  United States Court of Appeals
      for the Federal Circuit
              __________________________

                  MEDTRONIC INC.,
                Plaintiff-Cross Appellant,

                            v.
       BOSTON SCIENTIFIC CORPORATION
         AND GUIDANT CORPORATION,
                  Defendants,

                          AND

       MIROWSKI FAMILY VENTURES, LLC,
             Defendant-Appellant.
              __________________________

                   2011-1313, -1372
              __________________________

    Appeals from the United States District Court for the
District of Delaware in No. 07-CV-0823, Judge Sue L.
Robinson.
               __________________________

              Decided: September 18, 2012
              __________________________

    MARTIN R. LUECK, Robins, Kaplan, Miller & Ciresi
L.L.P., of Minneapolis, Minnesota, argued for plaintiff-
cross appellant. With him on the brief were JAN M.
CONLIN and STACIE E. OBERTS.
2                            MEDTRONIC   v. BOSTON SCIENTIFIC

    ARTHUR I. NEUSTADT, Oblon, Spivak, McClelland,
Maier & Neustadt, LLP, of Alexandria, Virginia, argued
for defendant-appellant. With him on the brief were
THOMAS J. FISHER and JOHN F. PRESPER.
              __________________________

        Before LOURIE, LINN, and PROST, Circuit Judges.

LINN, Circuit Judge.

     Medtronic, Inc. (“Medtronic”) filed a complaint in the
United States District Court for the District of Delaware
seeking declaratory judgment of noninfringement and
invalidity of Mirowski Family Ventures, LLC’s (“MFV”)
U.S. Reissue Patents No. RE38,119 (“RE’119 Patent”) and
No. RE39,897 (“RE’897 Patent”). The district court en-
tered judgment of noninfringement in favor of Medtronic
and judgment of validity and enforceability in favor of
MFV. Medtronic, Inc. v. Boston Scientific Corp., No. 07-
CV-0823 (D. Del. Mar. 30, 2011). MFV appeals the dis-
trict court’s judgment of noninfringement and Medtronic
cross appeals the district court’s claim construction on
which its judgment of validity is based. 1 Because the
district court relied on a legally incorrect allocation of the
burden of proof to find noninfringement in the limited
circumstances of this case and incorrectly construed the
claim terms in question, this court vacates and remands.

                       I. BACKGROUND

    Between 1969 and 1980, Dr. Morton Mower (“Mower”)
worked with Dr. Mieczyslaw Mirowski to develop the first
implantable cardioverter defibrillator (“ICD”). An ICD is
a device that is implanted into a patient’s chest to monitor

    1 Medtronic has not appealed the district court’s en-
forceability ruling and that issue is therefore not consid-
ered in this appeal.
MEDTRONIC   v. BOSTON SCIENTIFIC                        3
the patient’s heartbeat. When the ICD detects a very
rapid heartbeat that could cause cardiac arrest, it shocks
the heart causing all muscle fibers to contract and re-
synchronize with the sinus node. Thus, the ICD is in-
tended to prevent sudden death from heart attack, but is
not designed to improve the general efficacy of the heart.
The ICD is therefore not effective for treating heart
conditions like congestive heart failure, where the under-
lying problem is the heart’s decreasing ability to pump
enough blood.

    Between the 1960’s and 1980’s, Mower also analyzed
EKG readings from congestive heart failure patients.
Mower realized that slow conduction from one side of the
heart to the other might be the cause of the incoordinate
contractions that play a role in heart failure. Based on
this observation, Mower developed what he called a
biventricular pacer, a device that ultimately became
known as a cardiac resynchronization therapy (“CRT”)
device. Mower’s CRT device increases the heart’s efficacy
by causing both the patient’s left and right ventricles to
contract simultaneously as the heart beats. Mower
ultimately patented the CRT device in what are now the
RE’119 and RE’897 Patents, both assigned to MFV. MFV
exclusively licenses both patents to Guidant Corp.

    Medtronic is a leading manufacturer of medical de-
vices and equipment. In 1991, Medtronic entered into a
sublicense agreement covering the RE’119 Patent with Eli
Lilly & Co., Guidant’s predecessor-in-interest of the
patents-in-suit. That agreement allowed Medtronic to
challenge the RE’119 Patent’s validity, enforceability, and
scope via a declaratory judgment action. In 2003, as
required by the sublicense, Medtronic began paying
royalties into escrow while challenging the validity of the
RE’119 Patent. Ultimately the parties entered into a
Litigation Tolling Agreement (“LTA”) that tolled litigation
and obligated MFV to inform Medtronic of which Med-
4                          MEDTRONIC   v. BOSTON SCIENTIFIC

tronic products MFV deemed were covered by the RE’119
Patent, or subsequent reissue patents claiming priority
from the RE’119 Patent (here, the RE’897 Patent), and
subject to royalty payments. If Medtronic disagreed, the
LTA gave Medtronic the right to retain its license and
obligated Medtronic to seek a declaratory judgment of
noninfringement in the United States District Court for
the District of Delaware. In October and November of
2007, MFV identified several Medtronic products that
MFV thought practiced its patents. Pursuant to the LTA,
on December 17, 2007, Medtronic filed the complaint
giving rise to this declaratory judgment action. Because
Medtronic remained MFV’s licensee, MFV could not
counterclaim for infringement of either patent.

     Throughout this litigation the parties have disagreed
over whether MFV, the patentee, bore the burden of
proving infringement, or whether Medtronic, the declara-
tory judgment plaintiff, bore the burden of proving nonin-
fringement.     During discovery, MFV propounded an
interrogatory requesting Medtronic to state the basis for
its allegation in paragraph twenty-four of its complaint
that “Medtronic’s Accused Devices do not infringe any
valid claim of the ’119 Reissue Patent or the ’897 Reissue
Patent.” Complaint at 6, Medtronic, Inc. v. Boston Scien-
tific Corp., No. 07-CV-0823 (D. Del. Mar. 30, 2011), ECF
No. 1. Medtronic objected to MFV’s interrogatory, main-
taining that the burden to prove infringement rested on
MFV and that MFV had failed to provide its infringement
contentions.     Medtronic ultimately responded to the
interrogatory with reasons why it felt that its products do
not infringe MFV’s patents. On the date expert reports
were due, Medtronic served the report of its expert, Dr.
Charles Love (“Love”). MFV subsequently served the
report of its expert, Dr. Ronald Berger (“Berger”). Consis-
tent with MFV’s contention that Medtronic bore the
burden to prove noninfringement as it alleged in its
complaint, Berger’s report was largely responsive to
MEDTRONIC   v. BOSTON SCIENTIFIC                          5
Love’s report, and Berger admitted that he did not ex-
pressly map the products in question to every limitation
of the relevant claims. Medtronic, Inc. v. Boston Scientific
Corp., No. 07-CV-0823, slip op. at 22-23 (D. Del. Mar. 30,
2011) (“Opinion”).

    The district court held a bench trial on January 25-28,
2010, and March 13, 2010. The court relied on Under Sea
Industries, Inc. v. Dacor Corp., 833 F.2d 1551, 1557 (Fed.
Cir. 1987), which states that “[t]he burden always is on
the patentee to show infringement,” and thus held that
“[a]s the parties asserting infringement, defendants bear
the burden of proof by a preponderance of the evidence.”
Opinion at 17. “Having determined that defendants, as
patentees, have the burden to prove infringement,” id. at
20, the court found that Berger’s testimony lacked suffi-
cient foundation because of his failure to consider “each
limitation of each asserted claim in comparison to each
accused product before rendering his infringement opin-
ions,” and that defendants “failed to prove literal in-
fringement by a preponderance of the evidence,” id. at 24.
The court also found Berger’s report and testimony con-
clusory and insufficient to show that the products infringe
the patents under the doctrine of equivalents. Id. at 25-
26.

    Finally, the district court, in conducting its claim con-
struction, relied on portions of the specification that
describe the invention in the context of treating conges-
tive heart failure to construe the preamble terms “improv-
ing the hemodynamic efficiency of a heart,” RE’119 Patent
col. 10 ll. 1-2, 25-26, and “bi-ventricular pacemaker,”
RE’119 Patent col. 11 l. 1, col. 12 l. 1, as limited to the
treatment of congestive heart failure. Opinion at 12-14;
see, e.g., RE’119 Patent col. 1 ll. 18-22 (stating in the
specification that “[t]his invention pertains to . . . a
method for increasing the cardiac output of a patient
suffering from congestive heart failure by stimulating the
6                            MEDTRONIC   v. BOSTON SCIENTIFIC

heart of the patient at multiple sites simultaneously”), col.
3 ll. 13-15 (stating in the specification that “an objective of
the present invention is to provide a cardiac pacer for
increasing hemodynamic efficiency of a heart experiencing
a conduction deficiency.”).

    MFV appeals the district court’s grant of declaratory
judgment of no literal infringement and no infringement
under the doctrine of equivalents. Medtronic cross ap-
peals the district court’s claim construction ruling. This
court has jurisdiction pursuant to 28 U.S.C. § 1295(a)(1).

                       II. DISCUSSION

                   A. Standard of Review

    Claim construction is a question of law that this court
reviews de novo. Cybor Corp. v. FAS Techs., 138 F.3d
1448, 1451 (Fed. Cir. 1998) (en banc). This court also
reviews a district court’s other legal conclusions, such as
who bears the burden of proof, de novo. Madey v. Duke
Univ., 307 F.3d 1351, 1358 (Fed. Cir. 2002).

                     B. Burden of Proof

    MFV argues that because Medtronic is the declara-
tory judgment plaintiff—the party seeking court action—
Medtronic bore the burden of proving noninfringement, a
burden it failed to carry. MFV further explains that
because of the parties’ licensing agreement, it could not
have filed a counterclaim for infringement and the court
erred by viewing MFV as a party “asserting infringe-
ment.” Opinion at 17. MFV points out that all of the
cases the district court relied on to conclude that MFV
bore the burden to prove infringement are conventional
claims for patent infringement by the patentee as con-
trasted with declaratory judgment actions by licensees.
MFV also points out that the parties’ agreement requires
Medtronic to initiate litigation by filing a declaratory
MEDTRONIC   v. BOSTON SCIENTIFIC                         7
judgment action, as it has done in this case, making
Medtronic the party seeking relief from the court. Thus,
according to MFV, because Medtronic filed a complaint
seeking a judgment that its products do not infringe
MFV’s patents, Medtronic should have to prove that at
least one limitation of each claim of MFV’s patents is not
met by Medtronic’s products.

    Medtronic counters that, as the district court held, the
burden of proving patent infringement always lies with
the patentee; that burden never shifts to the accused
infringer. Opinion at 17. Medtronic cites Under Sea
Industries, 833 F.2d at 1557 (“The burden always is on
the patentee to show infringement.”), Technology Licens-
ing Corp. v. Videotek, Inc., 545 F.3d 1316, 1327 (Fed. Cir.
2008) (burden never shifts to an accused infringer), and
Laitram Corp. v. Rexnord, Inc., 939 F.2d 1533, 1535 (Fed.
Cir. 1991) (patentee must demonstrate every element of
the claim), as support for its position. Medtronic also
finds the District of Maryland’s reasoning persuasive in
MedImmune, Inc. v. Centocor, Inc., 271 F. Supp. 2d 762
(D. Md. 2003), where, on similar facts, the court placed
the burden on the patentee. Finally, Medtronic argues
that because MFV complied with the requirement of the
LTA to first notify Medtronic of the products accused to
infringe before Medtronic filed the declaratory judgment
action, MFV was in fact the party to “assert infringement”
notwithstanding that it did not and could not file an
infringement counterclaim.

    The question before us arises as a consequence of the
Supreme Court’s decision in MedImmune, Inc. v. Genen-
tech, Inc., 549 U.S. 118 (2007). In MedImmune the Court
found declaratory judgment jurisdiction notwithstanding
the fact that the declaratory judgment plaintiff licensee
continued to make royalty payments pursuant to a li-
cense. The Court reasoned that a licensee should not be
forced to cease royalty payments and risk infringement
8                            MEDTRONIC   v. BOSTON SCIENTIFIC

liability before the licensee can challenge the extent of
coverage of the license. MedImmune, 549 U.S. at 134.
Thus, MedImmune provided licensees with a shield from
the economic consequences of challenging their licensors’
patents while enabling those licensees to file declaratory
judgment suits to clarify the rights and obligations of the
parties under their license agreements. This case re-
quires us to determine the proper allocation of the burden
of persuasion in the post-MedImmune world, under cir-
cumstances in which a declaratory judgment plaintiff
licensee seeks a judicial decree absolving it of its respon-
sibilities under its license while at the same time the
declaratory judgment defendant is foreclosed from
counterclaiming for infringement by the continued exis-
tence of that license.

     Generally, the party seeking relief bears the burden of
proving the allegations in his complaint. See Schaffer ex
rel. Schaffer v. Weast, 546 U.S. 49, 56-57 (2005). “Perhaps
the broadest and most accepted idea is that the person
who seeks court action should justify the request . . . .”
Schaffer, 546 U.S. at 56 (quoting C. Mueller & L.
Kirkpatrick, Evidence § 3.1, p. 104 (3d ed. 2003)). “The
burdens of pleading and proof with regard to most facts
have been and should be assigned to the plaintiff who
generally seeks to change the present state of affairs and
who therefore naturally should be expected to bear the
risk of failure of proof or persuasion.” Id. (quoting 2 J.
Strong, McCormick on Evidence § 337, p. 412 (5th ed.
1999)). In Schaffer, a school district denied a student
educational services under the Individuals with Disabili-
ties Education Act. Id. at 54-55. The student filed suit
against the school district and the Court considered which
party bore the burden of proving the student was entitled
to the services. After finding no guidance in the statute
the Court applied “the ordinary default rule that plaintiffs
bear the risk of failing to prove their claims,” id. at 56-57,
MEDTRONIC   v. BOSTON SCIENTIFIC                           9
and placed the burden on the student, “where it usually
falls, upon the party seeking relief,” id. at 58.

    It is, of course, well settled that a patentee who files a
complaint or counterclaim alleging patent infringement
bears the burden of proving that infringement. See Under
Sea Indus., 833 F.2d at 1557; In re Tech. Licensing Corp.,
423 F.3d 1286, 1288-89 (Fed. Cir. 2005); see also Tech.
Licensing Corp. v. Videotek, Inc., 545 F.3d 1316, 1327
(Fed. Cir. 2007); Laitram Corp. v. Rexnord, Inc., 939 F.2d
1533, 1535 (Fed. Cir. 1991). In the absence of a license,
this court has recognized “that when the same patent is at
issue in an action for declaration of non-infringement, a
counterclaim for patent infringement is compulsory and if
not made is deemed waived.” Vivid Techs., Inc. v. Am.
Sci. & Eng’g, Inc., 200 F.3d 795, 802 (Fed. Cir. 1999).

    The substantive burden of proof normally does not
shift simply because the party seeking relief is a counter-
claiming defendant in a declaratory judgment action. See
In re Tech. Licensing Corp., 423 F.3d at 1288-89 (citing In
re Lockwood, 50 F.3d 966, 976 (Fed. Cir. 1995) and recog-
nizing that a declaratory judgment action of invalidity
with an infringement counterclaim is nothing more than
an inverted infringement suit); Ranbaxy Pharms. Inc. v.
Apotex, Inc., 350 F.3d 1235, 1237, 39-40 (Fed. Cir. 2003)
(requiring patentee seeking preliminary injunction on
infringement counterclaim to show inter alia a likelihood
of proving infringement). In Vivid Technologies, this
court explained that “the parties bore the same eviden-
tiary burdens whether or not the counterclaim was per-
mitted,” but did not further discuss what those burdens
were. 200 F.3d at 802. Moreover, that statement was
made before the Supreme Court’s MedImmune decision
and was based on the general proposition that mere role
reversal in a declaratory judgment action does not shift
the burden. Id. Specifically, Vivid Technologies quoted
Moore’s Federal Practice that “in patent cases ‘courts have
10                          MEDTRONIC   v. BOSTON SCIENTIFIC

generally recognized that any role reversal occasioned by
declaratory relief should not shift the burden of proof from
the manner in which it would be assigned in a coercive
infringement suit.’” Id. (quoting 12 James Wm. Moore et
al., Moore’s Federal Practice 57.62[2][d] (3d ed. 1997)).
But Moore’s Federal Practice did not consider allocating
the burden of proof post-MedImmune, when “a coercive
infringement suit” was not possible and therefore did not
address Medtronic’s simple role reversal argument at
issue here.

    These cases only stand for the rote proposition that
when there is a direct claim for infringement, in a com-
plaint or by way of counterclaim, the patentee cannot
prevail without proving all the elements of infringement
under 35 U.S.C. § 271. And in the customary declaratory
judgment case, like Vivid Technologies, the declaratory
judgment defendant must assert a counterclaim for
infringement to avoid risking the loss of that claim for-
ever. See id. But this is not such a case. In this case, as
sanctioned by MedImmune, the continued existence of the
license precludes the very infringement counterclaim that
normally would impose the burden of proving infringe-
ment on the patentee. Here, Medtronic is shielded from
any liability for infringement by its license. And MFV has
not asserted a claim of infringement, nor could it because
of the license. Thus, while Medtronic’s suit for declara-
tory judgment undoubtedly rests upon the infringement
provisions laid out in § 271, the relief it seeks relates
directly to its obligations under the license.

    The contract at issue here required MFV to identify
products it believed were covered by the contract. After
MFV identified those products, Medtronic was required to
either pay royalties on them, or sue for declaratory judg-
ment that the products were not covered. Medtronic is
unquestionably the party now requesting relief from the
court: it already has a license; it cannot be sued for in-
MEDTRONIC   v. BOSTON SCIENTIFIC                         11
fringement; it is paying money into escrow; and it wants
to stop. In contrast, regarding the patents at issue here,
MFV seeks nothing more than to be discharged from the
suit and be permitted to continue the quiet enjoyment of
its contract. 2 In other words, it is Medtronic and not
MFV that is asking the court to disturb the status quo
ante and to relieve it from a royalty obligation it believes
it does not bear. Consistent with the above, for the court
to disturb the status quo ante, Medtronic must present
evidence showing that it is entitled to such relief. If
neither party introduced any evidence regarding in-
fringement or noninfringement there is no principled
reason why Medtronic should receive the declaration of
noninfringement it seeks.

     This analysis is fully consistent with other areas of
the law. In insurance cases, courts generally place the
burden on the party seeking recovery under a policy. This
is true even when the insured is the declaratory judgment
defendant. See Am. Eagle Ins. Co. v. Thompson, 85 F.3d
327, 331 (8th Cir. 1996) (“Stripped of its procedural
posture, this action is, at base, a claim by Thompson [the
insured who ultimately bore the burden] that he is cov-
ered under an insurance policy and a denial by the in-
surer [declaratory judgment plaintiff] that coverage
properly exists.”). But the burden can shift to the de-
claratory judgment plaintiff where the insured is not
seeking affirmative relief. See Reliance Life Ins. Co. v.
Burgess, 112 F.2d 234, 237 (8th Cir. 1940) (holding that
when the declaratory judgment defendant insureds
“asked no affirmative relief [and] prayed only to be dis-

   2  MFV initially counterclaimed for declaratory judg-
ment of its right to recover money paid into escrow under
the 2003 escrow agreement regarding U.S. Patent No.
4,407,288. This counterclaim was dismissed without
prejudice pursuant to joint stipulation by the parties and
is not at issue in this appeal.
12                          MEDTRONIC   v. BOSTON SCIENTIFIC

charged with their costs,” the burden fell on the declara-
tory judgment plaintiff insurance company). The Third
Circuit cited Burgess as “[t]he leading case which ex-
pounded the[] guiding principles” for allocating the bur-
den of proof in a declaratory judgment action. Fireman’s
Fund Ins. Co. v. Videfreeze Corp., 540 F.2d 1171, 1175 (3d
Cir. 1974) (also noting that the burden often falls on the
insurer in personal disability insurance cases where the
issue is whether the insured is able to return to work and
the insurer may cease making payments).

    As noted, neither party here seeks money damages or
an injunction based on patent infringement, which are the
sorts of relief generally sought when a party seeks relief
for patent infringement. Instead, the one claim for relief
sought in this case is the claim Medtronic asserts to be
relieved from liability under the license by having a court
declare the products in question to be noninfringing.
Medtronic is the party seeking this relief and Medtronic
must bear the burden of proving it is entitled to such
relief. A contrary result would allow licensees to use
MedImmune’s shield as a sword—haling licensors into
court and forcing them to assert and prove what had
already been resolved by license. Because the declaratory
judgment plaintiff is the only party seeking the aid of the
court in the circumstances presented here, that party
must bear the burden of persuasion. Therefore, this court
holds that in the limited circumstance when an infringe-
ment counterclaim by a patentee is foreclosed by the
continued existence of a license, a licensee seeking a
declaratory judgment of noninfringement and of no conse-
quent liability under the license bears the burden of
persuasion.

    In view of the above holding, the district court’s find-
ing that Berger’s expert testimony lacked sufficient foun-
dation because his report “fail[ed] to demonstrate that
[he] considered each limitation of each asserted claim in
MEDTRONIC   v. BOSTON SCIENTIFIC                         13
comparison to each accused product before rendering his
infringement opinions” was clearly erroneous. Opinion at
24. MFV did not bear that burden of proof and its expert
was therefore not obliged to do more than rebut Med-
tronic’s contentions. The district court’s conclusion that
“[d]efendants have failed to prove literal infringement by
a preponderance of the evidence” can not stand. Id.
Because we reverse on this basis we need not reach the
district court’s conclusion regarding Berger’s opinions on
infringement by equivalents. We also need not address
MFV’s argument that Medtronic’s interrogatory responses
effectively conceded that all unaddressed claim limita-
tions were satisfied. Because Medtronic, and ultimately
the district court, did not appreciate the appropriate
allocation of the burden of proof and how the burden
affected the parties’ conduct during discovery, it is within
the district court’s discretion on remand whether to limit
Medtronic to its current interrogatory answer, or to allow
Medtronic to amend its interrogatory answer to include
any additional noninfringement contentions it may wish
to assert.

                 C.   Claim Construction

     In its cross-appeal, Medtronic contends that the dis-
trict court based its refusal to find the patents invalid on
an erroneous claim construction. Medtronic argues that
the district court improperly restricted the asserted
claims of the RE’119 patent to treating congestive heart
failure based only on the specification’s disclosure of such
treatment; nothing in the specification disclaims using
the invention to treat other conditions. According to
Medtronic, the specification is very broad and provides
examples of treating many conditions caused by conduc-
tion deficiency—some unrelated to heart failure (e.g.,
bundle branch blocks). Medtronic argues that the pat-
entee did not expressly narrow or clearly disavow a
broader claim scope. Finally, Medtronic notes that claim
14                           MEDTRONIC   v. BOSTON SCIENTIFIC

171 of the RE’897 Patent specifically recites the limitation
of “improv[ing] the pumping ability of the heart suffering
from heart failure,” while the other, broader claims do
not. RE’897 Patent col. 21 ll. 34-35.

    MFV argues that the patentee expressly defined his
invention for use only in congestive heart failure. MFV
also stresses that the inventor described the invention’s
use for treating congestive heart failure as a way to
distinguish this invention from a prior art reference
(“Funke”). See RE’119 Patent col. 2 ll. 28-33. Finally,
MFV cites SafeTCare Manufacturing, Inc. v Tele-Made,
Inc., 497 F.3d 1262 (Fed. Cir. 2007), to argue that it is
only trying to understand what the patentee has claimed
and disclaimed, not to import limitations from the specifi-
cation into the claims.

    “[T]he words of a claim ‘are generally given their or-
dinary and customary meaning’ . . . that the term would
have to a person of ordinary skill in the art in question at
the time of the invention . . . .” Phillips v. AWH Corp.,
415 F.3d 1303, 1312-13 (Fed. Cir. 2005) (en banc) (cita-
tions omitted). That person of ordinary skill in the art is
deemed to understand the terms in the context of the
entire patent, including the specification, id. at 1313, but
the claim terms should not be limited to the disclosed
embodiments, id. at 1323. Rather, claim terms should
generally be given their ordinary and customary meaning
unless “1) when a patentee sets out a definition and acts
as his own lexicographer, or 2) when the patentee dis-
avows the full scope of a claim term either in the specifi-
cation or during prosecution.” Thorner v. Sony Computer
Entm’t Am. LLC, 669 F.3d 1362, 1365 (Fed. Cir. 2012).
“To act as its own lexicographer, a patentee must ‘clearly
set forth a definition of the disputed claim term . . . .’” Id.
(quoting CCS Fitness, Inc. v. Brunswick Corp., 288 F.3d
1359, 1366 (Fed. Cir. 2002)). And “[w]here the specifica-
tion makes clear that the invention does not include a
MEDTRONIC   v. BOSTON SCIENTIFIC                          15
particular feature, that feature is deemed to be out-
side . . . the patent,” even if the terms might otherwise be
broad enough to cover that feature. Id. at 1366 (internal
citation omitted).

     Here, the district court did nothing more than append
the limitation “for the treatment of congestive heart
failure,” onto the ends of the disputed claim terms. Opin-
ion at 12-14. This unquestionably added a limitation.
This would only have been proper if the patentee specifi-
cally defined the terms to include that limitation, or
disavowed their otherwise broad scope. While the specifi-
cation explains the use of the invention to treat congestive
heart failure, it also discloses the invention’s value in
treating other diseases. See, e.g., RE’119 Patent col. 3 ll.
13-15 (“an objective of the present invention is
to . . . [treat] a heart experiencing a conduction defi-
ciency.”). As for the prior art Funke reference, the prose-
cution history reveals that the patentee distinguished
Funke based on the placement of electrodes to stimulate
only the ventricles, not based on any express use of the
disclosed device to treat any particular condition. The
statement in the specification that Funke does not dis-
close his invention’s “specific use as a method of improv-
ing the cardiac output of patients suffering from
congestive heart failure,” RE’119 Patent col. 2 ll. 30-32, is
a far cry from the clear disavowal needed to limit the
claims of the RE’119 Patent. Moreover, inclusion of the
express limitation “to improve the pumping ability of the
heart suffering from heart failure,” RE’897 Patent col. 21
ll. 33-35, in claim 171 of the RE’897 Patent, a continua-
tion of the RE’119 Patent, suggests that the other claims
that do not recite such a limitation should not be so
limited.      We therefore conclude that the district court
erred by restricting the claimed invention to the treat-
ment of congestive heart failure. The district court’s
determination of no invalidity predicated on its improper
claim construction is vacated. On remand, Medtronic
16                           MEDTRONIC   v. BOSTON SCIENTIFIC

may press its invalidity contention based upon the correct
claim construction.

                        CONCLUSION

    For the foregoing reasons, the judgment of the district
court is vacated, and the case is remanded for additional
proceedings consistent with this opinion.

              VACATED AND REMANDED

                            COSTS

     Each of the parties shall bear its own costs.
