Mutually Agreed Claim Construction Terminates Case Years Later

Following a reversal by the Federal Circuit, Judge Gorton denied an attempt to revise claim constructions agreed upon by the parties in a dispute over blood separating centrifuges.  The defendant then moved for summary judgment of non-infringement.  Judge Gorton agreed that the devices were non-infringing and entered judgment, declining to reach the issue of whether the asserted claims were indefinite.  The case turned, as it always does, on claim construction: 

Originally the patentee had identified a “plurality of tubes” in the accused device.  On remand, the patentee conceded that the originally identified tubes were not infringing but that another “plurality of tubes” did infringe.  Earlier in the case, however, both parties had agreed that a “plurality of tubes” meant “two or more conduits that transport liquid materials (e.g. blood and blood components) into and out of the vessel.”  The court ruled that because the newly identified set of tubes was entirely within the vessel, that it could not meet the agreed upon definition. 

I doubt the patentee had any idea that agreeing to a construction on a relatively undisputed term (at the time anyway) would end up being dispositive.  If the agreed upon definition had omitted the language “into and out of the vessel”, perhaps the case would have ended differently.  Practice point:  avoid extraneous language in your claim construction. 

Haemonetics Corp. v. Fenwal, Inc., 05-12572-NMG, 09-12107-NMG (D. Mass. Sep. 13, 2011)

05-12572-NMG 09-12107-NMG