Last Month at the Federal Circuit
Last Month at the Federal Circuit

May 2010

Court Affirms Board’s Finding of Adequate Written Description and Reverses Board’s Finding of Failure to Establish Actual Reduction to Practice in an Interference


Judges:  Michel (author), Gajarsa, Kendall (District Judge sitting by designation)
[Appealed from Board]

In Yorkey v. Diab, No. 08-1577 (Fed. Cir. Apr. 7, 2010), the Federal Circuit affirmed the Board’s denial of Thomas J. Yorkey’s motion seeking invalidity of claims 16-18 and 21 of Mohamed K. Diab et al.’s U.S. Patent Application Serial No. 09/110,542 (the “Diab application”) for inadequate written description.  Additionally, the Court reversed the Board’s finding that Yorkey failed to establish a prima facie case of actual reduction to practice, which had led the Board to award priority to the Diab application over Yorkey’s U.S. Patent No. 5,645,060 (the “Yorkey patent”).  The Court remanded the case to the Board for further proceedings.

The Diab application and the Yorkey patent were directed to methods of measuring the amount of oxygen in the blood of a patient.  The Court noted that a major problem in the detection of blood oxygen saturation is the presence of ambient interference (“noise”), and that the claims at issue involved methods of noise filtering.  The Diab application was filed on July 6, 1998, and claimed a priority benefit date of October 7, 1994.  The Yorkey patent was based on an application filed June 14, 1995.

In 2006, the Board declared an interference (No. 105,471) with two counts, and declared Yorkey as the junior party.  During the motions phase of the interference, Yorkey filed four motions that were denied by the Board, including a motion seeking invalidity of the Diab application for inadequate written description under 35 U.S.C. § 112, ¶ 1.  Yorkey appealed the Board’s denial of this motion to the Federal Circuit, and also appealed the Board’s decision that Yorkey failed to establish a prima facie case of actual reduction to practice prior to Diab’s benefit date.

On appeal, the Federal Circuit affirmed the Board’s decision that the Diab application met the written description requirement of 35 U.S.C. § 112, ¶ 1, noting that the record contained substantial evidence.  In so holding, the Court disagreed with Yorkey’s assertion that the Diab application failed to convey to a person of ordinary skill in the art that Diab had possession of the invention when he filed his application.  The Court noted that it was required to give deference to the Board’s evaluation of the credibility of expert witnesses, and that the Board found Diab’s expert to be a more credible witness than Yorkey’s expert.

However, the Court reversed the Board’s ruling that Yorkey failed to establish a prima facie case of actual reduction to practice prior to Diab’s benefit date, and remanded the case to the Board for further proceedings.  The Federal Circuit held that Yorkey met his burden of establishing a prima facie case of actual reduction to practice by showing that his invention met the limitations of the interference Count and that it worked successfully for its intended purpose.  The Court noted that Yorkey’s principal evidence of reduction to practice was a computer program, two versions of which were archived before Diab’s benefit date.  The computer program did not involve the first two data-collection steps of the interference Count, and instead used input data collected either at hospitals or from in-house breathe-down tests conducted by Yorkey’s research associate, Clark R. Baker.


“In order to corroborate a reduction to practice, it is not necessary to produce an actual over-the-shoulder observer.”  Slip op. at 15 (quoting Cooper v. Goldfarb, 154 F.3d 1321, 1330 (Fed. Cir. 1998)).

The Board found that the data presented in Yorkey’s motion could have corresponded to data collected at the hospitals or to data collected by Baker, and that if the presented data had been collected at hospitals, it could not be assumed to have been collected according to the first two steps of the Count, pointing particularly to the patient movement requirement of the Count.  The Board concluded that the presented data could not be used to establish an actual reduction to practice.  The Federal Circuit disagreed, holding that the Board clearly erred in finding the purported ambiguity in the source of the data to be fatal to Yorkey’s claim of reduction to practice.  The Court held that the source of the data did not matter, reasoning that even though Baker had no direct knowledge that the patients were moving during the tests conducted in hospitals, such direct knowledge was unnecessary for a showing of reduction to practice.  The Court stated, “In order to corroborate a reduction to practice, it is not necessary to produce an actual over-the-shoulder observer.”  Slip op. at 15 (quoting Cooper v. Goldfarb, 154 F.3d 1321, 1330 (Fed. Cir. 1998)).  Furthermore, the Court found that Baker was able to determine whether a motion component was included just by inspecting the collected data.  The Board further found that the two versions of the computer program were not self-explanatory and that Yorkey had not specifically identified the input interface, the output interface, or the sequence of computational steps and calculations that transformed the input data into the output determination of blood oxygen saturation.  The Court again disagreed with the Board, finding that the Board acknowledged that the first Count limitation was met, and that the other limitations were met by the software code and by Yorkey’s explanation of the code.  The Federal Circuit thus held that Yorkey met his burden of establishing a prima facie case of actual reduction to practice by showing that his invention met the limitations of the interference Count and that it worked successfully for its intended purpose.