United States Court of Appeals 

for the Federal Circuit ______________________ 

AMERICAN NATIONAL MANUFACTURING INC.,

Appellant

v.

SLEEP NUMBER CORPORATION, FKA SELECT 

COMFORT CORPORATION,

Cross-Appellant

KATHERINE K. VIDAL, UNDER SECRETARY OF 

COMMERCE FOR INTELLECTUAL PROPERTY 

AND DIRECTOR OF THE UNITED STATES 

PATENT AND TRADEMARK OFFICE,

Intervenor

______________________ 

2021-1321, 2021-1323, 2021-1379, 2021-1382

______________________ 

Appeals from the United States Patent and Trademark 

Office, Patent Trial and Appeal Board in Nos. IPR2019-

00497, IPR2019-00500.

______________________ 

Decided: November 14, 2022

______________________ 

KYLE L. ELLIOTT, Spencer Fane, LLP, Kansas City, 

MO, argued for appellant. Also represented by BRIAN T.

BEAR, KEVIN S. TUTTLE; ANDY LESTER, Oklahoma City, OK. 

 RUFFIN B. CORDELL, Fish & Richardson PC, 

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2 AMERICAN NATIONAL v. SLEEP NUMBER CORPORATION

Washington, DC, argued for cross-appellant. Also represented by ROBERT COURTNEY, MATHIAS WETZSTEIN 

SAMUEL, Minneapolis, MN; ANDREW S. HANSEN, ELIZABETH 

A. PATTON, LUKAS D. TOFT, Fox Rothschild LLP, Minneapolis, MN; STEVEN A. MOORE, Moore IP Law PC, San Diego, 

CA; KECIA JANNELL REYNOLDS, Paul Hastings LLP, Washington, DC. 

 SARAH E. CRAVEN, Office of the Solicitor, United States 

Patent and Trademark Office, Alexandria, VA, argued for 

intervenor. Also represented by THOMAS W. KRAUSE,

FARHEENA YASMEEN RASHEED; MEREDITH HOPE 

SCHOENFELD. 

 ______________________ 

Before STOLL, SCHALL, and CUNNINGHAM, Circuit Judges. 

STOLL, Circuit Judge. 

American National Manufacturing Inc. and Sleep 

Number Corp. each appeals the Patent Trial and Appeal 

Board’s final written decisions in two inter partes reviews. 

The Board issued mixed decisions in those proceedings, determining that some, but not all, of the challenged claims 

were not unpatentable. These appeals and cross-appeals 

involve two patents and numerous issues, including two on 

which the U.S. Patent and Trademark Office has intervened. 

Our opinion focuses on four of these issues: (1) whether the Board erred in permitting the patent 

owner to present proposed amended claims that both responded to a ground of unpatentability and made other 

wording changes unrelated to the IPR proceedings; 

(2) whether those proposed amended claims were not enabled because of an alleged error in the specification; 

(3) whether those proposed amended claims should have 

been rejected for allegedly raising an inventorship issue; 

and (4) whether the Board inappropriately considered the 

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AMERICAN NATIONAL v. SLEEP NUMBER CORPORATION 3

petitioner’s sales data in its secondary considerations analysis. For the below reasons, we affirm. Although we have 

thoroughly considered the other issues raised by both parties, we affirm the Board’s determinations regarding those 

issues without significant discussion. 

BACKGROUND

I 

Sleep Number owns U.S. Patent Nos. 8,769,747 and 

9,737,154. Both patents describe systems and methods 

that purport to adjust the pressure in an air mattress “in 

less time and with greater accuracy” than previously 

known. ’747 patent col. 1 ll. 6–10.1 Conventional air bed 

systems have a control panel that allows a user to select a 

desired inflation setting for each air chamber in the air bed 

for optimal comfort and to change the inflation setting at 

any time, allowing for changes in the firmness of the bed. 

Id. at col. 1 ll. 13–25. The air chambers are in fluid communication with an air pump manifold. Id. at col. 3 

ll. 10–19, 46–51. The patents disclose adjusting pressure 

in an air bed “in less time and with greater accuracy” by 

measuring the air pressure inside the valve enclosure assembly instead of in the air chambers themselves, thus 

“eliminating the need to turn off the pump in order to obtain a substantially accurate approximation of the chamber 

pressure.” Id. at col. 1 ll. 6–10, col. 4 ll. 53–59. 

As the patents’ shared specification explains, the pressure control system computes and iteratively refines what 

the patents call “pressure adjustment factors” or “offsets”—

the difference between the pressure in the valve enclosure 

assembly and the pressure in the bed’s air chambers. Id. at

1 The ’154 patent is a continuation of the application 

that matured into the ’747 patent. Because the patents 

share a common specification, we refer only to the ’747 patent specification unless otherwise specified.

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4 AMERICAN NATIONAL v. SLEEP NUMBER CORPORATION

col. 2 ll. 26–31, col. 5 l. 9–col. 6 l. 7. The system then uses 

the pressure adjustment factor to determine what the “target pressure” in the valve enclosure assembly must be for 

the air chamber to reach the user’s desired pressure setpoint. Id. at col. 7 l. 51–col. 8 l. 59. The system adjusts the 

valve enclosure assembly pressure until it meets the target 

pressure, then re-tests the pressure in the air chamber. 

Id. at col. 8 l. 63–col. 9 l. 43. If the air chamber has still not 

reached the desired pressure setpoint, the system revises 

its pressure adjustment factor, using what the patents call 

an “adjustment factor error,” and tries again. Id. at col. 2 

ll. 28–31, col. 9 l. 44–col. 10 l. 51; see also id. Fig. 6 (describing the process in flow diagram form). This process 

repeats until the air chamber reaches the desired pressure. 

The specification further explains that the process for 

determining the pressure adjustment factor varies depending on whether the system is inflating or deflating the air 

chamber. To differentiate between the two processes, the 

patents describe using an additive offset (i.e., an offset that 

is added to the measured valve enclosure pressure) for inflation and a multiplicative offset (i.e., an offset by which 

the measured valve enclosure pressure is multiplied) for 

deflation. Id. at col. 8 ll. 14–59, col. 9 ll. 51–61. 

Claim 1 of the ’747 patent recites:

1. A method for adjusting pressure within an air 

bed comprising: 

providing or receiving an air bed, the air bed including an air chamber and a pump having a pump 

housing;

selecting a desired pressure setpoint for the air

chamber;

determining an initial pressure within the pump 

housing; 

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AMERICAN NATIONAL v. SLEEP NUMBER CORPORATION 5

calculating a pressure target based upon the desired pressure setpoint and a pressure adjustment 

factor, wherein an inflate pressure adjustment factor is used to calculate the pressure target when 

the initial pressure within the pump housing is less 

than the desired pressure setpoint, and wherein a 

deflate pressure adjustment factor is used to calculate the pressure target when the initial pressure 

within the pump housing is greater than the desired pressure setpoint; 

adjusting pressure within the air chamber until a 

sensed pressure within the pump housing is substantially equal to the calculated pressure target;

determining an actual chamber pressure within 

the air chamber;

comparing the actual chamber pressure to the desired pressure setpoint to determine the adjustment factor error; and

modifying the pressure adjustment factor based 

upon the adjustment factor error. 

Id. at col. 12 ll. 43–67. Claim 1 of the ’154 patent is similar. 

See ’154 patent col. 13 ll. 11–29. Certain dependent claims 

of both patents require that the pressure adjustment factor 

be a multiplicative pressure adjustment factor. See

’747 patent col. 13 ll. 8–13, col. 14 ll. 1–3 (claims 5, 6, 

and 13); ’154 patent col. 13 ll. 39–44, col. 14 ll. 46–49

(claims 5, 6, and 15). Both patents also contain an independent claim requiring, among other things, a “pressure 

adjustment system for an air bed comprising . . . a pressure 

sensing means adapted to monitor pressure within the 

pump manifold.” ’747 patent col. 14 ll. 9–43 (claim 16); 

’154 patent col. 15 l. 16–col. 16 l. 18 (claim 20). 

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6 AMERICAN NATIONAL v. SLEEP NUMBER CORPORATION

II

American National filed petitions for inter partes review challenging many claims of the ’747 and ’154 patents. 

In its petitions, American National asserted that most of 

the challenged claims would have been obvious over Gifft2

in view of Mittal3 and Pillsbury,4 and that six of the dependent claims would have been obvious in further view of 

Ebel.5

Gifft is owned by Sleep Number and incorporated by 

reference in the patents-in-suit. Gifft discloses an air bed 

system including a sealed valve enclosure assembly with 

an air pump for inflating and deflating air chambers to a 

desired pressure. Gifft col. 2 l. 56–col. 3 l. 2. Similar to the 

patents-in-suit, Gifft discloses monitoring the pressure 

within the valve enclosure instead of the air chamber itself 

while the air pump is in operation, which the system 

equates as being the actual pressure in the air chamber. 

Id. at col. 9 ll. 57–67 (claim 9); ’747 patent col. 1 ll. 48–64 

(describing prior art). 

Mittal describes a system for quickly reaching a desired air pressure in vehicle tires. Mittal Abstract, col. 8 

l. 65–col. 9 l. 9. Mittal discloses that there is often a lag 

between the time tire pressure is monitored and the time 

the pressure adjustment cycle ends; that is, the tire may 

reach the desired pressure before the pressure adjustment 

system detects it has done so. Id. at col. 2 ll. 32–47. To 

resolve this problem, Mittal’s system adjusts the desired 

pressure with additive offsets to compensate for these lags 

and to avoid “wasteful repeated pressure adjustment cycles.” Id. at col. 2 ll. 3–9, 16–26, col. 4 ll. 44–49. 

2 U.S. Patent No. 5,904,172.

3 U.S. Patent No. 5,629,873.

4 U.S. Patent No. 5,277,187.

5 U.S. Patent Application Pub. No. 2007/0000559.

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AMERICAN NATIONAL v. SLEEP NUMBER CORPORATION 7

Pillsbury is directed to an automatic blood pressure 

cuff that measures a user’s blood pressure and employs a 

filter to “prevent dust, dirt, and other debris from clogging” 

the cuff’s air exit valve. Pillsbury Abstract, col. 8 ll. 25–63. 

The system detects and records the pressure in the cuff 

along with other data (including “oscillometric pulse amplitudes” recorded at each cuff pressure as the cuff pressure 

reduces to zero) to “determine relatively accurately the 

user’s blood pressure.” Id. at col. 1 ll. 39–48. A data processor adjusts the cuff pressure measurement to compensate for any resistance added by the filter. Specifically, by 

using an additive offset, Pillsbury explains, its blood pressure cuff can provide an accurate measure of the air pressure inside the cuff while compensating for the added air 

resistance caused by build-up on the filter. Id. at col. 2 

ll. 40–54, col. 8 ll. 25–63. 

Ebel discloses a method for measuring the pressure inside an air bag while filling or emptying the air bag. Ebel 

¶¶ 1, 7. Ebel explains that, because of what it calls “conduit effects,” a pressure sensor cannot accurately measure 

the actual pressure in the air bag during inflation or deflation. Id. ¶ 3. Ebel explains that it is “only in the idle state, 

i.e., after a certain slow-down period[,] that the actual bag 

pressure can be determined by the pressure sensor.” Id. 

To compensate for these effects during inflation and deflation, Ebel proposes mathematical equations for calculating 

the actual pressure inside the air bag. Those equations use 

the air bag pressure measured by the pressure sensor as 

one input parameter and include both additive and multiplicative components. Id. ¶¶ 4–7, 28–32. 

Before the Board, American National asserted that 

most of the challenged claims would have been obvious to 

the ordinarily skilled artisan over a combination of Gifft’s

air bed system, with its measurement of the valve assembly pressure to approximate the air chamber pressure, and 

Mittal’s and Pillsbury’s use of additive offsets, or pressure 

adjustment factors. For the six dependent claims requiring 

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8 AMERICAN NATIONAL v. SLEEP NUMBER CORPORATION

a multiplicative pressure adjustment factor, American National argued these would have been obvious over a combination of those three references as well as Ebel’s use of 

multiplicative offsets.

In opposition, Sleep Number argued that: (1) evidence 

of industry praise and commercial success strongly supported that the claims would not have been obvious;

(2) American National had not adequately explained how 

and why the skilled artisan would have combined the asserted references to meet the claim limitations; and 

(3) American National had not proposed a construction for 

the means-plus-function term “pressure sensing means” in 

violation of the Board’s rules. 

For industry praise, Sleep Number relied on two American National internal business documents that Sleep 

Number asserted praised Sleep Number’s patents. The 

Board determined that one of these documents weighed 

“slightly in favor” of industry praise but that the other did 

not. 

For commercial success, Sleep Number relied on the

commercial success not of its own products, but of American National’s products—specifically, the products that 

Sleep Number had accused of infringement in a parallel 

district court proceeding. See J.A. 3647–49; see also First 

Am. Compl., Sleep No. Corp. v. Am. Nat’l Mfg., Inc., 

No. 5:18-cv-00357 (C.D. Cal. Mar. 23, 2018). To support its 

arguments, Sleep Number sought discovery before the 

Board on American National’s sales of products sold with 

and without certain versions of source code that allegedly 

infringed claim 1. See J.A. 3004–05, 3050–55. The Board 

granted this motion, explaining that the evidence could 

help illuminate issues of nonobviousness, assuming Sleep 

Number could show a nexus between the relevant American National products and the challenged patents. 

J.A. 3356–59. In its order, the Board noted that Sleep 

Number was not “seeking any admission of infringement,” 

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AMERICAN NATIONAL v. SLEEP NUMBER CORPORATION 9

because its request simply sought a list of “products that 

include the allegedly infringing source code[] and those 

that do not.” J.A. 3359. 

In its Patent Owner Response, Sleep Number asserted 

American National products were coextensive with the 

challenged claims based in part on the testimony of Sleep 

Number’s experts, Drs. John Abraham and George Edwards. J.A. 3648; see also J.A. 4634–35 ¶ 29 (Dr. Abraham 

testifying that American National’s products “read on” the 

challenged claims); J.A. 4725–26 ¶ 41 (Dr. Edwards testifying the same). 

Based in part on this expert testimony, the Board 

found that Sleep Number had demonstrated a nexus between American National’s increased sales numbers and 

its adoption of technology that “reads on” the challenged 

patents.6 See Am. Nat’l Mfg. Inc. v. Sleep No. Corp., 

No. IPR2019-00497, Paper 114, at 91–92 (P.T.A.B. 

Sept. 30, 2020) (’747 Decision); Am. Nat’l Mfg. Inc. v. Sleep 

No. Corp., No. IPR2019-00500, Paper 114, at 92–93

(P.T.A.B. Sept. 30, 2020) (’154 Decision).7 Nevertheless, 

the Board determined that the evidence did not show that 

6 The Board’s original final written decisions stated 

that American National “does not refute the testimonies of 

Dr. Abraham and Dr. Edwards that” certain versions of the 

source code “fall within the claims of the [challenged] patent[s] such that [American National]’s products using 

these versions infringe the claims.” ’747 Decision at 91

(emphasis added); ’154 Decision at 92. After American National sought rehearing, the Board modified its final written decisions, changing the word “infringe” to “read on.” 

J.A. 143–44, 294–95. 7 Although the Board issued separate final written 

decisions in these proceedings, the decisions are largely 

identical for many of the issues on appeal. In this opinion, 

we cite primarily to the ’747 Decision. 

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10 AMERICAN NATIONAL v. SLEEP NUMBER CORPORATION

American National’s products “were commercially successful because of the merits of the claimed invention,” and not, 

for example, because of increased advertising, consumer 

recognition, or lowered price. ’747 Decision at 94. Thus, 

the Board gave Sleep Number’s evidence of commercial 

success “minimal probative weight.” Id. 

The Board ultimately resolved the proceedings with 

split decisions. For the six dependent claims requiring a 

multiplicative pressure adjustment offset, the Board determined that American National had failed to establish unpatentability. See ’747 Decision at 139–40; ’154 Decision at 

145–50. Although the Board found that Ebel taught the 

use of multiplicative offsets, it also found that American 

National had not adequately shown why the skilled artisan 

would have applied Ebel’s multiplicative factors to the 

pressure targeting methods disclosed in Gifft as modified 

by Mittal and Pillsbury. See ’747 Decision at 81–84. Because American National had not sufficiently articulated 

why the skilled artisan would have combined Ebel with the 

remaining references, the Board found American National 

had not established that the claims requiring multiplicative pressure adjustment factors were unpatentable as obvious. 

For the remaining claims, the Board found that American National had proven they were unpatentable as obvious. See id. at 140. For these claims, the Board credited 

American National’s expert, who testified that the ordinarily skilled artisan, presented with Gifft’s air bed pressure 

adjustment system, would have understood that by “improving the accuracy of [Gifft’s] pressure adjust cycles on 

an ongoing basis, the number of pressure adjustments necessary to reach a target pressure could be reduced.” See 

id. at 45 (citing J.A. 1148 ¶ 101). The Board rejected Sleep 

Number’s assertion that American National had failed to 

explain how or why a skilled artisan would combine the asserted references and instead found that the skilled artisan 

would have a motivation to increase both speed and 

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AMERICAN NATIONAL v. SLEEP NUMBER CORPORATION 11

accuracy in Gifft’s system—and would have looked to techniques disclosed in other pneumatic systems references, 

such as Mittal and Pillsbury, to achieve these goals. See 

id. at 50–51. The Board therefore found that all claims not 

requiring a multiplicative pressure adjustment offset were 

unpatentable as obvious. See id. at 140. 

Finally, the Board rejected Sleep Number’s assertion 

that American National violated 37 C.F.R. § 42.104(b)(3), 

governing the contents of petitions, because American National’s petitions did not provide a sufficient construction 

for the means-plus-function term “pressure sensing 

means.” Although the Board acknowledged in both proceedings that American National’s petitions did not “explicitly state” how the means-plus-function term should be 

construed, it nonetheless determined that the petitions 

“fairly me[t] the requirements of” the regulation. ’747 Decision at 24–25; ’154 Decision at 23–25. 

In each proceeding, Sleep Number filed a motion to 

amend contingent on a finding that the challenged claims 

were unpatentable. ’747 Decision at 104. Each of the proposed claims added the requirement of a multiplicative 

pressure adjustment factor, id. at 105–07, matching the 

claims that the Board had determined were not proven unpatentable. The proposed amended claims also included 

other non-substantive amendments, described by Sleep 

Number as made “for consistency with terms used in the 

industry and in related patents.” J.A. 3470; see also 

J.A. 3473–77. These non-substantive amendments included, for example, changing the term “pump housing” to 

“valve enclosure” and the term “chamber” to “bladder.” 

J.A. 3474, 3504–05. 

American National challenged the proposed amended 

claims. Among other things, it argued that: the proposed 

amendments did not respond to a ground of unpatentability and thus were legally inappropriate; the relevant specification contained an error that rendered the claims 

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12 AMERICAN NATIONAL v. SLEEP NUMBER CORPORATION

nonenabled; and the proposed amended claims lacked written description support and were indefinite. 

The Board rejected American National’s challenges to 

the proposed amended claims, finding that the amendments—which added the substantive limitation requiring 

a multiplicative pressure adjustment factor—responded to 

a ground of unpatentability in the proceedings. ’747 Decision at 107–10. The Board also determined that the proposed amended claims were not unpatentable under 

35 U.S.C. § 112. Id. at 110–16. The Board thus granted 

Sleep Number’s contingent motions to amend. Id. at 120. 

American National appeals, and Sleep Number crossappeals, from both final written decisions. We have jurisdiction under 35 U.S.C. § 1295(a)(4)(A).

DISCUSSION

We review the Board’s legal conclusions de novo and its 

factual findings for substantial evidence. Univ. of Strathclyde v. Clear-Vu Lighting LLC, 17 F.4th 155, 160 

(Fed. Cir. 2021). Obviousness is a legal question based on 

underlying findings of fact, including the existence of and 

weight assigned to any objective indicia of nonobviousness. 

Adapt Pharma Operations Ltd. v. Teva Pharms. USA, Inc., 

25 F.4th 1354, 1364 (Fed. Cir. 2022). “The substantial evidence standard asks ‘whether a reasonable fact finder 

could have arrived at the agency’s decision,’ and ‘involves 

examination of the record as a whole, taking into account 

evidence that both justifies and detracts from the agency’s 

decision.’” OSI Pharms., LLC v. Apotex, Inc., 939 

F.3d 1375, 1381–82 (Fed. Cir. 2019) (quoting In re Gartside, 203 F.3d 1305, 1312 (Fed. Cir. 2000)). We review statutory and constitutional issues de novo. MCM Portfolio 

LLC v. Hewlett-Packard Co., 812 F.3d 1284, 1287 (Fed. Cir. 

2015). But “[d]ecisions related to compliance with the 

Board’s procedures are reviewed for an abuse of discretion.” Ericsson Inc. v. Intell. Ventures I LLC, 901 F.3d 

1374, 1379 (Fed. Cir. 2018). 

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AMERICAN NATIONAL v. SLEEP NUMBER CORPORATION 13

I 

We turn first to American National’s argument that 

the Board erred in permitting Sleep Number to present 

proposed amended claims that both responded to a ground 

of unpatentability involved in the proceedings and made 

other changes not responsive to an unpatentability ground. 

In its motion to amend, Sleep Number stated that some of 

its proposed amendments (like changing the phrase “pump 

housing” to “valve enclosure”) were made “to achieve consistency and accuracy in terminology and phrasing” 

throughout the patent family. J.A. 3474, 3504–05. Because this purpose was not directly “aimed at responding 

to a ground of unpatentability at issue in” the IPR proceeding, as required by 37 C.F.R. § 42.121, American National 

argues on appeal, as it did below, that these proposed 

amendments were improper. 

In considering this issue, the Board has previously determined that § 42.121 “does not require . . . that every 

word added to or removed from a claim in a motion to 

amend be solely for the purpose of overcoming an instituted 

ground.” Lectrosonics, Inc. v. Zaxcom, Inc., No. IPR2018-

01129, 2019 WL 1118864, at *2 (P.T.A.B. Feb. 25, 2019) 

(precedential). Instead, “once a proposed claim includes 

amendments to address a prior art ground in the trial, a 

patent owner also may include additional limitations to address potential § 101 or § 112 issues, if necessary.” Id. Allowing these amendments, the Board has explained, 

“serves the public interest by helping to ensure the patentability of amended claims” and “helps ensure a ‘just’ resolution of the proceedings and fairness to all parties.” 

Id. (quoting 37 C.F.R. § 42.1(b)). 

We agree with the Board’s thoughtful analysis of this 

issue in Lectrosonics. Indeed, nothing in the America Invents Act (AIA) or the Board’s regulations precludes a patent owner from amending a claim to both overcome an 

instituted ground and correct other perceived issues in the 

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14 AMERICAN NATIONAL v. SLEEP NUMBER CORPORATION

claim. The AIA explicitly restricts patent owner amendments in only two ways: amendments may not enlarge the 

scope of the claims or introduce new matter. 35 U.S.C. 

§ 316(d)(3). The Board’s regulations add another restriction: amendments must respond to a ground of unpatentability involved in the proceeding. 37 C.F.R. 

§ 42.121(a)(2)(i). As we have previously explained, the Director introduced this regulation “merely to ensure that the 

proposed amendment had a minimal level of relevancy to 

the IPR.” Aqua Prods., Inc. v. Matal, 872 F.3d 1290, 1317 

(Fed. Cir. 2017) (en banc) (plurality opinion) (citing 

Changes to Implement Inter Partes Review Proceedings, 

77 Fed. Reg. 48,680, 48,705 (Aug. 14, 2012)). Thus, so long 

as a proposed claim amendment does not enlarge the scope 

of the claims, does not add new matter, and responds to a 

ground of unpatentability in the proceeding, the patent 

owner may also make additional amendments to a claim

without running afoul of the relevant statutes and regulation. 

American National argues that allowing a patent 

owner to refine claims or correct potential § 112 errors “invites a violation of due process and the Administrative Procedure Act, by allowing the patent owner and the Board to 

address concerns that may be proper for [an] examination 

or reexamination proceeding, but that were never germane 

to an IPR process.” Appellant’s Br. 69–70. Specifically, according to American National, because a petition cannot 

challenge claims under § 112, it would be “asymmetr[ical]” 

and “unfair” to allow the patent owner to amend its claims 

to address § 112 concerns. We are not convinced. As we 

have previously explained, the petitioner can challenge the 

proposed amended claims on grounds beyond §§ 102 and 

103, including under § 112. See Uniloc 2017 LLC v. Hulu, 

Inc., 966 F.3d 1295, 1305–07 (Fed. Cir. 2020) (holding that 

petitioners may challenge proposed substitute claims outside of §§ 102 and 103); Samsung Elecs. Am. v. Prisua 

Eng’g Corp., 948 F.3d 1342, 1352 (Fed. Cir. 2020) (“[T]he 

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AMERICAN NATIONAL v. SLEEP NUMBER CORPORATION 15

Board’s authority with respect to new and amended claims 

necessarily extends to other possible grounds of unpatentability, in particular, a failure to comply with section 

112.”). Indeed, American National did so in its oppositions 

to Sleep Number’s motions to amend in these IPRs. Accordingly, we discern no unfairness or asymmetry in the 

Board’s granting of the motion to amend. 

In this case, each of Sleep Number’s proposed substitute claims included an amendment responsive to a ground 

of unpatentability raised in the proceedings. Specifically, 

each proposed substitute claim added a limitation requiring a multiplicative pressure adjustment factor—mirroring 

the claims that the Board had determined were not unpatentable. ’747 Decision at 105–07 (proposed substitute 

claims); see also J.A. 3474–77, 3504–08. Because each proposed substitute claim included at least one responsive 

narrowing limitation, Sleep Number was free to include 

other amendments, including any addressing perceived 

§§ 101 and 112 issues. American National was free to challenge these proposed claims, as it did in both proceedings. 

And the Board was free to determine whether the proposed 

claims were unpatentable under §§ 101, 102, 103, and 112. 

We thus see no error in the Board’s decision to consider 

Sleep Number’s proposed substitute claims. 

II

We turn next to American National’s enablement argument. Section 112(a) requires, among other things, that 

the specification enable a skilled artisan to make and use 

the claimed invention. In re Wands, 858 F.2d 731, 735 

(Fed. Cir. 1988). “Whether a claim satisfies the enablement requirement of 35 U.S.C. § 112 is a question of law 

that we review without deference, although the determination may be based on underlying factual findings, which we 

review for clear error.” Amgen Inc. v. Sanofi, Aventisub 

LLC, 987 F.3d 1080, 1084 (Fed. Cir. 2021) (citing Alcon 

Rsch. Ltd. v. Barr Lab’ys Inc., 745 F.3d 1180, 1188 

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16 AMERICAN NATIONAL v. SLEEP NUMBER CORPORATION

(Fed. Cir. 2014)). American National argues that an admitted error in the specification of the application to which 

the ’747 and ’154 patents claim priority necessarily means 

that the proposed amended claims are not enabled. Appellant’s Br. 70–71. We disagree. 

There is undisputedly an error in the specification of 

the challenged patents. ’747 Decision at 113–14. The specification states:

Updated Inflate Adjustment Factor = (Manifold 

Pressure from Step 168) – (Pressure Setpoint 

from Step 106)

Id. at 114 (citing J.A. 10163 ¶ 67) (emphasis added to erroneous portion). Both parties agree this equation should instead read:

Updated Inflate Adjustment Factor = (Manifold 

Pressure from Step 168 176) – (Pressure Setpoint from Step 106)

Id. (citing J.A. 10085 ¶ 20) (emphasis added to corrected 

portion). Sleep Number’s expert testified that the skilled 

artisan would understand that this “is a typographical error inconsistent with the remainder of the disclosure” in 

the specification. Id. (citing J.A. 10085 ¶ 20). This testimony is supported by the specification. For example, immediately before the equation, the specification correctly 

explains that the “manifold pressure sampled in step 176” 

is compared to the “setpoint pressure” of step 106. 

J.A. 10162 ¶ 63; see also, e.g., ’747 patent col. 9 ll. 33–38 

(discussing the “manifold pressure sampled in step 176”). 

On this record, the Board reasonably found that the error 

was a “mistake or typographical error,” ’747 Decision

at 114, and thus that American National had not shown 

the proposed claims were unpatentable for lack of enablement, id. at 115.

In an analogous case, we affirmed a district court’s 

finding that a patent was enabled, despite a calculation 

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AMERICAN NATIONAL v. SLEEP NUMBER CORPORATION 17

error in the specification. PPG Indus. v. Guardian Indus. 

Corp., 75 F.3d 1558 (Fed. Cir. 1996). In PPG Industries, 

the specification described how to make the patented “solar 

control” glass composition but included test results and calculations rendered “artificially high” by a software error. 

Id. at 1563–64. The district court had found that the error 

was “easily detectable by anyone who was skilled in the 

art.” Id. at 1564. And, we explained, the remainder of the 

specification described the process with sufficient detail to 

“indicate[] to one skilled in the art how” to make such a 

glass composition. Id. at 1565. We affirmed the district 

court’s finding that the patent was enabled, despite the error, because the skilled artisan would, “[i]n light of the 

guidance provided by the specification” as a whole, be enabled to make and use the claimed invention. Id. at 1564–

65. The same rationale and conclusion apply here.

American National nonetheless argues that this error 

was not obvious because it was not noted during the original examination process. And because the equation in the 

specification, as erroneously written, would not work, 

American National argues that the proposed amended 

claims are not enabled. Appellant’s Br. 70 (citing In re 

Wands, 858 F.2d at 737). We are not persuaded. 

In this case, regardless of whether the error was first 

discovered during examination or afterward, the specification itself makes clear that the reference to step 168 instead of step 176 is an obvious error. Indeed, the 

remainder of the specification consistently and correctly 

describes that the “manifold pressure [is] sampled in 

step 176.” J.A. 10162 ¶ 63; see also J.A. 10177, Fig. 6 

(showing step 176 as “Sample Manifold Pressure”); 

J.A. 10178, Fig. 7 (showing same). This conclusion is further supported by Sleep Number’s expert, who opined that 

a skilled artisan, reading the specification in its entirety, 

would view the reference to step 168 as an obvious typographical error and substitute the correct step—step 176—

in its place. J.A. 10085 ¶ 20. We thus conclude that the 

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18 AMERICAN NATIONAL v. SLEEP NUMBER CORPORATION

Board did not err in determining that the proposed 

amended claims were enabled, despite an admitted error 

in the specification, because that error and its correction 

would have been obvious to a person of ordinary skill in the 

art.

III

We now turn to American National’s argument that the 

Board should have denied the motion to amend because 

adding the term “valve enclosure” injected an inventorship 

issue into the patents. We review the Board’s decision to 

grant a motion to amend under the Administrative Procedure Act, and we may set aside the Board’s action if it is 

“arbitrary, capricious, an abuse of discretion, or otherwise 

not in accordance with law.” 5 U.S.C. § 706(2)(A); Bosch 

Auto. Serv. Sols., LLC v. Matal, 878 F.3d 1027, 1039 

(Fed. Cir. 2017). Inventorship is a question of law based on 

underlying findings of fact. Duncan Parking Techs., Inc. 

v. IPS Grp., Inc., 914 F.3d 1347, 1357 (Fed. Cir. 2019) (citing Gen. Elec. Co. v. Wilkins, 750 F.3d 1324, 1329 (Fed. Cir. 

2014)). 

According to American National, the term “valve enclosure” is used in related patents owned by Sleep Number, 

including the Gifft patent, which name different inventors 

than the ’747 and ’154 patents. For example, the Gifft patent lists James Gifft as an inventor while the ’747 and ’154 

patents do not. American National argues that amending 

the claims to use the term “valve enclosure” without adding 

James Gifft as an inventor renders the amendments “facially invalid.” Appellant’s Br. 72–73. We disagree. 

The ’747 and ’154 patents incorporate the prior art 

Gifft patent by reference. ’747 patent, col. 1 ll. 18–25; 

’154 patent, col. 1 ll. 28–35. That is, the patents themselves make clear that valve enclosures were well known 

in the art and incorporated into the patent specification. 

Sleep Number’s choice to recite these well-known structures in its amended claims does not make James Gifft an 

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AMERICAN NATIONAL v. SLEEP NUMBER CORPORATION 19

inventor of the ’747 and ’154 patents. See Trovan, Ltd. 

v. Sokymat SA, 299 F.3d 1292, 1302 (Fed. Cir. 2002) 

(“[T]he basic exercise of ordinary skill in the art . . . does 

not make one a joint inventor.”); see also Fina Oil & Chem. 

Co. v. Ewen, 123 F.3d 1466, 1473 (Fed. Cir. 1997) (“[A] person will not be a co-inventor if he or she does no more than 

explain to the real inventors concepts that are well known 

and the current state of the art.”). Accordingly, for at least 

this reason,8 we reject American National’s argument that 

the Board should have rejected Sleep Number’s motion to 

amend because of an alleged inventorship issue. 

IV

Next, we address American National’s argument that 

the Board violated due process and the APA when analyzing Sleep Number’s evidence of commercial success. Addressing nexus, the Board stated that American National

“does not refute the testimonies of Dr. Abraham and 

Dr. Edwards that these versions of the source code fall 

within the claims of the ’747 patent such that ANM’s products using these versions read on the claims.” Based on 

this sentence, American National argues that the Board inappropriately resolved infringement in violation of either 

8 There may well be additional reasons why this argument fails. For example, it is unclear whether the Board 

is authorized to address inventorship in the context of a 

motion to amend. Cf. 35 U.S.C. § 116(c) (providing that, 

outside the IPR context, “the Director may permit the application to be amended” to fix inventorship errors). Further, even if the proposed amended claims in this case did 

inject an inventorship issue, American National identifies 

no statutory or regulatory prohibition on patent owners 

making such amendments. See 35 U.S.C. § 316(d)(3); 

37 C.F.R. § 42.121. In any event, because American National has not shown that James Gifft is an inventor of the 

patents-in-suit, we do not address this issue further. 

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20 AMERICAN NATIONAL v. SLEEP NUMBER CORPORATION

or both of the Constitution or the APA. Appellant’s 

Br. 55–61. We disagree and note that the Board itself 

made clear that it was not resolving infringement issues

by, among other things, changing the wording from “infringe” to “read on” in its final written decisions. 

We decline to address this argument further because

American National does not challenge the Board’s finding 

that Sleep Number’s evidence of commercial success “has 

minimal probative weight.” ’747 Decision at 94. Accordingly, American National’s argument would not change the 

Board’s patentability determination on appeal. Indeed, 

American National concedes that its challenge to the 

Board’s “read on” finding “would not change the patentability determinations.” Appellant’s Br. 59. 

In SkyHawke Technologies, LLC v. DECA International Corp., we dismissed the appeal of a patent owner in 

an analogous situation. 828 F.3d 1373, 1375 (Fed. Cir. 

2016). There, the patent owner sought only to “correct” the 

Board’s claim construction underlying its patentability determination, not to alter the Board’s patentability determination itself. Id. We reasoned that SkyHawke was merely 

trying to preempt the possibility that the district court 

would adopt the Board’s construction. Id. at 1375–78; see 

also, e.g., Pirlott v. NLRB, 522 F.3d 423, 433 (D.C. Cir. 

2008) (“Where . . . a judgment gives a party all the relief 

requested, an appeal may not be taken simply to challenge 

the Board’s reasoning.”). Here, American National concedes that its challenge to the Board’s “read on” decision 

“would not change the patentability determinations.” Appellant’s Br. 59. Like the appellant in SkyHawke, American National will have the opportunity to argue 

infringement in the district court (and, if necessary, on appeal from the district court’s judgment). 

V 

The parties’ additional arguments on appeal are unpersuasive. We have considered American National’s 

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AMERICAN NATIONAL v. SLEEP NUMBER CORPORATION 21

challenges to the Board’s conclusion that the six dependent 

claims requiring multiplicative pressure adjustment factors (claims 5, 6, and 13 of the ’747 patent and claims 5, 6, 

and 15 of the ’154 patent) would not have been obvious at 

the time of the invention. We conclude that substantial evidence supports the Board’s finding that American National did not meet its burden to show that a skilled artisan 

would have been motivated to combine Ebel with Gifft in 

view of Mittal and Pillsbury to satisfy the elements of these 

claims. 

Turning to Sleep Number’s cross-appeal, we likewise 

conclude that substantial evidence supports the Board’s 

finding that a skilled artisan would have been motivated to 

combine Gifft, Mittal, and Pillsbury. The Board reasonably 

found that a person of ordinary skill (1) would have been 

motivated to improve the accuracy and speed of Gifft’s 

pressure adjust cycles; and (2) would have understood from 

Mittal that dynamic inflation/deflation offset values can be 

used to achieve that goal. Expert testimony and the references themselves support these findings. While the particular equations in Mittal and Pillsbury might not fit directly 

into Gifft, the Board’s findings are consistent with the Supreme Court’s guidance that the “person of ordinary skill 

is also a person of ordinary creativity, not an automaton.” 

KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398, 421 (2007); see 

also Fleming v. Cirrus Design Corp., 28 F.4th 1214, 1223 

(Fed. Cir. 2022) (affirming the Board’s obviousness determination which was “the result of a faithful application of 

our law on obviousness, including KSR’s directive to consider the creativity of the ordinarily skilled artisan”). 

Similarly, we are not persuaded to reweigh the Board’s 

assessment of the strength of Sleep Number’s evidence of 

commercial success and industry praise. The Board thoroughly analyzed and considered the parties’ evidence, and 

we cannot say that its findings were unreasonable.

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22 AMERICAN NATIONAL v. SLEEP NUMBER CORPORATION

We next consider Sleep Number’s argument that the 

Board misallocated the burden of persuasion. Contrary to 

Sleep Number’s assertion, we do not read the Board’s decisions as improperly placing the burden on Sleep Number 

to prove non-obviousness of its claims. See Cross-Appellant’s Principal & Resp. Br. 57–64. After reading the decisions as a whole, we are convinced that the Board properly 

analyzed the obviousness issue, first setting forth its fact 

findings and reasoning for why it concluded that the claims 

would have been obvious and then responding to Sleep

Number’s specific contrary arguments. See ’747 Decision

at 48–68. The portions of the opinion that Sleep Number 

quotes as allegedly improperly shifting the burden are 

largely taken from the later sections in the opinion where 

the Board affirmatively responded to Sleep Number’s arguments regarding the proposed combinations. See 

id. at 53–68. Overall, we conclude that the Board’s opinion 

is most fairly read as properly allocating the burden of persuasion. 

Finally, we see no abuse of discretion in the Board’s 

conclusion that American National satisfied the requirements of 37 C.F.R. § 42.104. That regulation requires petitioners to, for each means-plus-function term in the 

challenged claims, “identify the specific portions of the 

specification that describe the structure . . . corresponding 

to each claimed function.” Id. § 42.104(b)(3). Sleep Number argues that American National did not expressly provide a construction for the claim term “pressure sensing 

means” and thus did not comport with the Board’s rules for 

petitioners. In both decisions, however, the Board determined that American National sufficiently identified the 

structure and function of the “pressure sensing means” 

term. In other words, the Board found that American National had done enough to meet the requirements of this 

rule. We give deference to the Board’s application of its 

own rules. See Ericsson, 901 F.3d at 1379 (citing Bilstad 

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AMERICAN NATIONAL v. SLEEP NUMBER CORPORATION 23

v. Wakalopoulos, 386 F.3d 1116, 1121 (Fed. Cir. 2004)). Accordingly, we affirm on this issue. 

CONCLUSION

For the reasons stated above, we affirm the Board’s final written decisions in both proceedings.

AFFIRMED

COSTS

No costs.

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