Ex Parte Tuomela

Board of Patent Appeals and Interferences

Aug 28, 2007

10122683 (B.P.A.I. Aug. 28, 2007)

The opinion in support of the decision being entered today
is not binding precedent of the Board.

UNITED STATES PATENT AND TRADEMARK OFFICE
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BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
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Ex parte STEPHEN D. TUOMELA
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Appeal 2007-1384
Application 10/122,683
Technology Center 1700
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Decided: August 28, 2007
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Before BRADLEY R. GARRIS, CHUNG K. PAK, and
CHARLES F. WARREN, Administrative Patent Judges.

GARRIS, Administrative Patent Judge.

DECISION ON APPEAL
This is a decision on an appeal under 35 U.S.C. § 134 from the final
rejection of claims 1-5 and 8. We have jurisdiction under 35 U.S.C. § 6.
We AFFIRM.

Appeal 2007-1384
Application 10/122,683

2
Appellant claims an apparatus for detecting oxygen which comprises
a pair of galvanic cells containing KOH as an electrolyte and an absorbent
material containing an aqueous sodium chloride solution for humidifying the
galvanic cells.
Representative claim 1 reads as follows:
1. An apparatus for detecting oxygen in a test gas flow through a
galvanic cell of the type which develops a current flow between a cell
cathode and anode representative of oxygen content in the test gas;
comprising:

a. a pair of galvanic cells inside a sealed enclosure, said cells
containing KOH as an electrolyte and connected in series gas flow
arrangement, with an input adapted for connection to a source of test gas and
an output adapted for connection to a gas exhaust;

b. means for electrically connecting said galvanic cells to provide
an electrical signal representative of the oxygen content of said gas flow;
and

c. an absorbent material inside said sealed enclosure, said
absorbent material containing an aqueous sodium chloride solution for
humidifying the galvanic cells.
The references set forth below are relied upon by the Examiner as
evidence of obviousness:
Mayer US 4,973,395 Nov. 27, 1990
Fitterman US 5,957,380 Sep. 28, 1999
Appeal 2007-1384
Application 10/122,683

3
All appealed claims are rejected under 35 U.S.C. § 103 (a) as being
unpatentable over Mayer in view of Fitterman.1
On this record, it is undisputed that Mayer discloses all aspects of the
claim 1 apparatus except for the use of an aqueous sodium chloride solution
for humidifying the galvanic cells. In Mayer’s apparatus, KOH is used as
the humidifying solution as well as the electrolyte. According to the
Examiner, it would have been obvious for one with ordinary skill in this art
to replace Mayer’s KOH solution with a sodium chloride solution for
humidifying the galvanic cells in view of Fitterman’s teaching of using a
sodium chloride solution for humidifying purposes.
Appellant argues that an artisan would not have modified the Mayer
apparatus in the manner proposed by the Examiner because the artisan
would have believed that the electrolyte and the humidifying solution
needed to be the same salt in order to avoid deleterious cross-contamination
(Br. 4). As support for this argument, Appellant relies on the § 1.132
Affidavit of record by Michelle Stevens (id.) and particularly relies on ¶ 12
of this Affidavit (id. at 5). Paragraph 12 of the Stevens Affidavit is
reproduced below:
12. Prior to filing of the Application, it was widely
accepted that (i) KOH was the electrolyte of choice due [sic] in
an oxygen sensor due to its sensitivity to oxygen, while (ii)

1 Appellant has not separately argued the rejected claims (Br. 4-5).
Accordingly, in assessing the merits of the rejection on appeal, we will focus
on claim 1 which is the sole independent claim before us. The remaining
claims under rejection will stand or fall with claim 1.
Appeal 2007-1384
Application 10/122,683

4
NaCl solutions were the humidification solution of choice as
NaCl was much more benign than KOH towards both humans
and equipment. However, concerns over migration of the
humidification solution into the galvanic cell, resulting in
contamination of the KOH electrolyte with NaCl, dictated use
of the same salt (e.g., either KOH or NaCl) for both the
humidifying solution and the electrolyte.
As revealed by this paragraph, it was widely accepted by those with
ordinary skill in this art that KOH was the electrolyte of choice whereas a
sodium chloride solution was a more desirable humidification medium
because it is more benign than KOH. However, concerns over possible
contamination “dictated use” (id.) of the same salt (either KOH or NaCl) for
both the humidifying solution and the electrolyte. The circumstances lead
the Affiant (Affidavit 3, ¶ 13) as well as Appellant (Br. 4) to conclude that it
would not have been obvious to use different salts for the humidification
solution and the electrolyte. However, the evidence of record including the
Stevens Affidavit militates for rather than against a conclusion of
obviousness.
This is because the Affidavit evinces that KOH and NaCl were known
respectively for use as both an electrolyte and a humidifying solution and
that KOH was known as particularly desirable for electrolyte use whereas
NaCl was known as particularly desirable for humidifying use. This
knowledge and desiderata would have led an artisan to consider using KOH
as an electrolyte and NaCl solution as a humidifier.
According to the Affidavit and the Brief, an artisan would not have
so-used these different salts because of concerns over possible
Appeal 2007-1384
Application 10/122,683

5
contamination (Affidavit 2-3, ¶12; Br. 4). However, the record before us
contains no evidence that such concerns were based on scientific study as
opposed to unfounded assumption.
In any event, the fact remains that the use of KOH as an electrolyte
and NaCl solution as a humidifier unquestionably would have been desirable
whereas the potential for contamination resulting from this use of different
salts would have been merely a possibility. These circumstances support a
conclusion that, at a minimum, it would have been obvious for the artisan to
try using these different salts in the manner proposed by the Examiner.
The Supreme Court has recently clarified that a claim can be proved
obvious merely by showing that the combination of elements was obvious to
try. In this regard, the Supreme Court explained that, “[w]hen there is a
design need or market pressure to solve a problem and there are a finite
number of identified, predictable solutions, a person of ordinary skill has
good reason to pursue the known options within his or her technical grasp.”
KSR Int’l v. Teleflex Inc., 127 S. Ct. 1727, 1742, 82 USPQ2d 1385, 1397
(2007).
In this instance, there are only two solutions to the problem of salt-use
in an oxygen detecting apparatus of the type under consideration. In the first
solution, the same salt is used whereby the possibility of contamination is
avoided but at the expense of optimization for both the electrolyte and the
humidifier. In the second solution, different salts are used whereby the
electrolyte and the humidifier are both optimized but there is a possibility of
Appeal 2007-1384
Application 10/122,683

6
cross-contamination. An artisan would have had a reasonable expectation of
success for each of these solutions. In the first solution, the successful result
would have been less than optimal but possibly longer lasting whereas, in
the second solution, the successful result would have been optimized but
possibly shorter in length (i.e., due to the possibility of eventual cross-
contamination).
In light of these considerations, it would have been obvious for an
artisan to try using different salts in the manner proposed in order to
optimize the electrolyte and humidifier functions based upon a reasonable
expectation of success.
Concerning this matter, Appellant states “Applicant surprisingly
discovered that such cross-contamination of the electrolyte and the
humidifying solution simply does not occur to any appreciable extent” (Br.
4). In response, we emphasize that, on this record, it is unknown whether
Appellant’s discovery was surprising on the basis of unfounded assumption
versus scientific study regarding the possibility of contamination. Moreover,
the Examiner has reasonably determined that cross-contamination in
Mayer’s apparatus would not have been expected because the electrolyte salt
and the humidifier salt are separately compartmentalized (Answer 9), and
Appellant does not argue otherwise in the record of this appeal. For these
reasons, Appellant’s “surprising discovery” cannot be regarded as an
unexpected result indicative of nonobviousness.
Appeal 2007-1384
Application 10/122,683

7
In light of the foregoing, it is our ultimate determination that the
evidence as a whole in the record before us weighs most heavily in favor of
an obviousness conclusion. We hereby sustain, therefore, the § 103
rejection of all appealed claims as being unpatentable over Mayer in view of
Fitterman.
The decision of the Examiner is affirmed.
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

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