Apple Inc v. Masimo Corp

1. Case Identification

• Case #: IPR2020-01526
• Patent #: 6,771,994
• Filed: August 31, 2020
• Petitioner(s): Apple Inc.
• Patent Owner(s): Massi E. Kiani et al.
• Challenged Claims: 15

2. Patent Overview

• Title: Pulse Oximeter Probe-Off Detection System
• Brief Description: The ’994 patent discloses a pulse oximeter sensor designed to prevent false physiological readings when a probe is partially or completely dislodged from a patient. The invention uses a plurality of louvers placed in front of the sensor’s photodetector to block light arriving from oblique angles, thereby ensuring the detector primarily measures light that has passed directly through the patient's tissue.

3. Grounds for Unpatentability

Ground 1: Obviousness over Diab, Benjamin, and Melby - Claim 15 is obvious over Diab in view of Benjamin and Melby.

• Prior Art Relied Upon: Diab (Patent 5,638,818), Benjamin (Patent 4,015,595), and Melby (Patent 5,254,388).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Diab disclosed a conventional pulse oximeter probe with LEDs and a photodetector for measuring physiological parameters through tissue. Diab recognized the problem of signal noise and proposed using a "scattering medium" over the detector to improve the signal-to-noise ratio. Benjamin, addressing a similar physiological sensor, taught that inaccuracies from scattered light could be better solved by using a commercially available "light control film" to collimate light, making the sensor dependent only on the light beam reflected from the target tissue. Melby was cited as disclosing the specific technical details of a commercially available "louvered plastic film" from 3M, which corresponds to the light control film described in Benjamin and the ’994 patent itself.
  • Motivation to Combine: A POSITA would combine these references to improve the known device in Diab. Recognizing the shared problem of scattered light interference, a POSITA would have been motivated to replace Diab’s less effective "scattering medium" with the superior, known solution of Benjamin’s light control film. A POSITA would then look to a reference like Melby for the specific implementation details of such a commercially available louvered film.
  • Expectation of Success: The combination involved applying known solutions to solve a known problem. A POSITA would have reasonably expected that incorporating a light-collimating film into a standard pulse oximeter would predictably reduce noise from scattered light and improve measurement accuracy.

Ground 2: Obviousness over Webster and Melby - Claim 15 is obvious over Webster in view of Melby.

• Prior Art Relied Upon: Webster (a 1997 book, "Design of Pulse Oximeters") and Melby (Patent 5,254,388).

• Core Argument for this Ground:

  • Prior Art Mapping: Petitioner asserted that Webster, as a comprehensive summary of the state of the art, described the standard components and functioning of pulse oximeters, including LEDs and a photodiode. Critically, Webster explicitly identified the problem of "optical shunting," where light reaches the detector without passing through the tissue, causing erroneous readings. Webster proposed solving this by placing "some type of light filter" or "light impervious barriers" between the LEDs and the photodiode. As in Ground 1, Melby provided a detailed description of a commercially available louvered light control film that functions as the "light filter" suggested by Webster.
  • Motivation to Combine: A POSITA, when designing a pulse oximeter according to Webster, would be confronted with the known problem of optical shunting. Webster’s own suggestion to use a "light filter" would directly motivate a POSITA to select a known, off-the-shelf component for this purpose. The louvered film in Melby, designed to control the direction of light, was presented as an obvious choice to implement Webster’s proposed solution.
  • Expectation of Success: A POSITA would have a high expectation of success in applying Melby's known light-filtering technology to a standard pulse oximeter to solve the well-documented problem of optical shunting identified in Webster.

• Additional Grounds: Petitioner asserted additional obviousness challenges over Fine (WO 1996/41566) alone and in combination with Benjamin and Melby. These grounds argued that Fine’s reflectance-type sensor, which used obliquely-cut optical fibers to guide light, inherently taught the claimed louvers or, alternatively, would have been obviously combined with a louvered film to address light shunting.

4. Key Claim Construction Positions

• Petitioner argued for a specific construction of the claim phrase “a plurality of louvers positioned over the light sensitive detector to accept light from the at least one light emission device originating from a general direction of the...device and then transmitting through body tissue...”.
• Petitioner contended this language required a transmissive configuration where the light emission device and the detector are positioned opposite each other, with the patient's tissue in between. This construction was based on the patent’s specification and figures, which exclusively depict a transmissive arrangement. This construction was central to Petitioner's primary grounds and served to distinguish them from alternative grounds based on reflectance-type sensors.

5. Arguments Regarding Discretionary Denial

• Petitioner argued that discretionary denial under Fintiv would be inappropriate.
• The co-pending district court litigation was in its early stages, with no claim construction order issued and a trial date set for April 2022, well after the 18-month IPR schedule would conclude with a Final Written Decision (FWD) in March 2022. Petitioner also stipulated that, if the IPR was instituted, it would not pursue the same invalidity grounds in the district court, mitigating concerns of duplicative efforts. Petitioner contended that these factors weighed heavily in favor of institution to promote efficiency and resolve validity issues definitively.

6. Relief Requested

• Petitioner requests institution of an inter partes review and cancellation of claim 15 of the ’994 patent as unpatentable.