  United States Court of Appeals
      for the Federal Circuit
                 ______________________

        HILL-ROM SERVICES, INC., HILL-ROM
           COMPANY, INC., AND HILL-ROM
              MANUFACTURING, INC.,
                Plaintiffs-Appellants,

                            v.

   STRYKER CORPORATION (doing business as
     Stryker Medical) AND STRYKER SALES
               CORPORATION,
              Defendants-Appellees.
             ______________________

                       2013-1450
                 ______________________

   Appeal from the United States District Court for the
Southern District of Indiana in No. 11-CV-1120, Judge
Jane Magnus-Stinson.
                ______________________

                 Decided: June 27, 2014
                 ______________________

    DAVID K. CALLAHAN 1, Kirkland & Ellis, LLP, of Chi-
cago, Illinois, argued for plaintiffs-appellants. With him
on the brief were MARY E. ZAUG and JOSHUA M. REED.



    1   Mr. Callahan subsequently withdrew from the
case.
2              HILL-ROM SERVICES, INC.   v. STRYKER CORPORATION



    STEVEN E. DERRINGER, Bartlit Beck Herman Pa-
lenchar & Scott LLP, of Chicago, Illinois, argued for
defendants-appellees.  With him on the brief were
CHRISTOPHER J. LIND and BRIAN C. SWANSON.
                ______________________

        Before MOORE, SCHALL, and REYNA, Circuit Judges.
    Opinion for the court filed by Circuit Judge MOORE.
        Dissenting opinion filed by Circuit Judge REYNA.
MOORE, Circuit Judge.
    Hill-Rom Services, Inc., Hill-Rom Company, Inc., and
Hill-Rom Manufacturing, Inc. (collectively, Hill-Rom)
appeal from the district court’s grant of summary judg-
ment that Stryker Corporation and Stryker Sales Corpo-
ration (collectively, Stryker) do not infringe asserted
claims of U.S. Patent Nos. 5,699,038 (’038 patent),
6,147,592 (’592 patent), and 7,538,659 (’659 patent).
Because the district court’s judgment of non-infringement
was premised on erroneous claim constructions, we re-
verse and remand.
                         BACKGROUND
    The patents-in-suit, which claim priority to the same
parent application, 2 are directed to systems and methods
for enabling hospital personnel to remotely monitor the
status of hospital beds. ’038 patent col. 1 l. 61–col. 2 l. 38.
The patents-in-suit disclose hospital beds equipped with
sensors that monitor bed parameters, such as the pa-
tient’s presence in the bed and the bed height. Id. col. 2 ll.
6–9, col. 5 l. 63–col. 6 l. 23. These systems send data
about the status of a hospital bed to a remote location for
monitoring by hospital personnel. Id. col. 2 ll. 59–65.


    2   The ’592 and the ’659 patents are continuations of
the ’038 patent.
HILL-ROM SERVICES, INC.   v. STRYKER CORPORATION        3



Claim 1 of the ’038 patent, from which asserted claim 13
depends, contains three of the four disputed claim limita-
tions and is treated by the parties as representative:
   A bed status information system . . . comprising:
       at least one bed condition input signal
       generator . . . ;
       an interface board including a proces-
       sor . . . said interface board operable for
       receiving said bed condition input signal
       and processing said input signal to create
       bed condition messages indicating the sta-
       tus of the monitored condition;
       a processing station remote from the bed
       and coupled with said interface board by a
       datalink, the processing station operable
       for receiving said bed condition messages
       over the datalink and processing said
       messages . . . such that the status of the
       monitored condition of the patient bed is
       indicated to attending personnel at a loca-
       tion remote from the bed.
’038 patent claim 1 (emphases added). Claim 17 of the
’592 patent includes the fourth disputed claim term and
recites: “The patient monitoring system . . . wherein the
message includes message validation information.” ’592
patent claim 17 (emphasis added).
    Hill-Rom brought suit against Stryker alleging in-
fringement of various claims. The parties stipulated to
non-infringement based on the court’s construction of the
claim terms “datalink,” “interface board including a
processor,” “message validation information,” and “bed
condition message.” Hill-Rom appeals. We have jurisdic-
tion under 28 U.S.C. § 1295(a)(1).
4           HILL-ROM SERVICES, INC.   v. STRYKER CORPORATION



                       DISCUSSION
     We review claim construction de novo. Lighting Bal-
last Control LLC v. Philips Elecs. N. Am. Corp., 744 F.3d
1272, 1276–77 (Fed. Cir. 2014) (en banc). Claim terms
are generally given their plain and ordinary meanings to
one of skill in the art when read in the context of the
specification and prosecution history. See Phillips v.
AWH Corp., 415 F.3d 1303, 1313 (Fed. Cir. 2005) (en
banc). “There are only two exceptions to this general rule:
1) when a patentee sets out a definition and acts as his
own lexicographer, or 2) when the patentee disavows the
full scope of the claim term either in the specification or
during prosecution.” Thorner v. Sony Computer Entm’t
Am. LLC, 669 F.3d 1362, 1365 (Fed. Cir. 2012).
                      A. “datalink”
    The district court construed the term “datalink” to
mean “a cable connected to the bed that carries data.”
Hill-Rom Servs., Inc. v. Stryker Corp., No. 1:11-CV-1120,
2013 WL 364568, at *8 (S.D. Ind. Jan. 30, 2013) (District
Court Decision). Hill-Rom argues that the district court
erred by limiting “datalink” to a “cable,” i.e., a wired
datalink. It argues that “datalink” should be given its
plain and ordinary meaning, which is a link that carries
data and encompasses both wired and wireless connec-
tions. Stryker argues that the district court was correct
that the plain and ordinary meaning of “datalink” is
limited by the specification to a wired connection. We
agree with Hill-Rom.
    While we read claims in view of the specification, of
which they are a part, we do not read limitations from the
embodiments in the specification into the claims. Liebel-
Flarsheim Co. v. Medrad, Inc., 358 F.3d 898, 904 (Fed.
Cir. 2004). We depart from the plain and ordinary mean-
ing of claim terms based on the specification in only two
instances: lexicography and disavowal. Thorner, 669 F.3d
at 1365. The standards for finding lexicography and
HILL-ROM SERVICES, INC.   v. STRYKER CORPORATION           5



disavowal are exacting. “To act as its own lexicographer,
a patentee must clearly set forth a definition of the dis-
puted claim term other than its plain and ordinary mean-
ing” and must “clearly express an intent to redefine the
term.” Id. at 1365 (quotations omitted).
     “[T]his court has expressly rejected the contention
that if a patent describes only a single embodiment, the
claims of the patent must be construed as being limited to
that embodiment.” Liebel-Flarsheim, 358 F.3d at 906
(listing cases rejecting attempts to import limitations
from the specification into the claims). The court contin-
ued, “[e]ven when the specification describes only a single
embodiment, the claims of the patent will not be read
restrictively unless the patentee has demonstrated a clear
intention to limit the claim scope using ‘words or expres-
sions of manifest exclusion or restriction.’” Id. (quoting
Teleflex, Inc. v. Ficosa N. Am. Corp., 299 F.3d 1313, 1327
(Fed. Cir. 2002)).
      Disavowal requires that “the specification [or prosecu-
tion history] make[] clear that the invention does not
include a particular feature,” SciMed Life Sys., Inc. v.
Advanced Cardiovascular Sys., Inc., 242 F.3d 1337, 1341
(Fed. Cir. 2001), or is clearly limited to a particular form
of the invention, Edwards Lifesciences LLC v. Cook Inc.,
582 F.3d 1322, 1330 (Fed. Cir. 2009) (“[W]hen the pre-
ferred embodiment is described in the specification as the
invention itself, the claims are not necessarily entitled to
a scope broader than that embodiment.”) (quotation
omitted). For example, we have held that disclaimer
applies when the patentee makes statements such as “the
present invention requires . . . ” or “the present invention
is . . . ” or “all embodiments of the present invention
are . . . .” See Regents of Univ. of Minn. v. AGA Med.
Corp., 717 F.3d 929, 936 (Fed. Cir. 2013); Honeywell Int’l,
Inc. v. ITT Indus., Inc., 452 F.3d 1312, 1316–19 (Fed. Cir.
2006); SciMed, 242 F.3d at 1343–44; Astrazeneca AB v.
Hanmi USA, Inc., 554 F. App’x 912, 915 (Fed. Cir. 2013)
6           HILL-ROM SERVICES, INC.   v. STRYKER CORPORATION



(nonprecedential). We have also found disclaimer when
the specification indicated that for “successful manufac-
ture” a particular step was “require[d].” Andersen Corp.
v. Fiber Composites, LLC, 474 F.3d 1361, 1367 (Fed. Cir.
2007) (“Those statements are not descriptions of particu-
lar embodiments, but are characterizations directed to the
invention as a whole.”). We found disclaimer when the
specification indicated that the invention operated by
“pushing (as opposed to pulling) forces,” and then charac-
terized the “pushing forces” as “an important feature of
the present invention.” SafeTCare Mfg., Inc. v. Tele-
Made, Inc., 497 F.3d 1262, 1269–70 (Fed. Cir. 2007). We
found disclaimer when the patent repeatedly disparaged
an embodiment as “antiquated,” having “inherent inade-
quacies,” and then detailed the “deficiencies [that] make it
difficult” to use. Chicago Bd. Options Exch., Inc. v. Int’l
Sec. Exch., LLC, 677 F.3d 1361, 1372 (Fed. Cir. 2012)
(“[T]he specification goes well beyond expressing the
patentee’s preference . . . and its repeated derogatory
statements about [a particular embodiment] reasonably
may be viewed as a disavowal . . . .”). Likewise, we found
disclaimer limiting a claim element to a feature of the
preferred embodiment when the specification described
that feature as a “very important feature . . . in an aspect
of the present invention” and disparaged alternatives to
that feature. Inpro II Licensing, S.A.R.L. v. T-Mobile
USA Inc., 450 F.3d 1350, 1354–55 (Fed. Cir. 2006).
    There is no such disclaimer or lexicography here.
There are no words of manifest exclusion or restriction.
The patents-in-suit do not describe the invention as
limited to a wired datalink. There is no disclosure that,
for example, the present invention “is,” “includes,” or
“refers to” a wired datalink and there is nothing express-
ing the advantages, importance, or essentiality of using a
wired as opposed to wireless datalink. Nor is there lan-
guage of limitation or restriction of the datalink. Nothing
in the specification or prosecution history makes clear
HILL-ROM SERVICES, INC.   v. STRYKER CORPORATION           7



that the invention is limited to use of a cable as a data-
link. Absent such language, we do not import limitations
from the specification into the claims.
    It is true that the specifications of the patents-in-suit
use the terms “datalink 39,” “cable 39,” and “serial data-
link 39” to describe the same component of the preferred
embodiment. ’038 patent col. 12 ll. 61–64, col. 6 ll. 29–33,
47–50. However, those terms are used synonymously only
in describing a particular numbered component in the
figure depicting the preferred embodiment, and never in
describing the datalink of the invention generally. See id.
This disclosed embodiment undisputedly uses a cable to
convey data, and the patent does not disclose an alterna-
tive embodiment that uses a wireless datalink. However,
absent some language in the specification or prosecution
history suggesting that the wired connection is important,
essential, necessary, or the “present invention,” there is
no basis to narrow the plain and ordinary meaning of the
term datalink to one type of datalink—a cable. There are
no magic words that must be used, but to deviate from the
plain and ordinary meaning of a claim term to one of skill
in the art, the patentee must, with some language, indi-
cate a clear intent to do so in the patent. And there is no
such language here.
    In fact, this specification states that the figures de-
picting the use of a wired datalink merely “illustrate
embodiments of the invention.” ’038 patent col. 4 ll. 59–
65; see also id. col. 5 ll. 30–31 (“DETAILED
DESCRIPTION OF SPECIFIC EMBODIMENTS”); id. col.
22 ll. 20–31 (the “description of various embodiments” is
not intended “to restrict or in any way limit the scope of
the appended claims to such detail”). Nothing in the
language of the specification suggests that datalink
should be limited to the cable used in the preferred em-
bodiment. Therefore, we see no basis for deviating from
the plain and ordinary meaning.
8            HILL-ROM SERVICES, INC.   v. STRYKER CORPORATION



    An examiner’s statement during prosecution of later
unrelated U.S. Patent Application No. 13/336,044 (’044
application) that the ’038 patent does “not teach . . . the
bed having a wireless receiver” does not convince us that
one of skill in the art at the time of filing (i.e., the effec-
tive filing date of the patents-in-suit) would understand
“datalink” to be limited to wired connections. The exam-
iner stated only that the ’038 patent specification does
“not teach” a wireless receiver, and he expressed no views
on the meaning of the term “datalink.” No doubt the
patentee would agree with the examiner that the specifi-
cation does not contain an embodiment that teaches use of
a wireless receiver. However, a patent specification need
not disclose or teach what is known in the art. Streck,
Inc. v. Research & Diagnostic Sys., Inc., 665 F.3d 1269,
1288 (Fed. Cir. 2012) (“It is well-established . . . that a
specification need not disclose what is well-known in the
art.”); see also Hybritech Inc. v. Monoclonal Antibodies,
Inc., 802 F.2d 1367, 1384 (Fed. Cir. 1986). The absence of
an embodiment teaching a wireless receiver does not
prevent the claimed datalink from being given its plain
and ordinary meaning at the relevant time. Holding that
the plain meaning of datalink at the time of the filing
included both wired and wireless connections for carrying
data is not inconsistent with the examiner’s statement
that the ’038 patent does not teach a wireless receiver.
We do not interpret the examiner’s statement about the
teachings of the specification as one about his under-
standing of the meaning of the term “datalink” to one of
skill in the art at the time of filing.
    Indeed, the only evidence in the record of how one of
ordinary skill in the art at the time of filing would under-
stand the term “datalink” is from Hill-Rom’s expert. He
testified that as of the effective filing date of the patents-
in-suit, “a person of ordinary skill would understand that
‘datalink’ does not refer solely to physical connection” and
HILL-ROM SERVICES, INC.   v. STRYKER CORPORATION         9



“can be established over wired, wireless, optical, or other
connection.” J.A. 454, 472.
    Stryker does not dispute that wireless datalinks were
known at the time the patent was filed, nor does it sug-
gest that the plain meaning of datalink at the relevant
time was a cable. Instead, Stryker insists that “datalink”
ought to be given its plain and ordinary meaning in the
context of the specification. We agree. This is not, how-
ever, a license to read limitations from the embodiments
in the specification into the claims. The plain and ordi-
nary meaning of datalink at the relevant time is a connec-
tion that carries data. And neither the specification nor
the prosecution history gives reason to limit the term to a
wired connection.
    This construction—a datalink is a link that carries
data and can be wired or wireless—is supported by the
claims of the patent. The ’659 patent contains several
dependent claims that expressly recite the requirement of
a wired datalink, and they depend from independent
claims that do not contain such a requirement. Claim 2,
which depends from claim 1, recites “[t]he system of claim
1, wherein the datalink comprises a wired datalink.” ’659
patent claim 2. The only distinction between claim 1 and
claim 2 is the limitation that the “datalink” is a wired
datalink. See also id. claims 10, 18. “[T]he presence of a
dependent claim that adds a particular limitation raises a
presumption that the limitation in question is not found
in the independent claim.” Liebel-Flarsheim, 358 F.3d at
910. This presumption is especially strong where the
limitation in dispute is the only meaningful difference
between an independent and dependent claim. Id. Of
course, claim differentiation is not a hard and fast rule,
and the presumption can be overcome by a contrary
construction required by the specification or prosecution
history. Seachange Int’l, Inc. v. C-COR, Inc., 413 F.3d
1361, 1369 (Fed. Cir. 2005). However, nothing in this
specification or prosecution history rebuts the presump-
10          HILL-ROM SERVICES, INC.   v. STRYKER CORPORATION



tion established by the doctrine of claim differentiation.
    The district court explained that if datalink was not
limited to a wired link, and in particular, if the term were
construed to “include wireless communication,” the claim
would not be enabled. District Court Decision at *7.
Enablement concerns do not justify departing from the
plain and ordinary meaning of “datalink.” Where the
meaning of a claim term is clear, as it is here, we do not
rewrite the claim to preserve its validity.           Liebel-
Flarsheim, 358 F.3d at 911. Moreover, the parties point
to no evidence in this record that establishes an enable-
ment problem and the district court did not cite to any.
Id. Courts should be cautious not to allow claim construc-
tion to morph into a mini-trial on validity. Claim terms
should be given their plain and ordinary meaning to one
of skill in the art at the relevant time and cannot be
rewritten by the courts to save their validity. We hold
that “datalink” in the claims at issue is any link over
which data is transferred and can be wired or wireless.
    The dissent argues that our construction is incorrect
because it defines “datalink” in functional terms. But, as
we have previously explained, defining a particular claim
term by its function is not improper and “is not sufficient
to convert a claim element containing that term into a
‘means for performing a specified function’ within the
meaning of [35 U.S.C. § 112(6)].” Greenberg v. Ethicon
Endo-Surgery, Inc., 91 F.3d 1580, 1583 (Fed. Cir. 1996).
Indeed, “[m]any devices take their names from the func-
tions they perform. The examples are innumerable, such
as ‘filter,’ ‘brake,’ ‘clamp,’ ‘screwdriver,’ or ‘lock.’” Id.
There is nothing improper about defining “datalink” as a
link that conveys data. If one of skill in the art at the
relevant time would understand that datalinks can be
both wired and wireless, then the patentee is entitled to
HILL-ROM SERVICES, INC.   v. STRYKER CORPORATION         11



the full range of that claim term. 3
     Next, the dissent contends that a person of ordinary
skill could not have understood “datalink” to include
wireless connections because there is no evidence that
wireless connections were known to persons of ordinary
skill in the art at the relevant time. To the contrary, the
record evidence establishes that wireless connections
were known and used by persons of ordinary skill during
the relevant time frame. The Background of the Inven-
tion of the patents-in-suit describes a prior art patent
disclosing a “personnel locating system” using “infrared
transmitters,” i.e., wireless transmitters, to transmit a
“pulse-coded signal which corresponds to the identity of
the wearer.” ’038 patent col. 1 ll. 42–46 (describing U.S.
Patent No. 4,275,385). This is an unequivocal disclosure,
in the patent itself, of wireless datalinks. Furthermore,
Hill-Rom’s expert testified that at the time of the patent’s
filing, a person of ordinary skill would have understood
“datalink” to include a wireless connection. J.A. 454, 472.
Even Stryker does not dispute that, at the relevant time
period, data could be carried through a wired or wireless
connection. We hold that, consistent with the record
evidence, the plain and ordinary meaning of datalink at
the time of the patent filing would be a link that carries
data in a wired or wireless fashion.
         B. “interface board including a processor”
    The district court construed “interface board including
a processor” as “a board that processes an input signal to



    3   The dissent also raises a concern that our con-
struction of “datalink” could theoretically cover unknown
technologies created in the future. Dissent at 2. Such
unknown technologies are not at issue here, however, and
we see no persuasive reason to depart from the plain and
ordinary meaning of a term based on such unknowns.
12          HILL-ROM SERVICES, INC.   v. STRYKER CORPORATION



create bed condition messages and sends those messages
to a remote location via the wall interface unit.” District
Court Decision at *9. The court noted that “[i]t can also
receive messages through the wall interface unit.” Id.
Hill-Rom argues that the “interface board including a
processor” should be given its plain and ordinary mean-
ing, which is the interface between the bed components
and the off-bed components that processes the bed condi-
tion input signals into bed condition messages. First,
Hill-Rom argues that the district court improperly im-
ported “the wall interface unit” limitation into “interface
board including a processor.” Second, it contends that the
district court erred by requiring the “interface board
including a processor” to receive messages from a remote
location.
     Stryker responds that the district court’s inclusion of
the “wall interface” unit in its construction is supported
by the specification, and argues further that the construc-
tion should require “a board that includes the electronics
that control the sending of messages to, and the receiving
of messages from, a remote location.” It argues that the
patents-in-suit describe the invention as including an
interface board that is capable of sending and receiving
messages from a remote location through the wall inter-
face unit. See ’038 patent col. 3 ll. 53–56; col. 4 ll. 18–21;
col. 19 ll. 4–17. Moreover, Stryker argues that several
dependent claims describe sending messages to the inter-
face board, suggesting that the interface board must be
capable of receiving messages from a remote location. See
id. claims 9, 13, 14, 15, 24.
     We hold that the “interface board including a proces-
sor” is the interface between the bed components and the
off-bed components that processes the bed condition input
signals. An interface is a point of interaction. Interface
devices are sometimes capable of both sending and receiv-
ing data and sometimes limited to sending data. Claim 1
of the ’038 patent articulates with specificity the functions
HILL-ROM SERVICES, INC.   v. STRYKER CORPORATION          13



that the claimed interface board must perform: the inter-
face board must “receiv[e] . . . bed condition input sig-
nal[s],” “process[] said input signal to create bed condition
messages,” and send “bed condition messages over the
datalink” to “the [remote] processing station.” ’038 patent
claim 1. That is all this claim requires in terms of the
functionality of the interface board. Thus the “interface
board including a processor” must receive bed condition
inputs, create the bed condition message, and send it to
the remote processing station. Asserted claim 13 adds the
limitation that the interface board must include a “net-
work port electrically coupled to the operating network for
receiving said network data message, the interface board
operable to process said data message and create a bed
condition message.” While the plain meaning of claim 1
does not require that the interface board be capable of
receiving messages from the remote processing station,
claim 13 adds this functional requirement. Dependent
claims 9, 13, 14, 15, and 24 each add, among other re-
quirements, the functional requirement that the interface
board receive messages from a remote location. ’038
patent claims 9, 13, 14, 15, 24. Under the principles of
claim differentiation, the independent claims are pre-
sumed to be broader. Liebel-Flarsheim, 358 F.3d at 910.
    The asserted claims of the ’038 patent are 13, 20, and
26. The district court is correct that the interface board of
claim 13 must be capable of both sending and receiving
messages from a remote location because the claim ex-
pressly includes these limitations. Claim 20, in contrast,
does not require the interface board to receive messages
from a remote location. Claim 20 depends from independ-
ent claim 19. Claim 19, like claim 1, only requires that
the interface board receive bed condition inputs, create
the bed condition message, and send it to the remote
processing station. Claim 20 only adds a limitation
regarding a data field in the bed condition message that
will allow the processing station to determine the identity
14          HILL-ROM SERVICES, INC.   v. STRYKER CORPORATION



of the patient bed that generated the message. Claim 20
does not include any limitation that would require the
interface board to receive messages from a remote station.
Therefore, claim 20 is not so limited. In fact, claim 24
adds this limitation to claim 19 and under principles of
claim differentiation, claim 20 is presumed not to include
it. Finally, claim 26 is an independent claim that, like
independent claims 1 and 19, requires only that the
interface board receive bed condition inputs, create the
bed condition message, and send it to the remote pro-
cessing station. The interface board of claim 26 is not
required to be capable of receiving messages from a
remote location.
    To be clear, the plain meaning of interface could in-
clude one-way or two-way communication. The claims of
this patent expressly define the requirements of the
interface board. Some of the claims require the interface
board to be able to send messages to a remote location
and other claims require it be capable of both sending and
receiving messages from a remote location.
     There is no disavowal or lexicography in this specifi-
cation that causes us to import the receiving from a
remote location limitation into the claims in which it does
not appear. The specification discloses embodiments in
which the interface board receives messages from a re-
mote location. ’038 patent col. 3 ll. 56–59, col. 18 ll. 27–
44. But there is nothing in the specification that requires
that the interface board include this functionality. There
is no language that extolls the virtues of interfaces that
both send and receive messages or language that dispar-
ages interfaces that only send messages. There is no
language in this patent that an interface board capable of
both sending and receiving is an important, essential, or
critical part of the present invention. The “interface
board including a processor” in claim 20 and 26 is a board
with a processor that is capable of receiving bed condition
HILL-ROM SERVICES, INC.   v. STRYKER CORPORATION            15



inputs, creating the bed condition message and sending it
to the remote processing station.
     Finally, the “interface board including a processor” in
the asserted claims is not required to send messages to a
remote location through a wall interface unit. While it is
true that the specification discloses embodiments in which
the interface board sends the message to a wall interface
unit, which then sends it to a remote location, such a
disclosure does not cause the importation of this structure
into the claims at issue. See, e.g., id. col. 3 ll. 34–44. The
specification states: “In one embodiment of the inven-
tion . . . [t]he LON messages would be received by an
appropriate line transceiver 160 from lines 159 and
processed by microprocessor 140 and sent to the wall
interface unit 40 in accordance with the present inven-
tion.” Id. col. 12 ll. 41–54. The fact that the specification
indicates that in one embodiment, messages are sent to
the wall interface unit “in accordance with the present
invention,” does not mean that a wall interface unit must
be present in all embodiments of the invention. The
specification contains no discussion of the importance,
essentiality, or criticality of the wall unit to the present
invention. In fact, the specification discloses an embodi-
ment in which the interface board sends information to a
remote location without using a wall interface unit inter-
mediary. Id. col. 2 ll. 49–52. The claims at issue do not
require, or even mention, a wall interface unit. There is
no lexicography or disavowal that would support import-
ing this structural limitation from the specification into
the claims. Finally, there are dependent claims that
expressly add this structure. See id. claims 7, 23 (adding
an “interface unit electrically coupled between said inter-
face board and said processing station”). Under principles
of claim differentiation, we presume that the claims
without this limitation do not require it.              Liebel-
Flarsheim, 358 F.3d at 910. To the extent that the dis-
trict court required the “interface board including a
16          HILL-ROM SERVICES, INC.   v. STRYKER CORPORATION



processor” of the claims at issue to send messages to a
remote location via a wall interface unit, it erred.
           C. “message validation information”
    The term “message validation information” appears
only in asserted claim 17 of the ’592 patent, which recites
that “the message includes message validation infor-
mation.” ’592 patent claim 17. The district court con-
strued “message validation information” as “a data field
within a message that is used to verify that the message
was received exactly the same as it was sent.” District
Court Decision at *13. Relevant to this conclusion is the
district court’s undisputed construction of “message” as
“[a] plurality of data fields of appropriate length assem-
bled into a defined structure.” Id. at *9.
     Hill-Rom contends that the term should be given its
plain and ordinary meaning: “information that validates a
message.” It argues that the specification describes
message verification as simply a status message that
indicates that a bed condition message “was received
properly or was not received properly.” ’592 patent col. 14
ll. 12–13. It argues that the message verification embod-
iment disclosed in the specification detects the presence of
certain errors, but cannot evaluate all aspects of a re-
ceived message to confirm that it is exactly the same as
the sent message. See id. col. 18 ll. 20–35. It argues that
the district court’s construction would exclude this embod-
iment, and is therefore presumptively incorrect.
     As an initial matter, we see no reason that “message
validation information” must be limited to a single data
field. There is nothing in the plain meaning of the term
or in the specification that requires all message validation
information to be contained to a single data field. The
district court is correct that “message validation infor-
mation” must be limited to data fields because, based on
the claim language, “message validation information” is
part of a message, and the parties do not dispute that a
HILL-ROM SERVICES, INC.   v. STRYKER CORPORATION          17



message is limited to “a plurality of data fields.” Id. claim
17. The summary of the invention states that the mes-
sage includes “a field for verifying that the message was
received by a node exactly the same as it was sent by the
sending node.” Id. col. 3 ll. 55–57. The preferred embod-
iment also discloses using a CHECKSUM for the verifica-
tion field. Id. col. 13 ll. 47–51. These references are not
sufficient to limit the structure of the message validation
information to a single field. There is no suggestion that
utilizing only a single field is important, essential, criti-
cal, or valuable to the present invention. There are no
words of manifest exclusion. We conclude that “message
validation information” is limited to data fields within the
message, but is not limited to a single data field.
     The parties also dispute what it means to validate the
message. And more particularly, whether the claimed
“message validation information” must verify that the
message is properly received or received exactly, bit by
bit, as sent. To what level of accuracy or detail must the
verification process confirm the message? The plain
meaning of message validation is to ensure that the
message is valid, i.e., that it confirms the message, that it
ensures that the message fulfills its intended purpose,
that the message conveys the intended information. The
specification is consistent with this understanding of
message validation. The patent explains that the bed
message data “includes a plurality of data fields which
indicate the type of message being sent, (i.e., status
message or bed data message), the length of the message
being sent, the actual data of the message (such as status
data or bed data), and a field for verifying that the mes-
sage was received by a node exactly the same as it was sent
by the sending node such as the bed interface board.” Id.
col. 3 ll. 51–57 (emphasis added). This suggests that the
verification should determine whether exactly the same
message was sent. However, the only disclosed embodi-
ment for message verification is a parity checking routine
18           HILL-ROM SERVICES, INC.   v. STRYKER CORPORATION



that uses a CHECKSUM field to determine whether a
“message was received properly or was not received
properly and should be resent.” Id. col. 14 ll. 11–13.
“[T]he CHECKSUM byte [is] equal to the inverted sum of
the other nine message bytes plus one (1). Then, when
the message is received by the receiving mode, the nine
message bytes are added to the CHECKSUM byte . . . .”
Id. col. 18 ll. 26–30. As the specification acknowledges,
the disclosed CHECKSUM is a primitive, coarse verifica-
tion filter. Id. col. 18 ll. 25, 33 (“simple routine”). It sums
up nine bytes each with eight bits. If any two bytes
contain opposite and inaccurate data in the same bit, the
CHECKSUM may not catch the error. For example, if
data field 1 contains a 1 in the first bit (but should have
contained a 0) and data field 2 contains a 0 in the first bit
(but should have contained a 1), the CHECKSUM would
add these up and conclude that the message was properly
sent even though two fields had errors. The specification
acknowledges that errors could also occur in the scenario
the message sent begins with zeros. Id. col. 18 ll. 33–35.
    If, therefore, the “message validation information” is
required to accurately validate that the message sent is
exactly bit-by-bit the same as the message received 100%
of the time, then the only disclosed embodiment, the
simple CHECKSUM, might not be covered by the claim
language. A construction that would exclude the pre-
ferred embodiment “is rarely, if ever, correct and would
require highly persuasive evidentiary support.” Vitronics
Corp. v. Conceptronic, Inc., 90 F.3d 1576, 1583 (Fed. Cir.
1996). That, however, is not the case here. The patent-
ee’s own disclosure contemplates an acceptable rate of
error in the verification process in which the CHECKSUM
embodiment can often, but not always, verify the message
was received exactly as sent. Thus, the claimed valida-
tion need not be flawless to meet the claimed message
validation information limitation—an issue to be resolved
in an infringement analysis.
HILL-ROM SERVICES, INC.   v. STRYKER CORPORATION           19



    As such, we construe “message validation infor-
mation” as one or more data fields within a message that
is used to verify that the message was received exactly
the same as it was sent.
                D. “bed condition message”
    The district court construed “bed condition message”
as “a message not generated in response to any user
request that contains the status of all conditions the bed
is capable of monitoring.” District Court Decision at *12.
As an initial matter, there is nothing in the plain and
ordinary meaning of “bed condition message” that would
require either that the message not be generated by a
user request or that the message is required to contain
the status of all conditions (and cannot be a subset of the
data). The plain and ordinary meaning of “bed condition
message” is a message that indicates the status of a
monitored bed. There is no lexicography or disavowal
that has been argued to support the additional limitations
the court imposed. There is no mention in the specifica-
tion of the “bed condition message” including all status
conditions. Likewise, there is no discussion of user re-
quests. The specification does disclose an embodiment
that periodically polls: “In a preferred embodiment . . . the
bed interface board 35 polls every 250 millisec-
onds . . . [a]t each poll, a message is sent.” See ’038 patent
col 13 ll. 39–col. 14 ll. 13. This disclosure of periodic
polling in one embodiment does not justify reading period-
ic polling into the claim. There is no argument that one of
skill in the art would read this specification or its associ-
ated prosecution history as incorporating these limita-
tions.
    The court’s construction was based entirely upon its
conclusion that judicial estoppel prevented Hill-Rom from
any broader construction. The district court explained
that there are three factors that ought to be considered in
determining whether to apply judicial estoppel: 1) a
20           HILL-ROM SERVICES, INC.   v. STRYKER CORPORATION



party’s position must be clearly inconsistent with an
earlier position taken; 2) the party must have prevailed
on the basis of the earlier position; and, 3) the party
asserting the inconsistent position would derive an unfair
advantage or impose an unfair detriment on the opposing
party if not estopped. District Court Decision at *11. The
court concluded that all three factors in this case weighed
in favor of applying judicial estoppel.
    In this case, during prosecution of a later, unrelated
patent, U.S. Patent No. 8,121,856 (’856 patent), the
examiner rejected claims as obvious over three references.
One of the prior art references cited was U.S. Patent
Application Publication No. 2002/0151990 (the Ulrich
reference), which has the same specification as the ’038
patent. Hill-Rom argued that the examiner “relies on
Ulrich as teaching” “transmissions of subsets of data of
features of a bed frame and air mattress.” J.A. 390. In
response, Hill-Rom added a limitation that the monitoring
device receives a user request for a specific subset of data
and that the specific subset of data be transmitted with-
out transmitting the other available data. Hill-Rom
argued that adding this limitation overcame the obvious-
ness rejection because this added limitation was not
disclosed in the Ulrich reference:
     Neither Sievenpiper nor Haller nor Ulrich have
     any disclosure of a monitoring device from which
     such a user request can be made for subsets of da-
     ta and those subsets of data are transmitted with-
     out transmitting other subsets of available data.
     The undersigned is quite familiar with the Ulrich
     reference because it is assigned to the assignee as
     the present application. In Ulrich’s systems, us-
     er[s] cannot request specific subsets of data be
     transmitted without transmitting other available
     data subsets. The data transmissions in Ulrich’s
     system happen in response to periodic pro-
HILL-ROM SERVICES, INC.   v. STRYKER CORPORATION         21



   grammed polling by individual electronic devices
   of the system, not in response to any user request.
J.A. 391. Based on this statement, the district court
found judicial estoppel was warranted and that “bed
condition message” should be limited to “a message not
generated in response to any user request that contains
the status of all conditions the bed is capable of monitor-
ing.” District Court Decision at *12.
    We conclude that there are several errors in this
analysis. As an initial matter, we decided this issue in
Pfizer, Inc. v. Ranbaxy Laboratories, Inc., 457 F.3d 1284,
1290 (Fed. Cir. 2006), and are bound to follow Pfizer. In
Pfizer, claim 1 of the patent at issue (the ’893 patent) was
directed to a particular compound and depicted the
R-trans isomer. The patentee argued that claim 1 covered
the R-trans isomer by itself and was not limited to a
mixture of isomers. The defendant argued that prosecu-
tion history estoppel or, alternatively, judicial estoppel
should bar the patentee from advancing this construction
because, during the prosecution of the unrelated ’995
patent, the patentee repeatedly stated that the ’893
patent was not directed to isolated enantiomers but
rather was limited to a mixture of enantiomers. The
defendant argued that the ’893 claims should thus be
limited to mixtures, and should not cover the isolated
R-trans isomer. We held that “statements made during
prosecution of the later, unrelated ’995 patent cannot be
used to interpret claims of the ’893 patent.” Id. at 1290.
We went on to hold that “insofar as Ranbaxy restates the
same argument under the guise of judicial estoppel, we
are not persuaded.” Id.
    If we accept as true Stryker’s argument that Hill-
Rom’s prosecution statements are inconsistent with the
construction of “bed condition message” Hill-Rom now
seeks, there would be no distinction between this case and
Pfizer. Stryker acknowledged as much in its brief. It
22          HILL-ROM SERVICES, INC.   v. STRYKER CORPORATION



never argued that Pfizer did not govern this case or was
distinguishable from the present case, but rather that
Pfizer was wrongly decided. Appellee’s Br. at 52–53. We
see no reason to question the rule in Pfizer, and, in any
event, we are bound by prior panel decisions. Barclay v.
United States, 443 F.3d 1368, 1373 (Fed. Cir. 2006).
Thus, statements made during prosecution of a later,
unrelated patent cannot form the basis for judicial estop-
pel.
    But there is a second error in the district court’s judi-
cial estoppel analysis. For judicial estoppel to apply, a
parties’ later position must be clearly inconsistent with
the earlier position. New Hampshire v. Maine, 532 U.S.
742, 749 (2001); see also United States v. Christian, 342
F.3d 744, 747 (7th Cir. 2003). Hill-Rom’s current position,
that “bed condition message” should be given its plain and
ordinary meaning, is not clearly inconsistent with its
statements during prosecution of the ’856 patent. None of
the statements Hill-Rom made during the ’856 patent’s
prosecution purport to define “bed condition message.”
Instead, they generally describe the disclosure of the
Ulrich reference or the Ulrich systems. It is undisputed
that the Ulrich reference did not teach “transmissions of
subsets of data features.” The Ulrich reference is com-
pletely silent on this point. Ulrich neither requires all
bed conditions to be transmitted nor explains that a
subset can be transmitted. Acknowledging that Ulrich
does not teach transmitting a subset of bed conditions
therefore is not a clear limitation of claim scope. A patent
is used as prior art in an anticipation or obviousness
rejection for what it discloses. By contrast, the scope of
the claims is not generally limited to the embodiments
disclosed in the patent.
    Claim 1 of the ’038 patent requires that the “bed con-
dition message” be transmitted to the processing station
over the datalink. The claim is silent regarding the
trigger for this transmission: whether the transmission
HILL-ROM SERVICES, INC.   v. STRYKER CORPORATION        23



occurs in response to user request or is automatic. The
specification gives one example of periodic polling, but
does not suggest that the inventor intended this embodi-
ment to limit the invention claimed. Thus, claim 1 covers
transmission of the bed condition message regardless of
whether the transmission occurs in response to a user
request or periodically at some timed interval. That does
not mean that the ’038 patent discloses or teaches user
requests; it undisputedly does not disclose an embodiment
where the data is transmitted in response to a user re-
quest. Accordingly, we do not agree that the statements
made during the unrelated patent’s prosecution are
clearly inconsistent with the position Hill-Rom takes
regarding the meaning of “bed condition message.”
    Finally, the statement about the Ulrich reference is
itself confusing and self-contradictory. Hill-Rom stated
that “[t]he data transmissions in Ulrich’s system happen
in response to periodic programmed polling . . . not in
response to any user request,” J.A. 391, suggesting that
data is not transmitted in response to a user request. The
previous sentence, however, stated that “[i]n Ulrich’s
systems user[s] cannot request specific subsets of data be
transmitted without transmitting other available data
subsets,” id., suggesting that data can be transmitted in
response to a user request, but that when a user requests
data, all available data is transmitted. These statements
are internally inconsistent, and thus Hill-Rom’s current
argument regarding claim scope is not “clearly incon-
sistent” with them. We conclude that these facts do not
present a case for application of the doctrine of judicial
estoppel.
    We hold that that a “bed condition message” is a mes-
sage that indicates the status of a monitored bed condi-
tion. The parties do not dispute that this is the plain and
ordinary meaning of the term. And the specification
provides us with no reason to depart from the plain and
ordinary meaning.
24        HILL-ROM SERVICES, INC.   v. STRYKER CORPORATION



                     CONCLUSION
    We reverse the district court’s grant of summary
judgment of non-infringement and remand for further
proceedings in view of this opinion.
          REVERSED AND REMANDED
  United States Court of Appeals
      for the Federal Circuit
                  ______________________

      HILL-ROM SERVICES, INC., HILL-ROM
         COMPANY, INC., AND HILL-ROM
            MANUFACTURING, INC.,
              Plaintiffs-Appellants,

                             v.

   STRYKER CORPORATION (doing business as
     Stryker Medical) AND STRYKER SALES
               CORPORATION,
              Defendants-Appellees.
             ______________________

                        2013-1450
                  ______________________

   Appeal from the United States District Court for the
Southern District of Indiana in No. 11-CV-1120, Judge
Jane Magnus-Stinson.
                ______________________

REYNA, Circuit Judge, dissenting.
     I dissent for three reasons. First, the intrinsic record
is devoid of any description of a wireless “datalink” struc-
ture. Second, credible extrinsic evidence belies the major-
ity’s conclusion that “datalink” encompasses wireless
communications. Third, the majority relies on expert
testimony that is conclusory and unreliable.
    Despite these determinative criteria, the majority
construes “datalink” as covering any way of communi-
2           HILL-ROM SERVICES, INC.   v. STRYKER CORPORATION



cating data, including wireless structures. This construc-
tion literally encompasses all data communication tech-
nology regardless of whether it existed in 1993 when the
patents were filed, whether it was created yesterday, or
whether it shall be created in the future. Neither the
record before us nor our case law supports such a con-
struction. Because I will not extend the literal scope of
the patent beyond what is clearly claimed, I respectfully
dissent.
                              I.
    The claim language demonstrates that “datalink” is a
meaningful structural limitation. The asserted claims are
system claims. They recite that messages are sent “over
a/the datalink,” “by a/the datalink,” and “via a/the data-
link.” They also indicate that the “datalink” is the struc-
ture used to “couple” or “communicatively couple” the
remote station and the interface board on the bed. This is
clearly indicated by the recited claim language: “cou-
pled . . . by a datalink” and “communicatively cou-
pled . . . by a datalink.” See ’038 patent claim 13; ’659
patent claim 13. Thus, the context in which the “data-
link” limitation is recited indicates that “datalink” must
be more precise than anything that would “couple” or
“communicatively couple” the interface board and the
remote station.
    Further, the written description does not describe
“datalink” as any way of communicating data. To the
contrary, the written description emphasizes that a
“datalink” is physical structure. First, the written de-
scription consistently refers to a “datalink” as a “serial
datalink.” See, e.g., ’038 patent col. 20 ll. 27-41. Second,
as the majority recognizes, the written description uses
“datalink” in a manner synonymous with a cable, which is
a physical structure. See, e.g., ’038 patent col. 6 ll. 30-31,
47. This is consistent with the sole depiction of a datalink
in figure 1 as a physical cable connecting the interface
HILL-ROM SERVICES, INC.   v. STRYKER CORPORATION             3



board to the wall interface unit. Id. fig. 1, col. 6 ll. 29-33.
Finally, the patent teaches that the “datalink” serves to
“electrically couple” components of the system. See id.
abstract, col. 6 l. 49. Such an electrical coupling would be
impossible without a medium for carrying the electrical
signals.
    The recitations in other, non-asserted claims further
indicate that the patent’s “datalink” must be a physical
structure. Claim 12 expressly requires the “datalink” to
be “in line” with an “optical isolator electrically connected
between said interface board and said processing station.”
Id. col. 23 ll. 43-47. The only way the “datalink” could
also connect the interface board and processing station
while being “in line” with the electrically connected “opti-
cal isolator” is if it is a physical structure. See Phillips v.
AWH Corp., 415 F.3d 1303, 1314 (Fed. Cir. 2005) (en
banc), cert. denied, 546 U.S. 1170, 126 S. Ct. 1332 (2006)
(“the usage of a term in one claim can often illuminate the
meaning of the same term in other claims”) (citation
omitted).
    Put simply, everything within the intrinsic record
identifies the claimed “datalink” as a physical structure.
There is nothing in the claims, written description, or file
history that indicates the claimed “datalink” embraced
wireless communications.
                              II.
    In addition to clear intrinsic evidence, the majority al-
so disregards credible extrinsic evidence regarding the
understanding of “datalink” in the context of the patents-
in-suit. Specifically, the majority ignores that in 2007,
fourteen years after the filing date of the patents-in-suit,
Hill-Rom filed Patent Application No. 11/672,367 (“the
’367 application”), which was expressly directed to wire-
less bed connections. See J.A. 344. As originally filed, the
only material difference between claim 1 of the ’367
application and the inventions disclosed and claimed in
4           HILL-ROM SERVICES, INC.   v. STRYKER CORPORATION



the patents-in-suit was the explicit use of wireless com-
munication technology:
    1. A hospital bed having wireless communication
       circuitry operable to transmit bed status data
       wirelessly to a network and to receive messag-
       es wirelessly from the network, the bed having
       a mattress associated therewith and the bed
       status data including information regarding at
       least one feature of the mattress.
J.A. 348-49. The ’367 application did not claim priority to
any of the patents-in-suit. The application further char-
acterized the patents-in-suit as “Background of the Inven-
tion,” J.A. 345 ([0003]), and described these background
systems as limited to wired systems:
    Hospital beds that connect to nurse call systems,
    typically do so via a wired connection established
    by a nurse call cable that extends between the bed
    and an interface unit having a jack mounted on a
    wall or headwall unit in the hospital room in
    which the bed is situated.
J.A. 345 ([0004]) (emphasis added). Then, in the “Sum-
mary of the Invention,” the ’367 application contrasted
itself against the prior art through the use of wireless
connectivity. E.g., J.A. 345 ([0006]). The ’367 application
expressly differentiated itself from the patents-in-suit in
this exact manner by asserting that “according to this
disclosure, the standard bed status data is transmitted
wirelessly.” J.A. 346 ([0052]). The only reasonable con-
clusion that can be drawn from the filing of the ’367
application, now patented, is that Hill-Rom itself—
presumably one of ordinary skill in the art—both recog-
nized and understood the earlier patents-in-suit as lack-
ing a wireless datalink.
    Additionally, in 2011, a patent examiner reviewing
the patentability of Hill-Rom’s wireless bed patent con-
HILL-ROM SERVICES, INC.   v. STRYKER CORPORATION           5



cluded that the patents-in-suit do not themselves embrace
wireless “datalinks.” The examiner stated that the pa-
tents-in-suit do “not teach” either “a first transmitter that
transmits the first ID wirelessly” or “the bed having a
wireless receiver and a second transmitter.” J.A. 354.
The examiner further concluded that it was necessary to
combine the patents-in-suit with another reference that
expressly taught “wireless transmission between a wire-
less unit associated with a bed, and a remote unit” in
order to achieve an overall, combined system that includ-
ed “wireless communication capabilities.” J.A. 355. The
examiner’s remarks do not, as the majority contends,
simply confirm that the patents do “not teach . . . the bed
having a wireless receiver.” Maj. Op. at 8. Rather, the
examiner understood that the patents-in-suit did not
include wireless communications, which necessarily
means that he did not consider the “datalink” disclosed in
the patents-in-suit to reach such wireless technology. The
majority fails to acknowledge the full scope of the exam-
iner’s statements, which were made by an uninterested
party outside the scope of the present litigation, a materi-
al element in the analysis of the evidentiary record.
                              III.
    Despite the limited scope of the intrinsic and extrinsic
record, the majority construes “datalink” as “any link over
which data is transferred and can be wired or wireless.” 1


    1      The phrase “can be wired or wireless” is permis-
sive and renders itself superfluous. It therefore does not
meaningfully add to the majority’s construction. On
remand, the full scope of “any link over which data is
transferred” must be considered in evaluating both in-
fringement and invalidity. See Source Search Techs., LLC
v. LendingTree, LLC, 588 F.3d 1063, 1075 (Fed. Cir. 2009)
(“‘[i]t is axiomatic that claims are construed the same way
for both invalidity and infringement’”) (quoting Amgen
6           HILL-ROM SERVICES, INC.   v. STRYKER CORPORATION



Maj. Op. at 10. This construction reaches any and every
method of communicating data, which is an expansive
functional interpretation—defining the “datalink” struc-
ture by what it does rather than what it is. This func-
tional claiming is not only prohibited outside of the
context allowed by 35 U.S.C. § 112(f), but is also not
supported by the record.
    The majority justifies the construction by relying on a
single piece of evidence created solely for Hill-Rom’s use
in the present litigation. In doing so, the majority states:
    Indeed, the only evidence in the record of how one
    of ordinary skill in the art at the time of filing
    would understand the term “datalink” is from
    Hill-Rom’s expert. He testified that as of the ef-
    fective filing date of the patents-in-suit, “a person
    of ordinary skill would understand that ‘datalink’
    does not refer solely to physical connection” and
    “can be established over wired, wireless, optical,
    or other connection.” J.A. 454, 472.
Maj. Op. at 8-9. This testimony from Hill-Rom’s expert,
however, does not directly speak to the meaning of the
term in 1993 and, at best, is ambiguous on the issue
before us.
    Importantly, the expert report never expressly states
that one of ordinary skill in the art in 1993 would under-
stand that a “datalink” encompassed wireless connections.
We have long recognized that, although the understand-
ing of a claim term can evolve over time, the literal scope
of a patent claim “cannot have different meanings at
different times.”     PC Connector Solutions LLC v.
SmartDisk Corp., 406 F.3d 1359, 1363 (Fed. Cir. 2005).
The literal scope of a claim is fixed by the meaning of its


Inc. v. Hoechst Marion Roussel, Inc., 314 F.3d 1313, 1330
(Fed. Cir. 2003)).
HILL-ROM SERVICES, INC.   v. STRYKER CORPORATION           7



terms in the relevant art as of the effective filing date of
the application. Phillips, 415 F.3d at 1313 Cir. 2005)
(“We have made clear . . . that the ordinary and custom-
ary meaning of a claim term is the meaning that the term
would have to a person of ordinary skill in the art in
question at the time of the invention, i.e., as of the effec-
tive filing date of the patent application.”). Here, the
patents-in-suit claim priority to an application filed in
1993 and, a proper construction of the claims must be
tethered to that date.
     Hill-Rom’s expert, however, testified before the dis-
trict court that “datalink” needed no construction and
provided explanations that were each phrased in the
present tense. J.A. 471-72. Specifically, the expert testi-
fied:
    Datalinks are used by network designers to trans-
    fer data from one device to another. Thus, a “dat-
    alink” is used in many different fields and
    applications, and is not confined solely to the con-
    nection to a hospital bed. A person of ordinary
    skill in the art would understand that a datalink
    can be used in an unlimited number of contexts
    where digital data is to be transmitted.
Id. (emphases added); see also id. at 472 (“would under-
stand that ‘datalink’ does not refer solely to physical
connection” and “a datalink can be established over wired,
wireless, optical or other connection”) (emphases added).
In view of Hill-Rom’s bare attempt to embrace wireless
communications under the purported plain meaning of
the term “datalink,” the expert testimony does not
demonstrate a temporal connection to 1993, as it must.
    Beyond ambiguity, the expert’s testimony is also con-
clusory. There is no documentary evidence—dictionary
definition, paper, article, advertisement, product, system,
method, etc.—to support his testimony. As such, the
reasoning set forth in SkinMedica, Inc. v. Histogen Inc.,
8           HILL-ROM SERVICES, INC.   v. STRYKER CORPORATION



727 F.3d 1187 (Fed. Cir. 2013) is applicable to this case.
There we recognized that the evidentiary value of conclu-
sory expert testimony in the context of claim construction
is suspect and unhelpful:
    Expert testimony, in particular, is less reliable be-
    cause it “is generated at the time of and for the
    purpose of litigation and thus can suffer from bias
    that is not present in intrinsic evidence.” For that
    reason, “conclusory, unsupported assertions by
    experts as to the definition of a claim term are not
    useful to a court.”
                          *   *   *
    In whole, [the expert’s] opinions are unhelpful to
    our analysis here. They are conclusory and in-
    complete; they lack any substantive explanation
    tied to the intrinsic record; and they appear to
    conflict with the plain language of the written de-
    scription. Without a more detailed explanation of
    how [the expert] formed his conclusions and why
    they conflict with the plain language of the speci-
    fication, we must agree with the district court that
    [the expert’s] testimony deserves no weight.
Id. at 1195, 1210 (citations omitted).
    In sum, the record before us does not clearly establish
that the claims of the asserted patents encompass wire-
less datalinks. Where there is no support in the intrinsic
record for a proffered construction, a party seeking a
purported “plain meaning” construction that is broader
than what is supported by the intrinsic record must
supply credible extrinsic evidence that sufficiently
demonstrates the subject matter embraced by the “plain
meaning” was known to one of ordinary skill in the rele-
vant art at the time the patent was filed. Hill-Rom has
not made such a showing here.
HILL-ROM SERVICES, INC.   v. STRYKER CORPORATION        9



    The majority’s conclusion to the contrary is out-
weighed by reliable record evidence that the majority
either miscomprehends or ignores. Under these circum-
stances, the asserted term is properly limited to a physi-
cal connection. Moreover, limiting the claimed “datalink”
to a physical connection is entirely consistent with Hill-
Rom’s claim differentiation arguments, as a physical
connection encompasses, but is not limited to, a wired
datalink.
   For the foregoing reasons, I respectfully dissent.
