A split Federal Circuit panel has affirmed a district court’s holding that patent claims directed to a “temporal artery temperature detector” are patent-eligible under 35 USC § 101 and the Mayo/Alice test. Exergen Corp. v. Kaz USA, Inc., Nos. 2016-2315, 2016-2341 (Fed. Cir. Mar. 8, 2018) (opinion by Judge Moore, joined by Judge Bryson; dissent by Judge Hughes) (non-precedential). This case has several instructive aspects. First, the dispute between the majority and Judge Hughes in dissent concerning whether the claims involved steps that were not conventional, routine, and well understood, is interesting. But perhaps even more interesting is Judge Moore’s dicta concerning the role of factual determinations in patent-eligibility analysis, especially in light of other recent Federal Circuit opinions (also authored by Judge Moore) addressing this topic.
The patents at issue were U.S. Patent Nos. 6,292,685 and 7,787,938. Representative method claims from the ’938 patent  recite:
14. A method of detecting human body temperature comprising making at least three radiation readings per second while moving a radiation detector to scan across a region of skin over an artery to electronically determine a body temperature approximation, distinct from skin surface temperature.
24. The method of claim 14 wherein the artery is a temporal artery.
Representative system claims from the ’938 patent recite:
48. A body temperature detector comprising:
a radiation detector; and
electronics that measure radiation from at least three readings per second of the radiation detector as a target skin surface over an artery is viewed, the artery having a relatively constant blood flow, and that process the measured radiation to provide a body temperature approximation, distinct from skin surface temperature, based on detected radiation.
49. The body temperature detector of claim 48 wherein the artery is a temporal artery.
The majority’s opinion began by acknowledging the well-settled law that patent-eligibility under § 101 is a matter of law to be reviewed de novo at the Federal Circuit. Then the court dived into the dispute about The court's opinion (page 3) appears to have inadvertently listed claims 14 and 24 from the ’938 patent as being from the ’685 patent.
whether the additional claim steps beyond calculating the temperature present a novel technique in this computation “to calculate core temperature based on ambient and skin temperature readings] or add an inventive concept sufficient to transform the claims into a patent-eligible application.
The district court, following trial, had found that there was no evidence that the claimed techniques “were well-understood, routine, and conventional prior to the introduction of Exergen’s invention.” The majority of this Federal Circuit panel agreed, and then went out of its way – as Judge Moore has done in the opinions linked to above – to stress the factual component of § 101 analysis.
The patent-eligibility analysis in this case was different than than both Mayo and Ariosa Diagnostics, Inc. v. Sequenom, Inc., 788 F.3d 1371 (Fed. Cir. 2015), because in those cases “well-known, existing methods were utilized to determine the existence of a natural phenomenon.” In this case, even if a measurement was made using “a natural phenomenon and is abstract at step one, the measurement method here was not conventional, routine, and well-understood.” The court seem influenced by the fact that the patent owner had invested considerable time and money in research and development to discover “the coefficient representing the relationship between temporal-arterial temperature and core body temperature.”
The determination of “whether claim elements are well-understood, routine, and conventional in a particular art at a particular time is a fact-finding,” said the majority opinion, and such fact findings “are entitled to deference and should be reviewed for clear error.” The defendant-appellant, Kaz, had argued that it was improperly deprived of its Seventh Amendment right to a jury trial on the question of patent-eligibility. But, as Kaz acknowledged, patent cases could present legal questions that included “underlying factual components such as claim construction to which there is no right to a jury.” Then, after seeming to head in the direction of endorsing jury trials for patent-eligibility questions, the majority turned away, saying that it could leave the Seventh Amendment question for another day because Kaz had waived its right to a jury trial.
The court thus affirmed the district court’s holding with respect to § 101 patent-eligibility. Although beyond the scope of this post, we note that the court also affirmed a denial of enhanced damages, and reversed a verdict of infringement with respect to claims of the ’685 patent, and because of this, vacated and remanded the trial court’s damage award.
Judge Hughes’ Dissent
Judge Hughes dissented, arguing that the claims at issue failed under step one (abstract idea or law of nature) of the Mayo/Alice test, and that the court never should have reached step two (additional inventive step). According to Judge Hughes, the claims were directed to a patent-ineligible law of nature, specifically to using a “heat balance equation” which was “a mathematical representation of the law of nature that governs the relationship between skin, air, and core temperatures.”
Judge Hughes then took the majority to task for reaching step two of the Mayo/Alice test. The majority had stated that Judge Hughes did not dispute that the trial court’s factual findings or subject to clear error review; his actual statement was a little different, that “[e]ven under a deferential standard of review,” there was clear error in finding an inventive concept in the claims at issue. Looking at previously existing products, discussed in the patent specifications, Judge Hughes noted that “prior art products combined skin scanning, obtaining peak temperatures, and taking multiple temperature measurements per second.” Therefore the claimed invention, “aside from its use of a newly discovered heat balance coefficient,” simply used pre-existing and conventional technology. As such, there was no inventive concept to make the claims patent-eligible.
Finally, Judge Hughes took pains to state that it was not always improper to consider “the integration of a law of nature into the claimed invention . . . at every stage of the § 101 analysis.” Claims should be looked at holistically under step one of the Mayo/Alice test. But under step two, a more narrow focus is appropriate. The majority had looked at the claims as a whole, but that was a step one analysis, and regardless, “a claimed invention’s unconventionality, by itself, is not sufficient to render the claim patent eligible.”
Lessons for Practice
Not every non-precedential decision by a Federal Circuit panel is worth reading, but this one is if your practice in any way touches patent-eligibility questions under § 101. First, the question of how much, if any, of a factual component and/or question for a jury lies in the patent-eligibility analysis is one we can expect to hear more of. Second, this case is a poster child for the subjectivity of patent-eligibility law at present. Can anyone dispute that the § 101 questions would have come out differently with different judges constituting the panel? Finally, if you are a patent prosecutor and an examiner rejects your claim on the basis that simply taking a measurement can never be patent-eligible, this case (perhaps alongside cases designated precedential) demonstrates that such a rejection would be improper. The court's opinion (page 3) appears to have inadvertently listed claims 14 and 24 from the ’938 patent as being from the ’685 patent.