Abstract:
Disclosed is a folding endoscope with incorporated optical sensors and light sources. The foldable endoscope includes a housing having first and second ends and a longitudinal axis and at least one channel extending between the first and second ends and associated ports at the first and second ends for inserting surgical instruments through the housing into a surgical site. The endoscope includes three elongate arms having first and second ends and being pivotally connected at the first ends thereof to the first end of the housing. A camera and light source are mounted on each of the elongate arms such that when the elongate arms are deployed the cameras have a field of view in a generally forward direction away from the housing. A linkage mechanism is connected to the elongate arms, and an actuator is connected to the linkage mechanism. The linkage mechanism, upon activation by the actuator, is configured to pivotally deploy the three elongate arms from a closed position in which the elongate arms are aligned along the longitudinal axis to an open position with the second ends of the elongate arms radially spaced from the longitudinal axis.

Description:
CROSS REFERENCE TO RELATED U.S. PATENT APPLICATION 
       [0001]    This patent application relates to U.S. provisional patent application Ser. No. 61/353,948 filed on 11 Jun. 2010 entitled FOLDING ENDOSCOPE AND METHOD OF USING THE SAME, filed in English, which is incorporated herein in its entirety by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates generally to the field of endoscopes, and more particularly the present invention relates to folding endoscopes with incorporated optical sensors and light source. 
       BACKGROUND OF THE INVENTION 
       [0003]    Generally speaking, endoscopes are thin tubular cameras that are typically utilized in the diagnosis of a disease. These cameras are usually inserted into the body cavity either through a natural opening like the mouth or the anus or through a tiny incision made into the skin. The endoscopes are extensively used intra-operatively to assist the surgeon in visualizing the anatomy of interest to perform the procedure and to avoid damage to critical surrounding organs. Most of the endoscopes available in the market to date can be classified into either a rigid or a flexible endoscope. Commonly found endoscopes are available with two-dimensional cameras and have limited image resolution and depth perception. These endoscopes are disorienting to the surgeon after a prolonged use and lack the natural spectrum of direct human visualization. 
         [0004]    Recently some manufacturers have started producing three-dimensional (stereoscopic) endoscopes. The optical version of these endoscopes use two tubular lenses inside a long shaft and two standard cameras mounted outside of the body. The next generation of stereo endoscopes employs custom designed semiconductor circuitry mounted at the tip of the endoscope (inside the body) that is capable of producing stereo images. In these endoscopes, either two close proximity mounted chips or a special chip with a large array of micro lenses manufactured onto the chip is utilized to create stereo images. In addition, such endoscopes also include LED or fiber optic light sources for illumination.  FIG. 1  shows a conventional stereo endoscope. 
         [0005]    U.S. Pat. No. 4,862,873 issued to Yajima et al. discloses a stereo endoscope that utilizes two thin optical guides mounted in a tubular shaft and two CCD image sensors mounted outside the body to create three-dimensional images of the organ. 
         [0006]    U.S. Patent application US2002/0007110, to Irion discloses a stereo endoscope that utilizes two lateral mounted cameras with a flexible endoscope head to create three-dimensional images of the organ. 
         [0007]    The field of surgical intervention has evolved from open invasive approach to the paradigm of minimally invasive surgery due to its benefits to the patients and the healthcare system. From the surgeon&#39;s perspective, the transition has resulted in a procedure with limited and un-natural field of view and surgical skills that have a steep learning curve. The existing three-dimensional endoscopes have resulted in incremental enhancement to the visualization, but have failed to match the natural spectrum of direct human visualization. The 3D depth perception of these endoscopes is also constrained by the limited physical separation between the two cameras. Additionally, it is projected that the surgical paradigm will shift from the three or four incision laparoscopic approach to a single incision (single port access (SPA)) surgery. 
         [0008]    Thus, there is a need and good market potential for improved endoscopes that can provide a better visualization of the surgical site. 
       SUMMARY OF THE INVENTION 
       [0009]    The present invention provides a foldable endoscope, comprising:
       a) a housing having a first and second end and a longitudinal axis, said housing including at least one channel extending between said first and second end, and associated ports at said first and second end for inserting surgical instruments through said housing into a surgical site;   b) at least two elongate arms each having a first and second end and each being pivotally connected at said first end thereof to said first end of said housing;   c) at least one camera each camera being mounted on one of said at least two elongate arms; and   d) a linkage mechanism connected to said at least two elongate arms, said linkage mechanism, upon activation, being configured to pivotally deploy said at least two elongate arms from a closed position in which said at least two elongate arms are aligned along said longitudinal axis to an open position in which said second ends of said at least two elongate arms radially spaced from said longitudinal axis.       
 
         [0014]    The disclosed endoscope taps nicely into the emerging market due to its improved visualization capabilities and integrated support to pass surgical tools through the other ports making it a versatile surgical tool. 
         [0015]    A further understanding of the functional and advantageous aspects of the invention can be realized by reference to the following detailed description and drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]    Preferred embodiments of the invention will now be described, by way of example only, with reference to the drawings, in which: 
           [0017]      FIG. 1  shows a conventional prior art stereo endoscope; 
           [0018]      FIG. 2  shows an embodiment of the foldable endoscope in a fully closed or retracted state; 
           [0019]      FIG. 3  shows the foldable endoscope in a partially open state; 
           [0020]      FIG. 4  shows the foldable endoscope in the fully open state; 
           [0021]      FIG. 5  shows another embodiment of the foldable endoscope that includes a mirror arrangement; and 
           [0022]      FIG. 6  shows the block diagram of the image processing of the images acquired by the cameras mounted on the foldable endoscope. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0023]    Without limitation, the majority of the systems described herein are directed to folding endoscopes with incorporated optical sensors and light source. As required, embodiments of folding endoscopes are disclosed herein. However, the disclosed embodiments are merely exemplary, and it should be understood that the disclosure may be embodied in many various and alternative forms. In certain instances, well-known or conventional details are not described in order to provide a concise discussion of embodiments of the present disclosure. 
         [0024]    The Figures are not to scale and some features may be exaggerated or minimized to show details of particular elements while related elements may have been eliminated to prevent obscuring novel aspects. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention. For purposes of teaching and not limitation, the illustrated embodiments are directed to folding endoscopes with incorporated optical sensors and light source. 
         [0025]    As used herein, the term “about” and “approximately”, when used in conjunction with ranges of dimensions, temperatures or other physical properties or characteristics is meant to cover slight variations that may exist in the upper and lower limits of the ranges of dimensions so as to not exclude embodiments where on average most of the dimensions are satisfied but where statistically dimensions may exist outside this region. For example, in embodiments of the present invention dimensions of components of a folding endoscope are given but it will be understood that these are not meant to be limiting. 
         [0026]    Referring to  FIG. 2 , herein is disclosed a foldable endoscope  10  that utilizes multiple cameras  30  to create three-dimensional images of the target.  FIG. 2  shows the endoscope  10  in collapsed form, and  FIG. 3  shows the endoscope  10  in half open form. In the collapsed form, the endoscope  10  assumes a very compact formation and can be easily introduced into the patient&#39;s body through a standard trocar. In the preferred embodiment, the endoscope  10  contains a slender body  12  that forms a generally cylindrical housing, a center spoke  40 , three connecting linkages  16 , and three folding arms  14  with cameras  30  and light sources  34  integrated into each of the arms. Each folding arm  14  in the preferred embodiment includes two hinge joints; a first hinge joint  18  with the endoscope body  12  and a second hinge joint  20  with the connecting linkage  16 . In the preferred embodiment, each connecting linkage  16  also has a hinge joint  22  with the center spoke  40 . The center spoke  40  includes a telescopingly movable hollow drive shaft  44  and may optionally include a plurality of integrated light sources  36  (light emitting diodes (LEDs), fiber optic light sources, etc). 
         [0027]    The optical sensors or cameras are preferably charge coupled device (CCD) images sensors, but other types of image sensors may be used. For example, complementary metal-oxide-semiconductor (CMOS) image sensors may be preferred in some embodiments due to their low cost. 
         [0028]    The endoscope  10  also includes one or more instrument ports  50  through which various surgical instruments can be introduced to perform the procedure. Non-limiting examples of such instruments include scalpels, incision devices, tweezers, scissors, etc. In the preferred embodiment, the diameter of slender body  12  is preferably about 10 mm and the diameter of each instrument port  50  is preferably about 2.5 mm. The disclosed invention is particularly suitable for the case of a single port access surgery where both the visualization and the surgical procedure is performed through one incision as opposed to the three or four of a typical laparoscopic procedure. Endoscope  10  may optionally include a fiber optic illumination port  42  mounted on the center spoke  40  to enhance visibility of the surgical site. In the preferred embodiment, the diameter of fiber optic illumination port  42  is preferably about 1.75 mm. The fiber optic illumination port  42  is a hollow shaft that runs concentrically through the center spoke  40  and the hollow drive shaft  44 . 
         [0029]      FIG. 3  shows the preferred embodiment of the disclosed invention in the half open form. The hollow drive shaft  44  is designed to translate in and out through the center port  46  of the endoscope body  12 . 
         [0030]    Here “in” motion is referred to as the motion of the center spoke  40  towards the endoscope body  12  and “out” motion is referred to as the motion of the center spoke  40  away from the endoscope body  12 . Each hinge joint ( 18 ,  20 , and  22 ) is a low friction joint that allows two mating components to freely rotate with respect to each other about the hinge axis. A hollow drive shaft  44  is connected on one end to the center spoke  40  and is connected at the other end to the endoscope body  12  to create the linear “in” and “out” motion of the center spoke  40  with respect to the endoscope body  12 . In a preferred embodiment, this motion is provided by an actuator (not shown here, preferably located outside the body). Those skilled in the art will appreciate that any actuator may be used; some non-limiting examples include solenoids, motors with rack and pinion gears, hydraulic actuators, pneumatic actuators, cable actuators, worm gears, and wheels with tracks. 
         [0031]    A fiber optic illumination source may be passed through the hollow shaft  44  to enhance visibility of the surgical site. Optionally, one of more of the illumination sources  36  on the center spoke  40  may be replaced with one or more cameras  30  that can facilitate easy insertion of the endoscope into patient&#39;s body cavity. 
         [0032]    One preferred method of utilizing the disclosed invention in a single port access surgery can be as following. Initially with the endoscope  10  outside the body, the hollow shaft  44  is actuated such that the center spoke  40  is at its farthest “out” position and as a result the endoscope is fully collapsed (as shown in  FIG. 2 ) and can be easily introduced into the patient&#39;s body through a standard trocar. Once inside the body, the hollow shaft  44  is actuated to cause “in” motion of the center spoke  40  towards the endoscope body  12 . The umbrella structure of the mechanism causes it to unfold and gradually take up its open shape as the center spoke  40  is actuated towards the fully “in” position (as shown in  FIG. 4 ). The tile angle for cameras  30  can be simultaneously controlled by “in” and “out” motions of the center spoke  40  in the direction of arrow  64 . The actuator is used to control how much the umbrella structure opens up, and this depends on the user of endoscope and how much overlap is required between the cameras  30 . 
         [0033]    Once fully deployed, endoscope  10  can be firmly held in place (outside the body) by an assistant, a passive support arm, or a robotic system. The endoscope  10  can also be rolled through the use of an optional second actuator about axis  60  in the direction of arrows  62  until desired visualization of the anatomy is achieved. 
         [0034]      FIG. 5  shows another embodiment of the foldable endoscope that includes a mirror arrangement  14  that assists in the insertion of the endoscope into the body cavity. In its collapsed form (as shown), the mirror  14  is oriented such that it reflects light rays that are parallel to the longitudinal axis of endoscope body  12  onto the image sensor  30  thereby creating an image that is orthogonal to the endoscope longitudinal axis. This image is the same image as obtained using the conventional endoscopes as they are being inserted into the body cavity. Once inside the body and after the mechanism has been unfolded, mirror  14  has no function and the endoscope creates 3D images as explained before. This mirror arrangement obviates the need of another 2D image sensor on the center spoke  40  that can assist in endoscope insertion through the trocar.  FIG. 6  shows the block diagram of the disclosed invention. The video outputs  122  from various cameras  120  go to an image processor  100  that performs various image processing algorithms for example stereo generation, image stitching etc. on these images. The processed images are provided to the surgeon&#39;s in either a two-dimensional or a three-dimensional format through the use of a display device  104  or  106  (monitor, projector, 3D monitor, 3D goggles, etc). The image processor  100  may also control camera tilt and roll system  110  in order to generate a view from a different orientation and perspective. The roll and tilt system is preferably composed of two actuators that cause the linear motion of center spoke  40  along arrows  64  and roll of body  12  about axis  60  (as shown by arrow  62 ). Depending upon the anatomy, the image processor may also control the illumination system  102  to adjust for optimal image quality. The illumination system  102  may automatically adjust camera parameters based on feedback from image signals received from the cameras. The illumination system  102  may include any manual input device such as a physical button, knob, or slider, or it may be a graphical user interface element displayed on a monitor. Further, when producing three-dimensional images, the image processor  100  may further rotate, translate, and scale the produced images either by decisions made from software control systems or from manual control from the user, or both. 
         [0035]    The surgeon may interact with the image processor  100  through a user interface that includes an input device (computer mouse, keyboard, microphone, buttons, joystick, touch screen etc) to select various features and options. The surgeon can optionally switch between two-dimensional and three-dimensional views or can visualize them side by side on displays  104  and  106 . The surgeon may use the user interface to change views, to change brightness or contrast parameters, to rotate, scale, or translate 3D views, or to make other parameter changes that influences the display shown on monitors. 
         [0036]    Those skilled in the art will appreciate that many computer vision algorithms may be performed by the image processor  100  including but not limited to: image stitching, 3D reconstruction from multiple views, shape from shading, depth from focus, feature detection, feature matching for pose estimation, optical flow algorithms, background subtraction, automatic object classification, and image segmentation. These techniques may be used to assist the user of the endoscope in performing operations with the device. Further, those skilled in the art that the image processor  100  may be a dedicated computer processor such as a CPU, DSP microchip, or microprocessor, or the image processor  100  may be integrated in a computer system such as a software program running on a desktop computer, laptop, mobile device, or mobile phone. The disclosed invention utilizes an umbrella type mechanism to mount and control one or more cameras (preferable two or more) that is not found in conventional two-dimensional and three-dimensional endoscopes. The increased physical separation between different cameras of the disclosed invention will lead to an improved 3D depth perception than that of the close mounted dual cameras in the existing systems. The increased number of cameras (preferably three or more) present in the disclosed invention will lead to enhanced visualization of the anatomy through image stitching. The mechanism disclosed herein is fairly simple and low cost to produce. The number of folding arms can be limited to two if reduced cost or functionality is desired. 
         [0037]    As used herein, the terms “comprises”, “comprising”, “includes” and “including” are to be construed as being inclusive and open ended, and not exclusive. Specifically, when used in this specification including claims, the terms “comprises”, “comprising”, “includes” and “including” and variations thereof mean the specified features, steps or components are included. These terms are not to be interpreted to exclude the presence of other features, steps or components. 
         [0038]    The foregoing description of the preferred embodiments of the invention has been presented to illustrate the principles of the invention and not to limit the invention to the particular embodiment illustrated. It is intended that the scope of the invention be defined by all of the embodiments encompassed within the following claims and their equivalents.