Abstract:
In a bicarbonate container for one-time use with a hemodialysis apparatus which container consists of a bottom part with a trough for containing the bicarbonate, a cover for closing the trough and a two-channel plug-in connector for connection to a dialysis apparatus, the bottom part and the top part include flanges which are joined and form therebetween a conduit channel extending from one end of the container where the plug-in connector is disposed to the other end of the container for conducting liquid supplied through one of the plug-in connector channels through the bicarbonate filling of the trough of the container in which the bicarbonate is disposed to the other channel of the plug-in connector.

Description:
BACKGROUND OF THE INVENTION 
   The invention relates to a bicarbonate container for one time use in dialysis apparatus for hemodialysis that is a rigid plastic container including a two-channel plug-in connector for connection of the container to a dialysis apparatus. 
   A bicarbonate container with a two-channel plug-in connector is already known from EP-0 575 970 A2, wherein the container is shown as a flexible bag. Since, because of the two-channel plug-in connector for the connection to a dialysis apparatus, the inlet and outlet for the solution circuit are disposed at the same location of the container, the container must include a conduit which extends within the container from one of the two plug-in connector channels to the opposite end of the container so that the solution can flow through the whole bicarbonate container. In the container disclosed in EP 0 575 970 A2, a flexible hose extends from one of the two plug-in connector channels through the interior of the bag to the end thereof about opposite the plug-in connector. 
   However, this arrangement requires relatively high manufacturing expenses and, more importantly, the end of the hose is not fixed so that, after filling the bag with bicarbonate, the end of the hose may not be in the most desirable position within the bag whereby the solution conducted through the bag flows only through part of the bicarbonate contained in the bag. 
   It is the object of the present invention to provide a bicarbonate container for a hemodialysis apparatus which is easy to manufacture and wherein the opening of the duct extending from the plug-in connection to the opposite end of the container is securely arranged at an optimal location. 
   SUMMARY OF THE INVENTION 
   In a bicarbonate container for one-time use with a hemodialysis apparatus which container consists of a bottom part with a trough for containing the bicarbonate, a cover for closing the trough and a two-channel plug-in connector for connection to a dialysis apparatus, the bottom part and the top part include flanges which are joined and form therebetween a conduit channel extending from one end of the container where the plug-in connector is disposed to the other end of the container for conducting liquid supplied through one of the plug-in connector channels through the bicarbonate filling of the trough of the container in which the bicarbonate is disposed to the other channel of the plug-in connector. Two embodiments of the invention will be described below in detail with reference to the accompanying drawings: 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a top view of a bottom part of a first embodiment of the bicarbonate container according to the invention, 
       FIG. 2  is a sectional view taken along lines II—II of  FIG. 1 , 
       FIG. 3  is a horizontal sectional view of the container taken in a plane extending through the conduit extending from the plug-in connector to the opposite end of the container as seen from the bottom, 
       FIG. 4  is a cross-sectional view of the container cover, 
       FIG. 5  is a top view of the assembled container wherein the weld connections between the bottom part and the top part of the container are shown by hatching, 
       FIG. 6  is a top view of a second embodiment of the bicarbonate container according to the invention, 
       FIG. 7  is a bottom view of the bicarbonate container of  FIG. 6 , 
       FIG. 8  is a cross-sectional view of the bicarbonate container taken along line VIII—VIII of  FIG. 7 , 
       FIG. 9  is an enlarged representation of the encircled area IX of  FIG. 8 , and 
       FIG. 10  is an enlarged representation of the encircled area X of  FIG. 8 . 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   The bicarbonate container of the first embodiment as shown in  FIGS. 1 to 5  comprises a bottom part  1  ( FIGS. 1 and 2 ) and a cover part  2  ( FIGS. 3 and 4 ), which is disposed on the bottom part  1  and welded thereto. Both parts are manufactured from plastic material by injection molding. 
   The bottom part  1  is in the form of a trough  11  with a bottom  12  and a top flange  13 . The trough  11  has, in the embodiment shown, an essentially oblong shape with rounded corners and is slightly narrowing toward the bottom  12 . However, the trough  19  could have any other shape, it could for example, be round or semispherical. The flange  13  is flat and extends in the top opening plane of the trough  11  that is around the top opening. The top side of the flange  13  forms a welding surface for welding a corresponding flange surface of the cover part  2  to the bottom part  1 . 
   As shown in  FIGS. 3 and 4 , the cover part  2  is in the form of a flat tray  21  with a bottom  22  and a flat flange  23  extending around the tray  21 . At a narrow side of the tray  21 , the flange  23  is enlarged and provided with a plug-in connector  3  which, as shown in the cross-sectional view of  FIG. 4 , comprises an outer guide sleeve  31 . Concentrically, within the outer guide sleeve  31 , there are two concentric conductor bushings  32  and  33 . The outer guide sleeve  31  forms a guide structure for the mechanical attachment to, and interlocking of, the bicarbonate container with the corresponding complementary plug-in receptacle of the dialysis apparatus. The outer conductor bushing  32  and the inner conductor bushing  33  form two concentric conduit channels providing inlets and, respectively, outlets for the solution conducted through the container. The inner conduit channel formed by the conductor bushing  33  ends in the flange plane in a central opening  34 . The outer tubular conduit channel formed between the inner and outer conductor bushings  33 ,  32  is closed by an end wall  35  provided with a passage  36  extending to a flat circular recesses  24  of the flange  23 . 
   The flange  13  of the bottom part  1  includes in accordance with  FIGS. 1 and 2  at one of the narrow sides of the trough  11  a circle segment-shaped extension  14 . The extension is complementary in shape to the part of the flange  23  of the cover part  2 , which is provided with the plug-in connecter  3 . Furthermore, the flange  13  of the bottom part  1  includes a channel  15  extending from the center of the flange extension  14  in the top flange  14  along one of the longitudinal sides of the trough  11  around the trough opening to the narrow side of the trough opposite the flange extension  14  such that the channel  15  is separated from the trough opening by a web-like flange area disposed between the channel  15  and the through opening. This channel also extends essentially over the whole length of the narrow side of the trough  11  opposite the flange extension  14  and is in communication with the trough  11  by a number of inlet passages  16  formed in the flange  13  in spaced relationship. 
   As further apparent from  FIGS. 1 and 2 , the trough  11  or rather the bottom part  1  includes at the side below the flange extension  14  an outwardly curved area  17 . 
     FIG. 5  is a top view of the bicarbonate container according to the invention with the cover part  2  disposed on the container bottom part  1  and connected thereto by welding of the flange areas which are in contact with each other. 
   The area via which the flange  13  of the bottom part  1  is welded together with the flange  23  of the cover part  2  is indicated in  FIG. 5  by broken hatching lines. The respective welding surface areas in the cover part  2  are also indicated in  FIG. 3  by hatching. It can be seen therefrom that flange areas corresponding to the channel  15  in the flange  13  of the bottom part  1  are not welded together. 
   From  FIG. 5 , particularly in connection with  FIGS. 1–4 , it is apparent that, after the flanges  13  and  23  of the bottom container part  1  and the cover part  2  have been joined, the originally open channel  15  in the bottom part flange  13  is closed by this cover part flange  23  so as to form a conduit which extends from the plug-in connecter  3  through the flange structure to the end of the container opposite the plug-in connector  3 . Along the narrow side of the container opposite the plug-in connector  3 , the conduit is in communication with the container interior via the inlet passages  16 . In the area of the plug-in connector  3 , the duct formed by the inner conductor bushing  33 . The circular recess  24  of the cover part flange  23  which is in communication, by way of the opening  36  in the bottom wall  35 , with the annular flow passage formed between the inner conductor sleeve  33  and the outer conductor sleeve  32  is disposed above the respective end area of the trough  11  which includes the outwardly curved area  17  when the bicarbonate container is assembled. 
   In this way, the annular conduit of the plug-in connector  3  is in communication with the end of the container interior adjacent the plug-in connector  3  whereas the inner conduit of the plug-in connector  3  is in communication with the opposite end of the container via the conduit formed by channel  15  and the inlet passages  16 . 
   In the bicarbonate container of the second embodiment as shown in  FIGS. 6–10  corresponding components are designated by the same reference numerals as used in connection with  FIGS. 1–5 . The bicarbonate container of the second embodiment also comprises a bottom part  1  and a cover part  2  disposed on the bottom part  1  and welded thereto. Both parts are also manufactured of plastic material by injection molding. The bottom part  1  is again in the form of a trough  11  with a bottom  12  and an upper flange  13  and is of oblong shape with rounded corners and with side walls which extend upwardly from the bottom  12  so as to be slightly inclined outwardly but may have a different shape. The flange  13  is flat and extends in the plane of the opening of the trough  11  around the trough opening. The top side of the flange forms a welding surface for interconnection with a corresponding flange surface of the cover part  2 . 
   The cover part  2  also is provided at its circumference with a flat flange  23  which cooperates with the flange  13  of the bottom part  1 . The flange  23  of the cover part  2  includes a channel  25 —in contrast to the first embodiment where the channel is formed in the flange of the bottom part—which forms a conduit when the flange  23  of the top part  2  is welded onto the flange  13  of the bottom part  1 . 
   Further, as apparent from  FIGS. 6 ,  8 , and  9 , the cover part is in the second embodiment—like in the first embodiment—provided with a plug-in connector  3  which, as apparent from the cross-sectional view of FIG.  9 —includes an outer guide sleeve  31  and, concentrically within the guide sleeve  31 , two co-axial conductor bushings  32  and  33 . The inner conduit formed by the inner conductor busing  32  of the plug-in-connector  3  ends again in the plane of the flange  23  which has a central opening  34  which provides for communication with the interior of the container that is the trough  11  of the container bottom part  1 . But in this case, the central opening  34  is separated from the trough  1  by a filter disc  4  which is supported at the bottom side of the cover part  2  by a support ring  26 . 
   The tubular conduit formed between the inner and the outer conductor bushings  33 ,  32  of the plug-in connector is again closed by a bottom wall  35  which has an opening  36 , which, in the second embodiment, is in direct communication with the channel  25  formed into the flange  23 . 
   Like in the first embodiment, the trough  11  of the bottom part  1  is provided also in the second embodiment with an outwardly projecting area  17 , which in this case however is arranged at the end wall of the trough  11  opposite the plug-in connector  3 . The channel  25  formed in the flange  23  of the cover part  2  is in communication with the area  17  formed by the outward projection by way of a flow transfer passage  27 . As shown in  FIG. 10  in an enlarged sectional view, the interior space of the projection  17  is separated from the interior space of the trough  11  by a filter disc  5  which extends between the trough  11  and the cover part  2  where it is retained by profile members  18  and, respectively,  28 . 
   With the arrangement of the two filter discs  4  and  5  at the opposite ends of the bicarbonate container of the second embodiment, the container can be oriented relative to the dialysis apparatus in any way without the possibility that bicarbonate can be washed out of the trough  11  without being dissolved (In  FIG. 8 , the carbonate filling is shown by hatching). 
   For the assembly of the bicarbonate container according to the invention (in both embodiments shown), the bottom part  1  and the cover part  2  which are both manufactured by injection molding only need to be joined along their flanges by welding for example by ultrasound welding (after the bicarbonate has been filled into the trough  11  and the filter discs have been inserted). No hose has to be installed into the container which must be manufactured separately and properly installed so that it cannot be displaced in the bicarbonate filling. 
   In the embodiments shown, the plug-in connector  3  is formed onto the cover part  2  so that it projects upwardly from the cover part  2  when the bicarbonate container is assembled. This arrangement is advantageous also with regard to a simple design of the injection molding tools since, except for a locking structure  37  at the plug-in connector  3 , there are no recesses which would require a slide member in the tool. 
   However, it is to be understood that other plug-in connector arrangements could be provided on the cover part  2  as well as on the bottom part  1 —depending, to a large extent, on the plug-in connector receptacle of the dialysis apparatus—for example a receptacle with non-concentric conductors. 
   In embodiments wherein the plug-in connector  3  is not disposed on the cover part, but on the bottom part  1  and wherein also the channel  15  is formed in the flange  14  of the bottom part, it would be possible to form only the bottom part  1  by injection molding. The cover  2  could then be simply formed by a foil which, after introduction of the bicarbonate into the trough  11  of the bottom part  1 , is placed onto the flange around the trough opening of the bottom part and welded thereto for closing the trough opening and forming in connection with the channel in the flange of the bottom part, the conduit extending between the opposite ends of the trough.