Abstract:
An improved surgical apparatus for use in endoscopic surgery having a user interface operatively coupled to an articulating tool assembly via an elongate tubular member. Movement at the articulating tool directly translates movement at the user interface thereby providing intuitive operation of the surgical apparatus. The apparatus is configured such that the range of motion of the articulating tool assembly emulates the range of motion of the human wrist. The improved apparatus is configured to provide precise and controlled movements such as to not endanger the life of the subject and minimizes any errant or unexpected movements or locking experienced in other surgical instruments.

Description:
BACKGROUND 
       [0001]    Minimally invasive surgery (MIS), such as laparoscopic surgery and thoracoscopic surgery are specialized types of surgery in the broader field of endoscopy. Laparoscopic surgery includes operations within the abdominal and pelvic cavities; thoracoscopic surgery includes operations within the thoracic cavity. Various tools and instruments are utilized during these procedures. 
         [0002]    Such tools for MIS include robotic assisted instruments and various forms of hand-operated instruments. Unfortunately, robotic assisted instruments require extensive training, are expensive and bulky. Additionally, some hand-operated instruments are counter-intuitive, i.e. movement in the tool end is opposite from movement at the user interface or actuation end. For instance, when the operator moves the user interface right, the tool end moves left. Like the counter-intuitive instruments, intuitive hand-operated instruments have limited mobility and flexibility. Movements are more discrete, such as left, right, up, down, and do not provide transitional movement through all angular ranges. Thus, in order to obtain further articulation of the tool end, the user must physically reposition him/herself and/or the instrument. 
         [0003]    All surgeries require precision and control, otherwise the patient&#39;s or subject&#39;s well-being is comprised. Some instruments do not provide sufficient routing and/or tension on cabling members and experience locking where the instrument is unable to return to its original neutral position. The locking of the instrument may also cause the tool end of the instrument to exhibit unexpected, unintentional, and/or errant movements, where the tool end either has a delayed movement based on input and/or the tool end unexpectedly releases itself from a locked position. In instruments where a solid pivot fastener is used, i.e. no central passageway through the center of the pivot point, cabling members are directed around the pivot point. In these instruments for example, moving the tip assembly (graspers, pincers etc.) down causes the tool end to also move left and the tip assembly to open as these cabling members experience tension due to the pulling on the down cable. Such errant movement is unacceptable in surgical procedures. These instruments may also suffer from “locking up” or becoming stuck in a position once actuated. For example, a cabling member will cross over the longitudinal axis of the instrument and become entangled with another cabling member and/or be unable to be able to return to its initial position or any other position as the requisite tension to move the component is not longer present. 
       SUMMARY 
       [0004]    The instrument described herein provides an intuitive hand-operated instrument capable of intricate movements with a range of motion comparable to that of a human wrist. The user provided with tactile feedback of the instrument&#39;s movements. The instrument described herein also provides the precision and control needed and expected by the operator in order to maintain the well-being of the patient. Further, the instrument described herein is a low cost, reliable, portable instrument that is safe for use in surgery, durable for repeated use, adaptable to the physical limitations of various procedures, and is easy to learn and use. 
         [0005]    In one embodiment, an improved surgical instrument includes a user interface operatively coupled to an articulating tool assembly through an elongate tubular member having a distal end and a proximal end. The user interface is coupled to the proximal end of the elongate tubular member and the articulating tool assembly coupled to the distal end of the elongate tubular member. At least one cabling member extends through the elongate tubular member connecting the user interface and the articulating tool assembly such that movement of the user interface causes corresponding movement in the same direction of the user interface at the articulating tool assembly. The articulating tool assembly includes a grip assembly and a dual hinge member pivotally coupled together. The dual hinge member has a central passageway passing therethrough and includes at least one cable alignment surface. The user interface includes a ball and socket assembly. The ball and socket assembly has a socket with openings carrying a ball. The ball has protruding arms carrying a spring tension assembly projecting from the socket openings. 
         [0006]    In another embodiment, an improved articulating tool assembly includes a tip assembly pivotally coupled to a dual hinge member. The dual hinge member has a central passageway passing therethrough and includes at least one cable alignment surface. The articulating tool assembly is configured to provide precise movements and prevent errant movements. 
         [0007]    The objects, features, and advantages of the instrument will be readily apparent to those skilled in the art upon a reading of the description of preferred embodiments which follows when taken in conjunction with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIG. 1  is an isometric view of the improved surgical instrument. 
           [0009]      FIG. 2  is an exploded isometric view of the articulating tool assembly. 
           [0010]      FIG. 3  is a side view of the articulating tool assembly. 
           [0011]      FIG. 4  is a top view of the articulating tool assembly. 
           [0012]      FIG. 5   a  is a cross sectional view of  FIG. 3 . 
           [0013]      FIG. 5   b  is another cross sectional side view of the articulating tool assembly. 
           [0014]      FIG. 6   a  is a cross sectional view of  FIG. 4 . 
           [0015]      FIG. 6   b  is another cross sectional top view of the articulating tool assembly. 
           [0016]      FIG. 7  shows one embodiment of the cabling in the improved surgical instrument. 
           [0017]      FIG. 8  is an exploded isometric view of user interface. 
           [0018]      FIG. 9  is an isometric view of the contents within the head casing of the user interface. 
           [0019]      FIG. 10  is a top view of user interface partially exposing the contents within the head casing. 
           [0020]      FIG. 11  is an isometric view of the user interface. 
           [0021]      FIG. 12  is cross sectional view of the user interface. 
       
    
    
     DETAILED DESCRIPTION 
       [0022]    The present invention is an improvement of the instrument disclosed in Application Number PCT/US2011/027061 published as WO 2011/109640, the entirety of its contents is incorporated herein. 
         [0023]      FIG. 1  depicts an isometric view of instrument  100 . Instrument  100  may be manufactured from any suitable surgically safe materials, such as, but not limited to, stainless steel, aluminum, titanium, plastics, poly(methyl methacrylate), polytetrafluorethylene, composites, or some combination thereof. A sample instrument  100  suitable for teaching and demonstration purposes may use a lightweight, transparent material, such as a transparent thermoplastic, for example poly(methyl methacrylate) in place of the standard surgical material. Instrument  100  includes a user interface  120 . Using user interface as a point of reference, instrument  100  includes elongate tubular member  102  having a distal end  104  and a proximal end  106 . User interface  120  is coupled to proximal end  106 . Instrument  100  also includes an articulating tool assembly  140  coupled to distal end  104 . User interface  120  is operatively connected to articulating tool assembly  140  by at least one cabling member  108  extending through elongate tubular member  102 . User interface  120  controls or manipulates articulating tool assembly  140  such that movement at user interface  120  is translated to articulating tool assembly  140  through cabling member  108 . It is also through cabling member  108  that the user receives the tactile feedback of the movements. Some non-limiting examples of the ratio of movement at articulating tool assembly  140  to movement at user interface  120  may be any ratio suitable for the various surgical procedures including, a 1:1 ratio up to a 4:1 ratio and all ratios therebetween to accommodate for different types of articulating tool assemblies and procedures. For example, suitable ratios include: 1:1, 1.25:1, 1.5:1, 1.75:1, 2:1, 2.25:1, 2.5:1, 2.75:1, 3:1, 3.25:1, 3.5:1, 3.75:1, 4:1, and all ratios therebetween. The desired ratio may be specified at the time of manufacture and/or adjustable within instrument  100 . The range of motion of articulating tool assembly  140  is comparable to that of the human wrist. 
         [0024]    Instrument  100  provides one-handed operation and direct tactile sensations transmitted to the user during use. Since user input or movement of user interface  120  provides corresponding movement in the same direction at articulating tool assembly  140 , instrument  100  is intuitive and easy to learn and operate. Instrument  100  will normally be used in a variety of fields where the distal end  104  and articulating tool assembly  140  will be separated from the user interface  120  by a barrier. Typically, articulating tool assembly  140  will be disposed within a cavity, for example but not limited to, an anatomical cavity (not depicted), with user interface  120  disposed external to the cavity. In a preferred embodiment, instrument  100  is used for performing open surgical procedures and endoscopic procedures such as laparoscopic and/or thorascopic surgeries on human subjects and veterinary subjects. 
         [0025]      FIGS. 2 and 8  depict exploded views of the tool end of instrument  100  including articulating tool assemblies  140 , and the user interface  120 , respectively. User interface  120  as depicted in FIGS.  1  and  8 - 12  includes handle assembly  124  operatively coupled to ball and socket assembly  128 , and a support assembly  176 . Support assembly  176  includes head casing  130 . In other embodiments, support assembly  176  also includes outer head cover  132  and guide member  134 . Support assembly  176  secures ball and socket assembly  128  within head casing  130  as shown in  FIGS. 10 and 11 . As shown in  FIG. 10 , socket assembly  128  is secured to head casing  130  by securing mechanisms such as screws, pins, dowels, snaps, etc. For clarity of the drawings, securing mechanisms are not shown. 
         [0026]    As depicted in FIGS.  8  and  11 - 12 , user interface  120  provides an attachment site for securing elongate tubular member  102  to user interface  120 . Elongate tubular member  102  may be secured to interface  120  by any convenient means including but not limited to a press fit within a bore of guide member  134  or threaded into a bore of guide member  134 . Additionally, guide member  134  provides a passage  135  for cabling members  108  to enter elongate tubular member  102 . As shown in the figures, head casing  130  has a tapered portion  131 . Guide member  134  may be positioned at any convenient location within head casing  130 . As shown in  FIGS. 11 and 12 , guide member  134  is positioned within head casing  130  where head casing  130  begins to taper. Preferably, guide member  134  is made from stainless steel and has an approximate outermost diameter ranging from about 5 mm to about 15 mm. In one embodiment the preferred outermost diameter of guide member  134  is about 11 mm. It should be appreciated that the preferred dimensions of instrument  100  will vary according to the type of surgical procedure and/or size of the patient. Elongate tubular member  102  is made from stainless steel and preferably has an outside diameter of about 5 mm to about 12 mm. In one embodiment, elongate tubular member  102  has a preferred outside diameter of about 5 mm. The length of elongate tubular member  102  ranges from about 304.8 mm to about 457.2 mm with a typical length of about 304.8 mm (12 in) depending upon the procedure to be performed. 
         [0027]    In a preferred embodiment, ball and socket assembly  128  is supported by support assembly  176 . Ball and socket assembly  128  is secured within head casing  130  as shown in  FIG. 10 . Head casing  130  is generally round in shape, but any other shape or casing capable securing ball and socket assembly  128  is suitable for the claimed invention. Handle assembly  122  is directly coupled to ball and socket assembly  128  by protruding arm  139   b  for direct transference of movement of handle assembly  122  to the articulating tool assembly  140  via cabling member  108 . 
         [0028]    As depicted in  FIGS. 8-12 , ball and socket assembly  128  is positioned within support assembly  176 . Ball and socket assembly  128  includes ball  138 , depicted in  FIGS. 8 ,  9 ,  11  and  12 . Ball  138  is generally spherical in shape. Ball  138  has a central bore  137  thereby allowing cabling members  108   e  and  108   f  to pass therethrough and into elongate tubular member  102 . Ball  138  has top, bottom, left, and right protruding arms  139   a ,  139   b ,  139   c , and  139   d , respectively. In a preferred embodiment, protruding arms  139  are cylindrical in shape; however, arms  139  can be any suitable shape for coupling cabling member  108  to ball  138 . Each protruding arm  139  provides an attachment point for one cabling member  108  ( 108   a ,  108   b ,  108   c , and  108   d ). In one embodiment ball  138  has a diameter of about 15 mm to about 25 mm. In one embodiment, the diameter of ball  138  is about 18 mm-about 19 mm. Ball  138  is made surgically safe material. In one embodiment, ball  138  is made of stainless steel, in other embodiments ball  138  is made of polytetrafluorethylene. 
         [0029]    Cabling members  108  are made of a material that is strong and surgically safe. Suitable material includes, but is not limited to, 304 stainless steel nylon coated cable. Any similar component suitable for operatively coupling user interface  120  with articulating tool assembly  142  will perform satisfactorily in the current invention, such similar component can be used in, for example, non-surgical procedures such as training or demonstrative purposes. In the depicted embodiments, cabling members  108  are pre-tensioned cables each having swage balls  107  attached on the ends. Cabling members  108  may be directly attached to arms  139 , including, but not limited to, tying, solding, or other suitable direct attachments. Alternatively, any suitable securing device known in the art, for example, bolts, pins, buttons, press-fitted pins, and screws or any similar component suitable for securing cabling member  108  to protruding arm  139  will perform satisfactorily in the current invention. In a preferred embodiment, cabling member  108  is secured to protruding arms  139  as shown in  FIGS. 8-12  by spring tension assembly  162 . Spring tension assembly  162  is carried by protruding arms  139 . Spring tension assembly includes a spring  164  and a cable stopper  166 . Spring  164  carries cable stopper  166 . Cable member  108  is disposed within spring  164  of spring tension assembly  162  as shown in  FIGS. 9-11 . Cable stopper  166  has a recessed cavity, similar to cable termination points  109 , to receive swage ball  107  thereby securing cable  108  to arm  139 . Cable stopper  166  is made of surgically safe material, including, for example, stainless steel. Spring tension assembly  162  provides sufficient tension in cabling members  108  to compensate for minor cable length differences as ball  138  moves, to compensate for cable length tolerances, and to compensate for cable stretch or wear on cabling members during use of instrument  100 . Protruding arms  139  also have guide grooves  141  as depicted in  FIGS. 9-11  to guide cabling members  108 . 
         [0030]    Referring to  FIGS. 8-12 , ball  138  is disposed within a generally spherical cavity formed by socket members  136   a ,  136   b  of socket  136 . Assembled socket  136  has openings  170  for protruding arms  139   a ,  139   b ,  139   c , and  139   d  to extend through to define the range of movement for ball  138  and permit unobstructed movement of ball  138  within socket  136 . This configuration provides the optimal range of movement for ball  138 . As discussed above, this range of movement translates directly to articulating tool assembly  142 . 
         [0031]    In one embodiment shown in  FIG. 10 , top and bottom openings  170   a ,  170   b  (only one depicted) of socket  136  through which top and bottom protruding arms  139   a ,  139   b  project are generally elliptical in shape thereby restricting the range of motion of the top and bottom protruding arms  139   a  and  139   b . Openings  170   c ,  170   d  through which left and right protruding arms  139   c ,  139   d  project are generally rectangular in shape thereby permitting a full range of left and right movement of arms  139   c  and  139   d  with respect to the location of the top and bottom protruding arms  139   a ,  139   b.    
         [0032]    As shown in  FIGS. 9-12 , socket  136  has elevated surfaces  163  to guide and support cabling members  108  as cabling members are channeled through passage  135  of guide member  134 . The dimensions and material of socket  136  can vary per application; in one embodiment socket  136  is made of stainless steel, in other embodiments socket  136  is made of polytetrafluorethylene. As shown in  FIG. 8 , socket  136  is depicted as two pieces secured together via securing mechanisms (not shown) such as screws, pins, snaps, dowels, etc. Depending on the application, the dimensions of socket  136  can vary. Socket  136  may have outermost dimensions of about 25 mm-about 30 mm long, about 25 mm-about 30 mm wide, and about 25 mm-about 30 mm high. As shown in  FIG. 10 , socket  136  is secured to head casing  130  by securing mechanisms (not shown) such as screws, pins, dowels, etc. 
         [0033]    As shown in  FIGS. 8-12 , outer head cover  132  covers the tapered portion  131  of head casing  130 . Outer head cover  132  can be secured to head casing  130  by any suitable mechanism for securing outer head cover  132  to head casing  130 . In one embodiment, outer head cover  132  is snapped into place against head casing  130 . In another embodiment, outer head cover  132  is pushed against head casing  130  over the tapered portion  131  and twisted (rotated about longitudinal axis  159 ) into a final position as the tapered portion contains a thread for receiving and coupling with outer head cover  132 . Such a configuration increases strength of the connection point and improves clamping on elongate tubular member  102 . 
         [0034]    In a preferred embodiment, handle assembly  122  includes grip member  124  and lever member  126  pivotally coupled to grip member  124  at pivot point  110   a . Preferably, grip member  124  and lever member  126  are ergonomically designed to comfortably fit within the surgeon&#39;s hand. Grip member  124  is about 100 mm-150 mm tall, about 30 mm-50 mm wide at its widest point, and 100 mm-130 mm long. Grip member is made of materials suitable for use in surgery. In one embodiment, grip member  124  is made of polytetrafluorethylene. Lever member  126  is made of the same materials of grip member  124 ; in alternative embodiments, lever member  126  and grip member  124  are different materials. 
         [0035]    Lever member  126  actuates the opening and closing of tip assembly  142 . Movement of lever member  126  clockwise and counterclockwise about pivot point  110   a  causes tip assembly  142  to move between fully closed and fully open, and all positions therebetween. 
         [0036]    Grip member  124  is directly coupled to ball  138  at bottom protruding arm  139   b , thereby directly translating movement of handle assembly  122  to ball and socket assembly  128 . As shown in  FIGS. 8 ,  11  and  12 , protruding arm  139   b  extends down into the handle assembly  122  and has a retention mechanism  145  which is positioned within a complimentary-shaped cavity  147  for receiving retention mechanism  145 . Retention mechanism may be made of any suitable low friction material and any suitable shape that will enable the retention mechanism to fit snugly within a complimentary-shaped cavity  147 . In the depicted embodiment shown in  FIGS. 8 and 11 , retention mechanism  145  is shaped as a rectangular prism and the complimentary-shaped cavity  147  is shaped to receive a rectangular prism. Suitable low friction materials for retention mechanism provide the user with a smooth or more fluid-like tactile sensation. Use of high friction materials will impart a sticking sensation and/or erratic movements at the user interface  120  precluding the desired tactile sensations. 
         [0037]    User interface  120  is made of surgically safe materials, in one embodiment user interface utilizes stainless steel, aluminum, titanium, plastics, composites, and combinations thereof. The length of user interface  120  is approximately 120 mm to about 175 mm with a preferred length of about 146 mm and a height of about 110 mm to about 200 mm with a preferred height of about 150 mm and width ranging from about 30 mm to about 70 mm and a preferred width of approximately 46 mm. Again, the dimensions of instrument  100  will vary per application. 
         [0038]    In a preferred embodiment, articulating tool assembly  140  includes interchangeable tip assembly  142  and dual hinge member  148 . Depending on the intended use of instrument  100 , tip assembly  142  may be selected from any of the following non-limiting examples: graspers, dissectors, scissor and blade tip assemblies. To provide cauterization capabilities, one of the cabling members  108  or an additional wire (not shown) provides an electrical current to the distal end  143  of tip assembly  142 . For cauterization purposes, the material forming the distal end  143  of tip assembly  142  responds to the electrical current by producing heat sufficient to cauterize tissue. Except with regard to the distal end  143  of tip assembly  142 , the remaining portion of instrument  100 , which comes into contact with tissue, will be insulated to protect the surrounding tissue from injury. 
         [0039]      FIGS. 1-6  depict a grasper embodiment of tip assembly  142 . As shown, tip assembly  142  includes a moving member  144  pivotally connected to base member  146  at pivot point  110   b  with pivot fastener  160   b . Pivot fasteners  160  can be any fastener, suitable for operatively connecting the various components which are pivotally connected. Fasteners such as snap fasteners, dowels, rods, bolts, pins, buttons, press-fitted pins, screws, or any similar component will perform satisfactorily in the current invention. Modified versions of the exemplary fasteners include a fastener having a central bore passing perpendicularly therethough along either the horizontal or vertical axis of the fastener will perform satisfactorily in the current invention. As shown in  FIG. 2 , pivot fastener  160   b  is a smooth type fastener, such as, but not limited to, a dowel, rod, pin, press-fitted pin, etc. and pivot fasteners  160   c  and  160   d  are capable of being fastened to another object via a snapping mechanism. 
         [0040]    To open tip assembly  142 , the user will move actuating lever member  126  clockwise with respect to pivot point  110   a  when viewing instrument  100  as depicted in  FIGS. 1 and 11 . Conversely, to close tip assembly  142 , the user will move actuating lever member  126  counterclockwise with respect to pivot point  110   a  when viewing instrument  100  as depicted in  FIGS. 1 and 11 . As shown in  FIG. 1 , the neutral position for tip assembly  142  is closed. In one embodiment, as shown in  FIGS. 11 and 12 , a user&#39;s hand will grasp handle assembly  122  with the user&#39;s thumb positioned within thumb hole  127  of the lever member  126 . Depending on the user&#39;s comfort, the user can optionally place one or more fingers within finger hole  125  on grip member  124 . To open tip assembly  142 , the user will press his/her thumb against the structure of lever member  126  defining thumb hole  127  causing lever member  126  to rotate clockwise about pivot point  110   a . The motion the user will make to open tip assembly is akin to making a “thumbs up” or a hitchhiking thumb hand gesture. 
         [0041]    In the embodiment where instrument  100  is equipped with cautery capabilities, a control mechanism (not depicted), such as a button, switch, plug, or other actuation device for initiating and terminating the cautery feature is located on the grip member  124  near finger hole  125 . The control mechanism for the cautery feature may also be elsewhere on instrument  100 . 
         [0042]    In a preferred embodiment, lever member  126  and tip assembly  142  are operatively connected via cabling member  108 . A single cabling member is suitable for operatively connecting lever member  126  and tip assembly  142 . A preferred embodiment is depicted in  FIGS. 7 ,  11  and  12  with two cabling members  108   e  and  108   f  operatively connecting lever member  126  and tip assembly  142 . Use of two cabling members to open tip assembly  142  provides for sufficient tension for opening, as well as provides the user with a more fluid/smooth (e.g. not jerk-like) tactile feedback, when opening and closing tip assembly  142 . 
         [0043]    As shown in  FIGS. 7 ,  8 , and  11 - 12 , cabling members  108   e  and  108   f  are positioned on opposite sides of lever pivot member  129 . Lever pivot member  129  has a circumferential groove and cable guide grooves  141  for receiving and guiding cabling members  108   e  and  108   f  along the circumference of lever pivot member  129  during actuation. Referring to  FIG. 7  in combination with  FIGS. 11 and 12 , cabling members  108   e  and  108   f  extend up through grip member  124  and through a central bore  137  in ball  138  and through elongate tubular member  102  (along the longitudinal axis  159 ). Referring now to  FIG. 7  in combination with  FIGS. 2-6   b , cabling members  108   e  and  108   f  are positioned within circumferential guide grooves  141  on moving member  144  and are secured to cable termination points  109   e  and  109   f  via swaged balls  107 . Thus, actuating lever member  126  causes moving member  144  of tip assembly  142  to move in relation to base member  146  about pivot point  110   b.    
         [0044]    Spring tension assembly  162  provides the securing mechanism of cabling members  108   e  and  108   f  to lever pivot member  129 . For brevity, the description of spring tension assembly  162  described will not be repeated here. 
         [0045]    Precise and controlled movements during surgical procedures are paramount to ensuring the patient&#39;s safety and reducing unnecessary injuries and/or death. One embodiment of routing for cabling members  108  is shown in the figures. To provide precise, smooth, non jerk-like, and/or controlled movements, cabling members  108  extend as close as possible through the longitudinal axis  159  of elongate tubular member  102 . As shown in  FIGS. 5   a ,  5   b ,  6   a , and  6   b , tip assembly  142 , dual hinge member  148 , and elongate guide member  154  are configured to align the appropriate cabling members through a central passageway  157  defined by at least one cable alignment surface  156 ,  158 , through cable guide grooves  141  (e.g. within tip assembly  142 ), and/or position cables along cable alignment surfaces  156 ,  158 . Such cabling configuration precludes entanglement with adjacent cabling members  108 , provides for sufficient tension and/or pull on the respective cabling members during operation thereby preventing the instrument from becoming “locked” and/or causing errant or unexpected movements in the articulating tool assembly  140 . 
         [0046]    Turning now to  FIGS. 2-6   b , in one embodiment articulating tool assembly  140  also includes elongate guide member  154 . As depicted in the  FIG. 2 , elongate guide member  154  is depicted as a separate piece that connects to elongate tubular member  102  and dual hinge member  148 . In another embodiment (not depicted), elongate guide member  154  and elongate tubular member  102  are an integral single component. 
         [0047]    Referring to  FIGS. 2-6   b , dual hinge member  148  has a first side  150  and a second side  152 . First side  150  of dual hinge member  148  is an outwardly projecting surface as shown in  FIG. 2 . Dual hinge member is generally hollow and has a central passageway  157  passing therethrough to allow cabling members  108  to be routed through the center of dual hinge member. The central passageway  157  is defined by cable alignment surfaces  158  of dual hinge member  148 . Tip assembly  142  and elongate guide member  154  are pivotally coupled to dual hinge member  148  at pivot points  110   c  and  110   d , respectively. The depicted coupling provides a snap pivot point. Any type of pivot mechanism is suitable so long as the desired effect is achieved and appropriate tension on cabling members  108  is achieved. As shown in  FIGS. 2-4 , tip assembly  142 , specifically base member  146  has an outwardly projecting flexible tab  149  capable of receiving pivot fastener  160   c . As shown in  FIG. 2 , pivot fastener  160   c  projects out (up and down) from the first side  150  of dual hinge member  148 . Pivot fastener  160   c  is an outwardly projecting connecting surface capable of being received by outwardly projecting tab  149  of base member  146 . As used herein the outwardly projecting flexible tab is a component that flexes around an object or post and returns to its original position thereby connecting one component to another. 
         [0048]    As depicted in  FIG. 2 , the operative coupling of base member  146  with dual hinge member  148  permits lateral movement, i.e. left and right movement, of tip assembly  142  with respect to the longitudinal axis  159  of elongate tubular member  102  as depicted in  FIG. 2 . For example, cabling members  108   c  and  108   d , shown in  FIGS. 4 ,  6   a ,  6   b ,  7 , and  9 - 12  operatively connect to the left and right protruding arms  139   c ,  139   d , respectively, of ball  138 . From the perspective of looking down instrument  100  from user interface  120 , when a user moves handle assembly  122 , for example, twisting or rotating clockwise or counterclockwise, or right or left with respect to longitudinal axis  159  of elongate tubular member  102 , the tip assembly  142  laterally pivots about point  110   c.    
         [0049]    As shown in  FIGS. 5   a ,  5   b ,  6   a , and  6   b  cable alignment surface  158  of elongate guide member  154  and cable alignment surface  156  of dual hinge member  148  define a central passageway  157  through elongate guide member  154  and dual hinge member  148 , respectively. Central passageway  157  guides passive cabling members through pivot points  110   d  and  110   c , to prevent any change in length of the cable, and also guides active cabling members away from the pivot point to prevent active cabling members from crossing over longitudinal axis  159  and causing tip assembly  142  to “lock up” or become stuck in a position. If instrument  100  becomes “locked,” instrument  100  is unable to return to a neutral position (as shown in  FIG. 1 ) or capable of being moved to another position, or capable of having full range of motion and/or smooth, tactile, non jerk-like movements. 
         [0050]    As used herein passive cabling members are cabling members passing through a pivot point, active cabling members are cabling members pulled to bend at a specific pivot point. As will be described below, whether a cabling member  108  is active or passive is determined by the movement imparted to articulating tool assembly  140  by user interface  120 . For example, referring to  FIGS. 5   a  and  5   b , cabling members  108   a ,  108   b ,  108   e , and  108   f  are shown. Due to the cross section of  FIGS. 5   a  and  5   b , cabling members  108   c  and  108   d  are not depicted. As shown in  FIGS. 5   a  and  5   b , cabling members  108   e  and  108   f  are considered passive cabling members as they are guided through pivot point  110   d . Although not depicted, cabling members  108   c  and  108   d  are also passive cabling members through pivot point  110   d . As shown in  FIG. 5   b , as the tool end is manipulated, passive cabling members are guided along the cable alignment surface  156  to dual hinge member  148  and tip assembly  142  in such a manner as to prevent any change in length in the cabling members thereby preventing any undue tension on the passive cable members and preventing any errant movements in the tip assembly  142 . In  FIG. 5   b , active cabling members are cabling members  108   a  and  108   b . Cabling members  108   a  and  108   b  are directed away from the pivot axis and guided toward the exterior of cable alignment surface  156  and secured to dual hinge member  148  at cable termination points  109   a  and  109   b . As shown in  FIG. 5   b , cabling member  108   a  is being pulled by user interface  120  thereby causing the articulating tool assembly to move up with respect to longitudinal axis  159  of elongate tubular member  102 . 
         [0051]    Referring to  FIGS. 5-6 , cabling members  108   c ,  108   d ,  108   e , and  108   f  continue onward from elongate guide member  154  until they arrive at their respective cable termination points  109 . In  FIGS. 6   a  and  6   b , dual hinge member  148  also has cable alignment surface  158 . As shown in  FIG. 6   b , cabling members  108   e  and  108   f  are still passive cabling members and are guided to tip assembly  142  to their respective cable termination points  108   e  and  108   f  by central passage  157 . In  FIG. 6   b , cabling members  108   c  and  108   d  are active cabling members and are guided away from passing though the center of pivot point  110   c . As shown in  FIG. 6   b , cabling members  108   c  and  108   d  are guided along the exterior walls of cable alignment surface  158  to cable termination points  109   c  and  109   d , respectively. As shown in  FIG. 6   b , cabling member  108   c  is being pulled by user interface  120  thereby causing articulating tool assembly  140  to move left with respect to longitudinal axis  159  of elongate guide member  102 . 
         [0052]    Preferably, cable alignment surfaces  156  and  158  are smooth surfaces without any sharp edges in order to reduce friction and wear on the cabling members. Cable alignment surfaces can be beveled, rounded, or any other contoured surface suitable for guiding active and passive cabling members will perform satisfactorily in the current invention. 
         [0053]    At the tool end, cabling members  108  are received within cable termination points  109 . Other ways to secure the terminated end of the cable are envisioned, and any method capable of maintaining the desired tension for proper operation of instrument  100  will perform satisfactorily in the current invention. For example, cabling members may be secured to the termination point  109  via adhesive, tying, and/or by use of nuts and other fasteners, or press fitted. As shown in  FIGS. 1-7 , cabling members  108  have a swaged ball  107  attached to the ends of cabling members  108 . In the handle assembly, swaged ball  107  is received by cable stopper  166 . 
         [0054]    Pivot point  110   d  controls vertical movement, i.e. up and down movement, with respect to the longitudinal axis  159  of elongate tubular member  102 . As depicted in  FIGS. 2-4 , elongate guide member  154  is pivotally connected to the second side  152  of dual hinge member  148 . Similar to the base member  146 , the second side  152  of dual hinge member  148  is an outwardly projecting flexible tab capable of receiving pivot fastener  160   d  of elongate guide member  154 . The outwardly projecting flexible tab is depicted in  FIG. 2  running along longitudinal axis  159 . Like the connection between dual hinge member  148  and tip assembly  142 , the connection between elongate guide member  154  and dual hinge member  148  is a snap pivot. Elongate guide member  154  connects to dual hinge member  148  by an outwardly extending connecting surface  160   d  as shown in  FIG. 2 . As shown in  FIG. 2 , the outwardly projecting connecting surface  160   d  is capable of being received by the outwardly projecting tab  152  of dual hinge member  148 . 
         [0055]    For example, cabling members  108   a  and  108   b , shown in  FIGS. 4 ,  6   a ,  6   b ,  7 , and  9 - 12 , operatively connect the top and bottom protruding arms  139   a ,  139   b , respectively, of ball  138  to dual hinge member  154 . As discussed above, the configuration of openings  170   a ,  170   b ,  170   c , and  170   d  define the limits of movement for protruding arms  139 . Thus, operation of handle assembly  122 , for example forwards or backwards along longitudinal axis  159  of elongate tubular member  102 , the tip assembly  142  vertically pivots about point  110   d . Such manipulation translates down cabling members  108   a  and  108   b  causing dual hinge member  148  to vertically pivot about point  110   d . As already discussed, socket  136  has openings  170  to allow for protruding arms  139  to move unobstructed within a defined area. Vertical movement occurs as a result of the position of top and bottom protruding arms  139   a  and  139   b , respectively. 
         [0056]    It should be appreciated that the orientation of the outwardly extending tab  149  of base member  146 , the first side  156  of dual hinge member  148 , the second side of dual hinge member  152 , and elongate guide member  154  are not limited to configuration described above or shown in the drawings. For example, pivot points  110   c  and  110   d  can provide vertical and horizontal movements, respectively. Other arrangements may be dictated by the nature of tip assembly  142  and the intended use instrument  100 . 
         [0057]    As shown in  FIGS. 1-4 , elongate guide member  154  is optionally coupled to elongate tubular member  102  by being slideably positioned within elongate tubular member  102 . When assembled elongate guide member  154  is flush with elongate tubular member  102 . In other embodiments elongate guide member  154  and elongate tubular member are a single integral component. 
         [0058]    Instrument  100  is not limited to the dimensions and types of material used and configurations described above. Such characteristics of instrument  100  will vary depending on the application or use, for example, the type of surgical procedure, e.g. human or veterinary surgical procedures; size of patient or subject; use for training such as, but not limited to, use on mannequins or cadavers; use for demonstrative purposes in various environments such as: commercial settings like trade shows; medical offices; academic settings; or private settings. It should be appreciated that any similar component suitable for satisfactorily performing the function of the corresponding component can be used in the current invention. 
         [0059]    Thus, the present invention is well adapted to carry out the objects and attain the ends and advantages mentioned above as well as those inherent therein. While certain embodiments of the invention have been described for the purpose of this disclosure, numerous changes in the construction and arrangement of parts and the performance of steps can be made by those skilled in the art, which changes are encompassed within the scope and spirit of this invention defined by the appended claims.