The US Court of Appeals for the Federal Circuit affirmed a district court’s construction of a claim, finding that the plain and ordinary meaning of a disputed term was redefined by the patentee under principles of lexicography and use of intrinsic claim construction evidence. Aortic Innovations LLC v. Edwards Lifesciences Corp., et al., Case No. 24-1145 (Fed. Cir. Oct. 27, 2025) (Prost, Reyna, Chen, JJ.)

Aortic sued Edwards Lifesciences for infringing its patents directed toward a transcatheter valve with a frame component. During claim construction, the district court determined that Aortic had acted as its own lexicographer and redefined the term “outer frame” to be “a self-expanding frame,” based on the interchangeable use of the terms “outer frame,” “self-expanding frame,” and “self-expanding outer frame” when referring to the same structure in two embodiments. Based on this construction, the parties stipulated to noninfringement of the asserted patents since Edwards’ accused valve did not have a self-expanding frame. Aortic appealed the judgment of noninfringement, challenging the district court’s construction of the claim term “outer frame.” Aortic appealed.

Aortic contended that “outer frame” should be given its plain and ordinary meaning of “positioned outside” and argued that the specification did not support limiting “outer” to require “self-expanding.” The Federal Circuit disagreed, relying on both lexicographical and specification-based grounds for its construction.

In applying principles of lexicography, the Federal Circuit reasoned that if a person of ordinary skill in the art (POSITA) would understand that two claim terms were used consistently and interchangeably throughout a patent specification, those terms may be considered definitionally equivalent. Referring to several examples, the Court observed that Aortic used “outer frame,” “self-expanding frame,” and “self-expanding outer frame” interchangeably throughout the specification when describing the frame, and concluded that “outer frame” was properly construed to require “self-expanding.”

With regard to using the specification as intrinsic claim construction evidence, the Federal Circuit reasoned that the specification consistently described the “outer frame” as a “self-expanding frame” and did not restrict that feature to a particular embodiment. From this, the Court concluded that the absence of any express exception or explanation would lead a POSITA to understand that the valve’s construction required a self-expanding outer frame in all embodiments.

Aortic alternatively argued that Edwards should be judicially estopped from arguing for a construction of “outer frame” that departed from its plain and ordinary meaning. Aortic asserted that Edwards had previously argued before the Patent Trial & Appeal Board that “outer frame” should be defined using its plain and ordinary meaning, but later adopted a contrary position in front of the district court, contending that the term referred only to a “self-expanding frame.” The Federal Circuit disagreed and explained that Aortic failed to sufficiently develop its judicial estoppel argument before the district court. Absent any exceptional circumstances, the Court concluded that Aortic had forfeited the argument.

Finding Aortic’s arguments unpersuasive, the Federal Circuit affirmed the district court’s judgment of noninfringement as to the asserted patents, upholding the district court’s construction of the disputed claim [...]

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