PHARMA TECH SOLUTIONS, INC., DECISION IT CORP., Plaintiffs-Appellants
v.
LIFESCAN, INC., LIFESCAN SCOTLAND, LTD., JOHNSON AND JOHNSON, Defendants-Appellees
Appeal
from the United States District Court for the District of
Nevada in No. 2:16-cv-00564-RFB-PAL, Judge Richard F.
Boulware, II.
John
J. Shaeffer, Fox Rothschild LLP, Los Angeles, CA, argued for
plaintiffs-appellants. Also represented by Jeffrey H. Grant;
William A. Rudy, Denver, CO.
Eugene
M. Gelernter, Patterson Belknap Webb & Tyler LLP, New
York, NY, argued for defendants-appellees. Also represented
by Gregory Diskant; Charles Davison Hoffmann, Sean Reeves
Marshall, Hoffmann Marshall Strong LLP, New York, NY.
Before
Moore, Reyna, and Stoll, Circuit Judges.
Stoll,
Circuit Judge.
This is
an appeal from the district court's summary judgment of
noninfringement under the doctrine of equivalents. Because
prosecution history estoppel bars the claims for infringement
under the doctrine of equivalents, we affirm.
Background
I
Pharma
Tech Solutions, Inc. sued LifeScan, Inc. for infringement of
its U.S. Patent Nos. 6, 153, 069 and 6, 413, 411, which
concern blood glucose monitoring systems for home use by
individuals with diabetes. To test blood glucose, an
individual typically draws blood by pricking a finger,
placing the blood on the end of a test strip, and placing the
test strip into a meter. The test strip contains a pair of
electrodes, including a working electrode and a second
electrode. The working electrode is coated with an enzyme
that oxidizes glucose in the blood sample. Following an
incubation period, the meter (1) applies a known electric
potential across the electrodes, creating a diffusion
limiting electric current (referred to as the "Cottrell
current") through the sample; and (2) measures Cottrell
current. A proportional relationship exists between the
measured current and blood glucose concentration. Based on
this proportional relationship, a microprocessor in the meter
converts the measured electric current to a blood glucose
level and then reports the blood glucose level to the user.
The
shared specification of Pharma Tech's '069 and
'411 patents states that the claimed inventions improve
on these prior art blood glucose monitoring systems by
"eliminat[ing] several of the critical operator
depend[e]nt variables that adversely affect the accuracy and
reliability" of these systems. '069 patent col. 4 l.
66-col. 5 l. 3. The specification explains that the invention
accomplishes this objective by performing multiple Cottrell
current measurements and comparing the results. "In a
system that is operating correctly, the results should agree
within reasonable limits." Id. at col. 4 ll.
51-52. Results outside of a prescribed percentage of each
other, however, generally indicate a system error, and the
system will alert the user of a potential measurement error.
With
emphasis added to highlight the claim limitation at issue on
appeal, illustrative claim 1 of the '069 patent recites:
1. An apparatus for measuring compounds in a sample fluid,
comprising:
a) a housing having an access opening therethrough;
b) a sample cell receivable into said access opening of said
housing, said sample cell being composed of;
(i) a first electrode which acts as a working electrode;
(ii) a second electrode which acts to fix the system
potential and provide opposing current flow with respect to
said first electrode, said second electrode being made of the
same electrically conducting material as said first
electrode, and being operatively associated with said first
electrode, the ratio of the surface area of said second
electrode to the surface area of said first electrode being
1:1 or less;
(iii) at least one non-conducting layer member having an
opening therethrough, said at least one non-conducting layer
member being disposed in contact with at least one of said
first and second electrodes and being sealed against at least
one of said first and second electrodes to form a known
electrode area within said opening such that said opening
forms a well to receive the sample fluid and to allow a user
of said apparatus to place the sample fluid in said known
electrode area in contact with said first electrode and said
second electrode;
c) means for applying an electrical potential to both said
first electrode and said second electrode;
d) means for creating an electrical circuit between said
first electrode and said second electrode through the sample
fluid;
e) means for measuring a first Cottrell current reading
through the sample fluid at a first predetermined time after
the electrical potential is applied and for obtaining at
least one additional Cottrell current reading through the
sample fluid, the at least one additional Cottrell current
reading occurring at a second predetermined time following
the first predetermined time;
f) microprocessor means for converting the first Cottrell
current reading into a first analyte concentration
measurement using a calibration slope and an intercept
specific for the first Cottrell current measurement, for
converting the at least one additional Cottrell current
reading into an additional analyte concentration using a
calibration slope and an intercept specific for the at least
one additional Cottrell current measurement, and for
comparing the first analyte concentration measurement with
the at least one additional concentration measurement to
confirm that they are within a prescribed percentage of each
other; and
g) means for visually displaying the results of said analyte
concentration measurements.
Id. at col. 13 ll. 10-61.
II
The
product accused of infringing under the doctrine of
equivalents is LifeScan's OneTouch® Ultra®
system, a blood glucose meter for home use. When blood is
detected on a test strip inserted into LifeScan's meter,
the meter measures current from two working electrodes during
a five-second countdown period. LifeScan's meter obtains
final current measurements from the first and second working
electrodes at "5 seconds 40 milliseconds
(±25ms) after the ...