California Patent Attorney® Blog

Federal Circuit Breathes New Life Into Abbott Glucose Monitor Patents

September 29, 2012

glucose.jpgCalifornia - The Federal Circuit on Friday resurrected two Abbott Diabetes Care Inc. patents for a diabetes-related glucose monitoring system, ruling that the U.S. Patent and Trademark Office's rejection of the patents was based on unreasonable claim constructions.

Abbott had appealed from ex parte reexamination proceedings in which the Board of Patent Appeals and Interferences rejected numerous claims of U.S. Patent Numbers 6,175,752 and 6,565,509.

"The board's construction of 'electrochemical sensor' and its modified construction of 'substantially fixed' are unreasonable and inconsistent with the specification," the Federal Circuit ruled.

The appeals court vacated the board's decisions as to the patentability of Abbott's independent claims at issue and remanded the case for the board to apply the correct claim constructions.

Both the '752 patent and the '509 patent share a common specification that describes methods and devices "for the in vivo monitoring of an analyte using an electrochemical sensor to provide information to a patient about the level of the analyte" in the bloodstream. In particular, the patent specification describes methods and devices for monitoring glucose levels for diabetics.

The specification describes the claimed "electrochemical sensor" at issue as "a device configured to detect the presence and/or measure the level of an analyte in a sample via electrochemical oxidation and reduction reactions on the sensor."
The PTO granted third-party requests for ex parte reexamination of Abbott's patents in March 2006, in relation to consolidated infringement litigation involving Abbott and DexCom Inc., which remains pending.

During reexamination, the examiner finally rejected all of the claims subject to the reexamination as being indefinite, anticipated, or obvious over several combinations of prior art references.

In reviewing the examiner's rejections, the board first had to determine the correct construction of "electrochemical sensor," namely, whether "the transcutaneous electrochemical sensor recited in the claims includes wires and cables," according to the Federal Circuit. The board ultimately concluded that the sensor did have to include wires and cables.

The board also construed the proper construction of the term "substantially fixed" to allow some movement of the sensor relative to the position of the sensor control unit.
Relying on those claim constructions, the board ruled that Abbott's claimed invention was not patentable. Abbott filed requests for rehearing, which the board denied, and from there appealed to the Federal Circuit.