US 20050090837 A1
A flexible endoscopic clip applier includes a flexible coil with a manual actuator coupled to one end and a jaw assembly coupled to the other end. A store of clips is arranged adjacent to the jaw assembly and a clip pusher is arranged adjacent to the store of clips. The actuator includes a lever for opening and closing the jaws, a knob for rotating the jaw assembly, and a crank for dispensing clips. The knob and the lever are coupled to a single control member which extends through the coil to a joiner where it is joined to a pair of pull wires coupled to the jaws. The crank is coupled to a second control member which is threaded along a distal portion. The threaded portion engages a threaded member near the pusher and is coupled to the pusher such that rotation of the threaded control member by the crank causes the pusher to be moved distally.
1. An endoscopic surgical instrument, comprising:
a flexible tube having a proximal end and a distal end;
an end effector coupled to said distal end;
an actuator coupled to said proximal end;
a control member extending through said flexible tube, said control member coupled to said end effector and to said actuator, wherein
said actuator has means for rotating said control member and means for translating said control member, said means for translating said control member including means for limiting force applied to said control member.
2. The instrument according to
said means for limiting force includes a spring coupled between said control member and said actuator.
3. The instrument according to
said spring is a compression spring.
4. The instrument according to
said spring is a torsion spring.
5. The instrument according to
said actuator includes a two part lever and said means for limiting force is a spring coupled to first and second parts of said two part lever.
6. The instrument according to
said spring is a torsion spring.
7. The instrument according to
said two part lever includes a rotation post about which said first part of said two part lever can rotate.
8. The instrument according to
said actuator includes a ball which is coupled to said control member and to said second part of said two part lever.
9. The instrument according to
said means for rotating is coupled to said control member by a spline coupling.
10. The instrument according to
said means for limiting force includes a compression spring coupled between said flexible tube and said actuator.
11. The instrument according to
said means for limiting force includes
spaced apart proximal coupling and distal coupling,
both coupled to said control member,
a compression spring located between said proximal coupling and distal coupling, a distal end of said compression spring coupled to said means for translating.
12. The instrument according to
said means for limiting force includes
a compression spring having a proximal end and a distal end, said means for translating being coupled to said distal end of said spring, and
a shuttle member coupled to said control member, said shuttle member being located between said proximal end of said spring and said means for translating.
13. The instrument according to
said means for limiting force includes
a cup located between said compression spring and said proximal coupling,
a rod coupled to said distal end of said compression spring and extending through said compression spring into said cup.
14. The instrument according to
said means for limiting force includes
a member extending adjacent said compression spring, one end of said member being coupled to said distal end of said spring and the other end of said member being coupled to said means for translating.
15. The instrument according to
said member extending adjacent said compression spring is a U-shaped member.
16. A method for applying an endoscopic clip, comprising:
delivering an endoscopic instrument through the lumen of an endoscope to a site for applying a clip, the instrument including a pair of manually operable jaws and a supply of clips; and
automatically limiting the force applied to the jaws while the instrument is being delivered through the endoscope.
17. The method according to
opening the jaws at the site for applying a clip;
positioning the open jaws about a tissue;
closing the jaws about the tissue; and
automatically limiting the force applied to the jaws when they are closed about the tissue.
This application is a continuation-in-part of U.S. Ser. No. 10/396,962 entitled “Flexible Housing Element for a Surgical Tool” filed Mar. 25, 2003 which is hereby incorporated by reference herein in its entirety. This application is related to U.S. Ser. No. (Docket #ISD-083) entitled “SURGICAL CLIP”, filed on an even date herewith, the complete disclosure of which is hereby incorporated by reference herein.
1. Field of the Invention
This invention relates broadly to surgical instruments. Particularly, this invention relates to flexible endoscopic instruments for use through an endoscope. More particularly, this invention relates to a surgical clip applier which is adapted for use through an endoscope and may be used to clamp and/or suture, ducts, vessels, and other tissues, to anchor a tissue, or to attach a foreign body to a tissue.
2. State of the Art
Surgical clips are generally used to apply clamping force to ducts, vessels, and other tissues. In addition, surgical clips are particularly useful in controlling bleeding of a tissue in lieu of suturing or stapling where suturing or stapling is difficult.
Surgical clips are typically applied to tissue by clip appliers. All of the currently available surgical multi-firing clip appliers are substantially rigid devices intended to extend through a trocar port or through an incision to a surgical site requiring application of a clip. The devices have been rigid because a stiff pushing element has been required in order to exert the required pushing force to move the clip over the tissue.
There is a substantial need for a flexible clip applier, particularly one insertable through a lumen of an endoscope. The ability to apply clips through an endoscope would permit myriad minimally invasive surgical solutions to medical problems, especially those of the gastrointestinal tract. However, it is accepted theory that the transmitted force required to advance or form a clip over tissue cannot be produced in the distal end of a long flexible device that is commonly constructed with a metal tubular coil, or polymer tube, such as an endoscopic device or catheter.
Generally a flexible endoscopic device (e.g., a biopsy forceps device) includes an outer tubular member, typically being constructed of a metal tubular coil or a polymer tube which is poor in transmitting forces that impart tensile stresses to the outer tubular member, a control element longitudinally movable relative to the tubular member, an end effector coupled to the distal ends of both the tubular member and the control element such that relative movement of the control element and the tubular member causes operation of the end effector, and a handle which moves the control element relative to the handle. This type of flexible endoscopic instrument is limited in the amount of pushing force it can generate for several reasons. First, compression of a flexible control element (pushing element) tends to cause the pushing element to buckle within the outer flexible sheath of the device. If a relatively larger diameter flexible pushing element is used such that it better resists buckling, the pushing element may impart too much stiffness to permit it to flex as it bends with the endoscopic instrument. Second, a flexible pushing element of larger diameter is subject to greater frictional forces within the outer sheath, which reduces the force transmitted from the handle to the end effector. If the flexible pushing element is made relatively smaller in diameter, it is subject to kinking, which will result in little to no force being transmitted to the distal end. Kinking is especially a problem in endoscopic instruments, because the endoscope and its lumen may be extended through a tortuous path. For most flexible devices, especially metal coils, the outer sheath begins to stretch when force is applied to the pushing element. This reduces or eliminates the force and relative movement of the pushing element. For these reasons and others, mechanical application of a relatively large distal end pushing force, and particularly clip application, have been absent from the capability of flexible endoscopic tools.
In addition, it is important that the tissue about which a clip is to be applied be substantially compressed. While the jaws apply a clamping force which compresses the tissue, large clamping forces are difficult to achieve because of the dimensions of the relatively small jaw assembly. That is, the dimensions are such that the lever arm between a pivot of the jaw assembly and each jaw tang is relatively short, limiting the mechanical leverage of the jaw assembly.
Our previous application Ser. No. 10/396,962, which is hereby incorporated by reference herein in its entirety, discloses a flexible clip applier that includes a ratchet mechanism adapted to locate a clip pusher to a known location after deployment of a clip. In addition, the clip applier includes a flexible housing into which a train of clips may be chambered. The flexible housing does not elongate when subject to tensile forces. In addition, the jaw assembly is adapted to have relatively high mechanical leverage which facilitates tissue compression prior to application of a clip.
Since the development of the clip applier disclosed in Ser. No. 10/396,962, we have developed an improved flexible endoscopic clip applier which is the subject of the instant application.
It is therefore an object of the invention to provide a flexible endoscopic clip applier.
It is also an object of the invention to provide a flexible endoscopic clip applier capable of dispensing multiple clips.
It is another object of the invention to provide a flexible endoscopic clip applier which limits the amount of force which can be applied to the jaws of the device.
It is still another object of the invention to provide a flexible endoscopic clip applier which limits the amount of force which can be applied to the jaws of the device while adjusting for relative changes in the length of the outer sheath due to tortuosity of the path of the endoscope.
It is a further object of the invention to provide a flexible endoscopic clip applier which has two jaws which are rotatable about different axes to improve the mechanical advantage of the jaws.
It is also an object of the invention to provide a flexible endoscopic clip applier which dispenses clips via smooth movement of a manual actuator.
It is an additional object of the invention to provide a flexible endoscopic clip applier which has an actuator that dispenses clips precisely one at a time.
Another object of the invention is to provide a flexible endoscopic clip applier which uses a single control wire to open and close jaws as well as to rotate them about the longitudinal axis.
A further object of the invention is to provide a flexible endoscopic clip applier having improved jaws.
An additional object of the invention is to provide a flexible endoscopic clip applier which prevents the accidental dispensing of the penultimate clip when the device is moved away from the ultimate clip after it is applied.
It is yet another object of the invention to provide a flexible endoscopic clip applier which forms clips as they are dispensed.
It is even another object of the invention to provide a flexible endoscopic clip applier having a handle having a resistance force which is substantially constant during a cycle of forming and applying a clip.
Yet another object of the invention is to provide a clip applier with clip-forming jaws which indicate a tissue fixation point for the applied clip.
Even another object of the invention is to provide a clip applier with a mechanism which stably advances clips through a coil and into an end effector.
A further object of the invention is to provide an endoscopic clip applier which can fire a clip only when the jaws of the applier are closed.
Another object of the invention is to provide an endoscopic clip applier which can fire only one clip at a time, i.e. between closing and opening the jaws.
An additional object of the invention is to provide an endoscopic clip applier which provides a visual indication to the practitioner of the number of clips which are left in the applier.
Still another object of the invention is to provide an endoscopic clip applier which stops operating after all of the clips have been dispensed.
In accord with these objects, which will be discussed in detail below, a flexible endoscopic clip applier according to the invention has a relatively long flexible coil (or tube) having a proximal end and a distal end. As used herein, the term proximal end means the end closest to the practitioner and the term distal means the end closest to the patient. A manual actuator is coupled to the proximal end of the coil and a pair of jaws is coupled to the distal end of the coil. A store of clips is disposed inside the coil adjacent to the jaws. The interiors of the jaws form anvils for bending a clip as it is pushed from the store into the closed jaws. The manual actuator has three controls: a lever for opening and closing the jaws, a knob for rotating the jaws (and a distal portion of the coil) about the longitudinal axis of the coil, and a crank for dispensing a clip. The lever and knob are coupled to a single first control member which extends through the coil to a point proximal of the store of clips. The crank is coupled to a second control member which extends through the coil up to a point adjacent to the store of clips and is threaded along a distal portion thereof.
According to the presently preferred embodiment, the lever is coupled to a force limiter which prevents too much force from being applied to the jaws when closing them. The force limiter also effectively adjusts for the relative changes in the length of the outer sheath with respect to the jaw control member. The knob is coupled to the first control member via a spline coupling. The crank is coupled to the second control member via a transmission and an energy storage device, e.g. a flywheel.
The first control member terminates proximal of the store of clips and is coupled to a joiner which is coupled to a pair of pull wires. The pull wires extend on opposite sides of the store of clips, each being coupled to one of the jaws.
According to the invention, the coil is bifurcated proximal of the store of clips and the two portions of the coil are joined by a rigid member having four bores, one of which is threaded. The rigid member is disposed distal of the joiner and the first control member extends into one of the bores of the rigid member. In this way, rotation of the first control member causes the rigid member to rotate which causes the distal portion of the coil and the jaws to rotate about the longitudinal axis. This helps orient the jaws properly before closing the jaws on a tissue to be clipped. The two pull wires extend through two other bores in the rigid member and the threaded portion of the second control member threadably engages the threaded bore of the rigid member. In this way, when the threaded control member is rotated (by the crank), it is translated distally. The distal end of the threaded control member is coupled to a clip pusher. The clip pusher is arranged adjacent to the proximally closest clip in the store of clips which are axially arranged one after the other. When the threaded control member is translated distally, the store of clips is moved distally until the ultimate clip (the one at the distal end of the store) enters the closed jaws and is applied to tissue through the bending of its ends by the interior anvils of the jaws.
The transmission and the pitch of the threads on the threaded portion of the second control member are arranged such that exactly one rotation of the crank causes exactly one clip to be dispensed. The crank is preferably provided with a detent lock which must be engaged to release the crank and which automatically stops the crank after one rotation.
Further according to the invention, the jaws are identical hermaphroditic jaws which are respectively rotatably coupled on offset axes to a clevis at the distal end of the distal coil. Each jaw has a distal tooth and a proximal tang. The tang is coupled to one of the pull wires and lies on one side of the longitudinal axis. The distal tooth of that jaw lies on the opposite side of the longitudinal axis, which prevents side-to-side misalignment of the jaws when they are closed.
The store of clips is housed in a “garage” which is coupled to the clevis and extends proximally therefrom. The garage is a substantially rigid rectilinear structure which keeps the clips properly aligned and allows them to be smoothly pushed out of the garage into the closed jaws. The distal portion of the garage is provided with a pair of biased stops which prevent the penultimate clip from moving out of the garage when the applier is moved away from the ultimate clip after it has been applied. In an alternate embodiment, the stops are made part of the clevis rather than the garage.
According to presently preferred embodiments, the crank is located on both sides of the manual actuator to accommodate left hand and right hand use. A counter mechanism is coupled to the crank and indicates the number of clips remaining in the garage. The detent lock is engagable by the lever so that the crank can only be operated when the jaws are closed. The crank is also provided with a ratchet mechanism so that it can only be rotated in one direction. The counter also includes a stop which prevents the crank from being rotated after all of the clips have been dispensed.
Additional objects and advantages of the invention will become apparent to those skilled in the art upon reference to the detailed description taken in conjunction with the provided figures.
Turning now to
The Manual Actuator
A first embodiment of a manual actuator is shown in
The manual actuator 18 of
Turning now to the details of the manual actuator 18 and with continued reference to
The lever 22 is coupled to the distal end of the spring 38 by a linkage 44 seen best in
With the provided arrangement, movement of the lever 22 towards the finger grip 28 causes the linkage 44 to move proximally which moves the overload nut 38 d proximally. The overload nut 38 d in turn pushes against the spring 38 moving it proximally. The spring 38 pushes against the cup 38 c which presses against the limiter cap 38 b which in turn presses against the proximal coupling 38 a. Since the proximal coupling 38 a is affixed to the control member 36, proximal movement of the proximal coupling 38 a causes proximal movement of the control member 36. Effectively, then, the entire force limiting assembly 37 is moving proximally and pulls the control member 36 proximally.
If at any time during the closing of the jaws the tension on the control member 36 exceeds a predetermined force limit of the spring 38 (e.g., seventeen pounds), the spring force of the spring 38 will be overcome such that the spring 38 will compress and the overload shaft 38 f and the overload nut 38 d will move away from the distal coupler 38 e without moving the control member 36 as seen in
If, after the lever 22 has moved to a position as shown in
In either case, when the lever 22 is released, the spring 38 will decompress by linkage 44 causing the nut 38 d to move distally until it abuts the distal coupling 38 e (which is coupled to the control member 36). The distal movement of the nut 38 d causes distal movement of the distal coupling 38 e which is coupled to the control member 36 causing the control member 36 to move distally.
According to the presently preferred embodiment, the spring is always compressed when the lever 22 is moved to the locked position.
To permit rotation of the control member 36, the knob 24 is coupled to the control member 36 via a spline 40 mounted in a shaft bearing 24 a held by a clamp 24 b. The proximal end of the control member 36 is bent into a shepherd's crook 36 a which slidably engages the spline 40 coupled to the knob 24. A shepherd's crook is illustrated in
It should be noted that in the force limiting mechanism 37, the distal coupling 38 e and the proximal coupling 38 a are assembled in such a way as to allow clearance with the rest of the force limiting assembly 37. This clearance allows for ease of rotation since and friction created by the preloaded spring 38 is not translated into torsional resistance.
Still referring to
According to the presently preferred embodiment, an energy storing flywheel 56 is coupled to the cylinder 54. Alternatively, the flywheel and cylinder could be a single molded part. The flywheel smoothes the operation of the crank which would otherwise require the application of increasing force through its rotation, as in the beginning of its rotation, the control member is causing a clip to be advanced, whereas at the end of its rotation, the control member is causing the clip to be formed by pushing it against an anvil in the end effectors (as discussed in more detail below). Those skilled in the art will appreciate that in order to be effective, the flywheel is preferably provided with a relatively large rotational mass for energy storage. When the flywheel is spun (rotated) by rotation of the crank, a certain amount of energy is invested which increases the kinetic energy (mass×velocity) of the flywheel. Some of this energy is lost over time to friction; however, some of the energy used to spin the flywheel is stored in the form of kinetic energy. Later, it is possible to retrieve this energy through direct mechanical translation. In the case of the present invention, when the crank 26 is first rotated, the control member 48 offers little resistance (as the clips are moving forward easily) and most of the energy applied to the crank is used to put the flywheel 56 in rotation. Near the end of the crank's rotation, torsional resistance is built up by the control member 48 because it is near the end of the cycle where the clip is being bent into its final shape. At this point, the kinetic energy in the flywheel is released and eases the remainder of the crank cycle. Preferably, according to the invention, the flywheel 56 is chosen so that the force which is applied to the crank 26 is substantially even (e.g., does not change by more than 25%) over the entire movement of the crank 26 necessary to dispense a single clip.
As seen best in
According to the embodiment illustrated in
According to an exemplary embodiment, the transmission causes the second control member to be rotated 58.1875 revolutions when the crank is turned one revolution. The pitch of the threads on the control member result in the control member advancing 0.285 inches when the crank is turned one revolution. The gears and the thread pitch are selected for a particular clip length. According to the presently preferred embodiment, it is only necessary to change the crown gear (by increasing or decreasing the number of teeth) to accommodate clips of different length.
As illustrated in
The Control Members
Referring now to
Two of the other holes, 60 a and 60 b, in the rigid member 60 allow the passage of a pair of pull wires 62, 64 which are described in more detail below with reference to
As seen best in
According to a presently preferred embodiment, both control members have smaller diameters in their distal portions to add flexibility and larger diameters in the proximal portions to optimize torque transmission.
Turning now to
As seen best in
As seen best in
Those skilled in the art will appreciate that the arrangement of threads could be changed while still achieving the same or similar results. For example, rather than arranging the threaded control member to advance distally, threads could be supplied on the pusher with the threaded control member being translationally stationary. In this arrangement, rotation of the threaded control member causes the pusher to be translated along the control member.
As seen best in
As seen best in
According to the presently preferred embodiment, the garage is made from a single piece of stamped and folded stainless steel.
Unlike our earlier clip appliers, there is no need to chain the clips together so that they can be pulled back. There is also no need to pull any of the clips back at any time.
The Jaw Assembly
As seen best in
The interior surfaces of the distal teeth are forming anvils which cause the two tines of the clip to be bent through approximately 90-180° as shown in
As seen best in
As shown in
Alternate Embodiment, Self-Pushing Clip
Referring now to
The Presently Preferred Manual Actuator
As seen best in
According to a third aspect of this embodiment, as seen best in
The counter gear 512 is provided with indicia 516, preferably on both sides, and a standing rib 518. The body of the actuator 418 is provided with at least one, but preferably two windows 520, 522 (see
Those skilled in the art will appreciate that means other than the standing rib 518 could be used to stop rotation. For example, the threads on the control member 48 can be arranged to run out upon dispensing the last clip. Alternatively, a bump can be provided on the control member 48 at a location to be stopped by engaging the rigid member 60 upon dispensing the last clip. Still another alternative is to arrange the pusher 70 to engage and lock on the detent fingers 80 m, 80 n after the last clip has been fired. The purpose of the stop is to prevent the pusher from entering the jaws and to indicate that all of the clips have been used.
According to a fourth aspect of this embodiment and as illustrated in
The lever 422 has a tongue 534 with a lifting ramp 536 at its end. A mouth 538 opens into the cylindrical structure 502 adjacent to the step 528. The tongue 534 is arranged so that it enters the mouth 538 when the lever 422 is moved to the closed position, closing the jaws. When the tongue 534 enters the mouth 538, the lifting ramp 536 engages the upturned lip 532 and raises the leaf spring 530 above the step 528. In this position, the leaf spring and the step no longer impede rotation of the cranks, and a clip may be dispensed. Rotation of the crank moves the leaf spring down the ramp 526 onto the floor of the cylindrical structure where it is free to move around in a complete rotation. The tongue 534 is provided with a lower recess 540 which allows the leaf spring 530 to pass under it at the end of a single rotation of the crank, at which point the spring will once again abut the step 528. The tongue 534 is resilient enough so that the recess 540 can pass over the upturned lip 532 when the lever 422 is moved back to open the jaws. Thus, the crank will move exactly one rotation after the jaws are closed and will not move again until the jaws are opened and then closed again.
Alternate Embodiments of Force Limiting Springs
With the foregoing in mind, it will also be appreciated that when the lever 602 is moved from the open position (
It will be appreciated by those skilled in the art that the function of the washer 608 is to provide a positive interference between the spring 606 and the shuttle 610. One manner of providing the positive interference is to partially close the end of spring 606 by bending the end of the spring 606 into an “e” shape. Alternatively, the end of the spring wire can be flattened and broadened to interfere with the shuttle. It will also be appreciated by those skilled in the art that instead of providing a stop wall 611 on the linkage 604 for the shuttle 610, the lever 602 can be arranged to directly push the shuttle (and hence wire 612) distally upon the release of the lever from the closed position.
With the foregoing in mind, it will be appreciated that when the lever 702 is moved from an open position toward the closed position shown in
Pre-Loaded Clip Ejector
In the presently preferred embodiment, at least a distal portion of the flexible coil (in this case the distal coil 12 b) is pre-loaded to provide sufficient columnar stiffness. When the jaws 84, 86 are closed, the pull wire(s) increase the load between the clevis and the nut. After the clip is deployed, the pull wires are actuated distally to open the jaws. The force of the compressed clip train, and if necessary, the force from the pull wires is sufficient to overcome the pre-load of the distal coil so that the jaws and clevis move away from the tines of the clip, which have been compressed against the forming anvils of the jaws. An alternate embodiment of this concept provides oblong holes in the jaws for attachment to the bosses on the clevis. When the jaws are closed, the pull wires move the jaws proximally with respect to the clevis. When the pull wires are released from tension and actuated distally, the jaws are also able to move distally with respect to the clevis to release the compressive load on the tines of the clip.
According to an alternative embodiment, the distal coil 12 b is pre-loaded to spring distally. When the jaws 84, 86 are closed, the pull wire(s) 62 pull against the distal coil, shortening the distal coil against its pre-load. After the clip is dispensed, the jaws are opened. When the jaws are opened, the pre-load on the distal coil causes the clevis 82, jaws 84, 86, and garage 80 all to move a slight distance distally. At the same time, the clips do not move, as they are freely disposed in the garage which is moving over them. This action has the effect of separating the distal anvils on the jaws from the tines on the formed clip, thereby easing the opening of the jaws.
The pre-loading of the distal coil provides the coil with sufficient columnar strength to allow for tangential bites, prevents buckling during jaw closure, and provides reaction force to overcome frictional forces as the jaws open.
Alternate Jaw Embodiment
There have been described and illustrated herein several embodiments of a flexible endoscopic clip applier. While particular embodiments of the invention have been described, it is not intended that the invention be limited thereto, as it is intended that the invention be as broad in scope as the art will allow and that the specification be read likewise. Thus, while the coils of the invention have been described as being formed from flat stock, it will be appreciated that the stock can be of circular or other cross-section. Also, while particular materials have been described as preferred in making various of the elements of the invention, it will be appreciated that other materials can be utilized. Further, while the invention has been described as utilizing a gear arrangement which provides a specific number of turns to a wire control element for advancing the clips, it will be appreciated that other gear arrangements which provide the same or different numbers of turns of the wire control element can be provided. Further, while the invention has been disclosed in conjunction with two different kinds of end effectors, i.e. the jaws and the clip pusher, other components of the invention may be used with different end effectors. It will therefore be appreciated by those skilled in the art that yet other modifications could be made to the provided invention without deviating from its spirit and scope as claimed.