
• Context and Importance: This pair of relative terms is the technological crux of claim 1, defining the composite nature of the invention. The case may turn on whether the materials of the accused Swift LT mask exhibit the claimed relative flexibility.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The specification describes the materials functionally, stating the mask body should be "soft and pliable" while the mask base provides "stability" (’741 Patent, col. 5:22, 5:55-56). This could support a construction covering any pair of materials that achieve this functional difference.
  • Evidence for a Narrower Interpretation: The specification identifies specific exemplary materials, such as silicone for the flexible body and a harder plastic like polypropylene for the less flexible base (’741 Patent, col. 5:20-21, 5:53-54). This could be used to argue that the terms require a significant and noticeable difference in material properties akin to that between the disclosed examples.

VI. Other Allegations

• Indirect Infringement: For each of the nine asserted patents, the complaint alleges induced infringement under 35 U.S.C. § 271(b). The allegations are based on Defendant allegedly providing "directions, demonstrations, guides, manuals, training for use, and/or other materials" that instruct customers and end-users on how to use the accused products in an infringing manner (e.g., Compl. ¶28-29, 41-42, 53).
• Willful Infringement: For each asserted patent, the complaint alleges willful infringement. The basis for willfulness is alleged pre-suit knowledge of the patents and their infringement, stemming from written communications sent by Plaintiff to Defendant on specific dates in 2015 and 2016 (e.g., Compl. ¶27, 40, 52).

VII. Analyst’s Conclusion: Key Questions for the Case

• A threshold issue for the entire case will be the viability of the asserted claims: given that numerous claims asserted in the complaint (e.g., claim 6 of the '072 patent; claims 24-25 of the '547 patent) were cancelled or disclaimed in subsequent IPR proceedings, a foundational question is which, if any, of the original infringement counts remain enforceable.
• For the patient interface patents ('807, '741), a core issue will be one of structural and material correspondence: do the specific mechanical connections (e.g., a "ring engaging the mask body") and relative material properties (e.g., "substantially flexible" versus "less flexible") of the accused masks map onto the claimed limitations as defined by the patents, or are there dispositive technical differences in their construction and operation?
• For the apparatus patents related to humidifiers and tubing, a central question will be one of functional architecture: do the accused ResMed systems, which connect humidifiers, water chambers, and heated tubing, perform the specific functions required by the claims—particularly concerning the "single motion" engagement of components and the use of heater wire circuits to identify conduits and measure gas properties?