Inventist Inc., Shane Chen v. Ninebot Inc. (usa), Dba Ninebot Us Inc., Ninebot (tianjin) Technology Co., Ltd.,…

N OTE: This disposition is nonprecedential.
United States Court of Appeals
for the Federal Circuit
______________________
INVENTIST INC., SHANE CHEN,
Plaintiffs-Cross-Appellants
v.
NINEBOT INC. (USA), DBA NINEBOT US INC.,
NINEBOT (TIANJIN) TECHNOLOGY CO., LTD.,
NINEBOT INC. (CHINA),
Defendants-Appellants
______________________
2024-1010, 2024-1267
______________________
Appeals from the United States District Court for the
Western District of Washington in No. 3:16-cv-05688-BJR,
Senior Judge Barbara Jacobs Rothstein.
______________________
Decided: November 14, 2025
______________________
D EVRA R. COHEN, Foster Garvey PC, Seattle, WA, ar-
gued for plaintiffs-cross-appellants. Also represented by
BENJAMIN J AMES HODGES .
ANDREW C. A ITKEN, Aitken Law Offices, Bethesda, MD,
argued for defendants-appellants.
______________________
Case: 24-1010 Document: 83 Page: 1 Filed: 11/14/2025

-- 1 of 12 --

INVENTIST INC. v. NINEBOT INC. ( USA) 2
Before D YK, HUGHES , and STARK, Circuit Judges.
D YK, Circuit Judge.
Inventist, Inc. and Shane Chen (collectively, “Invent-
ist”) sued Ninebot Inc. (USA) and its affiliates (collectively,
“Ninebot”) for infringement of U.S. Patent No. 8,807,250
(the “’250 patent”). Ninebot appeals a judgment of in-
fringement awarding lost profits and a reasonable royalty
on the grounds that Inventist failed to mark its products as
required by 35 U.S.C. § 287(a) and that Ninebot’s evidence
of noninfringing substitutes was improperly excluded on
the issue of lost profits. Inventist cross appeals the district
court’s grant of summary judgment of noninfringement as
to the second generation of Ninebot’s products. We affirm
the district court’s summary judgment grant as to the sec-
ond-generation products, dismiss Ninebot’s appeal of the
district court’s denial of its new trial motion related to the
marking issue for lack of jurisdiction, and conclude that a
new trial is required on the issue of lost profits because the
district court erred in excluding evidence of noninfringing
substitutes. We accordingly dismiss in part, affirm in part,
reverse in part, vacate in part, and remand.
BACKGROUND
Inventist owns the ’250 patent, which issued on Au-
gust 19, 2014. Shane Chen is the inventor of the ’250 pa-
tent and the principal owner of Inventist. The ’250 patent
discloses an electrically powered self-balancing unicycle.
To allow a user to ride the claimed unicycle while standing,
the unicycle “is controlled by gripping the device with the
legs.” ’250 patent, col. 2, ll. 23–27. The user’s legs grip on
to leg contact surfaces that “protrude slightly from the
sides of the device, to the extent that they come into contact
with the legs while the user is standing in a natural up-
right stance with his feet upon the foot platforms.” Id.,
col. 2, ll. 14–18.
Claim 1 provides:
Case: 24-1010 Document: 83 Page: 2 Filed: 11/14/2025

-- 2 of 12 --

INVENTIST INC. v. NINEBOT INC. ( USA) 3
A powered unicycle device, comprising:
a single wheel having an axis of rotation
and defining a central vertical plane in the
line of direction of travel that is rotatably
coupled to a seatless frame;
a motor which drives the wheel;
an electronic fore-and-aft balance control
system which controls said motor;
first and second foot platforms coupled to
the frame and each having a standing sur-
face that is below the axis of rotation of the
wheel;
a first leg contact surface that in its en-
tirety extends substantially longitudinally
in the line of travel of the device and is con-
figured to be readily contactable by the side
of a user’s leg, at or below the knee, when
that user is standing on the first foot plat-
form; and
a second leg contact surface that in its en-
tirety extends substantially longitudinally
in the line of travel of the device and is con-
figured to be readily contactable by the side
of a user’s leg, at or below the knee, when
that user is standing on the second foot
platform;
wherein the first and second foot platforms
extend in a direction perpendicular to the
central vertical plane of the wheel further
than the contact surfaces extend perpen-
dicular to the central vertical plane, and
further wherein the leg contact surfaces
are configured so as to not substantially en-
circle a user’s leg.
Case: 24-1010 Document: 83 Page: 3 Filed: 11/14/2025

-- 3 of 12 --

INVENTIST INC. v. NINEBOT INC. ( USA) 4
’250 patent, claim 1.1
On August 4, 2016, Inventist sued Ninebot in the West-
ern District of Washington, alleging Ninebot’s unicycles in-
fringed at least claim 1 of the ’250 patent. Chen was later
joined as a plaintiff. Following claim construction and the
close of discovery, the district court determined that no rea-
sonable jury could find that Ninebot’s second-generation
unicycles included “leg contact surface[s],” and thus
granted Ninebot’s noninfringement summary judgment
motion for the second-generation models.2
Ninebot also moved for summary judgment on Invent-
ist’s lost profits damages, arguing Inventist could not make
the required showing under Panduit of the absence of non-
infringing substitutes. J.A. 151–54 (citing Panduit Corp.
v. Stahlin Bros Fibre Works, Inc., 575 F.2d 1152, 1156
(6th Cir. 1978)).3 The district court denied Ninebot’s mo-
tion. Following a pretrial conference on July 25, 2023, the
district court ruled “[n]o non-infringing substitutes hav[e]
been shown to be available for sale during the infringement
period,” and excluded “any proposed evidence” of “[n]on-in-
fringing substitutes not on sale during period of infringe-
ment.” J.A. 30–31.
1 Claim 18 similarly requires “first and second leg
contact members that each, in its entirety, extends sub-
stantially longitudinally in the line of travel of the device
and is configured to be readily contactable by the side of a
user’s leg, at or below the knee, when that user is standing
on the foot platforms.” ’250 patent, claim 18.
2 The district court also determined the first-genera-
tion Ninebot unicycles infringed the ’250 patent as a mat-
ter of law. Ninebot does not challenge this ruling on
appeal.
3 Citations to the J.A. refer to the Corrected Joint
Appendix filed by the parties in this case. Dkt. No. 56.
Case: 24-1010 Document: 83 Page: 4 Filed: 11/14/2025

-- 4 of 12 --

INVENTIST INC. v. NINEBOT INC. ( USA) 5
The case proceeded to a jury trial on August 14, 2023,
to determine Inventist’s entitlement to damages, including
lost profits. Before the close of evidence, Ninebot again ar-
gued that it should be permitted to introduce evidence of
noninfringing substitutes and made an offer of proof. It
argued that “we sought to have our witness explain how he
could have altered a first-generation product fairly eas-
ily . . . so it would no longer have . . . protruding leg contact
surfaces, and we were precluded from providing that evi-
dence in the pretrial order.” J.A. 905. The district court
ruled, “[W]e’re going to continue with the case in the pre-
sent form the way it is,” and told Ninebot’s counsel, “I think
you have made your offer of proof.” J.A. 907. In instructing
the jury, the district court did not include either of the par-
ties’ proposed instructions about the absence of noninfring-
ing substitutes. The jury awarded Inventist $835,220 in
lost profits and $29,593 as a reasonable royalty.
After the verdict, Ninebot moved for a new trial, argu-
ing there was not legally sufficient evidence to support the
jury’s finding that Inventist complied with the marking re-
quirement of 35 U.S.C. § 287. J.A. 591.
On September 21, 2023—one day after filing its motion
for new trial—Ninebot appealed. Inventist timely filed a
cross appeal. Thereafter, the district court denied
Ninebot’s motion for new trial. Ninebot did not file a sup-
plemental notice of appeal.
We have jurisdiction under 28 U.S.C. § 1295(a). The
parties dispute whether Ninebot’s notice of appeal is suffi-
cient to cover the denial of Ninebot’s new trial motion.
D ISCUSSION
I
We first address Inventist’s cross appeal of the district
court’s summary judgment order that the second-genera-
tion Ninebot unicycles do not infringe the ’250 patent
Case: 24-1010 Document: 83 Page: 5 Filed: 11/14/2025

-- 5 of 12 --

INVENTIST INC. v. NINEBOT INC. ( USA) 6
because they do not satisfy the leg contact surfaces limita-
tion of claims 1 and 18.
The parties agreed that the claim terms “leg contact
surface” and “leg contact members” are “a surface, which
protrudes from the sides of the device, and which may come
into contact with a user’s leg, enabling the user to hold the
device in place with the lower leg.” J.A. 129. Under the
district court’s agreed claim construction, Inventist was re-
quired to show that a reasonable jury could find that a com-
ponent of the second-generation Ninebot unicycle
“protrudes from the sides of the device.” Id. The district
court concluded that the second-generation Ninebot unicy-
cles do not infringe as a matter of law because they “do not
possess anything that could be construed by a reasonable
observer as ‘protrud[ing] from the sides of the device.’”
J.A. 21 (alteration in original).
Primarily relying on photographs of the second-gener-
ation Ninebot unicycles, Inventist argues that whether
these models have “leg contact surfaces” was a question of
fact for the jury to decide.4
4 The plates where the users rest their feet in the be-
low pictures are the claimed “foot platforms.” ’250 patent,
claim 1. Neither Inventist nor Ninebot allege these compo-
nents are “leg contact surfaces.”
Case: 24-1010 Document: 83 Page: 6 Filed: 11/14/2025

-- 6 of 12 --

INVENTIST INC. v. NINEBOT INC. ( USA) 7
J.A. 180.
J.A. 220.
Case: 24-1010 Document: 83 Page: 7 Filed: 11/14/2025

-- 7 of 12 --

INVENTIST INC. v. NINEBOT INC. ( USA) 8
Notably, the specification differentiates the “leg con-
tact surfaces 350” and a “casing [wheel cover] 360.” E.g.,
’250 patent, col. 5, ll. 19–23. Figure 6 discloses these fea-
tures.
’250 patent, fig. 6. The photographs do not show a surface
“protruding from the sides of the device,” but rather a
rounded wheel cover, which corresponds to a “casing 360.”
We see no error in the district court’s conclusion that no
reasonable jury could find that the second-generation
Ninebot unicycles have leg contact surfaces that satisfy the
construed claims.
II
A
On the main appeal, Ninebot, while not contesting in-
fringement with respect to the first-generation unicycle,
claims that a new trial is required because the evidence
was insufficient to establish marking of Inventist’s
Case: 24-1010 Document: 83 Page: 8 Filed: 11/14/2025

-- 8 of 12 --

INVENTIST INC. v. NINEBOT INC. ( USA) 9
products in compliance with 35 U.S.C. § 287(a).5 Inventist
argues that we do not have jurisdiction over Ninebot’s new
trial motion because Ninebot did not amend its notice of
appeal to include the district court’s later ruling on the new
trial motion.
“If a party files a notice of appeal after the court an-
nounces or enters a judgment—but before it disposes of any
motion listed in Rule 4(a)(4)(A) [including a motion for new
trial]—the notice becomes effective to appeal a judgment or
order, in whole or in part, when the order disposing of the
last such remaining motion is entered.” Fed. R. App.
P. 4(a)(4)(B)(i). But “[a] party intending to challenge an or-
der disposing of any motion listed in Rule 4(a)(4)(A) . . .
must file a notice of appeal, or an amended notice of ap-
peal—in compliance with Rule 3(c)—within the time pre-
scribed by this Rule measured from the entry of the order
disposing of the last such remaining motion.” Fed. R. App.
P. 4(a)(4)(B)(ii). “The authorities point to a single conclu-
sion: When an appellant challenges an order ruling on a
motion governed by Appellate Rule 4(a)(4)(B)(ii), a new or
amended notice of appeal is necessary even if the issue
raised in the motion and sought to be challenged could also
have been challenged in an appeal from the final judg-
ment.” Husky Ventures, Inc. v. B55 Invs., Ltd., 911 F.3d
1000, 1010 (10th Cir. 2018); see also Texas Peanut Farmers
v. United States, 409 F.3d 1370, 1375 (Fed. Cir. 2005);
United States v. McGlory. 202 F.3d 664, 668 (3d Cir. 2000)
(en banc). Without an amended or additional notice of
5 Inventist cross appeals the district court’s decision
to allow Ninebot to present evidence related to marking to
the jury. This is not a proper cross appeal because success
on this issue would not expand the scope of the judgment.
TypeRight Keyboard Corp. v. Microsoft Corp., 374 F.3d
1151, 1157 (Fed. Cir. 2004).
Case: 24-1010 Document: 83 Page: 9 Filed: 11/14/2025

-- 9 of 12 --

INVENTIST INC. v. NINEBOT INC. ( USA) 10
appeal addressing the new trial motion, we lack jurisdic-
tion to consider it.
III
Finally, we address Ninebot’s arguments related to the
lost profits award. Ninebot challenges the lost profits
award in two aspects. First, Ninebot argues that the lost
profits award cannot be sustained because “the district
court’s acceptance of Inventist’s flawed lost profit theory
was unsupported by the evidence and contrary to well es-
tablished law.” Appellant’s Br. 32. Although Ninebot
made a Rule 50(a) motion for judgment as a matter of law
related to lost profits, it did not file a Rule 50(b) motion af-
ter the verdict, nor did it file a motion for new trial on this
ground. There is therefore “no basis for review” of these
arguments. Unitherm Food Sys., Inc. v. Swift-Eckrich,
Inc., 546 U.S. 394, 407 (2006).
Second, Ninebot argues that the lost profits award can-
not stand because the district court improperly excluded
evidence of noninfringing substitutes. Ninebot clearly
raised and preserved the noninfringing substitutes issue.6
To be awarded lost profits, a patentee must establish a
prima facie case that “but for” the infringer’s sales, the pa-
tentee would have received the claimed lost profits. Rite-
Hite Corp. v. Kelley Co., Inc., 56 F.3d 1538, 1545 (Fed. Cir.
1995). As Inventist attempted to do here, a patentee may
prove but-for causation by providing proof of each of the
four Panduit factors: “(1) demand for the patented product;
6 Ninebot presented its noninfringing substitute ar-
guments throughout its summary judgment briefing, in the
joint pretrial statement, and at trial. During trial, when
Ninebot’s counsel explained why its evidence of noninfring-
ing substitutes was proper during trial, the district court
judge responded, “I think you have made your offer of proof,
and that’s enough.” J.A. 907.
Case: 24-1010 Document: 83 Page: 10 Filed: 11/14/2025

-- 10 of 12 --

INVENTIST INC. v. NINEBOT INC. ( USA) 11
(2) absence of acceptable non-infringing substitutes;
(3) manufacturing and marketing capability to exploit the
demand; and (4) the amount of the profit it would have
made.” Id. (citing Panduit, 575 F.2d at 1156).
The district court excluded “any proposed evidence” of
“[n]on-infringing substitutes not on sale during period of
infringement” and did not instruct the jury about the sec-
ond Panduit factor. J.A. 31. Under our precedent in Grain
Processing Corp. v. American Maize-Products Co., 185 F.3d
1341, 1349 (Fed. Cir. 1999), the noninfringing substitutes
need not be on sale. Evidence of “available alternatives—
including but not limited to products on the market”—may
be used “to preclude lost profits damages.” Id. We held
that under Panduit, “[t]he ‘but for’ inquiry . . . requires a
reconstruction of the market, as it would have developed
absent the infringing product, to determine what the pa-
tentee would . . . have made.” Id. at 1350 (internal quota-
tion marks omitted; second omission in original). This
means that just as a patentee engages in a “hypothetical
enterprise” to construct its lost profits model, “alternative
actions the infringer foreseeably would have undertaken
had he not infringed” must also be taken into account. Id.
at 1350–51. Thus, “an available technology not on the mar-
ket during the infringement can constitute a noninfringing
alternative.” Id. at 1351 (citing Slimfold Mfg. Co.
v. Kinkead Indus., Inc., 932 F.2d 1453 (Fed. Cir. 1991)); see
also Siemens Med. Sols. USA, Inc. v. Saint-Gobain Ceram-
ics & Plastics, Inc., 637 F.3d 1269, 1288–89 (Fed. Cir.
2011). We agree with Ninebot that the district court erred
in applying the wrong legal standard. Indeed, Inventist
conceded at oral argument that the district court applied
the wrong legal standard. Oral Arg. at 16:49–17:10.
However, Inventist contends that under the correct
standard, Ninebot did not show that its proposed nonin-
fringing substitute could be readily commercialized, as re-
quired by Grain Processing. In its summary judgment
motion, Ninebot argued that first-generation models could
Case: 24-1010 Document: 83 Page: 11 Filed: 11/14/2025

-- 11 of 12 --

INVENTIST INC. v. NINEBOT INC. ( USA) 12
be modified to become noninfringing through a “simple de-
sign change, namely removing the pads from the lateral
side cover,” and referred the Court to its later unicycle
models. J.A. 152. In the first joint pretrial statement,
Ninebot offered several witnesses who would testify:
[P]urpose of protruding pad was just a battery
cover. Cost of wheel cover was minimal. About
$20.00–30.00 US.
J.A. 343, accord. J.A. 344. Contrary to Inventist, no more
detailed offer of proof was required. Fed. R. Evid. 103(b)
(“Once the court rules definitively on the record—either at
or before trial—a party need not renew an objection or offer
of proof to preserve a claim of error for appeal.”); see also
Micro Chem., Inc. v. Lextron, Inc., 317 F.3d 1387, 1391
(Fed. Cir. 2003). This evidence, if credited by a jury, could
have been sufficient to establish the existence of nonin-
fringing substitutes, which would have defeated the lost
profits claim, and Ninebot is entitled to a new trial.
CONCLUSION
On the cross appeal, we affirm the district court’s rul-
ing that the second-generation Ninebot unicycles do not in-
fringe the ’250 patent. On the main appeal, we dismiss
Ninebot’s arguments related to its new trial motion for lack
of jurisdiction and reverse the district court’s exclusion of
Ninebot’s evidence of noninfringing substitutes because it
applied an incorrect legal standard to its evidentiary rul-
ing. Accordingly, we affirm the royalty award, vacate the
lost profits award, and remand to the district court for fur-
ther proceedings consistent with this opinion.
DISMISSED-IN-PART, AFFIRMED-IN-PART,
REVERSED-IN-PART, VACATED-IN-PART, AND
REMANDED
COSTS
Costs to Ninebot.
Case: 24-1010 Document: 83 Page: 12 Filed: 11/14/2025

-- 12 of 12 --