Ex Parte Heruth et al

Board of Patent Appeals and Interferences

Jan 26, 2012

10745965 (B.P.A.I. Jan. 26, 2012)

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.
10/745,965 12/23/2003 Kenneth T. Heruth 134.02040101 7838
26813 7590 01/26/2012
MUETING, RAASCH & GEBHARDT, P.A.
P.O. BOX 581336
MINNEAPOLIS, MN 55458-1336
EXAMINER
KOHARSKI, CHRISTOPHER
ART UNIT PAPER NUMBER
3763
MAIL DATE DELIVERY MODE
01/26/2012 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 BOARD OF PATENT APPEALS
AND INTERFERENCES
__________

Ex parte KENNETH T. HERUTH,
MARK S. LENT, and JUSTIN A. BLANCO
__________

Appeal 2010-007760
Application 10/745,965
Technology Center 3700
__________

Before DEMETRA J. MILLS, ERIC GRIMES, and LORA M. GREEN,
Administrative Patent Judges.

GREEN, Administrative Patent Judge.

DECISION ON APPEAL
This is a decision on appeal under 35 U.S.C. § 134 from the
Examiner‟s rejection of claims 1, 2, 4-7, 9-15, and 61-64. We have
jurisdiction under 35 U.S.C. § 6(b).
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STATEMENT OF THE CASE
Claim 1 is representative of the claims on appeal, and reads as
follows:
1. A drug delivery catheter comprising:
an elongated body comprising a proximal end and distal end;
a lumen extending from the proximal end of the body to an infusion
section spaced from the proximal end of the body;
two or more openings in the lumen within the infusion section; and
a permeable membrane covering the two or more openings in the
infusion section, wherein the permeable membrane comprises a molecular
weight cut-off of 80 kiloDaltons or less;
and wherein the two or more openings and the permeable membrane
covering them create a back pressure in the lumen such that the drug exits
the infusion section through all of the two or more openings in the infusion
section when a drug is delivered to the infusion section through the lumen at
a continuous rate of 1 milliliter per hour or less.

The following grounds of rejection are before us for review:
I. Claims 1, 2, 4-7, and 9-15 stand rejected under 35 U.S.C. § 103(a)
as being rendered obvious by the combination of Deniega
1
with
Kucharczyk
2
or Aebischer.
3
As Appellants do not argue the claims
separately, we focus our analysis on claim 1, and claims 2, 4-7, and
9-15 stand or fall with that claim. 37 C.F.R. § 41.37(c)(1)(vii).
II. Claims 61-64 stand rejected under 35 U.S.C. § 103(a) as being
rendered obvious by the combination of Deniega, Kucharczyk, or
Aebischer, as further combined with Purdy.
4

1
Deniega et al., US 6,350,253 B1, issued Feb. 26, 2002.
2
Kucharczyk et al., US 6,061,587, issued May 9, 2000.
3
Aebischer et al., US 5,156,844, issued Oct. 20, 1992.
4
Purdy et al., US 2003/0097082 A1, published May 22, 2003.
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We affirm.
ISSUE
Does the preponderance of the evidence of record support the
Examiner‟s conclusion that the combination of Deniega with Kucharczyk or
Aebischer renders the apparatus of claim 1 obvious?

FINDINGS OF FACT
FF1. We adopt the Examiner‟s findings and conclusions as our own. We
also make special note of the following findings.
FF2. The Examiner finds that Deniega teaches a drug delivery catheter
meeting all of the limitations of claim 1 (Ans. 3-4).
FF3. Specifically, as to the membrane, Deniega teaches:
The porous membrane . . . is preferably a sponge-like or foam-
like material or a hollow fiber. The membrane . . . may be
formed from a variety of suitable materials, giving due
consideration to the goals of being flexible and non-reactive to
anatomical systems. The membrane . . . preferably has a
porosity resulting in substantially uniform dispensation of fluid
along the surface area of the infusion section . . . of the catheter
. . . , and has an average pore size sufficiently small to limit the
flow of bacteria through the membrane walls. Some suitable
materials for the membrane . . . are polyethylene, polysulfone,
polyethersulfone, polypropylene, polyvinylidene difluoride,
polycarbonate, nylon, or high density polyethylene. These
materials are advantageously biocompatible. The porous
membrane . . . may filter out unwanted bacteria from the fluid
medication as it passes through the membrane . . . . It is known
that the smallest bacteria cannot pass through a pore any
smaller than 0.23 microns. Thus, the average pore size, or pore
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diameter, of the porous membrane . . . may be less than 0.23
microns to prevent bacteria from traversing the membrane . . . .

(Deniega, col. 7, l. 57-col. 8, l. 13.)
FF4. The Examiner finds that Kucharczyk teaches an infusion device
having a multi-lumen catheter that has both porous and nonporous sections,
wherein the porous membrane has a molecular weight cut-off of
approximately 100-200 kD (Ans. 4).
FF5. Kucharczyk is drawn to a drug delivery device for targeted drug
delivery (Kucharczyk, col. 1, ll. 10-12).
FF6. Kucharczyk teaches the use of
a variable molecular weight cut-off membrane . . . which
permits unimpeded movement of cerebrospinal fluid, small
ions, and small molecular weight drugs, but is substantially
impermeable to blockage by cellular material, said
semipermeable membrane having a molecular weight exclusion
of approximately 100-200 kD. The dialysis membranes can be
made of regenerated cellulose hollow fiber tubing, as well as
various polymeric compositions including polyvinylchloride,
polyacrylonitrile, polyvinylidene fluoride, polystyrene,
polyurethane, polyamides, cellulose acetates and nitrates,
polymethylmethacrylate, polysulfones, polyacrylates, and
derivatives, copolymers and mixtures thereof.

(Kucharczyk, col. 16, ll. 45-58.)
FF7. The Examiner finds that Aebischer teaches an infusion device with a
multi-lumen tubular section having both porous and nonporous sections,
having a porous membrane having a molecular weight cut-off of
approximately 25-100 or 50-100 kD (Ans. 4).
FF8. Aebischer is drawn to “[n]eurological therapy devices . . . for the local
and controlled delivery of a neurotransmitter to the brain of a subject
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suffering from a neurotransmitter deficiency or dysfunction” (Aebischer,
col. 3, ll. 14-17).
FF9. Specifically, Aebischer teaches:
[V]arious polymeric materials have the ability to protect various
“effector-type” substances, such as neurotransmitters and
growth factors, from oxidation, hydrolysis, and degradation
when such substances are embedded therein. In addition, these
polymeric materials have the capacity for sustained release of
the embedded substance at a controlled rate.

(Id. at col. 3, ll. 19-24.)
FF10. In the device of Aebischer:
Permeable portion . . . of insert . . . is implanted at or near
the target region, while the impermeable portion . . . confines
the neurotransmitter (i.e., having a particular molecular weight
cut-off) that excludes some molecules from passage
therethrough, while permitting the passage of others. In this
way, the diffusion of neurotransmitter from the insert to the
target region, or growth factor to the neurotransmitter-
producing cells, is allowed, while the passage of larger
deleterious elements such as viruses, antibodies, complement,
and various proteases is effectively barred. For example,
inserts with pores having a molecular weight exclusion of from
about 1 kD to about 1000 kD are useful, with those having
pores with a molecular weight cut off of from about 25 kD to
about 100 kD being particularly preferred.

(Id. at col. 6, ll. 31-46.)
FF11. The Examiner concludes:
At the time of the invention, it would have been obvious
to substitute the membranes of either Kucharczyk [ ] or
Aebischer [ ] with the membrane of Deniega [ ] to additionally
prevent migration of viruses, antibodies and other small cellular
proteins from entering the catheter and creating blockages. All
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of the combined references disclose several porosity ranges that
are used depending on the treatment with the common thread of
further decreasing pore size to limit access of foreign materials
from the body to the interior of the catheter and yet allow
specific size drug molecules through the membrane.

(Ans. 4.)
FF12. The Examiner further finds as to the combination of Deniega with
Kucharczyk that “membrane porosity is considered to be a variable that can
be optimized within the prior art conditions (i.e. a result effective variable),”
and thus concludes “that the membrane porosity range of 80 kiloDaltons or
less would be a variable with a recognized result (i.e. smaller membrane port
[sic, pore] yields a smaller size exclusion) and that the workable range is
known in the art and capable of being determined through routine
experimentation” (id. at 8-9).

ANALYSIS
As to the rejection as it is based on the combination of Deniega and
Kucharczyk, Appellants argue that “nothing has been identified within the
disclosures of Deniega [ ] or Kucharczyk [ ] that teaches or suggests a
permeable membrane comprising a molecular weight cut-off of 80
kiloDaltons or less as recited in each of independent claims 1, 7, and 12”
(App. Br. 12). Appellants assert that Kucharczyk‟s teaching of a “„porous
membrane being constructed of a variable molecular weight cut-off of
approx. 100-200kD‟” does not teach or suggest a “permeable membrane
comprising a molecular weight cut-off of 80 kiloDaltons or less” (id.).
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As to the Examiner‟s finding that membrane porosity is a result
effective variable, and thus it would be obvious to optimize within the prior
art conditions as both Deniega and Kucharczyk teach a reduction in pore
size for the purpose of exclusion of smaller particles and prevention of
foreign material migration, Appellants assert that purpose is already
accomplished by the membranes of Deniega and Kucharczyk, and thus the
ordinary artisan would have no reason to use a more restrictive membrane as
claimed. (See Reply Br. 2.)
Appellants‟ arguments are not convincing. Deniega teaches the
function of the porous membrane, that is, to provide substantially uniform
dispensation of fluid along the surface area of the infusion section, as well as
filtering out unwanted contaminants, such as bacteria, from the fluid
medication as it passes through the membrane (see FF3). Deniega also
teaches different pore sizes, specifically teaching that “the average pore size,
or pore diameter, of the porous membrane . . . may be less than 0.23 microns
to prevent bacteria from traversing the membrane,” but the patent does not
provide a lower limit (see id.).
Kucharczyk also teaches an infusion device having a multi-lumen
catheter that has both porous and nonporous sections, and teaches that the
porous membrane may have a molecular weight cut-off of approximately
100-200 kD to provide unimpeded movement of cerebrospinal fluid, small
ions, and small molecular weight drugs, while being substantially
impermeable to blockage by cellular material (FF6).
Thus, while Kucharczyk teaches a pore size of approximately 100-200
kD, we agree with the Examiner that it would have been well within the
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level of ordinary skill in the art to optimize the pore size of the porous
membrane of Deniega to obtain provide substantially uniform dispensation
of fluid along the surface area of the infusion section, as well as serving to
exclude unwanted contaminants. See In re Boesch, 617 F.2d 272, 276
(CCPA 1980) (noting that determining the optimum values of result
effective variables is ordinarily within the skill of the art).
As to the rejection as it is based on the combination of Deniega and
Aebischer, Appellants argue that modifying the porous membrane of
Deniega with the polymeric insert of Aebischer changes the functions of
each, and that the combination would not yield predictable results (App. Br.
14). Appellants assert that Deniega provides a catheter for the delivery of
fluid medication, and as such, the “the function of the porous membrane of
Deniega [ ] is to allow fluid to flow therethrough at a substantially uniform
rate - under both low and high pressure delivery” (id. at 15). Appellants
argue that in contrast, the polymeric insert of Aebischer provides a different
function—it is used to protect neurotransmitter secreting cells or a
neurotransmitter embedded therein, while the neurotransmitter is allowed to
diffuse or leach out of the polymeric insert (id.). Appellants thus argue that
the “polymeric insert of Aebischer [ ] is not designed to promote fluid flow
therethrough at a substantially uniform rate under both low and high
pressure” (id. at 16). Specifically, Appellants argue that the obviousness
combination requires “a significant change in function, i.e., from flow-based
permeable membrane to a diffusion-based permeable membrane” (Reply Br.
3-4).
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Appellants therefore assert that the combination requires a “change in
the respective function of the polymeric insert of Aebischer [ ] from
providing protection and controlled diffusion, release or leaching of a
substance to providing fluid flow at a substantially uniform rate under both
high and low pressure delivery,” and thus its substitution for the membrane
of Deniega would not provide predictable results as “nothing within the cited
references (or elsewhere) has been cited to show that substituting the
significantly more restrictive polymeric materials of Aebischer[ ] would
provide the functions and advantages of fluid flow at a substantially uniform
rate under both low and high pressures as do the permeable membranes
taught by Deniega [ ]” (App. Br. 16). Thus, Appellants argue, “the asserted
prima facie case of obviousness appears to be based on hindsight in view of
Appellants‟ own disclosure” (id. at 18).
Again, Appellants‟ arguments are not convincing. Both Deniega and
Aebischer are concerned with the delivery of drugs through the porous
membrane, while preventing the flow of contaminants. Aebischer is
evidence that the use of membranes having “a molecular weight exclusion of
from about 1 kD to about 1000 kD are useful, with those having pores with a
molecular weight cut off of from about 25 kD to about 100 kD being
particularly preferred” (FF10). Thus, as discussed above with respect to the
combination of Deniega and Kucharczyk, we agree with the Examiner that it
would have been well within the level of ordinary skill in the art to optimize
the pore size of the porous membrane of Deniega to provide substantially
uniform dispensation of fluid along the surface area of the infusion section,
as well as serving to exclude unwanted contaminants.
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CONCLUSION OF LAW
We conclude that the preponderance of the evidence of record
supports the Examiner‟s conclusion that the combination of Deniega with
Kucharczyk or Aebischer renders the apparatus of claim 1 obvious. We thus
affirm the rejection of claim 1 under 35 U.S.C. § 103(a) as being rendered
obvious by the combination of Deniega with Kucharczyk or Aebischer. As
Appellants do not argue the claims separately, we also affirm the rejection as
to claims 2, 4-7, and 9-15.
We also affirm the rejection of claims 61-64 under 35 U.S.C. § 103(a)
as being rendered obvious by the combination of Deniega with Kucharczyk
or Aebischer, as further combined with Purdy, as Appellants do not argue
that rejection separately (see App. Br. 23-25).

TIME PERIOD FOR RESPONSE
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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