The Danger Of Double Patenting

In St. Jude Medical, Inc. v. Access Closure, Inc., the Federal Circuit found that one of St. Jude's patents was invalid under the doctrine of obviousness-type double patenting. This case highlights the potential difficulty of maintaining consonance with an original restriction requirement in a multi-generational patent family.

The Patent At Issue

Although there were three St. Jude patents at issue in the case before the Federal Circuit, only one was caught up in the double patenting issue, U.S. Patent 7,008,439 (the Janzen patent).

The Janzen patent stems from a grandparent application that was subject to a restriction requirement that restricted the claims along the following lines:

Group I. Claims . . . drawn to a device for use in sealing a puncture in a wall of a blood vessel.

Group II. Claims . . . drawn to a method of sealing a puncture in a wall of a blood vessel.

Species A: Claims relating to the apparatus comprising a solid tissue dilator.

Species B: Claims relating to the apparatus comprising a hollow dilator and guidewire.

Species C: Claims relating to the apparatus comprising a guidewire and no dilator.

Group I, Species B, was elected in the grandparent application, which issued as U.S. Patent 5,391,183.

The parent application was filed as a "divisional" application, and was subject to a similar restriction requirement. The Applicant again elected Group I, Species B. The parent application issued as U.S. Patent 5,830,130.

The Janzen application was filed as a "continuation" application of the parent application. The Applicant canceled the original claims and "copied both device and method claims from a different patent to provoke an interference proceeding." As summarized by the Federal Circuit, "[t]he Janzen application ultimately prevailed in the interference, and issued with both device and method claims."

The Applicant filed another continuation of the parent application, which issued before the Janzen patent as U.S. Patent 5,725,498 with method claims.

The District Court Proceedings

St. Jude asserted its patents against ACI. The district court construed the claims, and issues of validity and infringement were tried to a jury. As summarized by the Federal Circuit,

The jury rendered a verdict that ACI had infringed claims 7 and 8 of the Janzen patent, but that claims 7, 8, and 9 of the Janzen patent were invalid for double patenting in light of the sibling '498 patent. Implicit in the jury's double patenting finding was the...