When patent owners prevail in Section 337 investigations before the International Trade Commission, the resulting exclusion orders can be commercially devastating. But sophisticated respondents increasingly prepare redesign strategies while the investigation is still pending, particularly where the accused functionality is controlled through firmware or software logic.
The Federal Circuit’s decision in Bissell, Inc. v. International Trade Commission, Case No. 24-1509 (Fed. Cir. May 11, 2026), illustrates how relatively narrow firmware timing modifications can successfully avoid infringement findings, even after the original products were found infringing and subjected to an exclusion order.
The case also offers several broader lessons for patent litigators and technology companies:
- the distinction between claim construction and factual infringement determinations,
- the continued difficulty of prevailing under the doctrine of equivalents,
- the deferential substantial evidence standard governing ITC appeals, and
- expert reliance on source code under Federal Rule of Evidence 703.
Charles Gideon Korrell notes that the opinion is less significant for its underlying wet/dry vacuum technology than for its broader implications regarding software redesign strategies and appellate framing in patent litigation.
The Patented Technology
The asserted patents, U.S. Patent Nos. 11,076,735 and 11,071,428, involve wet/dry floor cleaning systems with automated self-cleaning functionality.
The patents describe devices that automatically clean the brushroll while docked on a charging station. A key feature of the invention was a safeguard relating to battery charging during the self-cleaning cycle. According to the specification, allowing simultaneous charging and self-cleaning could overload the wall charger’s power capacity.
As a result, the patents required that:
- the “battery charging circuit is disabled by the actuation of the self-cleaning mode input control”; and
- the charging circuit “remains disabled during the unattended automatic cleanout cycle.”
That “remains disabled” language ultimately became the centerpiece of the appeal.
Tineco’s Redesign Strategy
Bissell filed its ITC complaint against Tineco’s original products, including the Floor One S3 and S5 Pro devices. The Commission ultimately found those original products infringed and entered a limited exclusion order.
But during the investigation itself, Tineco implemented redesigned firmware for later product versions. The redesign did not eliminate the self-cleaning cycle altogether. Instead, it altered the timing of battery charging during the 120-second automated cleanout process.
The timing diagrams reproduced in the opinion show that the redesigned products briefly activated charging twice during the cleanout cycle: once near the beginning and once again around the midpoint.
That seemingly minor firmware modification became dispositive.
The Administrative Law Judge concluded that because the battery charging circuit activated during the cycle, it no longer “remained disabled during the unattended automatic cleanout cycle.”
Accordingly, the redesigned products were found noninfringing.
Google v. EcoFactor and the Boundary Between Claim Construction and Fact Finding
The most important precedential discussion in the opinion involves the Federal Circuit’s treatment of Google LLC v. EcoFactor, Inc.
Bissell attempted to characterize the dispute as involving improper claim construction. That strategy was important because claim construction issues receive de novo review on appeal, while factual infringement findings are reviewed only for substantial evidence.
The Federal Circuit rejected Bissell’s characterization and distinguished EcoFactor directly.
In EcoFactor, the Federal Circuit had concluded that the tribunal effectively supplied substantive “scope and boundaries” for claim language where the claim text itself did not provide sufficient guidance. In Bissell, however, the panel concluded that the ALJ merely applied the ordinary meaning of the phrase “remains disabled” to the operational behavior of the redesigned products.
According to the court, no new claim construction occurred.
Instead, the ALJ simply evaluated competing infringement theories, made credibility determinations regarding expert testimony, and concluded that the redesigned products charged during the cleanout cycle.
That distinction was outcome determinative.
Because Bissell framed its appeal almost entirely as a claim construction issue, and did not substantially challenge the evidentiary sufficiency of the Commission’s factual findings, the Federal Circuit had little difficulty affirming.
Charles Gideon Korrell believes this portion of the opinion provides an important warning for appellate practitioners. Parties frequently attempt to recharacterize unfavorable factual findings as legal claim construction disputes in order to obtain de novo review. Bissell demonstrates the risk of relying too heavily on that strategy where the Federal Circuit views the dispute as ordinary application of claim language to technical facts.
Doctrine of Equivalents Also Failed
Bissell alternatively argued infringement under the doctrine of equivalents.
Again, the Federal Circuit affirmed the Commission.
The ALJ had found unpersuasive Bissell’s theory that a charging circuit which intermittently charges during the cleanout cycle was insubstantially different from a claim requiring the charging circuit to remain disabled during that cycle.
The Federal Circuit concluded this was a factual determination regarding equivalence, not a legal application of claim vitiation.
This portion of the opinion is particularly important because it underscores how difficult it can be to establish equivalence where the accused redesign intentionally reverses or negates a claimed operational requirement.
Here, the claim required charging to remain disabled. The redesign intentionally introduced charging activity into the cycle. That made the equivalence argument considerably weaker.
The opinion fits within a broader Federal Circuit trend of limiting doctrine of equivalents theories where the proposed equivalent threatens to erase meaningful claim limitations. Although the panel avoided explicitly invoking “claim vitiation” as a standalone doctrine, the practical effect was similar.
Broader Implications
Bissell v. ITC illustrates several important realities about modern patent enforcement:
First, firmware and software redesigns can be extraordinarily effective in avoiding exclusion orders where claim limitations are tied to operational timing or state transitions.
Second, parties must carefully distinguish between factual disputes and claim construction disputes on appeal. Mischaracterizing the nature of the issue can substantially narrow appellate review.
Third, doctrine of equivalents theories remain difficult where the accused redesign intentionally alters a core claimed behavior.
Finally, evidentiary attacks on expert reliance materials must often be developed aggressively at the trial level. Rule 703 gives experts considerable flexibility to rely on technical materials that are not themselves formally admitted into evidence.
For ITC practitioners especially, the case reinforces the importance of developing redesign analyses early, preserving factual appellate challenges carefully, and treating software timing logic as a potentially decisive infringement issue.
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