Exergen Corp. v. Thermomedics, Inc. – How to Flunk s. 101

On June 22d, the Fed. Cir. issued a summarily affirmed the district courts Order that the method claims in suit did not pass the Alice/Mayo test for patentable subject matter. Claim 51 of U.S. patent no. 7787938 is representative:

“A method of detecting human body temperature comprising: measuring temperature of a region of skin of the forehead; and processing the measured temperature to provide a body [core] temperature approximation based on heat flow from an internal body temperature to ambient temperature.”

No thermometer claims were in suit. So what’s left is the use of an algorithm – note the “processing step” – that improves the accuracy of the measured temperature of the forehead. Exergen’s thorough brief tried hard to distinguish Mayo, but they were stuck with the fact that discovery of a natural correlation is considered by the Fed. Cir. to be a natural phenomenon that envelops both the in vivo correlation and its practical application. Since the algorithm is not patent eligible, the district court examined the remaining claim steps for the elusive “inventive concept” and did not find one. Exergen argued that, prior to the invention, deriving the core temperature from the forehead temperature – as opposed to, say, measuring the rectal temperature – had not been accepted by the medical community, and so the other steps were unconventional. However, Exergen rather somewhat gratuitously – I think – summarized the state of the art:

“The measuring step, standing alone, does not amount to much: ‘measuring temperature of a region of skin of the forehead.’ After all, people have for millennia touched each others’ foreheads to gain a rough impression of whether someone is feverish or not.”

This evokes images of a mother touching her lips to her baby’s tender forehead to “check its temperature”. The draftsman had employed his/her dark art to obtain a patent on something as simple as taking someone’s pulse(!). This concession, true though it is, nullified pages of Exergen’s brief urging the Court to see this claim as a healthcare cousin of Diehr and remote from the regimen claims of Mayo. After all, the mother is “measuring” the baby’s forehead temperature and the step of “processing the measured temperature” could be seen as encompassing a mental step. And isn’t the mother arriving at a “body temperature approximation” – “He’s burning up!”?

Exergen argued that the algorithm “demonstrated that a reliable method could be developed for converting forehead skin temperature (or radiation) to body temperature approximation.” Perhaps if this unexpected result had been put into  the claims in some way, such as by reciting the degree of accuracy added by the algorithm, the Fed. Cir. would have deemed the claims worthy of a full opinion.

These were not claims to a diagnostic method, and I am still waiting for a specific “If A, then B” claim’s patent-eligibility to be addressed by the Fed. Cir. Until then, the patent-eligibility of  the tests necessary to realize Obama’s “precision medicine” initiative remains in doubt.

Law 360 Article

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