Abstract:
The present disclosure provides a urine meter ( 40 ) having a housing ( 14 ) which includes an inlet ( 16 ) and an outlet ( 20 ). The housing ( 14 ) further includes a first measurement chamber ( 24 ) and a second measurement chamber ( 26 ) arranged such that liquid entering the inlet ( 16 ) enters the first measurement chamber ( 24 ) before passing to the second measurement chamber ( 26 ). The housing ( 14 ) is further provided with a non-return valve ( 42 ) between the first and second measurement chambers ( 24,26 ) which, in use, prevents the flow of liquid from the second measurement chamber ( 26 ) to the first measurement chamber ( 24 ).

Description:
BACKGROUND 
       [0001]    1. Technical Field 
         [0002]    The present invention relates to a urine meter, and in particular to a urine meter for monitoring the flow of urine from a catheterised patient. 
         [0003]    2. Background of Related Art 
         [0004]      FIG. 1  shows a known urine meter, generally designated  10 , and a urine collection bag  12 . The urine meter  10  includes a housing  14  that is provided with an inlet  16  having an inlet conduit  18 . The inlet conduit is in use, connectable to a urinary catheter of a patient. The housing  14  is further provided with an outlet  20  which is connected by an outlet conduit  22  to the collection bag  12 . Straps  30  are provided on the urine meter  10  to permit both the meter  10  and collection bag  12  to be mounted to an appropriate support. The support may, for example, be the rail of a patient bed. 
         [0005]    The housing  14  further defines first, second and third measurement chambers  24 ,  26 ,  28 . For the urine meter  10  shown, the first measurement chamber  24  has a volume of 100 millilitres, the second measurement chamber  26  has a volume of 200 millilitres, and the third measurement chamber  28  has a volume of 200 millilitres. The housing  14  is formed from a clear plastic material such as, for example, a styrene-butadiene copolymer. One such suitable material is K-Resin® SBC. The interior of each measurement chamber  24 ,  26 ,  28  is viewable through the housing  14 , and each chamber  24 ,  26 ,  28  is marked with graduations which permit the volume of liquid in each chamber  24 ,  26 ,  28  to be measured. The first chamber  24  is marked with graduations from 0 ml to 100 ml, the second chamber  26  is marked with graduations from 100 ml to 300 ml, and the third chamber is marked with graduations from 300 ml to 500 ml. The first chamber  24  is separated from the second chamber  26  by an interior wall  32  of the housing  14  which defines a weir between the chambers  24 ,  26 . The second chamber  26  is similarly separated from the third chamber  28  by a further interior wall  34  of the housing  14  which defines a weir between the chambers  26 ,  28 . 
         [0006]    The housing  14  is configured such that liquid entering the meter  10  through the inlet  16  flows firstly into the first chamber  24 . Once the first chamber  24  has been filled, incoming liquid spills over the weir defined by the wall  32  separating the first and second chambers  24 ,  26  and into the second chamber  26 . Once the second chamber  26  has been filled, incoming liquid spills over the weir defined by the wall  34  separating the second and third chambers  26 ,  28  and into the third chamber  28 . The urine meter  10  is further provided with an overflow conduit  36  which connects the third chamber  28  to the outlet  20 . In the event that the first, second and third chambers  24 ,  26 ,  28  become filled, excess liquid is conducted through the overflow conduit  36  to the outlet  20 . 
         [0007]    The meter  10  is further provided with a drainage tap  38  which is located in a lower region of the housing  14 . The drainage tap  38  enables the chambers  24 ,  26 ,  28  to be placed in fluid communication with the outlet  20  and thereby permit liquid present in the chambers  24 ,  26 ,  28  to be drained to the collection bag  12 . The drainage tap  38  is configured so as to permit the sequential drainage of the chambers  24 ,  26 ,  28 . 
         [0008]    One drawback of the urine meter  10  of  FIG. 1  is that in the event of the meter  10  being tipped or shaken, for example when the meter  10  is moved, liquid can transfer between the chambers  24 ,  26 ,  28  by passing over the chamber separating walls  32 ,  34 . This can thus lead to the meter  10  providing an incorrect reading. 
       SUMMARY 
       [0009]    According to the present invention there is provided a urine meter having a housing which includes an inlet and an outlet, the housing further including a first measurement chamber and a second measurement chamber arranged such that liquid entering the inlet enters the first measurement chamber before passing to the second measurement chamber, wherein the housing is further provided with a non-return valve between the first and second measurement chambers which, in use, prevents the flow of liquid from the second measurement chamber to the first measurement chamber. 
         [0010]    The non return valve may be biased to an open condition to permit fluid communication between the first chamber and the second chamber, and urged to a closed condition to prevent fluid communication between the chambers by the action of liquid present within the second chamber. In such an embodiment the non return valve may be biased to the open condition by gravity. The non return valve may be urged to the closed condition by the impact of liquid contained in second chamber. Such impact may occur as a result of sloshing of the liquid within the second chamber resulting from movement of the meter. The non return valve may be urged to the closed condition due to the buoyancy of a portion of the non return valve. In such an embodiment, the non return valve is urged to the closed condition by the rising free surface of the liquid. 
         [0011]    The non return valve is provided in an internal partition of the housing which separates the first chamber from the second chamber. The non return valve may include a valve member which is mounted to the internal partition, and at least one aperture which extends through the internal partition and which defines fluid communication channel between the first and second measurement chambers. In such an embodiment the valve member may include a stem and a head, wherein the head defines a sealing surface which is movable into contact with the internal partition to close the at least one aperture. The sealing surface many be an annular sealing surface. 
         [0012]    The stem of the valve member may received in an aperture of the internal partition. In such an embodiment, the valve member may be retained in the aperture of the internal partition by the head of the valve member and a formation on the stem of the valve member. The formation on the stem of the valve member is resiliently deformable so as to enable the valve member to be fitted to the aperture of the internal partition. The internal partition is provided with a plurality of apertures which extend through the internal partition and which define fluid communication channels between the first and second measurement chambers. 
         [0013]    In an alternative embodiment, the housing including a third measurement chamber which, in use receives liquid from the second measurement chamber, wherein the housing is provided with a further non-return valve between the second and third measurement chambers which, in use, prevents the flow of liquid from the third measurement chamber to the second measurement chamber. In such an embodiment it will be appreciated that the non return valve may have the same configuration and operating characteristics as non return valve described with reference to the previously described two chamber embodiment. 
         [0014]    In such an embodiment the further non-return valve is preferably positioned lower in the housing than the first non-return valve. This ensures liquid is able to flow from the second measurement chamber to the third measurement chamber before closure of the non-return valve provided between the first and second measurement chambers. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]    An embodiment of the present invention will now be described with reference to the accompanying drawings in which: 
           [0016]      FIG. 1  shows a known urine meter and collection bag; 
           [0017]      FIG. 2  shows a cross-sectional view of a urine meter according to the present invention; 
           [0018]      FIG. 3  shows a cross-sectional view of a non-return valve of the urine meter of  FIG. 2 , the valve being in an open position; 
           [0019]      FIG. 4  shows a cross-sectional view of the non-return valve of the urine meter of  FIG. 2 , the non-return valve being in a closed position; 
           [0020]      FIG. 5  shows a perspective view of the non-return valve; 
           [0021]      FIG. 6  shows a perspective view of the valve member; and 
           [0022]      FIG. 7  shows a perspective view of the non-return valve with the valve member removed. 
       
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
       [0023]    Referring now to  FIGS. 2 to 7  there is shown a urine meter, generally designated  40 . According to the present invention. Features common to the urine meter  10  described with reference to  FIG. 1  are identified with like reference numerals. 
         [0024]      FIG. 2  shows a cross-sectional view of the housing  14  of the urine meter  40  viewed from the opposite side to that shown in  FIG. 1 . The housing  14  of the meter  40  differs from that described with reference to  FIG. 1  in that non return valves, generally designated  42 , are provided between the first and second chambers  24 ,  26 , and the second and third chambers  26 ,  28  respectively. Each non return valve  42  is provided in an extension of the wall  32 ,  34  that separates the first and second chambers  24 ,  26 , and the second and third chambers  26 ,  28  respectively. 
         [0025]    Looking firstly at the wall  32  which separates the first and second chambers  24 ,  26 , the upper edge of the wall  32  in the meter  10  of  FIG. 1  is indicated by broken line  44 . In the meter  40  of the present invention, the wall  32  is extended such that it extends fully across the housing  14  from the base wall  45  to the top wall  46  thereof. The wall  32  is extended by an extension generally designated  48 . The extension  48  includes a first portion  32   a  which lies on a plane substantially perpendicular to the plane of the major portion of the wall  32 . The wall  32  is further extended by a second portion  32   b  which lies on a plane substantially perpendicular to that of the first portion  32   a,  and substantially parallel to the plane of the major portion of the wall  32 . The first and second portions  32   a,    32   b  of the wall extension  48  thus define a step in the wall  32 . 
         [0026]    Referring also to  FIGS. 3-7 , the first portion  32   a  of the wall extension  48  is provided with an aperture  50  configured to receive a non return valve  42 . Aperture  50  may have any cross sectional area which corresponds to a cross sectional area of a portion of the return valve received within aperture  50 . Wall extension  48  further comprises at least one second aperture  52  positioned in relation to aperture  50  so that when non return valve  42  is in the open position, fluid may flow through the at least one second aperture  52 , and when non return valve  42  is in the closed position, fluid is prevented from flowing through the at least one second aperture  52 . The at least one second aperture  52  may, but need not have a cross sectional area less than the cross sectional area of aperture  50 . In one embodiment of the invention, the wall extension  48  is provided with a substantially circular first aperture  50  and a plurality of substantially circular second apertures  52  ( FIG. 7 ). In the embodiment shown, the first aperture  50  is provided a substantially central position on the first portion  32   a  of the wall extension  48 . In the embodiment shown, the wall extension  48  is further provided with six second apertures  52  which are equidistantly spaced in a circular arrangement around the first aperture  50 . The second apertures  52  have a diameter that is less than that of the first aperture  50 . It will be appreciated that the extension  48  may be provided with a greater or lesser number of second apertures  52 . As will be described in greater detail below, the first aperture  50  serves to locate and retain a valve member  54  of a non return valve  42 , while the second apertures  52 , in conjunction with the valve member  54 , define fluid conduits extending through the wall  32 . 
         [0027]    A similar wall extension  49  is provided in the wall  34  that separates the second and third chambers  26 ,  28 . This wall extension  49  similarly includes a first portion  34   a  which lies on a plane substantially perpendicular to the plane of the major portion of the wall  34 . The wall  34  is further extended by a second portion  34   b  which lies on a plane substantially perpendicular to that of the first portion  34   a,  and substantially parallel to the plane of the major portion of the wall  34 . The wall extension  49  is provided with a similar array of apertures having a first aperture surrounded by a plurality of smaller second apertures. The upper edge of the wall  34  that separates the second and third chambers is indicated by broken line  47  ( FIG. 2 ). The upper edge of the wall  34  is spaced a greater distance from the top wall  46  of the housing  14  than the upper edge of the wall  32  separating the first and second chambers  24 ,  26 . This results in the non-return valve  42  provided between the first and second chambers  24 ,  26  being positioned higher in the housing  14  than the non-return valve  42  provided between the second and third chambers  26 ,  28 . 
         [0028]      FIG. 6  shows a valve member, generally designated  54 , of a non return valve  42 . The valve member  54  includes a stem  56  and a head  58 . The head  58  of the valve member  54  may have any size and shape suitable to cover all second apertures when the non return valve  42  is in the closed position. In one embodiment, the head  58  of the valve member  54  is substantially disc shaped and is provided with an annular and substantially flat sealing surface  60 . Alternately, other valve member configurations are envisioned. The stem  56  extends from a substantially central position on the head  58  such that the annular sealing surface  60  extends around the location at which the stem  56  meets the head  58 . The opposite side of the head  58  is provided with a substantially circular face  61 . The stem  56  has a first generally cylindrical portion  62 , a second generally cylindrical portion  64  and a bulbous portion  66  provided between the first and second generally cylindrical portions  62 ,  64 . The diameter of the first cylindrical portion  62  is substantially equal to the diameter of the second cylindrical portion  64 . The diameter of the first and second cylindrical portions  62 ,  64  is less than the diameter of the first aperture  50  of a wall extension  48  of the housing  14 . The bulbous portion  66  has an at rest diameter at its largest cross sectional area that is greater than that of the cylindrical portions  62 ,  64  and the first aperture  50 . The bulbous portion  66  is resiliently deformable so that its diameter can be reduced by compression or elongation. The valve member  54  is manufactured from a flexible plastics material. 
         [0029]      FIGS. 3 ,  4  and  6  show the valve member  54  fitted to the extension  48  of a wall  32  of the housing  14 . The valve member  54  is fitted to the extension  48  by first inserting the second cylindrical portion  64  of the stem  56  into the first aperture  50  of the extension  48  from the side of the extension  48  that faces the downstream chamber  26  of the meter  40 . The stem  56  is inserted further into the aperture  50  such that the bulbous portion  66  deforms and passes through the aperture  50 . Once clear of the aperture  50  the bulbous portion  66  returns to its original shape. It will thus be appreciated that the valve member  54  is thus retained in the aperture  50  by the presence of the bulbous portion  66  of the stem  56  on one side of the aperture  50 , and the head  58  of the valve member  54  on the other side of the aperture  50 . The outer diameter of the bulbous portion  66  which contacts a first surface of wall extension  48  is smaller than an inner cross sectional area of a periphery defined by each innermost point of each of the at least one second aperture  52  so that the bulbous portion does not interfere with flow through the at least one second aperture  52 . The cross sectional area of the sealing surface  60  is greater than an outer cross sectional area of a periphery defined by each outermost point of each of the at least one second aperture  52  so that the sealing surface  60  interrupts flow through the at least one second aperture  52  when the sealing surface  60  contacts a second surface of wall extension  48 . In one embodiment, the outer diameter of the sealing surface  60  of the head  58  is greater that the outer diameter of the circular arrangement of the second apertures  52 . 
         [0030]    The length of the first cylindrical portion  62  of the stem  56  is greater than the thickness of the portion  32   a  of the wall extension  48  in which the first aperture  50  is provided. It will thus be understood that the valve member  54  is able to move between an open position, shown in  FIG. 3 , where the bulbous member  66  abuts the first aperture and the sealing surface  60  is spaced from the wall extension  48 , and a closed position, shown in  FIG. 4 , where the sealing surface  60  abuts the wall extension  40  and the bulbous member  66  is spaced from the first aperture  50 . 
         [0031]    In use, the valve member  54  is gravity biased towards the open position shown in  FIG. 3 . In the first position, the arrangement of second apertures  52  are open and each second aperture  52  defines a fluid communication path through the wall extension  48 . Liquid is this able to pass from the upstream chamber  24  to the downstream chamber  26  as indicated by arrows  68 . In the event that liquid attempts to flow back from the downstream chamber  26  to the to the upstream chamber the liquid contacts the circular face  61  of the head  58  as indicated by arrows  70  and urges the valve member  54  to the closed position as indicted by arrow  72 . The sealing surface  60  abuts a second surface of the wall extension  48  and thus closes the second apertures  52 . Liquid may come into contact with the circular face  61  as a result of the downstream chamber  26  filling to the level of the first portion  32   a  of the wall extension  48 . In such an instance, the valve member  54  is moved to the closed position due to buoyancy of the valve member  54  in the liquid. Alternatively, in instances where the downstream chamber  26  is only partially filled, the valve member  54  may be urged to the closed position as a result of sloshing of the liquid contained in the downstream chamber  26 . 
         [0032]    As described above, the non return valve  42  provided between the first and second chambers  24 ,  26  is positioned at a higher level within the housing  14  than the non return valve  42  provided between the second and third chambers  26 ,  28 . During normal use of the urine meter  40 , i.e. when it is positioned level and stably mounted to, for example, a bed frame, the differing non- return valve heights permit the chambers  24 ,  26 ,  28  to fill sequentially. The upper edge of the wall  34  separating the second and third chambers  26 ,  28  is provided below the level adopted by the circular face  61  of the non return valve  42  between the first and second chambers  24 ,  26  in the open position. As such, it will be appreciated that upon filling of the second chamber  26  to the level of the top of the wall  34  separating the second and third chambers  26 ,  28 , further liquid introduced into the second chamber  26  will flow into the third chamber  28 . 
         [0033]    In the embodiment of the invention described above, the urine meter  40  is provided with three measurement chambers  24 ,  26 ,  28 . It will be appreciated that non-return valves  42  of the present invention may be provided in urine meters having two measurement chambers or more than three measurement chambers. 
         [0034]    Persons skilled in the art will understand that the devices and methods specifically described herein and illustrated in the accompanying drawings are non-limiting exemplary embodiments. It is envisioned that the elements and features illustrated or described in connection with one exemplary embodiment may be combined with the elements and features of another without departing from the scope of the present disclosure. As well, one skilled in the art will appreciate further features and advantages of the disclosure based on the above-described embodiments. Accordingly, the disclosure is not to be limited by what has been particularly shown and described, except as indicated by the appended claims.