Lifetech Scientific (Shenzhen) Co., Ltd.

Patent Trials and Appeals Board

Apr 23, 2021

2020005441 (P.T.A.B. Apr. 23, 2021)

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.
15/241,349 09/13/2016 Wei Guo PAT-2133 5735
7590 04/23/2021
Raymond Sun
20 Corporate Park, Suite 155
Irvine, CA 92606
EXAMINER
WOZNICKI, JACQUELINE
ART UNIT PAPER NUMBER
3774
MAIL DATE DELIVERY MODE
04/23/2021 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 WEI GUO, DEYUAN ZHANG, BENHAO XIAO,
WUYANG LI, and CAIPING LIU
____________

Appeal 2020-005441
Application 15/241,349
Technology Center 3700
____________

Before JOHN C. KERINS, BRETT C. MARTIN, and WILLIAM A. CAPP,
Administrative Patent Judges.

CAPP, Administrative Patent Judge.

DECISION ON APPEAL

STATEMENT OF THE CASE
Appellant1 seeks our review under 35 U.S.C. § 134(a) of the final
rejection of claims 16–23. We have jurisdiction under 35 U.S.C. § 6(b).
We AFFIRM.

1 We use the word “Appellant” to refer to “applicant” as defined in 37
C.F.R. § 1.42(a). Appellant identifies Lifetech Scientific (Shenzhen) Co.,
Ltd. as the applicant and real party in interest. Appeal Br. 1.
Appeal 2020-005441
Application 15/241,349
2
THE INVENTION
Appellant’s invention relates to vascular stent grafts. Spec. 1.
Claim 16, reproduced below, is illustrative of the subject matter on appeal.
16. A method for treating an aneurysm, the
aneurysm located at a diseased aorta and wherein the
diseased aorta has at least one branch blood vessel
branching from the diseased aorta, characterized in that
the method comprises:
providing an aortic stent graft having a trunk
portion, a side branch and a main branch, with a first
end at the trunk portion and a second end at the side
branch;
implanting the aortic stent graft into the diseased
aorta to isolate the aneurysm by securing the first end of
the aortic stent graft to a healthy wall portion of the
diseased aorta upstream of the aneurysm;
introducing a bifurcated stent graft into the diseased
aorta, wherein the bifurcated stent graft comprises a
body portion and a branch portion communicating with
and extending at an acute angle from the body portion
with respect to a proximal end of the aortic stent graft,
the body portion having opposing first and second ends,
with the first end of the body portion communicating
with a healthy blood vessel downstream of the
aneurysm, and the second end of the body portion
coupled to the second end of the aortic stent graft;
advancing a straight stent graft through the body
portion of the bifurcated stent graft towards the branch
portion from a location downstream of the bifurcated
stent graft; and
deploying the straight stent graft to communicate
the branch portion and the branch blood vessel, and
positioning the straight stent graft inside the branch
blood vessel.

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THE REJECTIONS
The Examiner relies upon the following as evidence in support of the
rejections:
NAME REFERENCE DATE
Stockert US 5,662,675 Sept. 2, 1997
Taheri US 6,099,548 Aug. 8, 2000
Chuter US 2010/0249899 A1 Sept. 30, 2010
Isch US 2012/0123527 A1 May 17, 2012
The following rejections are before us for review:
1. Claims 16–17 and 19–23 are rejected under 35 U.S.C. § 103 as
being unpatentable over Stockert, Taheri, and Chuter.
2. Claim 18 is rejected under 35 U.S.C. § 103 as being unpatentable
over Stockert, Taheri, Chuter, and Isch.2,3
OPINION
Unpatentability of Claims 16–17 and 19–23
over Stockert, Taheri, and Chuter
Appellant argues claims 16–17 and 19–23 as a group. Appeal
Br. 9–11. Claim 16 is representative. See 37 C.F.R. § 41.37(c)(1)(iv).
The Examiner finds that Stockert discloses the invention substantially
as claimed except for having a trunk portion, a main branch, and a side
branch that extends at an acute angle as claimed, and for which the

2 The final rejection also mentions a reference identified only as “Schaeffer.”
Final Act. 16. No facts are found using Schaeffer as evidence and the
reference is not otherwise mentioned in the final rejection or the Answer.
We will treat the Examiner’s extraneous mention of Schaeffer as an
inadvertent typographical error.
3 Alternative grounds of rejection relying on Taheri, instead of Stockert, as
the primary reference have been withdrawn by the Examiner. Ans. 9–17.
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Application 15/241,349
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Examiner relies on Taheri and Chuter. Final Act. 11–12. The Examiner
concludes that it would have been obvious to a person of ordinary skill in the
art at the time of the invention to modify Stockert with the teachings of
Taheri and Chuter to achieve the claimed invention. Id. 12–14. According
to the Examiner, a person of ordinary skill in the art would have done this to
cover longer aneurysms and to cover a variety of branch geometries in the
circulatory system. Id. The Examiner considers modular and integral stent-
graft systems to be well-known, routine, predictable, and obvious
alternatives in the art. Id. at 13.
Appellant argues that it is “unclear” how the Figure 15 embodiment of
Taheri helps the person of ordinary skill in the art to create a bifurcated stent
graft with the recited structural features. Appeal Br. 9. Appellant argues
that the rejection fails to adequately explain how Taheri can be used to
modify Stockert’s stent grafts 110 and 112 into the specific structure
claimed. Id. at 10; see Stockert Fig. 1. Appellant’s argument distinguishes
Stockert’s elements 110 and 112 (Stockert Fig. 1) from Appellant’s own
elements 20 and 30 (Appellant’s Fig. 6). Id. Appellant characterizes these
differences as a “very big” gap that cannot be filled without applying
impermissible hindsight reconstruction. Id.
In response, the Examiner reminds Appellant that the rejection is over
a combination of references that include Stockert and Taheri. Ans. 18. The
Examiner states that the rejection contemplates attaching the stent of Taheri
Figure 15 to the aortic section of Stockert. Id. The Examiner explains that
such combination results in a main branch and a side branch as claimed. Id.
The Examiner relies on Stockert as disclosing a bifurcated stent graft with a
body portion and a branch portion. Id.
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Appellant argues that the Examiner’s rejection “ignores” the steps
recited in Stockert. Appeal Br. 10. Appellant asserts that the steps recited in
Stockert are opposite to the claimed steps in that the downstream stent graft
is secured first, before securing the upstream stent graft. Id. Appellant
argues that a person of ordinary skill in the art would have to change the
structures of the grafts and reverse the deployment steps taught by Stockert.
Id.
In response, the Examiner points out that the claimed method does not
require the various steps to be performed in any particular order. Ans. 20.
According to the Examiner, the only step that indicates any sequence of
implanting is the limitation directed to advancing the straight stent graft
through the bifurcated stent graft. Id. Otherwise, no steps indicate an order
of implanting. Id.
In reply, Appellant argues that the limitation directed to introducing a
bifurcated stent graft must be performed after the aortic stent graft is
delivered. Reply Br. 4. According to Appellant, “you cannot introduce a
bifurcated stent graft and have the second end of the body portion coupled to
the second end of the aortic stent graft unless the aortic stent graft has been
first implanted.” Id.
Appellant’s sequence of steps argument is not persuasive. As a
general rule, a method claim is not limited to performing the steps in the
order recited, unless it explicitly or implicitly requires a specific order.
Interactive Gift Express, Inc. v. Compuserve Inc., 256 F.3d 1323, 1342–43
(Fed. Cir. 2001). With respect to the aortic stent graft and the bifurcated
stent graft, claim 16 recites three distinct steps: (1) implanting an aortic
stent graft on the upstream side of an aneurysm; and (2) disposing a
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bifurcated stent graft downstream of the aortic stent graft; and (3) coupling
the aortic stent graft to the bifurcated stent graft. Claims App. Although we
agree with Appellant that the coupling step cannot be completed until both
the aortic and bifurcated stent grafts are in position, we do not agree that the
claim requires either stent graft to be positioned before the other.
Further in regard to the sequence of steps, Appellant argues that the
Examiner’s rejection requires reversing the sequence of deployment steps in
Stockert which would also entail modifying the structure of the modular
components thereof. Appeal Br. 10. We understand this to mean that, if
Stockert’s base member 112 is introduced through graft 114, as shown in
Figures 3C–3E, instead of vice versa, this would require modifying the
structure of the joint connection features of member 112 and graft 114. In
the Final Action, the Examiner finds, and Appellant does not dispute, that
modular and integral stent-graft systems are well-known, routine,
predictable, and obvious alternatives. Final Act. 13. Thus, even if we were
to find that Stockert’s elements 112 and 114 are assembled in a different
sequence than Appellant (we do not), Appellant does not explain how the
particular claimed sequence and corresponding connection structure is non-
obvious, requires more than ordinary skill, or produces unexpected results.
It appears to us that Stockert teaches all that is required for a person of
ordinary skill in the art to understand how to assemble an intraluminal,
multi-component stent graft, which involves advancing one component
through another during the assembly process.
Appellant challenges the Examiner’s finding regarding a motivation to
combine Taheri with Stockert. Appeal Br. 10. Appellant characterizes the
Examiner’s findings in this regard as “strange” and “confusing.” Id.
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In response, the Examiner explains that making a stent graft long
enough to span the length of an aneurysm is neither strange nor confusing,
but rather, is a simple concept for a person of ordinary skill in the art.
Ans. 19. The Examiner finds that Taheri is designed to span from above the
aortic arch to below the renal arteries. Id. The Examiner further finds that
Stockert extends from below the renal arteries and into the iliac arteries. Id.
The person of ordinary skill in the art understands that in order
to correct an aneurysm which spans this entire location, a stent-
graft which spans the corresponding length is required. The
Examiner respectfully points out this is not strange, nor
irrelevant, nor confusing.
Id.
Stockert discloses a bifurcated graft that is formed from a series of
individual components that are delivered apart from one another and are then
assembled to form a completed structure within the circulatory system.
Stockert, Abstract. Stockert’s system includes a primary graft 110, a base
member 112, and first and second grafts 114, 116, that are fabricated as
separate components and then assembled within the circulatory system. Id.
col. 5, ll. 37–57, Figs. 1, 2. The components are provided in a range of sizes
and are assembled in various combinations with each other to accommodate
the arterial morphology experienced by a patient. Id. As illustrated in
Figures 1–4, the various components form joints and connections that
correspond to the branching of blood vessels in the circulatory system. Id.
Figs. 1–4. Stockert’s graft is introduced into the body through the right
femoral artery, the right iliac artery, and into the aorta, while being guided
by guidewire 400. Id. col. 12, ll. 62–66. Another branch of the stent may be
introduced through the left femoral artery, the left iliac artery, and similarly
guided by guidewire 410. Id. col. 13, l. 64 – col. 15, l. 4.
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Taheri is directed to an arterial stent for use in aortic aneurysms.
Taheri, Abstract. Taheri features a main branch and a plurality of side
branches. Id. Fig. 15. Various branches of Taheri’s device are disposed in
their respective positions by a plurality of guidewires 56 that are passed into
various arteries. Id. col. 15, ll. 31–67. Once Taheri’s graft 20 is in position,
stents 59 are passed over guide wires 56 by means of stent catheter 62. Id.
Stents 59 are deployed into each of the branches of graft 20 by balloon
catheter 62 so that an aneurysm is excluded. Id.
In the Examiner’s rejection, Taheri is disposed upstream of Stockert.
Ans. 18 (“the stent graft of Taheri Figure 15 is actually attached to the aortic
section of [Stockert]”). As we understand the rejection, Stockert is attached
to Taheri at a point that corresponds to the junction of Appellant’s
elements 20 and 30 as shown in Appellant’s Figure 9. Attaching one
component of a modular stent graft to another component is expressly taught
by Stockert. Thus, we consider intraluminal attachment of one modular
stent graft component to another to be within the ambit of ordinary skill in
the art. Thus, the only structural element that is missing from the
combination of Stockert and Taheri is the acute angle element. Appellant
does not challenge the Examiner’s finding that Chuter discloses the acute
angle element. Final Act. 13 (citing Chuter, Fig. 3, element 34).
The Examiner’s reason for making the combination, namely, to cover
a long aneurysm, is sufficient to support the rejection. See In re Kahn, 441
F.3d 977, 988 (Fed. Cir. 2006) (requiring an obviousness conclusion to be
based on explicit articulated reasoning with rational underpinning), cited
with approval in KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398, 418 (2007).
The Examiner’s reasoning is also sufficient to obviate Appellant’s hindsight
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objection. See In re Cree, Inc., 818 F.3d 694, 702 n.3 (Fed. Cir. 2016)
(explaining that a hindsight argument is of no moment where the Examiner
provides a sufficient, non-hindsight reason to combine the references).
The Examiner’s findings of fact are supported by a preponderance of
the evidence and the Examiner’s legal conclusion of unpatentability is well-
founded. In view thereof, we sustain the Examiner’s unpatentability
rejection of claims 16–17 and 19–23.
Unpatentability of Claim 18
Stockert, Taheri, Chuter, and Isch
Claim 18 depends from claim 16 and adds the limitations:
advancing a cuff stent graft along the body portion from a
location downstream of the bifurcated stent graft, wherein the
cuff stent graft has opposite first and second ends;
attaching the first end of the cuff stent graft to the second
end of the aortic stent graft; and
attaching the second end of the cuff stent graft to the second
end of the body portion, wherein the cuff stent graft is
positioned between the aortic stent graft and the bifurcated stent
graft.
Claims App. The Examiner relies on Isch as teaching the cuff stent
limitations of claim 18. Final Act. 16–17. The Examiner concludes that it
would have been obvious to a person of ordinary skill in the art at the time
of the invention to further modify the combination used in the claim 16
rejection to achieve the invention of claim 18. Id. According to the
Examiner, a person of ordinary skill in the art would have done this to
provide extra sealing means. Id. at 17.
In the Appeal Brief, Appellant presents arguments in traverse of a
ground of rejection of claim 18 where Taheri, not Stockert, is relied on as
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the primary reference. Appeal Br. 11–12. In the Answer, the Examiner
notes that Appellant does not direct any arguments against the rejection of
claim 18 where Stockert, not Taheri, is relied on as the primary reference.
Ans. 21.
In the Reply Brief, Appellant argues that the Examiner “did not
respond” to Appellant’s arguments relating to claim 18. Reply Br. 5.
However, Appellant neglects to mention that its Appeal Brief arguments
regarding claim 18 were directed to a ground of rejection that has been
withdrawn and that Appellant otherwise, did not present any arguments in
traverse of the ground of rejection that the Examiner maintained.
It appears to us that the Examiner, in withdrawing grounds of
rejection where Taheri is the primary reference, considered that the prior art
may have led to different outcomes depending on which reference is
considered primary and how the references are combined. Under the
circumstances, Appellant did not provide the Examiner with a reasonable
opportunity to consider arguments that Appellant might have advanced
against the ground of rejection over claim 18 that the Examiner maintained
in the Answer. When Appellant fails to contest a ground of rejection, “the
Board may treat any argument with respect to that ground of rejection as
waived.” Hyatt v. Dudas, 551 F.3d 1307, 1314 (Fed. Cir. 2008).
We apply the waiver doctrine of Hyatt here and sustain the rejection
of claim 18.

Appeal 2020-005441
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CONCLUSION
Claim(s)
Rejected
35 U.S.C.
§
Reference(s)/Basis Affirmed Reversed
16, 17,
19-23
103 Stockert, Taheri, Chuter 16, 17,
19-23

18 103 Stockert, Taheri, Chuter,
Isch
18
Overall
Outcome
16-23

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)(iv).
AFFIRMED