What Is Claim Vitiation And How Does It Affect Me?

Courts and litigants alike have struggled to make sense of claim vitiation, the idea that reading a claim element to encompass an accused product would so stretch the claim language as to "vitiate" (i.e., make ineffective) that claim element. Claim vitiation has been invoked as an exception to the judicially created doctrine of equivalents, which allows courts to find infringement even though a claim element is not literally present in the accused product. Over the past year, however, the Federal Circuit has emphasized that claim vitiation is not an exception to the doctrine of equivalents, but merely a finding under the doctrine of equivalents test.

Under the doctrine of equivalents, an accused product can be found to infringe a claim where an "equivalent" of the claimed feature is present in the accused product. There are a number of tests for determining what an "equivalent" is, perhaps the most common of which is to ask whether the allegedly equivalent feature of