NOTE: This disposition is nonprecedential. 

United States Court of Appeals for the Federal Circuit 

2007-1420, -1440 

LEXION MEDICAL, LLC, 

Plaintiff-Cross Appellant, 

v. 

NORTHGATE TECHNOLOGIES, INC., 

SMITH & NEPHEW, INC., and LINVATEC CORPORATION, 

Defendants-Appellants. 

David G. Wille, Baker Botts L.L.P., of Dallas, Texas, argued for plaintiff-cross 

appellant. With him on the brief was David O. Taylor. 

Meredith Martin Addy, Brinks Hofer Gilson & Lione, of Chicago, Illinois, argued 

for defendants-appellants. With her on the brief were Timothy Q. Delaney, Timothy P. 

Lucier, and Laura A. Lydigsen. 

Appealed from: United States District Court for the Northern District of Illinois 

Judge James M. Rosenbaum (sitting by designation) 
NOTE: This disposition is nonprecedential. 

United States Court of Appeals for the Federal Circuit 

2007-1420, -1440 

LEXION MEDICAL, LLC, 

Plaintiff-Cross Appellant, 

v. 

NORTHGATE TECHNOLOGIES, INC., SMITH & NEPHEW, INC., 

and LINVATEC CORPORATION, 

Defendants-Appellants. 

Appeals from the United States District Court for the Northern District of Illinois in 

case no. 1:04-CV-5705, Judge James M. Rosenbaum (sitting by designation). 

 DECIDED: August 28, 2008 

Before MICHEL, Chief Judge, RADER and SCHALL, Circuit Judges. 

SCHALL, Circuit Judge. 

DECISION 

 Defendants-Appellants Northgate Technologies, Inc., Smith & Nephew, Inc., and 

Linvatec Corp. (“Northgate” or “defendants”) appeal from the final judgment of the 

United States District Court for the Northern District of Illinois, entered following a jury 

trial, that Claims 11 and 12 of United States Patent No. 5,411,474 (“the ’474 patent”) are 

valid and were infringed by Northgate. Plaintiff-Cross Appellant Lexion Medical, LLC 
(“Lexion”) cross-appeals the district court’s determination that Northgate’s post-verdict 

sales did not constitute willful infringement. It also cross-appeals the district court’s 

grant of judgment as a matter of law (“JMOL”) that the asserted claims of United States 

Patent No. 6,068,609 (“the ’609 patent”) are invalid for obviousness. We affirm-in-part, 

vacate-in-part, and remand for further proceedings. 

DISCUSSION 

I 

During laparoscopic surgery, a small incision is made in the patient’s abdomen, 

and the abdominal cavity is then inflated with carbon dioxide gas to create an empty 

space in which a surgeon performs surgery. An important advantage of laparoscopic 

surgery is its minimally invasive nature, as it avoids the larger incisions and longer 

recovery times associated with conventional surgery. A common side effect, however, 

is that patients often suffer from post-operative shivering and shoulder pain. 

Lexion’s ’474 and ’609 patents disclose and claim a method and apparatus for 

heating and humidifying the gas used to inflate a patient’s abdomen during laparoscopic 

surgery. The heated gas helps reduce the side effects of post-operative shivering and 

shoulder pain frequently experienced following laparoscopic surgery. 

 Claim 11 of the ’474 patent (with the pertinent limitations underscored) recites the 

following: 

A method of providing heated, humidified gas into a patient for an endoscopic 

procedure comprising the steps of: 

a) directing pressure- and volumetric flow rate-controlled gas, received from an 

insufflator into a chamber having a means for heating the gas to a temperature 

within a predetermined range and a means for humidifying the gas and being 

disposed immediately adjacent to the patient, wherein the chamber is in flow 

2007-1420, -1440 2
communication with and immediately adjacent to a means for delivering the gas 

to the interior of the patient; 

b) sensing the temperature of the gas as it exits the chamber to determine if it is 

within the predetermined range; and 

c) actuating the heating means if the temperature of the gas is without the 

predetermined range; 

d) humidifying the gas within the chamber; and 

e) flowing the gas into the delivering means such that the gas enters the patient 

humidified and having a temperature within 2oC of the predetermined 

temperature and thus providing the gas. 

Claim 12 of the ’474 patent recites: 

The method of claim 11, wherein the heating means and the humidifying means 

heat and humidify the gas simultaneously. 

The ’609 patent improves upon the ’474 patent by including a recharge port on 

the humidifier that allows the humidifier’s water supply to be replenished during 

extended surgeries. 

II 

The Insuflow is Lexion’s commercial embodiment of the patented inventions. 

The Humi-Flow is the accused device marketed and sold by defendants.1

 Like the 

inventions which are the subjects of the ’474 and ’609 patents, the accused Humi-Flow 

device both heats and humidifies gas inside a chamber before delivering it into a 

patient’s body for use in laparoscopic surgery. Specifically, the Humi-Flow features a 

tubular chamber housing a central heater core surrounded by a layer of humidification 

media. The surface of the humidification media contains grooves which define hollow 

 1

 Northgate Technologies, Inc. serves as the original equipment 

manufacturer for Smith & Nephew, Inc. and Linvatec Corp., who sell their own versions 

of the Humi-Flow. 

2007-1420, -1440 3
ducts through which gas flows. As gas flows through these hollow ducts, the heater 

core and humidification media impart both heat and moisture to the gas. Temperature 

sensors embedded within the heater core help maintain the temperature of the core at 

70oC, by triggering the heater whenever the core temperature falls below 70oC. In this 

manner, the surrounding gas temperature is indirectly maintained at a temperature 

between 32-41oC. 

III 

 Lexion filed suit against defendants in the United States District Court for the 

Northern District of Illinois, asserting that their Humi-Flow devices infringed claims 11 

and 12 of the ’474 patent, and claims 1, 8, 9, 16, and 23 of the ’609 patent. Prior to 

submitting the case to the jury, the district court granted JMOL that the asserted claims 

of the ’609 patent were invalid for obviousness. Thereafter, the jury returned a verdict 

that claims 11 and 12 of the ’474 patent were not invalid and had been literally infringed 

by the defendants. The jury awarded Lexion $721,662 in damages.2

 Before entry of a 

permanent injunction, Northgate liquidated its remaining inventory of Humi-Flow 

devices. In response, Lexion moved to modify the judgment to include enhanced 

damages for willful infringement. The district court denied the motion, however, electing 

instead to award compensatory damages for the post-verdict sales, as well as the 

attorney fees incurred by Lexion in bringing its motion. 

 2

 Even though the district court granted JMOL that the asserted claims of 

the ’609 patent were invalid for obviousness, the infringement and validity of the ’609 

patent were nonetheless submitted to the jury. On those questions, the jury (1) found 

defendants liable for direct, contributory, and induced infringement of the asserted 

claims of the ’609 patent, (2) found the asserted claims of the ’609 patent not invalid, 

and (3) awarded damages. 

2007-1420, -1440 4
IV 

Northgate now appeals with respect to the infringement and validity of the ’474 

patent. Lexion has cross-appealed with respect to willful infringement of the ’474 patent 

and invalidity of the ’609 patent. We have jurisdiction over the appeal and the crossappeal pursuant to 28 U.S.C. § 1295(a)(1). 

Claim construction is a question of law which this court reviews de novo. Cybor 

Corp. v. FAS Techs., Inc., 138 F.3d 1448, 1454 (Fed. Cir. 1998) (en banc). Literal 

infringement is a question of fact, reviewed for substantial evidence when tried to a jury. 

ACCO Brands, Inc. v. ABA Locks Mfrs. Co., 501 F.3d 1307, 1311 (Fed. Cir. 2007). We 

review a 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. TI Group Automotive Systems (N. Am.), Inc. v. VDO N. Am., 

L.L.C., 375 F.3d 1126, 1133 (Fed. Cir. 2004). The grant or denial of JMOL is reviewed 

under the law of the regional circuit in which an appeal from the district court would 

normally lie. Union Carbide Chems. & Plastics Tech. Corp. v. Shell Oil Co., 425 F.3d 

1366, 1372 (Fed. Cir. 2005). The regional circuit in this case is the Seventh Circuit, 

which reviews without deference a district court’s grant of JMOL. See Harper v. Albert, 

400 F.3d 1052, 1061 (7th Cir. 2005). We review the district court’s finding of no willful 

infringement for clear error. BIC Leisure Prods., Inc. v. Windsurfing Int’l, Inc., 1 F.3d 

1214, 1222 (Fed. Cir. 1993). 

V 

 On appeal, Northgate challenges the judgment that claims 11 and 12 of the ’474 

patent were infringed and valid. It argues that its accused devices do not infringe the 

2007-1420, -1440 5
’474 patent because they do not meet three limitations of the asserted claims: (1) the 

“means for heating” and “means for humidifying” limitations of claim 11(a); (2) the 

“sensing the temperature of the gas as it exits the chamber” limitation of claim 11(b); 

and (3) the delivery of gas “within 2oC of the predetermined temperature” limitation of 

claim 11(e). Northgate further argues that the ’474 patent is invalid for obviousness in 

view of various prior art references. We address these contentions in turn. 

A. “means for heating” and “means for humidifying” 

 The prosecution history is pertinent to Northgate’s argument relating to these 

limitations. During prosecution of the ’474 patent, in an office action dated February 1, 

1994, the examiner rejected various claims as anticipated by U.S. Patent No. 4,825,863 

to Dittmar et al. (“Dittmar”). The claims rejected as anticipated by Dittmar were 

application claims 1-3, 6, 7, 9, 10, 12, 14, 15, and 22. Application claims 17 and 18, 

corresponding to claims 11 and 12 of the ’474 patent, were allowed. In her rejection, 

the Examiner stated: “Dittmar et al. disclose an apparatus for treating gas comprising a 

housing 1, a chamber 20 within the housing, a humidifier 25 in the chamber and a 

heating means 21 and 22 within the humidifier.” 

The applicants responded to this rejection on May 2, 1994, by cancelling claim 

12 and by amending independent claims 1, 14, and 22 (all previously rejected over 

Dittmar), and hence their dependent claims, to include a limitation specifying that the 

claimed invention was for use in an “endoscopic” procedure. With the exception of 

application claim 22, all of the rejected claims that were amended to include the 

“endoscopic” procedure limitation also contained the limitation that the humidification 

means in the chamber be “in the path of travel of the gas through the chamber,” as well 

2007-1420, -1440 6
as the limitation of a heating means “within the humidification means.” In that regard, 

the applicants stated: Dittmar discloses a humidification means which is not in the path 

of travel of gas through the chamber, as claimed, e.g., in Claim 1, and which is not a 

volume of water in flow communication with the gas as claimed, e.g., in Claim 3.” 

(emphasis added). They added: “Thus, amended Claims 1, 14, and 22 and the claims 

dependent from them should now be allowable.” Concluding their response to the 

anticipation rejection, the applicants stated: 

Dittmar . . discloses a heater/humidifier subassembly wherein the 

humidifier is retained within a compartment, separated from a hollow 

center . . . Air freely flows through this hollow center which acts as a duct 

for air flow and within which are heating elements. Therefore, Dittmar’s 

humidification means is not in the path of travel of the gas, the heating 

means is not disposed within the humidification means, and the humidifier 

does not comprise a volume of water in flow communication with the gas, 

as claimed by applicants. As a result, even without the additional 

limitations provided herein by amendment of the claims, applicant’s 

invention is not anticipated by Dittmar. (emphases added) 

Eventually, on November 2, 1994, the Examiner allowed the pending claims. 

Reviewing the prosecution history, the district court concluded that the applicants 

had effectively disclaimed a “means for humidifying” that was not in the path of travel of 

the gas, i.e., where air freely flows past the humidifier, as well as a “means for heating” 

not disposed within the humidification means. Accordingly, the district court instructed 

the jury that, as far as claims 11 and 12 of the ’474 patent were concerned, Lexion had 

surrendered a humidifying means where “gas flows freely past a humidifying bed.” At 

the same time, the court defined the heating means as a structure found “within” the 

humidifying means. 

 On appeal, Northgate takes the position that the district court did not err in its 

construction of the part of limitation (a) of claims 11 and 12 which relates to “means for 

2007-1420, -1440 7
heating” and “means for humidifying” or in its instructions to the jury. It argues, 

however, that the jury verdict of infringement is not supported by substantial evidence, 

in view of the structure of its Humi-Flow device. In response, Lexion contends that 

prosecution disclaimer was improperly applied by the district court to the asserted 

claims. Nevertheless, it argues that the verdict of infringement, which it says was 

rendered under an incorrect claim construction based on disclaimer, is supported by 

substantial evidence. 

We agree with Lexion that the applicants’ response to the February 1, 1994 office 

action did not trigger a prosecution disclaimer with respect to the asserted claims. In 

our view, the attempt to distinguish Dittmar was limited in scope to those particular 

claims that explicitly recited the allegedly disclaimed subject matter. As noted, on 

February 1, 1994, the Examiner rejected then-pending independent claim 1 and its 

various dependent claims, as well as independent claims 14 and 22, as anticipated by 

Dittmar. Except for application claim 22, the rejected claims which the applicants did 

not cancel (claims 1-3, 6, 7, 9, 10, 14, and 15) recited, in relevant part, “a humidification 

means in the chamber that is in the path of travel of the gas” and a heating means 

“disposed within the humidification means.” Because the alleged disclaimer 

corresponds precisely with the limitations expressly recited in those particular claims, 

and was clearly in response to a rejection of those particular claims, any disclaimer 

must accordingly be limited to those claims, under our approach set forth in Golight, 

Inc., v. Wal-Mart Stores, Inc., 355 F.3d 1327, 1333 (Fed. Cir. 2004) (limiting disclaimer 

to the particular claims that explicitly recited the allegedly disclaimed subject matter, and 

declining to extend disclaimer to claims that did not). Here, the alleged disclaimer 

2007-1420, -1440 8
clearly arose in connection with the rejected claims reciting a humidifying means “in the 

path of travel of the gas” and a heating means “disposed within the humidification 

means,” and any resulting disclaimer must therefore be limited to those claims. 

Because asserted claims 11 and 12 of the ’474 patent, which were allowed on February 

1, 1994, as application claims 17 and 18, do not recite those limitations, the prosecution 

disclaimer does not extend to them. 

Northgate argues, however, that the disclaimer is not limited to only those claims 

explicitly reciting the allegedly surrendered subject matter, because the alleged 

disclaimer was also used to obtain allowance of then-pending application claim 22, 

which did not recite the limitations of a humidification means “in the path of travel of the 

gas through the chamber” and a heating means “within the humidification means.” We 

disagree with this reading of the prosecution history. First, as noted, application claim 

22 was amended to include a limitation specifying that the claimed method was for use 

in “an endoscopic” procedure. We believe it was on that basis that the applicants 

argued that claim 22 was allowable. Second, examination of the material from the 

prosecution history set forth above reveals that the applicants’ statements did not 

implicate application claim 22. Instead, the applicants’ statements, which distinguished 

Dittmar on the basis of a humidifying means “not in the path of travel of the gas” and a 

heating means “not disposed within the humidification means,” were clearly directed to 

those claims that explicitly recited those features, as evidenced by the qualifying phrase 

“as claimed by applicants.” Claim 22 did not claim these distinguishing features, nor did 

previously allowed application claim 17 (corresponding to asserted independent claim 

11) or previously allowed application claim 18 (corresponding to asserted dependent 

2007-1420, -1440 9
claim 12). We therefore reject Northgate’s attempt to extend the alleged disclaimer to 

these claims. In any event, we note that because the disputed statements in the 

prosecution history are subject to multiple reasonable interpretations, they do not 

constitute the clear and unmistakable surrender required to trigger prosecution 

disclaimer. See Golight, 355 F.3d at 1332. 

In short, the means for heating and means for humidifying limitations of claims 11 

and 12 of the ’474 patent were considered by the jury under an incorrect claim 

construction. The result is that the jury’s finding that those limitations were met in the 

accused Humi-Flow device necessarily is nullified. See Union Carbide Chems. & 

Plastics Tech. Corp. v. Shell Oil Co., 308 F.3d 1167, 1179 (Fed. Cir. 2002) (remanding 

for further proceedings without reaching the merits of the district court’s underlying 

conclusions because the district court’s judgment was based upon an incorrect claim 

construction). 

B. “sensing the temperature of the gas as it exits the chamber” 

As far as limitation (b) of claims 11 and 12 is concerned, the district court 

construed “sensing the temperature of the gas” to mean “the thermal temperature of the 

gas is measured by a device after the gas has been humidified, but prior to delivery into 

the patient.” The district court did not, however, construe “as it exits the chamber.” 

 Northgate contends that the “sensing the temperature of the gas as it exits the 

chamber” limitation requires that the gas temperature is measured directly and locally 

by temperature sensors positioned at the exit of the chamber. It urges that, under this 

construction of the limitation, the Humi-Flow device does not infringe, the reason being 

that it does not have a temperature sensor at the point where the gas exits the 

2007-1420, -1440 10
chamber. Lexion responds that the disputed language imposes no such requirement. It 

maintains that indirect and remote measurement of gas temperature using temperature 

sensors internally embedded within the heater core, as in the case of the Humi-Flow 

device, is sufficient to meet this limitation. 

 We agree with Lexion. Claim 11 merely requires the measurement of whatever 

gas temperature exists at the exit of the chamber. It does not require any particular 

positioning of components relative to each other, nor does it specify that the 

temperature measurement must be performed directly rather than indirectly. We 

therefore find no error in the district court’s construction of this disputed limitation. 

Furthermore, there is substantial evidence in the record that supports the jury verdict 

that this limitation is met in the accused device. During trial, Lexion presented 

testimony that the Humi-Flow device indirectly measures gas temperature by correlating 

the temperature of the heater core to that of the surrounding gas. Lexion also 

presented testimony that this indirect method of temperature measurement was 

effective for purposes of remotely detecting the gas temperature at the exit of the 

chamber. In view of this substantial evidence under the district court’s proper claim 

construction, we see no basis for disturbing the jury’s finding that this limitation was met 

in the accused device. 

C. “gas . . . having a temperature within 2oC of the predetermined temperature” 

 Limitation (e) of claim 11 requires that the gas be delivered to the patient within 

2oC of a “predetermined temperature.” Though its meaning was vigorously disputed by 

the parties, the district court never construed the “predetermined temperature” limitation. 

On appeal, Northgate contends that the “predetermined temperature” is a single 

2007-1420, -1440 11
temperature point, whereas Lexion maintains that the “predetermined temperature” 

represents a range of temperatures. The parties therefore dispute the level of precision 

required by the claim language. 

 We agree with Northgate that the “predetermined temperature” is properly 

construed as a single temperature point. As an initial observation, the word “range” 

appears elsewhere in the language of claim 11 but is not used in limitation 11(e) to 

describe the “predetermined temperature.” This suggests that the applicants 

affirmatively employed the word “range” where that meaning was intended, but 

specifically declined to do so in connection with the “predetermined temperature” 

limitation of claim 11(e). Second, the specification of the ’474 patent repeatedly 

contemplates the “predetermined temperature” as a single temperature point rather than 

a range. For instance, at column 5, lines 21-25, the specification states that “[a]s used 

herein, a ‘predetermined temperature’ is one that has been preset and is not altered 

during a procedure. For laparoscopic procedures the desireable [sic] predetermined 

temperature is physiological body temperature, i.e., approximately 36o-38o C.” 

(emphasis added). This passage clearly indicates that the predetermined temperature 

is the single temperature point that best approximates the patient’s body temperature. 

Likewise, Table 1, footnote (4) of the ’474 patent’s specification describes various “listed 

temperatures indicat[ing] the range of temperatures from which the predetermined 

temperature was selected.” Col.11 ll.33-35. This language clearly conveys that the 

“predetermined temperature” is a single temperature point that is selected from a 

broader temperature range. Construing the “predetermined temperature” as a single 

temperature point therefore comports with the language of claim 11 and the ’474 

2007-1420, -1440 12
patent’s specification. In contrast, Lexion’s proposed construction contradicts this 

intrinsic evidence and also departs from the primary purpose of the invention, the 

delivery of gas that has been humidified and heated to human body temperature for use 

in laparoscopic surgery. We therefore conclude that the “predetermined temperature” is 

best viewed as a single temperature point rather than a temperature range. The jury did 

not have this construction before it when it considered whether limitation (e) of claim 11 

was met in the accused device. Under these circumstances, the jury’s finding that this 

limitation was met is nullified. 

 In sum, we have not affirmed the verdict of infringement insofar as it relates to 

limitations (a) and (e) of claims 11 and 12 of the ’474 patent. We have declined to do so 

on account of reasons relating to claim construction, as discussed above. We therefore 

vacate the judgment of infringement and remand the case to the district court for further 

proceedings on the issue of infringement. See Harris Corp. v. Ericsson Inc., 417 F.3d 

1241, 1260 (Fed. Cir. 2005) (vacating the jury verdict of infringement and remanding for 

further proceedings under the proper claim construction). We of course vacate as well 

the permanent injunction entered against Northgate. 

D. Obviousness of the ’474 patent

 The district court declined to grant JMOL of obviousness following the jury verdict 

which found the asserted claims of the ’474 patent not invalid for obviousness. On 

appeal, Northgate maintains that this ruling was in error. In support of this argument, 

Northgate provides extensive claim charts summarizing prior art references which 

allegedly teach every limitation of the asserted claims. Northgate urges that, under the 

principles articulated by the Supreme Court in KSR Int’l Co. v. Teleflex Inc., 127 S. Ct. 

2007-1420, -1440 13
1727 (2007), it would have been obvious for a skilled artisan to combine these prior art 

references to achieve the asserted claims of the ’474 patent. Having considered 

Northgate’s arguments regarding obviousness, however, we see no error in the decision 

of the district court denying Northgate’s motion for JMOL of invalidity of the ’474 patent. 

VI 

 Lexion cross-appeals the district court’s finding of no willful infringement with 

respect to Northgate’s post-verdict liquidation of its Humi-Flow inventory. It also crossappeals the district court’s grant of JMOL that the ’609 patent is invalid by reason of 

obviousness. We have considered the arguments raised in Lexion’s cross-appeal, and 

have found no error in the district court’s determinations on these issues. 

A. Willful Infringement

 As noted, following the jury verdict of infringement, and prior to entry of an 

injunction by the district court, Northgate liquidated its remaining inventory of Humi-Flow 

devices. In so doing, it relied on an oral opinion from its counsel that, despite the jury 

verdict, the Humi-Flow did not infringe the asserted claims. The district court denied 

Lexion’s subsequent motion for willful infringement. Instead, it awarded compensatory 

damages to Lexion, as well as the attorney fees incurred by Lexion in bringing its 

motion. 

Preliminarily, we note that our vacatur of the judgment of infringement 

necessarily means that we also vacate the award of compensatory damages and 

attorney fees in favor of Lexion for bringing its motion with respect to willful 

infringement. At the same time it is appropriate that we address the district court’s 

2007-1420, -1440 14
ruling of willfulness. The reason is that the proceedings on remand could result in a 

reinstated verdict of infringement.3

 

 On appeal, Lexion contends that the district court clearly erred in finding that 

Northgate’s post-verdict sales did not constitute willful infringement. We disagree with 

Lexion, and affirm the district court’s determination of no willful infringement. Under our 

decision in In re Seagate Tech., LLC, 497 F.3d 1360 (Fed. Cir. 2007), proof of willful 

infringement requires at least a showing of objective recklessness, id. at 1371. We do 

not think it was objectively reckless for Northgate to obtain and rely on the opinion of 

counsel, which had predicted a favorable outcome in view of the renewed motion for 

JMOL then pending before the district court. Although the district court ultimately 

denied that motion, Northgate’s reliance on that opinion was nonetheless justified, as 

we have vacated the judgment of infringement and remanded for further proceedings 

based upon our new claim construction. 

 3

 Northgate has not challenged the district court’s award to Lexion of 

compensatory damages and attorney fees. If, after remand proceedings, the judgment 

of infringement is reinstated, the district court can reinstate as well its award of 

compensatory damages and attorney fees. 

2007-1420, -1440 15
B. Obviousness of the ’609 patent 

 Prior to trial, the district court granted JMOL of obviousness with respect to the 

’609 patent. On appeal, Lexion contends that the district courts’ grant of JMOL was 

erroneous for reasons which we find unpersuasive. The ’609 patent simply modifies the 

invention described in the ’474 patent via a simple and minor improvement: adding a 

recharge part that allows for the replenishment of water for extended use during 

laparoscopic surgeries. In KSR, the Supreme Court stated: 

[w]hen a work is available in one field, design incentives and other market 

forces can prompt variations of it, either in the same field or in another. If 

a person of ordinary skill in the art can implement a predictable variation, 

and would see the benefit of doing so, § 103 likely bars its patentability. 

Id. at 1731. We think that the ’609 patent was nothing more than a predictable variation 

or improvement of the ’474 patent that was well within the skill and ordinary creativity of 

a skilled artisan. We therefore affirm the district court’s grant of JMOL of obviousness 

with respect to the ’609 patent. 

CONCLUSION 

 For the foregoing reasons, we affirm-in-part, vacate-in-part, and remand for 

further proceedings consistent with this opinion. On remand, the district court should 

reconsider the infringement of the asserted claims of the ’474 patent by treating the 

“means for humidifying” and “means for heating” limitations as construed without 

application of prosecution disclaimer, and by treating the “predetermined temperature” 

limitation as calling for a single temperature point. Because we vacate the judgment of 

infringement, we also vacate the permanent injunction previously entered against 

Northgate, as well as the district court’s award of damages and attorney’s fees in 

connection with the post-verdict sales and Lexion’s motions. The district court may 

2007-1420, -1440 16
2007-1420, -1440 17

reinstate the injunction and those awards in the event that a judgment of infringement is 

entered on remand. 

 Each party shall bear its own costs.