Opinions — Thursday, September 17, 2026

The Federal Circuit vacated and remanded the PTAB's affirmance of an obviousness rejection of claim 1 of Incept LLC's patent application directed to a medical catheter with an anchoring strain relief member. The central dispute concerned construction of the claim term "flow barrier," which the claim recited as forming "between the catheter outer surface along a circumference at the ridge and the top of that ridge." The Board had adopted the examiner's construction that any solid structure positioned somewhere between those two points satisfied the limitation, and on that basis found the prior art reference (Thomspon Smith) disclosed all claim elements except a specific taper angle, making the claim obvious.

The court held that the Board's construction was unreasonably broad under the broadest reasonable interpretation standard. Applying general claim construction principles, the court found that the claim language itself—requiring each ridge to "form" a flow barrier "between" two specified points—and the specification's repeated description of the invention as providing sealing capability through a fluid-tight connection between the strain relief member and an elastomeric valve required the flow barrier to actually block flow across that span. The court construed "flow barrier" as "a solid surface that spans from the catheter outer surface to the top of the ridge along a circumference at the location of the ridge," rejecting the Director's argument that this improperly imported functional limitations, and remanded for reconsideration of obviousness under the corrected construction.

The Federal Circuit affirmed the district court's award of $3.2 million in attorney fees and expenses to defendant Fenix Diamonds LLC under 35 U.S.C. § 285 and the court's inherent power, and also affirmed the denial of pre-judgment interest. Carnegie Institution of Washington had sued Fenix for infringement of two patents covering lab-grown diamond manufacturing methods, but the district court granted summary judgment of non-infringement and later determined the case exceptional based on plaintiffs' objectively baseless infringement positions following claim construction and discovery showing extensive non-monocrystalline growth in the accused process.

The court applied abuse of discretion review to all aspects of the § 285 determination and affirmed on the ground that plaintiffs' infringement theory became objectively baseless after the district court's claim construction order and defendant's production of manufacturing evidence from its Indian supplier. The court analogized to AdjustaCam and Taurus IP, where infringement positions that contradicted or ignored claim constructions supported exceptional case findings. Here, the claims as construed required only "insubstantial" non-monocrystalline growth, but the evidence showed "extensive" such growth that plaintiffs' own expert conceded was polycrystalline material—a position the district court found "flatly at odds" with the constructions, supporting fee-shifting from the point the infringement theory became untenable.