Be careful what you wish for: broad claims found invalid

March 22, 2007
Post by Blog Staff

In another case making a return trip to the Federal Circuit, the court held that under its broad claim construction decided in the first appeal, the asserted claims were invalid in two patents as not enabled and in two more as anticipated. In order to secure a finding of infringement, the patentee, Liebel-Flarsheim, argued for the broader claim construction in the first appeal, only to be unable to sustain the broadly-construed claims' validity on summary judgment at the district court and on the second appeal. As stated by the Federal Circuit:

The irony of this situation is that Liebel successfully pressed to have its claims include a jacketless system, but, having won that battle, it then had to show that such a claim was fully enabled, a challenge it could not meet. The motto, "beware of what one asks for," might be applicable here.
More details of the case after the jump.There were four patents at issue. Two of the patents (the '669 and '261 patents) related to front-loading fluid injectors with replaceable syringes capable of withstanding high pressures for delivering a contrast agent to a patient (the "front-loading patents"). The other two patents (the '612 and '197 patents) related to computer-controlled injectors where a motor advances and retracts a plunger located in a syringe (the "syringe-sensing patents").

The front-loading patents

The defendant, Medrad, produced a fluid injector that could withstand high pressures without the need for a pressure jacket. On the first appeal, Liebel successfully argued that its claims were not limited to embodiments having a pressure jacket, as that limitation had been amended out of the claims in a continuation application in order to cover Medrad's product. The problem Liebel ran into is that there was insufficient disclosure in its original application to enable one of ordinary skill in the art to make an injector without a pressure jacket. In order to satisfy the enablement requirement of 35 U.S.C. § 112, the patent must enable one of ordinary skill in the art to make and use the full breadth of the claimed invention without undue experimentation. Here, the inventors admitted that they tried, without success, to make a jacketless system, and that making such a system would have required more experimentation and testing. This evidence, combined with similar testimony from Medrad's engineers, sealed Liebel's fate on these patents, and the asserted claims were held invalid under § 112.

The syringe-sensing patents

With these patents too, Liebel was a victim of a broad claim construction. In this case, the operative limitation was "physical indicia on said syringe related to the capacity of said syringe." In the first appeal, the Federal Circuit held that the physical indicia relationship was not limited to just the length of the syringe, but also could include other indicia relating to the capacity of the syringe, such as the amount fluid in the syringe or the distance of the plunger from the end of the syringe. Liebel's problem is that a prior art patent (owned by Medrad no less) disclosed every element of the asserted claims when construed this broadly. Medrad's prior patent disclosed using physical indicia to encode, inter alia, the dimensions of the syringe. Because the capacity of the syringe can be computed from a formula when the dimensions are known, the court held that this disclosed the critical limitation in the asserted claims of Liebel's patents, and they were thus invalid as anticipated under § 102. As stated by the Federal Circuit, Liebel's successes on the first appeal turned out to be Pyrrhic victories. To read the full decision in Liebel-Flarsheim Co. v. Medrad, Inc., click here.

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