Appellate deference: Reinforcing limits on reweighing evidence

By on May 21, 2026
Posted In Patents

Clarifying the proper scope of appellate review, the US Court of Appeals for the Federal Circuit affirmed an International Trade Commission final determination in full. The Court upheld the scope of the exclusion of only certain accused products and permitted importation of redesigned versions, concluding that the Commission correctly viewed the evidence and claim terms. Bissell, Inc. v. ITC, Case No. 24-1509 (Fed. Cir. May 11, 2026) (Moore, Taranto, Stoll, JJ.)

Bissell initiated a Section 337 investigation alleging that Tineco Intelligent imported wet/dry surface-cleaning devices that infringed Bissell’s patents. Following an evidentiary hearing, the administrative law judge (ALJ) found infringement of Tineco’s original products and recommended exclusion but concluded that Tineco’s redesigned products did not infringe and therefore fell outside the scope of relief.

The Commission affirmed the ALJ’s determination, which resulted in a limited exclusion order directed to the infringing products only. Both parties appealed.

Bissell challenged the finding that Tineco’s redesigned products did not literally infringe a limitation requiring that “the battery charging circuit is disabled” during the “self-cleaning mode . . . and remains disabled during the . . . cleanout cycle.” Tineco modified its products so that some battery charging did occur during a “self-cleaning mode,” but battery charging was disabled for most of the cleaning cycle. Before the ALJ, Bissell’s expert opined that infringement of this claim essentially only required a period in which self-cleaning occurred and while the battery charger was disabled. The ALJ rejected Bissell’s theory, determining that the claim required the battery charger to “remain[] disabled during the . . . cleanout cycle.”

According to Bissell, the ALJ’s conclusion amounted to improper claim construction. The Federal Circuit disagreed, finding that the ALJ had merely applied the plain and ordinary meaning of the claim term. As Bissell had not disputed that the ALJ’s findings were supported by substantial evidence, the Federal Circuit affirmed these findings.

Tineco cross-appealed the ALJ’s determination that Bissell’s domestic industry products satisfied the disabled battery limitation. According to Tineco, the evidence was inadequate to support the ALJ’s determination because the source code that Bissell’s expert relied on was never produced during the Commission trial.

The Federal Circuit found that Bissell’s expert testimony was sufficient under Federal Rule of Evidence 703, which permits experts to rely on facts or data they have been made aware of or personally observed, even if those materials are not themselves admissible, as long as they are of a type reasonably relied upon in the field. The Court emphasized that neither party disputed that experts in this context routinely rely on source code to assess infringement. The Court further concluded that substantial evidence supported the ALJ’s determination, highlighting that:

  • The source code had been produced during discovery.
  • The expert’s opinions were not conclusory.
  • Tineco did not meaningfully test the testimony through cross-examination or offer competing expert analysis.
  • The ALJ’s findings were independently corroborated by a Bissell internal document admitted at trial.

Practice note: Where the Commission uses the “face of the claim to discern the scope and boundaries” of the plain and ordinary meaning, a litigant may not challenge the Commission on appeal for engaging in improper claim construction. Additionally, since Federal Rule of Evidence 703 applies in Commission determinations, expert testimony is sufficient even when supported only by inadmissible or unadmitted evidence. Litigants wishing to challenge expert testimony on such a basis should do so through cross-examination or the presentation of countervailing testimony at trial.

Ian J. Howard
Ian J. Howard focuses his practice on intellectual property litigation matters. Read Ian Howard's full bio.

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