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When Supported by Specification, Numerical Range Interpreted to Permit “Minor Fluctuations” Outside Claimed Range

09-1494
April 22, 2011

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Last Month at the Federal Circuit - May 2011

Judges: Rader (author), Dyk, Prost

[Appealed from: N.D. Ill., Judge Kokoras]

In Lexion Medical, LLC v. Northgate Technologies, Inc., No. 09-1494 (Fed. Cir. Apr. 22, 2011) (“Lexion II”), the Federal Circuit affirmed a ruling on SJ that Northgate Technologies, Inc., Smith & Nephew, Inc., and Linvatec Corp. (collectively “Northgate”) infringed U.S. Patent No. 5,411,474 (“the ’474 patent”) held by Lexion Medical, LLC (“Lexion”).  The appeal hinged on the district court’s claim construction of the phrase, “having a temperature within 2˚C of the predetermined temperature,” which the district court construed to include minor, temporary fluctuations outside of the 2˚C window.  The Federal Circuit unanimously affirmed.

At issue in Lexion II was a method and apparatus for heating and humidifying gas used to inflate the abdominal cavity of a patient during laparoscopic surgery.  The ’474 patent, entitled “Method and Apparatus for Conditioning Insufflation Gas for Laparoscopic Surgery,” recites in claim 11 a five-step method, summarized as follows:  (a) directing gas received from an insufflator into a preparation chamber; (b) sensing the temperature of the gas; (c) actuating a heating means if the temperature is without the predetermined range; (d) humidifying the gas; and (e) flowing the gas into a patient-delivery means so that the gas enters the patient having a temperature within 2˚C of the predetermined temperature.  Lexion accused Northgate’s Humi-Flow device of infringing this method.  There was no dispute on appeal that the Humi-Flow heats and humidifies gas from an insufflator, and directs the gas into a chamber where its temperature is raised to approximately 37˚C.  The sole question for the Court was whether the Humi-Flow delivers gas to the patient within the claimed temperature range, i.e., “within 2˚C of the predetermined temperature.”

Lexion II follows a previous Federal Circuit appeal in Lexion Medical, LLC v. Northgate Technologies, Inc., 292 Fed. App’x 42 (Fed. Cir. 2008) (“Lexion I”).  In Lexion I, the Court vacated a jury finding of infringement and remanded the case for proceedings consistent with the Court’s construction of the claim term “predetermined temperature.”  Specifically, the Court found that “predetermined temperature” means “a single temperature point” and could not include a range.  On remand, Lexion submitted a declaration from its expert, Dr. John Burban, indicating that the Humi-Flow device delivered gas “almost always”—but not always—within 2˚C of 37˚C, the temperature of the human body.  Lexion argued that Northgate’s Humi-Flow device still infringed, even under the “single temperature point” construction, because the “within 2˚C” limitation did not require that the temperature range be “always within 2˚C.”  Northgate did not submit any competing expert declarations or data concerning the temperature fluctuations in the Humi-Flow.  Instead, Northgate argued that Dr. Burban’s new declaration made arguments that contradicted prior positions, and therefore violated Federal Rules of Civil Procedure 26(a)(2) and
37(c)(1).  The district court agreed with Lexion’s construction and found infringement.  

On appeal for the second time, the Court focused on the district court’s construction of “within 2˚C of the predetermined temperature.”  The Court agreed with the district court’s construction, citing Phillips v. AWH Corp., 415 F.3d 1303, 1315-16 (Fed. Cir. 2005), for the proposition that constructions that “harmonize” all claim limitations into a working invention are preferred.  In claim 11 of the ’474 patent, limitations (b) and (c) recite continuous temperature sensing and actuation of the heating means “if the temperature of the gas is without the predetermined range”—clearly contemplating gas temperature fluctuations.  To “harmonize” these limitations with the “within 2˚C” limitation, the Court found that “[i]n the context of this particular invention, ‘within’ does not mean ‘always within’.”  Slip op. at 8.  The Court found additional support for the “‘within’ does not mean ‘always within’” construction in the ’474 patent specification, which expressly acknowledges that there can be “lags” within the system for sensing and adjusting heat.  At one point, the specification indicates that the patient will receive gas “at least within about 2˚C,” which is fully consistent with a construction that tolerates minor fluctuations outside of the expressly claimed range.  Because the claim limitations and specification support a construction tolerant of minor fluctuations outside of the expressly claimed range, the Court affirmed the district court’s claim construction.

Turning to infringement, the Court agreed with the district court that under a claim construction permitting minor fluctuations, no genuine issue of material fact remained in dispute.  Lexion’s supplemental Burban declaration provided data that Humi-Flow provides gas within the four degree range for “all but 15 seconds” of every 20 minutes.  During those 15 seconds, the Humi-Flow gas senses the temperature fluctuation and actuates the heating means to raise the temperature, as contemplated by limitations (b) and (c).  Northgate failed to provide any countervailing evidence.  The Court rejected Northgate’s evidentiary argument, stating:  “This court remanded to permit the trial court to reassess the case in the context of the new claim construction.  In that context, the district court had wide discretion to permit the parties to supplement the record with new factual declarations consistent with the new understanding of the claim.”  Id. at 12 (citing Bowers v. BayState Techs., Inc., 320 F.3d 1317, 1334 (Fed. Cir. 2003)).  Therefore, the district court did not abuse its discretion by permitting Lexion’s expert to submit a second, potentially inconsistent declaration in the context of responding to a new claim construction.

Accordingly, because the district court was correct to permit minor fluctuations outside of the claimed range, and has wide discretion to accept factual declarations responsive to new claim constructions, the Court affirmed the district court’s SJ of infringement.

 

Summary authored by Phillip K. Decker, law clerk at Finnegan.