CAFC says PTAB Entitled to Weigh the Credibility of Experts, Ignore Attorney Argument

CAFC says PTAB Entitled to Weigh the Credibility of Experts, Ignore Attorney ArgumentElbit Sys. of Am., LLC v. Thales Visionix, Inc., No. 2017-1355, (Fed. Cir. Feb. 6, 2018) (Before Moore, Wallach, and Stoll, J.) (Opinion for the court, Wallach, J.).

Elbit filed a petition for inter partes review of U.S. Patent No. 6,474,159 (the ‘159 Patent). The ‘159 Patent generally relates to a system for tracking motion relative to a moving platform. The claimed system eliminates the need to calculate an object’s position relative to the ground, which improves functionality when tracking moving vehicles. The Board issued a final written decision finding that Elbit failed to demonstrate by a preponderance of the evidence that claims 3-5, 13, 24-28, 31, and 34 would have been obvious over U.S. Patent No. 4,722,602 (“McFarlane”) in combination with two other prior art references. Elbit appealed the Board’s decision and the Federal Circuit affirmed.

The sole issue on appeal was whether the method of integrating the “relative angular rate signal” taught in representative claim 3 of the ‘159 Patent would have been obvious to a person having ordinary skill in the art in view of McFarlane. The Federal Circuit found that it would not.

Specifically, the prior art asserted by Elbit and the asserted claims each employed different steps to calculate the orientation or position of a moving object relative to a moving reference. Thales’s expert explained that the prior art calculated an object’s relative orientation using a three-step method whereas the asserted claims employed a two-step method. Thales’s expert also outlined the benefits of a two-step method over a three-step method, including the ability to determine relative orientation with fewer calculations and fewer errors.

Elbit’s expert argued that the asserted claims were obvious because the two-step and three-step methods are “mathematically equivalent” in that the three-step method simply reorders steps employed in the prior art without producing a new or unexpected result. The Federal Circuit disagreed, finding that Thales’s expert sufficiently explained the differences between the two-step and three-step methods. The panel also agreed with the Board that Elbit’s expert’s testimony was “unsupported” and not entitled to weight because he failed to account for or address the relative angular rate signal limitation in claim 3 anywhere in his opinion.

Elbit also argued that the Board failed to acknowledge that a person of ordinary skill in the art would understand that the sum of integrals principle—which holds that the same result will be reached whether data is “first integrated, then subtracted” or “first subtracted, then integrated”—applies. The Federal Circuit again disagreed, noting that Elbit failed to present any evidence supporting its contention beyond attorney argument, which was not sufficient to rebut the admitted evidence. In contrast, Thales’s expert explained that a person of ordinary skill in the art would have found it inappropriate to apply the principle to the equations disclosed in the ‘159 Patent.

The Federal Circuit held that the Board’s determination that the asserted claims would not have been obvious was supported by substantial evidence, including the testimony of Thales’s expert.

Take Away

The PTAB is entitled to weigh the credibility of each party’s expert witness and the Federal Circuit is not inclined to disturb the Board’s credibility determinations. Attorney argument, without more, is not evidence and cannot be used to rebut admitted evidence.




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