Abstract:
An inter-ureter signaling device intended to provide a surgeon with a signal to identify when a ureter is grasped by a surgical clamping device, such as a pair of forceps, the device being comprised of a catheter, a signal generator, and wiring, such that when the catheter component of the device, having been inserted into a ureter, is compressed by the surgical clamping device an electrical circuit is closed and the signal generator generates a human perceptible signal, indicating that the clamp has been placed on the ureter.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority to a provisional application, U.S. Ser. No. 62/003,585, filed May 28, 2014, entitled Inter-Ureter Signaling Device, by Pellegrini, Joanmarie D., which is hereby incorporated by reference. 
     
    
     BACKGROUND 
       [0002]    Surgeons operating on human patients often experience some difficulty in properly identifying tissue structures. If the wrong tissue structure is cut, the patient may suffer serious or even deadly consequences. This is a significant concern when surgery is performed proximate to the ureters. Because patients often have unique anatomy and because of the similarity in appearance of a ureter with other tissue structures, especially when viewed using laparoscopic instruments, inadvertent ureter dissections occur too frequently. What is therefore needed is a device that can easily and accurately alert the surgeon to the presence of a ureter, even when the ureter is not visually or otherwise identifiable by the surgeon. 
       SUMMARY 
       [0003]    The device of the present invention is intended to provide a surgeon with a signal to identify when a ureter is grasped by a surgical clamping device, such as a pair of forceps. The device is comprised of a catheter, a signal generator, and wiring. The catheter component of the device contains at least two conducting members which together with the wiring comprise an electrical circuit suitable to enable operation of the signal generator. In one mode the conducting members of the catheter are separated from each other, resulting in an open circuit and thus preventing the signal generator from generating a signal. In another mode the conducting members of the catheter are in contact with each other, resulting in a closed circuit causing the signal generator to generate a signal. 
         [0004]    To use the device, the catheter component is inserted into the ureter of a patient. The surgeon, prior to cutting any tissue structure proximate to the ureter, places a clamping device on the tissue structure intended to be cut. If the structure happens to be the ureter into which the catheter has been inserted, the pressure of the clamping device will cause the catheter to be compressed, thus bringing the conducting members into contact with each other, completing the electrical circuit and causing the signal generator to generate a signal perceptible to the surgeon, such as an audio tone. The surgeon, upon discerning the signal, is thus alerted to the fact that the structure being grasped by the clamping device is a ureter and can avoid cutting that structure. 
         [0005]    In one embodiment, the catheter component is comprised of a single hollow tube, with the conducting members located on different portions of the inner surface of the tube. Compression of the catheter component brings the conducting members together. In this embodiment, the distal end of the catheter component is closed off, to prevent urine from entering the tube and potentially causing a short circuit. This embodiment may include longitudinal channels formed into the outer surface of the tube to permit urine to flow past the outer surface of the catheter. 
         [0006]    In an alternate embodiment, the catheter component is comprised of a pair of hollow tubes, with the tubes having different diameters and the smaller diameter tube being placed within the larger diameter tube and spaced apart from the larger diameter tube by spacer elements. In this embodiment one of the conducting members is located along the inner surface of the larger diameter tube, and the other conducting member is located along the outer surface of the smaller diameter tube. Compression of the catheter component brings the conducting members together. The larger diameter outer tube is closed off at both ends, while the smaller diameter inner tube is open at both ends, with said open ends extending from the closed ends of the larger diameter outer tube, thus allowing urine to pass through the inner portion of the smaller diameter tube without coming into contact with the conducting members, avoiding a short circuit. 
         [0007]    In yet another alternate embodiment, the catheter component is comprised of a pair of parallel hollow tubes, adjacent to each other and surrounded by a flexible outer sheath. One of the flexible hollow tubes is configured as described in the first embodiment, above, with its ends closed off, while the other flexible hollow tube is a standard ureteral catheter. Compression of the catheter component brings the conducting members together, as described above. This embodiment allows urine to pass through the inner portion of the second flexible hollow tube while preventing urine from coming into contact with the conducting members contained within the first flexible hollow tube, thus avoiding a short circuit. 
     
    
     
       DESCRIPTION OF THE DRAWINGS 
         [0008]      FIG. 1A  depicts a perspective view of one embodiment of the present invention, showing inner portions of the catheter in ghost lines. 
           [0009]      FIG. 1B  depicts a cross-sectional view of the embodiment of the present invention shown in  FIG. 1A  where the catheter is in its compressed state. 
           [0010]      FIG. 1C  depicts a cross-sectional view of the embodiment of the present invention shown in  FIG. 1A  where the catheter is in its uncompressed state. 
           [0011]      FIG. 2A  depicts a cross-sectional view of an alternate embodiment of the present invention (spacers not shown). 
           [0012]      FIG. 2B  depicts a cut-away side plan view of the embodiment of the present invention shown in  FIG. 2A . 
           [0013]      FIG. 2C  depicts a cross-sectional view of the embodiment of the present invention shown in  FIG. 2A  where the catheter is in its compressed state. 
           [0014]      FIG. 3  depicts a cross-sectional view of yet another embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0015]    The device  1  of the present invention comprises a catheter  100 , a signal generator  200 , and wiring  310 , 320 . See  FIG. 1A . 
         [0016]    The catheter  100  must be suitably configured to be inserted into the ureter of a human subject. Its basic configuration is well known in the art, being a flexible hollow tube  110  with an outside diameter sufficiently small to fit within a ureter. The catheter  100  may be made of any suitable material known in the art, provided the material is non-conductive of an electrical charge. In the preferred embodiments the catheter  100  is made of silicone. Polyurethane is yet another alternative material for the catheter. 
         [0017]    The flexible hollow tube  110  of the catheter  100  has an outer surface  113  and an inner surface  115 , a proximate end  140  and a distal end  150 , and defines an inner void  111 . 
         [0018]    The catheter  100  also comprises a first conducting member  120  and a second conducting member  130 . The first and second conducting members  120 , 130  may be made of any suitable material, provided they are flexible and capable of conducting an electrical charge. In the preferred embodiments the first and second conducting members  120 , 130  are made of a thin layer of metallic material, such as copper foil. 
         [0019]    The first and second conducting members  120 , 130  are located along the inner surface  115  of the flexible hollow tube  110  of the catheter  100 . The first conducting member  120  is located at a first portion  116  of the inner surface  115  of the flexible hollow tube  110  of the catheter  100 , and the second conducting member  130  is located at a second portion  117  of the inner surface  115  of the flexible hollow tube  110  of the catheter  100 . The first and second portions  116 , 117  of the inner surface  115  of the flexible hollow tube  110  of the catheter  100  are separated by at least a third portion  118  of the inner surface  115  of the flexible hollow tube  110  of the catheter  100  and a fourth portion  119  of the inner surface  115  of the flexible hollow tube  110  of the catheter  100 . That is, the first and second conducting members  120 , 130  are not directly adjacent to each other. In a preferred embodiment, the first conducting member  120  is a thin ribbon arrayed in longitudinal orientation along the inner surface  115  of the flexible hollow tube  110  and the second conducting member  130  is a thin ribbon arrayed in longitudinal orientation along the inner surface  115  of the flexible hollow tube  110 . The widths of the first and second conducting members  120 , 130  are each slightly less than fifty percent of the inner circumference of the flexible hollow tube  110 , and the lengths of the first and second conducting members  120 , 130  are each substantially the same as the length of the flexible hollow tube  110 . See  FIG. 1A . Other configurations of the first and second conducting members  120 , 130  are also contemplated by the present invention. 
         [0020]    The catheter  100  has a compressed state and an uncompressed state. The compressed state of the catheter  100  is achieved when the flexible hollow tube  110  of the catheter  100  is distorted by external pressure exerted on the outer surface  113  of the flexible hollow tube  110 , with the distortion being sufficient to cause portions of the inner surface  115  of the flexible hollow tube  110  of the catheter  100  to be brought into close proximity with each other resulting in at least a portion of the first conducting member  120  being brought into contact with at least a portion of the second conducting member  130 . See  FIG. 1B . The uncompressed state of said catheter  100  is achieved when the first conducting member  120  is not in contact with the second conducting member  130 . See  FIG. 1C . Even a partially compressed catheter  100  is deemed to be in its uncompressed state as long as the first conducting member  120  is not in contact with the second conducting member  120 . 
         [0021]    The signal generator  200  of the present invention is any device powered by an electrical current that is capable of generating a human perceivable signal. The signal may be audible, such as a musical tone or a buzzing noise or even a verbal prerecorded warning statement, or any other audible sound. The signal may be visual, such as a lamp. The signal may be a combination of audible and visual signals. The signal may be constant or intermittent. The signal generator  200  may be powered by alternating current or by direct current. It may use batteries, either rechargeable or disposable, as its power supply. The signal generator  200  may be integrated with one or more speakers, or visual display devices, or both. The signal generator  200  may be remotely in connection with one or more speakers, or visual display devices, or both, through wireless technology. These and other known configurations of the signal generator  200  are contemplated by the present invention. 
         [0022]    The wiring component of the present invention must be capable of conducting an electrical current. The wiring connects the first and second conducting members  120 , 130  of the catheter  100  to the signal generator  200 . The wiring has a first wire  310  and a second wire  320 , with the first wire  310  being in connection with the first conducting member  120  and the signal generator  200  and the second wire  320  being in connection with the second conducting member  130  and the signal generator  200 . The wiring can be made of any suitable material. 
         [0023]    The wiring is configured as an open circuit when the first and second conducting members  120 , 130  of the catheter  100  are not in contact with each other and the wiring is configured as a closed circuit when the first and second conducting members  120 , 130  of the catheter  100  are in contact with each other. Thus, when the wiring is configured as the closed circuit an electrical current travels through the wiring causing the signal generator  200  to generate a human perceivable signal, and when the catheter  100  is configured as the open circuit the electrical current is interrupted by the separation between the first and second conducting members  120 , 130  of the catheter  100 , thereby preventing the signal generator  200  from generating a human perceivable signal. As evident from the previous discussion, the open circuit configuration of the wiring is achieved when the catheter  100  is in its uncompressed state, and the closed circuit configuration of the wiring is achieved when the catheter  100  is in its compressed state. 
         [0024]    In alternative embodiments of the present invention, there may be multiple first conducting members  120  and multiple second conducting members  130 . Each of the multiple first conducting members  120  is separated from each of the multiple second conducting members  130  by portions of the inner surface  115  of the flexible hollow tube  110  of the catheter  100 . Each of the multiple first conducting members  120  is further in connection with the first wire  310 , and each of the multiple second conducting members  130  is further in connection with the second wire  320 . When the catheter  100  is in its uncompressed state none of the multiple first conducting members  120  is in contact with any of the multiple second conducting members  130 . When the catheter  100  is in its compressed state at least one of the multiple first conducting members  120  is in contact with at least one of the multiple second conducting members  130 . In a preferred embodiment, the multiple first conducting members  120  are thin ribbons arrayed in longitudinal orientation along the inner surface  115  of the flexible hollow tube  110  and the multiple second conducting members  130  are thin ribbons arrayed in longitudinal orientation along the inner surface  115  of the flexible hollow tube  110 , with the multiple first and second conducting members  120 , 130  alternating with each other so that between any two first conducting members  120  there is one second conducting member  130  and between any two second conducting members  130  there is one first conducting member  120 . Other configurations, orientations, and numbers of first and second conducting members  120 , 130  are also contemplated by the present invention. 
         [0025]    In the preferred embodiments of the present invention, the wiring enters the catheter  100  at the proximate end  140  of the flexible hollow tube  110 , and the proximate end  140  and the distal end  150  of the flexible hollow tube  110  are closed off. This configuration of the catheter  100  prevents urine from entering the flexible hollow tube  110  and potentially causing a short circuit. This embodiment may also include one or more longitudinal channels  160  formed into the outer surface  113  of the flexible hollow tube  110  and running substantially the entire length of the flexible hollow tube  110 , to permit urine to flow past the outer surface  113  of the catheter  100 . See  FIG. 1C . 
         [0026]    In yet another embodiment of the present invention, the catheter  100  is comprised of a pair of concentrically aligned flexible hollow tubes  170 , 180 . See  FIG. 2A . The flexible outer hollow tube  170  of the catheter  100  has an outer surface, an inner surface, and an inside diameter, and defines a first inner void  171 . The flexible inner hollow tube  180  of the catheter  100  has an outer surface, an inner surface, and an outside diameter, and defines a second inner void  181 . The outside diameter of the flexible inner hollow tube  180  of the catheter  100  is smaller than the inside diameter of the flexible outer hollow tube  170  of the catheter  100 . The flexible inner hollow tube  180  of the catheter  100  is located within the first inner void  171 , and is further located spaced apart from the flexible outer hollow tube  170  of the catheter  100 . A plurality of spacers  190  keeps the flexible inner hollow tube  180  spaced apart from the flexible outer hollow tube  170 , such that the outer surface of the flexible inner hollow tube  180  does not directly contact the inner surface of the flexible outer hollow tube  170 . See  FIG. 2B . Each of the plurality of spacers  190  may be an annular ring, with each annular ring having an inner diameter and an outer diameter. The inner diameter of each said annular ring is substantially the same as the outer diameter of the flexible inner hollow tube  180  of the catheter  100 , and the outer diameter of each said annular ring is substantially the same as the inner diameter of the flexible outer hollow tube  170  of the catheter  100 . The spacers  190  are made of any suitable material, and should be flexible so that they compress when an external force is applied to the outer surface of the flexible outer hollow tube  170 . They may be made of the same material as the flexible hollow tubes  170 ,  180 . The spacers  190  should not be electrically conductive. The spacers  190  may be configured other than as annular rings, as long as they satisfy the requirement of keeping the flexible outer hollow tube  170  spaced apart from the flexible inner hollow tube  180  when the catheter  100  is in its uncompressed state. 
         [0027]    In this embodiment, the first conducting member  120  is located along the inner surface of the flexible outer hollow tube  170  of the catheter  100  and the second conducting member  130  is located along the outer surface of the flexible inner hollow tube  180  of the catheter  100 . The first conducting member  120  may completely cover the inner surface of the flexible outer hollow tube  170  of the catheter  100  or just a portion thereof. Similarly, the second conducting member  130  may completely cover the outer surface of the flexible inner hollow tube  180  of the catheter  100  or just a portion thereof. When the catheter  100  is in its compressed state, the inner surface of the flexible outer hollow tube  170  is placed in close proximity to the outer surface of the flexible inner hollow tube  180  such that at least a portion of the first conducting member  120  comes into contact with at least a portion of the second conducting member  130 . See  FIG. 2C . The proximate and distal ends of the flexible outer hollow tube  170  are partially closed off, having apertures aligned with the proximate and the distal ends of the flexible inner hollow tube  180 , which are both open. Urine may thus flow through the catheter  100  within the second inner void  181  without coming into contact with the first or second conducting members  120 , 130 . 
         [0028]    In yet another embodiment of the present invention, the catheter  100  is comprised of a pair of parallel flexible hollow tubes  400 , 500 . See  FIG. 3 . The flexible first hollow tube  400  of the catheter  100  has an outer surface  402 , an inner surface  404 , a proximate end, and a distal end, and defines a first inner void  410 . The flexible second hollow tube  500  of the catheter  100  defines a second inner void  510 . The flexible second hollow tube  500  of the catheter  100  is located adjacent to and runs along the length of the flexible first hollow tube  400  of the catheter  100 . 
         [0029]    In this embodiment, the first and second conducting members  120 , 130  are located along the inner surface  404  of the flexible first hollow tube  400  of the catheter  100 . The first conducting member  120  is located at a first portion of the inner surface  404  of the flexible first hollow tube  400  of the catheter  100 , and the second conducting member  130  is located at a second portion of the inner surface  404  of the flexible first hollow tube  400  of the catheter  100 . The first and second portions of the inner surface  404  of the flexible first hollow tube  400  of the catheter  100  are separated by at least a third portion of the inner surface  404  of the flexible first hollow tube  400  of the catheter  100  and a fourth portion of the inner surface  404  of the flexible first hollow tube  400  of the catheter  100 . That is, the first and second conducting members  120 , 130  are not directly adjacent to each other. In a preferred embodiment, the first conducting member  120  is a thin ribbon arrayed in longitudinal orientation along the inner surface  404  of the flexible first hollow tube  400  and the second conducting member  130  is a thin ribbon arrayed in longitudinal orientation along the inner surface  4004  of the flexible first hollow tube  400 . The widths of the first and second conducting members  120 , 130  are each slightly less than fifty percent of the inner circumference of the flexible first hollow tube  400 , and the lengths of the first and second conducting members  120 , 130  are each substantially the same as the length of the flexible first hollow tube  400 . Other configurations of the first and second conducting members  120 , 130  are also contemplated by the present invention. 
         [0030]    When the catheter  100  is in its compressed state, at least a portion of the first conducting member  120  comes into contact with at least a portion of the second conducting member  130 , as described above. The proximate and distal ends of the flexible first hollow tube  400  are closed off, thus preventing urine from entering the flexible first hollow tube  400 . Urine may flow through the catheter  100  through the open proximate and distal ends and the second inner void  510  of the flexible second hollow tube  500  without coming into contact with the first or second conducting members  120 , 130 . 
         [0031]    In alternative configurations of this embodiment, there may be multiple first conducting members  120  and multiple second conducting members  130 . Each of the multiple first conducting members  120  is separated from each of the multiple second conducting members  130  by portions of the inner surface  404  of the flexible first hollow tube  400  of the catheter  100 . Each of the multiple first conducting members  120  is further in connection with the first wire  310 , and each of the multiple second conducting members  130  is further in connection with the second wire  320 . When the catheter  100  is in its uncompressed state none of the multiple first conducting members  120  is in contact with any of the multiple second conducting members  130 . When the catheter  100  is in its compressed state at least one of the multiple first conducting members  120  is in contact with at least one of the multiple second conducting members  130 . In a preferred embodiment, the multiple first conducting members  120  are thin ribbons arrayed in longitudinal orientation along the inner surface  404  of the flexible first hollow tube  400  and the multiple second conducting members  130  are thin ribbons arrayed in longitudinal orientation along the inner surface  404  of the flexible first hollow tube  400 , with the multiple first and second conducting members  120 , 130  alternating with each other so that between any two first conducting members  120  there is one second conducting member  130  and between any two second conducting members  130  there is one first conducting member  120 . Other configurations, orientations, and numbers of first and second conducting members  120 , 130  are also contemplated by the present invention. 
         [0032]    The catheter  100  may also comprise a flexible outer sheathing  600 . The flexible outer sheathing  600  is suitably adapted to encase the flexible first hollow tube  400  and the flexible second hollow tube  500 . The flexible outer sheathing  600  may be made of the same material as the flexible hollow tubes  400 , 500  or other suitable material. This configuration is well known in the art, for example, as used in double lumen ureteral catheters. 
         [0033]    Modifications and variations can be made to the disclosed embodiments of the device  1  without departing from the subject or spirit of the invention as defined in the following claims.