The opinion of the court was delivered by: Morton Denlow, United States Magistrate Judge.
MEMORANDUM OPINION AND ORDER
Plaintiffs, Dr. Sakharam D. Mahurkar ("Dr.Mahurkar"), owner of
United States Patent No. 4,583,968 and Patent No. 4,895,561 and
patent licensee, Sherwood Medical Company d/b/a
Kendall/Sherwood-Davis & Geck ("Kendall") (collectively
"Plaintiffs"), bring this patent infringement claim against
Defendant Arrow International, Inc. ("Arrow"). A Markman hearing
was held July 12, 2001 to construe the disputed claims of the
4,583,968 patent and the 4,895,561 patent. A detailed analysis
of the Court's construction of the claims is set forth below.
The patents-in-suit and the accused Arrow products all involve
double-lumen catheters for use in hemodialysis. The role of
kidneys in the body is to remove toxins from blood. When kidneys
fail to function properly due to disease or injury, blood must
be cleaned externally. In hemodialysis, blood is removed from a
patient, diverted to a blood treatment unit where it is
cleansed, and then returned to the patient. Hemodialysis
catheters are devices that are inserted into a patient's vein
for removal and return of blood. A double lumen hemodialysis
catheter has two separate lumens, or channels, one for removing
and one for returning blood. In re Mahurkar, 831 F. Supp. 1354
(N.D.Ill. 1993) (Easterbrook, J. sitting by designation).
A typical hemodialysis blood treatment system includes a blood
treatment unit for cleansing the blood, a catheter inserted into
a patient's vein for removal of the uncleansed blood and return
of cleansed blood, and various connectors and extension tubes
that connect the catheter to the blood treatment unit. Patients
with diseased or damaged kidneys generally return to a hospital
or clinic for regular hemodialysis.
There are over 25,000 U.S. patents that contain the term
"catheter" in their specifications and almost 5,000 U.S. patents
with this term in their title. The patents-in-suit relate to a
certain subset of catheters, double lumen catheters.
B. DR. MAHURKAR, THE INVENTOR
Dr. Mahurkar is a licensed nephrologist who has lived in
Chicago for the past 29 years. Until his retirement in 1995, Dr.
Mahurkar conducted research and taught nephrology and internal
medicine at Cook County Hospital in Chicago. In addition, Dr.
Mahurkar has been an inventor, receiving 28 U.S. patents,
primarily dealing with catheters and syringes. He has also
published a number of academic articles on hemodialysis.
In the 1970s, Dr. Mahurkar designed a catheter divided
internally by a septum which created two equal "D" shaped or
semi-circular lumens ("double D") and having a beveled tip. This
catheter is the subject of Dr. Mahurkar's first patent, U.S.
Patent No. 4,134,402 ("the '402 patent"), which expired in 1997
and is not asserted in this suit.
In the early 1980s, Dr. Mahurkar filed a series of patent
applications covering variations to his original double D
catheter design relating to the catheter tip, and the holes or
ports on the catheter. These improvements resulted in two
inventions: (1) smooth bore septum-type double lumen catheters;
and (2) bent extension catheter assemblies. The patents
protecting these two inventions, U.S. Patent No. 4,583,968 ("the
'968 patent") and U.S. Patent No. 4,895,561 ("the '561 patent"),
are the two patents involved in this litigation.
C. THE '968 PATENT-SMOOTH BORE SEPTUM TYPE DOUBLE LUMEN
The '968 patent,*fn1 entitled "Smooth Bore Double Lumen
Catheter," was issued to Dr. Mahurkar on April 22, 1986. The
'968 patent is a catheter which is made of a cylindrical tube
divided into two separate lumens. One lumen is used for removing
unclean blood, and the other for returning cleansed blood. The
exterior of the cylindrical tube is a smooth bore, and the tip
of the tube is conical, making the catheter easy to insert.
D. PRIOR LITIGATION BETWEEN THE PARTIES
The present suit is not the first litigation between Dr.
Mahurkar and Arrow concerning the '968 patent. In 1991, Dr.
Mahurkar sued Arrow for infringement of the '968 patent. On July
22, 1992, the parties entered into an agreed order which
terminated the case. Pursuant to the order, Arrow agreed to stop
selling catheters having double D designs.
In July 1998, Dr. Mahurkar filed a motion for contempt, in
which Kendall intervened, alleging that Arrow's post-agreed
order catheters violated the agreed order and infringed claim 19
of the '968 patent. Judge Andersen denied Dr. Mahurkar's motion
holding that the issues raised should be the subject of a new
lawsuit. This action follows that decision.
E. OTHER LITIGATION INVOLVING THE '968 PATENT
In 1990, Dr. Mahurkar and Quinton Instrument Company
("Quinton"), Dr. Mahurkar's then licensee, filed a lawsuit
against IMPRA, Inc., a non-party to the pending litigation,
alleging infringement of the '968 patent. The case went to trial
against defendant IMPRA before Judge Easterbrook in the Northern
District of Illinois. In re Mahurkar, 831 F. Supp. 1354
(N.D.Ill. 1993), aff'd, 71 F.3d 1573 (Fed.Cir. 1995).
Claims 1 and 19 of the '968 patent were at issue in the case.
Judge Easterbrook found IMPRA infringed on Mahurkar's patent.
Id. Judge Easterbrook's reasoning and conclusions are
extremely useful for the Court in construing the claims
presented in this case. The Court will address relevant portions
of Judge Easterbrook's opinion.
F. THE '561 PATENT-BENT EXTENSION CATHETER ASSEMBLIES
The '561 patent,*fn2 entitled "Dual-Lumen
Catheter-Connecting System," was issued to Dr. Mahurkar on
January 23, 1990. The '561 patent concerns the portion of the
catheter assembly that connects the catheter tube to the blood
treatment unit. This invention improves patient comfort for
certain types of catheter placements, and reduces the likelihood
the catheters will pull out of the vein during or between
The present litigation involves two separate patent
infringement suits that have been consolidated for discovery.
The first suit, 98 C 4890, alleges infringement of the '561
patent, and the second suit, 99 C 5711, alleges infringement of
the '968 patent. The parties have consented to this Court
conducting the Markman hearing.
The Court will first explain the rules of claim construction
and will then apply those rules to the disputed claims in the
'968 patent and the '561 patent.
II. RULES OF CLAIM CONSTRUCTION
An infringement analysis involves two steps. The first step is
determining the meaning and scope of the patent claims allegedly
infringed, also known as claim construction or interpretation.
Markman v. Westview Instruments, Inc., 52 F.3d 967, 976
(Fed.Cir. 1995) (en banc) aff'd 517 U.S. 370, 116 S.Ct. 1384,
134 L.Ed.2d 577 (1996). Claim construction is a matter of law
for decision by the courts. Id. at 970. The second step is
comparing the properly construed claim to the instrument accused
of infringing. Id. at 976. This proceeding is concerned with
the first step, commonly known as a Markman hearing.
A. SOURCES AND HIERARCHY FOR CLAIM INTERPRETATION
In interpreting a claim, a court first looks to the language
of the claim, which defines the breadth and depth and bounds of
the claim. York Products, Inc. v. Central Tractor Farm & Family
Ctr., 99 F.3d 1568, 1572 (Fed.Cir. 1996). The general rule is
that terms in the claim are to be given their ordinary and
accustomed meaning. Johnson Worldwide Assoc., Inc. v. Zebco
Corp., 175 F.3d 985, 989 (Fed.Cir. 1999). A court must presume
that the terms of the claim mean what they say, and give full
effect to the ordinary and accustomed meaning of the claim terms
unless otherwise compelled. Id. There are two instances in
which a court may be compelled to give the definition of a term
a meaning outside of the ordinary and accustomed one. The first
one arises when a patentee has chosen to be his own
lexicographer, as long as the special definition of the term is
clearly stated in the patent specification or file history.
Id. at 990; Vitronics Corp. v. Conceptronic, Inc.,
90 F.3d 1576, 1582 (Fed.Cir. 1996). The second arises when the terms
chosen by the patentee "so deprive the claim of clarity that
there is no means by which the scope of the claim may be
ascertained from the language used." Zebco, 175 F.3d at 990.
Second, the court looks to the patent specification,
containing a written description of the invention which must be
clear and complete enough to enable those of ordinary skill in
the art to make and use it. Vitronics, 90 F.3d at 1582. It is
here where, if the patentee chooses to be his own lexicographer,
the special meanings of the claim terms are typically found.
Id. The specification is "always highly relevant" and is
usually dispositive; it is the "single best guide to the
meaning" of a disputed term. Id. All claims must be read in
view of the specification, which acts as a sort of dictionary to
explain the invention and may define the terms used in the
claim. Markman, 52 F.3d at 979.
Third, the court may also consider the prosecution history of
the patent, which contains the complete record of the
proceedings before the Patent and Trademark Office ("PTO"),
including any express representations made by the patentee
regarding the scope of the claims. Vitronics, 90 F.3d at 1582.
The prosecution history is often significant when determining
the scope of a claim. Id. The prosecution history can and
should be used to understand the language used in the claim,
however, it can not be used to enlarge, diminish or vary the
terms in the claim. Markman, 52 F.3d at 980. Included within
an analysis of the file history may be an examination of the
prior art cited therein, as the prior art gives guidance as to
what the patent does and does not cover. Vitronics, 90 F.3d at
In terms of hierarchy, evidence that is objective, reliable,
and publicly accessible, such as prior art documents,
dictionaries and treatises are preferred over other types of
extrinsic evidence. Id. at 1585. Although dictionaries and
treatises fall within the category of extrinsic evidence, they
are worthy of special consideration. Judges are free to consult
such resources at any time to better understand the underlying
technology, and may rely on dictionary definitions as the
ordinary and accustomed meaning of a term, as long as the
dictionary definition does not contradict any definition found
in or ascertained by a reading of the patent. Id. at 1584 n.
6. Prior art, although also extrinsic evidence, may be included
in an analysis of the prosecution history if cited therein.
Id. at 1583. A court may rely on prior art proffered by one of
the parties, even if not cited in the specifications and file
history, to aid in the court's understanding and to demonstrate
how a disputed term is used by those skilled in the art. Id.
at 1584. Opinion testimony of experts and the inventor should be
treated with "utmost caution" and may only be relied upon if the
patent documents taken as a whole are insufficient to enable the
court to construe disputed claim terms, which is rare, if ever.
Id. at 1584-85.
B. PATENTS ARE GENERALLY UNAMBIGUOUS
In most situations, there is no "ambiguity" in the claim
language. Markman, 52 F.3d at 986. Statutory language
requirements are designed to avoid ambiguity in a patent. Id.
The statute requires that the specification contain a written
description in "full, clear, concise and exact terms."
35 U.S.C. § 112. Patent applications are reviewed by examiners at the PTO
who are "trained in the law and presumed to have some expertise
in interpreting the prior art references and to be familiar from
their work with the level of skill in the art and whose duty it
is to issue only valid patents." Markman, 52 F.3d at 986.
Thus, "[i]f the patent's claims are sufficiently unambiguous for
the PTO, there should exist no factual ambiguity when those same
claims are later construed by a court of law in an infringement
However, because "a judge is not usually a person conversant
in the particular technical art involved and is not the
hypothetical skilled in the art to whom a patent is addressed,
extrinsic evidence may be necessary to inform the court about
the language in which the patent is written. But this evidence
is not for the purpose of clarifying ambiguity in claim
terminology. It is not ambiguity in the document that creates
the need for extrinsic evidence but rather unfamiliarity of the
court with the terminology of the art to which the patent is
C. LIMITATIONS NOT SET FORTH IN THE CLAIM MAY NOT BE READ
INTO THE CLAIM
There are two familiar claim construction canons regarding
limitations imposed on claims, setting forth the relationship
between the claims and the written description: 1) one may not
read a limitation into a claim from the written description, and
2) one may look to the written description to define a term
already in a claim limitation, as a claim must be read in view
of the specifications of which it is a part. Renishaw PLC v.
Marposs Societa' per Azioni, 158 F.3d 1243, 1248 (Fed.Cir.
1998). Thus, a limitation must appear in the language of the
claim before one looks to the written description to define that
limitation. "This is so because the claims define the scope and
the right to exclude, and the claim construction inquiry . . .
begins and ends in all cases with the actual words of the
Without a term in the claim that would direct us to the
written description for clarification, there is no legitimate
way to narrow the claim. Id. Similarly, if the written
description provides us a definition of a term used in the
claim, then reading in a further limiting definition would be
improper. Mantech Environmental Corp. v. Hudson Environmental
Serv. Inc., 152 F.3d 1368, 1374 (Fed.Cir. 1998). The Supreme
Court explained this requirement, stating, "We know of no
principle of law which would authorize us to read into a claim
an element which is not present, for the purpose of making out a
case of novelty of infringement. The difficulty is that if we
once begin to include elements not mentioned in the claim in
order to limit such claim. . . ., we should never know where to
stop." Renishaw, 158 F.3d at 1248 (quoting McCarty v. Lehigh
Val R.R., 160 U.S. 110, 116, 16 S.Ct. 240, 40 L.Ed. 358
Words in a claim should be accorded their ordinary and
accustomed meaning, not a narrower scope than what is ordinarily
accorded it. Renishaw, 158 F.3d at 1249. Thus, when a claim
term contains a general descriptive term, the term will not be
limited to a numerical range that is included in the written
description. Similarly, a general term cannot be reduced to a
narrower scope or subset of that term by a modifier if the claim
does not expressly contain the modifier. For example, if the
claim term recites a general noun without limiting that noun
with an adjective, the claim should be construed to cover all
known types of that general noun supported by the patent
disclosure. Id. at 1250. Likewise, if the words of the claim
recite a general verb without limiting it with an adverb, the
claim should be construed to cover the ordinary broader meaning
of the verb. Id. (citing Virginia Panel Corp. v. MAC Panel
Co., 133 F.3d 860 (Fed.Cir. 1997) (holding that "reciprocating"
is not limited to linearly reciprocating)). In looking at the
written description to define the scope of a claim term, the
varied use of a term demonstrates the breadth of the term,
demanding a broad construction, rather than a narrow one.
Zebco, 175 F.3d at 991.
However, a common meaning, such as one found in a dictionary,
that is inapposite to the context of the patent disclosure is
not one that the court should adopt. Id. Indiscriminate
reliance on definitions found in dictionaries can produce absurd
results if not read in light of, and in the context of, the
patent specifications. Id.
D. THE SCOPE OF THE CLAIM IS NOT LIMITED TO THE PREFERRED
As a general rule, the claim is not limited by the language of
the preferred embodiments or specific examples included in the
specification. Karlin Technology Inc. v. Surgical Dynamics,
Inc., 177 F.3d 968, 972 (Fed.Cir. 1999). "It is well settled
that device claims are not limited to devices which operate
precisely as the embodiments described in detail in the patent."
Id. (quoting Virginia Panel, 133 F.3d at 866). Similarly,
mere inferences drawn from the description of an embodiment
cannot serve to limit claim terms. Johnson, 175 F.3d at 992.
"Although the specification may aid the court in interpreting
the meaning of disputed claim
language, particular embodiments and examples in the
specification will not generally be read into the claims."
Comark Communications, Inc. v. Harris Corporation,
156 F.3d 1182, 1186 (Fed.Cir. 1998). The law "does not require that an
applicant describe in his specification every conceivable and
possible future embodiment of his invention. The law . . .
requires only that the inventor describe the `best mode' known
at the time to him in making the invention." SRI International
v. Matsushita Electric Corp. of America, 775 F.2d 1107,
E. THE LITERAL SCOPE OF A MEANS-PLUS-FUNCTION CLAIM IS THE
RECITED FUNCTION PERFORMED BY THE CORRESPONDING DISCLOSED
STRUCTURE OR ITS EQUIVALENT STRUCTURES
Pursuant to 35 U.S.C. § 112, T 6, a claim element "may be
expressed as a means or step for performing a specified function
without the recital of structure, material, or acts in support
thereof." The claim elements written in this format are
construed to cover the corresponding structures described in the
specification, and equivalents thereof. Id.
A court's task in construing a means-plus-function element
involves two steps. First, the court identifies the function
portion of the element and construes any disputed terms in the
function language. Second, the court identifies the
corresponding structure(s) disclosed in the specification linked
or associated with that function. Chiuminatta Concrete
Concepts, Inc. v. Cardinal Indus., Inc., 145 F.3d 1303, 1308
(Fed.Cir. 1998); B. Braun Medical, Inc. v. Abbott Lab.,
124 F.3d 1419, 1424 (Fed.Cir. 1997) (corresponding structure must be
linked or associated with recited function). To determine the
claimed function, the court must construe the specific terms in
the claim. Chiuminatta Concrete Concepts, 145 F.3d at 1308. A
means-plus function claim is indefinite, and thus invalid, if
the specification fails to disclose an adequate structure
corresponding to the means limitation. Kemco Sales, Inc. v.
Control Papers Co., 208 F.3d 1352, 1360-61 (Fed.Cir. 2000).
Not all aspects of the structure disclosed in the
specification should be included in the court's claim
construction. Details of the disclosed structure that are
"unrelated to the recited function" are not "corresponding
structure," and do not limit the scope of the means clause.
Chiuminatta Concrete, 145 F.3d at 1308.
F. DIFFERENT CLAIMS IN A PATENT ARE PRESUMED TO HAVE A
The doctrine of claim differentiation creates a presumption
that different claims in a patent have a different scope.
Comark Communications, Inc. v. Harris Corp., 156 F.3d 1182,
1187 (Fed.Cir. 1998). The doctrine "is ultimately based on the
common sense notion that different words or phrases used in
separate claims have different meaning and scope." Karlin
Technology, Inc.,. 177 F.3d at 971-72. For example, a
limitation found in a dependent claim ordinarily should not be
read into the independent claim from which it depends. Id. at
972; See also Whittaker Corp. v. UNR Indus., Inc.,
911 F.2d 709, 712 (Fed.Cir. 1990) ("it is inconsistent with the principle
of claim differentiation that . . . an independent claim should
be given the same meaning" as claims that depend from the
III. CLAIM INTERPRETATION-THE '968 PATENT
Claim 12 reads as follows, with language to be construed in
A double lumen catheter comprising an elongated
cylindrical tube including a planar axial divider
bisecting said cylindrical tube into first and
second lumens, the proximal end of said cylindrical
tube connecting two separate tubes communicating
with the respective first and second lumens for the
injection and removal of fluid, the first lumen
extending from the proximal end of said cylindrical
tube to a first opening at the distal end of said
cylindrical tube, the second lumen extending from
the proximal end of said cylindrical tube to a
second opening in the side of the cylindrical
surface of said cylindrical tube, said second lumen
terminating at said second opening and a relative
concentration of material extending axially from
the second opening to the distal end of said
cylindrical tube, the distal end of said
cylindrical tube having a smooth conical tapered
tip that smoothly merges with the cylindrical
surface of said cylindrical tube, the cylindrical
surface of said cylindrical tube having at least
one side hole exposing said first lumen axially
spaced between said second opening and said conical
tapered tip and circumferentially disposed on the
opposite side of said cylindrical tube as said
second opening, and the cylindrical surface of said
cylindrical tube having at least one side hole
exposing said second lumen axially spaced between
said second opening and the proximal end of said
cylindrical tube and circumferentially disposed on
the same side of said cylindrical tube as said
1. Language in Dispute: "A relative concentration of
*fn4 Does "a relative concentration of material" mean (1)
the presence of some material relative to the hollow lumens or
(2) sufficient material to stiffen the tip relative to the
remainder of the catheter body?
Answer: "A relative concentration of material" means sufficient
material to stiffen the tip relative to the remainder of the
The Court must interpret the term "relative concentration of
material." The term "relative" is a comparative term and
requires a determination of what is being compared. The claim
does not explain to what the relative concentration of material
should be compared. Plaintiffs argue it should be compared to
the hollow lumen. Arrow argues that when looking at the claim
language in the patent, the meaning of "relative concentration
of material" cannot be determined because it does not say to
what it is relative. The Court agrees. Therefore, the Court must
look to the specification and written descriptions for guidance.
The specification of the '968 patent supports Arrow's
construction of the claim. The specification clearly
demonstrates that the term "relative" relates to a comparison of
the stiffness or rigidity between the catheter tube, the body,
and the tip. Each time the words "relative concentration of
material" appear in the specification, they appear as a relative
concentration to stiffen the tip. This is true in the Abstract,
the Summary of the Invention, and also in the Preferred
The abstract explains: "to provide improved dilator
characteristics, preferably the tip includes a relative
concentration of material for rigidity." (Abstract). Similarly,
the summary of the invention describes the conical tapered tip:
"[it] comprises a relative concentration of material to impart
relative rigidity so that the tip functions as an effective
dilator for soft tissue and veins." ('968 patent, col. 2, lines
38-41). In the preferred embodiment, the specification describes
figure 7 as showing a conical tip formed with "a relative
concentration of material 23 to stiffen the tip 20. This
stiffening aids penetration of the tip 20 into the body cavity
(not shown) and also aids the dilation of soft tissue such as
veins." ('968 patent, col. 4, lines 16-21).
The prosecution history is also consistent with Arrow's claim
construction. Dr. Mahurkar described the purpose of the relative
concentration of material in his prosecution of the '968 patent:
"This relative concentration of material further prevents
kinking of the catheter tip during insertion." (Def. Ex. 2 at
NSHN 128717). Thus, it is the relative concentration of material
that stiffens the tip relative to the catheter body, which
prevents it from kinking.
Judge Easterbrook in his opinion In re Mahurkar, 831 F. Supp. 1354,
1359 (N.D.Ill. 1993) discussed figure 7 of the '968
patent. He explained that figure 7 "shows that the intake lumen
of the Mahurkar catheter is sealed off below the intake ports
and replaced with a plug of plastic, which the claims of the
patent call a `relative concentration of material.' (This both
stiffens the tip and eliminates space in which blood may pool
and clot.)" In re Mahurkar, 831 F. Supp. at 1359.
2. Language in Dispute: "Extending Axially."
Does material "extending axially from the second opening to
the distal end of said cylindrical tube" mean (1) material
present in the second lumen between the inlet opening and the
tip or (2) material to run continuously from the inlet opening
through the tip?
Answer: Material "extending axially from the second opening to
the distal end of said cylindrical tube" means material to run
continuously from the inlet opening through the tip.
The issue in construing this language is whether the material
must run continuously from the inlet opening through the tip.
Dr. Mahurkar argues the term "extends axially" means that the
material extends, or reaches toward the base of the conical tip
from the inlet opening, but does not have to be continuous.
The Court holds the claim limitation requires the relative
concentration of material to go continuously from the inlet
opening to the tip. The use of the term "extends axially"
describes both the direction and the fact that it is continuous
in that direction. To extend means to straighten out or to
stretch out to full length. (Webster's II New Riverside
University Dictionary 456 (1994)).
Figure 7 is the only illustration in the patent of the
"relative concentration of material." Arrow argues this figure
is consistent with its construction of claim 12 because it
depicts a solid material which runs continuously from the
opening of the inlet through the tip.
The specification regarding figure 7 says, "As shown in fig.
7, the inlet lumen 14 terminates at the inlet aperture 19 and in
place of the inlet lumen the relative concentration of material
extends axially from the aperture to the distal end of the tube
at the truncated apex of the conical tip." ('968 patent, col. 4,
lines 21-25). The parties agree the specification calls for the
relative concentration of material to be continuous, however Dr.
Mahurkar argues this is one embodiment, and is not a
requirement. The Court holds the written description accurately
describes the claim.
In the earlier litigation, Judge Easterbrook stated that
"extending axially" means "a relative concentration `extending'
from intake through outlet." In re Mahurkar, 831 F. Supp. at
1382. To demonstrate what the court meant by "extending
axially," Judge Easterbrook provided the following example,
"[O]ne would suppose that a highway `extending' from Chicago to
Milwaukee goes all the way; just so a relative concentration
`extending' from intake through outlet." Id. However, Judge
Easterbrook noted in the opinion, "Because Mahurkar and Quinton
would not be entitled to any relief under Claims 12 and 25 that
they do not obtain under claims 1 and 19, it is unnecessary for
me to decide who is right." In re Mahurkar, 831 F. Supp. at
1382. Thus, although Judge Easterbrook did not make a ruling,
this Court finds his reasoning to be correct and adopts it.
3. Language in Dispute: "conical tapered tip" and "a
Does "smooth conical tapered tip" mean (1) a shape with a
circular base tapering to a point as in either a centered (right
circular) cone or an off-center (oblique circular) cone or (2) a
shape tapering evenly on all sides as in a right circular cone?
Does "cone" mean (1) a shape with a circular base tapering to a
point as in either a centered (right circular) cone or an
off-center (oblique circular) cone or (2) a shape tapering
evenly on all sides as in a right circular cone?
Answer: Both "smooth conical tapered tip" and "cone" mean a
shape with a circular base tapering to a point as in either a
centered (right circular) cone or an off-center (oblique
The parties do not dispute that the limitation in this claim
covers an ordinary
centered (right circular) cone. Where they do not agree is
whether the claim limitations also cover an off-center (oblique
circular) cone. A right circular cone, or a centered cone, is a
cone in which the apex is aligned with the center of the circle
(i.e., an ice cream cone shape). In an oblique circular cone, or
an off-center cone, the apex is above the circle, but not
directly above the center of the circle. The Court holds the
term "cone" includes both a right circular cone and an oblique
circular cone. The claim language is helpful because in claim
12, it refers only to a "smooth conical tapered tip," whereas in
claim 13, it specifies a type of cone when it states "said
conical tip is substantially aligned with the axis of said
cylindrical tube." Under the doctrine of claim differentiation,
these two claims must mean different things. Thus, under claim
12, the cone may be either a right circular cone or an oblique
circular cone and claim 13 is limited to only a right circular
The specification also supports construction of this claim as
not limited to right circular cones. The specification states
that in accordance with the invention:
the distal end portion of the tube 11 has a conical
tip generally designated 20 which smoothly merges
with the cylindrical body of the tube11. Preferably
the apex of the conical tip 20 is centered on the
axis of the cylindrical body of the tube 11 thus
serving as a guidance point to uniformly distribute
the frictional resistance encountered by the conical
tip when the tube is inserted into the body cavity
. . . Since the frictional resistance is uniformly
distributed and the conical tip smoothly merges with
the body of the tube 11, insertion trauma and kinking
are minimized. ('968 patent, col. 3, lines 47-54;
62-64). (Emphasis added).
In order for the frictional resistance to be uniformly
distributed, the conical tip must be a right circular cone and
not an oblique circular cone. The use of the term "preferably"
indicates that the centered cone is Dr. Mahurkar's preferred
configuration, but that he also contemplates other types of
cones. Because claim 12 does not explicitly recite that the apex
of the conical tip is centered on the axis of the cylindrical
tube, claim 12 is not limited to this preferred approach. Had
Dr. Mahurkar intended to limit claim 12 to right circular cones,
he would simply have included the "centered apex" language of
claim 13 within claim 12. See Rodime PLC v. Seagate Technology,
Inc., 174 F.3d 1294, 1305 (Fed.Cir. 1999) ("Had [the patentee]
intended or desired to claim thermal compensation as a function
of the positioning means in the asserted claims, it could have
done it explicitly as in claim 11").
It is agreed that all of the figures in the '968 patent depict
right circular cones, not oblique circular cones. Arrow claims
that "conical" must be limited to the described preferred
embodiment because "no other embodiment of a tip shape is shown
or described in the '968 patent." (Def. Br., at p. 22). Arrow is
wrong about the law. A claim term can be limited to the
described preferred embodiment only when the specification
clearly and unambiguously so limits that term. See e.g.,
Johnson Worldwide Associates, 175 F.3d at 991. And, "just as
the preferred embodiment itself does not limit claim
terms.. . . ., mere inferences drawn from the description of an
embodiment of the invention cannot serve to limit claim terms."
Id. at 992.*fn6
Arrow also seeks to support its narrow construction with
passages from the prosecution history contending that Dr.
Mahurkar was forced to distinguish a prior art oblique circular
cone by limiting his claims to a right circular cone. During
prosecution of the '968 patent, Dr. Mahurkar distinguished the
Edelman structure. Arrow incorrectly characterizes Edelman's tip
as an oblique circular cone. It is not. First, the Edelman tip
has a rounded blunt end, not an apex. Second, one entire side of
the Edelman tip is flat, and the base, therefore, is not a
circle. The Edelman tip structure is perhaps best described as a
"beak" or a "nose," not as a circular cone. The prosecution
history statements cited by Arrow, therefore, do not support
Perhaps more importantly, the actual grounds upon which Dr.
Mahurkar distinguished Edelman was that Edelman lacked the
claimed smooth conical tip, not just that it lacked a conical
tip. Regarding Edelman, Dr. Mahurkar described why his invention
differed from Edelman's structure:
The Edelman et al. patent 4,403,983 shows a
septum-type dual-lumen catheter in which the septum
is inserted as a separate piece; the outer wall of
one of the two lumens formed by the insertion of the
septum is tapered toward the septum, and the other is
cut off "normal to both the septum and the tube axis"
(column 2, lines 59-60), thereby forming a sharply
stepped tip which would also seem to produce high
insertion trauma. . . . None of these septum-type
catheters has applicant's smooth conical tapered tip
which smoothly merges with the surface of the
cylindrical tube. . . .
(Def. Ex. 2 at NSHN 128765-66.) This passage clearly shows
that Dr. Mahurkar's primary concern with the Edelman structure
was the sharp step between the tube and the tip. Dr. Mahurkar's
claims distinguished this structure by reciting a smooth conical
tapered tip that smoothly merges with the tube.
Dr. Mahurkar's statements during the prosecution history,
therefore, never limited the word "cone" to right circular
cones, and do not constitute a clear and deliberate surrender of
claim scope. See Northern Telecom Ltd. v. Samsung Electronics
Co., Ltd., 215 F.3d 1281, 1294-95 (Fed.Cir. 2000) ("We cannot
conclude that [the defendant] has demonstrated that the
patentees — with reasonable clarity and deliberation [citation
omitted] — defined `plasma etching' as excluding ion
d). Dictionary Definition
Medical dictionaries also support Plaintiffs' contention that
"conical" is not limited to a centered (right circular) cone.
Cone is defined as "a solid figure or body with a circular base
tapering to a point." (Dorland's Illustrated Medical Dictionary,
Twenty-Sixth Edition). Cone is defined as "a solid figure or
body having a circular base and tapering to a point, . . ."
(Miller-Keane Encyclopedia & Dictionary of Medicine, Nursing &
Allied Health (5th Ed. 1992)). Cone is defined as "a figure or
anatomic structure tapering to a point from a circular base."
(Melloni's Illustrated Medical Dictionary (2nd Ed. 1985)).
4. Language in Dispute: "Same Side" and "Opposite Side."
Does "same side of said cylindrical tube" refer to (1) the
position on the cylindrical tube relative to the axial divider
(i.e., the holes are on the portions of the tube on the same
side of the axial divider) or (2) to the position on the
cylindrical tube relative to the circumference of the
cylindrical tube (i.e., the holes are aligned on the portions of
the tube along the length of the tube)?
Answer: "Same side of said cylindrical tube" refers to the
position on the cylindrical tube relative to the axial divider.
Does "opposite side of said cylindrical tube" refer to (1)
the position on the cylindrical tube relative to the axial
divider (i.e., the holes are on the portions of the tube on
different sides of the axial divider) or (2) the position on the
cylindrical tube relative to the circumference of the
cylindrical tube (i.e., the holes are aligned on the portions of
the tube along the length of the tube)?
Answer: "Opposite side of said cylindrical tube" refers to the
position on the cylindrical tube relative to the axial divider.
These claim limitations concern additional side holes exposing
the two lumens of the catheter to the blood stream. The dispute
involves the meaning of the phrases "opposite side" and "same
side." The Court holds "opposite side" to mean on the other side
of the axial divider of the cylindrical tube without reference
to any particular point and "same side" to mean on the same side
of the axial divider of the tube without reference to any
The Court's construction is based largely upon the common
usage and meaning of the terms "opposite" and "same" as they
relate to the term "side." For example, during a tennis match,
one player is on one side of the court and his opponent is on
the opposite side of the net which divides the court in half.
The opponent need not be directly opposite the player to be on
the opposite side, he must just be on the other side of the net.
Similarly, in a doubles tennis match teammates are considered to
play on the same side when they are on the same side of the
court as divided by the net. They need not be in the same
service box, but just on the same side of the court.
The illustrations in figs. 1 and 2 of the '968 patent
illustrate one embodiment of the claimed side holes. Opening 19,
the primary inlet opening for the second lumen, is "said second
opening." Multiple holes 21 constitute "at least one side hole
circumferentially disposed on the opposite side" of the tube as
opening 19, and multiple holes 22 make up "at least one side
hole circumferentially disposed on the same side" of the tube as
The specification supports Dr. Mahurkar's construction of this
The return holes 21 and the inlet holes 22 are
further disposed circumferentially on opposite sides
of the divider 12. Thus, there is axial as well as
circumferential separation of the inlets and outlets
for fluid circulation. ('968 patent, col. 4, lines
c). Dictionary Definition
The construction of the words "opposite side" and "same side"
is simple. The ordinary and accustomed meaning of the words
provide their construction. The parties agree the cylindrical
tube is divided in half by the axial divider. Therefore, the
"opposite side" is simply the opposite side of the divider, and
"same side" means the same side of the divider. This does not
mean the holes must be exactly 180 degrees apart to be on
"opposite sides" nor does it mean the holes must be axially
aligned to be on the "same side." Webster's Dictionary defines
"side" as "a place, space, or direction with respect to a center
or to a line of division (as of an aisle, river, or street)."
(Webster's Collegiate Dictionary 1089 (10th ed. 1996)).
Common usage of the words here, leads the Court to construct
"opposite side" as on the opposite side of the tube as
determined by a center line, which in this case is the axial
divider. Similarly, "same side" is on the same side of the tube
as determined again by the axial divider.
Claim 13 reads as follows, with language to be construed in
The double lumen catheter as claimed in claim 12,
wherein the apex of said conical tip is
substantially aligned with the axis of said
1. Language in Dispute: "the apex of said conical tip is
substantially aligned with the axis of said cylindrical
Does Claim 13 mean that (1) the apex is substantially
centered on the cylindrical tube, and therefore, the "conical
tip" is a centered (right circular) cone or (2) the apex is
substantially centered on the cylindrical tube, and therefore,
the "conical tip" is centered on the cylindrical tube?
Answer: Claim 13 means that the apex is substantially centered
on the cylindrical tube, and therefore, the "conical tip" is a
centered (right circular) cone.
Claim 13 is a dependent claim. The basis for the Court's
holding is found in the Court's discussion of claim 12 at III.
A. 3 supra.
Claim 19 reads as follows, with language to be construed in
A double lumen catheter comprising an elongated
unitary tube including an integral septum
extending axially along the entire length of the tube
and dividing the interior of said tube into a first
and a second lumen, the outer circumference of said
tube converging smoothly at the distal end portion of
said tube defining a truncated cone, the first lumen
opening at the truncated apex of said cone, and the
second lumen being shorter in axial length than the
first lumen and opening upon the outer circumference
of said tube, said tube having a uniform diameter
from its distal end portion to proximally beyond the
opening of the second lumen upon the outer
1. Language in Dispute: "A double lumen catheter comprising
an elongated unitary tube including an integral septum . . ."
Does "unitary tube" mean (1) the tube and tip are a single
unit or (2) a tube and tip are of single-piece construction
(i.e. integrally formed)?
Answer: "Unitary tube" means the tube and tip are a single
The issue in this claim is whether the term "unitary" requires
the tube and tip to be formed from one piece of material. The
Court answers this question no.
The claim language says "elongated unitary tube including
integral septum." Integral means one-piece formation, as opposed
to bonded, which is a two-piece construction. The patent does
not say integral tube including integral septum. If that were
the case it would be clear that the claim only covers a tube
formed from a single piece and a septum formed from one piece.
However, that is not what we have in claim 19.
The words integral and unitary are two different terms which
are presumed to have two different meanings. Comark
Communications, Inc., 156 F.3d at 1182. The patent, the
prosecution history and the common usage of the terms all
suggest "integral" means being formed from one piece of material
while "unitary" requires the object be a single unit. Therefore,
the adjective "unitary" describing the tube, requires that the
elongated tube including its tip and integrated septum, be a
single unit in the completed catheter product.
The specification in the patent supports the construction that
the elongated tube must be one unit in the completed catheter,
but may be manufactured either integrally or by bonding. The
specification shows an example of a unitary tube in the figures
and states the tube can be made from one piece of material or
multiple pieces joined together to form one unit:
It is readily apparent to persons of ordinary skill
in the art that the tip 20 as shown in FIG. 7 is
easily formed from thermo-plastic material. The tip
20 including the relative concentration of material
23 is easily molded and bonded or is integrally
formed from the cylindrical tube 11 by the use of
internal and external mandrels and the application of
heat by any number of conventional means such as RF
forming, thermal forming, or infrared forming. ('968
patent, col. 4, lines 29-37). (Emphasis added).
Thus, the written description in the patent corroborates Dr.
Arrow contends the word "unitary" requires that the entire
tube, including the tip, be constructed from a single piece of
material. In support of this construction, Arrow cites a passage
from the prosecution history which includes a discussion of the
"unitary" and "integral septum" limitations:
Claim 21[now claim 19] further recites a double lumen
catheter comprising an elongated unitary tube
including an integral divider. Edelman et al. does
not disclose a unitary structure. The unitary
structure prevents mis-matching of components, the
clotting of blood and tips breaking off into the
patient. (Def. Ex. 2 at NSHN 128717).
This passage cites the advantages of the unitary structure, but
does not limit the construction of the unitary tube to integral
formation from a single material. This passage was presented by
Dr. Mahurkar to demonstrate that the Edelman catheter is not
unitary and his is. He was not equating the word "unitary" with
"integral" but rather was equating "unitary" with a single unit,
and explaining that the Edelman catheter has multiple pieces
(the septum and the cylinder) that are not sealed. (See Edelman
et al. Patent No. 4,403,983, col. 2 lines 29-32 and 46-49).
d). Dictionary Definition
The word "unitary" is best construed by its ordinary usage and
accustomed meaning. Webster's defines "unitary" as "having the
character of a unit: whole." (Webster's II New Riverside
University Dictionary 1262 (1994)). Therefore, the word
"unitary" an adjective describing the elongated tube, provides
that the tube, including the septum, be a single unit in the
As discussed supra, the '968 patent was also the subject of
previous litigation. Judge Easterbrook analyzed claim 19 in
terms of its best mode, but did not decide the issue before this
Court. In re Mahurkar, 831 F. Supp. at 1378.
2. Language in Dispute: "An integral septum."
Does "septum" mean (1) a dividing wall or (2) a flat
Answer: "Septum" means a dividing wall.
The issue is whether the septum is limited to being flat. The
Court holds the septum extending along the tube and dividing the
tube into first and second lumens is not limited to a flat
divider. The claim language provides that there must be a septum
which is integral with the tube which divides the interior of
the tube into the "first lumen" and the "second lumen." The
claim language does not specify the type of septum, only that it
must be integral. Therefore, the Court will not read another
adjective into the claim language but will instead construe
"septum" in accordance with its ordinary usage and accustomed
meaning. The ordinary meaning of "septum" is divider.
The specification supports the construction that a "septum" is
The tube 11 is circular in cross section . . . And
has an internal divider 12 defining a return lumen 13
and an inlet lumen 14 within the interior of the
hollow tube. ('968 patent col. 3, lines 17-20).
This language does not specify what type of divider must divide
the tube into two lumens. Furthermore, the specification does
not limit the "septum" of claim 19 to a planar septum, it merely
discloses one preferred embodiment.
That Dr. Mahurkar intended for claim 19 to cover cathaters
with a non-planar septum is made particularly clear by comparing
claim 19 to the other independent claims of the '968 patent:
claims 1, 12, and 25. Claims 1 and 25, unlike claim 19, both
explicitly recite a "planar septum," and claim 12 recites a
"planar axial divider." The patentee's use of the limiting
adjective "planar" in some claims, but not others, must be given
meaning. See Karlin, 177 F.3d at 972 ...