NOTE: This disposition is nonprecedential.

United States Court of Appeals 

for the Federal Circuit ______________________

BLACKBIRD TECH LLC, DBA BLACKBIRD 

TECHNOLOGIES,

Appellant

v.

FITBIT, INC., WAHOO FITNESS LLC,

Appellees

______________________

2019-1879

______________________

Appeal from the United States Patent and Trademark 

Office, Patent Trial and Appeal Board in Nos. IPR2017-

02012, IPR2018-00275.

______________________

Decided: August 6, 2020

______________________

JEFFREY AHDOOT, Blackbird Tech LLC, Boston, MA, for 

appellant. Also represented by WENDY VERLANDER; 

STAMATIOS STAMOULIS, Stamoulis & Weinblatt LLC, Wilmington, DE; DAVID ALEXANDER GERASIMOW, The Law Offices of David A. Gerasimow, P.C., Chicago, IL. 

 CLEMENT ROBERTS, Orrick, Herrington & Sutcliffe 

LLP, San Francisco, CA, for appellee Fitbit, Inc. Also represented by ELIZABETH MOULTON, Menlo Park, CA; ERIC 

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2 BLACKBIRD TECH LLC v. FITBIT, INC.

SHUMSKY, Washington, DC. 

 MATTHEW L. CUTLER, Harness, Dickey & Pierce, PLC, 

St. Louis, MO, for appellee Wahoo Fitness LLC. Also represented by DOUGLAS ALAN ROBINSON. 

 ______________________

Before PROST, Chief Judge, REYNA and TARANTO, Circuit 

Judges.

TARANTO, Circuit Judge.

Blackbird Tech LLC, d/b/a Blackbird Technologies,

owns U.S. Patent No. 6,434,212, which describes and 

claims a device that counts an individual’s steps and, based 

on the length and rate of those steps, provides the individual with information such as distance traveled and speed. 

Fitbit, Inc. and Wahoo Fitness LLC each sought an inter 

partes review of claims 2, 5, and 6 of the ’212 patent. The 

Patent Trial and Appeal Board of the Patent and Trademark Office instituted the requested reviews and consolidated the proceedings. The Board ultimately determined 

that Fitbit had proven claim 6 of the ’212 patent unpatentable for obviousness but had not proven claims 2 and 5 unpatentable. See FitBit, Inc. v. Blackbird Tech, LLC, No. 

IPR2017-02012, 2019 WL 1118863 (P.T.A.B. Mar. 11, 

2019). Blackbird appeals the Board’s ruling on claim 6. We 

affirm. 

I

A

The ’212 patent describes purported improvements in 

a pedometer, i.e., a device “for determining the distance a 

person travels on foot.” ’212 patent, col. 1, lines 18–19. The

basic components of the assertedly inventive pedometer 

are a step counter, a wearable receiver, and a data processor programmed to use the step count, as well as the stride 

length and the rate of steps, to derive information such as 

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distance traveled or speed. See id., col. 2, line 15–23. The 

patent “recognizes the interdependency of stride length 

and stride rate” (how many steps per unit of time), id., col. 

2, lines 24–25, and provides for adjusting the stride length 

with new data—based on, e.g., the wearer’s actual walking—to improve accuracy in calculating the figures of interest, such as distance or speed, id., col. 2, at lines 25–26, 

33–35. 

For example, starting with an initially input “base 

stride length,” id., col. 3, lines 56–64, the device can use a 

wearer’s actual walking to “correct[]” the base stride length 

to “arrive at an accurate Actual Stride Length,” id., col. 4, 

lines 30–46. Once the walker’s “actual stride length is calculated for a given period of time, the value can be multiplied by the number of strides in that period to obtain a 

total distance for that period.” Id., col. 6, lines 33–38. This 

total distance can then be used to calculate speed. See id., 

col. 6, lines 43–45. 

Claim 6, the only claim at issue here, recites:

6. A pedometer comprising:

a step counter;

a transmitter in communication with the step 

counter to generate a step count signal corresponding to each step and transmit the step 

count signal;

a receiver mountable on a user body portion to receive the step count signal transmitted from 

the transmitter; and

a data processor programmed to calculate a distance traveled by multiplying a number of 

steps counted by a stride length that varies according to a rate at which steps are taken, and 

further programmed to derive an actual stride 

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length from a range of stride lengths calculated 

from a range of corresponding stride rates.

Id., col. 8, lines 5–19. 

B

In August 2017, Fitbit petitioned for an inter partes review of claims 2, 5, and 6 of the ’212 patent. Fitbit argued 

that the claims are unpatentable on three grounds: first, 

claims 2 and 5 are anticipated by U.S. Patent No. 6,241,684 

(Amano); second, claims 2 and 5 are unpatentable for obviousness over Amano; and third, claim 6 is unpatentable for 

obviousness over a combination of Amano and U.S. Patent 

No. 5,033,013 (Kato). In December 2017, Wahoo petitioned 

for an inter partes review of claims 2, 5, and 6, relying on 

the same grounds as Fitbit.

The Board instituted a review based on Fitbit’s petition, though not on the first ground. The Board then instituted a review based on Wahoo’s petition and joined Wahoo 

to the Fitbit proceeding. After the Supreme Court’s decision in SAS Institute Inc. v. Iancu, 138 S. Ct. 1348 (2018), 

the Board added the first ground to the proceedings.

In its final written decision, the Board determined that 

Fitbit had not proven claims 2 and 5 unpatentable but that 

Fitbit had proven claim 6 unpatentable for obviousness 

over a combination of Kato and Amano. FitBit, 2019 WL 

1118863, at *11–14. Blackbird timely appealed; Fitbit and 

Wahoo did not appeal. We have jurisdiction under 28 

U.S.C. § 1295(a)(4)(A). 

II

On appeal, Blackbird limits its challenge to one point, 

contending that the Board erred in finding that Kato discloses claim 6’s limitation “a data processor programmed to 

calculate a distance traveled by multiplying a number of 

steps counted by a stride length.” Although we review the 

Board’s determination of obviousness de novo, we review 

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its underlying factual findings for substantial evidence 

support, Personal Web Technologies, LLC v. Apple, Inc., 

848 F.3d 987, 991 (Fed. Cir. 2017), and “findings as to the 

scope and content of the prior art” are factual findings, Ariosa Diagnostics v. Verinata Health, Inc., 805 F.3d 1359, 

1364 (Fed. Cir. 2015). Accordingly, we review the Board’s 

finding as to what Kato taught a relevant skilled artisan

for whether it is supported by substantial evidence, i.e.,

“whether a reasonable fact finder could have arrived at the 

agency’s decision” on the record as a whole. Intelligent BioSystems, Inc. v. Illumina Cambridge Ltd., 821 F.3d 1359, 

1366 (Fed. Cir. 2016); In re Gartside, 203 F.3d 1305, 1312 

(Fed. Cir. 2000). 

Kato discloses a processing means that uses a walker’s 

stride length, along with the walker’s “pitch,” to determine 

the walker’s speed. When the walker’s foot hits the ground, 

a detector notifies the processing means of the contact.

Kato, col. 3, line 67, through col. 4, line 3. Over a “predetermined unit of time,” the processing means counts the 

number of contacts received to obtain the walker’s “pitch,” 

i.e., the walker’s step rate (number of steps per selected 

time unit). Id., col. 4, lines 4–6; see id., col. 4, line 16 (“PI 

is the pitch in number of steps every 10 seconds”). Because 

of a “predetermined empirical relationship” between the

walker’s pitch, height, and stride length, Kato explains, obtaining the walker’s pitch also allows the processing means 

to calculate the walker’s stride length (which Kato just 

calls “stride”). See id., col. 4, lines 7–10. Then, “the stride 

is multiplied by the pitch [] to obtain a walking speed of the 

walker in said unit of time.” Id., col. 4, lines 50–51. Kato 

expresses this step in the form of a simple equation:

SP = ST × PI

Id., col. 4, line 27. In this equation, SP is “speed of walking,” ST is “stride in meters,” and PI is “pitch in number of 

steps every 10 seconds” (i.e., steps/unit of time). Id., col. 4, 

lines 17–19, 25–27. 

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Using the “same steps as in the method of measuring 

walking speed,” Kato discloses calculating the distance 

traveled by the walker over a given period of time by adding an extra step—“multiplying the walking speed by said 

unit of time.” Id., col. 4, lines 59–68. Although Kato does 

not present this calculation in equation form, the equation 

form of those words is simply D = SP × T, where D is distance in meters and T is the period of time in seconds. Because Kato has just explained that SP = ST × PI, it is 

evident from Kato that:

D = ST × PI × T.

Substantial evidence supports the Board’s finding that

a relevant skilled artisan would read Kato as teaching a 

“data processor programmed to calculate a distance traveled by multiplying a number of steps counted by a stride 

length.” As the Board noted, Kato’s equation for calculating distance can be expressed “in measurement terms: meters * (steps/time) * (time).” FitBit, 2019 WL 1118863, at 

*11. That is directly supported by the above equation, because ST is the stride length in meters, PI is steps/time, 

and T is the period of time (for which the distance is being 

derived). Given that “[n]othing in Kato precludes the period of time and unit time from being the same,” the Board 

observed, the “period of time” in the numerator and the 

“unit time” in the denominator cancel out. Id. at *12. In 

other words, D = ST × steps. As a result, the Board explained, Kato’s method for calculating distance travelled 

can be expressed as simply “determining the number of 

steps and multiplying them by a stride length.” Id.

On appeal, Blackbird argues that the Board was obligated to explain why a relevant skilled artisan would have 

taken the steps of expressing pitch as “steps/time” and cancelling out the numerator-time with the denominator-time. 

According to Blackbird, the Board “worked backward, with 

knowledge of the claimed invention, to modify the Kato 

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reference in such a way so as to arrive at the claimed invention.” Appellant’s Br. at 13.

But the Board’s conclusion of unpatentability did not 

rely on a modification of Kato’s equation—it relied on a

finding that a relevant skilled artisan would consider 

Kato’s equation to teach claim 6’s limitation. To determine 

the “meaning of a prior art reference,” the Board must incorporate “the understanding of an artisan of ordinary 

skill.” Finisar Corp. v. DirecTV Grp., Inc., 523 F.3d 1323, 

1336 (Fed. Cir. 2008). Here, the Board determined that a 

relevant skilled artisan would be an engineer with either a 

master’s degree or multiple years of work experience. FitBit, 2019 WL 1118863, at *5. The Board could readily find 

that such a person would understand Kato’s teaching of a 

very simple multiplicative relationship to teach the form of 

that relationship that involves the elementary process of 

unit cancellation between numerator and denominator. 

Accordingly, the Board had a sufficient basis to find that a 

relevant artisan would have considered Kato’s method for 

calculating distance traveled to be identical to claim 6’s 

limitation. 

III

For the foregoing reasons, the Board’s decision is affirmed. 

Costs awarded to appellees.

AFFIRMED

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