Maquet Cardiovascular LLC v. Abiomed Inc. et al. (D. Mass 17-cv-12311).

In this patent lawsuit involving assertions of clams to intravascular blood pumps, Abiomed raised the reverse doctrine of equivalents as a defense, and Maquet moved for summary judgment on the issue.

The reverse doctrine of equivalents is a judicially-created doctrine that applies, at least in theory, where an accused product includes every element of a claim, literally construed, but operates in such a different way from the claimed invention as to be deemed outside the scope of infringement.  It was first recognized by the Supreme Court in 1898, and was again favorably referred to in dicta in the Court’s 1950 Graver Tank decision.

Maquet nevertheless asserted that the doctrine was no longer a viable defense as a result of the Federal Circuit’s Steuben Foods decision of 2025.  Judge Saylor (somewhat reluctantly) disagreed.  He noted that the Federal Circuit had twice in recent years affirmed that it had never affirmed a noninfringement finding based on the doctrine, but the Federal Circuit still had addressed it as viable on many occasions.  Further, while the appellant in Steuben Foods argued that the passage of the 1952 Patent Act had effectively eliminated the defense (and the Federal Circuit indicated that the argument to that effect was “compelling,” the case was decided on other grounds.  Accordingly, Judge Saylor deemed the doctrine to remain viable.  He deemed the application of the doctrine to be a legal, rather than equitable, defense, and determined that there was no evidentiary record sufficient to support a grant of summary judgment on the issue, and determined that the matter would be deferred until trial.