An earlier prosecution disclaimer applies to a later application so long as the two have the same or closely related claim limitation language.  

Regents of the University of Minnesota v. ADA Medical Corp., No. 2012-1167 (Fed. Cir. June 3, 2013).

The patentee owned and asserted two patents, the ’281 patent and the ’291 patent, directed to medical devices that block holes in the muscle and tissue that divides the two chambers of the heart. The patents are divisions of an earlier filed ’951 application. Following claim construction, the district court ruled that the ’291 patent was not infringed and that the ’281 patent was invalid as anticipated. The patentee appealed, but the Federal Circuit affirmed.

First, the Federal Circuit held that the representative claim, as properly interpreted by the district court, required two occluding disks affixed to one another at their centers to form a conjoint disk. In finding that the accused device did not have this structure and did not infringe the claims of the ’291 patent, the Court noted that the prosecution history of the ‘951 application buttressed this result, because the patentee distinguished their conjoint disk from prior art disclosing two separate disks. 

Second, the Federal Circuit agreed that the asserted claim of the ’281 patent was anticipated by certain prior art devices. The patentee argued that it had disclaimed the use of the invalidating prior art devices as equivalents to the claimed structure during the prosecution of the ’951 application. The Court held that the patentee’s earlier disclaimer did not carry forward to the asserted claim of the ’281 patent. In making this determination, “the proper inquiry is whether the scope of the claim limitation is substantially the same in the subsequent application as it was in the earlier application.” (Op. at 25.) Here, the disclaimer did not carry forward because the asserted claim of the ’281 patent contains a different claim limitation than the claims of the ’951 application, and captures different subject matter. The Court stated that it would be inappropriate both to import the first application's limitations into the different context of the second application, as well as to apply a narrowing disclaimer to limitations that are materially different from the limitation to which it originally applied.

A copy of the opinion can be found here