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September 23, 2010

Masked

7,156,100 claims a mask stuck down the throat, to deliver anesthetic gas during surgery, and provide an unobstructed airway. The poetically named Lanryngeal Mask Company (LMA) sued Ambu for infringement. For that, "all claims were invalid for lack of written description under 35 U.S.C. § 112" in summary judgment, along with noninfringement. Gasping for air, LMA appealed. At issue was claim construction, and whether the inventor had acted as his own lexicographer. "A patentee may act as its own lexicographer and assign to a term a unique definition that is different from its ordinary and customary meaning; however, a patentee must clearly express that intent in the written description."

Lanryngeal Mask Company v. Ambu (CAFC 2010-1028, -1062) precedential

The '100 patent concerns laryngeal mask airway devices, which are artificial airway devices used to deliver anesthetic gases during surgery and to establish unobstructed airways in patients in emergency situations. '100 patent col.1 ll.10-13. As shown below, these devices include an airway tube [47] attached to a backplate [52], which is surrounded by an inflatable cuff [55]. The device is inserted into the patient's mouth and throat until the far (distal) end of the cuff meets the opening of the esophagus [37]. The cuff is inserted in a deflated state. Once in place, the cuff is inflated using a cuff airway tube [62], forming a seal around the patient's laryngeal inlet and preventing gases from entering the esophagus. Anesthetic gas or air can then flow into the patient's laryngeal inlet via the airway tube [47].

This court reviews a grant of summary judgment de novo. Immunocept, L.L.C. v. Fulbright & Jaworski, L.L.P., 504 F.3d 1281, 1286 (Fed. Cir. 2007). "Summary judgment is appropriate when there is no genuine issue as to any material fact and the moving party is entitled to judgment as a matter of law." Id.

Claim Construction

We review claim construction de novo. Cybor Corp. v. FAS Techs., Inc., 138 F.3d 1448, 1455-56 (Fed. Cir. 1998) (en banc). The words of a claim are generally given their ordinary and customary meaning as understood by a person of ordinary skill in the art in question at the time of the invention when read in the context of the specification and prosecution history. See Phillips v. AWH Corp., 415 F.3d 1303, 1313 (Fed. Cir. 2005) (en banc).

The contested claim term was "backplate." LMA argued that "the district court improperly read a tube joint limitation into the claims."

Ambu contends that backplate is a technical term coined by the inventor, Dr. Brain. Ambu does not argue that the plain and ordinary meaning of backplate includes a tube joint, but rather that Dr. Brain acted as his own lexicographer and defined backplate as a bowl containing a passage and a tube joint, fitted between the airway tube and the inflatable cuff.

The CAFC found this "a difficult case of claim construction," yet seemed to have no trouble coming to the right conclusion.

We have a specification replete with discussion of a tube joint, which is the point of attachment between the mask structure and the airway tube. And we are mindful that the specification is the single best guide to the meaning of a disputed term. The preferred embodiment states that the backplate has a tube joint: It is this tube joint that connects the mask structure to the airway tube. See, e.g., '100 patent figs. 2-3. Ambu is correct that the patent does not disclose an integrally molded mask/airway tube. Certainly, it would be improper to add a tube joint limitation to the claims at issue where none appears. Kara Tech. Inc. v. Stamps.com Inc., 582 F.3d 1341, 1348 (Fed. Cir. 2009) ("The patentee is entitled to the full scope of his claims, and we will not limit him to his preferred embodiment or import a limitation from the specification into the claims."). Ambu, however, does not ask this court to import the tube joint limitation into the claims generally, but rather argues that the claim limitation "backplate" should be construed to include a tube joint.

Although it is a close case, in light of the claim language, specification, and prosecution history, we conclude that the term backplate is not so limited. The claims themselves are limited to the mask structure. The claims require "a backplate defining a passage." Claim 1 further defines that "the cuff ... [is] attached to the backplate." There is no mention of the airway tube or how the backplate or mask structure would attach to the airway tube. The claims cover only a laryngeal mask airway device comprising the backplate and cuff.

Some of the quandary went to whether the inventor was intending to act as lexicographer.

Although there is ample discussion of the tube joint throughout the specification, there is only one place where the specification indicates that the tube joint is part of the backplate (in the preferred embodiment's description of Figures 5 and 6): "The backplate 52 has a one-piece, integral spoon-shape including a bowl 90 and an external tube-joint 92 oriented proximally relative to the bowl, as shown in FIGS. 5 and 6." '100 patent col.6 ll.3-5. This sentence, which as its language indicates, describes what is shown in Figures 5 and 6, is not enough to require every backplate to include a tube joint. To be his own lexicographer, a patentee must use a "special definition of the term [that] is clearly stated in the patent specification or file history." Vitronics Corp. v. Conceptronic, Inc., 90 F.3d 1576, 1580 (Fed. Cir. 1996); see also CCS Fitness, Inc. v. Brunswick Corp., 288 F.3d 1359, 1366 ("[T]he claim term will not receive its ordinary meaning if the patentee acted as his own lexicographer and clearly set forth a definition of the disputed claim term in either the specification or prosecution history."). The specification does not clearly contain such a special definition. Although the preferred embodiment includes a backplate that contains a tube joint, we do not generally limit claims to the preferred embodiment. Phillips, 415 F.3d at 1323 ("[W]e have expressly rejected the contention that if a patent describes only a single embodiment, the claims of the patent must be construed as being limited to that embodiment."). The specification here does not clearly indicate the patentee's intent to give backplate a unique meaning different from its ordinary and customary meaning to one of skill in the art. See Helmsderfer v. Brobrick Washroom Equip., Inc., 527 F.3d 1379, 1381 (Fed. Cir. 2008) ("A patentee may act as its own lexicographer and assign to a term a unique definition that is different from its ordinary and customary meaning; however, a patentee must clearly express that intent in the written description.").

The specification does not clearly convey the patentee's intent to appoint a special meaning to the term backplate. Having concluded that the patentee did not act as his own lexicographer in this case by clearly defining a claim term, we must determine the ordinary meaning of backplate as used in these claims to one of skill in the art in light of the specification and prosecution history.

The prosecution history also indicates that the backplate is not required to have a tube joint. Just prior to issuance, the applicant deleted language concerning the airway tube and the tube joint.

To determine what one of skill in the prior art might understand "backplate" to mean, the CAFC looked at the inventor's prior patents which used the term, to no conclusion. And so, resort to the self-apparent...

The term backplate has a somewhat self-descriptive nature. As the prior art patents indicate it is the plate on the back. In light of the claims, specification, prosecution history, and prior art patents, we conclude that one of skill in the art would understand the claimed backplate to be "the relatively rigid mask structure surrounded by the cuff." We conclude that one of skill in the art would not conclude that the backplate must have a tube joint. We also conclude that the inventor did not act as his own lexicographer here and clearly require the backplate to have a tube joint. Because the district court's judgment of noninfringement was based on an erroneous claim construction, we vacate that judgment and remand for further proceedings.

Written Description

The district court granted summary judgment that all claims of the '100 patent were invalid for failure to satisfy the written description requirement of 35 U.S.C. § 112, ¶ 1. Invalidity Order at 7. "Compliance with the written description requirement is a question of fact." ICU Med., Inc. v. Alaris Med. Sys., Inc., 558 F.3d 1368, 1376 (Fed. Cir. 2009). Adequate written description requires that the applicant "convey with reasonable clarity to those skilled in the art that, as of the filing date sought, he or she was in possession of the [claimed] invention." VasCath Inc. v. Mahurkar, 935 F.2d 1555, 1563-64 (Fed. Cir. 1991) (emphasis omitted). Issued patents are presumed valid under 35 U.S.C. § 282, and thus Ambu must demonstrate by clear and convincing evidence that the claims at issue are invalid for lack of written description. ICU Medical, 558 F.3d at 1376.

The district court was off the cuff and into the weeds.

We conclude that the district court erred in granting summary judgment that the patent was invalid for failing the written description requirement. The Summary of the Invention does not require that the cuff reinforcement be connected to the backplate. Rather, it describes a reinforcement incorporated into the distal end of the cuff. '100 patent col.1 ll.47-63. The Summary of the Invention further states that "[i]n a preferred aspect," the reinforcement extends from the backplate. See id. at col.1 ll.64-67. We agree with LMA that one of ordinary skill in the art could read these disclosures as providing for a cuff reinforcement in the distal region that need not be connected to the backplate. In addition, we agree with LMA that one of ordinary skill in the art could read the Cuff Wall Thickening Passage as disclosing a thickened cuff portion that need not be connected to the backplate. Id. col.8 ll.9-12. LMA has raised a genuine issue of material fact on this issue, and therefore we reverse the court's grant of summary judgment and remand for further proceedings consistent with this opinion.

Vacated and remanded.

Posted by Patent Hawk at September 23, 2010 5:16 PM | Claim Construction

Comments

My favourite sentence from the Decision was: "We conclude that one of skill in the art would not conclude that the backplate must have a tube joint". Why? Because the drafter and prosecuter did indeed conclude it was essential. Right up until he saw the competing product without the joint.

What standards are expected of a patent attorney claim drafter. Is claim drafting taught, in the USA?

Posted by: MaxDrei at September 24, 2010 10:24 PM

"Is claim drafting taught, in the USA?"

Case law might not be an accurate indicator of quality. I imagine ambiguous and arbitrarily-limited claims tend to cause these sorts of messes. In this case, for example, if infringement were definitive, this lawsuit (or the negative outcome for the plaintiff) is less likely to happen.

Posted by: InMuenchen at September 25, 2010 8:36 AM

"Is claim drafting taught, in the USA?"

Here's what I use, Max:

Slusky's "Invention Analysis and Claiming" ; which is excellent.

Posted by: Fan Boy at September 26, 2010 5:01 PM

Yeah, I know Slusky. It is good. When was it published? About two years ago, right? I wonder how many copies he has sold.

Posted by: MaxDrei at September 26, 2010 10:19 PM