In discussing the recent ICU Medical case, I noted that Judge Moore's decision did not rely on the "essential element" test or even cite Gentry Gallery. In Gentry Gallery, the patent covered a sectional recliner. During prosecution, the patentee had amended its claims to drop any reference to the location of the recliner controls. The Federal Circuit held those later-drafted claims invalid because the location of the controls was an "essential element" of the invention that must be included in the claims – otherwise, the claim scope would be unduly broad. Following Gentry Gallery, however, the Federal Circuit stepped-back from the essential element language– instead narrowing the case holding to the well trod notion that claims should be limited to the supporting disclosure. In both Johnson Worldwide, and Cooper Cameron, for instance, the Federal Circuit explicitly denied that Gentry Gallery created any new requirement.
"[W]e did not announce a new 'essential element' test mandating an inquiry into what an inventor considers to be essential to his invention and requiring that the claims incorporate those elements." Cooper Cameron, 291 F.3d 1317 (Fed. Cir. 2002)
In parallel fashion to Gentry Gallery, ICU had included a "spike" in every embodiment and each original claim. During prosecution, and apparently after seeing competing products, ICU amended its claims to drop the "spike" limitation. This was important because the market had moved to a spikeless version of IV valves. This district court in ICU discussed Gentry Gallery and the essential element test, but found no need to base its ruling on that "disfavored" theory. Rather, the court based its analysis on the traditional notion that claims must be described in the specification.
"[T]he Court's analysis employs the accepted rule that the claims may be no broader than the supporting disclosure, or, conversely, that claims are invalid when the entirety of the specification clearly indicates that the invention is of a much narrower scope. By focusing on the language of the Common Specification in a manner that highlights the function of the "spike" element, and the frequency and ubiquity with which it is referenced, the Court is only attempting to discern the breadth and substance of the invention ICU actually disclosed in the original 1992 Application."
Although the district court denied its application of any "essential element" test, it went on to hold that any valid claims must include a spike:
"The pervasiveness of the "spike" element in the invention description clearly informs the Court, and would inform any reasonable juror, that what was disclosed and claimed as the invention in the 1992 Application was a needleless medical valve with at a minimum, a "body," a "seal" and a "spike.""
Likewise, the Federal Circuit's version denies an omitted element test, but held that any valid claim must include a spike limitation because "a person of skill in the art would not understand the inventor ... to have invented a spikeless medical valve."
Notes:
- ICU Medical Part I
- ICU Medical Part II
- ICU Medical Part III
- The essential element and omitted element test are largely interchangeable, although some logical distinction could perhaps be made.



