Pharmatech Solutions, Inc.v.LifeScan Scotland Ltd.

Patent Trial and Appeal Board

Aug 6, 2014

10431140 (P.T.A.B. Aug. 6, 2014)

Trials@uspto.gov Paper 27
Tel: 571-272-7822 Entered: August 6, 2014

UNITED STATES PATENT AND TRADEMARK OFFICE
_______________
BEFORE THE PATENT TRIAL AND APPEAL BOARD
_______________
PHARMATECH SOLUTIONS, INC.,
Petitioner,

v.

LIFESCAN SCOTLAND LTD.,
Patent Owner.
_______________

Case IPR2013-00247
Patent 7,250,105 B1
_______________

Before SALLY C. MEDLEY, SCOTT E. KAMHOLZ, and
SHERIDAN K. SNEDDEN, Administrative Patent Judges.

KAMHOLZ, Administrative Patent Judge.

FINAL WRITTEN DECISION
35 U.S.C. § 318(a) and 37 C.F.R. § 42.73(b)

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I. INTRODUCTION
A. Background
Pharmatech Solutions, Inc. (“Pharmatech”) filed a Petition (Paper 1,
“Pet.”) to institute an inter partes review of claims 1-3 (the “challenged
claims”) of U.S. Patent No. 7,250,105 B1 (Ex. 1002, “the ’105 patent”). We
instituted trial for the challenged claims on the following grounds of
unpatentability asserted by Pharmatech:
References
1
Basis Claims challenged
Nankai and Schulman § 103 1-3
Winarta and Schulman § 103 1-3
Decision to Institute 19 (Paper 11, “Dec.”).
After institution of trial, LifeScan Scotland Ltd. (“LifeScan”) filed a
Patent Owner Response (Paper 16, “Resp.”). Pharmatech filed a Reply
(Paper 17, “Reply”). LifeScan did not file a motion to amend claims.
Pharmatech relies upon a declaration of Joseph Wang, D.Sc.
(Ex. 1024) in support of its Petition. LifeScan relies upon a declaration of
John L. Smith, Ph.D. (Ex. 2008) in support of its Response.
Oral argument was conducted on May 14, 2014. A transcript is
entered as Paper 26 (“Tr.”).
We have jurisdiction under 35 U.S.C. § 6(c). This final written
decision is issued pursuant to 35 U.S.C. § 318(a) and 37 C.F.R. § 42.73.

1
The references are: U.S. Patent No. 5,120,420 (Ex. 1003, “Nankai”), U.S.
Patent No. 5,791,344 (Ex. 1007, “Schulman”), and U.S. Patent No.
6,258,229 (Ex. 1005, “Winarta”).
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Pharmatech has proved that claims 1-3 are unpatentable.
B. The ’105 Patent
The ’105 patent relates to monitoring the level of a substance in a
liquid, particularly the level of glucose in blood. Ex. 1002, 1:7-10. A
glucose assay is performed by inserting a test strip into a meter and then
applying a drop of blood to the test strip. Id. at 5:14-25. The test strip is
made from layers of various materials, built up on a plastic base and capped
with a cover. Id. at 4:35-5:14. Figure 2 is reproduced below:

Figure 2 illustrates one layer of the test strip, in which a pattern of carbon
ink is screen-printed onto the test strip base. Id. at 4:23-24. The carbon ink
forms three tracks 4, 6 (not labeled), and 8 (not labeled), along the strip, as
well as a connecting bridge 10. Id. at 4:44-51. Each track has a connecting
terminal 4a, 6a, 8a at one end of the strip and an electrode 4b, 6b, 8b at the
other, distal, end. Id. A layer of glucose oxidase (“GOx”) is printed on the
electrodes. Id. at 4:65-66. Various other layers are deposited to define the
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rest of the structure, such as the precise sizes of the electrodes and a flow
path for the blood. Id. at 4:54–5:14.
A user begins a glucose measurement by inserting the terminal end of
the test strip into a meter device; the connecting bridge completes a circuit
upon insertion to turn on the device. Id. at 5:16-18. The device applies a
voltage between the reference terminal 4a and terminal 6a, and also between
the reference terminal 4a and terminal 8a. Id. at 5:19-22. A drop of blood is
deposited at the distal end of the strip, and the blood is drawn by capillary
action over electrode 4b for the reference sensor part and electrodes 6b and
8b for the working sensor parts. Id. at 5:23-26. The blood thereby comes
into contact with the GOx printed on the electrodes, and the GOx reacts with
glucose in the blood to release electrons.
The resulting electric currents through carbon tracks 4 and 6 are
proportional to both the surface area of the electrode covered by GOx and
the amount of glucose in the blood sample. Id. at 1:27-38. Because the
GOx surface area is known, the electric current is indicative directly of the
amount of glucose in the blood. Id. The currents are measured by the meter
device after a predetermined time. Id. at 5:26-27. The current
measurements are compared to one another, and if they differ by more than
10%, an error message is displayed so that the user will know to repeat the
test. Id. at 5:27-30. If they are within 10% of each other, the measured
currents are summed and converted into a glucose level, which is then
displayed. Id. at 5:30-33. Regarding arrangement of the sensor parts, the
’105 patent discloses that it is “preferred that both working sensor parts are
downstream of the reference sensor part.” Id. at 3:56-58.
The challenged claims are reproduced below:
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1. A method of measuring the concentration of
a substance in a sample liquid comprising the steps
of:
providing a measuring device said device
comprising:
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
proportion 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 generated
by said first working sensors part are
substantially identical to the quantity 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 reference
sensor part and said first and second
working sensor parts being arranged such
that the sample liquid is constrained to
flow substantially unidirectionally across
said reference sensor 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;
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applying the sample liquid to said measuring
device;
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.

2. The method as claimed in claim 1
comprising measuring the current at each working
sensor part after a predetermined time following
application of the sample.

3. The method as claimed in claim 1 wherein
the substance to be measured is glucose, and each
of the working sensor parts generates charge
carriers in proportion to the concentration of
glucose in the sample liquid.

II. DISCUSSION
A. Claim Construction
In an inter partes review, claim terms in an unexpired patent are
interpreted according to their broadest reasonable construction in light of the
specification of the patent in which they appear. 37 C.F.R. § 42.100(b);
Office Patent Trial Practice Guide, 77 Fed. Reg. 48756, 48766 (Aug. 14,
2012). Also, claim terms are given their ordinary and customary meaning,
as would be understood by one of ordinary skill in the art in the context of
the entire disclosure. In re Translogic Tech., Inc., 504 F.3d 1249, 1257
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(Fed. Cir. 2007). Any special definition for a claim term must be set forth in
the specification with reasonable clarity, deliberateness, and precision. In re
Paulsen, 30 F.3d 1475, 1480 (Fed. Cir. 1994).
We construed several claim terms as follows:
1. “Proportion” and “proportional to” as “correlated to” (Dec. 8);
2. “Downstream” as “further along a stream from its source” (id. at
8-9); and
3. “Substantially unidirectionally” as “along, or nearly along, one
direction” (id. at 9).
The parties do not contest these constructions (Tr. 4:9-12, 16:1-21),
and we maintain them.
B. Obviousness over Nankai and Schulman
Pharmatech argues that claims 1-3 are unpatentable under
35 U.S.C. § 103(a) over Nankai in combination with Schulman. Pet. 16-21.
LifeScan responds, both arguing that Pharmatech has not demonstrated the
obviousness of the claims (Resp. 17-21, 26-43), and presenting objective
evidence of nonobviousness. Resp. 45-49.
We undertake the four factual inquiries of an obviousness analysis:
determining the scope and content of the prior art; ascertaining the
differences between the prior art and the claims at issue; resolving the level
of ordinary skill in the pertinent art; and assessing objective evidence of
nonobviousness. Graham v. John Deere Co., 383 U.S. 1, 17-18 (1966).
1. The level of skill in the pertinent art
“The person of ordinary skill in the art is a hypothetical person who is
presumed to know the relevant prior art.” In re GPAC Inc., 57 F.3d 1573,
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1579 (Fed. Cir. 1995). This person is of ordinary creativity, not merely an
automaton, and is capable of combining teachings of the prior art. KSR Int’l
Co. v. Teleflex Inc., 550 U.S. 398, 420-21 (2007).
LifeScan argues that one of ordinary skill in the relevant art is a
person having a Bachelor’s degree in chemistry or electrical engineering, or
an equivalent degree in a related field, such as physics or chemical
engineering, and also having five years of experience working in the field of
electrochemical glucose sensors. Resp. 13-14 (citing Ex. 2008 ¶ 13).
Pharmatech does not dispute this proposed definition. The definition is
reasonable, and we adopt it for purposes of this decision.
2. Scope and content of the prior art
a. Overview of Nankai
Nankai describes disposable biosensors for measuring, e.g., glucose
concentration in blood. Ex. 1003, 3:65-68. Figure 12 of Nankai is
reproduced below:

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Figure 12 shows a glucose sensor having base plate 1 on which is
formed lead 3 and corresponding counter electrode 5, and leads 21, 22, and
23, and corresponding measurement electrodes 41, 42, and 43. Id. at 8:5-10.
Spacer 7 overlies the base plate, and space 8 cut out from the spacer
provides a conduit for a blood sample to flow from introducing port 10 to
the measurement and counter electrodes. Id. at Abstr., 8:15-18. Cover 9
provides discharge ports 11, 12, and 13, through which air leaves space 8 as
it is displaced by the flowing blood. The measurement electrodes are coated
with GOx. Id. at 5:1, 8:11-14. During use, blood enters through the
introducing port and flows along the main conduit of space 8, with portions
of the sample entering successive branches along the main conduit. Id. at
8:25-27. A current measurement is made at each sensor, and the
measurements are averaged to give a final result. Id. at 8:42-46. The shape
or arrangement of sensors may vary. Id. at 8:50-52.
b. Overview of Schulman
Schulman describes an implantable sensor used to monitor blood
glucose continuously by GOx-mediated current measurements. Ex. 1007,
3:17-28, 4:20-30, 7:35-37. Two or more sensors may be used to confirm the
correctness of the measurement. Id. at 4:46-50. The readings from two
sensors are compared, and if they are not within 10% of one another, the
system requests sensor recalibration (id. at 11:16-22, 20:50-54), and issues
an error message advising the user to check the sensors. Id. at 21:9-13.
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3. Differences between the claimed subject matter and the
prior art
a. Petitioner’s Case-in-Chief
Pharmatech argues that Nankai discloses all limitations of claim 1
except (a) the position of the reference sensor part “upstream” of the first
and second working sensor parts; (b) the step of comparing the electric
current from each of the working sensor parts to establish a difference
parameter; and (c) the step of giving an indication of an error if the
difference parameter is greater than a predetermined threshold. Pet. 16-21.
With regard to limitation (a), Pharmatech points to Nankai’s teaching
that the arrangement of the sensors may vary. Id. at 16 (citing Ex. 1003,
8:47-52). Pharmatech argues that the ’105 patent discloses that the sensors
may be arranged “as convenient” and does not identify any benefit or
unexpected result from the claimed arrangement. Id. (citing Ex. 1002,
3:36-58). Pharmatech cites evidence, from the testimony of Dr. Wang, that
a person of ordinary skill in the art would have known that there was a finite
number of ways to arrange a reference sensor part in relation to a working
sensor part and that repositioning the reference sensor part upstream from
the working sensor parts, as opposed to downstream from the working
sensor parts, would have been obvious to try. Id. at 16, 19 (citing
Ex. 1024 ¶ 25).
With regard to limitation (b), Pharmatech argues that Schulman
discloses taking multiple measurements in order to identify errors and that
modifying Nankai to include this step would have been nothing more than
the application of a known technique to improve a similar device with
predictable results. Id. at 16-17, 21; Ex. 1024 ¶¶ 27-28. With regard to
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limitation (c), Pharmatech argues that Schulman discloses giving an error
indication if the difference parameter exceeds a predetermined threshold.
Pet. 17 (citing Ex. 1007, 3:17-28; Ex. 1024 ¶¶ 27-28); see also Reply 3
(citing Ex. 1007, 21:32-36 (disclosing generating a signal only if sensor
signals are within a prescribed amount of one another); id. at 22:20-23
(disclosing generating an error message if they are not within the prescribed
amount)).
b. Patent Owner’s Response
LifeScan presents several arguments in response to Pharmatech’s
challenge. We address them in turn.
(1) Position of Nankai’s reference sensor part
relative to working sensor parts
LifeScan argues that Nankai’s test strip provides a reference sensor
part downstream of the working sensor parts, rather than upstream as
claimed. Resp. 17. This is not in dispute. See Pet. 11:2-3; see also section
II.B.2.a, supra (Nankai Fig. 12 showing that reference electrode 5 is
downstream of working electrodes 41, 42, 43).
(2) Criticality of positioning reference sensor part
upstream
LifeScan argues that it would not have been obvious to reposition
Nankai’s reference sensor part to be upstream of the working sensor parts,
because there is criticality in positioning the reference sensor part upstream.
Resp. 17-18 (citing Ex. 2008 ¶ 43); Resp. 37 (citing Ex. 2008 ¶ 77).
LifeScan argues that positioning the reference sensor part downstream of the
working sensor parts, as Nankai does, would result in the reference sensor
part being covered incompletely in the event an insufficient blood sample is
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applied. Id. If the reference sensor part is covered incompletely, it will give
an unreliable baseline potential, which would then cause measurements
relative to the working sensor parts to be erroneous. Id. at 18. Nankai then
would average those erroneous readings and not detect the error. Id. In
contrast, if an inadequate sample is applied to a device in which the
reference electrode is upstream, it will be instead one of the working
electrodes that is covered incompletely. Ex. 2008 ¶ 38. That electrode will
give a reading that differs significantly from the other working electrode. Id.
If that difference exceeds the threshold, the error will be detected and an
inaccurate measurement avoided. Id. LifeScan argues that Pharmatech’s
expert, Dr. Wang, does not address this criticality in his testimony. Id. at 50.
The criticality of a claimed feature may be demonstrated by showing
that the specific feature claimed achieves unexpected results compared to the
generic prior art. In re Woodruff, 919 F.2d 1575, 1578 (Fed. Cir. 1990)
(addressing criticality of a claimed range within a broader prior-art range).
Without such a showing, the advantage is no more than a new benefit of an
old method, and cannot, by itself, render the method again patentable. Id.
LifeScan’s argument is unpersuasive, because it does not explain how
the advantage it identifies is an unexpected consequence of how the
reference sensor part and the working sensor parts are positioned relative to
one another. Whichever sensor part is furthest downstream is the one most
likely to be covered incompletely when a sample of inadequate volume is
applied. See Ex. 2008 ¶¶ 38, 43. LifeScan does not offer any credible
evidence to suggest that it is unexpected that a downstream working sensor
part, covered incompletely by the dregs of an inadequate sample, will report
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a current measurement with a detectible discrepancy from the other, fully
covered working sensor part.
(3) Disclosure in Nankai of multiple measurements
LifeScan argues that Nankai simply averages its multiple
measurements, instead of comparing them to a difference parameter.
Resp. 18-19 (citing Ex. 2008 ¶ 44); Resp. 37. LifeScan argues that Nankai’s
blind averaging would give inaccurate results if one of more of Nankai’s
working sensor parts were not completely filled with sample. Id. at 19.
This argument is unpersuasive, because Pharmatech relies on
Schulman, not Nankai, for disclosing the comparison of multiple
measurements to a difference parameter. See Pet. 16-17, 21. Pharmatech
argues that it would have been obvious to apply this comparison technique
to measurements made using Nankai’s test strip. Id. How Nankai itself
performs the comparison is irrelevant.
(4) Adequate sample size
LifeScan argues that Nankai fails to address the detection of an
inadequately sized sample. Resp. 20-21 (citing Ex. 2008 ¶¶ 46-48).
LifeScan argues that the ’105 patent is directed to avoiding the incomplete
coverage problem by minimizing sample size. Id. at 21 (citing Ex. 1002,
2:51-55). According to LifeScan, Nankai gives no consideration to this
problem because it uses sample sizes so much larger than those disclosed in
the ’105 patent (five microliters or more, compared to two microliters or
less), that samples were guaranteed to cover all the electrodes fully. Id. at
20-21. LifeScan acknowledges that the challenged claims do not place any
limitations on the sample size, but argues that Nankai’s failure to appreciate
the problem of inadequate sample size is evidence that one of ordinary skill
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in the art, attempting to solve the problem the ’105 patent’s inventors
confronted, would not have considered Nankai. Id. at 21 (citing Ex. 2008
¶ 48).
This argument is unpersuasive because, as LifeScan acknowledges,
the claims do not limit the sample size, and LifeScan does not identify any
other limitation in the claims to which the sample-size argument relates.
Consequently, the claims encompass subject matter that this argument does
not reach. See In re Lintner, 458 F.2d 1013, 1015 (CCPA 1972) (“Claims
which are broad enough to read on obvious subject matter are unpatentable
even though they also read on nonobvious subject matter.”); In re
Muchmore, 433 F.2d 824, 826 (CCPA 1970) (affirming obviousness
rejection where claim “reads on both obvious and unobvious subject
matter.”).
This argument also is not persuasive because, when considering the
rationale for combining references, “the problem examined is not the
specific problem solved by the invention but the general problem that
confronted the inventor before the invention was made.” In re Kahn, 441
F.3d 977, 988 (Fed. Cir. 2006). The rationale for combining references may
be different from the inventor’s specific reasons or goals for making the
invention. Id. In the present case, the general problem confronting the
inventors of the ’105 patent was one of improving accuracy of the test strips.
Ex. 1002, 1:15-18 (“the accuracy . . . is very important since an inaccurate
reading could lead to the wrong level of insulin being administered which
could be very harmful”). Pharmatech’s rationale for combining Nankai and
Schulman—that one of ordinary skill in the art would have recognized that
Schulman’s multisensor comparison method could improve the accuracy of
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Nankai’s multisensor test strip (Pet. 17)—addresses the same general
problem.
(5) Whether Schulman discloses a disposable test
strip
LifeScan argues that Schulman does not disclose a test strip having
the claimed structure. Resp. 30. Specifically, LifeScan argues that
Schulman does not disclose a test strip which has two working sensor parts
and a common reference sensor part. Id. LifeScan also argues that
Schulman does not disclose applying sample liquid to the test strip. Id.
Specifically, LifeScan argues that Schulman’s device is implanted in the
body and is, therefore, in continuous contact with sample. Id. LifeScan
describes Schulman’s arrangement as “not related” to test strips that are used
for intermittent measurements. Id. LifeScan also argues that Schulman uses
the term “sensor” differently from how the term is used in the ’105 patent.
Resp. 28-29. According to LifeScan, the term “sensor,” or more
specifically, “sensor part,” is used in the ’105 patent to refer to a single
electrode on a test strip, whereas a “sensor” in Schulman is an entire
assembly of several electrodes and other structure. Id. at 29 (citing
Ex. 1002, claims 1-3; Ex. 1007, 7:28-30; Ex. 2008 ¶ 59).
These arguments are unpersuasive, because Pharmatech does not rely
on Schulman for any of these disclosures. Pharmatech relies on Schulman
simply for the limited disclosure that multiple measurements of a sample can
be made, compared to establish a difference parameter, and rejected if the
difference exceeds a threshold. Pet. 16-17, 21; Reply 3; see id. at 6 (“the
proposed [challenges] do not rely upon the specific sensor of Schulman”).
That Schulman happens to disclose this technique in the context of
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continuous monitoring by an implanted electrode, instead of intermittent
monitoring by a disposable electrode, is of no moment.
LifeScan’s arguments that (a) Schulman’s measurement of oxygen
depletion is not “in proportion” to the glucose concentration
(Resp. 31-32, 37); (b) Schulman does not disclose a second sensor making
an independent measurement (id. at 32-33); (c) Schulman does not compare
the currents from its two sensors with one another directly because they
measure different things (id. at 34, 37-38); and (d) Schulman does not
disclose a single measuring device with multiple sensor parts (id. at 34-36,
38) each are unpersuasive for the same reason.
(6) “Fundamental technique” of measuring
glucose.
LifeScan disputes our initial determination that Nankai, Schulman,
and the ’105 patent use the same “fundamental technique” for measuring
glucose oxidase (“GOx”)-mediated electrical current. Resp. 30-31 (citing
Dec. 13). LifeScan argues that Schulman measures current resulting from
oxygen reduction, not from a GOx-mediated oxidation of glucose followed
by oxidation of a mediator. Resp. 31 (citing Ex. 2008 ¶ 68).
This argument is unpersuasive because LifeScan does not explain its
relevance to the combinability of Nankai and Schulman. We also disagree
with LifeScan’s assertion. Schulman measures a GOx-mediated electrical
current in the sense that the oxygen reduction it measures results from
consumption of the oxygen by GOx to oxidize glucose in the blood. Ex.
1007, 3:35-62. We pointed out this similarity—the use of GOx and current
measurements by each of Nankai, Schulman, and the ’105 patent—to
explain why we were not persuaded by LifeScan’s Preliminary Response
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argument that Schulman is non-analogous to single-use test strip
technologies. Dec. 12-13 (citing Paper 10, 28).
(7) Combination of Nankai and Schulman
LifeScan argues that there is no evidence supporting a rationale to
combine Nankai and Schulman and that, instead, the evidence shows that
one of ordinary skill would have been led away from the combination.
Resp. 38-43.
LifeScan argues that Schulman’s glucose calculation method, which
involves subtracting an oxygen depletion signal from a background oxygen
signal to obtain a glucose result, is less accurate than the claimed method of
comparing two glucose results. Id. at 40-41 (citing Ex. 2008 ¶ 83).
This argument is unpersuasive for the reason discussed above in
subsection (5): Pharmatech relies on Schulman not for disclosure of the
particular glucose measurement method, but rather only for disclosure of
making multiple measurements and signaling an error if a difference
parameter between the measurements exceeds a threshold. LifeScan does
not credibly explain why it would not have been reasonable for one of
ordinary skill in the art to have taken away from Schulman only this limited
teaching. See EWP Corp. v. Reliance Universal Inc., 755 F.2d 898, 907
(Fed. Cir. 1985) (“A reference must be considered for everything it teaches
by way of technology and is not limited to the particular invention it is
describing and attempting to protect.”).
LifeScan identifies other purported disadvantages of Schulman’s
glucose measurement method, including errors that would be introduced by
the local generation of hydrogen peroxide and local deficit of oxygen.
Resp. 41-42 (citing Ex. 2008 ¶¶ 84-85). These arguments are unpersuasive
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for the same reason, because they depend on the incorporation of disclosure
from Schulman beyond that which Pharmatech argues.
LifeScan argues that Schulman was less concerned with accuracy of
individual measurements, because the continuous operation of the sensor
would, instead, permit error detection by comparison of results over time.
Id. at 42 (citing Ex. 2008 ¶ 88). Again, this argument is unpersuasive
because it is not responsive to the challenge as Pharmatech has framed it.
LifeScan argues that Schulman’s device has not been commercialized,
and also that Dr. Smith never had any reason to consider implantable
monitors in the course of decades of work seeking to improve disposable test
strips. Id. at 43 (citing Ex. 2008 ¶¶ 86, 88-90). These arguments are
unpersuasive, because they do not address why one of ordinary skill in the
art would have been dissuaded from adapting the disclosure from Schulman
that Pharmatech cites.
4. Objective evidence of nonobviousness
LifeScan argues that Pharmatech’s copying of LifeScan’s test strips
demonstrates nonobviousness of claims 1-3. Resp. 45-49 (citing Ex. 2008
¶¶ 92-95). LifeScan argues that Pharmatech’s “GenStrip” test strip is similar
to LifeScan’s commercial strip. Id. at 46-48. LifeScan argues, and
Pharmatech does not dispute in its Reply, that use of either a LifeScan test
strip or a Pharmatech test strip with LifeScan’s “One Touch Ultra” meter, to
measure blood glucose, falls within the scope of claims 1-3. Id. at 47-48
(citing Ex. 2008 ¶¶ 92, 95). Pharmatech argues that its copying is not
probative of obviousness because at least some level of copying was
necessary to make its test strips operable with LifeScan’s meter device, and
because evidence of copying, without more, is not persuasive of
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nonobviousness. Reply 14 (citing Cable Elec. Products, Inc. v. Genmark,
Inc., 770 F.2d 1015, 1028 (Fed. Cir. 1985), overruled on other grounds by
Midwest Indus., Inc. v. Karavan Trailers, Inc., 175 F.3d 1356, 1359 (Fed.
Cir. 1999)).
5. Analysis
Nankai discloses a test strip having the structure recited in claim 1,
expect for the position of the reference sensor part being upstream from the
two working sensor parts. Supra at section II.B.2.a. Nankai’s disclosure
that the arrangement of its sensors may vary (Ex. 1003, 8:50-52) provides
adequate reason for one of ordinary skill in the art to have repositioned the
reference sensor part, in view of Dr. Wang’s unrebutted
2
testimony
(Ex. 1024 ¶ 25) that positioning the reference sensor part upstream of the
working sensor parts was one of a finite number of possibilities and would
have been obvious to try. See KSR, 550 U.S. at 417 (arrangement of prior-
art elements that yields no more than expected results is obvious); In re
Kuhle, 526 F.2d 553, 555 (CCPA 1975) (particular placement of electrical
contact an obvious matter of design choice absent showing of an unexpected
result). As discussed above in section II.B.3.b(2), we are unpersuaded that
there is criticality in the positioning of the reference sensor, because
LifeScan has not explained how any benefits flowing from the claimed
position are unexpected.
The combination of Nankai with Schulman similarly is reasonable.
Schulman’s teachings about the need to compare independent concentration

2
Dr. Smith acknowledges Dr. Wang’s testimony but does not respond to it
directly. See Ex. 2008 ¶ 42.
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measurements, and signal an error if they diverge, transcend the particular
sensor systems for which they are implemented. We agree with Pharmatech,
and credit Dr. Wang’s testimony, that one of ordinary skill in the art, seeking
to improve the accuracy of a multisensor test strip such as Nankai’s, would
have had reason to use Schulman’s comparison and error techniques. See
Pet. 17; Ex. 1024 ¶ 27.
LifeScan’s arguments to the contrary, discussed above in sections
II.B.3.b(5)-(7), dwell on technical details of Schulman’s sensor assemblies,
not on the more general discussion of the need to detect divergence between
redundant measurements in order to signal error. See, e.g., Ex. 1007,
3:21-24 (calling for a “prescribed degree of correlation . . . to validate the
correctness” of the measurement). LifeScan does not explain credibly why
one of ordinary skill would have been deterred from using the general
disclosure of Schulman by differences between Nankai’s and Schulman’s
sensor structure or intended use.
Set against Pharmatech’s evidence is LifeScan’s evidence of copying
by Pharmatech. LifeScan argues, and Pharmatech does not dispute, that
measuring blood glucose with either company’s test strip and LifeScan’s
meter falls within the scope of the claims. Resp. 47-48.
It is not sufficient, however, that a product or its use merely be within
the scope of a claim in order for objective evidence of nonobviousness tied
to that product or use to be given substantial weight. There must also be a
causal relationship, termed a “nexus,” between the evidence and the claimed
subject matter. Merck & Co., Inc. v. Teva Pharm. USA, Inc., 395 F.3d 1364,
1376 (Fed. Cir. 2005). A nexus is required in order to establish that the
evidence relied upon traces its basis to the claimed subject matter, not to
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another source. Institut Pasteur & Universite Pierre Et Marie Curie
v. Focarino, 738 F.3d 1337, 1347 (Fed. Cir. 2013). The stronger the
showing of nexus, the greater the weight accorded the objective evidence of
nonobviousness. See Ashland Oil, Inc. v. Delta Resins & Refractories, Inc.,
776 F.2d 281, 306 (Fed. Cir. 1985), cert. denied, 475 U.S. 1017 (1986).
Like other types of objective evidence, evidence of copying must be shown
to have nexus. Wm. Wrigley Jr. Co. v. Cadbury Adams USA LLC, 683 F.3d
1356, 1364 (Fed. Cir. 2012). A showing of nexus is required in order to
demonstrate that the claimed subject matter drove the copying. See Institut
Pasteur, 738 F.3d at 1338; see also Cable Elec. Products, 770 F.2d. at 1028
(copying could result from lack of concern about patent property, contempt
for the patent, or accepted practices in the industry, among others).
LifeScan does not direct any argument or credible evidence to the
issue of nexus. Instead, LifeScan argues, and Pharmatech does not dispute,
that the copying was motivated by a desire to make Pharmatech’s test strips
compatible with LifeScan’s “One Touch Ultra” meter system. Resp. 47
(citing Ex. 2008 ¶ 43); Reply 14 (acknowledging that “some level of
copying was necessary to get the GenStrip to work with Lifescan OneTouch
Ultra meters”). LifeScan does not show or explain credibly how this reason
for copying relates to the claimed subject matter, as opposed to unclaimed
features, or to considerations unrelated to the invention.
Pharmatech makes a rational argument for obviousness of claims 1-3
over Nankai and Schulman. As discussed above, we agree with Pharmatech
that the evidence of record establishes that it would have been a matter of
design choice to reposition Nankai’s reference sensor to be upstream of the
working sensor parts, and that one of ordinary skill would have had reason
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to adapt Schulman’s comparison and error-signaling methods to Nankai’s
system.
LifeScan’s objective evidence of copying is not sufficient to
overcome Pharmatech’s obviousness argument. As noted above, evidence
of copying requires a nexus with the claimed subject matter. But LifeScan’s
evidence has not been tied credibly to the claims under review. As a result,
the causal relationship between the claimed subject matter and the objective
evidence is tenuous.
Because LifeScan has not shown nexus convincingly, the objective
evidence does not persuade us that the apparent copying of its test strips can
be traced to the claimed subject matter. When we balance Pharmatech’s
evidence of obviousness against the objective evidence of nonobviousness,
we determine that a preponderance of the evidence supports Pharmatech’s
argument that it would have been obvious to combine Nankai and Schulman
to reach the subject matter of claims 1-3.
Accordingly, we conclude that Pharmatech has demonstrated the
unpatentability of claims 1-3 for obviousness over Nankai and Schulman, by
a preponderance of the evidence.
C. Obviousness over Winarta and Schulman
Pharmatech argues that claims 1-3 are unpatentable under
35 U.S.C. § 103(a) over Winarta in combination with Schulman. Pet. 42-46.
LifeScan responds, both arguing that Pharmatech has not demonstrated the
obviousness of the claims (Resp. 21-43), and presenting objective evidence
of nonobviousness. Resp. 45-49.
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Again, we undertake the four factual inquiries of an obviousness
analysis.
1. The level of skill in the art
The discussion presented above in section II.B.1 is equally applicable
here.
2. Scope and content of the prior art
a. Overview of Winarta
Winarta describes a disposable GOx-coated electrode test strip used to
calculate glucose in a blood sample by measuring current. Ex. 1005,
7:11-42. Detail from Figure 2 of Winarta is reproduced below:

The detail from Figure 2 shows the tip of a test strip. Reference
electrode R, working electrode W, and pseudo-working electrode W0 are
positioned in electrode area 26. Id. at 8:63-67. All three electrodes are
coated with a reagent mix that includes GOx. Id. at 7:25-26, 28, 41-42. A
fluid channel runs over the electrodes, and the electrodes are arranged in the
order R–W–W0 from the open end, so that fluid entering the strip flows first
over R, then W, and then W0. Id. at 5:59-62. Flow onto W0 causes a current
that triggers a meter to begin a measurement. Id. at 5:64-65. W0 also may
be used as a counter electrode, and measurements may be taken between R
and W0. Id. at 6:1-10.
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b. Schulman
The overview of Schulman presented above in section II.B.2.b is
equally applicable here.
3. Differences between the claimed subject matter and the
prior art
a. Petitioner’s Case-in-Chief
Pharmatech argues that Winarta discloses all limitations of claim 1
except (a) measuring an electric current at a second working sensor part;
(b) comparing the electric current from each of the working sensor parts to
establish a difference parameter; and (c) giving an indication of an error if
the difference parameter is greater than a predetermined threshold.
Pet. 42-46. Pharmatech argues that Schulman discloses all three missing
limitations. Id. at 43, 45-46. With particular reference to the claim
requirement that the first and second working sensor generate “substantially
identical” quantities of charge carriers in the absence of an error condition,
Pharmatech argues that Winarta Figure 2 shows that W and W0 are the same
size, but that, even if they are not, it would have been obvious to make them
the same size in order to take advantage of Schulman’s comparisons based
on multiple measurements. Id. at 44-45 (citing Ex. 1024 ¶ 61).
With regard to limitation (a), Pharmatech argues that, because
Winarta describes W0 as capable of being used to take measurements, it
would have been obvious to modify Winarta to do so in view of Schulman’s
disclosure to use two or more sensors to confirm reliability of a
measurement. Id. at 43, 45 (citing Wang Decl. ¶ 63). With regard to
limitations (b) and (c), Pharmatech argues, as it did in the Nankai/Schulman
challenge, that modifying Winarta to include these steps would have been
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nothing more than the application of a known technique to improve a similar
device with predictable results. Id.
b. Patent Owner’s Response
LifeScan presents several arguments in response to Pharmatech’s
challenge. We address them in turn.
(1) Uses of W0
LifeScan argues that electrode W0 is not disclosed by Winarta as
being a working sensor part. Resp. 21-22. LifeScan argues W0 is incapable
of making a glucose measurement, because none of the roles for W0
disclosed in Winarta—as counter electrode, resistance sensor, or trigger—
can be used to make such a measurement. Id. at 22-25 (citing Ex. 2008
¶¶ 18, 53-55).
This argument is unpersuasive, because Pharmatech’s challenge is not
premised on operating W0 in the role of a counter electrode, resistance
sensor, or trigger in order to obtain a glucose measurement. LifeScan
presents numerous technical explanations as to why, for example, an
electrode serving as a counter electrode could not be used to measure
glucose, but none of those explanations is germane to the challenge that
Pharmatech has presented. Pharmatech argues that the structural features of
W0 (such as its reagent coating), and its arrangement with the other parts of
Winarta’s test strip, make it capable of being operated in an additional
manner: as a working electrode. Pet. 42-44. In this mode, W0 could be used
to make a second glucose measurement, in addition to the measurement
made at W.
Pharmatech has presented a reasonable explanation, supported by
expert testimony, that W0 is capable of being used as a working electrode.
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In particular, Pharmatech has shown that W0 is formed as an electrode and is
coated with the same reagents as W. See Pet. 42-44; Ex. 1024 ¶ 49. We are
persuaded that W0 is capable of being operated as a working electrode.
LifeScan has not explained what essential structural feature W0 lacks, or
what extraneous structural feature it possesses, that would render W0
incapable of functioning as a working electrode. LifeScan has not credibly
explained why Pharmatech’s argument on this point is in error.
(2) External circuit arrangement in Winarta
LifeScan argues that Winarta does not disclose any external circuit
arrangement or calculation method in a device to allow glucose
measurement at W0. Resp. 25 (citing Ex. 2008 ¶ 55).
This argument is unpersuasive, because Winarta does have circuitry
for making measurements involving W0. See Ex. 1005, 6:5-7 (W0 can be
used with R to measure sample resistance). Upon consideration of the
record, we are persuaded that the modifications required to the existing
external circuitry would have been within the ability of one of ordinary skill
in the art.
(3) Modification of W0 to make glucose
measurements
LifeScan argues that, because Winarta already discloses three uses for
W0, there would have been no reason for one of ordinary skill to employ it
for the undisclosed use of making a glucose measurement. Resp. 25 (citing
Ex. 2008 ¶ 55). This argument is not persuasive, because LifeScan does not
explain why three disclosed uses would have prevented or dissuaded one of
ordinary skill from considering a fourth use.
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(4) Size of W0
LifeScan argues that, even if there were reason to use W0 as a second
working electrode, it would need to be of equal size to W, in order to meet
the claim limitation that the two working sensor parts generate substantially
identical quantities of charge carriers. Resp. 25-26. LifeScan argues that
Winarta is silent as to whether W0 is the same size as W. Id. at 26 (citing
Ex. 2008 ¶ 54). As noted above, Pharmatech argues that Figure 2 of
Winarta shows that W and W0 have the same size and that, even if they were
not uniform in size, it would have been obvious to make them so, in order to
employ Schulman’s methods for comparing multiple measurements.
Pet. 44-45 (citing Ex. 1024 ¶ 61).
We agree with LifeScan that Winarta is silent as to whether W and W0
are of the same size. Pharmatech relies on a patent drawing, and on an
expert’s interpretation of that patent drawing. See Pet. 44; Ex. 1024 ¶ 61.
But unless a patent drawing is indicated as being to scale, it generally is not
to be relied upon for precise proportions. In re Wright, 569 F.2d 1124, 1127
(CCPA 1977). There are, then, three possibilities for the size of W0 relative
to W: smaller, equal, or larger. We credit Dr. Wang’s testimony that it
would have been obvious to make them the same size in the course of
adapting Schulman’s comparison method to Winarta’s test strip. See
Ex. 1024 ¶ 61.
(5) Whether the combination of Winarta and
Schulman meets all limitations
LifeScan argues that the combination of Winarta and Schulman fails
to meet all limitations of the challenged claims. Resp. 44-45. LifeScan
points out that Winarta does not disclose a test strip with two working sensor
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parts, and that Schulman does not remedy this deficiency. Id. at 44 (citing
Ex. 2008 ¶¶ 50-55). LifeScan also argues that, because of this deficiency,
neither Winarta nor Schulman discloses comparing the electric current from
two working sensor parts. Id. at 44-45 (citing Ex. 2008 ¶ 81).
These arguments are unpersuasive, because they address the
references individually. The relevant inquiry is what the combination of the
references would have conveyed to one of ordinary skill in the art.
Pharmatech argues that Schulman’s comparison method would have led one
of ordinary skill to make Winarta’s W0 electrode the same size as W and to
use it as a second working sensor part. Pet. 44-45. Under Pharmatech’s
argument, the notion of a test strip with two working sensor parts would
have emerged from the combination of Winarta and Schulman, not from
either reference by itself. See EWP, 755 F.2d at 907 (“On the issue of
obviousness, the combined teachings of the prior art as a whole must be
considered.”).
(6) Whether one of ordinary skill would have been
led to combine Winarta and Schulman
LifeScan asserts that the arguments it gave concerning the
combination of Nankai and Schulman, discussed above in section
II.B.3.b(7), are applicable to the combination of Winarta and Schulman.
Resp. 45. These arguments are not persuasive, for the reasons given in that
section.
4. Objective evidence of nonobviousness
The discussion presented above in section II.B.4 is equally applicable
here.
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5. Analysis
Winarta discloses a test strip having the structure recited in claim 1,
except for specifying that one of the electrodes, W0, is a working sensor part
and would generate a number of charge carriers substantially identical to the
number of charge carriers generated by the other working sensor part. As
discussed above in section II.C.3.b(1), we agree with Pharmatech that W0
has the structural features necessary to function as a working sensor part.
The combination of Winarta with Schulman is reasonable, for the
reasons discussed above. We credit Dr. Wang’s testimony that one of
ordinary skill in the art would have had reason to implement Schulman’s
multiple measurement and comparison method in Winarta’s device and
would have thought to adapt W0 as a second working electrode during that
implementation. See Ex. 1024 ¶¶ 63-64. LifeScan’s technical critique of
Schulman’s sensor assemblies does not persuade us that one of ordinary skill
in the art would not have adapted other disclosure from Schulman for use in
Winarta. LifeScan’s evidence of copying is entitled to little weight, because
LifeScan has not shown a nexus between that evidence and the claims, as
discussed above in section II.B.5. When we balance Pharmatech’s evidence
of obviousness against the objective evidence of nonobviousness, we
determine that a preponderance of the evidence supports Pharmatech’s
argument that it would have been obvious to combine Winarta and
Schulman to reach the subject matter of claims 1-3.
Accordingly, we conclude that Pharmatech has demonstrated the
unpatentability of claims 1-3 for obviousness over Winarta and Schulman,
by a preponderance of the evidence.
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III. CONCLUSION
Pharmatech has proved, by a preponderance of the evidence, that the
subject matter of claims 1-3 would have been obvious over the combined
teachings of Nankai and Schulman, as well as over the combined teachings
of Winarta and Schulman.
IV. ORDER
For the reasons given, it is
ORDERED that claims 1-3 of U.S. Patent No. 7,250,105 B1 are
determined to be UNPATENTABLE; and
FURTHER ORDERED that because this is a final decision, parties to
the proceeding seeking judicial review of the decision must comply with the
notice and service requirements of 37 C.F.R. § 90.2.

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FOR PETITIONER:

William A. Rudy
A. Justin Poplin
LATHROP & GAGE LLP

FOR PATENT OWNER:

Dianne B. Elderkin
Steven Maslowski
AKIN GUMP STRAUSS HAUER
& FELD LLP