Abstract:
A dialyzing machine is provided with a cartridge holder to which a filter cartridge ( 11 ) or a dialyzer cartridge can be fastened. The cartridge holder ( 25 ) comprises a holding element ( 35 ) retaining the cartridge ( 11 ) and a clamping element ( 36 ) which is movable relatively to the holding element and radially to the inserted cartridge. The clamping element can be moved from an open position into a closed position. It comprises two connecting members ( 41,42 ) cooperating with the lateral connecting studs ( 26,27 ) of the cartridge, the connecting members ( 41,42 ) sealingly engaging with the two connecting studs ( 26,27 ) of the cartridge when the clamping element ( 36 ) is moved into the closed position. In this way a connection with the two connecting studs of the cartridge is produced by simply attaching the cartridge to the cartridge holder. It is no longer necessary to individually connect hoses to the connecting studs.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a cartridge holder for a dialyzing machine designed for fastening and connecting a cartridge which contains a filter or a dialyzer. 
     Dialyzing machines need at least one filter for fine filtering a haemodialysis solution before said solution is fed to the dialyzer. Said filter is normally configured as a hollow fibre filter contained in a cartridge. The cartridge comprises two axial connecting studs located at opposite ends, which connecting studs are connected to the supply line, and two connecting studs laterally projecting from the cylindrical cartridge body, which connecting studs are interconnected and form the filtrate outlet leading to the dialyzer. Said dialyzer also comprises hollow fibres arranged in a cartridge. The dialysate path leads through two connecting studs laterally projecting from the cartridge body, and the blood path leads axially through the cartridge. Normally the filter cartridge and the dialyzer cartridge are connected with corresponding hose lines of the dialyzing machine. Since the filter and the dialyzer require a total of eight connections it may happen that hose lines are incorrectly connected which may have fatal consequences. Further, change of the filter or the dialyzer involves relatively great efforts. 
     It is an object of the present invention to provide a cartridge holder for a dialyzing machine, the cartridge holder facilitating connection of a cartridge to the dialyzing machine and precluding incorrect connections. 
     SUMMARY OF THE INVENTION 
     The cartridge holder according to the invention comprises on the one hand a holding element retaining the cartridge in a defined position and on the other hand a clamping element sealingly connecting two connecting members with the lateral connecting studs of the cartridge when brought from an open position into the closed position. In the case of the cartridge holder according to the invention it is thus no longer necessary to push hose lines individually onto the connecting branches of the cartridge. The cartridge is rather retained by the holding element and the connections are simultaneously produced by the clamping element. Thus the cartridge needs only to be inserted into the cartridge holder, and subsequently the clamping element must be actuated. Manipulation of the connecting studs of the cartridge is no longer required. Further, there is no danger of confusing the lines since the lines are permanently fixed to the corresponding connecting members of the cartridge holder in the works and the user needs not to manipulate the lines at all. 
     The invention is suitable for both cartridge holders for filter cartridges and cartridge holders for dialyzer cartridges. However, in both cases the cartridge sizes may vary from each other but the connection principle is in both cases substantially the same. Filter cartridges and dialyzer cartridges differ from each other in that filter cartridges comprise four identical connecting studs whereas in dialyzer cartridges the connecting studs for the blood circulation are configured in a different way as compared with those for the haemodialysis solution. According to the invention the two lateral connecting studs of the cartridge are simultaneously connected with the corresponding connecting members via a closing action effected by an automatic connecting device. Here, the ends of the connecting studs are pushed into sealing rings of the connecting members. 
     The holding element retaining the cartridge during the coupling process and in the coupled condition preferably comprises holding openings for engaging with the connecting studs of the cartridge. Said holding openings are configured as keyhole openings and they are designed such that their edges protrude into grooves provided in the connecting studs of the cartridge so as to protect the cartridge against being pulled out. The cartridge is removed by being shifted inside the keyhole opening until the the connecting studs reach the wider head area of the keyhole opening from where they can be pulled out. 
     According to a preferred embodiment of the invention the clamping element is movable via a swivel bar articulated to the holding element, which swivel bar locks the inserted cartridge in its closed position. The swivel bar protects the cartridge from being unintentionally pulled out of the cartridge holder as well as against any other movement of the cartridge. 
     The cartridge holder may be configured such that it does not only make the connection with the lateral connecting studs of the cartridge but also the connection with the axial connecting studs. For this purpose a connecting member for an axial connecting stud is appropriately integrated in the swivel bar. When the swivel bar is closed the axial connecting member sealingly engages with the corresponding connecting stud of the cartridge. At the opposite end of the cartridge a supporting device is provided which comprises another connecting member for an axial connecting stud of the cartridge. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Hereunder embodiments of the invention are explained in detail with reference to the drawings in which: 
     FIG. 1 shows a schematic flow chart of a filter and a dialyzer in a dialyzing machine, 
     FIG. 2 shows a vertical section of a cartridge holder with inserted cartridge in the open position of the former, 
     FIG. 3 shows a front view of FIG. 2 as seen in the direction of arrow III, 
     FIG. 4 shows the same representation as FIG. 2 of the cartridge holder in operating condition with the swivel bar in the closed position, 
     FIG. 5 shows a section along line V—V of FIG. 4, 
     FIG. 6 shows a part-sectional side view a cartridge holder for a dialyzer cartridge, 
     FIG. 7 shows a front view of the cartridge holder of FIG. 6, 
     FIG. 8 shows the same representation of the cartridge holder as FIG. 7 with the cartridge holder in tilted position for the purpose of examining for bubbles, and 
     FIG. 9 shows the cartridge holder of FIGS. 6-8 in the extended condition and with a short-circuit bar connecting the connecting members. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1 show a schematic respresentation of a part of the dialysate path and the blood path of a dialyzing machine. The haemodialysis solution is supplied via a line  10  to the opposing end sides of a filter cartridge  11 . The filter cartridge contains at its one end a chamber  12  and at the other end a chamber  13 . Between said chambers  12 , 13  a hollow fibre bundle  14  extends through whose hollow fibres the haemodialysis solution flows. The hollow fibre walls are permeable to the haemodialysis solution but not to particles contained therein. The cartridge  11  comprises two lateral outlets  15 , 16  which are connected with each other and via a line  17  with a lateral connection of the dialyzer cartridge  18 . The haemodialysis solution flows along the hollow fibres and is branched off by a lateral connection  19 . The dialyzer cartridge  18  also comprises a chamber  20  and  21  respectively at each end. Between said chambers hollow fibres  22  extend. The blood is supplied from the patient&#39;s body via the supply line  23  and leaves the dialyzer through the discharge line  24 . 
     FIGS. 2 to  5  show a cartridge holder for a filter cartridge  11 , the cartridge holder being fixed to a dialyzing machine (not shown). The filter catridged  11  comprises a tubular cartridge body  25  provided with two lateral connecting studs  26 , 27 . Said connecting studs are identical to each other. They comprise a circumferential groove  29  near the cartridge body, adjacent to which groove a portion  30  enlarging towards the outside is provided. The outer end of the connecting stud forms a cylindrical sealing surface  31  of a smaller diameter than that of the enlarged portion  30 . 
     The filter cartridge  11  further comprises two axial connecting studs  32 , 33  each provided at its end with a cylindrical sealing surface  34  of a reduced diameter. 
     The cartridge holder comprises a holding element  35  which forms a carrying and holding device and to which a clamping element  36  can be movably fastened. The holding element  35  is generally U-shaped and comprises a front plate  37  and lateral legs  38 . Inside the holding element  35  the clamping element  36  made up of a plate is arranged. Between the legs  38  axes  39  extend on each of which a link  40  is supported. The other end of the link  40  is articulately connected with the clamping element  36 . In this way the holding element  35 , the clamping element  36  and the links  40  form a parallelogram linkage. The clamping element  36  can be tilted relatively to the holding element  35  with its parallel orientation being maintained with the clamping element  36  approaching the front plate  37  or moving away from the front plate  37 . 
     The clamping element  36  carries two connecting members  41 , 42 . Each connecting member comprises a holder  43  with an inserted sealing ring  44  into which the cylindrical sealing surface  31  of the connecting stud  26  and  27  respectively can be sealingly inserted. At its rear end the holder  43  is provided with a hose connection  45  projecting rearwardly. 
     The front plate  37  of the holding element  35  is provided with holding openings  46 , 47  which are configured as keyholes. This means that each holding opening has a relatively narrow vertical slot  48  and a wider circular head opening  49  (FIG.  3 ). The head opening  49  serves for receiving the lateral connecting stud  26  and  27  respectively, and the slot  48  is wide enough so that its slot edges engage with the groove  29  of the connecting stud thus fixing the connecting stud in axial direction. The cartridge is inserted such that the two connecting studs  26 , 27  are threaded through the head opening  49 , and subsequently the cartridge is pulled down to be fixed in the slot  48 . After this fixing process the clamping element  36  is moved towards the front plate  37  (FIG. 4) such that the holders  43  are pushed, together with the sealing rings  44 , over the sealing surfaces  31  of the connecting studs. Thereby the connecting studs are fixed in each direction. 
     The horizontal parallel movement of the clamping element  36  is effected by a swivel bar  50  which can be swivelled about a horizontal axis  51  at the upper end of the holding element  35 . The swivel bar  50  is L-shaped and comprises a short top leg  52  adjacent to the axis  51  and a longitudinal leg  53  with a U-shaped cross-section, the longitudinal leg  53  projecting at right angles form the top leg  52 . In the swivelled-down condition (FIG. 4) the longitudinal leg  53  encloses the cartridge  11  on three sides. On the fourth side the cartridge is enclosed by the holding element. The swivel bar  50  extends over the overall cartridge length. The top leg  52  of the swivel bar  50  comprises a connecting member  54  which is similarly configured as the connecting members  41  and  42 . Upon closing of the swivel bar  50  the connecting member  54  is tilted by 90° and pushed with vertical axis onto the end of the connecting stud  33  of the cartridge. The swivel bar  50  is also configured as heat protection hood which reduces temperature losses in particular during the disinfection process. 
     The holding element  35  ist provided at its lower end with a projecting supporting device  44  comprising another connecting member for the connecting stud  33  of the cartridge. The connecting member  56  is aligned with vertical axis. When the swivel bar  50  is in the open position the lower connecting stud  33  is located at an axial distance above the connecting element  56 . 
     The clamping element  36  is controlled by a link  57  which is connected with the swivel bar  50  via an articulation  58  and with the clamping element  36  via an articulation  59 . When the swivel bar  50  is closed the clamping element  36  is pushed down via the link  57 . The tilted links  40  induce the clamping element  36  to perform a forward movement towards the front plate  37 . During this process the holders  41 , 42  are pushed onto the ends of the connecting studs  26 , 27 . Further, the connecting studs are moved down in the respective holding openings  46 , 47  in the area of the slot  48 . 
     FIG. 5 shows the U-shaped swivel bar  50  in the closed condition in which its lower end encloses the supporting device  55 . In the supporting device  55  a magnetic sensor  60  is provided which responses to a magnet  61  of the swivel bar  50  thus detecting the closing condition of the swivel bar. The sensor  60  allows the dialyzing machine to be operated only when the swivel bar is closed. In the swivel bar  50  and in the supporting device  55  magnets  62 , 63  are arranged which pull the swivel bar into the closed position. 
     For insertion purposes the cartridge  11  is threaded, with the connecting studs  26 , 27 , through the head openings  49  of the keyhole-shaped holding openings  46 , 47  while the clamping element  36  is in the retracting position when the swivel bar  50  is open. Then the cartridge  11  is pressed down so that the connecting studs  26 , 27  reach the area of the slots  48  and are then positioned in axial alignment with the respective connecting member  41 , 42 . In this condition the swivel bar  50  is swivelled from the open position into the closed position. During this process the clamping device  36  is also advanced into the closed position. The connecting members  41 , 42  are pushed onto the connecting studs  26 , 27 , and the connecting studs in the respective holding opening  46 , 47  are moved further down in the slot  48 . During this downward movement the lower axial connecting stud  33  is inserted into the corresponding connecting member  56  of the supporting device  55 . At the end of the swivel movement of the swivel bar the upper connecting member  54  is sealingly pushed onto the upper connecting stud  33  of the cartridge. Now all connecting studs are sealingly connected with the respective connecting members, and the cartridge can be taken into operation. 
     FIGS. 6-9 show a cartridge holder for a dialyzer cartridge  18 . Those parts which correspond to those of the first embodiment bear the same reference numerals. The following description is limited to the explanation of the differences. 
     In contrast to the filter cartridge, in the case of the dialyzer cartridge only the two lateral connecting studs  26 , 27  of the cartridge holder are connected while the axial connecting studs  33  are manually connected to the corresponding hose lines. Thus the swivel bar  70  is of smaller configuration in the present embodiment so that it surrounds the cartridge  18  from three sides as seen from above but extends only over a part of the cartridge length. Here too, the swivel bar  70  controls the movement of the clamping element  36  which is connected via links  40  with the holding element  35 . 
     In the present embodiment the clamping element  36  is adjustable in length. For this purpose a slide  36   b  is inserted into a body  36   a  of the clamping element. The slide is provided with a plurality of holes  71  each of which can be aligned with a counterhole  72  in the body  36   a  and fixed by inserting a guide pin  73 . At the lower end of the slide  36   b  the connecting member  42  is arranged and at this end the lower link  40  engages. FIG. 6 shows the clamping element in the retracted condition and FIG. 9 shows the clamping element in the extended position. At the lower end of the slide  36   b  a carrier  74  is located upstream of the connecting member  42 , at which carrier  74  the lower holding opening  47  is located. Said carrier is coupled via a carrier pin  75  with the lower part of the slide  36   b  such that the holding opening  47  is always located upstream of the lower connecting member  42 . 
     On the rear side of the holding element  35  a swivel device  76  is arranged which is fastened by bolts  77  to the housing of the dialyzing machine. By loosening the bolts  77  the entire cartridge holder can be swivelled about a horizontal transverse axis. This serves the purpose of detecting air bubbles in the transparent cartridge  18  by visual inspection. In the operating condition the cartridge holder is brought into the vertical position shown in FIGS. 6 and 7. 
     FIG. 9 shows the cartridge holder in the extended condition. Here, no cartridge is inserted in the holding element but a short-circuit bar  78  with connecting studs  79  and  80  provided at its ends, the connecting studs  79  and  80  being configured in the same way as the connecting studs of a cartridge. The line system can be flushed using the short-circuit bar.