Patent Publication Number: US-2010121141-A1

Title: Endoscopic cutting and debriding device mounted on a flexible and maneuverable tube employing a fluid-driven turbine

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority of U.S. Provisional Patent Application Ser. No. 61/113,929 filed Nov. 12, 2008, which is incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to endoscopes, laparoscopes or the like, and more particularly to a steerable, endoscopically guided fluid turbine powered device with detachable distal tip tools for cutting and burring that can be passed through body cavities to affect cutting and grind/milling of either hard or soft tissue. 
     BACKGROUND OF THE INVENTION 
     In certain surgical procedures performed within passages of the human body, it may be necessary to remove bone or bard tissue by a grinding or milling process as well as removing softer tissue with a debriding instrument. For example, in sinus surgery it is often necessary to debride soft tissue overlying a bony structure and then grind away portions of the bone to remove infected areas. These surgical operations were originally performed using manual instruments which had to be inserted through bodily passages to the surgical site and then manipulated by the surgeon without the benefit of any image of the surgical site to remove the infected areas. More recently, elongated tubular endoscopes with steerable end sections have been employed for these operations. These endoscopes include optical systems which allow the physician to view the operating site from the proximal end of the instrument, outside of the body. Certain of these devices have employed illumination systems comprising light sources at the proximal end, usually LEDs, which pass light through optical fibers extending at least partially through the endoscope tube to illuminate the surgical site at the distal end, and imaging optics feeding return fibers which allow the surgeon to visualize the surgical site from the proximal end. 
     The use of optical fibers eliminates the need to transmit electrical currents through the endoscope to power the illumination of the surgical site by means of an electrically energized illumination source disposed at the distal end. The passage of electric currents through the endoscope always creates the possibility of accidental introduction of the electrical currents to the area of the surgical site. 
     However, when rotary powered surgical instruments such as mills, grinders, or debriders must be powered, either electrical currents must be introduced to the distal end through the endoscope to power electric motors or rather cumbersome rotary shafts must carry power from the proximal to the distal ends of the device. This may be relatively easy to do if the instrument is rigid, but flexible, steerable endoscopes can reach surgical sites unattainable by rigid instruments. 
     SUMMARY OF THE INVENTION 
     The present invention overcomes these problems by providing an endoscope with a flexible section that may be manipulated from the proximal end by the surgeon to steer the instrument to a desired surgical site in which no electrical power is provided to the distal end. 
     In a preferred embodiment of the invention these goals are achieved by providing a fluid powered rotary turbine adjacent the distal end and powering the turbine by fluids pumped through a flexible lumen in the endoscope tube. The turbine shaft is connected to selected surgical cutters, mills, grinders and the like which operate on the surgical site. 
     In a preferred embodiment of the invention, which will be subsequently disclosed in detail, the turbine shaft powers the operating surgical instruments through a detachable connection which allows different surgical tools to be connected to the endoscope. For example, a debrider of the type employing an interior cutting tube mounted within an outer cutter housing may be used to remove soft tissue. The inner cutter member may be hollow and connected to a source of suction introduced from the proximal end, which passes through a second lumen in the endoscope. The fluid which turns the turbine may also be used to cool the surgical cutter or bathe the surgical area, with biofilm reducing agents or the like. 
     In a preferred embodiment of the invention, the control of the bendable distal end of the endoscope tube to allow the surgeon to steer the endoscope through bodily passages is achieved by employing two pairs of guide wires which extend through the length of the endoscope and may be manually manipulated by the surgeon to impose steering forces on the distal tip. One pair of diametrically opposed guide wires may be used to steer the end in a first direction and another pair, rotated by 90 degrees with respect to the first pair, may be used to manipulate the end in an orthogonal direction. Either individual control levers may be used for the two wire pairs or a single joystick-type arrangement may be used to manipulate all four guide wires simultaneously. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Other objects, advantages and applications of the present invention will be made apparent by the following detailed description of preferred embodiments of the invention. The description makes reference to the accompanying drawings in which: 
         FIG. 1  is a perspective view of a preferred embodiment of the surgical endoscope of the present invention being used to operate upon the sinus in patient&#39;s head illustrated in cross section; 
         FIG. 2  is a cross sectional view of the distal end of the endoscope of  FIG. 1  with a debriding cutter attached to the end; 
         FIG. 3  is a cross sectional view similar to  FIG. 2  in which the debriding attachment is separated from the distal end of the endoscope; 
         FIG. 4  is a cross-sectional view through the distal end of the endoscope of  FIG. 1  with a burring or milling attachment joined to the distal end and connected to the shaft of a fluid turbine; and 
         FIG. 5  is a cross-sectional view through a distal end of an alternative embodiment of the endoscope with a debriding attachment of the type illustrated in  FIG. 2  connected. 
     
    
    
     DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT 
     Referring to the drawings, and  FIG. 1  in particular, a surgical endoscope forming a preferred embodiment of the invention, generally indicated at  10 , comprises an elongated, tubular section  12  supported by a surgeon at the proximal end with a handle member, generally indicated at  14 . The handle  14  is of the pistol grip type having a thumb actuated joystick  16  which the surgeon may use to bend the distal end of the tube  12  to guide it through passages to the operating site, in this case constituting a frontal sinus. The site is then operated on by a rotary tool  18  which is illustrated as a debriding tool in  FIG. 1 . 
     A fiber optic bundle  20  extends through the inside of the tube  12  from a point slightly separated from the proximal end. It ends at an ocular eyepiece  22  which may include appropriate controls such as a dioptric adjustment control  24 . It could further include a photo electric converter which converts the optical signals passing through the fiber optic bundle  20  to an electrical signal which could be connected to a video display (not shown), or, alternatively to a radio transmitter for wirelessly connecting to a video display. 
     The proximal end  14  of the endoscope tube  12  connects to a fluid pump  26  and a suction pump  28  which are respectively connected to a source and a sump for a fluid (not shown), typically water. The fluid may include various additives such as biofilm reducing agents, antiseptics and the like. The pump  26  is adapted to the pump fluid from the source into a lumen in the endoscope tube  12  and the suction device  28  removes the fluid from the distal end of the endoscope tube through a second lumen. 
     A light source, preferable a LED  30 , is connected to a fiber optic bundle  32  which extends through the handle into the endoscope tube  12 . 
     The endoscope tube  12  is either flexible along its entire length or has a flexible section near the distal end, which may be controlled by the joystick  16  to form a gradual bend in the distal end to steer the endoscope through nonlinear bodily passages during insurtion to the surgical site as well subsequently described in more detail. 
       FIG. 2  illustrates a cross section through the endoscope tube adjacent to the distal end. A debriding cutter  18  detachably connected to the distal end of the tube  12 . The tube  12  includes a pair of lobes  34  and  36  which extend outwardly from diametrically opposed points on the distal end of the tube and house the termination of two fiber optic bundles  38  an  40 . The lobe  34  receives the distal termination of a fiber optic bundle  38 , which is an extension of the fiber optic bundle  32  which is connected to the light source  30 . It preferably has a lens  40  connected on its distal end which acts to illuminate the operating site for the surgeon&#39;s viewing. The lobe  36  carries the termination of a second fiber optic bundle  42  which forms an extension of the bundle  20  which connects to the eyepiece  22 . It similarly terminates in a collecting lens  44 . The lens transmits an image of the surgical site illuminated by a light from the lens  40  back to the eyepiece  22 . 
     A turbine housing  50  is detachably coupled to the distal end of the tube  12  by connectors  52  and  54  so as to be removable for maintenance purposes. 
     Four cables  56 , two of which are visible in the cross section of  FIG. 2 , extend through the endoscope tube  12  and the turbine housing  50 , at 90 degree spacings to one another. Each of the cables  56  terminates in an attachment  58  at the distal end of the turbine housing  50 . These cables  56  are used to bend the distal end of the endoscope tube  12  under control of the joystick  16 . By manipulating the joystick  16  in a particular direction, the surgeon pulls on certain cables  56  and relaxes the tension on others, so as to impose a bending force on the tube. The joystick allows the tube end to be manipulated in a selected direction. 
     The particular manner of steering of the distal end of the endoscope is not critical to the present invention and other systems, such as any of the systems disclosed in patents classified in class 600, subclass 139 of the U.S. patent classification system, such as U.S. Pat. Nos. 7,311,659; 7,169,105; or 7,044,906 may be employed in other embodiments of the invention. 
     The endoscope has two lumens extending through its length for carrying fluid provided by the pump  26 . One of the lumens,  62 , extends through the turbine housing  50  to provide cooling fluid to the debriding tool  18  or whatever other tool may be connected, such as the burr illustrated in  FIG. 4 . Another lumen  64 , evacuates the cooling fluid under forces imposed by the suction pump  28 , and returns them to a sump. A third lumen  66  is connected to the pump  26  at the proximal end of the endoscope is  66  which provides pressured fluid to a rotary turbine  68  rotatably supported in the turbine housing  50 . The fluid exiting the turbine  68  returns through a suction passage  70  under force of the suction pump  28 . 
     The turbine  68  rotates a shaft  74  which extends beyond the distal end of the turbine housing  50  and drives rotary tools which may be attached to the distal end of the turbine head. In the case of  52  this constitutes a debrider  18 . The debrider  18  has a stationary section  74  and a rotatable section  76 . The rotatable section  76  has a coupling  78  with a female opening that slips over the shaft  74  of the turbine and is thus rotated by the turbine. The rotatable section  76  has a plurality of cutters  78  disposed about its periphery which pass over openings  80  spaced along the stationary section  74  of the debrider. Tissue is caught within the openings  80  and cut off by the cutters  78  in the same manner as an electric razor. The stationary debrider section  74  connects to the end of the turbine housing  50  by means of connectors  84  which extend outwardly from the turbine housing and lock into suitable connectors in the stationary section  74  of the debrider. 
     In use, the surgeon manually guides the endoscope tube  12  through body passages, using the joystick  16  to bend the end of the tube and bring the debrider  18  into contact with tissue that the surgeon desires to remove. The interior of the debrider is flushed with fluid coming through the passage  62  and the return fluid and debris from the debriding operation are extracted through the passage  64  to the suction pump  28 . This system may incorporate an appropriate filter (not shown) to remove the debris from the returning fluid. The speed at which the rotary section of the debriders turn might be adjusted by controlling the flow from the pump  26  through manual controls associated with the hand piece  14 . 
       FIG. 3  illustrates the manner in which the debrider  18  may be attached to and removed from the endoscope tube  12  and the turbine drive. The turbine shaft  74  has radially extending flanges  90  which engage slots  92  formed in the female opening of the debrider rotary section  78 . The extending sections  84  on the distal end of the turbine housing  50  lock within slots  94  formed in the stationary section  74  of the debrider  18  to secure the debrider to the turbine housing. 
       FIG. 4  illustrates an alternative embodiment of the invention supporting a burr or milling head  100  attached to the turbine housing  50  at the distal end of the surgical endoscope tube  12 . The burr or milling cutter  100  has a female slot  102  which accepts the driving shaft  74  of the turbine  68 . It also has receptors  104  adapted to receive the extending sections  84  at the distal end of the turbine housing  50 . The endoscope tube has a flow line  110  that connects at the proximal end of the endoscope to the pump  26  and drives a turbine  68 . Rather than providing a separate flow line like the flow line  62  shown in  FIG. 2 , the line  110  taps off into a flow line  112  which connects to a cooling passage  114  that passes through the burr  100  and returns through a tap off passage  116  to the return flow line  70  in the endoscope and the turbine housing. 
     The burr or milling head  100  comprises a number of cutter blades  122  extending about its outer periphery. These blades take any conventional form such as spiral or the like. The blades are water cooled by relatively small diameter passages  124  connecting the roots of the blades to the cooling fluid passage  114 . 
       FIG. 5  illustrates an alternative embodiment of the surgical endoscope which only differs from the version of  FIG. 2  in that the turbine housing  50  is smaller in diameter than the distal end  130  of the endoscope tube  12  and the turbine housing  50  is not centrally located but with respect to the surface  130  but is formed with one of its peripheral edges tangential to a peripheral edge of the tube section  130 . This allows a section of the end  130  to avoid obstruction by the turbine housing  50  so that the two fiber optic bundles  134  and  136 , which respectively convey the light from the LED  30  and captured an image of the surgical site for transmission back to the eyepiece  22  through the fiber optic bundle  20 , are exposed to the surgical site at one side of the turbine housing  50 . Otherwise  FIG. 5  is identical to  FIG. 2 .