Patent Publication Number: US-11660101-B2

Title: Surgical instrument with articulating region

Description:
PRIORITY CLAIM 
     This a continuation of co-pending U.S. application Ser. No. 15/553,825, filed Feb. 26, 2016, which is a national stage entry of International Patent Application No. PCT/US2016/019880, filed Feb. 26, 2016, which claims priority to and all the benefits of U.S. Provisional Patent Application No. 62/121,265, filed Feb. 26, 2015, and U.S. Provisional Patent Application No. 62/121,080, filed Feb. 26, 2015, the entire contents of each are hereby incorporated by reference. 
    
    
     TECHNICAL FIELD 
     The present invention relates generally to surgical instruments and, more particularly to, a surgical instrument with tube articulation and illumination for use on patients. 
     BACKGROUND 
     It is known that medical practitioners have found it useful to use surgical instruments to assist in the performance of surgical procedures. A surgical instrument is designed to be applied to a surgical site on the patient. The practitioner is able to position the surgical instrument at the site on the patient at which the instrument is to perform a medical or surgical procedure. Today many procedures such a lateral and central foramenal decompression must be performed by removing considerable healthy tissue, specifically the lamina and the facet joints, just to access the portion of the foramen that is impinging the neural elements. This added morbidity is because the surgeons do not have tools that enable them to visualize or remove the impingement any other way. 
     Many articulating devices have been developed for use in surgical procedures. They are valuable because they facilitate reduced incision size, improved access and visibility, while enhancing surgical outcome and quicker recovery. Some articulate at a single hinge joint creating an abrupt angle at that location. While suitable for some applications, a hinge joint is not suitable for many applications such as those which require tissue extraction or rotary or reciprocating power transmission through a region of articulation. These and other applications require a more gradual curve to their articulation. Devices with such a gradual curve are generally constructed of multiple segments which shift or flex with respect to each other to accomplish the gradual curve. Many of these devices available today are extremely complicated assemblies with dozens of tiny moving parts, requiring painstaking assembly and considerable expense to maintain. One limitation to such multi-segment articulation devices is their lack of stiffness. A force applied off axes from the device can cause the device to shift slightly as the segments shift with respect to one another. This type of “snaking” movement is acceptable in certain application such as steerable endoscopes or steering catheters, but in others such as power-tool applications such as shavers or burs, such movement would result in highly undesirable poor control and stability. 
     Further, during arthroscopic surgery, there are occasions where bone needs to be removed from an area of anatomy of the patient that is difficult to access using a straight tool. For example, during an Anterior Interior Illicac Spine (AIIS) pincer removal in the hip, it can be difficult to access the AIIS region using traditional hip arthroscopy portal placements and straight tools. Additionally, the Psoas canal region of the hip is difficult to access using a straight tool. 
     For both of the above cases, an angled bur is potentially more useful than a straight bur. However, angled burs are difficult to almost impossible to insert down a standard hip arthroscopy cannula depending on the degree of angle of the tool. In this case, it would be desirable to have an articulating bur which can be toggled from straight to angled by the surgeon. However, this would require the bur to be rigid enough to allow the bur head to be pressed against the bone to enable fast debridement. 
     In addition, line of sight is a common limitation in the surgical field. The surgical site is often enlarged in order to improve the surgeon&#39;s line of sight. This enlarging of the surgical site results in significant collateral damage, pain, and longer recovery times for the patient. An endoscope goes a long way to address these issues and has moved the surgeon&#39;s point of view from outside the surgical site to inside the patient. Angled tipped endoscopes and articulating endoscopes have further changed the surgeon&#39;s point of view by enabling off axis viewing, or a view that is no longer along a central axis of a rigid scope shaft. 
     In many situations, as a surgical instrument is introduced to the surgical site, the distal end of the instrument, and the tissue it contacts, is not visible to the surgeon because the instrument itself obstructs the surgeon&#39;s view. Curved instruments and articulating instruments are capable of reaching and working around corners, but because the surgeon&#39;s line of sight is limited to a straight line, the safety and effectiveness of these tools is limited. 
     While the traditional or open endoscopic techniques used today by surgeons provide a “global view” of the surgical site, there is a need to provide a secondary “local view” that is otherwise not available to the surgeon. Further, in some cases, the surgical site can be difficult to illuminate sufficiently. Therefore, there is a need in the art to provide a surgical instrument having tube articulation and illumination for use on a patient. 
     SUMMARY 
     Accordingly, the present invention provides a surgical instrument including an articulating tube assembly having a proximal end and a distal end, an articulating region disposed between the proximal end and the distal end, and a proximal axis axially extending from the proximal end to the articulating region. The articulating tube assembly includes an inner tube and an outer tube each having the articulating region. The inner tube and the outer tube are movable relative to each other proximal to the articulating region and fixed axially relative one another distal to the articulating region. The surgical instrument also includes an actuation assembly coupled to the articulating tube assembly for moving the inner tube and the outer tube axially relative to each other for articulating the articulating region of the articulating tube assembly between a first configuration and a second configuration. The articulating region is rigid in the first configuration and the second configuration. 
     The present invention also provides a surgical instrument including an articulating tube assembly having a proximal end and a distal end, an articulating region disposed between the proximal end and the distal end, and a proximal axis axially extending from the proximal end to the articulating region. The articulating tube assembly includes an inner tube and an outer tube each having the articulating region. The inner tube and the outer tube are movable relative to each other proximal to the articulating region and fixed axially relative one another distal to the articulating region. The surgical instrument also includes an actuation assembly coupled to the articulating tube assembly for moving the inner tube and the outer tube axially relative to each other for articulating the articulating region of the articulating tube assembly between a first configuration and a second configuration in only a single plane. The surgical instrument further includes a viewing assembly coupled to the articulating tube assembly for allowing an operator to view the distal end of the articulating tube assembly and an illumination assembly coupled to the articulating tube assembly for providing illumination to the distal end of the articulating tube assembly. 
     The present invention further provides a surgical instrument including an articulating tube assembly having a proximal end and a distal end, an articulating region disposed between the proximal end and the distal end, and a proximal axis axially extending from the proximal end to the articulating region. The articulating tube assembly includes an inner tube and an outer tube each having the articulating region. The inner tube and the outer tube are movable relative to each other proximal to the articulating region and fixed axially relative one another distal to the articulating region. The surgical instrument also includes an actuation assembly coupled to the articulating tube assembly for moving the inner tube and the outer tube axially relative to each other for articulating the articulating region of the articulating tube assembly between a first configuration and a second configuration in only a single plane. The surgical instrument further includes a torque member disposed within the inner tube, a rotatable end effector disposed distal of the articulating region and coupled to the torque member, and a driveshaft coupled to the torque member and adapted to be coupled to a drive assembly to drive the torque member and the rotatable end effector. 
     In addition, the present invention provides a method of operating a surgical instrument including the steps of providing an articulating tube assembly having a proximal end and a distal end, an articulating region disposed between the proximal end and the distal end, and a proximal axis axially extending from the proximal end to the articulating region. The articulating tube assembly includes an inner tube and an outer tube each having the articulating region. The inner tube and the outer tube are movable relative to each other proximal to the articulating region and fixed axially relative one another distal to the articulating region. The method also includes the steps of providing an actuation assembly coupled to the articulating tube assembly, rotating a rotation assembly of the actuation assembly with one hand of a user and, moving with one hand of the user the inner tube and the outer tube axially relative to each other for articulating the articulating region of the articulating tube assembly between a first configuration and a second configuration in only a single plane. 
     Other features and advantages of the present invention will be readily appreciated, as the same becomes better understood, after reading the subsequent description 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a perspective view of one embodiment of a surgical instrument, according to the present invention, illustrated in operational relationship with a surgical tool. 
         FIG.  2    is an exploded view of the surgical instrument, a tool view assembly, and one or more surgical tools for the surgical instrument of  FIG.  1   . 
         FIG.  3    is an end view of the surgical instrument of  FIG.  1   . 
         FIG.  4    is a sectional view taken along line  4 - 4  of  FIG.  3   . 
         FIG.  5    is a sectional view taken along line  5 - 5  of  FIG.  4   . 
         FIG.  6    is a top view of an articulating region of a tube assembly of the surgical instrument of  FIG.  1   . 
         FIG.  7    is a side view of an articulating region of the tube assembly of the surgical instrument of  FIG.  1   . 
         FIG.  8    is a bottom view of an articulating region of the tube assembly of the surgical instrument of  FIG.  1   . 
         FIG.  9    is a sectional view taken along line  9 - 9  of  FIG.  8   . 
         FIG.  10    is a sectional view taken along line  10 - 10  of  FIG.  8   . 
         FIG.  11    is an exploded view of the tube assembly of the surgical instrument of  FIG.  1   . 
         FIG.  12    is a perspective view of an articulating region of an inner tube of the tube assembly of  FIG.  11   . 
         FIG.  13    is a top view of an articulating region of an inner tube of the tube assembly of  FIG.  11   . 
         FIG.  14    is a side view of an articulating region of an inner tube of the tube assembly of  FIG.  11   . 
         FIG.  15    is a bottom view of an articulating region of an inner tube of the tube assembly of  FIG.  11   . 
         FIG.  16    is a perspective view of an articulating region of an outer tube of the tube assembly of  FIG.  11   . 
         FIG.  17    is a top view of an articulating region of an outer tube of the tube assembly of  FIG.  11   . 
         FIG.  18    is a side view of an articulating region of an outer tube of the tube assembly of  FIG.  11   . 
         FIG.  19    is a bottom view of an articulating region of an outer tube of the tube assembly of  FIG.  11   . 
         FIG.  20    is a top view of the tube assembly of the surgical instrument of  FIG.  11   . 
         FIG.  21    is a sectional view taken along line  21 - 21  of  FIG.  20   . 
         FIG.  22    is an enlarged view of a portion in circle  22  of  FIG.  21   . 
         FIG.  23    is a perspective view of a handle of the surgical instrument of  FIGS.  1  and  2   . 
         FIG.  24    is a sectional view of the handle of  FIG.  23   . 
         FIG.  25    is a perspective view of an upper trigger for the surgical instrument of  FIGS.  1  and  2   . 
         FIG.  26    is a perspective view of a lower trigger for the surgical instrument of  FIGS.  1  and  2   . 
         FIG.  27    is a perspective view of a portion of a tool view assembly of the surgical instrument of  FIGS.  1  and  2   . 
         FIG.  28    is a perspective view of an end of a tool view assembly of the surgical instrument of  FIGS.  1  and  2   . 
         FIG.  29    is a top view of another embodiment, according to the present invention, of the surgical instrument of  FIGS.  1  and  2   . 
         FIG.  30    is an end view of the surgical instrument of  FIG.  29   . 
         FIG.  31    is a sectional view taken along line  31 - 31  of  FIG.  30   . 
         FIG.  32    is a sectional view taken along line  32 - 32  of  FIG.  30   . 
         FIG.  33    is an exploded perspective view of an actuation assembly of the surgical instrument of  FIGS.  29 - 32   . 
         FIG.  34    is a perspective view of the surgical instrument of  FIG.  28    illustrated in operational relationship with a working tool. 
         FIG.  35    is a sectional view of the surgical instrument and working tool of  FIG.  34   . 
         FIG.  36    is a perspective view of the working tool of  FIGS.  34  and  35   . 
         FIG.  37    is a sectional view of the working tool of  FIGS.  34  through  36   . 
         FIG.  38    is an enlarged view of a distal end of the working tool of  FIGS.  34  through  36   . 
         FIG.  39    is a perspective view of the distal end of the working tool of  FIGS.  34  through  36   . 
         FIG.  40    is a perspective view of yet another embodiment, according to the present invention, of the surgical instrument. 
         FIG.  41    is a cross-sectional view of the surgical instrument of  FIG.  40   . 
         FIG.  42    is an enlarged view of a distal end of the surgical instrument of  FIG.  41   . 
         FIG.  43    is an enlarged view of a proximal end of the surgical instrument of  FIG.  41   . 
         FIG.  44    is a perspective view of a proximal bearing of the surgical instrument of  FIG.  41   . 
         FIG.  45    is a perspective view of a driveshaft of the surgical instrument of  FIG.  41   . 
         FIG.  46    is still another embodiment, according to the present invention, of the surgical instrument illustrating a locking assembly. 
         FIG.  47    is a perspective view of a floating collet of the locking assembly for the surgical instrument of  FIG.  46   . 
         FIG.  48    is a perspective view of the surgical instrument of  FIG.  46    with the locking assembly assembled. 
         FIG.  49    is a perspective view of the surgical instrument of  FIG.  46    with a locking wheel of the locking assembly removed. 
         FIG.  50    is a perspective view of the surgical instrument of  FIG.  46    with the floating collet and the locking wheel of the locking assembly removed. 
         FIG.  51    is an enlarged view of an articulating section of the surgical instrument in a curved configuration. 
         FIG.  52    is a flowchart of a method, according to the present invention, of operating a surgical instrument. 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIGS.  1  and  2   , a surgical instrument  10 , according to the present invention, is shown for use in a medical procedure for a patient (not shown). As illustrated in  FIG.  2   , the surgical instrument  10  is used with one or more working tools  12 . The surgical instrument  10  is capable of receiving and releaseably securing one of the working tools  12 . 
     Exemplary working tools  12  may be a flexible bur  12   a , a flexible bur  12   b , a flexible high speed bur  12   c , a flexible suction device  12   d , a flexible internal imaging and suction device  12   e , and/or a flexible manual instrument  12   f  such as graspers, bipolar forceps, etc. Powered tissue devices  12   a ,  12   b , and  12   c  and manual instrument  12   f  comprise a shaft portion  14  and a flexible region  15  along the shaft portion  14  near a distal end. The flexible suction device  12   d  and flexible internal imaging and section device  12   e  of the working tools  12  are devices that are configured to flex along at least a portion, of the entire length of the shaft portion  14 . 
     In the illustrated embodiment, each of these working tools  12  also have a generally cylindrical enlarged insertion portion  16  along the shaft portion  14  near a proximal end and a flange portion  17  extending radially outwardly at the end of the insertion portion  16 . Each of these working tools  12   a ,  12   b ,  12   c  further comprise a connecting portion  18  extending axially away from the flange portion  17 . The connecting portion  18  is configured to couple the working tool  12  to a power source, a suction source, and/or irrigation source (not shown). Alternatively, it is further contemplated that each of these working tools  12   d ,  12   e ,  12   f  have a connecting portion  18  for connection to a suction source only. It should be appreciated that the working tools  12  illustrated herein are mere examples of the various working tools  12  that are configured to be inserted into the surgical instrument  10 . Thus, it should also be appreciated that other working tools  12  may be introduced through and controlled by the surgical instrument  10  such as reciprocating devices like rasps, rotating devices, electrosurgical devices, laser devices, screwdriver devices, obturators, and trocars are further contemplated for use with the surgical instrument  10 . It should further be appreciated that the working tool  12  is configured to be inserted into the surgical instrument  10  and extend outwardly from the surgical instrument  10 . It should still be further appreciated that the surgical instrument  10  may be operated by a user (not shown) such as a surgeon. 
     Referring to  FIGS.  3  through  5   , the surgical instrument  10  includes an articulating tube assembly, generally indicated at  20 , and an actuation assembly, generally indicated at  22 , coupled to the articulating tube assembly  20  and which controls the articulating tube assembly  20 . The articulating tube assembly  20  includes an articulating region  23  along a length of the articulating tube assembly  20 . The articulating region  23  is disposed proximal the distal end and may be axially spaced from the distal end of the articulating tube assembly  20  or may be axially abutting the distal end of the articulating tube assembly  20 . 
     It should be appreciated that one or more of the working tools  12  have a shaft portion  14  capable of fitting within the articulating tube assembly  20  such that the flexible region  15  of the working tool  12  tends to align or at least partially align with the articulating region  23  when the working tool  12  is disposed in the surgical instrument  10 . The flexible region  15  of the working tool  12 , when aligned with the articulating region  23  of the articulating tube assembly  20 , allows these regions to bend or curve together. 
     It should also be appreciated that the distal end of many of these working tools  12  might protrude slightly beyond the distal end of the articulating tube assembly  20  in order to perform their function, while other working tools may be operable without their distal ends extending through the distal end of the surgical instrument  10 . Furthermore, some working tools  12  may be operable even if their distal ends are proximal to the distal end of the surgical instrument  10 . It should further be appreciated that other working tools  12  have the ability to be extended beyond to varying degrees, brought even with, or withdrawn into the distal end of the articulating tube assembly  20 . 
     Referring to  FIGS.  4  through  19   , in the illustrated embodiment, the articulating tube assembly  20  includes a first or inner tube  24  and a second or outer tube  26 . Each of the inner tube  24  and outer tube  26  are generally hollow cylinders and has a generally circular cross-sectional shape. The outer tube  26  has a diameter greater than a diameter of the inner tube  24  such that the inner tube  24  is disposed within the outer tube  26 . The inner tube  24  and outer tube  26  extend axially between a proximal end and a distal end. In this embodiment, the inner tube  24  has an axial length longer than an axial length of the outer tube  26  such that the inner tube  24  extends past a distal end of the outer tube  26  when the inner tube  24  is disposed within the outer tube  26  and the proximal end of the inner tube  24  extends axially past a proximal end of the outer tube  26  when the inner tube  24  is disposed within the outer tube  26 . 
     The inner tube  24  and outer tube  26  each independently comprise a metal material such as stainless steel or a non-metallic material such as a plastic composite depending on the application of the surgical instrument  10 . It should be appreciated that the wall thickness of the inner tube  24  and outer tube  26  may be relatively thin such as approximately 0.1 to approximately 0.5 millimeters (mm) to allow the articulating tube assembly  20  to have a relatively small diameter and also to be light-weight. It should also be appreciated that, in certain embodiments, the diameters of the inner tube  24  and outer tube  26  have a diameter of from approximately 1.0 mm to approximately 3.0 mm so as to work in a small opening of the patient and to prevent the user&#39;s view from being obstructed. It should further be appreciated that, in some applications, the inner tube  24  and outer tube  26  may have larger diameters such as approximately 10 mm or larger sufficient to accommodate the working tools  12  such as a screwdriver. It should still further be appreciated that, in certain embodiments, the diameter of the inner tube  24  and outer tube  26  may be scaled larger or smaller depending on the application and the size of the working tool  12 . 
     Referring to  FIGS.  12  through  15   , the inner tube  24  and outer tube  26  each include the articulating region  23  are fixed together distal of the articulating regions  23  to allow the inner tube  24  and outer tube  26  to be pushed and pulled relative to each other. The inner tube  24  includes apertures  32 , beams  34 , tie straps  40 , apertures  42 , and bottom segments  44  to form the articulating region  23  in the inner tube  24 . The outer tube  26  includes apertures  60 , beams  62 , tie straps  68 , apertures  70 , and bottoming segments  72  to form the articulating region  23  in the outer tube  26 . 
     The inner tube  24  includes an aperture  28  extending diametrically therethrough near the distal end thereof to allow the inner tube  24  to be fixed to the outer tube  26 . The aperture  28  is generally circular in shape, but may be any suitable shape. The inner tube  24  includes an aperture  30  extending through a wall thereof and disposed between the articulating region  23  and the proximal end for a connection to be described. In one embodiment, the aperture  30  is generally elongated, but may be any suitable shape. 
     The articulating region  23  of the inner tube  24  includes one or more apertures  32  extending through a wall thereof. In the illustrated embodiment, the apertures  32  are generally rectangular in shape. However, other shapes of the apertures  32  are contemplated. As illustrated, the apertures  32  have an axial length greater than a circumferential width, but need not be so. The inner tube  24  includes a plurality of beams  34  formed by cutting the apertures  32  and  42 . The beams  34  extend axially to form generally linear beams  34 . These beams  34  are parallel and extend from a long proximal portion  36  of the inner tube  24  to a shorter distal portion  38  of the inner tube  24 . The beams  34  are located approximately ninety degrees (90°) from each other as illustrated in  FIG.  10   . 
     The inner tube  24  also includes one or more of tie straps  40  formed by cutting the apertures  32 . The tie straps  40  extend circumferentially between and spaced axially along the beams  34 . It should be appreciated that each of the beams  34  may be instead one continuous axially extending beam or a plurality or series of axially extending beams  34 . It should also be appreciated that the tie straps  40  collectively maintain a cylindrical profile of the articulating region  23  of the inner tube  24  and prevent the beams  34  from buckling during compression of the inner tube  24 . It should further be appreciated that the beams  34  are the main tension or compression members, deliver loads, and have to bend. It should also be appreciated that the apertures  32  are formed by cutting the inner tube  24 . 
     The inner tube  24  includes one or more apertures  42  extending radially therethrough below the beams  34 . The apertures  42  have an inverted generally pentagonal shape. The apertures  42  are formed by cutting the inner tube  24 . The inner tube  24  also includes one or more bottoming segments  44  formed by cutting the apertures  42  disposed below and extending from the beams  34 . The bottoming segments  44  are generally triangular or pentagonal in shape, but may be any suitable shape. The bottoming segments  44  extend circumferentially between and spaced axially along the beams  34 . Each of the bottoming segments  44  have a lower side  46  that is inclined by a predetermined angle, for example such as approximately two and one half degrees) (2.5°) in one embodiment. The bottoming segments  44  have a bottom  48  that extends axially a distance greater than a top  50  thereof. It should be appreciated that the bottoming segments  44  bottom out and provide surface to surface contact against each other in an articulated or curved configuration. It should also be appreciated that an axial gap or space is formed between the bottoming segments  44 . It should further be appreciated that the apertures  42 , beams  34 , and bottoming segments  44  allow the articulating region  23  of the inner tube  24  to articulate. It should further be appreciated that each of the bottoming segments  44  has, when articulated, a small angular displacement such as approximately three and one-half degrees (3.5°) or approximately four degrees (4°). 
     Referring to  FIGS.  11  and  16  through  19   , the outer tube  26  also includes an aperture  52  extending diametrically therethrough near the distal end thereof for a function to be described. The outer tube  26  includes a slot aperture  54  extending through a wall thereof and disposed between the articulating region  23  and the proximal end for a function to be described. The slot aperture  54  extends axially and is elongated. The outer tube  26  includes a pad  56  disposed in the slot aperture  54  and a tab  58  extending axially between the outer tube  26  and the pad  56  to temporarily connect the pad  56  to the outer tube  26 . The pad  56  is generally elongated axially. 
     The articulating region  23  of the outer tube  26  includes one or more apertures  60  extending through a wall thereof. In the illustrated embodiment, the apertures  60  are generally rectangular in shape. The apertures  60  are formed by cutting the outer tube  26 . The outer tube  26  also includes a plurality of beams  62  formed by cutting the apertures  60 . The beams  62  extend axially to form generally linear beams  62 . These beams  62  are parallel to each other and extend from a long proximal portion  64  of the outer tube  26  to a shorter distal portion  66  of the outer tube  26  as illustrated in  FIGS.  6  and  7   . The beams  62  are located approximately ninety degrees (90°) circumferentially from each other. It should be appreciated that the beams  62  are the main tension or compression members, deliver loads, and have to bend. 
     The outer tube  26  includes a plurality of tie straps  68  formed by cutting the apertures  60  extending circumferentially between and axially spaced along the beams  62 . The tie straps  68  prevent the beams  62  from buckling during axial compression of the outer tube  26 . The tie straps  68  are generally “V” shaped axially toward the distal portion  66  to prevent snagging on the bottoming segments  44  of the inner tube  24  when the tube assembly  20  is articulated. It should be appreciated that each of the beams  62  may instead be one continuous axially extending beam or a plurality or series of axially extending beams  62 . It should be appreciated that the tie straps  68  maintain a cylindrical profile of the articulating region  23  of the outer tube  26  and prevent the beams  62  from buckling during compression of the outer tube  26 . It should also be appreciated that the tie straps  68  have a slight “V” form so to facilitate the passage of the segments  44  of the inner tube  24  past the tie straps  68  of the outer tube  26 . 
     The outer tube  26  includes one or more apertures  70  extending radially therethrough below the beams  62 . The apertures  70  have an inverted generally pentagonal shape. The apertures  70  are formed by cutting the outer tube  26 . The outer tube  26  includes one or more bottoming segments  72  formed by cutting the apertures  70  disposed below and extending from the beams  62 . The bottoming segments  72  are generally pentagonal in shape, but may be any suitable shape. The bottoming segments  72  extend circumferentially between and are spaced axially along the beams  62 . The bottoming segments  72  have a bottom  74  that extends axially a distance greater than a top  76  thereof. It should be appreciated that the bottoming segments  72  provide rigidity in an axial extending or straight configuration. It should also be appreciated that a narrow axial gap or space is formed between the bottoming segments  72 . 
     Each bottom  74  of the bottoming segments  72  has a first protrusion  78  extending axially from a proximal end toward the proximal end of the outer tube  26  and a first recess  80  extending axially from the proximal end toward the distal end of the outer tube  26 . Each bottom  74  of the bottoming segments  72  has a second protrusion  82  extending axially from a distal end toward the distal end of the outer tube  26  and a second recess  84  extending axially from the distal end toward the proximal end of the outer tube  26  in one embodiment. 
     For the articulating region  23  in the inner tube  24 , the inner tube  24  has a greater number of apertures  42  forming the bottoming segments  44 . In one embodiment, the inner tube  24  has fourteen apertures  42  and thirteen bottoming segments  44 . For the articulating region  23  in the outer tube  26 , the outer tube  26  has a greater number of apertures  70  forming the bottoming segments  72 . In one embodiment, the outer tube  26  has six apertures  70  and five bottoming segments  72 . It should be appreciated that, in other embodiment, the number of apertures  42 ,  70  and segments  44 ,  72  may be greater or less. 
     Adjacent the articulating region  23 , the distal portion  66  of the outer tube  26  has a first protrusion  78  extending axially from a proximal end toward the proximal end of the outer tube  26  and a first recess  80  extending axially from the proximal end toward the distal end of the outer tube  26 . The proximal portion  64  of the outer tube  26  has a second protrusion  82  extending axially from a distal end toward the distal end of the outer tube  26  and a second recess  84  extending axially from a distal end toward the proximal end of the outer tube  26 . The protrusions  78 ,  82  and recesses  80 ,  84  are generally rectangular in shape. The first protrusion  78  is disposed in the second recess  84  and the second protrusion  82  is disposed in the first recess  80  when the articulating region  23  is in an axially straight configuration. It should be appreciated that the protrusions  78 ,  82  and recesses  80 ,  84  are formed by cutting the outer tube  26  in a narrow cut to form a general “zig zag” or “Z” shape pattern such that each segment  72  has protrusions  78 ,  82  that extend into the neighboring segments  72 . It should also be appreciated that the protrusions  78 ,  82  and recesses  80 ,  84  facilitate the smooth passage of the tie straps  40  of the inner tube  24  past the edges of the bottoming segments  72  on the outer tube  26  and increase torsional and rotational stiffness of the outer tube  26 . It should further be appreciated that the apertures  70 , beams  62 , and segments  72  allow the articulating region  23  of the outer tube  26  to articulate. 
     In one example, when the inner tube  24  and outer tube  26  are fixed together axially distal of the articulating region  23 , the outer tube  26  is pushed/pulled proximally with respect to the inner tube  24 , causing the articulating tube assembly  20  to articulate until the bottoming segments  44  of the inner tube  24  bottom on each other and moves the outer tube  26  proximally with respect to the inner tube  24 , causing the articulating tube assembly  20  to articulate until the bottoming segments  72  of the outer tube  26  bottom on each other. When the proximal end of the outer tube  26  is pulled distally relative to the inner tube  24 , the beams  62  of the outer tube  26  are put in compression and the beams  34  of the inner tube  24  are put in tension. This loading causes a curve in the articulating region  23  of the articulating tube assembly  20  toward the beams  34  of the inner tube  24 , which are in tension. The articulating region  23  of the articulating tube assembly  20  curves until the bottoming segments  72  of the outer tube  26  bottom on each other, closing the small gap between these bottoming segments  72 . With a significant load applied in this bottomed condition, the articulating region  23  of the articulating tube assembly  20  is rigid as there is considerable loading about the circumference holding the bottoming segments  72  in place. Because there are relatively few and narrow gaps between bottoming segments  72  of the outer tube  26 , it should be appreciated that relatively minimal tube curvature occurs. As this force is increased, the articulating tube assembly  20  becomes increasingly rigid in a nearly straight condition. It should be appreciated that the inner tube  24  and outer tube  26 , when assembled, may lock in two directions such that the curves are in opposite directions or one curve in one direction is greater than the other curve in the other direction. It should also be appreciated that the outer tube  26  limits flexion for a straight configuration and the inner tube  24  limits flexion in a curved configuration. 
     Referring to  FIGS.  5  through  10   , the pair of beams  34  of the inner tube  24  and the pair of beams  62  of the outer tube  26  are oriented opposite at approximately one hundred eighty degrees (180°) from each other to provide lateral stiffness and rigidity of the articulating tube assembly  20 . In other embodiments, the pair of beams  34  of the inner tube  24  and the pair of beams  62  of the outer tube  26  are oriented opposite at approximately one hundred seventy degrees (170°) to one hundred ninety degrees (190°) from each other. From these beams  34  and  62 , the bottoming segments  44  and  72  and tie straps  40  and  68 , respectively, are hung. The bottoming segments  44  and  72  project toward and around a central axis or centerline A extending axially along the articulating tube assembly  20  and connect the two beams  34  and  62  together. The tie straps  40  and  68  project away from, but around the centerline A and connect the two beams  34  and  62  together, respectively. The bottoming segments  44  and  72  have distal and proximal surfaces and a small gap separating the distal surface of one bottoming segment  72  from the proximal surface of the next or adjacent bottoming segment  72 . In the embodiment illustrated, the bottoming segments  72  of the outer tube  26  are considerably axially wider than the bottoming segments  44  of the inner tube  24  and the gap between the bottoming segments  72  of the outer tube  26  is considerably smaller than the gap between the bottoming segments  44  of the inner tube  24 . It should be appreciated that while in the embodiment illustrated, each tube  24  and  26  has two beams  34  and  62 , respectively, at 90 degrees and each pair diametrically opposed from each other, other embodiments might have only one beam per tube. It should further be appreciated that, in still other embodiments, there may be more than two beams per tube. It should still further be appreciated that, at the proximal end of the surgical instrument  10 , there are components that enable the surgeon to control the articulation and allow the surgical instrument  10  to attach to and be driven by a drive assembly (not shown). 
     Referring to  FIGS.  1 ,  10 ,  11 , and  20  through  22   , the articulating tube assembly  20  includes a rotation assembly, generally indicated at  88 , for angularly rotating a distal end of the articulating tube assembly  20 . In the embodiment illustrated, the rotation assembly  88  includes an angular rotation tube  90  configured for rotating the inner tube  24  and outer tube  26 . The angular rotation tube  90  is a generally hollow cylinder having a generally circular cross-sectional shape. The angular rotation tube  90  has a diameter greater than a diameter of the outer tube  26  such that the angular rotation tube  90  is disposed about the outer tube  26 . The angular rotation tube  90  extends axially a predetermined distance and has an axial length substantially less than an axial length of the outer tube  26 . The angular rotation tube  90  includes a slot aperture  92  extending through a wall thereof for a function to be described. The slot aperture  92  is elongated axially. The angular rotation tube  90  includes a pad  94  disposed in the slot aperture  92  and a tab  96  extending axially between the pad  94  and the angular rotation tube  90 . The angular rotation tube  90  is made of a metal material or non-metallic material depending on the application. It should be appreciated that the angular rotation tube  90  is fixed to the outer tube  26  and the outer tube  26  is fixed to the inner tube  24  in a manner to be described. 
     The rotation assembly  88  also includes an angular rotation collar  98  to be rotated by the user of the surgical instrument  10 . The angular rotation collar  98  may be generally circular in shape and include a pair of opposed protrusions  100  extending radially for a function to be described. The angular rotation collar  98  also includes an aperture  102  extending axially therethrough to allow the angular rotation collar  98  to be disposed over and about the angular rotation tube  90 . The angular rotation collar  98  may include a knurled area  104  disposed in the aperture  102  for connection to the angular rotation tube  90 . The angular rotation collar  98  has an outer surface with a plurality of grooves  106  and a plurality of gripping members  108  extending axially and spaced circumferentially. The grooves  106  and gripping members  108  are generally “V” shaped, but may be any suitable shape. One of the protrusions  100  may include a recess  111  extending radially therein and axially therealong to allow the user to feel which way the articulating tube assembly  20  will articulate. It should be appreciated that the grooves  106  and  108  are formed on the protrusions  100 . It should also be appreciated that the angular rotation collar  98  is coupled to the angular rotation tube  90  through a suitable mechanism such as the knurled area  104  to form a friction fit, adhesive bonding, or induction bonding. 
     Referring to  FIG.  11   , the articulating tube assembly  20  also includes an inner thrust ring  112  attached to a proximal end of the inner tube  24 . The inner thrust ring  112  is generally cylindrical in shape with a generally circular cross-section. The inner thrust ring  112  has an aperture  114  extending axially therethrough to be disposed about the inner tube  24 . The aperture  114  is generally circular in shape. The inner thrust ring  112  also has a groove  116  extending radially therein and circumferentially thereabout for a function to be described. The groove  116  has a generally “U” shaped cross-section. It should be appreciated that the inner thrust ring  112  is fixed to the inner tube  24  by a suitable mechanism such as knurling, adhesive bonding, or induction bonding. 
     The articulating tube assembly  20  also includes an outer thrust ring  118  attached to a proximal end of the outer tube  26 . The outer thrust ring  118  is generally cylindrical in shape with a generally circular cross-section. The outer thrust ring  118  has an aperture extending axially therethrough to be disposed about the outer tube  26 . The aperture is generally circular in shape. It should be appreciated that the outer thrust ring  118  is fixed to the outer tube  26  by a suitable mechanism such as knurling, adhesive bonding, or induction bonding. 
     The articulating tube assembly  20  includes one or more spring washers  122  disposed about the outer tube  26  and adjacent each side of the outer thrust ring  118 . Each spring washer  122  is generally circular in shape with an aperture  125  extending axially therethrough to be disposed about the outer tube  26 . The aperture  125  is generally circular in shape. Each spring washer  122  extends radially and axially. In the illustrated embodiment, each spring washer  122  is of a Bellville type. The articulating tube assembly  20  also includes one or more flanged sleeve  127  disposed about the outer tube  26  and adjacent the washer  122  on each side of the outer thrust ring  118 . Each flanged sleeve  126  has a sleeve portion  128  with a generally hollow cylindrical in shape and a generally circular cross-section and a flange portion  130  extending radially from one end of the sleeve portion  128  and having a generally circular shape. Each flanged sleeve  127  includes an aperture  132  extending axially through the sleeve portion  128  and flange portion  130 . The aperture  132  has a generally circular cross-section. The articulating tube assembly  20  also includes one or more washers  134  disposed about the outer tube  26  and adjacent each of the flanged sleeves  127 . Each washer  134  is generally circular in shape with an aperture  136  extending axially therethrough to be disposed about the outer tube  26 . The aperture  136  is generally circular in shape. Each washer  134  extends radially. The articulating tube assembly  20  further includes one or more springs  138  disposed about the outer tube  26  and adjacent each washer  134 . Each spring  138  is of a coil type having a plurality of helical shaped coils  140  extending circumferentially and axially. 
     Referring to  FIGS.  20  through  22   , the assembly of the articulating tube assembly  20  is illustrated. In assembly, the inner tube  24  is inserted into the outer tube  26  and oriented such that the beams  34  of the inner tube  24  are one hundred eighty degrees (180°) opposed to the beams  62  of the outer tube  26 . In this embodiment, the apertures  28  and  52  act as an alignment hole through both tubes  24  and  26  such that a fixture pin (not shown) can align and position the tubes  24  and  26 . With the pin in place, the distal ends of the tubes  24  and  26  are welded together in one embodiment. In another embodiment, a suitable mechanism such as an adhesive may used to secure the distal ends of the tubes  24  and  26  together. After the distal ends of the tubes  24  and  26  are fixed together, the fixture pin is removed. Once the distal ends of the tubes  24  and  26  are secured to one another, the remainder of the articulating tube assembly  20  is assembled. It should be appreciated that fixing the distal ends of the tubes  24  and  26  together results in the proximal ends of the tubes  24  and  26  being axially and rotationally keyed together to prevent distal relative movement, while still enabling the proximal ends of the tubes  24  and  26  to move axially with respect to each other. 
     After the distal ends of the tubes  24  and  26  are fixed, a pad  56  of the outer tube  26  is also welded to the proximal end of the inner tube  24 . The pad  94  of the angular rotation tube  90  is then welded to the pad  56  of the outer tube  26 . The tab  58  of the outer tube  26  is then removed. It should be appreciated that the slot aperture  92  in the angular rotation tube  90  and the aperture  30  in the inner tube  24  allow for this tab  58  to be cut and removed through a suitable mechanism such as a laser (not shown). It should also be appreciated that a second person is not needed to hold the tubes  24 ,  26 , and  90  to perform the assembly. It should further be appreciated that, in another embodiment, a window may be provided to weld the tubes  24 ,  26 , and  90  together. It should yet be appreciated that the pad  94  acts as a leaf spring to allow the pad  56  to be drawn down against the inner tube  24 . It should still further be appreciated that a torque applied to angular rotation collar  98  is transferred to the angular rotation tube  90  to which it is attached, and then to the pad  94  of the angular rotation tube  90  because it is constrained within its slot aperture  92 . It should yet further be appreciated that, in this way, the tubes  24 ,  26 , and  90  are all rotationally constrained to one another yet the proximal end of the outer tube  26  is free to move axially with respect to the other tubes  24  and  90 . 
     Referring to  FIGS.  2  through  5  and  23  through  26   , in one embodiment, the actuation assembly  22  is coupled to the articulating tube assembly  20  for moving the inner tube  24  and the outer tube  26  axially relative to each other for articulating the articulating region  23  of the articulating tube assembly  20  between a straight configuration and a curved configuration in only one direction. The actuation assembly  22  includes a handle  144  and one or more triggers  146 ,  148  coupled to the handle  144  to enable control of the articulating tube assembly  20 . The handle  144  includes a tube receiving portion  150  extending axially and a handle portion  152  extending radially downward from the tube receiving portion  150 . The tube receiving portion  150  is generally cylindrical shape. The tube receiving portion  150  has a first or forward cavity  154  extending axially rearward therein. The forward cavity  154  is generally cylindrical and circular in cross-sectional shape. The tube receiving portion  150  includes one or more apertures  156  extending radially into the forward cavity  154 . The apertures  156  are generally circular in shape and spaced circumferentially. The tube receiving portion  150  also has a second or rearward cavity  158  extending axially forward therein. The rearward cavity  158  is generally cylindrical and circular in cross-sectional shape. The tube receiving portion  150  includes one or more apertures  160  extending radially into the rearward cavity  158 . The apertures  160  are generally circular in shape and spaced circumferentially. The apertures  160  are also semi-hemispherical shaped for a function to be described. The tube receiving portion  150  has a central cavity  162  extending axially therein. The central cavity  162  is generally cylindrical and circular in cross-sectional shape. The tube receiving portion  150  includes one or more apertures  164  extending perpendicularly with respect to axis A into the central cavity  162 . The apertures  164  are generally circular in shape and spaced symmetrically off-axis. The tube receiving portion  150  also has a passageway  166  extending axially between and communicating with the rearward cavity  158  and the central cavity  162 . The passageway  166  has a generally circular cross-section. The tube receiving portion  150  includes an aperture  168  extending radially therethrough. The aperture  168  has a generally circular cross-section. The tube receiving portion  150  further includes an aperture  170  disposed above the central cavity  162  and extending perpendicularly therethrough for a function to be described. It should be appreciated that the passageway  166  is used to support the proximal end of the inner tube  24 . 
     The handle portion  152  extends downwardly and away from the tube receiving portion  150  adjacent the central cavity  162 . The handle portion  152  is generally rectangular in shape. The handle portion  152  includes an aperture  172  extending generally perpendicular therethrough. The aperture  172  is generally elongated along the handle portion  152 . The handle portion  152  also includes a cavity  174  extending from the forward side toward the rearward side to receive the triggers  146 ,  148 . The cavity  174  is generally rectangular in shape. The cavity  174  communicates with the aperture  172 . The handle portion  152  also includes an aperture  176  extending generally perpendicular therethrough and communicating with the cavity  174 . The aperture  176  is generally circular in shape. The handle portion  152  may include one or more apertures  178  extending generally perpendicular therethrough and communicating with the cavity  174 . The apertures  178  extend through the wall of the handle  144 . The apertures  178  are generally rectangular in shape, but may be any suitable shape. The apertures  178  are spaced in a circumferential or arcuate manner for a function to be described. The handle portion  152  may include a pair of slots  180  extending axially along and communicating with the cavity  174 . The handle portion  152  and tube receiving portion  150  are made of a rigid material such as plastic. The handle portion  152  and tube receiving portion  150  are integral, unitary, and one-piece. 
     The triggers  146 ,  148  include an upper or top trigger  146  and a lower or bottom trigger  148 . The upper trigger  146  has a trigger portion  182  extending forward and a flange portion  184  extending upwardly from the trigger portion  182 . The trigger portion  182  is generally rectangular in shape, but may be any suitable shape, and includes a trigger surface  186  being generally arcuate in shape to receive a finger of the user. The flange portion  184  includes a pair of opposed flanges  190  extending from the trigger portion  182  and spaced laterally. The flanges  190  include an aperture  192  extending therethrough. The aperture  192  is generally circular in shape. The upper trigger  146  includes a pin  194  extending through the apertures  192  in the flanges  190  and the aperture  170  in the tube receiving portion  150  to pivotally connect the upper trigger  146  to the handle  144 . The upper trigger  146  is made of a rigid material such as plastic. The upper trigger  146  is integral, unitary, and one-piece. It should be appreciated that the upper trigger  146  moves the outer tube  26  proximally when actuated causing articulation. 
     The lower trigger  148  has a connecting portion  196  coupled to the handle portion  152  and a trigger portion  198  coupled to the connecting portion  196 . The connecting portion  196  includes a body portion  200  extends axially. The body portion  200  is generally rectangular in shape with a lower surface  202  having a generally arcuate shape. The body portion  200  includes a slot  204  extending radially therein and generally perpendicular thereto. The slot  204  is generally rectangular in shape. The body portion  200  has a first aperture  206  extending axially therethrough and a second aperture  208  extending generally perpendicular therethrough. The apertures  206  and  208  are generally circular in shape. The connecting portion  196  includes a flange portion  211  extending upwardly from the body portion  200 . The flange portion  211  includes a pair of opposed flanges  211  extending from the body portion  200  and spaced laterally. The flanges  212  are disposed in the slots  180 . The lower trigger  148  includes a pin  214  extending through the aperture  208  in the connecting portion  196  and the aperture  176  in the handle portion  152  to pivotally connect the lower trigger  198  to the handle  144 . The pin  214  is generally cylindrical in shape with a generally circular cross-section. The connecting portion  196  is made of a rigid material such as plastic. The connecting portion  196  is integral, unitary, and one-piece. 
     The trigger portion  198  has a body portion  216  extending vertically and a finger portion  218  extending forward from the body portion  216 . The body portion  216  has an upper surface  221  with a generally arcuate shape. The body portion  216  includes a projection  222  extending upwardly to be disposed in the slot  204  of the connecting portion  196 . The trigger portion  198  includes a pin  225  extending through the aperture  206  in the connecting portion  196  and the aperture  176  in the handle portion  152  to pivotally connect the trigger portion  198  to the connecting portion  196 . The pin  225  is generally cylindrical in shape with a generally circular cross-section. The finger portion  218  is generally rectangular in shape, but may be any suitable shape, and includes a trigger surface  229  being generally arcuate in shape to receive a finger of the user. The finger portion  218  has a lower surface  227  being generally arcuate in shape. The finger portion  218  may include a recess  228  extending perpendicularly therein. The finger portion  218  may include one or more projections or teeth  230  extending generally perpendicular into the recess  228 . The teeth  230  are generally rectangular in shape, but may be any suitable shape. The teeth  230  are spaced in a circumferential or arcuate manner adjacent the lower surface  227  of the finger portion  218  for a function to be described. The trigger portion  198  is made of a rigid material such as plastic. The trigger portion  198  is integral, unitary, and one-piece. It should be appreciated that the lower trigger  148  moves the inner tube  24  distally when actuated pushing the articulating tube assembly  20  to a straight configuration. It should also be appreciated that, another configuration, besides the handle  144  and triggers  146 ,  148  may be used to push or pull the inner tube  24  and outer tube  26  relative to each other to actuate and articulate the articulating tube assembly  20 . 
     Referring to  FIGS.  1  through  5   , the assembly of the actuation assembly  22  is illustrated. In assembly, the proximal end of the assembled articulating tube assembly  20  is extended through the forward cavity  154  and into the central cavity such that the inner thrust ring  112  is disposed at the end of the central cavity  162  and the end of the inner tube  24  is disposed in the passageway  166 . Pins through apertures  164  and groove  116  secure the inner tube  24  axially, but allows rotation. A split sleeve bushing  232  disposed in the forward cavity  154  extends axially and supports the tube assembly  20 . The split sleeve bushing  232  is generally a hollow cylinder having a generally circular cross-sectional shape to allow the articulating tube assembly  20  to extend therethrough. The split sleeve bushing  232  may include a groove  234  to receive pins  236 , which retain the bushing  232  and resist distal spring  138  in  FIG.  11   . The pins  236  are generally cylindrical in shape with a generally circular cross-section. The pins  236  extend through apertures  237  in the tube receiving portion  250  to secure the inner tube axially in the handle  144 , but enables rotation. 
     The upper trigger  146  is disposed in the cavity  174  and the flanges  190  are extended around the articulating tube assembly  20  between the washer  134  and flanged sleeve  127  and upwardly into the slots  180  such that the apertures  192  and  170  align. The pin  194  is then extended through the aperture  170  and apertures  192  to pivotally connect the upper trigger  146  to the actuation assembly  22 . It should be appreciated that the articulating tube assembly  20  extends axially through a space between the flanges  190  of the upper trigger  146 . It should also be appreciated that the pin  194  allows pivotal movement of the upper trigger  146  forward and rearward and the flanges  190  and slots  180  guide the movement. 
     Once the connecting portion  196  and trigger portion  198  are assembled together for the lower trigger  148 , the lower trigger  148  is disposed in the cavity  174  and the flanges  212  are extended around the articulating tube assembly  20  between the flanged sleeve  127  and washer  134  and upwardly into the slots  180  such that the apertures  208  and  176  align. The pin  214  is then extended through the apertures  208  and aperture  176  to pivotally connect the lower trigger  148  to the actuation assembly  22 . It should be appreciated that the articulating tube assembly  20  extends axially through a space between the flanges  212  of the lower trigger  148 . It should also be appreciated that the pin  214  allows pivotal movement of the lower trigger  148  forward and rearward and the flanges  190  and slots  180  guide the movement. It should further be appreciated that the pin  225  allows pivotal movement of the trigger portion  198  of the upper trigger  146  perpendicularly from side to side. 
     As illustrated in  FIGS.  1  through  5   , the working tool  12  is inserted into the surgical instrument  10 . The shaft portion  14  is inserted into the rearward cavity of the actuation assembly  22  and extended axially through the inner tube  24 . The insertion portion  16  is also inserted into the rearward cavity  158  of the actuation assembly  22  and extended axially until the flange portion  17  abuts the rear of the actuation assembly  22 . When this occurs, a spherically shaped ball  238  a is disposed in one of the apertures  160  engages one of a plurality of detents  238  b in the insertion portion  16  as illustrated in  FIG.  5   . A collar  239  may be disposed about the proximal end of the tube receiving portion  250 . The collar  239  is generally cylindrical with a generally circular cross-section and is pushed against the ball  238  a by a spring  239  c. The collar  239  has an inner ramp  239  a that engages the ball  238  a to prevent rotation of the working tool  12  and lock the working tool  12  in place relative to the tube receiving portion  250  of the actuation assembly  22 . It should be appreciated that a plurality of detents  238  b may be provided for multiple positions to vary amount of exposure of the distal end of the working tool  12  out of the distal end of the articulating tube assembly  20 . It should also be appreciated that the connecting portion  18  of the working tool  12  may be connected to a power source (not shown). 
     In operation, when a finger of the user pulls the upper trigger  146  into the handle  144 , the lower trigger  148  moves out, and the outer tube  26  is pushed proximally with respect to the inner tube  24 , causing the tube assembly  20  to articulate as described below until the bottoming segments  44  of the inner tube  24  bottom on each other. While in this state, the lower trigger  148  can pivot to the side about the pin  225  and engage the bottom trigger teeth  230  into the slots  180  in the handle portion  152  of the handle  144 , locking the instrument  10  in this condition. Pushing the lower trigger  148  to the opposite side disengages these teeth  230 , unlocking the articulation control. Pushing the lower trigger  148  now into the handle  144  causes the upper trigger  146  to move out and moves the outer tube  26  distally with respect to the inner tube  24 , causing the tube assembly  20  to articulate as described below until the bottoming segments  72  of the outer tube  26  bottom on each other. 
     When a force from the lower trigger  148  is applied to the proximal end of the outer tube  26  pushing it distally relative to the inner tube  24 , the beams  62  of the outer tube  26  are put in compression and the beams  34  of the inner tube  24  are put in tension. This loading causes a curve in the articulating region  23  of the articulating tube assembly  20  toward the beams  34  of the inner tube  24 , which are in tension. The articulating region  23  of the articulating tube assembly  20  curves until the bottoming segments  72  of the outer tube  26  bottom on each other, closing the small gap between these bottoming segments  72 . With a significant load applied in this bottomed condition, the articulating region  23  of the articulating tube assembly  20  is rigid as there is considerable axial loading about the circumference holding the bottoming segments  72  in place. Because there are relatively few and narrow gaps between bottoming segments  72  of the outer tube  26 , it should be appreciated that relatively minimal tube curvature occurs. As this force is increased, the articulating tube assembly  20  becomes increasingly rigid in a nearly straight condition. 
     When an opposite force is applied to the proximal end of the outer tube  26 , pulling it proximally relative to the inner tube  24 , the beams  62  of the outer tube  26  are placed in tension while the beams  34  of the inner tube  24  are placed in compression. This loading causes a curve in the articulating region  23  of the articulating tube assembly  20  toward the beams  62  of the outer tube  26 , which are in tension. The articulating region  23  of the articulating tube assembly  20  curves until the bottoming segments  44  of the inner tube  24  bottom on each other, closing the gap between these bottoming segments  44 . With a significant load applied in this bottomed condition, the articulating tube assembly  20  is rigid as there is considerable axial loading about the circumference holding the bottoming segments  44  in place. Because there are relatively more and wider gaps between the bottoming segments  72  of the outer tube  26 , it should be appreciated that considerable curvature of the articulating region  23  of the articulating tube assembly  20  occurs. As this force is increased, the articulating region  23  of the articulating tube assembly  20  becomes increasingly rigid in a substantially curved condition. The compliance allowed by the springs  122  enables the bottoming segments  44  and  72  to remain under load and so the tubes  24 ,  26  are rigid while the trigger teeth  230  are engaged in the apertures  178 . 
     Because this articulating tube assembly  20  now enables the ability to do work around a corner, the users&#39; ability to safely perform this work will now be limited by their ability to see the working tip. In some versions, the surgical instrument  10  may be configured to include a tool view or viewing assembly, generally indicated at  240  in  FIGS.  1  and  2   , which is an option provided for the user. The viewing assembly  240  may include relatively small visualization and illumination elements at its distal tip that are able to present the user real time video from their perspective at the tip of the viewing assembly  240 . In certain circumstances where the working tool  12  must be advanced beyond the view of other visualization tools (e.g. endoscope or surgical microscope), the viewing assembly  240  can be slipped over the articulating tube assembly  20  of the surgical instrument  10 . Other configurations are also contemplated such that the viewing assembly  240  may be disposed within the articulating tube assembly  20  or integral with one or more components of the articulating tube assembly  20 . 
     Referring to  FIGS.  1  through  5   , the viewing assembly  240  includes a main tube  242  extending axially. The main tube  242  is a generally hollow cylinder and has a generally circular cross-sectional shape. The main tube  242  has a diameter greater than a diameter of the outer tube  26  such that the outer tube  26  is disposed within the main tube  242 . The main tube  242  extends axially between a proximal end and a distal end. The main tube  242  has an axial length shorter than an axial length of the outer tube  26  such that the outer tube  26  extends past a distal end of the main tube  242  when the outer tube  26  is disposed within the main tube  242 . The main tube  242  is made of a metal material such as stainless steel or a non-metallic material such as a composite depending on the application. It should be appreciated that the wall thickness of the main tube  242  is relatively thin such as approximately 0.1 to approximately 0.5 millimeters (mm). It should also be appreciated that the diameter of the main tube  242  has a relatively small diameter so as to work in a small opening of the patient and to prevent the user&#39;s view from being obstructed. 
     The main tube  242  also includes a flexible region  23   a  along a length thereof. The flexible region  23   a  is disposed between the proximal end and distal end of the main tube  242 . The flexible region  23   a  may have any suitable configuration to allow it to flex such as apertures  245  extending radially through and circumferentially across a wall of the main tube  242 . The apertures  256  are spaced axially along the flexible region  23   a  of the main tube  242 . It should be appreciated that the apertures  256  may be cut in the main tube  242  by a laser or wire EDM (not shown). It should also be appreciated that the main tube  242  is capable of fitting over the articulating tube assembly  20  and the flexible region  23   a  of the main tube  242  tends to align when seated on the surgical instrument  10  with the articulating region  23  of the articulating tube assembly  20 . 
     Referring to  FIGS.  27  and  28   , the viewing assembly  240  may include at least one imaging element  246  located at a distal end of the main tube  242 . The imaging element  246  is a camera, video camera, or of a camera chip, with wires (not shown) to the camera. The imaging element  246  is connected to the distal end of the main tube  242  by a suitable mechanism such as an adhesive or epoxy. The viewing assembly  240  may include an illumination assembly, generally indicated at  248 , for illuminating the surgical site at a distal end of the articulating tube assembly  20 . The illumination assembly  248  includes one or more illuminators  250  such as light emitting diodes (LEDs) located at the distal end of the main tube  242 . As illustrated, one illuminator  250  is located on one side of the imaging element  246  and another illuminator  250  is located on the other side of the imaging element  246 . The illuminators  250  are connected to the distal end of the main tube  242  by a suitable mechanism such as an adhesive or epoxy. The illuminators  250  are also connected by wires  252  to a power source (not shown). It should be appreciated that the illuminators  250  may be configured as plastic optical fibers coupled to a remote light source (not shown). 
     The viewing assembly  240  may include a shroud  255  attached to the main tube  242  to cover the imaging element  246 , illuminators  250 , and wires  252 . The shroud  255  extends axially along the main tube  242  from the distal end toward the proximal end and over the articulating region  23 . The shroud  255  has a generally arcuate configuration to form a passageway for the wires  252  and camera wires (not shown). The shroud  255  may be connected to the main tube  242  by a suitable means such as welding. The shroud  255  is made of a metal material such as stainless steel or a non-metallic material such as a composite depending on the application. 
     The shroud  255  also includes a flexible region  23   a  along a length thereof. The flexible region  23   a  is disposed between the proximal end and distal end of the shroud  255 . The flexible region  23   a  may have any suitable configuration to allow it to flex such as apertures  256  extending radially through and circumferentially across a wall of the shroud  255 . The apertures  256  are spaced axially along the flexible region  23   a  of the shroud  255 . It should be appreciated that the apertures  256  may be cut in the shroud  255  by a laser or wire EDM (not shown). It should also be appreciated that the main tube  242  and shroud  255  flex left to right, but not up and down to prevent the wires  252  from being compressed and extended. 
     The viewing assembly  240  also includes a connector  258  having a distal end connected to a proximal end of the main tube  242 . The connector  258  extends axially and has a slot  263  extending radially therethrough to form a generally “U” shape. The connector  258  has a diameter larger than a diameter of the tube receiving portion  150  of the actuation assembly  22 . It should be appreciated that the collar  98  is disposed in the slot  263  and the amount of rotation is limited by the protrusions  100  on the collar  98  to prevent flexing at the six o&#39;clock and twelve o&#39;clock positions, but allowing flexing at the three o&#39;clock and nine o&#39;clock positions. 
     The viewing assembly  240  includes a grasping member  267  disposed at a proximal end of the connector  258 . The grasping member  267  is generally circular in shape. The grasping member  267  also includes an aperture  263  extending axially therethrough to allow the grasping member  267  to be disposed over and about the tube receiving portion  150  of the actuation assembly  22 . The grasping member  267  has an outer surface with a plurality of grooves  269  and a plurality of gripping members  266  extending axially and spaced circumferentially. The grooves  269  and gripping members  266  are generally arcuate shaped, but may be any suitable shape. It should be appreciated that the grasping member  267  is coupled to the tube receiving portion  150  of the actuation assembly  22  to form a friction fit. It should be appreciated that the viewing assembly  240  may be manually moved axially by a user. 
     In operation, the viewing assembly  240  allows real time video to be presented to the user on a video monitor (not shown) for a primary view, and in another embodiment, as a small picture-in-picture in the corner of the screen of the video monitor for a secondary view for an endoscope (not shown), or in the corner of their microscope image. In this way, the user maintains the “global view” they currently have with their current visualization tools, while being provided a perspective deep within the surgical site very near the tip of the working tool  12 . In one embodiment, the viewing assembly  240  may be advanced or retracted along the length of the articulating tube assembly  20  such that in the fully retracted position, the distal tip of the viewing assembly  240  is proximal of the articulating region  23  of the articulating tube assembly  20 , and in more advance positions the distal tip of the viewing assembly  240  is just distal of the articulating region  23  or, in even more advanced positions, the distal tip of the viewing assembly  240  is distal of the tip of the working tool  12 . 
     One advantage of the present invention is that the surgical instrument provides a primary view in one embodiment and a secondary local view in another embodiment for a surgeon. Yet another advantage of the present invention is that the surgical instrument includes imaging elements at a distal tip to provide the secondary local view for the surgeon. Still another advantage of the present invention is that the surgical instrument includes an imaging element capable of being moved along an axis of the instrument. A further advantage of the present invention is that the surgical instrument includes an illumination device to provide illumination at the surgical site. 
     Referring to  FIGS.  29  through  35   , another embodiment, according to the present invention, of the surgical instrument  10  is shown. Like parts of the surgical instrument  10  have like reference numerals increased by one hundred (100). In this embodiment, the surgical instrument  110  includes the articulating tube assembly  120  and a new actuation assembly  122  coupled to the articulating tube assembly  120  for moving the inner tube  124  and the outer tube  126  axially relative to each other for articulating the articulating region  123  of the articulating tube assembly  120  between a straight configuration and a curved configuration in only one direction. It should also be appreciated that, at the proximal end of the surgical instrument  110 , there are components that enable the surgeon to control the articulation and allow the surgical instrument  110  to attach to and be driven by a drive assembly (not shown). 
     The actuation assembly  122  includes a handle  244  including a tube receiving portion  250  extending axially. The tube receiving portion  250  is generally cylindrical shape. The tube receiving portion  250  has a first or forward cavity  254  extending axially rearward therein. The forward cavity  254  is generally cylindrical and circular in cross-sectional shape. The tube receiving portion  250  also has a second or rearward cavity  259  extending axially forward therein. The rearward cavity  259  is generally cylindrical and circular in cross-sectional shape. The rearward cavity  259  communicates axially with the forward cavity  254 . The tube receiving portion  250  includes one or more apertures  260  extending perpendicularly into the rearward cavity  259 . The apertures  260  are generally circular in shape and spaced symmetrically about the axis. The tube receiving portion  250  has a central cavity  262  extending radially and axially therein. The central cavity  262  is generally rectangular in shape. The tube receiving portion  250  includes one or more apertures  264  extending radially into the central cavity  262 . The apertures  264  are generally circular in shape and spaced circumferentially. The tube receiving portion  250  further includes an aperture  265  disposed below the central cavity  262  and extending radially therethrough for a function to be described. The tube receiving portion  250  may include a pair of slots  280  extending axially therein and communicating with the central cavity  262 . One of the slots  280  is spaced radially from one side of the forward cavity  254  and another slot  280  is spaced radially from an opposed side of the forward cavity  254 . The tube receiving portion  250  is made of a rigid material such as plastic. The tube receiving portion  250  is integral, unitary, and one-piece. It should be appreciated that the forward cavity  254  is used to support the proximal end of the inner tube  124 . 
     The actuation assembly  122  also includes a collar  368  connected to a proximal end of the outer tube  126 . The collar  368  is generally rectangular in shape. The collar  368  includes an aperture  370  extending axially therethrough. The aperture  370  is generally circular in shape. The collar  368  also includes a plurality of apertures  372  extending axially therethrough. The apertures  372  are generally rectangular in shape. One of the apertures  372  is spaced radially from one side of the aperture  370  and another aperture  372  is spaced radially from an opposed side of the aperture  370 . The collar  368  further includes one or more apertures  374  extending radially therethrough and communicating with the apertures  372 . The apertures  374  are generally circular in shape. One of the apertures  374  is located on one side of the collar  368  and communicating with the aperture  372  and another aperture  374  is located on another side of the collar  368  and communicating with the aperture  372 . It should be appreciated that the aperture  370  has a diameter to receive the outer tube  126  to form a friction fit, adhesive bond, or induction bond therebetween. 
     The actuation assembly  122  includes one or more links  376  connected to the collar  368 . The links  376  extend axially. The links  376  are generally rectangular in shape. The links  376  have an aperture  378  extending through each end thereof. The distal end of the links  376  is disposed in the apertures  372  of the collar  368  until the apertures  378  and  374  are aligned. The actuation assembly  122  includes one or more pins  381  to connect the distal end of the links  376  to the collar  368 . The pins  381  are generally cylindrical in shape with a generally circular cross-section. The pins  381  are disposed in the apertures  374  and  378  to connect the links  376  to the collar  368 . It should be appreciated that the proximal end of the links  376  are disposed in the slots  280  of the tube receiving portion  250 . 
     The actuation assembly  122  also includes a lever  380  connected to the proximal end of the links  376 . The lever  380  has a generally inverted “U” shape. The lever  380  has a top portion  382  and a pair of side portions  384  being spaced and extending from the top portion  382 . The side portions  384  include an upper aperture  386  and a lower aperture  388  extending therethrough. The upper aperture  386  is spaced from the lower aperture  388 . The side portions  384  are disposed in the central cavity  262  until the apertures  388  and  265  are aligned and the apertures  386  and  264  are aligned. The actuation assembly  122  includes one or more pins  390  and  392  to connect the side portions  384  of the lever  380  to the proximal end of the links  376 . The pins  390  and  392  are generally cylindrical in shape with a generally circular cross-section. The pin  390  has a length greater than a length of the pins  392 . The pins  390  are disposed in the apertures  388  and  265  to connect the lever  380  to the tube receiving portion  250  of the handle  244  and the pins  392  pass through the apertures  264  and are disposed in the apertures  386  and  378  to connect the lever  380  to the links  376 . 
     Referring to  FIGS.  34 ,  35 , and  37   , the surgical instrument  110  is illustrated with one of the working tools  12 . The surgical instrument  110  is capable of receiving the working tool  12  and releaseably securing the working tool  12  by a friction fit. The working tool  12  is a flexible shaver  12   g  for use on the patient. In one embodiment, the flexible shaver  12   g  may include a housing hub  394  disposed in a proximal end of the handle  244  of the actuation assembly  122 . The housing hub  394  is generally cylindrical in shape with a generally circular cross-section. The housing hub  394  extends axially from a proximal end to a distal end. The housing hub  394  has a reduced diameter plug portion  395  at the distal end. The plug portion  395  includes a groove  396  to receive pins  397  that extend through the handle  244  to lock the housing hub  394  to the handle  244 . The housing hub  394  also includes a cavity  398  extending axially into the proximal end thereof. The cavity  398  is generally cylindrical in shape with a generally circular cross-section. The housing hub  394  is integral, unitary, and one-piece. 
     The flexible shaver  12   g  also has a shaft portion  14  and a flexible region  15  along the shaft portion  14  near a distal end. The shaft portion  14  includes an inner tube  14   a  and an outer tube  14   b . The outer tube  14   b  is fixedly connected to the housing hub  394 . The flexible shaver  12   g  also have a generally cylindrical enlarged insertion portion  16  along the shaft portion  14  near a proximal end and a connecting portion  18  extending axially away from the proximal end of the insertion portion  16  for connection to a power source and suction (not shown). The inner tube  14   a  extends through the insertion portion  16  and is connected to the connecting portion  18 . It should be appreciated that the connecting portion  18  is a cutter driveshaft that oscillates by rotating two to five turns and then changes direction. 
     The outer tube  14   b  has an opening  14   c  at the distal end thereof. In one embodiment, the inner tube  14   a  has a plurality of teeth  14   d  at its distal end to form a cutter that rotates relative to the outer tube  14   b . It should be appreciated that the opening  14   c  in the outer tube  14   b  forms a window where tissue is pulled in and cut by the teeth  14   d  of the inner cutter. 
     Referring to  FIG.  38   , the inner tube  14   a  has a bur  14   e  at its distal end to form a spinning bur. It should be appreciated that the opening  14   c  in the outer tube  14   b  allows the cutting by the spinning bur  14   e  of the inner tube  14   a.    
     Referring to  FIG.  39   , the surgical instrument  10 ,  110  allows the opening  14   c  of the outer tube  14   b  of the working tool  12   g  to be rotated with respect to the articulating tube assembly  20 ,  120 . It should be appreciated that the flexible region  15  of the working tool  12   g  allows it to be rotated when the articulating region  23 ,  123  is bent or curved in only one direction. 
     One advantage of the present invention is that the surgical instrument  10 ,  110  has tube articulation to facilitate reduced incision size, improved access and visibility, while enhancing surgical outcome and quicker recovery. Another advantage of the present invention is that the surgical instrument  10 ,  110  includes a relatively simple, inexpensive, articulating tube assembly  20 ,  120  constructed of two laser cut tubes which are welded or bonded together at the distal end. Yet another advantage of the present invention is that the surgical instrument  10 ,  110  includes a relatively inexpensive articulating tube assembly  20 ,  120  that is capable of locking very rigidly in both straight and curved positions. Still another advantage of the present invention is that the surgical instrument  10 ,  110  includes tube articulation that provides rigidity in these positions sufficient to resist off axis loading such as that seen with power-tool cutting. A further advantage of the present invention is that the surgical instrument  10 , 110  includes tube articulation that allows for a large central opening to facilitate tissue extraction. Yet a further advantage of the present invention is that the surgical instrument  10 ,  110  includes an articulating tube assembly  20 , 120  that may provide a large central cannula that enables a variety of flexible devices to be inserted and so enables the articulating tube assembly  20 ,  120  to control their movement. Still a further advantage of the present invention is that the surgical instrument  10 ,  110  includes an articulating tube assembly  20 ,  120  capable of becoming rigid to resist off-axis loading. Yet still a further advantage of the present invention is that the surgical instrument  10 ,  110  includes an articulating tube assembly  20 ,  120  that has the ability to latch or bottom out in a straight position without snaking, and in a curved position, without snaking. 
     Referring to  FIGS.  40  through  50   , yet another embodiment, according to the present invention, of the surgical instrument  10  is shown. Like parts of the surgical instrument  10  have like reference numerals increased by one hundred (100). In one embodiment illustrated in  FIGS.  40  through  45   , the surgical instrument  210  includes the articulating tube assembly  220  having a proximal end and a distal end. The articulating tube assembly  220  includes the articulating region  223  disposed between the proximal end and the distal end and a proximal axis “P” axially extending from the proximal end to the articulating region  223 . The articulating tube assembly  220  includes the inner tube  224  and the outer tube  226  each having the articulating region  223 . The inner tube  224  and the outer tube  226  are movable relative to each other proximal to the articulating region  223  and fixed axially relative one another distal to the articulating region  223 . It should be appreciated that the articulating tube assembly  220  is similar to the articulating tube assembly  20 . It should also be appreciated that, in this embodiment of the surgical instrument  210 , the articulating tube assembly  220  is a single integrated instrument that is devoid of a working channel for receiving the working tool  12 . 
     The articulating region  223  is rigid in a first configuration and a second configuration relative to the proximal axis P to resist off-axial loading. In one embodiment, the first configuration may be a straight configuration relative to the proximal axis P and the second configuration may be a curved configuration relative to the proximal axis P. In another embodiment, the first configuration may be a curved configuration and the second configuration may be a curved configuration having a curvature greater than a curvature of the first configuration.  FIG.  50    illustrates one example of a curved configuration. The curved configuration extends only in a single plane up to one hundred eighty degrees relative to the proximal axis P. In another embodiment, the curved configuration extends in only a single plane up to one hundred twenty degrees relative to the proximal axis P. In yet another embodiment, the curved configuration extends in only a single plane up to ninety degrees relative to the proximal axis P. The inner tube  224  and outer tube  226  form an outer lumen and the mechanical mechanism for articulation. The inner tube  224  and outer tube  226  are sized so that the tubes  224 ,  226  slide over one another with a close fit. For example, the outer tube ( 226 ) has an outer diameter of approximately two millimeters (2 mm) to approximately twelve millimeters (12 mm). In one embodiment, lasercuts are made in each tube  224 ,  226  and the tubes  224  and  226  are welded together at the distal end in a position so that the lasercut sections overlap. The sections cut away from the tubes  224  and  226  allow them to bend in one direction, but not the other. In one embodiment, the inner tube  224  extends axially past a distal end of the outer tube  226 . When the tubes  224  and  226  are welded, and one tube  224 ,  226  is pushed or pulled axially relative to the other, the articulating region  223  of the articulating tube assembly  220  is caused to bend to a curved configuration. It should be appreciated that, at the extremes of motion (i.e., straight or fully bent), the tubes  224 ,  226  do not have mechanical backlash and thus are rigid. It should also be appreciated that, at the proximal end of the surgical instrument  210 , there are components that enable the surgeon to control the articulation and allow the surgical instrument  210  to attach to and be driven by a drive assembly (not shown). It should be further appreciated that a lasercut pattern for the inner tube  224  extends beyond the proximal and distal limits of the lasercut pattern for the outer tube  226  to prevent the articulating tube assembly  220  from possible fatiguing. 
     The inner tube  224  is fixed to a hub  400  to be described. The outer tube  226  includes a slot aperture  254  extending through a wall thereof and disposed between the articulating region  223  and the proximal end. The slot aperture  254  extends axially and is elongated. The outer tube  226  includes a pad  257  disposed in the slot aperture  254  and a tab  261  extending axially between the outer tube  226  and the pad  257  to temporarily connect the pad  257  to the outer tube  226 . The pad  257  is generally elongated axially. After the distal ends of the tubes  224  and  226  are fixed, the pad  257  of the outer tube  226  is welded to the inner tube  224 . The tab  261  of the outer tube  226  is then removed. It should be appreciated that the pad  257  acts as an anti-rotation mechanism between the inner tube  224  and the outer tube  226 . 
     The surgical instrument  210  also includes an actuation assembly  222   a  coupled to the articulating tube assembly  220  for moving the inner tube  224  and the outer tube  226  axially relative to each other for articulating the articulating region  223  of the articulating tube assembly  220  between a straight configuration and one or more curved configurations in only a single plane. The actuation assembly  222   a  includes a rotation assembly  288  disposed about the outer tube  226  to be rotated by a user. The rotation assembly  288  includes a tube receiving portion or hub  400  connected to the inner tube  224 . The hub  400  is generally cylindrical and circular in shape, but may be any suitable shape. The hub  400  includes a cavity  402  extending axially inward from a proximal end thereof and an aperture  404  extending axially inward from a distal end thereof to receive the inner tube  224 . The inner tube  224  is connected to the hub  400  by a suitable mechanism such as a friction fit, an adhesive, knurling, or thermally staking or thermally bonding to plastic. The hub  400  includes a groove  406  extending axially inward from the distal end of thereof. The groove  406  is generally circular in shape, but may be any suitable shape. The hub  400  includes a flange  408  extending radially from the distal end thereof and having an external groove  410  extending radially inward. The hub  400  may include one or more projections  412  extending axially and radially for coupling to a drive assembly (not shown). The hub  400  is made of a plastic material. The hub  400  is integral, unitary, and one-piece. 
     The rotation assembly  288  also includes a rotatable articulation control wheel  416  coupled to the outer tube  226  and being continuously adjustable to adjust a degree of curvature of the articulating region  223  of the articulating tube assembly  220  relative to the proximal axis P. The articulation control wheel  416  is generally cylindrical and circular in shape, but may be any suitable shape. In one embodiment illustrated in  FIGS.  40 - 43   , the articulation control wheel  416  includes a cavity  418  extending axially inward from a proximal end thereof and an aperture  420  extending axially inward from a distal end thereof into which the outer tube  226  extends. The cavity  418  includes one or more internal threads  422  extending axially and radially therealong. The articulation control wheel  416  includes a flange  424  extending axially from a proximal end thereof to form a recess  426  for receiving a portion of the hub  400 . The flange  424  includes a radial projection  428  disposed in the external groove  410  to attach the articulation control wheel  416  to the hub  400  by a radial snap fit. The articulation control wheel  416  may include a plurality of external projections  430  extending radially and axially and spaced circumferentially thereabout to be gripped by a hand of the user. The articulation control wheel  416  is made of a plastic material. The articulation control wheel  416  is integral. It should be appreciated that the articulation control wheel  416  is rotatable by the hand of the user of the surgical instrument  210 . It should also be appreciated that the only mechanical connection between the articulation control wheel  416  and the outer tube  226  is via the threads  422  of the articulation control wheel  416  interacting with threads of a lead screw  432  to be described that is bonded to the outer tube  226 . 
     The rotation assembly  288  includes a gear mechanism or lead screw  432  connected to the outer tube  226  and disposed in the cavity  418  of the articulation control wheel  416 . The lead screw  432  is generally cylindrical and circular in shape. The lead screw  432  has an aperture  434  extending axially therethrough to receive the outer tube  226 . The lead screw  432  is bonded to the proximal end of the outer tube  226 . The lead screw  432  has one or more external threads  436  extending radially and axially therealong to matingly engage the internal threads  422  in the cavity  418  of the articulation control wheel  416 . The internal threads  422  of the cavity  418  and the external threads  436  of the lead screw  432  contain a matching thread pattern that drives the lead screw  432 . The external threads  436  have a pitch of approximately 0.2 inches to approximately 0.6 inches to prevent unintentional translation of the lead screw  432  under load. It should be appreciated that the pitch used on the lead screw  432  ensures that the articulation control wheel  416  does not rotate under load and is dependent on the material and the size of the threads. 
     The rotation assembly  288  may further includes a wave spring  438  disposed between the hub  400  and the articulation control wheel  416  to keep the hub  400  under load between the straight and curved configurations. The wave spring  438  is generally circular in shape. The wave spring  438  is made of a spring material. The wave spring  438  may be disposed in the groove  406  of the hub  400 . It should be appreciated that, by turning the articulation control wheel  416  clockwise and anti-clockwise, the outer tube  226  of the articulating tube assembly  220  is pushed/pulled proximal/distal, causing articulation of the articulating region  223 . 
     In another embodiment illustrated in  FIGS.  46  through  50   , the articulation assembly  222   a  may include a locking assembly, generally indicated at  440 , cooperating with the rotation assembly  288  to lock the rotation assembly  288  in one or more positions such that the articulating region  223  is locked in one or more curvature configurations and prohibits the articulation control wheel  416  from turning. In the embodiment illustrated, the locking assembly  440  includes a projection  442  extending axially from a distal end of the articulation control wheel  416  and having a cavity  444  extending axially inward. The cavity  444  has a generally frustoconical or tapered shape. The projection  442  includes one or more external threads  446  extending axially and radially and disposed circumferentially thereabout. The projection  442  is integral, unitary, and one-piece with the articulation control wheel  416 . It should be appreciated that the cavity  444  communicates with the aperture  420  of the articulation control wheel  416 . 
     The locking assembly  449  also includes a floating collet  448  partially disposed in the cavity  444  of the projection  442  on the articulation control wheel  416 . The floating collet  448  is generally cylindrical and circular in shape, but may have any suitable shape. The floating collet  448  has a central aperture  450  extending axially therethrough to receive the articulating tube assembly  220 . The floating collet  448  has a plurality of slits or slots  452  extending axially therealong and disposed circumferentially thereabout and spaced from the central aperture  450  to allow the central aperture  450  to be compressed about the outer tube  226  of the articulating tube assembly  220 . The floating collet  448  includes a first frustoconical portion  454  at a proximal end thereof and a second frustoconical portion  456  at a distal end thereof. The cavity  444  of the projection  442  of the articulation control wheel  416  and the proximal end of the floating collet  448  have a tapered surface or shape to matingly engage each other. The floating collet  448  is made of a plastic material or a metal material. The floating collet  448  is integral, unitary, and one-piece. It should be appreciated that the locking assembly  440  engages with the outer tube  226  of the articulating tube assembly  220  and prevents the articulating tube assembly  220  from being actuated by the articulation control wheel  416  and lead screw  432 . It should also be appreciated that the locking assembly  440  may be engaged when the user has achieved their desired level of articulation and desires to lock the curvature of the articulating region  223  of the articulating tube assembly  220  in place. It should further be appreciated that the locking assembly  440  may only be necessary when the user is applying high levels of force. 
     The locking assembly  440  further includes a rotatable locking wheel  458  cooperating with the floating collet  448  and the projection  442  on the articulation control wheel  416 . The locking wheel  458  is generally cylindrical and circular in shape, but may have any suitable shape. The locking wheel  458  has a cavity  460  extending axially inward from a proximal end thereof and a plurality of internal threads  462  disposed in the cavity  460  and extending radially and axially therealong to mate with the external threads  446  on the projection  442  of the articulation control wheel  416 . The locking wheel  458  also has a frustoconical recess  464  extending axially inward from the cavity  460  to receive the second frustoconical portion  456  of the floating collet  448 . The frustoconical recess  464  of the locking wheel  458  and the second frustoconical portion  456  of the floating collet  448  have a tapered surface or shape to matingly engage each other to cause a friction lock on the outer tube  226  to prevent the outer tube  226  from moving axially. The locking wheel  458  may include a plurality of external projections  466  extending radially and axially and spaced circumferentially thereabout to be gripped by a hand of the user. The locking wheel  458  is made of a plastic material. The locking wheel  458  is integral, unitary, and one-piece. It should be appreciated that the floating collet  448  is shaped so that its internal diameter reduces as the locking wheel  458  is screwed down onto the projection  442  of the articulation control wheel  416 . It should also be appreciated that this causes a friction lock on the outer tube  226  of the articulating tube assembly  220 , thereby preventing the outer tube  226  from moving axially and causing unwanted bending or straightening of the articulating region  223  of the articulating tube assembly  220 . It should further be appreciated that the locking assembly  440  is optional. It should still be further appreciated that other articulating mechanisms may be used to provide a similar function of preventing the outer tube  226  from moving axially and causing unwanted bending or straightening of the articulating region  223  of the articulating tube assembly  220 . 
     Referring again to  FIGS.  40  through  45   , the surgical instrument  210  includes a torque member  470  disposed within the inner tube  224  and extending axially. The torque member  470  is generally cylindrical and circular in shape, but may be any suitable shape. The torque member  470  may be a hollow tube or a solid member. The torque member  470  may have a hollow distal end  472 . The torque member  470  may have a variable stiffness with a first stiffness in the articulating region  223  and a second stiffness greater than the first stiffness outside the articulating region  223 . The torque member  470  is made of a metal material. In one embodiment, the torque member  470  may be formed from wrapping wires helically into a tube shape known as a torque coil. The torque member  470  is integral. It should be appreciated that the rigidity of the torque member  470  in the straight section of the articulating tube assembly  220  reduces vibration during operation of a rotatable end effector  496  to be described. It should also be appreciated that the torque member  470  can transmit torque around the bent or curved articulating region  223  of the articulating tube assembly  220 . 
     The surgical instrument  210  also includes a driveshaft  474  coupled to the torque member  470 . The driveshaft  474  is generally cylindrical and circular in shape, but may have any suitable shape. The driveshaft  474  includes a cavity  476  extending axially inward from a distal end thereof for receiving a proximal end of the torque member  470 . The torque member  470  is mechanically bonded to the driveshaft  474  by a suitable mechanism such as a friction fit, adhesive, or keyway system (proximal end of the torque member  470  is machined to have a specific shape and is received with a matching shape in the driveshaft  474 ). The driveshaft  474  also includes a plurality of external cutaways  478  spaced from the cavity  476  and extending axially partially therealong that are adapted to be coupled to a drive assembly (not shown). The driveshaft  474  may be made of a plastic material or a metal material. The driveshaft  474  is integral, unitary, and one-piece. It should be appreciated that torque member  470  passes through the hub  400  and the proximal end is disposed in the cavity  402  and bonded to the driveshaft  474 , which interfaces with a drive mechanism of the drive assembly. 
     The surgical instrument  210  may include a suction path  480  formed between the inner tube  224  and the torque member  470 . The suction path  480  extends axially and circumferentially between the inner tube  224  and the torque member  470 . The suction path  480  includes at least one or more suction ports  482  extending through the inner tube  224  and the outer tube  226  and disposed axially between the articulating region  223  and a proximal end of a distal bearing to be described to allow removal of cutting debris and fluid therethrough and into the suction path  480 . The suction ports  482  are spaced circumferentially about the distal end of the outer tube  226 . The distal end of the suction path  480  fluidly communicates with the suction ports  482 . The proximal end of the suction path  480  fluidly communicates with the cavity  402  of the hub  400 . It should be appreciated that the suction ports  482  may be formed by lasercuts into the distal end of the articulating tube assembly  220  to allow removal of cutting debris and fluid from a joint undergoing arthroscopy. 
     The surgical instrument  210  also includes a proximal bearing  484  disposed in the suction path  480  proximal the articulating region  223  to support the torque member  470 . The proximal bearing  484  is generally cylindrical and circular in shape, but may be any suitable shape. The proximal bearing  484  has a central aperture  486  extending axially therethrough to allow the torque member  470  to extend through the proximal bearing  484 . The proximal bearing  484  includes a plurality of external cutaways  488  spaced from the central aperture  486  and extending axially therealong to allow fluid flow along the suction path  480  between the distal end and the proximal end of the suction path  480 . The proximal bearing  484  may be made of a plastic, ceramic, metal, or other suitable bearing material. The proximal bearing  484  may be integral, unitary, and one-piece. 
     It should be appreciated that, in order to prevent a rotatable end effector  496  to be described from vibrating due to the whip of the torque member  470  during rotation, the proximal bearing  484  is fixed just proximal to the articulating region  223  of the articulating tube assembly  220 . It should also be appreciated that the suction path  480  is in the lumen formed between the articulating tube assembly  220  and the torque member  470  and, for this reason, specific geometries are necessary on the proximal bearing  484  and the driveshaft  474  to allow unobstructed fluid flow therethrough to the drive assembly. 
     The surgical instrument  210  includes a distal bearing  490  disposed in the distal end of the inner tube  224  distal of the articulating region  223  to support an end effector to be described. The distal bearing  490  is generally cylindrical and circular in shape, but may have any suitable shape. The distal bearing  490  has a central aperture  492  extending axially therethrough. The distal bearing  490  has a flange  494  extending radially from a distal end thereof to abut the distal end of the inner tube  224 . The distal bearing  490  has a clam shell configuration. The distal bearing  490  may be made of a ceramic, metal, or other suitable bearing material. The distal bearing  490  may be integral. 
     The surgical instrument further includes an end effector disposed distal of the articulating region  223  and coupled to the torque member  470 . In one embodiment, the end effector is a rotatable end effector, generally indicated at  496 , such as a bur. The rotatable end effector  496  includes a head  498  at a distal end thereof and a shaft  500  extending from the head  498  to a proximal end coupled to the torque member  470 . The head  498  is generally spherical in shape, but may be any suitable shape. The head  498  may be fluted or coated with a diamond grit to enable cutting of bone. The shaft  500  is generally cylindrical and circular in shape, but may be any suitable shape. The shaft  500  extends through the central aperture  492  of the distal bearing  490 . The rotatable end effector  496  includes a flange  502  extending radially from the shaft  500  and disposed axially between the head  498  and the proximal end of the shaft  500 . The rotatable end effector  496  includes a groove  504  extending radially and axially between the flange  502  and the head  498 . The distal bearing  490  is disposed in the groove  504  to prevent the rotatable end effector  496  from exiting the distal bearing  490 . The rotatable end effector  496  includes a barb  506  at the proximal end of the shaft  500  to be disposed in the hollow distal end  472  of the torque member  470  and the flange  502  abuts the end of the torque member  470 . The barb  506  is secured to the torque member  470  by a suitable mechanism such as welding. It should be appreciated that the head  498  is machined with the groove  504 , allowing the rotatable end effector  496  to be held by the clamshell distal bearing  490  that fits into the distal end of the inner tube  224  of the articulating tube assembly  220 . It should also be appreciated that the rotatable end effector  496  has the barb  506  machined at the proximal end, allowing the hollow distal end  472  of the torque member  470  to be welded onto the rotatable end effector  496 . It should be further appreciated that other end effectors are contemplated other than rotatable end effectors such as any rotatable cutting element or tool. 
     In addition, a method of operating a surgical instrument ( 10 ,  110 ,  210 ) is disclosed in  FIG.  51   . The method includes the steps of providing an articulating tube assembly ( 20 ,  120 ,  220 ) having a proximal end and a distal end, an articulating region ( 23 ,  123 ,  223 ) disposed between the proximal end and the distal end, and a proximal axis P axially extending from the proximal end to the articulating region ( 23 ,  123 ,  223 ), the articulating tube assembly ( 20 ,  120 ,  220 ) including an inner tube ( 24 ,  124 ,  224 ) and an outer tube ( 26 ,  126 ,  226 ) each having the articulating region ( 23 ,  123 ,  223 ), the inner tube ( 24 ,  124 ,  224 ) and the outer tube ( 26 ,  126 ,  226 ) being movable relative to each other proximal to the articulating region ( 23 ,  123 ,  223 ) and fixed axially relative one another distal to the articulating region ( 23 ,  123 ,  223 ) in block  600 . The method also includes the steps of providing an actuation assembly ( 22 ,  122 ,  222   a ) coupled to the articulating tube assembly ( 20 ,  120 ,  220 ) in block  602 . 
     The method is used typically for joint arthroscopy to examine and reshape/perform surgery on the inside structure of the joint. The method is commonly used on knee joints. The procedure is performed by inserting the distal end of the articulating tube assembly ( 20 ,  120 ,  220 ) into the joint through a small incision in a patient. During this procedure, a separate tool is provided for irrigation of the joint. In addition, the inside of the joint is visualized using a separate arthroscopic camera. 
     The method includes the steps of rotating the rotation assembly ( 288 ) of the actuation assembly ( 222   a ) with one hand of the user in block  604  and moving the inner tube ( 24 ,  124 ,  224 ) and the outer tube ( 26 ,  126 ,  226 ) axially relative to each other in block  606 . The method includes the step of articulating the articulating region ( 23 ,  123 ,  223 ) of the articulating tube assembly ( 20 ,  120 ,  220 ) between a first configuration and a second configuration in only a single plane in block  608 . The method includes the steps of rotating the rotation assembly ( 288 ) of the actuation assembly ( 222   a ) by a user to move the inner tube ( 224 ) and the outer tube ( 226 ) axially relative to each other. The method includes the steps of locking a locking assembly  440  cooperating with the rotation assembly ( 288 ) to lock the rotation assembly ( 288 ) in one or more positions such that the articulating region ( 223 ) is locked in one or more curvature configurations and does not straighten under load. 
     The method includes the steps of providing a working tool  12  separate from the surgical instrument ( 10 ,  110 ). The working tool  12  may provide irrigation fluid adjacent the distal end of the articulating tube assembly ( 20 ,  120 ) and/or may provide visualization of the joint such as an arthroscopic camera. The method further includes the steps of using the working tool  12  with another or other hand of the user. 
     Accordingly, the surgical instrument  10 ,  110 ,  210  of the present invention incorporates a ridged locking articulation described above that provides the ability to remove the impingement among other clinical needs, and a viewing assembly  240  described above places a tiny visualization imaging element  246  very near the tip of the working tool  12  to give the surgeon the vision required to perform the task. The surgical instrument  10 ,  110  of the present invention includes an articulation tube assembly  20  that is capable of locking in a rigid position that becomes useful when there are tools  12  capable of being controlled by the articulating tube assembly  20 . It should be appreciated that, in another embodiment, the surgical instrument  10 ,  110  may be used with the working tools  12  or the articulating tube assembly  20 ,  120  is integrated as part of the working tool  12  and might serve as the shaft portion  14  of the working tool  12  to be a dedicated tool or instrument. 
     Further, the surgical instrument  210  of the present invention has the ability to articulate from straight to up to one hundred eighty degree bend and an articulating end effector that is rigid with no backlash at extremes of articulation (straight or fully bent), allowing a surgeon to place sufficient force on a head of the end effector to debride bone in a controlled manner. The surgical instrument  210  of the present invention has a locking assembly to provide robust lock at the desired bend position, giving the surgeon assurance that the articulating region  223  will not straighten under load at intermediate bend positions where there will be some mechanical backlash. A method of operating the surgical instrument  210  of the present invention provides positioning of the head immediately distal of the articulating portion while also having suction functionality, which is a necessity in arthroscopy where the joint spaces are very small. The method of operating the surgical instrument  210  of the present invention allows for controlling the articulation that can be actuated using one hand, which is necessary for arthroscopy where the surgeon&#39;s other hand is using the arthroscope. 
     Clause 1: A surgical instrument ( 10 ,  110 ,  210 ) comprising: an articulating tube assembly ( 20 ,  120 ,  220 ) having a proximal end and a distal end, an articulating region ( 23 ,  123 ,  223 ) disposed between the proximal end and the distal end, and a proximal axis axially extending from the proximal end to the articulating region ( 23 ,  123 ,  223 ), the articulating tube assembly ( 20 ,  120 ,  220 ) including an inner tube ( 24 ,  124 ,  224 ) and an outer tube ( 26 ,  126 ,  226 ) each having the articulating region ( 23 ,  123 ,  223 ), the inner tube ( 24 ,  124 ,  224 ) and the outer tube ( 26 ,  126 ,  226 ) being movable relative to each other proximal to the articulating region ( 23 ,  123 ,  223 ) and fixed axially relative one another distal to the articulating region ( 23 ,  123 ,  223 ); and an actuation assembly ( 22 ,  122 ,  222   a ) coupled to the articulating tube assembly ( 20 ,  120 ,  220 ) for moving the inner tube ( 24 ,  124 ,  224 ) and the outer tube ( 26 ,  126 ,  226 ) axially relative to each other for articulating the articulating region ( 23 ,  123 ,  223 ) of the articulating tube assembly ( 20 ,  120 ,  220 ) between a first configuration and a second configuration, wherein the articulating region ( 23 ,  123 ,  223 ) is rigid in the first configuration and the second configuration. 
     Clause 2: A surgical instrument ( 10 ,  110 ,  210 ) as set forth in claim  1  wherein the rigidity of the articulating region ( 23 ,  123 ,  223 ) in the first configuration and the second configuration relative to the proximal axis is defined as resisting off-axis loading and the second configuration has a different curvature from the first configuration relative to the proximal axis. 
     Clause 3: A surgical instrument ( 10 ,  110 ,  210 ) as set forth in claim  1  or  2  wherein the first configuration and the second configuration extends in only a single plane up to one hundred twenty degrees relative to the proximal axis. 
     Clause 4: A surgical instrument ( 10 ,  110 ,  210 ) as set forth in any one of claim  1 - 3  wherein the articulating tube assembly ( 20 ,  120 ,  220 ) includes a rotation assembly ( 88 ,  188 ,  288 ) disposed about the outer tube ( 26 ,  126 ,  226 ) to be rotated by a user. 
     Clause 5: A surgical instrument ( 10 ) as set forth in any one of claims  1 - 4  including a viewing assembly ( 240 ) coupled to the articulating tube assembly ( 20 ) for allowing an operator to view the distal end of the articulating tube assembly ( 20 ). 
     Clause 6: A surgical instrument ( 10 ) as set forth in claim  5  wherein the view assembly ( 240 ) includes a main tube ( 242 ) and an imaging device ( 246 ) coupled to the main tube ( 242 ) and being capable of being moved along and rotated about the proximal axis of the articulating tube assembly ( 20 ). 
     Clause 7: A surgical instrument ( 10 ) as set forth in any one of claims  1 - 5  including an illumination assembly ( 248 ) coupled to the articulating tube assembly ( 20 ) for providing illumination to the distal end of the articulating tube assembly ( 20 ). 
     Clause 8: A surgical instrument ( 10 ) as set forth in claim  7  wherein the illumination assembly ( 248 ) includes a main tube ( 242 ) and an illumination device ( 250 ) coupled to the main tube ( 242 ) and being capable of being moved along and rotated about the proximal axis of the articulating tube assembly ( 20 ). 
     Clause 9: A surgical instrument ( 10 ,  110 ) as set forth in any one of claim  1 - 5  wherein the articulating region ( 23 ,  123 ) includes one or more articulating segments ( 72 ,  172 ) in the outer tube ( 26 ,  126 ). 
     Clause 10: A surgical instrument ( 10 ,  110 ) as set forth in claim  9  wherein the one or more articulating segments ( 72 ,  172 ) each include a protrusion ( 78 ,  178 ) extending axially in one direction and a recess ( 80 ,  180 ) extending axially in an opposed direction, the protrusion ( 78 ,  178 ) of one segment ( 72 ,  172 ) being disposed in the recess ( 80 ,  180 ) of an adjacent segment ( 72 ,  172 ). 
     Clause 11: A surgical instrument ( 10 ,  110 ) as set forth in claim  9  or  10  wherein the outer tube ( 26 ,  126 ) includes a plurality of apertures ( 60 ,  160 ) spaced axially and forming a plurality of beams ( 62 ,  162 ) extending axially and a plurality of tie straps ( 668 ,  168 ) extending circumferentially to the beams ( 62 ,  162 ). 
     Clause 12: A surgical instrument ( 10 ,  110 ) as set forth in claim  11  wherein articulating region ( 23 ,  123 ) includes one or more articulating segments ( 44 ,  144 ) in the inner tube ( 24 ,  124 ). 
     Clause 13: A surgical instrument ( 10 ,  110 ) as set forth in claim  12  wherein the inner tube ( 24 ,  124 ) includes a plurality of apertures ( 42 ,  142 ) spaced axially and forming a plurality of beams ( 34 ,  134 ) extending axially and a plurality of tie straps ( 40 ,  140 ) extending circumferentially to the beams ( 42 ,  142 ). 
     Clause 14: A surgical instrument ( 10 ,  110 ) as set forth in claim  13  wherein the beams ( 34 ,  134 ) of the inner tube ( 24 ,  124 ) and the beams ( 62 , 162 ) of the outer tube ( 26 ,  126 ) are approximately 180 degrees opposed from one another. 
     Clause 15: A surgical instrument ( 10 ,  110 ) as set forth in any one of claim  12  or  13  wherein the outer tube ( 26 ,  126 ) includes a plurality of faces configured to seat and secure the articulating region ( 23 ,  123 ) in a straight configuration. 
     Clause 16: A surgical instrument ( 10 ,  110 ) as set forth in any one of claims  1 - 5  wherein the actuation assembly ( 22 ,  122 ) includes a tube receiving portion ( 150 ,  250 ) to receive the articulating tube assembly ( 20 ,  120 ). 
     Clause 17: A surgical instrument ( 10 ) as set forth in claim  16  wherein the actuation assembly ( 22 ) includes at least one trigger ( 146 ,  148 ) for articulating the articulating tube assembly ( 20 ). 
     Clause 18: A surgical instrument ( 110 ) as set forth in claim  16  wherein the actuation assembly ( 122 ) includes at least one lever ( 380 ) for articulating the articulating tube assembly ( 120 ). 
     Clause 19: A surgical instrument ( 10 ) as set forth in claim  4  wherein the rotation assembly ( 88 ) includes a rotatable member to allow the user to rotate the articulating tube assembly ( 20 ). 
     Clause 20: A surgical instrument ( 10 ,  110 ) as set forth in any one of claims  1 - 5  wherein the articulating tube assembly ( 20 ,  120 ) is hollow to form a working channel adapted to receive a surgical tool ( 12 ). 
     Clause 21: A surgical instrument ( 10 ,  110 ) as set forth in any one of claim  1 - 5  wherein the articulating tube assembly ( 20 ,  120 ) is a single integrated instrument devoid of a passage adapted to receive fluid flow for irrigation. 
     Clause 22: A surgical instrument ( 210 ) as set forth in claim  4  wherein the rotation assembly ( 288 ) comprises a rotatable articulation control wheel ( 416 ) coupled to the outer tube ( 226 ) and being continuously adjustable to adjust a degree of curvature of the articulating region ( 223 ) relative to the proximal axis. 
     Clause 23: A surgical instrument ( 210 ) as set forth in claim  22  wherein the articulation control wheel ( 416 ) includes a first cavity ( 444 ) extending axially inward from a distal end thereof and a second cavity ( 418 ) extending inward from a proximal end thereof. 
     Clause 24: A surgical instrument ( 210 ) as set forth in claim  23  wherein the second cavity ( 418 ) includes one or more internal threads ( 422 ). 
     Clause 25: A surgical instrument ( 210 ) as set forth in claim  24  including a lead screw ( 432 ) connected to the outer tube ( 226 ) and having one or more external threads ( 436 ) disposed in the second cavity ( 418 ) of the articulation control wheel ( 416 ) to matingly engage the internal threads ( 422 ). 
     Clause 26: A surgical instrument ( 210 ) as set forth in claim  25  wherein the external threads ( 436 ) have a pitch of approximately 0.2 inches to approximately 0.6 inches to prevent translation of the lead screw ( 432 ) under load. 
     Clause 27: A surgical instrument ( 210 ) as set forth in claim  25  or  26  including a hub ( 400 ) connected to the inner tube ( 224 ) and having an external groove ( 410 ) at a distal end thereof. 
     Clause 28: A surgical instrument ( 210 ) as set forth in claim  27  wherein the articulation control wheel ( 416 ) includes a radial projection ( 428 ) disposed in the external groove ( 410 ) to attach the articulation control wheel ( 416 ) to the hub ( 400 ) by a radial snap fit. 
     Clause 29: A surgical instrument ( 210 ) as set forth in claim  27  or  28  including a wave spring ( 438 ) disposed between the hub ( 400 ) and the articulation control wheel ( 416 ) to keep the lead screw ( 432 ) under load and to prevent translation of the lead screw ( 432 ) during use. 
     Clause 30: A surgical instrument ( 210 ) as set forth in any one of claims  23 - 29  including a locking assembly ( 440 ) cooperating with the rotation assembly ( 288 ) to lock the rotation assembly ( 288 ) in one or more positions such that the articulating region ( 223 ) is locked in one or more curvature configurations and prohibits rotation of the rotation assembly ( 288 ). 
     Clause 31: A surgical instrument ( 210 ) as set forth in claim  30  wherein the locking assembly ( 440 ) includes a floating collet ( 448 ) disposed in the first cavity ( 444 ) of the articulation control wheel ( 416 ) and having a central aperture ( 450 ) to allow the articulating tube assembly ( 220 ) to extend axially therethrough. 
     Clause 32: A surgical instrument ( 210 ) as set forth in claim  31  wherein the floating collet ( 448 ) has a plurality of slits ( 452 ) disposed circumferentially thereabout and spaced from the central aperture ( 450 ) to allow the central aperture ( 450 ) to be compressed about the outer tube ( 226 ). 
     Clause 33: A surgical instrument ( 210 ) as set forth in claim  32  wherein the first cavity ( 444 ) of the articulation control wheel ( 416 ) and a proximal end of the floating collet ( 448 ) having a tapered shape to matingly engage each other. 
     Clause 34: A surgical instrument ( 210 ) as set forth in claim  33  wherein the articulation control wheel ( 416 ) includes one or more external threads ( 446 ) at a distal end thereof. 
     Clause 35: A surgical instrument ( 210 ) as set forth in claim  34  wherein the locking assembly ( 440 ) includes a locking wheel ( 458 ) having a cavity ( 460 ) extending axially inward from a proximal end thereof and a plurality of internal threads ( 462 ) disposed in the cavity ( 460 ) to mate with the external threads ( 446 ) of the articulation control wheel ( 416 ). 
     Clause 36: A surgical instrument ( 210 ) as set forth in claim  35  wherein the locking wheel ( 458 ) and a distal end of the floating collet ( 448 ) have a tapered shape to matingly engage each other to cause a friction lock on the outer tube ( 226 ) to prevent the outer tube ( 226 ) from moving axially. 
     Clause 37: A surgical instrument ( 210 ) as set forth in any one of claims  22 - 36  including a torque member ( 470 ) disposed within the inner tube ( 224 ) and extending axially. 
     Clause 38: A surgical instrument ( 210 ) as set forth in claim  37  wherein the torque member ( 470 ) has a variable stiffness with a first stiffness in the articulating region ( 223 ) and a second stiffness greater than the first stiffness outside the articulating region ( 223 ). 
     Clause 39: A surgical instrument ( 210 ) as set forth in claim  37  or  38  including a suction path ( 480 ) formed between the inner tube ( 224 ) and the torque member ( 470 ). 
     Clause 40: A surgical instrument ( 210 ) as set forth in claim  39  including a proximal bearing ( 484 ) disposed in the suction path ( 480 ) proximal the articulating region ( 223 ) and having a central aperture ( 486 ) extending therethrough to allow the torque member ( 470 ) to extend through the proximal bearing ( 484 ). 
     Clause 41: A surgical instrument ( 210 ) as set forth in claim  40  wherein the proximal bearing ( 484 ) includes a plurality of external cutaways ( 488 ) spaced from the central aperture ( 484 ) and extending axially therethrough to allow fluid flow along the suction path ( 480 ) between the proximal end to the distal end. 
     Clause 42: A surgical instrument ( 210 ) as set forth in claim  40  or  41  including a distal bearing ( 490 ) disposed in the distal end of the inner tube ( 224 ) distal of the articulating region ( 223 ) and having a central aperture ( 492 ) extending axially therethrough. 
     Clause 43: A surgical instrument ( 210 ) as set forth in claim  42  including at least one suction port ( 482 ) extending through the inner tube ( 224 ) and the outer tube ( 226 ) and disposed between the articulating region ( 223 ) and a proximal end of the distal bearing ( 490 ) to allow removal of cutting debris and fluid therethrough and into the suction path ( 480 ). 
     Clause 44: A surgical instrument ( 210 ) as set forth in claim  42  or  43  including a rotatable end effector ( 496 ) disposed distal of the articulating region ( 223 ) and coupled to the torque member ( 470 ). 
     Clause 45: A surgical instrument ( 210 ) as set forth in claim  44  wherein the rotatable end effector ( 496 ) includes a head ( 498 ) at a distal end thereof and a shaft ( 500 ) extending from the head ( 498 ) through the central aperture ( 492 ) of the distal bearing ( 490 ) to a proximal end coupled to the torque member ( 470 ). 
     Clause 46: A surgical instrument ( 210 ) as set forth in claim  45  wherein the rotatable end effector ( 496 ) includes a flange ( 502 ) extending radially from the shaft ( 500 ) and disposed axially between the head ( 498 ) and the proximal end of the shaft ( 500 ) and a groove ( 504 ) extending radially into the shaft ( 500 ) axially between the flange ( 502 ) and the head ( 498 ). 
     Clause 47: A surgical instrument ( 210 ) as set forth in claim  46  wherein the distal bearing ( 490 ) has a clam shell configuration disposed in the groove ( 504 ) to prevent the rotatable end effector ( 496 ) from exiting the distal bearing ( 490 ). 
     Clause 48: A surgical instrument ( 210 ) as set forth in claim  46  or  47  wherein the torque member ( 470 ) has a hollow distal end ( 472 ) and the rotatable end effector ( 496 ) includes a barb ( 506 ) at the proximal end of the shaft ( 500 ) to be disposed in the hollow distal end ( 472 ) of the torque member ( 470 ). 
     Clause 49: A surgical instrument ( 210 ) as set forth in any one of claim  37 - 48  including a driveshaft ( 474 ) coupled to the torque member ( 470 ). 
     Clause 50: A surgical instrument ( 210 ) as set forth in claim  49  wherein the driveshaft ( 474 ) includes a cavity ( 476 ) for receiving a proximal end of the torque member ( 470 ) and a plurality of external cutaways ( 478 ) spaced from the cavity ( 476 ) and extending axially therethrough adapted to be coupled to a drive assembly. 
     Clause 51: A surgical instrument ( 210 ) as set forth in any one of claims  22 - 50  wherein the outer tube ( 226 ) has an outer diameter of approximately two millimeters (2 mm) to approximately twelve millimeters (12 mm). 
     Clause 52: A surgical instrument ( 210 ) as set forth in any one of claims  22 - 51  wherein the articulating tube assembly ( 220 ) is a single integrated instrument devoid of a working channel for receiving a surgical tool ( 12 ). 
     Clause 53: A surgical instrument ( 10 ,  110 ) comprising: an articulating tube assembly ( 20 ,  120 ) having a proximal end and a distal end, an articulating region ( 23 ,  123 ) disposed between the proximal end and the distal end, and a proximal axis axially extending from the proximal end to the articulating region ( 23 ,  123 ), the articulating tube assembly ( 20 ,  120 ) including an inner tube ( 24 ,  124 ) and an outer tube ( 26 ,  126 ) each having the articulating region ( 23 ,  123 ), the inner tube ( 24 ,  124 ) and the outer tube ( 26 ,  126 ) being movable relative to each other proximal to the articulating region ( 23 ,  123 ) and fixed axially relative one another distal to the articulating region ( 23 ,  123 ); an actuation assembly ( 22 ,  122 ) coupled to the articulating tube assembly ( 20 ,  120 ) for moving the inner tube ( 24 ,  124 ) and the outer tube ( 26 ,  126 ) axially relative to each other for articulating the articulating region ( 23 ,  123 ) of the articulating tube assembly ( 20 ,  120 ) between a first configuration and a second configuration in only a single plane; a viewing assembly ( 240 ) coupled to the articulating tube assembly ( 20 ,  120 ) for allowing an operator to view the distal end of the articulating tube assembly ( 20 ,  120 ); an illumination assembly ( 248 ) coupled to the articulating tube assembly ( 20 ,  120 ) for providing illumination to the distal end of the articulating tube assembly ( 20 ,  120 ). 
     Clause 54: A surgical instrument ( 210 ) comprising: an articulating tube assembly ( 220 ) having a proximal end and a distal end, an articulating region ( 223 ) disposed between the proximal end and the distal end, and a proximal axis axially extending from the proximal end to the articulating region ( 223 ), the articulating tube assembly ( 220 ) including an inner tube ( 224 ) and an outer tube ( 226 ) each having the articulating region ( 223 ), the inner tube ( 224 ) and the outer tube ( 226 ) being movable relative to each other proximal to the articulating region ( 223 ) and fixed axially relative one another distal to the articulating region ( 223 ); an actuation assembly ( 222   a ) coupled to the articulating tube assembly ( 220 ) for moving the inner tube ( 224 ) and the outer tube ( 226 ) axially relative to each other for articulating the articulating region ( 223 ) of the articulating tube assembly ( 220 ) between a first configuration and a second configuration; a torque member ( 470 ) disposed within the inner tube ( 224 ); a rotatable end effector ( 496 ) disposed distal of the articulating region ( 223 ) coupled to the torque member ( 470 ); and a driveshaft ( 474 ) coupled to the torque member ( 470 ) and adapted to be coupled to a drive assembly to drive the torque member ( 470 ) and the rotatable end effector ( 496 ). 
     Clause 55: A surgical instrument ( 210 ) as set forth in claim  54  wherein the actuation assembly ( 222   a ) comprises a rotation assembly ( 288 ) disposed about the outer tube ( 226 ) to be rotated by a user to move the inner tube ( 224 ) and the outer tube ( 226 ) axially relative to each other. 
     Clause 56: A surgical instrument ( 210 ) as set forth in claim  55  including a locking assembly ( 440 ) cooperating with the rotation assembly ( 288 ) to lock the rotation assembly ( 288 ) in one or more positions such that the articulating region ( 223 ) is locked in one or more curvature configurations and prohibits rotation of the rotation assembly ( 288 ). 
     Clause 57: A surgical instrument ( 210 ) as set forth in any one of claims  54 - 56  wherein the articulating region ( 223 ) is rigid in a straight configuration and in a curved configuration in only one a single plane up to one hundred eighty degrees relative to the proximal axis. 
     Clause 58: A surgical instrument ( 210 ) as set forth in any one of claims  54 - 57  including a suction path ( 480 ) formed between the inner tube ( 224 ) and the torque member ( 470 ). 
     Clause 59: A surgical instrument ( 210 ) as set forth in claim  58  including a proximal bearing ( 484 ) disposed in the suction path ( 480 ) proximal the articulating region ( 223 ) and having a central aperture ( 486 ) extending axially therethrough to allow the torque member ( 470 ) to extend through the proximal bearing ( 484 ). 
     Clause 60: A surgical instrument ( 210 ) as set forth in claim  59  wherein the proximal bearing ( 484 ) includes a plurality of external cutaways ( 488 ) spaced from the central aperture ( 486 ) and extending axially therethrough to allow fluid flow along the suction path ( 480 ) between the proximal end to the distal end. 
     Clause 61: A surgical instrument ( 210 ) as set forth in claim  59  or  60  including a distal bearing ( 490 ) disposed in the distal end of the outer tube ( 226 ) distal of the articulating region ( 223 ) and having a central aperture ( 492 ) extending axially therethrough. 
     Clause 62: A surgical instrument ( 210 ) as set forth in claim  61  including at least one suction port ( 482 ) extending through the inner tube ( 224 ) and the outer tube ( 226 ) and disposed between the articulating region ( 223 ) and a proximal end of the distal bearing ( 490 ) to allow removal of cutting debris and fluid therethrough and into the suction path ( 480 ). 
     Clause 63: A surgical instrument ( 210 ) as set forth in claim  61  or  62  wherein the end effector ( 496 ) includes a head ( 498 ) at a distal end thereof, a shaft extending from the head, a flange ( 502 ) extending radially from the shaft ( 500 ) and disposed axially between the head ( 498 ) and the proximal end of the shaft ( 500 ), and a groove ( 504 ) extending radially into the shaft ( 500 ) axially between the flange ( 502 ) and the head ( 498 ). 
     Clause 64: A surgical instrument ( 210 ) as set forth in claim  63  wherein the distal bearing ( 490 ) has a clam shell configuration disposed in the groove ( 504 ) to prevent the end effector ( 496 ) from exiting the distal bearing ( 490 ). 
     Clause 65: A surgical instrument ( 210 ) as set forth in claim  63  or  64  wherein the torque member ( 470 ) has a hollow distal end ( 472 ) and the rotatable end effector ( 496 ) includes a barb ( 506 ) at the proximal end of the shaft ( 500 ) to be disposed in the hollow distal end ( 472 ) of the torque member ( 470 ). 
     Clause 66: A method of operating a surgical instrument ( 10 ,  110 ,  210 ), the method comprising the steps of: providing an articulating tube assembly ( 20 ,  120 ,  220 ) having a proximal end and a distal end, an articulating region ( 23 ,  123 ,  223 ) disposed between the proximal end and the distal end, and a proximal axis axially extending from the proximal end to the articulating region ( 23 ,  123 ,  223 ), the articulating tube assembly ( 20 ,  120 ,  220 ) including an inner tube ( 24 ,  124 ,  224 ) and an outer tube ( 26 ,  126 ,  226 ) each having the articulating region ( 23 ,  123 ,  223 ), the inner tube ( 24 ,  124 ,  224 ) and the outer tube ( 26 ,  126 ,  226 ) being movable relative to each other proximal to the articulating region ( 23 ,  123 ,  223 ) and fixed axially relative one another distal to the articulating region ( 23 ,  123 ,  223 ); providing an actuation assembly ( 22 ,  122 ,  222   a ) coupled to the articulating tube assembly ( 20 ,  120 ,  220 ); and rotating a rotation assembly ( 288 ) of the actuation assembly ( 222   a ) with one hand of a user and moving the inner tube ( 24 ,  124 ,  224 ) and the outer tube ( 26 ,  126 ,  226 ) axially relative to each other for articulating the articulating region ( 23 ,  123 ,  223 ) of the articulating tube assembly ( 20 ,  120 ,  220 ) between a first configuration and a second configuration in only a single plane. 
     Clause 67: A method as set forth in claim  66  including the step of locking a locking assembly ( 440 ) cooperating with the rotation assembly ( 288 ) to lock the rotation assembly ( 288 ) in one or more positions such that the articulating region ( 223 ) is locked in one or more curvature configurations. 
     Clause 68: A method as set forth in claim  66  or  67  including the step of rotating a rotatable end effector ( 496 ) extending out a distal end of the inner tube ( 224 ). 
     Clause 69: A method as set forth in any one of claims  66 - 68  including the step of providing a tool ( 12 ) separate from the surgical instrument ( 10 ,  110 ) for providing irrigation fluid adjacent the distal end of the articulating tube assembly ( 20 ,  120 ). 
     Clause 70: A method as set forth in any one of claims  66 - 69  including the step of using the tool ( 12 ) with another hand of the user. 
     The present invention has been described in an illustrative manner. It is to be understood that the terminology, which has been used, is intended to be in the nature of words of description rather than of limitation. Many modifications and variations of the present invention are possible in light of the above teachings. Therefore, the present invention may be practiced other than as specifically described.