U.S. patent application number 15/258586 was filed with the patent office on 2017-03-30 for frequency agile generator for a surgical instrument.
The applicant listed for this patent is Ethicon Endo-Surgery, LLC. Invention is credited to Eitan T. Wiener, David C. Yates.
Application Number | 20170086909 15/258586 |
Document ID | / |
Family ID | 58406061 |
Filed Date | 2017-03-30 |
United States Patent
Application |
20170086909 |
Kind Code |
A1 |
Yates; David C. ; et
al. |
March 30, 2017 |
FREQUENCY AGILE GENERATOR FOR A SURGICAL INSTRUMENT
Abstract
Disclosed is a system comprising a generator and a surgical
instrument, wherein the generator is configured to deliver a
combined signal comprising a radio frequency (RF) component and an
ultrasonic component to the surgical instrument; and the surgical
instrument comprises: an RF energy output, an ultrasonic energy
output, a circuit configured to steer the RF component to the RF
energy output and steer the ultrasonic component to the ultrasonic
energy output, wherein the generator is configured to adjust a
frequency of the RF component based on a characterization of a
circuit component of the circuit.
Inventors: |
Yates; David C.; (West
Chester, OH) ; Wiener; Eitan T.; (Cincinnati,
OH) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Ethicon Endo-Surgery, LLC |
Guaynabo |
PR |
US |
|
|
Family ID: |
58406061 |
Appl. No.: |
15/258586 |
Filed: |
September 7, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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62235260 |
Sep 30, 2015 |
|
|
|
62235368 |
Sep 30, 2015 |
|
|
|
62235466 |
Sep 30, 2015 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61B 18/1206 20130101;
A61B 2017/00017 20130101; A61B 2018/1293 20130101; A61B 2018/00642
20130101; B06B 1/0207 20130101; A61B 2018/00994 20130101; A61B
18/1445 20130101; G06F 1/022 20130101; A61B 2018/128 20130101; A61B
2018/1273 20130101; A61B 18/1482 20130101; A61B 2017/00137
20130101; A61B 2017/0015 20130101; H03K 5/01 20130101; A61B
2017/320094 20170801 |
International
Class: |
A61B 18/12 20060101
A61B018/12; A61N 7/00 20060101 A61N007/00; A61B 18/14 20060101
A61B018/14 |
Claims
1. A system comprising a generator and a surgical instrument,
wherein the generator is configured to deliver a combined signal
comprising a radio frequency (RF) component and an ultrasonic
component to the surgical instrument; and the surgical instrument
comprises: an RF energy output, an ultrasonic energy output, a
circuit configured to steer the RF component to the RF energy
output and steer the ultrasonic component to the ultrasonic energy
output, wherein the generator is configured to adjust a frequency
of the RF component based on a characterization of a circuit
component of the circuit.
2. The system of claim 1, wherein the circuit component comprises a
band-stop filter.
3. The system of claim 1, wherein the circuit further comprises a
variable component.
4. The system of claim 1, wherein the characterization of the
circuit component comprises sending a ping signal to the circuit
component.
5. The system of claim 1, wherein a result of the characterization
is stored in the surgical instrument.
6. The system of claim 1, wherein the characterization is performed
when the surgical instrument is manufactured.
7. The system of claim 1, wherein the characterization is performed
when the surgical instrument is connected to the generator.
8. The system of claim 1, wherein the characterization is performed
after the surgical instrument delivers energy to a tissue.
9. The system of claim 1, wherein the characterization is performed
while the surgical instrument is delivering energy to a tissue.
10. The system of claim 1, wherein the characterization is
performed periodically.
11. A method for providing a combined signal comprising a radio
frequency (RF) component and an ultrasonic component by a generator
to a surgical instrument, the surgical instrument comprising an RF
energy output, an ultrasonic energy output and a circuit, the
method comprising: performing characterization on a circuit
component of the circuit; adjusting a frequency of the RF component
based on a result of the characterization; delivering, by the
generator, the combined signal to the surgical instrument;
steering, by the circuit, the RF component to the RF energy output;
and steering, by the circuit, the ultrasonic component to the
ultrasonic energy output.
12. The method of claim 11, wherein the circuit component comprises
a band-stop filter.
13. The method of claim 11, wherein the circuit further comprises a
variable component.
14. The method of claim 11, wherein performing characterization on
the circuit component comprises sending a ping signal to the
circuit component.
15. The method of claim 11, further comprising storing a result of
the characterization in the surgical instrument.
16. The method of claim 11, wherein the characterization is
performed when the surgical instrument is manufactured.
17. The method of claim 11, wherein the characterization is
performed when the surgical instrument is connected to the
generator.
18. The method of claim 11, wherein the characterization is
performed after the surgical instrument delivers energy to a
tissue.
19. The method of claim 11, wherein the characterization is
performed while the surgical instrument is delivering energy to a
tissue.
20. A generator for providing a combined signal comprising a radio
frequency (RF) component and an ultrasonic component to a surgical
instrument, the generator being configured to: perform
characterization on a circuit component of a circuit of the
surgical instrument for steering the RF component to an RF output
and steering the ultrasonic component to an ultrasonic output;
adjust a frequency of the RF component based on a result of the
characterization; and deliver the combined signal to the surgical
instrument.
Description
PRIORITY
[0001] This application claims the benefit of U.S. Provisional
Application Ser. No. 62/235,260, titled GENERATOR FOR PROVIDING
COMBINED RADIO FREQUENCY AND ULTRASONIC ENERGIES, filed Sep. 30,
2015, U.S. Provisional Application Ser. No. 62/235,368, titled
CIRCUIT TOPOLOGIES FOR GENERATOR, filed Sep. 30, 2015, and U.S.
Provisional Application Ser. No. 62/235,466, titled SURGICAL
INSTRUMENT WITH USER ADAPTABLE ALGORITHMS, filed Sep. 30, 2015, the
contents of each of which are incorporated herein by reference in
their entirety.
TECHNICAL FIELD
[0002] The present disclosure generally relates to ultrasonic
surgical systems, electrosurgical systems, and combination
electrosurgical/ultrasonic systems for performing surgical
procedures such as coagulating, sealing, and/or cutting tissue. In
articular, the present disclosure relates to a frequency agile
generator for a surgical instrument.
BACKGROUND
[0003] Ultrasonic surgical instruments are finding increasingly
widespread applications in surgical procedures by virtue of the
unique performance characteristics of such instruments. Depending
upon specific instrument configurations and operational parameters,
ultrasonic surgical instruments can provide substantially
simultaneous cutting of tissue and hemostasis by coagulation,
desirably minimizing patient trauma. The cutting action is
typically realized by an-end effector, or blade tip, at the distal
end of the instrument, which transmits ultrasonic energy to tissue
brought into contact with the end effector. Ultrasonic instruments
of this nature can be configured for open surgical use,
laparascopic, or endoscopic surgical procedures including
robotic-assisted procedures.
[0004] Some surgical instruments utilize ultrasonic energy for both
precise cutting and controlled coagulation. Ultrasonic energy cuts
and coagulates by vibrating a blade in contact with tissue.
Vibrating at high frequencies (e.g., 55,500 times per second), the
ultrasonic blade denatures protein in the tissue to form a sticky
coagulum. Pressure exerted on tissue with the blade surface
collapses blood vessels and allows the coagulum to form a
hemostatic seal. The precision of cutting and coagulation is
controlled by the surgeon's technique and adjusting the power
level, blade edge, tissue traction, and blade pressure.
[0005] Electrosurgical devices for applying electrical energy to
tissue in order to treat and/or destroy the tissue are also finding
increasingly widespread applications in surgical procedures. An
electrosurgical device typically includes a hand piece, an
instrument having a distally-mounted end effector (e.g., one or
more electrodes). The end effector can be positioned against the
tissue such that electrical current is introduced into the tissue.
Electrosurgical devices can be configured for bipolar or monopolar
operation. During bipolar operation, current is introduced into and
returned from the tissue by active and return electrodes,
respectively, of the end effector. During monopolar operation,
current is introduced into the tissue by an active electrode of the
end effector and returned through a return electrode (e.g., a
grounding pad) separately located on a patient's body. Heat
generated by the current flowing through the tissue may form
hemostatic seals within the tissue and/or between tissues and thus
may be particularly useful for sealing blood vessels, for example.
The end effector of an electrosurgical device may also include a
cutting member that is movable relative to the tissue and the
electrodes to transect the tissue.
[0006] Electrical energy applied by an electrosurgical device can
be transmitted to the instrument by a generator in communication
with the hand piece. The electrical energy may be in the form of
radio frequency (RF) energy that may be in a frequency range
described in EN 60601-2-2:2009+A11:2011, Definition 201.3.218--HIGH
FREQUENCY. For example, the frequencies in monopolar RF
applications are typically restricted to less than 5 MHz. However,
in bipolar RF applications, the frequency can be almost anything.
Frequencies above 200 kHz can be typically used for MONOPOLAR
applications in order to avoid the unwanted stimulation of nerves
and muscles which would result from the use of low frequency
current. Lower frequencies may be used for BIPOLAR techniques if
the RISK ANALYSIS shows the possibility of neuromuscular
stimulation has been mitigated to an acceptable level. Normally,
frequencies above 5 MHz are not used in order to minimize the
problems associated with HIGH FREQUENCY LEAKAGE CURRENTS. However,
higher frequencies may be used in the case of BIPOLAR techniques.
It is generally recognized that 10 mA is the lower threshold of
thermal effects on tissue.
[0007] In application, an electrosurgical device can transmit low
frequency RF energy through tissue, which causes ionic agitation,
or friction, in effect resistive heating, thereby increasing the
temperature of the tissue. Because a sharp boundary is created
between the affected tissue and the surrounding tissue, surgeons
can operate with a high level of precision and control, without
sacrificing un-targeted adjacent tissue. The low operating
temperatures of RF energy is useful for removing, shrinking, or
sculpting soft tissue while simultaneously sealing blood vessels.
RF energy works particularly well on connective tissue, which is
primarily comprised of collagen and shrinks when contacted by
heat.
[0008] Other electrical surgical instruments include, without
limitation, irreversible and/or reversible electroporation, and/or
microwave technologies, among others. Accordingly, the techniques
disclosed herein are applicable to ultrasonic, bipolar or monopolar
RF (electrosurgical), irreversible and/or reversible
electroporation, and/or microwave based surgical instruments, among
others.
SUMMARY
[0009] In one aspect, a system comprising a generator and a
surgical instrument is provided, wherein the generator is
configured to deliver a combined signal comprising a radio
frequency (RF) component and an ultrasonic component to the
surgical instrument; and the surgical instrument comprises: an RF
energy output, an ultrasonic energy output, a circuit configured to
steer the RF component to the RF energy output and steer the
ultrasonic component to the ultrasonic energy output, wherein the
generator is configured to adjust a frequency of the RF component
based on a characterization of at least one circuit component of
the circuit.
[0010] In another aspect, a method for providing a combined signal
comprising a radio frequency (RF) component and an ultrasonic
component by a generator to a surgical instrument is provided, the
surgical instrument comprising an RF energy output, an ultrasonic
energy output and a circuit, the method comprising: performing
characterization on at least one circuit component of the circuit;
adjusting a frequency of the RF component based on a result of the
characterization; delivering, by the generator, the combined signal
to the surgical instrument; steering, by the circuit, the RF
component to the RF energy output; and steering, by the circuit,
the ultrasonic component to the ultrasonic energy output.
[0011] In yet another aspect, A generator for providing a combined
signal comprising a radio frequency (RF) component and an
ultrasonic component to a surgical instrument is provided, the
generator being configured to: perform characterization on at least
one circuit component of a circuit of the surgical instrument for
steering the RF component to an RF output and steering the
ultrasonic component to an ultrasonic output; adjust a frequency of
the RF component based on a result of the characterization; and
deliver the combined signal to the surgical instrument.
FIGURES
[0012] The novel features of the described forms are set forth with
particularity in the appended claims. The described forms, however,
both as to organization and methods of operation, may be best
understood by reference to the following description, taken in
conjunction with the accompanying drawings in which:
[0013] FIG. 1 illustrates one form of a surgical system comprising
a generator and various surgical instruments usable therewith;
[0014] FIG. 2 is a diagram of the combination electrosurgical and
ultrasonic instrument shown in FIG. 1;
[0015] FIG. 3 is a diagram of the surgical system shown in FIG.
1;
[0016] FIG. 4 is a model illustrating motional branch current in
one form;
[0017] FIG. 5 is a structural view of a generator architecture in
one form;
[0018] FIG. 6 illustrates one form of a drive system of a
generator, which creates the ultrasonic electrical signal for
driving an ultrasonic transducer;
[0019] FIG. 7 illustrates one form of a drive system of a generator
comprising a tissue impedance module;
[0020] FIG. 8 illustrates an example of a combined radio frequency
and ultrasonic energy generator for delivering energy to a surgical
instrument;
[0021] FIG. 9 is a diagram of a system for delivering combined
radio frequency and ultrasonic energy to a plurality of surgical
instruments;
[0022] FIG. 10 illustrates a communications architecture of a
system for delivering combined radio frequency and ultrasonic
energy to a plurality of surgical instruments;
[0023] FIG. 11 illustrates a communications architecture of a
system for delivering combined radio frequency and ultrasonic
energy to a plurality of surgical instruments;
[0024] FIG. 12 illustrates a communications architecture of a
system for delivering combined radio frequency and ultrasonic
energy to a plurality of surgical instruments;
[0025] FIG. 13 is a flow diagram illustrating a method for
providing a combined signal by a generator to a surgical
instrument;
[0026] FIG. 14 displays an example of a notch filter;
[0027] FIG. 15 is an example graph of an analysis of the transfer
function of the notch filter in FIG. 14;
[0028] FIG. 16 is a plot illustrating adjustment of the RF
frequency based on characterization of the steering circuitry;
[0029] FIG. 17 provides an illustration of a system configuration
for an example circuit topology shown and described with regard to
FIGS. 13-16, including metal-oxide-semiconductor field effect
transistor (MOSFET) switches and a control circuit in the handle,
configured to manage RF and ultrasonic currents output by a
generator according to one aspect of the present disclosure;
[0030] FIG. 18 provides an illustration of a system configuration
for an example circuit topology shown and described with regard to
FIGS. 13-16, including bandstop filters and a control circuit in
the handle, configured to manage RF and ultrasonic currents output
by a generator according to one aspect of the present
disclosure;
[0031] FIG. 19 is an example graph of two waveforms of energy from
a generator;
[0032] FIG. 20 is an example graph of the sum of the waveforms of
FIG. 19;
[0033] FIG. 21 is an example graph of sum of the waveforms of FIG.
19 with the RF waveform dependent on the ultrasonic waveform;
[0034] FIG. 22 is an example graph of the sum of the waveforms of
FIG. 19 with the RF waveform being a function of the ultrasonic
waveform; and
[0035] FIG. 23 is an example graph of a complex RF waveform with a
high crest factor.
DESCRIPTION
[0036] Before explaining various forms of ultrasonic surgical
instruments in detail, it should be noted that the illustrative
forms are not limited in application or use to the details of
construction and arrangement of parts illustrated in the
accompanying drawings and description. The illustrative forms may
be implemented or incorporated in other forms, variations and
modifications, and may be practiced or carried out in various ways.
Further, unless otherwise indicated, the terms and expressions
employed herein have been chosen for the purpose of describing the
illustrative forms for the convenience of the reader and are not
for the purpose of limitation thereof.
[0037] Further, it is understood that any one or more of the
following-described forms, expressions of forms, examples, can be
combined with any one or more of the other following-described
forms, expressions of forms, and examples.
[0038] Various forms are directed to improved ultrasonic surgical
instruments configured for effecting tissue dissecting, cutting,
and/or coagulation during surgical procedures. In one form, an
ultrasonic surgical instrument apparatus is configured for use in
open surgical procedures, but has applications in other types of
surgery, such as laparascopic, endoscopic, and robotic-assisted
procedures. Versatile use is facilitated by selective use of
ultrasonic energy.
[0039] This application is related to the following commonly owned
patent applications filed contemporaneously herewith: [0040]
Attorney Docket No. END7768USNP1/150449-1, titled CIRCUIT
TOPOLOGIES FOR COMBINED GENERATOR, by Wiener et al.; [0041]
Attorney Docket No. END7768USNP2/150449-2, titled CIRCUITS FOR
SUPPLYING ISOLATED DIRECT CURRENT (DC) VOLTAGE TO SURGICAL
INSTRUMENTS, by Wiener et al.; [0042] Attorney Docket No.
END7768USNP4/150449-4, titled, METHOD AND APPARATUS FOR SELECTING
OPERATIONS OF A SURGICAL INSTRUMENT BASED ON USER INTENTION, by
Asher et al.; [0043] Attorney Docket No. END7769USNP1/150448-1,
titled GENERATOR FOR DIGITALLY GENERATING ELECTRICAL SIGNAL
WAVEFORMS FOR ELECTROSURGICAL AND ULTRASONIC SURGICAL INSTRUMENTS,
by Wiener et al.; [0044] Attorney Docket No. END7769USNP2/150448-2,
titled GENERATOR FOR DIGITALLY GENERATING COMBINED ELECTRICAL
SIGNAL WAVEFORMS FOR ULTRASONIC SURGICAL INSTRUMENTS, by Wiener et
al.; [0045] Attorney Docket No. END7769USNP3/150448-3, titled
PROTECTION TECHNIQUES FOR GENERATOR FOR DIGITALLY GENERATING
ELECTROSURGICAL AND ULTRASONIC DIGITAL ELECTRICAL SIGNAL WAVEFORMS,
by Yates et al.; [0046] each of which is incorporated herein by
reference in its entirety.
[0047] This application also is related to the following commonly
owned patent applications filed on Jun. 9, 2016: [0048] U.S. patent
application Ser. No. 15/177,430, titled SURGICAL INSTRUMENT WITH
USER ADAPTABLE TECHNIQUES; [0049] U.S. patent application Ser. No.
15/177,439, titled SURGICAL INSTRUMENT WITH USER ADAPTABLE
TECHNIQUES BASED ON TISSUE TYPE; [0050] U.S. patent application
Ser. No. 15/177,449, titled SURGICAL SYSTEM WITH USER ADAPTABLE
TECHNIQUES EMPLOYING MULTIPLE ENERGY MODALITIES BASED ON TISSUE;
[0051] U.S. patent application Ser. No. 15/177,456, titled SURGICAL
SYSTEM WITH USER ADAPTABLE TECHNIQUES BASED ON TISSUE IMPEDANCE;
[0052] U.S. patent application Ser. No. 15/177,466, titled SURGICAL
SYSTEM WITH USER ADAPTABLE TECHNIQUES EMPLOYING SIMULTANEOUS ENERGY
MODALITIES BASED ON TISSUE PARAMETERS; [0053] each of which is
incorporated herein by reference in its entirety.
[0054] The various forms will be described in combination with an
ultrasonic instrument as described herein. Such description is
provided by way of example, and not limitation, and is not intended
to limit the scope and applications thereof. For example, any one
of the described forms is useful in combination with a multitude of
ultrasonic instruments including those described in, for example,
U.S. Pat. Nos. 5,938,633; 5,935,144; 5,944,737; 5,322,055;
5,630,420; and 5,449,370, which are each incorporated by reference
herein in their entirety.
[0055] As will become apparent from the following description, it
is contemplated that forms of the surgical instrument described
herein may be used in association with an oscillator unit of a
surgical system, whereby ultrasonic energy from the oscillator unit
provides the desired ultrasonic actuation for the present surgical
instrument. It is also contemplated that forms of the surgical
instrument described herein may be used in association with a
signal generator unit of a surgical system, whereby electrical
energy in the form of radio frequencies (RF), for example, is used
to provide feedback to the user regarding the surgical instrument.
The ultrasonic oscillator and/or the signal generator unit may be
non-detachably integrated with the surgical instrument or may be
provided as separate components, which can be electrically
attachable to the surgical instrument.
[0056] One form of the present surgical apparatus is particularly
configured for disposable use by virtue of its straightforward
construction. However, it is also contemplated that other forms of
the present surgical instrument can be configured for
non-disposable or multiple uses. Detachable connection of the
present surgical instrument with an associated oscillator and
signal generator unit is presently disclosed for single-patient use
for illustrative purposes only. However, non-detachable integrated
connection of the present surgical instrument with an associated
oscillator and/or signal generator unit is also contemplated.
Accordingly, various forms of the presently described surgical
instruments may be configured for single use and/or multiple use
with either detachable and/or non-detachable integral oscillator
and/or signal generator unit, without limitation, and all
combinations of such configurations are contemplated to be within
the scope of the present disclosure.
[0057] In one aspect, the desired wave shape may be digitized by
1024 points, which are stored in a table, such as, for example, a
Direct Digital Synthesis (DDS) table with a field programmable gate
array (FPGA) of the generator. The generator software and digital
controls command the FPGA to scan the addresses in this table at
the frequency of interest which in turn provides varying digital
input values to a digital-to-analog converter (DAC) circuit that
feeds to power amplifier. This method enables generating
practically any (or many) types of wave shapes fed into tissue.
Furthermore, multiple wave shape tables can be created, stored and
applied to tissue.
[0058] According to various aspects, a method comprises creating
various types of lookup tables in memory such as lookup tables
generated by Direct Digital Synthesizers (DDS) and stored within
Field Programmable Gate Arrays (FPGA), for example. Waveforms may
be stored in the DDS table or tables as particular wave shapes.
Examples of wave shapes in the RF/Electrosurgery tissue treatment
field include high crest factor RF signals, which may be used for
surface coagulation in an RF mode, for example, low crest factor RF
signals, which may be used for deeper penetration into tissue in an
RF mode, for example, and waveforms that promote efficient touch-up
coagulation, for example.
[0059] The present disclosure provides for the creation of multiple
wave shape tables that allow for switching on the fly, either
manually or automatically, between the wave shapes based on tissue
effect desired. Switching could be based on tissue parameters, such
as, for example, tissue impedance and/or other factors. In addition
to a traditional sine wave shape, in one aspect a generator may be
configured to provide a wave shape that maximizes the power into
tissue per cycle. According to one aspect, the wave shape may be a
trapezoid wave, a sine or cosine wave, a square wave, a triangle
wave, or any combination thereof. In one aspect, a generator may be
configured to provide a wave shape or shapes that are synchronized
in such way that they make maximizing power delivery in the case
that both RF and ultrasonic energy modalities are driven, either
simultaneously or sequentially. In one aspect, a generator may be
configured to provide a waveform that drives both ultrasonic and RF
therapeutic energy simultaneously while maintaining ultrasonic
frequency lock. In one aspect, the generator may contain or be
associated with a device that provides a circuit topology that
enables simultaneously driving RF and ultrasonic energy. In one
aspect, a generator may be configured to provide custom wave shapes
that are specific to a surgical instrument and the tissue effects
provided by such a surgical instrument. Furthermore, the waveforms
may be stored in a generator non-volatile memory or in an
instrument memory, such as, for example, an electrically erasable
programmable read only memory (EEPROM). The waveform or waveforms
may be fetched upon instrument connection to a generator.
[0060] With reference to FIGS. 1-5, one form of a surgical system
10 including a surgical instrument is illustrated. FIG. 1
illustrates one form of a surgical system 10 comprising a generator
100 and various surgical instruments 104, 106, 108 usable
therewith, where the surgical instrument 104 is an ultrasonic
surgical instrument, the surgical instrument 106 is an RF
electrosurgical instrument 106, and the multifunction surgical
instrument 108 is a combination ultrasonic/RF electrosurgical
instrument. FIG. 2 is a diagram of the multifunction surgical
instrument 108 shown in FIG. 1. With reference to both FIGS. 1 and
2, the generator 100 is configurable for use with a variety of
surgical instruments.
[0061] According to various forms, the generator 100 may be
configurable for use with different surgical instruments of
different types including, for example, ultrasonic surgical
instruments 104, RF electrosurgical instruments 106, and
multifunction surgical instruments 108 that integrate RF and
ultrasonic energies delivered simultaneously from the generator
100. Although in the form of FIG. 1, the generator 100 is shown
separate from the surgical instruments 104, 106, 108 in one form,
the generator 100 may be formed integrally with any of the surgical
instruments 104, 106, 108 to form a unitary surgical system. The
generator 100 comprises an input device 110 located on a front
panel of the generator 100 console. The input device 110 may
comprise any suitable device that generates signals suitable for
programming the operation of the generator 100.
[0062] FIG. 1 illustrates a generator 100 configured to drive
multiple surgical instruments 104, 106, 108. The first surgical
instrument 104 is an ultrasonic surgical instrument 104 and
comprises a handpiece 105 (HP), an ultrasonic transducer 120, a
shaft 126, and an end effector 122. The end effector 122 comprises
an ultrasonic blade 128 acoustically coupled to the ultrasonic
transducer 120 and a clamp arm 140. The handpiece 105 comprises a
trigger 143 to operate the clamp arm 140 and a combination of the
toggle buttons 134a, 134b, 134c to energize and drive the
ultrasonic blade 128 or other function. The toggle buttons 134a,
134b, 134c can be configured to energize the ultrasonic transducer
120 with the generator 100.
[0063] Still with reference to FIG. 1, the generator 100 also is
configured to drive a second surgical instrument 106. The second
surgical instrument 106 is an RF electrosurgical instrument and
comprises a handpiece 107 (HP), a shaft 127, and an end effector
124. The end effector 124 comprises electrodes in the clamp arms
142a, 142b and return through an electrical conductor portion of
the shaft 127. The electrodes are coupled to and energized by a
bipolar energy source within the generator 100. The handpiece 107
comprises a trigger 145 to operate the clamp arms 142a, 142b and an
energy button 135 to actuate an energy switch to energize the
electrodes in the end effector 124.
[0064] Still with reference to FIG. 1, the generator 100 also is
configured to drive a multifunction surgical instrument 108. The
multifunction surgical instrument 108 comprises a handpiece 109
(HP), a shaft 129, and an end effector 125. The end effector
comprises an ultrasonic blade 149 and a clamp arm 146. The
ultrasonic blade 149 is acoustically coupled to the ultrasonic
transducer 120. The handpiece 109 comprises a trigger 147 to
operate the clamp arm 146 and a combination of the toggle buttons
137a, 137b, 137c to energize and drive the ultrasonic blade 149 or
other function. The toggle buttons 137a, 137b, 137c can be
configured to energize the ultrasonic transducer 120 with the
generator 100 and energize the ultrasonic blade 149 with a bipolar
energy source also contained within the generator 100.
[0065] With reference to both FIGS. 1 and 2, the generator 100 is
configurable for use with a variety of surgical instruments.
According to various forms, the generator 100 may be configurable
for use with different surgical instruments of different types
including, for example, the ultrasonic surgical instrument 104, the
RF electrosurgical instrument 106, and the multifunction surgical
instrument 108 that integrate RF and ultrasonic energies delivered
simultaneously from the generator 100. Although in the form of FIG.
1, the generator 100 is shown separate from the surgical
instruments 104, 106, 108, in one form, the generator 100 may be
formed integrally with any one of the surgical instruments 104,
106, 108 to form a unitary surgical system. The generator 100
comprises an input device 110 located on a front panel of the
generator 100 console. The input device 110 may comprise any
suitable device that generates signals suitable for programming the
operation of the generator 100. The generator 100 also may comprise
one or more output devices 112.
[0066] With reference now to FIG. 2, the generator 100 is coupled
to the multifunction surgical instrument 108. The generator 100 is
coupled to the ultrasonic transducer 120 and electrodes located in
the clamp arm 146 via a cable 144. The ultrasonic transducer 120
and a waveguide extending through a shaft 129 (waveguide not shown
in FIG. 2) may collectively form an ultrasonic drive system driving
an ultrasonic blade 149 of an end effector 125. The end effector
125 further may comprise a clamp arm 146 to clamp tissue located
between the clamp arm 146 and the ultrasonic blade 149. The clamp
arm 146 comprises one or more than one an electrode coupled to the
a pole of the generator 100 (e.g., a positive pole). The ultrasonic
blade 149 forms the second pole (e.g., the negative pole) and is
also coupled to the generator 100. RF energy is applied to the
electrode(s) in the clamp arm 146, through the tissue located
between the clamp arm 146 and the ultrasonic blade 149, and through
the ultrasonic blade 149 back to the generator 100 via the cable
144. In one form, the generator 100 may be configured to produce a
drive signal of a particular voltage, current, and/or frequency
output signal that can be varied or otherwise modified with high
resolution, accuracy, and repeatability suitable for driving an
ultrasonic transducer 120 and applying RF energy to tissue.
[0067] Still with reference to FIG. 2, It will be appreciated that
the multifunction surgical instrument 108 may comprise any
combination of the toggle buttons 137a, 137b, 134c. For example,
the multifunction surgical instrument 108 could be configured to
have only two toggle buttons: a toggle button 137a for producing
maximum ultrasonic energy output and a toggle button 137b for
producing a pulsed output at either the maximum or less than
maximum power level. In this way, the drive signal output
configuration of the generator 100 could be 5 continuous signals
and 5 or 4 or 3 or 2 or 1 pulsed signals. In certain forms, the
specific drive signal configuration may be controlled based upon,
for example, nonvolatile memory such as an electrically erasable
programmable read only memory (EEPROM) settings in the generator
100 and/or user power level selection(s).
[0068] In certain forms, a two-position switch may be provided as
an alternative to a toggle button 137c. For example, the
multifunction surgical instrument 108 may include a toggle button
137a for producing a continuous output at a maximum power level and
a two-position toggle button 137b. In a first detented position,
toggle button 137b may produce a continuous output at a less than
maximum power level, and in a second detented position the toggle
button 137b may produce a pulsed output (e.g., at either a maximum
or less than maximum power level, depending upon the EEPROM
settings). Any one of the buttons 137a, 137b, 137c may be
configured to activate RF energy and apply the RF energy to the end
effector 125.
[0069] Still with reference to FIG. 2, forms of the generator 100
may enable communication with instrument-based data circuits. For
example, the generator 100 may be configured to communicate with a
first data circuit 136 and/or a second data circuit 138. For
example, the first data circuit 136 may indicate a burn-in
frequency slope, as described herein. Additionally or
alternatively, any type of information may be communicated to
second data circuit for storage therein via a data circuit
interface (e.g., using a logic device). Such information may
comprise, for example, an updated number of operations in which the
instrument has been used and/or dates and/or times of its usage. In
certain forms, the second data circuit may transmit data acquired
by one or more sensors (e.g., an instrument-based temperature
sensor). In certain forms, the second data circuit may receive data
from the generator 100 and provide an indication to a user (e.g., a
light emitting diode (LED) indication or other visible indication)
based on the received data. The second data circuit 138 contained
in the multifunction surgical instrument 108. In some forms, the
second data circuit 138 may be implemented in a many similar to
that of the first data circuit 136 described herein. An instrument
interface circuit may comprise a second data circuit interface to
enable this communication. In one form, the second data circuit
interface may comprise a tri-state digital interface, although
other interfaces also may be used. In certain forms, the second
data circuit may generally be any circuit for transmitting and/or
receiving data. In one form, for example, the second data circuit
may store information pertaining to the particular surgical
instrument 104, 106, 108 with which it is associated. Such
information may include, for example, a model number, a serial
number, a number of operations in which the surgical instrument
104, 106, 108 has been used, and/or any other type of information.
In the example of FIG. 2, the second data circuit 138 may store
information about the electrical and/or ultrasonic properties of an
associated ultrasonic transducer 120, end effector 125, ultrasonic
energy drive system, or RF electrosurgical energy drive system.
Various processes and techniques described herein may be executed
by a generator. It will be appreciated, however, that in certain
example forms, all or a part of these processes and techniques may
be performed by internal logic 139 located in the multifunction
surgical instrument 108.
[0070] FIG. 3 is a diagram of the surgical system 10 of FIG. 1. In
various forms, the generator 100 may comprise several separate
functional elements, such as modules and/or blocks. Different
functional elements or modules may be configured for driving the
different kinds of surgical instruments 104, 106, 108. For example,
an ultrasonic drive circuit 114 may drive ultrasonic devices such
as the surgical instrument 104 via a cable 141. An
electrosurgery/RF drive circuit 116 may drive the RF
electrosurgical instrument 106 via a cable 133. The respective
drive circuits 114, 116, 118 may be combined as a combined
RF/ultrasonic drive circuit 118 to generate both respective drive
signals for driving multifunction surgical instruments 108 via a
cable 144. In various forms, the ultrasonic drive circuit 114
and/or the electrosurgery/RF drive circuit 116 each may be formed
integrally or externally with the generator 100. Alternatively, one
or more of the drive circuits 114, 116, 118 may be provided as a
separate circuit module electrically coupled to the generator 100.
(The drive circuits 114, 116, 118 are shown in phantom to
illustrate this option.) Also, in some forms, the electrosurgery/RF
drive circuit 116 may be formed integrally with the ultrasonic
drive circuit 114, or vice versa. Also, in some forms, the
generator 100 may be omitted entirely and the drive circuits 114,
116, 118 may be executed by processors or other hardware within the
respective surgical instruments 104, 106, 108.
[0071] In other forms, the electrical outputs of the ultrasonic
drive circuit 114 and the electrosurgery/RF drive circuit 116 may
be combined into a single electrical signal capable of driving the
multifunction surgical instrument 108 simultaneously with
electrosurgical RF and ultrasonic energies. This single electrical
drive signal may be produced by the combination drive circuit 118.
The multifunction surgical instrument 108 comprises an ultrasonic
transducer 120 coupled to an ultrasonic blade and one or more
electrodes in the end effector 125 to receive ultrasonic and
electrosurgical RF energy. The multifunction surgical instrument
108 comprises signal processing components to split the combined
RF/ultrasonic energy signal such that the RF signal can be
delivered to the electrodes in the end effector 125 and the
ultrasonic signal can be delivered to the ultrasonic transducer
120.
[0072] In accordance with the described forms, the ultrasonic drive
circuit 114 may produce a drive signal or signals of particular
voltages, currents, and frequencies, e.g., 55,500 cycles per second
(Hz). The drive signal or signals may be provided to the ultrasonic
surgical instrument 104, and specifically to the ultrasonic
transducer 120, which may operate, for example, as described above.
The ultrasonic transducer 120 and a waveguide extending through the
shaft 126 (waveguide not shown) may collectively form an ultrasonic
drive system driving an ultrasonic blade 128 of an end effector
122. In one form, the generator 100 may be configured to produce a
drive signal of a particular voltage, current, and/or frequency
output signal that can be stepped or otherwise modified with high
resolution, accuracy, and repeatability.
[0073] The generator 100 may be activated to provide the drive
signal to the ultrasonic transducer 120 in any suitable manner. For
example, the generator 100 may comprise a foot switch 130 coupled
to the generator 100 via a foot switch cable 132. A clinician may
activate the ultrasonic transducer 120 by depressing the foot
switch 130. In addition, or instead of the foot switch 130 some
forms of the ultrasonic surgical instrument 104 may utilize one or
more switches positioned on the handpiece that, when activated, may
cause the generator 100 to activate the ultrasonic transducer 120.
In one form, for example, the one or more switches may comprise a
pair of toggle buttons 137a, 137b (FIG. 2), for example, to
determine an operating mode of the ultrasonic surgical instrument
104. When the toggle button 137a is depressed, for example, the
generator 100 may provide a maximum drive signal to the ultrasonic
transducer 120, causing it to produce maximum ultrasonic energy
output. Depressing toggle button 137b may cause the generator 100
to provide a user-selectable drive signal to the ultrasonic
transducer 120, causing it to produce less than the maximum
ultrasonic energy output.
[0074] Additionally or alternatively, the one or more switches may
comprise a toggle button 137c that, when depressed, causes the
generator 100 to provide a pulsed output. The pulses may be
provided at any suitable frequency and grouping, for example. In
certain forms, the power level of the pulses may be the power
levels associated with toggle buttons 137a, 137b (maximum, less
than maximum), for example.
[0075] It will be appreciated that the ultrasonic surgical
instrument 104 and/or the multifunction surgical instrument 108 may
comprise any combination of the toggle buttons 137a, 137b, 137c.
For example, the multifunction surgical instrument 108 could be
configured to have only two toggle buttons: a toggle button 137a
for producing maximum ultrasonic energy output and a toggle button
137c for producing a pulsed output at either the maximum or less
than maximum power level. In this way, the drive signal output
configuration of the generator 100 could be 5 continuous signals
and 5 or 4 or 3 or 2 or 1 pulsed signals. In certain forms, the
specific drive signal configuration may be controlled based upon,
for example, EEPROM settings in the generator 100 and/or user power
level selection(s).
[0076] In certain forms, a two-position switch may be provided as
an alternative to a toggle button 137c. For example, the ultrasonic
surgical instrument 104 may include a toggle button 137a for
producing a continuous output at a maximum power level and a
two-position toggle button 137b. In a first detented position,
toggle button 137b may produce a continuous output at a less than
maximum power level, and in a second detented position the toggle
button 137b may produce a pulsed output (e.g., at either a maximum
or less than maximum power level, depending upon the EEPROM
settings).
[0077] In accordance with the described forms, the
electrosurgery/RF drive circuit 116 may generate a drive signal or
signals with output power sufficient to perform bipolar
electrosurgery using RF energy. In bipolar electrosurgery
applications, the drive signal may be provided, for example, to
electrodes located in the end effector 124 of the RF
electrosurgical instrument 106, for example. Accordingly, the
generator 100 may be configured for therapeutic purposes by
applying electrical energy to the tissue sufficient for treating
the tissue (e.g., coagulation, cauterization, tissue welding). The
generator 100 may be configured for sub-therapeutic purposes by
applying electrical energy to the tissue for monitoring parameters
of the tissue during a procedure.
[0078] As previously discussed, the combination drive circuit 118
may be configured to drive both ultrasonic and RF electrosurgical
energies. The ultrasonic and RF electrosurgical energies may be
delivered though separate output ports of the generator 100 as
separate signals or though a single port of the generator 100 as a
single signal that is a combination of the ultrasonic and RF
electrosurgical energies. In the latter case, the single signal can
be separated by circuits located in the surgical instruments 104,
106, 108.
[0079] The surgical instruments 104, 106, 108 additionally or
alternatively may comprise a switch to indicate a position of a jaw
closure trigger for operating jaws of the end effector 122, 124,
125. Also, in some forms, the generator 100 may be activated based
on the position of the jaw closure trigger, (e.g., as the clinician
depresses the jaw closure trigger to close the jaws, ultrasonic
energy may be applied).
[0080] The generator 100 may comprise an input device 110 (FIG. 1)
located, for example, on a front panel of the generator 100
console. The input device 110 may comprise any suitable device that
generates signals suitable for programming the operation of the
generator 100. In operation, the user can program or otherwise
control operation of the generator 100 using the input device 110.
The input device 110 may comprise any suitable device that
generates signals that can be used by the generator (e.g., by one
or more processors contained in the generator) to control the
operation of the generator 100 (e.g., operation of the ultrasonic
drive circuit 114, electrosurgery/RF drive circuit 116, combined
RF/ultrasonic drive circuit 118). In various forms, the input
device 110 includes one or more of buttons, switches, thumbwheels,
keyboard, keypad, touch screen monitor, pointing device, remote
connection to a general purpose or dedicated computer. In other
forms, the input device 110 may comprise a suitable user interface,
such as one or more user interface screens displayed on a touch
screen monitor, for example. Accordingly, by way of the input
device 110, the user can set or program various operating
parameters of the generator, such as, for example, current (I),
voltage (V), frequency (f), and/or period (T) of a drive signal or
signals generated by the ultrasonic drive circuit 114 and/or
electrosurgery/RF drive circuit 116.
[0081] The generator 100 also may comprise an output device 112
(FIG. 1), such as an output indicator, located, for example, on a
front panel of the generator 100 console. The output device 112
includes one or more devices for providing a sensory feedback to a
user. Such devices may comprise, for example, visual feedback
devices (e.g., a visual feedback device may comprise incandescent
lamps, LEDs, graphical user interface, display, analog indicator,
digital indicator, bar graph display, digital alphanumeric display,
liquid crystal display (LCD) screen, light emitting diode (LED)
indicators), audio feedback devices (e.g., an audio feedback device
may comprise speaker, buzzer, audible, computer generated tone,
computerized speech, voice user interface (VUI) to interact with
computers through a voice/speech platform), or tactile feedback
devices (e.g., a tactile feedback device comprises any type of
vibratory feedback, haptic actuator).
[0082] Although certain modules and/or blocks of the generator 100
may be described by way of example, it can be appreciated that a
greater or lesser number of modules and/or blocks may be used and
still fall within the scope of the forms. Further, although various
forms may be described in terms of modules and/or blocks to
facilitate description, such modules and/or blocks may be
implemented by one or more hardware components, e.g., processors,
Digital Signal Processors (DSPs), Programmable Logic Devices
(PLDs), Application Specific Integrated Circuits (ASICs), circuits,
registers and/or software components, e.g., programs, subroutines,
logic and/or combinations of hardware and software components.
Also, in some forms, the various modules described herein may be
implemented utilizing similar hardware positioned within the
surgical instruments 104, 106, 108 (i.e., the external generator
100 may be omitted).
[0083] In one form, the ultrasonic drive circuit 114,
electrosurgery/RF drive circuit 116, and/or the combination drive
circuit 118 may comprise one or more embedded applications
implemented as firmware, software, hardware, or any combination
thereof. The drive circuits 114, 116, 118 may comprise various
executable modules such as software, programs, data, drivers,
application program interfaces (APIs), and so forth. The firmware
may be stored in nonvolatile memory (NVM), such as in bit masked
read-only memory (ROM) or flash memory. In various implementations,
storing the firmware in ROM may preserve flash memory. The NVM may
comprise other types of memory including, for example, programmable
ROM (PROM), erasable programmable ROM (EPROM), electrically
erasable programmable read only memory (EEPROM), or battery backed
random-access memory (RAM) such as dynamic RAM (DRAM),
Double-Data-Rate DRAM (DDRAM), and/or synchronous DRAM (SDRAM).
[0084] In one form, the drive circuits 114, 116, 118 comprise a
hardware component implemented as a processor for executing program
instructions for monitoring various measurable characteristics of
the surgical instruments 104, 106, 108 and generating a
corresponding output control signals for operating the surgical
instruments 104, 106, 108. In forms in which the generator 100 is
used in conjunction with the multifunction surgical instrument 108,
the output control signal may drive the ultrasonic transducer 120
in cutting and/or coagulation operating modes. Electrical
characteristics of the multifunction surgical instrument 108 and/or
tissue may be measured and used to control operational aspects of
the generator 100 and/or provided as feedback to the user. In forms
in which the generator 100 is used in conjunction with the
multifunction surgical instrument 108, the output control signal
may supply electrical energy (e.g., RF energy) to the end effector
125 in cutting, coagulation and/or desiccation modes. Electrical
characteristics of the multifunction surgical instrument 108 and/or
tissue may be measured and used to control operational aspects of
the generator 100 and/or provide feedback to the user. In various
forms, as previously discussed, the hardware component may be
implemented as a DSP, PLD, ASIC, circuits, and/or registers. In one
form, the processor may be configured to store and execute computer
software program instructions to generate the output signals for
driving various components of the surgical instruments 104, 106,
108, such as the ultrasonic transducer 120 and the end effectors
122, 124, 125.
[0085] FIG. 4 illustrates an equivalent circuit 150 of an
ultrasonic transducer, such as the ultrasonic transducer 120,
according to one form. The equivalent circuit 150 comprises a first
"motional" branch having a serially connected inductance L.sub.s,
resistance R.sub.s and capacitance C.sub.s that define the
electromechanical properties of the resonator, and a second
capacitive branch having a static capacitance C.sub.o. Drive
current I.sub.g may be received from a generator at a drive voltage
V.sub.g, with motional current I.sub.m flowing through the first
branch and current I.sub.g-I.sub.m flowing through the capacitive
branch. Control of the electromechanical properties of the
ultrasonic transducer may be achieved by suitably controlling
I.sub.g and V.sub.g. As explained above, conventional generator
architectures may include a tuning inductor L.sub.t (shown in
phantom in FIG. 4) for tuning out in a parallel resonance circuit
the static capacitance Co at a resonant frequency so that
substantially all of generator's current output I.sub.g flows
through the motional branch. In this way, control of the motional
branch current I.sub.m is achieved by controlling the generator
current output I.sub.g. The tuning inductor L.sub.t is specific to
the static capacitance C.sub.o of an ultrasonic transducer,
however, and a different ultrasonic transducer having a different
static capacitance requires a different tuning inductor L.sub.t.
Moreover, because the tuning inductor L.sub.t is matched to the
nominal value of the static capacitance Co at a single resonant
frequency, accurate control of the motional branch current I.sub.m
is assured only at that frequency, and as frequency shifts down
with transducer temperature, accurate control of the motional
branch current is compromised.
[0086] Forms of the generator 100 do not rely on a tuning inductor
L.sub.t to monitor the motional branch current I.sub.m. Instead,
the generator 100 may use the measured value of the static
capacitance C.sub.o in between applications of power for a specific
ultrasonic surgical instrument 104 (along with drive signal voltage
and current feedback data) to determine values of the motional
branch current I.sub.m on a dynamic and ongoing basis (e.g., in
real-time). Such forms of the generator 100 are therefore able to
provide virtual tuning to simulate a system that is tuned or
resonant with any value of static capacitance C.sub.o at any
frequency, and not just at single resonant frequency dictated by a
nominal value of the static capacitance C.sub.o.
[0087] FIG. 5 is a simplified block diagram of a generator 200,
which is one form of the generator 100 (FIGS. 1-3). The generator
200 is configured to provide inductorless tuning as described
above, among other benefits. Additional details of the generator
200 are described in commonly assigned and contemporaneously filed
U.S. Pat. No. 9,060,775, titled SURGICAL GENERATOR FOR ULTRASONIC
AND ELECTROSURGICAL DEVICES, the disclosure of which is
incorporated herein by reference in its entirety. With reference to
FIG. 5, the generator 200 may comprise a patient isolated stage 202
in communication with a non-isolated stage 204 via a power
transformer 206. A secondary winding 208 of the power transformer
206 is contained in the isolated stage 202 and may comprise a
tapped configuration (e.g., a center-tapped or a non-center-tapped
configuration) to define drive signal outputs 210a, 210b, 210c for
delivering drive signals to different surgical instruments, such
as, for example, an ultrasonic surgical instrument 104, an RF
electrosurgical instrument 106, and a multifunction surgical
instrument 108. In particular, drive signal outputs 210a, 210c may
output an ultrasonic drive signal (e.g., a 420V root-mean-square
[RMS] drive signal) to an ultrasonic surgical instrument 104, and
drive signal outputs 210b, 210c may output an electrosurgical drive
signal (e.g., a 100V root-mean-square [RMS] drive signal) to an RF
electrosurgical instrument 106, with the drive signal output 2160b
corresponding to the center tap of the power transformer 206.
[0088] In certain forms, the ultrasonic and electrosurgical drive
signals may be provided simultaneously to distinct surgical
instruments and/or to a single surgical instrument having the
capability to deliver both ultrasonic and electrosurgical energy to
tissue, such as the multifunction surgical instrument 108 (FIGS.
1-3). It will be appreciated that the electrosurgical signal,
provided either to a dedicated electrosurgical instrument and/or to
a combined multifunction ultrasonic/electrosurgical instrument may
be either a therapeutic or sub-therapeutic level signal where the
sub-therapeutic signal can be used, for example, to monitor tissue
or instrument conditions and provide feedback to the generator. For
example, the ultrasonic and RF signals can be delivered separately
or simultaneously from a generator with a single output port in
order to provide the desired output signal to the surgical
instrument, as will be discussed in more detail below. Accordingly,
the generator can combine the ultrasonic and electrosurgical RF
energies and deliver the combined energies to the multifunction
ultrasonic/electrosurgical instrument. Bipolar electrodes can be
placed on one or both jaws of the end effector. One jaw may be
driven by ultrasonic energy in addition to electrosurgical RF
energy, working simultaneously. The ultrasonic energy may be
employed to dissect tissue while the electrosurgical RF energy may
be employed for vessel sealing.
[0089] The non-isolated stage 204 may comprise a power amplifier
212 having an output connected to a primary winding 214 of the
power transformer 206. In certain forms the power amplifier 212 may
be comprise a push-pull amplifier. For example, the non-isolated
stage 204 may further comprise a logic device 216 for supplying a
digital output to a DAC circuit 218, which in turn supplies a
corresponding analog signal to an input of the power amplifier 212.
In certain forms the logic device 216 may comprise a programmable
gate array (PGA), a field programmable gate array (FPGA),
programmable logic device (PLD), among other logic circuits, for
example. The logic device 216, by virtue of controlling the input
of the power amplifier 212 via the DAC circuit 218, may therefore
control any of a number of parameters (e.g., frequency, waveform
shape, waveform amplitude) of drive signals appearing at the drive
signal outputs 210a, 210b, 210c. In certain forms and as discussed
below, the logic device 216, in conjunction with a processor (e.g.,
a digital signal processor discussed below), may implement a number
of digital signal processing (DSP)-based and/or other control
algorithms to control parameters of the drive signals output by the
generator 200.
[0090] Power may be supplied to a power rail of the power amplifier
212 by a switch-mode regulator 220, e.g., power converter. In
certain forms the switch-mode regulator 220 may comprise an
adjustable buck regulator, for example. The non-isolated stage 204
may further comprise a first processor 222, which in one form may
comprise a DSP processor such as an Analog Devices ADSP-21469 SHARC
DSP, available from Analog Devices, Norwood, Mass., for example,
although in various forms any suitable processor may be employed.
In certain forms the DSP processor 222 may control operation of the
switch-mode regulator 220 responsive to voltage feedback data
received from the power amplifier 212 by the DSP processor 222 via
an analog-to-digital converter (ADC) circuit 224. In one form, for
example, the DSP processor 222 may receive as input, via the ADC
circuit 224, the waveform envelope of a signal (e.g., an RF signal)
being amplified by the power amplifier 212. The DSP processor 222
may then control the switch-mode regulator 220 (e.g., via a
pulse-width modulated (PWM) output) such that the rail voltage
supplied to the power amplifier 212 tracks the waveform envelope of
the amplified signal. By dynamically modulating the rail voltage of
the power amplifier 212 based on the waveform envelope, the
efficiency of the power amplifier 212 may be significantly improved
relative to a fixed rail voltage amplifier schemes.
[0091] In certain forms, the logic device 216, in conjunction with
the DSP processor 222, may implement a digital synthesis circuit
such as a DDS (see e.g., FIGS. 13, 14) control scheme to control
the waveform shape, frequency and/or amplitude of drive signals
output by the generator 200. In one form, for example, the logic
device 216 may implement a DDS control algorithm by recalling
waveform samples stored in a dynamically-updated lookup table
(LUT), such as a RAM LUT, which may be embedded in an FPGA. This
control algorithm is particularly useful for ultrasonic
applications in which an ultrasonic transducer, such as the
ultrasonic transducer 120, may be driven by a clean sinusoidal
current at its resonant frequency. Because other frequencies may
excite parasitic resonances, minimizing or reducing the total
distortion of the motional branch current may correspondingly
minimize or reduce undesirable resonance effects. Because the
waveform shape of a drive signal output by the generator 200 is
impacted by various sources of distortion present in the output
drive circuit (e.g., the power transformer 206, the power amplifier
212), voltage and current feedback data based on the drive signal
may be input into an algorithm, such as an error control algorithm
implemented by the DSP processor 222, which compensates for
distortion by suitably pre-distorting or modifying the waveform
samples stored in the LUT on a dynamic, ongoing basis (e.g., in
real-time). In one form, the amount or degree of pre-distortion
applied to the LUT samples may be based on the error between a
computed motional branch current and a desired current waveform
shape, with the error being determined on a sample-by-sample basis.
In this way, the pre-distorted LUT samples, when processed through
the drive circuit, may result in a motional branch drive signal
having the desired waveform shape (e.g., sinusoidal) for optimally
driving the ultrasonic transducer. In such forms, the LUT waveform
samples will therefore not represent the desired waveform shape of
the drive signal, but rather the waveform shape that is required to
ultimately produce the desired waveform shape of the motional
branch drive signal when distortion effects are taken into
account.
[0092] The non-isolated stage 204 may further comprise a first ADC
circuit 226 and a second ADC circuit 228 coupled to the output of
the power transformer 206 via respective isolation transformers
230, 232 for respectively sampling the voltage and current of drive
signals output by the generator 200. In certain forms, the ADC
circuits 226, 228 may be configured to sample at high speeds (e.g.,
80 mega samples per second [MSPS]) to enable oversampling of the
drive signals. In one form, for example, the sampling speed of the
ADC circuits 226, 228 may enable approximately 200.times.
(depending on frequency) oversampling of the drive signals. In
certain forms, the sampling operations of the ADC circuit 226, 228
may be performed by a single ADC circuit receiving input voltage
and current signals via a two-way multiplexer. The use of
high-speed sampling in forms of the generator 200 may enable, among
other things, calculation of the complex current flowing through
the motional branch (which may be used in certain forms to
implement direct digital synthesis (DDS) based waveform shape
control described above), accurate digital filtering of the sampled
signals, and calculation of real power consumption with a high
degree of precision. Voltage and current feedback data output by
the ADC circuits 226, 228 may be received and processed (e.g.,
first-in-first-out [FIFO] buffer, multiplexer, etc.) by the logic
device 216 and stored in data memory for subsequent retrieval by,
for example, the DSP processor 222. As noted above, voltage and
current feedback data may be used as input to an algorithm for
pre-distorting or modifying LUT waveform samples on a dynamic and
ongoing basis. In certain forms, this may require each stored
voltage and current feedback data pair to be indexed based on, or
otherwise associated with, a corresponding LUT sample that was
output by the logic device 216 when the voltage and current
feedback data pair was acquired. Synchronization of the LUT samples
and the voltage and current feedback data in this manner
contributes to the correct timing and stability of the
pre-distortion algorithm.
[0093] In certain forms, the voltage and current feedback data may
be used to control the frequency and/or amplitude (e.g., current
amplitude) of the drive signals. In one form, for example, voltage
and current feedback data may be used to determine impedance phase.
The frequency of the drive signal may then be controlled to
minimize or reduce the difference between the determined impedance
phase and an impedance phase setpoint (e.g., 0.degree.), thereby
minimizing or reducing the effects of harmonic distortion and
correspondingly enhancing impedance phase measurement accuracy. The
determination of phase impedance and a frequency control signal may
be implemented in the DSP processor 222, for example, with the
frequency control signal being supplied as input to a DDS control
algorithm implemented by the logic device 216.
[0094] In another form, for example, the current feedback data may
be monitored in order to maintain the current amplitude of the
drive signal at a current amplitude setpoint. The current amplitude
setpoint may be specified directly or determined indirectly based
on specified voltage amplitude and power setpoints. In certain
forms, control of the current amplitude may be implemented by
control algorithm, such as, for example, a
proportional-integral-derivative (PID) control algorithm, in the
DSP processor 222. Variables controlled by the control algorithm to
suitably control the current amplitude of the drive signal may
include, for example, the scaling of the LUT waveform samples
stored in the logic device 216 and/or the full-scale output voltage
of the DAC circuit 218 (which supplies the input to the power
amplifier 212) via a DAC circuit 234.
[0095] The non-isolated stage 204 may further comprise a second
processor 236 for providing, among other things user interface (UI)
functionality. In one form, the UI processor 236 may comprise an
Atmel AT91SAM9263 processor having an ARM 926EJ-S core, available
from Atmel Corporation, San Jose, Calif., for example. Examples of
UI functionality supported by the UI processor 236 may include
audible and visual user feedback, communication with peripheral
devices (e.g., via a Universal Serial Bus [USB] interface),
communication with the foot switch 130, communication with an input
device 110 (e.g., a touch screen display) and communication with an
output device 112 (e.g., a speaker), as shown in FIGS. 1 and 3. The
UI processor 236 may communicate with the DSP processor 222 and the
logic device 216 (e.g., via serial peripheral interface [SPI]
buses). Although the UI processor 236 may primarily support UI
functionality, it may also coordinate with the DSP processor 222 to
implement hazard mitigation in certain forms. For example, the UI
processor 236 may be programmed to monitor various aspects of user
input and/or other inputs (e.g., touch screen inputs, foot switch
130 inputs as shown in FIG. 3, temperature sensor inputs) and may
disable the drive output of the generator 200 when an erroneous
condition is detected.
[0096] In certain forms, both the DSP processor 222 and the UI
processor 236, for example, may determine and monitor the operating
state of the generator 200. For the DSP processor 222, the
operating state of the generator 200 may dictate, for example,
which control and/or diagnostic processes are implemented by the
DSP processor 222. For the UI processor 236, the operating state of
the generator 200 may dictate, for example, which elements of a
user interface (e.g., display screens, sounds) are presented to a
user. The respective DSP and UI processors 222, 236 may
independently maintain the current operating state of the generator
200 and recognize and evaluate possible transitions out of the
current operating state. The DSP processor 222 may function as the
master in this relationship and determine when transitions between
operating states are to occur. The UI processor 236 may be aware of
valid transitions between operating states and may confirm if a
particular transition is appropriate. For example, when the DSP
processor 222 instructs the UI processor 236 to transition to a
specific state, the UI processor 236 may verify that requested
transition is valid. In the event that a requested transition
between states is determined to be invalid by the UI processor 236,
the UI processor 236 may cause the generator 200 to enter a failure
mode.
[0097] The non-isolated stage 204 may further comprise a controller
238 for monitoring input devices 110 (e.g., a capacitive touch
sensor used for turning the generator 200 on and off, a capacitive
touch screen). In certain forms, the controller 238 may comprise at
least one processor and/or other controller device in communication
with the UI processor 236. In one form, for example, the controller
238 may comprise a processor (e.g., a Mega168 8-bit controller
available from Atmel) configured to monitor user input provided via
one or more capacitive touch sensors. In one form, the controller
238 may comprise a touch screen controller (e.g., a QT5480 touch
screen controller available from Atmel) to control and manage the
acquisition of touch data from a capacitive touch screen.
[0098] In certain forms, when the generator 200 is in a "power off"
state, the controller 238 may continue to receive operating power
(e.g., via a line from a power supply of the generator 200, such as
the power supply 254 discussed below). In this way, the controller
196 may continue to monitor an input device 110 (e.g., a capacitive
touch sensor located on a front panel of the generator 200) for
turning the generator 200 on and off. When the generator 200 is in
the power off state, the controller 238 may wake the power supply
(e.g., enable operation of one or more DC/DC voltage converters 256
of the power supply 254) if activation of the "on/off" input device
110 by a user is detected. The controller 238 may therefore
initiate a sequence for transitioning the generator 200 to a "power
on" state. Conversely, the controller 238 may initiate a sequence
for transitioning the generator 200 to the power off state if
activation of the "on/off" input device 110 is detected when the
generator 200 is in the power on state. In certain forms, for
example, the controller 238 may report activation of the "on/off"
input device 110 to the UI processor 236, which in turn implements
the necessary process sequence for transitioning the generator 200
to the power off state. In such forms, the controller 196 may have
no independent ability for causing the removal of power from the
generator 200 after its power on state has been established.
[0099] In certain forms, the controller 238 may cause the generator
200 to provide audible or other sensory feedback for alerting the
user that a power on or power off sequence has been initiated. Such
an alert may be provided at the beginning of a power on or power
off sequence and prior to the commencement of other processes
associated with the sequence.
[0100] In certain forms, the isolated stage 202 may comprise an
instrument interface circuit 240 to, for example, provide a
communication interface between a control circuit of a surgical
instrument (e.g., a control circuit comprising handpiece switches)
and components of the non-isolated stage 204, such as, for example,
the logic device 216, the DSP processor 222 and/or the UI processor
236. The instrument interface circuit 240 may exchange information
with components of the non-isolated stage 204 via a communication
link that maintains a suitable degree of electrical isolation
between the isolated and non-isolated stages 202, 204, such as, for
example, an infrared (IR)-based communication link. Power may be
supplied to the instrument interface circuit 240 using, for
example, a low-dropout voltage regulator powered by an isolation
transformer driven from the non-isolated stage 204.
[0101] In one form, the instrument interface circuit 240 may
comprise a logic circuit 242 (e.g., logic circuit, programmable
logic circuit, PGA, FPGA, PLD) in communication with a signal
conditioning circuit 244. The signal conditioning circuit 244 may
be configured to receive a periodic signal from the logic circuit
242 (e.g., a 2 kHz square wave) to generate a bipolar interrogation
signal having an identical frequency. The interrogation signal may
be generated, for example, using a bipolar current source fed by a
differential amplifier. The interrogation signal may be
communicated to a surgical instrument control circuit (e.g., by
using a conductive pair in a cable that connects the generator 200
to the surgical instrument) and monitored to determine a state or
configuration of the control circuit. The control circuit may
comprise a number of switches, resistors and/or diodes to modify
one or more characteristics (e.g., amplitude, rectification) of the
interrogation signal such that a state or configuration of the
control circuit is uniquely discernable based on the one or more
characteristics. In one form, for example, the signal conditioning
circuit 244 may comprise an ADC circuit for generating samples of a
voltage signal appearing across inputs of the control circuit
resulting from passage of interrogation signal therethrough. The
logic circuit 242 (or a component of the non-isolated stage 204)
may then determine the state or configuration of the control
circuit based on the ADC circuit samples.
[0102] In one form, the instrument interface circuit 240 may
comprise a first data circuit interface 246 to enable information
exchange between the logic circuit 242 (or other element of the
instrument interface circuit 240) and a first data circuit disposed
in or otherwise associated with a surgical instrument. In certain
forms, for example, a first data circuit 136 (FIG. 2) may be
disposed in a cable integrally attached to a surgical instrument
handpiece, or in an adaptor for interfacing a specific surgical
instrument type or model with the generator 200. The first data
circuit 136 may be implemented in any suitable manner and may
communicate with the generator according to any suitable protocol
including, for example, as described herein with respect to the
first data circuit 136. In certain forms, the first data circuit
may comprise a non-volatile storage device, such as an EEPROM
device. In certain forms and referring again to FIG. 5, the first
data circuit interface 246 may be implemented separately from the
logic circuit 242 and comprise suitable circuitry (e.g., discrete
logic devices, a processor) to enable communication between the
logic circuit 242 and the first data circuit. In other forms, the
first data circuit interface 246 may be integral with the logic
circuit 242.
[0103] In certain forms, the first data circuit 136 *FIG. 2) may
store information pertaining to the particular surgical instrument
with which it is associated. Such information may include, for
example, a model number, a serial number, a number of operations in
which the surgical instrument has been used, and/or any other type
of information. This information may be read by the instrument
interface circuit 240 (e.g., by the logic circuit 242), transferred
to a component of the non-isolated stage 204 (e.g., to logic device
216, DSP processor 222 and/or UI processor 236) for presentation to
a user via an output device 112 (FIGS. 1 and 3) and/or for
controlling a function or operation of the generator 200.
Additionally, any type of information may be communicated to first
data circuit 136 for storage therein via the first data circuit
interface 246 (e.g., using the logic circuit 242). Such information
may comprise, for example, an updated number of operations in which
the surgical instrument has been used and/or dates and/or times of
its usage.
[0104] As discussed previously, a surgical instrument may be
detachable from a handpiece (e.g., the multifunction surgical
instrument 108 may be detachable from the handpiece 109) to promote
instrument interchangeability and/or disposability. In such cases,
conventional generators may be limited in their ability to
recognize particular instrument configurations being used and to
optimize control and diagnostic processes accordingly. The addition
of readable data circuits to surgical instruments to address this
issue is problematic from a compatibility standpoint, however. For
example, designing a surgical instrument to remain backwardly
compatible with generators that lack the requisite data reading
functionality may be impractical due to, for example, differing
signal schemes, configuration complexity, and cost. Forms of
instruments discussed herein address these concerns by using data
circuits that may be implemented in existing surgical instruments
economically and with minimal configuration changes to preserve
compatibility of the surgical instruments with current generator
platforms.
[0105] Additionally, forms of the generator 200 may enable
communication with instrument-based data circuits. For example, the
generator 200 may be configured to communicate with a second data
circuit 138 (FIG. 2) contained in an instrument (e.g., the
multifunction surgical instrument 108 shown in FIG. 2). In some
forms, the second data circuit 138 may be implemented in a many
similar to that of the first data circuit 136 (FIG. 2) described
herein. The instrument interface circuit 240 may comprise a second
data circuit interface 248 to enable this communication. In one
form, the second data circuit interface 248 may comprise a
tri-state digital interface, although other interfaces may also be
used. In certain forms, the second data circuit may generally be
any circuit for transmitting and/or receiving data. In one form,
for example, the second data circuit may store information
pertaining to the particular surgical instrument with which it is
associated. Such information may include, for example, a model
number, a serial number, a number of operations in which the
surgical instrument has been used, and/or any other type of
information.
[0106] In some forms, the second data circuit 138 (FIG. 2) may
store information about the electrical and/or ultrasonic properties
of an associated ultrasonic transducer 120, end effector 125, or
ultrasonic drive system. For example, the first data circuit 136
(FIG. 2) may indicate a burn-in frequency slope, as described
herein. Additionally or alternatively, any type of information may
be communicated to second data circuit for storage therein via the
second data circuit interface 248 (e.g., using the logic circuit
242). Such information may comprise, for example, an updated number
of operations in which the instrument has been used and/or dates
and/or times of its usage. In certain forms, the second data
circuit may transmit data acquired by one or more sensors (e.g., an
instrument-based temperature sensor). In certain forms, the second
data circuit may receive data from the generator 200 and provide an
indication to a user (e.g., an LED indication or other visible
indication) based on the received data.
[0107] In certain forms, the second data circuit and the second
data circuit interface 248 may be configured such that
communication between the logic circuit 242 and the second data
circuit can be effected without the need to provide additional
conductors for this purpose (e.g., dedicated conductors of a cable
connecting a handpiece to the generator 200). In one form, for
example, information may be communicated to and from the second
data circuit using a 1-wire bus communication scheme implemented on
existing cabling, such as one of the conductors used transmit
interrogation signals from the signal conditioning circuit 244 to a
control circuit in a handpiece. In this way, configuration changes
or modifications to the surgical instrument that might otherwise be
necessary are minimized or reduced. Moreover, because different
types of communications implemented over a common physical channel
can be frequency-band separated, the presence of a second data
circuit may be "invisible" to generators that do not have the
requisite data reading functionality, thus enabling backward
compatibility of the surgical instrument.
[0108] In certain forms, the isolated stage 202 may comprise at
least one blocking capacitor 250-1 connected to the drive signal
output 210b to prevent passage of direct current (DC) to a patient.
A single blocking capacitor may be required to comply with medical
regulations or standards, for example. While failure in
single-capacitor configurations is relatively uncommon, such
failure may nonetheless have negative consequences. In one form, a
second blocking capacitor 250-2 may be provided in series with the
blocking capacitor 250-1, with current leakage from a point between
the blocking capacitors 250-1, 250-2 being monitored by, for
example, an ADC circuit 252 for sampling a voltage induced by
leakage current. The samples may be received by the logic circuit
242, for example. Based changes in the leakage current (as
indicated by the voltage samples in the form of FIG. 5), the
generator 200 may determine when at least one of the blocking
capacitors 250-1, 250-2 has failed. Accordingly, the form of FIG. 5
provides a benefit over single-capacitor configurations having a
single point of failure.
[0109] In certain forms, the non-isolated stage 204 may comprise a
power supply 254 for delivering DC power at a suitable voltage and
current. The power supply may comprise, for example, a 400 W power
supply for delivering a 48 VDC system voltage. The power supply 254
may further comprise one or more DC/DC voltage converters 256 for
receiving the output of the power supply to generate DC outputs at
the voltages and currents required by the various components of the
generator 200. As discussed above in connection with the controller
238, one or more of the DC/DC voltage converters 256 may receive an
input from the controller 238 when activation of the "on/off" input
device 110 by a user is detected by the controller 238 to enable
operation of, or wake, the DC/DC voltage converters 256.
[0110] FIG. 6 illustrates one form of a drive system 302 of a
generator 300, which is one form of the generator 100 (FIGS. 1-3).
The generator 300 is configured to provide an ultrasonic electrical
signal for driving an ultrasonic transducer (e.g., ultrasonic
transducer 120 FIGS. 1-3), also referred to as a drive signal. The
generator 300 is similar to and may be interchangeable with the
generators 100, 200 (FIGS. 1-3 and 5). The drive system 302 is
flexible and can create an ultrasonic electrical drive signal 304
at a desired frequency and power level setting for driving the
ultrasonic transducer 306. In various forms, the generator 300 may
comprise several separate functional elements, such as modules
and/or blocks. Although certain modules and/or blocks may be
described by way of example, it can be appreciated that a greater
or lesser number of modules and/or blocks may be used and still
fall within the scope of the forms. Further, although various forms
may be described in terms of modules and/or blocks to facilitate
description, such modules and/or blocks may be implemented by one
or more hardware components, e.g., processors, Digital Signal
Processors (DSPs), Programmable Logic Devices (PLDs), Application
Specific Integrated Circuits (ASICs), circuits, registers and/or
software components, e.g., programs, subroutines, logic and/or
combinations of hardware and software components.
[0111] In one form, the generator 300 drive system 302 may comprise
one or more embedded applications implemented as firmware,
software, hardware, or any combination thereof. The generator 300
drive system 302 may comprise various executable modules such as
software, programs, data, drivers, application program interfaces
(APIs), and so forth. The firmware may be stored in nonvolatile
memory (NVM), such as in bit-masked read-only memory (ROM) or flash
memory. In various implementations, storing the firmware in ROM may
preserve flash memory. The NVM may comprise other types of memory
including, for example, programmable ROM (PROM), erasable
programmable ROM (EPROM), EEPROM, or battery backed random-access
memory (RAM) such as dynamic RAM (DRAM), Double-Data-Rate DRAM
(DDRAM), and/or synchronous DRAM (SDRAM).
[0112] In one form, the generator 300 drive system 302 comprises a
hardware component implemented as a processor 308 for executing
program instructions for monitoring various measurable
characteristics of the ultrasonic surgical instrument 104 (FIG. 1)
and generating an output signal for driving the ultrasonic
transducer in cutting and/or coagulation operating modes. It will
be appreciated by those skilled in the art that the generator 300
and the drive system 302 may comprise additional or fewer
components and only a simplified version of the generator 300 and
the drive system 302 are described herein for conciseness and
clarity. In various forms, as previously discussed, the hardware
component may be implemented as a DSP, PLD, ASIC, circuits, and/or
registers. In one form, the processor 308 may be configured to
store and execute computer software program instructions to
generate the output signals for driving various components of the
ultrasonic surgical instrument 104, such as a transducer, an end
effector, and/or a blade.
[0113] In one form, under control of one or more software program
routines, the processor 308 executes the methods in accordance with
the described forms to generate an electrical signal output
waveform comprising current (I), voltage (V), and/or frequency (f)
for various time intervals or periods (T). The stepwise waveforms
of the drive signals may be generated by forming a piecewise linear
combination of constant functions over a plurality of time
intervals created by stepping the generator 300 drive signals,
e.g., output drive current (I), voltage (V), and/or frequency (f).
The time intervals or periods (T) may be predetermined (e.g., fixed
and/or programmed by the user) or may be variable. Variable time
intervals may be defined by setting the drive signal to a first
value and maintaining the drive signal at that value until a change
is detected in a monitored characteristic. Examples of monitored
characteristics may comprise, for example, transducer impedance,
tissue impedance, tissue heating, tissue transection, tissue
coagulation, and the like. The ultrasonic drive signals generated
by the generator 300 include, without limitation, ultrasonic drive
signals capable of exciting the ultrasonic transducer 306 in
various vibratory modes such as, for example, the primary
longitudinal mode and harmonics thereof as well flexural and
torsional vibratory modes.
[0114] In one form, the executable modules comprise one or more
algorithm(s) 310 stored in memory that when executed causes the
processor 308 to generate an electrical signal output waveform
comprising current (I), voltage (V), and/or frequency (f) for
various time intervals or periods (T). The stepwise waveforms of
the drive signals may be generated by forming a piecewise linear
combination of constant functions over two or more time intervals
created by stepping the output drive current (I), voltage (V),
and/or frequency (f) of the generator 300. The drive signals may be
generated either for predetermined fixed time intervals or periods
(T) of time or variable time intervals or periods of time in
accordance with the one or more algorithm(s) 310. Under control of
the processor 308, the generator 100 outputs (e.g., increases or
decreases) the current (I), voltage (V), and/or frequency (f) up or
down at a particular resolution for a predetermined period (T) or
until a predetermined condition is detected, such as a change in a
monitored characteristic (e.g., transducer impedance, tissue
impedance). The steps can change in programmed increments or
decrements. If other steps are desired, the generator 300 can
increase or decrease the step adaptively based on measured system
characteristics.
[0115] In operation, the user can program the operation of the
generator 300 using the input device 312 located on the front panel
of the generator 300 console. The input device 312 may comprise any
suitable device that generates signals 314 that can be applied to
the processor 308 to control the operation of the generator 300. In
various forms, the input device 312 includes buttons, switches,
thumbwheels, keyboard, keypad, touch screen monitor, pointing
device, remote connection to a general purpose or dedicated
computer. In other forms, the input device 312 may comprise a
suitable user interface. Accordingly, by way of the input device
312, the user can set or program the current (I), voltage (V),
frequency (f), and/or period (T) for programming the output of the
generator 300. The processor 308 then displays the selected power
level by sending a signal on line 316 to an output indicator
318.
[0116] In various forms, the output indicator 318 may provide
visual, audible, and/or tactile feedback to the surgeon to indicate
the status of a surgical procedure, such as, for example, when
tissue cutting and coagulating is complete based on a measured
characteristic of the ultrasonic surgical instrument 104, e.g.,
transducer impedance, tissue impedance, or other measurements as
subsequently described. By way of example, and not limitation,
visual feedback comprises any type of visual indication device
including incandescent lamps or LEDs, graphical user interface,
display, analog indicator, digital indicator, bar graph display,
digital alphanumeric display. By way of example, and not
limitation, audible feedback comprises any type of buzzer, computer
generated tone, computerized speech, voice user interface (VUI) to
interact with computers through a voice/speech platform. By way of
example, and not limitation, tactile feedback comprises any type of
vibratory feedback provided through an instrument housing handle
assembly.
[0117] In one form, the processor 308 may be configured or
programmed to generate a digital current signal 320 and a digital
frequency signal 322. These digital signals 320, 322 are applied to
a digital synthesis circuit such as the DDS circuit 324 (see e.g.,
FIGS. 13, 14) to adjust the amplitude and the frequency (f) of the
ultrasonic electrical drive signal 304 to the transducer. The
output of the DDS circuit 324 is applied to a power amplifier 326
whose output is applied to a transformer 328. The output of the
transformer 328 is the ultrasonic electrical drive signal 304
applied to the ultrasonic transducer 306, which is coupled to a
blade by way of a waveguide. The output of the DDS circuit 324 may
be stored in one more memory circuits including volatile (RAM) and
non-volatile (ROM) memory circuits.
[0118] In one form, the generator 300 comprises one or more
measurement modules or components that may be configured to monitor
measurable characteristics of the ultrasonic instrument 104 (FIGS.
1, 2) or the multifunction electrosurgical/ultrasonic instrument
108 (FIGS. 1-3). In the illustrated form, the processor 308 may be
employed to monitor and calculate system characteristics. As shown,
the processor 308 measures the impedance Z of the transducer by
monitoring the current supplied to the ultrasonic transducer 306
and the voltage applied to the transducer. In one form, a current
sense circuit 330 is employed to sense the current flowing through
the transducer and a voltage sense circuit 332 is employed to sense
the output voltage applied to the ultrasonic transducer 306. These
signals may be applied to the ADC circuit 336 via an analog
multiplexer 334 circuit or switching circuit arrangement. The
analog multiplexer 334 routes the appropriate analog signal to the
ADC circuit 336 for conversion. In other forms, multiple ADC
circuits 336 may be employed for each measured characteristic
instead of the analog multiplexer 334 circuit. The processor 308
receives the digital output 338 of the ADC circuit 336 and
calculates the transducer impedance Z based on the measured values
of current and voltage. The processor 308 adjusts the ultrasonic
electrical drive signal 304 such that it can generate a desired
power versus load curve. In accordance with programmed algorithm(s)
310, the processor 308 can step the ultrasonic electrical drive
signal 304, e.g., the current or frequency, in any suitable
increment or decrement in response to the transducer impedance
Z.
[0119] FIG. 7 illustrates one aspect of a drive system 402 of the
generator 400, which is one form of the generator 100 (FIGS. 1-3).
In operation, the user can program the operation of the generator
400 using the input device 412 located on the front panel of the
generator 400 console. The input device 412 may comprise any
suitable device that generates signals 414 that can be applied to
the processor 408 to control the operation of the generator 400. In
various forms, the input device 412 includes buttons, switches,
thumbwheels, keyboard, keypad, touch screen monitor, pointing
device, remote connection to a general purpose or dedicated
computer. In other forms, the input device 412 may comprise a
suitable user interface. Accordingly, by way of the input device
412, the user can set or program the current (I), voltage (V),
frequency (f), and/or period (T) for programming the output of the
generator 400. The processor 408 then displays the selected power
level by sending a signal on line 416 to an output indicator
418.
[0120] The generator 400 comprises a tissue impedance module 442.
The drive system 402 is configured to generate electrical drive
signal 404 to drive the ultrasonic transducer 406. In one aspect,
the tissue impedance module 442 may be configured to measure the
impedance Zt of tissue grasped between the blade 440 and the clamp
arm assembly 444. The tissue impedance module 442 comprises an RF
oscillator 446, an RF voltage sensing circuit 448, and an RF
current sensing circuit 450. The RF voltage and RF current sensing
circuits 448, 450 respond to the RF voltage Vrf applied to the
blade 440 electrode and the RF current irf flowing through the
blade 440 electrode, the tissue, and the conductive portion of the
clamp arm assembly 444. The sensed voltage Vrf and current Irf are
converted to digital form by the ADC circuit 436 via the analog
multiplexer 434. The processor 408 receives the digital output 438
of the ADC circuit 436 and determines the tissue impedance Zt by
calculating the ratio of the RF voltage Vrf to current Irf measured
by the RF voltage sensing circuit 448 and the RF current sense
circuit 450. In one aspect, the transection of the inner muscle
layer and the tissue may be detected by sensing the tissue
impedance Zt. Accordingly, detection of the tissue impedance Zt may
be integrated with an automated process for separating the inner
muscle layer from the outer adventitia layer prior to transecting
the tissue without causing a significant amount of heating, which
normally occurs at resonance.
[0121] In one form, the RF voltage Vrf applied to the blade 440
electrode and the RF current Irf flowing through the blade 440
electrode, the tissue, and the conductive portion of the clamp arm
assembly 451 are suitable for vessel sealing and//or dissecting.
Thus, the RF power output of the generator 400 can be selected for
non-therapeutic functions such as tissue impedance measurements as
well as therapeutic functions such as vessel sealing and/or
dissection. It will be appreciated, that in the context of the
present disclosure, the ultrasonic and the RF electrosurgical
energies can be supplied by the generator either individually or
simultaneously.
[0122] In various forms, feedback is provided by the output
indicator 418 shown in FIGS. 6 and 7. The output indicator 418 is
particularly useful in applications where the tissue being
manipulated by the end effector is out of the user's field of view
and the user cannot see when a change of state occurs in the
tissue. The output indicator 418 communicates to the user that a
change in tissue state has occurred. As previously discussed, the
output indicator 418 may be configured to provide various types of
feedback to the user including, without limitation, visual,
audible, and/or tactile feedback to indicate to the user (e.g.,
surgeon, clinician) that the tissue has undergone a change of state
or condition of the tissue. By way of example, and not limitation,
as previously discussed, visual feedback comprises any type of
visual indication device including incandescent lamps or LEDs,
graphical user interface, display, analog indicator, digital
indicator, bar graph display, digital alphanumeric display. By way
of example, and not limitation, audible feedback comprises any type
of buzzer, computer generated tone, computerized speech, VUI to
interact with computers through a voice/speech platform. By way of
example, and not limitation, tactile feedback comprises any type of
vibratory feedback provided through the instrument housing handle
assembly. The change of state of the tissue may be determined based
on transducer and tissue impedance measurements as previously
described, or based on voltage, current, and frequency
measurements.
[0123] In one form, the processor 408 may be configured or
programmed to generate a digital current signal 420 and a digital
frequency signal 422. These digital signals 420, 422 are applied to
a digital synthesis circuit such as the DDS circuit 424 (see e.g.,
FIGS. 13, 14) to adjust the amplitude and the frequency (f) of the
electrical drive signal 404 to the transducer 406. The output of
the DDS circuit 424 is applied to a power amplifier 426 whose
output is applied to a transformer 428. The output of the
transformer 428 is the electrical drive signal 404 applied to the
ultrasonic transducer 406, which is coupled to a blade by way of a
waveguide. The output of the DDS circuit 424 may be stored in one
more memory circuits including volatile (RAM) and non-volatile
(ROM) memory circuits.
[0124] In one form, the generator 400 comprises one or more
measurement modules or components that may be configured to monitor
measurable characteristics of the ultrasonic instrument 104 (FIGS.
1, 3) or the multifunction electrosurgical/ultrasonic instrument
108 (FIGS. 1-3). In the illustrated form, the processor 408 may be
employed to monitor and calculate system characteristics. As shown,
the processor 408 measures the impedance Z of the transducer by
monitoring the current supplied to the ultrasonic transducer 406
and the voltage applied to the transducer. In one form, a current
sense circuit 430 is employed to sense the current flowing through
the transducer and a voltage sense circuit 432 is employed to sense
the output voltage applied to the ultrasonic transducer 406. These
signals may be applied to the ADC circuit 436 via an analog
multiplexer 434 circuit or switching circuit arrangement. The
analog multiplexer 434 routes the appropriate analog signal to the
ADC circuit 436 for conversion. In other forms, multiple ADC
circuits 436 may be employed for each measured characteristic
instead of the analog multiplexer 434 circuit. The processor 408
receives the digital output 438 of the ADC circuit 436 and
calculates the transducer impedance Z based on the measured values
of current and voltage. The processor 308 adjusts the electrical
drive signal 404 such that it can generate a desired power versus
load curve. In accordance with programmed algorithm(s) 410, the
processor 408 can step the ultrasonic electrical drive signal 404,
e.g., the current or frequency, in any suitable increment or
decrement in response to the transducer impedance Z.
[0125] With reference to FIGS. 6 and 7, in various forms, the
various executable instructions or modules (e.g., algorithms 310,
410) comprising computer readable instructions can be executed by
the processor 308, 408 portion of the generator 300, 400. In
various forms, the operations described with respect to the
algorithms may be implemented as one or more software components,
e.g., programs, subroutines, logic; one or more hardware
components, e.g., processors, DSPs, PLDs, ASICs, circuits,
registers; and/or combinations of software and hardware. In one
form, the executable instructions to perform the algorithms may be
stored in memory. When executed, the instructions cause the
processor 308, 408 to determine a change in tissue state provide
feedback to the user by way of the output indicator 318, 418. In
accordance with such executable instructions, the processor 308,
408 monitors and evaluates the voltage, current, and/or frequency
signal samples available from the generator 300, 400 and according
to the evaluation of such signal samples determines whether a
change in tissue state has occurred. As further described below, a
change in tissue state may be determined based on the type of
ultrasonic instrument and the power level that the instrument is
energized at. In response to the feedback, the operational mode of
the surgical instruments 104, 106, 108 (FIGS. 1-3) may be
controlled by the user or may be automatically or
semi-automatically controlled.
[0126] FIG. 8 illustrates an example of a generator 500, which is
one form of the generator 100 (FIGS. 1-3). The generator 500 is
configured to deliver multiple energy modalities to a surgical
instrument. The generator 500 includes functionalities of the
generators 200, 300, 400 shown in FIGS. 5-7. The generator 500
provides RF and ultrasonic signals for delivering energy to a
surgical instrument. The RF and ultrasonic signals may be provided
alone or in combination and may be provided simultaneously. As
noted above, at least one generator output can deliver multiple
energy modalities (e.g., ultrasonic, bipolar or monopolar RF,
irreversible and/or reversible electroporation, and/or microwave
energy, among others) through a single port and these signals can
be delivered separately or simultaneously to the end effector to
treat tissue. The generator 500 comprises a processor 502 coupled
to a waveform generator 504. The processor 502 and waveform
generator 504 are configured to generate a variety of signal
waveforms based on information stored in a memory coupled to the
processor 502, not shown for clarity of disclosure. The digital
information associated with a waveform is provided to the waveform
generator 504 which includes one or more DAC circuits to convert
the digital input into an analog output. The analog output is fed
to an amplifier 1106 for signal conditioning and amplification. The
conditioned and amplified output of the amplifier 506 is coupled to
a power transformer 508. The signals are coupled across the power
transformer 508 to the secondary side, which is in the patient
isolation side. A first signal of a first energy modality is
provided to the surgical instrument between the terminals labeled
ENERGY1 and RETURN. A second signal of a second energy modality is
coupled across a capacitor 510 and is provided to the surgical
instrument between the terminals labeled ENERGY2 and RETURN. It
will be appreciated that more than two energy modalities may be
output and thus the subscript "n" may be used to designate that up
to n ENERGYn terminals may be provided, where n is a positive
integer greater than 1. It also will be appreciated that up to "n"
return paths RETURNn may be provided without departing from the
scope of the present disclosure.
[0127] A first voltage sensing circuit 512 is coupled across the
terminals labeled ENERGY1 and the RETURN path to measure the output
voltage therebetween. A second voltage sensing circuit 524 is
coupled across the terminals labeled ENERGY2 and the RETURN path to
measure the output voltage therebetween. A current sensing circuit
514 is disposed in series with the RETURN leg of the secondary side
of the power transformer 508 as shown to measure the output current
for either energy modality. If different return paths are provided
for each energy modality, then a separate current sensing circuit
should be provided in each return leg. The outputs of the first and
second voltage sensing circuits 512, 524 are provided to respective
isolation transformers 516, 522 and the output of the current
sensing circuit 514 is provided to another isolation transformer
518. The outputs of the isolation transformers 516, 518, 522 in the
on the primary side of the power transformer 508
(non-patient-isolated side) are provided to a one or more ADC
circuit 526. The digitized output of the ADC circuit 526 is
provided to the processor 502 for further processing and
computation. The output voltages and output current feedback
information can be employed to adjust the output voltage and
current provided to the surgical instrument and to compute output
impedance, among other parameters. Input/output communications
between the processor 502 and patient isolated circuits is provided
through an interface circuit 520. Sensors also may be in electrical
communication with the processor 502 by way of the interface
circuit 520.
[0128] In one aspect, the impedance may be determined by the
processor 502 by dividing the output of either the first voltage
sensing circuit 512 coupled across the terminals labeled
ENERGY1/RETURN or the second voltage sensing circuit 524 coupled
across the terminals labeled ENERGY2/RETURN by the output of the
current sensing circuit 514 disposed in series with the RETURN leg
of the secondary side of the power transformer 508. The outputs of
the first and second voltage sensing circuits 512, 524 are provided
to separate isolations transformers 516, 522 and the output of the
current sensing circuit 514 is provided to another isolation
transformer 516. The digitized voltage and current sensing
measurements from the ADC circuit 526 are provided the processor
502 for computing impedance. As an example, the first energy
modality ENERGY1 may be ultrasonic energy and the second energy
modality ENERGY2 may be RF energy. Nevertheless, in addition to
ultrasonic and bipolar or monopolar RF energy modalities, other
energy modalities include irreversible and/or reversible
electroporation and/or microwave energy, among others. Also,
although the example illustrated in FIG. 8 shows a single return
path RETURN may be provided for two or more energy modalities, in
other aspects multiple return paths RETURNn may be provided for
each energy modality ENERGYn. Thus, as described herein, the
ultrasonic transducer impedance may be measured by dividing the
output of the first voltage sensing circuit 512 by the current
sensing circuit 514 and the tissue impedance may be measured by
dividing the output of the second voltage sensing circuit 524 by
the current sensing circuit 514.
[0129] As shown in FIG. 8, the generator 500 comprising at least
one output port can include a power transformer 508 with a single
output and with multiple taps to provide power in the form of one
or more energy modalities, such as ultrasonic, bipolar or monopolar
RF, irreversible and/or reversible electroporation, and/or
microwave energy, among others, for example, to the end effector
depending on the type of treatment of tissue being performed. For
example, the generator 500 can deliver energy with higher voltage
and lower current to drive an ultrasonic transducer, with lower
voltage and higher current to drive RF electrodes for sealing
tissue, or with a coagulation waveform for spot coagulation using
either monopolar or bipolar RF electrosurgical electrodes. The
output waveform from the generator 500 can be steered, switched, or
filtered to provide the frequency to the end effector of the
surgical instrument. The connection of an ultrasonic transducer to
the generator 500 output would be preferably located between the
output labeled ENERGY1 and RETURN as shown in FIG. 8. An In one
example, a connection of RF bipolar electrodes to the generator 500
output would be preferably located between the output labeled
ENERGY2 and RETURN. In the case of monopolar output, the preferred
connections would be active electrode (e.g., pencil or other probe)
to the ENERGY2 output and a suitable return pad connected to the
RETURN output.
[0130] In other aspects, the generators 100, 200, 300, 400, 500
described in connection with FIGS. 1-3 and 5-8, the ultrasonic
drive circuit 114, and/or electrosurgery/RF drive circuit 116 as
described in connection with FIG. 3 may be formed integrally with
any one of the surgical instruments 104, 106, 108 described in
connection with FIGS. 1 and 2. Accordingly, any of the processors,
digital signal processors, circuits, controllers, logic devices,
ADCs, DACs, amplifiers, converters, transformers, signal
conditioners, data interface circuits, current and voltage sensing
circuits, direct digital synthesis circuits, multiplexer (analog or
digital), waveform generators, RF generators, memory, and the like,
described in connection with any one of the generators 100, 200,
300, 400, 500 can be located within the surgical instruments 104,
106, 108 or may be located remotely from the surgical instruments
104, 106, 108 and coupled to the surgical instruments via wired
and/or wireless electrical connections.
[0131] FIG. 9 shows a diagram of an electrosurgical system 9000
that allows for two ports on a generator 9001 and accounts for
electrical isolation between two surgical instruments 9007, 9008. A
scheme is provided for electrical isolation between the two
instruments 9007, 9008 as they are located on the same patient
isolation circuit. According to the configuration shown in FIG. 9,
unintended electrical power feedback is prevented through the
electrosurgical system 9000. In various aspects, power field effect
transistors (FETs) or relays are used to electrically isolate all
power lines for each of the two surgical instruments 9007, 9008.
According to one aspect, the power FETs or relays are controlled by
a 1-wire communication protocol.
[0132] As shown in FIG. 9, a generator 9001, which is one form of
the generator 100 (FIGS. 1-3), is coupled to a power switching
mechanism 9003 and a communications system 9005. In one aspect, the
power switching mechanism 9003 comprises power solid state switches
such as, for example, FET or MOSFET transistors, and/or relays,
such as electromechanical relays. In one aspect, the communications
system 9005 comprises components for D1 emulation, FPGA expansion,
and time slicing functionalities. The power switching mechanism
9003 is coupled to the communications system 9005. Each of the
power switching mechanism 9003 and the communications system 9005
are coupled to surgical instruments 9007, 9009 (labeled device 1
and device 2). Each of surgical instruments 9007, 9009 comprise
components for a combined RF and ultrasonic energy input 9011,
handswitch (HSW) 1-wire serial protocol interface 9013, HP 1-wire
serial protocol interface 9015, and a presence interface 9017
resistor. The power switching mechanism 9003 is coupled to the RF
and Ultrasonic energy input 9011 for each of surgical instruments
9007, 9008. The communications system 9005 is coupled to the HSW
1-wire serial interface 9013, 9014, the HP 1-wire serial protocol
interface 9015, 9016, and presence interface 9017, 9018 for each of
surgical instruments 9007, 9008. While two surgical instruments are
shown in FIG. 9, there may be more than two devices according to
various aspects.
[0133] FIGS. 10-12 illustrate aspects of an interface with a
generator to support two instruments simultaneously that allows the
instruments to quickly switch between active/inactive by a user in
a sterile field. FIGS. 10-12 describe multiple communication
schemes which would allow for a super cap/battery charger and dual
surgical instruments. The aspects of FIGS. 10-12 allow for
communications to two surgical instruments in the surgical field
from a generator with at least one communications port and allow
for an operator in sterile field to switch between devices, for
example, without modifying the surgical instruments.
[0134] FIG. 10 is a diagram of a communications architecture of
system 1001 comprising a generator 1003, which is one form of the
generator 100 (FIGS. 1-3), and surgical instruments 9007, 9008,
which are shown in FIG. 9. According to FIG. 10, the generator 9001
is configured for delivering multiple energy modalities to a
plurality of surgical instruments. As discussed herein the various
energy modalities include, without limitation, ultrasonic, bipolar
or monopolar RF, reversible and/or irreversible electroporation,
and/or microwave energy modalities. The generator 9001 comprises a
combined energy modality power output 1005, a communications
interface 1007, and a presence interface 1049. According to the
aspect of FIG. 10, the communications interface 1007 comprises an
handswitch (HSW) serial interface 1011 and an handpiece (HP) serial
interface 1013. The serial interfaces 1011, 1013 may comprise
inter-integrated circuit (I.sup.2C), half duplex SPI, and/or
Universal Asynchronous Receiver Transmitter (UART) components
and/or functionalities. The generator 1003 provides the combined
energy modalities power output 1005 to an adapter 1015, for
example, a pass-through charger (PTC). The adapter 1015 comprises
energy storage circuit 1071, control circuit 1019, a unique
presence element 1021, and associated circuit discussed below. In
one aspect, the presence element 1021 is a resistor. In another
aspect, the presence element 1021 may be a bar code, Quick Response
(QR) code, or similar code, or a value stored in memory such as,
for example, a value stored in NVM. The presence element 1021 may
be unique to the adapter 1015 so that, in the event that another
adapter that did not use the same wire interfaces could not be used
with the unique presence element 1021. In one aspect, the unique
presence element 1021 is a resistor. The energy storage circuit
1071 comprises a switching mechanism 1023, energy storage device
1025, storage control 1027, storage monitoring component 1029, and
a device power monitoring component 1031. The control circuit 1019
may comprise a processor, FPGA, PLD, complex programmable logic
device (CPLD), microcontroller, DSP, and/or ASIC, for example.
According to the aspect shown in FIG. 10, an FPGA or
microcontroller would act as an extension of an existing, similar
computing hardware and allows for information to be relayed from on
entity to another entity.
[0135] The switching mechanism 1023 is configured to receive the
combined energy power output 1005 from the generator 1003 and it
may be provided to the energy storage device 1025, surgical
instrument 9007, and/or surgical instrument 9008. The device power
monitoring component 1031 is coupled to the channels for the energy
storage device 1025, surgical instrument 9007, surgical instrument
9008, and may monitor where power is flowing. The control circuit
1019 comprises communication interface 1033 coupled to the
handswitch serial interface 1011 and an handpiece serial interface
1013 of the generator 1003. The control circuit 1019 is also
coupled to the storage control 1027, storage monitoring component
1029, and device power monitoring component 1031 of the energy
storage circuit 1071.
[0136] The control circuit 1019 further comprises a serial master
interface 1035 that is coupled to handswitch (HSW) #1 circuit 1037
and handswitch (HSW) #2 circuit 1038, includes generation and ADC,
a form of memory (non volatile or flash) 1039, along with a method
for detecting the presence of an attached instrument (Presence) #1
circuit 1041 and Presence #2 circuit 1042, which includes a voltage
or current source and ADC. The serial master interface 1035 also
includes handswitch NVM bypass channels, which couple the serial
master interface 1035 to the outputs of the handswitch #1 circuit
1037 and the handswitch #2 circuit 1038, respectively. The
handswitch #1 circuit 1037 and handswitch #2 circuit 1038 are
coupled to the HSW 1-wire serial protocol interfaces 9013, 9014 of
the surgical instruments 9007, 9008, respectively. The serial
master interface 1035 further includes handpiece serial channels
that are coupled to the HP 1-wire serial protocol interfaces 9015,
9016 of the surgical instruments 9007, 9008, respectively. Further,
Presence #1 and Presence #2 circuits 1041, 1042 are coupled to the
presence interfaces 9017, 9018 of the surgical instruments 9007,
9008, respectively.
[0137] The system 1001 allows the control circuit 1019, such as an
FPGA, to communicate with more surgical instruments using adapter
1015, which acts as an expansion adapter device. According to
various aspects, the adapter 1015 expands the Input/Output (I/O)
capability of the generator 1003 control. The adapter 1015 may
function as an extension of the central processing unit that allows
commands to be transmitted over a bus between the adapter 1015 and
the generator 1003 and unpacks the commands and use them to
bit-bang over interfaces or to control connected analog circuit.
The adapter 1015 also allows for reading in ADC values from
connected surgical instruments 9007, 9008 and relay this
information to the generator control and the generator control
would then control the two surgical instruments 9007, 9008.
According to various aspects, the generator 1003 may control the
surgical instruments 9007, 9008 as two separate state machines and
may store the data.
[0138] Existing interfaces (the handswitch serial interface 1011
and the handpiece serial interface 1013 lines from generator 1003)
may be used in a two-wire communication protocol that enables the
generator 1003 control to communicate with multiple surgical
instruments connected to a dual port interface, similar to the
topology of a universal serial bus (USB) hub. This allows
interfacing with two separate surgical instruments simultaneously.
The system 1001 may be able to generate and read hand switch
waveforms and be able to handle incoming handpiece serial buses. It
would also monitor two separate presence elements in the surgical
instruments 9007, 9008. In one aspect, the system 1001 may include
a unique presence element and may have its own NVM.
[0139] Further, according to various aspects, the control circuit
1019 may be controlled by the generator 1003. The communication
between the adapter 1015 and connected surgical instruments 9007,
9008 may be relayed to generator control. The generator 1003 would
control the waveform generation circuit connected to the adapter
1015 to simultaneously generate handswitch signals for surgical
instruments 9007, 9008.
[0140] The system 1001 may allow surgical instrument activity that
can be simultaneously detected/monitored for two surgical
instruments, even during activation. If upgradeable, the adapter
1015 would be capable of handling new surgical instrument
communications protocols. Further, fast switching between surgical
instruments may be accomplished.
[0141] FIG. 11 illustrates a communication architecture of system
1101 of a generator 1103, which is one form of the generator 100
(FIGS. 1-3), and surgical instruments 9007, 9008 shown in FIG. 9.
According to FIG. 11, the generator 1103 is configured for
delivering multiple energy modalities to a plurality of surgical
instruments. As discussed herein the various energy modalities
include, without limitation, ultrasonic, bipolar or monopolar RF,
reversible and/or irreversible electroporation, and/or microwave
energy modalities. As shown in FIG. 11, the generator 1103
comprises a combined energy modality power output 1105, an
handswitch (HSW) serial interface 1111, a handpiece (HP) serial
interface 1113, and a presence interface 1109. The generator 1103
provides the power output 1105 to an adapter 1115. According to the
aspect shown in FIG. 11, communications between the adapter 1115
and the generator 1103 may be done solely through serial
interfaces, such as the handswitch serial and handpiece serial
interfaces 1111, 1113. The generator 1103 may use these handswitch
and handpiece serial interfaces 1111, 1113 to control which
instrument the generator 1103 is communicating with. Further,
switching between instruments could occur between handswitch frames
or at a much slower rate.
[0142] The adapter 1115 comprises energy storage circuit 1117,
control circuit 1119, an adapter memory 1121 (e.g., a NV such as an
EEPROM), a serial programmable input/output (PIO) integrated
circuit 1133, an handswitch Switching Mechanism 1135, an handpiece
Switching Mechanism 1137, a Presence Switching Mechanism 1139, and
a Generic Adapter 1141. In one aspect, the serial PIO integrated
circuit 1133 may be an addressable switch. The energy storage
circuit 1117 comprises a switching mechanism 1123, energy storage
device 1125, storage control component 1127, storage monitoring
component 1129, and a device power monitoring component 1131. The
control circuit 1119 may comprise a processor, FPGA, CPLD, PLD,
microcontroller, DSP, and/or an ASIC, for example. According to the
aspect of FIG. 11, an FPGA or microcontroller may have limited
functionality and may solely comprise functionality for monitoring
and communicating energy storage.
[0143] The switching mechanism 1123 is configured to receive the
combined energy power output 1105 from the generator 1103 and it
may be provided to the energy storage device 1125, surgical
instrument 9007, and/or surgical instrument 9008. The device power
monitoring component 1131 is coupled to the channels for the energy
storage device 1125, surgical instrument 9007, surgical instrument
9008, and may monitor where power is flowing.
[0144] The control circuit 1119 is coupled to the serial PIO
integrated circuit 1133 and the serial PIO integrated circuit 1133
is coupled to the handpiece serial interface 1113 of the generator
1103. The control circuit 1119 may receive information regarding
charger status flags and switching controls from the serial PIO
integrated circuit 1133. Further, the control circuit 1119 is
coupled to the handswitch switching mechanism 1135, the handpiece
switching mechanism 1137, and the presence switching mechanism
1139. According to the aspect of FIG. 11, the control circuit 1119
may be coupled to the handswitch (HSW) switching mechanism 1135 and
the handpiece switching mechanism 1137 for device selection and the
control circuit 1119 may be coupled to the presence switching
Mechanism 1139 for presence selection.
[0145] The handswitch switching mechanism 1135, the handpiece
switching mechanism 1137, and the presence switching mechanism 1139
are coupled to the handswitch serial interface 1111, the handpiece
serial interface 1113, and the presence interface 1109 of generator
1103, respectively. Further, the handswitch switching mechanism
1135, the handpiece switching mechanism 1137, and the presence
switching mechanism 1139 are coupled to the HSW 1-wire serial
protocol interfaces 9013, 9014, the HP 1-wire serial protocol
interfaces 9015, 9016, and the presence interfaces 9017, 9018 of
the surgical instruments 9007, 9008, respectively. Further, the
presence switching mechanism 1139 is coupled to the generic adapter
1141.
[0146] The generator 1103 switches between monitoring the surgical
instruments 9007, 9008. According to various aspects, this
switching may require the generator 1103 control to keep track of
surgical instruments 9007, 9008 and run two separate state
machines. The control circuit 1119 will need to remember which
surgical instruments are connected, so that it can output an
appropriate waveform to the ports where appropriate. The generator
1103 may generate/monitor hand switch signals, as well as
communicating with serial NVM devices, such adapter memory 1121.
The generator 1103 may maintain constant communication with the
activating surgical instrument for the duration of the
activation.
[0147] System 1101 also allows for a generic adapter presence
element. When first plugged in or powered on, the adapter 1115
would present this adapter resistance to the generator 1103. The
generator 1103 may then relay commands to the adapter 1115 to
switch between the different presence elements corresponding to the
different surgical instruments 9007, 9008 connected to it.
Accordingly, the generator 1103 is able to use its existing
presence resistance circuit. The NVM memory 1121 exists on the
adapter 1115 for additional identification of the adapter and to
provide a level of security. In addition, the adapter 1115 has a
serial I/O device, i.e. serial PIO integrated circuit 1133. The
serial PIO integrated circuit 1133 provides a communication link
between the generator 1103 and the adapter 1115.
[0148] It may be possible to communicate over the handpiece serial
bus using serial communications to handpiece NVMs and UART style
communication to the control circuit 1119. According to one aspect,
if SLOW serial communication is used (i.e. not overdrive) and a
high speed serial protocol is used, system 1101 may need to ensure
that the communications protocol does not generate a signal that
looked like a serial reset pulse. This would allow better generator
1103 to adapter 1115 communications and faster switching times
between surgical instruments 9007, 9008.
[0149] The system 1101 uses generator communications protocol and
analog circuit and allows the generator to accomplish decision
making. It is a simple and efficient solution that uses a small
number of circuit devices.
[0150] FIG. 12 illustrates a communications architecture of system
1201 of a generator 1203, which is one form of the generator 100
(FIGS. 1-3), and surgical instruments 9007, 9008 shown in FIG. 9.
According to FIG. 12, the generator 1203 is configured for
delivering multiple energy modalities to a plurality of surgical
instruments. As discussed herein the various energy modalities
include, without limitation, ultrasonic, bipolar or monopolar RF,
reversible and/or irreversible electroporation, and/or microwave
energy modalities. As shown in FIG. 12, the generator 1203
comprises a combined energy modality power output 1205, an
handswitch serial interface 1211, an handpiece serial interface
1213, and a presence interface 1209. In one aspect, the handpiece
serial interface 1213 allows for communication with the handpiece
lines of the surgical instruments 9007, 9008 and also allows for
control of the adapter 1215. The generator 1203 provides the
combined energy modality power output 1205 to an adapter 1215. The
adapter 1215 comprises energy storage circuit 1217, control circuit
1219, a serial PIO integrated circuit 1233, handswitch (HSW) #1
circuit 1231, handswitch (HSW) #2 circuit 1271, handpiece switching
mechanism 1221, presence switching mechanism 1239, switching
mechanism 1235, instrument power monitoring 1237, and unique
presence 1241. As shown in FIG. 12, the handswitch #1 circuit 1231
and the handswitch #2 circuit 1271 may comprise generation and ADC
circuits. In one aspect, handswitch #1 circuit 1231 and/or
handswitch #2 circuit 1271 comprise generation circuit with the
ability to generate handswitch waveforms.
[0151] The control circuit 1219 is coupled to the handswitch serial
interface 1211 of the generator 1203 while the serial PIO
integrated circuit 1233 is coupled to the handpiece serial
interface 1213 as is the handpiece switching mechanism 1221.
Further, the control circuit 1119 is coupled to the handswitch #1
circuit 1231 and the handswitch #2 circuit 1271. The control
circuit 1119 may comprise a processor, FPGA, CPLD, PLD,
microcontroller, and/or ASIC, for example. In the example shown in
FIG. 12, the control circuit 1219 modulates two devices into at
least one digital waveform, which enable the generator 1203 to
perform the button monitoring and decision making. The control
circuit 1219 also may allow for communication to two independent
surgical instruments could receive either waveform. The serial PIO
integrated circuit 1233 is further coupled to the handpiece
switching mechanism 1221, the instrument power monitoring 1237, and
the presence switching mechanism 1239. The instrument power
monitoring 1237 and the serial PIO integrated circuit 1233 may
communicate results and failures to the generator 1203.
[0152] The switching mechanism 1223 is configured to receive the
combined RF/ultrasonic power output 1205 from the generator 1203
and it may be provided to the energy storage circuit 1225 or the
switching mechanism 1235. The control circuit 1219 is also coupled
to the storage control 1227 and storage monitoring 1229 of the
energy storage circuit 1217. The switching mechanism 1235 may
provide the power output received from the switching mechanism 1223
to surgical instrument 9007, and/or surgical instrument 9008. The
instrument power monitoring 1237 is coupled to the channels for the
power output to the surgical instrument 9007 and surgical
instrument 9008. The instrument power monitoring 1237 also may
ensure that the switching mechanism 1235 is outputting power to
correct location.
[0153] The handswitch #1 circuit 1231 and the handswitch #2 circuit
1271 are coupled to the HSW 1-wire serial protocol interfaces 9013,
9014 of the surgical instruments 9007, 9008, respectively. The
handpiece switching mechanism 1221 is coupled to the handpiece
serial interface 1213 of the generator 1203 and to the HP 1-wire
serial protocol interfaces 9015, 9016 of the surgical instruments
9007, 9008, respectively. Further, the presence switching mechanism
1239 is coupled to the presence interface 1209 of the generator
1203 and to the presence Interfaces 9017, 9018 of the surgical
instruments 9007, 9008, respectively. Further, Presence Switching
mechanism is coupled to the unique presence 1241. In one aspect,
different instrument presence elements may be switched on an
on-demand basis using serial I/O or an adapter micro protocol.
[0154] A first communications protocol will be used to communicate
to the control circuit 1219 on the adapter 1215. The generator 1203
also may have the ability to monitor surgical instruments 9007,
9008 at once. The adapter 1215 may comprise circuit to provide
handswitch signal generation (e.g., in handswitch #1 circuit 1231
and handswitch #2 circuit 1271) along with ADCs to interpret this
data. The adapter 1215 may modulate two surgical instrument signals
into at least a first waveform and may have the ability to read in
the first and second waveforms. In various aspects, the second
waveforms may be interpreted and translated into the format of the
first waveforms. Further, the first protocol has the ability to
send 12 bits at 615 bits/sec.
[0155] The control circuit 1219 may take the handswitch data from
surgical instruments 9007, 9008 and modulate it into a first
protocol. There are a few ways of doing this, but it may mean that
surgical instruments 9007, 9008 may comprise a first protocol
functionality. The system 1201 could communicate 4-6 buttons from
the surgical instrument 9007 and 4-6 buttons from the surgical
instrument 9008 in the first protocol frame. Alternatively, the
system 1201 could use some form of addressing to access the
surgical instruments 9007, 9008. The control circuit 1219 may have
the ability to address separate devices by having the generator
1203 send the control circuit 1219 different addresses split into
two different address spaces, one for surgical instrument 9007 and
one for surgical instrument 9008.
[0156] The handpiece communications may involve some form of switch
that could either be controlled via a serial I/O device or through
the control circuit 1219 via a first protocol style communication
interface from the generator 1203. In one aspect, energy storage
monitoring 1229 and switching between surgical instruments 9007,
9008 and charging states could be handled in this manner as well.
Certain first protocol addresses could be assigned to the data from
the energy storage circuit 1225 and to the surgical instruments
9007, 9008 themselves. Presence elements could also be switched in
with this format. Further, in one aspect, the control circuit 1219
may translate frames into a separate format, which may mean that
the control circuit 1219 might need to make some decisions on
whether button presses on surgical instruments 9007, 9008 are valid
or not. The system 1201 would, however, allow the generator 1203 to
fully monitor the surgical instruments 9007, 9008 at the same time
time-slicing or handling a new communications protocol on the
handswitch serial interface 1211 of the generator 1203. The system
1201 uses generator communications to simultaneously detect the
activity of two surgical instruments, even during activation.
[0157] As noted above, a single output generator can deliver both
RF and ultrasonic energy through a single port and these signals
can be delivered separately or simultaneously to the end effector
to treat tissue. One aspect of a combined RF and ultrasonic
generator is shown in FIG. 1. As shown in FIG. 1, a single output
port generator can include a single output transformer with
multiple taps to provide power, either RF or ultrasonic energy, to
the end effector depending on the type of treatment of tissue being
performed. For example, the generator can deliver energy with
higher voltage and lower current to drive an ultrasonic transducer,
with lower voltage and higher current as required to drive
electrodes for sealing tissue, or with a coagulation waveform for
spot coagulation using either monopolar or bipolar electrosurgical
electrodes. The output waveform from the generator can be steered,
switched, or filtered to provide the desired frequency to the end
effector of the surgical instrument.
[0158] The surgical instruments described herein can also include
features to allow the energy being delivered by the generator to be
dynamically changed based on the type of tissue being treated by an
end effector of a surgical instrument. An algorithm for controlling
the power output from a generator, such as generator 100, that is
delivered to the end effector of the surgical instrument can
include an input that represents the tissue type to allow the
energy profile from the generator to be dynamically changed during
the procedure based on the type of tissue being effected by the end
effector of the surgical instrument.
[0159] Various algorithms can be used to select a power profile to
allow the energy being delivered from the generator to dynamically
change based on the tissue type being treated by the surgical
instrument.
[0160] In order to determine the type of tissue being treated by
the end effector of the surgical instrument, a tissue coefficient
of friction can be calculated. The calculated tissue coefficient of
friction is compared to a database of tissue coefficients of
friction that correlates each tissue coefficient with a tissue
type, as will be discussed in more detail below. The calculated
tissue coefficient of friction and its related tissue type are used
by an algorithm to control the energy being delivered from the
generator to the surgical instrument. In one form, the tissue
coefficient of friction is described by:
.mu. = Q N ##EQU00001##
[0161] Where Q is the rate of heat generation, .phi. is the
velocity of the ultrasonic motion of the end effector, and N is the
force applied to the tissue by the end effector. The velocity of
the ultrasonic motion is a known value from the settings of the
generator. Since the value 19 is a known value, the tissue
coefficient of friction can be calculated using the slope of a
graph of heat generation versus force on the tissue.
[0162] The force applied to the tissue by the end effector can be
measured in a variety of ways using different type of components to
measure force. This force measurement can be used, for example in
the equation above, to determine the tissue coefficient of friction
of the tissue being treated to determine its tissue type.
[0163] According to aspects of the present disclosure, certain
filters, switching, etc. will be required to steer the components
of an ultrasonic signal to the transducer and the components of an
RF signal to the electrodes in a combination device. This is true
when RF and ultrasonic signals are occurring simultaneously. The
steering circuits may have sensitivity to component variations.
According to aspects of the present disclosure, a way of optimizing
such steering circuits is to provide a "tune" where values are
adjusted to provide the best performance or at least a reasonable
compromise of the performance of the steering circuits. Steering
may be performed using various filters and/or switches. For
example, band-stop filters or notch filters may be used.
[0164] Another way is to adjust the output frequency of the
ultrasonic and/or RF output such that the performance of the
steering circuitry is optimized. According to aspects of the
present disclosure, generator systems may have the capability of
frequency agility. Frequency agility may include the generators'
ability to produce various frequencies, and the time it takes to
change the frequency, due to the system design. At least one Direct
Digital Synthesizer (DDS) of a generator may drive what is
essentially a linear amplifier. The output of the amplifier is
coupled to a transformer which then provides the treatment energy
output for the surgical instrument. The RF treatment is quite
insensitive to frequency; the tissue's response to RF energy is
nearly independent of the driving frequency. According to aspects
of the present disclosure, tissue response to RF energy over a
range of, for example, 250-500 kHz, is nearly independent of the
driving frequency of the RF energy.
[0165] In addition, the steering circuitry can be characterized
during the manufacturing process. This characterization can include
the best operating frequency points for an individual steering
circuit. The characterization information can be stored in an
instrument's EEPROM or other suitable location and a generator can
then drive the RF energy at one or more of the best operating
frequency points.
[0166] The steering circuitry can also be characterized when the
device is connected to the generator. For example, during the
initial connection of the instrument to a generator, the surgical
instrument can be characterized. If the surgical instrument is
reusable, this characterization can be stored for future use.
According to aspects of the present disclosure, the
characterization may continue during the use of the surgical
instrument either in-between firings or during firings. The
components may change values depending on their temperature, aging,
etc. and periodic re-characterization of a surgical instrument
filter and steering may provide benefits.
[0167] Characterizing a surgical instrument can be accomplished by
several methods. In one aspect, the method would include sending a
ping signal to the steering circuitry and measuring a response from
the steering circuitry. This response contains information that
defines the frequency response of the steering circuitry. The RF
frequency may then be adjusted to match the appropriate point or
points along the frequency response.
[0168] An ultrasound transducer may be sensitive to changes in
frequency. Therefore, one or more variable components may be
provided, so that the frequency of the ultrasonic component does
not need to be changed even when circuit characteristics are
changed. For example, a variable capacitor or a variable inductor
in a band-stop filter may be provided.
[0169] Additionally, according to aspects of the present
disclosure, a steering filter for an RF energy component of a
combination surgical device may be made with looser tolerances and
the output frequency of the generator can be changed to tune the RF
steering filter of the RF energy component.
[0170] FIG. 13 shows a flow diagram illustrating a method 1300 for
providing a combined signal by a generator to a surgical
instrument. The combined signal may comprise a radio frequency (RF)
component and an ultrasonic component. The surgical instrument may
comprise an RF energy output, an ultrasonic energy output, and a
circuit. The circuit may be a steering circuitry.
[0171] Characterization is performed 1310 on at least one component
of the circuit. A frequency of the RF component is adjusted 1320
based on a result of the characterization. The generator delivers
1330 the combined signal to the surgical instrument. The circuit
steers 1340 the RF component to the RF energy output, and steers
1350 the ultrasonic component to the ultrasonic energy output.
[0172] FIG. 14 displays an example of a notch filter 1400 and FIG.
15 provides an analysis of the transfer function of the notch
filter 1400. A Monte Carlo analysis was run with the tolerances of
the capacitor 1401 and inductor 1402 set to 5%. According to plot
shown in FIG. 15, variations in the response of the filter 1400 can
be seen. According to aspects of the present disclosure, the
frequency of the output of a generator can be adjusted to fit the
response of the filter 1400.
[0173] FIG. 16 shows a plot illustrating adjustment of the RF
frequency based on characterization of the steering circuitry. As
shown in FIG. 16, a notch filter in the steering circuitry may have
a frequency response described by waveform 1610 when manufactured.
But when conditions such as temperature and aging change, the
filter's frequency response may be changed to look like waveform
1620. In this case, the generator may change the frequency of the
RF component from about 340 KHz to about 310 KHz. Therefore, the RF
component can always be filtered out for the ultrasonic output.
[0174] FIGS. 17 and 18 provide illustration of system configuration
for an example circuit topology shown and described with regard to
FIGS. 13-16 The system configuration comprises a plurality
sections, where the plurality of sections include a generator
(labeled GENERATOR), a proximal plug (labeled PLUG 1), a cable, a
distal plug (labeled PLUG 2), a handle of a surgical instrument,
and an application portion (labeled APP) of a surgical instrument.
According to various aspects, the proximal plug may be a component
of the generator, it may be a component of cable, or it may be
separate component. Similarly, the distal plug may be a component
of the cable, it may be a component of handle, or it may be
separate component.
[0175] FIG. 17 provides an illustration of a system 6600
configuration for an example circuit topology shown and described
with regard to FIGS. 13-16, including MOSFET switches and a control
circuit in the handle, configured to manage RF and ultrasonic
currents output by a generator according to one aspect of the
present disclosure. The system 6600 includes electro-mechanical or
solid state switches such as MOSFET switches and a control circuit
in the handle. The generator comprises interfaces for an ultrasonic
signal 6601, an interface for an RF signal 6603, a primary return
terminal interface 6605, an HSW interface 6607, a secondary return
terminal interface 6609, an identification interface 6611, and a
presence interface 6613. The proximal plug comprises matching
interfaces to those of generator, an EEPROM 6617, and presence
resistor 6619. The proximal plug outputs are carried through the
cable and the distal plug to the handle without any component
circuitry in either the cable or the distal plug. The handle
comprises the MOSFET switches 6615 that are each coupled to
rectifier circuits 6621, which are each coupled to a pair of
coupling inductors 6623, also in the handle. The rectifier circuits
6621 each comprise at least one diode and at least one capacitor.
The control circuit 6627 (e.g., ASIC) is coupled to a driver
circuit 6625 that feeds the coupling inductors 6623 and the
rectifier circuits 6621 to control the state of the MOSFET switches
6615. The driver circuit 6625 and control circuit 6627 are located
in the handle. The handle further comprises resonator 6629, diode
and capacitor circuits 6631, EEPROM 6635, and switch array 6637.
The switch array 6637 may comprise electro-mechanical devices,
transistor devices, and the like. The transistor devices may
include bipolar junction transistors (BJTs), FETs, MOSFETs, or a
combination thereof. The rectifier portion of the diode and
capacitor circuit 6631 is coupled to the HSW interface 6607 and the
secondary return terminal interface 6609 of the generator and feed
into control circuit 6627.
[0176] The application portion comprises EEPROM 6639, presence
resistor 6641, and outputs for RF and ultrasonic energy 6643, 6645,
respectively. EEPROM 6639 and presence resistor 6241 are coupled to
control circuit 6627. The system 6600 allows switching between an
RF mode and an ultrasonic mode and allows for a low cost cable
configuration.
[0177] FIG. 18 provides an illustration of a system 6900
configuration for an example circuit topology shown and described
with regard to FIGS. 13-16, including bandstop filters and a
control circuit in the handle, configured to manage RF and
ultrasonic currents output by a generator according to one aspect
of the present disclosure. The system 6900 includes bandstop
filters and a control circuit in the handle. The generator
comprises interfaces for an ultrasonic signal 6901, an interface
for an RF signal 6903, a primary return terminal interface 6905, an
HSW interface 6907, a secondary return terminal interface 6909, an
identification interface 6911, and a presence interface 6913. The
proximal plug comprises matching interfaces to those of generator,
an EEPROM 6917, and presence resistor 6919. The proximal plug
outputs are carried through the cable and distal plug without any
component circuitry in either the cable or the distal plug. The
handle comprises a pair of bandstop filters 6915, rectifier circuit
6931, EEPROM 6935, control circuit 6927, switch array 6937, and
resonator 6929. Rectifier circuit 6931 comprises at least one diode
and at least one capacitor. Control circuit 6927 is coupled to
EEPROM 6935, switch array 6937, and rectifier circuit 6931. The
switch array 6937 may comprise electro-mechanical devices,
transistor devices, and the like. The transistor devices may
include bipolar junction transistors (BJT), FETs, MOSFETs, or a
combination thereof.
[0178] The application portion comprises EEPROM 6939, presence
resistor 6941, and outputs for RF and ultrasonic energy 6943, 6945,
respectively. The pair of bandstop filters 6915 are coupled to the
outputs for RF and ultrasonic energy 6943, 6945. EEPROM 6939 and
presence resistor 6941 are coupled to control circuit 6927. The
system 6900 allows switching between an RF mode and an ultrasonic
mode and supports mixed output frequencies, which allows tissues
impedance sensing while the ultrasonic output is active. It also
provides for a low cost cable configuration.
[0179] Examples of waveforms representing energy for delivery from
a generator are illustrated in FIGS. 19-23. FIG. 19 illustrates an
example graph 600 showing first and second individual waveforms
representing an RF output signal 602 and an ultrasonic output
signal 604 superimposed on the same time and voltage scale for
comparison purposes. These output signals 602, 604 are provided at
the ENERGY output of the generator 100. Time (t) is shown along the
horizontal axis and voltage (V) is shown along the vertical axis.
The RF output signal 602 has a frequency of about 330 kHz RF and a
peak-to-peak voltage of .+-.1V. The ultrasonic output signal 604
has a frequency of about 55 kHz and a peak-to-peak voltage of
.+-.1V. It will be appreciated that the time (t) scale along the
horizontal axis and the voltage (V) scale along the vertical axis
are normalized for comparison purposes and may be different actual
implementations, or represent other electrical parameters such as
current.
[0180] FIG. 20 illustrates an example graph 610 showing the sum of
the two output signals 602, 604 shown in FIG. 19. Time (t) is shown
along the horizontal axis and voltage (V) is shown along the
vertical axis. The sum of the RF output signal 602 and the
ultrasonic output signal 604 shown in FIG. 19 produces a combined
output signal 612 having a 2V peak-to-peak voltage, which is twice
the amplitude of the original RF and ultrasonic signals shown (1V
peak-to-peak) shown in FIG. 19. An amplitude of twice the original
amplitude can cause problems with the output section of the
generator, such as distortion, saturation, clipping of the output,
or stresses on the output components. Thus, the management of a
single combined output signal 612 that has multiple treatment
components is an important aspect of the generator 500 shown in
FIG. 8. There are a variety of ways to achieve this management. In
one form, one of the two RF or ultrasonic output signals 602, 604
can be dependent on the peaks of the other output signal. In one
aspect, the RF output signal 602 may depend on the peaks of the
ultrasonic signal 604, such that the output is reduced when a peak
is anticipated. Such a function and resulting waveform is shown in
FIG. 21.
[0181] For example, FIG. 21 illustrates an example graph 620
showing a combined output signal 622 representative of a dependent
sum of the output signals 602, 604 shown in FIG. 19. Time (t) is
shown along the horizontal axis and voltage (V) is shown along the
vertical axis. As shown in FIG. 19, the RF output signal 602
component of FIG. 19 depends on the peaks of the ultrasonic output
signal 604 component of FIG. 19 such that the amplitude of the RF
output signal component of the dependent sum combined output signal
622 is reduced when an ultrasonic peak is anticipated. As shown in
the example graph 620 in FIG. 19, the peaks have been reduced from
2 to 1.5. In another form, one of the output signals is a function
of the other output signal.
[0182] For example, FIG. 22 illustrates an example graph of an
analog waveform 630 showing an output signal 632 representative of
a dependent sum of the output signals 602, 604 shown in FIG. 19.
Time (t) is shown along the horizontal axis and voltage (V) is
shown along the vertical axis. As shown in FIG. 22, the RF output
signal 602 is a function of the ultrasonic output signal 604. This
provides a hard limit on the amplitude of the output. As shown in
FIG. 22, the ultrasonic output signal 604 is extractable as a sine
wave while the RF output signal 602 has distortion but not in a way
to affect the coagulation performance of the RF output signal
602.
[0183] A variety of other techniques can be used for compressing
and/or limiting the waveforms of the output signals. It should be
noted that the integrity of the ultrasonic output signal 604 (FIG.
19) can be more important than the integrity of the RF output
signal 602 (FIG. 19) as long as the RF output signal 602 has low
frequency components for safe patient levels so as to avoid
neuro-muscular stimulation. In another form, the frequency of an RF
waveform can be changed on a continuous basis in order to manage
the peaks of the waveform. Waveform control is important as more
complex RF waveforms, such as a coagulation-type waveform 642, as
illustrated in the graph 640 shown in FIG. 23, are implemented with
the system. Again, time (t) is shown along the horizontal axis and
voltage (V) is shown along the vertical axis. The coagulation-type
waveform 642 illustrated in FIG. 23 has a crest factor of 5.8, for
example.
[0184] While various details have been set forth in the foregoing
description, it will be appreciated that the various aspects of the
serial communication protocol for medical device may be practiced
without these specific details. For example, for conciseness and
clarity selected aspects have been shown in block diagram form
rather than in detail. Some portions of the detailed descriptions
provided herein may be presented in terms of instructions that
operate on data that is stored in a computer memory. Such
descriptions and representations are used by those skilled in the
art to describe and convey the substance of their work to others
skilled in the art. In general, an algorithm refers to a
self-consistent sequence of steps leading to a desired result,
where a "step" refers to a manipulation of physical quantities
which may, though need not necessarily, take the form of electrical
or magnetic signals capable of being stored, transferred, combined,
compared, and otherwise manipulated. It is common usage to refer to
these signals as bits, values, elements, symbols, characters,
terms, numbers, or the like. These and similar terms may be
associated with the appropriate physical quantities and are merely
convenient labels applied to these quantities.
[0185] Unless specifically stated otherwise as apparent from the
foregoing discussion, it is appreciated that, throughout the
foregoing description, discussions using terms such as "processing"
or "computing" or "calculating" or "determining" or "displaying" or
the like, refer to the action and processes of a computer system,
or similar electronic computing device, that manipulates and
transforms data represented as physical (electronic) quantities
within the computer system's registers and memories into other data
similarly represented as physical quantities within the computer
system memories or registers or other such information storage,
transmission or display devices.
[0186] It is worthy to note that any reference to "one aspect," "an
aspect," "one form," or "an form" means that a particular feature,
structure, or characteristic described in connection with the
aspect is included in at least one aspect. Thus, appearances of the
phrases "in one aspect," "in an aspect," "in one form," or "in an
form" in various places throughout the specification are not
necessarily all referring to the same aspect. Furthermore, the
particular features, structures or characteristics may be combined
in any suitable manner in one or more aspects.
[0187] Some aspects may be described using the expression "coupled"
and "connected" along with their derivatives. It should be
understood that these terms are not intended as synonyms for each
other. For example, some aspects may be described using the term
"connected" to indicate that two or more elements are in direct
physical or electrical contact with each other. In another example,
some aspects may be described using the term "coupled" to indicate
that two or more elements are in direct physical or electrical
contact. The term "coupled," however, also may mean that two or
more elements are not in direct contact with each other, but yet
still co-operate or interact with each other.
[0188] It is worthy to note that any reference to "one aspect," "an
aspect," "one form," or "an form" means that a particular feature,
structure, or characteristic described in connection with the
aspect is included in at least one aspect. Thus, appearances of the
phrases "in one aspect," "in an aspect," "in one form," or "in an
form" in various places throughout the specification are not
necessarily all referring to the same aspect. Furthermore, the
particular features, structures or characteristics may be combined
in any suitable manner in one or more aspects.
[0189] Although various forms have been described herein, many
modifications, variations, substitutions, changes, and equivalents
to those forms may be implemented and will occur to those skilled
in the art. Also, where materials are disclosed for certain
components, other materials may be used. It is therefore to be
understood that the foregoing description and the appended claims
are intended to cover all such modifications and variations as
falling within the scope of the disclosed forms. The following
claims are intended to cover all such modification and
variations.
[0190] In a general sense, those skilled in the art will recognize
that the various aspects described herein which can be implemented,
individually and/or collectively, by a wide range of hardware,
software, firmware, or any combination thereof can be viewed as
being composed of various types of "electrical circuitry."
Consequently, as used herein "electrical circuitry" includes, but
is not limited to, electrical circuitry having at least one
discrete electrical circuit, electrical circuitry having at least
one integrated circuit, electrical circuitry having at least one
application specific integrated circuit, electrical circuitry
forming a general purpose computing device configured by a computer
program (e.g., a general purpose computer configured by a computer
program which at least partially carries out processes and/or
devices described herein, or a microprocessor configured by a
computer program which at least partially carries out processes
and/or devices described herein), electrical circuitry forming a
memory device (e.g., forms of random access memory), and/or
electrical circuitry forming a communications device (e.g., a
modem, communications switch, or optical-electrical equipment).
Those having skill in the art will recognize that the subject
matter described herein may be implemented in an analog or digital
fashion or some combination thereof.
[0191] The foregoing detailed description has set forth various
forms of the devices and/or processes via the use of block
diagrams, flowcharts, and/or examples. Insofar as such block
diagrams, flowcharts, and/or examples contain one or more functions
and/or operations, it will be understood by those within the art
that each function and/or operation within such block diagrams,
flowcharts, or examples can be implemented, individually and/or
collectively, by a wide range of hardware, software, firmware, or
virtually any combination thereof. In one form, several portions of
the subject matter described herein may be implemented via
Application Specific Integrated Circuits (ASICs), Field
Programmable Gate Arrays (FPGAs), digital signal processors (DSPs),
or other integrated formats. However, those skilled in the art will
recognize that some aspects of the forms disclosed herein, in whole
or in part, can be equivalently implemented in integrated circuits,
as one or more computer programs running on one or more computers
(e.g., as one or more programs running on one or more computer
systems), as one or more programs running on one or more processors
(e.g., as one or more programs running on one or more
microprocessors), as firmware, or as virtually any combination
thereof, and that designing the circuitry and/or writing the code
for the software and or firmware would be well within the skill of
one of skill in the art in light of this disclosure. In addition,
those skilled in the art will appreciate that the mechanisms of the
subject matter described herein are capable of being distributed as
a program product in a variety of forms, and that an illustrative
form of the subject matter described herein applies regardless of
the particular type of signal bearing medium used to actually carry
out the distribution. Examples of a signal bearing medium include,
but are not limited to, the following: a recordable type medium
such as a floppy disk, a hard disk drive, a Compact Disc (CD), a
Digital Video Disk (DVD), a digital tape, a computer memory, etc.;
and a transmission type medium such as a digital and/or an analog
communication medium (e.g., a fiber optic cable, a waveguide, a
wired communications link, a wireless communication link (e.g.,
transmitter, receiver, transmission logic, reception logic, etc.),
etc.).
[0192] All of the above-mentioned U.S. patents, U.S. patent
application publications, U.S. patent applications, foreign
patents, foreign patent applications, non-patent publications
referred to in this specification and/or listed in any Application
Data Sheet, or any other disclosure material are incorporated
herein by reference, to the extent not inconsistent herewith. As
such, and to the extent necessary, the disclosure as explicitly set
forth herein supersedes any conflicting material incorporated
herein by reference. Any material, or portion thereof, that is said
to be incorporated by reference herein, but which conflicts with
existing definitions, statements, or other disclosure material set
forth herein will only be incorporated to the extent that no
conflict arises between that incorporated material and the existing
disclosure material.
[0193] One skilled in the art will recognize that the herein
described components (e.g., operations), devices, objects, and the
discussion accompanying them are used as examples for the sake of
conceptual clarity and that various configuration modifications are
contemplated. Consequently, as used herein, the specific exemplars
set forth and the accompanying discussion are intended to be
representative of their more general classes. In general, use of
any specific exemplar is intended to be representative of its
class, and the non-inclusion of specific components (e.g.,
operations), devices, and objects should not be taken limiting.
[0194] With respect to the use of substantially any plural and/or
singular terms herein, those having skill in the art can translate
from the plural to the singular and/or from the singular to the
plural as is appropriate to the context and/or application. The
various singular/plural permutations are not expressly set forth
herein for sake of clarity.
[0195] The herein described subject matter sometimes illustrates
different components contained within, or connected with, different
other components. It is to be understood that such depicted
architectures are merely example, and that in fact many other
architectures may be implemented which achieve the same
functionality. In a conceptual sense, any arrangement of components
to achieve the same functionality is effectively "associated" such
that the desired functionality is achieved. Hence, any two
components herein combined to achieve a particular functionality
can be seen as "associated with" each other such that the desired
functionality is achieved, irrespective of architectures or
intermedial components. Likewise, any two components so associated
can also be viewed as being "operably connected," or "operably
coupled," to each other to achieve the desired functionality, and
any two components capable of being so associated can also be
viewed as being "operably couplable," to each other to achieve the
desired functionality. Specific examples of operably couplable
include but are not limited to physically mateable and/or
physically interacting components, and/or wirelessly interactable,
and/or wirelessly interacting components, and/or logically
interacting, and/or logically interactable components.
[0196] In some instances, one or more components may be referred to
herein as "configured to," "configurable to," "operable/operative
to," "adapted/adaptable," "able to," "conformable/conformed to,"
etc. Those skilled in the art will recognize that "configured to"
can generally encompass active-state components and/or
inactive-state components and/or standby-state components, unless
context requires otherwise.
[0197] While particular aspects of the present subject matter
described herein have been shown and described, it will be apparent
to those skilled in the art that, based upon the teachings herein,
changes and modifications may be made without departing from the
subject matter described herein and its broader aspects and,
therefore, the appended claims are to encompass within their scope
all such changes and modifications as are within the scope of the
subject matter described herein. It will be understood by those
within the art that, in general, terms used herein, and especially
in the appended claims (e.g., bodies of the appended claims) are
generally intended as "open" terms (e.g., the term "including"
should be interpreted as "including but not limited to," the term
"having" should be interpreted as "having at least," the term
"includes" should be interpreted as "includes but is not limited
to," etc.). It will be further understood by those within the art
that if a specific number of an introduced claim recitation is
intended, such an intent will be explicitly recited in the claim,
and in the absence of such recitation no such intent is present.
For example, as an aid to understanding, the following appended
claims may contain usage of the introductory phrases "at least one"
and "one or more" to introduce claim recitations. However, the use
of such phrases should not be construed to imply that the
introduction of a claim recitation by the indefinite articles "a"
or "an" limits any particular claim containing such introduced
claim recitation to claims containing only one such recitation,
even when the same claim includes the introductory phrases "one or
more" or "at least one" and indefinite articles such as "a" or "an"
(e.g., "a" and/or "an" should typically be interpreted to mean "at
least one" or "one or more"); the same holds true for the use of
definite articles used to introduce claim recitations.
[0198] In addition, even if a specific number of an introduced
claim recitation is explicitly recited, those skilled in the art
will recognize that such recitation should typically be interpreted
to mean at least the recited number (e.g., the bare recitation of
"two recitations," without other modifiers, typically means at
least two recitations, or two or more recitations). Furthermore, in
those instances where a convention analogous to "at least one of A,
B, and C, etc." is used, in general such a construction is intended
in the sense one having skill in the art would understand the
convention (e.g., "a system having at least one of A, B, and C"
would include but not be limited to systems that have A alone, B
alone, C alone, A and B together, A and C together, B and C
together, and/or A, B, and C together, etc.). In those instances
where a convention analogous to "at least one of A, B, or C, etc."
is used, in general such a construction is intended in the sense
one having skill in the art would understand the convention (e.g.,
"a system having at least one of A, B, or C" would include but not
be limited to systems that have A alone, B alone, C alone, A and B
together, A and C together, B and C together, and/or A, B, and C
together, etc.). It will be further understood by those within the
art that typically a disjunctive word and/or phrase presenting two
or more alternative terms, whether in the description, claims, or
drawings, should be understood to contemplate the possibilities of
including one of the terms, either of the terms, or both terms
unless context dictates otherwise. For example, the phrase "A or B"
will be typically understood to include the possibilities of "A" or
"B" or "A and B."
[0199] With respect to the appended claims, those skilled in the
art will appreciate that recited operations therein may generally
be performed in any order. Also, although various operational flows
are presented in a sequence(s), it should be understood that the
various operations may be performed in other orders than those
which are illustrated, or may be performed concurrently. Examples
of such alternate orderings may include overlapping, interleaved,
interrupted, reordered, incremental, preparatory, supplemental,
simultaneous, reverse, or other variant orderings, unless context
dictates otherwise. Furthermore, terms like "responsive to,"
"related to," or other past-tense adjectives are generally not
intended to exclude such variants, unless context dictates
otherwise.
[0200] In certain cases, use of a system or method may occur in a
territory even if components are located outside the territory. For
example, in a distributed computing context, use of a distributed
computing system may occur in a territory even though parts of the
system may be located outside of the territory (e.g., relay,
server, processor, signal-bearing medium, transmitting computer,
receiving computer, etc. located outside the territory).
[0201] A sale of a system or method may likewise occur in a
territory even if components of the system or method are located
and/or used outside the territory. Further, implementation of at
least part of a system for performing a method in one territory
does not preclude use of the system in another territory.
[0202] Although various forms have been described herein, many
modifications, variations, substitutions, changes, and equivalents
to those forms may be implemented and will occur to those skilled
in the art. Also, where materials are disclosed for certain
components, other materials may be used. It is therefore to be
understood that the foregoing description and the appended claims
are intended to cover all such modifications and variations as
falling within the scope of the disclosed forms. The following
claims are intended to cover all such modification and
variations.
[0203] In summary, numerous benefits have been described which
result from employing the concepts described herein. The foregoing
description of the one or more forms has been presented for
purposes of illustration and description. It is not intended to be
exhaustive or limiting to the precise form disclosed. Modifications
or variations are possible in light of the above teachings. The one
or more forms were chosen and described in order to illustrate
principles and practical application to thereby enable one of
ordinary skill in the art to utilize the various forms and with
various modifications as are suited to the particular use
contemplated. It is intended that the claims submitted herewith
define the overall scope.
[0204] While several forms have been illustrated and described, it
is not the intention of the applicant to restrict or limit the
scope of the appended claims to such detail. Numerous variations,
changes, and substitutions will occur to those skilled in the art
without departing from the scope of the present disclosure.
Moreover, the structure of each element associated with the
described forms can be alternatively described as a means for
providing the function performed by the element. Accordingly, it is
intended that the described forms be limited only by the scope of
the appended claims.
[0205] Reference throughout the specification to "various forms,"
"some forms," "one form," or "an form" means that a particular
feature, structure, or characteristic described in connection with
the form is included in at least one form. Thus, appearances of the
phrases "in various forms," "in some forms," "in one form," or "in
an form" in places throughout the specification are not necessarily
all referring to the same form. Furthermore, the particular
features, structures, or characteristics may be combined in any
suitable manner in one or more forms. Thus, the particular
features, structures, or characteristics illustrated or described
in connection with one form may be combined, in whole or in part,
with the features structures, or characteristics of one or more
other forms without limitation.
[0206] Various aspects of the subject matter described herein are
set out in the following numbered clauses:
[0207] 1. A system for managing RF and ultrasonic signals output by
a generator, comprising: a surgical instrument comprising an RF
energy output, an ultrasonic energy output, and a circuit
configured to receive a combined Radio Frequency (RF) and
ultrasonic signal from the generator; wherein the circuit is
configured to filter frequency content of the combined signal and
is configured to provide a first filtered signal to the RF energy
output and a second filtered signal to the ultrasonic energy
output.
[0208] 2. The system of clause 1, wherein the circuit comprises a
resonator.
[0209] 3. The system of clause 1 or 2, wherein the circuit
comprises a high frequency band-stop filter.
[0210] 4. The system of any one of clauses 1-3, wherein the high
frequency band-stop filter comprises a first LC filter circuit and
a second LC filter circuit.
[0211] 5. The system of any one of clauses 1-4, wherein the
combined signal comprises a 350 kHz component.
[0212] 6. The system of any one of clauses 1-5, wherein the
combined signal comprises a 55 kHz component.
[0213] 7. The system of any one of clauses 1-6, wherein the
surgical instrument is configured to apply a therapy from the RF
energy output and the ultrasonic energy output simultaneously.
[0214] 8. A system for managing RF and ultrasonic signals output by
a generator, comprising: a surgical instrument comprising an RF
energy output, an ultrasonic energy output, and a circuit
configured to receive a combined Radio Frequency (RF) and
ultrasonic signal from the generator; wherein the circuit is
configured to switch between the RF energy output and the
ultrasonic energy output according to the combined signal received
from the generator.
[0215] 9. The system of clause 8, wherein the circuit comprises two
pairs of MOSFET switches.
[0216] 10. The system of clause 9, wherein each of the two pairs of
MOSFET switches is connected source to source.
[0217] 11. The system of clause 9 or 10, further comprising a first
coupled inductor and a second coupled inductor.
[0218] 12. The system of clause 11, wherein the gate of each MOSFET
of a first pair of MOSFET switches is coupled together and is
coupled to the first coupled inductor.
[0219] 13. The system of clause 11 or 12, wherein the gate of each
MOSFET of a second pair of MOSFET switches is coupled together and
is coupled to the second coupled inductor.
[0220] 14. The system of any one of clauses 11-13, further
comprising a first capacitor and a second capacitor, wherein the
first capacitor is coupled to the primary side of the first coupled
inductor and the second capacitor is coupled to the primary side of
the second coupled inductor.
[0221] 15. The system of any one of clauses 9-14, further
comprising an ASIC, a first pulse transformer, and a second pulse
transformer, wherein the ASIC is coupled to the first and second
pulse transformers, and wherein the first pulse transformer is
coupled to a first pair of the two pairs of MOSFET switches and the
second pulse transformer is coupled to a second pair of the two
pairs of MOSFET switches.
[0222] 16. The system of clause 15, wherein each of the two pairs
of MOSFET switches are connected source to source.
[0223] 17. The system of clause 16, wherein the gate of each MOSFET
of the first pair of MOSFET switches is coupled together and is
coupled to the first pulse transformer.
[0224] 18. The system of clause 16 or 17, wherein the gate of each
MOSFET of a second pair of MOSFET switches is coupled together and
is coupled to the second pulse transformer.
[0225] 19. The system of clause 18, wherein the circuit comprises a
first switching element coupled to the RF energy output and a
second switching element coupled to the ultrasonic energy
output.
[0226] 20. The system of clause 19, wherein the first switching
element and the second switching element are each electromechanical
relays.
[0227] 21. The system of clause 19 or 20, wherein the first
switching element and the second switching element are coupled to
an ASIC.
[0228] 22. The system of any one of clauses 19-21, further
comprising a switch mechanism to actuate the first switching
element and the second switching element.
[0229] 23. The system of clause 22, wherein the switch mechanism is
a mechanical rocker style switch mechanism.
[0230] 24. A system for managing RF and ultrasonic signals output
by a generator, comprising: a surgical instrument comprising an RF
energy output, an ultrasonic energy output, and a circuit
configured to receive a combined Radio Frequency (RF) and
ultrasonic signal from the generator; wherein the circuit
comprises: a filter circuit configured to filter frequency content
of the combined signal; and a switching element configured to
switch between an on-state and an off-state to one of the RF energy
output or the ultrasonic energy output according to the combined
signal received from the generator.
[0231] 25. The system of clause 24, wherein the filter circuit is
coupled to the ultrasonic energy output and the switching element
is coupled to the RF energy output.
[0232] 26. A system comprising a generator and a surgical
instrument, wherein the generator is configured to deliver a
combined signal comprising a radio frequency (RF) component and an
ultrasonic component to the surgical instrument; and the surgical
instrument comprises: an RF energy output, an ultrasonic energy
output, a circuit configured to steer the RF component to the RF
energy output and steer the ultrasonic component to the ultrasonic
energy output, wherein the generator is configured to adjust a
frequency of the RF component based on a characterization of a
circuit component of the circuit.
[0233] 27. The system of clause 26, wherein the circuit component
comprises a band-stop filter.
[0234] 28. The system of clause 26 or 27, wherein the circuit
further comprises a variable component.
[0235] 29. The system of any one of clauses 26-28, wherein the
characterization of the circuit component comprises sending a ping
signal to the circuit component.
[0236] 30. The system of any one of clauses 26-29, wherein a result
of the characterization is stored in the surgical instrument.
[0237] 31. The system of any one of clauses 26-30, wherein the
characterization is performed when the surgical instrument is
manufactured.
[0238] 32. The system of any one of clauses 26-31, wherein the
characterization is performed when the surgical instrument is
connected to the generator.
[0239] 33. The system of any one of clauses 26-32, wherein the
characterization is performed after the surgical instrument
delivers energy to a tissue.
[0240] 34. The system of any one of clauses 26-33, wherein the
characterization is performed while the surgical instrument is
delivering energy to a tissue.
[0241] 35. The system of any one of clauses 26-34, wherein the
characterization is performed periodically.
[0242] 36. A method for providing a combined signal comprising a
radio frequency (RF) component and an ultrasonic component by a
generator to a surgical instrument, the surgical instrument
comprising an RF energy output, an ultrasonic energy output and a
circuit, the method comprising: performing characterization on a
circuit component of the circuit; adjusting a frequency of the RF
component based on a result of the characterization; delivering, by
the generator, the combined signal to the surgical instrument;
steering, by the circuit, the RF component to the RF energy output;
and steering, by the circuit, the ultrasonic component to the
ultrasonic energy output.
[0243] 37. The method of clause 36, wherein the circuit component
comprises a band-stop filter.
[0244] 38. The method of clause 36 or 37, wherein the circuit
further comprises a variable component.
[0245] 39. The method of any one of clauses 36-38, wherein
performing characterization on the circuit component comprises
sending a ping signal to the circuit component.
[0246] 40. The method of any one of clauses 36-39, further
comprising storing a result of the characterization in the surgical
instrument.
[0247] 41. The method of any one of clauses 36-40, wherein the
characterization is performed when the surgical instrument is
manufactured.
[0248] 42. The method of any one of clauses 36-41, wherein the
characterization is performed when the surgical instrument is
connected to the generator.
[0249] 43. The method of any one of clauses 36-42, wherein the
characterization is performed after the surgical instrument
delivers energy to a tissue.
[0250] 44. The method of any one of clauses 36-43, wherein the
characterization is performed while the surgical instrument is
delivering energy to a tissue.
[0251] 45. A generator for providing a combined signal comprising a
radio frequency (RF) component and an ultrasonic component to a
surgical instrument, the generator being configured to: perform
characterization on a circuit component of a circuit of the
surgical instrument for steering the RF component to an RF output
and steering the ultrasonic component to an ultrasonic output;
adjust a frequency of the RF component based on a result of the
characterization; and deliver the combined signal to the surgical
instrument.
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