Combined holder and connector for a dialyser

Abstract: Combined holder and connector for a dialyser, hemofilter or the like. The holder is provided with a connector (29) for cooperation with a nipple (7) on the dialyser intended for dialysis solution and/or ultrafiltrate. The holder is rotatable about a horizontal axis (28) by means of a motor. The holder can assume three different angular positions, a normal treatment position, a priming position with said connector displaced 180 degrees relative to the treatment position and a cleaning or stand-by position where the connector (29) is joined with a dialysate outlet (23) from the dialysis machine via a tube (25) and a connector (26).

Description: FIELD OF THE INVENTION The present invention relates to a combined holder and connector for a dialyser hemofilter or the like, arranged on a dialysis machine. The holder according to the invention is intended for use with hemodialysis, hemodiafiltration or hemofiltration when using a dialysis machine such as the GAMBRO AK 100 and during use of a dialyser, a hemofilter or the like. STATE OF THE ART A dialyser is used in order to clean the blood of patients who have a reduced kidney function or endstage renal decease ESRD. The dialyser consists in principle of a semi-permeable membrane, on the one side of which passes blood and on the other side of which passes a dialysis solution. By designing the composition of the dialysis solution in a specific manner, an exchange of electrolytes across the semi-permeable membrane and reconditioning of the blood occurs. A hemofilter is a dialyser, where a fraction, an ultrafiltrate, of the blood is separated and replacement fluid is supplied directly to the blood. The dialyser is operated and monitored by means of a dialysis machine, for example having a construction as described in EP-B1-278 100. Such a dialysis machine is sold by Gambro AB under the tradmark GAMBRO AK 100. Before using a dialyser, it is first primed, i.e. filled with sterile physiological common salt solution whereby all the air in the dialyser is forced out and any remaining impurities are flushed out. This often occurs in a separate priming stage in such a way that sterile priming solution is allowed to pass through the dialyser in the same way as the blood is to pass later, whilst ordinarily normal dialysis solution is supplied to the dialyser on the other side of the membrane. The priming step occurs preferably with the dialyser upside down in comparison with the treatment position in order to be more certain of having forced out all the air in the dialyser. To this end, the above-mentioned dialysis machine GAMBRO AK 100, is provided with a holder for the dialyser which allows placement of the dialyser in two positions, a priming position and a treatment position. This normally occurs by the holder gripping the dialyser around the middle and by the holder being rotatable 180° about a horizontal axis. The disadvantage with this procedure is that the priming stage has to be carried out manually which requires the personnel's time, which costs money. This manoeuvring of the dialyser between the two positions can additionally lead to tubes coming loose as a result of the human factor. US-A-4,191,351 describes a degassing means for a fluid flow transfer apparatus, such as hemodialysers. It mainly relates to plate dialysers and includes rotatable mounts and locking means, however no connector. Furthermore, DE-A1-3642671 discloses a holder for a dialyser, which is fixed and includes a quick release coupling for one of the connectors of the dialyser. The dialyser can be rotated 180 degrees around the axis of the connector to be primed in an inverted position. However, the drawback of these prior art dialyser holders is that the dialyser is rotated around a symmetry axis comprising the coupling to the dialyser. Consequently, there is a substantial risk of leakage in the coupling. This would be detrimental to the dialysis operation, since the pressure at the dialyser normally is below atmospheric pressure. A leakage would let in air in the dialysis compartment of the dialyser, leading to blockage of the membrane and decrease of the efficiency of the dialyser. Moreover, there is a risk of introducing air in the blood. DISCLOSURE OF THE INVENTION The object of the present invention is to provide a combined holder and connector for the dialyser, avoiding the above-mentioned drawback of the prior art constructions, a combined holder and connector for the dialyser, where the tube length is minimal and thus the risk of tubes becoming entangled or coming loose is minimal and a holder for a dialyser which can be motor-driven so that the dialyser can be placed in two positions, a priming position and a handling position, without intervention from the personnel. Accordingly, there is provided a combined holder and connector for a dialyser, hemofilter or the like, arranged on a dialysis machine, characterized in that the holder is pivotable around a horizontal symmetry axis and comprises a connector for cooperating with a coupling arrangement of the dialyser for flowing a fluid to and/or from the dialyser, whereby the connector comprises a symmetry axis which differs from said symmetry axis of the holder. Particular embodiments of the invention are the subject of the dependent claims. The connector and coupling arrangement are intended for a dialysis solution and/or ultrafiltrate. According to a preferred embodiment of the invention, the symmetry axis of the connector is perpendicular to the horizontal symmetry axis. Preferably, the holder comprises a shaft extending horizontally out from the front of the dialysis machine. The holder may be arranged for assuming two different angular positions, a normal treatment position and a priming position where said connector is displaced 180 degrees relative to the treatment position. Moreover, the holder may be arranged to assume a third angular position separate from said two angular positions, which third position is a cleaning position. In said cleaning position, the connector is connected to a dialysate outlet from the dialysis machine via a tube and a connector. According to a most preferred embodiment of the invention, the holder is motor driven between its various positions. Moreover, it comprises a guiding arrangement for cooperation with the outer surface of the dialyser. Such guiding arrangement may comprise a support member cooperating with the dialyser at a position remote from said holder and connector. BRIEF DESCRIPTION OF THE DRAWINGS The invention will be described in more detail with reference to a preferred embodiment of the invention shown in the drawings. Fig. 1 is a schematic front view of a dialyser holder according to prior art. Fig. 2 is a front view, corresponding to Fig. 1, of a first embodiment of the dialyser holder according to the present invention. Fig. 3 is a front view similar to Fig. 2, but with the dialyser in a priming position. Fig. 4 is a front view similar to Fig. 2, but with the dialysis machine in a cleaning position. Fig. 5 is a perspective view of the dialyser holder according to the invention. Fig. 6 is an end view of the dialyser holder according to Fig. 2 taken along the line VI-VI in Fig. 3. Fig. 7 is an end view similar to Fig. 6, where the dialyser holder is provided with another type of dialyser. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Fig. 1 shows the lower left-hand part of a prior art dialysis machine 1, e.g. of the GAMBRO AK 100 type. On its front side, the machine comprises a holder 2 for a dialyser 3, for example a hollow-fibre dialyser with substantially circular cross-section. The interior space of the hollow fibres are connected via tubes 4, 5 to the patient or, during priming, connected with a source of sterile priming solution such as physiological common salt solution. The exterior space outside the hollow fibres is enclosed by a cylindrical tube. The exterior space is connected to coupling arrangements in the form of two nipples 6, 7 for connection to the dialysis machine circuit for dialysis solution. The holder 2 comprises an engagement device 8 which cooperates with, and holds, the dialyser approximately at its middle. The engagement device 8 is provided with a rod 9 which is inserted into a horizontal hole 10 in a sleeve 11 in the side of the dialysis machine. The rod 9 is kept in the hole 10 with the aid of a screw 12. The dialysis machine 1 is provided with a drain 13 for dialysate solution and an inlet 14 for dialysate solution. The outlet 13 and the inlet 14 are provided with tubes 15, 16 which, in the stand-by position, are coupled to separate bypass couplings 17, 18, 19 positioned on the front of the dialysis machine. Fig. 1 shows the tube 15 from the outlet 13 coupled to the bypass coupling 17. The tube 16 is shown disconnected from the bypass coupling 18 and about to be attached to the lower nipple 7 of the dialyser, said lower nipple functioning as an outlet from the dialyser. The tube 15 is then disconnected from the coupling 17 and attached to the upper nipple 6 of the dialyser. The tubes 4 and 5 are coupled to the sterile priming solution. The dialyser is then ready for priming. For priming, sterile physiological common salt solution is fed through the dialyser from below via the tube 5 and out via the tube 4 so that all the air is forced out from the spaces within the hollow fibres. At the same time, dialysate solution is supplied via the inlet 6 and out through the outlet 7 in counter current flow. When it has been established that all the air has passed out through the outlet tube 4, the dialyser is turned 180° so that the nipple 7 will be uppermost and the nipple 6 lowermost. At the same time the priming continues until even the whole space above the hollow fibres is emptied of air. The tubes 4 and 5 are then coupled to the patient for treatment. Figs. 2, 3 and 4 show the same dialysis machine as in Fig. 1, but modified in accordance with the present invention. Reference is hereby made firstly to Fig. 4 which shows the machine in the stand-by position. The machine has been simplified according to the invention so that the inlet 14, the tube 16 and the bypass coupling 18 have been omitted. The machine is provided with a dialysate outlet 23 and a dialysate tube 25, which has a dialysate connector 26 at its end. In the stand-by position, the dialysate connector is coupled to a connector arrangement 27 which will be explained in more detail below. In the stand-by position, the dialysate solution can thus circulate from the machine through the outlet 23 and the tube 25 to the connector 26 and back into the machine through the connector arrangement 27. No separate inner bypass conduit is therefore required. The connector arrangement 27 consists of a shaft journal 28 or a cylindrical tube which extends horizontally outwardly from the front of the machine. In the lower side of the journal there is a connection 29 which leads to the connector 26. The shaft journal 28 is rotatable to three different positions shown in Fig. 4, Fig. 2 and Fig. 3 as indicated by arrow 30. In the position according to Fig. 4 the machine is in a stand-by position which is detected by a sensor (not shown) within the machine. The sensor detects the three angular positions according to Fig. 4, Fig. 2 and Fig. 3. In the position according to Fig. 4 the dialysis machine can perform different programme steps, such as rinsing, emptying, disinfection by means of heat or chemical means etc. From the position in Fig. 4, the shaft journal 28 is rotated 90° clockwise to the position shown in Fig. 2 which constitutes the treatment position. In this position the connector 26 is detached (manually or automatically) and a dialyser 3 is placed with its outlet nipple 7 (see Fig. 1) in the connector 29 which is now facing sideways, towards the left in Fig. 2. The connector 26 is connected to the nipple 6 and the tubes 4 and 5 are connected as previously. The shaft journal 28 is then rotated additionally 180° clockwise to the priming position as shown in Fig. 3. Sterile priming solution passes through the tube 5 and upwardly through the dialyser and out through the tube 4, thereby taking with it air within the hollow fibres. At the same time dialysis solution passes via the tube 25 into the dialyser in the space outside the hollow fibres as well as out through the shaft journal 28 and back to the machine. After priming has been effected in this position, for 10 minutes for example, the shaft journal 28 is rotated 180° anti-clockwise back to the position shown in Fig. 2 and priming is allowed to occur for an additional amount of time, whereupon the priming process is terminated and treatment can take place. Fig. 5 shows the shaft journal 28 in perspective in a position which corresponds to Fig. 2. The connector 26 has hereby been detached from the connection 29 which is in a position facing towards the left and is ready for receiving a dialyser. The outlet nipple 7 of the dialyser is put into a hole 31 in the connector 29. The connector is provided with a guiding surface 32 which is formed so as to cooperate with the dialyser in order to guide this so that it remains vertical as described in more detail in connection with Fig. 7 and Fig. 8. The shaft journal 28 is additionally provided with a button 33 which is used for releasing the dialyser after use. When the nipple 7 of the dialyser is put into the hole 31, the button 33 springs upwardly and returns downwardly in order to engage around the nipple 7 and keep the dialyser safely in the holder 28. The connector 26 can be detached with the help of the same button 33. Alternatively the shaft journal 28 is provided with an arrangement which releases the connector 26 when the shaft journal moves from the position shown in Fig. 4 to the position shown in Fig. 2. This arrangement can furthermore lock the connector 26 in the position shown in Fig. 4 so that the connector cannot be detached by mistake. In the same way, there may be an inner lock arrangement in the shaft journal 28 which prevents the dialyser from being able to be detached in the position according to Fig. 3 or that the shaft journal can be rotated to the position according to Fig. 4 with the dialyser in place. In this way, it can be safely ensured that the dialysis machine operates in the intended manner in its different operating modes. Fig. 6 shows the dialysis machine according to Fig. 3, seen from above and taken along the line VI-VI in Fig. 3. The shaft journal 28 is hereby shown from above with a dialyser 3 of the hollow-fibre type with circular cross-section, located in the connector 29. As is clear from Fig. 6, the connector 29 comprises a spring-biased plate 32 which cooperates with the outer surface of the dialyser 3 around the nipple 7 so that the dialyser 3 cannot rotate around the nipple 7. In this way the dialyser 3 is maintained securely gripped by the connector 29. Moreover, it is assured that the dialyser nipple does not rotate in the connector 29, which could result in leakage problems. Fig. 7 shows a corresponding arrangement for a plate dialyser. The plate dialyser is provided with an encircling flange 35 which cooperates with a separate guide 36 in the plate 32. The invention has been described above as a succession of steps from the position according to Fig. 4 to the position according to Fig. 2 and further to the position according to Fig. 3 for priming as well as finally returning to the position according to Fig. 2 for treatment. Other sequences can of course be performed, for example from the position in Fig. 4 directly to the position according to Fig. 3 and thereafter to the position according to Fig. 2. Additionally it is imaginable that other flow directions than those described above can be used. For example, the priming according to Fig. 3 can take place by a sterile priming solution passing via the tube 5 upwardly through the dialyser to the tube 4, at the same time as dialysate solution passes from the shaft journal 28 and upwardly through the dialyser as well as out through the tube 25, by the direction of the dialysate solution within the machine being reversed. With hemofiltration, the hemofilter is only provided with one connection nipple 7, whilst the nipple 6 is missing. The dialysis machine can thereby be provided with a connection (not shown) for the coupling 26, whereby attachment of the coupling 26 on to this connector signals the dialysis machine that hemofiltration should be carried out. Priming occurs in that the sterile priming solution passes through the hollow fibres to the outer space of the hemofilter, by using an under-pressure via the holder 28. The operation is otherwise clear for a skilled person. The dialyser normally has connector nipples 6, 7 but it is of course possible to use other coupling arrangements on the dialyser, such as recesses etc. The holder according to the invention is coupled into the circuit for dialysis solution and/or ultrafiltrate. It is possible to let the shaft journal rotate forwardly and backwardly over a small angular range (+/-10°) during the priming stage in order to additionally facilitate the priming. The invention is not limited to the characteristics described in the description above, but is limited only by the appended claims.

Claims: Combined holder and connector for a dialyser (3), hemofilter or the like, arranged on a dialysis machine (1), characterized in that the holder is pivotable around a horizontal symmetry axis (28) and comprises a connector (29) for cooperating with a coupling arrangement (7) of the dialyser (3) for flowing a fluid to and/or from the dialyser (3), whereby the connector (29) comprises a symmetry axis which differs from said symmetry axis (28) of the holder. Combined holder and connector according to claim 1, characterized in that said connector (29) is intended for a dialysis solution and/or ultrafiltrate. Combined holder and connector according to claim 1 or 2, characterized in that the symmetry axis of said connector (29) is perpendicular to the horizontal symmetry axis (28). Combined holder and connector according to claim 1, 2 or 3, characterized in that said holder comprises a shaft (28) extending horizontally out from the front (1) of the dialysis machine. Combined holder and connector according to claim 4, characterized in that the holder is arranged for assuming two different angular positions, a normal treatment position and a priming position where said connector is displaced 180 degrees relative to the treatment position. Combined holder and connector according to claim 5, characterized in that the holder is arranged to assume a third angular position separate from said two angular positions, which third position is a cleaning position. Combined holder and connector according to claim 6, characterized in that , in said cleaning position, said connector (29) is connected to a dialysate outlet (23) from the dialysis machine via a tube (25) and a connector (26). Combined holder and connector according to any one of the preceding claims, characterized in that said holder is motor driven between its various positions. Combined holder and connector according to any one of the preceding claims, characterized in that the holder comprises a guiding arrangement (32) for cooperation with the outer surface of the dialyser (3). Combined holder and connector according to claim 9, characterized in that said guiding arrangement (32) comprises a support member cooperating with the dialyser at a position remote from said holder and connector.

Inventors: HOEGLUND DANIEL, JOENSSON JOERGEN, HOEGLUND, DANIEL, JOENSSON, JOERGEN, Höglund, Daniel, JÖNSSON, Jörgen
Applicants: GAMBRO AB
Application year: 1996
Main classification: A61M1
IPC codes: B01D61, B01D65, A61M1