Judge Robinson recently issued an opinion following a bench trial in Medtronic v. Boston Scientific Corp., C.A. No. 07-823-SLR (Mar. 30, 2011). This was a declaratory judgment action by plaintiff Medtronic, Inc.
One interesting aspect of the case was the way that the parties treated the burden of proof regarding infringement. The parties each argued that the other side bore the burden due to the procedural nature of the case (a declaratory judgment action). The patentee (defendant) argued that the alleged infringer (plaintiff) had the burden of proof on non-infringement because “the plaintiff usually has the burden of proof,” and because prior agreements between the parties overrode caselaw that says that the patentee always bears the burden of proof. Id. at 16-17. Judge Robinson, however, held that “‘[t]he burden is always on the patentee to show infringement,'” and the burden never shifts to the other party. Id. at 17. Thus, the patentee defendants bore the burden of proving non-infringement.
The patentee’s expert, however, had focused only on rebutting the plaintiff’s expert’s allegations of non-infringement, rather than setting forth his own allegations of infringement. Judge Robinson held that the plaintiff had therefore failed to offer affirmative evidence that all limitations of the patents at issue were met by the accused products, either literally or through the doctrine of equivalents, and found that the defendant had failed to show infringement.