Opinion ID: 2641098
Heading Depth: 3
Heading Rank: 1

Heading: A method of measuring the concentration of a

Text: substance in a sample liquid comprising the steps of: providing a measuring device[,] said device com- prising: a first working sensor part for generating charge carriers in proportion to the concentration of said substance in the sample liquid; a second working sensor part downstream from said first working sensor part also for generating charge carriers in pro- portion to the concentration of said substance in the sample liquid wherein said first and second working sensor parts are arranged such that, in the absence of an error condition, the quantity of said charge carriers gener- ated by said first working sensor[] part [is] substantially identical to the quan- tity of said charge carriers generated by said second working sensor part; and a reference sensor part upstream from said first and second working sensor parts which reference sensor part is a common reference for both the first and second working sensor parts, said ref- erence sensor part and said first and second working sensor parts being ar- ranged such that the sample liquid is constrained to flow substantially unidi- rectionally across said reference sensor LIFESCAN SCOTLAND, LTD. v. SHASTA TECHNOLOGIES, LLC 5 part and said first and second working sensor parts; wherein said first and second working sensor parts and said reference sensor part are provided on a disposable test strip; applying the sample liquid to said measuring de- vice; measuring an electric current at each working sensor part proportional to the concentration of said substance in the sample liquid; comparing the electric current from each of the working sensor parts to establish a difference parameter; and giving an indication of an error if said difference parameter is greater than a predetermined threshold. ’105 patent col. 6 l. 52 to col 8 l. 4. In LifeScan’s OneTouch Ultra system, the “sensor parts” refer to the electrodes located on the strips. The “measuring an electric current . . . ,” “comparing the electric current . . . ,” and “giving an indication of an error . . .” steps are performed by the meter. LifeScan sells 40% of its meters at below cost prices. It distributes the remaining 60% of its OneTouch meters through health care providers, who in turn give the meters to diabetic individuals for free. LifeScan distributes its meters in this way “in the expectation and intent that customers will use its OneTouch Ultra meters with [its] OneTouch Ultra test strips, from which [it] derive[s] a profit.” JA 319. Shasta does not sell blood glucose meters, but competes with LifeScan in the market for test strips. Shasta’s “GenStrip” test strips are designed to work with LifeScan’s meters. 6 LIFESCAN SCOTLAND, LTD. v. SHASTA TECHNOLOGIES, LLC