Judges: Rader, Lourie, Moore (author)

[Appealed from S.D. Cal., Judge Sabraw]

In Laryngeal Mask Co. v. Ambu A/S, Nos. 10-1028, -1062 (Fed. Cir. Sept. 21, 2010), the Federal Circuit vacated the district court’s SJ of noninfringement because it was based on an erroneous claim construction, and vacated the SJ of invalidity for lack of written description because genuine issues of material fact existed.

The Laryngeal Mask Company Ltd. and LMA North America, Inc. (collectively “LMA”) asserted U.S. Patent No. 7,156,100 (“the ’100 patent”) against Ambu A/S, Ambu Inc., and Ambu Ltd. (collectively “Ambu”). The ’100 patent, which is directed to a laryngeal mask airway device, contains the claim term “backplate.” The district court construed “backplate” as “the relatively rigid mask structure surrounded by the cuff and including a tube joint.” Finding that the accused products were integrally molded and contained no tube joint, the district court granted Ambu’s motion for SJ of noninfringement. Additionally, finding a portion of claim 1 unsupported by the specification, the district court granted Ambu’s motion for SJ of invalidity for lack of written description.

In determining whether the district court properly granted SJ, the Federal Circuit began by interpreting the claim term “backplate.” Claim 1 recites a laryngeal mask airway device comprising a cuff attached to a backplate. But it makes no mention of an airway tube or how the backplate or mask structure might attach itself to that tube. The specification, on the other hand, contained ample discussion of a tube joint but made only a single reference to it being part of the backplate in a preferred embodiment. The Court found this single reference insufficient to require every backplate to include a tube joint. As the Court explained, a claim is generally not limited to a preferred embodiment. And though a patentee may act as his own lexicographer, the specification did not clearly indicate any intent of the patentee to give the term a unique definition. While the specification described connecting or attaching the backplate to an airway tube, it did not require that connection be made with a tube joint.

Following its consideration of the specification, the Federal Circuit turned to the prosecution history. Just prior to issuance, the applicant deleted language from the claims that required the backplate to have a tube joint. The examiner subsequently allowed the claims with no objection to the deletion. Though Ambu contended that LMA deleted the tube-joint limitation in order that the claims would read on Ambu’s products, the Court was not persuaded. As the Court explained, regardless of why LMA amended the claims, it would be improper to read the limitation back into them.

Turning finally to the extrinsic evidence, the Federal Circuit first noted that neither party introduced a treatise or dictionary definition for the term “backplate.” But this did not preclude a conclusion that a plain and ordinary meaning existed. And, the Court continued, it certainly did not mean that the patentee must have acted as his own lexicographer. Though no dictionary definition was available, the Court found guidance for construing the term in two related prior art patents. Both listed the same inventor as the patent at issue—Dr. Brain. While both prior art patents disclosed a backplate, the Court found that neither included a tube joint. In light of this and the intrinsic evidence, the Court concluded that one of ordinary skill in the art would understand “backplate” to mean “the relatively rigid mask structure surrounded by the cuff.” Because the district court based its decision on an erroneous construction, the Federal Circuit vacated the SJ of noninfringement.

The Federal Circuit next considered whether the district court erred in finding all claims of the ’100 patent invalid for failing to satisfy the written description requirement. Claim 1 requires that a portion of the cuff be “thicker and stiffer than other portions of the cuff.” Upon construing the phrase, the district court concluded that this reinforced portion need not be connected to the backplate. And because the specification did not describe an embodiment where the reinforced portion of the cuff was not connected to the backplate, the district court found the claims invalid. But the Federal Circuit disagreed.

As the Federal Circuit noted, the Summary of the Invention described a reinforcement incorporated into the distal end of the cuff. It also described the reinforcement extending from the backplate in a preferred embodiment. LMA’s experts testified that these passages combined with a Cuff Wall Thickening Passage provided support for the invention of claim 1. Based on this evidence, the Court concluded that a genuine issue of material fact existed as to written description. The Court therefore vacated the grant of SJ of invalidity for lack of written description and remanded.