Patent Description:
Ultrasonic surgical instruments utilize ultrasonic energy, i.e., ultrasonic vibrations, to treat tissue. More specifically, ultrasonic surgical instruments utilize mechanical vibration energy transmitted at ultrasonic frequencies to seal and/or cut tissue.

Typically, an ultrasonic surgical instrument is configured to transmit ultrasonic energy produced by a generator and transducer assembly along a waveguide to an end effector that is spaced-apart from the generator and transducer assembly. The end effector, in turn, is configured to transmit the ultrasonic energy to tissue to treat the tissue, e.g., to seal and/or cut tissue. With respect to cordless ultrasonic instruments, for example, a portable power source, e.g., a battery, and the generator and transducer assembly are mounted on the handheld instrument itself, while the waveguide interconnects the generator and transducer assembly and the end effector. Corded ultrasonic instruments operate in similar fashion except that, rather than having the generator and power source mounted on the handheld instrument itself, the handheld instrument is configured to connect to a standalone power supply and/or generator via a corded connection.

<CIT> discloses an ultrasonic surgical instrument.

As used herein, the term "distal" refers to the portion that is being described which is further from a user, while the term "proximal" refers to the portion that is being described which is closer to a user. Further, to the extent consistent any or all of the aspects detailed herein may be used in conjunction with any or all of the other aspects detailed herein.

The invention provides a system according to claim <NUM>. Further embodiments of the invention are provided in the dependent claims. In accordance with aspects of the present disclosure, an ultrasonic surgical system is provided including an ultrasonic generator configured to output a drive signal, an ultrasonic transducer coupled to the ultrasonic generator and configured to receive the drive signal and output mechanical motion in response thereto, a waveguide coupled to the ultrasonic transducer and configured to transmit the mechanical motion therealong, a blade disposed at a distal end portion of the waveguide, a sensor, and a controller. The blade is configured to oscillate in response to receipt of the mechanical motion from the waveguide. The blade defines a displacement when oscillating. The sensor is configured to sense a property indicative of tension on tissue. The controller is configured to adjust the drive signal to thereby adjust the displacement based upon the sensed property.

In an aspect of the present disclosure, the sensor is configured to sense a force on the waveguide. Alternatively or additionally, the sensor is configured to sense an impedance of the ultrasonic transducer.

In another aspect of the present disclosure, if the sensed property indicates tension on tissue is increased above a threshold, the controller is configured to adjust the drive signal to increase the displacement of the blade. Alternatively or additionally, if the sensed property indicates tension on tissue is decreased below a threshold, the controller is configured to adjust the drive signal to decrease the displacement of the blade.

In another aspect of the present disclosure, an activation switch is operably coupled to the ultrasonic generator and selectively activatable in a "CUT" mode and a "SEAL" mode.

In still another aspect of the present disclosure, when the activation switch is activated in the "SEAL" mode, if the sensed property indicates tension on tissue is increased, the controller is configured to adjust the drive signal to decrease the displacement of the blade.

In yet another aspect of the present disclosure, when the activation switch is activated in the "CUT" mode, if the sensed property indicates tension on tissue is increased, the controller is configured to adjust the drive signal to increase the displacement of the blade.

In still yet another aspect of the present disclosure, a handle assembly supports the ultrasonic transducer thereon and the waveguide extends distally from the handle assembly. In such aspects, the handle assembly may further support the ultrasonic generator and a battery assembly, configured to power the ultrasonic generator to produce the drive signal, thereon.

In another aspect of the present disclosure, the controller is configured to control an amount of power delivered from the battery assembly to the ultrasonic generator to thereby adjust the drive signal.

A method of treating tissue provided in accordance with aspects of the present disclosure includes applying a drive signal to an ultrasonic transducer to oscillate an ultrasonic blade adjacent tissue, sensing a property indicative of a tension on the tissue, and adjusting the drive signal applied to the ultrasonic transducer based upon the sensed property to thereby adjust a displacement of the blade.

In an aspect of the present disclosure, sensing the property includes sensing a force on a waveguide coupled to the ultrasonic blade. Alternatively or additionally, sensing the property includes sensing an impedance of the ultrasonic transducer.

In another aspect of the present disclosure, if the sensed property indicates tension on tissue is increased above a threshold, the drive signal is adjusted to increase the displacement of the blade. Alternatively or additionally, if the sensed property indicates tension on tissue is decreased below a threshold, the drive signal is adjusted to decrease the displacement of the blade.

In still another aspect of the present disclosure, the method further includes determining whether a "CUT" mode of operation or a "SEAL" mode of operation is selected and adjusting the drive signal applied to the ultrasonic transducer based upon the sensed property and the selected mode of operation to thereby adjust the displacement.

In yet another aspect of the present disclosure, in the "SEAL" mode of operation, if the sensed property indicates tension on tissue is increased, the drive signal is adjusted to decrease the displacement of the blade. Additionally or alternatively, in the "CUT" mode, if the sensed property indicates tension on tissue is increased, the drive signal is adjusted to increase the displacement of the blade.

In still yet another aspect of the present disclosure, adjusting the drive signal includes adjusting an amount of power delivered from a power source to an ultrasonic generator configured to output the drive signal.

The above and other aspects and features of the present disclosure will become more apparent in view of the following detailed description when taken in conjunction with the accompanying drawings wherein like reference numerals identify similar or identical elements and:.

Referring generally to <FIG>, the present disclosure provides ultrasonic surgical instruments and methods for sealing and/or cutting tissue. More specifically, the ultrasonic surgical instruments and methods of the present disclosure are configured to adjust the ultrasonic energy output, e.g., the displacement of the ultrasonic blade, based upon the tension on tissue, to facilitate sealing of tissue or cutting of tissue. An ultrasonic surgical instrument exemplifying the aspects and features of the present disclosure is shown generally identified by reference numeral <NUM>. For the purposes herein, ultrasonic surgical instrument <NUM> is generally described. Aspects and features of ultrasonic surgical instrument <NUM> not germane to the understanding of the present disclosure are omitted to avoid obscuring such aspects and features of the present disclosure in unnecessary detail. Further, the aspects and features of the present disclosure are equally applicable for use with any other suitable ultrasonic surgical instrument.

Ultrasonic surgical instrument <NUM> generally includes a handle assembly <NUM>, an elongated body <NUM> extending distally from handle assembly <NUM>, and a tool assembly <NUM> disposed at a distal end portion of elongated body <NUM> and including a blade <NUM> and a clamp member <NUM>. Handle assembly <NUM> supports a battery assembly <NUM> and an ultrasonic transducer and generator assembly ("TAG") <NUM>, and includes a rotatable nozzle <NUM>, an activation button <NUM>, and a clamp trigger <NUM>. Battery assembly <NUM> and TAG <NUM> are each releasably secured to handle assembly <NUM>, and are removable therefrom to facilitate disposal of the entire device, with the exception of battery assembly <NUM> and TAG <NUM>. However, it is contemplated that any or all of the components of ultrasonic surgical instrument <NUM> be configured as disposable single-use components or sterilizable multi-use components.

With reference to <FIG>, elongated body <NUM> of ultrasonic surgical instrument <NUM> includes a waveguide <NUM> which extends distally from handle assembly <NUM> to tool assembly <NUM>. A distal end portion of waveguide <NUM> defines blade <NUM> of tool assembly <NUM>. A proximal end portion of waveguide <NUM> is configured to engage TAG <NUM> (<FIG> and <FIG>), as detailed below. An isolation tube <NUM> is positioned about waveguide <NUM> to prevent the transfer of ultrasonic energy from waveguide <NUM> to an inner support tube <NUM>. One or more seal rings <NUM> is disposed about waveguide <NUM> to maintain spacing between waveguide <NUM> and isolation tube <NUM> while inhibiting fluid passage therebetween. Seal ring(s) <NUM> may be disposed at a node point(s) along waveguide <NUM> or in another suitable position(s). Waveguide <NUM> and inner support tube <NUM> are rotatably coupled to rotatable nozzle <NUM> (<FIG>) such that rotation of nozzle <NUM> (<FIG>) effects corresponding rotation of inner support tube <NUM> and waveguide <NUM>. An actuator tube <NUM> which, as detailed below, is coupled to inner support tube <NUM>, is similarly rotated upon rotation of nozzle <NUM> (<FIG>).

Inner support tube <NUM> is positioned about isolation tube <NUM> and includes a distal end portion having a pair of spaced clamp support arms <NUM>. Spaced clamp support arms <NUM> are configured to pivotally engage pivot members <NUM> (only one of which is visible in <FIG>) formed on clamp jaw <NUM> of tool assembly <NUM> to enable pivoting of clamp jaw <NUM> between an open position, wherein clamp jaw <NUM> is spaced from blade <NUM>, and a closed position, wherein clamp jaw <NUM> is approximated relative to blade <NUM>. Clamp jaw <NUM> is moved between the open and closed positions in response to actuation of clamp trigger <NUM> (<FIG>).

Outer actuator tube <NUM> is slidably supported about inner support tube <NUM> and is operably coupled to clamp jaw <NUM> such that, as actuator tube <NUM> is slid about inner support tube <NUM> between an advanced position and a retracted position, clamp jaw <NUM> is pivoted from the open position to the closed position. A proximal end of outer actuator tube <NUM> is operably coupled with rotatable nozzle <NUM> (<FIG>) such that outer actuator tube <NUM> is rotatably secured to but slidable relative to rotatable nozzle <NUM> (<FIG>). The proximal end of outer actuator tube <NUM> is also operably coupled with a drive mechanism <NUM>.

Referring also to <FIG>, drive mechanism <NUM> is supported within and configured for linear movement relative to handle assembly <NUM>. Handle assembly <NUM> also includes the aforementioned clamp trigger <NUM>, which is operably coupled with drive mechanism <NUM> such that, in use, when clamping trigger <NUM> is compressed towards battery assembly <NUM>, drive mechanism <NUM> is moved to thereby move outer actuator tube <NUM> from the advanced position to the retracted position to pivot clamp jaw <NUM> from the open position to the closed position in relation to blade <NUM>. Drive mechanism <NUM> is further configured to limit the application of clamping force to tissue grasped between clamp jaw <NUM> and blade <NUM>. A spring (not explicitly shown) may be provided to bias clamping trigger <NUM> towards the initial position and, thus, clamp jaw <NUM> towards the open position.

Activation button <NUM> is supported on handle assembly <NUM>. When activation button <NUM> is activated in an appropriate manner, an underlying switch assembly <NUM> is activated to effect communication between battery assembly <NUM> and TAG <NUM>. As detailed below, switch assembly <NUM> may be configured as a two operational mode switch assembly <NUM> enabling activation from an "OFF" condition to either a "CUT" mode of operation or a "SEAL" mode of operation, depending upon the manner in which activation button <NUM> is activated (see <FIG>). Alternatively, as also detailed below, a switch assembly <NUM> may be provided that enables activation from an "OFF" condition to an "ON" condition in response to appropriate activation of activation button <NUM> (see <FIG>) or from an "OFF" condition to either a "LOW" power mode of operation or a "HIGH" power mode of operation.

Continuing with reference to <FIG> and <FIG>, battery assembly <NUM> is connected to a lower end of handle assembly <NUM> to define a fixed handgrip portion of handle assembly <NUM> and includes an outer housing <NUM> that houses one or more battery cells <NUM> and a microcontroller <NUM> including a processor and a memory (see <FIG>). A series of contacts (not explicitly shown) disposed on outer housing <NUM> enable communication of power and/or control signals between the internal components of battery assembly <NUM>, switch assembly <NUM> (<FIG>), and TAG <NUM>, although contactless communication therebetween is also contemplated.

With additional reference to <FIG>, TAG <NUM> includes a generator <NUM> and an ultrasonic transducer <NUM>. Generator <NUM> includes an outer housing <NUM> that houses the internal operating components thereof, e.g., drive signal generating circuitry, a microcontroller, and a memory (not explicitly shown). TAG <NUM> further includes one or more support members <NUM> extending from outer housing <NUM> of generator <NUM> that define one or more cradles for rotatably supporting ultrasonic transducer <NUM>. Ultrasonic transducer <NUM> includes a piezoelectric stack <NUM> and a forwardly extending horn <NUM>. Horn <NUM> is configured to threadably engage the proximal end of waveguide <NUM> (<FIG>), although other suitable engagement mechanisms are also contemplated. A series of contacts <NUM> associated with TAG <NUM> enable communication of power and/or control signals between TAG <NUM>, battery assembly <NUM>, and switch assembly <NUM> (<FIG>), although contactless communication therebetween is also contemplated.

In general, in use, when battery assembly <NUM> and TAG <NUM> are attached to handle assembly <NUM> and waveguide <NUM> and ultrasonic surgical instrument <NUM> is activated, e.g., upon activation of activation button <NUM>, switch assembly <NUM> (<FIG>) signals battery cells <NUM> (<FIG>) to provide power to generator <NUM> of TAG <NUM> which, in turn, uses this power to provide a drive signal to ultrasonic transducer <NUM> of TAG <NUM>. Ultrasonic transducer <NUM>, in turn, converts the drive signal into high frequency mechanical motion. This high frequency mechanical motion produced by ultrasonic transducer <NUM> is transmitted to blade <NUM> via waveguide <NUM> such that blade <NUM> oscillates within the ultrasonic frequency range. In this manner, blade <NUM> may be utilized to treat, e.g., seal and/or cut, tissue adjacent to blade <NUM> or clamped between blade <NUM> and clamp jaw <NUM>.

Referring to <FIG>, the power provided from battery cells <NUM> to generator <NUM> effects the drive signal provided from generator <NUM> to ultrasonic transducer <NUM> which, in turn, effects the mechanical motion produced by ultrasonic transducer <NUM> and, thus, the displacement of blade <NUM> as blade <NUM> oscillates within the ultrasonic frequency range. As such, the power provided from battery cells <NUM> to generator <NUM> may be varied to vary the drive signal provided from generator <NUM> to ultrasonic transducer <NUM>, thereby varying the displacement of blade <NUM>, although other suitable controls for varying the drive signal and, thus, the displacement of blade <NUM> are also contemplated.

Different displacements of blade <NUM> affect tissue in different manners. For example, a greater displacement of blade <NUM> results in relatively faster tissue cutting and relatively less tissue sealing, while a smaller displacement of blade <NUM> results in relatively less tissue cutting and relatively better tissue sealing. Accordingly, where tissue cutting is desired, a greater displacement of blade <NUM> is utilized. Where tissue sealing is desired, a lesser displacement of blade <NUM> is utilized.

Differences in tension on tissue, e.g., tension applied by blade <NUM> and/or clamp jaw <NUM> (<FIG> and <FIG>), also result in different tissue effects. For example, applying ultrasonic energy from blade <NUM> to tissue under greater tension results in relatively faster tissue cutting and relatively less tissue sealing, while applying ultrasonic energy from blade <NUM> to tissue under less tension results in relatively less tissue cutting and relatively better tissue sealing.

Since both displacement of blade <NUM> and tension on tissue effect whether relatively faster tissue cutting is achieved or relatively better tissue sealing is achieved, the displacement of blade <NUM> can be varied based upon the tension on tissue to achieve a desired result, e.g., faster tissue cutting or better tissue sealing. To this end, ultrasonic surgical instrument <NUM> is provided with one or more sensors <NUM> (<FIG>) configured to sense a force that correlates to a relative amount of tension on tissue. Sensor <NUM>, in turn, is coupled to the microcontroller (not shown) of generator <NUM> and/or microcontroller <NUM> of battery assembly <NUM> to enable the drive signal provided from generator <NUM> to ultrasonic transducer <NUM> to be adjusted based upon whether or not, or the extent to which, there is tension on tissue, as detailed below.

Sensor <NUM>, more specifically, operates to sense, directly or indirectly, a relative amount of force acting on blade <NUM>, which is indicative of the tension on tissue, e.g., whether blade <NUM> is applying greater force to tissue such that tissue is relatively more tensioned or whether blade <NUM> is applying less force to tissue such that tissue is relatively less tensioned. Sensor <NUM> may take various forms and/or may be disposed at various positions on ultrasonic surgical instrument <NUM> (<FIG>). Exemplary sensors <NUM> and positions of sensor <NUM> on ultrasonic surgical instrument <NUM> (<FIG>) are detailed below; however, any suitable sensor <NUM> in any suitable position may be utilized in accordance with the present disclosure.

Sensor <NUM> may be configured as a strain gauge or other suitable progressive sensor configured to sense a relative degree of force across a range. Alternatively, sensor <NUM> may be configured as a contact (ON/OFF) sensor or other suitable sensor configured to sense whether a force exceeds a threshold force.

In accordance with the present invention, In with reference to <FIG> and <FIG>, sensor <NUM> is disposed at location "L1" at the junction between the fixed handle portion of handle assembly <NUM> and the body portion of handle assembly <NUM>, since force applied by a user to handle assembly <NUM> at "L1" to urge blade <NUM> into tissue to tension tissue is indicative of the tension on tissue.

Referring to <FIG> and <FIG>, sensor <NUM>, in examples, may be disposed at location "L2" or "L3" on waveguide <NUM>, since force applied by blade <NUM> to tissue will result in a torque applied to waveguide <NUM> that is indicative of the tension on tissue. Locations "L2" and "L3" may be at nodes of waveguide <NUM>, e.g., adjacent to the one or more seal rings <NUM> disposed about waveguide <NUM>, or at other suitable positions along waveguide <NUM>. At locations "L2" and "L3" on waveguide <NUM>, sensor <NUM> may be configured as a strain gauge printed directly onto waveguide <NUM> or may be any other suitable sensor coupled to waveguide <NUM> in any other suitable manner.

Continuing with reference to <FIG> and <FIG>, in embodiments, sensor <NUM> may be disposed at location "L4" on the interior of isolation tube <NUM>, since force applied by blade <NUM> to tissue will result in a torque applied to waveguide <NUM> which, in turn, will result in a force on isolation tube <NUM> (from direct contact with waveguide <NUM> or indirectly via contact of component(s) therebetween) that is indicative of the tension on tissue. To this end, waveguide <NUM> may include an outwardly-extending protrusion (not explicitly shown) and/or sensor <NUM> may protrude inwardly from isolation tube <NUM> to facilitate contact between waveguide <NUM> and sensor <NUM>. Alternatively, sensor <NUM> may be positioned adjacent one or more of the seal rings <NUM> disposed about waveguide <NUM> between waveguide <NUM> and isolation tube <NUM>. Instead of being disposed at location "L4," sensor <NUM> may alternatively be disposed at any suitable position on isolation tube <NUM>.

Turning to <FIG>, sensor <NUM> may be disposed at location "L5," on horn <NUM> of transducer <NUM> of TAG <NUM>. Similarly as with waveguide <NUM> (<FIG>), the force applied by blade <NUM> to tissue will result in a torque applied to horn <NUM> that is indicative of the tension on tissue.

In examples, sensor <NUM> is disposed at location "L6" and is configured as an impedance sensor configured to sense the impedance of transducer <NUM>. With a plurality of readings of the impedance of transducer <NUM> from sensor <NUM> over time, the resultant impedance curve can be analyzed to determine whether blade <NUM> is putting tension (or relatively more tension) on tissue or if blade <NUM> is not putting tension (or relatively less tension) on tissue, thus indicating the tension on tissue. More specifically, if the change in impedance over time is above a threshold, sensor <NUM> may indicate that there is tension (or relatively more tension) on tissue. On the other hand, if the change in impedance is below the threshold, sensor <NUM> may indicate that there is no tension (or relatively less tension) on tissue. Other suitable impedance to tissue tension correlations are also contemplated. Other suitable sensors configured to determine tension on tissue based upon electrical characteristics of transducer <NUM>, battery assembly <NUM>, and/or generator <NUM> are also contemplated.

Referring to <FIG>, as detailed above, sensor <NUM> is coupled to the microcontroller (not shown) of generator <NUM> and/or microcontroller <NUM> of battery assembly <NUM> to enable the drive signal provided from generator <NUM> to ultrasonic transducer <NUM> to be adjusted, to thereby adjust the displacement of blade <NUM>. More specifically, displacement of blade <NUM> is adjusted, e.g., increased, decreased, or maintained, based upon whether tension on tissue (or tension on tissue above a threshold) is detected, as indicated by sensor <NUM>, and based upon the operating mode of ultrasonic surgical instrument <NUM>, as indicated by switch assembly <NUM>, to facilitate treatment of tissue in the manner desired.

Activation button <NUM> of handle assembly <NUM> (see <FIG>), as noted above, is selectively activatable by a user in a first activated position or a second activated position to activate underlying switch assembly <NUM> in a "CUT" mode of operation or a "SEAL" mode of operation, respectively. Switch assembly <NUM> communicates with the microcontroller (not shown) of generator <NUM> and/or microcontroller <NUM> of battery assembly <NUM> to indicate whether the user has activated activation button <NUM> (<FIG>) in the first activated position, corresponding to the "CUT" mode of operation, or in the second activated position, corresponding to the "SEAL" mode of operation.

With additional reference to <FIG>, the use of ultrasonic surgical instrument <NUM> according to method <NUM> is detailed. Initially, as indicated at S410, the microcontroller (not shown) of generator <NUM> and/or microcontroller <NUM> of battery assembly <NUM> determines, based upon the information received from switch assembly <NUM>, whether switch assembly <NUM> has been activated in the "CUT" mode of operation or the "SEAL" mode of operation.

If it is determined at S410 that ultrasonic surgical instrument <NUM> is operating in the "CUT" mode of operation ("CUT MODE" in S410), the method proceeds to S420. In a default condition in the "CUT" mode of operation, blade <NUM> is oscillating with a relatively high displacement, as a relatively high displacement facilitates faster tissue cutting and relatively less tissue sealing. However, even with blade <NUM> oscillating with the relatively high displacement, some tissue sealing may still be effected. Thus, in order to further facilitate tissue cutting in the "CUT" mode of operation, it is determined, at S420, whether tension on tissue has increased, or has increased above a threshold. More specifically, the microcontroller (not shown) of generator <NUM> and/or microcontroller <NUM> of battery assembly <NUM> may determine whether tension on tissue has increased or has increased above a threshold based upon feedback received from sensor <NUM>, as detailed above.

If it is determined that tension on tissue has increased or increased above a threshold ("YES" at S420), the microcontroller (not shown) of generator <NUM> and/or microcontroller <NUM> of battery assembly <NUM> adjusts the drive signal provided from generator <NUM> to ultrasonic transducer <NUM> to thereby increase the displacement of blade <NUM> from the default relatively high displacement to a higher displacement, as indicated at S430. Such a feature enables even faster tissue cutting and even less tissue sealing (as a result of the higher displacement of blade <NUM>), in response to more tension on tissue, which is indicative of the user urging blade <NUM> into tissue, a motion typically indicative of an intent to cut through the tissue.

If it is determined that tension on tissue has not increased ("NO" at S420), the relatively high displacement, corresponding to the default condition in the "CUT" mode of operation, is maintained. Further, sensor <NUM> may be continuously or periodically monitored, repeating S420, to continuously or periodically determine whether tension on tissue has increased.

Continuing with reference to <FIG> and <FIG>, if it is determined at S410 that ultrasonic surgical instrument <NUM> is operating in the "SEAL" mode of operation ("SEAL MODE" in S410), the method proceeds to S440. In a default condition in the "SEAL" mode of operation, blade <NUM> is oscillating with a relatively low displacement, as a relatively low displacement facilitates better tissue sealing as compared to less tissue cutting. However, even with blade <NUM> oscillating with the relatively low displacement, some tissue cutting may still be effected. Thus, in order to further facilitate tissue sealing in the "SEAL" mode of operation, it is determined, at S440, whether tension on tissue has increased, or has increased above a threshold. More specifically, the microcontroller (not shown) of generator <NUM> and/or microcontroller <NUM> of battery assembly <NUM> may determine whether tension on tissue has increased or has increased above a threshold based upon feedback received from sensor <NUM>, as detailed above. If it is determined that tension on tissue has increased or increased above a threshold ("YES" at S440), the microcontroller (not shown) of generator <NUM> and/or microcontroller <NUM> of battery assembly <NUM> adjusts the drive signal provided from generator <NUM> to ultrasonic transducer <NUM> to thereby decrease the displacement of blade <NUM> from the default relatively low displacement to a lower displacement, as indicated at S450. A lower displacement enables better tissue sealing and less tissue cutting and, thus, serves to counteract the effect of increased tension on tissue, which tends to result in faster tissue cutting. Accordingly, the displacement of blade <NUM> is lowered in such instances to achieve the user-intended result, tissue sealing, since ultrasonic surgical instrument <NUM> is operating in the "SEAL" mode.

If it is determined that tension on tissue has not increased ("NO" at S440), the relatively low displacement, corresponding to the default condition in the "SEAL" mode of operation, is maintained. Further, sensor <NUM> may be continuously or periodically monitored, repeating S440, to continuously or periodically determine whether tension on tissue has increased.

Turning to <FIG>, another embodiment of an ultrasonic surgical instrument <NUM> and method of use <NUM> provided in accordance with the present disclosure are described. Ultrasonic surgical instrument <NUM> is similar to and may include any of the features of ultrasonic surgical instrument <NUM> (<FIG>), except as specifically contradicted below. Accordingly, similar features will be summarily described below or omitted entirely.

Ultrasonic surgical instrument <NUM> includes a handle assembly (not explicitly shown), an elongated assembly including a waveguide <NUM> having a blade <NUM> extending distally therefrom, and a battery assembly <NUM> and TAG <NUM>, each of which is configured for releasable mounting on the handle assembly. Ultrasonic surgical instrument <NUM> further includes a sensor <NUM> and a switch assembly <NUM> associated with an activation button (not shown). The activation button is selectively actuatable to activate switch assembly <NUM> from an "OFF" condition to an "ON" condition. When activated to the "ON" condition, switch assembly <NUM> communicates with the microcontroller (not shown) of generator <NUM> and/or microcontroller <NUM> of battery assembly <NUM> to indicate that the activation button has been actuated.

The use of ultrasonic surgical instrument <NUM> according to method <NUM> is detailed. Initially, ultrasonic surgical instrument <NUM> is activated to operate in a default condition, wherein the microcontroller (not shown) of generator <NUM> and/or microcontroller <NUM> of battery assembly <NUM> direct the application of an appropriate power from battery cells <NUM> to generator <NUM> to achieve an appropriate drive signal from generator <NUM> to ultrasonic transducer <NUM> to thereby transmit ultrasonic energy along waveguide <NUM> to blade <NUM> to oscillate blade <NUM> at a default displacement.

At S510, the tension on tissue is sensed using sensor <NUM>. The tension on tissue may be sensed continuously or periodically. At S520, based upon the information received from sensor <NUM>, the microcontroller (not shown) of generator <NUM> and/or microcontroller <NUM> of battery assembly <NUM> determines whether the tension on tissue is above an upper threshold or below a lower threshold.

If it is determined that the tension on tissue is above the upper threshold ("ABOVE" at S520), the method proceeds to S530, wherein the microcontroller (not shown) of generator <NUM> and/or microcontroller <NUM> of battery assembly <NUM> adjusts the drive signal provided from generator <NUM> to ultrasonic transducer <NUM> to thereby increase the displacement of blade <NUM> from the default displacement to a higher displacement, as indicated at S530. Such a feature enables faster tissue cutting and less tissue sealing (as a result of the higher displacement of blade <NUM>), in response to more tension on tissue, which is indicative of the user urging blade <NUM> into tissue, a motion typically indicative of an intent to cut through the tissue.

If it is determined that the tension on tissue is below the lower threshold ("BELOW" at S520), the method proceeds to S540, wherein the microcontroller (not shown) of generator <NUM> and/or microcontroller <NUM> of battery assembly <NUM> adjusts the drive signal provided from generator <NUM> to ultrasonic transducer <NUM> to thereby decrease the displacement of blade <NUM> from the default displacement to a lower displacement, as indicated at S530. Such a feature enables better tissue sealing and less tissue cutting (as a result of the lower displacement of blade <NUM>), in response to less tension on tissue, which is indicative of an intent to seal tissue.

If it is determined that the tension on tissue is neither above the upper threshold nor below the lower threshold ("NO" at S520), e.g., where the tension on tissue is between the upper and lower thresholds, the displacement of blade <NUM> is maintained at the default displacement. Method <NUM> may be repeated continuously or periodically to adjust the displacement of blade <NUM> according to the tension on tissue continuously or periodically, as detailed above.

As an alternative to the activation button of ultrasonic surgical instrument <NUM> selectively actuatable to activate switch assembly <NUM> from an "OFF" condition to an "ON" condition, the activation button may alternatively be configured to selectively activate switch assembly <NUM> from an "OFF" condition to a "LOW" power mode of operation or a "HIGH" power mode of operation, depending upon the manner in which the activation button is actuated. In such configurations, method <NUM> would proceed similarly as above except that a "LOW" default displacement is provided in the "LOW" power mode of operation and a higher, "HIGH" default displacement is provided in the "HIGH" power mode of operation (the upper and lower thresholds for each of the modes may also be different).

Claim 1:
An ultrasonic surgical system (<NUM>), comprising:
an ultrasonic surgical instrument comprising:
an ultrasonic generator (<NUM>) configured to output a drive signal;
an ultrasonic transducer (<NUM>) coupled to the ultrasonic generator and configured to receive the drive signal and output mechanical motion in response thereto;
a waveguide (<NUM>) coupled to the ultrasonic transducer and configured to transmit the mechanical motion therealong;
a blade (<NUM>) disposed at a distal end portion of the waveguide, the blade configured to oscillate in response to receipt of the mechanical motion from the waveguide, wherein the blade defines a displacement when oscillating; and
a handle wherein a sensor (<NUM>) is disposed on the surgical instrument at a location (L1) at a junction between a fixed handle portion of the handle assembly and a body portion of the handle assembly and is configured to sense an application of force applied by the user via the handle to urge the blade into the tissue which is a property indicative of tension on the tissue; and
a controller (<NUM>) configured to adjust the drive signal to thereby adjust the displacement based upon the sensed force.