       NOTE: This disposition is nonprecedential.


  United States Court of Appeals
      for the Federal Circuit
                ______________________

            HILL-ROM SERVICES, INC.,
                   Appellant

                           v.

JOSEPH MATAL, PERFORMING THE FUNCTIONS
 AND DUTIES OF THE UNDER SECRETARY OF
 COMMERCE FOR INTELLECTUAL PROPERTY
AND DIRECTOR, U.S. PATENT AND TRADEMARK
                 OFFICE,
                 Intervenor
           ______________________

                      2016-2199
                ______________________

    Appeal from the United States Patent and Trademark
Office, Patent Trial and Appeal Board in No. 95/002,055.
                  ______________________

              Decided: December 15, 2017
                ______________________

   LUKE DAUCHOT, Kirkland & Ellis LLP, Los Angeles,
CA, argued for appellant. Also represented by GARRET A.
LEACH, BRIAN VERBUS, Chicago, IL.

   FARHEENA YASMEEN RASHEED, Office of the Solicitor,
United States Patent and Trademark Office, Alexandria,
2                           HILL-ROM SERVICES, INC.   v. MATAL



VA, argued for intervenor. Also represented by NATHAN
K. KELLEY, THOMAS W. KRAUSE.
                ______________________

    Before O’MALLEY, HUGHES, and STOLL, Circuit Judges.
O’MALLEY, Circuit Judge.
     Hill-Rom Services, Inc. (“Hill-Rom”) appeals from a
final decision in an inter partes reexamination proceeding,
in which the Patent Trial and Appeal Board (“Board”)
affirmed an Examiner’s rejection of claims 1, 14–15, and
31–32 of U.S. Patent No. 7,669,263 (“’263 patent”). See
Stryker Corp. v. Hill-Rom Servs., Inc., No. 2015-007927,
2016 WL 1270198 (P.T.A.B. Mar. 31, 2016) (“Board Deci-
sion”). For the following reasons, we reverse in part,
vacate in part, and remand.
                 I. FACTUAL BACKGROUND
                    A. The ’263 Patent
    Hill-Rom’s ’263 patent, titled “Mattress Assembly In-
cluding Adjustable Length Foot,” is directed to a “patient
support” apparatus, such as a hospital bed. The specifica-
tion explains that prior art hospital beds typically con-
tained, among other things, a frame, a mattress, siderails,
and a “controller configured to control one or more fea-
tures of the bed.” ’263 patent, col. 1, ll. 48–55. The ’263
patent, however, purports to provide a more sophisticated
system in which various bed functions are controlled by
“modules” that communicate with one another through an
internal network. Id. col. 10, ll. 39–65; id. col. 29, ll. 39–
42.
    The claimed hospital bed includes a control system,
which, in turn, includes various controls, interfaces,
sensors, and actuators that communicate via a plurality of
modules connected to a network. In one embodiment, the
network is a “controller area network” (“CAN”) comprising
a serial data bus. Id. col. 29, ll. 46–51. Modules com-
HILL-ROM SERVICES, INC.   v. MATAL                     3



municate with each other by transmitting messages on
the bus, which rebroadcasts the messages to all other
modules on the network. Id. col. 29, ll. 51–59. The ’263
patent describes this CAN-based system “as a masterless
system, wherein each module operates substantially
autonomously.” Id. col. 30, ll. 40–43.
    As issued, the ’263 patent contains twenty claims.
During reexamination, however, Hill-Rom amended
certain claims and added others. In particular, Hill-Rom
amended claim 1 by adding language requiring the con-
trol system to “periodically” verify the functionality of
each module, as shown below:
   1. A patient-support apparatus comprising
       a control system including a serial data
        bus and a plurality of control modules
        coupled to the serial data bus, each con-
        trol module including a microcontroller
        and a transceiver operable to communi-
        cate over the serial data bus by sending
        a message out on the serial data bus,
       wherein the control system periodically
        verifies the functionality of each module
        present,
       wherein each of the modules is operable to
        monitor communications on the serial
        data bus to determine whether to pro-
        cess a particular message.
J.A. 2490 (emphasis added). Amended claim 14 and its
dependent claim, claim 15, recite the same “periodically”
limitation as recited in claim 1. J.A. 2490–91.
    Also during reexamination, Hill-Rom added claim 31
and its dependent claim, claim 32. Claim 31, which
depends from amended claim 2, requires that the control
system comprise a CAN, as well as a “module that oper-
4                           HILL-ROM SERVICES, INC.   v. MATAL



ates as a master for particular communications over the
control system.” 1 J.A. 2490; J.A. 2493 (emphasis added).
    On appeal, the parties dispute the meaning of the “pe-
riodically” limitation recited in amended claims 1 and 14–
15, as well as the “master module” limitation recited in
newly added claims 31–32.
               B. Overview of the Prior Art
    The Board affirmed in relevant part the Examiner’s
rejections of the claims based on several combinations of
prior art references. On appeal, however, the parties
focus on two references: (1) U.S. Patent No. 5,771,511, to
Kummer (“Kummer”), and (2) Holger Zeltwanger, Design-
ing Devices Using CAN and CANopen Buses for Network-
ing, Med. Elecs. Mfg. 64 (1999) (“Zeltwanger”). 2 We
therefore limit our review to only those references.
                        1. Kummer
    The Kummer patent is owned by Hill-Rom and is in-
corporated by reference in the ’263 patent. Like the ’263
patent, Kummer discloses an adjustable hospital bed
comprising a plurality of interconnected modules. Unlike
the ’263 patent, however, Kummer teaches that its mod-
ules are interconnected by “a twisted pair network chan-
nel in a peer-to-peer configuration.” Kummer, col. 5, ll.
25–27; ’263 patent, col. 29, ll. 42–49. Kummer’s peer-to-



    1   Claim 2 is similar to claim 1 but does not include
the “periodically” limitation, and instead specifies that the
control system comprises a CAN. J.A. 2490.
    2   According to Hill-Rom, “its arguments apply
equally to all of the anticipation and obviousness rejec-
tions maintained by the Examiner” as to all prior art of
record. Appellant’s Br. 19–20. Neither Hill-Rom nor the
PTO, however, addresses the other prior art references in
any meaningful detail.
HILL-ROM SERVICES, INC.   v. MATAL                         5



peer network enables each module “to communicate
directly with another module in the network without the
need for a master controller.” Kummer, col. 1, ll. 20–24.
    Kummer also teaches that a “diagnostic tool” can be
used to allow “a remote operator to interrogate every
module” to perform a diagnostic check. Id. col. 8, ll. 10–
23. Additionally, Kummer discloses that “each module is
able to perform internal diagnostics,” but specifies that
such self-diagnostic checks can only be executed “[a]fter a
module performs its dedicated function”—i.e., when the
module is not in use. Id. col. 20, ll. 28–32.
                       2. Zeltwanger
    Zeltwanger generally discloses a CAN for use in medi-
cal equipment. In particular, Zeltwanger employs a
standardized serial bus system to “develop devices that
can be easily linked to other systems.” J.A. 4236.
     Importantly for this appeal, Zeltwanger describes a
“standardized communication object” called a “service
data object” or “SDO.” An SDO is a protocol that allows
for the transmission of data objects of any size, in contrast
to other protocols, which generally restrict data transmis-
sion to fewer than eight bytes. J.A. 4235. Zeltwanger
explains that its control system can support an SDO for
communicating data across the network.
              II. PROCEDURAL BACKGROUND
    Third-party Stryker Corporation (“Stryker”) requested
inter partes reexamination of most claims of the ’263
patent. The Examiner rejected all challenged claims,
finding that, inter alia, claim 1 is anticipated by three
separate references, including Kummer. The Examiner
also found that claims 1, 14–15, and 31–32 are obvious
over Kummer and other references, including Zeltwanger.
The Board affirmed in relevant part. See Board Decision,
2016 WL 1270198, at *7, 10–14.
6                          HILL-ROM SERVICES, INC.   v. MATAL



    In its decision, the Board construed “periodically,” as
recited in amended claims 1 and 14–15, to mean “both at
regular and intermittent or irregular intervals.” Id. at *5
(emphases added). In so ruling, the Board rejected Hill-
Rom’s argument that the claims should be limited to a
preferred embodiment described in the patent, in which
each module “periodically” transmits a regular “heart-
beat” message to the other modules. Id. at *5–6. The
Board found that Kummer’s internal diagnostic check
satisfies the “periodically” limitation under the Board’s
construction.
    The Board also determined that Zeltwanger’s disclo-
sure of an SDO satisfies the master module limitation
recited in newly added claims 31–32, in part because Hill-
Rom failed to provide “a definition of ‘module’ that would
exclude an SDO.” Id. at *11. The Board agreed with the
Examiner that a skilled artisan would have found it
obvious to “make the diagnostic tool of Kummer an SDO
module” as taught by Zeltwanger. Id.
    Hill-Rom appealed the Board’s decision to this court,
and the parties subsequently reached a settlement
agreement pursuant to which Stryker withdrew from the
appeal. The Director of the U.S. Patent & Trademark
Office (“PTO”) thereafter intervened under 35 U.S.C.
§ 143.     We have jurisdiction under 28 U.S.C.
§ 1295(a)(4)(A).
                     III. DISCUSSION
    Hill-Rom raises two principal arguments on appeal.
First, with regard to claims 1 and 14–15, Hill-Rom argues
that the Board erred by construing “periodically” to
encompass both regular and irregular verification checks.
According to Hill-Rom, the term “periodically” should be
limited to regular checks, which Kummer does not dis-
close. Second, with regard to claims 31–32, Hill-Rom
argues that the Board erred both by interpreting the
master module limitation to encompass non-physical
HILL-ROM SERVICES, INC.   v. MATAL                       7



objects, and by finding that Zeltwanger’s non-physical
SDO is a master module. We address each argument in
turn.
                   A. Claims 1, 14–15
             1. Construction of “periodically”
    During inter partes reexamination, claims are given
their broadest reasonable construction consistent with the
specification. In re Rambus, Inc., 753 F.3d 1253, 1255
(Fed. Cir. 2014). We review the Board’s claim construc-
tions de novo and its underlying factual determinations
involving extrinsic evidence for substantial evidence.
Teva Pharm. USA, Inc. v. Sandoz, Inc., 135 S. Ct. 831,
841–42 (2015).
    As described above, the Board construed the “periodi-
cally” limitation to mean “both at regular and intermit-
tent or irregular intervals.” Board Decision, 2016 WL
1270198, at *5. While the parties vigorously debate
whether the claims cover “regular” or “irregular” verifica-
tion checks, they do not clearly explain what those terms
mean in the context of the claimed invention or in the
context of the rejections at issue in this appeal. Nor were
they able to do so when pressed at oral argument.
    In any event, to the extent the Board’s construction
does not limit the claims to verification checks that occur
at equally spaced time intervals (e.g., every 10 minutes),
we agree with that construction. As the Board correctly
determined, the plain and ordinary meaning of the term
“periodically” connotes repetition, but does not require
that the repeated action occur at regularly spaced time
intervals. Id. at *4–5. The claims’ recitation of this term
is entirely consistent with its plain meaning, and the
patentee’s decision to amend certain other claims to
require regular periodicity underscores this broad under-
standing. Claim 14, for example, requires that the control
system “periodically verif[y] the functionality of each
8                          HILL-ROM SERVICES, INC.   v. MATAL



module.” J.A. 2490. The claim was amended during
reexamination, however, to add language requiring that
the modules be “operable to transmit, at regular intervals,
a status message over the network.” Id. (emphasis add-
ed). The presence of both “periodically” and “at regular
intervals” in amended claim 14 strongly suggests that the
term “periodically,” standing alone, is not limited to
diagnostic checks that occur at regular intervals. See
CAE Screenplates Inc. v. Heinrich Fiedler GmbH & Co.
KG, 224 F.3d 1308, 1317 (Fed. Cir. 2000) (“In the absence
of any evidence to the contrary, we must presume that the
use of these different terms in the claims connotes differ-
ent meanings.”).
    To the extent the Board’s construction is broad
enough to encompass verification checks that occur ran-
domly (i.e., on an ad hoc basis), however, we disagree with
that construction. The verification checks must repeat at
spaced time intervals, though, not necessarily at equally
spaced intervals. The ’263 patent is replete with exam-
ples that support this conclusion. The specification de-
scribes, for example, an embodiment in which each
module “periodic[ally]” transmits a “heartbeat” message
to allow the control system to “periodically” verify the
module’s functionality:
    One feature of [the] network is the periodic
    transmission of each module of a “heartbeat” mes-
    sage or status message to the bus for receipt by
    each of the remaining modules. In this manner,
    control system periodically verifies the functional-
    ity of each module in [the] system, and is able to
    identify a non-operational module by the absence
    of the module’s “heartbeat” message.
’263 patent, col. 30, ll. 43–50 (emphases added, reference
numerals omitted). This passage states that the modules
repeatedly transmit a status message at specified time
intervals, and without prompting from the control system
HILL-ROM SERVICES, INC.   v. MATAL                            9



or any other external source. The absence of such a
message for a particular module signals to the control
system that the module is non-functional. Indeed, as
explained at column 30, lines 43 to 50, if the modules’
status messages were not repeated without the modules
being prompted, the control system would not know when
to receive a status message, and it would therefore be
unable to determine whether the absence of a message
indicates a problem. Thus, while we agree with the Board
that the claims are not limited to the regularly repeated
“heartbeat” verification check described in this passage,
the passage’s description of “periodically” at least sug-
gests that the modules must repeatedly transmit their
status messages at specified time intervals, and without
the modules being prompted.
    Other passages of the specification are consistent with
this embodiment. The specification states, for example,
that a “monitor activity step” “is a step that is periodically
executed during the turn assist operation,” that a “pres-
sure control system” “periodically measure[s] the pressure
of seat section air zone to make sure that it is within the
desired ranges,” and that pressure sensors “periodically
sense the pressure in one or more of controlled air zones”
of the mattress. Id. col. 81, ll. 65–66; id. col. 83, ll. 60–63;
id. col. 96, ll. 18–22 (emphases added). Each of these
descriptions suggests that an action is repeated without
prompting from an external source. The specification also
states that a “timer is used to periodically sample tem-
perature.” Id. col. 42, ll. 34–37 (emphasis added). The
requirement that a timer be used for this purpose implies
that the temperature is sampled at specified time inter-
vals. There would be no need for a timer if the tempera-
ture were sampled randomly.
    Finally, our interpretation is consistent with the pros-
ecution history. During reexamination, Hill-Rom amend-
ed claim 1 by adding the “periodically” limitation.
Contemporaneous with that amendment, Hill-Rom dis-
10                          HILL-ROM SERVICES, INC.   v. MATAL



tinguished Kummer on the basis that Kummer’s internal
diagnostic checks occur only when the modules are no
longer performing a function. J.A. 2495–96. Hill-Rom
also emphasized during the proceeding that Kummer
“teaches an ad hoc or intermittent self-diagnostic process”
and fails to “disclose that any self-diagnosis is done on
any periodic schedule.” J.A. 2862–64. These statements,
made when the “periodically” limitation was added to
claim 1, are relevant as part of the ’263 patent’s prosecu-
tion history. See Northpeak Wireless, LLC v. 3COM
Corp., 674 F. App’x 982, 986 n.1 (Fed. Cir. 2016) (“State-
ments made during reexamination procedures before the
PTO are part of the prosecution history.” (citing Krippelz
v. Ford Motor Co., 667 F.3d 1261, 1266 (Fed. Cir. 2012))).
Consistent with the specification, these statements sug-
gest that “periodically” cannot mean “ad hoc or intermit-
tent.”
    Thus, while the Board’s construction is correct, it is
incomplete. We find that, while the ’263 patent claims
are not limited to verification checks performed at equally
spaced time intervals, they do not cover random or ad hoc
verification checks, or checks that occur only when the
modules are prompted to transmit status messages. This
is the broadest reasonable interpretation that is con-
sistent with the claims, specification, and file history. See
In re Smith Int’l, Inc., 871 F.3d 1375, 1383 (Fed. Cir.
2017).
        2. Anticipation and Obviousness Findings
    As described above, the Board determined that Kum-
mer anticipates claim 1 and renders claim 1 and 14–15
obvious in view of the other prior art of record. We review
the Board’s anticipation determination, as well as the
Board’s factual findings underlying its obviousness de-
termination, for substantial evidence. Rambus, 753 F.3d
at 1256; In re Adler, 723 F.3d 1322, 1325 (Fed. Cir. 2013).
HILL-ROM SERVICES, INC.   v. MATAL                      11



We review the Board’s ultimate legal conclusion of obvi-
ousness, however, de novo. Adler, 723 F.3d at 1325.
    We find that the Board erred in determining that
Kummer discloses the “periodically” limitation. Kummer
discloses only that a “diagnostic check can be performed,”
and even then, only “[a]fter [the] module performs its
dedicated function.” Kummer, col. 20, ll. 28–35 (empha-
ses added); see also id. col. 2, ll. 20–24 (“The network is
capable of internally diagnosing hardware and software
failures and recommending a corrective action.” (empha-
sis added)). To the extent Kummer’s diagnostic checks
are performed at all, they are performed randomly or on
an ad hoc basis, and after the modules are prompted. As
we explained above, such verification checks fall outside
the scope of the claims. The Board’s finding that Kummer
satisfies this claim limitation is therefore unsupported by
substantial evidence.
    Because Stryker did not argue that Kummer inher-
ently discloses the “periodically” limitation, and because
the Board made no factual findings that would support
such a conclusion, we reverse the Board’s determination
that Kummer anticipates claim 1 of the ’263 patent. See
Home Semiconductor Corp. v. Samsung Elecs. Co., 701 F.
App’x 1006, 1013–14 (Fed. Cir. 2017) (reversing where the
appellee argued that a prior art reference inherently
disclosed a particular claim limitation but failed to so
argue below, and the Board did not make factual findings
that would support that conclusion).
    Similarly, with regard to its obviousness finding for
claim 1, the Board relied only on Kummer for its disclo-
sure of this limitation and did not find that a skilled
artisan would have modified Kummer to perform repeated
diagnostic checks. See Board Decision, 2016 WL 1270198,
at *9. And, as the PTO acknowledges, claims 14–15 stand
or fall with claim 1. Intervenor’s Br. 7. We therefore
12                         HILL-ROM SERVICES, INC.   v. MATAL



reverse the Board’s determination that Kummer renders
obvious claims 1 and 14–15 of the ’263 patent.
                    B. Claims 31–32
    As described above, the Board affirmed the Examin-
er’s rejections of claims 31–32 based on the Examiner’s
finding that Zeltwanger’s SDO satisfies the “module that
operates as a master” limitation recited in those claims.
Zeltwanger’s SDO is a non-physical communication
protocol, akin to the language used for transmission of
communications on a network. Although the Board did
not construe the master module limitation, Hill-Rom
argues that the Board improperly interpreted that term to
include non-physical objects, such that the Board erred in
finding that Zeltwanger’s SDO is a master module.
     As an initial matter, regardless of whether a master
module is a physical structure, the Board erred to the
extent it concluded that Zeltwanger’s SDO is a master
module. The ’263 patent states that the prior art SDO
protocol—i.e., the same protocol disclosed in Zeltwanger—
“is administered only by a master module.” ’263 patent,
col. 34, ll. 7–8 (emphasis added). This statement makes
clear that, although the existence of an SDO might imply
the existence of a master module, an SDO is not itself a
master module.       Zeltwanger’s SDO therefore cannot
expressly satisfy the master module limitation recited in
claims 31–32, and the Board erred in so finding.
    The Board also erred to the extent it concluded that a
master module need not be a physical structure. Claim 2,
from which claims 31–32 depend, states that “control
modules” are “coupled to the serial data bus,” and that
each module includes “a microcontroller and a transceiver
operable to communicate over the serial data bus.”
J.A. 2490. The modules’ inclusion of physical structure
implies that they are themselves physical structures. The
specification supports this interpretation. It states, for
example, that the modules “include[] a controller, a trans-
HILL-ROM SERVICES, INC.   v. MATAL                          13



ceiver and associated electronics,” and that the modules
contain hardware that enables “operation according to the
CAN specifications.” ’263 patent, col. 29, ll. 47–49; id. col.
32, ll. 60–64. The specification further states that a “logic
module” “is electrically coupled to detachable siderail
controller.” Id. col. 29, ll. 65–67; id. col. 30, ll. 1–5. Only
a physical device can be “electrically coupled” to another
physical device. And, because Zeltwanger’s SDO is not a
physical device, the Board’s finding that Zeltwanger’s
SDO satisfies the master module limitation is unsupport-
ed by substantial evidence.
    At oral argument before this court, the PTO asserted
that the Examiner and Board did not actually equate an
SDO with a master module, but instead used the term
“SDO” as “shorthand” for an “SDO module” or a “module
that administers an SDO.” Oral Argument at 14:00–
14:25, Hill-Rom Servs., Inc. v. Matal (No. 2016-2199),
http://oralarguments.cafc.uscourts.gov/default.aspx?fl=
2016-2199.mp3. We disagree with this characterization.
     Stryker argued during reexamination that “the SDO
feature of [Zeltwanger’s network protocol] meets” the
master module claim limitation. J.A. 2357. The Examin-
er appeared to agree, stating that Zeltwanger satisfies the
master module limitation because it teaches that “some
modules are SDOs that transmit particular messages of
any size compared to regular modules that are restricted
to less than 8 bytes[.]” J.A. 2666; J.A. 2991–92. The
Board itself agreed with the Examiner’s finding. Immedi-
ately after quoting Hill-Rom’s argument that SDOs are
not physical structures, the Board noted that Hill-Rom
failed to provide a definition of module “that would ex-
clude an SDO.” Board Decision, 2016 WL 1270198, at
*11. The Board also stated that “it would be inconsistent
for [Hill-Rom] to argue that an SDO cannot serve as a
master.” Id. We read these statements in context to
mean that the Board found that an SDO is a master
14                          HILL-ROM SERVICES, INC.   v. MATAL



module. As described above, that finding is unsupported
by substantial evidence.
     The PTO conceded at oral argument that a master
module is a physical structure. Oral Argument at 14:10–
14:15 (“We are talking about hardware.”). But, it asserted
that the Board made alternative findings that support
affirmance. Again, we disagree. The balance of the
Board’s analysis, in its entirety, is as follows:
     With respect to the SDO to [sic] operating on a
     module, the Examiner found “[i]t would have been
     obvious to one having ordinary skill in the art to
     make the diagnostic tool of Kummer an SDO
     module as taught in Zetlwanger [sic] (1999). One
     having ordinary skill in the art would do so to al-
     low the diagnostic tool to operate as a master to
     send messages over the bus line of any size.” Pa-
     tent Owner did not identify a defect in this rea-
     soning. Consequently, we affirm the rejection of
     claim 31 for the reasons set forth above.
Id. (citation omitted). To the extent the PTO argues that
these statements imply that the Board found that Kum-
mer’s unmodified diagnostic tool is a master module, or
that Zeltwanger inherently discloses a master module, we
reject that argument. The statements cannot be fairly
read to support such conclusions. 3



     3  Our case law establishes a “high standard in order
to rely on inherency to establish the existence of a claim
limitation in the prior art in an obviousness analysis[.]”
Par Pharm., Inc. v. TWI Pharm., Inc., 773 F.3d 1186,
1195–96 (Fed. Cir. 2014). The limitation at issue either
necessarily must be present, or must be the natural result
of the combination of elements explicitly disclosed by the
prior art. Id. There is no evidence in the record, and the
Board did not find, that Stryker satisfied this standard.
HILL-ROM SERVICES, INC.   v. MATAL                       15



     At most, these statements by the Board are ambigu-
ous. One reading of the statements is that the Board
found only that Zeltwanger’s SDO is a master module,
and that a skilled artisan would have been motivated to
convert Kummer’s diagnostic tool into an SDO. Another
plausible reading is that, even if an SDO is not itself a
master module, the Board found that a skilled artisan
would have known that Kummer’s diagnostic tool could
act as a master module by administering Zeltwanger’s
SDO. Based on the cursory nature of the Board’s analy-
sis, however, we cannot determine which, if either, inter-
pretation is correct. And we will not “guess at the theory
underlying the” Board’s action, SEC v. Chenery Corp., 332
U.S. 194, 196–97 (1947), or assume that the Board meant
one thing when it said something else.
     Our review of the Board’s decision “is rooted not just
in the law of obviousness but in basic principles of admin-
istrative law.” Personal Web Techs., LLC v. Apple, Inc.,
848 F.3d 987, 992 (Fed. Cir. 2017). The Board must
therefore “explicate its factual conclusions, enabling us to
verify readily whether those conclusions are indeed sup-
ported by ‘substantial evidence’ contained within the
record.” In re Gartside, 203 F.3d 1305, 1314 (Fed. Cir.
2000); see also Power Integrations, Inc. v. Lee, 797 F.3d
1318, 1326–27 (Fed. Cir. 2015) (holding that the Board’s
reasoning must be set out “in sufficient detail to permit
meaningful appellate review”). The Board has not done so
here, and it is not our role to make factual findings in the
first instance. See Mittal Steel Point Lisas Ltd. v. United
States, 542 F.3d 867, 875 (Fed. Cir. 2008) (“Appellate
courts do not make factual findings; they review them.”).
Because we are unable to discern the basis for the Board’s
obviousness determinations with respect to claims 31–32,
we vacate the Board’s decision as to those claims. See
Power Integrations, 797 F.3d at 1326–27.
   We conclude, moreover, that the Board’s motivation to
combine analysis for this claim limitation is likewise
16                         HILL-ROM SERVICES, INC.   v. MATAL



cursory. Rather than articulate reasons why it agreed
with the Examiner’s analysis, the Board affirmed the
rejection merely because, in its view, Hill-Rom did not
identify a defect in the Examiner’s reasoning. 4 But even
the Examiner’s reasoning—i.e., that a skilled artisan
would combine the references “to allow the diagnostic tool
to operate as a master to send messages over the bus line
of any size”—is conclusory. Board Decision, 2016 WL
1270198, at *11. In any event, it is not enough to merely
“summarize and reject arguments without explaining why
the [Board] accepts the prevailing argument.” In re
Nuvasive, Inc., 842 F.3d 1376, 1383–84 (Fed. Cir. 2016).
The Board’s failure to clearly articulate a motivation to
combine provides an additional reason for vacating its
obviousness ruling. See id.; see also In re Van Os, 844
F.3d 1359, 1361–62 (Fed. Cir. 2017) (vacating obviousness
determination where the Board “did not explain why
modifying” the prior art “would have been ‘intuitive’ or
otherwise identify a motivation to combine”); Personal
Web, 848 F.3d at 993–94 (vacating obviousness ruling
where Board’s motivation to combine analysis was “want-
ing”).



     4  In its analysis of claim 2, from which claims 31–32
depend, the Board incorporated by reference its decision
in another inter partes reexamination of a different patent
that involved the same parties and prior art. Board
Decision, 2016 WL 1270198, at *8–9 (citing Stryker Corp.
v. Hill-Rom Servs., Inc., No. 2014-6135 (P.T.A.B. Oct. 14,
2014), aff’d, 618 F. App’x 681 (Mem.) (Fed. Cir. 2015)).
But in that proceeding, the Board found only that a
skilled artisan would have been motivated to substitute
Kummer’s peer-to-peer network with Zeltwanger’s (and
other references’) CAN. The Board did not address moti-
vation to combine with respect to the master module
limitation at issue here.
HILL-ROM SERVICES, INC.   v. MATAL                     17



     Because the Board affirmed the Examiner’s rejection
of claims 31–32 based only on the combination of Kummer
and Zeltwanger, we vacate the Board’s decision as to
those claims and remand for the Board to set “out its
reasoning in sufficient detail to permit meaningful appel-
late review” under the proper interpretation of the master
module limitation. Power Integrations, 797 F.3d at 1326–
27.
                     IV. CONCLUSION
    For the reasons stated above, we reverse the Board’s
anticipation and obviousness determinations based on
Kummer as to claims 1 and 14–15. We also vacate the
Board’s obvious determinations based on Kummer and
Zeltwanger as to claims 31–32, and remand for proceed-
ings consistent with this opinion.
    Although the Board affirmed the Examiner’s rejec-
tions with respect to the other prior art of record, the
Board’s analysis was “specifically directed to Kummer” as
a primary reference and did not “address each of the
rejections individually.”    Board Decision, 2016 WL
1270198, at *3. Neither Hill-Rom nor the PTO addresses
in meaningful detail any prior art references other than
Kummer and Zeltwanger. Thus, because the other refer-
ences are not before us on appeal, we vacate the Board’s
decision as to claims 1, 14–15, and 31–32 with respect to
all prior art combinations other than those involving
Kummer and Zeltwanger. On remand, the Board is not
permitted to reconsider its invalidity determinations
based on references other than Kummer and Zeltwanger.
  REVERSED IN PART, VACATED IN PART, AND
                REMANDED
                            COSTS
   No costs.
