Abstract:
A steerable laparoscopic instrument is provided. The steerable laparoscopic instrument comprises a transmission part, a first disc, a second disc, a bending part, a third disc, a working part, and a handle part. The steerable laparoscopic instrument provides surgical operation with at least two directional controls, is easily disassembled and reassembled, can be operated by a single hand, and is easily to be cleaned and sterilized.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to a laparoscopic instrument, and more particularly to a steerable laparoscopic instrument. 
       BACKGROUND OF THE INVENTION 
       [0002]    As shown in  FIG. 1 , a conventional laparoscopic instrument typically has only a single directional control, i.e., the 360 degree rotational control of tube  1  allowing the working part  2  to work at various angles. The working part  2  may be scissors, pliers, or the like. However, to adjust the working part  2  of such instrument at a proper orientation during minimally invasive surgery would be difficult due to limited operation space. 
         [0003]    Therefore, it is urgently desired in this field to develop an improved laparoscopic instrument which provides multiple directional controls for the surgeon to have maximal degree of freedom in performing minimally invasive surgery. 
       SUMMARY OF THE INVENTION 
       [0004]    Accordingly, the present invention provides a steerable laparoscopic instrument, which has at least two directional controls. The steerable laparoscopic instrument comprises a transmission part, a first disc, a second disc, a bending part, a third disc, a working part, and a handle part. 
         [0005]    The transmission part has a first end and a second end, and comprises an inner tube and an outer tube, both of which extend along a first axis. 
         [0006]    The first disc is disposed at the first end of the transmission part. The first disc is coupled with the outer tube and is used to control the rotation of the outer tube on the first axis. 
         [0007]    The second disc is also disposed at the first end of the transmission part. The second disc is coupled with the inner tube and is used to control the movement of the inner tube along the first axis. 
         [0008]    The bending part is pivotally connected to the second end of the transmission part. Further, the bending part has a sliding linkage pivotally connected thereto. The sliding linkage is coupled with the inner tube. 
         [0009]    The third disc is disposed at the first end of the transmission part. The third disc comprises a center transmission rod coupled therewith. The center transmission rod extends along the first axis. 
         [0010]    The working part is connected to the bending part. The working part extends along a second axis and has a connecting member, a third end, a fourth end and a plier-like member. The connecting member is disposed at the third end, and the plier-like member is disposed at the fourth end. Further, the working part is coupled with the third disc through the center transmission rod. 
         [0011]    The handle part is disposed at a side of the first end of the transmission part. The handle part comprises a control member and a handle. The control member is coupled with the center transmission rod and is used to control the movement of the center transmission rod along the first axis. 
         [0012]    According to the present invention, it is preferable that at least a section of the center transmission rod is of superelastic material, wherein the section is a section of the center transmission rod that has a position corresponding to the bending part. 
         [0013]    In one embodiment of the present invention, the superelastic material is a shape memory alloy. 
         [0014]    According to the present invention, the movement of the sliding linkage changes the angle between the first and second axes by moving back and forth along the first axis. 
         [0015]    In one embodiment of the present invention, the connecting member connects to the bending part through a buckle. 
         [0016]    In certain embodiments of the present invention, the handle part further comprises a locking member. The locking member is disposed at a side of the handle part and is used to lock the control member to the handle in tooth-type, cam-type or spring-type. 
         [0017]    In certain embodiments of the present invention, the opening and closing of the plier-like member is controlled by a central screw driven by an inner torsion spring or an outer torsion spring. 
         [0018]    According to one embodiment of the present invention, the steerable laparoscopic instrument further comprises a housing for accommodating the first, second and third discs. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0019]    The foregoing summary, as well as the following detailed description of the invention, will be better understood when read in conjunction with the appended drawing. In the drawings: 
           [0020]      FIG. 1  is a schematic view of a conventional laparoscopic instrument. 
           [0021]      FIG. 2  is a perspective view of a steerable laparoscopic instrument of the present invention. 
           [0022]      FIG. 3  shows the relationship between the working part and the bending part of a steerable laparoscopic instrument of the present invention. 
           [0023]      FIG. 4  illustrates the locking member of the handle part of a steerable laparoscopic instrument of the present invention. 
       
    
    
     DESCRIPTION OF THE INVENTION 
       [0024]    Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by a person skilled in the art to which this invention belongs. 
         [0025]    As used herein, the singular forms “a”, “an”, and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a sample” includes a plurality of such samples and equivalents thereof known to those skilled in the art. 
         [0026]    Referring to  FIG. 2 , shown is an embodiment of the steerable laparoscopic instrument according to the present invention. A steerable laparoscopic instrument  9  comprises a transmission part  91 , a first disc  923 , a second disc  922 , a bending part  94 , a third disc  921 , a working part  95 , a handle part  93 , and a housing  97 . 
         [0027]    The transmission part  91  extends along a first axis  913 , and includes an outer tube  912  and an inner tube  911  movably disposed inside the outer tube  912 . Both of the inner and outer tubes  911  and  912  extend along the first axis  913 . The transmission part  91  has a first end  9141  and a second end  9142 . 
         [0028]    The first disc  923  is disposed at the first end  9141  of the transmission part  91 . The first disc  923  is coupled with the outer tube  912  and is used to control (or manipulate) the rotation of the outer tube  912  on the first axis  913 . In other words, the first disc  923  is coupled with the outer tube  912  in a manner such that the rotation of the first disc  923  on the first axis  913  drives the outer tube  912  to rotate on the first axis  913  correspondingly. 
         [0029]    The second disc  922  is also disposed at the first end  9141  of the transmission part  91 . As shown in  FIG. 2 , the second disc  922  may be disposed adjacent the first disc  923 . In addition, the second disc  922  is coupled with the inner tube  911  in a manner such that the rotation of the second disc  922  on the first axis  913  drives the inner tube  911  to move along the first axis  913  correspondingly. For example, when the second disc  922  is rotated clockwise on the first axis  913 , the inner tube  911  moves correspondingly toward the direction of the second end  9142  of the transmission part  91  (to the left in  FIG. 2 ) along the first axis  913 ; and when the second disc  922  is rotated counterclockwise on the first axis  913 , the inner tube  911  moves correspondingly toward the direction of the first end  9141  of the transmission part  91  (to the right in  FIG. 2 ) along the first axis  913 . In the present embodiment, the second disc  922  is coupled with the inner tube  911  through a screw nut  9221  which is co-axial with the first axis  913 . 
         [0030]    In addition, the bending part  94  is pivotally connected to the second end  9142  of the transmission part  91 . Specifically, the bending part  94  is pivotally connected to the outer tube  912  of the transmission part  91 . A sliding linkage  941  is pivotally connected to the bending part  94 . The sliding linkage  941  is coupled with the inner tube  911 , such that the movement of the inner tube  911  along the first axis  913  drives the sliding linkage to move along the first axis  913  correspondingly. Accordingly, when rotating the second disc  922  and the screw nut  9221 , the movement of the sliding linkage causes the rotation of the bending part  94  with respect to the pivot point where the bending part  94  is pivoted to the second end  9142  of the transmission part  91 . 
         [0031]    The third disc  921  is disposed at the first end  9141  of the transmission part  91 . A center transmission rod  9211  extends along the first axis  913  is coupled with the third disc  921 . Preferably, the center transmission rod  9211  is coupled with the third disc  921  in a manner such that the rotation of the third disc  921  on the first axis  913  drives the center transmission rod  9211  to rotate correspondingly on the first axis  913 . 
         [0032]    The working part  95  is connected to the bending part  94 . The working part  95  extends along a second axis  953  and has a connecting member  951 , a third end  9541 , a fourth end  9542  and a plier-like member  952 . The connecting member  951  is disposed at the third end  9541  and the plier-like member  952  is disposed at the fourth end  9542 . The working part  95  is coupled with the third disc  921  through the center transmission rod  9211  in a manner such that the rotation of the third disc  921  on the first axis  913  drives the rotation of the working part  95  on the first axis  913  correspondingly. Put differently, the center transmission rod  9211  run through the interior of the transmission part  91 , the bending part  94  and the working part  95 , and one end of the center transmission rod  9211  is connected to the working part  95  while the other end of the center transmission rod  9211  is connected to the third disc  921 . 
         [0033]    Further, the handle part  93  is disposed at a side of the first end  9141  of the transmission part  91 . The handle part  93  includes a control member  931  and a handle  932 . The control member  931  is coupled with the center transmission rod  9211  and is used to control the movement of the center transmission rod  9211  along the first axis  913 . The movement of the center transmission rod  9211  along the first axis  913  is for the control of the opening and closing of the plier-like member  952  of the working part  95 . 
         [0034]    The steerable laparoscopic instrument  9  may further comprise a housing  97  for accommodating the first disc  923 , the second disc  922  and the third disc  921 . The housing  97  may be connected to the handle  932 . 
         [0035]    Accordingly, the outer tube  923  (along with the working part  95 ) is up to  360  degree rotatable on the first axis  913  by rotating the first disc  923 ; the transmission part  94  (along with the working part  95 ) is steerable with respect to the first axis  913  by rotating the second disc  923  (the angle between the first and second axes  913  and  953  is changed accordingly); and the working part  95  (along with the plier-like member  952 ) is up to  360  degree rotatable on the second axis  953 , independently from the rotation of the outer tube  923 , by rotating the third disc  921 . 
         [0036]    With reference to  FIG. 2  again, in accordance with one preferred embodiment of the present invention, a section of the center transmission rod  9211  having a position corresponding to the bending part  94  is of superelastic (or termed as “pseudoelastic”) material. Alternatively, the whole center transmission rod  9211  may be made of a superelastic material. The superelastic material includes but is not limited to a shape memory alloy, for example, a nickel-titanium alloy. In one embodiment of the present invention, the nickel-titanium alloy used has the following properties: (I) Mechanical properties: (a) tensile strength: 830˜1170 MPa, (b) yield strength: 200 MPa, (c) Young&#39;s modulus: 70 GPa, (d) Poisson&#39;s ratio: 0.33, and (e) hardness: 80 RB; and (II) Shape memory properties: (a) transformation temperature: −20˜+150° C.; (b) shape memory strength: 550 MPa; and (c) deformation amount: 6%. 
         [0037]    Referring to  FIG. 2 , in accordance with one embodiment of the present invention, the movement of the sliding linkage  941  moves the working part  95  in link-type and changes the angle formed between the first and second axes  913  and  953 , wherein said angle may be greater than  90  degrees. 
         [0038]    With reference to  FIG. 3 , in accordance with one embodiment of the present invention, the connecting member  951  removably connects to the bending part  94  through a buckle  9511 . The plier-like member  952  may be pliers, scissors, claws pliers or a needle holder, but is not limited thereto. 
         [0039]    Referring to  FIG. 4 , the handle part  93  further comprises a locking member  96 . The locking member  96  is disposed at a side of the handle part  93  and is used to lock the control member  931  to the handle  932  in tooth-type, cam-type or spring-type. In one preferred embodiment, the locking member  96  comprises a switch  961 , a pawl  962 , and a spring sheet  963 . In operation, when the switch  961  is not pressed, the control member  931  can only be moved in one direction and the handle part  93  is in a locked state; for a semi-unlocked state, the pawl  962  is moved away from the locking member  96  when the switch  961  is pressed, and the control member  931  can be freely moved in both directions to control the opening and closing of the plier-like member  952  with the switch  961  being continuously pressed; and when the switch  961  is pushed upward, the pawl  962  would not bounce back by spring sheet  963  since the locking member  96  is in an irreversible position, and thus the handle part  93  is in an unlocked state. 
         [0040]    In one embodiment of the present invention, the opening and closing of the plier-like member  952  is controlled by a central screw driven by an inner torsion spring or an outer torsion spring. 
         [0041]    In the development of the present invention, considering the relevance between manipulation and transmission under displacement controlled design, the durability under elastic deformation, wear resistant shape design, assembly processing costs and mechanism durability, the difficulties on the small mechanism space, space limitation and durability of the transmission transition and whether a complicated mechanism can be easily disassembled and reassembled were overcome, and the following advantages were achieved: small limitation on the steering angle, multiple rotation/steering functions, convenience on disassembling, cleaning and replaceability, and high durability. 
         [0042]    It is believed that a person of ordinary knowledge in the art where the present invention belongs can utilize the present invention to its broadest scope based on the descriptions herein with no need of further illustration. Therefore, the descriptions and claims as provided should be understood as of demonstrative purpose instead of limitative in any way to the scope of the present invention.