Abstract:
A medical guidewire system for guiding thereon a medical implement includes an end effector, an actuation guidewire having a distal end permanently connected to the end effector, and a control assembly. The assembly has a handle, a shaft receiving the guidewire. The shaft has a proximal end permanently connected to the handle and a distal end temporarily connected to the end effector. A first actuator is movably connected to the handle and operatively connected to the guidewire to actuate the end effector. A second actuator is movably connected to the handle and operatively connected to a portion of the guidewire to disconnect the guidewire from the handle when actuated and, thereby, permit removal of the control assembly from the end effector and guidewire. When the control assembly is removed, the end effector and the guidewire form a surgical exchange or guidewire for guiding thereon the medical implement.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the priority, under 35 U.S.C. §119, of U.S. Provisional Patent Application No. 60/856,573 filed Nov. 3, 2006, the entire disclosure of which is hereby incorporated herein by reference in its entirety. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     n/a 
     FIELD OF THE INVENTION 
     The present invention lies in the field of endoscopic accessories and catheters, for example, devices that can be passed through the working channel of an endoscope (for example, a flexible endoscope) to manipulate tissue, a catheter sheath introducer in an intravascular procedure, and a trocar in a laparoscopic procedure. One possible catheter embodiment is a dissection device. An exemplary dissection device described in the present application is used, for example, to traverse a Chronic Total Occlusion (CTO). The present invention also relates to a medical exchange or guide wire system and device for guiding or exchanging a medical implement. One exemplary embodiment of the exchange wire system has a removable end effector-actuation wire assembly that can be separated from an actuation handle and the shaft surrounding the actuation wire. After use of the end effector in one medical process, the assembly can be decoupled from the handle and shaft to leave the actuation wire behind, which is, then, usable as a guidewire for another medical device for carrying out a subsequent surgical process. 
     BACKGROUND OF THE INVENTION 
     To gain access to treatment sites in the body, catheters must be flexible enough to conform to and follow natural anatomical pathways as they are advanced. These soft and delicate tissue pathways can be quite tortuous with many twists and turns. In the vasculature, this is especially the case, and even more so in certain areas of the vasculature such as the vessels of the brain and the coronary arteries. 
     When treating a site in the vasculature, the state-of-the-art practice is to first gain access to the treatment site with a flexible, steerable guidewire. Such a guidewire can be precisely controlled by the physician and steered into place using radiographic guidance. Once the guidewire is in-place, a device, referred to generally as a catheter, is advanced over the guidewire. The catheter must be flexible enough to smoothly follow the pathway of guidewire. After traversing the guidewire to the treatment site, the catheter can be used to deliver the treatment. 
     In the case of arterial blockage, the catheter may be a balloon dilatation catheter that is used to open the blockage. In such an embodiment, the guidewire is, first, passed up to and through the lesion. Then, the catheter is advanced over the guidewire and through the lesion. It is preferable to pass the guidewire through the blockage without aid of another device. However, if the guidewire is not able to penetrate the blockage, other aids are needed. 
     Currently, treatment of CTOs by catheter interventionalists is performed by attempting to pass the guidewire across the CTO. Once the guidewire is across, a low profile balloon catheter can be advanced over the guidewire to dilate the lesion. Such a procedure is almost always followed by placement of a stent. Specialty guidewires are available to aid the physician in this effort but they, too, are limited in their utility by the constraints of flexibility and compliance. It is noted that attempting to cross CTOs is a tedious practice with current equipment and is met with limited success. 
     In instances where the guidewire is not able to penetrate the blockage, different devices must be used successively to pass through the blockage and, then, effect the treatment. In one prior art procedure, the guidewire is advanced up to the blockage. Then, a micro-lumen catheter is advanced over the guidewire and against the blockage. A CTO penetrating device, such as the device sold by Cordis Corporation and referred to as the FRONTRUNNER® XP CTO, is threaded through the lumen of the micro-lumen catheter and up to the blockage. The penetrating device is actuated to penetrate through the blockage. When complete penetration is established, the micro-lumen catheter is advance over the penetrating device and through the blockage. The penetrating device is removed and the treatment catheter (e.g., balloon expanding or stent placing) is advanced through or around the micro-lumen catheter such that the treatment site surrounds the portion of the catheter used for treatment. If disposed within the micro-lumen catheter, it is removed before treatment is effected (i.e., before expansion of the balloon). A stent may or may not be deployed after the penetration of the blockage is widened. 
     It would be beneficial to provide a catheter, catheter system, and treatment process that can advance a device up to the treatment site with sufficient flexibility through a tortuous path, that can be used to penetrate a CTO, and that can also be used as an exchange wire for receiving thereover the treatment catheter to be used for opening the CTO for treatment with balloons or stents, for example. 
     SUMMARY OF THE INVENTION 
     The invention overcomes the above-noted and other deficiencies of the prior art by providing a catheter, a catheter system, a device for guiding or exchanging medical implements, a medical exchange wire system, and a treatment process that can advance a device up to the treatment site, penetrate a CTO, and be used as an exchange wire for receiving thereover the treatment catheter to be used for opening the CTO for treatment with balloons or stents. 
     Previously, many patients with CTOs did not have access to less-invasive procedures, like angioplasty or stenting, to open blockages. In order to treat CTOs with less-invasive methods, a doctor must first cross through the blockage. The present invention allows physicians to break through complete blockages and, thereby, allow treatment with stents or balloons. By using the catheter of the present invention, patients may avoid having to undergo difficult surgeries or even amputations. 
     With the foregoing and other objects in view, there is provided, in accordance with the invention, a medical guidewire system for guiding thereon a medical implement, including a surgical end effector for carrying out a medical procedure when actuated, an actuation guidewire having a distal end permanently connected to the end effector, and a control assembly. The control assembly has a handle, a hollow shaft receiving therein at least a portion of the actuation guidewire, a first actuator and a second actuator. The shaft has a proximal end permanently connected to the handle and a distal end temporarily connected to the end effector. The first actuator is movably connected to the handle and operatively connected to the actuation guidewire to actuate the end effector by the actuation guidewire through the shaft when the first actuator is actuated. The second actuator is movably connected to the handle and operatively connected to a portion of the actuation guidewire to disconnect the actuation guidewire from the handle when the second actuator is actuated and, thereby, permit removal of the control assembly from the end effector and the actuation guidewire and, when the control assembly is removed, the end effector and the actuation guidewire forming a surgical exchange wire or guidewire for guiding thereon the medical implement. As used herein, guidewire shall include both guidewires and exchanges wires and variations thereof. 
     With the objects of the invention in view, there is also provided a removable medical guidewire system, including a surgical end effector for carrying out a medical procedure when actuated, an actuation guidewire having a control connection portion and a distal end permanently connected to the end effector, and a control assembly. The control assembly has a handle, a hollow shaft receiving therein at least a portion of the actuation guidewire, an effector actuator, and a separation actuator. The shaft has a proximal end permanently connected to the handle and a distal end temporarily connected to the end effector. The effector actuator is movably connected to the handle for actuating the end effector and the separation actuator is movably connected to the handle for disconnecting the control assembly from the end effector and the actuation guidewire. The control connection portion has a guidewire connected state in which the control connection portion is operatively connected to the effector actuator to actuate the end effector in an actuation range when the effector actuator is actuated and a guidewire disconnected state in which the control connection portion is disconnected from the effector actuator by actuation of the separation actuator to permit removal of the control assembly from the end effector and the actuation guidewire, the end effector and the actuation guidewire together forming a surgical exchange wire or guidewire for guiding thereon a medical implement when the control assembly is removed. 
     With the objects of the invention in view, in a medical device having a handle with a shaft for receiving therein an actuation wire and an effector actuator movably connected to the handle for actuating an end effector, there is also provided an exchange wire or guidewire system including a surgical end effector temporarily connected to the effector actuator for carrying out a medical procedure when the effector actuator is actuated and temporarily connected to the shaft, an actuation guidewire having a distal end permanently connected to the end effector and being operatively connected between the effector actuator and the end effector through the shaft to actuate the end effector when the effector actuator is actuated, and a separation actuator movably connected to the handle and to a portion of the actuation guidewire, the separation actuator, when actuated, disconnecting the actuation guidewire from the effector actuator to permit removal of the handle from the end effector and the actuation guidewire and, when removed, the end effector and the actuation guidewire forming a surgical exchange wire or guidewire for guiding thereon a medical implement. 
     In accordance with another feature of the invention, the end effector and the shaft are sized to pass through a working channel of a flexible endoscope, a lumen of a catheter sheath introducer, and a lumen of a trocar to manipulate tissue. In one embodiment, the end effector is a dissection device shaped to traverse a Chronic Total Occlusion. 
     In accordance with a further feature of the invention, the shaft has an inner sheath surrounding a portion of the actuation guidewire, a coil surrounding the inner sheath, a sheath casing surrounding the coil, and a strain relief disposed at a junction of the handle and the coil and the sheath casing and surrounding the sheath casing. 
     In accordance with an added feature of the invention, the actuation guidewire moves inside the handle when the first actuator is actuated and the first actuator is a trigger assembly having an actuation coupler permanently connected to the actuation guidewire and movably disposed inside the handle to move in a corresponding manner with the actuation guidewire, a trigger body pivotally connected to the handle, and a trigger link having a first end pivotally connected to the trigger body and a second end pivotally connected to the actuation coupler, the trigger link moving the actuation coupler and, thereby, the actuation guidewire, when the trigger is actuated. 
     In accordance with an additional feature of the invention, the second actuator is connected to at least one of the actuation coupler and the actuation guidewire. 
     In accordance with yet another feature of the invention, the actuation coupler moves in an actuation range when the trigger body is actuated and the second actuator is connected to the actuation coupler and moves the actuation coupler outside the actuation range when actuated. 
     In accordance with yet a further feature of the invention, the handle has a boss; and the distal end of the actuation guidewire is a first end running from the end effector, through the shaft in a proximal direction, around the boss, back through the shaft in a distal direction, and terminating at a temporary connection on the end effector. 
     In accordance with yet an added feature of the invention, actuation of the first actuator moves the actuation guidewire in an actuation range insufficient to break the temporary connection and actuation of the second actuator moves the actuation outside the actuation range sufficient to break the temporary connection. 
     In accordance with yet an additional feature of the invention, the first actuator, when actuated, moves the actuation guidewire within an actuation range and the second actuator, when actuated, moves the actuation guidewire outside the actuation range to disconnect the actuation guidewire from the control assembly. 
     In accordance with again another feature of the invention, the second actuator, when actuated, moves at least portion of the actuation guidewire within the handle longitudinally further away from the end effector. 
     In accordance with again a further feature of the invention, the second actuator is a lever that, when pivoted, moves the actuation guidewire outside the actuation range. 
     In accordance with again an added feature of the invention, the second actuator is a screw that, when unscrewed, moves the actuation guidewire outside the actuation range. 
     In accordance with again an additional feature of the invention, the end effector has a frangible portion temporarily connecting the shaft to the end effector, the first actuator, when actuated, moves the actuation guidewire within an actuation range in which the frangible portion remains connected to the end effector, and the second actuator, when actuated, moves the actuation guidewire outside the actuation range to disconnect the actuation guidewire from the control assembly and disconnect the frangible portion from the end effector, thereby disconnecting the shaft from the end effector. 
     In accordance with still another feature of the invention, the frangible portion is fixed to the shaft when the second actuator is actuated and the frangible tube is disconnected from the end effector. 
     In accordance with a concomitant feature of the invention, the shaft has a coil surrounding at least a portion of the actuation guidewire and a sheath casing surrounding the coil, the end effector has a clevis with a proximal end, and the frangible portion is a fracture tube removably connected to the proximal end of the clevis and extending in a proximal direction therefrom into at least a portion of the coil and the sheath casing. 
     Other features that are considered as characteristic for the invention are set forth in the appended claims. 
     Although the invention is illustrated and described herein as embodied in a device for guiding or exchanging medical implements and medical exchange wire system, it is, nevertheless, not intended to be limited to the details shown because various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims. 
     The construction and method of operation of the invention, however, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Advantages of embodiments of the present invention will be apparent from the following detailed description of the preferred embodiments thereof, which description should be considered in conjunction with the accompanying drawings in which: 
         FIG. 1  is a fragmentary, perspective view of a device actuator according to an exemplary embodiment of the present invention from the side of a distal end thereof; 
         FIG. 2  is a fragmentary, perspective, longitudinally vertical cross-sectional view of the device actuator of  FIG. 1 ; 
         FIG. 3  is a fragmentary, perspective and partially transversely vertical cross-sectional view of a device actuator according to another exemplary embodiment of the present invention from the side of a proximal end thereof, shown with a side guidewire port; 
         FIG. 4  is a fragmentary, perspective and partially transversely vertical cross-sectional view of the proximal portion of the device actuator of  FIG. 3  in a further distal vertical plane therefrom; 
         FIG. 5  is a fragmentary, perspective and partially transversely vertical cross-sectional view of the proximal portion of the device actuator of  FIG. 4  in a further distal vertical plane therefrom; 
         FIG. 6  is a fragmentary, perspective and partially transversely vertical cross-sectional view of the proximal portion of the device actuator of  FIG. 5  in a further distal vertical plane therefrom; 
         FIG. 7  is a fragmentary, perspective and partially transversely vertical cross-sectional view of the proximal portion of the device actuator of  FIG. 6  in a further distal vertical plane therefrom; 
         FIG. 8  is a fragmentary, perspective and partially transversely vertical cross-sectional view of the proximal portion of the device actuator of  FIG. 7  in a further distal vertical plane therefrom; 
         FIG. 9  is a fragmentary, perspective and partially transversely vertical cross-sectional view of the proximal portion of the device actuator of  FIG. 8  in a further distal vertical plane therefrom; 
         FIG. 10  is a fragmentary, perspective and partially transversely vertical cross-sectional view of the proximal portion of the device actuator of  FIG. 9  in a further distal vertical plane therefrom; 
         FIG. 11  is a fragmentary, perspective and partially transversely vertical cross-sectional view of the proximal portion of the device actuator of  FIG. 10  in a further distal vertical plane therefrom; 
         FIG. 12  is an enlarged, fragmentary, horizontally longitudinal cross-sectional view of the proximal portion of  FIG. 3  with the guidewire port viewed from a bottom thereof; 
         FIG. 13  is a fragmentary, partially longitudinally vertical cross-sectional view of the device actuator of  FIG. 1  from a right side thereof with the actuation lever in the open position; 
         FIG. 14  is a fragmentary, partially longitudinally vertical cross-sectional view of the device actuator of  FIG. 13  with the actuation trigger in a first intermediate position and with the proximal portion removed; 
         FIG. 15  is a fragmentary, partially longitudinally vertical cross-sectional view of the device actuator of  FIG. 13  with the actuation trigger assembly in a closed position and with the trigger removed; 
         FIG. 16  is an enlarged, hidden line perspective view of a lock-out assembly of the device actuator of  FIG. 13  in the open position of the trigger; 
         FIG. 17  is an enlarged, hidden line perspective view of the lock-out assembly of  FIG. 16  in the closed position of the trigger before the lock engages a castellation space; 
         FIG. 18  is a fragmentary, longitudinally vertical cross-sectional view of a distal portion of the device actuator with a z-bend embodiment of the actuation wire and the trigger in the open position; 
         FIG. 19  is a fragmentary, longitudinally vertical cross-sectional view of the distal portion of  FIG. 18  with the trigger in a closed position; 
         FIG. 20  is a fragmentary, bottom elevational view of the end effector and a proximal portion of the device actuator of  FIG. 1  with the side guidewire port; 
         FIG. 21  is a fragmentary, partially broken away perspective view of a first embodiment of the end effector of  FIG. 20  viewed from the side of a distal end thereof; 
         FIG. 22  is a fragmentary, enlarged partially broken away perspective view of the end effector of  FIG. 21  with the jaws in a closed position; 
         FIG. 23  is an enlarged, fragmentary, hidden line perspective view of the end effector of  FIG. 21 ; 
         FIG. 24  is a fragmentary, enlarged partially broken away perspective view of the end effector of  FIG. 21  with the jaws in an open position; 
         FIG. 25  is a longitudinally vertical cross-sectional view of the end effector of  FIG. 21 ; 
         FIG. 26  is a longitudinally horizontal cross-sectional view of the end effector of  FIG. 21 ; 
         FIG. 27  is a fragmentary, partially broken away perspective view of a second embodiment of the end effector of  FIG. 20  viewed from the side of a distal end thereof with the jaws in a closed position; 
         FIG. 28  is a fragmentary, enlarged partially broken away perspective view of the end effector of  FIG. 27  with the jaws in an open position and with the clevis removed; 
         FIG. 29  is a fragmentary, enlarged, partially broken away and longitudinally vertical cross-sectional view of the end effector of  FIG. 27  along an actuation wire axis; 
         FIG. 30  is a fragmentary, enlarged, partially broken away and longitudinally vertical away cross-sectional view of the end effector of  FIG. 27  along a guidewire axis; 
         FIG. 31  is a fragmentary, enlarged, partially broken away and longitudinally horizontal cross-sectional view of the end effector of  FIG. 27 ; 
         FIG. 32  is a fragmentary, enlarged, partially broken away perspective view of a proximal portion of the end effector of  FIG. 27  with a first embodiment of an end effector disengagement device; 
         FIG. 33  is a fragmentary, enlarged, partially broken away perspective view of a third embodiment of the end effector of  FIG. 20  viewed from the side of a proximal end thereof with the jaws in a closed position and with the clevis removed; 
         FIG. 34  is a fragmentary, enlarged, partially broken away hidden line perspective view of the end effector of  FIG. 33 ; 
         FIG. 35  is a fragmentary, enlarged, partially broken away hidden line perspective view of the end effector of  FIG. 33  with the jaws in an open position; 
         FIG. 36  is a fragmentary, enlarged, partially broken away hidden line perspective view of the end effector of  FIG. 35  with clevis portions removed; 
         FIG. 37  is a fragmentary, enlarged, partially broken away hidden line perspective view of the end effector of  FIG. 36  with a fracturing portion removed; 
         FIG. 38  is a fragmentary, further enlarged, partially broken away hidden line perspective view of the end effector of  FIG. 35 ; 
         FIG. 39  is a fragmentary, enlarged, partially broken away hidden line perspective view of the end effector of  FIG. 35  with the jaws in a first intermediate fracture position and with the fracturing portion in a first fracturing position; 
         FIG. 40  is a fragmentary, enlarged, partially broken away hidden line perspective view of the end effector of  FIG. 39  and with the fracturing portion in a second fracturing position; 
         FIG. 41  is a fragmentary, enlarged, partially broken away hidden line perspective view of the end effector of  FIG. 40  and with the fracturing portion in a third fracturing position and a spring catch in a catching position; and 
         FIG. 42  is a fragmentary, further enlarged, partially broken away hidden line perspective view of the end effector of  FIG. 41  and with the fracturing portion in a fourth fracturing position. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Aspects of the invention are disclosed in the following description and related drawings directed to specific embodiments of the invention. Alternate embodiments may be devised without departing from the spirit or the scope of the invention. Additionally, well-known elements of exemplary embodiments of the invention will not be described in detail or will be omitted so as not to obscure the relevant details of the invention. 
     Before the present invention is disclosed and described, it is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. It must be noted that, as used in the specification and the appended claims, the singular forms “a,” “an,” and “the” include plural references unless the context clearly dictates otherwise. 
     While the specification concludes with claims defining the features of the invention that are regarded as novel, it is believed that the invention will be better understood from a consideration of the following description in conjunction with the drawing figures, in which like reference numerals are carried forward. The figures of the drawings are not drawn to scale. Further, it is noted that the figures have been created using a computer-aided design computer program. This program at times removes certain structural lines and/or surfaces when switching from a shaded or colored view to a wireframe view. Accordingly, the views should be considered as only illustrative. 
     Referring now to the figures of the drawings in detail and first, particularly to  FIG. 1  thereof, there is shown a first exemplary embodiment of a medical device handle  1  according to the invention. The present application applies the medical device handle to a blunt dissection device for ease of understanding only. The invention is not limited to such dissection devices and can be applied to any medical device that has an end effector operated by a single actuation wire or an end effector operated by a single actuation wire and co-axially guided by an integrated guidewire. 
     The device handle  1  of  FIGS. 1 to 2  includes a body casing  10 , a purge valve  20 , a trigger link  30 , a trigger  40 , a rotating distal nose  50 , a nose lock-out assembly  60 , and an actuation wire  70  (which is surrounded by a coil  220 , an outer sheath  222 , a strain relief portion  224 , and, possibly, an inner sheath  210 , the combination of which is only illustrated diagrammatically by dashed lines in  FIG. 1 ). It is noted that a lubricious coating on the actuation wire  70 , such as Teflon PTFE, can be used to perform the same function as the inner sheath  210 . The coil can be made from, for example, stainless steel, and the sheath can be made from, for example, fluoropolymers, polyolefins (e.g., PTFE, HDPE, or FEP). The strain relief can be made from, for example, a heat-shrinkable material such as polyurethane or polyolefin. 
     In the exemplary embodiment of the body casing  10  shown, there are two halves  12 ,  13 , the right half  12  only being illustrated in  FIG. 2 . The halves  12 ,  13  can be connected together in any manner, such as through solvent bonding, crush welding, and screws, to name a few. 
     An alternative configuration to the handle  1  of  FIGS. 1 to 2  is the configuration shown in  FIGS. 3 to 12  and  27  to  31 .  FIG. 2  can also be used with reference to this second configuration. This second handle  100  also has a body casing  110 , a purge valve  120 , a trigger link  130 , a trigger  140 , a rotating distal nose  150 , a nose lock-out assembly  160 , and an actuation wire  170 . 
     The handle  100  further has an integral guidewire assembly  180 . With such an assembly  180 , a guidewire  182  can be inserted through a fluid-tight port  184  (e.g., a touhy-borst connector) in a portion of the handle  100  (without compromising the interior filled with saline, for example) and can exit from a distal end of the device  100  where an end effector  200 , for example, is located. As will be described in detail below, the rotating nose  50 ,  150  is decoupled from the handle body  10 ,  110  and, therefore, the guidewire assembly  180  is connected to the nose  150  and not to the handle body  110 . 
     The progression of  FIGS. 3 to 11  illustrates a rotating distal nose  150  that includes this guidewire assembly  180 . The cross-section of  FIG. 2  illustrates the interior fluid passage of the purge valve  20 ,  120 . The upstream portion  22 ,  122  of the valve  20 ,  120  extending transverse to the longitudinal axis of the casing  10 ,  110  can be a standard medical female luer fitting, as illustrated. The downstream portion—valve body  24 ,  124 —is contained within a valve chamber  14 ,  114  of the body casing  10 ,  110 . The valve body  24 ,  124  has a longitudinal fluid cavity  242 ,  1242  through which projects the actuation wire  170  and a transverse fluid cavity  244 ,  1244  fluidically connected to the longitudinal fluid cavity  242 ,  1242 . It is noted that some of the figures of the drawings illustrate the actuation wire  70 ,  170  not centered at various portions of the handle. It is to be understood that the actuation wire  70 ,  170  is centrally disposed and aligned within the cavities of the handle and shaft and any figures illustrating an offset of the actuation wire should be deemed merely as an approximation of the device. 
     When the upstream portion  22 ,  122  of the purge valve  20 ,  120  is fluid-tightly connected to the valve body  24 ,  124 , the fluid passage  222 ,  1222  is in fluidic communication with the transverse fluid cavity  244 ,  1244  (in this embodiment, the two passages  222 ,  1222  and  244 ,  1244  are coaxial). Therefore, when fluid (such as saline) is injected into the upstream port  224 ,  1224  of this configuration, it passes therethrough and, then, through the transverse fluid cavity  244 ,  1244  and the longitudinal fluid cavity  242 ,  1242 , respectively. To prevent such fluid from passing anywhere proximal of the valve body  24 ,  124  (with respect to the longitudinal axis of the handle  1 ,  100 ):
         a seal disk  72 ,  172  is disposed at the proximal inside of the valve body  24 ,  124  and fluid tightly seals the space between the guidewire  70 ,  170  and walls of the longitudinal fluid cavity  242 ,  1242 . The seal disk  72 ,  172  can be made of, for example, a silicone rubber disk that is held in place with a seal cap  73 ,  173 ; and   an O-ring  74 ,  174  is disposed at the distal outside of the valve body  24 ,  124  and fluid tightly seals the space between the exterior surface of the valve body  24 ,  124  and the interior surface of a rear chamber of the nose  50 ,  150 , which is rotatably disposed within the valve chamber  14 ,  114 . The O-ring  74 ,  174  can be made of, for example, silicone rubber.
 
In this way, any injectate entering the upstream opening of the upstream portion  22 ,  122  travels out the distal opening  52 ,  152  of the nose  50 ,  150  and along the actuation wire  70 ,  170  (which is sealed within the coil  220  and the outer sheath  222  shown only diagrammatically with dashed lines in  FIG. 1 ) until the fluid exits at the end effector  200 .
       

       FIG. 2  illustrates the interior of the device handle  1  with the left half  13  removed to permit view of the rotational and fluid-tight connection between the nose  50 ,  150  and the valve body  24 ,  124  and body casing  10 ,  110 . The valve chamber  14 ,  114  is cylindrical. The O-ring  74 ,  174  is circular and, when installed within an O-ring groove  246 ,  1246 , projects sufficiently far outside the groove  246 ,  1246  to fluid-tightly seal the interposed space between the outside of the valve body  24 ,  124  and the interior circular proximal chamber  54 ,  154  of the nose  50 ,  150 , but not too far such that it presses the proximal end of the nose  50 ,  150  against the interior of the distal portion of the valve chamber  14 ,  114  that holds the nose  50 ,  150  therein. More specifically, the proximal end of the nose  50 ,  150  forms a circular tongue  56 ,  156  that fits, rotatably, within a circular-disc-shaped hollow groove  126 ,  1126  within the distal interior of the valve chamber  14 ,  114 . Also provided on the proximal-most end of the nose  50 ,  150  is a castellated ring  59 ,  159 , which is apparent in  FIG. 3 , for example. As will be discussed in detail below, the spaces between the castellations are used as a keyhole for receiving a locking tab  68 ,  168  that prevents the nose  50 ,  150  from rotating about its axis when the locking tab  68 ,  168  is positioned in one of the spaces between two castellations. 
     As will be described in further detail below, the end effector  200 , the actuation wire  70 ,  170 , the outer sheath  222  and the coil  220  surrounding the actuation wire  70 ,  170  are desired to turn together as one. When the sheath  222  and coil  220  are fastened to the nose  50 ,  150 , for example, by bonding, these features will turn with the nose  50 ,  150  directly. The actuation wire  70 ,  170  and the inner sheath  210 , however, are not coupled to either the nose  50 ,  150 , the outer sheath  222 , or the coil  220  because longitudinal uncoupling must be ensured to permit longitudinal movement of the actuation wire  70 ,  170  for end effector actuation. 
     To effect such a rotational coupling but provide the longitudinal uncoupling, a first embodiment of a torque couple is provided and is illustrated in  FIG. 2  and, especially, in  FIGS. 6 to 8 . More specifically, a torque puck  76 ,  176  (see  FIG. 14 ) is fastened to the actuation wire  70 ,  170  so that it rotates with the actuation wire  70 ,  170  and vice-versa—rotation of the puck  76 ,  176  causes rotation of the actuation wire  70 ,  170 . In the exemplary embodiment, the puck  76 ,  176  has a rectangular cross-section. A torque groove  58 ,  158  within the nose  50 ,  150  has a corresponding shape but is slightly larger than the puck  76 ,  176  so that longitudinal movement of the puck  76 ,  176  within the groove  58 ,  58  is unhindered by the nose  50 ,  150 . In such a configuration, when the nose  50 ,  150  is rotated with respect to the actuation wire  70 ,  170 , the inside surfaces of the torque groove  58 ,  158  act against the puck  76 ,  176  to rotate the puck  76 ,  176  along with the nose  50 ,  150 . An alternative embodiment of this connection is illustrated and described below with respect to  FIGS. 18 to 19 . 
       FIG. 12  illustrates the separation of the guidewire  182  and the actuation wire  170  within the guidewire assembly  180  and the rotating nose  150 . As can be seen in the progression of  FIGS. 3 to 8 , the guidewire  182  and the actuation wire  170  remain separate and traverse through separate passages at an angle to one another.  FIGS. 10 to 11  show that these two wires  170 ,  182  become parallel and enter a two-lumen tube  190  before exiting the distal opening  152  of the nose  150 .  FIG. 9  clearly shows that the two-lumen tube  190  begins at a point at an angle to the actuation wire  70 ,  170  and  FIG. 12  specifically illustrates the tube  190  extending along the guidewire  182  over a distance that does not include the actuation wire  170 . There are various ways to permit the actuation wire  170  to enter the second of the two lumens at a point distal of the proximal opening  192 . One such configuration creates a hole slightly larger than the actuation wire  170  at an entry point  194  shown in  FIG. 12 . Another such configuration cuts a groove between the second lumen and the outer circumference of the two-lumen tube  190  from the proximal opening  192  all the way to the entry point  194 . The latter configuration is easier to manufacture because the portion of the second lumen that is peeled open can act as a guiding groove through which the actuation wire  170  can be threaded. 
       FIGS. 13 to 15  illustrate the movement of the trigger  40 ,  140  to cause proximal movement of the actuation wire  70 ,  170  in both of the handle configurations  1 ,  100 . As can be seen in these figures and in  FIGS. 16 to 17 , the trigger  40 ,  140  is associated with a nose lock-out assembly  60 ,  160  at the pivot point of the trigger  40 ,  140 . It is noted that the pivot pin attaching the trigger link  30 ,  130  to the trigger piston  34 ,  134  is not illustrated in  FIGS. 13 to 15 . 
       FIG. 13  illustrates the trigger  40 ,  140  in the opened position. This opened position is ensured and maintained when the trigger  40 ,  140  is not actuated by the presence of a trigger biasing device  32 ,  132 . In the exemplary embodiment shown, this biasing device  32 ,  132  is a compression spring that is pre-biased in compression and exerts a distally directed force against a trigger piston  34 ,  134  that is pivotally connected to the proximal end of the trigger link  30 ,  130 . Thus, to depress the trigger  40 ,  140 , the prebiasing force of the spring  32 ,  132  must be overcome by the user. 
     The proximal end of the trigger link  30 ,  130  is pivotally connected to the proximal end of the trigger piston  34 ,  134  and the distal end of the trigger link  30 ,  130  is pivotally connected to the end of the trigger  40 ,  140  opposite the pivot point of the trigger  40 ,  140 . Thus, depression of the trigger  40 ,  140  causes the cylindrical trigger piston  34 ,  134  to move proximally within the correspondingly cylindrical piston chamber  16 ,  116  and, when longitudinally connected to the actuation wire  70 ,  170 , to actuate the actuation wire  70 ,  170  by moving it in the proximal direction. It is noted that the described configuration provides a trigger that applies a non-linear force to the trigger piston  34 ,  134 . In other words, the squeeze lever linkage provides a non-linear, increasing mechanical advantage as the lever  40 ,  140  is squeezed by the user. 
     As can be seen in  FIGS. 13 to 15 , the link between the actuation wire  70 ,  170  and the trigger piston  34 ,  134  is not direct. Instead, as mentioned above, the trigger piston  34 ,  134  is rotationally disconnected from the actuation wire  70 ,  170 . In handles such as the devices  1 ,  100  of the present invention, it is desirable to rotate the end effector  200  without rotating the handle body casing  10 ,  110 . Thus, the rotating nose  50 ,  150  is provided. Also provided for this particular connection is a slider  36 ,  136  that is similarly cylindrical and slides within the piston chamber  16 ,  116  longitudinally. The slider  36 ,  136  is rotationally and longitudinally fastened to the actuation wire  70 ,  170  by, for example, a set screw that presses against the actuation wire  70 ,  170  when thread through a central bore of the slider  36 ,  136 . In such a configuration, both the slider  36 ,  136  and the actuation wire  70 ,  170  remain centered within the piston chamber  16 ,  116  but still longitudinally and rotationally movable therein. The proximal end of the slider  36 ,  136  and the distal end of the trigger piston  34 ,  134  form the longitudinally fixed but rotationally free connection between the piston  34 ,  134  and the actuation wire  70 ,  170 . However, as is apparent from the progression of  FIGS. 13 to 14 , there exists a space (or play)  38 ,  138  preventing movement of the slider  36 ,  136  for a short distance when the trigger  40 ,  140  is first depressed. This connection can be embodied in any way to carry out the function. The connection is illustrated in an exemplary embodiment in the figures of the drawings as a U-shaped fork extending distally with tines pointing downwards (as viewed in the figures) from the distal end of the trigger piston  34 ,  134  around a mushroom-shaped boss  39  extending proximally from the proximal end of the slider  36 ,  136 . (See, in particular, the cross-section of  FIG. 18 .) With the inside diameter of the fork being slightly larger than the outer diameter of the mushroom shaft, the slider  36 ,  136  can rotate freely within the tines of the fork but remains longitudinally connected after the piston closes the space  38 ,  138 . 
     The space  38 ,  138  is provided to assist the nose lock-out assembly  60 ,  160 . While the assembly  60 ,  160  is apparent in  FIG. 15 , it is highlighted in the enlarged views shown in  FIGS. 16 to 17 . The lock-out assembly  60 ,  160  includes a pivoting key  62 ,  162  that rotates about the same pivot axis as the trigger  40 ,  140  but is not rotationally fixed with respect to the trigger  40 ,  140 . The key  62 ,  162  has a tab that is connected to one end of a bias device  64 ,  164  (a tension spring in the illustrated exemplary embodiment) and the other end of the bias device  64 ,  164  is connected to a boss on the inside of the trigger  40 ,  140 . In such a configuration, the key  62 ,  162  is biased to rotate in a clockwise direction with respect to  FIGS. 16 to 17 . A key stop  66 ,  166  is positioned on the inside of the trigger  40 ,  140  to prevent the key from so rotating when the trigger  40 ,  140  is in the open (rest) position (shown, for example, in  FIG. 16 ). Thus, when the trigger  40 ,  140  is unactuated, the nose  50 ,  150  can rotate freely. The key  62 ,  162  also has a locking tab  68 ,  168  that performs a locking function when inserted in between the castellations of the castellated ring  59 ,  159 . The key  62 ,  162  is positioned next to the castellated ring  59 ,  159  so that the initial depression of the trigger  40 ,  140  will allow the key  62 ,  162  to rotate about its axis and press the locking tab  68 ,  168  against the castellated ring  59 ,  159 . If one of the spaces between the castellations happens to be resting in line with the locking tab  68 ,  168  so that the tab  68 ,  168  enters the space, the locking assembly  60 ,  160  will have performed its locking function and prevent any rotation of the nose  50 ,  150  while the actuation wire  70 ,  170  is moved. Alternatively, if no space between the castellations is in line with the locking tab  68 ,  168 , the clockwise force acting upon the key  62 ,  162  remains throughout the time of trigger stroke; thus, any small rotation of the nose  50 ,  150  in either direction when the trigger  40 ,  140  is depressed will force the locking tab  68 ,  168  to enter the space most adjacent to the locking tab  68 ,  168 . As such, the lock-out assembly  60 ,  160  prevents any rotation of the nose  50 ,  150  when the end effector  200  is being actuated or only allows a small amount of rotation of the nose  50 ,  150 —the amount being insignificant to adversely affect the procedure that is being carried out by the end effector  200 . 
     Selection of the castellation size and, therefore, the spacing between the spaces, will determine the permitted rotation of the nose  50 ,  150  when the trigger  40 ,  140  is depressed. The illustrated embodiment of eight spaces is only exemplary and can be any desired amount. In this embodiment, the centerpoints of adjacent spaces are 45 degrees apart from one another. Assuming that the width of the locking tab  68 ,  168  is substantially equal to the width of the spaces, the most that the nose  50 ,  150  could rotate if the locking tab  68 ,  168  was not within a space is, therefore, less than 45 degrees. The locking tab  68 ,  168  is, however, envisioned to be substantially thinner than the width of the spaces between the castellations. Therefore, the amount of possible nose rotation when the trigger  40 ,  140  is depressed is substantially less than 45 degrees in an 8-space castellated embodiment. 
     The longitudinal space  38 ,  138  between the fork of the trigger piston  134  and the mushroom boss  39  of the slider  36 ,  136  is sized to be greater than the initial depression of the trigger  40 ,  140  sufficient to move the locking tab  68 ,  168  into its locking position before the actuation wire  70 ,  170  moves longitudinally in any amount. 
       FIG. 16  and illustrates the trigger  40 ,  140  in the open (rest) position and the key stop  66 ,  166  preventing clockwise movement of the key  62 ,  162 . In comparison,  FIG. 17  illustrates the trigger in the fully depressed position so that the key  62 ,  162  is in the orientation where it is pressing against the castellated ring  159  and is ready to enter any one of the two adjacent spaces when the nose  50 ,  150  is rotated in either direction. 
       FIGS. 18 to 19  illustrate a second exemplary embodiment of the connection and rotational coupling features of the actuation wire  70 ,  170 . Here, the torque puck  76 ,  176  is replaced by a bend  78 ,  178  in the actuation wire  70 ,  170 . The height of the torque groove  58 ,  158  is dependent upon the transverse height of the bend  78 ,  178  and is sized to be larger than this transverse height so that there is no or no significant friction between the bend  78 ,  178  and the torque groove  58 ,  158 . In such a configuration, as the wire  70 ,  170  is rotated, the nose  50 ,  150  will rotate and, conversely, as the nose  50 ,  150  is rotated, the wire  70 ,  170  rotates correspondingly.  FIGS. 17 to 18  also reveal a second exemplary embodiment of the connection between the proximal end of actuation wire  70 ,  170  and the slider  36 ,  136 . A tab  362 ,  1362  with a through-bore is disposed on the distal end of the slider  36 ,  136  to receive a Z-bend of the proximal end of the actuation wire  70 ,  170 . In this embodiment, the freely rotating slider  36 ,  136  can be connected to the actuation wire  70 ,  170  in a rotatingly fixed manner without impairing the rotatability of the slider  36 ,  136 . 
     The progression of  FIGS. 18 to 19  shows the trigger  40 ,  140  in its two extreme positions: open/unactuated ( FIG. 18 ) and closed/fully actuated ( FIG. 19 ). Like  FIG. 17 ,  FIG. 19  shows the key  62 ,  162  in the locked orientation but not in one of the spaces of the castellated ring  59 ,  159 ; a small rotation of the nose  50 ,  150  will cause the key  62 ,  162  to drop into one of the two adjacent spaces. 
       FIG. 20  illustrates the sub-assembly associated with the nose  50 ,  150  and a diagrammatic illustration of an end effector  200 . 
       FIGS. 21 to 26  illustrate a first exemplary embodiment of an end effector  300 . Attachment of this end effector  300  to the handle  1 ,  100  of the present invention is illustrated in  FIG. 21 . As can be seen therein, the actuation wire  70 ,  170  tapers from a relatively thicker diameter proximally to a relatively thinner diameter distally. This taper can begin and end at any point along the actuation wire  70 ,  170 . Having a thinner diameter at the distal end near the end effector  200  allows the area of thinness to be more flexible. Having the thinner diameter throughout most of the shaft length up to the end effector  200  increases the torqueability of the end effector  200  with respect to the handle  1 ,  100 . 
     Also visible in  FIG. 21  is an inner sheath  210  disposed between the actuation wire  70 ,  170  and the coil  220 . The inner sheath  210  can be provided to reduce or limit the friction that could be caused by rubbing against the interior of the coil  220 . As such, the inner sheath  210  is made from a friction reducing material, such as TEFLON® or PTFE. The outer sheath  222  is illustrated diagrammatically by dashed lines in  FIG. 21 . This outer sheath  222  is made of a material such as Polyurethane or PEBAX™. 
       FIG. 22  shows the entire end effector  300  having a clevis  310 , a clevis pivot pin  320 , and two jaws  330 . The hidden line view of  FIG. 23  shows the actuator cam  340  and one of two cam pins  342 , each of which slides respectively within a cam surface  332  of one of the jaws  330 , the cam surface  332  being a curved groove in the tang  334  of each jaw  330 . The view of  FIG. 24  shows the jaws  330  in an open position with the cam pin  342  at the other extreme of the cam surface  332 . The cross-sectional views of  FIGS. 25 to 26  reveals other features of the actuator cam  340 . For example, the actuator cam  340  has a cam surface  342  in the shape of a linear longitudinal groove surrounding the clevis pivot pin  320  that causes the jaws  330  to open when the actuator cam  340  is moved in a proximal direction and to close when the actuator cam  340  is moved in a distal direction. 
       FIGS. 27 to 31  illustrate a second exemplary embodiment of an end effector  400  that is used with the guidewire  182 . Attachment of this end effector  400  to the handle  1 ,  100  of the present invention can be similar to that illustrated in  FIG. 21 . 
       FIG. 27  shows the entirety of the end effector  400 , which includes a clevis  410 , a clevis pivot pin  420 , and two jaws  430 . The view of  FIG. 28  shows the actuator cam  440  and one of two cam pins  444  (the lower cam pin  444  is not illustrated). As illustrated in  FIG. 30 , each of the cam pins  444  slides respectively within a cam surface  432  of one of the jaws  430 . The cam surface  432  is, in this exemplary embodiment, a linear groove in the tang  434  of each jaw  430 . The groove is disposed at an angle to the axis of the actuation wire  70 ,  170  so that travel of the pin  444  within the cam surface  432  causes the respective jaw to pivot out of alignment with the axis of the end effector  400  (i.e., opening of the jaw). The view of  FIG. 28  shows the jaws  430  in this open position. The cross-sectional views of  FIGS. 29 to 30  reveal other features of the actuator cam  440 . For example, the actuator cam  440  includes a cam surface  442  shaped as a linear longitudinal groove in which is disposed the circular clevis pivot pin  420 . The actuator cam  440  also includes a cam pin  444  for each of the jaws  430 , which pin  444  travels within the cam surface  432  of the respective jaw  430 . This configuration of cam pins and surfaces in the jaws  430  and the actuator cam  440  allow the jaws  430  to open when the actuator cam  440  is moved in a proximal direction and to close when the actuator cam  440  is moved in a distal direction (the distal-most position of the cam  440  being shown in  FIGS. 29 to 30 ). 
     In this second embodiment, the jaws  430  each define one half of a guidewire recess  450 . Because both the actuation wire  70 ,  170  and the guidewire  182  are parallel within the two-lumen tube  90 ,  190 , neither of the wires are centrally disposed within the two-lumen tube  90 ,  190  (although one can be if desired). Accordingly, the guidewire recess  450  is not aligned with the central axis of the end effector  400 . The two lumens  92 ,  94  for receiving, respectively, the guidewire  182  and the actuation wire  70 ,  170  are apparent in  FIGS. 29 and 31 . 
     In some applications, it is desirable to eliminate the need of threading a guidewire to the site at which the end effector is to be applied in addition to having the shaft (e.g., two-lumen tube  190 , inner sheath  210 , coil  220 , outer sheath  222 ) of the actuation device at the operation site. If the end effector  200  is already at the site, it is desirable to keep the end effector  200  in place and to use that placement, along with a portion of the shaft of the device, to guide separate devices to the site with the shaft portion serving as the guidewire or exchange wire. The present invention provides various alternatives for removably fixing the end effector  200  to the distal end of the device. 
     An exemplary embodiment for disengaging the end effector  200 ,  300 ,  400 ,  500  from the distal end of the shaft has the actuation wire  70 ,  170  continues toward (or even out of) the proximal end  18 ,  118  of the body casing  10 ,  110 . In a configuration where the proximal end of wire  70 ,  170  is contained entirely within the handle, the wire  70 ,  170  wraps around a boss in the body casing  10 ,  110  in a 180 degree bend to form a proximally extending portion  71 ,  171 . In a configuration where the wire  70 ,  170  exits the proximal end of the body casing  10 ,  100 , then the wire  70 ,  170  is looped 180 degrees so that a user can place a hand or finger within the center of the loop. The wire  71 ,  171 , then, continues back in the distal direction all the way through the handle and the shaft until it makes contact with the clevis  310 ,  410  of the end effector  200 ,  300 ,  400 ,  500  as shown in  FIG. 32 . 
     Contact with the clevis  310 ,  410  is removable and removal can be effected by applying a proximally directed force to the proximally extending portion  71 ,  171  sufficient to break the contact. The portion of the wire  71 ,  171  adjacent a distal portion  312 ,  412  of the clevis  310 ,  410  is narrowed considerably as compared to the width of the actuation wire  70 ,  170 . As such, when the proximally directed force is applied, the break-away portion  71 ,  170  is broken instead of the actuation portion  70 ,  170 . The break-away portion  71 ,  171  is, then, removed entirely from the shaft and the handle  1 ,  100 . Because the tension of the folded wire  70 ,  71 ,  170 ,  171  holding the clevis  310 ,  410  inside the distal end of the shaft is no longer present, the shaft and handle  1 ,  100  can be entirely removed from the connected end effector  200  and actuation wire  70 ,  170 . The length of the actuation wire  70 ,  71 ,  170 ,  171  can, now, be used as a guidewire or exchange wire for conducting procedures at the operation site. 
     In the internal loop embodiment, a lever or other mechanical device is connected to the boss and, when breaking of the connection is desired, the lever is moved to place a proximally directed force on the wire  70 ,  71 ,  170 ,  171  and break the contact at the reduced diameter portion  71 ,  171 . In the external loop embodiment, the user places a finger or hand inside the loop and pulls proximally. This force breaks the contact at the reduced diameter portion  71 ,  171 . 
       FIGS. 33 to 42  illustrate a second exemplary embodiment for disengaging the end effector  500  from the distal end of the shaft. Some of the features of this embodiment are similar to the end effector  300  described above. Therefore, the description of similar features will not be repeated for the sake of brevity. 
       FIG. 33  shows the end effector  500  with a clevis  510 , a clevis pivot pin  520 , and two jaws  530 . Each of the jaws  530  has an L-shaped cam surface  532  within its tang  534  for receiving therein a cam pin  544 . The distal portion of the cam surface  532  is similar to the cam surface  532  and is utilized for opening and closing the jaws  530 . The proximal portion of the cam surface  532  is added and used for separating the end effector  500  from the shaft, as will be described in further detail below. The actuator cam  540  in this embodiment has, at its proximal end, a hollow fracture piston  550  that surrounds the actuation wire  70 ,  170 . As can be seen best in  FIG. 42 , protruding from the proximal end of the clevis  510  is a cylindrical, hollow barb  512 . A cylindrical hollow fracture tube  560  has an interior cylindrical cavity  562  shaped to fit snugly therein the barb  512 . A frangible portion  564  protrudes inwardly from an intermediate location of the interior cylindrical cavity  562 . When the fracture tube  560  is at its distal-most position surrounding the barb  512 , as shown in  FIGS. 34 to 36 , and most particularly in  FIG. 38 , the frangible portion  564  is in line with and protrudes into a groove  514  located between the barb head  516  and barb shaft  518 . 
       FIG. 34  illustrates the orientation of the fracture piston  550  when the jaws  530  are in the closed position of the end effector  500  and  FIGS. 35 to 37  illustrate the orientation of the fracture piston  550  when the jaws  530  are in the open position of the end effector  500 . In the open position illustrated in  FIGS. 35 to 37 , the location of the cam pin  544  corresponds to the jaws-open position within the L-shaped cam surface  532 . In this position, the cam pin  544  rests at the angle/middle point of the cam surface  532 . The clevis  510  is removed in  FIG. 36  to better reveal the features of the jaws  530  and the actuator cam  540  disposed therein. The fracture tube  560  is removed in  FIG. 37  to better reveal the features of the fracture piston  550  and its spring catch  552 .  FIG. 38  shows the alignment of the features of the fracture tube  560 , the fracture piston  550  before the proximal end of the fracture piston  550  hits the proximal transverse wall  566 , which is the stop limit for proximal movement of the fracture piston  550  within the fracture tube  560 . The proximal transverse wall  566  is best illustrated in  FIG. 42 . 
     Removal of the end effector  500  will be described with primary reference to  FIGS. 39 to 42 . When the user desires to remove the end effector  500  from the distal end of the shaft, a proximally directed force will be imparted on the actuation wire  70 ,  170  to move the actuation wire  70 ,  170  further than the position it would be in when the jaws  530  are in the open position, shown in  FIGS. 35 to 37 . One exemplary embodiment for so moving the actuation wire  70 ,  170  can be a pivoting lever  600  (see  FIG. 2 ) that is attached to the trigger piston  34 ,  134  to move the trigger piston  34 ,  134  against the bias of the spring  32 ,  132  further proximal in the handle than the proximal-most position of the piston  34 ,  134  (when the trigger  40 ,  140  is fully depressed as shown, for example, in  FIG. 15 ). Another embodiment can be a screw  700  (see  FIG. 13 ) threaded into the proximal end of the trigger piston  34 ,  134  that is screwed to, thereby, move the trigger piston  34 ,  134  in a similar proximal manner. 
     In any configuration, the actuation wire  70 ,  170  is caused to move the proximal transverse wall  554  of the fracture piston  550  against the proximal transverse wall  566  inside the cavity  562  of the fracture tube  560  and further than the location of the proximal transverse wall  566  shown in  FIGS. 34 to 36  and  38 . When the fracture piston  550  bottoms out against the proximal transverse wall  566  of the fracture tube  560 , a significant proximally directed force is imparted on the fracture tube  560 . As shown in  FIG. 38  in highlighted cross-section, the only feature preventing the fracture tube  560  from moving in the proximal direction is the frangible portion  564 . Because the removal force is significantly greater than the shear strength of the frangible portion  564 , the frangible portion  564  shears off from the fracture tube and is left within the barb groove  514  as the remainder of the fracture tube  560  moves proximally.  FIG. 39  illustrates the fracture tube  560  as the frangible portion is being sheared off and  FIGS. 40 to 41  illustrate the fracture tube  560  after the frangible portion is sheared off and is being removed from the barb  512  into the inside of the coil  220 . 
     It is noted at this point that the fracture tube  560  is no longer attached to the clevis  510  or to the shaft. Being in this unattached state, it is possible for the fracture tube  560  to impermissibly drop into the volume of the operation site of the end effector  500 . To prevent this occurrence, the outer diameter of the fracture tube  560  is selected to be slightly larger than the inner diameter of the coil  220 . Because the fracture tube  560  is made of a material that is significantly softer than the coil  200 , and due to the fact that the proximal removal force is sufficient to deform the outer surface of the fracture tube  560 , the removal force creates an interference fit between the coil  220  and the fracture tube  560  sufficient to ensure that the fracture tube  560  is retained within the coil  220 . At this point, the handle  1 ,  100  and the shaft, along with the fracture tube  560 , can be removed from the end effector  500  that is longitudinally fixed to the actuation wire  70 ,  170 . In such a state, the actuation wire  70 ,  170  becomes a guidewire that can be used to guide (from the proximal end thereof) other devices along the actuation wire  70 ,  170  up to the end effector  500 .  FIG. 42  illustrates the fracture tube  560  in a position proximal of the barb  512  and with the frangible portion  564  sheared off (indicated by cross-section lines). 
     Once the distal edge of the spring catch  552  passes the proximal-most exterior surface of the barb  512 , as shown in  FIGS. 40 to 41 , the spring catch  552  springs outward to prevent any later distal movement of the fracture piston  550  into the clevis  510 . 
     The foregoing description and accompanying drawings illustrate the principles, preferred embodiments and modes of operation of the invention. However, the invention should not be construed as being limited to the particular embodiments discussed above. Additional variations of the embodiments discussed above will be appreciated by those skilled in the art. 
     Therefore, the above-described embodiments should be regarded as illustrative rather than restrictive. Accordingly, it should be appreciated that variations to those embodiments can be made by those skilled in the art without departing from the scope of the invention as defined by the following claims.