Doctrine of Equivalents: Expert Testimony Must Include Limitation-by-Limitation Analysis

PatSeminar030Network Commerce v. Microsoft (Fed. Cir. 2005).

Network Commerce sued Microsoft for infringement of its e-commerce patent relating to the purchase of downloadable electronic content.  The district court awarded summary judgment to Microsoft, finding that the company did not infringe either literally or under the doctrine of equivalents (DOE).

Specifically, the lower court found that Network Commerce’s extension of the patent to include Microsoft’s metafile downloads would vitiate the claim requirement that the download an executable file or program.

On appeal, the CAFC did not reach the vitiation requirement.  Rather, the appellate panel found that even the basic requirements of element-by-element equivalents had not been sufficiently shown by the plaintiff because the expert declaration did not provide sufficiently specific testimony to prove a limitation-by-limitation analysis.

The expert declaration and other evidence relied on by Network Commerce supporting infringement by equivalents are generalized and do not provide particularized testimony and linking argument on a limitation-by-limitation basis. For this reason the evidence did not raise a genuine issue of material fact. Summary judgment of non-infringement under the doctrine of equivalents regarding metafiles was therefore proper.

Summary Judgment Affirmed