Ex Parte Woods

Patent Trial and Appeal Board

Jun 27, 2013

10311674 (P.T.A.B. Jun. 27, 2013)

UNITED STATES PATENT AND TRADEMARK OFFICE
__________

BEFORE THE PATENT TRIAL AND APPEAL BOARD
__________

Ex parte DAVID MALCOLM WOODS
__________

Appeal 2012-001312
Application 10/311,674
Technology Center 1600
__________

Before DEMETRA J. MILLS, LORA M. GREEN, and
JACQUELINE WRIGHT BONILLA, Administrative Patent Judges.

GREEN, Administrative Patent Judge.

DECISION ON APPEAL
This is a decision on appeal
1
under 35 U.S.C. § 134 from the
Examiner‟s rejection of claims 1, 3, 4, 7, 8, 10, 11, 14, 18, and 24-35. We
have jurisdiction under 35 U.S.C. § 6(b).
We affirm.

1
The Real Party in Interest is ConvaTec Technologies, Inc. (App. Br. 1).
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STATEMENT OF THE CASE
Claim 1 is the only independent claim on appeal, and reads as follows:
1. A wound dressing having anti-microbial activity, comprising a
first fibre having silver (I) cations bonded thereto and discoloring on
exposure to light, wherein the wound dressing consists of a uniform
blend of the first fibre and a second fibre which is substantially free
from silver, said wound dressing comprising from 0.01 to 5.0 percent
by weight of silver (I) cations based on the total weight of first and
second fibres, whereby the discoloration of the blend on exposure to
light is lessened compared with the discoloration on exposure to light
of a batch of the first fibre having the same average amount of silver
cations present as is present in the blend.

The following grounds of rejection are before us for review:
I. Claims 1, 27, 30, and 32 stand rejected under 35 U.S.C. § 103(a) as
being rendered obvious by the combination of Flick
2
and Minami
3

(Ans. 4).
II. Claims 1, 10, 11, 24, 25, and 33 stand rejected under 35 U.S.C.
§ 103(a) as being rendered obvious by the combination of Flick
and Minami as further combined with Gibbins
4
(Ans. 6).
III. Claims 1, 34, and 35 stand rejected under 35 U.S.C. § 103(a) as
being rendered obvious by the combination of Flick and Minami as
further combined with Ryan
5
(Ans. 7).

2
Flick, US 6,087,549, issued Jul. 11, 2000.
3
Minami et al., JP 11-001,895, published Jan. 6, 1999. All references to
Minami are to the English translation.
4
Gibbins et al., US 6,605,751 B1, issued Aug. 12, 2003.
5
Ryan et al., US 6,506,873 B1, issued Jan. 14, 2003.
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IV. Claims 1, 3, 4, 7, 8, 14, 18, 26, 28, 29, and 31 stand rejected under
35 U.S.C. § 103(a) as being rendered obvious by the combination
of Flick and Minami as further combined with Gibbins (Ans. 8).

ISSUE

Does the preponderance of the evidence of record support the
Examiner‟s conclusion that the combination of Flick and Minami render
claim 1 obvious?

FINDINGS OF FACT
FF1. Appellant does not argue the claims separately as to any of the
rejections (see App. Br. 3-9). We thus focus our analysis on the rejection of
claim 1 over the combination of Flick and Minami, as claim 1 has been
rejected in each of the rejections as set forth by the Examiner, and each
rejection relies on the combination of Flick and Minami. Thus, the issue is
the same as to all of the rejections.
FF2. The invention relates to a wound dressing having antimicrobial
activity (Spec. 1).
FF3. The Specification acknowledges that carboxymethylcellulose
containing silver in an amount of 0.02 to 1% for use as an antimicrobial
agent was known in the art (id.).
FF4. The Specification teaches that silver-containing fibers, such as those
in the prior art, discolor when exposed to light (id.). According to the
Specification, an object of the invention is to reduce or obviate that
discoloration (id.).
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FF5. The Specification thus teaches:
The present invention provides a wound dressing having
anti-microbial activity, which comprises a first fibre capable of
bonding with silver (1) cations, characterised in that the wound
dressing comprises a blend of the first fibre to which silver (1)
cations are bonded and a second fibre which is substantially
free from silver.

(Id.)
FF6. The Examiner finds that Flick “discloses a multilayered wound
dressing comprising a blend of two fibers (woven or non-woven), a first
fiber having silver metal bonded thereto, and a second a second fiber
substantially free of silver” (Ans. 5). The “disclosed dressing … „promotes
healing and also has antibacterial and antifungal efficacy‟” (id.).
FF7. The Examiner finds that “Flick explicitly teaches a mixture of silver
fibers with nonmetalized fibers by air to create a random, generally uniform
mixture of fibers as a preferred embodiment (see col. 6, lines 63-65),” and
also “explicitly teaches a 1:1 ratio of silver fibers to nonmetalized fibers (see
col. 7, line 13)” (id. at 10).
FF8. As to the amount of silver in the dressing of Flick, the Examiner finds
that Flick teaches that the silver is of a high purity, i.e., up to
99.999% (see col. 6, line 14). Flick further teaches that the
amount of coating may vary from about 5% to about 40% by
weight (see col. 6, lines 27-28). Thus, examiner interprets this
teaching to mean that the “silver fibers” contained in the
mixture may have a silver coating of between about 5% to 40%
by weight of the fiber. Since the teaching is disclosed by
weight of the fiber, as opposed to the percent of the fiber coated

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with silver, examiner respectfully submits that Flick teaches 5%
to 40% of silver content within the disclosed fiber population
that contains silver.

(Id. at 11.)
FF9. Flick is drawn to wound dressings that promote wound healing, and
also have antibacterial and antifungal activity (Flick, col.1, ll. 5-10).
FF10. Flick teaches that the antimicrobial and antifungal properties of silver
and silver compounds are well known, as is their use in wound dressings (id.
at col. 3, ll. 8-9 and 44-45). According to Flick, “[m]ost silver compounds
that dissociate readily and produce large numbers of free silver ions are
highly toxic to mammalian (including human) tissues” (id. at col. 3, ll. 18-
21).
FF11. Flick teaches a “multilayer laminate structure, wherein each layer
preferably had a different composition, such that a gradient is formed by the
layers” (id. at col. 5, ll. 63-65). The flexible material 12 is composed of
layers, which are composed of a mixture of silver fibers and nonmetalized
fibers (id. at col. 6, ll. 11-13).
FF12. Flick teaches that preferably the base fibers are 100% coated with
metallic silver, and that the amount of coating can vary from about 5% to
20% by weight (id. at col. 6, ll. 25-29).
FF13. Flick teaches:
Preferably, the silver fibers and nonmetalized fibers are
generally equally distributed throughout the material 12. In a
preferred embodiment, the silver fibers are mixed with the
nonmetalized fibers by air to create a random, generally
uniform mixture of fibers. Alternatively, it is contemplated as

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being within the scope of the present invention to have areas of
different fiber distribution for certain applications.

(Id. at col. 6, ll. 61-67.)
FF14. According to the Examiner, Flick differs from the wound dressing of
claim 1 in not disclosing silver cations bonded to the fiber (Ans. 5).
FF15. The Examiner relies on Minami as evidence that “bonding of silver
cations to a dressing having antimicrobial activity was well known in the art
at the time the instant application was filed” (id.).
FF16. The Examiner also finds that Minami teaches that “the bonding of an
antimicrobial metallic ion such as silver to carboxymethyl cellulose is
beneficial because, „ ... the antimicrobial property can be displayed safely
and powerfully in a small amount‟” (id. at 13 (quoting Minami, ¶ 11)).
FF17. Specifically, Minami teaches “[a]n antimicrobial agent composed of a
water-insoluble carboxymethyl cellulose with at least a part thereof
substituted by an antimicrobial metallic ion is used, therefore the
antimicrobial property can be displayed safely and powerfully in a small
amount” (Minami, p. 5, ¶ 11).
FF18. The Examiner concludes that an ordinary artisan would have bonded
silver ions to the fibers as taught by Minami in the dressing of Flick “in
order to create a safe product having powerful antimicrobial property using a
small amount of silver” (Ans. 13).

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ANALYSIS
Appellant argues that in Flick, metallic silver is coated on the fibers,
whereas the instant claims require silver cations to be bonded to the fibers
(App. Br. 3).
Appellant‟s argument is not convincing. The Examiner recognized
that Flick did not teach silver cations bonded to the fiber (FF14), and relied
upon Minami to meet that limitation.
Appellant argues further that “Flick does not appear to mention how
much metallic silver is present in the dressing overall” (App. Br. 3
(emphasis removed)). According to Appellant, it is not possible to calculate
the amount of silver in the dressing of Flick, as the passage at column 6, line
26, of Flick “refers to the amount of coating on the fibers and not the weight
in the dressing” (id. at 4).
According to Appellant, “Flick is only concerned with creating a
gradient of metalized fiber to nonmetalized fiber ratios,” and not with the
overall amount of silver in the dressing (id.). Thus, Appellant asserts, the
ordinary artisan would not find the claimed invention to be rendered obvious
by Flick (id. at 5).
Appellant‟s arguments are again not convincing. As found by the
Examiner (FF8), Flick teaches that the amount of coating may vary from
about 5% to about 40% by weight, and therefore meets the limitation that the
wound dressing comprises from 0.01 to 5.0 percent by weight of silver
(FF8). Moreover, we note that the Specification teaches that antimicrobial
carboxymethylcellulose containing silver in an amount of 0.02 to 1% was
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known (FF2), and thus the claims encompass amounts of silver that were
known to have antimicrobial properties at the time of invention.
Appellant also argues that there is “no unambiguous teaching in Flick
of a dressing consisting of a uniform blend of silver containing fibers and
fibers free from silver” (App. Br. 4). Specifically, according to Appellant,
Flick‟s teaching that “the silver fibers and nonmetalized fibers are
preferably, and generally, equally distributed throughout the material 12
could mean that they are in a 1:1 mixture overall, but does not necessarily
mean so” (id. at 3-4).
Here we agree with the Examiner (Ans. 12) that Flick teaches
different embodiments, one of which is drawn to a uniform blend of silver
containing fibers and fibers free from silver. Specifically, Flick teaches that
in one embodiment, the silver fibers and nonmetalized fibers are generally
equally distributed throughout the material (FF13). Flick then teaches in
other embodiments, there are areas of different fiber distribution (id.). Thus,
as found by the Examiner, Flick teaches an embodiment in which metalized
and nonmetalized fibers are equally distributed through the material. Note
that a reference disclosure is not limited only to its preferred embodiments,
but is available for all that it discloses and suggests to one of ordinary skill
in the art. In re Lamberti, 545 F.2d 747, 750 (CCPA 1976).
Appellant argues that neither Flick nor Minami are directed to the
problem solved by the invention, that is, the problem of discoloration of
dressing comprising silver ions (App. Br. 4-6). Appellant argues further that
Minami is drawn to sanitary articles, wherein the silver containing article is
hidden, and thus discoloration would not be an issue (id. at 5). Thus,
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Appellant asserts, there is no reason to combine Minami with Flick, absent
improper hindsight (id. at 5-6).
Appellant argues further that while Flick recognizes that silver ions
are antimicrobial, the reference also recognizes that the silver ions are highly
toxic (id. at 6). Flick, Appellant argues, is concerned with stimulating cell
growth, which is done by creating a silver gradient (id. (citing Flick, col. 4, l.
67). Appellant asserts that there is no suggestion in Flick that the gradient
could be created if the elemental silver were to be replaced with silver ions
(id.).
We agree with the Examiner (Ans. 10-11) that the references need not
recognize the problem solved by Appellant. In re Kemps, 97 F.3d 1427,
1430 (Fed. Cir. 1996); In re Beattie, 974 F.2d 1309, 1312 (Fed. Cir. 1992);
Ex parte Obiaya, 227 USPQ 58, 60 (BPAI 1985) (“The fact that appellant
has recognized another advantage which would flow naturally from
following the suggestion of the prior art cannot be the basis for patentability
when the differences would otherwise be obvious.”) The Supreme Court has
emphasized that “the [obviousness] analysis need not seek out precise
teachings directed to the specific subject matter of the challenged claim, for
a court can take account of the inferences and creative steps that a person of
ordinary skill in the art would employ.” KSR Int’l v. Teleflex Inc., 550 U.S.
398, 418 (2007). “If a person of ordinary skill can implement a predictable
variation, § 103 likely bars its patentability.” (Id. at 417.) Under the correct
obviousness analysis, “any need or problem known in the field of endeavor
at the time of invention and addressed by the patent can provide a reason for
combining the elements in the manner claimed.” Id. at 420.
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Here, the Examiner has provided a reason to combine the references
(FF18). That is, Flick recognizes that high levels of silver ions may be toxic
to human tissues (FF10), and Minami teaches that its antimicrobial agent is
safe and effective as only a small amount of silver is required (FF17).
Moreover, both Flick and Minami are drawn to the use of silver as an
antimicrobial agent. Thus, we agree with the Examiner that it would have
been obvious to use the bonding of silver ions to the polymer as taught by
Minami to create the wound dressing of Flick.
In regard to Appellant‟s argument that Flick does not suggest that a
gradient could be created using a silver ion rather than elemental silver, we
note that Flick teaches that the elemental silver produces silver ions, which
help promote wound healing (see, e.g., Flick, col. 8, l. 57-col. 9, l. 40).
Moreover, all that is required is a reasonable expectation of success, not an
absolute predictability of success. In re O’Farrell, 853 F.2d 894, 903-904
(Fed. Cir. 1988).

SUMMARY
We conclude that the preponderance of the evidence of record
supports the Examiner‟s conclusion that the combination of Flick and
Minami render claim 1 obvious.
We therefore affirm the rejection of claim 1 under 35 U.S.C. § 103(a)
as being rendered obvious by the combination of Flick and Minami. As
Appellant does not argue claims 27, 30, and 32 separately with respect to
that rejection, those claims fall with claim 1. 37 C.F.R. § 41.37(c)(1)(vii).
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All of the remaining rejections also rely on the combination of Flick
and Minami, as combined with other references, and all the remaining
rejections contain claim 1. As Appellant does not argue any of the claims
separately as to the remaining rejections, and as we have already concluded
that claim 1 is rendered obvious by the combination of Flick and Minami,
we also affirm the remaining rejections on appeal.

TIME PERIOD FOR RESPONSE
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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