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Means-Plus-Function Limitation for Ultrasound Device Includes Table- Mount Structure from Specification

February 04, 2004

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Last Month at the Federal Circuit - March 2004

Judges: Mayer (author), Gajarsa, and Dyk

In Nomos Corp. v. Brainlab USA, Inc., No. 03- 1364 (Fed. Cir. Feb. 4, 2004), the Federal Circuit affirmed the district court’s grant of SJ of noninfringement.

Nomos Corporation (“Nomos”) owns U.S. Patent No. 5,411,026 (“the ‘026 patent”), which relates to a table-mounted ultrasound device that helps to locate cancerous lesions. Brainlab USA, Inc. (“Brainlab”) also manufactures an ultrasound device that helps locate cancerous lesions, yet Brainlab’s device is a handheld device while the Nomos device is mounted to a treatment table. Nomos, however, sued Brainlab for infringement.

In the district court, Brainlab moved for SJ by asserting that their device did not meet the limitation “a means for generating at least one ultrasound image of the lesion in the patient’s body,” because the ‘026 patent required mounting the ultrasound device to a table. The district court agreed and found substantial differences.

At the Federal Circuit, Nomos argued that the corresponding structure of the limitation was simply “an ultrasound probe and nothing more.” Nomos also argued that the principle of claim differentiation precluded fixation devices as corresponding structure, because dependent claim 3 recited that feature.

The Federal Circuit found several portions of the specification that referenced the ultrasound probe in relation to a fixation device. For instance, the specification’s only embodiment consistently referred to the ultrasound device in relation to a fixation device by using language such as “disposed on,” “secured to,” and “is mounted” when referring to the probe. As a result, the Federal Circuit found that the corresponding structure of limitation (a) of claim 1 included a mounting device.

The Court rejected Nomos’s claimdifferentiation argument, because claim 1 is a means-plus-function claim and must be construed based on the corresponding structure from the specification.

Next, the Federal Circuit looked to determine whether Brainlab’s device literally infringed the ‘026 patent, taking into consideration that the corresponding structure of limitation (a) of claim 1 included a mounting device. While the Court did find that Brainlab’s device performed the same function as the Nomos device, it ultimately agreed that the Brainlab device functioned in a different manner.

Finally, the Federal Circuit determined that there was no equivalence because technology of Brainlab’s device predated that of the ‘026 patent and was not after-developed technology.