Ex Parte Zhou

Board of Patent Appeals and Interferences

Jul 18, 2012

11478095 (B.P.A.I. Jul. 18, 2012)

UNITED STATES PATENT AND TRADEMARK OFFICE
__________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
__________

Ex parte PU ZHOU
__________

Appeal 2012-001139
Application 11/478,095
Technology Center 1600
__________

Before TONI R. SCHEINER, STEPHEN WALSH, and ULRIKE W.
JENKS, Administrative Patent Judges.

JENKS, Administrative Patent Judge.

DECISION ON APPEAL
This is a decision on appeal under 35 U.S.C. § 134 involving claims
directed to an implantable intravascular stent comprising multiple coatings.
The Examiner has rejected the claims as obvious. We have jurisdiction
under 35 U.S.C. § 6(b). We reverse.
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STATEMENT OF THE CASE
Claims 2-4, 7, 8, 13-18, 20-22, 25-28, and 30-32 are on appeal, and
can be found in the Appendix of the Appeal Brief (App. Br. 14-16). The
claims are directed to a stent comprising two adjacent coatings, wherein
each coating makes contact with the sent sidewall structure, and wherein one
coating comprises a metallic material and the other coating is either a
therapeutic agent, a polymer or mixture thereof. Claim 25 is the sole
independent claim, and reads as follows (emphasis added):

25. An implantable intravascular stent comprising:
(a) a stent sidewall structure defining a surface; and
(b) a coating comprising
(i) a first coating composition formed of a material selected from the
group consisting of a one or more therapeutic agents and one or more
polymers, the first coating composition contacting at least a portion of
the surface of the stent sidewall structure wherein the first coating
composition has a first thickness measured from the surface of the
stent sidewall structure; and
(ii) a second coating composition comprising a material different from
the first coating composition, the second coating composition
comprising a metallic material and being substantially free of any
polymer, the second coating contacting at least a portion of the surface
of the stent sidewall structure, at least a portion of the second coating
composition being disposed adjacent to the first coating composition
on the surface of the stent sidewall structure, wherein the second
coating composition has a second thickness measured from the
surface of the stent sidewall structure; and wherein the second
thickness of the second coating composition is the same as or greater
than the first thickness of the first coating composition.

The following grounds of rejection are before us for review:
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The Examiner has rejected claims 25-27 under 35 U.S.C. § 103(a) as
unpatentable over Lye1 and Helmus,2 as evidenced by Merriam-Webster’s
Dictionary3 and Boyle.4
The Examiner has rejected claims 2-4, 7-8, 13-18, 20-22, 28, 31, and
32 under 35 U.S.C. § 103(a) as unpatentable over Lye and Helmus, as
evidenced by Merriam-Webster’s Dictionary and Boyle.
Appellant states that claim 25 is representative, and that the remaining
claims will stand or fall with claim 25. (App. Br. 4 and 12.)

ISSUE
The Examiner found that Lye suggested disposing different coating
patterns along the length of a stent, and that Helmus exemplified that it was
well known to design layers adjacent to one another. (Ans. 6-7.) The
Examiner concluded that it would have been obvious “to design the metallic
and polymer layers of Lye adjacent to one another on the surface of the
stent. One would have been motivated to do so particularly in view of
Helmus which exemplifies that such coatings are a matter of design choice
to be patterned longitudinally or vertically on stent surfaces.” (Id.)
Appellant agrees that Lye did not describe a stent comprising two
adjacent coating compositions, each contacting the same surface of a stent

1 Lye et al., US 2006/0121080 A1, published Jun. 8, 2006
2 Helmus, US 2006/0127443 A1, published Jun. 15, 2006
3 Merriam-Webster OnLine, accessed at www.merriam-
webster.com/dictionary/strut on Nov. 20, 2009.
4 Boyle et al., US 2004/0102837 A1, published May 27, 2004

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sidewall structure (App. Br. 6), and points out that instead, Lye’s polymer
layer is atop, and not adjacent to, Lye’s porous metal layer (id. at 7).
Appellant does not agree that Helmus remedied the deficiency in Lye’s
disclosure, and contends that Helmus only taught that “nanoporous coating
regions can be provided on the luminal surfaces, on the abluminal surfaces,
on the lateral surfaces between the luminal and abluminal surfaces, patterned
along the luminal or abluminal length of the devices, on the ends, and so
forth.” (Id. at 11, quoting Helmus ¶ 16.)
The dispositive issue, in Appellant’s phrasing, is whether
Helmus’ use of the single word ‘pattern’ would . . . have made
obvious appellant’s . . . first and second coating compositions as
recited in claim 25, at least because it would not have been obvious
for one skilled in the art to ‘pattern’ such that the first coating
composition and at least a portion of the second coating composition
are disposed adjacent to each other and contacting the same surface of
a stent sidewall structure.

(App. Br. 11.)

FINDINGS OF FACT
FF1. Lye disclosed using a nanoporous coating to improve adhesion of a
polymer coating to the stent surface (Lye 15, ¶0094). The metallic
nanoporous layer promotes adhesion of polymers or other material to the
surface of the stent (Id. 16, ¶0105).
FF2. The metallic coating serves to store therapeutic agents as well as
provide an improved bonding surface for other drug elution coatings (Lye
16, ¶0105). A second porous layer of polymer or other material can store
and release therapeutic agent (Id.).
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FF3. Lye disclosed that the pore size may range from 5 nanometers to
nearly the thickness of the film (Lye 17, ¶0112).
FF4. Helmus disclosed medical devices having two layers: one layer
comprising a therapeutic agent and a second layer comprising a metallic
nanoporous coating deposited over top of the therapeutic layer on a medical
device (Helmus 1, ¶0005, ¶0010). The metallic nanoporous layer may cover
all or just a portion of the device (Helmus 2, ¶0016).
FF5. Boyle disclosed patterning a metal onto a substrate; the pattern can be
made using masking or etching techniques. (Boyle 5, ¶0040, ¶0042.) The
substrate serves as the mold onto which the stent metal material is deposited.
Once formed, the metal stent is removed from the substrate (Id. ¶0043).
FF6. The Examiner finds that in Lye “[t]he polymer is either bonded or
adhered to the metallic nanoporous coating” (Ans. 13).
FF7. The Examiner finds that

Lye suggests that both porous layers can contain therapeutic agents,
therefore the drug and polymer carrier in Lye are not disposed in the
pores of the porous metal layer only. In fact, both porous coating
layers may contain active agents. Additionally, paragraph 0105 of
Lye does not disclose the layers as being on top of one another, but
merely being adhered or bonded to the metallic coating.

(Ans 15.)

PRINCIPLES OF LAW
“The Patent Office has the initial duty of supplying the factual basis
for its rejection. It may not . . . resort to speculation, unfounded assumptions
or hindsight reconstruction to supply deficiencies” in the cited references. In
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re Warner, 379 F.2d 1011, 1017 (CCPA 1967). “Rejections on obviousness
grounds cannot be sustained by mere conclusory statements; instead, there
must be some articulated reasoning with some rational underpinning to
support the legal conclusion of obviousness.” In re Kahn, 441 F.3d 977, 988
(Fed. Cir. 2006), cited with approval in KSR Int’l Co. v. Teleflex Inc., 550
U.S. 398, 417-18 (2007).

ANALYSIS
We begin our analysis by interpreting the limitations of claim 25.
Claim 25 defines a stent comprising first and second coating compositions
“contacting at least a portion of the stent sidewall structure.” We interpret
this to mean that each coating material makes actual contact with the
structure of the stent sidewall. A further requirement of the claim is that
“the second coating composition being disposed adjacent to the first coating
composition on the surface of the stent sidewall structure,” and we interpret
this limitation to mean that the two coating materials make contact with each
other while simultaneously making contact with the structure of the medical
device. Thus, we interpret the claim to define a stent covered by two
different coating materials, and each of the two coating materials makes
contact with the surface of the stent itself as well as making contact with the
other coating.5

5 We note that claim 25 contains one additional limitation directed to the
thickness of the coating materials in relation to each other, however, we do
reach this limitation in our analysis because we find that the cited art does
not disclose two adjacent coating materials each making contact with the
device structure.
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After reviewing the evidence, we agree with Appellant that the
Examiner has not set out a prima facie case. We find that Lye disclosed two
different coating materials, however, we find that only the metallic coating
material makes contact with the surface of the medical device (FF1, FF2).
The metal coating of Lye does not include pores that reach the surface of the
medical device (FF3). Further, the Examiner admits that the purpose of Lye
is to coat the medical device with a metal layer that serves to anchor the
polymer layer to the medical device (FF6, FF7). The Examiner asserts that
variation in the coating properties may be achieved using masking
techniques (Ans. 15-16). We find no evidence in Lye that the masking
technique prevents the metallic coating from reaching the surface of the
medical device. We find that one of the elements of the claim is that both
coating materials are in contact with the surface of the device, and it is
undisputed that this limitation is missing in Lye. Helmus disclosed making
patterns with the metallic coating using masking techniques. However, the
metallic layer is laid over the top of a therapeutic layer and thereby the metal
layer, even if applied in a pattern, would not reach the surface of the medical
device (FF4). Thus, Helmus is also missing the limitation of having two
adjacent coatings making contact with the medical device itself. In other
words, the rejection’s finding that Helmus “exemplified” such adjacent
coatings (Ans. 7) is not supported by evidence. Boyle does not show a
medical device with two coatings. The metal coating in Boyle is placed onto
a sacrificial structure, and this structure is removed from the metal once the
stent is formed (FF5). Thus, Boyle does not disclose the limitation of a
coating making contact with the device, let alone having two different
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coating materials adjacent to each other making contact with the device.
Accordingly, we find that the Examiner has not set out a prima facie case,
and for this reason we reverse the obviousness rejection.

CONCLUSION OF LAW
We conclude that the evidence of record does not support the
Examiner’s conclusion that the combination of Lye and Helmus as
evidenced by Webster’s and Boyle renders obvious the stent structure of
claim 25. We thus reverse the rejection of claim 2-4, 7, 8, 13-18, 20-22, 25-
28, and 30-32 under 35 U.S.C. § 103(a) as being obvious.

REVERSED

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