Brilliant Instruments v Guidetech

The Federal Circuit Court of Appeals reversed a district court’s finding of summary judgment that an accused product did not infringe the patent at issue under the doctrine of equivalents.  The Federal Circuit remanded the issue to be decided by the jury.  To succeed under the doctrine of equivalents a patentee must establish infringement according to either the “function-way-result” test or the “insubstantial differences” test.  The vitiation rule is addressed and found in this case to not remove the accused product from the realm of potential infringement.  Brilliant Instruments, Inc v Guidetech, LLC