Ex Parte Shah et al

Patent Trial and Appeal Board

Mar 7, 2018

13276183 (P.T.A.B. Mar. 7, 2018)

United States Patent and Trademark Office
UNITED STATES DEPARTMENT OF COMMERCE
United States Patent and Trademark Office
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APPLICATION NO. FILING DATE FIRST NAMED INVENTOR ATTORNEY DOCKET NO. CONFIRMATION NO.
13/276,183 10/18/2011 Rajiv Shah 130.111-US-Ul 9277
12813 7590 03/07/2018
Gates & Cooper LLP - Minimed
6701 Center Drive West
Suite 1050
Los Angeles, CA 90045
EXAMINER
WEARE, MEREDITH H
ART UNIT PAPER NUMBER
3735
MAIL DATE DELIVERY MODE
03/07/2018 PAPER
Please find below and/or attached an Office communication concerning this application or proceeding.
The time period for reply, if any, is set in the attached communication.
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte RAJIV SHAH, ERIC ALLAN LARSON,
KATHERINE T. WOLFE, and DANIEL E. PESANTEZ
Appeal 2017-001687
Application 13/276,183
Technology Center 3700
Before ERIC B. GRIMES, JEFFREY N. FREDMAN, and
JOHN E. SCHNEIDER, Administrative Patent Judges.
FREDMAN, Administrative Patent Judge.
DECISION ON APPEAL
This is an appeal1 under 35U.S.C. § 134 involving claims to an
amperometric glucose sensor system. The Examiner rejected the claims as
obvious. We have jurisdiction under 35 U.S.C. § 6(b). We affirm.
Statement of the Case
Background
“Analyte sensors such as biosensors include devices that use
biological elements to convert a chemical analyte in a matrix into a
detectable signal. . . . The most studied type of biosensor is the
amperometric glucose sensor” (Spec. 1:14—17). “[Gjlucose oxidase (GOx)
1 Appellants identify the Real Party in Interest as Medtronic MiniMed, Inc.
(see App. Br. 2).
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Application 13/276,183
is used to catalyze the reaction between glucose and oxygen to yield
gluconic acid and hydrogen peroxide .... The [hydrogen peroxide] reacts
electrochemically . . . and the current can be measured by a potentiostat”
(Spec. 1:21—23). “[SJensors may encounter technical challenges when
measuring the broad spectrum of hypoglycemic and hyperglycemic glucose
concentrations that can occur in diabetic patients. . . . [AJmperometric
glucose sensors may produce spurious signals in the presence of
interferants” (Spec. 1:27—30).
The Claims
Claims 1 and 21 are on appeal. Claim 1 is representative and reads as
follows:
1. An amperometric glucose sensor system comprising:
a processor;
a first working electrode comprising a first
electrochemically reactive surface formed from an iridium
oxide composition, wherein the first electrochemically reactive
surface generates an electrochemical signal that is assessed by
the processor in the presence of glucose within a first
concentration range, wherein the first concentration range is 40
mg/ dL to 100 mg/ dL;
a second working electrode comprising a second
electrochemically reactive surface formed from a platinum
black composition, wherein the second electrochemically
reactive surface generates an electrochemical signal that is
assessed by the processor in the presence of glucose within a
second concentration range, wherein the second concentration
range is 70 mg/ dL to 400 mg/ dL;
a counter electrode;
a reference electrode;
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Application 13/276,183
wherein the processor performs the steps of:
assessing electrochemical signal data obtained from the
first working electrode and the second working electrode; and
computing a glucose concentration based upon the
electrochemical signal data obtained from the first working
electrode and/or the second working electrode.
The Issues
The Examiner rejected claims 1 and 21 under 35 U.S.C. § 103(a) as
obvious over Simpson,2 Kaneko,3 Tian,4 Arkles,5 and Lewandowski6 (Final
Act. 4—15).
The Examiner finds Simpson teaches “an amperometric glucose
sensor system comprising: a processor” but that “[wjhile Simpson discloses
the first working electrode and second working electrode comprise a first
and second electrochemically reactive surface, respectively, formed of a
conductive body/material (1 [0176]), Simpson does not expressly disclose
any particular conductive materials that may/should be used” (Final Act. 4—
5).
The Examiner finds Kaneko teaches “the material of a working
electrode largely influences the kinds of substances which can be measured,
sensitivity, selectivity, and possibility of quantitative analysis” (Final Act.
5). The Examiner finds Tian’s sol-gel electrode “inherently comprise[s] an
2 Simpson et al., US 2011/0024307 Al, published Feb. 3, 2011.
3 Kaneko et al., US 5,218,757, issued June 15, 1993.
4 Tian et al., Sol-gel derived iridium composite glucose biosensor, 86
Sensors and Actuators B 266-10 (2002).
5 Arkles, US 5,371,262, issued Dec. 6, 1994.
6 Lewandowski et al., US 4,897,162, issued Jan. 30, 1990.
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iridium oxide composition” (Final Act. 7) and therefore Tian teaches “an
iridium oxide composition working electrode having a high selectivity
towards glucose at a low operating potential at which common interferences
cannot be sensed” (Final Act. 6).
The Examiner finds “Lewandowski teaches a working electrode
comprising an electrochemically reactive surface that generates an
electrochemical signal in the presence of glucose, wherein the
electrochemically reactive surface is formed from a platinum composition,
such as platinum black” (Final Act. 7).
The Examiner finds it obvious to
modify the sensor system of Simpson with the first working
electrode being formed from an iridium oxide composition as
taught/suggested by Tian and a second working electrode
formed from a different noble metal composition, such as a
platinum composition, in order to provide first and second
working electrodes with different sensitivities, with the first
working electrode capable of measuring concentrations in
hypoglycemic ranges with reduced interferents.
(Final Act. 7).
The issue with respect to this rejection is: Does the evidence of record
support the Examiner’s conclusion that Simpson, Kaneko, Tian, Arkles, and
Lewandowski render obvious the glucose sensor system of claims 1 and 21?
Findings of Fact
1. Simpson teaches: “Electrochemical sensors are useful in
chemistry and medicine to determine the presence or concentration of a
biological analyte. Such sensors are useful, for example, to monitor glucose
in diabetic patients and lactate during critical care events” (Simpson 13).
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2. Simpson teaches:
in the detection of glucose, glucose oxidase produces H2O2
[hydrogen peroxide] as a byproduct. The H2O2 reacts with the
surface of the working electrode to produce two protons (2H+),
two electrons (2e"), and one molecule of oxygen (O2), which
produces the electric current being detected. In the case of the
counter electrode, a reducible species, for example, O2 is
reduced at the electrode surface in order to balance the current
being generated by the working electrode.
(Simpson^ 142).
3. Figure IB of Simpson is reproduced below:
m
FIG. IB provides a perspective view of another embodiment
comprising a sensor system 180 having a first working
electrode 150 comprising a first sensor element 102 and a
second working electrode 160 comprising a second sensor
element 104. . . . the sensor system 180 also includes a
reference electrode 108 for providing a reference value for
measuring the working electrode potential of the sensor
elements 102,104.
(Simpson! 156).
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4. Simpson teaches “the sensor system comprises a first sensor
element configured to measure a glucose concentration of from about 30
mg/dL to about 120 mg/dL and a second sensor element configured to
measure a glucose concentration of from about 80 mg/dL to about 400
mg/dL” (Simpson^ 160).
5. Simpson teaches:
To overcome potential issues relating to a molar excess of
glucose relative to oxygen in a high sensitivity or high current
density sensor element, in some embodiments, the sensor
system is designed to comprise a plurality of sensor elements,
each of which is configured to have different membrane
characteristics, with respect to oxygen permeability and/or
glucose permeability. In some embodiments, each of the
plurality of sensor elements may have a different sensitivity or
current density. For example, in one embodiment, the sensor
system comprises a first sensor element configured with a high
sensitivity or high current density and a second sensor element
configured with a low sensitivity or low current density.
(Simpson! 170).
6. Simpson teaches “the processor module receives sensor data
(e.g., a data stream), including one or more time-spaced sensor data points,
from one or more of the plurality of sensor elements” and “the first signal
and the second signal may be averaged or integrated to generate an estimate
of a glucose concentration value” (Simpson !! 236, 248)
7. Kaneko teaches factors “determining the performance of the
electrochemical detector is a working electrode, and the kind of the selected
working electrode material largely influences on the kinds of substances
which can be measured, sensitivity, selectivity, and possibility of
quantitative analysis” (Kaneko 1:30—35).
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8. Tian teaches “iridium . . . exhibits a strong and preferential
electrocatalytic action towards the enzymatically produced hydrogen
peroxide, while displaying] no response to coexisting oxidizable
substances” (Tian 266, col. 2).
9. Tian teaches: “With combination of iridium powder with sol-
gel materials, the ceramic—iridium electrode exhibits not only good
electrocatalytic properties of iridium towards hydrogen peroxide by
electrooxidation and/or electroreduction, but also the favorable
biocompatibility and versatility of sol—gel materials” (Tian 270, col. 1).
10. Tian teaches the iridium sol-gel “glucose biosensor can be
renewed by mechanical polishing with favorable reproducibility and long­
term stability” (Tian 270, col. 1).
11. Arkles teaches: “Sol-gel is a method for preparing specialty
metal oxide glasses and ceramics” (Arkles 1:33—35).
12. Lewandowski teaches
prior enzymatic methods of glucose sensing avoided use of
platinum electrodes due to their poor selectivity to glucose.
The platinum electrode is, however, preferable due to its
increased stability to interaction with body fluids during in vivo
usage. The pulse voltammetry technique of the subject system
provides sufficient sensitivity to facilitate use of such platinum
electrodes. It is therefore preferable to have both the counter
electrode 10 and the sensing electrode 12 comprised of
platinum, and the reference electrode comprised of silver.
Stability of and reproductability of the electrocatalytic sensor is
related to the stability of its inorganic catalytic surface
(platinum black) of its platinum working electrode.
(Lewandowski 4:51—64).
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Principles of Law
“The combination of familiar elements according to known methods
is likely to be obvious when it does no more than yield predictable results.”
KSRInt’l Co. v. Teleflex Inc., 550 U.S. 398, 416 (2007).
Analysis
We adopt the Examiner’s findings of fact and reasoning regarding the
scope and content of the prior art (Final Act. 4—15; FF 1—12) and agree that
the claims are obvious over Simpson, Kaneko, Tian, Arkles, and
Fewandowski. We address Appellants’ arguments below.
Appellants contend:
[T]he Simpson, Kaneko, Tian, Arkles, and
Fewandowski disclosures all fail to teach or suggest
sensors designed to COUPLE the claimed electrode
materials with the claimed glucose concentrations in
order to monitor glucose by processing signals from
one electrode coupling of material#l/
concentration#! and another electrode coupling of
material#2/ concentration#2 (as recited in
Applicants’ claims).
(App. Br. 4).
We do not find this argument persuasive because Simpson teaches the
use of two different electrochemical sensor elements to detect two different
glucose concentrations (FF 1, 2, 4) and Simpson teaches the sensors may
differ in “sensitivity or current density” (FF 5). The ordinary artisan
implementing this suggestion by Simpson to use different electrode sensors
for different glucose concentrations would have reasonably looked to known
electrodes used in glucose measurement including the iridium electrodes of
Tian with favorable biocompatibility, reproducibility, and stability (FF 8—
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10) as well as the platinum black electrodes of Lewandowski with increased
stability and reproducibility (FF 12). Such a combination is merely a
“predictable use of prior art elements according to their established
functions.” KSR, 550 U.S. at 417.
Appellants contend
the Lewandowski disclosure teaches that platinum is the best
material for sensing/working electrodes in glucose sensors due
to platinum's increased stability to interaction with body fluids
during in vivo usage. The Lewandowski disclosure expressly
teaches artisans that “It is therefore preferable to have both
the counter electrode 10 and the sensing electrode 12
comprised of platinum, and the reference electrode
comprised of silver” (Lewandowski column 4, lines 51-64).
This shows that the Lewandowski disclosure teaches away
from the claimed glucose sensors, ones that utilize
sensing/working electrodes that are not formed from platinum.
(App. Br. 5). Appellants contend “because references cannot be combined
in situations where a reference teaches away from their combination and
Lewandowski teaches away from sensing/working electrodes formed from
iridium, there is no rational basis for combining the Lewandowski, Simpson,
Kaneko, Tian, and Arkles disclosures in a manner that results in the claimed
invention” (App. Br. 6).
We are not persuaded. A teaching away requires a reference to
actually criticize, discredit, or otherwise discourage the claimed solution.
See In re Fulton, 391 F.3d 1195, 1201 (Fed. Cir. 2004) (“The prior art’s
mere disclosure of more than one alternative does not constitute a teaching
away from any of these alternatives because such disclosure does not
criticize, discredit, or otherwise discourage the solution claimed”).
Appellants’ citation to Lewandowski does not criticize, discourage or
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otherwise discredit the use of two different electrodes as taught by Simpson
(FF 4—5) or the use of an iridium electrode as suggested by Tian (FF 8—10).
Disclosed examples and preferred embodiments do not constitute a teaching
away from a broader disclosure or non-preferred embodiments. In re Susi,
440 F.2d 442, 446 n.3 (CCPA 1971).
Appellants contend “the Simpson sensor is designed to have different
electrode sensitivities via a first principle of operation (i.e. different
diffusion membranes coating the electrodes), while the Appellants’ sensor is
designed to have different electrode sensitivities via a second principle of
operation (i.e. electrode reactive surfaces formed from different metals)”
(Reply Br. 4).
We find this argument unpersuasive because the ordinary artisan
would have recognized that different electrode sensitivities and current
densities of Simpson could be obtained by altering membrane parameters or
by altering electrode materials themselves as Kaneko notes “the kind of the
selected working electrode material largely influences on the kinds of
substances which can be measured, sensitivity, selectivity, and possibility of
quantitative analysis” (FF 7). Thus, Kaneko evidences that the ordinary
artisan would have recognized working electrode material as an optimizable
element in the electrochemical detection process (FF 7). Here, both Tian
and Lewandowski suggest the particular iridium and platinum black
electrodes improve glucose sensing (FF 8—10, 12), providing specific
reasons to use these electrode materials for the electrochemical glucose
detection sensors disclosed by Simpson (FF 1—6).
Our position finds substantial support in the underlying facts of the
KSR decision itself, where the Supreme Court was not persuaded by the
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Federal Circuit’s reliance upon a statement from an “expert that claim 4 was
nonobvious because, unlike in Rixon, the sensor was mounted on the support
bracket rather than the pedal itself.” KSR, 550 U.S. at 415. That is, like the
current case where selection of known and desired iridium oxide or platinum
black electrodes from the prior art of Tian and Lewandowski for use as the
glucose electrodes of Simpson would have been obvious, some
reconstruction of the prior art elements in KSR amounting to a change in the
principle of operation of the pedal sensor from mechanical to electrical
would have been required to arrive at the claimed invention. The Court,
however, found that “if a technique has been used to improve one device,
and a person of ordinary skill in the art would recognize that it would
improve similar devices in the same way, using the technique is obvious
unless its actual application is beyond his or her skill.” Id. at 417.
Appellants contend
Simpson teaches the use of different electrode membranes in
their sensors while the claimed sensors use different electrode
metals. Because Simpson directs artisans to tune electrode
properties through the use of different diffusion resistance
membranes, a person of ordinary skill, upon reading the
Simpson reference, would be led in a direction divergent from
the path that was taken by the Appellant.
(Reply Br. 6).
We remain unpersuaded by this teaching away argument because
Appellants do not identify a teaching in Simpson that criticizes, discredits, or
discourages the use of two different electrode metals. Fulton, 391 F.3d at
1201. Moreover, as the Examiner points out, claims 1 and 21 do not exclude
the use of electrode membranes based on the “comprising” language and
thus may include both electrodes with different metals and with different
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membrane materials (see Ans. 3 4). We further adopt and agree with the
Examiner’s reasoning explaining the benefits and reason to use two different
electrode materials (see Ans. 4—5).
Conclusion of Law
The evidence of record supports the Examiner’s conclusion that
Simpson, Kaneko, Tian, Arkles, and Lewandowski render obvious the
glucose sensor system of claims 1 and 21.
SUMMARY
In summary, we affirm the rejection of claims 1 and 21 under 35
U.S.C. § 103(a) as obvious over Simpson, Kaneko, Tian, Arkles, and
Lewandowski.
No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136(a).
AFFIRMED
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