IP Law Daily, PATENT—Fed. Cir.: New trial on lost profits ordered in powered self-balancing unicycle dispute, (Nov 17, 2025)

By Kevin M. Finson, J.D.

A district court’s decision on lost profits was reversed and remanded for a new trial because the court erred in excluding evidence of noninfringing substitutes.

A seller of self-balancing unicycles was entitled to a new trial on the issue of lost profits awarded against it for infringement of a patent owned by Inventist, Inc., the U.S. Court of Appeals for the Federal Circuit has held. The district court had improperly excluded evidence of a potential non-infringing substitute which prevented the jury from making a full decision in accordance with the applicable test (Inventist, Inc. v. Ninebot, Inc. (USA), Nos. 24-1010, 24-1267, (Fed. Cir. Nov. 14, 2025)).

Inventist, Inc. (Inventist) was the owner of U.S. Patent No. 8,807,250 (the ’250 patent), which claimed an electrically powered self-balancing unicycle. Inventist and Shane Chen, its owner, brought suit for infringement against Ninebot, Inc. (USA) and several related entities (collectively, Ninebot). After claim construction and discovery were completed the district court determined that no reasonable jury could find that Ninebot’s second-generation products infringed the ’250 patent because they lacked a key “leg contact surface” used to control the unicycle and granted summary judgment of non-infringement for those models. The court also determined at a pretrial conference that no non-infringing substitutes had been shown to be on sale during the infringement period of the first-generation products, and excluded any proposed evidence of non-infringing substitutes.

Ninebot made a proffer of evidence it would have offered at trial if allowed, and the jury returned a verdict of $835,220 in lost profits and $29,593 as a reasonable royalty. Ninebot moved for new trial, arguing there was insufficient evidence to support the jury’s finding that Inventist had complied with the statutory marking requirement. Before that motion was ruled upon, Ninebot appealed. Inventist cross-appealed, arguing that the court erred in granting summary judgment of non-infringement as to the second-generation products.

Summary judgment of non-infringement. The Federal Circuit began with Inventist’s cross-appeal, and found that the district court had properly relied on the photographs in the record to determine that the accused second-generation products lacked control surface “protruding from the side of the device” as required by the asserted claims. The cross-appeal was dismissed.

Marking requirement. Ninebot argued that there was not sufficient evidence before the district court to support the finding that Inventist had complied with the marking requirement. Inventist argued that the court lacked jurisdiction to decide the issue because the notice of appeal was filed before the trial court had ruled on Ninebot’s motion for new trial based on the same issue.

Reviewing the applicable Rules, the Federal Circuit found that Ninebot was required to have filed a new or supplemental notice of appeal within 30 days after the ruling on that motion for a new trial, and had failed to do so. The court lacked jurisdiction to consider this issue on appeal.

Lost profits. Ninebot argued that the district court erred in denying its motion for judgment as a matter of law under Federal Rule of Civil Procedure 50(a) and by excluding evidence of noninfringing substitutes at trial.

The Federal Circuit found that the Rule 50(a) issue was waived because Ninebot had failed to renew its motion under Rule 50(b) after the close of all the evidence, but that Ninebot had clearly raised and preserved the issue of evidence of noninfringing substitutes, in this case, the possibility of making a cheap and simple modification to the accused product to avoid infringement. The court found that by excluding this evidence, the district court had not given the jury the opportunity to make a complete lost profits analysis under the applicable case law.

The Federal Circuit affirmed the decision of the distrct court as to summary judgment and marking, but reversed and remanded on the issue of lost profits.

The Case is Nos. 24-1010, 24-1267.

Judge: Dyk, T.

Attorneys: Devra R. Cohen (Foster Garvey PC) for Inventist Inc. and Shane Chen. Andrew C. Aitken (Aitken Law Offices) for Ninebot Inc. [USA], d\b\a Ninebot US Inc., Ninebot [Tianjin]Technology Co., Ltd., Ninebot Inc. [China].

Companies: Inventist Inc.; Ninebot Inc. (USA), d\b\a Ninebot US Inc.; Ninebot [Tianjin] Technology Co., Ltd.; Ninebot Inc. [China]

Cases: Patent FedCirNews WashingtonNews