DE4113032A1 - Prepn. of conc. soln. for use in dialysis - comprises running water at constant temp. into container contg. prod. to be dissolved in powder form - Google Patents

Abstract

The prepn. of a conc. soln. which can be used to supply a device for generating a dialysis bath of volumetric type with discontinuous suction comprises allowing water at a temp. kept essentially constant to flow directly through a container contg. the prod. to be dissolved in powder form under an excess gas pressure kept essentially constant and then leading the soln. leaving the container directly into the device for generating the dialysis bath. USE/ADVANTAGE - The process is simpler, cheaper and more reliable than previous processes. The resulting solns. can be used in dialysis e.g. for kidney patients.

Description

The invention relates to a method and an apparatus to prepare a concentrated solution, the supply of a device for generating a dialysis bath of volumetric Kind with discontinuous suction, which in turn serves the Preparation of a bath to supply a dialysis machine serves.

It is known that dialysis is used to draw blood from one of the Artificially cleanse patients with kidney failure by blood along a surface of a semipermeable membrane lets flow, the other surface in contact with a flowing Solution is kept, preferably by sodium bicarbonate is buffered.

Adding the sodium bicarbonate to such solutions leaves realize yourself by diluting a concentrate that you beforehand by mixing the bicarbonate and water in one the tub provided for this purpose wins. However, there is the risk of physico-chemical degradation and bacterial Contamination of the concentrate, so that one is currently proceeding to to produce such solutions simultaneously with their application.

For this purpose there is a known method of manufacture such solutions in that water is continuous and only under the action of gravity through a reservoir which contains the product to be dissolved in powder form, and that the resulting concentrated solution into one Primary water cycle brings to the final solution for that  Obtain device, bringing it into the primary circuit based on the measured values for the concentration of the outflowing solution is regulated.

This known method leads to the disadvantage that despite the mentioned regulation the concentration of the generated solution Subject to fluctuations, in particular due to the inertia of the control system used. Furthermore the latter caused an increase in the net cost of the appropriate system, whereby reliability is often unsatisfactory leaves. Ultimately, such methods are used in applications Aspirators hardly suitable where the predetermined amounts of Solution discontinuously at regular times, mostly in of the order of a few seconds.

The object of the present invention is a method of the specified type, d. H. the way you go through the water at least one containing the product to be dissolved in powder form Container flows, suggesting the disadvantages of known devices overcomes and without difficulty to supply a device for generating a dialysis bath with discontinuous suction can be applied, the Processes easier, cheaper and more reliable to implement than the known method is.

According to the invention, this object is achieved by a method of above type, which is characterized in that the water, the temperature of which is essentially constant, can flow directly through the container with the product to be dissolved and exposing it to a substantially constant gas pressure and in that the solution leaving the container directly to the Feeds device for generating a dialysis bath.

In this context, the word "directly" should be understood to mean that in modification of the known methods in which the the container not in one with the solution to be dissolved powder  Primary circuit introduced, a suction through the device Generation of a dialysis bath without intermediate dilution with Regulation of concentration takes place.

It follows that this direct supply of the device to generate a dialysis bath any control according to Concentration of the outflowing solution becomes superfluous, resulting in corresponding advantages, because it has been surprising proved that in the method according to the invention the concentration remains remarkably constant at the drain.

The method according to the invention preferably comprises a Start-up phase in which the container with the powdered product is flushed out by the water that goes into the drain, a phase of dialysis in the narrower sense, in which the device for Generation of a dialysis bath predetermined amounts of solution is sucked in at regular intervals, and a phase of Sterilization and / or rinsing, the purpose of which is obvious.

The invention also relates to a device for Implementation of the above method, which is known to be a Includes water tub through a line with a detachable Container for the powdery product to be dissolved is connected, its outlet with the device for generating a dialysis bath connected, but which is not only completely autonomous but also more reliable and user-friendly than the known ones Devices of this type is.

According to the invention, such a device is thereby characterized in that they have facilities for maintaining an im essentially constant temperature and one essentially constant level of water in the water tub and facilities to maintain a substantially constant gas pressure in the the latter includes above the water level and in that the tub directly with the container for the powder to be dissolved is connected, the outlet of which is directly connected to the device for generation  a dialysis bath can be connected, with the word "directly" has the meaning explained in more detail above.

According to an advantageous embodiment of the invention, the Container that contains the product to be dissolved in powder form a flexible bag should be formed. In fact, you can Take advantage of a flexible bag in that the Air pressure above the device's water tub the possibility excludes that the bag is under atmospheric pressure during of suction through the device to generate a dialysis bath coincides.

It is advantageous if the device according to the invention has a Water supply circuit, a compressed air supply circuit, an air outlet and a circuit for sterilization and delivery to the drain comprises at least one solenoid valve between each of these Circles is interposed.

Then it is possible to have a programmable machine use these different circles about appropriate ones Solenoid valves to operate and also around the different Operations of the device, such as starting the Bag with the powder to be dissolved, supplying the device for Control generation of a dialysis bath in the narrower sense, whereby the expression "phase of dialysis" to make it easier to understand is used to sterilize the device and its To denote flushing. Except through your program, it will automatic device well understood by various Controllers controlled with the temperature, the Water level and / or the pressure of the water pan responsive Sensors work together. In particular, this tub with two Sensor pairs for the water level should be provided on the one hand for maintaining the target level and on the other hand for the Ensure compliance with the maximum and minimum water levels must not be exceeded or fallen below.  

According to a preferred embodiment of the invention, divides the water supply circuit is divided into two branches, one of which is in the corresponding tub opens at the top and from which the other through a downpipe is extended in the bottom area of this Tub opens, although the air supply circuit is in can split two branches, one of which flows into the tub above and the other is connected to the water supply down pipe.

So you can in the compressed air using the downpipe mentioned below let the tub run in, which leads to a temperature compensation in the Water leads. One can also for a direct contribution in the Provide the upper part of the tub if the corresponding quantities are large are.

It is advantageous if the air supply circuit of the tub Device a filter, a compressor and one Compressed air reservoir includes. It is also possible to do the latter during the phase of dialysis in the narrower sense, in which the flow quantities are low to operate, so the compressor only occasionally must be switched on.

The circuit preferably connects for sterilization and for Pumping to the outlet in the invention a pump with a Stock of sterilization fluid or with a source of Rinse water can be connected or a source of Rinsing water, and a connection to the outlet and to the bottom of the Water tub with each other. So it is possible to put one in the device suitable external liquid to promote it in the device Circuit of appropriate solenoid valves and circulate them then to convey to the outlet.

According to an advantageous embodiment of the invention Device can be the bag with the powder to be dissolved, the Device for generating a dialysis bath that supplies them Storage container for the sterilization liquid and / or Flushing water source to be releasably attached to pipe sockets  are in turn arranged outside on a wall of the device. This arrangement facilitates connection to the device of FIG various interchangeable parts used. On top of that, through the use of preliminary connections which the corresponding pipe socket can be connected, you can conveniently different phases of the device for example accomplish that closed circuits for different Liquids, for example the sterilization liquid or that can be rinse water.

The following description, which is in no way restrictive Character, should now lead to a better understanding the practical implementation of the present invention. she is to read in along with the drawing, its only figure one Overall diagram of the device for producing the solutions according to represents the invention.

Seen from the perspective of the user, the device has on a wall 1 a series of pipe sockets 2 which are accessible from the outside and on which corresponding connections are provisionally mounted. Two of the sockets 2 a and 2 b are used to connect flexible inlet or outlet hoses to a more flexible bag 3 made of PVC, for example, which contains a product in powder form, such as sodium bicarbonate, which, after being dissolved in water, is the solution for the device for generating a Represents dialysis bath. The bag 3 can be provided with a filter 4 which is arranged at the inlet of the outlet hose and which retains particles with dimensions below 25 μm. As for the device (not shown here) for generating a dialysis bath, it is connected to the wall 1 of the device for producing the solution via a pipeline 5 , which has a third connection piece 2 c, which in turn is connected to the connection piece 2 b via a connection 2 ' Is connected, which is arranged within the device relative to the wall 1 . Accordingly, the liquid leaving the pocket 3 flows through the nozzle 2 b, the connection 2 ' and the nozzle 2 c, to then flow through the pipeline 5 into the device for generating a dialysis bath. The function of the other nozzle 2 will be described later at a suitable point.

In order to supply the pocket 3 with water via the connection piece 2 a, the connection piece is connected to a water tub 6 via a pipeline 7 having a solenoid valve 8 . Since the water contained in the tub 6 has a constant temperature, such as. B. 37 ° ± 1 °, if the powder contained in the bag 3 is sodium bicarbonate, the height of the water level should be constant and the water a constant air pressure of z. B. should be exposed to 5 kPa, in particular to prevent the bag 3 from collapsing under the effect of atmospheric pressure and the suction of the solution during the first phase of dialysis, the tub 6 is provided with a water supply circuit 9 , a compressed air supply circuit 10 Vent opening 11 , with two water level controllers 12 and 13 , connected to a temperature controller 14 and to a circuit 15 , which ensures sterilization and delivery to the drain.

On closer inspection, the water supply circuit 9 leads from a pure water source 16 through a pressure reducer 17 and divides it into two branches, each of which is provided with a solenoid valve 18 or 19 and opens into the tub 6 or into a vertical downpipe 20 at the top, which ends at the bottom of the tub.

The compressed air supply circuit 10 draws in the outside air by means of a compressor 21 , specifically through a filter 22 which is able to retain all particles whose dimensions are less than 0.02 μm. This circuit 10 also divides into two branches, one of which opens into the tub 6 through a solenoid valve 23 and of which the other is connected to the downpipe 20 via a reservoir 24 and a solenoid valve 25 with a throttling effect.

The air outlet 11 , which completes the compressed air circuit 10 , is formed by a pipe which connects the tub 6 at the top to the outside atmosphere via a solenoid valve 26 and a calibrated valve 27 . Between the latter, a device 28 to be described later for regulating the pressure can be arranged.

The devices 12 and 13 , which are used to regulate the water level in the tub 6, are known per se. They are explained below. The sensors 12 of the former are arranged in the trough in the region of their bottom or their cover, although the sensors 13 of the second device are arranged somewhat below and somewhat above the desired level, which is approximately two thirds of the height of the trough. As far as the temperature controller 14 is concerned, this includes, in a manner known per se, a sensor, a control device and at least one heating resistor 14 a. In this case too, the device is known to the person skilled in the art and is therefore not to be described in detail here.

Ultimately, the circuit 15 for conveying to the drain and for sterilization comprises a pipe which extends from a nozzle 2 d of the above-mentioned nozzle 2 and which opens at the bottom into the tub 6 after being passed through a pump 29 and two solenoid valves 30 and 31 Has. A diversion 32 , which is connected between the solenoid valves 30 and 31 , leads via a solenoid valve 34 to a connection 33 with the drain. Ultimately, the connector 2 e of the above connector 2 is connected to a storage container 35 which contains a sterilizing liquid, such as. B. diluted chlorine water.

There now follows an explanation of the operation of the device, namely from a state in which the tub 6 is empty and the flexible bag 3 has not yet been installed between the connecting pieces 2 a and 2 b.

As a first step, the tub 6 is filled with water by opening the solenoid valve 18 , the solenoid valves 8 and 31 remaining closed. When the water level has reached the upper sensor of the controller 13 , the solenoid valve 18 closes and the heating resistor is supplied with current by the controller 14 until the temperature of the water has reached the desired value.

The compressor 21 can then be put into operation in order to fill the accumulator 24 with compressed air, the solenoid valves 23 and 25 being closed and the air present in the tub 6 then being brought up to the desired pressure value by opening the solenoid valve 25 . In the event of excess pressure, the excess air is discharged through the calibrated valve 27 , the solenoid valve 26 being opened to the latter.

The start-up phase of the use of the powder bag 3 can then be started, for which purpose the bag 3 is mounted on the socket 2 a and 2 b of the wall 1 . With the nozzle 2 c, which is connected to the nozzle 2 b via the connection 2 ' , the inlet pipe 5 of the device for generating a dialysis bath is not connected but also a connection 36 which is provisionally arranged outside the device relative to the wall 1 and which is connected to the nozzle 2 d, ie the circle 15 , the circle being connected in particular to the connection 33 .

The solenoid valve 8 is then opened, the pocket 3 filling up with water heated to the desired temperature. This water flows to the drain connection 33 , the solenoid valves 30 and 34 are already open, so that the system is flushed out. Since the rinsing leads to a considerable lowering of the water level in the tub 6 , the lower sensor of the controller 12 opens the solenoid valve 18 , so that the tub is filled with water up to the level of the upper sensor of the controller 12 , which prevents the supply of further water . Since the air pressure also drops, the solenoid valve 25 opens to supply air from the compressor 21 , the solenoid valve cooperating with the calibrated valve 27 to bring the pressure back to the desired value. Then is caused by the control device 14 of the heating resistor 14 a to heat the newly introduced into the tub 6 water.

If this stage of the preparation of the pocket 3 is ended, the preliminary connection 36 is interrupted, after which the inlet pipeline 5 of the dialysis machine is connected to the nozzle 2 c. The dialysis phase, which is known to last for several hours, is then started in a narrower sense, the amount of the solution supplied by the dilution device being relatively small, since the device for generating a dialysis bath at intervals of 3.5 seconds 1 ml of solution is sucked in.

During this, the water flows through the solenoid valve 18 , the solenoid valve 19 being closed. The air flows from the accumulator 24 through the solenoid valve 25 with a throttling effect while the compressor is switched off. The air enters the tub 6 through the downpipe 20 , so that a stirring effect is created which makes the water temperature even.

At the end of the dialysis phase in the narrower sense, the solenoid valve 8 is closed, which interrupts the flow of water into the pocket 3 , after which the latter is removed and removed. The inlet pipe 5 of the device for generating a dialysis bath is removed.

Then the device is sterilized by connecting the two connecting pieces 2 d and 2 e through a preliminary connection 37 and by starting the pump 29 , the solenoid valves 30 and 31 being opened, so that the sterilizing liquid contained in the storage container 35 is sucked in and in for as long as the tub is pumped until the water level reaches the upper sensor of controller 12 . The end of the preliminary connection is then removed from the connector 2 e and mounted on the connector 2 c.

At the same time, the connecting pieces 2 a and 2 b are connected to one another by another provisional connection 38 , which takes over the function of the flexible bag 3 , so to speak. In this way, one contains a closed circuit which extends through the connections 38, 2 ' and 36 , the solenoid valves 30 and 31 , the tub 6 and the solenoid valve, the pump 29 ensuring circulation of the sterilization liquid in the circuit. When the sterilization has ended, the solenoid valve 34 is opened, allowing the liquid to flow to the drain connection 33 by successively closing the solenoid valves 30 and 31 , the other valve remaining open.

Then you can accomplish a flush by letting the water flow from the connection 16 through a circle which extends through the tub 6 , the pipe 7 , the preliminary connection 38 , the pump 29 and the solenoid valves 30 and 34 and in The shape of the drain connection 33 ends.

The process can then be repeated.

It will be understood that the various just described Steps automatically through a programmed unit be carried out for a succession of cycles and includes the security and alarm devices required for such automatic units are essential and those of ordinary skill in the art are known. They are therefore not described in more detail here.

Without departing from the scope of the invention, various modifications can be made in the embodiment just described. For example, one can have several different products to be dissolved containing flexible bag to the nozzle 2 a and 2 b mounted in parallel, to prepare a solution containing various salts to supply the device for generating a dialysis bath.

In addition, the devices 12 and 13 for regulating the water level can be replaced by a device with three sensors, ie a device with a float.

As a further possibility, in the case of a regulation of the air pressure in the tub 6 with the above-described outlet valve 11 , which opens in the event of excess pressure, one can use a control unit with a sensor arranged in the tub 6 or on a line connected to it.

It is also possible to mount a pressure fuse 28 on the outlet valve 11 , the fuse being able to comprise a pressure sensor connected to a further fuse b and an indicator c, so that when the air pressure exceeds an upper limit value or falls below a lower limit value, the pressure fuse responds.

Likewise, a pressure safety device 24 a can be arranged on the air reservoir 24 .

Claims (14)

1. Process for the preparation of a concentrated solution which the Supply of a device for generating a dialysis bath serves volumetric type with discontinuous suction which the water through at least one reservoir, the one contains the product to be dissolved in powder form, flows, thereby characterized in that the water, the temperature in the is essentially constant, through the container with the to be solved Product flows directly and it essentially does exposed to constant gas pressure and by the fact that the Solution leaving the container directly to the device for generation of a dialysis bath. 2. The method according to claim 1, characterized in that the product to be dissolved is sodium bicarbonate and that the Temperature of the water flowing through the named reservoir Is 37 ° ± 1 °. 3. The method according to claim 1 or claim 2, characterized characterized in that successively a start-up phase, a phase of Dialysis in the narrower sense and a phase of sterilization and / or rinsing. 4. Apparatus for carrying out the method according to one of claims 1 to 3, with a water trough which is connected by a line with an exchangeable storage container to the product to be dissolved in powder form, the outlet of which is connected to the device for generating the dialysis bath, characterized in that the device comprises means ( 12, 13 and 14 ) which keep the water level and the water temperature within the trough ( 6 ) substantially constant and contains means ( 10 and 11 ) for maintaining a substantially constant gas pressure in the above the Maintaining water, and in that the tub ( 6 ) is connected directly to the reservoir ( 3 ), the outlet of which can be connected directly to the device ( 5 ) for generating a dialysis bath. 5. The device according to claim 4, characterized in that the storage container is formed by a flexible bag ( 3 ). 6. Device according to one of claims 4 and 5, characterized in that it comprises a water supply circuit ( 9 ), a compressed air supply circuit ( 10 ), an air outlet ( 11 ) and a circuit ( 15 ) for sterilization and transport to the outlet, wherein at least one solenoid valve ( 18, 19; 23, 25; 26; 30, 31 and 34 ) is arranged in each of these circles. 7. Device according to one of claims 4 to 6, characterized characterized as being a programmable automatic unit comprises, which is connected to various control bodies. 8. Device according to one of claims 4 to 7, characterized in that the water supply circuit ( 9 ) is divided into two branches, of which the other opens into the water pan ( 6 ) and of which one extends as a downpipe ( 20 ), that opens into the bottom area of the tub ( 6 ). 9. The device according to claim 8, characterized in that the air supply circuit ( 10 ) is divided into two branches, one of which opens into the tub ( 6 ) above and of which the other is connected to the downpipe ( 20 ). 10. Device according to one of claims 4 to 9, characterized in that the air supply circuit ( 10 ) comprises a filter ( 22 ), a compressor ( 21 ) and a compressed air reservoir ( 24 ). 11. The device according to one of claims 4 to 10, characterized in that the circuit ( 15 ) for sterilization and for delivery to the drain, a pump ( 29 ) with a reservoir ( 35 ) for a sterilizing liquid or with a source of rinsing water is connected, a drain connection ( 33 ) and the bottom of the tub ( 6 ) connects together. 12. The device according to one of claims 4 to 11, characterized in that the trough ( 6 ) is equipped with two pairs of water level sensors, each of which is associated with a device ( 12 and 13 ) which controls the water supply ( 9 ). 13. The device according to one of claims 4 to 12, characterized in that the storage container ( 3 ), the device ( 5 ) for generating a dialysis bath, the storage container ( 35 ) for the sterilizing liquid and / or a source of rinsing water detachably with nozzle ( 2 a to 2 e) can be connected, which are arranged outside on a wall ( 19 ) of the device. 14. The apparatus according to claim 13, characterized in that it comprises provisional connections ( 37, 38 and 39 ) which connect the nozzle ( 2 a to 2 e) with each other.