Ex Parte FRIEDRICHS et al

Patent Trials and Appeals Board

Jan 3, 2019

14174607 - (D) (P.T.A.B. Jan. 3, 2019)

UNITED STA TES p A TENT AND TRADEMARK OFFICE
APPLICATION NO. FILING DATE
14/174,607
90039 7590
Covidien LP
Attn: IP Legal
5920 Longbow Drive
Mail Stop A36
02/06/2014
01/07/2019
Boulder, CO 80301-3299
FIRST NAMED INVENTOR
DANIEL FRIEDRICHS
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.
H-EB-00581 (203-9329) 5711
EXAMINER
HUPCZEY, JR, RONALD JAMES
ART UNIT PAPER NUMBER
3794
NOTIFICATION DATE DELIVERY MODE
01/07/2019 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):
mail@cdfslaw.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 DANIEL FRIEDRICHS and JAMES A GILBERT 1
Appeal2018-005499
Application 14/174,607
Technology Center 3700
Before ERIC B. GRIMES, MICHAEL J. FITZPATRICK, and
JOHN E. SCHNEIDER, Administrative Patent Judges.
SCHNEIDER, Administrative Patent Judge.
DECISION ON APPEAL
This is an appeal2 under 35 U.S.C. § 134 of the Examiner's rejection
of claims to an electrosurgical generator which have been rejected as
obvious. We have jurisdiction under 35 U.S.C. § 6(b).
We AFFIRM.
1 Appellants identify the Real Party in Interest as Covidien LP. Appeal Br.
1.
2 We have considered and herein refer to the Specification of Feb. 6, 2014
("Spec."); Final Office Action of Aug. 1, 2017 ("Final Act."); Appeal Brief
of Jan 29, 2018 ("Appeal Br."); Examiner's Answer of Mar. 8, 2018
("Ans."); and Reply Brief of May 4, 2018 ("Reply Br.").
Appeal2018-005499
Application 14/174,607
STATEMENT OF THE CASE
"Electrosurgery involves application of high radio frequency
electrical current to a surgical site to cut, ablate, or coagulate tissue."
Spec. ,r 3. "[B]ipolar electro surgery generally involves the use of
instruments where it is desired to achieve a focused delivery of
electrosurgical energy between two electrodes positioned on the
instrument." Spec. ,r 4. "By controlling the intensity, frequency and
duration of the electro surgical energy applied through the [electrodes]
to the tissue, the surgeon can coagulate, cauterize and/or seal tissue."
Id. The Specification describes "electrosurgical generators that utilize
current-programmed control with a nonlinear control current to
produce a constant power source." Spec. ,r 2.
Claims 1, 3-10, 12, and21-31 are on appeal. Claim 1 is
representative and reads as follows:
1. An electrosurgical generator, comprising:
at least one DC-DC Cuk converter configured to output a
DC waveform and a nonlinear carrier control current;
at least one boost inverter coupled to the at least one
converter, the at least one boost inverter configured to convert
the DC waveform to generate at least one electrosurgical
waveform;
at least one inductor connected in series with the at least
one DC-DC Cuk converter and the at least one boost inverter,
the at least one inductor configured to output an inductor
current; and
at least one controller coupled to the at least one DC-DC
Cuk converter and the at least one boost inverter and configured
to maintain the inductor current at a predetermined value by
controlling a pulse duration of a duty cycle of the at least one
DC-DC Cuk converter based on a comparison of the inductor
current and the nonlinear carrier control current, the at least one
controller further configured to control a crest factor (CF) of the
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Application 14/174,607
at least one electrosurgical waveform using the at least one
boost inverter.
Claims 1, 3-10, 12, and 21-31 have been rejected under 35 U.S.C.
§ I03(a) as unpatentable over Friedrichs 3 in view of Chen. 4
DISCUSSION
Appellants have presented six separate sets of arguments for different
sets of claims. We will address each set of arguments in the order they are
presented in the briefs. In each set, the issue to be addressed is whether a
preponderance of the evidence supports the Examiner's conclusion that the
subject matter of the claims would have been obvious over Friedrichs
combined with Chen.
Set A- Claims 1, 3, 12, 21, 22, 30, and 31
The Examiner finds that Friedrichs discloses an electrosurgical
generator comprising a converter configured to output a DC waveform and a
nonlinear control current and at least one boost inverter coupled with the
converter where the boost inverter converts the DC waveform to generate an
electrosurgical waveform. Final Act. 3. The Examiner finds that the
generator of Friedrichs also comprises an inductor connected in series with
the converter and boost inverter where the inductor outputs an inductor
current. Id. The Examiner finds that the generator of Friedrichs further
comprises a controller coupled to the converter and boost inverter to
maintain the inductor current at a predetermined value and to control the
3 Friedrichs et al., EP 2 469 699 A2, published June 27, 2012 ("Friedrichs").
4 Chen, US 2007/0040516 Al, published Feb. 22, 2007 ("Chen").
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Application 14/174,607
crest factor of the electrosurgical waveform using the boost inverter. Id. at
4.
The Examiner finds that Chen discloses switching between buck
converters and Cuk converters. Id. at 4. The Examiner concludes
Id.
it would have been obvious to one of ordinary skill in the art at
the time the invention was made to utilize a Cuk converter in
place of the buck converter so as to provide a known alternative
manner of converter as taught by Chen. The Examiner is of the
position given the disclosure in Friedrichs that either
arrangement would be an obvious variant of one another that
would work equally as well as one another to accomplish the
requisite conversion. Furthermore, in view of the disclosure, of
Chen, it is the Examiner position that the control of each type of
converter via the controller is within the skill of one in the art to
achieve the desired output dependent upon the type used.
Appellants argue that Friedrichs does not teach or suggest controlling
the crest form of a waveform, let alone using a boost inverter to control the
waveform.
[T]he examiner bears the initial burden, on review of the
prior art or on any other ground, of presenting a prima facie
case of unpatentability. If that burden is met, the burden of
coming forward with evidence or argument shifts to the
applicant.
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 re Oetiker, 977 F.2d 1443, 1445 (Fed. Cir. 1992).
We adopt the Examiner's findings of fact, reasoning on scope and
content of the prior art, and conclusions set out in the Final Action and
Answer regarding this rejection. We find the Examiner has established that
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Application 14/174,607
the subject matter of the claims would have been obvious over Friedrichs
combined with Chen to one of ordinary skill in the art at the time the
invention was made. Appellants have not produced evidence showing, or
persuasively argued, that the Examiner's determinations on obviousness are
incorrect. Only those arguments made by Appellants in the Briefs have been
considered in this Decision. Arguments not presented in the Briefs are
waived. See 37 C.F.R. § 4I.37(c)(l)(iv) (2015). We have identified claim 1
as representative; therefore, all claims fall with claim 1. We address
Appellants' arguments below.
Appellants contend that Friedrichs does not teach or suggest
controlling a crest factor of a waveform using a boost inverter. Appeal Br.
7.
The Examiner acknowledges that Friedrichs does not explicitly refer
to controlling a crest factor of a waveform but finds that controlling a crest
factor is an inherent feature of Friedrichs. Ans. 4. The Examiner contends
that the control of the duty cycle d2 in Friedrichs would inherently result in
control of the crest factor. Id. The Examiner compares the discussion of
operation of the boost inverter in Friedrichs with that in the instant
disclosure and finds that they operate in the same manner. Id.
We find the Examiner's position to be persuasive. Friedrichs teaches
achieving constant power by setting the duty cycle d 1 to a fixed value and
"running the DC-AC boost inverter as a current-programmed boost inverter
by varying the duty cycle d2." Friedrichs ,r 30. The Specification teaches
"In particular, the DC-AC boost inverter 102 may be used to control the CF
of the waveform while the DC-DC buck converter 1 OOa is used to control
the output power. In this embodiment, DC-AC boost inverter 102 is fixed at
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a given cycle, which may be from about 0% to about 100 %, in
embodiments, from about 20 % to about 90%, while the DC-DC buck
converter 100a is run in NLC control." Spec. ,r 65. We agree with the
Examiner that, given the teachings cited above, one skilled in the art would
expect the boost inverter of Friedrichs to control a crest factor in the same
manner as the present invention. Ans. 4.
Appellants contend that the Examiner improperly relied on the
Appellants' Specification in making the rejection in that the Specification is
not prior art. Reply Br. 3. We are not persuaded. The Examiner only cited
to the Specification to show that the present invention operates in the same
manner as that disclosed in Friedrichs to support the Examiner's contention
that the boost inverter would inherently control the crest factor.
Appellants also contend that Friedrichs does not teach the use of a
controller to control the crest factor. Appeal Br. 5---6. Appellants argue that
Friedrich does not describe the action of the steering logic which controls
the boost inverter. Id.
Again we are not persuaded. As shown in Figure 1 of Friedrichs
reproduced below, the steering logic is part of a control system 110 which
controls the duty cycles d1 and d2.
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Application 14/174,607
Figure 1
122
Figure 1 of Friedrichs shows a schematic of an electrosurgical generator.
As the Examiner points out, Friedrichs describes how the controller operates
to control the different duty cycles. Ans. 3. As discussed above, controlling
the duty cycle d2 results in controlling the crest factor. Thus one skilled in
the art would understand that Friedrichs discloses a controller configured to
control a crest factor using a boost inverter.
Set B - Claims 5 and 2 4.
Claims 5 and 24 depend from claims 1 and 21 respectively and add a
limitation calling for switching elements included in converters or boosters,
and operated at the duty cycles of the respective element. Appeal Br. 9.
Appellants argue that Friedrichs does not teach or suggest the presence of
the recited switching elements. Appeal Br. 9-10.
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Appellants' argument is unpersuasive. The rejection is based on the
combined teachings of Friedrichs and Chen, not Friedrich alone. As the
Examiner points out, Chen teaches the switching elements recited in the
claims. "Non-obviousness cannot be established by attacking references
individually where the rejection is based upon the teachings of a
combination of references. . . . [The reference] must be read, not in
isolation, but for what it fairly teaches in combination with the prior art as a
whole." In re Merck & Co., 800 F.2d 1091, 1097 (Fed. Cir. 1986).
Set C - Claims 6 and 25.
Claims 6 and 25 depend from claims 1 and 20 respectively and add
the limitation that "the at least one controller is configured to control the at
least one DC-DC Cuk converter in a current-program mode and to maintain
the duty cycle of the at least one boost inverter at about 100% to operate the
at least one electrosurgical waveform in a constant current mode." Appeal
Br. 11. Appellants contend that Friedrichs does not teach or suggest this
limitation. Id.
We have considered Appellants' argument and find it unpersuasive.
As the Examiner points out, Friedrichs teaches controlling the duty cycle d2
at a fixed value in the constant current mode and teaches that the duty cycle
can be 100%. Ans. 6: Friedrichs ,r,r 62 and 70. We agree with the Examiner
that it would have been obvious to maintain the duty cycle of the boost
inverter at 100%.
Set D - claims 7 and 26.
Claims 7 and 26 depend from claims 1 and 21 respectively and add
the limitation that "the at least one controller is configured to control the at
least one DC-DC Cuk converter in a non-linear carrier control mode and to
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maintain the duty cycle of the at least one boost inverter at about 100% to
operate the at least one electro surgical waveform in a constant power mode."
Appeal Br. 12. Appellants contend that this limitation is not taught or
suggested by the references. Id.
Again we are not persuaded. As the Examiner points out, Friedrichs
teaches running a buck converter in a non-linear carrier control mode for
constant power output. An. 6, Friedrichs Table 2. Friedrichs also teaches to
maintain the duty cycle at 100% during a constant power mode. Chen
teaches that a Cuk converter can be substituted for a buck converter. See
Chen Abstract. We agree with the Examiner that the subject matter of
claims 7 and 26 would have been obvious over Friedrichs combined with
Chen.
Set E - Claims 8 and 2 7.
Claims 8 and 27 depend from claims 1 and 21 respectively and add
the limitation that "in the non-linear carrier control mode the at least one
controller calculates a set point current based on a ratio of elapsed time and
period length of each cycle of the DC waveform." Appeal Br. 13.
Appellants contend "there is no disclosure [in the references] relating to
calculating a set point current based on a ratio of elapsed time and period
length of each cycle of a DC waveform." Id.
Appellants' argument is unpersuasive. As the Examiner points out,
Friedrichs discusses calculating a set point current. Ans. 7; Friedrichs ,r,r
48-50. The equation used to calculate the set point current uses a ratio of
elapsed time and period wave length to calculate the set point current.
Friedrichs ,r 50. We agree with the Examiner that the subject matter of
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claims 8 and 27 would have been obvious over Friedrichs combined with
Chen.
Set F - Claims 9 and 2 8
Claims 9 and 28 depend from claims 1 and 21 respectively and add
the limitation that "the at least one controller is configured to control the at
least one boost inverter in a current-program mode and to maintain the duty
cycle of the at least one DC-DC Cuk converter at about 100% to operate the
at least one electrosurgical waveform in a constant power mode." Appeal
Br. 14. Appellants contend that this limitation is not taught or suggested by
the references. Id. at 15. Specifically Appellants argue that there is no
disclosure relating to controlling a boost inverter in a current-program mode.
Id.
We are not persuaded by Appellants' argument. Friedrichs teaches
that in current program mode, the duty cycle d2 is varied by the current mode
controller. Friedrich ,r 31. As shown in Figure 1 of Friedrichs reproduced
above, duty cycle d2 controls the action of the boost inverter. We agree with
the Examiner that the subject matter of claims 9 and 28 would have been
obvious over Friedrichs combined with Chen.
Set F- Claims 10 and 29.
Claims 10 and 29 depend from claims 1 and 21 respectively and add
the limitation that "the at least one controller is configured to maintain the
duty cycle of the at least one DC-DC Cuk converter at about 100% and the
duty cycle of the at least one boost inverter at less than 100% to operate the
at least one electro surgical waveform in a constant voltage mode." Appeal
Br. 15. Appellants contend "there is no disclosure relating to controlling a
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duty cycle of a boost inverter at less than 100% to operate an electro surgical
waveform in a constant voltage mode." Id. at 16.
Appellants' argument is unpersuasive. Friedrichs teaches:
In an exemplary embodiment, constant voltage output is
achieved by setting duty cycle 81 of DC-DC buck converter 101
to a fixed value, and duty cycle 82 of DC-AC boost inverter 102
is voltage-mode controlled. In an exemplary embodiment, the
voltage-mode control involves measuring the output voltage
Vout(t) of DC-AC boost inverter 102 with a sensor, feeding the
sensed output voltage to a control loop in voltage-mode
controller 512, and adjusting the converter's duty cycle
command based on the relative difference between the
measured output voltage and the reference output voltage. In
other words, the duty cycle 82 is set to increase or decrease the
output voltage to match V max· In an exemplary embodiment,
V max may be set by a user or based on values in a look-up table.
In an alternative embodiment, the boost inverter is run at a fixed
duty cycle with no feedback of the output voltage.
Friedrichs ,r 60. Friedrichs also teaches that the fixed value can be as high as
100%. Id. ,r 70. We agree with the Examiner that it would have been
obvious to one of ordinary skill in the art to set the duty cycle of the
converter to 100% and vary the duty cycle of the inverter during the constant
voltage mode. Ans. 8.
Conclusion
We conclude that a preponderance of the evidence supports the
Examiner's conclusion that claims 1, 5-10, and 24--29 would have been
obvious to one of ordinary skill in the art at the time the invention was made
over Friedrichs combined with Chen.
Claims 3, 4, 12, 21-24, 30 and 31 have not been argued separately
and therefore fall with claim 1. 37 C.F.R. § 4I.37(c)(l)(iv).
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Application 14/174,607
SUMMARY
We affirm the rejection under 35 U.S.C. § 103(a).
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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