EMD MILLIPORE CORPOR ATION v. ALLPURE TECHNOLOGIES on doctrine of equivalents

As to the doctrine of equivalents:


Even without literal infringe-
ment of a certain claim limitation,
a patentee may estab-
lish infringement under the doctrine of
equivalents if an element of the
accused device “performs substantially the
same function in substantially the same way to obtain the
same result as the claim limitation.”
AquaTex Indus., Inc. v. Techniche Solutions
, 419 F.3d 1374, 1382 (Fed. Cir.2005) (citation omitted)
(quotation marks omitted).



As to ambiguity in the file history:


And to the extent this statement is ambiguous, we note that the Supreme Court
has stated “[w]here no explanation is established . . . the
court should presume that the patent applicant had a
substantial reason related to patentability for including
the limiting element added by amendment.” Warner-Jenkinson, 520 U.S. at 33.


The district court should have proceeded under the
presumption that prosecution history estoppel applies.
Millipore then had the burden to rebut the presumption
through one of the three enumerated exceptions, but
Millipore chose not to present any argument on this issue
to the district court.
See Oral Arg. 24:06 - 24:20 ,
available at http://www.cafc.uscourts.gov/oral-argument-
recordings/14-1140/all (“Q:
You never argued in the alternative that
if in fact there was a conclusion by the trial court that the
amendment was narrowing or limiting, that you could
rebut the presumption that would arise under Festo?
A:That is correct, your honor . . . .”)



link: http://www.cafc.uscourts.gov/images/stories/opinions-orders/14-1140.Opinion.9-25-2014.1.PDF