Applicant Admitted Prior Art Can (Sometimes) Show Obviousness

SHOCKWAVE MED., INC., V. CARDIOVASCULAR SYS., INC.

Before Lourie, Dyk, and Cunningham.  Appeal from the United States Patent and Trademark Office, Patent Trial and Appeal Board in No. IPR2019-00405.

Summary: In inter partes review proceedings, applicant admitted prior art may be used as evidence of the background knowledge of a person of ordinary skill in the art, and that background knowledge can be used to supply missing claim limitations in an obviousness combination.

Cardiovascular Systems (“CSI”) filed an IPR petition challenging a Shockwave patent directed to angioplasty catheters used to break up plaque in blood vessels.  CSI argued that the challenged claims would have been obvious in view of a European patent publication, “Levy,” modified in view of the applicant’s admitted prior art (“AAPA”) discussed in the patent’s specification.  The Board originally treated the AAPA as falling withing the scope of “prior art consisting of patents or printed publications” under 35 U.S.C. § 311(b) and held claims 1-4 and 6-17 would have been obvious.  Shortly thereafter, the PTO issued binding guidance that AAPA does not qualify as prior art consisting of patents or printed publications under § 311(b).  The Board initiated rehearing to consider the guidance and ultimately held the same claims to be obvious.  In the rehearing decision, the Board still considered the AAPA, but this time as evidence of what was known in the art.

Shockwave appealed the Board’s determination of obviousness, arguing that the Board improperly relied on AAPA in violation of the PTO’s guidance and the statute’s language.  The Federal Circuit disagreed.  The court explained that AAPA cannot be the “basis of a ground” for a petition but it can be evidence of a skilled artisan’s background knowledge.  The court clarified that a skilled artisan’s background knowledge, in turn, could supply a missing claim limitation.  Thus, the court affirmed the Board’s analysis because the Board relied on AAPA only for the acceptable purpose of showing that a claimed feature was well-known in the art.   Shockwave also argued that the Board’s use of the phrase “basis” in its decision meant that AAPA was improperly considered as a basis for obviousness.  The court disagreed, explaining that “what matters for the purposes of § 311(b) is the grounds raised in the petition,” not the phrasing used in the Board’s decision.  In this instance, the court held, the grounds raised in the petition properly used the AAPA to establish well-known general knowledge.

Editor: Sean Murray