Abstract:
A cutting instrument comprising:
       an outer tube comprising a distal end and a proximal end;   an inner tube rotatably disposed within said outer tube, said inner tube comprising a distal end, a proximal end and a region intermediate said distal end and said proximal end, said region comprising a plurality of slits formed in said inner tube so as to render said region of said inner tube flexible; and   a bellows disposed adjacent to said plurality of slits so as to render said region of said inner tube fluid-tight.

Description:
FIELD OF THE INVENTION 
       [0001]    This invention relates to surgical apparatus and methods in general, and more particularly to surgical apparatus and methods for cutting tissue. 
       BACKGROUND OF THE INVENTION 
       [0002]    In many situations, tissue may need to be accessed at a remote surgical site, excised from the adjacent anatomy and then the excised tissue removed from the remote surgical site. By way of example but not limitation, during arthroscopic surgery, endoscopic surgery, ENT surgery, etc., relatively small visualization devices (e.g., “scopes”) and relatively small surgical tools (e.g., graspers, cutters, cauterizers, etc.) may be introduced into a restricted portion of the human body (e.g., the interior of a joint, the interior of the abdomen, the interior of a nasal passage, etc.) and then used at that location for a specific surgical procedure (e.g., to trim meniscal cartilage in a joint, to excise a tissue mass in the abdomen, to excise a tissue mass in a nasal passage, etc.). 
         [0003]    In many such surgeries, fluid may be introduced into the surgical site (and thereafter removed from the surgical site) so as to distend the anatomy for better access and/or visualization (e.g., so as to distend the knee joint for better access and/or visualization), and/or to improve visibility (e.g., so as to flush away blood), and/or to remove debris (e.g., so as to remove severed tissue by suction.) 
         [0004]    One of the surgical tools frequently employed in such surgeries is the so-called “powered shaver”. Powered shavers typically comprise an outer tube having a window, and an inner tube rotatably disposed within the outer tube and having an opening, wherein rotation of the inner tube within the outer tube causes the opening of the inner tube to repetitively sweep across the window of the outer tube, whereby to shear off tissue extending into the window of the outer tube and the opening of the inner tube. Suction is typically applied to the interior of the inner tube so as to remove the tissue sheared off by the powered shaver. 
         [0005]    Ideally, in addition to providing the aforementioned cutting action, the powered shaver is also able to provide either irrigation or suction to the remote surgical site, as desired by the surgeon, or to simultaneously provide both irrigation and suction to the remote surgical site. 
         [0006]    In one construction, irrigation fluid is supplied to the gap between the interior of the outer tube and the exterior of the inner tube so that the irrigation fluid can be used to distend the anatomy and/or flush away blood and/or debris, and the irrigation fluid (and/or blood and/or debris) is removed from the surgical site by suction which is applied to the interior of the inner tube. In this way, the powered shaver is able to provide irrigation, cutting and suction in a single device. 
         [0007]    Unfortunately, in many situations it may be desirable to form the powered shaver with a curved (i.e., non-linear) configuration. In this situation, the inner tube must be flexible in order to allow the inner tube to rotate about a curved axis (i.e., the curved axis of the outer tube), but must also be able to transmit torque along its length so as to enable cutting. 
         [0008]    One approach for forming a flexible, torque-transmitting inner tube for the powered shaver is to form the inner tube with a plurality of slits extending through the side wall of the inner tube—these slits enable the inner tube to flex as it rotates about a curved axis while still allowing torque to be transmitted along the length of the inner tube. 
         [0009]    Unfortunately, providing slits in the inner tube of a powered shaver is problematic where irrigation fluid is to be supplied to the surgical site through the gap between the interior of the outer tube and the exterior of the inner tube, and where suction is to be applied to the surgical site through the interior of the inner tube, since the slits in the inner tube effectively create a “short circuit” between the irrigation and suction lines, thereby undermining the irrigation and suction functions. Therefore, it can be problematic to provide a powered shaver which can provide irrigation, cutting and suction in a single device, and which has a curved (i.e., non-linear configuration). 
         [0010]    Also, in situations where suction is to be applied to the surgical site through the interior of the inner tube without supplying irrigation fluid to the surgical site through the gap between the interior of the outer tube and the exterior of the inner tube, the provision of slits in the inner tube may compromise suction effectiveness at the surgical site (i.e., the suction force at the distal end of the inner tube is reduced since the slits in the inner tube allow the suction source to pull through the wall of the inner tube from the gap between the interior of the outer tube and the exterior of the inner tube). 
         [0011]    A similar problem occurs where irrigation fluid is to be applied to the surgical site through the interior of the inner tube without applying suction to the gap between the interior of the outer tube and the exterior of the inner tube. 
         [0012]    Thus it would be advantageous to provide a new powered shaver which is able to provide, either independently or simultaneously, irrigation, cutting and/or suction in a single device, and which may have a curved (i.e., non-linear) configuration. Furthermore, it would be advantageous to provide a new powered shaver which may have a curved (i.e., non-linear) configuration, wherein the new powered shaver comprises an outer tube and an inner tube rotatably disposed within the outer tube, with the lumen of the inner tube being fluidically sealed from the gap between the exterior of the inner tube and the interior of the outer tube. 
       SUMMARY OF THE INVENTION 
       [0013]    The present invention comprises the provision and use of a novel powered shaver which is able to provide, either independently or simultaneously, irrigation, cutting and/or suction in a single device, and which may have a curved (i.e., non-linear) configuration. 
         [0014]    The present invention also comprises the provision and use of a new powered shaver which may have a curved (i.e., non-linear) configuration, wherein the new powered shaver comprises an outer tube and an inner tube rotatably disposed within the outer tube, with the lumen of the inner tube being fluidically sealed from the gap between the exterior of the inner tube and the interior of the outer tube. 
         [0015]    In one form of the invention, there is provided a cutting instrument comprising: 
         [0016]    an outer tube comprising a distal end and a proximal end; 
         [0017]    an inner tube rotatably disposed within said outer tube, said inner tube comprising a distal end, a proximal end and a region intermediate said distal end and said proximal end, said region comprising a plurality of slits formed in said inner tube so as to render said region of said inner tube flexible; and 
         [0018]    a bellows disposed adjacent to said plurality of slits so as to render said region of said inner tube fluid-tight. 
         [0019]    In another form of the invention, there is provided a method for cutting an object, said method comprising: 
         [0020]    providing a cutting instrument comprising:
       an outer tube comprising a distal end and a proximal end;   an inner tube rotatably disposed within said outer tube, said inner tube comprising a distal end, a proximal end and a region intermediate said distal end and said proximal end, said region comprising a plurality of slits formed in said inner tube so as to render said region of said inner tube flexible; and   a bellows disposed adjacent to said plurality of slits so as to render said region of said inner tube fluid-tight; and       
 
         [0024]    rotating said inner tube relative to said outer tube in order to cut the object. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0025]    These and other objects and features of the present invention will be more fully disclosed or rendered obvious by the following detailed description of the preferred embodiments of the invention, which is to be considered together with the accompanying drawings wherein like numbers refer to like parts and further wherein: 
           [0026]      FIG. 1  is a schematic view showing a novel powered shaver formed in accordance with the present invention; 
           [0027]      FIGS. 2 and 3  are schematic views showing the blade assembly of the powered shaver shown in  FIG. 1 ; 
           [0028]      FIGS. 4 ,  4 A and  5  are schematic views showing the outer tube of the blade assembly shown in  FIGS. 1-3 , with  FIG. 4A  being a schematic view showing the distal end of the outer tube of the blade assembly of  FIG. 4  but with the outer tube having been rotated 90 degrees about its longitudinal axis from the position shown in  FIG. 4 ; 
           [0029]      FIG. 6  is a schematic view showing the inner tube subassembly of the blade assembly shown in  FIGS. 1-3 ; 
           [0030]      FIG. 6A  is a schematic view showing the distal end of the inner tube subassembly of  FIG. 6  but with the inner tube subassembly having been rotated 90 degrees about its longitudinal axis from the position shown in  FIG. 6 ; 
           [0031]      FIGS. 7 ,  7 A and  8  are schematic views showing details of the inner tube subassembly shown in  FIGS. 1-3  and  6 ; 
           [0032]      FIGS. 8A and 8B  are schematic views showing alternative inner tubes which may be used with the inner tube subassembly shown in  FIGS. 1-3  and  6 ; and 
           [0033]      FIGS. 9 and 10  are schematic views showing an alternative form of bellows which may be utilized in the inner tube subassembly of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0034]    The present invention comprises the provision and use of a novel powered shaver which is able to provide, either independently or simultaneously, irrigation, cutting and/or suction in a single device, and which may have a curved (i.e., non-linear) configuration. 
         [0035]    The present invention also comprises the provision and use of a novel powered shaver having a curved (i.e., non-linear) configuration, wherein the new powered shaver comprises an outer tube and an inner tube rotatably disposed within the outer tube, with the lumen of the inner tube being fluidically sealed from the gap between the exterior of the inner tube and the interior of the outer tube. 
         [0036]    More particularly, and looking now at  FIG. 1 , there is shown a novel powered shaver  5  formed in accordance with the present invention. Novel powered shaver  5  generally comprises a blade assembly  10  and a handle assembly  15 . As will hereinafter be discussed in further detail, blade assembly  10  is intended to be mated to handle assembly  15  (or another handle assembly) at the time of use, and detached from handle assembly  15  (or another handle assembly) after use (e.g., for cleaning and sterilization, repair or replacement, etc.). Alternatively, blade assembly  10  may be mated to handle assembly  15  (or another handle assembly) at the time of manufacture, e.g., such as in the case of a one-piece disposable system. 
         [0037]    Blade assembly  10  is shown in greater detail in  FIGS. 2-8 . Blade assembly  10  generally comprises an outer tube  20  and an inner tube subassembly  25  rotatably disposed within outer tube  20 . 
         [0038]    Outer tube  20  is shown in greater detail in  FIGS. 2-5 . Outer tube  20  generally comprises a distal end  35 , a proximal end  40 , and a lumen  45  extending from distal end  35  to proximal end  40 . In one preferred form the present invention, outer tube  20  preferably comprises a distal end surface  48 . 
         [0039]    Outer tube  20  comprises a window  50  ( FIG. 4A ) comprising a distal edge  55 , a proximal edge  60 , a first side edge  65  and a second side edge  70 . 
         [0040]    In accordance with the present invention, outer tube  20  may be curved, e.g., as shown in  FIGS. 3 and 5 . 
         [0041]    Inner tube subassembly  25  is shown in greater detail in  FIGS. 2 ,  3 ,  6 ,  7 ,  7 A and  8 . Inner tube subassembly  25  generally comprises an inner tube  71  and a bellows  72 . 
         [0042]    Inner tube  71  comprises a distal end  75 , a proximal end  80 , and a lumen  83  extending from distal end  75  to proximal end  80 . In one preferred form of the present invention, inner tube  71  preferably comprises a distal end surface  84 . 
         [0043]    Inner tube  71  comprises an opening  85  ( FIG. 6A ) comprising a distal edge  90 , a proximal edge  95 , a first side edge  96  and a second side edge  97 . 
         [0044]    Inner tube  71  is rotatably disposed within outer tube  20  ( FIGS. 2 and 3 ) such that rotation of inner tube  71  within outer tube  20  causes opening  85  of inner tube  71  to repetitively sweep across window  50  of outer tube  20 , whereby to shear off tissue extending into window  50  of outer tube  20  and opening  85  of inner tube  71 . More particularly, as inner tube  71  is rotated within outer tube  20 , one or the other of first side edge  96  and second side edge  97  of inner tube  71  is swept across one or the other of first side edge  65  and second side edge  70  of outer tube  20 , depending on the direction of rotation of inner tube  71  relative to outer tube  20 , so as to create a shearing action at the interface of the overlapping side edges of inner tube  71  and outer tube  20 . This shearing action serves to cut away tissue extending into window  50  of outer tube  20  and opening  85  of inner tube  71 . 
         [0045]    In accordance with the present invention, in order to allow inner tube  71  to be rotated within a curved outer tube  20 , and also to transmit torque along its length so as to enable the aforementioned cutting action, inner tube  71  preferably also comprises a plurality of slits  100  ( FIGS. 7 and 7A ) which extend through the side wall of inner tube  71 . Slits  100  are provided in at least the region of inner tube  71  which flexes during rotation of inner tube  71  within curved outer tube  20 . 
         [0046]    Also in accordance with the present invention, novel powered shaver  5  is able to provide, independently or simultaneously, irrigation and/or suction to the surgical site. In one preferred form of the invention, irrigation is supplied to the surgical site through the gap  73  between the interior of outer tube  20  and the exterior of inner tube  71 , and suction is applied to the surgical site through the interior of inner tube  71  (i.e., through lumen  83 ). Alternatively, suction may be supplied to the surgical site through gap  73  (i.e., the gap between the interior of outer tube  20  and the exterior of inner tube  71 ), and irrigation may be applied to the surgical site through the interior of inner tube  71  (i.e., through lumen  83 ). 
         [0047]    In order to prevent slits  100  in inner tube  71  from creating a “short circuit” between the irrigation and suction lines, thereby undermining the irrigation and suction functions, inner tube subsassembly  25  comprises bellows  72  for effectively covering slits  100 , whereby to isolate the interior of inner tube  71  from the region exterior to inner tube  71 . 
         [0048]    More particularly, and looking now at  FIGS. 2 ,  3 ,  6 ,  7  and  8 , in one form of the invention, bellows  72  comprises an elongated structure having a distal end  105 , a proximal end  110  and a lumen  115  extending therebetween. Bellows  72  is mounted coaxially over inner tube  71 , and its distal end  105  and proximal end  110  sealingly secured to inner tube  71 , so that slits  100  in inner tube  71  are covered by bellows  72 . As a result, bellows  72  sealingly isolates lumen  83  of inner tube  71  from lumen  45  of outer tube  20 . At the same time, bellows  72  do not interfere with rotation of inner tube  71  within outer tube  20 . Bellows  72  are sized to cover at least the portion of inner tube  71  which comprises slits  100 . 
         [0049]    Thus, where gap  73  (i.e., the gap between the interior of outer tube  20  and the exterior of inner tube  71 ) is used for one of irrigation and suction, and/or where the interior of inner tube  71  (i.e., lumen  83 ) is used for the other of irrigation and suction, bellows  72  prevent slits  100  in inner tube  71  from creating a “short circuit” between the irrigation and suction lines. At the same time, inasmuch as bellows  72  do not interfere with rotation of inner tube  71  within outer tube  20 , bellows  72  do not undermine the cutting action of novel powered shaver  5 . 
         [0050]    In one preferred form of the invention, bellows  72  comprise a plurality of peaks  120  and troughs  125 , wherein peaks  120  and troughs  125  extend perpendicular to the axis of bellows  72  ( FIG. 6 ). Preferably peaks  120  are sized to contact (e.g., with a sliding fit) the interior surface of outer tube  20 . Note that the contact between peaks  120  and the interior surface of outer tube  20  may be sealing, substantially sealing or non-sealing. Alternatively, if desired, peaks  120  of bellows  72  can approach but be spaced from the interior of outer tube  20 . 
         [0051]    In one preferred form of the invention, peaks  120  preferably include notches  130  ( FIG. 8 ) for allowing fluid to easily pass between the exterior of bellows  72  and the interior of outer tube  20 , as will hereinafter be discussed. Note that notches  130  may be provided regardless of whether peaks  120  contact the interior surface of outer tube  20 . 
         [0052]    As shown in  FIG. 1 , blade assembly  10  is intended to be mated to handle assembly  15  (or another handle assembly) at the time of use, and detached from handle assembly  15  (or another handle assembly) after use (e.g., for cleaning and sterilization, repair or replacement, etc.). Alternatively, blade assembly  10  may be mated to handle assembly  15  (or another handle assembly) at the time of manufacture, e.g., such as in the case of a one-piece disposable system. 
         [0053]    Handle assembly  15  is provided with a housing  135  for securely mounting the distal end  40  of outer tube  20 , and means for coupling a drive shaft  140  to inner tube  71 , e.g., a connector  145  which is secured to inner tube  71 , whereby to drivingly rotate inner tube  71  (and its associated bellows  72 , not shown in  FIG. 1 ). Preferably connector  145  is provided with appropriate ports so that the interior of inner tube  71  is in fluid communication with a port  150 , whereby to deliver irrigation or suction from an irrigation or suction source  151  to blade assembly  10  via lumen  83  of inner tube  71 . In one preferred form of the invention, port  150  provides suction to blade assembly  10  via lumen  83  of inner tube  71 . 
         [0054]    Handle assembly  15  is also provided with a port  155  for accessing the gap between the interior of outer tube  20  and the exterior of inner tube subassembly  25 , whereby to deliver irrigation or suction from an irrigation or suction source  156  to blade assembly  10  via the gap  73  between the interior of outer tube  20  and the exterior of inner tube subassembly  25 . In one preferred form of the invention, port  155  is connected to irrigation source  156  so as to provide irrigation to blade assembly  10  via the gap  73  between the interior of outer tube  20  and the exterior of inner tube subassembly  25 . As noted above, in one preferred form of the invention, bellows  72  comprises notches  130  to allow fluid to pass easily between the exterior of bellows  72  and the interior of outer tube  20 . 
         [0055]    It should be appreciated that handle assembly  15  shown in  FIG. 1  is provided by way of example but not limitation, and other handle assemblies may be used in conjunction with blade assembly  10 . 
         [0056]    In  FIGS. 7 and 7A , slits  100  of inner tube  71  are shown as following a helical path. However, if desired, other slit configurations may be utilized. By way of example but not limitation, slits  100  may extend substantially perpendicular to the longitudinal axis of inner tube  71 . Thus, for example,  FIG. 8A  shows slits  100  extending substantially perpendicular to the longitudinal axis of inner tube  71 , with the slits being circumferentially staggered from one another.  FIG. 8B  shows slits  100  extending substantially perpendicular to the longitudinal axis of inner tube  71 , with the slits being circumferentially aligned with one another. Still other configurations will be apparent to those skilled in the art in view of the present disclosure. 
         [0057]    In another preferred form of the invention, and looking now at  FIGS. 9 and 10 , peaks  120  and troughs  125  of bellows  72  follow a helical path about the axis of bellows  72 . In this form of the invention, notches  130  may be omitted, inasmuch as fluid may pass between the exterior of bellows  72  and the interior of outer tube  20  by following the helical path of troughs  125  of bellows  72 . 
         [0058]    It should be appreciated that, by forming a helical path along the length of bellows  72  between peaks  120  and troughs  125 , bellows  72  may also act as a screw pump, i.e., as a mechanical transport. More particularly, rotation of inner tube  71  (and hence, rotation of bellows  72 ) in a first direction facilitates distal movement of material (solid or fluid) disposed in the helical path. Rotation of inner tube  71  (and hence, rotation of bellows  72 ) in a second, opposite direction facilitates proximal movement of material (solid or fluid) disposed in the helical path. Note that this movement of material (solid or fluid) in either direction is independent of (or in addition to) any irrigation or suction which may be provided to gap  73  by irrigation or suction source  156 . 
         [0059]    The novel powered shaver  5  of the present invention is a significant improvement in the art, since it is able to provide, either independently or simultaneously, irrigation, cutting and/or suction in a single device, where that device may have a curved (i.e., non-linear) configuration. 
         [0060]    The novel powered shaver  5  of the present invention also provides a device having a curved (i.e., non-linear) configuration, wherein the device comprises an outer tube and an inner tube rotatably disposed within the outer tube, with the lumen of the inner tube being fluidically sealed from the gap between the exterior of the inner tube and the interior of the outer tube. 
       Modifications of the Preferred Embodiments 
       [0061]    It should be understood that many additional changes in the details, materials, steps and arrangements of parts, which have been herein described and illustrated in order to explain the nature of the present invention, may be made by those skilled in the art while still remaining within the principles and scope of the invention.