Opinions — Wednesday, May 13, 2026

The Federal Circuit affirmed the Patent Trial and Appeal Board's final written decision that claims 1–6, 12, and 15–18 of Universal Electronics' U.S. Patent No. 9,847,083 are unpatentable as obvious. The appeal turned entirely on claim construction of the term "the provisioned codeset record comprising protocol and formatting information." Universal argued the term required all protocol and formatting information to be contained and stored in the codeset record itself and that "information" meant "a set of procedures," while the Board construed it more broadly as "information needed to transmit a signal from one device to another in a way that the receiving device can make sense of and use the signal."

The court applied de novo review to the claim construction question but reviewed the Board's factual findings based on extrinsic evidence for substantial evidence. The court's analysis focused on the claim language using "comprising" without requiring all protocol and formatting information be in the codeset record, rejecting Universal's attempt to import an "all" limitation and to narrow "information" to "a set of procedures." The specification similarly used permissive language ("may comprise") and provided only examples of protocol and formatting information without restricting the scope, and the court found the opponent's expert testimony did not support Universal's narrower construction. Because the court adopted the Board's construction, it affirmed the obviousness determination without separate analysis of that merits question.

The Federal Circuit affirmed the district court's finding of non-infringement of U.S. Patent Nos. 8,318,802 and 8,598,227, owned by Actelion Pharmaceuticals Ltd, in an ANDA litigation brought under 35 U.S.C. § 271(e)(2) against Mylan Pharmaceuticals Inc. The patents claim lyophilized epoprostenol pharmaceutical compositions formed from a bulk solution having "a pH of 13 or higher." The district court construed this phrase to require pH measurement at standard temperature (25±2°C) rather than at the bulk solution's actual operating temperature during manufacture, as Actelion argued. Applying Teva's framework, the Federal Circuit reviewed the ultimate claim construction de novo and subsidiary factual findings based on extrinsic evidence for clear error. The court held that the specification's implicit assumption that pH measurements are taken at standard temperature—evidenced by its definition of "alkaline environment" as "pH>7" (accurate only at standard temperature) and its straightforward comparative tables without accommodation for varying measurement temperatures—supported the district court's construction. The court also affirmed that Actelion was barred from asserting infringement under the doctrine of equivalents based on both prosecution history estoppel (Actelion narrowed the pH range during prosecution in response to an obviousness rejection) and the disclosure-dedication rule (the specification disclosed but did not claim pH ranges below 13).

The decision reinforces that claim terms lacking explicit conditions must be construed according to what a person of ordinary skill would understand as the ordinary meaning, informed by both intrinsic and extrinsic evidence of industry standards. The court's reliance on the specification's implicit assumptions—particularly the definition of alkaline pH that is accurate only under standard conditions—demonstrates how contextual clues within the patent document can resolve ambiguities about measurement conditions even when not explicitly stated. The ruling on prosecution history estoppel confirms that narrowing amendments to overcome prior art rejections surrender subject matter as equivalents, precluding patentees from recapturing through the doctrine of equivalents what was deliberately excluded during prosecution. The application of the disclosure-dedication rule further cabins the doctrine of equivalents where the specification describes but does not claim particular variations, treating such disclosures as dedicating the unclaimed matter to the public.