DE10100146B4 - Dialysis machine and method for operating the same - Google Patents

Abstract

Dialysis machine with
a device (11, 12) for providing fresh water and dialysis fluid concentrate (s),
a mixing point (10) for producing fresh dialysis liquid from dialysis liquid concentrate (s) and fresh water,
a dialyzer (1) which is divided by a semipermeable membrane (2) into a dialysis fluid chamber (3) and a blood chamber (4), a balancing device (7) for balancing fresh against used dialysis fluid in a volume-balanced system, and
a device (27, 29) for monitoring the concentration of the fresh dialysis liquid flowing into the dialysis liquid chamber,
characterized in that
Means (22, 23) for conveying liquid are provided, which can be operated alternately as a device for supplying dialysis liquid concentrate to the mixing point (10) and as a device for extracting dialysis liquid from the volume-balanced system.

Description

The The invention relates to a dialysis machine that has a balancing device for balancing fresh against used dialysis fluid and an ultrafiltration device for extracting ultrafiltrate features. About that In addition, the invention relates to a method for operating a such dialysis machine.

to Production of the dialysis liquid is in the known dialysis devices fresh water with a or several dialysis fluid concentrates mixed. Water and concentrate are generally included pump, their outputs are connected to each other at a mixing point. The supervision the mixing ratio is generally carried out by means of a conductivity measurement. If the electrical conductivity the mixture of water and concentrate from a given setpoint, d. H. the value of conductivity, that the fresh dialysis fluid has should, deviates, it is concluded that the concentrate pump with the wrong delivery rate works.

Because of the large exchange quantities, there is a need in the known dialysis devices for the exact balancing of withdrawn liquid on the one hand and supplied liquid on the other hand over the entire treatment time. The DE-A-28 38 414 describes a dialysis machine with a volumetric balancing system, which consists of two chambers each divided by a movable partition, each having a supply and discharge line for fresh and a supply and discharge line for used dialysis fluid. Shut-off valves, which are controlled by a control unit, are arranged in the feed and discharge lines. The balancing system is operated in such a way that fresh dialysis fluid is alternately supplied to the two balance chambers from a dialysis fluid source and used dialysis fluid is removed at the same time.

There an excessive ultrafiltration rate to a hazard of the patient known security standards prescribe a protection system, the one for dangerous to the patient Prevents ultrafiltration. Such a protection system can, for example on surveillance of the transmembrane pressure.

The DE-A-42 39 937 describes a method for determining the functionality of a device for volumetric ultrafiltration control, which provides for a pressure maintenance test to be carried out periodically during the dialysis treatment. The delivery accuracy of the ultrafiltration pump, however, is not checked directly. The DE-A-197 02 211 describes a method in which the amount of ultrafiltration is measured by means of a flow sensor. However, very precise flow sensors are required for this.

The The invention has for its object to provide a dialysis machine a balancing device and an ultrafiltration device to provide a reliable review of the Ultrafiltration amount without large apparatus expenditure allowed. Another object of the invention is a method of operating a dialysis machine to indicate that a reliable review of the Ultrafiltration amount without large Effort.

The solution These tasks are carried out according to the invention with those in the claim 1 or 9 specified features.

The device according to the invention and the method according to the invention are based on the fact that Ultrafiltration dialysis fluid, especially for hygiene reasons fresh dialysis fluid, is withdrawn from the volume-balanced system using the same means, with which dialysis fluid concentrate is promoted for the production of fresh dialysis fluid.

During the Production of fresh dialysis fluid can the means of funding of the dialysis fluid concentrate monitored in the known manner be that the The composition of the fresh dialysis fluid is checked. There the volume-balanced system for ultrafiltration of fresh dialysis fluid is withdrawn with the same means with which dialysis fluid concentrate promoted then it can be assumed that it is working properly, if an error has not occurred in the production of fresh dialysis fluid is. So there is no need further functional monitoring.

A review of the The amount of ultrafiltration can be achieved with the device according to the invention or the method according to the invention with those already available in the known dialysis machines Set up by means of a conductivity measurement. Thereby their structure is simplified.

On malfunction of the means for withdrawing the dialysis fluid or to promote of dialysis fluid concentrate is preferably closed when the concentration of fresh dialysis fluid, especially their conductivity, from deviates from a predetermined setpoint by a predetermined limit.

In a preferred embodiment the means for extracting the fresh dialysis fluid or for conveying dialysis fluid concentrate contain two pumps, which are operated alternately as a concentrate or ultrafiltrate pump. The delivery accuracy of the pumps is checked in the concentrate mode, in which the conductivity of the fresh dialysis fluid is monitored.

The dialysis fluid withdrawn from the volume-balanced system can be discarded. But when fresh dialysis fluid is withdrawn from the system will it is possible the dialysis fluid again to feed the mixing point. This is a particularly simple apparatus construction with a small number of lines and valves possible.

The Ultrafiltration pump and the concentrate pump can be constructed without major changes so installed in the hydraulic part of the known dialysis machines be that any can aspirate or convey both concentrate and fresh dialysis fluid. Fresh dialysate promotion corresponds to a withdrawal of fluid from the patient dialysate circuit separated by the balancing chamber in the off-balance dialysate area and thus an ultrafiltration. Switching is preferably carried out via two additional ones Valves per pump. Only the pump that is currently working as a concentrate pump is monitored. The two pumps are replaced so often that maximum in one cycle lack funding the ultrafiltration pump poses no risk to the patient.

The The advantages of the invention lie primarily in the small apparatus Effort to check the amount of ultrafiltration, being the high accuracy of that in the known dialysis machines provided by default conductivity measurement can be used. An additional volumetric calibration is not necessary.

in the the following is an embodiment of the Invention explained with reference to the drawings.

It demonstrate:

1 1 shows a simplified schematic illustration of the essential components of the dialysis device, a first cycle of a cycle being shown in which the first pump works as a concentrate pump, 2 the dialysis machine of 1 , wherein in the first cycle the second pump works as an ultrafiltrate pump, which extracts fresh Diaysier liquid from the volume-balanced system,

3 the dialysis machine of 1 , showing a second cycle of the cycle in which the second pump works as a concentrate pump, and

4 the dialysis machine of 1 , In the second cycle, the first pump works as an ultrafiltrate pump, which extracts fresh dialysis fluid from the volume-balanced system.

1 shows the essential components of the dialysis machine in a simplified schematic representation. The dialysis machine has a dialyzer 1 on through a semipermeable membrane 2 into a dialysis fluid chamber 3 and a blood chamber 4 is divided. There is a blood supply line at the inlet of the blood chamber 5 and a blood discharge line at the outlet of the blood chamber 6 connected. The dialysis device has a balancing device for balancing fresh dialysis fluid against used dialysis fluid 7 , the two balance chambers connected in parallel 8th . 9 has, each in two balance chamber halves 8a . 8b respectively. 9a . 9b are divided. The balance chamber halves each have an inlet 8c . 8e . 9c . 9e and an outlet 8d . 8f 9d . 9f on.

To produce fresh dialysis liquid, dialysis liquid concentrate and fresh water are mixed at one point 10 mixed. The dialysis fluid concentrate is in a concentrate source 11 and the fresh water in a water source 12 provided. A water pipe leads from the fresh water source 13 to the mixing point 10 , from which a dialysis fluid supply line 14 comes off, which branches into two line branches, of which the first branch at the inlet 8c the first half of the chamber 8a the first balance chamber 8th and the second branch at the inlet 9c the first half of the chamber 9a the second balance chamber 9 connected. In the dialysis fluid supply line 14 is a feed pump for pumping the dialysis fluid 15 , especially gear pump, and an air separator for separating air 16 connected.

At the outlet 8d the first half of the chamber 8a the first balance chamber 8th is the first branch of a dialysis fluid supply line 17 and at the outlet 9d the first half of the chamber 9a the second balance chamber 9 the second branch of the supply line connected to the entrance 3a the dialysis fluid chamber 3 of the dialyzer 1 leads. From the exit 3b the dialysis fluid chamber 3 goes a dialysis fluid discharge line 18 off, the first branch at the inlet 8e the second half of the chamber 8b the first balance chamber 8th and their second branch at the inlet 9e the second half of the chamber 9b the second balance chamber 9 connected. From the outlet 8f the second chamber 8b the first balance chamber 8th goes the first branch and from the outlet 9f the second half of the chamber 9b the second balance chamber 9 the second branch of a dialysis fluid drain line 19 from, leading to a drain 20 moves. An electromagnetically actuated valve V ₁ to V _{8 is} connected in each of the branches of the inlet and outlet line and the inlet and outlet line. The valves V ₁ to V ₈ are operated by a control device 21 controlled in such a way that one chamber half of both balancing chambers are filled with fresh or used dialysis fluid, while used or fresh dialysis fluid is displaced from the other chamber halves. This balances fresh dialysis fluid against used dialysis fluid. Such balancing devices are part of the prior art.

The dialyzer has two volumetric pumps for conveying the concentrate and the fresh dialysis fluid 22 . 23 , especially diaphragm pumps. The inlet pipe 22a the first pump 22 is on the one hand via a first line section 24a with one to the concentrate source 11 leading concentrate line 25 and on the other hand via a second line piece 24b with the dialysis fluid supply line 17 connected while the feed line 23a the second pump 23 on the one hand via a line section 26a with the concentrate line 25 and on the other hand via a line piece 26b with the dialysis fluid supply line 17 connected is. The drain pipe 22b the first pump 22 and the drain pipe 23b the second pump 23 are each with the mixing point 10 connected. In the inlet and outlet line 22a . 22b . 23a . 23b both pumps 22 . 23 as well as in the pipe sections 24a . 24b . 26a . 26b are each an electromagnetically actuated valve V ₉ -V ₁₆ connected via control lines to the control device 21 are connected.

In addition, the dialysis machine has a monitoring device 27 on that over a data line 28 with the control device 21 Exchanges data. A conductivity measuring cell is used to measure the mixing ratio of concentrate and fresh water, ie the composition of the fresh dialysis fluid 29 into the dialysis fluid supply line 17 switched that over a data line 30 with the monitoring device 27 connected is. There is also an alarm device 31 provided over a data line 32 with the control device 21 connected is. The control device 21 also controls the two pumps 22 . 23 via control lines P1, P2. The mode of operation of the dialysis machine is described in detail below. For clarification, the closed valves are highlighted in black in the figures.

The first pump operates in a first cycle 22 as a concentrate pump ( 1 and 2 ). To do this, the control device opens 21 valves V ₉ , V ₁₁ and V ₁₂ and closes valve V ₁₀ . While the second pump 23 stops, the first pump delivers 22 Concentrate from the concentrate source 11 to the mixing point 10 , on which the concentrate with that from the water source 12 incoming fresh water is mixed to produce the fresh dialysis fluid, which is fed through the feed line 14 to the first inflow 7a the balancing facility 7 flows. From the first run 7b the balancing device, the fresh dialysis fluid now flows through the supply line 17 via the conductivity measuring cell 29 to the dialysis fluid chamber 3 , of the used dialysis fluid through the discharge line 18 to the second inlet 7c the balancing device flows. From the second process 7d used dialysis fluid through the drain line 19 to the drain 20 directed.

The second pump operates during the first cycle 23 as an ultrafiltrate pump. As long as the second pump is not operating, there is no ultrafiltration. In this case, the valves V ₁₃ to V _{16 are} preferably closed ( 1 ).

The control device opens for ultrafiltration 21 the valves V ₁₃ , V ₁₄ and V ₁₅ , while the valve V ₁₆ remains closed. The second pump 23 now sucks fresh dialysis fluid from the supply line 17 and conveys the fresh dialysis fluid to the mixing point 10 , so that fresh dialysis fluid is withdrawn from the volume-balanced system ( 2 ). The concentrate pump 22 preferably continues or runs in parallel when the ultrafiltrate pump 23 is switched on so that the concentrate delivery is not interrupted.

The conductivity measuring cell 29 measures the conductivity of the fresh dialysis fluid continuously, i.e. whenever the first pump 22 running. The monitoring device 27 compares the conductivity with a specified target value. If the deviation between the actual value and the target value exceeds a predetermined limit value, the monitoring device controls the alarm device 31 on, which gives an acoustic and / or visual alarm and / or intervenes in the dialysis device, for example switches off the entire system.

The monitoring device 27 thus allows the delivery rate of the first pump 22 to monitor continuously. In the event that the delivery rate is too large or too small, ie the mixing ratio of concentrate and water does not correspond to the prescribed ratio, the incorrect composition of the dialysis fluid is immediately recognized by means of the conductivity measurement.

The 3 and 4 show the second stroke of the cycle in which the first pump 22 as an ultrafiltrate pump and the second pump 23 acts as a concentrate pump. To do this, the control device opens 21 the valves V ₁₃ , V ₁₄ and V ₁₆ , valve V ₁₅ closed is. As long as the first pump 22 valves V ₉ to V _{12 are} preferably closed ( 3 ). Now the delivery rate of the second pump 23 supervised.

The control device opens for ultrafiltration 21 the valves V ₁₀ , V ₁₁ and V ₁₂ , the valve V ₉ remaining closed. The first pump 22 is now put into operation, the fresh dialysis fluid from the feed line 17 sucked in and to the mixing point 10 promotes.

Since the delivery rate of the first pump now operating in the second cycle as an ultrafiltrate pump 22 during the first stroke in which the pump 22 worked as a concentrate pump, has been monitored, it can be assumed that the first pump 22 with the correct funding rate.

The second cycle is followed by the first cycle of a subsequent cycle, in which the first pump 22 as a concentrate pump and the second pump 23 works as an ultrafiltrate pump. Now the delivery rate of the first pump is again 22 supervised.

There the concentrate delivery rate while a dialysis treatment is generally greater than the ultrafiltration pump rate a predetermined ultrafiltration rate can be adjusted by a corresponding one Exposure of the respective ultrafiltration pump set during a cycle become.

That in the 1 to 4 The embodiment shown shows only a single concentrate source 11 , However, dialysis devices are also known which have several concentrate sources. For example, the dialysis liquid can be mixed from fresh water and bicarbonate, individual and common salt concentrate. In this case, the concentrate pump is monitored, which conveys the concentrate that has the largest proportion of conductivity in the finished dialysis fluid. In the case of a dialysis liquid mixed from bicarbonate, individual and saline concentrate, for example, this is the saline concentrate.

Claims (12)

Dialysis machine with a device ( 11 . 12 ) to provide fresh water and dialysis fluid concentrate (s), a mixing point ( 10 ) for the production of fresh dialysis fluid from dialysis fluid concentrate (s) and fresh water, a dialyzer ( 1 ) through a semipermeable membrane ( 2 ) into a dialysis fluid chamber ( 3 ) and a blood chamber ( 4 ) is divided into a balancing facility ( 7 ) for balancing fresh against used dialysis fluid in a volume-balanced system, and a device ( 27 . 29 ) for monitoring the concentration of the fresh dialysis liquid flowing into the dialysis liquid chamber, characterized in that means ( 22 . 23 ) are provided for conveying liquid, which as a device for supplying dialysis liquid concentrate to the mixing point ( 10 ) and can be operated alternately as a device for withdrawing dialysis fluid from the volume-balanced system. Dialysis machine according to claim 1, characterized in that the balancing device ( 7 ) a first inflow ( 7a ) and process ( 7b ) for fresh dialysis fluid and a second feed ( 7c ) and process ( 7d ) for used dialysis fluid, a dialysis fluid supply line ( 14 ) the mixing point ( 10 ) with the first inlet and a dialysis liquid supply line ( 17 ) the first sequence with an input ( 3a ) the dialysis fluid chamber ( 3 ) connects, and that a dialysis fluid discharge line ( 18 ) an exit ( 3b ) the dialysis fluid chamber with the second inlet and a dialysis fluid outlet line ( 19 ) the second drain with a drain ( 20 ) connects. Dialysis device according to claim 2, characterized in that the means for conveying liquid comprises a first pump ( 22 ) and that means (V ₉ , V ₁₀ , V ₁₁ ) for alternately connecting the inlet of the first pump on the one hand to the device ( 11 ) to provide dialysis fluid concentrate and on the other hand with the dialysis fluid supply line ( 17 ) are provided, and that means (V ₁₂ ) for connecting the outlet of the first pump to the mixing point ( 10 ) are provided. Dialysis device according to claim 2 or 3, characterized in that the means for conveying liquid a second pump ( 23 ) and that means (V ₁₄ , V ₁₅ , V ₁₆ ) for alternately connecting the inlet of the second pump on the one hand to the device ( 11 ) to provide dialysis fluid concentrate and on the other hand with the dialysis fluid supply line ( 17 ) are provided and that means (V ₁₃ ) for connecting the outlet of the second pump to the mixing point ( 10 ) are provided. Dialysis machine according to claim 3 or 4, characterized in that a control device ( 21 ) for the first and second pumps ( 22 . 23 ) is provided, which controls the means for connecting the inlets and outlets of the first and second pumps such that either the first pump is activated and the second pump is deactivated, the inlet of the first pump with the device ( 11 ) to provide dialysis fluid concentrate and the outlet of the first pump with the mixing point ( 10 ) is connected, or the second pump is activated and the first pump is deactivated, the inlet of the second pump being connected to the device for providing dialysis fluid concentrate and the outlet of the second pump being connected to the mixing point. Dialysis device according to one of claims 1 to 5, characterized in that the first and / or second pump ( 22 . 23 ) is a volumetric pump. Dialysis device according to one of claims 1 to 6, characterized in that in the dialysis fluid supply line ( 14 ) a feed pump ( 15 ) is switched. Dialysis device according to one of claims 1 to 7, characterized in that a device ( 27 ) to monitor the funds ( 22 . 23 ) is provided for conveying liquid, which is connected to the device ( 29 ) cooperates to monitor the concentration of the fresh dialysis fluid in such a way that a malfunction is concluded if the dialysis fluid concentration deviates from a predetermined target value by a predetermined limit value. Method for operating a dialysis machine, with the fresh dialysis fluid at a mixing point of dialysis fluid concentrate (s) and Fresh water mixed and the dialysis fluid chamber of a dialyzer supplied and used dialysis fluid from the dialysis fluid chamber of the dialyzer , the fresh balance against the used dialysis fluid will and the dialysis fluid chamber part a volume-balanced system, characterized in that for ultrafiltration dialysis fluid is withdrawn from the volume-balanced system using the same means, with which dialysis fluid concentrate for the production of fresh dialysis liquid is fed to the mixing point. A method according to claim 9, characterized in that the Concentration of the fresh dialysis fluid is monitored and for a malfunction Means for withdrawing the dialysis fluid or for supplying dialysis fluid concentrate is closed when the concentration of fresh dialysis fluid from a predetermined setpoint around a predetermined limit differs. A method according to claim 10, characterized in that the volume-balanced system withdrawn fresh dialysis fluid and the mixing point supplied becomes. Method according to one of claims 9 to 11, characterized in that that for Withdraw the dialysis fluid or to feed of dialysis fluid concentrate two pumps are used, which are operated alternately.