Size Matters in Obviousness Analysis
The US Court of Appeals for the Federal Circuit affirmed in part and reversed in part two Patent Trial and Appeal Board (Board) decisions, finding that the Board erred in its construction of certain claim terms relating to an artificial heart valve that does not require removal of the damaged native heart valve. St. Jude Medical, LLC v. Snyders Heart Valve LLC, Case Nos. 19-2108, -2109, -2140 (Fed. Cir. Oct. 15, 2020) (Taranto, J.).
St. Jude filed two petitions for inter partes review (IPR) of a patent for an artificial heart valve and a system for inserting the valve. Both petitions were instituted by the Board and resulted in final written decisions. In the first decision, the Board found that St. Jude failed to establish unpatentability of the challenged claims, rejecting St. Jude’s contention that all challenged claims were anticipated by and obvious over the Leonhardt prior art reference. In the second decision, the Board found that certain claims were anticipated by the Bessler prior art reference, but rejected St. Jude’s contentions as to all other claims. St. Jude appealed, arguing that the Board erred in the first decision by erroneously construing the term “band” and erred in the second decision by finding that St. Jude failed to prove that a skilled artisan would have made a particular combination of Bessler and the Johnson prior art. Snyders cross-appealed in the second decision as to the claims the Board found were anticipated by Bessler.
The Federal Circuit affirmed the Board’s conclusions in the first decision, finding that not only was the Board’s construction of the term “band” proper, but that it was actually broader than St. Jude’s proposed construction—and that St. Jude expressly accepted the Board’s construction. The Board construed the heart valve band to mean “a structure generally in the shape of a closed strip or ring” (replacing St. Jude’s “circular” with “closed”). In the prior art, Leonhardt discloses a graft material which extends the length of the entire structure. The Federal Circuit agreed with the Board’s finding that Leonhardt’s graft material was “like a sleeve” as opposed to “a closed strip or ring.” St. Jude argued that an ordinary skilled artisan’s understanding of the term “band” does not include a length restriction, that a Leonhardt’s material was just a long band, and that the Board effectively changed its construction of the term. The Federal Circuit, however, was not persuaded by St. Jude’s unlimited-length definition of “band,” instead turning to dictionary definitions that included terms like “thin” and “narrow,” and looking to the patent specification that did not explicitly disclaim any length restrictions. The Court ultimately rejected St. Jude’s arguments, finding that St. Jude should have proposed a claim construction that precluded any limitations on length if it wished to argue such. The Federal Circuit affirmed the Board’s findings as to first decision.
The Federal Circuit next addressed Snyder’s cross-appeal. Snyder disputed the board’s construction of the “size and shape” of a frame that the patent requires must be inserted between an “upstream region and downstream region.” The Board construed the term only to require that the frame be “sized and shaped” for insertion “in a position” between the upstream and downstream regions, as is done in Bessler. The Court pointed out, however, that Bessler relates to heart valve replacement, in which the faulty valve is removed, whereas the present invention is explicitly intended for use without removing the faulty valve. The Court looked to Snyders’ patent specification, noting that it in fact expressly described the Bessler patent and the ways in which the invention overcame Bessler’s invasive valve removal. The Court reversed the Board’s determination, concluding that it was “unreasonable” to read the “size and shape” language to cover an artificial valve fitted after removal of the native valve.
Finally, the Federal Circuit addressed St. Jude’s challenge to the claims upheld by the Board in the second decision. St. Jude argued that a skilled artisan would have been motivated to combine Bessler with Johnson, which disclosed a durable artificial heart valve. The Board agreed, but found that St. Jude failed to prove that a skilled artisan would have retained the “cuff” from Bessler but replaced its valve with Johnson’s valve. The Court agreed with the Board’s finding that retaining Bessler’s cuff while removing its valve would be illogical, and that St. Jude did not provide a persuasive or adequate explanation for why an artisan would keep the cuff while replacing the valve to which it is attached.