A 'Clear Disavowal' In A Patent Specification Is Not Required To Disclaim Claim Scope

In In re Abbott Diabetes Care Inc., Nos. 11-1516, -1517 (Fed. Cir. Sept. 28, 2012), the Federal Circuit vacated-in-part the Board's final rejection of numerous claims in the ex parte reexamination of U.S. Patent Nos. 6,175,752 ("the '752 patent") and 6,565,509 ("the '509 patent") due to the Board's unreasonably broad claim construction. The Court also vacated the Board's official notice rejections based on the PTO's concession that they should be withdrawn.

The '752 and '509 patents describe methods and devices for monitoring glucose levels in the blood stream for diabetics. Both claim inventions comprising, in addition to other features, an "electrochemical sensor." The '752 and '509 patents share a common specification, which disparages electrochemical sensors in the prior art because they employ external cables and wires that hinder the convenient use of these devices for everyday applications. The '509 patent claims also recite the additional limitation that the electrochemical sensor in the claims must be in a "substantially fixed" position.

During reexamination, the examiner finally rejected all of the claims under reexamination as indefinite, anticipated, or obvious over various references, and Abbott Diabetes Care, Inc. ("Abbott") appealed to the Board. In construing the "electrochemical sensor" claim element, the Board noted that the specification criticizes external cables and wires, and that none of the embodiments in the '752 and '509 patents include external cables or wires. But the Board determined that the absence of any explicit disclaimer meant that the broadest reasonable interpretation in light of the specification included the external cables and wires present in the prior art. The Board also determined that the "substantially fixed" limitation in the '509 patent would be understood to "allow some movement of the sensor." Slip op. at 7 (citation omitted). Applying these claim constructions, the Board found that the lead wires of the prior art are part of the electrochemical sensor and that the wires are "somewhat restrained in movement, and are therefore 'substantially fixed.'" Id. at 9 (citation omitted). Thus, the Board affirmed all of the examiner's rejections and rejected Abbott's arguments in its requests for rehearing.

"[T]his is not an instance where the specification would necessarily have to disavow an embodiment that would otherwise be covered by the plain language of the claims . . . . We have held that...