Ex Parte Gershowitz

Board of Patent Appeals and Interferences

Jun 22, 2009

11118726 (B.P.A.I. Jun. 22, 2009)

UNITED STATES PATENT AND TRADEMARK OFFICE
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BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
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Ex parte ARTHUR D. GERSHOWITZ
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Appeal 2009-004788
Application 11/118,726
Technology Center 3700
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Decided:1 June 22, 2009
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Before TONI R. SCHEINER, ERIC GRIMES and STEPHEN WALSH,
Administrative Patent Judges.

WALSH, Administrative Patent Judge.

DECISION ON APPEAL
This is an appeal under 35 U.S.C. § 134 involving claims to a device
that removes air from blood in a perfusion system. The Patent Examiner

1 The two-month time period for filing an appeal or commencing a civil
action, as recited in 37 C.F.R. § 1.304, begins to run from the decided date
shown on this page of the decision. The time period does not run from the
Mail Date (paper delivery) or Notification Date (electronic delivery).
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Application 11/118,726

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rejected the claims as obvious. We have jurisdiction under 35 U.S.C. § 6(b).
We reverse.

STATEMENT OF THE CASE
The invention relates to a device used in an extracorporeal blood
perfusion system. (Spec. 1:18-19.) When heart surgery is performed “on
pump,” steps are taken to remove air entrained in the blood flowing in the
extracorporeal blood circuit. (Id. at 1:20-22.) Appellant claims an air
removal device and a method of separating air from blood. Claims 1, 3-12,
14 and 16-25 are on appeal.2 Claims 1 and 20 are representative:
1. An air removal device for removing air from blood flowing in a
perfusion system, comprising:

a chamber comprised of a substantially rigid shell of a
biocompatible material and having a blood flow region at a lower end
thereof and having an air collection region at an upper end thereof,
said chamber further having an inlet, a blood outlet, and an air
outlet vertically higher than said inlet, wherein said air outlet includes
an outlet mating surface proximate to an exit passage, and wherein a
portion of said chamber disposed around said blood flow region is
generally cylindrical about a vertical axis to provide a centrifugal
flow of said blood that causes air within said blood to migrate toward
said vertical axis; and

a float disposed for vertical movement in said chamber along
said vertical axis, wherein said float has an effective density less than
the density of said blood, and wherein said float includes a generally

2 Claim 13 is also pending but has been withdrawn from consideration by
the Examiner. (App. Br. 2.) Claims 2 and 15 were cancelled. (Id.)
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toroidally shaped body and a sealing surface for engaging said outlet
mating surface and blocking said exit passage when said float is at its
vertically highest position.

20. A method of separating air from blood in a perfusion system
coupled to a patient, said method comprising the steps of:

pumping an input blood supply through a chamber of a
substantially rigid shell formed of a biocompatible material;

forming a centrifugal blood flow of said input blood supply in a
bottom region of said chamber that is generally cylindrical about a
vertical axis to cause air to leave said blood and migrate upward in
said chamber;

buoyantly suspending a float on said blood flow, wherein said
float is disposed for vertical movement in said chamber along said
vertical axis, wherein said float includes a generally toroidally shaped
body, and wherein said float has an effective density less than the
density of said blood;

when a volume of air present within said chamber is less than a
predetermined volume, then said float closing a valve at an air outlet
from said chamber as a result of a sealing surface of said float
engaging an outlet mating surface of said air outlet to block said air
outlet; and

when a volume of air present within said chamber is greater
than said predetermined volume, then said float opening said valve to
remove air from said chamber.

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The Examiner relied on the following evidence:
US 3,849,071 Kayser Nov. 19, 1974
US 4,708,157 Sabatino Nov. 24, 1987
US 5,824,212 Brockoff Oct. 20, 1998
US 6,267,926 B1 Reed et al. Jul. 31, 2001
US 6,337,049 B1 Tamari Jan. 8, 2002

The Examiner rejected the claims as follows:
• claims 1, 3-8, 11, 12, 14, 16-23, and 25 under 35 U.S.C. § 103(a)
over the combined teachings of Tamari, Sabatino, and Kayser;
• claims 9 and 10 under 35 U.S.C. § 103(a) over the combined
teachings of Tamari, Sabatino, Kayser, and Brockhoff; and
• claim 24 under 35 U.S.C. § 103(a) over the combined teachings of
Tamari, Sabatino, Kayser, and Reed.

OBVIOUSNESS
The Issue
The Examiner found that Tamari and Kayser described air removal
devices used in blood perfusion systems, and that Sabatino described a fluid
handling device. The Examiner’s position is that Sabatino’s float performed
the same function as Tamari’s float, and that replacing Tamari’s ball float
with Sabatino’s toroidal float would have increased the float buoyancy in
Tamari’s device. (Ans. 4.) The Examiner concluded that it would have also
been obvious “to combine” the modified device with Kayser’s rigid shell “to
allow for air to flow centrifugally through the chamber, and to prevent the
need for an additional container for regulating the ambient pressure
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surrounding the chamber.” (Ans. 5.) The Examiner found the cylindrical
shape critical for centrifugal blood flow. (Id.)
Appellant contends that Sabatino’s device has an open air vent at the
top, and that the function of Sabatino’s float is not related to air flow out of
the device, in contrast to how Tamari’s float functions. (App. Br. 6-7.)
Appellant thus disputes the Examiner’s finding that Sabatino’s float
performs the same function as Tamari’s float. (Id. at 7.) Appellant argues it
would not have made sense to replace Tamari’s soft shell collapsible blood
chamber with Kayser’s rigid blood chamber, because Tamari emphasized
the advantages of the collapsible chamber and taught away from using a
rigid shell. (Id. at 5-6.)
The issue is whether Tamari’s float and Sabatino’s float perform the
same function.

Findings of Fact
Tamari
1. Tamari described a blood reservoir useful for cardiopulmonary bypass
and having a tubular structure with a screened wall that improved gas
bubble removal from blood transiting the reservoir. (Col. 1, ll. 13-23.)
2. Tamari’s device comprised a blood reservoir with a compliant wall,
aka “venous bag,” sealed within a rigid housing. (Id.)
3. Tamari described the collapsible venous bag as enabling “vacuum
augmented venous drainage (VAVD).” (Id.)
4. According to Tamari, “a venous bag is used because it provides
significant safety features.” (Col. 1, l. 56 – col. 2, l. 8.)
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5. In Tamari’s device, blood outlet 5 was vertically lower than blood
inlet 1, and air outlet 4 was vertically higher than blood inlet 1. (Fig.
2a.)
6. At Tamari’s air outlet 4, float 61 engaged an outlet mating surface
proximate the exit passage, blocking the exit passage when the float
was at its highest position. (Fig. 6d, col. 14, ll. 1-15.)
7. Tamari’s float 61 inherently had a density less than that of blood.
8. The air collection region of Tamari’s device comprised a cylindrical
body. (Figs. 2b-2d.)

Sabatino
9. Sabatino described a cylindrical air eliminator for a fluid handling
system.
10. Sabatino’s device was cylindrical and comprised float 40 having a
toroidally shaped body. (Fig. 1.)
11. Sabatino’s toroidal float 40 was attached to bushing 41. (Col. 6, ll.
32-56; Figs. 3 and 4.)
12. In Sabatino’s device, curtain seals 42 and 43, attached to bushing 41
and rod 21, were lifted or lowered by float 40 as it rose or fell, thereby
opening or sealing fluid outlets 29a-29n. (Id.)
13. Sabatino’s device vented accumulated air at atmospheric pressure
through a vent opening, “the vent opening being free of any valving
mechanism.” (Col. 3, ll. 16-21.)

Kayser
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14. Kayser’s liquid-gas separator was “particularly applicable to a blood-
gas separating system for extra-corporeal perfusate circulation.” (Col.
1, ll. 44-51.)
15. Kayser’s device had a rigid cylindrical chamber (6). (Figs. 2, 3.)
16. The cylindrical chamber was disposed about a vertical axis causing a
centrifugal flow of blood and migration of air toward the vertical axis.
(Fig. 3.)
17. Kayser’s chamber was inherently made of biocompatible material
because it was used to process circulating blood.

Principles of Law
A rejection for obviousness must include “articulated reasoning with
some rational underpinning to support the legal conclusion.” KSR Int’l Co.
v. Teleflex Inc., 550 U.S. 398, 418 (2007), quoting In re Kahn, 441 F.3d 977,
988 (Fed. Cir. 2006). The proper question to ask is whether a person of
ordinary skill in the art, facing the wide range of needs created by
developments in the field of endeavor, would have seen a benefit to
combining the prior art teachings. KSR, 550 U.S. at 424; see also In re
Fulton, 391 F.3d 1195, 1200 (Fed. Cir. 2004) (the desirability of the
combination may arise from nature of the problem, teachings of references,
or the ordinary knowledge of those skilled in the art). “[I]f a technique has
been used to improve one device, and a person of ordinary skill in the art
would recognize that it would improve similar devices in the same way,
using the technique is obvious unless its actual application is beyond his or
her skill.” KSR, 550 U.S. at 401.
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Analysis
Tamari’s valve works to seal an air outlet by engaging an outlet
mating surface. (FF6.) Sabatino’s valve does not seal the air outlet in
Sabatino’s device, in which the air outlet has no valving mechanism.
(FF13.) Contrary to the Examiner’s finding, Tamari’s valve and Sabatino’s
valve do not perform the same functions. It appears that if Tamari’s ball
float were replaced with Sabatino’s toroidal float, the hole in the toroid
would eliminate the outlet sealing function of Tamari’s ball float. We
conclude that a person of ordinary skill in the art would not have seen a
benefit to making the change. As all the device claims require a toroidal
float, it is unnecessary for us to discuss the separately argued claims 14 and
17-19. (App. Br. 8.) Appellant presented a separate argument for method
claim 20. (Id.) Like the device claims, method claim 20 requires a toroidal
float that closes a valve by engaging a mating surface to block an air outlet.
The Examiner’s Answer did not provide an explanation showing that
Sabatino’s toroidal float could close Tamari’s outlet.

CONCLUSIONS OF LAW
Tamari’s ball float and Sabatino’s toroidal float did not perform the
same function.

SUMMARY
We reverse the rejections of claims 1, 3-8, 11, 12, 14, 16-23, and 25
under 35 U.S.C. § 103(a) over the combined teachings of Tamari, Sabatino,
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and Kayser; claims 9 and 10 under 35 U.S.C. § 103(a) over the combined
teachings of Tamari, Sabatino, Kayser, and Brockhoff; and claim 24 under
35 U.S.C. § 103(a) over the combined teachings of Tamari, Sabatino,
Kayser, and Reed.

REVERSED

TERUMO CARDIOVASCULAR SYSTEMS CORPORATION
ATTN: GAEL DIANE TISACK
6200 JACKSON ROAD
ANN ARBOR, MI 48103