This case saw a return to the question of what is meant by 35 USC 112 paragraph 6 which has been troubling the Federal Circuit and practitioners for much of the past decade. In this case the issue was what is meant by the term “corresponding structure” in the provision that a means plus function claim “shall be construed to cover the corresponding structure, material or acts described in the specification, and equivalents thereof.” In B. Braun Med Inc. v. Abbott Labs it had been held that:
Structure disclosed in the specification is “corresponding” structure only if the specification or prosecution history clearly links or associates that structure to the function recited in the claim.
In Northrup the court has made it clear that what is regarded as “corresponding structure” is confined that part of what is described that is needed to perform the stated function and not expanded to incorporate other limitations into the claim.
 66 USPQ2d 1341 (Fed. Cir. 2003)
 124 F.3d 1419 43 USPQ2d 1896 (Fed Cir 1997).