Medtronics et al. v. BrainLAB et al.

This case brings home, again, the importance of the patent specification in claim construction.

In the District Court, an aggregate verdict of $60 million in favor of plaintiff Medtronics was set aside by the court and BrainLAB granted a judgment of noninfringement of U.S. Pat. Nos. 5,383,454 (“the ‘454 patent”) and 4,722,056 (“the ‘056 patent”). The Court of Appeals for the Federal Circuit affirmed.

Medtronics manufactures and sells image-guided surgery products, as does BrainLAB. Medtronics’ ‘454 patent claims a system and method for tracking the tip of a surgical probe while displaying a scanned image of the location of the probe and discloses use of an acoustic tracking system. The District Court construed “reference means” as “an array of microphones” not “one or more sensor(s) or receiver(s)” as urged by Medrtonics.  As the District Court noted, and the CAFC agreed, the specification of the ‘454 patent “consistently describes the use of ‘arrays’ to detect sound emissions” and describes that key component in terms of a “microphone array” or “microphones of the array”.

In construing the claims of the ‘056 patent, the District Court concluded, and the CAFC agreed, that “establishing the spatial relationship” excluded “the use of an optical reference system”. The District Court noted that the specification describes “an acoustic or ultrasonic range finding system” as well as “an electromagnetic position and orientation system” to track the movement of an object. The District Court further noted that “although the specification mentions the use of an optical system (“a single statement that appears in the specification, i.e., that ‘[a]n optical system can be used as an alternative to the acoustic system described earlier’”), the statements were ‘too general in nature’ to support Medtronic’s broad proposed construction.”  The CAFC agreed that such a passing reference to an optical tracking system failed to support an interpretation broader than that adopted by the District Court.  In addition, the CAFC noted that “[t]here is no enabling description of how to make and use an optical tracking system, and claims are best construed to preserve their validity.” Finally, “the inventor himself stated, in answer to a series of questions regarding whether an optical tracking unit was available to him at the time of his invention of the acoustic system that ‘[w]e weren’t aware of any commercial optical tracking system that was available’ and ‘[i]t seemed at the time that this would be an obvious development, that it would be coming in time. It was just that at this time that we were writing this, that such a system wasn’t available to us.’”

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