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Court Affirms Board’s Interference Ruling After Finding Claims Satisfied Written Description Requirement

April 07, 2010

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Last Month at the Federal Circuit - May 2010

Judges: Michel (author), Gajarsa, Kendall (District Judge sitting by designation)

[Appealed from: Board]

In Yorkey v. Diab, No. 08-1578 (Fed. Cir. Apr. 7, 2010), the Federal Circuit affirmed the Board’s decision denying Thomas J. Yorkey’s motion for judgment that claim 39 of U.S. Patent Application Serial No. 09/111,604 (“the ’604 application”) failed to comply with the written description requirement of 35 U.S.C. § 112, ¶ 1, and judgment of no interference-in-fact with respect to U.S. Patent No. 5,645,060 (“the ’060 patent”).

Yorkey owns the ’060 patent, which is directed to measuring the concentration of oxygen in blood and addresses the problem of accurate measurement in the presence of ambient noise interference.  Mohamed K. Diab and five other inventors filed the ’604 application, claiming priority to two earlier applications.  The Board declared an interference, identifying Yorkey as the junior party.

Yorkey filed motions seeking rulings that the ’604 application was invalid because it failed to comply with the written description requirement of 35 U.S.C. § 112, ¶ 1, and that there was no interference-in-fact.  The Board denied both motions, ultimately awarding priority to the ’604 application and invalidating the ’060 patent.

On appeal, the Federal Circuit affirmed.  The corresponding Yorkey and Diab claims at issue in this case were almost identical, as is common practice in an interference.  In Diab’s ’604 application, however, claim 39 specified a step for solving “functions,” while claim 6 of Yorkey’s ’060 patent referred to solving “three functions.”  The Board found the testimony of Diab’s expert to be more credible than that of Yorkey’s because it was more consistent with the language of the claims.  The Board was not persuaded by Yorkey’s argument that solving the three functions to obtain a value for oxygen saturation required solving the three functions directly or simultaneously, observing that Yorkey did not point to any terms in the claims or any description in the specification that compelled such a narrow construction of its own claims.

Ultimately, the Federal Circuit found that the Board’s denial was supported by substantial evidence and concluded that Diab’s claim anticipated Yorkey’s claim—a showing of either anticipation or obviousness is required for an interference finding—when given the broadest reasonable construction.

The Yorkey and Diab claims also differed in that the steps of the Diab invention as specified were performed sequentially to produce a value for saturation, while the claimed saturation calculation in Yorkey’s invention was based on matrix algebra.  Again, the “broadest reasonable construction” standard worked in Diab’s favor, as the Federal Circuit accepted Diab’s argument that it was well known in the art that while matrix algebra can be used to simplify mathematical calculations, in substance, it performs the same task of solving functions consecutively.

Yorkey then argued that the Diab specification contained an inadequate written description.  The Federal Circuit reviewed the Diab ’604 application specification in detail and concluded that the claim limitations at issue were adequately supported.  Specifically, the Federal Circuit found that the “solving the three functions” limitation was supported because the Diab application disclosed “using the third wavelength” to generate a reference signal and, therefore, the third signal is used in the ultimate calculation of saturation.  The Federal Circuit thus affirmed both Board judgments.


Summary authored by Troy A. Petersen, Esq.