Kinetic Concepts, Inc. v. Smith & Nephew, Inc. , 688 F.3d 1342 ( 2012 )

United States Court of Appeals
for the Federal Circuit
__________________________
KINETIC CONCEPTS, INC., KCI LICENSING, INC.,
KCI USA, INC., KCI MEDICAL RESOURCES, KCI
MANUFACTURING, AND MEDICAL HOLDINGS
LIMITED,
Plaintiffs,
AND
WAKE FOREST UNIVERSITY HEALTH SCIENCES,
Plaintiff-Appellant,
v.
SMITH & NEPHEW, INC.,
Defendant-Appellee.
__________________________
2011-1105
__________________________
Appeal from the United States District Court for the
Western District of Texas in case no. 08-CV-0102, Judge
W. Royal Furgeson, Jr.
_________________________
Decided: August 13, 2012
_________________________
MATTHEW D. POWERS, Weil, Gotshal & Manges LLP,
of Redwood Shores, California, argued for plaintiff-
appellant. With him on the brief were ELIZABETH
STOTLAND WEISWASSER, PETER SANDEL, JENNIFER H. WU,
KINETIC CONCEPTS v. SMITH & NEPHEW 2
DANIELLE ROSENTHAL and ERIN WIGGINS, of New York,
New York. Of counsel was ANDREW SWANSON BROWN.
JOSEPH R. RE, Knobbe, Martens, Olson & Bear, LLP,
of Irvine, California, argued for defendant-appellee. With
him on the brief were JAMES F. LESNIAK, SHELIA N.
SWAROOP and CHRISTY G. LEA. Of counsel on the brief
was MARK J. GORMAN, Smith & Nephew, Inc., of Cordova,
Tennessee.
__________________________
Before BRYSON, DYK and O’MALLEY, Circuit Judges.
Opinion for the court filed by Circuit Judge O’Malley.
Circuit Judge Dyk concurs in the result.
O’MALLEY, Circuit Judge.
Wake Forest University Health Sciences (“Wake For-
est”) appeals the district court’s grant of judgment as a
matter of law (“JMOL”) of invalidity for obviousness. In
granting Smith & Nephew, Inc.’s (“S&N”) motion for
JMOL, the district court overturned the jury’s determina-
tion that S&N had failed to prove that the asserted claims
of the patents in suit were obvious. We conclude that, on
the basis of the jury’s factual findings, S&N failed to
establish by clear and convincing evidence that the claims
were obvious. Accordingly, we reverse and remand.1
1 The concurrence raises, and then purports to re-
solve, issues that were neither raised nor discussed before
the district court, and were not argued in this appeal.
Because it is about matters not before us, we do not
respond to the concurrence except to the extent our dis-
cussions of the patents and the prior art already do so.
3 KINETIC CONCEPTS v. SMITH & NEPHEW
BACKGROUND
I. Asserted Patents
Kinetic Concepts, Inc., KCI Licensing, Inc., KCI USA,
Inc., KCI Medical Resources, KCI Manufacturing, and
Medical Holdings Limited (collectively “KCI”) and Wake
Forest brought suit against S&N, alleging infringement of
U.S. Patent Nos. 7,216,651 (“’651 patent”) and 5,645,081
(“’081 patent”). Wake Forest is the owner of the asserted
patents, and KCI are the exclusive licensees of the pat-
ents. Both patents claim methods and apparatuses for
treating difficult-to-heal wounds by applying suction or
negative pressure, e.g., ’651 patent Abstract; ’081 patent
Abstract. Wake Forest and KCI asserted that S&N
infringes apparatus claims 2 and 5 of the ’081 patent and
induces infringement of method claims 42, 109, 116, and
121 of the ’651 patent.
As described by the asserted patents, medical “treat-
ment of open wounds that are too large to spontaneously
close” is difficult. ’081 patent col.1 ll.11–12; ’651 patent
col.1 ll.29–30. “Wound closure requires that epithelial
and subcutaneous tissue migrate from the wound border
toward the wound.” ’081 patent col.2 ll.49–50. To facili-
tate such migration, doctors commonly use mechanical
closures, such as sutures or staples. Id. at col.1 ll.24–25.
Such mechanical closures create tension on the skin,
which encourages epithelial migration. Id. at col.1 ll.25–
28. “While suturing and stapling of wounds is widely
practiced, it has a major drawback: the tensile force
required to achieve closure with sutures or staples causes
very high localized stresses at the suture insertion points,
resulting in the rupture of the tissue at these points.” Id.
at col.1 ll.28–33. This rupturing inhibits healing of the
wound. Id. at col.1 ll.33–35. Additionally, it is not feasi-
KINETIC CONCEPTS v. SMITH & NEPHEW 4
ble to suture some large open wounds. Id. at col.1 ll.28–
33.
To address these shortcomings, the invention applies
“negative pressure to a wound over an area sufficient to
promote migration of epithelial and subcutaneous tissue
toward the wound, with the negative pressure being
maintained for a time sufficient to facilitate closure of the
wound.” Id. at col.2 ll.45–49; ’651 patent col.4 ll.18–23
(“[A] method of treating tissue damage is provided which
comprises applying a negative or reduced pressure to a
wound over an area sufficient to promote the migration of
epithelial and subcutaneous tissue toward the wound and
for a time period sufficient to facilitate closure of the
wound.”). Claim 2 of the ’081 patent and claim 42 of the
’651 patent are illustrative:
2. An apparatus for facilitating the healing of
wounds, comprising:
vacuum means for creating a negative pressure
between about 0.1 and 0.99 atmospheres on the
area of skin including and surrounding the
wound;
sealing means operatively associated with said
vacuum means for maintaining said negative
pressure on said wound by contacting the skin
surrounding said wound; and
open-cell polymer for positioning at the wound
within the sealing means for preventing the over-
growth of tissue in the wound.
’081 patent col.9 ll.50–65.
42. A method of treating a wound comprising the
steps of:
i. providing a vacuum source capable of providing
at least 0.11 atm of reduced pressure;
5 KINETIC CONCEPTS v. SMITH & NEPHEW
ii. locating a flexible adhesive cover over the
wound, said cover having a suction port;
iii. locating a porous material comprising a syn-
thetic polymer under said cover at the wound;
iv. adhesively sealing and adhering the periphery
of said cover to tissue surrounding the wound to
form a continuous seal;
v. operably connecting said suction port with said
vacuum system for producing said reduced pres-
sure;
vi. interposing a fluid trap between said suction
port and said vacuum source; and
vii. maintaining reduced pressure of at least 0.11
atm at the
wound until the wound had progressed toward a
selected stage of healing.
’651 patent col.25 ll.31–48.
KINETIC CONCEPTS v. SMITH & NEPHEW 6
Figure 1 of the ’651 patent discloses the key compo-
nents of the claimed apparatus:
As depicted in this figure, the claimed apparatus includes:
(1) a vacuum pump (30) ; (2) tubing (12); (3) an open-
celled foam wound screen (10); and (4) an adhesive seal
(18). ’651 patent col.6 ll.31–61; see also ’081 patent col.2
ll.30–35 (“FlG. 1 shows a cross-sectional view of a nega-
tive pressure device comprising a open-cell polymer
screen, a flexible hose connecting the foam section to a
suction pump, and a flexible polymer sheet overlying the
foam-hose assembly to provide the necessary seal.”). To
utilize the apparatus, “[f]irst, the open cell foam is cut to
fit the shape of the wound and placed inside the wound.
Then the adhesive seal is placed over the foam that is
7 KINETIC CONCEPTS v. SMITH & NEPHEW
inside the wound.” Kinetic Concepts, Inc. v. Blue Sky
Med. Grp., Inc., No. 08-cv-102, slip op. at 2 (W.D. Tex.
Oct. 10, 2010) (order granting defendant’s motion for
judgment as a matter of law of invalidity for obviousness)
(ECF No. 605) (“JMOL Order”). Once the seal is in place,
“[o]ne end of the tubing is placed through the seal into the
foam and the other end is attached to the vacuum pump.
The vacuum pump is turned on and, because of the tight
seal around the wound, the edges of the wound immedi-
ately begin to move together.” Id.
II. Prior Art
In the present litigation, S&N asserted prior art that
generally falls into three primary categories: (1) the
Bagautdinov references; (2) the Zamierowski reference;
and (3) the Chariker-Jeter references. On appeal, there is
no dispute that these references are all prior art.
A. Bagautdinov References
The Bagautdinov references consist of two articles
written by Dr. Bagautdinov. The first reference (“Ba-
gautdinov I”) was published in 1986. Joint Appendix
(“J.A.”) 10001–03. It discusses “a method for vacuum
treatment of primary and secondary purulent wounds.”
J.A. 10002. The reference describes the method as fol-
lows:
After surgical treatment of the purulent wound
and hemostasis, a drain of polyurethane foam
adapted in shape and size is placed on the surface
(or in the cavity). The surrounding skin is
smeared with sterile vaseline, antiseptic or inert
salve on an oil base and covered with a polyethyl-
ene film. . . . Regardless of the method of sealing,
a tube is hermetically installed onto the foam
through a hole in the polyethylene made before-
KINETIC CONCEPTS v. SMITH & NEPHEW 8
hand. The latter is connected to the vacuum pump
through a collection vessel. At a vacuum of 10 to
60 mmHg the film clenches the wound strictly
along its skin boundaries with uniform vacuum
treatment of the walls only on the side of the cav-
ity and elimination of exudate because of the po-
rous structure of the drain. The duration of the
treatment sessions depends on the degree of vac-
uum and ranges from 30 minutes to 2 hours,
whereupon the polyethylene is removed and a
gauze bandage emplaced. The sessions are con-
ducted daily until the wound is clean. On average
this procedure takes 3 to 4 days.
Id. Bagautdinov I notes that use of this method “inevita-
bly obtain[s] acceleration of the healing periods and
rehabilitation of the patients.” J.A. 10003. The second
reference (“Bagautdinov II”) was also published in 1986.
J.A. 10026–27. Bagautdinov II describes application of a
method similar to that described in Bagautdinov I to 170
patients. J.A. 10026. The method employed requires
that,
[i]mmediately after surgical treatment of the in-
fected area in the commonly accepted manner or
using a Scalpel-1 laser, a drain made from poly-
urethane foam is placed in the wound. For sorp-
tion treatment, it is first filled with activated
charcoal powder. The wound is sealed with poly-
ethylene film in one of several ways, depending on
the localization of the purulent focus. Vacuum
aspiration is conducted through an aspiration
tube using a constant suction pump. Thus, the
polyethylene film “clenches” the wound strictly
along its edges, and the sorbent makes secure con-
tact with the walls. The porous structure of the
drain allows for removal of exudate and vacuumi-
9 KINETIC CONCEPTS v. SMITH & NEPHEW
zation of the wound only from the cavity side. The
session lasts 1-2 hours with negative pressure of
10-40 mmHg, after which the isolation is removed.
The drain is changed 1-2 times daily. Vacuum
treatment was continued for 3-4 days.
J.A. 10026–27. As a result of this method, “[o]n average,
the wound became clean by day 4-5, with the appearance
of granulated tissue. . . . The average duration of in-
patient treatment was 11.8 bed days, compared to 17.2 in
the control group; 61.7% of the patients were released
with healed wounds and did not require outpatient treat-
ment.” J.A. 10027.
B. Zamierowski Reference
The Zamierowski reference is a Patent Cooperation
Treaty Application filed on April 3, 1990. J.A. 10057. The
reference describes a “fluidic connection system . . . for
draining liquids from and introducing liquids to patients.”
J.A. 10059. As described by the reference, the system,
which amounts to a wound dressing, consists of:
[A] semipermeable membrane including a pair of
panels each having a perimeter and an edge strip.
The membrane is formed by connecting the panel
edge strips together to form a seam extending
transversely across the membrane. The panels
and the membrane include inner and outer sur-
faces. A tube opening extends through the seam
between the panel edge strips and between the
membrane inner and outer surfaces. The mem-
brane inner surface is coated with an adhesive for
attachment to the skin of a patient. A tube or
sheath includes a proximate end extending
through the tube opening and a distal end posi-
tioned in spaced relation from the membrane
outer surface. . . . A passage extend[s] through the
KINETIC CONCEPTS v. SMITH & NEPHEW 10
sheath between its ends. An inner conduit can be
placed in the sheath passage and can include a
connection seal assembly for forming a fluid-tight
seal with the sheath. . . . When the fluidic connec-
tion system is used as a wound dressing, an in-
termediate layer of material can be applied
between the wound and the cover membrane in-
ner surface. Furthermore, the fluidic connection
system of the present invention can be used to se-
cure a percutaneous drainage tube within a pa-
tient, e.g. by inserting the percutanious tube
through the sheath passage. . . . The cover mem-
brane can be releasably, adhesively fastened to
the skin around a periphery thereof. A tube flu-
idically communicates with the wound through an
opening in the membrane. Fluids from a draining
wound can be evacuated through the tube and
liquid medication and irrigation can be introduced
through the tube to the wound site. The fluid
evacuation and introduction steps of the method
can each be accomplished both actively and pas-
sively . . . .
J.A. 10061–63. The reference indicates that this wound
dressing “promotes healing.” J.A. 10063.
C. Chariker-Jeter References
The Chariker-Jeter references consist of two pub-
lished articles (“Chariker-Jeter I” and “Chariker-Jeter II,”
respectively), J.A. 10044–47; J.A. 10050–56, and Dr.
Chariker’s 1989 public use of the system described in the
articles on Gary Aderholt (“Chariker-Jeter public use”).
Both Chariker-Jeter I and Chariker-Jeter II describe the
same “closed wound drainage system.” J.A. 10052. As
described in Chariker-Jeter II, the drainage system is
created by:
11 KINETIC CONCEPTS v. SMITH & NEPHEW
1. Irrigat[ing] the wound bed thoroughly with
normal saline using a 30ml syringe with a 19-
gauge needle.
2. Moisten one 2X2 gauze square with normal sa-
line. Open completely and lay across the wound
bed.
3. Place Jackson-Pratt drain in wound bed.
Shorten the fenestrated drain as necessary so that
the flat drain is confined to the wound bed. The
drain is never placed in the fistula 2 tract. In the
case of fistula drainage at skin level, the fenes-
trated portion of the drain is simply centered over
the cutaneous opening. It may be helpful to encir-
cle the cutaneous wound with a pectin-based skin
barrier in order to create a “trough” in which to
situate the fenestrated drain.
4. Saturate 4X4 gauze squares with normal saline.
Open and fluff into wound to completely cover the
drain and fill the defect to skin level. In the case
of a cutaneous fistula, only enough moist gauze to
cover the flat fenestrated drain is required.
5. Apply skin sealant (Bard Barrier Film, Skin-
Prep, etc.) to all skin that will be covered by the
film dressing. Allow to dry until slick.
6. Cut the film dressing or select a size to allow at
least 1inch of intact skin beyond the wound edges.
Place the film dressing over the packed wound.
Carefully crimp the adhesive film dressing around
the Jackson-Pratt tube to seal.
7. “Caulk” the tube exit site with a small amount
of Stomahesive Paste where the film dressing is
2 A “fistula” is generally considered to be a hole in
an organ. Kinetic Concepts, Inc. v. Blue Sky Med. Grp.,
Inc., 554 F.3d 1010, 1016 (Fed. Cir. 2009).
KINETIC CONCEPTS v. SMITH & NEPHEW 12
crimped around the tube. This ensures air-tight
closure.
8. Reinforce this site with waterproof “pink tape”
as illustrated.
9. Turn your attention now to the connection of
the Jackson-Pratt to continuous suction. (Do not
attempt to use the bulb of the Jackson-Pratt sys-
tem.) With some brands of canister and tubing,
all that is necessary is to cut the funnel end off
the tubing and the small J-P tubing will fit snugly
into the larger lumen tube. The junction should
be taped securely with pink tape. Otherwise you
may use small “Christmas tree” connector or can-
nibalize IV tubing to get a small plastic adapter to
connect the tubing.
10. Turn on continuous suction to the upper range
of the low setting (approximately 60 to 80 mmHg)
and observe the wound site. The dressing should
contract noticeably. If it does not, the system is
not closed and wound drainage will not be effi-
ciently removed. When this occurs, fistula drain-
age will accumulate, causing skin damage and
leakage outside of the dressing. Another indica-
tion that you have not obtained a closed suction
system is a whistling sound indicating that the
dressing is not air-tight.
J.A. 10052 (footnote added). Chariker-Jeter II explains
that “[o]ur clinical observations suggest that fistula
effluent does inhibit wound healing. . . . By minimizing
the inflammatory response [associated with the presence
of effluent], fibroplasia is reduced. This, we believe,
encourages rapid wound contraction and re-
epithelialization.” J.A. 10055.
Finally, with respect to the Chariker-Jeter public use,
Dr. Chariker testified that he treated Mr. Aderholt in
13 KINETIC CONCEPTS v. SMITH & NEPHEW
1989 with his closed suction wound drainage system.
“[Mr. Aderholt] was injured with a log chain that flew off
another truck into his truck, entered his chest, his abdo-
men, ruptured his lung, his [diaphragm], his pancreas, his
spleen, his stomach.” J.A. 22032:8–11. With the aid of
pictures of Mr. Aderholt’s treatment, Dr. Chariker stated
that his treatment was an example of the drainage sys-
tem facilitating the healing of a wound on a patient
without a fistula. J.A. 22035:6–38:11.
III. Prior Litigation
In 2003, Wake Forest and KCI sued Blue Sky Medical
Group, Inc., (“Blue Sky”) et al., alleging that its gauze
based negative pressure wound therapy products in-
fringed U.S. Patent No. 5,636,643 3 (“’643 patent”) and the
’081 patent. At trial, a jury found the patents were not
infringed, not invalid, and not unenforceable. At the close
of trial, defendants filed a motion for judgment as a
matter of law, alleging that the asserted claims of the ’643
and ’081 patents were invalid as obvious under 35 U.S.C.
§ 103. The district court denied that motion.
On appeal, this court affirmed the jury’s finding that
invalidity was not established and that the asserted
claims were not infringed. Blue Sky, 554 F.3d at 1025–26.
In reaching that conclusion, however, we determined that
the district court committed harmless error by failing to
construe the term “wound.” Id. at 1019. While we did not
provide a definitive construction of “wound,” we concluded
that construing “ ‘wound’ to include fistulae and ‘pus
pockets’ would [] expand the scope of the claims far be-
yond anything described in the specification.” Id. Signifi-
cantly, for the present appeal, we also concluded that
“wound,” “as used in the asserted patents, does not cover
3 KCI has not asserted this patent in the present
litigation.
KINETIC CONCEPTS v. SMITH & NEPHEW 14
the fistulae described in the Chariker-Jeter publications
. . . .” Id. at 1018.
IV. Present litigation
During the appeal in the prior litigation, S&N ac-
quired Blue Sky. In December 2008, S&N announced it
was launching a new foam-based negative pressure
wound treatment product. Responding to this announce-
ment, Wake Forest and KCI filed this suit, asserting that
S&N’s Renasys product infringed the asserted patents.
After conducting a Markman hearing, the district
court construed various terms recited in the claims. For
this appeal, the court’s construction of only the term
“wound” is relevant; it construed this term to mean:
“tissue damage to the surface of the body, including the
epithelial and subcutaneous layers, and excluding fistulae
and pus pockets.” Kinetic Concepts, Inc. v. Blue Sky Med.
Grp., Inc., No. 08-cv-102, slip op. at 8 (W.D. Tex. Nov. 12,
2009) (claim construction order) (ECF No. 280) (“Claim
Construction Order”); see also JMOL Order at 4.
Before the case was given to the jury for determina-
tion, the parties disagreed about the form and content of
the jury instructions. Wake Forest and KCI had de-
manded a trial by jury. In response, S&N moved the
district court to strike the jury demand with respect to
questions of law, including the ultimate question of obvi-
ousness. Def.’s Mot. to Strike Pls.’ Jury Demand on
Questions of Law at 5–9, Kinetic Concepts, Inc. v. Blue
Sky Med. Grp., Inc., 08-cv-102 (W.D. Tex. Jan. 21, 2010)
(ECF No. 397) (“Motion to Strike”). Prior to ruling on the
merits of the motion to strike, the district court conducted
an on-the-record pre-trial hearing. During the hearing,
S&N made clear that it wanted the jury to make findings
with respect to the factors under Graham v. John Deere
Co. of Kansas City, 383 U.S. 1 (1966), and reserve the
15 KINETIC CONCEPTS v. SMITH & NEPHEW
ultimate question of obviousness for the judge. Pre-Trial
Conference Tr. at 16–22, Kinetic Concepts, Inc. v. Blue
Sky Med. Grp., Inc., No. 08-cv-102 (W.D. Tex. Jan. 25,
2010) (“Pre-Trial Conference Transcript”). To facilitate
this division of responsibility, S&N proposed a special
interrogatory verdict form:
[T]he way it’s done and the way the models show
. . . is the jury make[s] findings under Graham v.
John Deere. If the jury is actually asked what is
the level of skill in the art, that’s one of the Gra-
ham findings. What is the scope and content of
the prior art. . . . [W]e proposed and gave to KCI a
two-page set of questions where we are specifi-
cally asking the jury to make findings as to
whether or not the prior art contains a particular
suggestion.
Id. at 16. Under this proposal, the trial judge would
resolve the ultimate question of obviousness on the basis
of the jury’s factual findings as exemplified in their an-
swers to the interrogatories.
Wake Forest and KCI expressed the belief that this
proposal was “one of the worst ideas of all time” because it
would make the process so complicated that the jury could
not get it right, thereby “taking away from the jury the
power they have been given by the constitution.” Id. at
23. Highlighting their concern with S&N’s proposed
verdict form, Wake Forest and KCI explained that: “It’s
not two pages, but actually five pages of questions. Two
pages that look like this of detailed questions about
whether the prior art discloses teeny tiny aspects of the
patent, and two questions that call for a narrative answer
from the jury.” Id. at 26. Responding to this criticism,
the trial judge indicated that he was “very reluctant . . . to
KINETIC CONCEPTS v. SMITH & NEPHEW 16
give juries questions requiring narrative answers.” Id. at
27.
The trial judge summarized the parties’ arguments as
both saying essentially the same thing: “[N]o matter how
I present this to the jury I have to make a separate de-
termination as to obviousness. Even if I were to submit
this to the jury in a broad form submission – just is it
obvious – regardless of what the jury said, my analysis
would have to require that I do my own look at the matter
from a legal point of view . . . .” Id. at 30. The trial judge
concluded the discussion of the Motion to Strike by indi-
cating that he would read the materials presented by the
parties and consider using special interrogatories. He
cautioned, however, that, “while I’m open to a special
interrogatory presentation, I’m not open to a special
interrogatory presentation that goes on and on and on.”
Id. at 30–31.
Four days after conducting the pre-trial hearing, the
district court denied S&N’s request that it not submit the
ultimate question of obviousness to the jury. Kinetic
Concepts, Inc. v. Blue Sky Med. Grp., Inc., No. 08-cv-102,
slip op. at 4–5 (W.D. Tex. Jan. 29, 2010) (order granting in
part and denying in part defendant’s motion to strike
plaintiff’s jury demand on questions of law) (ECF No.
407). It concluded that “[t]he jury instructions shall
explain the underlying factual issues that the jury must
resolve as well as the legal standard for determining
obviousness. Additionally, the jury verdict form shall
specifically ask the jury to determine the underlying
Graham factors, and make a final determination of obvi-
ousness that the court will consider as advisory.” Id. at 5.
In accordance with this ruling, the parties began de-
veloping proposed joint jury instructions and a special
verdict form. At the close of the presentation of evidence,
17 KINETIC CONCEPTS v. SMITH & NEPHEW
the parties were still developing the instructions and the
verdict form. Jury Trial Tr. Day 10 at 2806, Kinetic
Concepts, Inc. v. Blue Sky Med. Grp., Inc., No. 08-cv-102
(W.D. Tex. Feb. 23, 2010) (“Day 10 Trial Transcript”).
Because the jury instructions and verdict form were not
complete and there was some disagreement over the exact
form the documents should take, the district court held a
charge conference to resolve any remaining disputes, and
finalize the instructions and the verdict form. At this
stage in the proceeding, the obviousness verdict form
proffered by S&N was eighteen pages in length, and Wake
Forest and KCI’s was slightly more than seven pages in
length. Id. at 2969–70. Each of the proposed verdict
forms contained specific questions addressing the differ-
ences, if any, between the asserted claims and the three
categories of prior art discussed above. After reviewing
the proposals, the judge stated, “I really can’t give them
this. . . . I may have to try to figure out something else to
give them, but this won’t work.” Id. at 2985.
The judge explained his belief that, if the verdict form
only posed the ultimate question to the jury, the court
would be left with little guidance regarding the factual
predicate for the jury’s resolution of that issue. Id. at
2990–91. The district court, therefore, expressed its
preference to ask the jury specific questions about the
various Graham factors, in addition to asking the jury its
view on the ultimate conclusion of obviousness. Id. at
2992–94.
After discussing the various options with the parties,
the judge decided that the best option was to allow the
parties to draft a 300-word description of what the parties
asserted were the differences between the three main
categories of prior art and each of the asserted claims.
These “jury contentions” would be included in the jury
instructions. Then the jury verdict form would ask what
KINETIC CONCEPTS v. SMITH & NEPHEW 18
differences, if any, the jury found between the given claim
and the three main categories of prior art, providing space
for the jury to list the differences in a narrative. Id. at
2997–3006.
With these guidelines, the judge dismissed the parties
to finish drafting the jury instructions and verdict form,
explaining that that they would meet that evening when
the instructions and verdict form were complete. Id. at
3003–04. The judge advised the parties, however, that “if
you’ve got any better idea on obviousness that you can
agree to, I’ll be glad to do it, but what you’ve come up with
so far we’re not going to do. And so, if you can’t come up
with anything, then you just have to do it the way I said,
which I think is not optimal.” Id. at 3062.
When the parties met that night with the judge, a
court reporter was not present, so there is no record of the
discussion. It is clear from looking at the jury instruc-
tions and the verdict form as presented to the jury, how-
ever, that the parties and the judge agreed to use a
different format than suggested by the judge at the close
of the charge conference. Although the jury instructions
contain a discussion of the parties’ contentions regarding
the differences between the prior art and the claims, Jury
Trial Tr. Day 11 at 3098–3102, Kinetic Concepts, Inc. v.
Blue Sky Med. Grp., Inc., No. 08-cv-102 (W.D. Tex. Feb.
24, 2010) (“Day 11 Trial Transcript”), the verdict form did
not allow the jury to provide a narrative about which
differences they found to exist, nor did it pose questions
regarding all of the Graham factors. J.A. 65–89. Instead,
in questions 5(A)–(C), the jury was asked whether several
enumerated differences between the prior art and the
asserted claims were the only differences that existed.
The jury was simply instructed to answer yes or no. In
addition, in question 5(D), the verdict form contained a
chart that allowed the jury to indicate whether they found
19 KINETIC CONCEPTS v. SMITH & NEPHEW
certain objective indicia of nonobviousness to be present
with respect to each of the asserted claims. J.A. 70.
Finally, in question 6, the verdict form asked the jury to
decide whether S&N had proven that the asserted claims
were obvious. J.A. 71.
The jury determined that the claims and the prior art
exhibited differences in addition to those listed, J.A. 64–
69, that most of the objective considerations favoring
nonobviousness were present with respect to each claim,
that infringement was proven, and that obviousness was
not established. J.A. 62–63; 71. After the verdict was
read to the parties, the district court indicated that the
parties should prepare post-trial motions if they wished to
challenge the jury’s verdict. Jury Verdict Tr. at 12–13,
Kinetic Concepts, Inc. v. Blue Sky Med. Grp., Inc., No. 08-
cv-102 (W.D. Tex. Mar. 10, 2010) (“Jury Verdict Tran-
script”).
Pursuant to Rule 50(b) of the Federal Rules of Civil
Procedure, S&N moved for JMOL, arguing that all of the
asserted claims of the ’081 and ’651 patents were obvious.
In its motion, S&N asserted that substantial evidence did
not support the jury’s explicit findings that (1) additional
differences between the prior art and the asserted claims
existed, and (2) that multiple objective indicia of nonobvi-
ousness were present.
Responding to S&N’s motion, Wake Forest and KCI
argued that, in addition to the explicit jury findings, the
jury’s implicit findings necessary to determine the ulti-
mate question of obviousness should be presumed to have
been found in Wake Forest and KCI’s favor. Further-
more, these findings, both explicit and implicit, should not
be disturbed by the trial court unless they are not sup-
ported by substantial evidence. In light of this standard,
Wake Forest and KCI asserted that substantial evidence
KINETIC CONCEPTS v. SMITH & NEPHEW 20
supported the jury’s factual determinations: (1) that
additional differences existed between the prior art and
the asserted claims; (2) that objective indicia of nonobvi-
ousness were present; and (3) that teaching away was
demonstrated with respect to the Bagautdinov and
Chariker-Jeter references. On the basis of these findings,
Wake Forest and KCI asserted that S&N’s motion should
be denied because it failed to establish that the asserted
claims were obvious as a matter of law.
Replying to Wake Forest and KCI, S&N highlighted
that the jury’s verdict of nonobviousness was advisory
only. Accordingly, it argued that there were no implicit
factual findings in support of the advisory verdict on
nonobviousness to which the court should defer. Instead,
S&N asserted that “as the ultimate decision-maker on
obviousness, th[e] [district] [c]ourt has the responsibility
to make its own findings, based upon the current record,
necessary to support its own legal conclusion regarding
obviousness.” Def.’s Reply in Supp. of its Renewed Mot.
for J. as a Matter of Law of Invalidity for Obviousness
and Mot. for New Trial at 1, Kinetic Concepts, Inc. v. Blue
Sky Med. Grp., Inc., No. 08-cv-102 (W.D. Tex. May 12,
2010) (ECF No. 548). Based upon this understanding of
how the jury’s verdict should be reviewed by the district
court, S&N argued that the asserted claims were obvious
as a matter of law.
Prior to ruling on the merits of S&N’s motion, the
court conducted a hearing. S&N began by arguing that,
because the jury’s verdict on the ultimate question of
obviousness was advisory, it is inappropriate to “just
assume every finding of fact in favor of” the jury’s nonob-
viousness verdict. Post-Trial Hr’g Tr. at 133, Kinetic
Concepts, Inc. v. Blue Sky Med. Grp., Inc., No. 08-cv-102
(W.D. Tex. May 17, 2010) (“Post-Trial Hearing Tran-
script”). Indeed, S&N argued that implied findings of fact
21 KINETIC CONCEPTS v. SMITH & NEPHEW
only arose with respect to questions 5(A)–(C), regarding
additional differences, and 5(D), regarding the existence
of objective indicia of nonobviousness. Id. at 133–34, 36.
“It is not simply enough to say the jury found obviousness,
implied every finding of fact in our favor, which is what
KCI is arguing, and therefore the verdict should be up-
held. Not true. They are only entitled to implied findings
to the extent they are encompassed by the Verdict Ques-
tion 5, not 6.” Id. at 136. S&N argued that substantial
evidence did not support the jury’s factual finding that
additional patentably significant differences existed
between the prior art and the asserted claims and that
objective indicia of nonobviousness were present.
Wake Forest and KCI, on the other hand, argued that
the jury’s verdict on the ultimate question of obviousness
is always advisory because, as a question of law, it must
be determined by the court. See id. at 153. Nonetheless,
“the case law is absolutely clear that . . . [w]hen the jury
finds that [the claims] are not obvious, you have to as-
sume that they find the right underlying facts, and then
the test is substantial evidence” for the underlying factual
findings. Id. at 155. Under this standard, Wake Forest
and KCI argued that substantial evidence supported the
jury’s explicit and implicit factual findings, and that
S&N’s motion should have been denied.
Ultimately, the district court indicated that it would
“review[] the jury’s conclusions on obviousness, a question
of law, without deference, and the underlying findings of
fact, whether explicit or implicit within the verdict, for
substantial evidence.” JMOL Order at 8. After thor-
oughly summarizing the relevant prior art, the district
court concluded that, contrary to the jury’s explicit find-
ings, “the differences between the claimed invention and
the prior art, if any, are minimal.” Id. at 18. Indeed, the
district court concluded that the differences were so minor
KINETIC CONCEPTS v. SMITH & NEPHEW 22
that “such minimal variations would have been apparent
to one having ordinary skill in the art . . . .” Id. at 34.
The court concluded, therefore, that “the evidence is clear
and convincing that there is no legally sufficient basis on
the record to conclude that all asserted claims of the
patents in suit were not obvious.” Id. The fact that the
jury also found that several objective indicia of nonobvi-
ousness were present did not alter the district court’s
conclusion because, it said, “the Court is not convinced
that they overcome the strong case of obviousness estab-
lished by the teaching in the prior art.” Id. at 35. Accord-
ingly, the court granted S&N’s motion and entered
judgment in its favor. Id. at 37.
Wake Forest timely appealed. 4 We have jurisdiction
pursuant to 28 U.S.C. § 1295(a)(1).
DISCUSSION
We review a district court’s grant of JMOL de novo,
applying the law from the regional circuit, the Fifth
Circuit in this case. Harris Corp. v. Ericsson Inc., 417
F.3d 1241, 1248 (Fed. Cir. 2005). In the Fifth Circuit,
JMOL may be granted by the trial court only if “the facts
and inferences point so strongly and overwhelmingly in
favor of one party that the Court believes that reasonable
men could not arrive at a contrary verdict . . . . On the
other hand, if there is substantial evidence opposed to the
[grant of JMOL] . . . [it] should be denied.” Broussard v.
State Farm Fire & Cas. Co., 523 F.3d 618, 624 (5th Cir.
2008) (quoting Brown v. Bryan Cnty., 219 F.3d 450, 456
(5th Cir. 2000)). When evaluating the district court’s
grant of JMOL, consideration is given to “all of the evi-
dence, drawing all reasonable inferences and resolving all
credibility determinations in the light most favorable to
4 KCI did not appeal this judgment and is not,
therefore, an appellant before this court.
23 KINETIC CONCEPTS v. SMITH & NEPHEW
the non-moving party.” Id. (quoting Brown, 219 F.3d at
456. Because obviousness is a mixed question of law and
fact, “[w]e first presume that the jury resolved the under-
lying factual disputes in favor of the verdict [] and leave
those presumed findings undisturbed if they are sup-
ported by substantial evidence. Then we examine the
[ultimate] legal conclusion [of obviousness] de novo to see
whether it is correct in light of the presumed jury fact
findings.” Jurgens v. McKasy, 927 F.2d 1552, 1557 (Fed.
Cir. 1991) (internal citations omitted); see also Bos. Scien-
tific Scimed, Inc. v. Cordis Corp., 554 F.3d 982, 990 (Fed.
Cir. 2009) (“When we consider that, even in light of a
jury’s findings of fact, the references demonstrate an
invention to have been obvious, we may reverse its obvi-
ousness determination.” (citing Richardson-Vicks, Inc. v.
Upjohn Co., 122 F.3d 1476, 1479 (Fed. Cir. 1997))).
In the face of what amounts to well settled law, S&N
argues that, because the jury’s verdict in this case was
“advisory,” “no factual findings implied within the advi-
sory verdict are binding . . . .” Appellee’s Br. at 39. S&N
asserts, therefore, that we should review only the jury’s
explicit factual findings with respect to questions 5(A)–(D)
for substantial evidence. Because the jury’s advisory
verdict on the ultimate question of obviousness gave rise
to no implied factual findings, S&N contends the district
court was free to make its own findings of fact with re-
spect to all issues not submitted to the jury. Id. at 39–40.
According to S&N, we should review these factual find-
ings for clear error. Finally, S&N argues that the district
court’s ultimate conclusion regarding obviousness should
be reviewed de novo in light of the factual findings we find
to be supported by the evidence. We disagree.
Although S&N is correct that the district court re-
peatedly referred to the jury in this case as “advisory,”
S&N is wrong about the implications use of that term
KINETIC CONCEPTS v. SMITH & NEPHEW 24
carries. We first address the ways in which the phrase
“advisory jury” is used by trial courts.
The term is sometimes used to refer to Rule 39(c)(1)
juries. Fed. R. Civ. P. 39(c)(1) (“In an action not triable of
right by a jury, the court, on motion or on its own: may try
any issue with an advisory jury . . . .”). Under Rule
39(c)(1), when an “advisory jury” is used, no jury findings
– either explicit or implicit – are binding on the trial court
and the court is obligated to make independent findings of
fact and conclusions of law on the issue presented to the
jury. S&N first claims that the district court submitted
the matter to the jury under Rule 39(c)(1) and that ac-
cordingly, neither the trial court nor we are bound by the
jury’s factual findings. We disagree.
We do not believe that the district court intended to
invoke Rule 39(c)(1) when it referred to an “advisory
jury.” First, a Rule 39(c)(1) advisory jury is available only
in an action not triable by right to a jury. Id. But, patent
infringement actions must be tried to a jury if demanded
by a party. Markman v. Westview Instruments, Inc., 517
U.S. 370, 377 (1996). Second, S&N did not ask and the
district court did not make special findings that Rule 52
requires in all actions tried “with an advisory jury.” Fed.
R. Civ. P. 52 (“[T]he court must find the facts specially
and state its conclusions of law separately.”); see also
Transmatic, Inc. v. Gluton Indus., Inc., 53 F.3d 1270,
1275 (Fed. Cir. 1995) (“When, as here, trial is held before
the district court with an advisory jury, the court must
find the facts specially just as it would when conducting a
bench trial without an advisory jury.” (citing In re Inci-
dent Aboard the D/B Ocean King, 758 F.2d 1063, 1072
(5th Cir.1985))). And, rather than filing a motion to have
the judgment amended under Rule 52(b), which applies to
actions tried before a Rule 39(c)(1) advisory jury, S&N
filed a motion pursuant to Rule 50, which governs “judg-
25 KINETIC CONCEPTS v. SMITH & NEPHEW
ment as a matter of law in a jury trial.” 5 Fed. R. Civ. P.
50. Finally, S&N concedes that the district court, and we,
must defer to the jury’s explicit factual findings, a conces-
sion that is inconsistent with its reliance on Rule 39(c)(1).
It is clear, therefore, that the court did not use the term
“advisory jury” to denote a Rule 39(c)(1) jury. 6
As a consequence, all of the cases cited by S&N for the
proposition that there are “no factual findings implied
5 During oral argument, S&N argued that this
court’s decision in Goodwall Construction Co. v. Beers
Construction Co., 991 F.2d 751 (Fed. Cir. 1993) required it
to file its motion under Rule 50 and not Rule 52(b). Oral
Argument at 30:12–30:49, Kinetic Concepts, Inc., v. Smith
& Nephew, Inc., No. 2011-1105, available at
http://www.cafc.uscourts.gov/oral-argument-
recordings/2011-1105/all. Goodwall does not address this
issue, however. Instead, it addresses whether a motion
on an issue unresolved by the jury, which utilized a Rule
49(a) special verdict form, is a motion for judgment under
Rule 49(a) or Rule 50(b). 991 F.2d at 756–57. We held
that it was a motion under Rule 49(a). Id. at 757.
6 To the extent S&N argues that KCI waived its
right to a jury trial, and agreed to use a Rule 39(c)(1) jury,
we find no merit in this argument. Waiver of the right to
a jury trial cannot be assumed under circumstances in
which a party continually requests a jury trial and the
district court never referenced Rule 39 or waiver of the
right to a jury trial when it referred to an “advisory jury.”
See Jennings v. McCormick, 154 F.3d 542, 545 (5th Cir.
1998) (“The right to jury trial is too important and the
usual procedure for its waiver is too clearly set out by the
Civil Rules for courts to find a knowing and voluntary
relinquishment of the right in a doubtful situation.”
(citation omitted)); McDonald v. Steward, 132 F.3d 225,
229 (5th Cir. 1998) (“Waiver should not be found in a
doubtful situation.” (internal quotation and citation
omitted)); McAfee v. Martin, 63 F.3d 436, 437 (5th Cir.
1995) (“[C]ourts should indulge every reasonable pre-
sumption against waiver.” (internal quotation and cita-
tion omitted)).
KINETIC CONCEPTS v. SMITH & NEPHEW 26
within the advisory verdict [that] are binding on the
district court” are irrelevant because all of the cases
involved actions that are not triable to a jury by right and
all addressed Rule 39(c)(1) advisory juries. E.g., Am.
Calcar, Inc. v. Am. Honda Motor Co., 651 F.3d 1318, 1333
(Fed. Cir. 2011) (“Inequitable conduct is equitable in
nature, with no right to a jury, and the trial court has the
obligation to resolve the underlying facts of materiality
and intent.” (citation omitted)); Sheila’s Shine Prods., Inc.
v. Sheila Shine, Inc., 486 F.2d 114, 122 (5th Cir. 1973).
Whether the jury’s verdict on obviousness gave rise to
implied factual findings is not, therefore, controlled by
these cases.
The term “advisory jury” can also be used to denote a
jury’s resolution of a legal issue that the court can per-
missibly give to the jury to decide, but whose ultimate
determination is reserved for the court. See e.g., Spectra-
lytics, Inc. v. Cordis Corp., 649 F.3d 1336, 1341–42 (Fed.
Cir. 2011); R.R. Dynamics, Inc. v. A. Stucki Co., 727 F.2d
1506, 1515 (Fed. Cir. 1984). As we have explained:
[I]t is neither error nor dangerous to justice to
submit legal issues to juries, the submission being
accompanied by appropriate instructions on the
law from the trial judge. The rules relating to in-
terrogatories, jury instructions, motions for di-
rected verdict, JNOV, and new trial, and the rules
governing appeals following jury trials, are fully
adequate to provide for interposition of the judge
as guardian of the law at the proper point and
when necessary. There is no question that the
judge must remain the ultimate arbiter on the
question of obviousness. He or she exercises that
role first in exercising the judge’s duty of giving
proper instructions on the law to the jury before it
considers its verdict. The judge exercises control
27 KINETIC CONCEPTS v. SMITH & NEPHEW
on the question again when presented with a mo-
tion for JNOV or new trial. In no sense need the
judge abdicate the guardianship role.
R.R. Dynamics, 727 F.2d at 1515. This appears to be the
manner in which the district court used the term “advi-
sory jury.” Pre-Trial Conference Transcript at 16–22
(“[N]o matter how I present this to the jury I have to
make a separate determination as to obviousness.”). This
conclusion is buttressed by the fact that the Patent Case
Management Judicial Guide, which the district court
explained it reviewed with respect to this issue, suggests
this use of the term “advisory jury.” Peter S. Menell et
al., Patent Case Management Judicial Guide 8-32 (2009)
(“[T]he court can submit only the relevant Graham factors
to the jury for its determination through special inter-
rogatories, with or without an advisory verdict on the
legal question of obviousness, and then determine the
ultimate question of obviousness itself based on the jury’s
factual determinations.”).
With this understanding of the district court’s use of
the term “advisory jury,” we now address S&N’s remain-
ing argument regarding the standard of review. S&N
asserts that the district court utilized a Rule 49(a) special
interrogatory verdict form. Based on this contention,
S&N asserts that there are no implied factual findings to
which deference is due because a party waives its right to
a jury trial on factual issues for which the party did not
demand a special interrogatory and “factual issues not
submitted to the jury as special interrogatories are
deemed decided by the district court in accordance with
the court’s judgment.” Appellee Br. at 40.
S&N is incorrect. First, a court employing a Fed. R.
Civ. P. 49 special verdict form can only require the jury to
return such findings as to “each issue of fact.” Rule
KINETIC CONCEPTS v. SMITH & NEPHEW 28
49(a)(1). Because the ultimate conclusion of obviousness
is a legal question, there is strength to the argument that
by including that question on its verdict form the court
chose to employ a general verdict with answers to written
questions governed by Rule 49(b). It is clear that factual
findings in support of the general verdict are implied
when a verdict form under Rule 49(b) is used. See Quaker
City Gear Works, Inc. v. Skil Corp., 747 F.2d 1446, 1453
(Fed. Cir. 1984) (explaining that when a Rule 49(a) ver-
dict form includes a legal question, “since the answer to
the legal question necessarily resolves any disputed
underlying factual issues, we have undertaken to review
the factual findings on which the legal conclusion is
based, applying the substantial evidence standard.”
(citation omitted)). Furthermore, we have indicated that,
while it is not error to submit legal questions to the jury
as part of a Rule 49(a) special verdict form, “since the
answer to the legal question necessarily resolves any
disputed underlying factual issues,” the court must accept
implicit factual findings upon which the legal conclusion
is based when they are supported by substantial evidence.
Id. (citing Connell v. Sears, Roebuck & Co., 722 F.2d 1542,
1550 (Fed. Cir. 1983)); see also Gia Techs. Inc. v. Recycled
Prods. Corp., 175 F.3d 365, 371 (5th Cir. 1999) (“Rule
49(a) does not permit a district court to make findings
contrary to the jury verdict.”). In essence, because the
district court included the ultimate question of obvious-
ness on the special verdict form, all of the factual deter-
minations underlying the ultimate question were
implicitly put to the jury for resolution. Wake Forest did
not, therefore, waive a jury trial on any factual issue not
submitted to the jury in an interrogatory, and the district
court was required to accept all implicit factual findings
supporting the jury’s conclusion with respect to the ulti-
mate conclusion of obviousness that were supported by
substantial evidence.
29 KINETIC CONCEPTS v. SMITH & NEPHEW
Accordingly, we review all of the jury’s explicit and
implicit factual findings for substantial evidence. We
then examine the legal conclusion of obviousness de novo
to determine whether it is correct in light of the factual
findings that we find adequately supported. Jurgens, 927
F.2d at 1557.
I.
A patent is obvious, and, therefore, invalid “if the dif-
ferences between the subject matter sought to be patented
and the prior art are such that the subject matter as a
whole would have been obvious at the time the invention
was made to a person having ordinary skill in the art to
which said subject matter pertains.” 35 U.S.C. § 103(a).
Obviousness is a question of law based on underlying
factual findings: (1) the scope and content of the prior art;
(2) the differences between the claims and the prior art;
(3) the level of ordinary skill in the art; and (4) objective
indicia of nonobviousness. Graham, 383 U.S. at 17–18. A
party seeking to invalidate a patent on the basis of obvi-
ousness must “demonstrate ‘by clear and convincing
evidence that a skilled artisan would have been motivated
to combine the teachings of the prior art references to
achieve the claimed invention, and that the skilled arti-
san would have had a reasonable expectation of success in
doing so.’ ” Procter & Gamble Co. v. Teva Pharm. USA,
Inc., 566 F.3d 989, 994 (Fed. Cir. 2009) (quoting Pfizer,
Inc. v. Apotex, Inc., 480 F.3d 1348, 1361 (Fed. Cir. 2007)).
While an analysis of any teaching, suggestion, or motiva-
tion to combine elements from different prior art refer-
ences is useful in an obviousness analysis, the overall
inquiry must be expansive and flexible. KSR Int’l Co. v.
Teleflex, Inc., 550 U.S. 398, 415, 419 (2007).
This court has explained, moreover, that the obvious-
ness inquiry requires examination of all four Graham
KINETIC CONCEPTS v. SMITH & NEPHEW 30
factors. E.g., Mintz v. Dietz & Watson, Inc., 679 F.3d
1372, 1375 (Fed. Cir. 2012). Indeed, courts must consider
all of the Graham factors prior to reaching a conclusion
with respect to obviousness. In re Cyclobenzaprine Hy-
drochloride Extended-Release Capsule Patent Litig., 676
F.3d 1063, 1076–77 (Fed. Cir. 2012) (collecting cases). At
all times, the burden is on the defendant to establish by
clear and convincing evidence that the patent is obvious.
Id. at 1077–78.
Because Wake Forest asserts that the district court
erred by granting judgment as a matter of law overturn-
ing the jury’s verdict, we must determine which of the
jury’s explicit and implicit factual findings with respect to
the Graham factors are supported by substantial evi-
dence. Each of the Graham factors is addressed in turn
below.
A. Scope and Content of the Prior Art
The parties agree on which references are prior art.
On appeal, S&N focuses its obviousness analysis on the
Bagautdinov references, Zamierowski reference, and the
Chariker-Jeter references. With respect to these refer-
ences, the parties dispute their content, 7 namely, whether
the prior art discloses the treatment of wounds with
negative pressure. This is the central issue on appeal
because all of the asserted claims, covering either the
method or apparatus, require the use of negative pressure
to either “treat a wound” or “facilitate the healing of
7 While the district court stated that the parties did
not contest the content of the prior art, this statement
was incorrect. JMOL Order at 7. Whether the prior art
disclosed the treatment of wounds with negative pressure
was a key dispute between the parties, see id. at 21, and
the district court resolved the issue in its JMOL order.
Id. at 25, 27–28, 33.
31 KINETIC CONCEPTS v. SMITH & NEPHEW
wound.” 8 The district court concluded that there was no
support for the proposition that these primary references
did not disclose the treatment of wounds utilizing nega-
tive pressure. JMOL Order at 25, 27–28, 33. As ex-
plained below, this was error: substantial evidence
supports the jury’s implied factual finding that none of
these references disclosed the treatment of wounds using
negative pressure.
1. Content of the Bagautdinov References
The Bagautdinov references disclose a device for
draining fluid from purulent wounds. The device involves
placement of a polyurethane foam in the purulent wound,
attaching the foam to a pump, and covering the apparatus
and the wound with a polyethylene film secured to the
skin with vaseline oil. J.A. 10002.
The jury was presented with conflicting evidence re-
garding whether the references treated wounds as con-
strued by the district court, and if they did, whether they
treated wounds with negative pressure. S&N’s experts
contended that the references disclosed the treatment of
wounds within the meaning of the asserted claims. See
J.A. 22345:13–17 (testimony of Dr. Gordon, S&N’s expert,
stating that Bagautdinov I disclosed the use of negative
pressure to treat a wound). In addition, Dr. Bagautdinov
displayed the method disclosed in the references to the
jurors with the aid of a manikin. J.A. 22204–05.
Wake Forest presented conflicting testimony, how-
ever. It proffered expert testimony that the purulent
wounds described in the Bagautdinov references are in
fact abscess or pus pockets not within the district court’s
8 While the district court indicated in the JMOL
Order that it was not sure the claims contained this
limitation, as explained below, they do. See infra p. 30.
KINETIC CONCEPTS v. SMITH & NEPHEW 32
construction of the term “wound.” J.A. 22871:19–21 (“Dr.
Bagautdinov is using a variant, or modification of a
technique, to aspirate, or to suck out, pus from a purulent
wound, which is a pus pocket.”); J.A. 21431:15–23 (dis-
cussing how Bagautdinov treated pus pockets by lancing
and then draining them with the disclosed method). In
addition, Wake Forest’s expert testified that the Bagaut-
dinov references indicate that use of the device is discon-
tinued when the purulent wound has been cleaned of
infection, whereas the patented method and apparatus
are utilized only after a wound has been cleaned of infec-
tion. J.A. 22878:7–80:16. S&N’s expert conceded, more-
over, that the Bagautdinov articles were “particularly
concerned about the problems related to putting negative
pressure on the area of skin surrounding the wound and
the risk of spreading infection, causing tissue damage
. . . .” J.A. 22343:5–8. In other words, the Bagautdinov
references explain that use of negative pressure on or
surrounding a wound is dangerous to the patient. This
amounts to teaching away. Ricoh Co. v. Quanta Com-
puter Inc., 550 F.3d 1325, 1332 (Fed. Cir. 2008) (quoting
In re Kahn, 441 F.3d 977, 990 (Fed. Cir. 2006) (“A refer-
ence may be said to teach away when a person of ordinary
skill, upon reading the reference, would be discouraged
from following the path set out in the reference, or would
be led in a direction divergent from the path that was
taken by the applicant.”)).
Finally, Wake Forest presented testimony that the
method disclosed in the Bagautdinov references could not
create an adequate seal, J.A. 21437:25–38:2; J.A.
21433:2–15, and did not treat wounds through negative
pressure because the pressure was not sustained for a
long enough period of time. J.A. 21433:18–34:11; J.A.
21437:19–38:2. Indeed, Dr. Bagautdinov admitted that he
only used his device to treat “infected wounds,” J.A.
33 KINETIC CONCEPTS v. SMITH & NEPHEW
22312:15–22, and that he “never considered using [his]
technique to treat wounds until closure.” J.A. 22310:17–
21.
Because of this conflicting expert testimony, the jury
was free to “make credibility determinations and believe
the witness it considers more trustworthy.” Streber v.
Hunter, 221 F.3d 701, 726 (5th Cir. 2000) (quotations
omitted). In light of the jury’s determination that S&N
failed to prove obviousness, we must infer that the jury
found Wake Forest’s experts to be credible and persuasive
on this point. Broussard, 523 F.3d at 624; Jurgens, 927
F.2d at 1557. Crediting their testimony over that of
S&N’s expert, there is substantial evidence supporting
the factual finding that the Bagautdinov references do not
disclose: (1) the treatment of “wounds” as described in
patents; or (2) use of negative pressure to treat wounds.
There is also substantial evidence to support the finding
that the references teach away from maintaining negative
pressure on a wound for extended periods of time because
of the perceived problems associated with doing so.
2. Content of the Zamierowski Reference
The parties agree that the Zamierowski reference’s
method is utilized on “wounds” within the district court’s
construction, and discloses placing a screen means into a
wound, sealing the wound by placing a membrane with an
adhesive coating over the wound, and connecting a tube
from under the membrane to a vacuum source. J.A. 28.
This system can then be used to either drain from or
inject fluid into the wound. J.A. 10063. S&N argues, and
the district court found, that the Zamierowski reference
also disclosed treating wounds with negative pressure.
JMOL Order at 27–28.
During trial, Wake Forest argued that this reference
does not disclose healing wounds with negative pressure
KINETIC CONCEPTS v. SMITH & NEPHEW 34
because it neither disclosed a seal capable of maintaining
negative pressure on a wound, nor disclosed treating the
wound towards a selected stage of healing as required by
the asserted method claims.
The district court concluded that Wake Forest’s first
argument was incorrect because it found that the patent
claims do not require healing to be accomplished by
negative pressure. Id. at 27. In the alternative, the
district court concluded that the Zamierowski reference
met this requirement because fluid is removed from the
wound with negative pressure and removal of fluid en-
abled healing, so “healing” was “accomplished by the
negative pressure.” Id. at 27–28.
The district court was incorrect with respect to its de-
termination that the claims of the asserted patents do not
require wounds to be healed by negative pressure. First,
in the Blue Sky appeal, we concluded that all of the claims
of the ’081 patent asserted in the present litigation re-
quire the use of negative pressure to treat a “wound.” 554
F.3d at 1015 (“[E]ach of the asserted claims in both the
’081 and ’643 patents requires using ‘reduced’ or ‘negative’
pressure to ‘treat a wound’ or ‘facilitate the healing of a
wound . . . .”). Thus, we have already construed the
claims to include this limitation and that legal conclusion
was binding on the district court and is binding on this
panel. The specifications of both the ’081 and ’651 patents
support our conclusion in Blue Sky, moreover. E.g., ’081
patent col.2 ll.45–49 (“The present invention includes . . .
applying a negative pressure to a wound over an area
sufficient to promote migration of epithelial and subcuta-
neous tissue toward the wound, with the negative pres-
sure being maintained for a time sufficient to facilitate
closure of the wound.”); ’651 patent col.2 ll.61–64 (“[A]
wound treatment apparatus is provided for treating a
wound by applying reduced pressure . . . to the wound
35 KINETIC CONCEPTS v. SMITH & NEPHEW
. . . .”). And, before the PTO, the patentees distinguished
their claims from the prior art by asserting that refer-
ences “do not disclose or suggest ‘an appliance for admin-
istering a reduced pressure treatment to a wound’; ‘an
apparatus/method for treating a wound’ with reduced
pressure.” J.A. 5501 (’651 patent); see also J.A. 5502 (’651
patent); J.A. 8267 (’081 patent) (Unlike the prior art,
“[the] claimed invention is directed to a device configured
to create and maintain negative pressure on a wound site
. . . for the purpose of administering a negative pressure
treatment to the wound.”). Finally, S&N never argued
before the district court that the asserted claims did not
require this limitation. In light of our prior holding in
Blue Sky, the language of the specification, and the pat-
entee’s statements made during reexamination, we find
that each of the asserted claims requires the use of nega-
tive pressure to heal or treat wounds.
With respect to the district court’s alternative holding,
whether the prior art discloses the limitations of a par-
ticular claim is a question of fact to be determined by the
jury, and Wake Forest presented ample evidence that the
Zamierowski reference does not disclose the use of nega-
tive pressure to heal wounds. J.A. 21453:19–25; J.A.
22667:24–70:10; J.A. 22866:19–68:12.
In support of its argument that the Zamierowski ref-
erence does not disclose a seal capable of maintaining
negative pressure, Wake Forest presented testimony that
the reference does not create a seal within the meaning of
the patent because it uses only a tight liquid seal that has
air gaps. J.A. 21472:19–73:11; J.A. 22668:25–69:4. This
testimony is consistent with the reference, which indi-
cates that the dressing material is “breathable semi-
permeable” and the seal is “relatively liquid-tight.” J.A.
10068; J.A. 10070. With respect to the contention that
“healing” is not accomplished as contemplated by the
KINETIC CONCEPTS v. SMITH & NEPHEW 36
patents, Wake Forest’s expert testified that the Zam-
ierowski reference failed to disclose maintaining negative
pressure until the wound has progressed to a selected
stage of healing. J.A. 22456:24–58:1; J.A. 22669:5–8.
Zamierowski, instead, uses a tubing system to medicate
and drain wounds, and thereby “promote[ ] healing”
generally, J.A. 10061–63; J.A. 10074; it does not disclose
the use and maintenance of negative pressure on a wound
site to facilitate wound closure and thereby promote
wound healing, as do the patents. And, unlike the system
specified in the patents, Zamierowski’s system is to be
removed once the process of medication and draining has
been completed. J.A. 10073. Indeed, the inventor of the
Zamierowski device testified that the inventors of the ’651
and ’081 patents invented the use of negative pressure for
wound therapy and that he had not. J.A. 22571:13–17;
see also J.A. 22571:10–12 (Zamierowski inventor indicat-
ing that his contribution to the commercial embodiment of
the asserted patents is primarily the methods of attaching
the “the rigid conduit to the flimsy film”).
Because the jury concluded that S&N failed to estab-
lish that the patents were obvious, we must assume that
the jury found Wake Forest’s expert to be credible and
persuasive on this point. In light of this assumption,
there is substantial evidence to support the factual find-
ing that the Zamierowski reference does not disclose a
sealing means capable of maintaining negative pressure,
or maintenance of pressure until the wound has pro-
gressed toward a selected stage of healing.
3. Content of the Chariker-Jeter References
The Chariker-Jeter references, as explained above,
disclose a system for treating wounds that are compli-
cated by a fistula. J.A. 10043. The parties dispute
whether these references disclose the treatment of a
37 KINETIC CONCEPTS v. SMITH & NEPHEW
wound within the meaning of the patents, and if it does
disclose treatment of such wounds, whether the disclosed
device used negative pressure to treat the wounds. With
the exception of the Chariker-Jeter public use, the two
Chariker-Jeter publications indisputably deal only with
the treatment of “[p]atients with draining wounds and
fistulae.” J.A. 10050.
In Blue Sky, we held that the term wound, as used in
these patents “does not cover the fistulae described in the
[Chariker-Jeter] publications . . . .” 554 F.3d at 1018.
Despite our conclusion that the injuries treated in the
Chariker-Jeter publications are not “wounds” within the
meaning of these patents, S&N presented testimony
attempting to establish that the references disclosed such
treatment. J.A. 22348:1–49:12; J.A. 22028:7–30:6. Re-
garding the Chariker-Jeter public use, which was not
addressed in Blue Sky, S&N proffered the testimony of
Dr. Chariker who, while he was a resident, helped treat
Mr. Aderholt with the system disclosed in the Chariker-
Jeter publications. In this testimony, Dr. Chariker testi-
fied that he used the system to heal Mr. Aderholt with
negative pressure. J.A. 22032:2–38:11.
Wake Forest presented testimony to contradict S&N’s
evidence. Its expert testified that all of the patients
mentioned in the Chariker-Jeter publications had fistu-
lae, and therefore, that the publications do not disclose
the treatment of wounds within the district court’s con-
struction. J.A. 21441:1–7; J.A. 22672:11–23. In fact, on
cross examination Dr. Chariker admitted that neither of
the Chariker-Jeter publications discloses wounds not
involving a fistula. J.A. 22045:15–25. Wake Forest’s
experts testified, moreover, that the device disclosed in
the Chariker-Jeter references did not use negative pres-
sure to treat wounds. J.A. 22671:12–91:24; J.A. 21439:1–
41:22; J.A. 22869:13–70:21. And, Wake Forest’s expert
KINETIC CONCEPTS v. SMITH & NEPHEW 38
testified that the Chariker-Jeter publications actually
taught to limit granulization, which is directly contrary to
the purpose of the ’651 and ’081 patents. J.A. 21441:12–
19 (“So according to their document, they seem to want to
limit granulation tissue formation.”); J.A. 22673:11–12
(“[Drs. Chariker and Jeter] actually wanted to inhibit
granulation tissue.”).
Significantly, Dr. Chariker conceded that he “didn’t
publish anything about negative pressure wound therapy
regarding fistulas or nonfistulas.” J.A. 22046:8–9. Simi-
larly, Dr. Jeter admitted on cross examination that she
never suggested using the disclosed device if there was
nothing to drain. J.A. 22147:8–11.
With respect to the Chariker-Jeter public use, Wake
Forest offered testimony that Mr. Aderholt’s wound
involved a fistula, so it was not a wound within the mean-
ing of the patents. J.A. 22696:4–13; J.A. 22698:22–99:5;
J.A. 22898:22–99:8. On cross examination, moreover, Dr.
Chariker refused to say that Mr. Aderholt did not have a
fistula; he only stated that one was never diagnosed. J.A.
22057:23; J.A. 22058:4; J.A. 22085:2–6. In addition, Wake
Forest’s expert testified that, based on his reading of Mr.
Aderholt’s operative notes and pictures of his treatment,
the system used on Mr. Aderholt was not the system
disclosed in the Chariker-Jeter publications. J.A.
22714:25–15:9. Wake Forest’s expert also testified that
the Chariker-Jeter public use did not have a seal capable
of maintaining negative pressure because Mr. Aderholt’s
skin had several sump drains that freely let air flow. J.A.
2900:14–02:14. In other words, his wound was not healed
with negative pressure. J.A. 2712:13–14:19.
Finally, Wake Forest’s experts testified that use of the
drainage system disclosed in the Chariker-Jeter publica-
tions was discontinued when the fistula closed or substan-
39 KINETIC CONCEPTS v. SMITH & NEPHEW
tial drainage from the fistula stopped, irrespective of the
state of any wound healing. J.A. 22869:20–70:12; J.A.
21438:13–39:18; J.A. 22672:24–74:4; J.A. 22870:3–5 (“In
every single case, every single case that they show in the
book chapter and in the article, the minute the fistula
stopped draining, they got rid of their device.”). Dr.
Chariker conceded this fact on cross examination. J.A.
22062:17–20. This, again, reasonably could be deemed a
teaching away from continued long-term use of the device,
as directed by the ’081 and ’651 patents.
Again, because of the procedural posture of this case,
we must assume that the jury found Wake Forest’s ex-
perts credible and persuasive. Rather than credit this
testimony, however, the district court impermissibly re-
weighed witness credibility, concluding that Wake For-
est’s expert’s testimony that Mr. Aderholt had a fistula
was “completely unsupported by the evidence.” JMOL
Order at 32. This was error. See Blue Sky, 554 F.3d at
1020. On the basis of this credited testimony, there is
substantial evidence to support the finding that: (1) none
of the Chariker-Jeter references discloses treatment of a
wound within the meaning of the patents (as distinct from
a fistula or pus pocket); (2) the Chariker-Jeter references
do not disclose use of negative pressure to heal or treat
wounds 9 ; (3) the Chariker-Jeter publications teach away
from promoting healing by using negative pressure; (4)
9 This is the same conclusion we reached in Blue
Sky with respect to the Chariker-Jeter references. 554
F.3d at 1020 (“[W]e find that the testimony of KCI’s
witnesses was sufficient to allow the jury to reach the
conclusion that the Chariker–Jeter method was not used
to ‘treat a wound with negative pressure’ as required by
the claims.”). On this point, the evidence presented in
this case by Wake Forest and KCI was just as strong as
the evidence presented in Blue Sky. We, of course, base
our conclusion on the evidence in the current record.
KINETIC CONCEPTS v. SMITH & NEPHEW 40
the Chariker-Jeter public use did not involve the device
disclosed in the Chariker-Jeter publications; and (5) the
public use did not involve a seal capable of maintaining
negative pressure. Finally, with respect to the method
claims, substantial evidence supports the finding that
negative pressure was not maintained until the wound
progressed toward a selected stage of healing.
B. Level of Ordinary Skill in the Art
Although the parties did not stipulate the level of or-
dinary skill in the art, S&N’s expert testified that the
level of ordinary skill in the art “would include health
care professionals, for example physicians or nurses, but
it could be a podiatrist or somebody else, who has addi-
tional training or knowledge about wound care. It could
also be engineers with experience operating or designing
equipment used in conjunction with wound care.” J.A.
22340:8–13. According to the district court, Wake Forest
asserted that the level of skill was higher. J.A. 393.
Because it is generally easier to establish obviousness
under a higher level of ordinary skill in the art, Innoven-
tion Toys, LLC v. MGA Entm’t, Inc., 637 F.3d 1314, 1323
(Fed. Cir. 2011) (“A less sophisticated level of skill gener-
ally favors a determination of nonobviousness, and thus
the patentee, while a higher level of skill favors the
reverse.” (citation omitted)), we must assume that, in
light of the jury’s verdict, it adopted the lower level of
skill proposed by S&N.
C. Differences Between the Claimed Invention and the
Prior Art
The jury explicitly found that the prior art and the as-
serted claims exhibited several differences, which S&N
conceded existed. J.A. 65–69. In addition, the jury stated
that each of the prior art references exhibited additional
differences from those explicitly mentioned on the verdict
41 KINETIC CONCEPTS v. SMITH & NEPHEW
form, although they were not asked to and, thus, did not
identify those additional differences.
Although there are many differences between the
primary prior art references and the asserted claims, for
the purpose of this appeal, we need only focus on three.
As discussed above, substantial evidence supports the
finding that none of the references discloses treating
wounds with negative pressure as required by the pat-
ents. Nor do the Bagautdinov and Chariker-Jeter refer-
ences relate to the treatment of wounds described in the
patents, as construed by this court in Blue Sky and the
district court here. Finally, the Bagautdinov references
and the Zamierowski reference do not disclose a seal
capable of maintaining negative pressure. Accordingly,
none of the references discloses healing or treatment with
negative pressure. Only the Zamierowski reference
discloses treating or healing wounds and only the
Chariker-Jeter printed publications disclose a seal that is
capable of maintaining pressure.
Even if the references disclosed all of the limitations
of the asserted claims, which they do not, S&N still
needed to proffer evidence indicating why a person having
ordinary skill in the art would combine the references to
arrive at the claimed invention. Innogenetics, N.V. v.
Abbott Labs., 512 F.3d 1363, 1374 (Fed. Cir. 2008) (hold-
ing that post-KSR “some kind of motivation must be
shown from some source, so that the jury can understand
why a person of ordinary skill would have thought of
either combining two or more references or modifying one
to achieve the patented [invention].” (citation omitted)).
Significantly, whether there is a reason to combine prior
art references is a question of fact. Transocean Offshore
Deepwater Drilling, Inc. v. Maersk Contractors USA, Inc.,
617 F.3d 1296, 1303 (Fed. Cir. 2010) (citing McGinley v.
Franklin Sports, Inc., 262 F.3d 1339, 1352 (Fed. Cir.
KINETIC CONCEPTS v. SMITH & NEPHEW 42
2001)). Here, not only did S&N offer no evidence estab-
lishing a reason to combine, but Wake Forest offered
substantial evidence that a person having ordinary skill
in the art had no reason to combine the prior art refer-
ences to arrive at the claimed invention. E.g., J.A.
22669:18–25; J.A. 22691:18–22; J.A. 22715:25–16:4; J.A.
22737:7–11; J.A. 22753:24–54:3. In light of the jury’s
verdict, we must assume that it determined there was no
reason to combine the prior art references, and we must
defer to this factual finding because it is supported by
substantial evidence.
D. Objective Indicia of Nonobviousness
With respect to the ’081 asserted claims, the jury
found the following indicia of nonobviousness: (1) com-
mercial success; (2) long felt need; (3) copying; (4) unex-
pected results; (5) acceptance by others; and (6) initial
skepticism. With respect to the ’651 asserted claims, the
jury found that for claims 109 and 116 on the basis of
performing the method of claim 42, and claim 121 on the
basis of performing the method of claim 42, the same
indicia of nonobvious were present. Regarding claim 116,
on the basis of performing the method of claim 20, and
claim 121, on the basis of performing the method of claim
20, the jury concluded that only copying existed.
Wake Forest presented testimony regarding each of
the objective indicia found by the jury. J.A. 22827:3–
32:10; J.A. 217771:11–23; J.A. 21077:19–79:15. Wake
Forest offered evidence that leading experts in the field
were skeptical that the “counterintuitive” device could
work. J.A. 22827:3–12, J.A. 22828:21–29:23, J.A.
21078:4–79:5. One expert testified that he “didn’t know
how you could put this [negative] pressure on a wound
and not cut off the blood supply, not cause infection, etc.”
J.A. 22827:3–9. Indeed, Dr. Argenta, an inventor of the
43 KINETIC CONCEPTS v. SMITH & NEPHEW
patents, testified that the hospital where he worked was
concerned about allowing him to try his device on a pa-
tient with a serious wound, which could not be healed
with conventional methods, but the “decision [was] do you
let [the patient] die or do you try something.” J.A.
20446:3–23. To everyone’s surprise, the device completely
healed this patient. J.A. 20446:21–47:6. The medical
community was so skeptical of the device, moreover, that
the patents’ inventors had difficultly publishing their
findings in peer-reviewed journals, J.A. 20501:1–19
(Reviewers from the journal Plastic and Reconstructive
Surgery stated that “there was no way that this was
possible, that this device could do this”), and they were
turned away by conference organizers when they at-
tempted to present the discovery. J.A. 20502:10–15; J.A.
20501:3.
Despite this initial skepticism, over time the device
was widely adopted and praised. J.A. 22830:6–31:8, J.A.
21079:10–12. Wake Forest presented testimony from
experts that the patented device “changed the way we do
surgery,” J.A. 21079:11–12, and “changed the way . . .
we’ve been treating wounds for the last twenty, thirty
years.” J.A. 22831:1–3. Indeed, S&N’s own expert testi-
fied that the device was “a paradigm shift in wound
healing” and that it “is so effective that it’s changed the
way that [he] and [his] fellow surgeons treat serious
wounds.” J.A. 22409:11–10:11. To date, the device has
been used on more than three million patients. J.A.
21753:22–25. Indeed, Harvard Medical School called the
device an “exciting novel therapeutic approach to
wounds,” J.A. 20504:22–05:2, and the American Associa-
tion of Plastic Surgeons recognized the device as the last
decade’s “biggest advance in the plastic surgery field.”
J.A. 22762:10–15. The effectiveness of the device and this
KINETIC CONCEPTS v. SMITH & NEPHEW 44
praise has made it a commercial success with $1.4 billion
in annual sales. J.A. 21771:12–13.
Finally, Wake Forest proffered testimony that the de-
vice has been copied. For example, in internal documents
and marketing materials, S&N repeatedly compares its
products to the V.A.C., the commercial embodiment of the
patents. J.A. 22760:11–61:23; J.A. 20537:17–39:18; J.A.
20999:1–21. Indeed, S&N’s expert admitted that he
authored an article explaining how to create “an off-the-
shelf or makeshift V.A.C.” J.A. 22410:18–12:6.
In the face of this evidence, S&N offered no rebuttal
evidence. S&N’s own invalidity expert even admitted that
he did not consider the objective indicia of nonobviousness
in reaching his conclusions regarding the invalidity of the
patents. J.A. 22396:20–97:8; J.A. 22415:24–16:15. Sig-
nificantly, the district court concluded that Wake Forest
“present[ed] ample evidence of success of V.A.C. product
and the other secondary considerations tending to show
non-obviousness.” J.A. 37. On the basis of this record,
there is more than substantial evidence supporting the
jury’s findings of commercial success, long-felt need,
copying, unexpected and superior results, wide spread
acceptance in the field, and initial skepticism.
E. The Ultimate Conclusion of Obviousness
Having determined that the jury’s explicit and several
implicit factual findings are supported by substantial
evidence, “we examine the [ultimate] legal conclusion [of
obviousness] de novo to see whether it is correct in light
of” these factual findings. Jurgens, 927 F.2d at 1557(internal citations omitted); see also Wyers v. Master Lock
Co., 616 F.3d 1231, 1248 (Fed. Cir. 2010) (Linn, J., con-
curring). Despite the district court’s detailed analysis, we
45 KINETIC CONCEPTS v. SMITH & NEPHEW
find that, on the basis of the jury’s factual findings, it
erred by granting S&N’s Motion for JMOL. 10
While the Supreme Court made clear that a mechani-
cal application of the teaching-suggestion-motivation test,
requiring an explicit teaching in the prior art, is inappro-
priate, “[w]e must still be careful not to allow hindsight
reconstruction of references to reach the claimed inven-
tion without any explanation as to how or why the refer-
ences would be combined to produce the claimed
invention.” Innogenetics, 512 F.3d at 1374 n.3.
As noted above, S&N never offered evidence articulat-
ing why a person having ordinary skill in the art would
combine the primary references to obtain the disclosed
inventions. Although expert testimony regarding motiva-
tion to combine is not always required, the technology at
issue here is not the type of technology where common
sense would provide the motivation to combine these
references. See Master Lock Co., 616 F.3d at 1240 n.5
(“However, as we [have] noted . . . ‘expert testimony
regarding matters beyond the comprehension of layper-
sons is sometimes essential,’ particularly in cases involv-
ing complex technology. In such cases, expert testimony
may be critical, for example, to establish . . . the existence
(or lack thereof) of a motivation to combine references.”
(internal citations omitted)).
At a minimum, creation of the claimed apparatus or
method requires combining the Zamierowski references,
which disclose treating or healing of wounds, with the
10This conclusion is consistent with the PTO’s de-
termination on reexamination that claims of the ’651 and
’081 patents were patentable in the face of some refer-
ences at issue here. While this determination is not
binding on this court, the jury was informed of the results
of the reexamination and S&N does not dispute the
admissibility of this evidence.
KINETIC CONCEPTS v. SMITH & NEPHEW 46
Chariker-Jeter publications that disclose a seal capable of
maintaining negative pressure. The record is devoid of
any reason someone would combine these references,
however. Indeed, Wake Forest’s experts testified that
there was no reason to combine them. J.A. 22865:15–
66:17; J.A. 22868:13–69:19; J.A. 22870:22–71:12. In
addition, both of these references independently accom-
plish similar functions, namely, draining fluids. Because
each device independently operates effectively, a person
having ordinary skill in the art, who was merely seeking
to create a better device to drain fluids from a wound,
would have no reason to combine the features of both
devices into a single device. Nor do the Bagautdinov
references provide such motivation to combine the Zam-
ierowski references and the Chariker-Jeter publications to
arrive at the method and apparatus claimed in the pat-
ents in suit. Again, the Bagautdinov references disclose
only the draining of purulent wounds; it says nothing
about treating wounds within the district court’s con-
struction, much less the healing of such wounds with
negative pressure.
As Dr. Argenta noted, moreover, if any of the doctors
who created the devices disclosed in the prior art thought
that negative pressure actually healed wounds, they
would have left the devices in place until the wounds were
fully healed. J.A. 22870. All of the doctors removed the
devices after the wounds were drained, but before healing
with negative pressure began. This indicates that the
doctors were not using the disclosed devices and methods
to heal wounds with negative pressure because they did
not believe that these devices were capable of such heal-
ing. In fact, several of the primary references disclosed
methods that purposefully minimize granulization while
the devices were in place because of the perceived dangers
associated with negative pressure. This amounts to
47 KINETIC CONCEPTS v. SMITH & NEPHEW
significant evidence of teaching away. On the basis of
this evidence, hindsight provides the only discernable
reason to combine the prior art references. Unless one
knew that negative pressure could be used to treat
wounds, there would be no reason to combine the prior art
to arrive at the claimed device and methods.
It is clear, moreover, that the district court concluded
that the invention was obvious because it believed the
claims contained elements that were not new. This
reasoning is incorrect: “a patent composed of several
elements is not proved obvious merely by demonstrating
that each of its elements was, independently, known in
the prior art.” KSR, 550 U.S. at 418. Because none of the
prior art references disclosed utilizing negative pressure
to heal wounds, this is not even a case where the inven-
tions at issue are merely composed of elements that were
known in the art. Indeed, nearly seven years after the
’081 patent was filed, Dr. Attinger testified that he still
did not believe the apparatus and method disclosed in the
patents would work. J.A. 22827:3–29:2.
Finally, the significant objective indicia of nonobvi-
ousness strongly weigh against a finding of obviousness.
Mintz, 679 F.3d at 1378 (Evidence of objective indicia of
nonobviousness “may often establish that an invention
appearing to have been obvious in light of the prior art
was not.” (citation omitted)); In re Cyclobenzaprine, 676
F.3d at 1075–76 (same); see also Crocs, Inc. v. Int’l Trade
Comm’n, 598 F.3d 1294, 1310 (Fed. Cir. 2010) (“Secondary
considerations ‘can be the most probative evidence of non-
obviousness in the record, and enables the . . . court to
avert the trap of hindsight.’ ” (quoting Custom Accessories,
Inc. v. Jeffrey-Allan Indus., Inc., 807 F.2d 955, 960 (Fed.
Cir. 1986)); Ortho-McNeil Pharm., Inc. v. Mylan Labs.,
Inc., 520 F.3d 1358, 1365 (Fed. Cir. 2008) (“Objective
indicia may often be the most probative and cogent evi-
KINETIC CONCEPTS v. SMITH & NEPHEW 48
dence of nonobviousness in the record.” (quoting Catalina
Lighting, Inc. v. Lamps Plus, Inc., 295 F.3d 1277, 1288
(Fed. Cir. 2002) (citation omitted)). We require analysis
of the objective indicia because they “provide objective
evidence of how the patented device is viewed in the
marketplace, by those directly interested in the product.”
Demaco Corp. v. F. Von Langsdorff Licensing Ltd., 851
F.2d 1387, 1391 (Fed. Cir. 1988). As discussed above, the
medical community scoffed at this device when it was
initially introduced. The industry was skeptical that the
device worked even after reading studies that established
that it did in fact work. J.A. 21078:19–21079:5. After the
system was disseminated, moreover, everyone began
using it, and the method and apparatus were copied. This
evidence provides a key objective insight into how the
medical community viewed the patented device.
Significantly, this is not a case where the jury found
the presence of only one or two objective indicia of nonob-
viousness. Nor is it a case where S&N seriously disputes
those findings. Rather, the evidence strongly establishes
the existence of nearly every objective indicia of nonobvi-
ousness, namely commercial success, long-felt need,
copying, unexpected and superior results, wide spread
acceptance in the field, and initial skepticism. See Allen
Archery, Inc. v. Browning Mfg. Co., 819 F.2d 1087, 1092
(Fed. Cir. 1987) (“[P]raise from a competitor tends to
indicat[e] that the invention was not obvious.” (alteration
in original) (internal quotation omitted)); Gambro Lundia
AB v. Baxter Healthcare Corp., 110 F.3d 1573, 1579 (Fed.
Cir. 1997) (acknowledging that the accused infringer’s
“recognition of the importance of this advance is relevant
to a determination of nonobviousness.”). We recently
warned about the dangers of ignoring objective indicia of
nonobviousness in Mintz, where we said: “[s]imply be-
cause the technology can be easily understood does not
49 KINETIC CONCEPTS v. SMITH & NEPHEW
mean that it will satisfy the legal standard of obvious-
ness. In fact, objective consideration of simple technology
is often the most difficult because, once the problem and
solution appear together in the patent disclosure, the
advance seems self-evident.” 679 F.3d at 1379. The
objective indicia of nonobviousness serve a particularly
important role in a case, like this one, where there is a
battle of scientific experts regarding the obviousness of
the invention. In such a case, the objective indicia provide
an unbiased indication regarding the credibility of that
evidence.
Here, the objective evidence strongly supports the
jury’s findings under the first three Graham factors and
cuts against the view that the claimed inventions were an
obvious combination of known elements from the prior
art.
On this record, S&N has not proven by clear and con-
vincing evidence that the asserted claims are obvious.
The district court committed error by failing to defer to
the jury’s factual findings and granting JMOL on obvi-
ousness. Because the district court concluded that the
other issues raised in S&N’s motion for JMOL were moot
in light of its decision to grant JMOL on obviousness, we
reverse and remand, so the district court can consider
those arguments in the first instance.
CONCLUSION
REVERSED AND REMANDED
COSTS
Each party shall bear its own costs.
United States Court of Appeals
for the Federal Circuit
__________________________
KINETIC CONCEPTS, INC., KCI LICENSING, INC.,
KCI USA, INC., KCI MEDICAL RESOURCES, KCI
MANUFACTURING, AND MEDICAL HOLDINGS
LIMITED,
Plaintiffs,
AND
WAKE FOREST UNIVERSITY HEATLH SCIENCES,
Plaintiff-Appellant,
v.
SMITH & NEPHEW, INC.,
Defendant-Appellee.
__________________________
2011-1105
__________________________
Appeal from the United States District Court for the
Western District of Texas in case no. 08-CV-0102, Judge
W. Royal Furgeson.
__________________________
DYK, Circuit Judge, concurring.
I agree with the majority that deference is owed to the
jury’s implied findings in support of its nonobviousness
verdict for the reasons ably set forth in the majority
opinion. However, I write separately because, in my view,
the majority errs in its construction of the “healing”
limitations of these claims. Because the jury was not
KINETIC CONCEPTS v. SMITH & NEPHEW 2
properly instructed on claim construction, it is impossible
to determine what findings the jury made. At the same
time, because the accused infringer did not seek a con-
struction of the “healing” limitations, we should assume
the jury used the correct construction. Under this con-
struction, there was not substantial evidence that the
claim limitations were absent from the prior art (though
not in a single reference) or that secondary considerations
supported a finding of non-obviousness, but there was
substantial evidence for the jury to have found insuffi-
cient motivation to combine. On this ground, I agree with
the majority that the accused infringer has not estab-
lished invalidity for obviousness as a matter of law.
I Claim Construction
As the majority describes, the asserted claims cover
an apparatus and method for treating wounds by applying
suction, or “negative pressure,” and Bagautdinov,
Chariker-Jeter, and Zamierowski are three groups of
prior art that disclose similar suction treatment systems.
The jury found that none of the asserted claims would
have been obvious over this prior art, but the district
court granted judgment as a matter of law (“JMOL”) that
all of the asserted claims were invalid for obviousness.
“It is elementary in patent law that, in determining
whether a patent is valid . . . the first step is to determine
the meaning and scope of each claim in suit.” Nat’l Steel
Car, Ltd. v. Canadian Pac. Ry., Ltd., 357 F.3d 1319, 1334
(Fed. Cir. 2004) (quoting Amazon.com, Inc. v. Barnesand-
noble.com, Inc., 239 F.3d 1343, 1351 (Fed. Cir. 2001)); see
also TI Grp. Auto. Sys. (N. Am.), Inc. v. VDO N. Am.,
L.L.C., 375 F.3d 1126, 1139 (Fed. Cir. 2004) (“Our validity
analysis is a two-step procedure: ‘The first step involves
the proper interpretation of the claims.’” (quoting Beach-
combers, Int’l, Inc. v. WildeWood Creative Prods., Inc., 31
3 KINETIC CONCEPTS v. SMITH & NEPHEW
F.3d 1154, 1160 (Fed.Cir.1994)). The meaning of a claim
is a purely legal issue, which we determine de novo. See
Cybor Corp. v. FAS Techs., Inc., 138 F.3d 1448, 1451 (Fed.
Cir. 1998). The majority disregards this well established
procedure by failing to directly address the proper con-
struction of the central claim limitations related to “heal-
ing.”
The majority excuses its failure to do so on the ground
that these claim construction issues “were neither raised
nor discussed before the district court, and were not
argued in this appeal.” Maj. Op. at 2 n.1. I agree with
the majority that the parties have failed to address the
claim construction issues directly, and have chosen in-
stead to address the issues without the benefit of a proper
claim construction. Nonetheless, defendant-appellee
Smith & Nephew does contest the extent to which “heal-
ing” is required by the claims, arguing that “Wake Forest
attempted to redefine its claimed invention throughout
this litigation and continues to do so on appeal” by “mis-
characterize[ing] the claims as requiring ‘active’ treat-
ment of ‘clean’ wounds for ‘extended’ periods of time in
order to heal the wounds,” even though “none of those
limitations is in the claims.” Def.-Appellee’s Br. 41. 1 And
despite the parties’ failure to seek a proper construction of
the “healing” limitations, it is simply not possible to
meaningfully address the question of obviousness without
construing these limitations either by making implicit
assumptions about claim scope (as the majority does) or
by explicitly construing the claims (as I propose).
1 Smith & Nephew also raises the argument that
“there is a lack of substantial evidence to support the
jury’s finding of nexus between the ’081 claims and the
secondary considerations.” Id. at 66.
KINETIC CONCEPTS v. SMITH & NEPHEW 4
The asserted claims are claims 2 and 5 of U.S. Patent
No. 5,645,081 (“the ’081 patent”) and claims 42, 109, 116,
and 121 of U.S. Patent No. 7,216,651 (“the ’651 patent”).
The ’081 claims both require the apparatus to create
negative pressure “for facilitating the healing of wounds” 2
and to have a “sealing means . . . for maintaining said
negative pressure.” ’081 Patent col. 9 ll. 52-58 (emphases
added). The asserted ’651 method claims all require
“maintaining” negative pressure until the wound has
“progressed toward a selected stage of healing.” ’651
Patent col. 23 l. 50, col. 25 ll. 47-48 (emphases added).
The district court was not asked to construe “maintain-
ing,” “healing,” or “a selected stage of healing” (collec-
tively, “the ‘healing’ limitations”), but it did rule that the
claims do not have a minimum-time limitation, a con-
struction not challenged on appeal. J.A. 13390. We are
unable to determine whether the asserted claims are
obvious as a matter of law without understanding the
meaning of these “healing” limitations. Because these
claim terms are central to these appeal, our obligation to
construe these limitations cannot be avoided simply
because the district court failed to do so.
In my view, the “healing” limitations are properly
construed as requiring only some progress toward heal-
ing—for example, the formation of some new tissue or
skin—and not complete healing or wound closure. The
language of the “selected stage of healing” limitation itself
clearly indicates that only some progress toward healing
is required. Additionally, claim 20 of the ’651 patent
(upon which claims 109, 116, and 121 depend) refers to
“maintaining reduced pressure to promote the formation
2 The accused infringer appears to agree that this
preamble language is a claim limitation. See Def.-
Appellee’s Br. 62 (“The ’081 claims merely require an
apparatus that facilitates the healing of wounds.”).
5 KINETIC CONCEPTS v. SMITH & NEPHEW
of granulation tissue,” and claim 121 specifies that “the
selected stage of healing comprises re-epithelialization of
at least a portion of the wound.” ’651 Patent col. 23 ll. 48-
49, col. 30 ll. 30-31. The district court construed “granu-
lation tissue” as “tissue formed during wound healing”
and “re-epithelialization” as “re-growth of skin.” J.A.
10373, 10377 (emphases omitted). Neither party objected
to these constructions on appeal. These additional limita-
tions in claims 20 and 121 demonstrate that “a selected
stage of healing” cannot refer to complete healing. Fur-
thermore, the unasserted dependent claims 118-120 and
122-124 of the ’651 patent provide other more restrictive
examples of “selected stage[s] of healing”: “substantial
closure of the wound,” “substantially filling the wound
with granulation tissue,” “migration of epithelial and
subcutaneous tissue toward the wound,” and “a reduction
in the volume [diameter or depth] of the wound by a
predetermined amount.” Under the “presumption that an
independent claim should not be construed as requiring a
limitation added by a dependent claim,” Curtiss-Wright
Flow Control Corp. v. Velan, Inc., 438 F.3d 1374, 1380
(Fed. Cir. 2006), “a selected stage of healing” is presumed
to not include these limitations.
There is also no indication in the specifications that
“healing” or “selected stage of healing” refers to any
particular stage of healing; the ’651 patent simply notes
that “[a]n initial stage of wound healing is characterized
by the formation of granulation tissue” and that “[a]
selected state of improved condition may include” a num-
ber of conditions, including any “stages of improvement or
healing appropriate to a given type of wound or wound
complex.” ’651 Patent col. 1 ll. 40-41, col. 12 ll. 59-66.
The ’081 patent does not define “facilitating . . . healing”
(as used in the claim preambles), but it notes that the
invention may be used to “promote the migration of . . .
KINETIC CONCEPTS v. SMITH & NEPHEW 6
tissue,” “reduce bacterial density in a wound,” or “pre-
vent[] the infection [in a burn wound] from becoming [too]
severe,” all of which seem to be examples of “facilitating
. . . healing.” ’081 Patent col. 1 ll. 57-58, col. 2 ll. 1-2, col.
3 l. 67-col. 4 l. 1. 3
Although the majority opinion does not explicitly con-
strue the “healing” limitations, it seems to make three
assumptions as to the meaning of these limitations. First,
the majority suggests that the claims require application
of negative pressure for a particular extended length of
time. For example, the majority explains that Bagautdi-
nov did not sustain pressure “for a long enough period of
time” and taught away from applying negative pressure
“for extended periods”; and that Chariker-Jeter taught
“away from continued long-term use of the device, as
directed by the ’081 and ’651 patents.” Maj. Op. at 32, 39.
But as discussed above, the district court correctly deter-
mined that the claims do not have a minimum time
limitation, and that construction is not challenged on
appeal.
Second, to some extent, the majority suggests that the
claims require more than some progress toward healing,
such as complete healing or closure. For example, the
majority states that “the invention applies ‘negative
pressure . . . for a time sufficient to facilitate closure of the
wound,’” that Bagautdinov was different from the claimed
invention because it was not used “to treat wounds until
3 While the patent does mention that the invention
includes application of negative pressure “for a time
sufficient to facilitate closure of the wound,” id. col. 2 ll.
48-49, it nowhere suggests that “healing” is synonymous
with “closure,” or that “facilitat[ing] closure” requires the
application of negative pressure until closure. As noted
the patentee did not challenge the court’s construction
that there is no time limit in the claims.
7 KINETIC CONCEPTS v. SMITH & NEPHEW
closure,” and that the asserted claims “require wounds to
be healed by negative pressure.” Maj. Op. at 4, 33-34
(emphases added). To the extent the majority reads a
requirement of complete closure into the claims, this
seems to me to be incorrect—as discussed above, the
“healing” limitations merely require some progress to-
ward healing, such as the formation of granulation tissue
or regrowth of skin.
Third, the majority seems to suggest that the prior art
was different from the claimed invention because the
purpose of the prior art was drainage and cleaning, rather
than healing. The majority explains that Bagautdinov
was “for draining fluid” and was “discontinued when the
purulent wound has been cleaned”; that Zamierowski is
“used to either drain from or inject fluid into the wound”
and was not used “for wound therapy”; and that Chariker-
Jeter was a “drainage system” that was “discontinued
when the fistula closed or substantial drainage from the
fistula stopped.” Maj. Op. 31-33, 36, 38-39. However, the
claims do not contain a purpose requirement—it is
enough that healing is disclosed by the prior art, even if
this was not the intention of the prior art inventors. As
the Supreme Court explained, “[i]n determining whether
the subject matter of a patent claim is obvious, neither
the particular motivation nor the avowed purpose of the
patentee controls. What matters is the objective reach of
the claim. If the claim extends to what is obvious, it is
invalid under § 103.” KSR Int’l Co. v. Teleflex Inc., 550
U.S. 398, 419 (2007); see also Nat’l Steel Car, Ltd. v.
Canadian Pac. Ry., Ltd., 357 F.3d 1319, 1339 (Fed. Cir.
2004) (“A finding that two inventions were designed to
resolve different problems . . . is insufficient to demon-
strate that one invention teaches away from another.”); In
re Beattie, 974 F.2d 1309, 1312 (Fed. Cir. 1992) (“[T]he
law does not require that the references be combined for
KINETIC CONCEPTS v. SMITH & NEPHEW 8
the reasons contemplated by the inventor.”). It is irrele-
vant that the prior art had the purpose of drainage as
long as it used negative pressure to heal wounds within
the meaning of the claims.
As discussed below, the majority’s erroneous claim
construction leads it to incorrectly conclude that the claim
limitations are not found in the prior art and that secon-
dary considerations supported a finding of non-
obviousness.
II Limitations Present in the Prior Art
Under the correct claim construction, contrary to the
majority, the claim limitations are disclosed in the prior
art. Because the jury received no instruction on the
meaning of the “healing” limitations, it is impossible to
determine whether the jury’s findings in support of its
nonobviousness verdict were based on the correct con-
struction. 4 However, the party challenging validity,
Smith & Nephew, did not seek a jury instruction on the
“healing” limitations. “[L]itigants waive their right to
present new claim construction disputes if they are raised
for the first time after trial.” Cordis Corp. v. Boston
Scientific Corp., 561 F.3d 1319, 1331 (Fed. Cir. 2009)
(quoting Conoco, Inc. v. Energy & Envtl. Int’l, L.C., 460
F.3d 1349, 1359 (Fed. Cir. 2006)). We therefore should
assume that the jury used the correct claim construction.
Under the proper construction, the Bagautdinov,
Chariker-Jeter, and Zamierowski groups of prior art all
meet the limitations of “maintaining” negative pressure
“for . . . healing” or until a “selected stage of healing”
4 The jury did answer some specific questions in
addition to giving a general verdict of nonobviousness, see
J.A. 65-70, but none of those specific questions is relevant
to this issue.
9 KINETIC CONCEPTS v. SMITH & NEPHEW
because they explicitly disclose the re-growth of tissue
and skin (i.e., the formation of granulation tissue and re-
epithelialization). The Bagautdinov method “accelerates
. . . sealing of purulent wounds,” and “the appearance of
granulated tissue” was seen around the fourth or fifth day
of vacuum treatment. J.A. 10003, 10027. One of the
Chariker-Jeter publications states that “an increased rate
of granulation and re-epithelialization is seen with the
closed suction wound drainage system.” J.A. 10051. And
Zamierowski states that it “promotes healing” and that
“the present invention is particularly well adapted for the
. . . regeneration of skin graft donor sites.” J.A. 10063,
10067. 5 Because each of these references applied nega-
tive pressure for “healing” within the meaning of the
claims, it is irrelevant whether these references teach
away from more prolonged application of negative pres-
sure. There is no substantial evidence to the contrary.
The majority errs in concluding that these claim limita-
tions were not present in the prior art.
III Secondary Considerations
The majority also errs, in my view, in finding that the
jury could properly rely on secondary considerations to
5 The majority’s suggestion that Zamierowski
“failed to disclose maintaining negative pressure until the
wound has progressed to a selected stage of healing,” Maj.
Op. at 36, is thus incorrect; the majority cites testimony
that merely states that Zamierowski does not discuss
granulation tissue formation. See J.A. 22457:15-19 (Q.
“It follows, from the fact that he doesn’t mention granula-
tion, that he’s not stating that he promotes granulation
tissue growth?” A. “Well . . . he doesn’t state: My device
promotes granulation tissue.”); J.A. 22669:5-8 (“[H]e
really does not talk about the healing, maintaining the
pressure until the wound has progressed to the selected
stage of healing. He doesn’t talk about granulation tissue
formation, promotion of that.”).
KINETIC CONCEPTS v. SMITH & NEPHEW 10
find the claims non-obvious. The failure to construe the
“healing” limitations affects not only the prima facie case
of obviousness, but also the analysis of secondary consid-
erations, as we cannot determine whether the jury’s
findings of secondary considerations were based on a
proper understanding of claim scope. “Evidence of secon-
dary considerations must be reasonably commensurate
with the scope of the claims.” In re Huai-Hung Kao, 639
F.3d 1057, 1068 (Fed. Cir. 2011). Secondary considera-
tions related to a patentee’s commercial product is not
probative of nonobviousness if the asserted claims are far
broader than that commercial embodiment. Here, as the
majority notes, there was substantial evidence that the
patentee’s product (1) was a commercial success; (2) was
responsive to a long-felt need; (3) was copied by others; (4)
had unexpected results; (5) was accepted by others; and
(6) faced initial skepticism. Maj. Op. at 42. These secon-
dary considerations, however, were related to the use of
the commercial device utilizing the patent for extended
periods to close and completely heal wounds. 6 This evi-
dence would clearly be relevant if the patent claims were
limited to complete healing or wound closure, but as
discussed above, the claims require only some progress
toward healing. There was no substantial evidence that
there were secondary considerations relevant to the
6 For example, Dr. Argenta, an inventor on the pat-
ents, testified that he was surprised when a patient with
a serious wound “heal[ed] completely” after several
months of treatment. J.A. 20446:22 (emphasis added).
Another expert testified that when a patient with an ulcer
that would not heal was healed after eight weeks of
treatment, he was “stunned” “[b]ecause we had used the
best techniques we knew to date to close this wound and
none had worked and this technique, which was counter-
intuitive, worked.” J.A. 22828:23-22829:2 (emphasis
added).
11 KINETIC CONCEPTS v. SMITH & NEPHEW
invention as set forth in the claims as opposed to the far
narrower commercial embodiment.
IV Motivation to Combine
As the majority describes, there is, however, substan-
tial evidence that Bagautdinov and Chariker-Jeter treat
pus pockets and fistulae, respectively, rather than
“wounds,” and that Bagautdinov, Zamierowski, and the
Chariker-Jeter public use do not disclose an adequate
seal. Thus, at the very least, to find obviousness, a person
of ordinary skill would have needed a motivation to
combine the treatment of “wounds” by Zamierowski with
the seal from the Chariker-Jeter publications. While
motivation to combine may be addressed on summary
judgment or JMOL in appropriate circumstances, see
Wyers v. Master Lock Co., 616 F.3d 1231, 1240 (Fed. Cir.
2010), it is still a question of fact, and the accused in-
fringers have failed to show that there was not substan-
tial evidence to support a finding of insufficient
motivation to combine. In other words, under the as-
sumption that the jury used the correct construction of
the “healing” limitations, there is substantial evidence for
the jury to have at least found the asserted claims nonob-
vious due to insufficient motivation to combine. Thus, I
agree with the majority’s ultimate conclusion that the
district court erred in granting JMOL of obviousness.