The doctrine of claim vitiation prevents  application  of the doctrine of equivalents in a way that would completely eliminate a claim element – i.e., renders the claim limitation inconsequential or ineffective. This doctrine has its roots in the all elements rule which is based on the requirement that  “[e]ach element contained in a patent claim is deemed material to defining the scope of the patented invention, . . . the doctrine of equivalents must be applied to individual elements of the claim, not to the invention as a whole.” Warner-Jenkinson Co. v. Hilton Davis Chem. Co., 520 U.S. 17, 29 (U.S. 1997). The doctrine of claim vitiation can be an important defense in patent infringement cases because it can preclude an argument for doctrine of equivalents infringement.  As stated in Warner- Jenkinson, “if a theory of equivalence would entirely vitiate a particular claim element, partial or complete judgment should be rendered by the court, as there would be no further material issue for the jury.” Id. at 39, fn.8.  

Since the Warner-Jenkinson case, the Federal Circuit has struggled with applying the doctrine of claim vitiation and appears to be diminishing the applicability of this doctrine. For example, in Deere & Co, the Federal Circuit held that “[v]itiation is not an exception to the doctrine of equivalents, but instead a legal determination that ‘the evidence is such that no reasonable jury could determine two elements to be equivalent. The proper inquiry for the court is to apply the doctrine of equivalents, asking whether an asserted equivalent represents an insubstantial difference from the claimed element or whether the substitute element matches the function, way, and result of the claimed element.’” Deere & Co. v. Bush Hog, LLC, 703 F.3d 1349, 1356 (Fed. Cir. 2012) (internal citations omitted).

In Brilliant Instruments, the Federal Circuit stated that “the vitiation test cannot be satisfied by simply noting that an element is missing from the claimed structure or process because the doctrine of equivalents, by definition, recognizes that an element is missing that must be supplied by the equivalent substitute.” Brilliant Instruments, Inc. v. GuideTech, LLC, 707 F.3d 1342, 1347 (Fed. Cir. 2013). The Federal Circuit instead held that “vitiation applies when one of skill in the art would understand that the literal and substitute limitations are not interchangeable, not insubstantially different, and when they do not perform substantially the same function in substantially the same way, to accomplish the same result.” Id. Recently, the Federal Circuit revisited the doctrine of claim vitiation in Akzo Nobel Coatings, Inc., v. Dow Chemical Company, 2016 WL 363443 (Fed. Cir. Jan. 29, 2016). The district court held that the use of a valve that did not allow for accumulation of a dispersion in downstream pipes was not equivalent to the claimed process of requiring the use of a pressurized collection vessel in which a dispersion accumulates to maintain backpressure in the extruder. Akzo Nobel Coatings, Inc., at *7-8. Akzo appealed to the Federal Circuit arguing that “the district court committed legal error by applying the concept of vitiation and impermissibly creating a binary choice in which an element is either present or not present.” Id. at *6. Akzo argued that the district court should have applied the doctrine of equivalents by determining “whether Dow’s equipment performed the same function in substantially the same way to reach the same result.” Id.

The Federal Circuit affirmed the district court’s ruling and reiterated that “[a] patentee must establish equivalency on a limitation-by-limitation basis by particularized testimony and linking argument as to the insubstantiality of the differences between the claimed invention and the accused device or process . . . . All claim limitations are not entitled to an equal scope of equivalents . . . . Ultimately, many limitations warrant little, if any, range of equivalents.” Id. at *6. The Federal Circuit held that “in order to survive summary judgment, Akzo had to show that a valve and a series of pipes and heat exchangers, wherein the dispersion flows continuously, generate backpressure in the extruder in substantially the same way to increase the boiling point of the carrier fluid.” Id. at *7. Accordingly, without showing how Dow’s valves, pipes and heat exchangers operate in substantially the same way as the “pressurized collection vessel”, the claim limitation would be rendered “inconsequential or ineffective.” Id. at 7. The Court went on to state that differences shown by “ambiguity and generality cannot create a genuine issue of material fact.” Id. at *7.

This recent decision appears to revive the doctrine of vitiation. This is very important to both patentees and accused patent infringers.  Patentees cannot rely on blanket legal assertions that vitiation is not a viable doctrine and will need to provide particularize testimony as to the equivalence of each element.  Accused infringers, on the other hand, should hold patentees to meeting their burden of proof of showing that missing elements are met through the doctrine of equivalents.