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Federal Circuit Affirms PTAB’s Unpatentability Finding Of Medical Alarm Patent
10/10/2023On September 28, 2023, the U.S. Court of Appeals for the Federal Circuit issued an opinion affirming the decision of the Patent Trial and Appeal Board finding unpatentable the challenged claims of a patent directed to an adaptive alarm system, used in combination with pulse oximetry sensors, for medical applications. Masimo Corp. v. Sotera Wireless, Inc., F.4th (Fed. Cir. Sept. 28, 2023).
Sotera petitioned for inter partes review of U.S. Patent No. RE47,218 (the “’218 Patent”) owned by Masimo. The Board found all challenged claims unpatentable over the combination of three prior art references: “Bock,” “Kiani,” and “Woehrle.”
On appeal to the CAFC, Masimo raised four main arguments: (1) the Board erred in construing the phrase “trigger a second alarm based on … exceeding the second alarm threshold” to mean that crossing the second alarm threshold is a “condition precedent” to the trigger of an alarm, but need not actually trigger the alarm; (2) the Board erred in construing “predetermined” to mean the formulaic calculation of a value, instead of a fixed value; (3) the Board abused its discretion in considering (i) an argument Sotera made in its Reply brief and (ii) a separate argument Sotera made at the Oral Hearing; and (4) the Board’s obviousness findings were not supported by substantial evidence.
With respect to Masimo’s first claim construction argument, the CAFC rejected Masimo’s arguments (i) that the Board applied “condition precedent” as a legal term of art in the context of contract law; (ii) that the Board improperly used a dictionary definition to construe “based on”; and (iii) that the Board should have limited the claim based on an embodiment shown in one of the patent figures. First, the CAFC explained that the Board simply applied the ordinary meaning of “condition precedent,” rather than a legal term of art. Second, the CAFC explained that nothing prohibits the Board from consulting a dictionary definition to help explain its construction when that definition does not contradict the intrinsic evidence. Third, the CAFC explained that the Board properly rejected Masimo’s argument because, except for one embodiment shown in one of the patent figures, there was nothing further in the claim language or specification that warranted limiting “threshold” to mean a value that directly triggers an alarm.
With respect to the second claim construction argument, the CAFC found that the ’218 Patent clearly explains that the alarm threshold is adaptive, rather than a fixed value. The claims themselves state that “the second alarm threshold replac[es] the first alarm threshold” through the adaptive mechanism. Accordingly, one of ordinary skill in the art would interpret “predetermined” in a broad sense, so as to include a calculation made from a predetermined formula to produce the threshold value from an input variable.
With respect to Masimo’s third argument, the CAFC explained (i) that the argument in Sotera’s Reply brief was not new, but rather an extension of an argument that it presented in its Petition, and (ii) that Sotera’s argument at the Oral Hearing was in response to direct questioning from the Board about an issue raised in the Petition and referenced in the Institution Decision. Accordingly, Masimo was on notice regarding both issues, and had a meaningful opportunity to respond.
With respect to Masimo’s fourth argument, the CAFC explained that, because it affirmed the Board’s claim constructions, and because it found Sotera’s arguments were not new or untimely, it also would affirm the obviousness determinations based on those constructions and arguments. Further, the CAFC rejected Masimo’s additional assertion that the obviousness combination would result in a non-functional device, because the Board properly considered the substantial evidence from the ’218 Patent, the prior art, and the expert testimony.
