United States Court of Appeals
for the Federal Circuit
__________________________
THE LARYNGEAL MASK COMPANY LTD. AND
LMA NORTH AMERICA, INC.,
Plaintiffs-Appellants,
v.
AMBU A/S, AMBU INC., AND AMBU LTD.,
Defendants-Cross Appellants.
__________________________
2010-1028, -1062
__________________________
Appeals from the United States District Court for the
Southern District of California in case No. 07-CV-1988,
Judge Dana M. Sabraw.
___________________________
Decided: September 21, 2010
___________________________
STEPHEN J. MARZEN, Shearman & Sterling LLP, of
Washington, DC, argued for plaintiffs-appellants. With
him on the brief were VICKI S. VEENKER and ADAM P.
NOAH. Of counsel on the brief were JOHN B. SGANGA, JR.,
FREDERICK S. BERRETTA, and JOSHUA J. STOWELL, Knobbe,
Martens, Olson & Bear, LLP, of Irvine, California.
CHARLENE M. MORROW, Fenwick & West LLP, of
Mountain View, California, argued for defendants-cross
LARYNGEAL MASK CO v. AMBU AS 2
appellants. With her on the brief were DARRYL M. WOO
and BRYAN A. KOHM, of San Francisco, California. Of
counsel was JEFFREY V. LASKER.
__________________________
Before RADER, Chief Judge, LOURIE and MOORE, Circuit
Judges.
MOORE, Circuit Judge.
The Laryngeal Mask Company Ltd. and LMA North
America, Inc. (collectively, LMA) appeal the district
court’s summary judgment that the Aura40™, Au-
raOnce™, and AuraStraight™ products made by Ambu
A/S, Ambu Inc., and Ambu Ltd. (collectively, Ambu) did
not infringe the asserted claims of U.S. Patent No.
7,156,100 (’100 patent) and that all claims were invalid
for lack of written description under 35 U.S.C. § 112. We
conclude that the district court erred in its construction of
the claim term “backplate.” Because its summary judg-
ment of no infringement was predicated on this erroneous
claim construction, we vacate. We further conclude that
LMA has raised a genuine issue of material fact preclud-
ing summary judgment on the issue of written descrip-
tion, and we therefore vacate the court’s judgment of
invalidity and remand for further proceedings.
BACKGROUND
The ’100 patent concerns laryngeal mask airway de-
vices, which are artificial airway devices used to deliver
anesthetic gases during surgery and to establish unob-
structed airways in patients in emergency situations.
’100 patent col.1 ll.10-13. As shown below, these devices
include an airway tube [47] attached to a backplate [52],
which is surrounded by an inflatable cuff [55]. The device
is inserted into the patient’s mouth and throat until the
3 LARYNGEAL MASK CO v. AMBU AS
far (distal) end of the cuff meets the opening of the
esophagus [37]. The cuff is inserted in a deflated state.
Once in place, the cuff is inflated using a cuff airway tube
[62], forming a seal around the patient’s laryngeal inlet
and preventing gases from entering the esophagus.
Anesthetic gas or air can then flow into the patient’s
laryngeal inlet via the airway tube [47].
’100 patent, fig. 2.
Laryngeal mask airway devices were pioneered in the
1980s by Dr. Archibald Brain, the inventor listed on the
’100 patent. According to the ’100 patent, one problem
with prior art laryngeal mask airway devices is that
during insertion, the leading edge of the deflated cuff will
occasionally fold over on itself, allowing the more rigid
distal end of the mask to catch the inside of the patient’s
throat. Id. col.1 ll.31-35. This can be unpleasant for the
patient and may prevent the cuff from making a full seal
around the patient’s laryngeal inlet. Id. col.1 ll.46-40.
The invention of the ’100 patent seeks to minimize the
risk that the deflated cuff will fold over on itself by adding
a “reinforcing rib which serves to stiffen the leading end
of the LMA-device during the course of the procedure for
its insertion.” Id. col.1 ll.47-54.
LARYNGEAL MASK CO v. AMBU AS 4
LMA filed suit against Ambu, asserting that certain of
Ambu’s laryngeal mask airway devices infringed claims 1
to 6 of the ’100 patent. Ambu’s accused products include
its Aura40™, AuraOnce™, and AuraStraight™ laryngeal
mask airway devices. The district court construed the
disputed terms of the ’100 patent. Relevant to this ap-
peal, the court construed the claim term “backplate” as
“the relatively rigid mask structure surrounded by the
cuff and including a tube joint.” The Laryngeal Mask Co.
v. Ambu A/S, Civ. No. 07-CV-1988, D.I. 171, 7 (S.D. Cal.
Mar. 17, 2009) (Claim Construction Order). The tube
joint is the connection between the mask and the airway
tube. See, e.g., ’100 patent figs. 2-3. The district court
concluded that Ambu’s accused devices 1 do not have a
tube joint because the mask structure and the airway
tube are integrally molded—they are one continuous piece
rather than two pieces joined together by a joint. Because
the accused products lacked a tube joint the district court
concluded they lacked a backplate. The Laryngeal Mask
Co. v. Ambu A/S, Civ. No. 07-CV-1988, D.I. 224, 5 (S.D.
Cal. June 25, 2009) (Noninfringement Order). Therefore,
the court granted summary judgment that Ambu’s
Aura40™, AuraOnce™, and AuraStraight™ products do
not literally infringe claims 1 to 6 of the ’100 patent. Id.
at 6. The court also granted summary judgment of nonin-
fringement under the doctrine of equivalents, concluding
that it would vitiate the backplate limitation to equate a
backplate that includes a tube joint to a backplate molded
directly to an airway tube. Id. at 8.
1 LMA also asserted that Ambu’s AuraFlex™ device
infringes the claims of the ’100 patent, but this model is
not integrally molded and was not part of the district
court’s summary judgment order.
5 LARYNGEAL MASK CO v. AMBU AS
The district court further granted Ambu’s motion for
summary judgment of invalidity for lack of written de-
scription. The Laryngeal Mask Co. v. Ambu A/S, Civ. No.
07-CV-1988, D.I. 476 (S.D. Cal. Sept, 25, 2009) (Invalidity
Order). The court determined that the specification failed
to adequately describe a mask having “at least a portion
of the posterior portion of a wall of the cuff in the distal
region being thicker and stiffer than other portions of the
cuff,” as required by claim 1. Id. at 4-6. The court thus
concluded that claim 1 and its dependent claims were
invalid under 35 U.S.C. § 112, ¶ 1. Invalidity Order at 7.
LMA appeals, challenging the court’s claim construc-
tion and judgments of noninfringement and invalidity.
We have jurisdiction under 28 U.S.C. § 1295(a)(1).
DISCUSSION
This court reviews a grant of summary judgment de
novo. Immunocept, L.L.C. v. Fulbright & Jaworski,
L.L.P., 504 F.3d 1281, 1286 (Fed. Cir. 2007). “Summary
judgment is appropriate when there is no genuine issue
as to any material fact and the moving party is entitled to
judgment as a matter of law.” Id.
I. Claim Construction
We review claim construction de novo. Cybor Corp. v.
FAS Techs., Inc., 138 F.3d 1448, 1455-56 (Fed. Cir. 1998)
(en banc). The words of a claim are generally given their
ordinary and customary meaning as understood by a
person of ordinary skill in the art in question at the time
of the invention when read in the context of the specifica-
tion and prosecution history. See Phillips v. AWH Corp.,
415 F.3d 1303, 1313 (Fed. Cir. 2005) (en banc).
LARYNGEAL MASK CO v. AMBU AS 6
Claims 1 to 6 are at issue. Claims 2 to 6 all depend
from claim 1, which reads:
1. A laryngeal-mask airway device comprising:
a backplate defining a passage;
an inflatable cuff, the cuff defining a distal
region and a central opening at least when
inflated, the cuff being attached to the
backplate, the cuff being insertable
through a mouth of a patient to an in-
serted location within the patient, an air-
way extending from a laryngeal inlet of
the patient, through the central opening,
to the passage when the cuff is inflated
and at the inserted location, at least a por-
tion of the posterior portion of a wall of
the cuff in the distal region being thicker
and stiffer than other portions of the cuff.
’100 patent, claim 1 (emphasis added).
On appeal, LMA argues that the district court im-
properly read a tube joint limitation into the claims. LMA
contends that the claim language requires only that the
backplate “defin[e] a passage” and that the “cuff be[]
attached to the backplate.” LMA asserts that because the
claims do not mention an airway tube, the claims need
not clarify or explain how the airway tube will attach to
the backplate.
LMA argues that the specification’s repetition of the
term tube joint does not justify adding it to the claims.
LMA states that the “Summary of the Invention” de-
scribes “a mask attached to one end of the airway tube,”
and LMA asserts that this statement is broad enough to
7 LARYNGEAL MASK CO v. AMBU AS
include a mask that is integrally molded to an airway
tube as well as devices with a tube joint. LMA Reply Br.
7.
LMA further argues that the prosecution history
weighs against the addition of a tube joint limitation.
LMA explains that during the final phase of prosecution,
when pursuing claims directed to a mask having a rein-
forced cuff, it deleted the airway tube and tube joint
language from the claims. LMA reiterates that the tube
joint has nothing to do with the claimed invention. LMA
asserts that because the terms “airway tube” and “tube
joint” were deliberately deleted, it is improper to read
these limitations back into the claims.
Ambu contends that backplate is a technical term
coined by the inventor, Dr. Brain. Ambu does not argue
that the plain and ordinary meaning of backplate includes
a tube joint, but rather that Dr. Brain acted as his own
lexicographer and defined backplate as a bowl containing
a passage and a tube joint, fitted between the airway tube
and the inflatable cuff. Ambu places great emphasis on
the specification statement that: “The backplate 52 has a
one-piece, integral spoon-shape including a bowl 90 and
an external tube-joint 92 oriented proximally relative to
the bowl, as shown in FIGS. 5 and 6.” ’100 patent col.6
ll.3-5. Ambu asserts that every figure, every embodiment,
and every description of the backplate in the ’100 patent
shows that the backplate is a separate structure from the
airway tube and comprises a tube joint for connection to
the airway tube. Ambu concludes that because “back-
plate” does not have a common meaning broader than
that described in the ’100 patent, the patentee must have
acted as his own lexicographer. Ambu further asserts
that the prosecution history does not compel excluding
the tube joint limitation. Ambu contends that by deleting
LARYNGEAL MASK CO v. AMBU AS 8
the tube joint language, LMA removed clarifying lan-
guage from the claims, but LMA did not remove any
limitation.
This is a difficult case of claim construction. We have
a specification replete with discussion of a tube joint,
which is the point of attachment between the mask struc-
ture and the airway tube. And we are mindful that the
specification is the single best guide to the meaning of a
disputed term. The preferred embodiment states that the
backplate has a tube joint: It is this tube joint that con-
nects the mask structure to the airway tube. See, e.g.,
’100 patent figs. 2-3. Ambu is correct that the patent does
not disclose an integrally molded mask/airway tube.
Certainly, it would be improper to add a tube joint limita-
tion to the claims at issue where none appears. Kara
Tech. Inc. v. Stamps.com Inc., 582 F.3d 1341, 1348 (Fed.
Cir. 2009) (“The patentee is entitled to the full scope of his
claims, and we will not limit him to his preferred em-
bodiment or import a limitation from the specification
into the claims.”). Ambu, however, does not ask this court
to import the tube joint limitation into the claims gener-
ally, but rather argues that the claim limitation “back-
plate” should be construed to include a tube joint.
Although it is a close case, in light of the claim lan-
guage, specification, and prosecution history, we conclude
that the term backplate is not so limited. The claims
themselves are limited to the mask structure. The claims
require “a backplate defining a passage.” Claim 1 further
defines that “the cuff … [is] attached to the backplate.”
There is no mention of the airway tube or how the back-
plate or mask structure would attach to the airway tube.
The claims cover only a laryngeal mask airway device
comprising the backplate and cuff.
9 LARYNGEAL MASK CO v. AMBU AS
Although there is ample discussion of the tube joint
throughout the specification, there is only one place
where the specification indicates that the tube joint is
part of the backplate (in the preferred embodiment’s
description of Figures 5 and 6): “The backplate 52 has a
one-piece, integral spoon-shape including a bowl 90 and
an external tube-joint 92 oriented proximally relative to
the bowl, as shown in FIGS. 5 and 6.” ’100 patent col.6
ll.3-5. This sentence, which as its language indicates,
describes what is shown in Figures 5 and 6, is not enough
to require every backplate to include a tube joint. To be
his own lexicographer, a patentee must use a “special
definition of the term [that] is clearly stated in the patent
specification or file history.” Vitronics Corp. v. Concep-
tronic, Inc., 90 F.3d 1576, 1580 (Fed. Cir. 1996); see also
CCS Fitness, Inc. v. Brunswick Corp., 288 F.3d 1359, 1366
(“[T]he claim term will not receive its ordinary meaning if
the patentee acted as his own lexicographer and clearly
set forth a definition of the disputed claim term in either
the specification or prosecution history.”). The specifica-
tion does not clearly contain such a special definition.
Although the preferred embodiment includes a backplate
that contains a tube joint, we do not generally limit
claims to the preferred embodiment. Phillips, 415 F.3d at
1323 (“[W]e have 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.”). The specification here does not clearly
indicate the patentee’s intent to give backplate a unique
meaning different from its ordinary and customary mean-
ing to one of skill in the art. See Helmsderfer v. Brobrick
Washroom Equip., Inc., 527 F.3d 1379, 1381 (Fed. Cir.
2008) (“A patentee may act as its own lexicographer and
assign to a term a unique definition that is different from
its ordinary and customary meaning; however, a patentee
LARYNGEAL MASK CO v. AMBU AS 10
must clearly express that intent in the written descrip-
tion.”).
The Summary of the Invention uses the term back-
plate to refer to the mask structure. See ’100 patent col.1
l.64 (referring to “the mask structure or backplate”). It
describes the mask structure as “having a generally
elliptical periphery provided with an inflatable cuff which
surrounds the hollow interior of the mask into which the
airway tube opens . . . .” Id. col.1 ll.59-61. It further
explains that the laryngeal airway mask device comprises
“a flexible airway tube and a mask attached to one end of
the airway tube.” Id. col.1 ll.58. This indicates that the
backplate will be connected or attached to the airway
tube, but does not require that connection to be formed
via a tube joint. We agree with LMA that this description
is broad enough to include integrally molded devices as
well as devices with a tube joint. The specification does
not clearly convey the patentee’s intent to appoint a
special meaning to the term backplate. Having concluded
that the patentee did not act as his own lexicographer in
this case by clearly defining a claim term, we must de-
termine the ordinary meaning of backplate as used in
these claims to one of skill in the art in light of the speci-
fication and prosecution history.
The prosecution history also indicates that the back-
plate is not required to have a tube joint. Just prior to
issuance, the applicant deleted language concerning the
airway tube and the tube joint. Reply to Office Action
dated Oct. 19, 2005, at 2 (Apr. 19, 2006). The claims
previously required that the backplate include a tube joint
in the pharyngeal side of the mask. See, e.g., U.S. Appl.
No. 09/412,954, 19 (Oct. 5, 1999); Reply to Office Action of
Dec. 15, 2004, 2 (Jun. 15, 2005). The applicant deleted
this requirement from the claims. See Reply to Office
11 LARYNGEAL MASK CO v. AMBU AS
Action dated Oct. 19, 2005, 2 (Apr. 19, 2006). Following
the amendment, the Examiner allowed the claims without
any objection to or rejection of the deleted airway tube or
tube joint language. See Notice of Allowance (Aug. 23,
2006). 2 Ambu asserts that LMA amended its claims in an
effort to cover Ambu’s recently marketed AuraOnce™
mask, which has a unitary structure lacking a tube joint.
Regardless of why LMA amended its claims, we agree
with LMA that it would be improper to read a tube joint
limitation back into the backplate. See Kister Instrumente
AG v. United States, 628 F.2d 1303, 1308 (Ct. Cl. 1980)
(“[D]efendant’s insist[e]nce upon this court’s reading back
into the claims limitations which were originally there
and were removed during prosecution of the application
through the Patent Office cannot be permitted.”).
Although there was no dictionary or treatise defini-
tion introduced for backplate, 3 there are two prior art
patents also related to laryngeal mask devices which use
the term. U.S. Patent No. 5,355,879 (’879 patent); U.S.
Patent No. 5,305,743 (’743 patent). Both prior art patents
list the same inventor as the patent at issue, Dr. Brain.
Both of these patents disclose a backplate, but neither
2 The Notice of Allowance contains an Examiner’s
amendment, but this amendment has nothing to do with
the deleted tube joint limitation. The amendment clari-
fied that the thicker and stiffer cuff reinforcement be
located on the “posterior” portion of the cuff, rather than
on a “first” portion of the cuff. Notice of Allowance (Aug.
23, 2006).
3 The failure to introduce a dictionary definition for
the disputed claim term does not preclude a conclusion
that there exists a plain meaning to one of skill in the art.
We will not adopt a categorical rule that absence of a
dictionary definition means that the applicant must be
held to have acted as his own lexicographer and is there-
fore constrained to the preferred embodiment.
LARYNGEAL MASK CO v. AMBU AS 12
includes a tube joint. This prior art use of the term would
further inform one of skill in the art as to the common
meaning of the term backplate.
The term backplate has a somewhat self-descriptive
nature. As the prior art patents indicate it is the plate on
the back. In light of the claims, specification, prosecution
history, and prior art patents, we conclude that one of
skill in the art would understand the claimed backplate to
be “the relatively rigid mask structure surrounded by the
cuff.” We conclude that one of skill in the art would not
conclude that the backplate must have a tube joint. We
also conclude that the inventor did not act as his own
lexicographer here and clearly require the backplate to
have a tube joint. Because the district court’s judgment of
noninfringement was based on an erroneous claim con-
struction, we vacate that judgment and remand for fur-
ther proceedings.
II. Written Description
The district court granted summary judgment that all
claims of the ’100 patent were invalid for failure to satisfy
the written description requirement of 35 U.S.C. § 112,
¶ 1. Invalidity Order at 7. “Compliance with the written
description requirement is a question of fact.” ICU Med.,
Inc. v. Alaris Med. Sys., Inc., 558 F.3d 1368, 1376 (Fed.
Cir. 2009). Adequate written description requires that
the applicant “convey with reasonable clarity to those
skilled in the art that, as of the filing date sought, he or
she was in possession of the [claimed] invention.” Vas-
Cath Inc. v. Mahurkar, 935 F.2d 1555, 1563–64 (Fed. Cir.
1991) (emphasis omitted). Issued patents are presumed
valid under 35 U.S.C. § 282, and thus Ambu must demon-
strate by clear and convincing evidence that the claims at
13 LARYNGEAL MASK CO v. AMBU AS
issue are invalid for lack of written description. ICU
Medical, 558 F.3d at 1376.
Claim 1 requires “at least a portion of the posterior
portion of a wall of the cuff in the distal region being
thicker and stiffer than other portions of the cuff.” ’100
patent, claim 1. The court construed this phrase accord-
ing to its plain meaning and thus concluded that the
phrase does not require that the “thicker and stiffer” cuff
portion be connected to the backplate. 4 Claim Construc-
tion Order at 9.
Ambu moved for summary judgment that the asserted
claims thus construed were invalid for lack of written
description because the specification nowhere describes a
thicker and stiffer cuff portion that is not connected to the
backplate. The court agreed, finding that the specifica-
tion failed to describe such an embodiment. Invalidity
Order at 5-6. LMA presented expert testimony that one
of ordinary skill in the art would read the specification to
describe a thicker and stiffer cuff portion disconnected
from the backplate, but the court found the testimony
“not helpful.” Id. at 6. It concluded that “[b]ased on the
Court’s review of the specification, the ’100 patent does
not meet the written description requirement.” Id. at 7.
On appeal, LMA argues that the specification ade-
quately describes a thicker and stiffer cuff portion. LMA
acknowledges that the specification does not describe an
embodiment with the reinforced cuff region disconnected
4 Ambu’s devices contain a V-shaped stiffener that
is located entirely within the cuff and not connected to the
mask structure, and thus Ambu urged the court to con-
strue the phrase to require that the thicker and stiffer
cuff reinforcement be attached to a backplate. Claim
Construction Order at 8.
LARYNGEAL MASK CO v. AMBU AS 14
from the backplate, but it argues that this does not render
the claims invalid. LMA explains that the specification is
silent as to whether the cuff reinforcement must be, or
even should be, connected to the backplate. LMA further
explains that the specification does not describe the
invention in terms of the connection, extol any advantages
of a connected cuff reinforcement, identify disadvantages
of a disconnected cuff reinforcement, or identify a connec-
tion as a critical feature.
LMA further contends that factual disputes exist that
render summary judgment of invalidity improper. LMA
presented the testimony of two experts that one of ordi-
nary skill in the art would read the specification as de-
scribing “at least a portion of the posterior portion of a
wall of the cuff in the distal region being thicker and
stiffer than other portions of the cuff,” as required by
claim 1. This testimony focused on a statement in the
specification that LMA refers to as the Cuff Wall Thicken-
ing Passage: “The distal rib 105a may be effectively
constituted by a thickening of the posterior wall of the
distal region 60a of the inflatable main-cuff 55a and, as
shown, forms a distal extension of the bowl 90a of the
backplate 52a.” ’100 patent col.8 ll.9-12. LMA stresses
that “as shown,” this thicker and stiffer cuff portion is
connected to the backplate, but LMA asserts that the “as
shown” clause is not limiting.
LMA’s experts also cited the Summary of the Inven-
tion for support. See J.A. 3670; J.A. 3700. LMA’s experts
opined that the Summary of the Invention refers broadly
to a reinforcement in the distal end of the cuff, and then
identifies a preferred embodiment in which the rein-
forcement extends from the backplate. J.A. 3671, 3700.
Specifically, the Summary of the Invention explains that
the present invention seeks to minimize the risk of the
15 LARYNGEAL MASK CO v. AMBU AS
deflated cuff folding over on itself during insertion “by
incorporating into the cuff at its distal end a reinforcing
rib which serves to stiffen the leading end of the LMA-
device during the course of the procedure for its inser-
tion.” ’100 patent col.1 ll.47-55. It also provides that “[i]n
accordance with the invention . . . the device includ[es] a
reinforcing rib incorporated into the distal end of the
inflatable cuff.” Id. col.1 ll.56-63. LMA’s experts con-
cluded that these statements describe the invention as
having a reinforcement in the distal end of the cuff, but
not as an extension of the backplate. See J.A. 3700. The
Summary of the Invention further provides that “in a
preferred aspect the mask structure or backplate which is
of more rigid material than that of the soft and inflatable
cuff formation has its back extended to the distal end of
the cuff, in order to form the reinforcing rib.” ’100 patent
col.1 ll.64-67. LMA’s experts contended that these state-
ments, combined with the Cuff Wall Thickening Passage,
provide support for the invention described in claim 1.
LMA argues that, at a minimum, this testimony presents
a genuine factual dispute on the issue of validity preclud-
ing summary judgment.
Ambu argues that “the district court properly found
that the specification lacks any disclosure of a cuff stiff-
ener detached from the backplate.” Ambu Br. 60. Ambu
asserts that LMA’s position is based on an implausible
interpretation of the specification and that its expert
testimony plainly contradicts the specification.
We conclude that the district court erred in granting
summary judgment that the patent was invalid for failing
the written description requirement. The Summary of
the Invention does not require that the cuff reinforcement
be connected to the backplate. Rather, it describes a
reinforcement incorporated into the distal end of the cuff.
LARYNGEAL MASK CO v. AMBU AS 16
’100 patent col.1 ll.47-63. The Summary of the Invention
further states that “[i]n a preferred aspect,” the rein-
forcement extends from the backplate. See id. at col.1
ll.64-67. We agree with LMA that one of ordinary skill in
the art could read these disclosures as providing for a cuff
reinforcement in the distal region that need not be con-
nected to the backplate. In addition, we agree with LMA
that one of ordinary skill in the art could read the Cuff
Wall Thickening Passage as disclosing a thickened cuff
portion that need not be connected to the backplate. Id.
col.8 ll.9-12. LMA has raised a genuine issue of material
fact on this issue, and therefore we reverse the court’s
grant of summary judgment and remand for further
proceedings consistent with this opinion.
CONCLUSION
For the foregoing reasons, we vacate the court’s order
of noninfringement and its judgment of invalidity for lack
of written description and remand for further proceedings
consistent with this opinion.
VACATED AND REMANDED
COSTS
No costs.