Claims Broadened Beyond Specification Are Invalid

In Liebel-Flarsheim Co. v. Medrad, Inc. (No. 06-1156; March 22, 2007), a Federal Circuit panel affirms a district court’s summary judgment of invalidity of Liebel’s “front-loading” patents for lack of enablement and its “syringe-sensing” patents on grounds of anticipation by the prior art.

The claims of the originally-filed application for the front-loading patents explicitly recited a pressure jacket in front of a syringe receiving opening, but all references in the claims to a pressure jacket were removed during prosecution. The specification of the front-loading patents is viewed as not having described an injector with a disposable syringe without a pressure jacket and as even teaching away from such an injector as being “impractical.” Additionally, the inventors admitted that they tried unsuccessfully to produce a system without a pressure jacket and decided not to pursue such a system because it was “too risky.” Thus, the claims of the front-loading patents are deemed invalid for not fulfilling the enablement requirement of 35 U.S.C. § 112, first paragraph.

The district court also decided that Medrad’s earlier U.S. patent (“the ‘858 patent”) anticipated Liebel’s syringe-sensing patents. The ‘858 patent discloses an injector controller, but does not discuss the details of how the controller interacts with the motor and plunger. But due to the incorporation by reference in the ‘858 patent of another U.S. patent that discusses the interaction of a control circuit and a plunger, the ‘858 patent is found to disclose the control circuit that computes the location of a plunger, as claimed in the syringe-sensing patents, leading the Federal Circuit panel to conclude that the claims of the syringe-sensing patents are invalid over the ‘858 patent.