Abstract:
A measuring portion ( 40 ) is attached to a flexible portion ( 10 ) allowing the measuring portion ( 40 ) to slide along the length of the flexible portion ( 10 ). The flexible portion comprises an expandable end ( 30 ) and a valvable end ( 50 ). The required lengths are determined from graduated markings of distance ( 20 ) along the length of the flexible portion ( 10 ).

Description:
FIELD OF THE INVENTION  
       [0001]     The invention is generally related to the field of gynecological instrumentation and more specifically to an apparatus for measuring the length of the uterine cavity and the endocervical canal.  
       BACKGROUND OF THE INVENTION  
       [0002]     The development of new gynecological procedures has resulted in the need for an accurate measure of the length of the cervix. Endometrial ablation is one such procedure that involves the destruction of a thin layer of the lining of the uterus. This thin layer is called the endometrium and is shed each month during a woman&#39;s menstrual period. This process is regulated by the hormones estrogen and progesterone. A normal cycle lasts twenty-eight days from the start of one period to the next. Normal flow lasts five to seven days and is equal to about a quarter cup of blood.  
         [0003]     About one in five women have excessive menstrual bleeding. This is more common for women between the ages of forty-to-fifty who are approaching menopause but can present at any age. Excessive menstrual bleeding can lead to fatigue, anemia, and embarrassing accidents and can have a very negative effect on a woman&#39;s quality of life.  
         [0004]     Treatment options for excessive menstrual bleeding include drug therapy which is the first line; these include oral contraceptives and also other hormones to help regulate the hormonal imbalances, D&amp;C which involves scraping the lining of the uterus, hysterectomy and endometrial ablation.  
         [0005]     Ablation will stop menses in most women. Other women will have light bleeding and very few may still have regular periods. The procedure is a very short and is done on an outpatient basis, with local anesthesia and light sedation. This makes for a quick recovery and minimal cramping post operatively. The techniques employed have evolved over time from the tedious rollerball and laser procedures to the more efficient and timely thermal, cryotherapy and electrical modalities.  
         [0006]     Present techniques for performing ablation require an accurate measure of the length of the endocervical canal. This is a dimension that is not routinely measured by gynecologists and there is no instrument available that provides an accurate measurement. Presently a very crude and inaccurate method of measurement is utilized that, if performed incorrectly, can lead to perforation of the uterus, infection, excessive blood loss, and possible accumulation of blood in the uterus due to scarring. There is therefore a need for a safe and accurate apparatus and method for measuring the length of the endocervical canal. The instant invention addresses this need.  
       SUMMARY OF THE INVENTION  
       [0007]     The instant invention comprises a measuring apparatus for measuring the length of the uterine cavity and the endocervical canal. The measurement apparatus comprises a flexible tube with graduated markings for measuring distance. The markings can represent any established measure of distance such as centimeters, inches and fractions thereof. The tube comprises an expandable end with an adjustable cross-section. The other end of the tube comprises a valve and locking mechanism allowing the ingress and/or egress of liquids and/or gases into tube. A measuring portion is fitted over the tube that can be slid along the length of the tube allowing measurements to be taken. The measurements can be read directly from the graduated markings on the tube by determining the position of an edge of the measuring portion on the tube. In addition, the measuring portion can be used to mark the tube thereby allowing the measurement to be recorded.  
         [0008]     In operation the expandable end of the measuring apparatus is inserted into the uterine cavity through the vagina and the cervix. At the point when the expandable end of the flexible tube is at the top of the uterine cavity (or fundus) the measuring portion is slid along the length of the flexible tube until it touches the cervix. The required length can then be measured by marking the flexible tube or by determining the position of the measuring portion along the flexible tube using the graduated markings along the tube.  
         [0009]     To determine the length of the endocervical canal, the end of the flexible tube is expanded and the flexible tube slowly withdrawn from the uterine cavity until the expanded end rests against the end of the endocervical canal. At this point the measuring portion is slid along the length of the flexible tube until it rests against the cervix. The required length can then be measured by marking the flexible tube or by determining the position of the measuring portion along the flexible tube using the graduated markings along the tube. The measuring apparatus can be removed from the uterus and vagina by reducing the cross-section of the expanded end and slowly withdrawing the flexible tube from the uterus and vagina.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]      FIG. 1 ( a ). A diagram of an embodiment of the measuring apparatus according to the instant invention.  
         [0011]      FIG. 1 ( b ). A cross-section of the measuring apparatus taken through the plane Z-Z′ shown in  FIG. 1 ( a ).  
         [0012]      FIG. 2 ( a ) A top view of an embodiment of the measuring and/or marking component of the apparatus of the instant invention.  
         [0013]      FIG. 2 ( b ). A cross-sectional view of the embodiment of the measuring and/or marking guide component of the apparatus shown in  FIG. 2 ( a ).  
         [0014]     FIGS.  3 ( a )- FIG. 3 ( b ). Diagrams of an embodiment of tip of the measurement apparatus in the (a) normal state and the (b) inflated or expanded state.  
         [0015]      FIG. 4 . A diagram showing an embodiment of a valve assembly in the base of the measuring apparatus.  
         [0016]      FIG. 5 ( a )- FIG. 5 ( b ). Diagrams illustrating the measuring apparatus according to an embodiment of the instant invention. 
     
    
       [0017]     Common reference numerals are used throughout the figures to represent like or similar features. The figures are not drawn to scale and are merely provided for illustrative purposes.  
       DETAILED DESCRIPTION OF THE INVENTION  
       [0018]     The invention will be described by referring to FIGS.  1  through  FIG. 5 ( b ). The Figures illustrate an embodiment of an apparatus and method for using the apparatus to measure the length of the uterine cavity and the length of the endocervical canal.  
         [0019]     Shown in  FIG. 1  is an embodiment of an apparatus  5  to measure the length of the uterine cavity and the length of the endocervical canal. The measurement apparatus comprises a flexible portion  10 , an expandable end portion  30 , a valvable end portion  50 , and a measuring/marking portion  40 . In an embodiment of the instant invention the cross-section of the flexible portion  10  is approximately 3 mm across but can be anywhere from 0.2 mm to 8 mm without departing from the scope of the instant invention. The flexible portion can be formed using any suitable flexible material such as various types of rubber or plastic. In addition, other combinations of flexible materials can be used to form the flexible portion  10 . The requirement for the flexibility or rigidity of the flexible portion  10  is such that it is flexible enough to facilitate insertion from outside the vaginal opening through the cervix and into the uterine cavity. The flexible portion  10  should however be rigid enough to maintain its shape in the uterine cavity thereby allowing accurate measurements to be obtained. Markings representing distance  20  are placed along the length of the flexible portion  10  to facilitate the taking of the measurements. In various embodiments the markings  20  can represent inches (as well as any usable fraction of an inch) or centimeters (as well as any usable fraction of a centimeter such as millimeters etc.) or any other suitable measure of distance. The markings start at a zero measure at the expandable end  3  and increase towards the valvable end  50  of the flexible portion  10 . In cross-section the flexible portion  10  can be circular, square, rectangular, octagonal, triangular, or any other suitable shape. Shown in  FIG. 1 ( b ) is an embodiment of a cross-section of the flexible portion  10  taken along the line ZZ′ as shown in  FIG. 1 ( a ) for an embodiment of the instant invention. As shown in  FIG. 1 ( b ) the flexible portion has a hollow center  15  allowing gas or liquid to be used to inflate the end  30  of the flexible portion. The hollow center runs the entire length of the flexible portion  10  from the valvable end  50  to the expandable end  30 .  
         [0020]     The measuring apparatus shown in  FIG. 1 ( a ) comprises an expandable end portion  30 . An embodiment of the expandable end portion is shown in  FIG. 3 ( a ) and  FIG. 3 ( b ). As shown in  FIG. 3 ( a ) in the unexpanded state the expandable end  30  of the flexible portion  10  is approximately the same size or dimension of the flexible portion  10 . On the introduction of a gas or liquid into the flexible portion  10  through the valvable end  50  as will be described below, the expandable end  30  will expand as shown in  FIG. 3 ( b ). The expanded end  35  will now have a cross-section x 3  that is greater than the unexpanded cross-section of the expandable end  30 . The embodiment of the expandable end  30  shown in FIGS.  3 ( a ) and  3 ( b ) represent one of many embodiments. In other embodiments a collapsible portion is expanded to increase the cross-section of the expandable end  30 .  
         [0021]     The measuring apparatus shown in  FIG. 1 ( a ) further comprises a measuring or marking portion (herein after referred to as the measuring portion)  40  that moves along the flexible portion  10 . An embodiment of the measuring portion is shown in  FIG. 2 ( a ) and  FIG. 2 ( b ). A top view of an embodiment of the measuring portion is shown in  FIG. 2 ( a ). In the embodiment shown in  FIG. 2 ( a ) the measuring portion  40  is circular with a hollow center portion  60  that allows the measuring portion  40  to move along the length of the flexible portion  10  as shown in  FIG. 1 ( a ). As shown in  FIG. 2 ( b ), the measuring portion  40  can be a length x 1  that allows the position of the measuring portion along the flexible portion  10  to be easily read. An example of this is shown in  FIG. 1 ( a ) where the distance of the end of the measuring portion  42  from the expandable end  30  can be read from the markings  20  on the flexible portion  10 . It should be noted that the measuring portion can be any shape that allows the distance of the measuring portion  40  from the expandable end  30  to be easily obtained. In a further embodiment the measuring portion can be used to mark the flexible portion thereby recording the distance from the expandable end  30  of the flexible portion to the position of the measuring portion at the time the mark was made.  
         [0022]     The measuring apparatus shown in  FIG. 1 ( a ) further comprises a valvable end  50 . The valvable end  50  is positioned along the flexible portion  10  at the end opposite to that of the expandable end  30 . The valvable end  50  allows gases and/or liquids to enter the flexible portion  10  to expand the expandable end  30 . Once expanded the valvable end  50  allows gas and/or liquids to leave the flexible portion  10  thereby allowing the expandable end  30  to return to its unexpanded size. An embodiment of the valvable end  50  is shown in  FIG. 4 . As shown in  FIG. 4 , the valvable end  50  comprises a locking mechanism  90  that locks an external device  80  in place. In an embodiment of the instant invention the external device  80  is a syringe that is used to inject liquid and/or gas into the flexible portion  10  to expand the expandable end  30 . In addition the syringe  80  can allow liquid and/or gas to leave the flexible portion  10  allowing the expanded end  30  to contract. Optional valves  70  that move along the arc AA′ and the arc BB′ can be used to hold the liquid and/or gas in the flexible portion  10  if the external device  80  is removed.  
         [0023]     Illustrated in  FIG. 5 ( a ) and  FIG. 5 ( b ) is an embodiment of a method for using the measuring apparatus to measure the length of the uterus and the endocervical canal. As shown in  FIG. 5 ( a ) the flexible portion  10  is inserted through the vagina and the cervix and into the uterine cavity. To measure the length of the uterine cavity the flexible portion  10  is inserted until the expandable end  30  of the flexible portion  10  touches the fundus or the end of the uterine cavity. The expandable end of the flexible portion is the zero point of the measurement. The measuring portion  40  is then slid along the length of the flexible portion  10  until it rests against the cervix as shown at point B in  FIG. 5 ( a ). At this point the measuring portion  40  can be used to mark the flexible portion  10  or the measurement can be read from the end of the measurement portion  40  at point C as shown in  FIG. 5 ( a ). For the case where the measurement is read at point C, the length of the uterus L 1  is found by subtracting the length of the measuring portion x 1  from the length read at point C.  
         [0024]     To measure the length of the endocervical canal, the expandable end  30  of the flexible portion  10  is expanded and the flexible portion  10  is slowly withdrawn from the uterine cavity. The flexible portion  10  is slowly withdrawn the expanded end  35  rests against the end of the endocervical canal as shown at point D in  FIG. 5 ( b ). It is important that the size of the expanded end  35  be such that it does not easily pass through the endocervical canal. There should be enough resistance to the expanded end  35  passing through the endocervical canal to signal the user that the expanded end  35  is at the edge D of the endocervical canal. When the expanded end  35  is at the edge D of the endocervical canal, the expanded end  35  becomes the zero point of the measurement, and the measuring portion  40  is slid along the flexible portion  10  to the edge of the cervix (point E) as shown in  FIG. 5 ( b ). To extract the length of the endocervical canal the measuring portion  40  can be used to mark the flexible portion  10 . Alternatively, the measurement can be read from the end of the measuring portion  40  at point F as shown in  FIG. 5 ( b ). In the case where the measurement is read at point F, the length of the endocervical canal L 2  is found by subtracting the length X 1  of the measuring portion  40  from the length measured at point F in  FIG. 5 ( b ). Following the measurement of the length of the endocervical canal, the size of the expanded end  35  is reduced and the flexible portion  10  is slowly removed from the uterine cavity through the cervix and the vagina.  
         [0025]     Although the present invention has been described in detail, various changes and modifications may be suggested to one skilled in the art. It is intended that the present invention encompass such changes and modifications as falling within the scope of the appended claims.