Abstract:
An endoscope having first and second viewing elements provides separate views of the passage being traversed or the organ being inspected. The endoscope is particularly useful for traversing restrictions and forming desired shapes in situ.

Description:
STATEMENT REGARDING FEDERALLY-SPONSORED RESEARCH/DEVELOPMENT 
       [0001]    Not applicable. 
       REFERENCE TO MICROFICHE APPENDIX 
       [0002]    Not applicable. 
       BACKGROUND OF THE INVENTION 
       [0003]    This invention relates generally to endoscopic devices, and more particularly to such devices with multiple fields of view. 
         [0004]    Endoscopes are used to assess surfaces of passages and/or organs in the human (or non-human) body. They conventionally include a tube for insertion into the body, a light delivery system to illuminate the organ or passage under inspection, an optical system for transmitting the image to the user, and an additional channel(s) to allow use of various medical instruments. The present invention is not limited to any particular endoscopic device, since it is well-suited for use with the vast variety of available endoscopes. Endoscopes are routinely used in visualizing the gastrointestinal tract (including the esophagus, stomach, duodenum, small intestine, colon, and bile duct), the respiratory tract, the urinary tract, vascular and other fluid channels, and various normally closed body cavities such as the abdominal cavity, joint interiors, thoracic cavity, and chest organs. 
         [0005]    Although endoscopes are very helpful in all these applications, they could be improved. For example, during routine interrogation of the colon for endoscopic screening, areas beneath colonic folds may remain undetectable to diagnostic interrogation since sites inspected are forward to the scope view. In order to see rearward to the normal scope view, a very tight rearward-facing configuration of 180 degrees would have to be created by shaping the scope in a downgoing shape (the direction of withdrawal of the scope rather than its normal upgoing shape direction of insertion of the scope). This maneuver would require a great deal of time, and result in significant wear and tear on endoscopic elements (fibroptics, pull wires, etc.), particularly if the maneuver is repeated multiple times during a procedure. 
         [0006]    It has been recently discovered that flat lesions in the colon are also more likely than previously thought to become cancerous, but are very difficult to detect using existing colonoscopes because they do not stand out in the forward-facing field of view of conventional colonoscopes. Moreover, existing endoscopes typically provide views in only one direction at a time, thereby giving an incomplete understanding of the surface or passage being inspected. In addition, conventional endoscopes suffer from difficulties in passing through restricted areas, areas with tight curvature of flexure, or other areas of tortuosity. At a minimum, this can resulted in failed procedures and sometimes can result in perforations of the passage by the endoscope. 
         [0007]    In many instances, one could tell from the endoscope viewing element that a particular shape is needed to access a particular passage or organ, but there is no way other than the insertion of a separate catheter of the desired shape into the additional channel of the endoscope to access that passage. If the shape were not precisely the needed shape, that catheter would have to be removed from the endoscope and another catheter inserted until the passage or organ is successfully accessed. 
       SUMMARY OF THE INVENTION 
       [0008]    Among the various objects and features of the present invention may be noted the provision of an improved endoscope and method of using same with improved fields of view. 
         [0009]    A second feature is the provision of an improved endoscope which allows the formation of a shape to be viewed by the user in situ, thereby facilitating the formation of the precise shape(s) needed to access desired passageways and organs. 
         [0010]    A third feature is the provision of an improved endoscope which allows visualization of areas which previously could not be visualized using conventional endoscopes. 
         [0011]    A fourth feature is the provision of an improved endoscope with improved ability to pass through tortuous or restricted passages in the body. 
         [0012]    Briefly, in a first aspect of the present invention, an endoscope includes a main viewing element disposed in a tube sized to fit into a body, said main viewing element being disposed to provide a primary view, and a secondary viewing element disposed in said tube, said secondary viewing element being capable of being disposed so as to provide an auxiliary view which differs from the primary view. 
         [0013]    In a second aspect of the present invention, a method of using an endoscope includes the steps of moving an endoscope having a main viewing element along a passage in the body until a restriction or tortuosity in said passage is reached, extending a secondary viewing element distally with respect to the main viewing element into the restriction or tortuosity, using the secondary viewing element to navigate the restriction or tortuosity, and moving the main viewing element of the endoscope distally along the path navigated by the secondary viewing element through the restriction and/or tortuosity. 
         [0014]    In a third aspect of the present invention, a method of using an endoscope includes the steps of placing an endoscope having a main viewing element in a passage in a human body at a desired position, said main viewing element having a primary field of view, and using a secondary viewing element to image a portion of the passage outside the primary field of view, said secondary viewing element having an auxiliary field of view. 
         [0015]    Other objects and features will be in part apparent and in part pointed out hereinafter. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]      FIG. 1  is a plan view of an endoscope of the present invention in a passage in a human body. 
           [0017]      FIG. 2  is a view similar to  FIG. 1  illustrating a different shape for the secondary viewing element of the endoscope. 
           [0018]      FIG. 3  illustrates a down-going shape for the secondary viewing element. 
           [0019]      FIG. 4  illustrates an up-going shape for the secondary viewing element. 
           [0020]      FIG. 5  illustrates an out-of-plane shape for the secondary viewing element. 
           [0021]      FIGS. 6 ,  7  and  7 A- 7 C illustrate the use of the endoscope of the present invention in traversing a restriction or tortuosity in a passage in the human body. 
           [0022]      FIG. 8  illustrates a second embodiment of the present invention in which the secondary viewing element is disposed out the side of the endoscope. 
           [0023]      FIG. 9  illustrates the embodiment of  FIG. 8  in which the secondary viewing element is further curved to view a proximal portion of the passage. 
       
    
    
       [0024]    Similar reference characters indicate similar parts throughout the several views of the drawings. 
       DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0025]    Turning to  FIG. 1 , an endoscope  11  of the present invention includes a tube  13  containing a conventional first viewing element  15  (such as a suitable fiber optic system for illuminating the primary field of view FOV 1  and for transmitting the image of that field of view back to a user (not shown)). Of course, other systems using CMOS or CCD sensors or the like could also be used to acquire the image or images of the field of view (or views) of the endoscope of the present invention. Illumination could also be provided in any conventional manner. Tube  13  is sized to fit into a body such as the passage  17  shown in  FIG. 1 . It is anticipated that the invention may be used on human and non-human bodies. By way of illustration, passage  17  can be the colon of a human subject. An auxiliary viewing element  21  is included in a secondary tube  23  which is movable in the additional channel  25  of endoscope  11 . Secondary tube  23  is preferably curved or curvable and may consist of multiple parts, as described below. The field of view FOV 2  of secondary viewing element  21  may (depending upon the position of secondary tube  23  with respect to endoscope tube  13 ) differ from the primary view FOV 1 . In  FIG. 1 , the fields of view FOV 1  and FOV 2  overlap, but the field of view FOV 1  is primarily forward-looking with respect to the endoscope  11 , while the field of view FOV 2  is primarily lateral-looking. 
         [0026]    Secondary tube  23 , along with secondary viewing element  21  which it carries, may be extended or retracted longitudinally with respect to the first viewing element  15  as indicated by the double-pointed arrow in  FIG. 1 . 
         [0027]    As will become apparent below, the distal section of secondary tube  23  may be shaped by the user to a vast variety of shapes while the distal section is disposed in the passage  17 . In  FIG. 2 , the secondary tube  23  has been reshaped from the shape of  FIG. 1  to that of  FIG. 2  while being in the field of view FOV 1  of the primary viewing element  15 . That is, using the configuration of  FIGS. 1 and 2 , the actual shape of the secondary tube  23  may be viewed as that shape is changed. Such a change may be desirable, for example, to access orifice  31  in passage  17 . 
         [0028]    The simple shape change from  FIG. 1  to  FIG. 2  may be accomplished by rotating the secondary tube  23  with respect to primary tube  13  and/or by use of a conventional pull-wire mechanism. But it is preferred that secondary tube  23  be shapeable in other ways. To provide maximum shapeability, secondary tube  23  preferably (see  FIG. 3 ) is a composite structure composed of two independently controllable tubes ( 23 A and  23 B), both of which are capable of assuming a curved shape. When both tubes  23 A and  23 B are curved in the same direction, extreme curvature of composite tube  23  may be achieved as shown in  FIG. 3 . That Figure illustrates a down-going shape for the composite tube (the distal end of the tube faces in a direction opposed to the direction the tube as a whole would move were it inserted farther into passage  17 ). Similarly, in  FIG. 4 , a complex up-going shape (the distal end of the tube faces in the direction in which the tube as a whole would move were it inserted farther into passage  17 ) has been created in the field of view of element  15 . This shape, and a multitude of similar shapes, may be formed by rotating tube  23 A with respect to tube  23 B 180 degrees from the position of  FIG. 3  and bending the distal portions of each tube a desired amount by the use of pullwires (not shown) or the like. 
         [0029]    It should be understood (see  FIG. 5 ) that the secondary tube  23  may be formed into shapes which are other than simple up-going and/or down-going shapes. By rotating the inner secondary tube  23 B with respect to outer tube  23 A and allowing the curved portions of both tubes to interact, a composite shape of the distal portion of composite tube  23  is formed which is out-of-plane (in this case perpendicular) to the longitudinal axis of primary tube  13 . Such out-of-plane shapes are known, but heretofore are not believed to have been available for endoscopes. More particularly, it is not believed that such shapes have heretofore been made under visual inspection by the user in situ. 
         [0030]    The endoscope  11  of the present invention is particularly well-suited to traversing restrictions in passage  17  (see  FIGS. 6 and 7 ). In  FIG. 6 , the restriction  41  is seen in the field of view FOV 1  of the primary viewing element. Secondary tube  23  is extended through the restriction, guided by the image from secondary viewing element  21  while the restriction is being traversed. Once the secondary tube  23  successfully passes through the restriction, it may be shaped into a down-going curve as discussed above so that the field of view FOV 2  of the secondary tube now includes the distal side of the restriction. The primary tube  13  is then advanced over secondary tube  23  while the secondary viewing element is held fixed with respect to the passage to safely traverse the restriction while the process is being imaged by both viewing elements. 
         [0031]    Endoscope  11  is also well-suited for traversing tortuosity in passage  17  (see  FIGS. 7A-7C ). Although the tortuosity  51  is shown in two-dimensions in  FIGS. 7A-7C , it should be realized that the tortuosity is routinely in three-dimensions, which makes passage therethrough even more difficult than that illustrated in  FIGS. 7A-7C . The sigmoid tortuosity  51  shown in passage  17  can be successfully imaged and traversed by endoscope  11  as follows: As outer tube  13  approaches the first curve of the tortuosity, inner tube  23  is curved into the “clockwise” curve shown in  FIG. 7A  and extended around the first curve. Note that the field of view FOV 1  of the outer tube  13  is such that the shape into which inner tube  23  is formed can be visually verified to be appropriate to the curve to be traversed. The shape of inner tube  23  may be adjusted as the curve of the tortuosity changes since the distal portion of the curve is visually available to the user since it falls in the field of view FOV 2  of the inner tube  23 . After the inner tube  23  has been advanced through the curve a distance sufficient to provide the necessary purchase for endoscope  11 , outer tube  13  is advanced over inner tube  23  to the position indicated in  FIG. 7B . At that point, the second curve of tortuosity  51  is encountered, so the process is repeated. Specifically, outer tube  13  may be used to view the tortuosity  51  and the inner tube  23  in field of view FOV 1  to determine both the appropriate curvature of inner tube  23  and whether tube  23  actually assumes the appropriate shape. Inner tube  23  is curved into the “counterclockwise” curve illustrated in  FIG. 7B  (which is accomplished by rotating the inner element 180 degrees with respect to the outer tube and then curving the inner tube). Curves are referred to as clockwise and counterclockwise herein with reference to the view shown in  FIG. 7A . If viewed from the opposite direction, the “clockwise” curve would become “counterclockwise” and vice versa, but from all points of view the curves are opposite each other in direction of curvature. Once inner tube  23  has been advanced a distance through the second curve to achieve the necessary purchase, outer tube  13  is then advanced over inner tube  23  to the position shown in  FIG. 7C . The third curve can then be traversed by recurving inner tube  23  into the clockwise curved shape shown in  FIG. 7C . Specifically, in  FIG. 7C  the outer tube  13  may again be used to view the tortuosity  51  and the inner tube  23  in field of view FOV 1  to determine both the appropriate curvature of inner tube  23  and whether tube  23  actually assumes the appropriate shape. The process can be repeated as needed to overcome any type of tortuosity. If the necessary shape for the inner tube to traverse a particular tortuosity is out-of-plane with respect to the distal end portion of the outer tube  13 , the inner tube  23  can be formed into the required out-of-plane shape by rotating the inner tube with respect to the outer tube by some required angle other than 180 degrees. Of course, inner tube  23  can also (if it is composed of two separate curved or curvable elements) be formed into an out-of-plane shape as described above in connection with  FIG. 5  and that formation can be observed by element  13  so long as it occurs in field of view FOV 1 . 
         [0032]    Although  FIGS. 1-7C  illustrate secondary tube  23  being disposed in the field of view FOV 1  of the primary viewing element  15 , the present invention is not so limited. In  FIGS. 8 and 9 , the secondary tube  23  with secondary viewing element  21  exits the side of primary tube  13  so that the side of the passage ( FIG. 8 ) or the proximal portion of the passage ( FIG. 9 ) may be visually imaged while the primary viewing element is imaging the distal portion of the passage. It should be understood that varying the amount of curvature of tube  23  as described above, changes the field of view FOV 2  from that of  FIG. 8  to that of  FIG. 9 . Any desired curvature may be imposed upon secondary tube  23  to obtain the desired secondary field of view FOV 2 . As indicated in  FIG. 9  by the double-arrow, both proximal and distal portions of the passage may be imaged both as the endoscope  11  is being inserted and as it is being removed. 
         [0033]    In view of the above it will be seen that the various objects and features of the present invention are achieved and other advantageous results obtained.