CAFC Reverses Indefiniteness Ruling Since Claims Meet ‘Demanding’ Standard for Judicial Correction

The U.S. Court of Appeals for the Federal Circuit (CAFC) today issued a precedential decision reversing a district court’s finding that an error in Canatex Completion Solutions, Inc.’s patent claims rendered the claims indefinite.

Canatex’s U.S. Patent No. 10,794,122, titled “Releasable Connection for a Downhole Tool String,” contains a phrase that reads “the connection profile of the second part,” which appears in all the independent claims, and should have read “the connection profile of the first part,” according to Canatex. The error also appears in the Abstract and twice in the written description. Canatex asked the district first to construe the phrase to reflect the correct meaning, but the district court refused, ultimately agreeing with the defendants, Wellmatics LLC, et. al., that the claims were invalid for indefiniteness.

According to the district court, the error was neither plainly evident or easy to correct, and the “‘pervasiveness of the error’ in both the claims and the specification suggested that the error ‘was an intentional drafting choice and not an error at all.’”

In a footnote to the CAFC opinion, the panel also noted that Canatex attempted to have the claims corrected with the U.S. Patent and Trademark Office (USPTO), but the Office “denied Canatex’s proposed correction in March 2025, stating without elaboration that the ‘corrections requested [sought] to change the scope of the patented claims.’”

On appeal, the CAFC disagreed with the district court’s analysis and reversed, finding “that it is evident that the claim contains an error and that a relevant artisan would recognize that there is only one correction that is reasonable given the intrinsic evidence.”

Because the intrinsic evidence in the case clearly established “that ‘second’ in the claim phrase could only be reasonably understood by a relevant skilled artisan to mean ‘first,’” the CAFC panel said it met the “very demanding standard” for judicial correction of a claim term.

The court said the error was best characterized as “a minor clerical or typographical error.” It also disagreed with Wellmatics’ argument that there were other reasonable corrections to consider, such as “that the device contains a ‘connection profile’ on the second part, though not so named in the figures or the specification, so that the disputed claim phrase could be corrected to retain ‘second’—presumably by changing ‘the’ to ‘a’ or by adding earlier language to the claim to provide an antecedent.”

The CAFC found “no reasonable basis” for this reading, and also rejected Wellmatics’ expert’s opinion that the errors “‘are not simply the result of a copy and paste mistake’ and are instead ‘a deliberate (yet unclear) drafting choice’ because ‘the language differs between some of the instances.’” The expert pointed to slight differences in the wording in the patent, such as “the connection profile of the second part” compared with another instance in which the language reads “connection profile 16 of second part 14.”

“This slight difference in wording cannot reasonably be thought significant,” wrote the CAFC, noting that the only change is in the addition of numbers corresponding to aspects of the figures in the patent. The panel also rejected the defendants’ alternative corrections as either not substantively different from the changing “second” to “first” or altering the meaning of the claims too substantively.

Finally, the CAFC distinguished the case from Chef America, Inc. v. Lamb-Weston, Inc., 358 F.3d 1371, 1374–75 (Fed. Cir. 2004), in which the court declined to apply judicial correction, because there, the prosecution history supported the construction in dispute. Here, said the court, “the district court did not conclude, and defendants make no convincing argument to us in their brief, that the prosecution history in this case precludes correction if, as we have concluded, the error at issue is evident on the face of the patent and the proposed correction is the only reasonable one based on the claims and specification.”

The district court’s decision was therefore reversed and the case remanded for proceedings based on the corrected claims.

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Author: almoond