Medtronic, Inc.

Patent Trials and Appeals Board

Apr 2, 2021

2020001640 (P.T.A.B. Apr. 2, 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.
13/757,792 02/02/2013 Bryant J. PUDIL C00004438.USU2_MED29026US 3669
84199 7590 04/02/2021
Hahn&Associates-Medtronic, Inc patent applications
Hahn&Associates-Medtronic, Inc patent applications
1012 14th Street, NW Suite 620
Washington, DC 20005
EXAMINER
PEO, JONATHAN M
ART UNIT PAPER NUMBER
1779
NOTIFICATION DATE DELIVERY MODE
04/02/2021 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):
roger.hahn@hvpatentlaw.com
rs.patents.two@medtronic.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
_________

BEFORE THE PATENT TRIAL AND APPEAL BOARD
__________

Ex parte BRYANT J. PUDIL,
MARTIN T. GERBER, DAVID B. LURA,
and THOMAS E. MEYER
__________

Appeal 2020-001640
Application 13/757,792
Technology Center 1700
___________

Before ADRIENE LEPIANE HANLON, JEFFREY B. ROBERTSON, and
LILAN REN, Administrative Patent Judges.

HANLON, Administrative Patent Judge.

DECISION ON APPEAL

A. STATEMENT OF THE CASE
The Appellant1 filed an appeal under 35 U.S.C. § 134(a) from an Examiner’s
decision finally rejecting claims 1, 3–5, 7, 8, 10–13, 16–35, 37, and 38. We have
jurisdiction under 35 U.S.C. § 6(b).
We AFFIRM and enter a new ground of rejection.

1 We use the word “Appellant” to refer to “applicant” as defined in 37 C.F.R.
§ 1.42. The Appellant identifies the real party in interest as Medtronic plc. Appeal
Brief dated December 20, 2018 (“Appeal Br.”), at 4.
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Representative claim 1 is reproduced below from the Claims Appendix to
the Appeal Brief.
1. A system for infusing a buffer into a dialysate, comprising:
a dialysate flow loop for circulating a dialysate through a
dialyzer, wherein acid or base equivalents are added to the dialysate
during operation of the dialysate flow loop;
a dialysate regeneration unit comprising a sorbent cartridge
comprising at least one sorbent material;
at least one urea sensor that measures or allows for the
calculation of urea content of the dialysate in at least one portion of
the dialysate flow loop; wherein the urea sensor measures the urea
content of the dialysate directly, or measures the urea content of the
dialysate indirectly by measuring changes in any one or more of
conductivity, pH, CO2, or ammonia concentration;
an infusate system configured to add a bicarbonate buffer
component or unbuffered sodium bicarbonate to the dialysate; and
a controller in communication with the urea sensor; the
controller programmed to determine the urea content of the dialysate
in the at least one portion of the dialysate flow loop upstream of the
dialysate regeneration unit and calculate an amount of bicarbonate
generated by the dialysate regeneration unit due to the urea content of
the dialysate in the at least one portion of the dialysate flow loop; the
controller controlling an amount of the bicarbonate buffer component
or unbuffered sodium bicarbonate for addition to the dialysate to
generate a predetermined total bicarbonate buffer concentration in the
dialysate entering the dialyzer, based at least in part on the amount of
bicarbonate generated by the dialysate regeneration unit;
wherein the controller is programmed to determine the total
bicarbonate buffer concentration of the dialysate in a first portion of
the dialysate flow loop based at least in part upon a determination of a
urea concentration of the dialysate in a second portion of the dialysate
flow loop;
wherein the second portion of the dialysate flow loop is
between an outlet of the dialyzer and an inlet of the dialysate
regeneration unit and the first portion of the dialysate flow loop is
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between an outlet of the dialysate regeneration unit and an inlet of the
dialyzer; and wherein the urea content of the dialysate in at least one
portion of the dialysate flow loop is measured by a first conductivity
sensor upstream of a urease layer of the sorbent cartridge and a second
conductivity sensor in the sorbent cartridge after the urease layer,
wherein the urea content of the dialysate in the at least one portion of
the dialysate flow loop is determined by a change in conductivity
measured before and after the urease layer in the sorbent cartridge.
Appeal Br. 26–27.
The Examiner maintains the following grounds of rejection on appeal:
(1) claims 1, 3–5, 7, 8, 10–13, and 16–35, 37, and 38 under 35 U.S.C.
§ 112, first paragraph, based on the written description requirement;2
(2) claims 1, 3–13, 16–19, 24, 26–35, and 38 under 35 U.S.C. § 103(a) as
unpatentable over Ding,3 as evidenced by Ash 141,4 in view of Ash 545,5 Updyke,6
Orhan,7 and Castellarnau;8
(3) claims 20–23 under 35 U.S.C. § 103(a) as unpatentable over Ding in
view of Ash 545, Updyke, Orhan, and Castellarnau, further in view of Garde;9
(4) claim 25 under 35 U.S.C. § 103(a) as unpatentable over Ding in view
of Ash 545, Updyke, Orhan, and Castellarnau, further in view of Ash 141; and

2 The Examiner includes claim 36 in the statement of the rejection. See Final
Office Action dated July 25, 2018 (“Final Act.”), at 3; Examiner’s Answer dated
April 12, 2019 (“Ans.”), at 3. Claim 36 was cancelled in an amendment dated June
8, 2018. The statement of the rejection has been corrected to omit claim 36.
3 US 2010/0224492 A1, published September 9, 2010, to Ding et al.
4 US 4,581,141, issued April 8, 1986, to Ash.
5 US 2012/0258545 A1, published October 11, 2012, to Ash et al.
6 US 2011/0017665 A1, published January 27, 2011, to Updyke et al.
7 US 2012/0273354 A1, published November 1, 2012, to Orhan et al.
8 US 2010/0213127 A1, published August 26, 2010, to Castellarnau.
9 US 7,704,361 B2, issued April 27, 2010, to Garde et al.
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(5) claim 37 under 35 U.S.C. § 103(a) as unpatentable over Ding in view
of Ash 545, Updyke, Orhan, Castellarnau, further in view of Pouchoulin.10
B. DISCUSSION
1. Rejection (1)
Claims 1 and 13 recite that “the urea content of the dialysate in at least one
portion of the dialysate flow loop is measured by a first conductivity sensor
upstream of a urease layer of the sorbent cartridge and a second conductivity
sensor in the sorbent cartridge after the urease layer.” Appeal Br. 27, 31
(emphasis added). The Examiner finds the original disclosure does not provide
written description support for “a second conductivity sensor in the sorbent
cartridge after the urease layer.” Final Act. 3–4 (emphasis added).
To satisfy the written description requirement, a patent applicant must
“convey with reasonable clarity to those skilled in the art that, as of the filing date
sought, he or she was in possession of the invention.” Vas-Cath Inc. v. Mahurkar,
935 F.2d 1555, 1563–64 (Fed. Cir. 1991). A disclosure may meet this burden by
providing either express or inherent support for a claimed limitation. See Tronzo v.
Biomet, Inc., 156 F.3d 1154, 1159 (Fed. Cir. 1998). “In order for a disclosure to be
inherent, . . . the missing descriptive matter must necessarily be present in the . . .
application’s specification such that one skilled in the art would recognize such a
disclosure.” Id.
The Appellant argues that “the Specification explicitly states that the sensors
can be integrally formed with one or more components of the system, including the
dialysate regeneration unit 32.” Appeal Br. 25 (citing 588 Application ¶ 28311).

10 US 2011/0168614 A1, published July 14, 2011, to Pouchoulin et al.
11 The Appellant refers to the Patent Application Publication, US 2014/0158588
A1, published June 12, 2014 (“588 Application”).
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Therefore, the Appellant argues that the sensors can be “part of the dialysate
regeneration unit.” Appeal Br. 25.
The Specification states that “the urea sensor can be placed on any part of
the dialysate loop and in one or more locations using multiple sensors. The urea
sensor can also be integrally formed with one or more components of the system
including the dialysate regeneration unit.” 588 Application ¶ 283 (emphasis
added). The Appellant discloses that “the term ‘urea sensor’ refers to a
combination of elements and sensors that are individually or collectively used to
directly or indirectly indicate urea concentration. Indirect indication of urea
concentration can be determined by measuring changes in conductivity, pH, CO2,
or ammonia concentration effected by urease breakdown of urea.”
588 Application ¶ 284 (emphasis added).
To the extent that one of ordinary skill in the art would have selected first
and second conductivity sensors from the disclosed list of urea sensors and
selected the inside of the sorbent cartridge for the location of the second
conductivity sensor, such selections are evidence of obviousness not compliance
with the written description requirement. See Lockwood v. American Airlines, Inc.,
107 F.3d 1565, 1572 (Fed. Cir. 1997) (“One shows that one is ‘in possession’ of
the invention by describing the invention, with all its claimed limitations, not that
which makes it obvious.”).
Nonetheless, in an attempt to show that the limitation at issue is inherently
described in the original disclosure, the Appellant argues that the sensors must be
“placed before and after the urease layer of the sorbent cartridge” because the
Specification discloses that urea content is determined by “measuring the
conductivity change before and after the urease layer of a sorbent cartridge.”
Appeal Br. 24 (citing 588 Application ¶ 284).
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In the case of a second conductivity sensor located after the urease layer, the
Appellant does not direct us to any portion of the original disclosure establishing
that the second conductivity sensor is necessarily located inside the sorbent
cartridge. To the contrary, Appellant’s Figure 1 shows conductivity sensor 40
located downstream and outside of the sorbent cartridge.
Referring to paragraph 281 of the 588 Application, the Appellant argues that
the conductivity sensor must be placed in the sorbent cartridge when the cartridge
includes both urease and a cation exchanger.12 Appeal Br. 24–25.
Paragraph 284 of the 588 Application discloses that “the dialysate
regeneration unit 32 consists of multiple sorbent layers, one of which is a urease
layer.” No other sorbent layers are identified in that embodiment. We recognize
that the Appellant discloses a group of materials, including a urease-containing
material and a cation exchanger, from which “one or more” materials may be
selected. See 588 Application ¶ 281. However, to satisfy the written description
requirement, the Appellant must establish that the selection of a urease layer and a
cation exchanger from the disclosed group is either express or inherent. On this
record, we conclude that the selection is, at best, obvious. Lockwood, 107 F.3d at
1572.
In sum, the Appellant does not direct us to any portion of the original
disclosure expressly describing “a second conductivity sensor in the sorbent
cartridge after the urease layer” as recited in claims 1 and 13. Moreover, the
Appellant does not direct us to any evidence establishing that such an arrangement

12 The Appellant does not explain why a conductivity sensor must be placed
between the urease and the cation exchanger. See Appeal Br. 25. We note that the
term “after” in claims 1 and 13 does not require the conductivity sensor to be
placed immediately after the urease layer.
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is inherently described in the original disclosure. Therefore, a preponderance of
the evidence supports a finding that the Appellant’s original disclosure does not
describe, within the meaning of 35 U.S.C. § 112, first paragraph, “a second
conductivity sensor in the sorbent cartridge after the urease layer” as recited in
claims 1 and 13.
2. New ground of rejection
Claims 1 and 13 recite that the system comprises, inter alia,
at least one urea sensor that measures or allows for the
calculation of urea content of the dialysate in at least one portion of
the dialysate flow loop; wherein the urea sensor measures the urea
content of the dialysate directly, or measures the urea content of the
dialysate indirectly by measuring changes in any one or more of
conductivity, pH, CO2, or ammonia concentration.
Appeal Br. 26, 30 (emphasis added).
Claims 1 and 13 also recite that
the urea content of the dialysate in at least one portion of the dialysate
flow loop is measured by a first conductivity sensor upstream of a
urease layer of the sorbent cartridge and a second conductivity sensor
in the sorbent cartridge after the urease layer; [and]
the urea content of the dialysate in the at least one portion of the
dialysate flow loop is determined by a change in conductivity
measured before and after the urease layer in the sorbent cartridge.
Appeal Br. 27, 31 (emphasis added).
It is unclear on this record whether the claimed first and second conductivity
sensors fall within the scope of “at least one urea sensor” that measures urea
content directly or indirectly, wherein conductivity is one of the alternatives for
measuring urea content indirectly, or whether the first and second conductivity
sensors are sensors in addition to the “at least one urea sensor.” For that reason,
claims 1 and 13 are indefinite.
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Claims 1, 3–5, 7, 8, 10–13, 16–35, 37, and 38 are rejected under 35 U.S.C.
§ 112, second paragraph, as indefinite. The rejection is a new ground of rejection
under 37 C.F.R. § 41.50(b).
3. Rejections (2)–(5)
Claims 1 and 13 recite a system comprising, inter alia,
at least one urea sensor that measures or allows for the
calculation of urea content of the dialysate in at least one portion of
the dialysate flow loop; wherein the urea sensor measures the urea
content of the dialysate directly, or measures the urea content of the
dialysate indirectly by measuring changes in any one or more of
conductivity, pH, CO2, or ammonia concentration.
Appeal Br. 26, 30 (emphasis added).
The Examiner finds Ding discloses a system for infusing a buffer into a
dialysate comprising, inter alia, a urea sensor that indirectly measures ammonia as
claimed. Final Act. 5–6, 17–18. The Appellant argues that Ding’s ammonia
sensor “detect[s] ammonia formed by the breakdown of urea in the event that the
EDI unit[13] ceases to function” and thus “only uses the ammonia sensor as a safety
check.” Appeal Br. 12–13. For that reason, the Appellant argues that “a person of
ordinary skill in the art would not use the ammonia sensor disclosed by Ding to
determine the urea content of the dialysate.” Appeal Br. 12.
The Appellant’s argument is not persuasive of reversible error. There is no
dispute on this record that Ding’s ammonia sensor detects ammonia formed by the
breakdown of urea. Moreover, the Examiner concludes that “[c]laim 1 only states
that the sensor must be in at least a portion of the dialysate flow loop, not any
specific location therein.” Ans. 33 (emphasis added). Thus, it is reasonable to

13 Ding discloses that an integrated electrodeionization (“EDI”) unit essentially
removes all ionic contaminants from the waste dialysate (not just selective ions),
resulting in verifiably pure recycled solution. Ding ¶ 5.
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conclude that Ding’s ammonia sensor is a urea sensor within the scope of the
claims on appeal.
The Appellant also argues that the prior art of record does not disclose the
following limitations recited in claims 1 and 13:14
the urea content of the dialysate in at least one portion of the dialysate
flow loop is measured by a first conductivity sensor upstream of a
urease layer of the sorbent cartridge and a second conductivity sensor
in the sorbent cartridge after the urease layer; [and]
the urea content of the dialysate in the at least one portion of the
dialysate flow loop is determined by a change in conductivity
measured before and after the urease layer in the sorbent cartridge.
Appeal Br. 27, 31 (emphasis added); see also Appeal Br. 10–16, 19–23.
The Examiner finds Updyke, Orhan, and Castellarnau each disclose
conductivity sensors and concludes that it would have been obvious to one of

14 Additionally, the Appellant argues that the prior art does not disclose or suggest
a controller in communication with the urea sensor programmed to “calculate an
amount of bicarbonate generated by a dialysate regeneration unit due to the urea
content of the dialysate in the at least one portion of the dialysate flow loop,” as
recited in claims 1 and 13. Appeal Br. 26–27, 30; see also Appeal Br. 16–19.
Claims 1 and 13 recite that the urea sensor is in the same portion of the dialysate
flow loop, i.e., “in at least one portion of the dialysate flow loop.” Appeal Br. 26,
30.
The Examiner finds Ash 545 calculates an amount of bicarbonate as recited
in claims 1 and 13. See Ans. 38 (finding that “some bicarbonate is in the dialysate
due to the urea content that was broken down in the urease of the sorbent
cartridge”). We note that the amount of bicarbonate in Ash 545, referred to by the
Examiner, is due to the urea content of the dialysate in the portion of the dialysate
flow loop between an outlet of the dialyzer and an inlet of the dialysate
regeneration unit whereas Ding’s ammonia sensor is located in a different portion
of the dialysate flow loop (i.e., between an outlet of the EDI unit (corresponding to
the claimed dialysate regeneration unit) and an inlet of the dialyzer).
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ordinary skill in the art to modify Ding’s system based on the teachings in Updyke,
Orhan, and Castellarnau. See Final Act. 10–14, 22–25.
As discussed above, claims 1 and 13 are indefinite. Therefore, it would be
necessary to make assumptions as to the scope of independent claims 1 and 13 in
considering whether the Appellant has identified a reversible error in the
obviousness rejections on appeal. We decline to engage in such assumptions. For
that reason, the obviousness rejections of claims 1, 3–5, 7, 8, 10–13, 16–35, 37,
and 38 are not sustained. See In re Steele, 305 F.2d 859, 862–63 (CCPA 1962)
(reversing obviousness rejection because it was based on speculation as to the
meaning of claim terms and assumptions as to claim scope). It should be
understood that our decision is based solely on the indefiniteness of the claimed
subject matter and not on the adequacy of the prior art references.
C. DECISION
The Examiner’s decision is affirmed. Additionally, a new ground of
rejection under 37 C.F.R. § 41.50(b) is entered.
In summary:

Claim(s)
Rejected
35 U.S.C.
§
Reference(s)/Basis Affirmed Reversed15 New
Ground
1, 3–5, 7,
8, 10–13,
16–35,
37, 38
112, first
paragraph
written description 1, 3–5, 7,
8, 10–13,
16–35,
37, 38

15 As explained above, our reversal of the obviousness rejections on appeal is based
solely on the indefiniteness of the claimed subject matter and not on the adequacy
of the prior art references.

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Application 13/757,792

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1, 3–13,
16–19,
24, 26–
35, 38
103(a) Ding, Ash 141,
Ash 545, Updyke,
Orhan,
Castellarnau
1, 3–13,
16–19, 24,
26–35, 38

20–23 103(a) Ding, Ash 545,
Updyke, Orhan,
Castellarnau,
Garde
20–23
25 103(a) Ding, Ash 545,
Updyke, Orhan,
Castellarnau,
Ash 141
25
37 103(a) Ding, Ash 545,
Updyke Orhan,
Castellarnau,
Pouchoulin
37
1, 3–5, 7,
8, 10–13,
16–35,
37, 38
112,
second
paragraph
indefinite 1, 3–5, 7,
8, 10–13,
16–35,
37, 38
Overall
Outcome
1, 3–5, 7,
8, 10–13,
16–35,
37, 38
1, 3–5, 7,
8, 10–13,
16–35,
37, 38

This decision contains a new ground of rejection pursuant to 37 C.F.R.
§ 41.50(b). 37 C.F.R. § 41.50(b) provides, “A new ground of rejection pursuant to
this paragraph shall not be considered final for judicial review.”
37 C.F.R. § 41.50(b) also provides that the Appellant, WITHIN TWO
MONTHS FROM THE DATE OF THE DECISION, must exercise one of the
following two options with respect to the new ground of rejection to avoid
termination of the appeal as to the rejected claims:
(1) Reopen prosecution. Submit an appropriate amendment of
the claims so rejected or new Evidence relating to the claims so
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rejected, or both, and have the matter reconsidered by the examiner, in
which event the prosecution will be remanded to the examiner. . . .
(2) Request rehearing. Request that the proceeding be reheard
under §41.52 by the Board upon the same Record. . . .
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; 37 C.F.R. § 41.50(b)