Interlocking trigger assembly for a suturing device

An endoscopic suturing device having an interlocking trigger assembly for preventing premature needle deployment. The suturing device comprises a handle assembly that includes a movable handle interlocking with a trigger. The suturing device further comprises an end effector having an upper jaw, a lower jaw and a needle/suture mechanism. The motion of the movable handle causes the upper jaw to move relative to the lower jaw. The activation of the trigger causes deployment of the needle/suture mechanism. The interlocking mechanism ensures that the needle/suture is deployed only when the upper jaw is below a maximum allowable distance from the lower jaw.

FIELD OF THE INVENTION

The present invention relates to a suturing device, and more particularly to a suturing device with an interlocking trigger assembly.

BACKGROUND OF THE INVENTION

Suturing or stitching of tissue is performed in surgical procedures or other cases where closing of incisions or cuts is required. Suturing is usually performed by grasping the tissue to be sutured, pushing a first end of a needle having a needle tip through one side of the tissue and then grasping the needle tip from the other side of the tissue to pull the needle through. The needle and a suture attached to a second end of the needle are then pulled through the tissue and the suture is tied.

Suturing is a simple procedure when it is performed on external tissues because the needle and suture can be easily manipulated. However, in endoscopic or other minimally invasive surgical procedures that require suturing of internal tissues access to the suturing area is limited and this limits the ability to manipulate the needle and suture.

Various types of endoscopic surgical instruments are known in the art that allow suturing and stitching of internal tissues during endoscopic surgical procedures. These instruments generally include a slender tube containing a push rod which is axially movable within the tube by means of a manual actuator. An end effector is coupled to a distal end of the tube and the push rod so that axial movement of the push rod is translated to rotational or pivotal movement of the end effector. Referring toFIG. 4, an end effector122that allows suturing of internal tissue usually includes an upper jaw124and a lower jaw126that grasp the soft tissue and at a predetermined minimum distance between the upper and lower jaw deploy a needle and a suture128. The needle and suture128are pushed from the lower jaw126to the upper jaw124, where the upper jaw captures them and pulls them through the soft tissue. In this prior art suturing devices there is no control of the distance between the upper and lower jaw and of the timing when the needle is deployed. As a result, in some cases, the needle is deployed prematurely, i.e., the needle is engaged in tissue, but not captured by the upper jaw. When premature needle deployment occurs, the suturing action needs to be repeated. Multiple premature needle deployments may results in soft tissue damage. Another problem of premature deployment is that it is difficult to back the needle out once it is into tissue but cannot be captured on the other side. Accordingly there is a need to prevent premature needle deployment in endoscopic suturing devices that utilize a jaw-type end effector for needle manipulation during endoscopic suturing procedures.

SUMMARY OF THE INVENTION

The present invention solves the problem of premature needle deployment in a suturing device by employing an interlocking trigger mechanism. The interlocking trigger mechanism accomplishes this by making the needle deployment trigger action dependent on the position of the jaw actuation handle. When the jaw actuation handle is in its forward position, and therefore the upper jaw is open beyond the maximum deployment position, the needle deployment trigger is blocked from moving by a portion of the jaw actuation handle. The jaw actuation handle is constructed such that once it reaches the proper position, it ceases to block the needle deployment trigger, and allows it to move, effectively interlocking the needle deployment trigger to the jaw actuation handle.

In general, in one aspect, the invention features a surgical instrument comprising a handle assembly having a stationary handle and a movable handle an end effector assembly and a trigger. The movable handle is pivotally connected to the stationary handle. The end effector assembly includes a first member movably connected to a second member and a third member deployable between the first and second members. The movable handle is operably connected to the end effector assembly thereby effectuating motion of the second end effector member relative to the first end effector member. The trigger is operably connected to the third end effector member and is adapted to effectuate deployment of the third end effector member only when a distance between the first and second end effector members is below a maximum allowable distance.

Implementations of this aspect of the invention may include one or more of the following features. The movable handle includes a first handle segment that interlocks with a first trigger segment when the distance between the first and second end effector members is larger than the maximum allowable distance thereby preventing activation of the trigger and accordingly deployment of the third end effector member. The first and second end effector members may be first and second jaws, respectively. The third end effector member may be a needle. The needle may further include a suture. The surgical instrument may further include a suture cartridge. The surgical instrument may further include first actuation means for operably connecting the movable handle to the end effector assembly thereby translating motion of the movable handle to motion of the second end effector member relative to the first end effector member. The surgical instrument may also include second actuation means for operably connecting the trigger to the third end effector member thereby translating trigger activation to deployment of the third end effector member. The handle assembly may also include a ratchet mechanism adapted to secure the movable handle relative to the stationary handle. The movable handle may further include an elongated handle segment extending from the first handle segment and an operator may use the elongated handle segment to move the movable handle relative to the stationary handle. The trigger may also include an elongated trigger segment extending from the first trigger segment and an operator may use the elongated trigger segment to activate the trigger and thereby the third end effector member deployment. The surgical instrument may further include a position indicator adapted to confirm that the distance between the first and second end effector members is below the maximum allowable distance. The position indicator may be an audible signal, an optical signal, a mechanical signal, a vibration signal, or a tactile feel. The maximum allowable distance between the first and second end effector members for the deployment of the third end effector member may be in the range between 0.5 and 0.01 inch. In one case the maximum allowable distance is 0.145 inch. The end effector assembly may be partially or entirely disposable.

In general, in another aspect, the invention features a handle for a surgical instrument comprising a stationary handle, a movable handle and a trigger. The movable handle is pivotally connected to the stationary handle and includes a first handle segment. The trigger is operably connected to an end effector member and includes a first trigger segment. The first trigger segment interlocks with the first handle segment thereby preventing activation of the trigger and deployment of the end effector member when a distance between the movable handle and the stationary handle is larger than a maximum allowable distance.

In general, in another aspect, the invention features in a surgical instrument having an end effector assembly, a method for controlling deployment of a first end effector member of the end effector assembly. The method includes providing a stationary handle, providing a movable handle pivotally connected to the stationary handle and operably connected to the end effector assembly thereby translating motion of the movable handle to motion of a second end effector member of the end effector assembly relative to a third end effector member of the end effector assembly, and finally providing a trigger being operably connected to the first end effector member and comprising a first trigger segment and wherein the first trigger segment interlocks with a first handle segment of the movable handle thereby preventing activation of the trigger and deployment of the first end effector member when a distance between the second end effector member and the third end effector member is larger than a maximum allowable distance.

Among the advantages of this invention may be one or more of the following. The interlocking mechanism ensures that the needle/suture is deployed only when the upper jaw is below a maximum allowable distance from the lower jaw. This prevents premature needle deployment and thereby soft tissue damage from multiple unsuccessful attempts.

The details of one or more embodiments of the invention are set forth in the accompanying drawings and description below. Other features, objects and advantages of the invention will be apparent from the following description of the preferred embodiments, the drawings and from the claims.

DETAILED DESCRIPTION OF THE INVENTION

Referring toFIG. 1A, the endoscopic instrument100includes a front end assembly120with an end effector122, and a handle assembly140. The end effector122includes a movable upper jaw124, a lower jaw,126and a needle/suture mechanism128. The handle assembly140includes a stationary handle142, a movable handle144, a trigger146and a base141, also shown inFIG. 1BandFIG. 1C. Stationary handle142is attached to the base141and movable handle144and trigger146are pivotally attached to the base141via pivot mechanisms148and149, respectively. In the embodiment ofFIG. 1Bmovable handle144is secured at a predetermined distance relative to the stationary handle142via a ratchet mechanism160. Movable handle144is further connected to the movable upper jaw124via an actuator rod152. Actuator rod152translates the motion of the movable handle144into a motion of the upper jaw124. Trigger146is further connected to the needle/suture mechanism128via a second actuator rod150. Actuator rod150translates the trigger motion into deployment of the needle/suture mechanism128. Movable handle144includes a finger loop154, a finger rest143, and an upper segment145. Upper segment145has a shape appropriate for preventing the motion of the trigger146, and therefore needle/suture128deployment, when the upper jaw124is beyond the allowable maximum distance from the lower jaw122for a successful needle deployment. Trigger146includes a downward extending segment155and a horizontally extending segment156. The horizontally extending segment156interlocks with the upper segment145of the movable handle144, when the jaws124and126are open and the distance between them is beyond a maximum allowable distance for achieving a successful needle/suture128deployment. The downward extending segment155is used to move the trigger146with a finger (not shown). Stationary handle142includes a finger loop139and a suture wrapping mechanism147.

Referring toFIG. 2A, an operator moves the handle144closer to the stationary handle142, by placing his finger inside the finger loop154and pivoting the handle144around the pivot point148clockwise. This pivoting motion of the handle144towards the stationary handle142causes the upper jaw124of the end effector122to move closer to the lower jaw126. At the point where the distance between the upper jaw124and the lower jaw126reaches the maximum allowable for achieving a successful needle/suture128deployment the upper segment145of the handle144disengages from the horizontally extending segment156of the trigger146, as shown inFIG. 2BandFIG. 2C. At this point the operator can activate the trigger146by pushing the downward extending segment155with his finger towards the movable handle144, thereby causing the trigger146to pivot around pivot point149clockwise and to deploy the needle/suture mechanism128via the actuator rod150. In the embodiment ofFIG. 2Bthe position of the movable handle144is secured to the stationary handle142via the ratchet mechanism160. An audible signal confirms the ratchet engagement and the securing of the movable handle144position relative to the stationary handle142. The operator can now safely activate the trigger146causing the deployment of the needle/suture mechanism128.

Referring toFIG. 3A, the operator activated the trigger146causing deployment of the needle/suture mechanism128. The trigger146pivots around pivot point149and the horizontally extending segment155moves freely beyond the upper segment145of the movable handle144in the space158. At this point the upper and lower jaws,124, and126, respectively, are fully closed.

In the next step the operator pivots the trigger146counter clockwise away from the movable handle144, then pivots the movable handle144counter clockwise away from the stationary handle142, thereby causing the jaws124,126to open and the needle/suture mechanism128to disengage, bringing the instrument back in the position ofFIG. 1A.

In one example, the maximum distance between the upper jaw and the lower jaw where needle/suture deployment can safely occur is 0.145 inches. Typical dimensions for the jaws are 0.500×0.175 inches. Typical dimensions for the handles are 0.230×4.5×1.75 inches. Typical dimensions for the trigger are 0.230×0.750×1.800 inches. The endoscopic instrument may be made of various types of biocompatible stainless steels, ceramics, plastics, or composites. The suture may be made of biocompatible material, Nylon, Dacron, Polypropylene, or other materials commonly used for anchoring soft tissue to bone. The end effector may be disposable or non-disposable and may be made of various types of biocompatible stainless steels, metals, alloys, composites and plastics.