Ex Parte Burgermeister et al

Patent Trial and Appeal Board

Mar 11, 2013

11172527 (P.T.A.B. Mar. 11, 2013)

UNITED STATES PATENT AND TRADEMARK OFFICE
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
APPLICATION NO. FILING DATE FIRST NAMED INVENTOR ATTORNEY DOCKET NO. CONFIRMATION NO.
11/172,527 06/30/2005 Robert Burgermeister CRD-5098-USNP 7552
100369 7590 03/11/2013
Dergosits & Noah LLP
Three Embarcadero Center, Suite 410
San Francisco, CA 94111
EXAMINER
OU, JING RUI
ART UNIT PAPER NUMBER
3773
MAIL DATE DELIVERY MODE
03/11/2013 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 ROBERT BURGERMEISTER,
RANDY GRISHABER, RAMESH MARREY, JIN PARK,
MATHEW KREVER, and DAVID OVERAKER
__________

Appeal 2011-002454
Application 11/172,527
Technology Center 3700
__________

Before DONALD E. ADAMS, JEFFREY N. FREDMAN, and
ERICA A. FRANKLIN, Administrative Patent Judges.

FREDMAN, Administrative Patent Judge.

DECISION ON APPEAL
This is an appeal under 35 U.S.C. § 134 involving claims to a stent.
The Examiner rejected the claims as obvious. We have jurisdiction under 35
U.S.C. § 6(b). We affirm-in-part.

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Statement of the Case
Background
The Specification teaches “an optimized stent having asymmetrical
strut and loop members, wherein at least one pair of circumferentially
adjacent radial strut members have unequal axial lengths” (Spec. 1, ll. 10-
13).
The Claims
Claims 1-10, 12, 13, 22-28, and 30 are on appeal. Claim 1 is
representative and reads as follows:
1. A stent comprising:
one or more hoop sections having a tubular configuration
with proximal and distal open ends defining a longitudinal axis
extending there between, each hoop section being formed from a
plurality of radial strut members and one or more radial arc
members connecting adjacent radial struts to form a sinusoidal
wave pattern, wherein at least one amplitude of the sinusoidal
wave pattern is greater than the adjacent amplitude of the
sinusoidal wave pattern when measured relative to the
longitudinal axis, and wherein at least one radial arc member has
non-uniform cross-sections to achieve near-uniform stress, strain,
or stress and strain distribution along the radial arc when the
radial arc undergoes deformation.

The issues
A. The Examiner rejected claims 1, 2, 4-10, 12, 13, and 22-28 under 35
U.S.C. § 103(a) as obvious over Duerig1 and Burgermeister2 (Ans. 3-9).

1 Deurig et al., US 6,190,406 B1, issued Feb. 20, 2001.
2 Burgermeister et al., US 2003/0069630 A1, published Apr. 10,
2003.
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B. The Examiner rejected claim 30 under 35 U.S.C. § 103(a) as obvious
over Limon3 and Gomez4 (Ans. 9-10).
A. 35 U.S.C. §103(a) over Deurig and Burgermeister
The Examiner finds that:
Duerig et al discloses a stent comprising: one or more hoop
sections (52(a)-(d), Fig. 4) having a tubular configuration
with proximal and distal open ends defining a longitudinal
axis (83, Fig. 3) extending there between (Figs. 2 and 3),
each hoop section being formed as a continuous series of
substantially longitudinally oriented radial strut members
(center, 94, Fig. 4A) and a plurality of radial arc members
(ends, 90 and 92, Fig. 4A) connecting adjacent radial struts,
wherein each of the plurality of radial arc members having
an amplitude perpendicular to the longitudinal axis, wherein
at least one radial arc member has non-uniform cross-
sections.

(Ans. 3-4). The Examiner finds that Deurig teaches “one or more
longitudinally oriented flex connectors (bridge, 70, Fig. 4) having at least
one flexible strut member (the bridge is a flexible strut member, 70, Fig. 4),
wherein the at least one flexible strut member has non-uniform cross-
sections” (Ans. 4).
The Examiner finds that Burgermeister teaches a stent comprising:
a) the at least one amplitude of the sinusoidal wave
pattern is greater than the adjacent amplitude of the
sinusoidal wave pattern when measure relative to the
longitudinal axis (Fig. 4A);
b) at least one radial arc member has a different
geometry (see Figure below) which includes different arc

3 Limon, T., US 6,273,910 B1, issued Aug. 14, 2001.
4 Gomez et al., US 6,656,220 B1, issued Dec. 2, 2003.
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cross-sections, different arc radii, and different lengths from
the immediately adjacent radial arc;
c) each flex connector having an amplitude
perpendicular to the longitudinal axis, wherein the amplitude
of the flexible connector is at least 1.5 times greater than a
amplitude of the connected radial arc (see Figure below, the
amplitude perpendicular to the longitudinal axis and is
almost 2 times greater than a circumferential amplitude of
the connected radial arc);
d) each flex connector is shaped so as to nest together
into the circumferentially adjacent flex connector (when the
stent is in the radially collapsed configuration, the wave
shape of flex connector 250 would must be nested together
into circumferentially adjacent flex connector, Fig. 4A);
e) and the corresponding points on longitudinal
adjacent loop sections are circumferentially displaced from
one another (Fig. 4A).

(Ans. 5-6). The Examiner finds it obvious to alter the amplitude of the waves
to “allow the attachment points at the end of the flexible connector can be
located at any point along the struts rigid section. . . . so that tenacity of the
stent, and its concomitant support are both maintained to a high degree at the
situs of the lesion” (Ans. 8). The Examiner finds it an obvious “design
choice and within level of one of ordinary skill in the art to include at least
one radial arc member has a different geometry which includes different arc
cross-sections, different arc radii, and different lengths from the immediately
adjacent radial arc to optimize the distribution of strain throughout the stent”
(Ans. 8).
The issue with respect to this rejection is: Does the evidence of record
support the Examiner’s conclusion that Deurig and Burgermeister render
claims 1, 8, and 13 obvious?
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Findings of Fact
1. Figure 3B of the Specification is reproduced below:

Figure 3B is a magnified detal view of “proximal hoop element 322a and
internal hoop element 322b” (Spec. 12, ll. 24-25A).
2. The Specification teaches that in Figure 3B, there are “two
different radial arcs 310a1 and 310a2. The differences in the two radial arcs
may include, different geometries, such as different arc cross-sections;
different arc radii; and different arc lengths” (Spec. 18, ll. 4-6). The
Specification teaches that “at least one radial arc member has nonuniform
cross-sections to achieve near-uniform strain distribution along the radial arc
when the radial arc undergoes deformation” (Spec. 4, ll. 20-22).
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3. The Specification teaches, regarding Figure 3F, that for
“references purposes, an imaginary reference line 375 is drawn
perpendicular to the longitudinal axis of the stent 300 midway between the
extreme positive and negative peaks of the sinusoidal wave pattern.
Progressing circumferentially along the internal hoop section, two
consecutive relatively high amplitudes 361 are followed by two consecutive
relatively low amplitudes 360” (Spec. 10, ll. 10-15).
4. Figure 3F of the Specification is reproduced below:

“Figure 3F illustrates a repeating sinusoidal wave pattern having alternating
high and low amplitude pairs” (Spec. 6, ll. 32-33).
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5. Deurig teaches that “[p]referably, the width W tapers
substantially continuously from the ends 90 and 92 to the center 94. The
effect of this tapering will be to cause a greater resistance to deformation at
the loops (where the bending moments are high), and to make the overall
strain deformation more uniform” (Duerig, col. 6, ll. 12-17).
6. Deurig teaches that the “tubular member is made from a
plurality of adjacent hoops 52 . . . hoops 52(a)-52(d), extending between the
front and back ends 81 and 82” (Deurig, col. 5, ll. 33-35).
7. Deurig teaches that the “the struts 60 are curved or bent so as to
form a plurality of loops 62, which connect adjacent struts. The struts are so
connected at their opposite ends so as to form an S or Z shape pattern”
(Deurig, col. 5, ll. 39-41).
8. Figure 4A of Duerig is reproduced below:

“FIG. 4A is an enlarged view of section of the stent” (Duerig, col. 5, ll. 1-2).
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9. Burgermeister teaches that in “the stent 200, the relatively rigid
sections R contain unequal struts 210, 220 of lengths a, b, as can best be
seen in FIG. 4” (Burgermeister 4 ¶ 0050).
10. Burgermeister teaches that:
In this fashion, when the stent is expanded, the relatively
more rigid section R “holds” the connector 250 along the
surface of the lesion, so that tenacity of the stent, and its
concomitant support are both maintained to a high degree at
the situs of the lesion. Yet, in the unexpanded configuration,
the “N”-shaped flexible connectors 250 are able to guide the
stent 200 around the curvature of generally any tortuous
vessel, including tortuous coronary arteries.

(Burgermeister 4 ¶ 0050).
11. Figure 4 of Burgermeister is reproduced below:

“FIG. 4 is a plan view of yet another embodiment of a stent” (Burgermeister
3 ¶ 0030).
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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.”
KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398, 416 (2007). “If a person of
ordinary skill can implement a predictable variation, § 103 likely bars its
patentability.” Id. at 417.
However, to establish a prima facie case of obviousness, the Examiner
must find “a reason that would have prompted a person of ordinary skill in
the relevant field to combine the elements in the way the claimed new
invention does.” Id. at 418.
Analysis
Claim 1
We begin with claim interpretation. Claim 1 requires that “at least
one radial arc member has non-uniform cross-sections”. In interpreting what
constitutes a “radial arc member”, we look to the Specification which
teaches that the “differences in the two radial arcs may include, different
geometries, such as different arc cross-sections; different arc radii; and
different arc lengths” (Spec. 18, ll. 4-6; FF 2). Independent claim 22 also
includes the same limitation.
The Examiner acknowledges that Deurig does not disclose a “radial
arc member [which] has a different geometry” (Ans. 5), relying upon Figure
4A of Burgermeister to show a stent with arcs having different geometries.
However, while there are differences between the connection of the arcs to
the struts in Figure 4A of Burgermeister, the figure does not clearly
demonstrate that the arcs differ in cross-section, radii, or length. Also,
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Burgermeister teaches different lengths 210 and 220 for the struts (FF 9), but
this does not necessarily imply differences in the arcs connecting the struts.
Since the Examiner has failed to identify textual teachings in Burgermeister
regarding the specific arc dimensions, reliance on Figure 4A is insufficient
since figures are not necessarily to scale and Figure 4A does not necessarily
define precise geometries of the arc. See In re Nash, 230 F.2d 428, 431
(CCPA 1956) (“[I]t is well settled that the drawings of patent applications
are not necessarily scale or working drawings....”); In re Olson, 212 F.2d
590, 592 (CCPA 1954) (“Ordinarily drawings which accompany an
application for a patent are merely illustrative of the principles embodied in
the alleged invention claimed therein and do not define the precise
proportions of elements relied upon to endow the claims with patentability.”)
The Examiner also finds that “it would have been a design choice and
within level of one of ordinary skill in the art to include at least one radial
arc member has a different geometry which includes different arc cross-
sections, different arc radii, and different lengths from the immediately
adjacent radial arc to optimize the distribution of strain throughout the stent”
(Ans. 8).
We are not persuaded since the Examiner lacks evidence that
changing the arc geometry was a known and obvious design choice. A
finding of obvious design choice is precluded in this instance because
Appellants have set forth reasons why the difference between the claimed
invention and the prior art would result in a different function. See In re
Chu, 66 F.3d 292, 298-99 (Fed. Cir. 1995) (“design choice” is appropriate
where the applicant fails to set forth any reasons why the differences
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between the claimed invention and the prior art would result in a different
function). More particularly, Appellants’ Specification teaches regarding
the prior art that:
Although a stent having strut or arc members with a uniform
cross-sectional area will function, when the width of the
members are increased to add strength or radio-opacity, the
sets of strut members will experience increased stress and/or
strain upon expansion. High stress and/or strain can cause
cracking of the metal and potential fatigue failure of the
stent under the cyclic stress of a beating heart.

(Spec. 2, l. 32 to 3, l. 3). The Specification teaches a solution to this
problem, teaching that “at least one radial arc member has nonuniform
cross-sections to achieve near-uniform strain distribution along the radial arc
when the radial arc undergoes deformation” (Spec. 4, ll. 20-22; FF 2). Thus,
Appellants have set forth reasons why the different arc geometry would
result in a different function.
Claim 8
We again begin with claim interpretation. Claim 8 is drawn to a
different embodiment than claim 1, since claim 8 does not include the
recitation that ““at least one radial arc member has non-uniform cross-
sections”. Instead, claim 8 requires that “at least one radial component has
non-uniform cross-sections”. The Specification expressly recognizes that
struts may be radial components, teaching “adjacent radial strut members”
(Spec. 4, l. 13).
Both Duerig and Burgermeister teach that adjacent struts may differ in
structure. Duerig shows in Figure 4A that the struts taper in length from the
ends 90 and 92 to the middle of the strut and 94 (FF 8). Duerig teaches that
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“[p]referably, the width W tapers substantially continuously from the ends
90 and 92 to the center 94. The effect of this tapering will be to cause a
greater resistance to deformation at the loops (where the bending moments
are high), and to make the overall strain deformation more uniform”
(Duerig, col. 6, ll. 12-17; FF 5). Similarly, Burgermeister teaches that in
“the stent 200, the relatively rigid sections R contain unequal struts 210, 220
of lengths a, b, as can best be seen in FIG. 4” (Burgermeister 4 ¶ 0050; FF
9). Therefore, the prior art recognizes that the radial struts may be altered in
length and in width, either change will result in “non-uniform cross-
sections” as required by claim 8. Further, Duerig expressly teaches that the
change will result in more uniform strain deformation (FF 5).
Appellants contend that “this strain distribution does not mean that
any portion of the stent, particularly the radial components, will have near
uniform stress, strain, or stress and strain” (App. Br. 9).
We are not persuaded. The evidence of Duerig (FF 5) combined with
the teaching in the Specification that non-uniform cross sections will result
in more uniform stress (see, e.g., FF 1) are sufficient for the Examiner to
reasonably find that Duerig’s tapering of the struts would inherently satisfy
the functional requirement of claim 8 “to achieve near-uniform stress, strain,
or stress and strain distribution along the radial component”. See 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.”) Appellants provide no
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evidence to rebut the inherency argument, providing only attorney argument
without specific evidence.
Claim 13
Appellants argue that “nothing in Duerig and/or Burgermeister
discloses a radial arc having non-uniform cross-sections and substantially
equivalent cross-sectional areas” (App. Br. 12).
We are not persuaded. Figure 4A of Deurig shows that each and
every strut appears to share the same taper, and while as discussed above we
do not read specific geometries from figures which may not be drawn to
scale, we also find that the showing in the figure of uniformity between the
struts supports the Examiner’s position that the cross-sectional areas
between struts at any given position would be “substantially equivalent” as
required by claim 13. Claim 13 does not require that the cross-sectional area
is equivalent at every position, only that the cross sections of the strut as a
whole have “substantially equivalent cross-sectional areas”. Appellants
have failed to direct us to evidence showing any contrary result. See In re
Pearson, 494 F.2d 1399, 1405 (CCPA 1974) (“Attorney’s argument in a
brief cannot take the place of evidence.”). We therefore agree with the
Examiner that “the areas of cross-sections of radial strut members are
substantially equivalent” (Ans. 13).
Conclusions of Law
The evidence of record does not support the Examiner’s conclusion
that Deurig and Burgermeister render claim 1 obvious.
The evidence of record supports the Examiner’s conclusion that
Deurig and Burgermeister render claims 8 and 13 obvious.
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B. 35 U.S.C. §103(a) over Limon and Gomez
The Examiner finds that:
Limon discloses a stent comprising: one or more hoop
sections having a tubular configuration with proximal and
distal open ends defining a longitudinal axis extending there
between, each hoop section being formed from a plurality of
radial strut members and one or more radial arc members
connecting adjacent radial strut, each radial strut member
having two opposing end portions and a mid portion there
between (Fig. 7), wherein the stent achieves near-uniform
strain distribution along the radial arc when the radial arc
undergoes deformation (Col. 10, lines 1-18, portion 29
expands more uniformly. In addition, Limon discloses that
the stresses applied to the stent are being even out.
Therefore, the stress distribution would also be near
uniform).

(Ans. 9-10). The Examiner finds that “Gomez et al teaches a stent
comprising: a radial strut member (68, Fig. 15), wherein the middle section
(84) of the radial strut member has a larger cross-sectional area than the end
portions (82) of the radial strut member” (Ans. 10). The Examiner finds it
obvious to “modify the radial strut member of Limon to include that the
middle section to have a larger cross-sectional area than the end portions as
taught by Gomez. The suggestion/motivation for doing so would have been
to create variable flexibility for the stent” (Ans. 10).
The issue with respect to this rejection is: Does the evidence of record
support the Examiner’s conclusion that Limon and Gomez render claim 30
obvious?

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Findings of Fact
12. Limon teaches “an elongated cylindrical stent body formed with
a central section located between at least one end section having different
radial expansion characteristics” (Limon, col. 2, ll. 38-40).
13. Figure 7 of Limon is reproduced below:

“FIG. 7 is an enlarged plan view of a flattened section” of a stent. (Limon,
col. 5, l. 46).
14. Limon teaches that the “stresses involved during expansion
from a low profile to an expanded profile are much more evenly distributed
among the various peaks 26 and valleys 28 of individual cylindrical
elements” (Limon, col. 9, ll. 58-61).
15. Limon teaches that these “differing degrees of curvature along
the peak portion 26 allow for the more even expansion of the cylindrical
element 18 as a whole” (Limon, col. 10, ll. 20-22).
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16. Gomez teaches that “first struts 66 and second struts 68 may
vary in thickness (radial thickness) along their length in order to create
variable flexibility in the rings. As shown in FIG. 15, second peak 61 has
second struts 68 that have radial thick portion 84 in the middle of the struts
and radial thin portion 82 near the ends of the struts” (Gomez, col. 10, ll. 44-
50).
17. Figure 15 of Gomez is reproduced below:

“FIG. 15 is an enlarged partial perspective view of a portion of a peak and
associated struts depicting variable radial thickness struts” (Gomez, col. 5, ll.
27-29).
Analysis
Limon teaches a stent comprising hoop sections with a tubular
configuration comprising a plurality of struts and arc members (FF 12-15).
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The Examiner finds that “Limon does not appear to disclose that the middle
section has a larger cross-sectional area than the end portions” (Ans. 10).
However, Gomez teaches that “first struts 66 and second struts 68 may vary
in thickness (radial thickness) along their length in order to create variable
flexibility in the rings. As shown in FIG. 15, second peak 61 has second
struts 68 that have radial thick portion 84 in the middle of the struts and
radial thin portion 82 near the ends of the struts” (Gomez, col. 10, ll. 44-50;
FF 16).
Applying the KSR standard of obviousness to the findings of fact, we
agree with the Examiner that the ordinary artisan would have reasonably
found it obvious to vary the thickness of Limon’s struts as suggested by
Gomez in order to create variable flexibility for the stent to maximize the
desired flexibility. 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 that “the assertions appear to be Official Notices
taken by the Examiner, yet the Examiner has not provided any evidence in
support of the Official Notices” (App. Br. 13).
We are not persuaded. The Examiner is reasonably contending that
since Limon in view of Gomez shares the identical structure with the claim,
the resulting stent would share the property of “near-uniform strain
distribution along the radial arc” required by claim 30. This is an inherency
argument, and Appellants have provided no evidence that the stent of Limon
in view of Gomez would not achieve the required strain distribution. Best,
562 F.2d 1252, 1255 (CCPA 1977). Further, given the express teachings of
Limon to even distribute the stresses and strains of expansion (FF 14-15)
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and the teaching of Gomez that varying thickness of the struts to vary
flexibility was known (FF 16), the ordinary artisan would have routinely
optimized the stent structure to maximize the even distribution of stresses
and strains.
Conclusion of Law
The evidence of record supports the Examiner’s conclusion that
Limon and Gomez render claim 30 obvious.
SUMMARY
In summary, we reverse the rejection of claims 1, 2, 4-7, and 22-28
under 35 U.S.C. § 103(a) as obvious over Duerig and Burgermeister.
We affirm the rejection of claims 8 and 13 under 35 U.S.C. § 103(a)
as obvious over Duerig and Burgermeister. Pursuant to 37 C.F.R.
§ 41.37(c)(1)(2006), we also affirm the rejection of claims 9, 10, and 12, as
these claims were not argued separately.
We affirm the rejection of claim 30 under 35 U.S.C. § 103(a) as
obvious over Limon and Gomez.

No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136(a)(1).

AFFIRMED-IN-PART

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