Device status feedback for bipolar tissue spacer

A surgical instrument includes an end effector and a feedback system. The end effector includes a first jaw and a second jaw, wherein at least one of the first jaw and the second jaw is movable relative to the other one of the first jaw and the second jaw to transition the end effector during a closure stroke between an open configuration, a first approximated configuration, and a second approximated configuration. The feedback system includes an indicator, the indicator transitionable between a first indicator position, a second indicator position, and a third indicator position, wherein the indicator is in the first indicator position when the end effect is in the open configuration, wherein the indicator is in the second indicator position when the end effector is in the first approximated configuration, and wherein the indicator is in the third indicator position when the end effector is in the second approximated configuration.

BACKGROUND

The present invention relates to surgical instruments and, in various circumstances, to surgical sealing and transecting instruments.

DETAILED DESCRIPTION

Turning to the Drawings wherein like numerals denote like components throughout the several views,FIG. 1depicts one form of an electrosurgical instrument2. The electrosurgical instrument2comprises a handle assembly4, a shaft assembly12coupled to a distal end of the handle assembly4, and an end effector10coupled to the distal end of the shaft assembly12. The handle assembly4is configured as a pistol grip and comprises left and right handle housing shrouds6a,6b, a closure trigger8, a pistol-grip handle14, a firing trigger16, an energy button18, and a rotatable shaft knob20. An electrical cable may enter the handle assembly4at a proximal end.

In some circumstances, the end effector10can be coupled to the distal end of the shaft assembly12. The end effector10may include a first jaw22aand a second jaw22b. The first jaw22ais pivotably coupled to the second jaw22b. The first jaw22ais pivotally moveable with respect to the second jaw22bto grasp tissue therebetween. In some circumstances, the second jaw22bis fixed. In other circumstances, the first jaw22aand the second jaw22bare pivotally movable. The end effector10may include at least one electrode92. The electrode92is configured to deliver energy. Energy delivered by the electrode92may comprise, for example, radiofrequency (RF) energy, sub-therapeutic RF energy, ultrasonic energy, and/or other suitable forms of energy. In some circumstances, a cutting member (not shown) is receivable within a longitudinal slot defined by the first jaw22aand/or the second jaw22b. The cutting member can be configured to cut tissue grasped between the first jaw22aand the second jaw22b. In some circumstances, the cutting member may include an electrode for delivering energy, such as, for example, RF and/or ultrasonic energy.

In certain instances, an energy button18is configured to deliver energy to the at least one electrode92coupled to the end effector10from a power source. In certain instances, when the energy button18is depressed, a circuit is completed allowing delivery of energy to the electrode92. In some embodiments, the power source is a generator. In certain instances, the generator is external to the surgical instrument2which is separably coupled to the generator. In other instances, the generator is integrated with the surgical instrument2. In certain instances, feedback systems described by the present disclosure comprise indicators which are housed within the generator and can be separably coupled to the surgical instrument2in the instances where the generator is separably coupled to the surgical instrument2, for example. In certain instances, the power source may be suitable for therapeutic tissue treatment, tissue cauterization/sealing, as well as sub-therapeutic treatment and measurement.

In certain instances, the surgical instrument2may include a closure drive assembly which may comprise an outer sheath23, for example. In certain instances, the closure trigger8can be operatively coupled to at least one of the jaws22a,22bthrough the closure drive assembly such that actuation of the closure trigger8in a closure stroke may transition the jaws22a,22bbetween a plurality of configurations including an open configuration and an approximated configuration, for example. In certain instances, the surgical instrument2may include a firing drive assembly. In certain instances, the firing trigger16may be operatively coupled to the cutting member of the end effector10through the firing drive assembly such that actuation of the firing trigger16in a firing stroke may cause the cutting member to be advanced relative to the end effector10to cut tissue captured between the jaws22a,22b, for example.

FIG. 2illustrates a side perspective view of the electrosurgical instrument2illustrated inFIG. 1.FIG. 2illustrates the right handle housing6b. The energy button18extends through the handle assembly4and is accessible on both sides of the handle assembly4. The closure trigger8, the firing trigger16, and the energy button18may comprise an ergonomic design. In some circumstances, the handle assembly4is thinner near the energy button18to allow ease of access to the energy button18by a clinician. In some circumstances, the energy button18is disposed on either the left handle housing6aor the right handle housing6b.FIG. 3illustrates a side view of the electrosurgical instrument2and the right handle housing6b. Various electrosurgical instruments suitable for use with the present disclosure are described in U.S. patent application Ser. Nos. 14/075,839 and 14/075,863. U.S. patent application Ser. No. 14/075,839, entitled ELECTROSURGICAL DEVICES, and filed Nov. 8, 2013, is hereby incorporated by reference herein in its entirety. Furthermore, U.S. patent application Ser. No. 14/075,863, entitled ELECTROSURGICAL DEVICES, and filed Nov. 8, 2013, is hereby incorporated by reference herein in its entirety.

FIG. 4illustrates one embodiment of the surgical instrument2ofFIG. 1with the left handle housing6aremoved. The handle assembly4comprises a plurality of components for actuating the surgical instrument2, such as, for example, mechanisms for affecting closure of the jaws22a,22bof the end effector10, deploying the cutting member within the end effector10, and/or delivering energy to the one or more electrodes92coupled to the end effector10. In certain instances, a closure trigger8may be operably coupled to a closure drive assembly which can be configured to transition the jaws22a,22bbetween an open configuration and an approximated configuration. In certain instances, the closure trigger8is connected to a closure actuator located within the handle assembly4. In certain instances, the closure actuator comprises a toggle arm24which may be coupled to the closure trigger8at a first pivot25and to a yoke26at a second pivot27. In certain instances, the closure actuator may comprise any suitable actuator for coupling the closure trigger8to a jaw actuator of the shaft assembly. For example, in some embodiments, the closure actuator comprises an L-shaped lever arm. In certain instances, when the closure trigger8is actuated towards the pistol grip handle14, the toggle arm24may drive movement of the yoke26in a first direction along a longitudinal axis L-L. Longitudinal movement of the yoke26in the first direction may drive a closure drive, such as, for example, the outer sheath23, to transition the jaws22a,22bfrom the open configuration to the approximated configuration, for example. Furthermore, the longitudinal movement of the yoke26in a second direction, opposite the first direction, may drive the closure drive to transition the jaws22a,22bfrom the approximated configuration to the open configuration, for example.

In certain instances, a firing trigger16is configured to deploy the cutting member within the end effector10. The firing trigger16can be operatively coupled to firing drive assembly including, for example, a compound gear42, as illustrated inFIG. 4. The compound gear42may interface with a rack44, for example. The rack44can be coupled to a firing drive which may extend through the outer sheath23and may transmit axial motions to the cutting member of the end effector10. In certain instances, when the firing trigger16is actuated, the compound gear42rotates and moves the rack44distally. The distal movement of the rack44may cause distal movement of the firing drive and deployment of the cutting member within the end effector10. The cutting member can be deployed from a proximal end of the end effector10to a distal end of the end effector10. In certain instances, the firing trigger16comprises a high pivot to provide a linear feel during actuation of the firing trigger16. The linear feel provides increased control and comfort to a clinician actuating the firing trigger16.

In certain instances, the compound gear42can be operably coupled to a motor (not shown). Rotational motions generated by the motor may cause the rack44to be advanced distally, and in turn cause the cutting member to be deployed from the proximal end of the end effector10to the distal end of the end effector10, for example. In certain instances, the motor can be powered by a power source such as, for example, a battery (not shown). In certain instances, the firing trigger16may comprise a switch (not shown), for example, which can be operably coupled to a circuit, for example, such that movement of the firing trigger16from a first position to a second position may cause the switch to close the circuit which may activate the motor to deploy the cutting member, for example.

Referring toFIGS. 4 and 5, in some instances, the surgical instrument2may comprise a locking mechanism which may be configured to engage the firing drive assembly to interfere with, resist, and/or prevent deployment of the cutting member of the end effector10. In certain instances, the locking mechanism may include a locking member38. In certain instances, the locking member38can be transitioned between a locked configuration and an unlocked configuration; in the locked configuration, the locking member38can be configured to engage a rack unlock block40of the firing drive assembly to interfere with, resist, and/or prevent deployment of the cutting member of the end effector10. In certain instances, as illustrated inFIG. 5, a lock spring64may be coupled to the locking member38to apply a biasing force against the locking member38. The biasing force may bias the locking member38to maintain a locking engagement with the firing drive assembly.

In certain instances, the closure drive assembly is movable to release the firing drive assembly by causing the locking member38to transition from locking engagement with the rack unlock block40, as illustrated inFIG. 5, to the unlocked configuration, as illustrated inFIG. 7, for example. In certain instances, the closure drive assembly may comprise an unlocking member41which may be movable to raise the locking member38from locking engagement with the rack unlock block40, for example. In other words, actuation of the trigger8may transition the jaw22a,22bto the approximated configuration and may release the locking mechanism of the firing drive assembly by causing the unlocking member41to motivate the locking member38out of locking engagement with the rack unlock block40, for example. In certain instances, when the closure trigger8is released and the yoke26returns to a rest position, the lock spring64may bias the locking member38back into a locking engagement with the rack unlock block40, for example.

In certain instances, the locking mechanism of the surgical instrument2may be employed as a safety mechanism which may prevent deployment of the cutting member of the end effector10while the jaws22a,22bare in the open configuration and/or while the jaws22a,22bare not sufficiently transitioned to the closed configuration. In use, a clinician may orient the end effector10to position the jaws22a,22baround a desired tissue to seal and cut the desired tissue. Furthermore, the clinician may actuate the closure trigger8to transition the jaws22a,22bfrom the open configuration toward the approximated configuration to clamp the desired tissue, for example. In certain instances, however, the surgical instrument2may not be appropriate for safely treating the clamped tissue. For example, the clamped tissue may comprise a thickness that is too large to be safely treated with the surgical instrument2. In such instances, the locking mechanism may be employed to prevent deployment of the cutting member of the end effector10to cut the clamped tissue if the clinician actuates the firing trigger16to deploy the cutting member to cut the clamped tissue. In other words, the thickness of the clamped tissue may not permit sufficient closure of the jaws22a,22baround the clamped tissue for the jaws22a,22bto reach the approximated configuration. Accordingly, the clinician may not be able to sufficiently actuate the closure trigger8to complete a closure stroke. In turn, the unlocking member41may not be sufficiently motivated to release the locking member38out of locking engagement with the rack unlock block40.

In certain instances, the yoke26can be coupled to an unlocking member41. In certain instances, when the yoke26is moved in response to the actuation of the closure trigger8, the locking member41lifts the locking member38vertically away from the rack unlock block40. In certain instances, when the locking member38has been lifted a sufficient distance, the rack44is allowed to move and the firing trigger16is actuatable to deploy the cutting member within the end effector10. In certain instances, the firing trigger16is unlocked when the jaws22a,22bare sufficiently closed such that the cutting member cannot skip out of a slot formed in the end effector10. For example, in some instances, the locking member38is released when the closure trigger8is rotated about 30 degrees. In other instances, the locking member38may be released at a lower or higher degree of rotation of the closure trigger8. In certain instances, the firing trigger16is unlocked when the clamped tissue between the jaws22a,22bis sufficiently compressed to enable the cutting member to fully transect the clamped tissue. In certain instances, the firing trigger16is unlocked when the clamped tissue between the jaws22a,22bis sufficiently compressed to a thickness that is less than or equal, or at least substantially equal, to the height of the cutting surface of the cutting member of the end effector10, for example.

The reader will appreciate that it may be desirable to provide a clinician utilizing the surgical instrument2with feedback at various stages during operation of the surgical instrument2. In certain instances, the surgical instrument2may comprise one or more mechanical feedback systems. In certain instances, the surgical instrument2may comprise one or more electrical feedback systems. In certain instances, the surgical instrument2may comprise combinations of mechanical feedback systems and electrical feedback systems. In certain instances, some of the feedback systems described herein may include one or more indicators. In certain instances, the indicators may comprise, for example, visual indicators such as display screens, backlights, and/or LEDs, for example. In certain instances, the indicators may comprise audio indicators such as speakers and/or buzzers, for example. In certain instances, the indicators may comprise tactile indicators such as haptic actuators, for example. In certain instances, the indicators may comprise combinations of visual indicators, audio indicators, and/or tactile indicators, for example.

In certain instances, one or more of the feedback systems of the surgical instrument2may be configured to alert a clinician actuating the closure trigger8if a tissue bite clamped by the end effector10comprises a thickness that is too large for proper treatment via the surgical instrument2. In certain instances, one or more of the feedback systems of the surgical instrument2may be configured to alert a clinician actuating the firing trigger16if the firing drive assembly is locked by the locking mechanism of the surgical instrument2. For example, the one or more of the feedback systems of the surgical instrument2may be configured to alert the clinician actuating the firing trigger16if the locking member38is in locking engagement with the rack unlock block40. In certain instances, one or more of the feedback systems of the surgical instrument2may be configured to alert a clinician actuating the closure trigger8when the firing drive assembly becomes unlocked. In other words, one or more of the feedback systems of the surgical instrument2may be configured to alert a clinician actuating the closure trigger8when the jaws22a,22bare sufficiently closed such that the rack unlock block40is released from locking engagement with locking member38.

Referring toFIGS. 5-7, the surgical instrument2may comprise an electrical feedback system202(FIG. 5A). In certain instances, the system202may include an indicator circuit204which may comprise an indicator205. In certain instances, the circuit204may include a plurality of switches such as, for example, normally open, normally closed, and/or other switch types. In certain instances, the circuit204may include a switch206which may be associated with the firing trigger16, for example. In certain instances, as illustrated inFIG. 5A, the switch206can be transitioned between an inactive or open configuration or position206aand an active or closed configuration or position206b. In certain instances, the switch206can be coupled to the firing trigger16such that actuation of the firing trigger16between an unactuated position and a first actuated position during the firing stroke may cause the switch206to move from the inactive configuration206ato the active configuration206b. In certain instances, the actuation of the firing trigger16from the unactuated position to the first actuated position may be a slight actuation that may not cause movement of the cutting member of the end effector10or may cause a slight movement of the cutting member of the end effector10that may not cause the cutting member to be sufficiently advanced to cut tissue clamped between the jaws22a,22b.

Referring again toFIGS. 5-7, in certain instances, the circuit204may include a switch208which may be associated with the locking member38, for example. In certain instances, as illustrated inFIG. 5A, the switch208can be transitioned between an inactive or open configuration or position208aand an active or closed configuration or position208b.

As described above, the locking member38can be transitioned between the locked position, wherein the locking member38is in locking engagement with the firing drive assembly, and the unlocked position, wherein firing drive assembly is released from locking engagement with the locking member38. In certain instances, the switch208can be coupled to the locking member38such that the switch208remains in the active configuration208bwhile the locking member38is in the locked configuration. Furthermore, the switch208may be transitioned from the active configuration208bto the inactive configuration208awhen the locking member38is transitioned from the locked configuration to the unlocked configuration, for example.

Referring primarily toFIG. 5A, in certain instances, the indicator circuit204is closed and the indicator205is activated when the switch206and the switch208are both in the active configuration, for example. In certain instances, the indicator circuit204is open and the indicator205is inactive if one of the switch206and the switch208is in the inactive configuration, for example. In certain instances, the indicator circuit204is open and the indicator205is inactive if both of the switches206and208are in the inactive configuration, for example.

In certain instances, when the locking member38is in the locked configuration and the firing trigger16is in the first actuated position, the indicator circuit204is closed and the indicator205is activated. For example, a clinician may actuate the closure trigger8to clamp tissue comprising a thickness that is too large for proper treatment via the surgical instrument2. In such instances, the locking member38may remain in the locked configuration because the unlocking member41has not been sufficiently moved by the closure trigger8to separate the locking member38from locking engagement with the firing drive assembly, as described above. In result, the switch208may remain in the active configuration208b. In such instance, if the clinician attempts to actuate the firing trigger16from the unactuated position to the first actuated position, as described above, the switch206may also be transitioned to the active configuration206bwhich may cause the indicator circuit204to be closed and the indicator205to be activated to alert the clinician that the cutting member cannot be advanced to cut tissue captured by the end effector10because the firing drive assembly is locked, for example. In other words, the indicator205may alert the clinician that the jaws22a,22bare too far apart and that the cutting member cannot be advanced. In response, the clinician may release the captured tissue and may attempt to capture a more suitable tissue target, for example.

The reader will appreciate that if the captured tissue is not too large for proper treatment with the surgical instrument2, the closure trigger8may be sufficiently actuated to allow the unlocking member41to sufficiently motivate the locking member38to the unlocked configuration to release the rack unlock block40and free the firing drive assembly. The transitioning of the locking member38to the unlocked configuration causes the switch208to be transitioned to the inactive configuration208a. In such instance, if the clinician attempts to actuate the firing trigger16from the unactuated position to the first actuated position, as described above, the switch206may be transitioned to the active configuration206bbut since the switch208is in the inactive configuration208a, the indicator circuit204will not be closed and the indicator205will not be activated; and since the firing drive assembly is free from locking engagement with the locking member38, the clinician may continue actuating the firing trigger16to advance the cutting member of the end effector10to cut the tissue captured between the jaws22a,22b, for example. In other words, the indicator205is not activated since the jaws22a,22bare sufficiently closed around captured tissue and, accordingly, the firing trigger16can be fully actuated in a complete firing stroke to advance the cutting member of the end effector10to cut the captured tissue.

In certain instances, as illustrated inFIG. 5B, the indicator205, the switch206, and the switch208can be operably coupled to a microcontroller220(“controller”), for example. In certain instances, the controller220may include a microprocessor222(“processor”) and one or more memory units224operationally coupled to the processor222, for example. A power source such as, for example, a battery226can be configured to supply power to the controller220and/or the indicator205, for example. In certain instances, the memory224may include program instructions that can be executed from the memory224to cause the processor220to transmit activation signals to the indicator205in response to simultaneous active signals received from the switches206and208, for example.

The controller220may be implemented using integrated and/or discrete hardware elements, software elements, and/or a combination of both. Examples of integrated hardware elements may include processors, microprocessors, microcontrollers, integrated circuits, application specific integrated circuits (ASIC), programmable logic devices (PLD), digital signal processors (DSP), field programmable gate arrays (FPGA), logic gates, registers, semiconductor devices, chips, microchips, chip sets, microcontrollers, system-on-chip (SoC), and/or system-in-package (SIP). Examples of discrete hardware elements may include circuits and/or circuit elements such as logic gates, field effect transistors, bipolar transistors, resistors, capacitors, inductors, and/or relays. In certain instances, the controller220may include a hybrid circuit comprising discrete and integrated circuit elements or components on one or more substrates, for example.

In certain instances, the microcontroller220may be an LM 4F230H5QR, available from Texas Instruments, for example. In certain instances, the Texas Instruments LM4F230H5QR is an ARM Cortex-M4F Processor Core comprising on-chip memory of 256 KB single-cycle flash memory, or other non-volatile memory, up to 40 MHz, a prefetch buffer to improve performance above 40 MHz, a 32 KB single-cycle serial random access memory (SRAM), internal read-only memory (ROM) loaded with StellarisWare® software, 2 KB electrically erasable programmable read-only memory (EEPROM), one or more pulse width modulation (PWM) modules, one or more quadrature encoder inputs (QEI) analog, one or more 12-bit Analog-to-Digital Converters (ADC) with 12 analog input channels, among other features that are readily available. Other microcontrollers may be readily substituted for use with the present disclosure. Accordingly, the present disclosure should not be limited in this context.

Referring toFIGS. 8 and 9, in certain instances, the surgical instrument2may comprise one or more mechanical feedback systems such as, for example, a mechanical feedback system212. In certain instances, the mechanical feedback system212may replace the electrical feedback system202, for example. In certain instances, the mechanical feedback system212can be employed to provide feedback to a clinician using the surgical instrument2as to the whether the firing drive assembly is locked, for example.

As illustrated inFIG. 8, the mechanical feedback system212may include an indicator window214positioned on an outer wall of the handle housing4, for example. In addition, the mechanical feedback system212may include a locked indicator216which indicates that the firing drive assembly is locked, for example, and an unlocked indicator218which indicates that the firing drive assembly is unlocked, for example. In certain instances, as illustrated inFIG. 8, the indicators216and218can be operably coupled to the locking member38. For example, as illustrated inFIG. 8, the indicators216and218can be pivotally coupled to the locking member38via a pivot member220. In certain instances, the indicators216and218can be operably movable with the locking member38and can be aligned with the indicator window214such that the locked indicator216is visible from the indicator window214, as illustratedFIG. 8, while the locking member38is in the locked configuration, and the unlocked indicator218is visible from the indicator window214, as illustrated inFIG. 9, while the locking member38is in the unlocked configuration, for example.

In some instances, the jaws22a,22bare configured to maintain a minimal spacing therebetween to prevent damage to components of the surgical instrument2and/or the tissue section. In some instances, full actuation of the closure trigger8corresponds to a rotation of about 30 degrees. When the closure trigger8is fully rotated against the pistol grip handle14, a closure trigger lock46is engaged to maintain the jaws22a,22bin a closed position. Once the trigger lock46has been engaged, the clinician may release the closure trigger8and the trigger lock46maintains the closure trigger8in a closed position.

In certain instances, the trigger lock46may maintain the closure trigger8in a less than fully retracted position to prevent damage to components of the surgical instrument2due to over application of force to the jaws22a,22b. The trigger lock46may maintain the closure trigger8in a sufficiently rotated position to release the locking member38from the rack unlock block40. For example, in the some instances, the trigger lock46maintains the closure trigger8at a rotation of about 28 degrees. With the closure trigger8in a locked position, the clinician may actuate the firing trigger16to deploy the cutting member within the end effector10. In some instances, the clinician may actuate the energy button18to deliver energy to a tissue section grasped between the jaws22a,22bprior to or simultaneously with, deployment of the cutting member.

Referring toFIGS. 10 and 11, the surgical instrument2may include closure feedback systems that are associated with the closure trigger8such as, for example, an electrical feedback system240and/or a mechanical feedback system242. As described above, the closure trigger8is actuatable between an initial unactuated position and an actuated locked position to close the jaws22a,22baround tissue, for example. In certain instances, the closure feedback systems240and/or242may be configured to warn or alert a clinician actuating the trigger8in the event the captured tissue comprises a thickness that cannot be properly treated utilizing the surgical instrument2. In certain instances, the closure feedback systems240and/or242may be configured to warn or alert a clinician actuating the trigger8in the event the tissue captured between the jaws22a,22bcannot be safely compressed to a thickness that is less than or equal, or at least substantially equal, to the height of the cutting surface of the cutting member of the end effector10, for example. In certain instances, the closure feedback systems240and/or242may be configured to warn or alert a clinician if the actuation force exerted against the trigger8by the clinician exceeds a safe threshold, for example. In certain instances, the closure feedback systems240and/or242may be configured to warn or alert a clinician actuating the trigger8in the event the tissue captured between the jaws22a,22bprevents approximation for the end effector10during a closure stroke from a first approximated configuration, for example, to a second approximated configuration, for example. In certain instances, the first approximated configuration corresponds to a tissue thickness that is not safely treatable by the surgical instrument2; and the second approximated configuration corresponds to a tissue thickness that is safely treatable by the surgical instrument2.

Referring toFIG. 10, the electrical feedback system240may include an indicator circuit244. In certain instances, the indicator circuit244may comprise an indicator245. In certain instances, the circuit244may include a plurality of switches such as, for example, normally open, normally closed, and/or other switch types. In certain instances, the circuit244may include a switch246which may be associated with the closure trigger8, for example. In certain instances, the switch246can be transitioned between an inactive or open configuration or position246aand an active or closed configuration or position246b, as illustrated inFIG. 10. In certain instances, the switch246can be coupled to the closure trigger8such that actuation of the closure trigger8between the initial unactuated position and the actuated locked position during the closure stroke may cause the switch246to move from the inactive configuration246ato the active configuration246b, for example.

Further to the above, as illustrated inFIG. 10, the circuit244may comprise a switch248. In certain instances, the switch248can be transitioned between a first inactive or open configuration or position248a, an active or closed configuration or position248b, and a second inactive or open configuration or position248cduring the closure stroke, for example. In certain instances, the switch248can be associated with one of the jaws22a,22b, for example. In certain instances, the switch248can be coupled to the jaw22a, for example, such that motion of the jaw22aduring the closure stroke from an open unactuated or initial position to a first actuated position may cause the switch248to be transitioned from the first inactive configuration248a, for example, to the active configuration248b, for example; and motion of the jaw22aduring the closure stroke beyond the first actuated position to a second actuated position, for example, may cause the switch248to be transitioned from the active configuration248b, for example, to the second inactive configuration248c, for example. In certain instances, the circuit244can be closed and the indicator245can be activated when the switches246and248are in the closed configurations246band248b, respectively.

In use, a clinician may position the jaws22a,22baround tissue and may actuate the closure trigger8through a closure stroke to actuate the jaws22a,22bto clamp the tissue, for example. In certain instances, the first actuated position of the jaw22acan be associated with a first tissue thickness, for example; and the second actuated position of the jaw22acan be associated with a second tissue thickness, for example. In certain instances, the first tissue thickness is too large for proper treatment with the surgical instrument2. In certain instances, the second tissue thickness is suitable for treatment with the surgical instrument2. In certain instances, if the tissue clamped between the jaws22a,22bcomprises the first tissue thickness, the jaw22amay remain in the first actuated position and may not be able to transition beyond the first actuated position to the second actuated position, as the clinician continues to actuate the trigger8, due to the large thickness of the tissue clamped between the jaws22a,22b. Accordingly, the switch248may remain in the active configuration248b, for example. If the clinician continues actuating the closure trigger8through the remainder of the actuation stroke, the closure trigger8may ultimately reach the actuated locked position; at such instance, the switch246may reach the active configuration246band since the switch248is also in the active configuration248b, the circuit244will become closed and the indicator245activated to alert the clinician that the captured tissue comprises a thickness that is too large for proper treatment with the surgical instrument2.

The reader will appreciate that if the tissue clamped between the jaws22a,22bcomprises a thickness suitable for treatment via the instrument2such as, for example, the second tissue thickness, the jaw22amay continue to move past the first actuated position and toward the second actuated position as the clinician continues to actuate the trigger8through the closure stroke. Accordingly, the switch248may move past the active configuration248bto the inactive configuration248c. If the clinician continues actuating the closure trigger8through the remainder of the actuation stroke, the closure trigger8may ultimately reach the actuated locked position; at such instance, the switch246may reach the active configuration246b. But since the switch248is in the inactive configuration248c, the circuit244will remain open and the indicator245will remain inactive when the switch246reaches the closed configuration246b. In other words, since the tissue clamped between the jaws22a,22bcomprises a thickness that is not too large for treatment with the surgical instrument2, the indicator245may remain inactive.

In certain instances, the switch248can be associated with the closure drive assembly at a position proximal to the jaw22aand can be operable in a similar manner as described above. In certain instances, the switch248can be associated with the jaw22band can be operable in a similar manner as described above. In certain instances, the circuit244may comprise a third switch (not shown) which can be associated with the jaw22bsuch that the circuit244is closed and the indicator245is activated when the third switch and the switches246and248are all in the active configuration, for example.

Referring toFIG. 11, in certain instances, the mechanical feedback system242may replace the electrical feedback system240, for example, to provide feedback to a clinician actuating the trigger8in the event the tissue clamped between the jaws22a,22bcomprises a thickness that cannot be properly treated with the surgical instrument2. As illustrated inFIG. 11, the mechanical feedback system242may include an indicator window264positioned on an outer wall of the handle housing4, for example. In certain instances, as illustrated inFIG. 12, the indicator window264can be positioned on the outer sheath23of the shaft assembly12, for example.

In any event, the mechanical feedback system242may include an indicator266. In certain instances, as illustrated inFIGS. 14 and 15, the indicator266can be movable between a first indicator position280, a second indicator position282, and a third indicator position284, for example. In certain instances, as illustrated inFIG. 15, the indicator266is not visible through the indicator window264while in the first indicator position280and while in the third indicator position284. However, in certain instances, the indicator266is visible through the indicator window264while in the second indicator position282, for example. In certain instances, the indicator266is movable between a plurality of indicator positions that may be defined by color coded sections depicted on the outer sheath23, for example.

In certain instances, as illustrated inFIG. 11, the indicator266can be movably coupled to the closure drive assembly via an indicator arm268, for example. In certain instances, the indicator266can be pivotally coupled to the closure drive assembly of the surgical instrument2such that motion of the closure drive assembly between a first closure position corresponding to the unactuated open position of the jaw22a, a second closure position corresponding to the first actuated position of the jaw22a, and a third closure position corresponding to the second actuated position of the jaw22amay cause the indicator266to move between the first indicator position, the second indicator position, and the third indicator position, respectively, for example.

In use, a clinician may position the jaws22a,22baround tissue and may actuate the closure trigger8through a closure stroke to actuate the jaws22a,22bto clamp the tissue, for example. As the clinician actuates the trigger8, the closure drive assembly may be transitioned from the first closure position to the second closure position which may cause the jaw22ato be transitioned from the initial unactuated position to the first actuated position, and may cause the indicator266to be transitioned from the first indicator position280to the second indicator position282. As described above, the indicator266may be visible through the indicator window264in the second indicator position282. Also described above, if the tissue clamped between the jaws22a,22bcomprises the first tissue thickness, the jaw22amay remain in the first actuated position and may not be able to transition to the second actuated position, as the clinician continues to actuate the trigger8, due to the large thickness of the tissue clamped between the jaws22a,22b. Accordingly, the indicator266may remain in the second indicator position282and may remain visible through the indicator window264to provide the clinician with feedback that the captured tissue cannot be properly treated with surgical instrument2, for example.

The reader will appreciate that if the tissue clamped between the jaws22a,22bcomprises a thickness suitable for treatment with the instrument2such as, for example, the second tissue thickness, the closure drive assembly may continue to move past the second closure position to the third closure position, for example, and the jaw22amay continue to move past the first actuated position to the second actuated position, for example, as the clinician continues to actuate the trigger8through the closure stroke. In result, the indicator266may be moved past the second indicator position282toward the third indicator position284, for example, and away from indicator window264.

In certain instances, referring toFIG. 13, the surgical instrument2may include one or more feedback systems such as, for example, a feedback system270. In certain instances, as illustrated inFIG. 13, the feedback system270may include the controller220which may include the processor222and the memory224, for example. In certain instances, the feedback system270can be powered by a power source such as, for example, the battery226. In certain instances, the feedback system270may comprise one or more indicators such as, for example, the indicator205. In certain instances, the feedback system270may comprise one or more load cells such as, for example, strain gauges272and274.

Strain gauges suitable for use in the present invention include (a) feedback electroactive polymer elements whose impedance or resistance varies as a function of the amount of strain in the device and (b) conventional strain gauges in which the resistance of the device varies as a function of the amount of strain in the device, thus allowing the amount of strain to be readily quantified and monitored. Such strain gauges are commercially from a number of different sources, including National Instruments Co., Austin, Tex., and include piezoresistive strain gauges (for which resistance varies nonlinearly with strain) and bonded metallic strain gauges (for which resistance typically varies linearly with strain). The later strain gauges consist of very fine wire or metallic foil that is arranged in a grid pattern. The grid is bonded to a thin backing or carrier, which may be directly attached to the substrate being monitored for strain. Consequently, the strain experienced by the substrate is transferred directly to the strain gauge, which responds with a change in electrical resistance. Commercially available strain gauges typically have nominal resistance values within the range of 30 to 3000Ω, with 120Ω, 350Ω and 1000Ω devices being especially common.

In certain instances, the strain gauge272is operable to monitor closure actuation forces applied by a clinician to the surgical instrument2through the closure trigger8, for example. In certain instances, the strain gauge272can be placed on various locations of the surgical instrument2that are associated with the closure stroke. In certain instances, the strain gauge272can be placed on the closure drive, for example. In certain instances, the strain gauge272can be placed on the closure trigger8, for example. In certain instances, the strain gauge272can be placed on toggle arm24, for example.

In certain instances, the strain gauge274is operable to monitor firing actuation forces applied by a clinician to the surgical instrument2through the firing trigger16, for example. In certain instances, the strain gauge274can be placed on various locations of the surgical instrument2that are associated with the firing stroke. In certain instances, the strain gauge274can be placed on the firing drive, for example. In certain instances, the strain gauge274can be placed on the firing trigger16, for example.

In certain instances, the memory224may include program instructions that can be executed from the memory224to cause the processor220to monitor strain measurements transmitted from the strain gauge272and/or the strain gauge274to the processor222. In certain instances, the strain measurements of the strain gauge272and/or the strain gauge274can be transmitted to the processor222through an analogue to digital converter, for example. In certain instances, the memory224may include program instructions that can be executed from the memory224to cause the processor220to detect an increase in the monitored closure actuation forces beyond a predetermined threshold and to transmit an activation signal to the indicator205in response to the detection of such an increase. In certain instances, the memory224may include program instructions that can be executed from the memory224to cause the processor220to detect an increase in the monitored firing actuation forces beyond a predetermined threshold and to transmit an activation signal to the indicator205in response to the detection of such increase.

The reader will appreciate one or more of the switches described by the present disclosure may comprise mechanical switches, electro-mechanical switches, and/or solid state switches. In certain instances, one or more of the switches of the present disclosure may comprise open, inactive, and/or non-conductive positions, states, and/or configurations. In certain instances, one or more of the switches of the present disclosure may comprise closed, active, and/or conductive positions, states and/or configurations. In certain instances, one or more of the switches of the present disclosure can be transitioned from the open, inactive, and/or non-conductive positions, states, and/or configurations to the closed, active, and/or conductive positions, states and/or configurations to close and/or activate one or more circuits associated with such switches, for example.