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A “Clear Disavowal” in a Patent Specification Is Not Required to Disclaim Claim Scope

September 28, 2012
DeRoo, Pier D.

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Last Month at the Federal Circuit - October 2012

Judges: Lourie, Prost (author), Wallach

[Appealed from: Board]

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 The Court also vacated the Board’s official notice rejections based on the PTO’s concession that they should be withdrawn.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.

On appeal, the Federal Circuit held that the Board’s claim constructions were unreasonable in light of the specifications of the ’752 and ’509 patents. The PTO argued that, while the specification disparages external cables or wires, Abbott was still required to make a “clear disavowal” or “express disclaimer” of external cables and wires in order to disclaim those features. Id. at 11-12. But the Court recognized that “the specification contains only disparaging remarks with respect to the external cables and wires of the prior-art sensors,” and that none of the disclosed embodiments contain external cables or wires. Id. at 13. Furthermore, other limitations in the claims (e.g., “coupled” and “receiving”) were consistent with electrochemical sensors having no external cables or wires. Id. at 14. Thus, the Court stated that “this 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,” distinguishing from Federal Circuit case law requiring an explicit disclaimer. Id. Concluding that the Board’s claim construction went beyond the broadest reasonable interpretation in light of the ’752 and ’509 patents’ specifications, the Court vacated and remanded to the Board to apply the correct claim construction of an electrochemical sensor devoid of external connection cables or wires.

Regarding the “substantially fixed” limitation in the ’509 patent claims, the parties disputed whether “some movement” of the Board’s original construction includes the “somewhat restrained” movement of the prior art. The Court concluded that the Board’s modified construction requiring only a “somewhat restrained” sensor resulted in a degree of movement significantly greater than that described in the specification, and was therefore unreasonable. Thus, the Court remanded to the Board with instructions to apply the original claim construction.

Finally, the Court addressed the Board’s rejection of certain claims based on the examiner’s invoking of the doctrine of official notice in combination with other primary references. Because the PTO agreed that the rejection should be remanded and withdrawn, the Court vacated the rejection and remanded to the Board.

Summary authored by Pier D. DeRoo, Esq.