Earlier this week in Bissell, Inc. v. International Trade Commission, the Federal Circuit affirmed the ITC’s determination that Tineco’s original wet/dry surface cleaning devices infringed Bissell’s patents and were properly subject to a limited exclusion order. But Tineco managed to stay one step ahead of the ban by redesigning its products after the investigation began, and the Federal Circuit confirmed that those redesigned products are in the clear. In doing so, the decision addresses several issues of practical significance: the boundaries of claim language in the context of software-implemented features, the scope of expert reliance on undisclosed source code, and the standards for challenging fact findings as legal errors on appeal.
Background
Bissell Inc. owns U.S. Patent Nos. 11,076,735 and 11,071,428, which share a specification and relate to wet/dry floor cleaning systems that feature an automated self-cleaning mode. The key innovation at issue in the Bissell patents is the relationship between the self-cleaning cycle and the battery charging circuit of the device. The specification explains that disabling the battery charging circuit during the self-cleaning mode is “beneficial because if the battery charging circuit [] is not disabled and power not supplied by the battery [] during the self-cleaning mode, the capacity of the wall charger [] can be exceeded.” Claim 1 of the ’735 patent captures this concept directly, requiring that “the battery charging circuit is disabled by the actuation of the self-cleaning mode input control and remains disabled during the unattended automatic cleanout cycle.” During the dispute, the parties referred to the italicized portion as the “disabled battery limitation.”
Bissell filed a Section 337 complaint at the ITC alleging that Tineco’s Floor One S3 and Floor One S5 Pro products infringed claims 1, 13, and 15 of the ’735 patent and claim 1 of the ’428 patent. After the investigation was instituted, Tineco introduced redesigned versions of the accused products with altered source code. Following an evidentiary hearing, the Administrative Law Judge (ALJ) issued an Initial Determination finding that Tineco’s original products infringed the asserted claims but that the redesigned products did not — because the redesigned products’ battery charging circuit did not meet the disabled battery limitation required by the claims. In particular, timing diagrams showed that Tineco’s redesigned products charge twice during the 120-second self-cleaning period. The Commission adopted the ALJ’s findings and entered a limited exclusion order covering only the original accused products.
Bissell’s Challenge for the Redesigned Products
Bissell appealed the finding that Tineco’s redesigned products do not infringe the disabled battery limitation, both literally and under the doctrine of equivalents. In both instances, Bissell tried to reframe fact findings as legal errors — a strategy the Federal Circuit rejected.
Bissell first argued that the ALJ had implicitly construed the disabled battery limitation for the first time in the Initial Determination and that this construction was erroneous. The Federal Circuit was not persuaded. Reviewing the Initial Determination, the appellate panel found that the ALJ simply applied the plain and ordinary meaning of the claim language, made credibility determinations regarding Bissell’s expert (finding his testimony neither “credible nor persuasive”), and concluded that the redesigned products do not complete a cleanout cycle during which the battery charging circuit remains off.
The panel distinguished this case from its 2024 decision in Google LLC v. EcoFactor, Inc., 92 F.4th 1049 (Fed. Cir. 2024), where the Federal Circuit had found that the tribunal “established the scope of [a] limitation” when “there [was] nothing on the face of the claim to discern the scope and boundaries” imposed by the tribunal. Here, the panel explained that no such construction occurred; rather, the ALJ simply applied what the claim language plainly says. Because Bissell conceded at oral argument that it was only challenging literal infringement as a matter of claim construction — and did not separately argue that the Commission’s fact findings lacked substantial evidence — the Federal Circuit found no basis to disturb the no-infringement finding.
Bissell’s doctrine of equivalents argument fared no better. Bissell contended that the ALJ relied on the legal doctrine of claim vitiation rather than applying the insubstantial differences test under Warner-Jenkinson. The Federal Circuit rejected this framing. The ALJ found Bissell’s expert unpersuasive in opining “that a battery circuit that does the opposite [of what the claim requires] (i.e., a battery circuit that charges during an automatic cleanout cycle) is insubstantially different from the claim.” While the ALJ also stated that the expert’s “opinion renders meaningless the ‘remains disabled’ requirement,” the Federal Circuit read these two observations together as a coherent factual analysis — not a legal shortcut. The panel emphasized that the ALJ’s analysis “summarized the parties’ positions, considered Bissell’s expert’s opinion, and explained that that opinion was unpersuasive” and was not “legally inadequate.”
Once again, Bissell failed to challenge the underlying fact findings as lacking substantial evidence in its opening brief, which proved fatal on appeal. As the Federal Circuit noted, “[b]ecause Bissell does not dispute that the Administrative Law Judge’s fact findings are supported by substantial evidence in its opening brief . . . we affirm the Commission’s finding of no infringement under the doctrine of equivalents.”
The Cross-Appeal: Tineco’s Three-Pronged Challenge
Tineco cross-appealed three issues: (1) whether Bissell’s domestic industry products satisfy the disabled battery limitation; (2) whether all of Tineco’s accused products meet the brushroll limitation; and (3) whether all of Tineco’s accused products satisfy the suction nozzle limitation. The Federal Circuit affirmed all three.
Tineco’s most interesting argument on cross-appeal was procedural. Tineco contended that Bissell’s expert could not rely on source code that was produced during discovery but never introduced as an exhibit at the evidentiary hearing to support his opinion that Bissell’s domestic industry products satisfy the disabled battery limitation. The Federal Circuit disagreed, relying on Federal Rule of Evidence 703, which permits experts to base opinions on facts or data they were made aware of — even if those facts or data are not themselves admitted into evidence — as long as experts in the field would reasonably rely on such materials. The court found all the relevant factors satisfied: (1) the source code was produced in discovery; (2) Bissell’s expert reviewed it and relied on it to conclude that Bissell’s domestic industry products satisfied the disabled battery limitation; (3) experts in this field would reasonably rely on source code to understand the operation of the domestic industry products; and (4) Tineco never provided expert opinions or theories contrary to Bissell’s expert’s opinions on the issue. In fact, Tineco never challenged this limitation in its prehearing brief and did not cross-examine Bissell’s expert on the issue at the hearing.
The court also pointed to a corroborating internal Bissell document in the record stating that “[c]harging starts [in Bissell’s product] once the machine is placed onto the plugged-in dock. Charging stops once the Clean Out Cycle runs, then resumes once the cycle completes” — consistent with the disabled battery limitation. Together, Bissell’s expert’s testimony and this corroborating document constituted substantial evidence of technical domestic industry.
Tineco’s challenges to the brushroll and suction nozzle limitations were more straightforward, and both failed under the substantial evidence standard. On the brushroll limitation — requiring “a brushroll within the recovery pathway of the recovery system” — the ALJ found the limitation met under both parties’ competing interpretations of “recovery pathway.” Even under Tineco’s narrower view, the ALJ relied on Tineco’s own expert testimony and demonstratives. Specifically, Tineco’s expert conceded that a brushroll at least 50% inside the recovery pathway satisfies the “within” requirement — and Tineco’s own demonstrative showed “no material difference[] . . . between a brushroll that is 50% ‘inside of’ the recovery pathway and the brushrolls of the accused products.” Under the substantial evidence standard, which merely asks whether “a reasonable mind might accept a particular evidentiary record as adequate to support” a fact finding, the Federal Circuit declined to second-guess the ALJ’s reasonable inference from evidence that Tineco itself put before the tribunal.
On the suction nozzle limitation — requiring that the suction nozzle “is configured to extract fluid and debris from the brushroll” — the ALJ relied on Tineco’s own expert, who conceded that the suction nozzle draws fluid and debris off the metal blade and off the floor. From that concession, the ALJ reasonably inferred that “it was more probable than not that the suction nozzle could also suction fluid and debris off the brushroll, which is between the suction nozzle and the floor.” The ALJ also relied on an experiment performed by Bissell’s expert demonstrating that the suction nozzle, when the metal blade was removed, was powerful enough to extract fluid and debris directly from the brushroll. The Federal Circuit concluded that the ALJ’s finding “was not based on mere speculation but rather on substantial evidence.”
The Takeaways
- Design-arounds work — if they are genuinely different. Tineco escaped the exclusion order by altering its source code so that the battery charging circuit re-enabled twice during the self-cleaning cycle. That change, while seemingly minor, was enough to take the redesigned products outside the literal scope of the claims. The message for respondents facing ITC investigations is that targeted, well-documented redesigns can be an effective tool for limiting exposure under an exclusion order, provided the redesign addresses the specific claim limitation at issue.
- Framing a factual dispute as a legal error will not unlock de novo review. Both of Bissell’s appeals — on literal infringement and the doctrine of equivalents — were undercut by the same strategic misstep: Bissell challenged the Commission’s findings as matters of claim construction and claim vitiation rather than engaging directly with the factual record. A party seeking to overturn an infringement (or non-infringement) finding must engage with the substantial evidence standard, or risk having the challenge dismissed as a repackaged legal argument.
- Source code does not need to be formally introduced as an exhibit for an expert to rely on it. The appellate panel’s application of Federal Rule of Evidence 703 confirms that experts in patent cases may rely on source code produced in discovery to form opinions, even if the code is not formally admitted into evidence, as long as practitioners in the field would reasonably do so. That said, formal admission remains the safer practice — both to preclude challenges like Tineco’s and to give the factfinder direct access to the supporting materials, especially when source code is central to proving infringement or domestic industry.
- Expert concessions are fair game. In both the brushroll and suction nozzle analyses, the ALJ and the Federal Circuit relied heavily on testimony and demonstratives from Tineco’s own expert to support findings against Tineco. Litigants preparing expert witnesses should carefully review any concessions that could be weaponized by opposing counsel, as those concessions can — and in this case did — provide substantial evidence for the very findings a party is trying to defeat.
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