Ex Parte Chu et al

Patent Trial and Appeal Board

Feb 22, 2019

14554537 (P.T.A.B. Feb. 22, 2019)

UNITED STA TES p A TENT AND TRADEMARK OFFICE
APPLICATION NO. FILING DATE FIRST NAMED INVENTOR
14/554,537 11/26/2014 AmyH.Chu
71331 7590 02/26/2019
NIXON PEABODY LLP
UNITED STATES DEPARTMENT OF COMMERCE
United States Patent and Trademark Office
Address: COMMISSIONER FOR PATENTS
P.O. Box 1450
Alexandria, Virginia 22313-1450
www .uspto.gov
ATTORNEY DOCKET NO. CONFIRMATION NO.
MSE-2728.1 7621
EXAMINER
70 West Madison, Suite 3500 MARTIN, PAUL c
CHICAGO, IL 60602
ART UNIT PAPER NUMBER
1653
NOTIFICATION DATE DELIVERY MODE
02/26/2019 ELECTRONIC
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.
Notice of the Office communication was sent electronically on above-indicated "Notification Date" to the
following e-mail address(es):
docketingchicago@nixonpeabody.com
ipairlink@nixonpeabody.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte AMY H. CHU and HOP G. SPRADLIN
Appeal2018-002009
Application 14/554,537
Technology Center 1600
Before DEMETRA J. MILLS, JEFFREY N. FREDMAN, and
ERICA A. FRANKLIN, Administrative Patent Judges.
MILLS, Administrative Patent Judge.
DECISION ON APPEAL
This is an appeal under 35 U.S.C. § 134. The Examiner has rejected the
claims for obviousness. We have jurisdiction under 35 U.S.C. § 6(b ).
We affirm.
STATEMENT OF CASE
According to the Specification, the "invention relates to the biosensors
that are used to measure the amount of analytes in bodily fluids, particularly in
measuring glucose in samples of whole blood. Optical methods are often used
for making such measurements, but the present invention relates to
improvements in electrochemical biosensors." Spec., ,r 2. The pending claims
are related to a reagent composition for making electrochemical biosensors.
Appeal2018-002009
Application 14/554,537
The following claim is representative claim for purposes of this appeal.
18. An electrochemical biosensor comprising:
(a) a substrate;
(b) at least two electrodes disposed on said substrate; and
( c) a reagent composition deposited on said at least two electrodes,
said composition comprising:
(1) about 1-8 units of glucose dehydrogenase (GDH) and co-
factor pyrroloquinoline quinone (PQQ), for each milligram of the total
weight of said composition;
(2) 2 to about 10 wt% of a hydrophilic polymer selected from the
group consisting of cellulose derivatives based on the total weight of
the composition;
(3) a thickening agent selected from the group consisting of
amorphous untreated silica powder, talc, mica, diatomaceous earth, and
natural and modified clays;
( 4) a buffer sufficient to maintain pH in the range of from about
4.5 to about 6.5;
(5) a surfactant; and
( 6) a mediator.
Cited References
Crismore et al.
Mosoiu et al.
Cui et al.
Davies et al.
us 5,997,817
US 2005/0008537 Al
US 7,288,174 B2
US 2005/0139489 Al
2
pat. Dec. 7, 1999
pub.Jan. 13,2005
pat. Oct. 30, 2007
pub.Jun.30,2005
Appeal2018-002009
Application 14/554,537
Grounds of Rejection
1. Claims 18, 20, 21, 24, 26, 33, 34, 35, 37, 38 and 40-47 are rejected
under pre- AIA 35 U.S.C. § 103(a) as being unpatentable over
Mosoiu, Crismore, and Cui.
2. Claims 18, 20, 21, 24, 26, 33, 34, 35, 37, 38 and 40-47 are rejected
under 35 U.S.C. § 103(a) as being unpatentable over Mosoiu,
Crismore, Cui, and Davies.
FINDINGS OF FACT
The Examiner's findings of fact are set forth in the Answer at pages 3-
29. The follow facts are highlighted.
1. Mosoiu discloses reagents for use in biosensors. Mosoiu, ,r 2. The
reagent may include thickeners such as Keltrol® [ xanthan gum] and
carboxymethylcellulose (CMC). Id. ,r 44.
2. Mosoiu discloses the reagent may also include surfactants "such as
Mega 8®, Geropon®; Triton®, Tween®, Mega 9®, DONS; film
formers, such as Keltrol®, Propiofan®, polyvinyl pyrrolidone,
polyvinyl alcohol, Kluccl ®." Id. ,I48.
3. Mosoiu discloses that
One aspect of the present invention is the inclusion of Xanthan gum
into the reagent coating mass .... Preferably, the reagent layer dried
films have a thickness less than 10 µm particularly preferred are dried
reagent layers in the range of 1.5 to 5 µm thick. Id. ,I29.
4. Mosoiu discloses that
Yet another additive for the enhancement of viscosity and thixotropy of
the reagent is carboxymethyl cellulose (CMC). Especially preferred
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Application 14/554,537
embodiments of the inventive reagent composition therefore comprise
Xanthan gum, for example, Keltrol®, silica and CMC. Id. ,r 31.
5. Mosoiu discloses a desired coating viscosity of between about
70 and about 130 mPa-s, most preferably in the range
between 95 and 115 mPa-s. ,r 28.
6. Crismore et al. teaches a reagent composition for electrochemical
biosensors comprising: GDH-PQQ; hydroxyl ethyl cellulose polymer;
potassium ferricyanide, potassium phosphate buffer; TRITONâ„¢ X-100
surfactant (Column 5, Lines 60-67 and Column 6, Lines 67) and
wherein the composition comprises from about 2000 to about 9000
units of enzyme activity per gram of reagent ( or from about 2 to 9 units
of enzyme per milligram of reagent) (Column 7, Lines 45-49). Ans. 5.
7. Cui et al. teach a reagent composition for electrochemical biosensors
comprising: carboxy methyl cellulose (CMC) at 0.1 -10 wt% to help
disperse and stabilize enzyme (wherein glucose dehydrogenase/GDH
may be used), a mediator and the surfactant TRITONâ„¢ X-100 at 0.8
wt% (Column 6, Lines 26-27 and Column 7, Lines 4- 10, 51 -52 and
61-63).
8. According to the Specification page 9,
As has been shown, hydroxyethyl cellulose can be used as a matrix
component in the reactant layer in electrochemical biosensors using
GDH-PQQ without causing undue loss of enzyme activity. Other
related hydrophilic polymers may also be used, to make the viscosity of
the composition suitable for screen printing. Other cellulose derivatives
include, but are not limited to, sodium carboxymethyl cellulose,
hydroxypropyl-cellulose, hydroxyethyl- cellulose, or hydroxypropyl
methylcellulose. Other water soluble polymers that may be useful
include xanthan gums, guar gum, locust bean gum, carrageenan,
agarose, and synthetic polymers including polyvinyl alcohol, polyvinyl
pyrrolidone, and the like.
9. The Specification describes a typical electrode coating thickness is
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Application 14/554,537
about 10 µm. ,r 30.
10. The Specification describes a desired coating viscosity of about
60,000 to about 180,000 cps (mPa•s ). i-f70.
Discussion
ISSUE
The primary claim limitation in contention is Claim 1, component (b ),
"2 to about 10 wt% of a hydrophilic polymer selected from cellulose
derivatives, based on the total weight of the composition." The Examiner
finds that
Mosoiu et al. teaches a biosensor, comprising a reagent composition
comprising: a hydrophilic polymer (sodium carboxymethylcellulose or
CMC) at about 0.5 w/w%. Cui et al. teach a reagent composition for
electrochemical biosensors comprising: carboxymethyl cellulose
( CM C) at O .1-10 wt% ( thus encompassing the claimed concentration) to
help disperse and stabilize enzyme, a mediator and the surfactant
TRITONâ„¢ X-100 at 0.8 wt%. It would have been obvious to one of
ordinary skill in the art at the time of the instant invention to combine
the electrochemical biosensor composition of Mosoiu et al. with the
electrochemical biosensor compositions of Grismore [sic] et al. and
Cui et al. because this is no more than combining known
electrochemical biosensor compositions comprising similar components
to yield a predicable electrochemical biosensor composition.
Ans. 11.
Appellants contend that, "none of the applied references discloses,
teaches, or suggests a composition having 2 to about 10 wt% of a hydrophilic
polymer selected from cellulose derivatives, as recited by independent claims
18, 3 5, and 44, much less in combination with the remaining elements of
claims 18, 35, and 44." App. Br. 5-6. Appellants further argue that
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Application 14/554,537
selectively culling composition components and amounts thereof from
two different references (Crismore and Cui) to modify the composition
of a third reference (Mosoiu) - without regard to how the other
components of Mosoiu's composition would need to be modified to
maintain its desired properties - would not have been obvious and
would not lead to a "predictable electrochemical composition", as
alleged by the Examiner.
App. Br. 7. Appellants argue that
CMC is considered by Cui to "help disperse or stabilize the enzyme"
(Cui, col. 7, 11. 10-12) and is considered by Mosoiu to be a "thickener"
used in the "enhancement of viscosity and thixotropy" (Mosoiu ,r,r 31,
48). Likewise, polyvinyl pyrrolidone (PVP) is considered by Cui to
"help disperse or stabilize the enzyme" (Cui, col. 7, 11. 10-12) and is
considered by Mosoiu to be a "film former" (Mosoiu ,r,r 31, 48). See
Final Office Action, p. 18. Thus, "a substitution of Cui's thixotropic
agents for the thixotropic agents of Mosoiu," as proposed by the
Examiner, would not be obvious because such a substitution would
likely change other properties of the resulting composition. See id. at p.
10 ( emphasis in original).
Appellants argue that, "it would not have been obvious from the broad
disclosure of Cui to select 2 to about 10 wt% of CMC, much less to modify
Mosoiu's composition to include the same." App. Br. 9.
The issue is: Does the cited prior art support the Examiner's finding that
the claimed subject matter is obvious?
PRINCIPLES OF LAW
In making our determination, we apply the preponderance of the
evidence standard. See, e.g., Ethicon, Inc. v. Quigg, 849 F .2d 1422, 1427
(Fed. Cir. 1988) (explaining the general evidentiary standard for proceedings
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before the Office).
"In rejecting claims under 35 U.S.C. § 103, the examiner bears the
initial burden of presenting a prima facie case of obviousness. Only if that
burden is met, does the burden of coming forward with evidence or argument
shift to the applicant." In re Rijckaert, 9 F.3d 1531, 1532 (Fed. Cir. 1993)
( citations omitted). In order to determine whether a prima facie case of
obviousness has been established, we consider the factors set forth in Graham
v. John Deere Co., 383 U.S. 1, 17 (1966): (1) the scope and content of the
prior art; (2) the differences between the prior art and the claims at issue; (3)
the level of ordinary skill in the relevant art; and ( 4) objective evidence of
nonobviousness, if present. "The combination of familiar elements according
to known methods is likely to be obvious when it does no more than yield
predictable results." KSR Int 'l Co. v. Teleflex Inc., 127 S.Ct. 1727 (2007).
"Reading a list and selecting a known compound to meet known
requirements is no more ingenious than selecting the last piece to put into the
last opening in a jig-saw puzzle. It is not invention." Sinclair & Carroll Co.
v. Interchemical Corp., 325 U.S. 327,335 (1945); see also, Merck & Co. Inc.
v. Biocraft Laboratories, Inc., 874 F.2d 804, 807 (Fed. Cir. 1989)
("Disclos[ ure of] a multitude of effective combinations does not render any
particular formulation less obvious").
The burden of demonstrating unexpected results rests on the party
asserting them, and "it is not enough to show that results are obtained which
differ from those obtained in the prior art; that difference must be shown to be
an unexpected difference." In re Klosak, 455 F.2d 1077, 1080 (CCPA 1972).
"Unexpected results must be established by factual evidence. Mere argument
or conclusory statements in the specification does not suffice." In re
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DeBlauwe, 736 F.2d 699, 705 (Fed. Cir. 1984). "[W]hen unexpected results
are used as evidence of nonobviousness, the results must be shown to be
unexpected compared with the closest prior art." In re Baxter-Travenol Labs.,
952 F.2d 388, 392 (Fed. Cir. 1991).
The Board may rely on less than all of the references applied by an
Examiner in an obviousness rationale without designating it as a new ground
of rejection. In re Bush, 296 F.2d 491,496, (CCPA 1961); In re Boyer, 363
F.2d 455,458, (CCPA 1966).
ANALYSIS
Appellants do not argue individual claims separately, but instead group
independent claims 18, 35, and 44 together. App. Br. 5. Claim 18 is selected
as representative claim for purposes of this appeal. We group rejections 1 and
2 together, as Appellants do not provide specific arguments with respect to
rejection 2 and Appellants arguments for rejection 1 are also dispositive of
rejection 2. Arguments not made are waived.
We find that the Examiner has provided sufficient evidence to support a
prima facie case of obviousness.
The Examiner acknowledges that
While Mosoiu et al. teaches a composition comprising a total
amount of hydrophilic polymer at a concentration of 5.53 wt%, the
reference does not teach a composition comprising 2 to about 10 wt%
of hydrophilic polymers that are cellulose derivatives, ... based on the
total weight of the composition.
Ans. 5. The Examiner further relies on the analogous art of Cui, directed to an
electrode biosensor that includes a specific reagent layer, coating. Col. 1, 11.
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10-21. The reagent layer of Cui may include the water soluble polymer,
carboxymethyl cellulose (CMC), at 0.1-10 wt%. Col. 7, 11. 4-15. We agree
that the Examiner has set forth a prima facie case of obviousness on the
evidence before us.
In particular, Cui teaches an electrode biosensor having a similar range
of CMC, 0.1-10 wt%, as claimed. Cui' s biosensor may include potassium
ferricyanide. Col. 6, 1. 48. Cui discloses that it is well known in the art to use
a silica filler in a biosensor reagent layer. Col. 1, 11. 61. Cui discloses that the
reagent layer may include an enzyme dehydrogenase. Col. 6, 1. 23. Cui
discloses that the reagent may include an electron transfer mediator such as a
quinone. Col. 6, 1. 43. Cui discloses a buffer solution of a pH of about 6.5.
Col. 7, 1. 50. Crismore is relied on, in particular, for the claimed amount of
glucose dehydrogenase enzyme units. Ans. 5. It would have been obvious to
one of ordinary skill in the art at the time of the invention to modify Cui's
biosensor electrode comprising enzyme dehydrogenase with Crismore's
glucose dehydrogenase enzyme units, as both Crismore and Cui are both
analogous art in the field of electrochemical biosensors, and in particular,
biosensors for glucose testing.
Appellants contend that, "none of the applied references discloses,
teaches, or suggests a composition having 2 to about 10 wt% of a hydrophilic
polymer selected from cellulose derivatives, as recited by independent claims
18, 3 5, and 44, much less in combination with the remaining elements of
claims 18, 35, and 44." App. Br. 5-6. Appellants further argue that
selectively culling composition components and amounts thereof
from two different references (Crismore and Cui) to modify the
composition of a third reference (Mosoiu) - without regard to how the
other components of Mosoiu's composition would need to be modified
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Application 14/554,537
to maintain its desired properties - would not have been obvious and
would not lead to a "predictable electrochemical composition", as
alleged by the Examiner.
App. Br. 7. We are not convinced by Appellants arguments. Cui discloses
the claimed range of hydrophilic polymer/CMC. FF 7.
In addition, Appellants claim no "desired properties", e.g. coating
thickness, thixotropy or viscosity. Furthermore, the viscosity of the electrode
reagent of Mosoiu is preferably between about 70 and 130 mPa-s (p. 2 i-f28).
This overlaps the viscosity in the Specification. FF. 9. Mosoiu discloses that
reagent layer dried films have a thickness less than 10 µm, particularly
preferred. (p. 2 i-f29). This overlaps the electrode thickness in the
Specification. FF 8.
Moreover, the electrode of Cui requires no modification of the amount
of CMC to meet the hydrophilic polymer limitation of the pending claims, and
Cui meets most of the claim 18 requirements. (The Board may rely on less
than all of the references applied by an Examiner in an obviousness rationale
without designating it as a new ground of rejection. In re Bush, 296 F.2d 491,
496 (CCPA 1961).) We find no inappropriate case of picking and choosing
amongst references, or hindsight on the part of the Examiner. The Examiner's
rejections are supported by the evidence of record.
In addition, it is noted that the claimed amount of hydrophilic cellulose
polymer (CMC) is a broad range. Claim 18. Appellants argue that the Table
at paragraph 114 of Mosoiu discloses that, "making even small modifications
to CMC and the other hydrophilic polymers had substantial and inconsistent
effects on the composition properties." App. Br. 9. If Appellants' arguments
are accurate, than the claimed broad range of hydrophilic polymer/CMC is
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likely to give unpredictable results as well. Moreover, if Appellants intend to
present this argument to support a conclusion of unexpected results, we are
not persuaded. "Unexpected results must be established by factual evidence.
Mere argument or conclusory statements in the specification does not suffice."
In re DeBlauwe, 736 F.2d 699, 705 (Fed. Cir. 1984). "[W]hen unexpected
results are used as evidence of nonobviousness, the results must be shown to
be unexpected compared with the closest prior art." In re Baxter-Travenol
Labs., 952 F.2d 388,392 (Fed. Cir. 1991). Appellants provide no legally
sufficient evidence of unexpected results on this record.
The obviousness rejection over Mosoiu, Cui, and Crismore is affirmed.
With respect to the second rejection that also includes Davies,
Appellants argue only that Davies does not cure the deficiencies of the
primary combination of references. App. Br. 11. Having found no
deficiencies in the primary combination of references, this rejection is also
affirmed.
CONCLUSION OF LAW
The preponderance of the evidence supports the Examiner's
obviousness rejections, which are affirmed for the reasons of record.
No time period for taking any subsequent action in connection with this
appeal may be extended under 3 7 C.F .R. § 1.13 6( a)( 1 )(iv). See 3 7 C.F .R. §
41.50(±).
AFFIRMED
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