Apple Inc v. Masimo Corp

1. Case Identification

• Case #: IPR2022-01299
• Patent #: 7,761,127
• Filed: July 22, 2022
• Petitioner(s): Apple Inc.
• Challenged Claims: 1-30

2. Patent Overview

• Title: Multiple Wavelength Sensor Substrate
• Brief Description: The ’127 patent describes a physiological sensor that uses optical radiation to measure parameters such as blood oxygen saturation. The sensor incorporates a plurality of light emitters and a temperature sensor on a substrate that includes an internal thermal mass to stabilize the bulk temperature of the emitters, thereby allowing for more accurate determination of the emitted wavelengths.

3. Grounds for Unpatentability

Ground 1: Obviousness over Yamada and Chadwick - Claims 1-3, 6-10, 26-27, 30 are obvious over Yamada in view of Chadwick.

• Prior Art Relied Upon: Yamada (Japanese Patent Publication No. JP 2004-337605 A) and Chadwick (Patent 3,514,538).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Yamada disclosed a physiological optical sensor with all the core components of the challenged claims, including multiple light emitting sources (LEDs), a substrate, and a temperature sensor. However, while Yamada recognized the problem of heat generation from the LEDs, it did not explicitly describe a thermal mass within the substrate for temperature stabilization. Chadwick, a decades-old patent, taught the well-known technique of constructing printed circuit boards (PCBs) with an internal metallic core (a thermal mass) specifically to dissipate heat from mounted components. The combination of Yamada's sensor with Chadwick's thermal core PCB allegedly rendered the key limitations of the independent claims obvious, including a thermal mass disposed within the substrate and thermally coupled to the emitters and the temperature sensor.
  • Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) would combine Chadwick’s well-known thermal core with Yamada’s optical sensor for several predictable reasons. The primary motivations were to improve the sensor's thermal performance by sinking heat from the LEDs, which would reduce heat exposure to the patient and, crucially, mitigate heat-induced spectral shifts in the LED wavelengths, thereby improving the accuracy of the physiological measurements.
  • Expectation of Success: A POSITA would have had a high expectation of success, as implementing a thermal core was a standard, well-established technique for managing heat in PCBs. Applying this known solution to Yamada’s sensor to achieve the predictable benefit of thermal stability would have been straightforward.

Ground 2: Obviousness over Yamada, Chadwick, and Leibowitz - Claims 4-5, 11-12, 18-19, 24-25, 28-29 are obvious over Yamada in view of Chadwick and Leibowitz.

• Prior Art Relied Upon: Yamada, Chadwick, and Leibowitz (Patent 4,591,659).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground built upon the combination of Yamada and Chadwick by adding Leibowitz, which taught an alternative method for creating a thermally conductive PCB. Leibowitz described a multi-layered board structure with interleaved layers of graphite and copper to enhance thermal conductivity. Petitioner asserted that this multi-layer construction directly teaches the limitations in several dependent claims requiring the thermal mass to be a "plurality of layers" of the substrate and for those layers to be "substantially copper clad."
  • Motivation to Combine: A POSITA seeking to implement a thermal core in Yamada's sensor would have recognized Leibowitz's multi-layered structure as a known and predictable alternative to Chadwick's single metal sheet core. The motivation was to achieve superior thermal performance, control the coefficient of thermal expansion, and enhance signal propagation, all benefits explicitly described by Leibowitz. This combination represented a simple substitution of one known heat-dissipating core design for another to optimize a known device.
  • Expectation of Success: Success was expected because Leibowitz's design was specifically for a PCB on which electronic components are mounted, making its application to the substrate in Yamada's sensor a direct and predictable implementation.

Ground 3: Obviousness over Yamada, Chadwick, and Noguchi - Claims 1-4, 6-10, 26-27, 30 are obvious over Yamada in view of Chadwick and Noguchi.

• Prior Art Relied Upon: Yamada, Chadwick, and Noguchi (Patent 5,334,916).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground added Noguchi to the base combination of Yamada and Chadwick to address the limitation that the emitter wavelengths are "determinable as a function of the drive currents and the bulk temperature." Noguchi explicitly taught a system for precisely controlling an LED’s emission spectrum by calculating its wavelength based on inputs from both a temperature sensor and measurements of the LED’s drive current.
  • Motivation to Combine: It was well-known that LED emission wavelengths are sensitive to both temperature and drive current. A POSITA seeking to improve the accuracy of Yamada's oximetry system would have been motivated to incorporate Noguchi's teachings to compensate for variations in both parameters. This would allow the system to maintain emission wavelengths at a target value optimized for accurate blood oxygen measurements.
  • Expectation of Success: A POSITA would have expected a high likelihood of success because Yamada’s sensor already included a temperature sensor and a CPU for processing signals, making it an ideal platform for implementing Noguchi’s well-known compensation and control techniques.
• Additional Grounds: Petitioner asserted numerous other obviousness challenges, including grounds based on Yamada alone or in combination with Cheung (which taught temperature compensation) and various permutations of the references cited above (e.g., Yamada, Cheung, and Leibowitz). These grounds relied on similar rationales of combining known elements for their predictable functions.

4. Arguments Regarding Discretionary Denial

• §314(a) (Fintiv): Petitioner argued that discretionary denial under the Fintiv factors would be inappropriate. It asserted that the only parallel proceeding is an International Trade Commission (ITC) investigation. Citing then-recent guidance from the USPTO Director, Petitioner contended that the Board will not discretionarily deny petitions based on applying Fintiv to a parallel ITC proceeding.
• §325(d): Petitioner argued that denial under §325(d) would be unwarranted because the petition presented new prior art and arguments not previously considered by the USPTO. Specifically, the primary references of Yamada, Chadwick, Leibowitz, and Noguchi were never cited or applied during the original prosecution of the ’127 patent.

5. Relief Requested

• Petitioner requests institution of an inter partes review (IPR) and cancellation of claims 1-30 of the ’127 patent as unpatentable.