Surgical stapler having powered handle

Abstract

To provide a powered handle for a reliable surgical stapling system for clamped tissue without any complex mechanism.SOLUTION: A powered handle for a surgical stapler has a drive system including an electric motor. The powered handle includes a manual articulation mechanism to articulate a jaw assembly coupled to a reload shaft connected to the handle. The manual articulation mechanism includes a ball screw mechanism that translates an articulation member in response to rotation of an articulation knob. The articulation mechanism includes a release function that allows the jaw assembly to return to a longitudinally centered orientation state. The powered handle includes a battery pack serving as the power supply for the drive system. A control system should control actuation of the motor on the basis of user input and operating parameters of the stapler. The powered handle includes a manual return mechanism.SELECTED DRAWING: Figure 14

Description

Technical Field

[0001] This application generally relates to surgical occlusion devices, and more particularly to electric surgical staplers.

[0002]

Description of Related Applications

Background Art

[0003] Surgical staplers are used to approach or clamp tissue and staple the clamped tissue together. Thus, surgical staplers have a mechanism for properly positioning and capturing the tissue and driving staples into the tissue. As a result, this gives rise to, for example, multiple triggers and handles in connection with complex mechanisms to enable proper stapling of the clamped tissue. These complex mechanisms increase the manufacturing burden for surgical staplers and may create potential sources of device failure and confusion for the user. Thus, reliable stapling of clamped tissue without complex mechanisms is desired.

Summary of the Invention

[0004] In certain embodiments, an electric handle for a surgical stapling system is provided herein. The electric handle may have a drive system powered by a power source to selectively activate an actuation adapter. The electric handle may have a manual articulation mechanism for selectively activating an articulation adapter. The electric handle may further have a coupler with a plug coupling for simultaneously coupling the articulation adapter and the actuation adapter to an articulation member and a drive member provided within a replaceable shaft.

[0005] In certain embodiments, the electric handle of the surgical stapling system has a control system for actuating the drive system in response to user input from a movable trigger and a fire / retract button provided on the electric handle. The control system can further vary the actuation profile of the drive system in response to various operating parameters including the drive system actuation torque, the longitudinal position of the actuating adapter, and the identification of the length or configuration of the jaw assembly.

[0006] In certain embodiments, the electric handle of the surgical stapling system includes a manual articulation system having a ball screw mechanism. The ball screw mechanism can enable continuous articulation of the jaw assembly of the stapling system within a predetermined range of articulation. The ball screw mechanism is biasingly positionable in a longitudinal centering position and is quickly centerable by use of a release mechanism.

[0007] In certain embodiments, a handle assembly for a surgical stapler is provided. The handle assembly includes a handle body, an electric motor, an actuating shaft, and a mechanical retraction mechanism. The handle body has a stationary handle and a trigger rotatably coupled to the handle body. The electric motor is provided within the handle body. The actuating shaft is slidable along a longitudinal axis within the handle body and is rotatable about the longitudinal axis within the handle body. A rack is formed on the actuating shaft. The actuating shaft is rotatable from a first position where the rack is operatively engaged with the electric motor such that the rack slides the actuating shaft longitudinally to a second position where the rack is disengaged from the electric motor and engaged with the manual retraction mechanism.

[0008] In certain embodiments, a handle assembly for a surgical stapler is provided. The handle assembly includes a handle body, an electric motor, an actuating shaft, a motor gear, an auxiliary gear, a crown gear, a potentiometer, and a control system. The handle body has a stationary handle and a trigger rotatably coupled to the handle body. The electric motor is provided within the handle body. The electric motor has an output shaft. The actuating shaft is slidable within the handle body along a longitudinal axis. The motor gear is coupled to the output shaft of the motor. The auxiliary gear is in a passive meshing relationship with the motor gear. The motor gear is operatively engaged with a rack. The crown gear is provided within the handle in a meshing engagement relationship with the motor gear. The potentiometer is coupled to the crown gear. The control system is electrically coupled to the trigger, the electric motor, and the potentiometer.

[0009] In certain embodiments, a handle assembly for a surgical stapler is provided. The handle assembly includes a handle body, a power system, an actuating shaft, and an articulation mechanism. The handle body has a stationary handle and a trigger rotatably coupled to the handle body. The power system is provided within the handle body. The actuating shaft is operatively coupled to the power system. The actuating shaft is slidable within the handle body along a longitudinal axis. The articulation mechanism includes a manual articulation knob and an articulation adapter. The manual articulation knob is positioned at a proximal end of the handle body and is rotatable about the longitudinal axis. The articulation adapter is positioned at a distal end of the handle body. The articulation adapter is operatively coupled to the articulation knob such that rotation of the actuating knob about the longitudinal axis causes the articulation adapter to slide longitudinally.

Brief Description of the Drawings

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DETAILED DESCRIPTION OF THE INVENTION

[0011] Referring to FIGS. 1 and 2, one embodiment of a surgical stapling system is shown. The illustrated embodiment of the surgical stapler 10 has an elongated shaft 20, a jaw assembly 30, and a handle assembly 40. FIG. 1 shows the surgical stapler 10 with the jaw assembly 30 in an open configuration, and one embodiment of the electric handle is of an electric staple firing type and an electric jaw assembly articulation type. FIG. 2 shows another embodiment of the electric handle 40 of the surgical stapler system with the elongated shaft removed. The electric handle 40 of FIG. 2 is of an electric staple firing type and a manual jaw assembly articulation type. In the illustrated embodiment, the shaft 20 and the jaw assembly 30 are freely rotatable about the longitudinal axis defined by the shaft 20 by rotation of a rotary knob provided on the handle 40. In other embodiments, the stapling system may be configured to allow rotation of the jaw assembly about the longitudinal axis in a defined range or a rotationally fixed jaw assembly.

[0012] Continuing to refer to FIG. 1, the surgical stapler 10 as shown in the illustrated embodiment may be sized and shaped to be usable in laparoscopic surgical procedures. For example, the elongated shaft 20 and the jaw assembly 30 may be sized and shaped to be introduced into the surgical field through an access port or trocar cannula. In some embodiments, the elongated shaft 20 and the jaw assembly 30 may be sized and shaped to be inserted through a trocar cannula having a relatively small working channel diameter, for example, less than 8 mm. In other embodiments, the elongated shaft 20 and the jaw assembly 30 may be sized and shaped to be inserted through a trocar cannula having a large working channel diameter, for example, 10 mm, 11 mm, 12 mm, or 15 mm. In other embodiments, it is contemplated that certain aspects of the surgical stapler described herein can be incorporated into a surgical stapling instrument that is usable in open surgical procedures.

[0013] Continuing to refer to FIG. 1, as shown, the elongated shaft 20 has a generally tubular member. The elongated shaft 20 extends from a proximal end to a distal end. The elongated shaft 20 defines the longitudinal central axis L of the surgical stapler 10 that extends between the proximal end 22 and the distal end 24.

[0014] Continuing to refer to FIG. 1, in the illustrated embodiment, the jaw assembly 30 is coupled to the elongated shaft 20 at the distal end of the elongated shaft 20. The jaw assembly 30 includes a first jaw 32 and a second jaw 34 rotatably coupled to the first jaw 32. In the illustrated embodiment, the first jaw 32 is fixed to the distal end 24 of the elongated shaft 20 such that it extends distally along the longitudinal central axis L, and this first jaw is articulable relative to the elongated shaft 20 in response to an articulation mechanism within the handle 40. In an initial configuration, a plurality of staples 36 are disposed within the first jaw 32 and housed within the replacement portion 50. In other embodiments, the replacement portion 50 may be integrated with the jaw assembly 30 such that the entire shaft assembly 20 and the jaw assembly 30 loaded with staples form a single replaceable assembly. In some embodiments, the staples may initially be positioned within the second jaw 34.

[0015] Continuing to refer to FIG. 1, in the illustrated embodiment, the jaw assembly 30 can be actuated from an open configuration (FIG. 1) to a closed configuration, i.e., a stapling configuration, by a drive member or beam that is longitudinally slidable within the elongated shaft. In an initial position, the beam may be positioned at the distal end 24 of the elongated shaft 20. With the beam in the initial position, the second jaw 34 is rotated away from the first jaw 32 such that the jaw assembly 30 is in an open configuration. The actuating beam engages the second jaw 34 upon translation of the actuating member or beam distally along the longitudinal axis L. Translating the actuating beam distally from the initial position by a first distance can actuate the jaw assembly from the open configuration to the closed configuration. With the jaw assembly 30 in the closed configuration, returning the actuating beam proximally by the first distance can return the jaw assembly 30 to the open configuration. The distal end of the actuating beam can advance a staple slider configured to deploy the staples from the first jaw 32 such that further translation of the actuating beam distally beyond the first distance causes a plurality of staples 36 to be deployed from the replacement portion 50 within the first jaw 32.

[0016] Continuing to refer to FIG. 1, in the illustrated embodiment, the handle assembly is coupled to the elongate shaft 20 at the proximal end of the elongate shaft 20. As shown, the handle assembly 40 has a pistol grip configuration with a housing that includes a stationary handle 42 and a movable handle 44 or trigger that is rotatably coupled to the stationary handle 42. In other embodiments, it is contemplated that the surgical stapler instrument, including the aspects described herein, may have a handle assembly with other configurations, such as a scissor grip configuration or an in-line configuration. As will be described in more detail below, the handle assembly 40 houses an electric actuation mechanism configured to selectively advance an actuating shaft in response to movement of the movable handle 44.

[0017] In the illustrated embodiment, the surgical stapler 10 may have a plurality of staples 36 positioned within a disposable cartridge replacement section 50, while the jaw assembly 30 is configured to be reused in a single procedure with a number of staple cartridge replacement sections 50. In some embodiments, the elongate shaft 20 and the jaw assembly 30 constitute a disposable replaceable shaft that can be removably coupled to the handle assembly 40. Thus, in the illustrated embodiment, the handle assembly 40 includes a coupler 46 at its distal end. The coupler 46 is adapted to engage the elongate shaft 20 of the surgical stapler 10. The coupler 46 may have a plug connection portion including an outer connector that can removably couple the elongate shaft 20 to the handle assembly 42 and an inner connector that can removably couple the actuating shaft of the handle assembly 40 to the drive member of the elongate shaft 20. Thus, the surgical stapler 10 may be configured to be reusable with a number of replaceable shafts 20 during a surgical procedure with the handle assembly 40. In other embodiments, it is contemplated that certain portions of the handle assembly and the elongate shaft may be reusable with the remainder of the elongate shaft within the jaw assembly constituting a disposable cartridge. In certain other embodiments, the handle assembly and the elongate shaft may be reusable with the jaw assembly constituting a disposable cartridge. In yet other embodiments, a jaw insert containing a plurality of staples can constitute a disposable cartridge while the remainder of the surgical stapler is reusable.

[0018] Referring to FIG. 2, an embodiment of an electric handle for a surgical stapling system is shown. The electric handle can be used with various shaft replacement parts and cartridges, and as a result, the shaft configuration, jaw assembly configuration, and staple configuration can be selected for a particular procedure. The illustrated embodiment of the handle provides for an electric (motor-driven) clamping operation and release of the jaws as well as the firing of a staple line. The articulation of the jaw assembly can be manually controlled by an articulation knob turned by the operator. The motor is controlled by an embedded control system that defines the functions of the handle during different usage phases.

[0019] Continuing to refer to FIG. 2, the electric handle 40 has a pistol grip configuration with a stationary handle 42 and a movable handle 44 or trigger rotatably coupled to the stationary handle. A power source 130 or battery may be provided on the lower surface of the stationary handle. The electric handle 40 may further include a user control, such as a fire or fire / reverse button 150, to enable the user to selectively control the staple sequence. The electric handle 40 may further include a redundant manual return system 170 to enable the user to manually return the stapling system to the open configuration in the event of a failure of the electric system, control system, power source, or "locked jaw" or other mechanical binding. The electric handle may further include a manual articulation mechanism including a rotatable articulation knob 190. In the illustrated embodiment, the articulation knob 190 is provided at the proximal end of the electric handle and is rotatable about an axis generally coincident with the longitudinal axis of the stapling system.

[0020] Referring to FIG. 2A, the electric handle of FIG. 2 is shown in an exploded view. Various elements of the illustrated embodiment of the electric handle, which are further described herein, are shown in the exploded view.

[0021] Referring to FIG. 3, a partially cut-away view of the power handle is shown with the shaft 20 positioned within the handle cup 46. In the illustrated cut-away view, several components of the power handle have been omitted to clearly show the drive system of the power handle. In the illustrated embodiment, the drive system includes a motor 112 positioned within the stationary handle 42, a motor gear 114 attached to the output shaft of the motor 112, and an auxiliary gear 116 in passive meshing engagement with the motor gear 114. In some embodiments, the motor 112 is a brushed DC gear motor. Advantageously, by transmitting power through the auxiliary gear 116, the motor 112 can be laterally offset within the stationary handle, thereby enhancing the balance and ergonomic condition of the handle. Further, in some embodiments, the motor gear 114 and the auxiliary gear 116 may be configured to provide a desired operating torque at the rack 122. In some embodiments, the motor 112 may have a multi-gear type transmission operatively coupled between the motor 112 and the motor gear 114 coupled to the auxiliary gear 116 to provide a desired operating torque. The motor 112 may be electrically coupled to a power source 130 via a control system. The control system within the handle interfaces with the drive system to measure the position of the actuating shaft 120 and thus the operating state of the jaw assembly.

[0022] The drive system is attached to hardware that provides information to a control system including a microprocessor within the handle. This embedded system can control the speed and torque of the motor. This system can also control the function of the device based on user input (moving the trigger and pressing the fire / reverse button) and the position of the drive system. The control system can also measure feedback from the motor to determine whether the load is too high to continue stapling or whether a replaceable cartridge lockout has been actuated. The control system can also measure the battery life and further limit the number of firings of the device.

[0023] Referring to FIG. 20, a schematic flow diagram showing data and power flow for an exemplary control system for an electric handle is shown. In the illustrated flow diagram, the control system includes the illustrated microcontroller. In various embodiments, the microcontroller may have an application-specific integrated circuit or a general-purpose microprocessor that executes application-specific firmware and / or software. As shown, the microcontroller receives power and data regarding the battery state from the battery in the power supply. The microcontroller further receives data from various mechanical hardware of the stapler, such as a motor drive and a current monitor, an operating rack position detection mechanism, and a shaft connection and type monitor. The microcontroller further receives data from the user via a trigger position sensor, a push button switch, and a Bluetooth® communication transceiver. The control system can output a control signal to operate the drive system of the electric handle via the motor drive. The control system can also output certain operating parameter information to a memory module provided in the power supply, and can output certain data for the user to observe via an LED light provided in the handle and the Bluetooth® communication transceiver.

[0024] In certain embodiments, the control system is also configured to further define the operating parameters of the electric handle. For example, by querying a memory module provided in the power supply or the control system itself, the control system can detect whether the electric handle has been used for more than one procedure. In some embodiments, the stapling system is designed to be used in a single procedure and is not designed for resterilization. Additionally, the control system can also query a memory module provided in the power supply or the control system to detect the number of staple firings and thereby evaluate whether sufficient battery power remains to complete additional firings.

[0025] In certain embodiments, the control system is configured to detect tissue characteristics that can prevent staple firing. In some embodiments, the control system can monitor the position, speed, and supply torque of the motor in the drive system. The control system can detect whether excessive torque is required to close the jaw assembly if it takes excessive time to close the jaw assembly or if the jaws are closing at a low speed. These conditions may indicate that the tissue within the jaw assembly is too thick or too dense for the stapler to be effective. In certain embodiments, the control system can monitor the position of the operating shaft over time and evaluate the monitored position and time against a baseline "zero load" time-based position to evaluate tissue characteristics such as thickness and density. If the drive system exceeds predetermined operating parameters, the control system can indicate an error condition and stop the firing operation.

[0026] In some embodiments, the control system can provide user information by means of a Bluetooth® connection. The electric handle may preferably have a low-power Bluetooth® transceiver that can discreetly display data regarding operating parameters such as the state of the battery, the remaining number of firings, and the estimated tissue thickness on a Bluetooth® connection display.

[0027] Referring to FIG. 21, a schematic of an operational flow diagram regarding an exemplary firing sequence of the control system is shown. As illustrated, the control system integrates user input from the trigger and firing button, as well as hardware input from various sensors and monitors, to advance the jaw assembly from a fully open state to a fully closed state in accordance with the firing sequence and then back to the fully open state.

[0028] Referring to FIGS. 3-5, during electric operation, the auxiliary gear 116 is in meshing engagement with a rack 122 provided on an operating shaft 120 that extends longitudinally within the handle body. In the illustrated embodiment, the auxiliary gear is supported within a guide member, and the operating shaft 120 slides through this guide member. The guide member helps maintain the meshing contact state between the auxiliary gear and the rack 122. The distal end of the operating shaft 120 is rotatably coupled to an operating adapter 124 that extends longitudinally into a coupler 46 at the distal end of the electric handle.

[0029] With the shaft 20 coupled to the coupler 46 of the electric handle 40, the operating adapter 124 is coupled to a drive member within the shaft 20 by an insertion connection. Thus, when the shaft 20 is attached to the handle 40, the motor 112 and the rack 122 will drive the drive member 22 coupled to the jaw assembly. Thus, the drive system within the handle is of the "rack and pinion" design type. By the operation of the motor 112 in response to user input, the operating shaft 120 is driven longitudinally back and forth, thereby closing, firing, or opening the stapler and selectively operating it in the open state.

[0030] Referring to FIGS. 6 and 7, an embodiment of a power source 130 for the electric handle 40 is shown. The power source 130 may be configured to deliver direct current to the electric handle motor and the control system. In the illustrated embodiment, the stapler can operate at 12V. The illustrated power source may consist of four 3V lithium-ion batteries 132 connected in series to produce a 12V power source. As shown, the batteries 132 are stacked in a 4×1 configuration within a plastic housing 134 to form a battery pack (battery pack). In other embodiments, other numbers and configurations of individual storage battery cells may be used to form the battery pack. For example, in certain embodiments, the battery pack may be composed of AA, AAA, or another standard or proprietary disposable or rechargeable chemical battery. In the illustrated embodiment of the electric handle 40, the battery pack is disposed at the bottom of the stationary handle. Desirably, this positioning provides a stable surface for installing the handle 40 on a flat surface. In other embodiments, it is envisioned that the power source can be positioned elsewhere within the handle, for example, near its proximal end (see, e.g., the embodiment of FIG. 1).

[0031] Continuing to refer to FIGS. 6 and 7, in some embodiments, power source 130 may be packaged with handle 40 but not attached until use. During use, the user may attach the battery pack by inserting the battery pack into battery cavity 136 disposed in handle 40. Advantageously, transporting the battery pack in a non-attached state can reduce the incidence of accidental battery discharge prior to use. Further, the removable battery pack allows the stapler system to be easily upgraded with a new battery when new battery technology becomes available. In other embodiments, the power source may be packaged in a handle in a stowed state with a removable strip blocking the electrical connection of the battery pack. In yet another embodiment, the handle is provided with a power cable configured to be plugged into an AC or DC power source, such as a wall socket or outlet, a USB connector, or another standard electrical connection.

[0032] In some embodiments, the power source further includes a memory module, such as non-volatile memory, that can store a digital record of the use state of the stapler. For example, the memory module may be configured to record details of each stapler firing, including battery voltage and motor current during firing, the sequence of states of the software state machine, any unforeseen events that occur, the shaft format used, the number of firings, the interval between firings, and the model and serial number of the stapler handle. The memory module may also be able to record whether the user can reuse the battery pack using the battery pack itself.

[0033] In some embodiments, the electric handle 40 and associated power source 130 may be configured to be used in a single procedure and then disposable for the next procedure. The power source 130 may have a power drain to reduce the likelihood of reuse. Following use in a surgical procedure, the user may remove the battery pack from the handle 40. Removing the battery pack from the handle 40 can initiate battery drain or depletion. For example, mechanical features that can short-circuit the battery by connecting the terminals to a low-value resistor or electrical feature after the battery pack has been used once can achieve the same job in the same circuit. Additionally, if the battery pack remains within the handle 40 after the surgical procedure is complete, in some embodiments, the handle's control system is programmed to disable functionality after a maximum time limit to deplete the battery pack.

[0034] Referring to FIGS. 2 and 8, one embodiment of a position sensor mechanism used in an electric handle is shown. To explain the operating principle, the rotation of the motor gear 114 causes the corresponding crown gear 142 provided within the handle 40 to rotate. The crown gear 142 is coupled to a potentiometer, and as a result, the position of the motor gear 114 and thus the actual position of the actuating rack can be determined based on the measurement of the change in resistance at the potentiometer. In some embodiments, the potentiometer may be attached to a circuit board 144 on which the control system can be implemented. The illustrated embodiment includes a position sensor mechanism using a potentiometer, but in other embodiments, it is contemplated that other position detection mechanisms can be used, and such other position detection mechanisms include, for example, the use of a magnetic encoder with a Hall effect sensor, the use of a limit switch that actuates when the actuating shaft has moved over a predetermined distance, the use of an optical system, such as a photodiode, to measure the amount of movement of a pattern along the actuating shaft, or the use of other position detection systems.

[0035] Referring to FIGS. 9A - 9D, the operating sequence of the engagement between the stapler shaft 20 and the handle cup 46 is shown. In the illustrated embodiment, the connection between the replaceable shaft 20 and the handle 40 consists of a plug - in connection. In this plug - in connection, the user axially aligns and inserts the replaceable shaft 20 into the handle 40 and then rotates the replaceable shaft 20 by approximately 90° to connect it. This plug - in connection operatively couples two mechanical functions of the plug - in shaft 20 to corresponding actuators of the handle 40. When the plug - in connection is fully engaged, the articulating member within the shaft 20 is coupled to the handle's articulating adapter, and the drive member within the shaft 20 is coupled to the operating adapter. Further, the handle 40 and the shaft 20 are preferably configured with a latch mechanism provided at the coupler 46 to prevent the user from removing the shaft 20 once the operating adapter and the drive member are actuated. Additionally, the connection at the coupler 46 preferably has a replacement part identification mechanism so that the handle's control system can detect whether the replaceable shaft is connected and what the jo - length of the attachment state of the replacement part is. It is envisioned that an electric handle can be used with the replaceable shaft 20 including jo - mechanisms of various lengths. For example, in some embodiments, the same handle 40 can be used with either a 45 - mm - long or a 60 - mm - long jo - assembly. Thus, when the jo - assembly length is identified by the control system of the electric handle, the control system can define a motor - operation profile regarding the firing stroke of the stapler corresponding to the identified length of the jo - assembly.

[0036] In FIG. 9A, the shaft 20 is positioned in parallel with a coupler 46 provided on a handle, and a release knob of the coupler 46 is retracted so as to expose an insertion channel 152 of the coupler 46 when the coupler 46 is rotationally inserted. The shaft 20 may preferably have a holding post 22 or a boss that can be positioned within the insertion channel 152. In the illustrated embodiment, the shaft has two bosses positioned at 180° intervals on its outer surface, and the coupler 46 has two corresponding insertion channels 152. In other embodiments, it is assumed that other numbers and configurations of bosses and insertion channels can be used to achieve a desired connection strength and ease of alignment.

[0037] Referring to FIG. 9B, the holding post 22 of the shaft is positioned within the insertion channel 152. Referring to FIG. 9C, the replaceable shaft 20 is rotated 90° with respect to the handle, and as a result, the holding shaft 22 of the shaft has reached the connecting end of the insertion channel 152. Referring to FIG. 9D, the release knob of the coupler is released so that a holding recess 154 provided in the release knob can hold the holding post 22 of the replaceable shaft 20.

[0038] Referring to FIGS. 10A and 10B, a cutaway side view of the coupler 46 together with the replaceable shaft 20 is shown. The holding post 22 of this shaft is positioned within a holding recess of the insertion channel. The actuating adapter 124 is coupled to a drive member 26 that extends longitudinally within the shaft 20. FIG. 10B shows a lock-in or holding mechanism that operates when the actuating adapter 124 is advanced distally initially. As shown, a locking member 24 is rotatably coupled to the proximal end of the shaft 20.

[0039] Continuing to refer to FIG. 10B, the locking member 24 may have an inclined or tapered locking surface at its proximal edge. As shown in FIG. 10A, the shaft 20 is coupled to the coupler 46 but is in an unlocked configuration. In the uncoupled and unlocked configuration, the shaft 20 can be removed from the coupler 46 through the insertion coupling by reversing the order of the operations of FIGS. 9A - 9D. Once the actuating adapter 124 advances to actuate the stapler, the actuating adapter 124 interacts with the inclined surface of the locking member 24 to advance the locking member radially outward to a locked position. In the locked position (FIG. 10B), the locking member 24 engages a locking ledge projection provided in the coupler 46 so as to lock into the shaft. With the shaft 20 locked in to the handle 40, the shaft 20 cannot be removed from the handle 40 until the actuating adapter 124 is retracted completely proximally (representatively corresponding to the full closure of the jaw assembly and the return to the open jaw configuration following the staple - firing cycle).

[0040] Thus, the "lock - in" feature prevents the user from removing the shaft from the handle once the drive member 26 is driven forward. Once the locking member 24 is positioned within a slot or ledge projection of the rotary insert of the coupler 46, the release knob of the coupler 46 cannot be pulled back. This locking action on the coupler prevents the user from rotating the shaft 20 out of the insertion coupling of the coupler 46 once stapler operation has begun.

[0041] Referring to FIGS. 11, 12, and 13A - 13F, an embodiment of the articulation mechanism for the power handle 40 is shown. In the illustrated embodiment, the handle can be articulated up to 45° in either direction from the fully articulated position relative to the longitudinal centering position at the distal end of the shaft for the joystick assembly. In some embodiments, the power handle uses a manual articulation mechanism that includes a series of components coupled to a manual actuation knob 190 at the proximal end of the handle. In other embodiments, the manual actuation knob and certain associated elements of the articulation mechanism may be positioned at other locations on the handle, such as adjacent to the distal end of the handle.

[0042] Referring to FIGS. 11 and 12, when the replaceable shaft is coupled to the handle, the articulation mechanism is coupled to an articulation member 206 that extends longitudinally within the replaceable shaft. Actuating the articulation mechanism longitudinally causes the articulation member 206 to translate proximally or distally relative to the shaft to articulate the joystick assembly at the distal end of the shaft.

[0043] Referring to FIG. 11, the articulation mechanism includes a ball screw 192 having at least one helical groove or thread 195 in which one or more ball bearings 194 can ride. In the illustrated embodiment, the articulation mechanism includes two ball bearings 194 that can fit into two threads 195. The ball bearings 194 are positioned within ball bearing holes 189 provided in a ball sleeve 191 positioned radially outward of the ball screw 192. The ball bearings 194 are maintained within the threads 195 by a release sleeve 196 positioned radially outward of the ball bearings 194. For example, rotation of an articulation knob 190 coupled to the ball sleeve 191 by a connecting pin 193 causes the ball sleeve 191 to rotate about the axis of rotation, whereby the ball bearings 194 move within the threads 195 and correspondingly translate the ball screw 192 longitudinally. The articulation of the joe assembly is achieved by rotating the articulation knob 190 and correspondingly rotating the ball sleeve 191 and the ball bearings 194 about the axis of rotation with their longitudinal positions fixed along the axis of rotation. Next, the ball bearings 194 fitted within the threads 195 of the ball screw 192 translate the ball screw 192 back and forth along the axis of rotation. In the illustrated embodiment, the ball sleeve 191 is generally tubular, and a cavity is formed in the ball sleeve, and a portion of the ball screw 192 is positioned within the cavity and translates longitudinally within the cavity. The articulation mechanism as an illustrated embodiment includes two ball bearings engageable with the threads within the ball screw, but in other embodiments, the articulation mechanism can include fewer than two or more than two ball bearings, such as a single ball bearing positioned within a single helical thread or three or more ball bearings positioned within corresponding numbers of helical threads.

[0044] Referring to FIGS. 11 and 12, the ball screw 192 extends to a distal end 200 coupled to a pair of articulating links 202. The articulating links 202 are spaced apart from each other, whereby preferably, the articulating links can be positioned radially outward of the drive system and the actuating shaft within the handle. As shown in FIG. 12, the articulating links 202 may preferably be formed with mating features, such as slots, whereby the articulating links can be keyed into corresponding mating features, such as posts, extending radially inward from the handle body. The slots can stabilize the articulating links relative to the handle, and the interaction between the handle post and the ends of the slots can define the range of articulation for the articulating mechanism. The distal ends of the articulating links 202 can be rotatably coupled to an articulating adapter 204, which can be coaxially positioned radially outward at the distal end of the handle with respect to the actuating adapter. This rotary coupling preferably includes an articulating bearing 205 with relatively low friction characteristics. This articulating bearing 205 can facilitate the rotation of the replaceable shaft in a coupled state with respect to the handle assembly and the longitudinal movement of the articulating adapter 204 during the operation of the articulating mechanism. The articulating mechanism of the illustrated embodiment includes two articulating links laterally offset from the actuating mechanism within the handle, but in other embodiments, it is envisioned that the articulating mechanism can include fewer than two or more than two articulating links, such as one articulating link or three or four or more articulating links.

[0045] Continuing to refer to FIG. 12, when the shaft is coupled to the handle, the articulating adapter 204 can be coupled to an articulating member 206 within the shaft by an insertion connection. The thread 195 may preferably be configured such that when the ball screw is moved in the proximal direction, the jaw assembly articulates to the left as viewed from the handle with respect to the longitudinal centering position, and when the ball screw 192 is moved in the distal direction, the jaw assembly articulates to the right as viewed from the handle with respect to this longitudinal centering position.

[0046] Advantageously, the helical thread 195 of the ball screw 192 is continuous, so that the articulation mechanism can articulate the joe assembly to virtually infinite angular positions within a desired range of motion relative to each other. In some embodiments, the articulation mechanism may be configured to provide an articulation range of motion of -45° to +45° of the joe assembly relative to the longitudinal centering position defined by the longitudinal axis of the shaft. In other embodiments, the articulation mechanism may be configured to provide other operating articulation ranges, including ranges that result in articulation beyond ±45° or ranges that result in articulation less than ±45°. In some embodiments, the articulation mechanism may be configured to provide articulation in a single direction relative to the longitudinal centering position.

[0047] In some embodiments, the pitch of the thread 195 provided on the ball screw 192 varies. For example, the thread 195 may preferably have a relatively small pitch towards the end of the thread to advantageously provide a greater mechanical advantage when the joe assembly may require a greater force to articulate. The thread 195 may preferably have a relatively large pitch towards the center of the thread to enable rapid movement with a relatively small mechanical advantage when the joe assembly may require a small force to articulate. In other embodiments, the thread 195 results in a proportional amount of articulation of the stapler joe assembly that does not vary over the articulation range of the articulation mechanism as a result of rotation of the articulation knob. Desirably, such a constant pitch threaded ball screw can result in an easily predictable response during operation of the actuating mechanism.

[0048] Referring to FIGS. 13A-13F, the articulation mechanism may preferably include a release mechanism that enables the articulation mechanism to be reset from any post-articulation position to the longitudinal centering position. The release mechanism is actuated by the user pressing the release button 198. In the illustrated embodiment, the release button 198 is positioned radially fitted within the articulation knob 190.

[0049] Referring to FIG. 13B, upon actuation of the release button 198, the release sleeve 196 advances distally. The radially inner surface of the release sleeve 196 is stepped to have an engagement surface 186 with a relatively small inner diameter and a release surface 188 with a relatively large inner diameter, and the slope between the engagement surface and the release surface is smooth. To explain the operating principle, the engagement surface of the release sleeve holds the ball bearing 194 within the thread 195 of the ball screw 192. Once the release button 198 is pressed, the engagement surface is advanced distally, whereby the ball bearing 194 can disengage from the thread 195 and advance radially outward through the ball bearing hole 189 provided in the ball sleeve to contact the release surface.

[0050] Referring to FIGS. 13C and 13D, with the ball bearing 194 disengaged from the thread 195, the articulation mechanism body is preferably biased to the centering position. In some embodiments, the ball screw 192 is biased to the centering position by a biasing member, such as two springs 197 and the spring force from the shaft. The ball bearing 194 positioned at the centering position (FIG. 13D) along the thread 195 corresponds to the longitudinal centering position of the jaw assembly.

[0051] Referring to FIGS. 13E and 13F, once the release button 198 is returned to an unobstructed configuration, the release sleeve 196 is retracted proximally (as indicated by arrow 199) by a spring. The proximal movement of the release spring 196 causes the ball bearing 194 to engage the thread 195 of the ball screw. Thus, when the articulation mechanism body is used next, the jaw assembly can be articulated from the longitudinal centering position or the stapler can be used with the jaw assembly in the longitudinal centering position.

[0052] Referring to FIGS. 14, 15, and FIGS. 16A and 16B, an embodiment of a manual return mechanism for an electric handle is shown. The manual return mechanism can advantageously be a redundant return mechanism in the event of a power failure, failure of other electric components, or mechanical failure or binding.

[0053] Referring to FIGS. 14 and 15, the manual return mechanism includes two separately and independently operable sub-assemblies that are actuated in sequence to return the actuating shaft 120 to the most proximal position within the handle, which corresponds to the open configuration of the jaw assembly. As shown, the manual return mechanism 170 includes a shaft rotation mechanism and a shaft retraction mechanism. To explain the operating principle, when it is desired to manually return the stapler to the open configuration, the shaft rotation mechanism is actuated first.

[0054] Referring to FIGS. 14 and 15, to operate the shaft rotation mechanism of the manual return mechanism 170, the user pulls the engagement release or disengagement tab 172 positioned on the outer surface of the handle. An engagement release or disengagement rack 174 is formed on the engagement release tab 172. The engagement release rack 174 is in meshing engagement with a shaft rotation rack 176 formed on the shaft rotation collar 176. The actuating shaft 120 passes through and is slidable through the shaft rotation collar 176. Thus, by pulling the engagement release tab 172, the rotating shaft 120 rotates approximately 90° about its longitudinal axis. By this rotation, the rack 122 of the actuating shaft is positioned to disengage from the engagement with the auxiliary gear 116 of the drive system. Further, in some embodiments, removal of the engagement release tab 172 from the handle can also disengage the power from the drive system or, in a different way, disengage the control system, thereby preventing further electric operation of the electric handle. In addition, the shaft rotation mechanism may be configured to be actuated only once. For example, in the illustrated embodiment, a return claw 182 provided on the shaft retraction mechanism, once it pulls the shaft rotation engagement release tab 172, has an interference lobe 183 sized and shaped to prevent the return lever from closing and to interfere with the drive system to prevent the rotation of the rotating shaft 120 from returning to the engaged state with the auxiliary gear. Thus, once the shaft rotation mechanism is actuated, the handle can be disabled so that it cannot be used further.

[0055] Referring to FIGS. 15 and 16A and 16B, once the shaft rotation mechanism is actuated, the shaft retraction mechanism is operable to return the actuating shaft proximally within the handle. Removal of the engagement release tab 172 from the handle exposes a return lever 180 provided on the power handle. The return lever 180 is pivotally coupled to a return pawl 182 at a pivot joint 184. When the rack 122 of the actuating shaft 120 is rotated to disengage from the drive system, this rack is rotated to engage with the shaft retraction mechanism. Rotating the return lever 180 through one or a series of return cycles (FIGS. 16A, 16B) allows the return pawl 182 to engage the rack 122 of the actuating shaft 120, and the actuating shaft 120 can be retracted proximally within the handle in a ratchet-type actuation manner.

[0056] Referring to FIGS. 17, 18, and FIGS. 19A and 19B, another embodiment of a manual return mechanism for an electric handle is shown. The components and operating principles of the manual return mechanism 170' are substantially the same as the components and operating principles described above with reference to the manual return mechanism 170 of FIGS. 14, 15, and FIGS. 16A and 16B. However, in using the manual return mechanism 170', removal of the release tab 172' from the handle assembly exposes the shaft rotation collar 176' from which the rotation lever 178' protrudes. When the handle assembly is in an electrically actuated state, the release tab 172' covers the shaft rotation collar 176' provided on the outer surface of the handle. Once the release tab is removed, the user can then operate the rotation lever 178' to rotate the actuating shaft 120, and as a result, actuate the shaft retraction mechanism to retract the actuating shaft proximally within the handle. The shaft retraction mechanism of the manual return mechanism 170' has the same ratchet-type operating mode as described above with respect to the manual return mechanism 170. Desirably, in some handle configurations, the rotation lever 178' can provide a significant mechanical advantage in facilitating rotation of the actuating shaft as compared to the shaft rotation mechanism including the release rack 174 of FIGS. 14, 15, and FIGS. 16A and 16B.

[0057] Although the present application discloses certain preferred embodiments and examples, as will be understood by those skilled in the art, the present invention extends beyond the specifically disclosed embodiments to other alternative embodiments and / or uses of the invention as well as obvious modifications and equivalents thereof. Further, the various features of these inventions can be used alone or in combination with other features of these inventions other than those explicitly described above. Thus, it is intended that the scope of the invention disclosed herein should not be limited by the specific disclosed embodiments described above, but should be determined only by a fair interpretation of the claims.

Claims

1. 1. A handle assembly for a surgical stapler, comprising: a handle body having a stationary handle and a trigger pivotally coupled to the handle body; an electric motor disposed within the handle body; an actuation shaft slidable along a longitudinal axis within the handle body and rotatable about the longitudinal axis within the handle body, the actuation shaft having a rack formed thereon; A manual return mechanism is included. the actuation shaft is rotatable from a first position in which the rack operatively engages the electric motor to slide the actuation shaft longitudinally to a second position in which the rack disengages from the electric motor and engages the manual return mechanism, a handle assembly.

2. 2. The handle assembly of claim 1, wherein the electric motor has an output shaft, the handle assembly further including a motor gear coupled to the output shaft and an auxiliary gear in driven mesh with the motor gear and engaging the rack when the rack is in the first position.

3. 3. The handle assembly of claim 2, further comprising a guide member supporting said auxiliary gear and said actuation shaft and maintaining said auxiliary gear in meshing engagement with said rack.

4. The manual return mechanism includes: a shaft rotation mechanism configured to rotate the shaft from the first position to the second position; a shaft retraction mechanism configured to proximally retract the actuation shaft.

5. The handle assembly of claim 4 , wherein the shaft rotation mechanism includes a shaft rotation collar on the actuation shaft.

6. 6. The handle assembly of claim 5, wherein said shaft rotation collar has a shaft rotation rack formed thereon.

7. 7. The handle assembly of claim 6, wherein the shaft rotation mechanism further includes a disengagement tab positioned on an outer surface of the handle body, the disengagement rack being formed on the disengagement tab in engaging relationship with the shaft rotation rack.

8. The handle assembly of claim 7 , wherein removal of the disengagement tab from the outer surface of the handle assembly causes the actuation shaft to rotate from the first position to the second position.

9. The shaft retraction mechanism comprises: A return lever and With a back claw, a pivot joint pivotally connecting said return lever to said return pawl.

10. The handle assembly of claim 9 , wherein the return pawl engages the rack with the actuation shaft in the second position.

11. The handle assembly of claim 10 , wherein actuating the return lever through a return cycle advances the actuation shaft proximally with the actuation shaft in the second position.

12. 10. The handle assembly of claim 9, wherein the shaft retraction mechanism further includes an impeding lobe projecting from the return lever to impede rotation of the actuation shaft from the second position to the first position.

13. 1. A handle assembly for a surgical stapler, said handle assembly comprising: a handle body having a stationary handle and a trigger pivotally coupled to the handle body; an electric motor disposed within the handle body, the electric motor having an output shaft; an actuation shaft slidable along a longitudinal axis within the handle body; a motor gear coupled to the output shaft of the motor; an auxiliary gear in driven mesh with said motor gear and in operative engagement with a rack; a crown gear mounted within said handle in meshing engagement with said motor gear; a potentiometer coupled to said crown gear; A handle assembly including a control system electrically coupled to the trigger, the electric motor, and the potentiometer.

14. The handle assembly of claim 13 , wherein the control system is configured to measure a longitudinal position of the actuation shaft.

15. The handle assembly of claim 14, wherein the control system measures a change in resistance at the potentiometer to determine a position of the actuation shaft.

16. 1. A handle assembly for a surgical stapler, said handle assembly comprising: a handle body having a stationary handle and a trigger pivotally coupled to the handle body; a power system provided within the handle body; an actuation shaft operatively coupled to the power system, the actuation shaft slidable within the handle body along a longitudinal axis; an articulation mechanism comprising: a manual articulation knob positioned at a proximal end of the handle body and rotatable about the longitudinal axis; and an articulation adapter positioned at a distal end of the handle body, the articulation adapter operatively coupled to the articulation knob such that rotation of the actuation knob about the longitudinal axis causes the articulation adapter to slide longitudinally.

17. The handle assembly of claim 16 , wherein the articulation mechanism further comprises a release mechanism configured to reset the articulation adapter to a longitudinally centered position.

18. The articulation mechanism includes: a ball screw having a helical thread formed therein; a ball sleeve positioned radially outward of the ball screw and having a hole formed therein; 17. The handle assembly of claim 16, further comprising a ball bearing positioned within the bore of the ball sleeve and fitted within the helical threads of the ball screw.

19. 20. The handle assembly of claim 18, wherein the ball screw is movable longitudinally relative to the handle body, and movement of the ball bearings within the helical threads causes the ball screw to move longitudinally.

20. 20. The handle assembly of claim 18, wherein the ball screw has a distal end, the handle assembly further including an articulation link coupled to the distal end of the ball screw and extending distally within the handle body to the articulation adapter.

21. The handle assembly of claim 18 , wherein the ball sleeve is rotatably coupled to the articulation knob.

22. The handle assembly of claim 18 , wherein the articulation mechanism further comprises a release mechanism configured to reset the articulation adapter to a longitudinally centered position.

23. 23. The handle assembly of claim 22, wherein the release mechanism includes a release button in operative engagement with a release sleeve, actuation of the release button disengaging the ball bearing from the helical threads.

24. 23. The handle assembly of claim 22, wherein the release sleeve has an inner surface including an engagement surface with a first inner diameter and a release surface with a second inner diameter larger than the first inner diameter.

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