Ex Parte ARMITAGE et al

Patent Trials and Appeals Board

May 16, 2019

13652832 - (D) (P.T.A.B. May. 16, 2019)

UNITED STA TES p A TENT AND TRADEMARK OFFICE
APPLICATION NO. FILING DATE
13/652,832
158229 7590
Covidien LP
Attn: IP Legal
5920 Longbow Drive
Mail Stop A36
10/16/2012
05/20/2019
Boulder, CO 80301-3299
FIRST NAMED INVENTOR
Paul ARMITAGE
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
ATTORNEY DOCKET NO. CONFIRMATION NO.
HUS02127USCON(00021-00101 7869
EXAMINER
REYNOLDS, FRED H
ART UNIT PAPER NUMBER
1654
NOTIFICATION DATE DELIVERY MODE
05/20/2019 ELECTRONIC
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.
Notice of the Office communication was sent electronically on above-indicated "Notification Date" to the
following e-mail address(es):
rs. patents. two@medtronic.com
eofficeaction@appcoll.com
docket@wrciplaw.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte PAUL ARMITAGE and CHRISTINE ELIZABETH DAWSON
Appeal2017-009959 1
Application 13/652,832
Technology Center 1600
Before FRANCISCO C. PRATS, JOHN G. NEW, and
MICHAEL J. FITZPATRICK, Administrative Patent Judges.
PRATS, Administrative Patent Judge.
DECISION ON APPEAL
This appeal under 35 U.S.C. § 134 involves claims to processes of
making collagen pads. The Examiner rejected the claims for obviousness.
We have jurisdiction under 35 U.S.C. § 6(b ).
We affirm.
1 Appellants state that "[t]he real party in interest for this application is the
Assignee of record, Covidien AG. The ultimate parent of Covidien AG is
Medtronic PLC." Appeal Br. 1.
Appeal2017-009959
Application 13/652,832
STATEMENT OF THE CASE
The sole rejection before us for review is the Examiner's rejection of
claims 27, 29-31, 37, 38, 41, 42, and 49-53, under 35 U.S.C. § I03(a) as
being unpatentable over Lieberman,2 Salo, 3 Oliver, 4 Fagan, 5 Highberger, 6
Itoh,7 Yang, 8 Carr,9 and Kosanke. 10 Ans. 3-8.
Claims 27 and 41 are representative and read as follows:
27. A process for the manufacture of a collagen pad from a
plurality of collagen particles, the process comprising the steps
of:
dispersing a plurality of collagen particles having a mean
diameter from about 50 µm to about 500 µm in an aqueous acid
solution to form a dispersion;
adding sodium hydroxide to the dispersion to raise a pH
of the dispersion to 9 to allow the plurality of collagen particles
of the dispersion to aggregate to form a collagen floe;
applying a compressive force to the collagen floe to form
a collagen pad;
dehydrating the collagen pad to form a dehydrated
collagen pad;
cross-linking the dehydrated collagen pad to form a
cross-linked collagen pad; and
storing the cross-linked collagen pad in an aqueous
solution.
2 US 3,014,024 (issued Dec. 19, 1961).
3 US 2,598,608 (issued May 27, 1952).
4 US 5,397,353 (issued Mar. 14, 1995).
5 US 3,194,865 (issued July 13, 1965).
6 US 2,934,446 (issued Apr. 26, 1960).
7 Hiroshi Itoh et al., A Honeycomb Collagen Carrier for Cell Culture as a
Tissue Engineering Scaffold, 25 ARTIF. ORGANS 213-17 (2001 ).
8 US 2006/0222680 Al (published Oct. 5, 2006).
9 Carr, Jr. et al., US 5,733,337 (issued Mar. 31, 1998) ("Carr").
10 SHOW ME GOLD, http://www.showmegold.org/news/Mesh.htm (last
visited Sept. 21, 2015) ("Kosanke").
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Application 13/652,832
41. A process for the manufacture of a collagen pad, the
process compnsmg:
producing a flocculation reaction by adding sodium
hydroxide to a dispersion of collagen particles in an aqueous
acid solution to raise a pH of the dispersion to 9 to allow the
plurality of collagen particles of the dispersion to aggregate to
form a collagen floe, wherein the collagen particles have a
mean diameter from about 50 µm to about 500 µm;
centrifuging the collagen floe to form a collagen pad;
cross-linking the collagen pad to form a cross-linked
collagen pad; and
storing the cross-linked collagen pad in an aqueous
solution.
Appeal Br. 34--36 (Claims App'x).
DISCUSSION
The Examiner's Prima Facie Case
The Examiner cited Lieberman as disclosing processes of making
collagen films, the processes having substantially the same basic steps as
recited in Appellants' claims, including treating collagen with acid,
neutralizing the collagen to form a collagen precipitate (floe), forcibly
compressing the precipitated collagen by centrifugation, dehydrating the
resulting collagen film, and crosslinking the collagen. Ans. 3--4.
As to the particle size of the collagen material required by Appellants'
claims, the Examiner noted that Lieberman disclosed slicing the collagen-
containing starting material, and then straining the collagen through a 20
mesh screen after an initial acid treatment. Id. at 3. The Examiner cited
Kosanke as evidence that a 20 mesh screen would have an 850 micron
spacing. Id. The Examiner also cited Salo ( cited in Lieberman) as
disclosing that the size of the slices of the collagen starting material "was
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Application 13/652,832
found to affect the interaction with the acid (column 3, line[s] 31-34). This
reference shows that the size of the collagen particles is a result oriented
variable affecting how the material swells in acid." Ans. 4.
The Examiner reasoned, therefore, that it would have been obvious to
optimize the size of the particles of the collagen starting material in
Lieberman's processes and, based on that reasoning, concluded that the
particle size range of the acid-treated collagen starting material recited in
Appellants' claims would have been obvious. See id. at 8 ( citing In re Aller,
220 F.2d 454,456 (CCPA 1955); In re Peterson, 315 F.3d 1325, 1330 (Fed.
Cir. 2003); MPEP § 2144.05.II).
The Examiner cited Oliver, Fagan, and Highberger as disclosing
processes similar to those taught in Lieberman, in which purified collagen
products were prepared from natural starting materials. Ans. 4--6.
As to the requirement in Appellants' claims of forming a collagen floe
by raising the acid-treated collagen to a pH of 9 with sodium hydroxide, the
Examiner cited Fagan as showing "that pH extremes will damage the
collagen, making it obvious to control the pH of the collagen solutions." Id.
at 5. The Examiner cited Highberger as teaching, in a similar process, to
raise the pH up to, but not above, 9.5 and describing "the optimum pH range
for the precipitation of collagen, which is relatively narrow." Id. at 5---6.
Based on these teachings, the Examiner concluded that it would have
been obvious to "raise the pH to within the range described by Highberger et
al[.] as being optimal for the processing of collagen for the various
precipitation processes of Lieberman et al." Id. at 7. In particular, the
Examiner reasoned, "[a]s the process described by Highberger et al is
similar to the process described by many of the references, an artisan in this
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Application 13/652,832
field would attempt this process with a reasonable expectation of success."
Id.
The Examiner cited Itoh, Yang, and Carr as evidence that, when
preparing purified collagen products, crosslinking was known to be a useful
modification, and also that it was known in the art to use aqueous solutions
to store purified collagen products intended for biomedical applications. Id.
at 6. Based on those teachings, as well as the teachings in Oliver, the
Examiner reasoned that it would have been obvious to crosslink
Lieberman's purified collagen product, and to store it in an aqueous solution.
See id. at 7-8.
Analysis
As stated in In re Oetiker, 977 F.2d 1443, 1445 (Fed. Cir. 1992):
[T]he examiner bears the initial burden ... of presenting a
prima facie case of unpatentability ....
After evidence or argument is submitted by the applicant
in response, patentability is determined on the totality of the
record, by a preponderance of evidence with due consideration
to persuasiveness of argument.
In the present case, having carefully considered the evidence and
arguments advanced by Appellants and the Examiner, Appellants do not
persuade us that a preponderance of the evidence fails to support the
Examiner's conclusion of obviousness. In particular, Appellants do not
persuade us that the Examiner erred in concluding that it would have been
obvious to subject collagen particles having the particle size required by
Appellants' claims to the acid treatments taught by Lieberman. See Appeal
Br. 5-17, 21-31; Reply Br. 3-5.
Appellants also do not persuade us that the Examiner erred in
determining that it would have been obvious to raise Lieberman's acid-
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treated collagen particles to a pH of 9 to form a collagen precipitate (floe).
See Appeal Br. 17-21; Reply Br. 6. Nor are we persuaded that the Examiner
erred in determining that it would have been obvious to centrifuge
Lieberman's precipitated collagen (floe), as recited in Appellants' claim 41.
See Appeal Br. 31-33.
As Appellants contend, claim 27 recites a process of preparing a
collagen pad, in which the first step of the process is dispersing a plurality of
collagen particles having a mean diameter from about 50 µm to about 500
µmin an aqueous acid solution. Id. at 34.
Lieberman discloses a process of preparing a collagen film in which a
starting material composed of collagen (beef tendon) is sliced, then
dispersed in an aqueous acetic acid solution, then filtered through a 20-mesh
screen to remove impurities, then precipitated by neutralization to pH 7 .0,
and then re-dispersed in an aqueous solution of malonic acid. See
Lieberman 2: 18--41.
Lieberman thus discloses twice performing the acid treatment step of
Appellants' claim 27. Although Lieberman does not disclose that the
collagen particles dispersed in either of its acid treatment steps have the
about 50 to about 500 micron mean particle size required by Appellants'
claim 27, we agree with the Examiner that it would have been obvious to use
particles of the claimed size in Lieberman's acid treatments.
Before Lieberman's second acid treatment step, Lieberman discloses
that the collagen is filtered under pressure through a 20-mesh screen.
Lieberman 2:25-27. Kosanke discloses that a 20-mesh screen has an 841
micron aperture. Kosanke 1.
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It might be true, as Appellants contend, that Lieberman's 20-mesh
screen, thus, allows passage of particles larger than the about 500 micron
maximum mean diameter recited in Appellants' claim 27. Lieberman,
however, teaches that before the second acid treatment step, the collagen
particles may be filtered through screens finer than the 20-mesh screen. See
Lieberman 2:30-31 ("[I]mpurities may be removed by additional filtration
through successively finer screens .... ").
Given Lieberman's teaching of filtering collagen particles through
screens having apertures successively smaller than 841 microns before
subjecting the particles to acid treatment, Appellants do not persuade us that
the Examiner erred in determining that it would have been obvious to use
particles having the about 50 to about 500 micron mean particle size
required by Appellants' claim 27, when performing Lieberman's second
acid treatment step. To the contrary, viewing Lieberman's teachings
alongside relevant teachings in other references cited by the Examiner, we
agree with the Examiner that, when processing collagen in procedures like
those disclosed in Lieberman, a skilled artisan would have considered the
collagen particle size used in an acid treatment step to be a routinely
optimized result-effective parameter.
The Salo reference cited in Lieberman (Lieberman 2:2--4), discloses
that, prior to acid treatment, it is desirable to reduce the collagen-containing
starting material in size by preparing approximately 1 millimeter slices. See
Salo 3:31--40 ("[S]licing to a thickness of the order of 1 mm is of aid in
securing a uniform gel. . . . The tendon slices, after soaking and washing,
preferably in distilled water, are caused to swell by the action of acid to
obta[i]n a jelly-like mass.").
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The teachings of Highberger and Fagan are consistent with the
teachings in Lieberman and Salo that, when subjecting a collagen-containing
material to an acid treatment in a collagen purification process, small-sized
collagen particles are preferred. See Highberger 2:27--45 ("The subdivision
of the skin [ collagen-containing material] may involve a mincing of the
unhaired skin, for example in a power meat grinder, to a particle size not
substantially larger than about 3/16" to 1/4" in diameter" (emphasis
added).); see also Fagan 3 :44--48 ("The hide corium [ collagen-containing
material] after neutralization and washing is in a deswollen condition and
may be subdivided, using conventional grinding equipment, to a particle
size that is readily dispersible in dilute acid solution" (emphasis added).).
The cited references, thus, teach the desirability of small-sized
particles when subjecting collagen-containing material to acid treatment in
collagen purification processes, and in particular suggest a relationship
between small particle size and dispersibility in the acid solution. The cited
references also teach that a variety of particle sizes are useful in such
processes, including sizes significantly smaller than one millimeter, and
suggest certain maximum sizes should not be exceeded. We, therefore,
agree with the Examiner that, when processing collagen in procedures like
those disclosed in Lieberman, a skilled artisan would have considered the
collagen particle size used in an acid treatment step to be a routinely
optimized result-effective parameter, with smaller particle sizes being
preferred. See E.I. DuPont de Nemours & Co. v. Synvina C. V., 904 F.3d
996, 1006 (Fed. Cir. 2018) ("'[A] recognition in the prior art that a property
is affected by the variable is sufficient to find the variable result-
effective. "').
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We therefore also agree with the Examiner that a skilled artisan would
have considered it obvious to determine through routine optimization a
suitable collagen particle size, such as the range of about 50 to about 500
microns recited in Appellants' claim 27, for Lieberman's acid treatments,
including Lieberman's second malonic acid treatment. See id. at 1009
("' [T]he discovery of an optimum value of a variable in a known process is
normally obvious."').
Our reviewing court has explained that where, as here, the prima
facie obviousness of a claimed parameter's range has been established
through teachings in the prior art, the presumed prima facie obviousness
based on that showing may be rebutted "by establishing that the claimed
range is critical, generally by showing that the claimed range achieves
unexpected results relative to the prior art range." Peterson, 315 F.3d at
1330 (internal quotations and bracketing omitted). In the present case,
Appellants do not advance persuasive evidence that the claimed particle
produces an unexpected result.
We acknowledge Appellants' contention, presented for the first time
in the Reply Brief, that an example in Appellants' Specification shows that
collagen pads prepared according to the claimed process have enhanced
tensile strength as compared to a commercial product, Promogran®. See
Reply Br. 6; see also Spec. 17 (The collagen pad of Appellants' invention
prepared according to Example 1 "was found to have a tensile strength of
around 2.0 Nin the hydrated state. The hydrated Promogran® material[, an
existing wound care product comprising a freeze-dried composite of
oxidised regenerated cellulose and collagen,] had a tensile strength of around
0.1 N.").
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We are not persuaded, however, that this new argument is properly
presented for the first time in the Reply Brief. As explained in 37 C.F.R.
§ 4I.37(c)(l)(iv), except in certain circumstances not applicable here, "any
arguments or authorities not included in the appeal brief will be refused
consideration by the Board for purposes of the present appeal." Because,
Appellants did not advance any argument regarding secondary
considerations in the Appeal Brief, we are not persuaded that we should
consider the new arguments in the Reply Brief relating to that issue. See 37
CPR § 41.41 (b )(2) ("Any argument raised in the reply brief which was not
raised in the appeal brief, or is not responsive to an argument raised in the
examiner's answer, including any designated new ground of rejection, will
not be considered by the Board for purposes of the present appeal, unless
good cause is shown."); Ex parte Borden, 93 USPQ2d 1473, 1477 (BPAI
2010) (The reply brief is not "an opportunity to make arguments that could
have been made in the principal brief on appeal to rebut the Examiner's
rejections, but were not.") ("Informative").
In any event, Appellants do not identify any persuasive evidence
suggesting that the comparison described in the Specification represents an
unexpected result, or that the comparison was to the closest prior art.
Accordingly, even if it were proper to consider Appellants' new secondary
considerations argument, we are not persuaded that Appellants' evidence of
secondary considerations is sufficient to overcome the prima facie
obviousness of the claimed process, as it relates to the claimed collagen
particle size. Indeed, we note that, rather than asserting criticality in relation
to the claimed particle size, Appellants' Specification states that "[ t ]he
collagen particles may be of any suitable size." Spec. 10.
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We also acknowledge, but are unpersuaded by, Appellants' contention
that the Yang reference teaches away from the claimed invention. See
Appeal Br. 1 7; Reply Br. 6. Although it might be true, as Appellants
contend, that Yang involves soluble collagen, Appellants fail to identify any
specific disclosures in Yang disparaging or discrediting the processes
described in Lieberman.
In sum, for the reasons discussed, Appellants do not persuade us that
the Examiner erred in determining that, when preparing dispersions of
collagen particles in an aqueous acid solution as taught in Lieberman, it
would have been obvious to use particles with mean diameters from about
50 to about 500 microns, as recited in Appellants' claim 27.
Appellants also do not persuade us that the Examiner erred in
determining that it would have been obvious to use sodium hydroxide to
raise an acidic collagen dispersion of Lieberman to a pH of 9, to aggregate
the dispersion as form a collagen floe, as also recited in Appellants' claim
27. As explained in Appellants' Specification, and is undisputed on this
record, a collagen floe is essentially a dispersion containing precipitated
collagen. See Spec. 6 ("Flocculation is defined by the International Union of
Pure and Applied Chemistry as a process of contact and adhesion whereby
dispersed particles are held together by weak physical interactions ultimately
leading to phase separation by the formation of precipitates of larger than
colloidal size.").
Lieberman discloses that after its mesh-filtered collagen particles are
dispersed in a solution of malonic acid, the dispersion is placed in a
centrifuge, and then treated with ammonia to produce a collagen precipitate,
as claim 2 7 requires:
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A canvas filter cloth is wetted down with concentrated
ammonia and placed into a basket centrifuge 4Yz inches in
diameter. Two hundred and fifty cubic centimeters of the 0.5%
aqueous [ malonic acid] collagen dispersion described in
Example I above is added to the centrifuge, which is rotated at
just sufficient speed to bring the dispersion evenly up the sides
of the basket onto the canvas cloth. The film so formed is then
sprayed with about 20 cc. of ammonia to precipitate the
collagen fibers and the basket is allowed to spin at a speed of
2500 r.p.m.for 11h hours. The centrifuge is then operated at a
speed of 3500 r.p.m. for an additional half hour. Finally, a draft
of warm air is directed into the basket for an additional half
hour to completely dry the film.
Lieberman 2:44--56 (emphasis added). As is evident, Lieberman's process
also includes claim 27's step of applying a compressive force
(centrifugation) to the precipitated collagen floe, as well as claim 27's step
of dehydrating the compressed collagen product.
We acknowledge, as Appellants contend, that Lieberman does not
state the pH of the ammonia solution used to precipitate the collagen.
However, Highberger discloses a process similar to Lieberman's, in which
collagen subjected to an acid treatment is precipitated by a process involving
the use of a base to raise the pH to 5.2 to 9.5:
It has also been found that a skin-like or leather-like
material is obtainable by combining finely divided skin in an
acid bath at pH 3 to 4.5 with collagen solution in quantity to
provide for the mixture an amount of precipitable collagen
equal to 1/20% by weight of the resultant mixture.
The fluid or pasty collagenous material ... prepared by
acid treatment of skin particles ... is adjusted as to ionic
concentration by addition of a salt to a value between 0.1 to 1.0,
preferably 0.4 to 0.6, and is treated with basic agents to raise
its pH to a value of from 5.2 to 9.5, the temperature of the fluid
being maintained below 5° C.
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These ionic strength and pH ranges are important to
successful formation of fiber sheets, for, if the ionic strength is
low, precipitation occurs almost immediately on neutralization
and if the ionic strength is high the gel formed does not
synerese well, the fibers may be melted together and the gel
may be reversible. At low pH values, the fibers do not knit
together but form as individual fibers, and at high pH values
the fibers do not form satisfactorily.
Highberger 3: 51-68 ( emphasis added). Highberger discloses that sodium
hydroxide is a useful base in its process. Id. at 4: 12-13.
Given Highberger's teaching that collagen subjected to an acid
treatment may be precipitated by a process involving the use of sodium
hydroxide to raise the pH to 5.2 to 9.5, we agree with the Examiner that an
ordinary artisan performing Lieberman's similar collagen precipitation step
had good reason for, and a reasonable expectation of success in, using
sodium hydroxide to raise Lieberman's acidic collagen dispersion to a pH of
9, in order to precipitate the collagen for subsequent compression and
dehydration steps. Appellants, therefore, do not persuade us that the
Examiner erred in determining that it would have been obvious to use
sodium hydroxide to raise Lieberman's acidic dispersion to a pH of 9, in
order to form a collagen floe, as recited in Appellants' claim 27.
In sum, for the reasons discussed, Appellants do not persuade us that
preponderant evidence fails to support the Examiner's determination that the
process recited in Appellants' claim 27 would have been obvious to an
ordinary artisan. We, therefore, affirm the Examiner's rejection of claim 27
under§ 103(a). Because they were not argued separately, claims 29-31, 37,
38, 42, and 49, 50, 52, and 53 fall with claim 27. 37 C.F.R.
§ 4I.37(c)(l)(iv).
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As to Appellants' claim 41, for essentially the same reasons discussed
above, we are not persuaded that the Examiner erred in determining that,
when preparing an aqueous acidic dispersion of collagen particles, for
example Lieberman's malonic acid dispersion (see Lieberman 2:38--41), it
would have been obvious to use collagen particles having a mean particle
size of about 50 to about 500 microns. For essentially the same reasons
discussed above, moreover, we are not persuaded that, when forming a
collagen precipitate/floe from that dispersion as taught in Lieberman (see id.
at 2:44--54), the Examiner erred in determining that it would have been
obvious to use sodium hydroxide to raise that dispersion to a pH of 9 to form
the precipitate.
As noted above, moreover, Lieberman teaches that the collagen
precipitate produced from the malonic acidic collagen dispersion is
subjected to centrifugation, which is precisely the sequence of steps required
by Appellants' claim 41. See id. at 2:39--55. Appellants do not persuade us,
therefore, that Lieberman fails to suggest a process having the claimed
sequence of steps. See Appeal Br. 31-32.
We acknowledge that Lieberman's process includes an initial acid
dispersion step that precedes the malonic acid dispersion step. Lieberman
2: 18-21. Appellants' claim 41, however, uses the transitional term
"comprising" to describe the claimed steps. Appeal Br. 35. Appellants do
not persuade us, therefore, that claim 41 does not encompass a process that
includes the initial acidification step of Lieberman's process. See Invitrogen
Corp. v. Biocrest Mfg., L.P., 327 F.3d 1364, 1368 (Fed. Cir. 2003) ("The
transition 'comprising' in a method claim indicates that the claim is open-
ended and allows for additional steps.").
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In sum, for the reasons discussed, Appellants do not persuade us
preponderant evidence fails to support the Examiner's determination that the
process recited in Appellants' claim 41 would have been obvious to an
ordinary artisan. We, therefore, affirm the Examiner's rejection of claim 41
under§ 103(a). Claim 51, which depends from claim 41, falls with claim
41. 37 C.F.R. § 4I.37(c)(l)(iv).
SUMMARY
For the reasons discussed, we affirm the Examiner's obviousness
rejection of claims 27, 29--31, 37, 38, 41, 42, and 49--53.
TIME PERIOD
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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