IP Law Daily Intraluminal stent patent not invalid as obvious
Friday, February 5, 2016

Intraluminal stent patent not invalid as obvious

By Jody Coultas, J.D.

The Patent Trial and Appeal Board did not err in holding that a stent patent was not invalid as obvious in light of prior art, according to the U.S. Court of Appeals for the Federal Circuit (TriVascular, Inc. v. Samuels, February 5, 2016, O’Malley, K.). The Board’s findings regarding the lack of a sufficient motivation to combine and the lack of a reasonable expectation of success in combining the prior art were supported by substantial evidence.

U.S. Patent No. 6,007,575 (the ’575 patent) claims intraluminal stents that can be affixed to a vascular wall via the use of “an inflatable and deflatable cuff” without penetrating the vessel wall. After patent owner Dr. Shaun L. Samuels sued TriVascular, Inc. for infringement, TriVascular was granted inter partesreview of the patent. The Board held that TriVascular failed to meet its burden of demonstrating that the challenged claims were invalid as obvious. TriVascular appealed.

Claim construction. In its decision, the Board construed the phrase “circumferential ridge” to mean “raised strip disposed circumferentially about the outer surface of the inflatable cuff.” The Board also noted that the term did not encompass discontinuous points arranged in a circular pattern on the surface of a stent. TriVascular argued that this construction was unreasonably narrow in light of the common definition of a topological “ridge.”

The Board’s construction of the term “circumferential ridge” was affirmed by the court. TriVascular failed to explain why the Board should have resorted to a topological or cartographical definition of “ridge,” over a general dictionary definition consistent with both the specification’s teachings and the remaining claim limitations. Even adopting that definition of “ridge,” TriVascular failed to explain why such a topological definition would encompass discontinuous peaks in a mountain range, when mountain ranges typically consist of adjacent, continuous mountain peaks.

TriVascular’s argument that the Board should have applied prosecution history disclaimer to prohibit a construction of “circumferential ridges” that was limited to continuous ridges was also rejected by the court. Patent claims must be interpreted in light of the proceedings in the USPTO during the application process. A party that invokes prosecution history disclaimer must show a “clear and unmistakable” disclaimer that would have been evident to one skilled in the art. The prosecution history highlighted “that the positions of the Examiner and the patent applicant changed following a telephone interview,” regarding the allowability of the claims without the “continuously” limitation. There was no error in the Board finding that the examiner was convinced by these alternate claim amendments rather than the “continuously” circumferential ridges amendment.

Obviousness. The Board did not err in finding that TriVascular failed to satisfy its burden of proving that the challenged claims of the ’575 patent are invalid as obvious, according to the court. The prior art at issue was directed at stent technology. TriVascular argued it would have been obvious for a skilled artisan to substitute the inflatable, penetrating barbs of one prior art reference with the noninflatable, nonpenetrating protuberances of the other reference. A key point of distinction between the ’575 patent and the prior art was that the ’575 patent teaches the use of inflatable, circumferential ridges that do not penetrate the vessel wall. TriVascular’s proposed substitution would destroy the basic objective of the barbs, which was to penetrate surrounding tissue.

TriVascular also argued that the Board’s conclusion should be reversed because it was inconsistent with its own findings in its Institution Decision. In the Institution Decision, the Board found that TriVascular demonstrated a reasonable expectation of success in demonstrating obviousness. However, the Board was not bound by any findings made in its Institution Decision. Also, the Board’s findings in its Final Written Decision were not inconsistent with those in its Institution Decision because they were made under a qualitatively different standard.

The case is No. 2015-1631.

Attorneys: David K.S. Cornwell (Sterne Kessler Goldstein & Fox, PLLC) for TriVascular, Inc. James D. Petruzzi (Petruzzi Law Firm) for Shaun L. Samuels.

Companies: TriVascular, Inc.

MainStory: TopStory Patent FedCirNews

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