Surgical stapler with powered handle

Abstract

To provide a surgical stapler capable of reliably stapling a clamped tissue without a complicated mechanism.SOLUTION: A powered handle 40 for a surgical stapler 10 can have a drive system including an electric motor. The powered handle can include a manual articulation mechanism to articulate the jaw assembly 30 coupled to a reload shaft connected to the handle. The manual articulation mechanism can include a ball screw mechanism that translates the articulation member in response to rotation of the articulation knob when the instrument shaft is engaged to the handle. The articulation mechanism includes a release feature that allows the jaw assembly to return to the longitudinally centered orientation. The powered handle includes a battery pack that serves as a power source for the drive system.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Patent Application No. 62 / 636,070, entitled "Surgical Stapler Having a Powered Handle," filed February 27, 2018, and U.S. Provisional Patent Application No. 62 / 734,154, entitled "Surgical Stapler Having a Powered Handle," filed September 20, 2018, each of which is incorporated herein by reference in its entirety.

[0002] FIELD OF THE INVENTION This application relates generally to surgical occlusion instruments, and more particularly to powered surgical staplers. [Background technology]

[0003] Surgical staplers are used to approximate or clamp tissue and staple the clamped tissue together. Accordingly, surgical staplers have mechanisms for clamping tissue and driving staples through the tissue. As a result, for example, multiple triggers and handles have been produced, each associated with complex mechanisms for properly stapling the clamped tissue. These complex mechanisms can result in surgical staplers with high manufacturing overhead and potential sources of device failure and user confusion. Therefore, it would be desirable to be able to reliably staple clamped tissue without complex mechanisms. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] U.S. Patent Application Publication No. 15 / 486,227 [Patent Document 2] U.S. Patent Application Publication No. 15 / 486,008 Summary of the Invention [Means for solving the problem]

[0005] Some embodiments herein provide a powered handle for a surgical stapling system. The powered handle can include a drive system driven by a power source to selectively actuate an actuation adapter. The powered handle can include a manual articulation mechanism that selectively actuates an articulation adapter. The powered handle can further include a coupler having a bayonet coupling that simultaneously couples the articulation adapter and the actuation adapter to an articulation member and a drive member of a reload shaft.

[0006] In some embodiments, the powered handle of the surgical stapling system includes a control system that actuates the drive system in response to user input from a movable trigger and a fire / return button on the powered handle. The control system can further vary the actuation profile of the drive system in response to various operating parameters, including the operating torque of the drive system, the longitudinal position of the actuation adapter, and the identity of the length or configuration of the jaw assembly.

[0007] In some embodiments, the powered handle of the surgical stapling system includes a manual articulation system including 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 biased to a longitudinally centered position and can be quickly centered through the use of a release mechanism.

[0008] In some embodiments, 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 includes a fixed 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. The actuation shaft includes a rack formed thereon. The actuation shaft is rotatable from a first position in which the rack is operatively engaged with the electric motor to slide the actuation shaft longitudinally to a second position in which the rack is disengaged from the electric motor and engaged with the manual return mechanism. The manual return mechanism includes a return lock mechanism slidable within the handle body, a shaft rotation mechanism, and a shaft retraction mechanism.

[0009] In some 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, and an auxiliary gear. The handle body includes a fixed handle and a trigger pivotally coupled to the handle body. The electric motor is disposed within the handle body. The motor includes an output shaft. The actuation 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 driving engagement with the motor gear. The auxiliary gear is operably engaged with the rack. The auxiliary gear includes a first gear segment rotatably coupled to a second gear segment and a central region extending between the first and second gear segments. The first gear segment is in driving engagement with the motor gear, and the second gear segment is operably engaged with the rack.

[0010] In some embodiments, a handle assembly for a surgical stapler having a removably coupled instrument shaft is provided. The handle assembly includes a handle body, a power system, an actuation shaft, an articulation mechanism, and an articulation lockout mechanism. The handle body includes a fixed handle and a trigger pivotally coupled to the handle body. The power system resides within the handle body. The actuation shaft is operably coupled to the power system. The actuation shaft is slidable within the handle body along a longitudinal axis. The articulation mechanism includes a manually actuated articulation knob and an articulation adapter. The manually actuated articulation knob is disposed at a proximal end of the handle body and is rotatable about the longitudinal axis. The articulation adapter is disposed at a distal end of the handle body. The articulation adapter is operably coupled to the articulation knob such that rotation of the articulation knob about the longitudinal axis causes the articulation adapter to slide longitudinally. The articulation lockout mechanism releases the articulation knob from the articulation adapter when the instrument shaft is not coupled to the surgical stapler.

[0011] In some embodiments, a handle assembly for a surgical stapler is provided. The handle assembly includes a handle body, a power system, an actuation shaft, a position sensor, and a control system. The handle body includes a fixed handle and a trigger movably coupled to the handle body. The power system resides within the handle body. The power system includes a motor and a power source that can be disposed within the handle body. The actuation shaft is operably coupled to the power system. The actuation shaft is longitudinally slidable within the handle body. The position sensor is configured to determine a longitudinal position of the actuation shaft. The control system is electrically coupled to the power system, the trigger, and the position sensor. The control system is configured to define a motor drive logic profile that defines at least one operating parameter of the motor at positions of the actuation shaft corresponding to the grasper zone, the lockout zone, and the firing zone.

[0012] In some embodiments, a handle assembly for a surgical stapler having a removably coupled instrument shaft with a lockout mechanism is provided. The handle assembly includes a handle body, a power system, an actuation shaft, a position sensor, and a control system. The handle body includes a fixed handle and a trigger pivotally coupled to the handle body. The power system resides within the handle body. The power system includes a motor and a power source that can be disposed within the handle body. The actuation shaft is operably coupled to the power system. The actuation shaft is longitudinally slidable within the handle body. A position sensor is configured to determine a longitudinal position of the actuation shaft. The control system is electrically coupled to the power system, the trigger, and the position sensor. The control system includes a lockout module configured to monitor the current draw of the motor and the longitudinal position of the actuation shaft, calculate a slope of the motor's current draw profile, and use the monitored slope to detect engagement of the lockout mechanism. The lockout module is configured to depower the motor upon detecting engagement of the lockout mechanism. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a perspective view of an embodiment of a surgical stapling system having an embodiment of a powered handle. [Figure 2] FIG. 2 is a side view of a powered handle of the surgical stapling system of FIG. 1; [Figure 3] FIG. 3 is a partially cutaway perspective view of the power handle of FIG. 2 with components removed to show the drive system. [Figure 4] 3 is a perspective view of an embodiment of a drive system for the powered handle of FIG. 2. FIG. [Figure 5] FIG. 5 is a perspective view of the drive system of FIG. 4. [Figure 6] FIG. 5 is an exploded perspective view of the drive system of FIG. 4. [Figure 7] FIG. 5 is a perspective view of the drive system of FIG. 4. [Figure 8]FIG. 3 is a perspective view of an embodiment of a power supply for the powered handle of FIG. 2. [Figure 9] FIG. 9 is a cross-sectional perspective view of an embodiment of the power supply of FIG. 8. [Figure 10] FIG. 3 is a cutaway top view of the electric handle of FIG. 2. [Figure 11] FIG. 3 is a cutaway top view of an embodiment of an articulation mechanism of the powered handle of FIG. 2. [Figure 12] FIG. 11 is a cutaway top view of the articulation mechanism of FIG. 10 in an articulated position. [Figure 13] FIG. 11 is a cutaway top view of the articulation mechanism of FIG. 10 in another articulated position. [Figure 14] FIG. 11 is a cutaway top view of the articulation mechanism of FIG. 10 in a center position with the release button actuated. [Figure 15] FIG. 11 is a cutaway top view of the articulation mechanism of FIG. 10 in a center position with the release button actuated. [Figure 16] FIG. 3 is a cutaway top view of the powered handle of FIG. 2 with the articulation mechanism in a locked out configuration. [Figure 17] FIG. 3 is a cutaway top view of the powered handle of FIG. 2 with the articulation mechanism in an unlocked configuration. [Figure 18] FIG. 3 is a perspective view of the drive system and articulation mechanism of the powered handle of FIG. 2. [Figure 19] FIG. 3 is a perspective view of an articulation link and a lockout link of the articulation mechanism of the powered handle of FIG. 2. [Figure 20] FIG. 3 is a perspective view of the power handle of FIG. 2 with the override return mechanism in a released configuration. [Figure 21] 3 is a perspective view of the power handle of FIG. 2 with the override return mechanism unlocked to move to the return configuration. [Figure 22] 3 is a partially cutaway perspective view of the power handle of FIG. 2 with the override return mechanism unlocked to move to the return configuration. FIG. [Figure 23] FIG. 3 is a partial cutaway side view of the power handle of FIG. 2 with the override return mechanism in a released configuration. [Figure 24]FIG. 3 is a partial cutaway side view of the power handle of FIG. 2 with the override return mechanism unlocked to move to the return configuration. [Figure 25] FIG. 3 is a perspective view of the power handle of FIG. 2 with the override return mechanism in a return configuration. [Figure 26] 3 is a partially cutaway perspective view of the power handle of FIG. 2 with the override return mechanism in a return configuration. [Figure 27] 3 is a partially cutaway perspective view of the power handle of FIG. 2 with the override return mechanism in the return configuration and a manual return cycle initiated. FIG. [Figure 27A] FIG. 3 is a perspective view of a return claw of the override return mechanism of the electric handle of FIG. 2. [Figure 27B] FIG. 3 is a side view of the override return mechanism of the electric handle of FIG. 2. [Figure 27C] FIG. 3 is a side view of the override return mechanism of the electric handle of FIG. 2. [Figure 28] FIG. 10 is a side view of another embodiment of an override return mechanism of a surgical stapler. [Figure 29] FIG. 29 is a perspective view of the override return mechanism of FIG. 28. [Figure 30] FIG. 29 is a perspective view of the override return mechanism of FIG. 28. [Figure 31] FIG. 29 is a side view of the override return mechanism of FIG. 28. [Figure 32] FIG. 12 is a perspective view of a reload cartridge used in some embodiments of the surgical stapling apparatus; [Figure 33] FIG. 10 is a perspective view of a firing beam and firing member used in some embodiments of the elongated shaft assembly of the surgical stapling device. [Figure 34] 12A and 12B are partially exploded perspective views of the proximal end of the jaw assembly of some embodiments of the elongated shaft assembly of a surgical stapling device; [Figure 35] 12A-12C are cutaway side views of the proximal end of the jaw assembly of some embodiments of the elongated shaft assembly of a surgical stapling device; [Figure 36]FIG. 36 is a cutaway side view of the proximal end of the jaw assembly of FIG. 35 with an unfired reload partially inserted. [Figure 37] FIG. 36 is a cutaway side view of the proximal end of the jaw assembly of FIG. 35 with an unfired reload partially inserted. [Figure 38] FIG. 36 is a cutaway side view of the proximal end of the jaw assembly of FIG. 35 with an unfired reload partially inserted. [Figure 39] FIG. 36 is a cutaway side view of the proximal end of the jaw assembly of FIG. 35 with an unfired reload inserted. [Figure 40] FIG. 36 is a cutaway side view of the proximal end of the jaw assembly of FIG. 35 with an at least partially fired reload inserted therein; [Figure 41] FIG. 36 is a cutaway side view of the proximal end of the jaw assembly of FIG. 35 without a reload inserted. [Figure 42] FIG. 3 is a partial cutaway side view of the power steering wheel of FIG. 2 having an electrically coupled light ring user display. [Figure 43] FIG. 3 is a side view of the light ring user display of the power steering wheel of FIG. 2. [Figure 44] FIG. 3 is a perspective view of the light ring user display of the power steering wheel of FIG. 2. [Figure 45] FIG. 3 is a block diagram of information and power flow for an embodiment of the control system of the power steering wheel of FIG. [Figure 46] 3 is an operation sequence flowchart of an exemplary operation sequence of the electric handle of FIG. 2. [Figure 47] FIG. 3 is a schematic diagram of one embodiment of a motor control logic profile that can be executed by the controller of the powered handle of FIG. 2. [Figure 48] 3 is a plot of motor load versus actuation rack position for one exemplary jaw assembly grip and pre-fire lockout of a powered handle such as the powered handle of FIG. 2; [Figure 49] 3 is a plot of motor load versus actuation rack position for one exemplary jaw assembly grip through a full firing of a powered handle such as the powered handle of FIG. 2; [Figure 50] 3 is a schematic diagram of one embodiment of a motor control logic profile that can be implemented by the controller of the powered handle of FIG. 2 operating in a power-on configuration and a tissue-grasping configuration. [Figure 51] FIG. 51 is a schematic diagram of an embodiment of the motor control logic profile of FIG. 50 operating in a launch configuration. [Figure 52] FIG. 51 is a schematic diagram of an embodiment of the motor control logic profile of FIG. 50 operating in an inverted configuration. [Figure 53] 10 is a schematic diagram of another embodiment of a motor control logic profile that can be implemented by the controller of the powered handle of FIG. 2 operating in a power-on configuration and a tissue-grasping configuration. [Figure 54] FIG. 54 is a schematic diagram of an embodiment of the motor control logic profile of FIG. 53 operating in a launch configuration. [Figure 55] FIG. 54 is a schematic diagram of an embodiment of the motor control logic profile of FIG. 53 operating in an inverted configuration. [Figure 56] 10A-10C are schematic diagrams of embodiments of motor drive profiles for haptic feedback modules. [Figure 57] FIG. 10 is a schematic diagram of another embodiment of a motor drive profile for a haptic feedback module. [Figure 58] 10 is an exemplary plot of measured current draw versus actuation shaft position over several operating states of an embodiment of a powered handle assembly. [Figure 59] 10 is an exemplary plot of measured current draw versus actuation position across a first lockout engagement state of an embodiment of a powered handle assembly. [Figure 60] 10 is an exemplary plot of measured current draw versus actuation position across a second lockout engagement state of an embodiment of a powered handle assembly. [Figure 61] 10 is an exemplary lockout mechanism control logic profile for an embodiment of a powered handle assembly. [Figure 62] 10 is a motor polarity verification logic structure for an embodiment of a powered handle assembly. [Figure 63]FIG. 10 is a perspective view of one embodiment of a removable memory module for a powered handle assembly. [Figure 64A] FIG. 64 is a side view of the removable memory module of FIG. 63 removed. [Figure 64B] FIG. 64 is a side view of the removable memory module of FIG. 63 removed. [Figure 65] FIG. 10 is a perspective view of another embodiment of a removable memory module of some embodiments of the powered handle assembly. [Figure 66] FIG. 10 is a perspective view of another embodiment of a removable memory module of some embodiments of the powered handle assembly. DETAILED DESCRIPTION OF THE INVENTION

[0014] 1-2 illustrate an embodiment of a surgical stapling system. The illustrated embodiment of a surgical stapler 10 includes an elongate shaft 20, a jaw assembly 30, and a handle assembly 40. FIG. 1 illustrates the surgical stapler 10 with the jaw assembly 30 in an open configuration and an embodiment of a powered handle having powered staple firing and manual jaw assembly articulation. FIG. 2 illustrates the powered handle 40 of the surgical stapler system 10 with the elongate shaft removed. The powered handle 40 of FIG. 2 has powered staple firing and manual jaw assembly articulation. In the illustrated embodiment, rotation of a rotation knob on the handle 40 allows free rotation of the shaft 20 and jaw assembly 30 about a longitudinal axis defined by the shaft 20. In other embodiments, the stapling system can be configured to allow rotation of the jaw assembly within a predetermined range about the longitudinal axis or to allow a rotatably fixed jaw assembly.

[0015] With continued reference to FIG. 1 , the illustrated embodiment of the surgical stapler 10 can be sized and configured for use in laparoscopic surgery. For example, the elongate shaft 20 and jaw assembly 30 can be sized and configured to be introduced into the surgical field through an access port or trocar cannula. In some embodiments, the elongate shaft 20 and jaw assembly 30 can be sized and configured to be inserted through a trocar cannula having a relatively small working channel diameter, such as less than 8 mm. In other embodiments, the elongate shaft 20 and jaw assembly 30 can be sized and configured to be inserted through a trocar cannula having a larger working channel diameter, such as 10 mm, 11 mm, 12 mm, or 15 mm. In other embodiments, it is contemplated that some aspects of the surgical stapler described herein may be incorporated into a surgical stapling device used in open surgical procedures.

[0016] 1 , as shown, the elongate shaft 20 comprises a generally tubular member. The elongate shaft 20 extends from a proximal end to a distal end. The elongate shaft 20 defines a central longitudinal axis L of the surgical stapler 10 extending between the proximal end 22 and the distal end 24.

[0017] Continuing with reference to FIG. 1 , in the illustrated embodiment, a jaw assembly 30 is coupled to the elongate shaft 20 at its distal end. 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 extends distally along a central longitudinal axis L and is fixed to the distal end 24 of the elongate shaft 20 so as to be articulatable relative to the elongate shaft 20 in response to an articulation mechanism of the handle 40. In an initial configuration, the first jaw 32 includes a plurality of staples 36 disposed within a reload 50. In other embodiments, the reload 50 can be integral with the jaw assembly 30, such that the entire shaft assembly 20 and the staple-loaded jaw assembly 30 define a single reload assembly. In some embodiments, the staples can be initially positioned within the second jaw 34.

[0018] 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 configuration relative to the stapling configuration by a drive member or beam 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, thereby placing the jaw assembly 30 in the open configuration. As the actuation member or beam translates distally along the longitudinal axis L, the actuation beam engages the second jaw 34. As the actuation beam translates distally a first distance from the initial position, the jaw assembly can be actuated from the open configuration to the closed configuration. With the jaw assembly 30 in the closed configuration, as the actuation beam is returned proximally a first distance, the jaw assembly 30 can be returned 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, causing multiple staples 36 to be deployed from the reload 50 of the first jaw 32 as the actuation beam is further translated distally past the first distance.

[0019] 1 , in the illustrated embodiment, a handle assembly is configured to be coupled to elongate shaft 20 at its proximal end. As shown, handle assembly 40 has a pistol-grip configuration including a housing defining a fixed handle 42 and a movable handle 44, or trigger, pivotally coupled to fixed handle 42. In other embodiments, it is contemplated that surgical stapler devices incorporating aspects described herein may have handle assemblies in other configurations, such as, for example, a scissor-grip configuration or an in-line configuration. As described in further detail below, handle assembly 40 houses a powered actuation mechanism configured to selectively advance the actuation shaft in response to movement of movable handle 44.

[0020] In the illustrated embodiment, the surgical stapler 10 can include 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 elongate shaft 20 and the jaw assembly 30 define a disposable reload shaft that can be removably coupled to the handle assembly 40. Accordingly, 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 can have a bayonet connection having an outer connector that can removably couple the handle assembly 42 to the elongate shaft 20, a first inner connector that can removably couple the actuation shaft of the handle assembly 42 to the drive member of the elongate shaft 20, and a second inner connector that can removably couple the articulation coupler of the handle assembly 42 to the articulation link of the elongate shaft 20. These three releasable couplings occur simultaneously when the elongate shaft 20 is coupled to the handle assembly 42. Thus, the surgical stapler 10 can be configured to allow the handle assembly 40 to be reused with multiple reload shafts 20 during a surgical procedure. In other embodiments, it is envisioned that some portions of the handle assembly and elongate shaft can be reused, while the remainder of the elongate shaft within the jaw assembly defines a disposable cartridge. In some other embodiments, the handle assembly and elongate shaft can be reused, while the jaw assembly defines a disposable cartridge. In still other embodiments, a jaw insert containing multiple staples can define a disposable cartridge, while the remainder of the surgical stapler is reusable.

[0021] FIG. 2 illustrates an embodiment of a powered handle for a surgical stapling system. The powered handle can be used with a variety of shaft reloads and cartridges so that the shaft configuration, jaw assembly configuration, and staple configuration can be selected for a particular procedure. In the illustrated handle embodiment, the clamping and opening of the jaws and the firing of the staple line are motorized (motor driven). Articulation of the jaw assembly can be manually controlled by an articulation knob rotated by the operator. The motor is controlled by an embedded control system that determines the function of the handle during different phases of use.

[0022] With continued reference to FIG. 2 , the powered handle 40 includes a pistol-grip configuration having a fixed handle 42 and a movable handle 44 or trigger pivotally coupled to the fixed handle 42. A power source 130 or battery may be located on the underside of the fixed handle. The powered handle 40 may further include user controls, such as a fire or fire / reverse button 150, that allow a user to selectively control the stapling sequence. The powered handle 40 may further include a redundant manual override return system 170 that allows a 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, a "lockjaw," or other mechanical binding. The powered handle may further include a manual articulation mechanism that includes a rotatable articulation knob 190. In the illustrated embodiment, the articulation knob 190 is located at the proximal end of the powered handle and is rotatable about an axis that generally corresponds to the longitudinal axis of the stapling system. In some embodiments, the powered handle may further include an illuminated user display, such as an annular light ring, that displays desired status indicia to the user.

[0023] Various embodiments of powered handle assemblies and associated actuation mechanisms are disclosed in U.S. patent application Ser. No. 15 / 486,227, filed April 12, 2017, entitled "Reload Shaft Assembly for Surgical Stapler," and U.S. patent application Ser. No. 15 / 486,008, filed April 12, 2017, entitled "Surgical Stapler Having a Powered Handle," both of which are incorporated herein by reference in their entireties.

[0024] Electric Drive System FIG. 3 shows a cutaway view of a portion of the power handle. The cutaway view removes several components of the power handle to clearly show the drive system of the power handle. In the illustrated embodiment, the drive system includes a motor 112 located within the fixed handle 42, a motor gear 114 located on the output shaft of the motor 112, and an auxiliary gear 116 in driving engagement with the motor gear 114. In some embodiments, the motor 112 is a brushed DC gear motor. Transmitting power through the auxiliary gear 116 has the advantage that the motor 112 can be laterally centered within the fixed handle, allowing for improved handle balance and user ergonomics. Furthermore, in some embodiments, the motor gear 114 and the auxiliary gear 116 can be configured to provide a desired actuation torque to the rack 122. In some embodiments, the motor 112 can include a multi-gear transmission operatively coupled between the motor 112 and the motor gear 114, which is coupled to the auxiliary gear 116, to provide the desired actuation torque. The motor 112 can be electrically coupled to a power source 130 via a control system. A control system in the handle, in conjunction with the drive system, measures the position of the actuation shaft 120 and therefore the actuation of the jaw assembly.

[0025] The drive system is attached to hardware that provides information to a control system that includes a microcontroller in the handle. This embedded system can control the speed and torque of the motor. This embedded system can also control the function of the device based on user input (trigger movement and fire / reverse button press) 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 if a reload cartridge lockout has been activated. The control system can also measure battery life to limit the number of times the device can be fired. While the drive system is primarily configured for powered operation, in some embodiments it may be desirable to provide a manual return mechanism that overrides powered operation, as described further herein.

[0026] 4-6 show detailed views of the drive system of the power handle. In the embodiment shown, the drive system includes a bifurcated auxiliary gear 116 supported between its end points by a support plate 121. This support configuration for the auxiliary gear 116 has the advantage of providing a robust mechanism that significantly reduces the tendency for the motor gear 114 to separate from the auxiliary gear 116 under heavy load conditions.

[0027] 5-6 , the bifurcated auxiliary gear 116 includes a first gear segment 113 rotatably coupled to a second gear segment 115. The first gear segment 113 can include a first engagement surface, and the second gear segment 115 can include a second engagement surface, whereby the first and second engagement surfaces mate to rotatably couple the first gear segment 113 to the second gear segment 115. In the illustrated embodiment, the first gear segment 113 includes an axially extending boss that defines the first engagement surface, and the second gear segment 115 includes an axially extending boss that defines the second engagement surface. The axially extending bosses of the first and second gear segments each include a square toothed or “castle” cross-sectional shape that enables rotational coupling between the first gear segment 113 and the second gear segment 115. In some embodiments, when the first and second gear segments 113, 115 are rotatably coupled, the axially extending bosses engage to form a central region having an outer diameter smaller than the outer diameter of either the first gear segment 113 or the second gear segment 115.

[0028] FIG. 6 shows an exploded view of a drive system having a bifurcated auxiliary gear 116. As shown, the drive system further includes a support plate 121 disposed between the first and second ends of the auxiliary gear 116. The support plate 121 can be a rigid plate having an auxiliary gear bore 123 and a motor gear bore 125 formed therein. In some embodiments, the support plate 121 can include a metallic material. The drive system can further include an auxiliary gear bushing 117 located within the auxiliary gear bore 123 and a motor gear bushing 119 located within the motor gear bore 125. The bushings 117, 119 can include a material with a relatively low coefficient of friction, such as a DELRIN® material. An actuation shaft bracket or guide member 127 can facilitate engagement between the rack 122 of the actuation shaft 120 and the second gear segment 115 of the auxiliary gear 116.

[0029] 5-6 , the first gear segment 113 of the auxiliary gear 116 and the second gear segment 115 of the auxiliary gear can be assembled around the support plate 121 such that a central region of the auxiliary gear 116 passes through the auxiliary gear bore 123 and the auxiliary gear bushing 117 to provide support between the first and second ends of the auxiliary gear 116. In the illustrated embodiment, the first gear segment 113 of the auxiliary gear 116 is in geared engagement with the motor gear 114. The second gear segment 115 of the auxiliary gear 116 is in geared engagement with a rack surface 122 of the actuation shaft 120. The support plate 121 can be enclosed by the walls of the handle assembly housing and bosses formed thereon to support the drive system.

[0030] 7, during powered operation, the auxiliary gear 116 is in meshed engagement with a rack 122 on an actuation shaft 120 that extends longitudinally within the handle body. In the illustrated embodiment, the auxiliary gear is supported within a guide member through which the actuation shaft 120 slides. A guide member 127 helps maintain meshed contact between the auxiliary gear 116 and the rack 122. The distal end of the actuation shaft 120 is freely rotatably coupled to an actuation adapter 124 that extends longitudinally within coupler 46 (FIG. 1) at the distal end of the powered handle.

[0031] The actuation adapter 124 is connected to a drive member within the shaft 20 via a bayonet connection by coupling the shaft 20 to the coupler 46 of the powered handle 40. Thus, when the shaft 20 is attached to the handle 40, the motor 112 and rack 122 drive a drive member extending within the instrument shaft 20 and coupled to the jaw assembly. The drive system within the handle thus comprises a "rack and pinion" design. Operation of the motor 112 in response to user input drives the actuation shaft 120 longitudinally forward and rearward to selectively operate the stapler in a closing, firing, or opening action.

[0032] 8 and 9 illustrate an embodiment of the power supply 130 for the powered handle 40. The power supply 130 can be configured to provide direct current to the powered handle motor and control system. In the illustrated embodiment, the stapler can operate at 12V. The illustrated power supply can include four 3V lithium-ion batteries 132 connected in series to form a 12V power supply. As shown, the batteries 132 are stacked in a 4x1 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 some embodiments, the battery pack can be made up of AA, AAA, or other standard or proprietary disposable or rechargeable chemistry batteries. In the illustrated embodiment of the powered handle 40, the battery pack is located at the bottom of the fixed handle. This positioning is desirable to provide a stable surface for setting the handle 40 on a flat surface. It is contemplated that the power supply can be located elsewhere within the handle, such as at the proximal end of the handle, in other embodiments. The power supply 130 can include a master power switch and an indicator light, such as a light-emitting diode. The indicator lights can be configured to display other power supply status information, such as power on / off status, low power status, or recharging status, through the use of solid colors, flashing sequences, or solid illumination.

[0033] Continuing with reference to FIGS. 8 and 9 , in some embodiments, the power supply 130 can be packaged with the handle 40 but not installed prior to use. A user can install the battery pack by engaging the power supply 130 with the bottom of the handle 40 during use. Shipping without the battery pack has the advantage of reducing the risk of unintentional battery discharge prior to use. Additionally, a removable battery pack allows the stapler system to be easily upgraded with new batteries as they become available. In other embodiments, the power supply can be packaged and installed within the handle, with a removable strip interrupting the battery pack's electrical connections. In yet other embodiments, the handle can include a power cable configured to plug into an AC or DC power source, such as a wall outlet, a USB connector, or another standard electrical connection.

[0034] In some embodiments, the power supply further includes a memory module, such as a non-volatile memory, capable of storing a digital record of stapler usage. For example, the memory module can be configured to record details of each stapler firing, including periodic sampling of battery voltage and motor current during firing, the sequence of states of the software state machine, any possible unexpected events, the type of shaft used, the number of firings, the interval between firings, and the model and serial number of the stapler handle. The memory module can also record whether the battery pack itself has been used, so that a user cannot reuse the battery pack. In other embodiments, the memory module can be located separate from the power supply within the handle assembly, such as by being located on or electrically coupled to circuit board 144 (FIG. 4), or by being easily removable from an electrical port on the handle assembly, so that the memory module is not integrated with the power supply.

[0035] In some embodiments, the powered handle 40 and associated power source 130 can be configured to be used in a single procedure and then discarded. The power source 130 can include a power drain, reducing the chances of reuse. A user can remove the battery pack from the handle 40 after use in a surgical procedure. Removing the battery pack from the handle 40 can initiate battery drain. For example, a low-value resistor or other mechanical feature that can short the battery by connecting the terminals to an electrical feature can accomplish the same task for the circuit after the battery pack has been used once. Also, if the battery pack remains 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. For example, in embodiments of a power source that includes a memory module, a microcontroller can include a firing management module that can modify a memory location, such as a firing count memory location on the memory module, after a predetermined number of firing strokes. The microcontroller can be configured to evaluate the firing count memory location in a startup sequence. If the memory location indicates that the battery is being used, in some embodiments, the microcontroller can be configured to disable the stapler and activate a discharge circuit within the power supply. The microcontroller may also be configured to activate the discharge circuit under other predetermined operating conditions, such as if the handle assembly has been on for a predetermined period of time, such as greater than 12 hours in one embodiment, if more than a predetermined number of firings have been made, such as 12 firings in one embodiment, if the manual override return mechanism is deployed, or if an irrecoverable failure occurs.

[0036] 4-10 illustrate an embodiment of a position sensor mechanism for use within a powered handle. In operation, rotation of the motor gear 114 causes a corresponding rotation of a crown gear 142 mounted within the handle 40. The crown gear 142 is coupled to a potentiometer such that the position of the motor gear 114, and therefore the actual position of the actuation rack, can be determined based on a measured change in resistance in the potentiometer. In some embodiments, the potentiometer can be mounted on a circuit board 144 upon which a control system may reside. While the illustrated embodiment includes a potentiometer-based position sensing mechanism, it is envisioned that other embodiments may use other position sensing mechanisms, including, for example, the use of a magnetic encoder including a Hall Effect sensor, the use of a limit switch that activates when the actuation shaft has moved a predetermined distance, the use of optical systems such as a photodiode that measures the movement of a pattern along the actuation shaft, an optical encoder located on the shaft of the motor, or other position sensing systems.

[0037] Articulation mechanism 11-17 illustrate embodiments of the articulation mechanism of the powered handle 40. In the illustrated embodiment, the handle is capable of articulating the jaw assembly at the distal end of the shaft up to 45° in either direction relative to a longitudinal center position in the fully articulated position. In some embodiments, the powered handle uses a manual articulation mechanism that includes a series of components coupled to a manually actuated articulation knob 190 at the proximal end of the handle. In other embodiments, the manually actuated articulation knob and some associated elements of the articulation mechanism may be located elsewhere on the handle, such as adjacent the distal end of the handle.

[0038] 11 and 12, when the reload shaft is coupled to the handle, the articulation mechanism is coupled to an articulation member that extends longitudinally within the reload shaft. Longitudinal actuation of the articulation mechanism translates the articulation member proximally or distally relative to the shaft to articulate the jaw assembly at the distal end of the shaft.

[0039] 11 , the articulation mechanism includes a ball screw 192 having at least one helical groove or thread 195 upon which one or more ball bearings 194 can ride. In the illustrated embodiment, the articulation mechanism includes two ball bearings 194 that can engage within the two threads 195. The ball bearings 194 are disposed within ball bearing apertures 189 of a ball sleeve 191 located radially outward of the ball screw 192. The ball bearings 194 are maintained within the threads 195 by a release sleeve 196 located radially outward of the ball bearing 194. Rotation of an articulation knob 190, which is coupled to the ball sleeve 191 by a connecting pin 193 or the like, causes the ball sleeve 191 to rotate about an axis of rotation and the ball bearing 194 to move within the threads 195, correspondingly translating the ball screw 192 longitudinally. Articulation of the jaw assembly is achieved by rotating ball sleeve 191 and ball bearing 194 about an axis of rotation in response to rotation of articulation knob 190, while their longitudinal positions remain constant along the axis of rotation. At this time, ball bearing 194 engaged within threads 195 of ball screw 192 translates ball screw 192 forward and backward along the axis of rotation. In the illustrated embodiment, ball sleeve 191 is generally tubular and defines a cavity therein, and a portion of ball screw 192 resides within the cavity and translates longitudinally within the cavity. While the illustrated embodiment of the articulation mechanism includes two ball bearings engageable with the threads of the ball screw, it is contemplated that in other embodiments, the articulation mechanism may have fewer or more ball bearings than two, such as a single ball bearing located within a single helical thread, or three or more ball bearings within a corresponding number of helical threads.

[0040] 11 and 12 , ball screw 192 extends to a distal end 200 coupled to a pair of articulation links 202. Articulation links 202 are desirably spaced apart so that they can be positioned radially outward of the drive system and actuation shaft within the handle. The distal end of articulation link 202 can be rotatably coupled to an articulation adapter 204, which can be positioned coaxially radially outward of an actuation adapter at the distal end of the handle. This rotational coupling can include an articulation bearing 205 having relatively low friction characteristics. This articulation bearing 205 can facilitate rotation of the coupled reload shaft relative to the handle assembly and longitudinal movement of articulation adapter 204 during operation of the articulation mechanism. While the illustrated embodiment of the articulation mechanism includes two articulation links laterally offset from the actuation mechanism within the handle, it is contemplated that in other embodiments, the articulation mechanism can have fewer or more than two articulation links, such as one articulation link, or three or four or more articulation links.

[0041] 11-13, the articulation adapter 204 can connect to the articulation members in the shaft with a bayonet connection when the shaft is coupled to the handle. The threads 195 can be configured so that moving the ball screw proximally articulates the jaw assembly to the left relative to the longitudinal center when viewed from the handle, and moving the ball screw 192 distally articulates the jaw assembly to the right relative to the longitudinal center when viewed from the handle. Figures 12 and 13 show the articulation mechanism in a fully articulated configuration defining the end of its range of motion.

[0042] Because the helical thread 195 of the ball screw 192 is continuous, the articulation mechanism advantageously allows the jaw assembly to articulate to a virtually infinite number of angular positions between desired ranges of motion. In some embodiments, the articulation mechanism can be configured to provide a range of articulation motion of the jaw assembly from −45° to +45° relative to a central longitudinal position defined by the longitudinal axis of the shaft. In other embodiments, the articulation mechanism can be configured to provide other ranges of articulation motion, including ranges providing articulation motion greater than + / −45° or ranges providing articulation motion less than + / −45°. In some embodiments, the articulation mechanism can be configured to provide articulation motion in a single direction relative to the central longitudinal position.

[0043] In some embodiments, the pitch of the threads 195 on the ball screw 192 is variable. For example, the threads 195 can include a pitch that is relatively narrower toward the end of the thread, advantageously providing a higher mechanical advantage when the jaw assembly may require a large force to articulate. The threads 195 can include a pitch that is relatively wider toward the center of the thread, allowing for quick movement with a relatively low mechanical advantage when the jaw assembly may require a small force to articulate. In other embodiments, the threads 195 include a constant pitch so that the amount of articulation of the stapler jaw assembly by rotating the articulation knob is proportional and does not change over the articulation range of the articulation mechanism. A ball screw with such a constant pitch thread desirably provides an easily predictable response during operation of the actuation mechanism.

[0044] 14-15 , the articulation mechanism can include a release mechanism that advantageously resets the articulation mechanism to a centered longitudinal position from any articulated position. The release mechanism is activated by a user pressing a release button 198. In the illustrated embodiment, the release button 198 is radially nested within the articulation knob 190.

[0045] 14, actuation of release button 198 advances release sleeve 196 distally. The radially inner surface of release sleeve 196 is stepped to include an engagement surface 186 having a relatively small inner diameter and a release surface 188 having 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 ball bearing 194 within threads 195 of ball screw 192. When release button 198 is pressed, the engagement surface advances distally, disengaging ball bearing 194 from threads 195 and allowing ball bearing 194 to advance radially outward through ball bearing aperture 189 in the ball sleeve to contact the release surface.

[0046] 14 , with ball bearing 194 disengaged from threads 195, the articulation mechanism can be biased to a centered position. In some embodiments, ball screw 192 is biased to a centered position by a biasing member, such as two springs, and a spring force from the shaft. Ball bearing 194, located in a centered position along threads 195, corresponds to the longitudinal center of the jaw assembly.

[0047] 15, when release button 198 is allowed to return to its undisturbed configuration, release sleeve 196 is retracted proximally by a spring. Proximal movement of release sleeve 196 urges ball bearings 194 into engagement with ball screw threads 195. As a result, the articulation mechanism can be used to articulate the jaw assembly from the longitudinally centered position, or the stapler can be used with the jaw assembly in the longitudinally centered position.

[0048] 16-17 show a shaft recognition and articulation lockout mechanism 300 for some embodiments of the articulation mechanism. The articulation mechanism can include an articulation lockout mechanism that maintains the articulation mechanism in a centered position when an instrument shaft is not coupled to the handle assembly. Thus, the centered position of the articulation adapter 204 is maintained, facilitating the bayonet coupling between the instrument shaft and the handle assembly described above. If the articulation mechanism were maintained in an engaged configuration when the instrument shaft was not coupled to the handle assembly, it could be difficult to align the articulation member within the instrument shaft with the articulation adapter 204 when attempting to couple the instrument shaft to the handle assembly. In the illustrated handle assembly embodiment, the articulation lockout mechanism can be coupled to the shaft recognition mechanism.

[0049] 16-17 , the shaft recognition and articulation lockout mechanism includes a lockout sleeve 302 at the distal end of the handle assembly and at least one lockout arm 304 coupled to the lockout sleeve. In the illustrated embodiment, the lockout sleeve 302 may be located radially outward of the articulation adapter 204. As shown, the articulation lockout mechanism includes two lockout arms 304 extending longitudinally within the handle assembly from a proximal end coupled to the release sleeve 196 to a distal end coupled to the lockout sleeve 302. The lockout arms may be located laterally outward of the articulation link 202 and actuation shaft 120 and other drive mechanism components. In other embodiments, more than one or two lockout arms 304 may be coupled to the release sleeve 196, or the lockout arms 304 may be located in different lateral positions than in the illustrated embodiment.

[0050] In operation, when the instrument shaft is coupled to the handle assembly, the lockout sleeve 302 contacts a boss, tab, collar, or other element on the proximal end of the instrument shaft. Because of the bayonet connection, this contact causes the lockout sleeve to translate proximally a predetermined amount. When the instrument shaft is not coupled to the handle assembly ( FIG. 16 ), the articulation lockout mechanism and release sleeve 196 are configured such that the release sleeve 196 is positioned with the ball bearing against the release surface of the release sleeve 196. The articulation mechanism is therefore in the locked configuration. Thus, when the instrument shaft is not coupled to the handle assembly, the ball bearing is disengaged from the ball screw threads, allowing the articulation knob to be rotated without actuating the articulation mechanism.

[0051] 17 , when an instrument shaft is coupled to the handle assembly, the articulation lockout mechanism transitions to an engaged configuration. Engagement of the instrument shaft with the lockout sleeve causes the lockout sleeve 302 and associated lockout arm 304 to translate proximally. The proximal end of the lockout arm 304 is coupled to the release sleeve 196 of the articulation mechanism, such that proximal movement of the lockout arm 304 also advances the release sleeve 196 proximally, engaging the ball bearing with the ball screw threads. Thus, when an instrument shaft is attached, rotation of the articulation knob translates the articulation adapter, thereby articulating the end effector coupled to the instrument shaft.

[0052] 18 and 19 , each of the articulation mechanism and the shaft recognition / articulation lockout mechanism may include sensors 306, 308 that identify the position of the respective mechanism. In the illustrated embodiment, the articulation mechanism sensor may include a potentiometer geared with a toothed rack formed on one of the articulation links 202, and the shaft recognition / articulation lockout mechanism sensor may include a potentiometer geared with one of the lockout arms 304. In some embodiments, the articulation mechanism and shaft recognition / articulation latch mechanism sensors may be mounted on a circuit board 144 on which a control system may be located. Thus, the control system may incorporate articulation position data and / or shaft recognition position data to modify a motor drive profile during opening / closing, firing, and return operations of the power handle. For example, the control system may incorporate articulation positions and apply corrections to the measured actuator rack and actuator positions, thereby controlling a particular operating state of the motor based on the corrected actuator position taking into account a given measured articulation movement. Although the illustrated embodiment includes a potentiometer-based position sensor mechanism, it is envisioned that other position sensing mechanisms may be used in other embodiments.

[0053] Manual Override Reset System 20 to 27 show embodiments of manual return mechanisms for powered handles. The manual return mechanism can advantageously provide a redundant return mechanism in the event of a power supply failure, failure of other powered components, or mechanical failure or binding.

[0054] 20-25, the manual return mechanism includes three separate, independently operable subassemblies that are manipulated in sequence to return the actuation shaft 120 to a proximal-most position within the handle corresponding to the open configuration of the jaw assembly. As shown, the manual return mechanism 170 includes a return lock mechanism, a shaft rotation mechanism, and a shaft retraction mechanism. FIG. 20 illustrates the powered handle in a powered mode of operation with the return lock mechanism in the locked configuration. During operation, if it is desired to manually return the stapler to the open configuration, the return lock mechanism is first actuated to unlock the manual return mechanism.

[0055] As shown in FIGS. 21-22 , to activate the return lock mechanism, the return lock 171 is first slid proximally relative to the housing of the handle assembly. This movement of the return lock 171 unlocks the shaft rotation mechanism and the shaft retraction mechanism. In the illustrated embodiment, the return lock 171 moves from a position that prevented movement of the shaft rotation mechanism, exposing it for use. At the same time, the return lock 171 disengages from a lock protrusion 173 or tab on the shaft retraction mechanism, allowing the shaft retraction mechanism to pivot away from the handle assembly. As the return lock slides proximally, the lever of the shaft retraction mechanism is biased away from the handle assembly, allowing it to pivot away from the handle assembly.

[0056] 23 and 24, when the return lock 171 is slid proximally to unlock the return mechanism, it electrically couples to the handle assembly's controls, thereby stopping the handle assembly. Therefore, once the return lock mechanism is operated, the handle can be prevented from further use, even if a user attempts to manually reposition the manual return mechanism and drive system for repeated use. In the illustrated embodiment, when the handle assembly is configured for powered operation ( FIG. 23 ), the return lock is electrically disconnected from the circuit board 144 containing the controls. When the return lock is slid proximally to unlock the return mechanism, it moves a stamped spring component 175 proximally, which electrically engages circuitry on the circuit board 144, stopping the handle assembly. The spring component 175 is configured to move only proximally and not distally, even if the return lock is returned distally toward its initial position. Therefore, unlocking the return mechanism by sliding the return lock 171 permanently disables the powered function of the handle assembly.

[0057] 25 and 26, to operate the shaft rotation mechanism of the manual return mechanism 170, a user rotates a rotation lever 172 extending from the exterior surface of the handle, which is not currently blocked by the movement of the return lock. The rotation lever 172 is coupled to a shaft rotation collar that is rotatably coupled to the actuation shaft. In the illustrated embodiment, the actuation shaft 120 is slidable through the shaft rotation collar 176. Thus, rotating the shaft rotation collar 176 rotates the actuation shaft 120 approximately 90 degrees about its longitudinal axis. This rotation positions the actuation shaft rack 122 out of engagement with the drive system auxiliary gear 116. Because the actuation shaft 120 is rotatably coupled to the actuation adapter (FIG. 5), this rotation can occur without affecting the actuation adapter.

[0058] While the illustrated embodiment includes a shaft rotation mechanism having a rotation lever 172 that is rotated by the user, in other embodiments, the shaft rotation mechanism can be configured to self-deploy when the return lock is moved proximally. For example, a self-deploying shaft rotation mechanism can include a shaft rotation collar with a torsional bias. In some embodiments, the shaft rotation collar is coupled to the handle assembly by a torsional spring. When the return lock is slid proximally, the torsional bias of the shaft rotation rotates the actuation rack, disengaging it from the auxiliary gear and facilitating engagement with the shaft retraction mechanism.

[0059] 26 and 27, when the shaft rotation mechanism is operated, a shaft retraction mechanism operates to return the actuation shaft proximally within the handle. Sliding the return lock proximally within the handle assembly unlocks a return lever 180 on the power handle. The return lever 180 is pivotally coupled to a return pawl 182 at a pivot joint 184. A rack 122 on the actuation shaft 120 rotates to engage the shaft retraction mechanism when rotated out of engagement with the drive system. The return lever 180 rotates through one or a series of return cycles (FIGS. 26, 27) to engage the return pawl 182 with the rack 122 on the actuation shaft 120, allowing the actuation shaft 120 to be retracted proximally within the handle in a ratcheting action.

[0060] 27A-27C, the return pawl 182 can be configured to facilitate retraction of the actuation shaft. In the illustrated embodiment, the return pawl 182 includes a protruding boss or second pawl tooth 183 positioned to interact with the motor mount's guide member 127 during a portion of the return cycle. When the second pawl tooth 183 contacts the guide member 127, the return pawl 182 is limited from engaging with the rack 122 of the actuation shaft 120 (FIG. 27B). The second pawl tooth 183 can desirably be positioned to limit engagement between the return pawl 182 and the rack 122 during a portion of the return cycle when the user would otherwise have relatively low mechanical advantage. As shown, the second pawl tooth 183 prevents the return pawl 182 from engaging the rack 122 until the return lever 180 is positioned at a predetermined angle relative to the longitudinal axis of the actuation shaft 120 to provide the desired mechanical advantage (FIG. 27C).

[0061] FIGS. 28-31 illustrate another embodiment of a manual return mechanism for an electric handle. The components and operation of the manual return mechanism 170′ are similar to those described above with respect to the manual return mechanism 170 of FIGS. 20-27. However, when using the manual return mechanism 170′, the functions of the return lock and shaft rotation mechanism are provided by a worm gear-driven shaft rotation collar 176′. Thus, a user can first rotate the actuation shaft 120 away from the electric drive system by rotating the worm gear drive, for example, with a hexagonal key. The shaft rotation mechanism releases the shaft retraction mechanism through worm gear rotation, disengaging the actuation rack from the electric drive and positioning the actuation rack to engage the shaft retraction mechanism (FIG. 31). The shaft retraction mechanism of the manual return mechanism 170′ includes a ratcheting action similar to that described above with respect to the manual return mechanism 170, with a return lever 180′ pivotally coupled to a return pawl 182′.

[0062] Two-position lockout mechanism 32 illustrates a reload cartridge 250 for use with the elongated shaft of a surgical stapler device having a separate empty jaw assembly and a fired reload lockout mechanism. As described further below, if a user attempts to grasp the jaw assembly through an open-close stroke without the reload cartridge 250 being present in the jaw assembly, a two-position lockout lever moves to a first, locked position. As shown, the reload cartridge includes a first lockout actuator sized and positioned to place the two-position lockout lever in a second position that defeats the empty jaw assembly lockout mechanism when a reload is located within the reload support of the jaw assembly. The first lockout actuator can include a ramped boss 252 extending laterally inward from a sidewall of the cartridge body.

[0063] 32 , in the illustrated embodiment, the reload cartridge 250 includes a second lockout actuator sized and configured to place the two-position lockout lever in an unlocked position that disables the fired reload lockout mechanism when an unfired reload is located within the jaw assembly. Thus, the two-position lockout lever can pivot to the unlocked position in addition to the two locked positions. In some embodiments, the second lockout actuator includes a tail 254 extending proximally from a slider 255 of the reload cartridge 250. When the reload cartridge 250 is unfired, the slider 255 is in a proximal position such that the slider tail 254 extends proximally to engage the lockout lever. As the firing member advances distally during the firing stroke, it abuts against the slider within the reload cartridge, advancing the slider distally. Thus, when the reload cartridge 250 is in a partially fired (or fully fired) state, the proximally extending slider tail 254 is no longer in a position to disable the fired reload lockout mechanism.

[0064] FIG. 33 illustrates a firing beam 226 for use with an elongated shaft assembly of a surgical stapler device having a separate empty jaw assembly and a fired reload lockout mechanism. The firing beam 226 extends from a proximal end to a distal end 230. Disposed at the distal end 230 of the firing beam 226 is a firing member 240 having a generally I-beam configuration. Upper and lower horizontal flanges 242, 244 of the I-beam firing member 240 ride in channels in the first and second jaws of the jaw assembly to approximate the jaws and maintain their spacing during subsequent staple firing. Disposed on the vertical portion of the I-beam profile is a cutting blade 245 that cuts tissue between the rows of staples. The I-beam firing member 240 can be attached to the distal end of the firing beam 226 by an interlock fit, welding, another joining method, or some combination thereof. The proximal edge of the I-beam firing member 240 can have a proximally extending protrusion or tail 247 that can rest on the proximal portion of the lockout lever when the firing beam 226 is in a fully retracted position corresponding to the open jaw assembly.

[0065] 33 , the firing beam can include a first lockout notch 222 for use with the empty jaw assembly lockout mechanism and a second lockout notch 224 for use with the fired reload lockout mechanism. In the illustrated embodiment, the first lockout notch 222 extends a first height from the adjacent lower edge 220 of the firing beam 226. As explained further below, the first height is selected to correspond to the height of the proximal end of the lockout lever when the empty jaw assembly lockout is activated by an attempt to approximate the jaw assembly without a reload cartridge present.

[0066] 33, in the illustrated embodiment, a second lockout notch 224 is located on the firing beam proximal to the first lockout notch 222. The second lockout notch 224 extends a second height from the adjacent lower edge 220 of the firing beam 226. As explained further below, the second height is selected to correspond to the height of the proximal end of the lockout lever when the fired reload lockout mechanism is activated by an attempt to fire a previously fired or partially fired reload.

[0067] The illustrated embodiment of the firing beam 226 has substantially continuous first and second lockout notches 222, 224 such that the adjacent lower edge 220 of the firing beam is relieved over a longitudinal distance corresponding to the first and second lockout notches 222, 224. It is contemplated that in other embodiments, the first and second lockout notches may be spaced apart from one another by an unrelieved segment of the lower edge of the firing beam. As described further below, the height and longitudinal position of the first and second lockout notches may be configured to achieve desired operating characteristics of the stapler handle assembly.

[0068] 34 and 35 show a portion of the jaw assembly 270 in a partially exploded view ( FIG. 34 ) and a cutaway side view ( FIG. 35 ) with various components hidden to illustrate the empty jaw assembly lockout mechanism and the fired reload lockout mechanism. In some embodiments, the lockout mechanism includes a two-position lockout lever 280, a biasing spring 290, a first lockout notch 222, and a second lockout notch 224. The three-position lockout lever 280 has a distal end 282 configured to engage the first and second lockout actuators on the reload cartridge, a pivot 284 adjacent the distal end, and a proximal end 286 configured to engage either the first lockout notch, the second lockout notch, or neither. The biasing spring 290 has at least one lower spring arm 292 that biases the end of the lockout lever 280 distal to the pivot 284 downward toward the reload support of the second jaw 274. In the illustrated embodiment, the biasing spring has two lower spring arms 292 with a gap between them to allow the firing member 240 and firing beam 226 to pass through. The biasing spring 290 can have at least one upper spring arm 294 that biases the first jaw 272 toward the open configuration. The biasing spring 290 can be configured to straddle the firing beam 226 and can have a central saddle member from which the at least one lower spring arm 292 and the at least one upper spring arm 294 extend.

[0069] Figures 36-41 illustrate the operation of the two lockout mechanisms. These partial cutaway side views of the proximal ends of some embodiments of the jaw assemblies do not show some elements of the jaw assemblies (such as the biasing spring) and show some components (such as the firing member 240) as transparent elements to enhance visibility of the operation of the lockout mechanisms. Figures 36-39 illustrate the function of the lockout mechanisms when a full, unfired staple reload 250 cartridge is located within the reload support of the second jaw 274. Figure 40 illustrates the operation of the fired reload lockout mechanism. Figure 41 illustrates the operation of the empty jaw assembly lockout mechanism.

[0070] 36 shows a cutaway view of the proximal end of the jaw assembly. The jaw assembly is in an open configuration such that the first jaw 272 is biased in an open position relative to the second jaw 274. The firing member 240 and firing beam 226 are in a fully proximally retracted position such that the proximal face of the lockout lever 280 rests on the proximally extending tail 247 of the firing member 240. Thus, the distal end 282 of the lockout lever 280 is raised slightly away from the reload support, thereby allowing a lockout actuator to be positioned between the reload support and the lockout lever 280.

[0071] 36, the distal end 282 of the lockout lever 280 can be slightly raised to receive the angled proximal surface or angled boss 252 of the first lockout actuator formed on the reload cartridge body. The distal end 282 of the lockout lever 280 has a lateral extension 283 (FIG. 34) positioned to engage the first lockout actuator when the reload cartridge 250 is slid proximally upon insertion of the jaw assembly into the reload support, and an inner surface 281 (FIG. 34) positioned to engage the second lockout actuator.

[0072] 37 shows a cutaway view of the proximal end of the jaw assembly with a reload 250 cartridge partially inserted. As shown, the lateral extension 283 of the distal end 282 of the lockout lever 280 engages the sloped proximal surface 283 of the angled boss 252. As the reload 250 cartridge slides further proximally, the lateral extension 283 rises up the sloped surface to a first height relative to the reload support, pivoting the lockout lever 280 to a second position and disabling the empty jaw assembly lockout mechanism. Operation of the empty jaw assembly lockout mechanism is further described below with reference to FIG. 41. In the illustrated embodiment, when the distal end 282 of the lockout lever 280 is raised to a first height from the reload support by the first lockout actuator, the second lockout actuator or slider tail 254 of an unfired reload 250 cartridge is positioned at a height that is positioned to engage the inner surface 281 of the distal end 282 of the lockout lever 280, just distal to the first lockout actuator. Thus, when viewed in cutaway side view as shown in FIG. 37 , the first and second lockout actuators define a progressive ramped profile configured to raise the distal end 282 of the lockout lever 280 to two predetermined positions when a reload 250 cartridge is inserted into the reload support.

[0073] 38 shows a cutaway view of the proximal end of the jaw assembly with the reload 250 cartridge nearly fully inserted. As shown, the inner surface 281 of the distal end 282 of the lockout lever 280 engages the sloped proximal surface of the second lockout actuator or slider tail 254. In the illustrated embodiment, the proximally extending tail 254 of the slider of the reload 250 has a lead-in ramped surface that engages the distal end 282 of the lockout lever 280 when the reload cartridge is in an unfired state. In some embodiments, the lockout lever 280 and slider tail 254 can be configured to provide a smooth, relatively low-friction insertion of the reload and reduce the possibility of the slider binding or unintentional advancement during cartridge insertion. For example, in some embodiments, the inner surface 281 of the distal end 282 of the lockout lever 280 can have a radiused distal end so that the lockout lever 280 will pivot upon interaction with the slider tail despite the possibility of slight angular misalignment between the reload 250 cartridge and the reload support. Additionally, in some embodiments, the sloped proximal surface of the slider tail 254 can extend from a first height relative to the reload support at a proximal end that is lower than the height of the first lockout actuator relative to the reload support. Thus, when an unfired reload 250 cartridge is positioned within the reload support, the distal end 282 of the lockout lever 280 can smoothly transition from the first lockout actuator to the second lockout actuator over a wide range of angular alignments between the reload cartridge and the reload support.

[0074] 39 shows a cutaway view of the proximal end of the jaw assembly with a reload 250 cartridge fully inserted. As shown, the inner surface 281 of the distal end 282 of the lockout lever 280 is advanced onto the second lockout actuator or slider tail 254 along the sloped proximal surface of the second lockout actuator. This advancement of the slider tail 254 along the sloped surface causes the lockout lever 280 to pivot about pivot axis 284, positioning the distal end 282 of the lockout lever 280 at a second height relative to the reload support. When the distal end of the lockout lever 280 is at the second height, the lockout lever is in an unlocked position corresponding to the unlocked state of the empty jaw assembly lockout mechanism and the unlocked state of the fired reload lockout mechanism.

[0075] 39 , when lockout lever 280 is in the unlocked position, proximal end 286 of lockout lever 280 is at a height lower than the lower edge of the firing beam. Thus, firing member 240 and firing beam 226 can advance distally through an opening / closing stroke and a firing stroke in response to user input from an operably coupled mechanical or motorized handle assembly ( FIGS. 1-5 ). Thus, when an unfired reload cartridge is inserted into the reload support of the jaw assembly, both the empty jaw assembly lockout mechanism and the fired reload lockout mechanism are disabled, allowing a user to manipulate the stapler handle assembly to grasp tissue with the jaw assembly and fire staples from the jaw assembly by distally translating the firing beam and firing member within the jaw assembly.

[0076] 40 , when the reload 250 cartridge is at least partially fired, a slider within the reload 250 advances distally from a proximal, unfired position. Upon completion of the firing stroke, the slider remains in its distal position within the reload cartridge, allowing the firing beam 226 and firing member 240 to be proximally retracted in response to manipulation of the handle assembly on a return or retraction stroke. Thus, when the reload 250 cartridge is partially or fully fired, the second lockout actuator or slider tail is no longer in a position to engage the distal end 282 of the lockout lever 280. However, in some embodiments, the first lockout actuator or angled boss 252 does not move relative to the cartridge body. Thus, when a partially or fully fired reload 250 is positioned within the reload support, the first lockout actuator engages the distal end 282 of the lockout lever 280, positioning the distal end 282 of the lockout lever 280 at a first height relative to the reload support. When the distal end 282 of the lockout lever 280 is at a first height corresponding to a second position of the lockout lever, the empty jaw assembly lockout mechanism is disabled but the fired reload lockout mechanism is locked.

[0077] 40 , when the lockout lever 280 is in the second position, the proximal end 286 of the lockout lever 280 resides at a height corresponding to the second lockout notch 224 on the firing beam 226. Additionally, in some embodiments, a biasing spring 290 ( FIG. 34 ) exerts a force on an upper surface of the distal end 282 of the lockout lever 280 tending to maintain the proximal end 286 of the lockout lever 280 at a height corresponding to the second lockout notch 224 on the firing beam 226. Thus, if a user attempts to actuate the jaw assembly with a fired reload cartridge present in the jaw assembly, the firing beam 226 will advance distally until the proximal end 286 of the lockout lever 280 is received within the second lockout notch 224 of the firing beam 226, indicating engagement of the fired reload lockout mechanism and preventing further distal movement of the firing beam and firing member.

[0078] 40 , in some embodiments, the fired reload lockout mechanism can be configured to allow operation of the jaw assembly of the stapling device through at least a portion of an opening or closing stroke. For example, in some embodiments, the location of second lockout notch 224 and the length of lockout lever 280 can be sized and configured to arrest firing beam 226 upon engagement of the fired reload mechanism in a position corresponding to a fully closed or nearly fully closed configuration of the jaw assembly. A jaw assembly configured in this manner maintains cutting edge 245 in a substantially retracted position even though firing member 240 has advanced to a distal position that approximates the first and second jaws. A fired reload lockout configured to allow an opening or closing stroke advantageously allows a user, after firing staples from a reload cartridge, to operate the jaw assembly through one or more opening or closing strokes to assess tissue thickness and consistency at various locations for applying a potential second reload. Similarly, because insertion of the stapling device through a surgical access port, such as a trocar, may generally require the jaw assembly to be in a closed configuration, a user may also retract and reinsert the jaw assembly through one or more surgical access ports to assess tissue thickness and consistency at various locations in the surgical site.

[0079] With continued reference to FIG. 40 , in some embodiments, the fired reload lockout mechanism can be further configured to prevent operation of the stapling device in a firing stroke. Typically, mechanical power stapler handle assemblies configured for use with the elongated shaft and jaw assemblies described herein, such as those described with respect to FIGS. 1-5 , include a firing mode selector mechanism or firing safety switch that allows a user to actively select operation of the firing stroke of the jaw assembly only when the jaw assembly is in a closed configuration. Accordingly, in some embodiments, the location of second lockout notch 224 and the length of lockout lever 280 can be sized and configured to stop firing beam 226 upon engagement of the fired reload lockout mechanism in a position corresponding to a position proximal to the fully closed configuration of the jaw assembly. Thus, in these embodiments, engagement of the fired reload lockout mechanism prevents a user from selecting operation of the firing stroke on the handle assembly. Operation of the fired reload lockout mechanism, which prevents selection of a firing stroke on the handle assembly, advantageously serves as an indication to the user that the lockout is engaged.

[0080] FIG. 41 shows a cutaway view of the proximal end of the jaw assembly with no reload cartridge inserted and the firing member and firing beam slightly advanced longitudinally. When no reload is present, as the tail 247 of the firing member 240 advances from the proximal end 286 of the lockout lever 280, the biasing spring 290 ( FIG. 34 ) exerts a force on the upper surface of the distal end 282 of the lockout lever 280 toward the reload support. Thus, when the firing beam 226 initially advances in response to a user actuating the handle assembly to advance the jaw assembly through an open or closed stroke, the lockout lever 280 pivots to a first position corresponding to the locked configuration of the empty jaw assembly lockout mechanism. As the firing beam 226 advances distally, the proximal end 286 of the lockout lever 280 is received in the first lockout notch 222 on the firing beam 226, engaging the empty jaw assembly lockout mechanism and preventing further distal translation of the firing beam 226 and firing member 240.

[0081] Continuing with reference to FIG. 41 , in some embodiments, the empty jaw assembly lockout mechanism can be configured to stop movement of the firing beam at a position corresponding to a substantially open configuration of the jaw assembly. For example, the location of the first lockout notch 222 on the firing beam 226, the length of the lockout lever 280, and the length of the tail 247 of the firing member 240 can be sized and configured to lock the empty reload lockout mechanism early in the opening or closing stroke of the jaw assembly. An empty jaw assembly lockout mechanism configured to lock during the early portion of the opening or closing stroke advantageously prevents a user from actuating the handle assembly to close the jaw assembly sufficiently to insert a reload cartridge through a surgical access port if no reload cartridge is present in the jaw assembly. Thus, with an empty jaw assembly lockout mechanism configured in this manner, a user has a tactile indication that a reload cartridge is not present in the jaw assembly before inadvertently introducing the empty jaw assembly into a surgical site. Furthermore, such an empty jaw assembly lockout desirably maintains the cutting edge 245 of the firing member 240 in a substantially retracted, shielded position for a jaw assembly without a reload cartridge present in the jaw assembly.

[0082] Optical Ring User Display In some embodiments, the handle assembly can include a controller that processes and, in some cases, stores or saves operational data, including firing difficulty information, test time information, and device status, in a memory module. Accordingly, it may be desirable for a stapler to include a user display that conveys certain operational information to the surgeon so that the surgeon can make an intelligent decision regarding the firing they are about to perform. For example, in some cases, it may be desirable to provide the user with some information regarding clamping time and whether the thickness of the clamped tissue is suitable for stapling within the operating parameters of the staple reload cartridge at the stapler's end effector.

[0083] 42, in some embodiments, the handle assembly can include a multi-function illuminated display as a user display, such as an annular illuminated "light ring" user display subassembly 402. Because the handle assembly is repositioned and manipulated at various angular orientations during a surgical procedure, the annular configuration of the light ring subassembly advantageously provides a highly visible user display to the operator from any device orientation.

[0084] 43-44 , in the illustrated embodiment, a light ring user display 402 includes an annular light reflector 404, an annular light ring 406, and a plurality of light sources 408. The annular light reflector 404 is positioned radially inward of the annular light ring 406 so that illumination from the light sources 408, which emit light radially inward, is reflected from the annular light reflector and propagates through the annular light ring. The material of the light ring 406 can be selected to allow a high degree of light transmittance while controlling light dispersion to prevent external bright spots from being visible to the user. As shown, the user display 402 includes four light sources 408 spaced approximately equally spaced around the periphery of the light ring user display 402. In some embodiments, each of these light sources can include an RGB light-emitting diode capable of illuminating at various colors and intensities. The light ring user display 402 can be electrically coupled to a controller for the handle assembly, such as a circuit board on a flexible printed circuit board, such as a rigid-flex printed circuit board. As shown, the flexible printed circuit board 410 can be formed in an annular configuration and positioned between the annular light ring 406 and the annular light reflector 404. The light source 408 can be attached to the inner surface of the flexible electrical cable 410 so as to emit light radially inward toward the annular light reflector 404. The shape of the flexible printed circuit board and the housing reflector desirably can easily allow the light source to be held at any angle that maximizes reflected light and minimizes bright spots.

[0085] While one embodiment of the light ring user display 402 has been shown and described above, it is contemplated that other embodiments of the light ring user display may include other aspects. For example, in some embodiments, more or fewer than four light sources 408 may be used in the light ring user display, and different or additional lighting technologies may be used. In some embodiments, the light sources may be positioned on the exterior surface of the flexible electrical cable 410 to emit light directly through the annular light ring 406 without including an annular light reflector in the light ring user display. In other embodiments, surfaces formed on one or both halves of the handle assembly housing may be used to emit light from the light sources without using a separate annular light ring.

[0086] With reference to FIG. 42 , it is envisioned that the light ring user display 402 can also be electrically coupled to the controller and configured to display various status messages to the user. For example, color, brightness, flashing sequence, or steady on / off illumination can be controlled to convey desired information to the user. In some embodiments, the occurrence and / or rate of particular color or brightness transitions can also be used to convey information to the user. In some display control profiles, a first color can be used to indicate that the handle is in an open-to-clamp functionality with no possibility of firing activation, and a second color can be used to indicate that the stapler is in a firing mode configured to fire staples. Additional colors or other indicia can also be used to represent other events or operational states of the stapler, such as completion of firing, reversal of the firing mechanism, and the occurrence of a firing error.

[0087] Control device As described above with respect to some features of the illustrated handle assembly, the handle assembly can further include a controller. As illustrated, the controller can include a microcontroller electrically coupled to a circuit board to which various additional sensors, power sources, and user display components are electrically coupled. The controller can be configured to drive the motor to provide an open-clamp function followed by a staple firing function in the stapler jaw assembly. The controller can be further configured to modify operating parameters of the motor based on sensor data from one or more of a motor load sensor, an actuation rack position sensor, a shaft recognition sensor, and an articulation position sensor.

[0088] FIG. 45 shows a schematic flow diagram illustrating data and power flow for an exemplary control system for a powered handle. In the illustrated flow diagram, the control system includes a microcontroller 502, as shown. In various embodiments, the microcontroller may include an application-specific integrated circuit or a general-purpose microcontroller executing application-specific firmware and / or software. As shown, the microcontroller receives power and data regarding battery status from a battery 504 in a power supply. The microcontroller further receives data from various mechanical hardware of the stapler, such as a motor driver 506, a current monitor 508, an actuation rack position sensing mechanism 510, and a shaft connection and type monitor 512. As described above with respect to the articulation mechanism, the microcontroller 502 may further receive articulation position information from an articulation position sensing mechanism 514. The microcontroller may further receive data from a user via a trigger position sensor 516 and a pushbutton switch. The control system may output control signals that operate the drive system of the powered handle through the motor driver 506. The control system can output some operating parameter information to a memory module 520, which in some embodiments can include a removable module, as well as some data visible to the user through LED illumination 522 on the handle, such as the light ring user display described herein. In some embodiments, the control system can be configured to provide haptic feedback to the user, such as through activation of an independent haptic module or a haptic generation motor drive profile that can command one or more small forward and reverse displacements in the rotation of the motor, as further described herein with reference to FIGS. 56-57, such that the user feels a feedback sensation but the position of the actuation rack is not significantly affected. In some embodiments, the microcontroller can be configured to send and receive information wirelessly, for example, via Bluetooth, WiFi, or another wireless protocol.

[0089] In some embodiments, the control system is also configured to further determine operating parameters of the powered handle. For example, the control system can detect whether the powered handle has been used for more than one procedure by interrogating a memory module on the power source or the control system itself. In some embodiments, the stapling system is designed to be used for a single procedure and is not designed to be resterilized. The control system can also interrogate a memory module on the power source or the control system to detect the number of staple firings to assess whether sufficient battery power remains to complete additional firings.

[0090] In some 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 drive system motor. 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 too slowly. These conditions can indicate that the tissue within the jaw assembly is too thick or dense for the stapler to be effective. In some embodiments, the control system can monitor the position of the actuation shaft over time and evaluate this monitored position and time against a baseline "zero load" time reference position and time to calculate 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.

[0091] A block diagram of an operational flow chart of an exemplary firing sequence for the control system is shown in Figure 46. As shown, the control system integrates user input from the trigger and fire button and hardware input from various sensors and monitors to advance the jaw assembly from a fully open state 530 to a fully closed state 532 in a firing sequence 534, and then back to the fully open state 530.

[0092] During a firing operation, the controller can monitor the position of the actuation shaft to provide a desired motor drive profile. In some embodiments, a microcontroller can operate using a motor drive logic profile that identifies various operating zones of the actuation rack position and apply predetermined motor drive parameters, such as motor speed and motor load monitoring, for each of these zones and for various actuation rack positions within these zones. In some embodiments, the motor drive logic profile can be a software or firmware-based calculation program stored in a memory module, such as a computer-readable medium, within or electrically coupled to the controller. In some embodiments, the motor drive logic profile can define operating parameters and a sequence of operation through one or more of a grasper zone, a lockout zone, a firing zone, a full firing zone, a return zone, and an open zone. In some embodiments, the motor drive logic profile can be configured to adjust associated zones and positions in response to sensor inputs received from one or more of an articulation position sensor, a shaft recognition sensor, a motor load monitor, or other sensor inputs.

[0093] The grasper zone corresponds to the movement zone of the actuation rack between the jaw-open and jaw-clamped positions of an end effector attached to the instrument shaft. In this region, the microcontroller can be configured to drive the jaw assembly in proportion to the degree of trigger movement input by the user and transmitted to the microcontroller by a trigger position sensor, such as a trigger potentiometer. When the trigger is fully depressed, the device advances the actuation shaft to a position where the jaws of the end effector are fully closed. When the trigger is fully released, the device returns to open jaws. A full trigger squeeze and simultaneous press of the fire button advances the actuation shaft to the lockout zone. In other embodiments, in the grasper zone, the microcontroller can be configured to drive the motor at a rate proportional to the trigger's angular displacement so that the trigger movement determines the rate of jaw closure in the grasper zone, rather than the amount of jaw closure.

[0094] In some embodiments, the motor speed can be varied to a desired travel speed in a particular zone through pulse width modulation. In some embodiments, the motor can be pulse width modulated at a duty cycle of less than 100% in the gripper zone. In some embodiments, it may be desirable to drive the motor at a duty cycle of approximately 50% to 90% in the gripper zone. In some embodiments, the motor drive logic profile can be configured such that the motor is pulse width modulated at a duty cycle of 70% in the gripper zone.

[0095] When the user presses the fire button on the handle, the controller advances from the jaw-closed position in the gripping instrument zone to the lockout zone of the motor drive logic profile. The lockout zone can be configured to provide a motor control profile for the instrument shaft and jaw assembly that includes a firing lockout that prevents stapler firing operation when a fired stapler reload cartridge is present or when no stapler reload cartridge is present. Operation of this type of lockout can significantly increase motor load by preventing any portion of the firing mechanism in the instrument shaft or jaw assembly from advancing further beyond the actuator's predetermined actuation position. Thus, during the lockout zone, the controller can monitor sensor information from the actuator rack position sensor and the motor load sensor for anticipated motor load spikes.

[0096] While the handle assembly and controller embodiments shown herein include a trigger and a fire button, it is contemplated that in other embodiments, the handle assembly and controller may be configured to operate with a single control, such as a single trigger without a fire button or a single button on the trigger. In these single-control embodiments, the controller may be configured to operate in the grip zone upon an initial trigger squeeze or button press and advance to the lockout zone upon subsequent release and a second trigger squeeze or button press. Additionally, in other embodiments, the handle assembly and controller may be configured to operate with a dual-input trigger, such as a fire button configured by the controller to advance the motor and actuator distally or forward through the firing sequence, and a reverse button configured to operate the motor and actuator proximally or reverse.

[0097] The controller applies a motor drive profile that ramps up a pulse-width modulated duty cycle to achieve a lockout zone motor speed from an initial stop position at the beginning of the lockout zone. In some embodiments, the lockout zone duty cycle is less than the gripper zone duty cycle. For example, in some embodiments, a lockout zone duty cycle of about 30% to about 60% may be desirable. In other embodiments, the lockout zone duty cycle is about 45% to 55%. In some embodiments, the lockout zone duty cycle can be about 50% throughout the lockout zone. Within the lockout zone, the controller monitors the actuation rack position to assess the motor load for several predetermined positions. The controller does not initially actively monitor the motor load for load spikes from the jaw closed position. Relatively high loads may exist as the actuator duty cycle ramps up to the lockout zone duty cycle, which settles to a relatively low operating load. Once the actuation rack position reaches a predetermined lockout low position, the controller begins monitoring for potential motor load spikes. The controller continues to monitor the motor load until the actuation rack translates to a position defined as the lockout high position.

[0098] The lockout low and lockout high positions define a predetermined buffer around a lockout nominal position, which corresponds to the expected motor load spike location due to operation of the lockout mechanism. However, the actual motor load spike location may deviate from the expected lockout nominal position due to various factors related to tissue thickness and jaw articulation, and therefore the lockout zone is configured to detect motor load spikes within a range that extends to the buffer zone on either side of the lockout nominal position.

[0099] In some embodiments, the controller monitors the motor load by tracking the current drawn by the motor. In some embodiments, a lockout current spike is defined as any value above a predetermined current threshold. As described further below, in other embodiments of the control system, the controller can include a lockout module that detects engagement of other embodiments of the lockout mechanism that engage the grasper zone. In some embodiments, the threshold can be defined as the current value sampled at a predetermined position, such as the lockout low position, plus an additional amount that can indicate a load spike. In some embodiments, the threshold can be at least an additional 20 mA plus the lockout low current value. In other embodiments, the threshold can be at least an additional 50 mA plus the lockout low current value. In yet other embodiments, the threshold can be 30 mA plus the current value sampled at the lockout low position. In other embodiments, other motor parameters can be monitored and other thresholds can be used to define a load spike. If the controller detects a motor load spike between the lockout low and lockout high positions, this condition typically indicates that a firing lockout has been triggered due to a missing or used reload. If the controller detects a fire lockout, the motor drive profile is configured to immediately return the actuation shaft to return the jaw assembly to open jaws. If the controller does not detect a motor load spike corresponding to a fire lockout in the lockout zone, the controller proceeds to the fire zone.

[0100] The firing zone occurs between the lockout high at the end of the lockout zone and the start of the first full firing of the full firing zone. The controller has a motor drive profile that ramps the motor drive duty cycle from the lockout zone duty cycle to a relatively high duty cycle and moves at this rate for the duration of the zone. For example, in some embodiments, the firing zone duty cycle can be between 70% and 100%. In some embodiments, the firing zone duty cycle can be approximately 100% for the duration of the cycle.

[0101] The full fire zone begins when translation of the actuation rack reaches a predetermined full fire start position. As the actuation rack translates to the full fire start position, the controller applies a motor drive profile that ramps the motor duty cycle down to the full fire zone duty cycle. In some embodiments, the full fire zone duty cycle can be approximately 30%-80%, desirably approximately 40%-60%. In some embodiments, the full fire zone duty cycle can be approximately 50%. The controller also monitors the motor load to begin detecting current spikes. A current spike in the full fire zone indicates that the firing mechanism and reload of the jaw assembly have reached the distal end of its travel. In some embodiments, the I-beam jaw closure and firing beam are fully extended and impacting the distal end of the jaw assembly. In some embodiments, the motor load can be monitored during the full fire zone to detect current spikes, defined as any value above the current sampled at the full fire start position.

[0102] The controller can incorporate sensor data from the shaft recognition sensor described above and assign different values ​​for the full-fire start position that initiates the full-fire zone based on the length of the jaw assembly coupled to the handle assembly. For example, a jaw assembly with 30 mm jaws will have a relatively lower full-fire start position than a jaw assembly with 45 mm jaws. Similarly, a jaw assembly with 45 mm jaws will have a relatively lower full-fire start position than a jaw assembly with 60 mm jaws. In some embodiments, the shaft recognition sensor and controller can be configured to recognize multiple shaft lengths and determine full-fire zone positions corresponding to these recognized shaft lengths. For example, in one embodiment, the shaft recognition sensor and controller can be configured to determine separate full-fire zone positions for shafts including one or more of the following jaw assemblies: 30 mm, 45 mm, and 60 mm. The shaft recognition sensor and controller can also be configured to recognize when no shaft is coupled to the handle assembly and prevent operation of the motor through some or all of the actuation zone when such a condition is recognized.

[0103] The full fire zone ends at the full fire position. The full fire position corresponds to the calculated location where the controller should detect a full fire current spike. However, in some embodiments, the controller advances to the return zone only upon detection of a current spike, which may occur before or after this location due to various factors, including tissue thickness and articulation. Similar to the full fire start position, the controller can incorporate sensor data from a shaft recognition sensor and assign different values ​​for the full fire start position based on the length of the jaw assembly coupled to the handle assembly. Additionally, in some embodiments, the controller can incorporate sensor data from the articulation sensor described above with reference to FIG. 19 to determine the full fire start position and adjustment positions for the full fire position.

[0104] Once the device is fully fired, the controller advances to a return zone. In the return zone, the controller is configured to drive the motor at a relatively high speed. For example, in some embodiments, the controller can drive the motor at a duty cycle of 70% to 100% in the return zone. In other embodiments, the controller can drive the motor at a duty cycle of 85% to 100% in the return zone. In yet other embodiments, the controller can drive the motor at approximately a 100% duty cycle until the actuation shaft is positioned in a position corresponding to the jaw-closed position of the jaw assembly. At this time, the user can advance the controller to the open zone by pulling the trigger to drive the motor at a 100% duty cycle to an actuation rack position corresponding to the jaw-open position of the jaw assembly.

[0105] 47-49 illustrate exemplary aspects of operation of the handle assembly using the example motor drive logic profile described above. FIG. 47 shows a schematic diagram of a complete fire and return operating cycle of a powered handle assembly, including several aspects of the motor drive logic profile. The central arrow 540 represents the position of the actuation rack, starting from a calibrated "0" corresponding to the jaw-open position of the coupled jaw assembly, and increasing by an indicated number of 'counts' as labeled, determined by monitoring an actuation rack sensor, such as an actuation rack potentiometer described herein. The various zones described above are labeled across the central arrow, and some positions are numbered, with the first position corresponding to the jaw-open position 1, the second position corresponding to the jaw-closed position 2, the third position corresponding to the lockout low position 4, the fourth position corresponding to the lockout nominal position 4, the fifth position corresponding to the lockout high position 5, the sixth position corresponding to the full-fire start position 6, and the seventh position corresponding to the full-fire position 7. Full fire start position 6 and full fire position 7 are repeated to indicate different position values ​​associated with different shaft geometries recognized by the shaft recognition sensor. While the above description includes specific motor operating speeds, positions, and jaw sizes, it is contemplated that in other embodiments, the handle assembly controller may incorporate motor drive logic profiles that include different speeds, positions, and jaw sizes, or motor drive logic profiles that incorporate sensor data from other sensors.

[0106] 47, the motor control logic profile can include a gripper zone 542 extending between jaw open position 1 and jaw closed position 2, a lockout zone 544 extending between jaw closed position 2 and lockout high position 5, a fire zone 546 extending between lockout high position 5 and full fire start position 6, a full fire zone 548 extending between full fire start position 6 and full fire position 7, a return zone 550 extending from full fire position 7 to jaw closed position 2, and an open zone 552 extending from jaw closed position 2 to jaw open position 1. While the illustrated embodiment of the motor control logic profile includes a lockout zone 544 outside of the gripper zone 542, as further described with respect to the lockout mechanism of FIGS. 32-41, the lockout zone can overlap the gripper zone such that the control system can include a lockout module as described with reference to FIGS. 58-61.

[0107] 48 and 49 show plots of motor load (in milliamps) versus actuation rack position (in counts) for an exemplary firing stroke of a handle assembly operating using an embodiment of the motor control logic profile described herein. FIG. 48 shows an example of motor load through the lockout and lockout zones, where a lockout motor load spike is encountered during the lockout zone between the lockout low position 3 and the lockout nominal position 4 of the actuation rack. As described above, when such a motor load spike is encountered, the controller returns the actuation rack to a position corresponding to the jaw-open configuration of the end effector. As shown, the motor load also spikes around the jaw-closed position 2. This load spike can correspond to stopping the motor and restarting it at a different speed as the controller progresses from the grasper zone to the lockout zone. This initial movement load spike can require a small translation of the actuation rack, such as about 15 counts, to settle down. Thus, in the lockout zone, the controller does not monitor the load spike corresponding to a lockout condition until lockout low position 3, which exceeds the transient load spike at the beginning of the lockout zone.

[0108] 49 shows an example of motor load versus actuation rack position 1 from jaw open through full fire position 7. As shown, the motor load can spike temporarily at actuation rack positions corresponding to the start of the lockout zone at jaw closed position 2 and the start of the firing zone at lockout high position 5. At these positions, the controller can command a motor speed change that temporarily increases the monitored motor load.

[0109] As described above with respect to FIGS. 45-46 , the microcontroller can be configured with a control system to integrate user input and system hardware input in the grip, firing, and return sequences of the powered handle described herein. The control system can be embodied in a software or firmware system running on the microcontroller. In some embodiments, the microcontroller can be configured with a single control system that defines the motion sequence of the powered handle. In other embodiments, the microcontroller can be configured with multiple control systems that allow the user to select a desired motion sequence for desired stapling motion characteristics. Some aspects of two exemplary control systems are described with respect to the schematic diagrams of FIGS. 50-52 and 53-55 . Generally, the control systems of FIGS. 50-52 are configured to require manual input from the user in the form of actuation of a trigger or fire button before the handle begins motion. Such control systems can desirably provide a high degree of user control and predictability over the stapling operation. The control systems of FIGS. 53-55 are configured to automate portions of the stapling operation to proceed without further user input. Desirably, such control systems can facilitate a more efficient stapling sequence and reduce the likelihood of user fatigue. It is contemplated that in other embodiments, the control system may include some, but not all, of the automated features of the system shown in Figures 53-55 in a more manual control system, such as the system of Figures 50-52. It is contemplated that in still other embodiments of the control system, additional automated operating sequences may be added to the system of Figures 53-55.

[0110] 50-52 show block diagrams that generally illustrate operational flow charts for exemplary grasp (FIG. 50), fire (FIG. 51), and return (FIG. 52) sequences for the control system. As shown, the control system integrates user input from the trigger and firing button (shown as "User Action" in the generally rectangular block), handle position information reported from various sensors and monitors (shown as "Handle Position" in the elongated hexagonal block), and corresponding handle actions (shown as "Handle Action" in the diamond-shaped block) as the handle assembly operates to advance the jaw assembly from a fully open state to a fully closed state in the firing sequence and then back to the fully open state.

[0111] Figure 50 schematically illustrates several aspects of the power-on and gripping operation of the control system. In addition to the various shapes shown in the legend that schematically illustrate several aspects of the control system as described above, an example user feedback indicia, which may be represented by a multi-colored LED, such as the light ring described with reference to Figures 42-44, is shown in quotation marks along with an example selected color, flash frequency, and duty cycle that indicates to the user the operational status of the handle. It is contemplated that other user feedback indicia may be presented in connection with the control systems of Figures 50-52 in other embodiments.

[0112] 50 , the initial power-on operation is indicated by a smooth white pulse. In the initial position, the jaw assembly is open and the stapler is in a gripping configuration that allows the jaws to open and close in response to movement of the trigger 560. When an unfired reload cartridge is present in the jaw assembly, the handle assembly is configured to operate such that movement of the jaw assembly between the open and closed positions corresponds to movement of the trigger from an initial position generally spaced from the handle to a squeezed position close to the handle. This generally proportional movement of the trigger and jaw assembly has the advantage of allowing the user to repeatedly open and close the jaws to precisely locate the desired staple location and tissue placement within the surgical field.

[0113] 50, the illustrated control system closes the jaws when the user fully approaches the handle, with the user feedback indicator indicating this closed configuration 562 with blue illumination. When the jaws are in this closed state, the illustrated control system maintains the handle in the grasping configuration without further user input. Thus, if the user releases the trigger from the fully approached position, the jaws will open (to a position corresponding to the amount of trigger release). Further user input is required to configure the control system to command the handle assembly into the firing configuration.

[0114] 50, if there is no reload in the jaw assembly, or if there is a spent or partially spent reload in the jaw assembly, the jaws will not close fully. In the illustrated control system, a user feedback indicator displays a yellow light 564 prompting the user to release the trigger to allow the jaws to return to the open configuration.

[0115] 50 and 51 schematically illustrate operation of the gripping and firing configurations of the motorized handle control system. In the illustrated control system, when the trigger is held in the fully approximated position and the jaws are fully closed (indicated by a solid blue user feedback indicator), the user must press a fire button 566 on the handle to command the control system to enter the firing configuration (FIG. 51). Once in the firing configuration, the user feedback indicator displays a solid green light. If the button is pressed a second time while the trigger is held in the fully approximated position, the control system commands the handle to return to the gripping configuration and causes the user feedback indicator to display a blue light. To initiate firing, with the handle assembly in the firing configuration and the user feedback indicator displaying a green light, the user first releases the trigger, then approaches and holds the trigger 568 in the fully approximated position, thereby activating the motor and directing the handle to advance the firing member of the jaw assembly toward the fully fired position where all staples are deployed from the stapler. If the user wishes to abort the firing of staples, releasing the trigger causes the control system to command the motor to stop. If the user wishes to return to the firing action from the paused state, the user can re-approach the trigger to re-enter the firing action, or if the user wishes to abort stapling from this trigger-released paused state, the user can press a button to instruct the control system to cause the handle to bypass the full-fire position and enter a return configuration, causing a distinct flashing of the user feedback indicator reflecting this return configuration.

[0116] 51 and 52 schematically illustrate several aspects of the firing and return motions of the control system of the electric stapler handle. When a user commands the control system to enter the reverse configuration, either by fully executing the firing motion or by interrupting and then stopping the firing motion by releasing the trigger and then depressing the fire button, maintaining the trigger in an approximated position will cause the control system to command the handle to move in the reverse direction, retracting the firing member longitudinally within the jaw assembly. If the user desires to interrupt the return motion, they can release the trigger. They can then resume the return motion by again approximating the trigger relative to the handle. This manual control of the return motion has the advantage of providing the user with the option to inspect staple formation and tissue compression, if desired, without fully retracting the firing member. The return motion is completed with the jaw assembly in the closed position and the trigger still proximate the handle body.

[0117] 50 and 52, once the return motion is complete, the control system commands the handle assembly to return to the grasping configuration. The user can then release the trigger to return the jaw assembly to the open configuration. This manual control of jaw opening after the firing and return motion has the advantage of allowing the user additional time to monitor tissue compression before fully releasing the jaw assembly from the stapled tissue.

[0118] Figure 53 shows a schematic representation of some aspects of the power-on and gripping operations of the control system of Figures 53-55. The block shapes and user feedback indicia in the control system schematics of Figures 53-55 correspond to the conventions presented for the control systems of Figures 50-52.

[0119] Continuing with reference to FIG. 53, the initial power-on operation is indicated by a smooth white pulse. In the initial position, the jaw assembly is open, and the control system commands the handle to remain in a gripping configuration that allows the jaws to open and close in response to trigger movement (570). When an unfired reload cartridge is present in the jaw assembly, the handle assembly is configured to operate such that movement of the jaw assembly between the open and closed positions generally corresponds to movement of the trigger from an initial position spaced from the handle to a compressed position closer to the handle. This generally proportional movement of the trigger and jaw assembly has the advantage of allowing the user to repeatedly open and close the jaws to precisely locate the desired stapling location and tissue placement within the surgical field.

[0120] Continuing with reference to FIG. 53 , the illustrated control system closes the jaws when the user fully closes the trigger relative to the handle, and a user feedback indicator indicates this closed configuration 572 with blue illumination. The control system commands the handle to automatically maintain this closed configuration, even if the trigger is subsequently released. When the jaws are in this latched closed state, the illustrated control system maintains the handle in a grasping configuration with the jaws fully closed without further user input. This latched closed position has the advantage of allowing the user to release the trigger to maintain tissue compression while manipulating the handle to gain visibility at the surgical site. When the user desires to release the jaw assembly from the latched closed configuration, the user can again close the trigger, causing the control system to command the handle to position the jaws in an unlatched closed configuration (correspondingly turning the user feedback indicator “off”). Subsequent release of the trigger causes the control system to command the handle to move the jaws to the open configuration.

[0121] 53, if there is no reload in the jaw assembly, or if there is a spent or partially spent reload in the jaw assembly, the jaws will not close fully. In the illustrated control system, a user feedback indicator displays a yellow light 574 prompting the user to release the trigger to allow the jaws to return to the open configuration.

[0122] 53 and 54 schematically illustrate operation of the gripping and firing configurations of the control system for the motorized handle. In the illustrated control system, when the trigger is released and the jaws are in the locked configuration with the trigger fully closed (indicated by a solid blue user feedback indicator), the user must press (566) the fire button on the handle to command the control system to enter the firing configuration (FIG. 54). Once in the firing configuration, the user feedback indicator displays a flashing green light. When the button is pressed a second time (576) with the trigger held in the fully released position, the control system commands the handle to return to the gripping configuration with the jaw assembly in the locked closed position and causes the user feedback indicator to display a blue light. With the handle assembly in the firing configuration and the user feedback indicator displaying a flashing green light, the user can initiate firing by approaching (578) and holding the trigger in the fully approached position, which causes the control system to activate the motor and advance the firing member of the jaw assembly toward the fully fired position where all staples are deployed from the stapler. As the trigger is approached during this firing motion, the user feedback indicator displays a solid green illumination. Upon reaching the fully fired position, the control system commands the handle to stop operating the motor and commands the user display indicator to present a different pattern indicating the handle has entered the return configuration. If the user desires to abort the firing of staples during the firing motion, the trigger is released (580), causing the control system to command the motor to stop. If the user desires to return to the firing motion from the paused state, the user can again approach the trigger (578) to re-enter the firing motion. Alternatively, if the user desires to abort stapling from this trigger-released paused state, the user can press (582) to cause the control system to cause the handle to bypass the fully fired position and enter the return configuration, causing a distinct flashing of the user feedback indicator reflecting this return configuration.

[0123] 54 and 55 schematically illustrate several aspects of the firing and return motions of the control system of the electric stapler handle. When a user commands the control system to enter the reverse configuration, either by fully executing the firing motion or by interrupting and then stopping the firing motion by releasing the trigger and then depressing the fire button, returning the trigger to an approximated state and releasing the trigger (584) causes the control system to command the handle to operate in the reverse direction, retracting the firing member longitudinally within the jaw assembly. This return motion proceeds automatically until the firing member retracts within the jaws to a jaw-closed position, allowing the user to release the trigger during the return motion. The user can then resume the return motion by again approximating the trigger relative to the handle. This automated control of the return motion desirably enhances user convenience by reducing the need for user interaction upon completion of staple firing. The return motion is completed with the jaw assembly in the closed position.

[0124] 53 and 55, once the return motion is complete, the control system commands the handle assembly to return to the grasping configuration with the jaws in the locked closed configuration and the user feedback indicator illuminating blue. The user can then again approximate and then release the trigger to unlock the closed jaw assembly and return the jaw assembly to the open configuration. This manual control of jaw opening after the firing and return motion has the advantage of allowing the user additional time to monitor tissue compression before fully releasing the jaw assembly from the stapled tissue.

[0125] Haptic Feedback Module In addition to the light ring user display described with reference to FIGS. 42-44 , further user feedback can be provided through the use of haptic feedback, such as by having the handle hum or vibrate in certain patterns to indicate particular operating states of the handle assembly. In some embodiments, a dedicated haptic feedback generator, such as a vibration feedback motor, can be disposed within the handle assembly and configured to provide user feedback in certain states. However, in some embodiments, it may be desirable to be able to provide haptic feedback without the use of additional components. Because the handle assembly can include a DC motor and reduction drive that provides a linear actuation force to cut and approximate tissue, this motor and drive system can include backlash due to mechanical clearances between components. Due to this backlash, there is an initial period of actuation of the DC motor output shaft that does not result in movement of the actuator and jaw assembly of the stapling system. Thus, in some embodiments, driving the DC motor clockwise and counterclockwise in rapid succession can produce significant vibration of the handle assembly to the user without significant translation of the actuator. To achieve this haptic feedback mode of the DC motor, the control system can include a haptic feedback module operable to drive the motor with a substantially square wave motor drive waveform profile 590 having alternating clockwise and counterclockwise peaks 592 and 594, each having a predetermined duration that does not result in movement of the actuation shaft due to backlash in the motor and drive system. Figure 56 shows an example motor drive profile 590 that provides haptic feedback in the form of a buzzing or vibrating handle in the handle assembly. This square wave and resulting motor vibration can also be varied, for example, by introducing a depowered pause or delay between adjacent peaks in the waveform.57 illustrates an exemplary motor drive waveform profile 590' that incorporates a depowered time delay 596 between alternating clockwise and counterclockwise peaks 592, 594 to create a pulsating haptic feedback sensation. Thus, the haptic feed module can be configured to produce different patterns or pulsating buzzing or vibration patterns that correspond to different operating states of the handle assembly. While the exemplary motor drive waveform profiles 590, 590' are shown as idealized square waves, it is contemplated that in other embodiments, the haptic module can include other waveform profiles configured to produce motor movement without significant movement of the actuation shaft.

[0126] Lockout Control Module As described above with reference to FIGS. 47-49 , in some embodiments, the control system can be configured to monitor current within a defined “lockout zone” of actuator position. In these embodiments, the control system can rely solely on a current threshold to determine the presence of lockout mechanism engagement. In some embodiments, the current threshold is determined based on a sample at the beginning of the lockout zone plus a constant 300 mA, which indicates that the reload lockout has not been disabled and actuator movement has stopped. However, this control system's one-factor lockout sensing module is most effective outside the gripping zone when the actuator is nearing the firing stroke of the jaw assembly. The control system commands constant PWM operation of the motor outside the gripping zone. Furthermore, by the time the actuator advances distally beyond the gripping zone, tissue clamping has already occurred, thus minimizing any potential current fluctuations due to variations in tissue thickness and consistency. However, because the two-position lockout mechanism described above with reference to FIGS. 32-41 offers several operational advantages when engageable within the grasper zone, further refinement of the control system's lockout detection module may be required.

[0127] As discussed above with reference to FIGS. 32-41 , the two-position lockout mechanism is desirably engageable at two distinct actuator positions corresponding to an empty jaw assembly and an at least partially fired reload. In some embodiments, the lockout notch formed in the firing beam can be substantially continuous, such that these lockout actuator positions are relatively close to one another. Furthermore, in some embodiments, each of these actuator positions can reside within a gripping zone or region of control system operation. In the gripping region, the control system can be configured to provide full user control of opening and closing the jaws of the jaw assembly before entering the firing state. The user can partially close, reopen, and reclose the jaws without restriction. In some embodiments, in the gripping region, the trigger is mapped to proportional jaw closure, i.e., a 25% pull on the trigger results in 25% jaw closure. However, the motor stops and restarts each time the user interrupts, opens, or closes the jaws. Additional power is required for the motor to overcome inertia and ramp up to full speed, resulting in a large momentary current spike. Furthermore, because the jaw assembly typically compresses tissue during jaw closure in the grasping region, the load on the motor increases in response to an increase in the thickness or density of the tissue located between the jaws. Thus, in some cases, a lockout module in a control system based solely on current detection may result in false positive indications where transient user input and tissue compression conditions may cause one or more lockout mechanisms to engage at actuator locations within the grasping instrument region.

[0128] FIG. 58 shows an overlap plot of 25 exemplary current profiles 600 for various operating states of a powered stapler. The plot shows the motor load or current draw (measured in milliamps) tracked over the actuation position of the actuation shaft or actuator, as measured in “counts” of a position-sensing device, such as a potentiometer. Note that the experienced load and sensed position may vary based on the motor, battery, and gearing specifications, as well as the size and configuration of the elongate shaft, jaw assembly, and lockout mechanism. Therefore, this plot is only indicative of the performance of some embodiments of a powered stapler. The plot shows current versus position for a powered handle assembly operating in a no-reload-present state 602 as described above with reference to FIG. 41 to trigger the empty-jaw assembly lockout mechanism, a powered handle assembly operating in a fired-reload-present state 604 as described above with reference to FIG. 40 to trigger the fired-reload lockout mechanism, and a powered handle assembly operating in an unfired-reload-present state 606 to complete a clamping operation without engaging the lockout mechanism. This plot shows data from operation of the handle assembly with an unfired reload when both a lightly loaded mock tissue 608 and a heavily loaded mock tissue 610 are positioned within the jaw assembly to compare the effect of tissue compression on current draw. Despite the different lockout positions and nominal current draws, the slope of the current profile when the lockout state is engaged appears consistent between all tests.

[0129] In terms of lockout conditions that the control system can monitor, time and position can be unreliable, and the rate of change is inconsistent across different loads that may occur in the gripping zone of the actuator's travel. Current thresholds can be falsely triggered by current draw conditions encountered during normal gripping tool use, and voltage also changes as the battery depletes. However, one consistent lockout condition is the slope of the current profile versus actuator position, as shown in FIG. 58, which falls within different tolerance ranges when a lockout condition exists. While nominal current draw exhibits a low slope, gripping tool use has a much steeper slope. Except in rare cases, lockout engagement has a unique current versus time plot that falls between the other cases. The lockout slope tolerance for a particular elongated shaft configuration can be calculated by examining the lockout slope from a large sample size. In some embodiments, the control system can include a lockout module that monitors the slope of the current draw versus actuation shaft position to detect whether the current profile slope falls within the lockout tolerance range, indicating that the lockout mechanism is engaged. The lockout module of the control system can be configured to disengage the motor when lockout mechanism engagement 564, 574 is indicated and configure the control system to take further actions as described with respect to the motor drive profiles of FIGS. 50-55. FIG. 59 shows a plot of motor current draw data versus actuator position for an exemplary actuation sequence in which no reload is present (602), such as when the empty jaw assembly lockout mechanism of FIG. 41 is engaged. The plotted data reflects an initial current spike 610, a nominal current draw region 612, and a lockout engagement region 614 with a relatively consistent current profile slope. FIG. 60 shows a plot of motor current draw data versus actuator position for an exemplary actuation sequence in which the fired reload lockout mechanism of FIG. 40 is engaged and has a previously fired reload (604). The plotted data reflects an initial current spike 620, a nominal current draw region 622, and a lockout engagement region 624 with a relatively consistent current profile slope.The plotted data includes an exemplary actuation sequence in which the jaw assembly lightly compresses the tissue (626) and an exemplary actuation sequence in which the jaw assembly hard compresses the tissue (628) to show the consistency of the slope of the current profile in the lockout engagement region 624 regardless of the tissue load within the jaw assembly.

[0130] In some embodiments, the lockout module of the control system can be further improved to provide more consistent lockout engagement detection, even in the event of transient inconsistencies in monitoring motor retraction versus position that should indicate a slope corresponding to engagement of the lockout mechanism. In some instances, the current profile may be prone to momentary inconsistencies due to changes in tissue density, wear on driveline components, or delays in data collection. The current may temporarily deviate from the expected slope if one of the gears has a nick or burr or if an abnormally thick pocket of tissue is compressed. To combat these variations, some embodiments of the lockout module in the control system can average the change in current (slope) over multiple data entries to display a stable and reliable trend. In some embodiments, the slope of the current profile can be averaged over five data entries. While this averaging may result in a slight delay in lockout detection, the benefit to the false detection rate may outweigh the slight additional force that the component may withstand during this delay period.

[0131] As mentioned above, there are rare occasions when a slope can accidentally fall within the acceptance window. One such instance is due to transient load conditions surrounding trigger activation. After the trigger is activated, the current profile exhibits a corresponding current spike. At the peak of this spike, the current settles briefly before dropping back down to nominal. During these few counts of settling, occasionally the current change falls within the lockout tolerance.

[0132] In embodiments of the lockout module that detect lockout engagement based solely on the current slope or profile, these data points will falsely indicate lockout mechanism engagement. Thus, in some embodiments, the lockout module can be configured to detect lockout mechanism engagement only when the lowest of multiple consecutive averages of the current slope falls within a predetermined tolerance. For example, the lockout module can be configured to detect lockout mechanism engagement only when three consecutive averages of the current slope fall within the tolerance. If the average (of the previous multiple current slope profiles) falls within the lockout tolerance, the control system stores this average, and the lockout module, upon next data collection by the control system (in some embodiments, 10 ms later), again calculates the average of the previous multiple current profiles using the new data points (with the oldest current profile value from the initial multiple current profiles no longer being considered) and compares this new average to the lockout tolerance. If three consecutive values ​​fall within the lockout tolerance, the lockout module can indicate that the lockout mechanism has engaged. If the second or third average does not fall within the tolerance window, the control system can erase any stored averages and continue to monitor three consecutive current profile averages within the predetermined lockout range.

[0133] In some embodiments, the lockout module can be further improved to eliminate transient conditions that can provide a false indication of lockout engagement. Some motor load profiles in the gripping region have current spikes that can produce multiple consecutive current profile averages within a predetermined tolerance range, corresponding to a slope of the current profile empirically determined to be within the lockout engagement region. In some embodiments, the tolerance range can be 12 to 40, calculated from the current profile measured as current draw in mA and the actuator position measured in counts in a potentiometer-based position sensing mechanism. In other embodiments, the tolerance range can have different calculation units or different ranges based on different handle assembly, shaft assembly, or lockout mechanism configurations. Thus, in some embodiments, in addition to monitoring for lockout engagement when multiple consecutive averages fall within a predetermined lockout tolerance range, the lockout module can compare the last average of multiple consecutive acceptable averages to the first averages. The lockout module can then indicate that the lockout mechanism is engaged if the last average is greater than the first average. Referring to FIG. 56, during lockout mechanism engagement, the slope falls within a consistent range but still gradually increases over time. However, the current slope average following a current spike typically decreases over time, and therefore the lockout module can be configured to further reduce errors in detecting engagement of the lockout mechanism by evaluating whether multiple current slope averages are likely to indicate a transient current spike.

[0134] In light of the above description of some aspects of detecting engagement of a lockout mechanism in the gripping region, in some embodiments, the control system may include a lockout module configured to consistently distinguish engagement of the lockout mechanism from other transient load conditions on the motor in the gripping region. In some embodiments, the control system may periodically monitor motor current, actuator position, and elapsed time, and the lockout module may include a set of computer processor-executable instructions embodied in software or firmware for calculating whether a current slope profile indicates engagement of the lockout mechanism. In one embodiment, the lockout module may be configured to indicate that the lockout is engaged based on the following criteria: If pmw = maximum pmw yn = motor current Δyn = slope = change in current = (yn-yn-1) xn = average of previous 5 Δy = [(Δyn+Δyn-1+Δyn-2+Δyn-3+Δyn-4) / 5] 12~40 = Tolerance range = 12≦xn<40 Three consecutive values ​​are required = 12≦xn, xn-1, xn-2<40 The last consecutive value must be greater than the first = xn>xn-2 If the above is TRUE = LOCKOUT ENGAGED

[0135] While the majority of lockout engagements are detected by the lockout module applying the above logic structure, in some embodiments the control system can further enhance the lockout module to further enhance detection of lockout engagements under certain operating conditions. As noted above, one of the operating conditions for the lockout module is when the monitored motor pmw is pmw max, i.e. the lockout module is engaged when the trigger is fully depressed and the control system commands the motor in the handle to run at full speed.

[0136] However, when the PLLC trigger is pressed or released during gripping engagement, the motor must transition from a stationary state to full speed. If the motor were commanded to rotate at full speed instantly, the resulting current spike would be large due to the sudden increase in speed. Alternatively, current spikes can be minimized by controlling the motor's speed through a ramp-up cycle. This control utilizes PWM, or pulse-width modulation. PWM determines the percentage of power the motor receives. If PWM=100, the motor runs at full speed. If PWM=50, the motor runs at 50% of its maximum speed. By ramping up PWM at a set interval after the trigger movement, the motor transitions to full speed more slowly, and any resulting current spikes, while still present, are significantly reduced. In some embodiments, the ramp-up profile of the PWM ramp-up in the gripping region takes less than 100 ms to complete, so the lockout module described above functions throughout the majority of the lockout region (which can transition in approximately 1.5 seconds in some embodiments).

[0137] On the other hand, when the PWM is not at maximum PWM, the lockout module's lockout detection can be improved by applying several corrective sub-modules that account for certain unlikely but conceivable scenarios. For example, a user may pull the trigger just enough to move the actuator within a few position counts of the lockout mechanism and then stop it. Upon re-engaging the trigger, the user causes the PWM to ramp up the shaft, and the jaw assembly simultaneously physically engages the lockout mechanism. Relying on the lockout module described above during this unstable region would result in delayed detection of the lockout mechanism. Instead, in some embodiments, the lockout module can further include a lockout ramp-up sub-module that more quickly detects engagement of the lockout mechanism in the above usage scenario.

[0138] The lockout ramp-up submodule can be configured as an end condition for the lockout module. After the lockout module indicates that the lockout mechanism is engaged, the lockout ramp-up submodule can be executed to determine whether the PWM is in a current ramp-up state, which can be identified by monitoring the increase in current over position index counts. If so, the lockout ramp-up submodule can apply further evaluation before the lockout module can indicate that the lockout mechanism is engaged. This lockout ramp-up submodule has the advantage of reducing the risk of false lockout mechanism detection due to transient user trigger inputs. For example, in addition to the usage scenario described above, if a user intentionally repeatedly presses and releases the trigger by a small amount, the trigger will vibrate and the current will follow. If the user continues to wiggle the trigger in this manner, the current can eventually match the lockout tolerance range that includes the continuous average required for the lockout module to indicate that the lockout mechanism is engaged. In this trigger vibration usage scenario, which requires intentional action beyond normal hand tremors, the ramp-up sub-module can be configured to identify whether a particular monitored current profile is due to engagement of the lockout mechanism or due to trigger vibration.

[0139] When the lockout ramp-up submodule is initiated (after the lockout module evaluates that pwm is in the ramp-up state, indicating the presence of a lockout mechanism), it compares the monitored current to a calculated threshold. This current threshold ensures that the current is above nominal, thus indicating that the motor is being loaded by the engagement of the lockout mechanism. The submodule evaluates the first instance of pwm=max pwm to date to calculate the current threshold that must be overcome. The control system stores this current value as the current baseline and can reset it any time the trigger is fully released and the jaws return to their open position. If the trigger is incrementally pressed, only the first instance of pwm=max pwm is saved as the current baseline. This baseline provides a reference for the expected current value at that time given the particular motor, driveline components, and battery in the handle. This initial value can be stored as the current baseline because drivetrain travel has so far been minimal and the lockout mechanism is still relatively far away, posing no risk to a previously triggered lockout.

[0140] A position-dependent current correction value is added to this current baseline to establish a current threshold. This current correction value accounts for the increase in nominal current with position due to subsequent clamping and tissue compression within the gripping region. Position-based current correction values ​​can be empirically determined for a given elongate shaft and lockout mechanism assembly by plotting the maximum nominal current values ​​at ideal lockout positions and calculating a linear equation connecting them. These predetermined current correction values ​​can then be stored for use by the lockout ramp-up sub-module in evaluating the presence of lockout mechanism engagement.

[0141] In operation of the lockout ramp up sub-module, once a current threshold is established, the monitored current is compared and if it exceeds the threshold, the lockout ramp up sub-module indicates that the lockout mechanism has engaged. In some embodiments, the lockout ramp up sub-module may be embodied in a software or firmware program that operates according to the following logical structure: Lockout module = TRUE When pwm≠ maximum pwm (ramp up) yn = motor current yb = current baseline = max y at first instance of pwm ·yths=current threshold=current baseline+[(5*position)-200] · The current must exceed the current threshold = yn>yths If the above is TRUE = LOCKOUT ENGAGED

[0142] In some embodiments, the lockout module of the control system can include a lockout transition submodule that further improves the lockout module's detection of the lockout mechanism. The lockout transition submodule can operate at the peak of the PWM ramp-up. When the motor finally reaches maximum speed (PWM = Max PWM) after trigger movement and current spikes, the current settles and stabilizes, often dropping slightly. During a stapler usage scenario, if the lockout mechanism engages when the current is settling down due to reaching maximum speed, the lockout module may not indicate that the lockout mechanism has engaged. In such a scenario, the final current average is lower than the initial current average. To prevent this false negative, in some embodiments, the lockout transition submodule executes during the first instance of each ramp-up, PWM = Max PWM.

[0143] The lockout transition submodule can further enhance detection of the lockout mechanism in the event of a current drop by taking additional averages. The lockout transition submodule can operate during the transition from ramp up to maximum pwm. During operation, the lockout transition submodule averages the previous three averages (each average representing the previous five current changes) to form a more stable data point. Instead of comparing the first average to a tolerance window, the lockout transition submodule compares the second obtained average to another tolerance window. This submodule operates only once per ramp up, so it cannot wait for consecutive values, and therefore only this single second average value is analyzed. If the second average falls within the tolerance range (empirically determined for the particular stapler configuration), the next step is to calculate a current threshold using the same current threshold calculation as for the lockout ramp up submodule. Once the current threshold is established, the monitored current is compared to the current threshold, and if this current exceeds the threshold, the lockout transition submodule indicates that the lockout mechanism has engaged.

[0144] In some embodiments, the lockout transition sub-module may be embodied in a software or firmware program that operates according to the following logical structure: Lockout module = false If pwm=max pwm (first instance per ramp-up) yn = motor current Δyn = slope = change in current = (yn-yn-1) xn = average of previous 5 Δy = [(Δyn+Δyn-1+Δyn-2+Δyn-3+Δyn-4) / 5] zn = average of previous 3 X = (xn+xn-1+xn-2) / 3 15~40=Tolerance=15 <zn<40 yb = current baseline = max y at first instance of pwm ·yths=current threshold=current baseline+[(5*position)-225] · The current must exceed the current threshold = yn>yths If the above is TRUE = LOCKOUT ENGAGED

[0145] In some embodiments, the lockout module can further include a post-lockout transition submodule that activates for a predetermined range of motion of the actuation shaft after the lockout transition submodule. In one embodiment, the post-lockout transition submodule activates 10 counts after the lockout transition submodule. As the current settles from the transition to pwm max, it oscillates and drops slightly, resulting in rapid succession. However, if the lockout mechanism is engaged, the current steadily increases after this transition or throughout the entire 10-count window. In the case of a transient, oscillating current draw condition during the post-transition period, the lockout module may require several counts to indicate the presence of an engaged lockout mechanism due to the need for a trend of several counts affecting the calculated average. Therefore, activation of the post-lockout transition submodule after the lockout transition submodule can improve lockout module performance and reduce wear on the device. The post-lockout transition submodule activates for a predetermined displacement after the lockout transition module and compares the monitored current change with the current change of the previous indicator to determine whether there is an upward trend over the predetermined measurement period. In some embodiments, if there are three consecutive increasing changes in current, the post-lockout transition sub-module indicates engagement of the lockout mechanism.

[0146] In some embodiments, the lockout post-transition sub-module may be embodied in a software or firmware program that operates according to the following logical structure: Lockout module = false Transition submodule = false - Within 10 counts after maximum PWM transition yn = motor current Δyn = slope = change in current = (yn-yn-1) Increase in current change = Δyn>Δyn-1 Three consecutive values ​​are required = Δyn>Δyn-1>Δyn-2>Δyn-3 If the above is TRUE = LOCKOUT ENGAGED

[0147] The lockout module may further include a lockout ramp-down submodule that improves lockout mechanism detection during a PWM ramp-down of the motor drive from the control system. In some embodiments, the lockout ramp-down submodule operates during a PWM ramp-down, which occurs whenever the control system commands the motor to slow down or stop. Similar to how the control system commands the motor via a PWM ramp-up to avoid current spikes, the PWM ramps down when the trigger is released or when the actuator reaches a position proportional to the trigger position within the gripping region. As the PWM ramps down, the current is expected to similarly decrease due to reduced power requirements. The lockout ramp-down submodule verifies that the current decreased as expected during a PWM ramp-down event. The lockout ramp-down submodule can compare the change in current to a zero condition. If the change in current is greater than zero over multiple consecutive measurements, the lockout ramp-down submodule indicates that the lockout mechanism has engaged. In some embodiments, the lockout ramp-down submodule compares the change in current to a zero condition over three measurement periods.

[0148] In some embodiments, the lockout ramp down sub-module may be embodied in a software or firmware program that operates according to the following logical structure: Lockout module = false Transition submodule = false - If the transition submodule is false (FALSE) When pwm≠maximum pwm (ramp down) yn = motor current Δyn = slope = change in current = (yn-yn-1) Increase in current change = Δyn>0 Three consecutive values ​​required = Δyn, Δyn-1, Δyn-2>0 If the above is TRUE = LOCKOUT ENGAGED

[0149] FIG. 61 shows an example flow chart of the lockout module, including various sub-modules. In the illustrated embodiment, when the control system refreshes its current and position monitoring (every 10 ms in some embodiments), the handle reads the actuation shaft position potentiometer to determine if it is still within the lockout region. If the actuator is within the lockout region, the handle assembly's control system executes the lockout module 630. If the lockout module indicates a lockout mechanism is engaged, the control system determines whether the lockout ramp-up sub-module 632 is applicable and executes it if applicable. If the ramp-up sub-module 632 is not applicable, the control system indicates that the lockout mechanism has engaged and stopped the motor. If the ramp-up sub-module 632 is applicable and indicates that the lockout mechanism is engaged, the control system indicates that the lockout mechanism has engaged and stopped the motor. If the ramp-up sub-module 632 is applicable and does not find the lockout mechanism engaged, the lockout module 630 terminates and waits 10 ms before resuming. If the lockout module 630 does not find the lockout mechanism engaged, the control system evaluates the transition sub-module 634 , followed by the post-transition sub-module 636 , and finally the ramp-down sub-module 638 .

[0150] In some embodiments, if the lockout module and various sub-modules of the control system do not indicate the presence of an engaged lockout mechanism, the control system can erase any stored X and Z variables (averages) used in the lockout module. If the control system resets the lockout module because there still have not been three consecutive passes (but the current attempt passed), the handle will retain the variable values. The current baseline is also retained until the handle is reset to the fully jaw-open position.

[0151] Motor Polarity Verification Module In some embodiments, the control system can include a polarity verification module that evaluates and corrects for the direction of movement of the DC motor. During the manufacture of stapler handle assemblies, it is possible for DC motors to be installed in a reverse polarity orientation. Several handle assembly and testing procedures can be performed to significantly reduce the occurrence of reverse motor polarity. However, these procedures can be time-consuming and add overhead. If the motor is unintentionally installed in a reverse polarity orientation, the stapler will not function as intended in response to user input. To mitigate the effects of reverse motor installation, in some embodiments, the control system can include a motor polarity verification module configured to monitor the actuator position upon application of power to the DC motor. Thus, the motor polarity verification module has the advantage of eliminating the polarity verification procedure from handle assembly production, thereby increasing the efficiency and reducing costs of handle assembly production. The polarity verification module can include a default polarity assumption that a particular motor polarity results in a particular actuation direction. The polarity verification module can apply power to the motor with a known polarity and monitor the change in actuator position.

[0152] 62 illustrates an exemplary logic flow structure for a motor polarity verification module 640 that may be incorporated into the handle assembly's control system. If the actuator position has changed consistent with the default polarity hypothesis after applying power to the motor 642, the control system's motor drive logic remains unchanged (644). If the actuator position has changed in a direction opposite to that of the default polarity hypothesis after applying power to the motor 642, the control system's motor drive logic is modified to reverse the polarity of the power 646 to be applied during the grasping, stapling, and return operations. In some embodiments, if the polarity verification module reverses the polarity after the polarity reversal, the polarity verification module can be configured to retest the direction of movement by applying power to the motor with reversed polarity 648 to verify that the direction of movement of the actuation shaft is forward.

[0153] Removable Data Log As can be appreciated, operation of the control system during one or more of the grasping, firing, and retracting movements of the surgical stapler can store various data related to motor current draw, motor speed, power, torque, lockout actuation, number of fired reload cartridges, battery life, and the like in a memory device, such as a solid-state memory module located within the handle assembly. It may be desirable to retrieve and analyze this data. In some embodiments, this data can be retrieved by electronically coupling to the handle assembly via a wired or wireless communication protocol. However, because the handle assembly is a surgical device, there can be logistical challenges associated with accessing a previously used handle assembly to retrieve data. Accordingly, in some embodiments, the surgical stapler handle assembly can include a removable memory module that can be removed from the handle assembly upon completion of a surgical procedure.

[0154] 63 and 64A-64B, in some embodiments, the power supply or battery pack 650 can include a removable memory module 652. In the illustrated embodiment, the battery pack includes an electrically coupled printed circuit board assembly (PCBA) that includes the memory module 652. The PCBA can be connected to a microprocessor through a communication interface for read and write access to operational data parameters of the handle assembly, including the memory module 652. The PCBA can further include a data interface surface, such as electrical contact pads, located on the PCBA. During use, once a surgical procedure is completed, a user can detach the battery pack 650 from the handle assembly and remove the PCBA, including the memory module 652, from the battery pack 650. In some embodiments, the PCBA can be coupled to the battery pack 650 by a removable pull tab that facilitates quick separation of the memory module 652. In other embodiments, the memory module 652 can be removed from the battery pack through the use of a dedicated removal tool or other hand tool. Once the memory module 652 is removed, the stapler and battery pack can be properly disposed of as medical waste.

[0155] 63 and 64A-64B, in some embodiments, the battery pack 650 can further include a battery discharge circuit 654 electronically coupled to the memory module 652 and one or more battery cells 656. As shown, upon removal of the memory module from the battery pack, the discharge circuit 654 housed within the battery pack 650 can drain the battery to reduce electrical or fire hazards due to potential shorting of the battery terminals after disposal. In some embodiments, the battery discharge circuit 654 can include a discharge resistor configured to drain the battery upon removal of the memory module.

[0156] 65, in some embodiments, a removable memory module 660 can be disposed on a removable portion of a PCB. As shown, the removable portion of the PCB can be joined to the PCB by a breakaway or perforated portion 664 to allow a user to quickly separate the memory module 660 from the PCB 662. The removable portion of the PCB can further include an electrical interface surface 668, such as a plurality of contact pads, electrically coupled to the memory module 660.

[0157] 66 , in some embodiments, a removable memory module 670 can be coupled to a main printed circuit board (PCB) 662 in the handle assembly by a connector that can be selected to be easily disconnected using scissors or other readily available instruments. In the illustrated embodiment, the memory module is located on a memory PCB 672 that is electronically coupled to the main PCB 662 by a flexible PCB 674. After use of the handle assembly, a user can disconnect the flexible PCB 674 to remove the memory module 670 and memory PCB 672. The memory PCB 672 can further include an electronic interface surface 678, such as a plurality of contact pads, electrically coupled to the memory module 670.

[0158] The memory module described herein can be positioned within the handle assembly to prevent inadvertent access to the memory module during operation of the handle assembly, while allowing access to the memory module upon completion of handle assembly. For example, as described with reference to FIGS. 63 and 64A-64B, in some embodiments, the memory module can be housed within a battery pack or battery compartment of the handle assembly so that it can be removed when the battery is removed. In other embodiments, the memory module can be located behind a dedicated access panel on the handle assembly. In some embodiments, the dedicated access panel can require a dedicated tool or key to open. In other embodiments, the memory module can be accessible during operation of a manual override return system, such as those described with reference to FIGS. 21-31.

[0159] While certain preferred embodiments and examples have been disclosed in this application, those skilled in the art will recognize that the present invention extends beyond the specifically disclosed embodiments to other alternative embodiments and / or uses of the invention and obvious modifications and equivalents thereof. Moreover, various features of these inventions can be used alone or in combination with other features of these inventions other than those expressly described above. Accordingly, the scope of the invention disclosed herein should not be limited by the particular disclosed embodiments described above, but should instead be determined solely by a fair reading of the following claims. [Explanation of symbols]

[0160] 10 Surgical stapler 20 Long and thin shaft 22 proximal end 24 distal end 30 Jaw Assembly 32 First Joe 34 The Second Joe 36 Staples 40 Handle assembly 42 Fixed Handle 44 Trigger 46 Coupler 50 Reload L central longitudinal axis

Claims

1. 1. A handle assembly for a surgical stapler, the handle assembly comprising: a handle body having a fixed 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 including a rack formed thereon; a mechanical return mechanism including a return lock mechanism, a shaft rotation mechanism, and a shaft retraction mechanism slidable within the handle body; the actuation shaft is rotatable from a first position in which the rack is in operative engagement with the electric motor to slide the actuation shaft longitudinally, to a second position in which the rack is disengaged from the electric motor and engaged with the manual return mechanism; A handle assembly comprising:

2. The return lock mechanism includes a return lock that is slidable longitudinally relative to the handle body from a locked position to an unlocked position. The handle assembly of claim 1 .

3. the shaft retraction mechanism includes a protrusion extending therefrom, the return lock engaging the protrusion in the locked position and disengaging from the protrusion in the unlocked position; The handle assembly of claim 2 .

4. a control device electrically coupled to the electric motor, the return lock mechanism being electrically coupled to the control device; The handle assembly of claim 1 .

5. Activation of the return lock mechanism disables the control device. The handle assembly of claim 4.

6. the return lock mechanism includes a spring that slides longitudinally by the return lock mechanism to electrically engage and disable the control device. The handle assembly of claim 5 .

7. 1. A handle assembly for a surgical stapler, the handle assembly comprising: a handle body including a fixed handle and a trigger pivotally coupled to the handle body; an electric motor disposed within the handle body and including an output shaft; an actuation shaft slidable along a longitudinal axis within the handle body, the actuation shaft including a rack formed thereon; a motor gear coupled to the output shaft of the motor; an auxiliary gear including a first gear segment in driving engagement with the motor gear, in operative engagement with the rack, and rotatably coupled to a second gear segment, and a central region extending between the first gear segment and the second gear segment; the first gear segment is in driving engagement with the motor gear and the second gear segment is in operative engagement with the rack; A handle assembly comprising:

8. a support plate supporting the auxiliary gear in the central region, The handle assembly of claim 7.

9. the support plate includes an auxiliary gear bore extending therethrough and a motor gear bore extending therethrough; The handle assembly of claim 8.

10. the support plate comprises a metal material; The handle assembly of claim 8.

11. the first gear segment includes a first engagement surface and the second gear segment includes a second engagement surface, the first engagement surface and the second engagement surface being coupled to rotatably couple the first gear segment and the second gear segment; The handle assembly of claim 7.

12. the first engagement surface is defined by an axially extending boss defining a square tooth profile, and the second engagement surface is defined by an axially extending boss defining a square tooth profile. The handle assembly of claim 11.

13. the central region has an outer diameter smaller than outer diameters of the first gear segment and the second gear segment; The handle assembly of claim 7.

14. 1. A handle assembly for a surgical stapler having a removably coupled instrument shaft, the handle assembly comprising: a handle body including a fixed handle and a trigger pivotally coupled to the handle body; a power system within the handle body; an actuation shaft operably coupled to the power system; an articulation mechanism including a manually actuated articulation knob and an articulation adapter; an articulation lockout mechanism; the manually actuated articulation knob is disposed at a proximal end of the handle body and is rotatable about the longitudinal axis, and the articulation adapter is disposed at the distal end of the handle body; the articulation adapter is operably coupled to the articulation knob such that rotation of the articulation knob about the longitudinal axis causes the articulation adapter to slide longitudinally; the articulation lockout mechanism disengages the articulation knob from the articulation adapter when an instrument shaft is not coupled to the surgical stapler. A handle assembly comprising:

15. the articulation lockout mechanism maintains the articulation mechanism in a centered position when an instrument shaft is not coupled to the surgical stapler.

15. The handle assembly of claim 14.

16. the articulation lockout mechanism includes a lockout sleeve at the distal end of the handle assembly and at least one lockout arm coupled to the lockout sleeve.

15. The handle assembly of claim 14.

17. the at least one lockout arm includes two lockout arms; 17. The handle assembly of claim 16.

18. further comprising an articulation mechanism position sensor configured to identify a position of the articulation mechanism.

15. The handle assembly of claim 14.

19. further comprising an articulation lockout mechanism position sensor configured to identify a position of the articulation lockout mechanism.

15. The handle assembly of claim 14.

20. 1. A handle assembly for a surgical stapler, the handle assembly comprising: a handle body including a fixed handle and a trigger movably coupled to the handle body; a power system within the handle body including a motor and a power source, the power system being positionable within the handle body; an actuation shaft operably coupled to the power system and longitudinally slidable within the handle body; a position sensor configured to determine the longitudinal position of the actuation shaft; a control system electrically coupled to the power system, the trigger, and the position sensor, the control system configured to define a motor drive logic profile that defines at least one operating parameter of the motor at positions of the actuation shaft corresponding to a grasper zone, a lockout zone, and a firing zone; A handle assembly comprising:

21. the handle assembly further comprising a user display; 21. The handle assembly of claim 20.

22. the user display includes a multicolor LED light ring; 22. The handle assembly of claim 21.

23. the at least one operating parameter includes a pulse width modulation duty cycle; 21. The handle assembly of claim 20.

24. the control system is configured to monitor a current load on the motor; 21. The handle assembly of claim 20.

25. the control system further includes a haptic feedback module.

21. The handle assembly of claim 20.

26. the haptic feedback module drives the motor with a substantially square wave profile that rapidly alternates direction to generate vibrations in the handle assembly without movement of the actuation shaft; 26. The handle assembly of claim 25.

27. the substantially square wave profile further comprises a delay segment.

27. The handle assembly of claim 26.

28. the control system further includes a motor polarity verification module; 21. The handle assembly of claim 20.

29. further comprising a removable memory module electrically coupled to the control system; 21. The handle assembly of claim 20.

30. the memory module is electrically coupled to the power source; 30. The handle assembly of claim 29.

31. the power source includes a battery pack; 31. The handle assembly of claim 30.

32. the battery pack further includes a discharge resistor electrically coupled to the battery pack and the memory module, such that removing the memory module electrically couples the battery pack to the discharge resistor, causing the battery pack to be depleted; 32. The handle assembly of claim 31.

33. 1. A handle assembly for a surgical stapler having a removably coupled instrument shaft with a lockout mechanism, the handle assembly comprising: a handle body including a fixed handle and a trigger pivotally coupled to the handle body; a power system within the handle body including a motor and a power source, the power system being positionable within the handle body; an actuation shaft operably coupled to the power system and longitudinally slidable within the handle body; a position sensor configured to determine the longitudinal position of the actuation shaft; a control system electrically coupled to the power system, the trigger, and the position sensor, the control system including a lockout module configured to monitor a current draw of the motor and the longitudinal position of the actuation shaft, calculate a slope of the motor's current draw profile, and use the monitored slope to detect engagement of the lockout mechanism; the lockout module is configured to disable operation of the motor upon detecting engagement of the lockout mechanism. A handle assembly comprising:

34. the lockout module is configured to detect engagement of the lockout mechanism when a plurality of successive averages of the slope of the current draw profile fall within a predetermined lockout tolerance range.

34. The handle assembly of claim 33.

35. the lockout module includes a lockout ramp-up sub-module configured to detect engagement of the lockout mechanism when the control system is driving the motor in a duty cycle ramp-up.

35. The handle assembly of claim 34.

36. the lockout ramp-up sub-module detects engagement of the lockout mechanism with the motor in a duty cycle ramp-up where the current draw of the motor exceeds a current threshold.

36. The handle assembly of claim 35.

37. the lockout module includes a lockout transition sub-module configured to detect engagement of the lockout mechanism when the control system is driving the motor during a transition period after a duty cycle ramp-up.

34. The handle assembly of claim 33.

38. the lockout module includes a lockout post-transition sub-module configured to detect engagement of the lockout mechanism when the control system is driving the motor through a range of predetermined actuation shaft positions after the transition period following a duty cycle ramp-up.

38. The handle assembly of claim 37.

39. the lockout module includes a lockout transition sub-module configured to detect engagement of the lockout mechanism when the control system is driving the motor in a duty cycle ramp down.

34. The handle assembly of claim 33.

40. the lockout ramp-down sub-module detects engagement of the lockout mechanism while the motor is in a duty cycle ramp-down state where the current draw of the motor does not decrease over a number of consecutive monitored events.

40. The handle assembly of claim 39.

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