Abstract:
An apparatus and method for dilating a body canal such as a cervix is provided. The apparatus comprises a threaded cylindrical rod with an inflatable member at one end. The apparatus also comprises a tubular member with a threaded bore that is capable of threaded engagement with the threaded rod.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     Not Applicable.  
       STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT  
       [0002]     Not Applicable.  
       BACKGROUND OF THE INVENTION  
       [0003]     1. Field of the Invention  
         [0004]     The present invention relates generally to a system for dilating a body canal such as a cervix. In one aspect, and more particularly, the invention relates to a system for dilating a cervix comprising a cylindrical rod with an inflatable member disposed on one end. Still more particularly, the invention relates to a system for dilating a cervix comprising a tubular member that is capable of threaded engagement with the cylindrical rod.  
         [0005]     2. Description of the Related Art  
         [0006]     A common system for dilating a cervix in the existing art involves the use of long metal rods. A rod of smaller diameter is inserted into the cervix and advanced until it reaches the uterine cavity. The rod is then removed and a larger diameter metal rod is inserted in a similar fashion. The process is repeated until the cervix has been dilated to the desired size. This process has several disadvantages.  
         [0007]     One disadvantage is that the person performing the dilation procedure cannot insert the metal rod in a controlled manner. This procedure requires that a force be applied in the direction of insertion by the person performing the procedure. If there is a change in the resistance, the rod may be accidentally inserted farther than desired. Furthermore, there is nothing in these systems to prevent the dilating rod from being inserted into the uterine cavity. This can cause soft tissue damage or other injuries to the cervical or uterine cavities, such as cervical lacerations or uterine perforations. Injuries such as these may lead to increased blood loss, infection, and overall recovery time. Therefore, it is desired that such injuries be avoided whenever possible.  
         [0008]     A further disadvantage of existing dilation systems such as those described above is that the person performing the dilating procedure has no way of knowing how far the rod has been inserted or if it has extended beyond the cervix and into the uterine cavity.  
       SUMMARY OF PREFERRED EMBODIMENTS OF INVENTION  
       [0009]     Preferred embodiments of the present invention are disclosed as having a cylindrical rod with an inflatable member at one end and a tubular member capable of threaded engagement with the cylindrical rod. Preferred embodiments control the insertion of the tubular member by threaded engagement between the tubular member and cylindrical rod. Preferred embodiments also utilize the inflatable member to prevent the tubular member from being inserted past a desired point. Preferred embodiments also comprise graduated markings on the cylindrical rod to allow the person performing the procedure to know how far the cylindrical rod or tubular member has been inserted.  
         [0010]     Thus, the embodiments of the cervical dilation system summarized above comprise a combination of various features and advantages that enable the system to overcome various problems of prior devices. Preferred embodiments of the present invention will allow more user control while also decreasing the risk of uterine perforation, cervical laceration, and soft tissue injury. This decrease in complication will lower surgical morbidity by decreasing infection, blood loss and overall recovery time. Preferred embodiments of the present invention may be utilized in any procedure that requires access to a body cavity such as the intrauterine cavity. Such procedures include diagnostic hysteroscopy, operative hysteroscopy, and dilation with suction or curettage. The various characteristics mentioned above, as well as other features and characteristics described in more detail below, will be readily apparent to those skilled in the art upon reading the following detailed description of preferred embodiments, and by referring to the accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]     For a more detailed description of the preferred embodiment of the present invention, reference will now be made to the accompanying drawings, wherein:  
         [0012]      FIG. 1  is a side view of a threaded cylindrical rod with an inflatable member (prior to inflation) attached to one end.  
         [0013]      FIG. 2  is a side view of a threaded cylindrical rod with an inflatable member (after inflation) attached to one end.  
         [0014]      FIG. 3  is a section side view of a tubular member.  
         [0015]      FIG. 4  is an end view of the tubular member shown in  FIG. 2 .  
         [0016]      FIG. 5  is an assembly view of the tubular member shown in  FIG. 2  disposed on the threaded cylindrical rod shown in  FIG. 1 . 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0017]     It is contemplated that embodiments of the present invention may be utilized to dilate various body canals. However, dilation of a cervix will be discussed below in an exemplary manner.  
         [0018]     Referring first to  FIG. 1 , cylindrical rod  10  comprises inflatable member  20  disposed on first end  30  and opposed to second end  40 . Cylindrical rod  10  also comprises threaded portion  50  and graduated markings  60  between first end  30  and second end  40 . Second end  40  also comprises connection mechanism  70 , such as threads or a nipple. Preferably, cylindrical rod  10  is 3 mm in diameter and 30 cm in length. With inflatable member  20  in a deflated condition as shown in  FIG. 1 , first end  30  of cylindrical rod  10  is inserted into a cervix (not shown). Insertion of cylindrical rod  10  is continued until first end  30  extends beyond the cervix and enters the uterus (not shown). Insertion may be continued until first end  30  contacts the fundus (the top of the uterus—not shown) to ensure that first end  30  and inflatable member  20  are past the cervix and in the uterus. Graduated markings  60  may also be used to determine how far cylindrical rod  10  has been inserted and therefore determine the depth of the cervix and uterus.  
         [0019]     With inflatable member  20  in the uterus, a Luer Lock syringe (not shown) or other similar device may be connected to connection mechanism  70 . The syringe or other inflation device is then used to inflate inflatable member  20 , as shown in  FIG. 2 , by means of an acceptable sterile fluid or gas. Inflatable member  20  preferably comprises a 15-30 ml bulb or balloon, but devices of other sizes may be used. After inflatable member  20  has been inflated, cylindrical rod  10  is retracted until inflatable member  20  contacts the cervix. Inflatable member  20  in an inflated state is larger in diameter than the cervix and therefore does not enter the cervix. In this position, inflatable member  20  separates the cervix from the uterus. The syringe or inflation device is then removed from second end  40  while inflatable member  20  stays in an inflated condition. Inflatable member  20  preferably comprises a valve or other mechanism that allows it to stay inflated after the syringe or inflation device is removed.  
         [0020]     Referring now to  FIGS. 3 through 5 , tubular member  100  comprises outer surface  160  and threaded bore  110 . Tubular member also comprises first end  130  and second end  140  with extensions  150 . With cylindrical rod  10  retracted so that inflatable member  20  is in contact with the cervix, tubular member  100  is positioned so that second end  40  of cylindrical rod  10  is disposed within threaded bore  110  near first end  130  of tubular member  100 . Tubular member  100  is then moved towards first end  30  of cylindrical rod  10  until threaded bore  110  engages threaded portion  50 . Extensions  150  may then be used to rotate tubular member  100  and advance tubular member  100  towards first end  30  of cylindrical rod  10 . Because advancement of tubular member  100  is accomplished through engagement of threaded portion  50  and threaded bore  110 , the movement may be accomplished in a controlled manner. In addition, inflatable member  20  prevents tubular member  100  from advancing beyond first end  30  of cylindrical rod  10 , as shown in  FIG. 5 . This prevents tubular member  100  from accidentally entering the uterus and potentially causing damage to the uterine cavity. In addition to increasing safety, embodiments of the present invention may also increase patient comfort. The gradual advancement of tubular member  100 , as opposed to the potentially abrupt insertion of prior art devices, should decrease the discomfort experienced by the patient.  
         [0021]     As tubular member  100  is advanced into the cervix and towards inflatable member  20 , outer surface  160  expands or dilates the cervix. First end  130  of tubular member  100  is preferably rounded or tapered to minimize patient discomfort and the chance of injury during advancement. It is also preferred that outer surface  160  is approximately 5 mm in diameter when tubular member  100  is initially inserted into the cervix. This smaller diameter minimizes the chance of damage or injury during the dilation procedure. The person performing the procedure will know that tubular member  100  has been fully inserted when first end  130  of tubular member  100  contacts inflatable member  20 . Inflatable member  20  prevents tubular member from being inserted past the cervix and into the uterus, thereby increasing safety and reducing the risk of injury. The person performing the procedure may use the graduated markings to note the distance at which tubular member  100  is fully inserted. After tubular member  100  has been fully inserted, it may then be retracted by turning it in the direction opposite of that used to advance tubular member  100 . Tubular member  100  may be retracted to the point that threaded bore  110  is no longer engaged with threaded portion  50 . At this point, tubular member  100  may be removed from the cylindrical rod  10 . A second tubular member (not shown) with an outer surface of increased diameter may then be inserted in a similar manner to further dilate the cervix. Preferably, tubular members are 15 cm in length and include diameters of 5 mm, 7 mm, 10 mm, 12 mm, and 14 mm. Tubular members of increasing diameter may be inserted until the cervix reaches the desired size. For example, many medical devices include scopes of 8 or 10 mm diameter and therefore require the cervix to be dilated to such a size. Graduated markings  60  may be used to confirm that subsequent tubular members are fully inserted. When the cervix has reached the desired size and tubular member  100  has been removed, inflatable member  20  may deflated and cylindrical rod  10  may be removed. Inflatable member  20  may be deflated by connecting a syringe or other device to second end  40  and creating a vacuum or suction to deflate inflatable member  20 .  
         [0022]     While preferred embodiments of this invention have been shown and described, modifications thereof can be made by one skilled in the art without departing from the spirit or teaching of this invention. The embodiments described herein are exemplary only and are not limiting. Many variations and modifications of the system and apparatus are possible and are within the scope of the invention. Accordingly, the scope of protection is not limited to the particular embodiments described herein, but is only limited by the claims which follow, the scope of which shall include all equivalents of the subject matter of the claims.