US Federal Circuit Upholds a Method of Detecting Body Temperature as Patent-Eligible

In Exergen Corp v Kaz USA, Inc, Appeal Nos. 2016-2315, 2016-2341 (Fed Cir, March 8, 2018) (non-precedential disposition), the majority upheld a lower court’s post-trial ruling that claims to a method for detecting body temperature using temperature readings from the forehead skin and ambient temperature were patent-eligible under 35 USC § 101.

The majority followed the two-prong test for subject matter eligibility as set out in Alice Corporation v CLS Bank International (Alice): the claims must not be directed to a law of nature, natural phenomenon or an “abstract idea”, or there must be “something more” amounting to an “inventive concept” that is not merely “routine, conventional, and well-understood” in the prior art.

Here, the parties agreed that the claims are directed to a patent-ineligible concept, so the sole issue remaining for the panel was to decide if the lower court properly found that the claims contained a further inventive concept that was not “well-understood, routine [and] conventional activity previously engaged in by researchers in the field.”

The majority held that the lower court’s conclusion that certain claim elements were not routine, well-understood, or conventional (ie additional steps such as scanning while moving a radiation detector, and using a calculated coefficient for translating measurements taken at the forehead into core body temperature readings) was a factual determination that must be given “clear error deference.” On that basis, the majority refused to overturn the lower court’s decision.

However, in dissent, Justice Hughes was of the view that the lower court committed a clear error in not deciding that the undisputed presence in the prior art of apparatus for detecting “hot spots” was enough known for the claimed methods to be routine, conventional and well understood.

Summary By: Sumaiya Sharmeen