Ex Parte Girton

Board of Patent Appeals and Interferences

Mar 22, 2012

10858589 (B.P.A.I. Mar. 22, 2012)

UNITED STATES PATENT AND TRADEMARK OFFICE
__________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
__________

Ex parte TIMOTHY SAMUEL GIRTON
__________

Appeal 2011-000229
Application 10/858,589
Technology Center 3700
__________

Before FRANCISCO C. PRATS, JEFFREY N. FREDMAN, and
STEPHEN WALSH, Administrative Patent Judges.

WALSH, Administrative Patent Judge.

DECISION ON APPEAL
This is an appeal under 35 U.S.C. § 134(a) from the rejection of
claims directed to an endoprosthesis device. The Patent Examiner rejected
the claims for obviousness. We have jurisdiction under 35 U.S.C. § 6(b).
We affirm.
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STATEMENT OF THE CASE
Claims 1-6, 13, 15-17, and 19 are on appeal. Claim 1 is representative
and reads as follows (emphasis added):
1. An endoprosthesis device comprising:
an elongate radially expandable tubular stent having an interior
surface and an exterior surface extending along a longitudinal
stent axis; and
a stent cover on said interior surface, exterior surface or both, said
stent cover being formed of a non-expanded
polytetrafluoroethylene having no node and fibril structure, the
non-expanded polytetrafluoroethylene having a porous
structure defined by voids formed from removal of siloxane
from an interpenetrating network of siloxane/polytetrafluoro
ethylene.

The Examiner rejected the claims as follows:
 claims 1-6, 13, 15-17, and 19 under 35 U.S.C. § 103(a) as
unpatentable over Lombardi1 and Lo2 (Ans. 4-5);
 claims 1-6, 13, 15-17, and 19 under 35 U.S.C. § 103(a) as
unpatentable over Chao,3 Lee,4 and Chaouk5 (id. at 5-7); and
 claims 1-6, 13, 15-17, and 19 under 35 U.S.C. § 103(a) as
unpatentable over Lee, Chao, and Chaouk (id. at 7-9).

1 Sylvie Lombardi et al., US 7,083,640 B2, issued Aug. 1, 2006.
2 Lawrence Y. Lo et al., US 4,863,604, issued Sept. 5, 1989.
3 Kwang C. Chao et al., US 4,196,070, issued April 1, 1980.
4 Peter Y. Lee, US 5,123,917, issued June 23, 1992.
5 Hassan Chaouk et al., US 6,015,609, issued Jan. 18, 2000.
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OBVIOUSNESS
The Issue
The Examiner found that stent materials made of porous non-
expanded polytetrafluoroethylene (PTFE) were known in the art, and that the
known processes for making the pores included using an extractable or
removable filler, such as an organic salt. The Examiner produced evidence
that organic salts and solvents form interpenetrating network structures in
PTFE and similar polymers, that on removal leave a network of intersecting
pores, having an overall sponge-like structure with an interconnected porous
network. The Examiner found that the prior art void structure, although
produced by salt or other solvent removal, was no different from the claimed
voids formed by removal of siloxane from an interpenetrating network of
siloxane/polytetrafluoroethylene. Based on the evidence, set out in three
rejections, the Examiner found that the stent and stent cover material
produced or suggested by the prior art methods was the same as the stent
cover material made by Appellants’ siloxane removal process, and
concluded it would have been obvious to make an endoprosthesis device
with the porous stent cover material taught and suggested by the prior art.
Appellant contends that “removal of siloxane from an interpenetrating
network (‘IPN’) of siloxane/polytetrafluoroethylene (‘PTFE’) imparts
distinctive structural characteristics to the voids present in the remaining
structure.” (App. Br. 9.) Noting that none of the references teach or suggest
an IPN of siloxane/PTFE, Appellant argues that “the Examiner has not
shown that any of the references teach or suggest that the pores made with
their processes would be the same as the pores made by removing siloxane
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from an IPN with PTFE.” (Id. at 10.) Further, “[n]one of the references
teach or suggest that the pores made with their processes would be the same
as the pores made by removing siloxane from an IPN with PTFE.” (Id. at
12.) As summarized in the Reply Brief:
Because salt and siloxane have very different chemical
structures and properties, a combination of PTFE and salt would
necessarily have a different structure than the IPN of PTFE and
siloxane taught by the present invention. Thus, the pores of the
remaining structure formed by removing the salt would necessarily be
different in size and shape than those formed by removing siloxane.
As a result the remaining PTFE structure from the salt/PTFE
combination would be structurally distinct from the remaining PTFE
structure from the IPN with siloxane.

(Reply Br. 4.)
The dispositive issue with respect to the three rejections is whether the
Examiner produced sufficient evidence to shift the burden to Appellant to
prove by evidence that the porous structure in their PTFE is different from
the porous structures made by prior art methods in PTFE.
Findings of Fact
1. We adopt the Examiner’s findings concerning the scope and content
of the prior art.
2. Appellant states:
An IPN is commonly understood by those of ordinary skill in the art
to mean “two or more polymer components, each of which is a cross-
linked three-dimensional network, one of which is formed (cross-
linked) in the presence of the other.” MCGRAW-HILL
DICTIONARY OF SCIENTIFIC AND TECHNICAL TERMS, p.
1102 (6th ed. 2003). “The polymer networks are physically entangled
with, but not covalently bonded to each other.” Id.

(App. Br. 9-10.)
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Principles of Law
“[W]hen the PTO shows sound basis for believing that the products of
the applicant and the prior art are the same, the applicant has the burden of
showing that they are not.” In re Spada, 911 F.2d 705, 708 (Fed. Cir. 1990).
“If the product in a product-by-process claim is the same as or obvious from
a product of the prior art, the claim is unpatentable even though the prior
product was made by a different process.” In re Thorpe, 777 F.2d 695, 697
(Fed. Cir. 1985).
“Attorney’s argument in a brief cannot take the place of evidence.” In
re Pearson, 494 F.2d 1399, 1405 (CCPA 1974); In re Geisler, 116 F.3d
1465, 1471 (Fed. Cir. 1997) (same).
Analysis
The McGraw-Hill Dictionary describes an IPN as a physically
entangled polymer network, with no covalent bonding between the
polymers. (FF 2.) When siloxane and PTFE form the IPN, siloxane can be
removed, leaving a porous structure in the PTFE. We find the definition of
IPN does not establish that there is necessarily a difference between a porous
structure formed by removing salt from PTFE and removing siloxane from
PTFE.
Appellant’s Reply Brief presents drawings to illustrate structural
differences between a salt such as sodium benzoate and a siloxane such as
polydimethylsiloxane. (Reply Br. 4.) We agree that the two have different
structures. However, Appellant does not provide evidence of a difference in
the structure of salt and siloxane networks formed by mixing salt or siloxane
into PTFE. The prior art states that when a salt such as sodium benzoate is
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mixed with PTFE, the salt forms a network. When the salt is removed per
methods described in the prior art, the salt leaves voids in the PTFE that
form a porous network.
The Examiner found the porous structures created in the prior art by
salt removal were described in terms equivalent to those Appellant uses to
describe the claimed voids, and the prior art porous structures were the same
as the porous structures Appellant claims, made by siloxane removal. What
remains unknown on this record is whether Appellant is correct to argue that
the porous structures formed by salt removal and siloxane removal are
necessarily different. We find the Examiner’s evidence and reasoning set
out in the rejections (Ans. 3-9) and in the “Response to Argument” (id. at 9-
10) persuasive. We agree with the Examiner that the prior art describes a
similar process of porous structure formation in terms similar to those used
in the claims, and that Appellant must provide evidence that the porous
structures are different. See Spada, 911 F.2d at 708; Thorpe, 777 F.2d at
697; In re Best, 562 F.2d 1252, 1255 (CCPA 1977) (“Where, as here, the
claimed and prior art products are identical or substantially identical, or are
produced by identical or substantially identical processes, the PTO can
require an applicant to prove that the prior art products do not necessarily or
inherently possess the characteristics of his claimed product.… Whether the
rejection is based on ‘inherency’ under 35 U.S.C. § 102, on ‘prima facie
obviousness’ under 35 U.S.C. § 103, jointly or alternatively, the burden of
proof is the same, and its fairness is evidenced by the PTO’s inability to
manufacture products or to obtain and compare prior art products.”).
Against the evidence presented in the rejections, we find that the
arguments presented in the Appeal and Reply Briefs are insufficient because
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they do not provide persuasive rebuttal evidence. See Pearson, 494 F.2d at
1405; Geisler, 116 F.3d at 1471.
Claims 1-6, 13, 15-17, and 19 have not been argued separately and
therefore fall with claim 1. 37 C.F.R. § 41.37(c)(1)(vii).

SUMMARY
We affirm the rejection of claims 1-6, 13, 15-17, and 19 under
35 U.S.C. § 103(a) as unpatentable over Lombardi and Lo.
We affirm the rejection of claims 1-6, 13, 15-17, and 19 under
35 U.S.C. § 103(a) as unpatentable over Chao and Lee.
We affirm the rejection of claims 1-6, 13, 15-17, and 19 under
35 U.S.C. § 103(a) as unpatentable over Lee, Chao, and Chaouk.

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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