Surgical stapler with motorized handle

Abstract

To provide reliable stapling of clamped tissue without complex mechanisms.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. The powered handle includes a battery pack serving as a power supply for the drive system. A control system controls actuation of the motor based on user inputs and operating parameters of the stapler. The powered handle includes a manual return mechanism.SELECTED DRAWING: Figure 14

Description

[Technical field]

[0001] FIELD OF THE DISCLOSURE This application relates generally to surgical closure instruments, and more particularly to powered surgical staplers.

[0002] Description of Related Applications This application is a claim of benefit of U.S. Provisional Patent Application No. 62 / 321,629, filed April 12, 2016, entitled "SURGICAL STAPLER HAVING A POWERED HANDLE," which is currently pending. [Background technology]

[0003] Surgical staplers are used to approximate or clamp tissue and staple the clamped tissue together. Thus, surgical staplers have mechanisms that ensure the tissue is properly positioned and captured, and drive the staples into the tissue. This results in, for example, multiple triggers and handles in conjunction with complex mechanisms to enable proper stapling of the clamped tissue. These complex mechanisms can increase the manufacturing burden for surgical staplers and create potential sources of device failure and confusion for users. Thus, there is a need for reliable stapling of clamped tissue without complex mechanisms. Summary of the Invention

[0004] In certain embodiments, provided herein is a powered handle for a surgical stapling system. The powered handle can include a drive system powered by a power source to selectively actuate an actuation adapter. The powered handle can include a manual articulation mechanism for selectively actuating the articulation adapter. The powered handle can further include a coupler with a bayonet coupling for simultaneously coupling the articulation adapter and the actuation adapter to an articulation member and a drive member provided in a replaceable shaft.

[0005] In certain embodiments, the powered 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 / return button on the powered handle, and the control system can further vary the actuation profile of the drive system in response to various operating parameters including drive system actuation torque, longitudinal position of the actuation adapter, and identification of the length or configuration of the jaw assembly.

[0006] In one particular embodiment, the powered handle of the surgical stapling system includes a manual articulation system having a ball screw mechanism that can permit continuous articulation of the jaw assembly of the stapling system through a predetermined range of articulation that can be biased into a longitudinally centered position and can be rapidly centered through the use of a release mechanism.

[0007] In one particular embodiment, a handle assembly for a surgical stapler is provided. The handle assembly includes a handle body, an electric motor, an actuation shaft, and a mechanical return mechanism. The handle body has a stationary handle and a trigger pivotally coupled to the handle body. The electric motor is disposed within the handle body. The actuation shaft is slidable along a longitudinal axis within the handle body and rotatable about the longitudinal axis within the handle body. A rack is formed on the actuation shaft. 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.

[0008] In certain embodiments, a handle assembly for a surgical stapler is provided. The handle assembly includes a handle body, an electric motor, an actuation 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 pivotally coupled to the handle body. The electric motor is disposed within the handle body. The electric motor has an output shaft. The actuation shaft is slidable along a longitudinal axis within the handle body. The motor gear is coupled to the motor output shaft. The auxiliary gear is in driven meshing relationship with the motor gear. The motor gear is operatively engaged with the rack. A crown gear is disposed within the handle in meshing engagement 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 actuation shaft, and an articulation mechanism. The handle body has a stationary handle and a trigger pivotally coupled to the handle body. The power system is disposed within the handle body. The actuation shaft is operatively coupled to the power system. The actuation 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 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 actuation knob about the longitudinal axis causes the articulation adapter to slide longitudinally. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a perspective view of one embodiment of a surgical stapling system including an embodiment of a powered handle. [Diagram 2]FIG. 2 is a side view of another embodiment of a powered handle for the surgical stapling system of FIG. [Figure 2A] FIG. 3 is an exploded perspective view of a powered handle for the surgical stapling system of FIG. 2; [Diagram 3] 3 is a partial cutaway perspective view of the powered handle of FIG. 2 with some components removed to show the drive system of the powered handle of FIG. 2.

[0023] FIG. [Figure 4] FIG. 3 is a perspective view of an embodiment of a drive system for the powered handle of FIG. [Diagram 5] FIG. 3 is a side view of an embodiment of a drive system for the powered handle of FIG. 2. [Figure 6] FIG. 3 is a perspective view of one embodiment of a power supply for the powered handle of FIG. [Figure 7] FIG. 3 is a side view of the powered handle of FIG. 2 with the power supply in place for installation. [Figure 8] FIG. 3 is a perspective view of an embodiment of a position indexing system for the motorized handle of FIG. [Figure 9A] 3 is a perspective view of an embodiment of a shaft coupler for the powered handle of FIG. 2 with an embodiment of a shaft in a removed position. FIG. [Figure 9B] 3 is a perspective view of an embodiment of a shaft coupler for the powered handle of FIG. 2 with an embodiment of a shaft in a partially inserted position. FIG. [Figure 9C] 3 is a perspective view of an embodiment of a shaft coupler for the powered handle of FIG. 2 with an embodiment of a shaft in a fully inserted position. [Figure 9D] 3 is a perspective view of an embodiment of a shaft coupler for the powered handle of FIG. 2 with an embodiment of a shaft in a retaining position. FIG. [Figure 10A] FIG. 3 is a cutaway side view of an embodiment of the shaft coupler of FIG. 2 with an embodiment of the shaft in a retaining position. [Figure 10B]FIG. 3 is a cutaway side view of an embodiment of the shaft coupler of FIG. 2 with an embodiment of the shaft in a latched position. [Figure 11] FIG. 3 is a cutaway side view of one embodiment of an articulation mechanism of the powered handle of FIG. [Figure 12] FIG. 12 is a perspective view of the articulation mechanism of FIG. 11 in an articulated position. [Figure 13A] FIG. 12 is a cutaway side view of the articulation mechanism of FIG. [Figure 13B] FIG. 12 is a cutaway side view of the articulation mechanism of FIG. 11 with the release button pressed. [Figure 13C] FIG. 12 is a cutaway side view of the articulation mechanism of FIG. 11 with the release button pressed and partially returned to the centered position. [Figure 13D] FIG. 12 is a cutaway side view of the articulation mechanism of FIG. 11 with the release button pressed back into the centered position. [Figure 13E] FIG. 12 is a cutaway side view of the articulation mechanism of FIG. 11 in a centered position with the release button partially released. [Figure 13F] FIG. 12 is a cutaway side view of the articulation mechanism of FIG. 11 in a centered position. [Figure 14] FIG. 3 is a perspective view of one embodiment of a manual return assembly for the powered handle of FIG. [Figure 15] FIG. 15 is a perspective view of the manual return assembly of FIG. 14 with the decoupling mechanism activated. [Figure 16A] FIG. 15 is a side view of the manual return assembly of FIG. 14 with the return mechanism partially actuated. [Figure 16B] FIG. 15 is a side view of the manual return assembly of FIG. 14 with the return mechanism actuated through the full return stroke. [Figure 17] FIG. 3 is a perspective view of one embodiment of a manual return assembly for the powered handle of FIG. [Figure 18] FIG. 18 is a perspective view of the manual return assembly of FIG. 17 with the decoupling mechanism activated. [Figure 19A]FIG. 18 is a side view of the manual return assembly of FIG. 17 with the return mechanism partially actuated. [Figure 19B] FIG. 18 is a side view of the manual return assembly of FIG. 17 with the return mechanism actuated through the full return stroke. [Figure 20] 3 is a schematic diagram of information and power flows for one embodiment of a control system for the powered handle of FIG. 2. [Figure 21] 3 is an actuation sequence flow diagram for an example actuation sequence of the powered handle of FIG. 2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] With reference to Figures 1 and 2, one embodiment of a surgical stapling system is shown. The illustrated embodiment of a surgical stapler 10 includes an elongated shaft 20, a jaw assembly 30, and a handle assembly 40. Figure 1 illustrates the surgical stapler 10 with the jaw assembly 30 in an open configuration, and one embodiment of a powered handle provides for both powered staple firing and powered jaw assembly articulation. Figure 2 illustrates another embodiment of a powered handle 40 for a surgical stapler system with the elongated shaft removed. The powered handle 40 of Figure 2 provides for both powered staple firing and manual jaw assembly articulation. In the illustrated embodiment, the shaft 20 and jaw assembly 30 are freely rotatable about a longitudinal axis defined by the shaft 20 by rotation of a rotation knob on the handle 40. In other embodiments, the stapling system may be configured to allow rotation of the jaw assembly about a longitudinal axis within a defined range or a rotationally fixed jaw assembly.

[0012] With continued reference to FIG. 1 , the illustrated embodiment of the surgical stapler 10 may be sized and configured for use in laparoscopic surgical procedures. For example, the elongate shaft 20 and jaw assembly 30 may be sized and configured for introduction into a surgical field through an access port or trocar cannula. In some embodiments, the elongate shaft 20 and jaw assembly 30 may be sized and configured for insertion through a trocar cannula with a relatively small working channel diameter, e.g., less than 8 mm. In other embodiments, the elongate shaft 20 and jaw assembly 30 may be sized and configured for insertion through a trocar cannula with a large working channel diameter, e.g., 10 mm, 11 mm, 12 mm, or 15 mm. In other embodiments, it is envisioned that certain aspects of the surgical stapler described herein may be incorporated into a surgical stapling instrument that may be used in open surgical procedures.

[0013] 1, as shown, the elongated shaft 20 comprises a generally tubular member. The elongated shaft 20 extends from a proximal end to a distal end. The elongated shaft 20 defines a central longitudinal 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 elongate shaft 20 at the distal end thereof. The jaw assembly 30 includes a first jaw 32 and a second jaw 34 pivotally coupled to the first jaw 32. In the illustrated embodiment, the first jaw 32 is fixed to the distal end 24 of the elongate shaft 20 such that it extends distally along a central longitudinal axis L, and the first jaw is articulatable relative to the elongate shaft 20 in response to an articulation mechanism in the handle 40. In an initial configuration, the first jaw 32 has a plurality of staples 36 disposed therein and housed within a reload 50. In other embodiments, the reload 50 may be integral with the jaw assembly 30 such that the shaft assembly 20 and the staple-loaded jaw assembly 30 together form a single reloadable assembly. In some embodiments, the staples may be initially positioned within the second jaw 34.

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

[0016] 1, in the illustrated embodiment, the handle assembly is coupled to the elongate shaft 20 at a proximal end thereof. As shown, the handle assembly 40 has a pistol-grip configuration with a housing having a stationary handle 42 and a movable handle 44 or trigger pivotally coupled to the stationary handle 42. In other embodiments, it is contemplated that surgical stapler instruments incorporating aspects described herein may have handle assemblies with other configurations, such as a scissor-grip configuration or an in-line configuration. As described in more detail below, the handle assembly 40 contains a powered actuation mechanism configured to selectively advance an actuation shaft in response to movement of the movable handle 44.

[0017] In the illustrated embodiment, the surgical stapler 10 can have a plurality of staples 36 positioned within a disposable cartridge reload 50, while the jaw assembly 30 is configured to be reused with multiple staple cartridge reloads 50 in a single procedure. In some embodiments, the elongated shaft 20 and jaw assembly 30 form a disposable, replaceable shaft that is removably coupleable to a 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 elongated shaft 20 of the surgical stapler 10. The coupler 46 can have a bayonet connection with an outer connector that can removably couple the elongated shaft 20 to the handle assembly 42 and an inner connector that can removably couple the actuation shaft of the handle assembly 40 to the drive member of the elongated shaft 20. Thus, the surgical stapler 10 can be configured to allow the handle assembly 40 to be reused with multiple replaceable shafts 20 during a surgical procedure. In other embodiments, it is envisioned that the handle assembly and a portion of the elongate shaft may be reusable with the remainder of the elongate shaft within the jaw assembly forming a disposable cartridge. In certain other embodiments, the handle assembly and the elongate shaft may be reusable with the jaw assembly forming a disposable cartridge. In still other embodiments, the jaw insert containing the plurality of staples may form a disposable cartridge, while the remainder of the surgical stapler is reusable.

[0018] Referring to Figure 2, one embodiment of a powered handle for a surgical stapling system is shown. The powered handle can be used with a variety of shaft replacements and cartridges, so that shaft configurations, jaw assembly configurations, and staple configurations can be selected for a particular procedure. The illustrated embodiment of the handle provides powered (motor driven) clamping and opening of the jaws and firing of the staple line. 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 function of the handle during different phases of use.

[0019] 2, the motorized handle 40 is in a pistol grip configuration with a stationary handle 42 and a movable handle 44 or trigger pivotally coupled to the stationary handle. A power source 130 or battery can be provided on the underside of the stationary handle. The motorized handle 40 can also include user controls, such as a firing or fire / reverse button 150, to allow the user to selectively control the stapling sequence. The motorized handle 40 can also include a redundant manual return system 170 to allow the user to manually return the stapling system to the open configuration in the event of a power system failure, a control system failure, a power supply failure, or a "lockjaw" or other mechanical binding. The motorized handle can also 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 motorized handle and is generally rotatable about an axis coincident with the longitudinal axis of the stapling system.

[0020] Referring to Figure 2A, the powered handle of Figure 2 is shown in an exploded view, showing various elements of an illustrative embodiment of the powered handle, which will be described further herein.

[0021] Referring to FIG. 3, a partial cutaway view of the electric handle is shown with the shaft 20 positioned within the coupler 46 of the handle. In the cutaway view shown, some components of the electric handle are omitted to clearly show the drive system of the electric 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 driven mesh 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 centered within the stationary handle, thereby enhancing balance and user ergonomics of the handle. Furthermore, in some embodiments, the motor gear 114 and the auxiliary gear 116 can be configured to provide a desired operating torque at the rack 122. In some embodiments, the motor 112 can have a multi-gear type transmission operatively coupled between the motor 112 and the motor gear 114, which is coupled to the auxiliary gear 116 to provide the desired operating torque. The motor 112 may be electrically coupled to a power source 130 through a control system. The control system in the handle interfaces with the drive system to measure the position of the actuation shaft 120 and thus the actuation status of the jaw assembly.

[0022] The drive system is attached to hardware that provides information to a control system that includes a microprocessor in 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 if the load is too high to continue firing staples or activate a lockout of the replaceable cartridge. The control system can also measure the battery life and further limit the number of times the device can be fired.

[0023] Referring to FIG. 20, a schematic flow diagram illustrating data and power flow for an exemplary control system for a motorized handle is shown. In the illustrated flow diagram, the control system includes a microcontroller as shown. In various embodiments, the microcontroller may comprise an application specific integrated circuit or a general purpose microprocessor executing application specific firmware and / or software. As shown, the microcontroller receives data regarding power and battery status from a battery in the power supply. The microcontroller also receives data from various mechanical hardware of the stapler, such as a motor drive and current monitor, an actuation rack position detection mechanism, and a shaft coupling and type monitor. The microcontroller also receives data from a user via a trigger position sensor, a push button switch, and a Bluetooth® communication transceiver. The control system can output control signals to operate the drive system of the motorized 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 LED lights provided in the handle and the Bluetooth® communication transceiver.

[0024] In certain embodiments, the control system is also configured to further define operating parameters of the motorized handle. For example, by interrogating a memory module on the power source or on the control system itself, the control system can detect whether the motorized 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 interrogate a memory module on the power source or on the control system to detect the number of staple firings, thereby assessing whether there is enough battery power remaining to complete additional firings.

[0025] In certain embodiments, the control system is configured to detect tissue characteristics that may prevent staple firing. In some embodiments, the control system can monitor the position, speed, and applied torque of the motor in the drive system. The control system can detect if excessive torque is required to close the jaw assembly if excessive time is required to close the jaw assembly or if the jaws are closing at a slow speed. These conditions may indicate that the tissue in the jaw assembly is too thick or dense for the stapler to be effective. In certain embodiments, the control system can monitor the position of the actuation shaft versus time, and this monitored position and time can be evaluated against a baseline "zero load" time reference 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 through a Bluetooth® connection. The motorized handle can have a low power Bluetooth® transceiver that can unobtrusively display data regarding operating parameters, such as battery status, number of shots remaining, and estimated tissue thickness, on a Bluetooth® connected display.

[0027] 21, a simplified operational flow diagram for an exemplary firing sequence for the control system is shown. As shown, the control system integrates user input from the trigger and fire 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 and then back to a fully open state in a firing sequence.

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

[0029] With the shaft 20 coupled to the coupler 46 of the powered handle 40, the actuation adapter 124 couples to a drive member within the shaft 20 by a bayonet connection. Thus, when the shaft 20 is attached to the handle 40, the motor 112 and rack 122 drive the drive member 22 coupled to the jaw assembly. Thus, the drive system within the handle is of a "rack and pinion" design. Operation of the motor 112 in response to user input drives the actuation shaft 120 longitudinally back and forth, thereby selectively operating the stapler in a closed, fired, or open operating condition.

[0030] 6 and 7, one embodiment of a power supply 130 for the motorized handle 40 is shown. The power supply 130 can be configured to deliver direct current to the motorized handle motor and control system. In the illustrated embodiment, the stapler can operate on 12V. The illustrated power supply can consist of four 3V lithium-ion batteries 132 connected in series to produce a 12V power supply. As shown, the batteries 132 are stacked in a 4×1 configuration within a plastic housing 134 to form a battery pack. In other embodiments, other numbers and configurations of individual battery cells can be used to form the battery pack. For example, in one particular embodiment, the battery pack can consist of AA, AAA, or other standard or proprietary single-use or rechargeable chemistry batteries. In the illustrated embodiment of the motorized handle 40, the battery pack is located at the bottom of the stationary handle. Desirably, this positioning provides a stable surface for placing the handle 40 on a flat surface. It is envisioned that in other embodiments, the power source may be positioned elsewhere within the handle, such as at its proximal end (see, eg, the embodiment of FIG. 1).

[0031] With continued reference to FIGS. 6 and 7, in some embodiments, the power source 130 may be packaged with the handle 40 but not installed prior to use. During use, a user may install the battery pack by inserting it into a battery cavity 136 located at the handle 40. Advantageously, shipping the battery pack in an unattached state may reduce the incidence of accidental battery discharge prior to use. Additionally, a removable battery pack allows the stapler system to be easily upgraded with new batteries as new battery technologies become available. In other embodiments, the power source may be packaged housed within the handle with a removable strip preventing electrical connection of the battery pack. In yet another embodiment, the handle is supplied with a power cable configured to plug 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 supply further includes a memory module, e.g., a non-volatile memory, capable of storing a digital record of the usage status of the stapler. For example, the memory module may be configured to record details of each firing of the stapler, including the battery voltage and motor current during firing, the sequence of states of the software state machine, any contingencies that may have occurred, the shaft type used, the number of firings, the interval between firings, and a periodic sampling of the model and serial number of the stapler handle. The memory module may also record whether the user is unable to reuse the battery pack with the battery pack itself.

[0033] In some embodiments, the powered handle 40 and associated power source 130 may be configured to be used in one procedure and then disposable. The power source 130 may have a power drain to reduce the risk 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 may initiate draining or draining of the batteries. For example, after a battery pack has been used once, a mechanical feature may short the battery by connecting the terminals to a low value resistor or electrical feature to accomplish the same task with the same circuit. Additionally, if the battery pack is left in the handle 40 after the surgical procedure is completed, in some embodiments, the handle's control system is programmed to disable the function and drain the battery pack after a maximum time limit.

[0034] 2 and 8, one embodiment of a position sensor mechanism for use in an electric handle is shown. In operation, rotation of the motor gear 114 causes a corresponding rotation of a crown gear 142 located within the handle 40. The crown gear 142 is coupled to a potentiometer such that the position of the motor gear 114, and thus the actual position of the actuation rack, can be determined based on measuring the change in resistance at the potentiometer. In some embodiments, the potentiometer may be mounted on a circuit board 144 on which a control system may be implemented. While the illustrated embodiment includes a position sensor mechanism utilizing a potentiometer, it is contemplated that other position sensing mechanisms may be used in other embodiments, including, for example, the use of a magnetic encoder with a Hall effect sensor, the use of a limit switch that is activated when the actuation shaft has traveled a predetermined distance, the use of an optical system, such as a photodiode, to measure the amount of movement of a pattern along the actuation shaft, or other position sensing systems.

[0035] 9A-9D, an operational sequence for engagement of the stapler shaft 20 with the coupler 46 of the handle is shown. In the illustrated embodiment, the connection between the replaceable shaft 20 and the handle 40 comprises a bayonet connection in which the user inserts the replaceable shaft 20 into the handle 40 in axial alignment and then rotates the replaceable shaft 20 approximately 90 degrees to couple. The bayonet connection operatively couples two mechanical functions of the bayonet shaft 20 to corresponding actuators of the handle 40. When the bayonet connection is fully engaged, an articulation member within the shaft 20 is coupled to an articulation adapter of the handle and a drive member within the shaft 20 is coupled to an actuation adapter. Additionally, the handle 40 and shaft 20 may be configured with a latch mechanism at the coupler 46 to prevent the user from removing the shaft 20 once the actuation adapter and drive member have been actuated. Additionally, the connection at the coupler 46 may include a replacement identification mechanism so that the handle's control system can detect whether a replaceable shaft has been coupled and what the jaw length is with the replacement installed. It is envisioned that the motorized handle may be used with replaceable shafts 20 including jaw mechanisms of various lengths. For example, in some embodiments, the same handle 40 may be used with either a 45 mm long or a 60 mm long jaw assembly. Thus, when the jaw assembly length is identified by the motorized handle's control system, the control system may define a motor actuation profile for the firing stroke of the stapler that corresponds to the identified jaw assembly length.

[0036] 9A, the shaft 20 is positioned in juxtaposition with the coupler 46 on the handle, with the release knob of the coupler 46 retracted to expose the bayonet channel 152 of the coupler 46 upon rotational insertion of the coupler 46. The shaft 20 may have a retention post 22 or boss positionable within the bayonet channel 152. In the illustrated embodiment, the shaft has two bosses positioned 180° apart on its exterior surface, and the coupler 46 has two corresponding bayonet channels 152. It is contemplated that other numbers and configurations of bosses and bayonet channels may be used in other embodiments to facilitate the desired connection strength and alignment.

[0037] With reference to Fig. 9B, the shaft's retaining post 22 is positioned within the bayonet channel 152. With reference to Fig. 9C, the replaceable shaft 20 is rotated 90° relative to the handle so that the shaft's retaining post 22 reaches the coupling end of the bayonet channel 152. With reference to Fig. 9D, the coupler's release knob is released to allow a retaining recess 154 on the release knob to retain the retaining post 22 of the replaceable shaft 20.

[0038] 10A and 10B, cutaway side views of coupler 46 are shown along with a replaceable shaft 20. The shaft's retention post 22 is positioned within a retention recess in the bayonet channel. An actuation adapter 124 is coupled to a drive member 26 that extends longitudinally within shaft 20. FIG. 10B illustrates a lock-in or retention mechanism that is actuated upon initial distal advancement of actuation adapter 124. As shown, a locking member 24 is pivotally coupled to the proximal end of shaft 20.

[0039] With continued reference 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 in a coupled but unlocked configuration relative to the coupler 46. In the coupled, unlocked configuration, the shaft 20 may be removed from the coupler 46 via the bayonet connection by reversing the sequence of operations of FIGS. 9A-9D. Once the actuation adapter 124 is advanced to actuate the stapler, the actuation adapter 124 interacts with the inclined surface of the locking member 24 to advance the locking member radially outward to the locked position. In the locked position (FIG. 10B), the locking member 24 engages a locking ledge provided on the coupler 46 to lock-in within the shaft. With the shaft 20 locked in to the handle 40, the shaft 20 cannot be removed from the handle 40 until the actuation adapter 124 returns to its fully proximally retracted position (typically corresponding to full closure of the jaw assembly and return to the jaw open configuration following a stapling cycle).

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

[0041] 11, 12, and 13A-13F, one embodiment of an articulation mechanism for a powered handle 40 is shown. In the embodiment shown, the handle is capable of articulating the jaw assembly up to 45° in either direction relative to a fully articulated position relative to a longitudinal centered position at the distal end of the shaft. In some embodiments, the powered handle employs 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 elsewhere on the handle, such as adjacent the distal end of the handle.

[0042] 11 and 12, the articulation mechanism is coupled to an articulation member 206 that extends longitudinally within the replaceable shaft when the replaceable shaft is coupled to the handle. When the articulation mechanism is actuated longitudinally, the articulation member 206 translates proximally or distally relative to the shaft to articulate the jaw assembly at the distal end of the shaft.

[0043] 11, the articulation mechanism includes a ball screw 192 with at least one helical groove or thread 195 upon which one or more ball bearings 194 may fit. In the illustrated embodiment, the articulation mechanism includes two ball bearings 194 that may fit within the two threads 195. The ball bearings 194 are positioned within ball bearing bores 189 in a ball sleeve 191 positioned radially outwardly of the ball screw 192. The ball bearings 194 are maintained within the threads 195 by a release sleeve 196 positioned radially outwardly of the ball bearings 194. Rotation of an articulation knob 190 coupled to the ball sleeve 191 by, for example, a connecting pin 193, causes the ball sleeve 191 to rotate about the axis of rotation, which causes the ball bearings 194 to move within the threads 195, correspondingly translating the ball screw 192 longitudinally. Articulation of the jaw assembly is accomplished by rotating the articulation knob 190 and correspondingly rotating the ball sleeve 191 and ball bearing 194 about the axis of rotation with their longitudinal positions fixed along the axis of rotation. The ball bearing 194, which is then fitted within the threads 195 of the ball screw 192, translates the ball screw 192 back and forth along the axis of rotation. In the illustrated embodiment, the ball sleeve 191 is generally tubular with a cavity formed therein and a portion of the ball screw 192 positioned within the cavity for longitudinal translation therein. While the illustrated embodiment of the articulation mechanism includes two ball bearings engageable with threads in the ball screw, it is envisioned that in other embodiments the articulation mechanism may include fewer 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 a corresponding number of helical threads.

[0044] 11 and 12, the ball screw 192 extends to a distal end 200 coupled to a pair of articulation links 202. The articulation links 202 are spaced apart from one another so that the articulation links can desirably be positioned radially outward of the drive system and actuation shaft within the handle. As shown in FIG. 12, the articulation links 202 can be formed with a mating feature, such as a slot, so that the articulation links can be keyed into a corresponding mating feature, such as a post, that extends radially inward from the handle body. The slot can stabilize the articulation link relative to the handle, and the interaction of the handle post with the end of the slot can define a range of articulation for the articulation mechanism. The distal end of the articulation link 202 can be rotatably coupled to an articulation adapter 204, which can be positioned coaxially radially outward of the actuation adapter at the distal end of the handle. The rotational coupling can include an articulation bearing 205 with relatively low friction characteristics. The articulation bearing 205 can facilitate rotation of the coupled interchangeable shaft and longitudinal movement of the articulation adapter 204 relative to the handle assembly during actuation of the articulation mechanism. Although the articulation mechanism of the illustrated embodiment includes two articulation links that are laterally offset from the actuation mechanism in the handle, it is envisioned that in other embodiments the articulation mechanism can include less than two or more than two articulation links, for example, one articulation link or three or more than three articulation links.

[0045] 12, when the shaft is coupled to the handle, the articulation adapter 204 may be connected to an articulation member 206 in the shaft by a bayonet connection. The threads 195 may be configured such that moving the ball screw in a proximal direction articulates the jaw assembly to the left, as viewed from the handle, relative to the longitudinal centered position, and moving the ball screw 192 in a distal direction articulates the jaw assembly to the right, as viewed from the handle, relative to the longitudinal centered position.

[0046] Advantageously, the helical threads 195 of the ball screw 192 are continuous, allowing the articulation mechanism to articulate the jaw assembly to a virtually infinite number of angular positions between desired ranges of motion. In some embodiments, the articulation mechanism may be configured to provide an articulation range of motion of the jaw assembly from -45° to +45° relative to a longitudinal centered position defined by the longitudinal axis of the shaft. In other embodiments, the articulation mechanism may be configured to provide other articulation ranges of motion, including ranges providing articulation of more than ±45° or ranges providing articulation of less than ±45°. In some embodiments, the articulation mechanism may be configured to provide articulation in a single direction relative to the longitudinal centered position.

[0047] In some embodiments, the pitch of the threads 195 on the ball screw 192 can vary. For example, the threads 195 can have a smaller pitch toward the end of the thread to advantageously provide a larger mechanical advantage when the jaw assembly may require a larger force to articulate. The threads 195 can have a larger pitch toward the center of the thread to allow for quick movement with a smaller mechanical advantage when the jaw assembly may require a smaller force to articulate. In other embodiments, the threads 195 provide a proportional amount of articulation of the stapler jaw assembly that does not change over the articulation range of the articulation mechanism as a result of rotation of the articulation knob. Desirably, such a constant pitch thread ball screw can result in an easily predictable response during operation of the actuation mechanism.

[0048] 13A-13F, the articulation mechanism can include a release mechanism that allows the articulation mechanism to be reset to the longitudinal centering position from any post-articulation position. The release mechanism is activated by a user pressing a release button 198. In the illustrated embodiment, the release button 198 is positioned radially recessed within the articulation knob 190.

[0049] 13B, actuation of the release button 198 advances the release sleeve 196 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, with a smooth slope between the engagement and release surfaces. In operation, the engagement surface of the release sleeve maintains the ball bearings 194 within the threads 195 of the ball screw 192. Once the release button 198 is pressed, the engagement surface is advanced distally, allowing the ball bearings 194 to disengage from the threads 195 and advance radially outward through the ball bearing holes 189 in the ball sleeve against the release surface.

[0050] 13C and 13D, the articulation mechanism can be biased to a centered position with the ball bearings 194 disengaged from the threads 195. In some embodiments, the ball screw 192 is biased to the centered position by a spring force from a biasing member, such as two springs 197 and a shaft. The ball bearings 194 positioned in the centered position (FIG. 13D) along the threads 195 correspond to the longitudinal centered position of the jaw assembly.

[0051] 13E and 13F, once the release button 198 is caused to return to its unobstructed configuration, the release sleeve 196 is retracted proximally (indicated by arrow 199) by a spring. The proximal movement of the release spring 196 causes the ball bearings 194 to engage the ball screw threads 195. Thus, the articulation mechanism can then be used to articulate the jaw assembly out of the longitudinally centered position or the stapler can be used with the jaw assembly in the longitudinally centered position.

[0052] 14, 15, and 16A-16B, one embodiment of a manual return mechanism for a powered handle is shown, which can advantageously provide a redundant return mechanism in the event of power failure, failure of other powered components, or mechanical failure or binding.

[0053] 14 and 15, the manual return mechanism includes two separate and independently actuable subassemblies that are actuated in sequence to return the actuation shaft 120 to a proximal-most 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. In operation, when it is desired to manually return the stapler to the open configuration, the shaft rotation mechanism is actuated first.

[0054] 14 and 15, to activate the shaft rotation mechanism of the manual return mechanism 170, a user pulls a disengagement or disengagement tab 172 positioned on an exterior surface of the handle. A disengagement or disengagement rack 174 is formed on the disengagement tab 172. The disengagement rack 174 is in meshing engagement with a shaft rotation rack 176 formed on a shaft rotation collar 176. The actuation shaft 120 passes through and is slidable therethrough. Thus, pulling the disengagement tab 172 rotates the rotation shaft 120 approximately 90° about its longitudinal axis. This rotation positions the rack 122 of the actuation shaft out of engagement with the auxiliary gear 116 of the drive system. Additionally, in some embodiments, removal of the disengagement tab 172 from the handle may also disengage the power source from the drive system or otherwise disengage the control system, thereby preventing further powered actuation of the powered handle. Additionally, the shaft rotation mechanism may be configured to be actuated only once. For example, in the illustrated embodiment, the shaft retraction mechanism may have an obstruction lobe 183 sized and shaped to prevent closure of the return lever and obstruct the drive system to prevent rotation of the rotating shaft 120 back into engagement with the auxiliary gear once the shaft rotation mechanism is actuated, thus disabling the handle from further use.

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

[0056] 17, 18, and 19A-B, another embodiment of a manual return mechanism for a powered handle is shown. The components and operating principles of the manual return mechanism 170' are substantially the same as those described above with reference to the manual return mechanism 170 of FIGS. 14, 15, and 16A-B. However, in use of the manual return mechanism 170', removal of the disengagement tab 172' from the handle assembly exposes a shaft rotation collar 176' from which a rotation lever 178' protrudes. When the handle assembly is in a powered operating condition, the disengagement tab 172' covers the shaft rotation collar 176' on the outer surface of the handle. Once the disengagement tab is removed, the user can then operate the rotation lever 178' to rotate the actuation shaft 120, which in turn activates the shaft retraction mechanism to return the actuation shaft proximally within the handle. The shaft retraction mechanism of the manual return mechanism 170' has the same ratchet type of action as described above with respect to the manual return mechanism 170. Desirably, in some handle configurations, the rotating lever 178' can provide a significant mechanical advantage in facilitating rotation of the actuation shaft as compared to the shaft rotation mechanism including the disengaging rack 174 of Figures 14, 15, and 16A-B.

[0057] Although the present application discloses certain preferred embodiments and examples, those skilled in the art will appreciate that the present invention extends to other variations and / or uses of the invention beyond the specifically disclosed embodiments, as well as obvious modifications and equivalents thereof. Moreover, various features of the invention can be used alone or in combination with other features of the invention other than those expressly 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: The handle assembly includes: a stationary handle and a handle body pivotally connected to the handle body; a handle body having a trigger; an electric motor disposed within the handle body and having an output shaft; an actuation shaft slidable along a longitudinal axis within the handle body; a motor gear coupled to an output shaft of the electric motor; an auxiliary gear in driven mesh with said motor gear and in operative engagement with said actuation shaft; a crown gear disposed within the handle body in meshing engagement with the motor gear; a potentiometer connected to said crown gear; a control system electrically connected to the trigger, the electric motor, and the potentiometer. A handle assembly comprising:

2. the control system is configured to measure a longitudinal position of the actuation shaft. The handle assembly of claim 1 .

3. The control system measures a change in resistance at the potentiometer to determine a position of the actuation shaft. The handle assembly of claim 2.

4. Further comprising a circuit board; the potentiometer and the control system are mounted on the circuit board; The handle assembly of claim 1 .

5. the actuation shaft having a rack extending along a longitudinal axis of the actuation shaft; The auxiliary gear meshes with the rack. The handle assembly of claim 1 .

6. a guide member through which the actuation shaft slides; The auxiliary gear is supported by the guide member.

6. The handle assembly of claim 5.

7. Further comprising a manual return mechanism; the manual return mechanism is selectively operable to disengage the auxiliary gear from the actuation shaft and return the actuation shaft proximally within the handle body. The handle assembly of claim 1 .

8. The method of claim 1, further comprising: a manual articulation mechanism including a manual articulation knob configured to articulate a jaw assembly removably coupled to the handle body. The handle assembly of claim 1 .

9. the manual articulation mechanism includes a manual articulation knob rotatably mounted on a proximal end of the handle body about a longitudinal axis, and a ball screw operatively connected to the manual articulation knob and adapted to move longitudinally upon rotation of the manual articulation knob.

9. The handle assembly of claim 8.

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