DE19655227B4 - Home dialysis machine components and methods of operation - where the machine includes water treatment, dialysate preparation and disinfection systems in user friendly, efficient and affordable haemodialysis package - Google Patents

Abstract

Dialysis apparatus which includes water pre-treatment (20), dialysate preparation (26) and an extra corporeal circuit (28), for circulating blood from a patient through a dialysis circuit and back to the patient is described in detail and the following different inventions in, or for, a dialysis machine are claimed: (a) a water pre-treatment apparatus in which hot and cold water is fed to a thermostatically controlled mixing valve which feeds water at controlled temperature through a filter to the water inlet of the dialysis machine; (b) methods of disinfecting a dialysis machine by placing the patient ends of the arterial and venous blood lines into communication with a source of hot water which is circulated through the lines, the water treatment module and the dialysate circuit; (c) as (b) with the hot water being filtered in a reverse osmosis unit in the water treatment module (24) before it is heated; (d) a connector for establishing connection of disinfection fluid line to the arterial and venous blood lines, in which the connector has a space about the blood line ends to provide disinfection of the exterior surfaces of the ends; (e) apparatus for supply of chemicals to a dialysate tank form three vessels via a housing having two ports for passage of chemicals from two of the vessels and a third port to which the third vessel, which contains dialysate chemical, salt, nutritional supplement, medication, cleaning agent or disinfecting agent, is attached; (f) a dialysate preparation apparatus including a dialysate preparation tank and a vessel containing a batch of chemical with a device which automatically introduces the batch of chemical into the tank; (g) a bottle for a unit batch of medical chemical and a machine readable indicator attached to the bottle carrying cooled information of the bottle contents; (h) a system for applying chemicals to a dialysis tank which accepts a bottle as in (g) and has a vertically movable spike and a device for removing the machine readable indicator; (i) system as in (h) in which the indicator is read prior to applying the chemical to the tank and the patient alerted if the information does not correspond to appropriate stored information; (j) method of separating old and new dialysate in a tank by conditioning the two types to two different temperatures; (k) method of operating the dialyser by periodically pumping fluid through the dialysis membrane from the dialysis side to remove blood products from the blood side; (l) method of dialysis in which priming fluid and blood are pumped through respective circuits of the membrane to prevent priming fluid reaching the patient; (m) a method of testing the integrity of a dialysate filter by pressurising the membrane with air and monitoring the rate of decrease of pressure; (n) a method of approximating the sodium clearance of a dialyser by circulating sodium solution and water on respective sides of the membrane and measuring the sodium solution conductivity once conditions have stabilised; (o) apparatus for in-situ cleaning of dialyser and tubing set after dialysis without exposing the dialyser or tubing set to airborne contaminants; and (p) cleaning a reusable extra corporeal circuit installed in a dialyser by back flushing and cyclically changing flow rate and direction of flow of cleaning fluid.

Description

The The present invention relates to methods for determining whether a Dialyzer of an extracorporeal circuit should be replaced taking the urea clearance of the dialyzer over its sodium clearance determined, for example in a modular dialysis system, in particular one outside the usual Dialysis clinics, for example, at home or in care facilities suitable dialysis system.

The Dialysis, especially hemodialysis and peritoneal dialysis, is a method of treatment for patients the malfunctions of the kidneys. In hemodialysis gets blood out of the body of the patient by one as artificial Kidney-acting extracorporeal circulation, the so-called dialyzer, where in the blood carried Toxins and excess water through a semipermeable membrane from the blood into an electrolyte, the so-called dialysate medium to be filtered. A widespread Shape of the dialyzer has a large number semipermeable, hollow Membrane fibers, whereby the involved in the dialysis surface strong is enlarged, so that diffusion and convection over the membranes are facilitated.

Known dialysis systems usually consist of two parts:
One part comprises an extracorporeal blood circulation and the other a circuit or flow path for the dialysate. Typically, the entire blood circulation circuit is disposable and includes: 1) an arterial and venous fistula needle, 2) an arterial (inflow) and venous (outflow) tubing set, 3) a dialysis machine, 4) a physiological pre-fill solution (saline ) with infusion set and 5) a coagulation inhibitor such. As heparin or sodium citrate with infusion set. About the arterial needle blood is taken from the patient through a suitable access, which is then passed through the arterial blood tubes to the dialysis machine.

To The arterial line usually belongs a pump section equipped with a rotary or peristaltic blood pump the hemodialysis machine connected, pressure monitoring chambers, the hoses have, which also provided in the machine transducers for the Pressure, to measure the pressure before and / or after the pump, inlet ports for the saline solution and the anticoagulant, as well as one or more injection sites, to withdraw blood or inject medication.

The dialysis machine itself included a box in which a bundle of hollow fibers with semipermeable Membranes are located. The blood circulates inside the hollow fibers, while the dialysis solution Outside circulated so that both never get in direct contact. Due to a concentration gradient toxins from the blood diffuse into the dialysis solution. Excess water in the patient's blood enters due to a pressure gradient in the dialysate. The membranes can from cellulosic or synthetic polymers consist.

About the venous Line and the associated needle the freshly dialyzed blood is removed from the dialysis machine and back led into the bloodstream of the patient. The venous cutlery consists of a pressure monitoring chamber with hoses, the to another provided in the machine transducers for the Pressure, Injection sites, and a section of tubing with an air detector connected to the machine, so that the risk of air embolism Patients is prevented.

at Today's dialysis machines typically make the dialysis solution continuous produced by water, the first was purified by a water treatment system with liquid electrolyte concentrates is mixed. In the last decade, the dialysate concentrates of a single formulation containing acetate as a physiological buffer for correction of circulatory acidosis, to two separate components bicarbonate replaces the acetate as a buffer. Two dosing pumps are needed the first being the bicarbonate concentrate with water and the second mix this mixture with the concentrated electrolyte to the final, physiologically compatible solution to obtain.

Most of today's hemodialysis machines measure the pressure at the blood outlet of the dialysis machine by means of pressure transducers which are connected to the blood tubes or provided in the dialysate circuit. Microprocessors calculate an estimated transmembrane pressure (TMP) that correlates with the amount of water passing through the membrane. These machines also have means to measure the amount of dialysis solution flowing in and out of the dialysis machine so that the total amount of water removed from the patient by ultrafiltration can be calculated. By electronically comparing the amount of water entering or exiting the blood at a given transmembrane pressure, the system is able to actively control the amount of water to be removed from the patient's blood to achieve a preprogrammed value. If cellulose membranes are used with low water permeability, on the side of the dialysate, a negative pressure from the machine must be applied to the membrane, so that a sufficient adequate disposal of water. Because of the negative pressure acting on the dialysate when flowing through the dialyzer, it must first be placed in a degassing chamber under a larger vacuum, so that no air bubbles are generated in the dialyzer, resulting in miscalculations of ultrafiltration by the sensors and a reduction in the efficiency of the dialyzer would lead. On the other hand, when synthetic membranes with high water permeability are used, it is often necessary to exert a positive pressure on the dialysate side in order to control the otherwise too high ultrafiltration rate.

In In the US, most dialyzers are reused. Worldwide there is a trend to reuse dialyzers.

It are numerous, both manual and automatic methods, to reprocess dialyzers. In the dialysis centers will be special machines for multiple, simultaneous processing of Dialyzers used.

These Need to process carried out in areas which allow the handling of biohazardous material, there is always the danger of contact with human blood and both hepatitis and AIDS are relatively common in dialysis patients. About that In addition, the OSHA and the US Federal Environment Agency (EPA) give a variety of Working guidelines regarding the used, for humans dangerous Sterilization and cleaning agents before.

The preparation of the dialyzers and the lines can also be performed in the dialysis machine. The American patent US Pat. No. 4,695,385 A von Boag describes a purifier for dialyzers and lines. The device described there is permanently or at least for a certain time connected to the dialysis machine.

Finally, the Fluid circuits the dialysis machine cleaned at regular intervals and disinfected. Therefor There are two reasons. The first reason concerns the fact that in the past none sterile dialysates were used. Since dialysis as a treatment method is used, one has to rely on the fact that the membrane of the dialyzer a sterile barrier between the dialysate and represents the blood of the patient. This is certainly true for whole bacteria, but in recent years, concern has grown that with the Use of synthetic membranes and their more porous structure, Endotoxins or their components pass through these membranes and inflammatory processes in the patient can. When dialysates containing bicarbonate are used, it inevitably falls Calcium carbonate and accumulates in the fittings, so that it with an acid solution dissolved again must become.

In the past, many artificial kidneys have used a dosing system to make the dialysis solution and deliver it to the hemodialysis machine. In the early years of hemodialysis, only a so-called container or batch system was used. The machine had a large container in which purified water was premixed with dry chemicals to make the dialysis solution, and then reheated and recirculated through the dialysate flow pathway of the dialyzer. Bicarbonate was used as a buffer; CO ₂ was bubbled through the solution or lactic acid was added to prevent precipitation of calcium / magnesium carbonate. Dialysis times of 12 or more hours were the norm with the then ineffective dialysis machines. The warm dialysate was an excellent culture medium for bacterial growth. The long treatment time during dialysis increased the problem. To solve this problem, systems have been developed in which the dialysis solution at the time of use of purified water and concentrate was prepared. The concentrate contained acetate as a physiological buffering agent because bicarbonate readily precipitates with calcium and magnesium when present in the same concentrate.

center In the 90's, there are about 180,000 in the US and almost worldwide 500,000 dialysis patients. Most of them receive their dialysis in hemodialysis centers, while About 17% received home peritoneal dialysis and less than 3% at home hemodialysis carried out becomes. Hemodialysis is in the centers typically three times a week each for a duration between two and four hours. One four times a week Although dialysis takes place physiologically cheaper, it is only at Patients who have important contraindications Dialysis takes place three times a week, which in general with cardiovascular instabilities related. Home hemodialysis is also typically done three times a week.

Three dialysis units per week are considered the standard schedule in the majority of dialysis centers, but there are numerous scientific indications that more frequent dialysis, each with a shorter duration, is more favorable. While the healthy human kidneys work constantly and produce gradual changes in the body's total fluid volume and in the level of metabolic wasting, the three times a week dialysis treatments lead to abnormal physiologi fluctuations associated with a significant burden on the patient.

Of the with the arrival and departure to and from the dialysis center and dialysis self-related time expenditure is most acceptable to the patients who have three treatments a week. Consequently, vote only the patients who have intolerable intolerances related to fluctuations in body fluid volume and related Show symptoms, more common, d. H. four times a week for dialysis. at Home dialysis patients leads one more frequent Dialysis as the usual three times a week, to a greater use of relatives, helping with the set-up and monitoring the patient and also the patient himself, usually the most work in construction and dismantling and the Cleaning the plant makes. Consequently, the more common, d. H. at least four times per Weekly use of home dialysis, at least until now, not very common yet.

Lots Patients have great Difficulty, a "dry" body weight to reach when between them between the dialysis treatments accumulate three, four or more kilograms of fluid. Some patients, especially those with heart disease, tolerate a fluid increase of only two kilograms extremely bad. They are short of breath before dialysis and have muscle cramps during dialysis Hypotension. They feel "washed out" and are extremely weak and take several hours to regain balance and to be able to work again. The serum concentration of highly toxic potassium is often reached dangerous Level (more than seven mEq / L), especially before the first Dialysis after a longer one dialysis-free period is the case, for. B. after a weekend. As another important parameter would be To name the calcium concentration and pH, which in many patients too low before dialysis and too high after dialysis. by virtue of Of the empirical findings, these patients are in many hemodialysis centers for four Provided dialysis treatments per week.

In the past became artificial Kidneys under the premise developed that Device for dialysis itself should be very well developed and largely automated, while this for the preparation and cleaning was considered less important. This premise was true as long as the dialysis treatments took place less frequently and took a long time, with the time required for construction and cleaning of the device was relatively short compared to the total duration of the dialysis.

in the Over time, however, more and more efficient dialysis machines have been developed and the duration of treatment for a single dialysis continued to sink to 8, 4 and even up two hours. With the more modern, more efficient dialysis machines, the Patients an excess of acetate administered to the body was unable to metabolize, resulting in cardiovascular instability. to Eliminating this problem one returned to bicarbonate as Back buffer, however, the plant was designed as a metering system. By the chemical incompatibility of bicarbonate with calcium and magnesium are two dosing pumps needed the first pump mixing the bicarbonate concentrate with water and the second pump adds this mixture to the concentrated electrolyte dosed, whereby the final, chemically compatible Solution is available. With a short, daily 1-3-hour dialysis treatment opens up the possibility, to drop the need for a dosing system.

If but the short daily Hemodialysis in a dialysis clinic takes place, thus increasing for the patient associated arrival times, costs and other inconvenience dramatically. Should this practice be with a large number enforcing the patients of the dialysis center is thus also one additional Burden for the staff connected. Furthermore would have to capacity the clinic increased be to the larger number to master the resulting individual treatments, which of course also higher Funds would be necessary. From the above explanations it follows that a daily, Short dialysis treatment is best done at the patient's home.

The American patent US No. 5,336,165 A by Twardowski describes a method that can overcome many of the problems associated with conventional dialysis machines. This patent describes a hemodialysis system having a built-in water treatment system. It also has means for automatically formulating dialysis solution batches, for automatic reprocessing, for automatic adjustment, for automatic cleaning and disinfection of the blood and dialysate circuits, and it requires only a small storage space due to the use of dry and concentrated chemical reagents. This system is suitable for home dialysis.

The Fact that the Home dialysis has not yet found widespread use, depends on Share with that until no user-friendly, efficient home dialysis system today a cheap one Price available This is time consuming for the patient and the patient's family and relieved complicated construction and dismantling of the home dialysis system.

The present invention is based on a modular hemodialysis machine, which is particularly suitable for use at home, and which is a low-cost, portable, easy-to-use and extremely reliable home dialysis system, in which essentially the entire process is automated and only a minimum of inputs and labor required by the patient. The invention underlying hemodialysis is in the published patent application DE 196 05 260 A to the present patent, the disclosure of which is fully incorporated by reference, described in detail. By substantially reducing labor and disposal costs as compared to conventional home dialysis systems, the present invention allows a larger group of hemodialysis patients to perform short daily home hemodialysis treatments. By employing the present invention, these patients benefit from this method of treatment, which has been shown to produce excellent clinical results without inconvenience to those traveling to remote treatment centers.

All in all considered, the present invention relates to a hemodialysis machine with integrated Water treatment, dialysis production and extracorporeal circulation, which are under the control of a central computer, by a control unit, which simultaneously has an interface to the patient is controlled. A water pre-treatment unit for the Device becomes installed at home and with the hot and cold water pipes connected to the household. The water preparation unit has one temperature controlled mixing valve, water filter, carbon filter and if necessary, depending the composition and type of local water supply, other cleaning and treatment agents on. In addition, the device has an integrated Pressure relief valve, which provides a sampling outlet for the water has to check the treated water for chlorine or chloramine residues. The water pre-treatment unit supplies the device with treated water at a temperature of about 30 ° C or lower and with a substantially constant pressure.

The Dialysis preparation unit contains a substantially unyielding container for dialysis production, the over a new and advantageous subunit for addition and dispersion of chemicals, the subunit being mounted on the container and automatically dispenses dialysate chemicals into the dialysate preparation container. The subunit for adding and dispersing chemicals comprises bottles with dialysis chemicals, on the outer surface of which machine-readable markings are attached for identification. If the patient is the wrong one Install bottles on sub-unit for addition and dispersion wants, an alarm is triggered and the user will be shown the bottle through the correct bottle exchange.

The Water treatment, dialysis and the operation of the extracorporeal circulation module need new and beneficial Process control procedures, thus the reliability and efficiency during the dialysis process is guaranteed. The ultrafiltration system, the dialysate filter (or "ultrafilter / pyrogen filter"), the dialyzer, the extracorporeal circulation, the dialysate circulation and the clearance capacity of the Dialyzers are automatically checked before the dialysis treatment performed becomes. For reasons the accuracy of measurement Furthermore before each dialysis the essential pressure sensors and the blood pump automatically calibrated. To these and other process control features had to get new and advantageous subunits, flow paths, and system subcomponents in the structure of the device to get integrated.

By means of a clearance test, as described in the above-mentioned US Patent US 4 695 385 A is described, it can be checked whether an in-use dialyzer must be replaced.

The present invention is based on the technical problem that arises US 4 695 385 A to make known methods safe.

Is solved this object by the method according to claim 1. Advantageous Further developments of the invention are subject matters of the dependent claims.

The inventive method is particularly used in a modular home dialysis machine, with which one besides, without the use of disinfectants, a de-infection process on the basis of hot, pure water for that entire device, including the water treatment unit. The computer controlled Water of the infection process uses strategically in the flow paths of the device placed thermistors to monitor the water temperature and a feedback control for the procedure provide. However, the system can also be chemical in an emergency be disinfected.

On the basis of the above-mentioned features and other features, the present invention is a highly effective and user-friendly device which requires only minimal user operation. Thus, the device according to the invention is particularly suitable for use in short, daily hemodialysis treatments. The entire device is structured that results in a portable machine that can be used especially outside the conventional dialysis clinics and in particular at home, in a nursing home or the like. It is understood that many of the process monitoring techniques of the present invention, either directly or after minor changes, can be used in other therapies than hemodialysis, such as hemodiafiltration, hemofiltration, and peritoneal dialysis.

The The present invention will be described below with reference to FIG on attached drawings described embodiment in more detail explained. In the drawings, like reference numerals refer to the same Elements in different views.

It demonstrate:

1 a schematic block diagram of the overall system, in particular, the connection between the water pre-treatment module, the modular home dialysis machine and the patient is shown;

2 a more detailed, schematic diagram of the hydraulic or dialysate production module 26 of the 1 ;

3 a schematic diagram of the extracorporeal circulation module 28 of the 1 ;

4 a flow chart of the timing of the operations of the machine;

5 a flowchart of the sequence of events during the Dialysatherstellungsschritts from 4 ;

6 a diagram showing the conductivity as a function of time, measured by the conductivity sensor 426 during the clearance test 743 out 5 ;

7 a representation of a hemofiltration unit according to the invention with predilution;

8th a representation of a hemofiltration unit according to the invention with redilution; and

9 a representation of a hemodiafiltration unit according to the invention with redilution.

In the course of the editorial revision of the patent specification are the original 2 - 5 . 7 - 12 . 14 - 16 . 18 . 20 - 25 and 27 - 32 the publication has fallen away.

In 1 a preferred embodiment of the entire device according to the invention is shown in the form of a block diagram. The modular dialysis machine 22 receives water from a pretreatment module 20 , The presentation of the 1 shows an example of an installation of the pretreatment module 20 and the modular dialysis machine 22 in the apartment of a patient. However, there are any sites conceivable. The main function of the pre-treatment module 20 consists in a first treatment of the originating from a household water, the heating of this water to a certain temperature and its delivery under a certain pressure to the dialysis machine 22 , In addition, the module takes 20 Dirty water from the dialysis machine 22 on and deliver it to the sewer of the household. The dialysis machine 22 is preferably a movable wheel mounted unit. It contains three functionally separate modules: a water treatment unit 24 , a hydraulic or dialysis production module 26 and an extracorporeal circuit 28 , The dialysis patient, not shown in the drawing, is connected to the extracorporeal circuit 28 with two lines, namely a "aterial line" and a "venous line" connected in a conventional manner.

The dialysis machine 22 also includes a patient interface control module 25 with a display and a touch-screen (or other patient input devices, such as a keyboard or a voice-controlled system) connected to one or more central processors. The interface and control module 25 takes over the monitoring and control of the entire operation of the system, displays the current status of the device, prompts the user for inputs and information, receives data from various sensors and other passive components of the system, records the data in memory, controls the data Operate the active components of the device (such as valves, pumps, heaters, etc.), alerts the patient to any irregularities or faults in the device through an alarm or other indication, calculates parameters related to hemodialysis, and performs other tasks that may occur in the device will be described in more detail below. In addition, the interface and control module 25 contain further device component, which allow, for example during the dialysis treatment to send patient data electronically, such as by means of a modem, to a central monitoring station. Referring to 2 will be the dialysis production module below 26 described in more detail. The main task of the dialysis production module 26 is the automatic mixing and preparation of the dialysate solutions and the delivery of the solutions to the dialyzer 404 , The dialysis production mo dul 26 has an inlet conduit 200 that with the line 111 ( 5 the published patent application) and filtered water from the water treatment unit 24 via valve 108 ( 5 the published patent application). The administration 200 feeds the water through a CV10 check valve into a chemical mixing tank 202 , which preferably consists of polypropylene. In a communicating connection with the container 202 at its side is a chemical addition and dispersion subunit 204 appropriate. The loading platform 250 the chemical addition subunit 204 is in the 7A - 7F the published patent application. The chemical applicator 260 the chemical addition subunit 204 is in the 8A - 8C and 9A - 9C the published patent application. The chemical containers (ideally bottles) 270 are in the 10A - 10F of the published patent.

The addition and dispersion subunit 204 preferably comprises two chemical applicators 260 , each for opening a container 270 are provided which contains an individual batch of dialysis chemicals directly above the applicator.

Typically, a container contains 270 Chemicals in liquid form and the other in powder form. The chemical batches are located in individual batches, preferably polyethylene and / or polypropylene bottles 270 is. When the container 202 filled to the intended level with purified water, pierce the chemical applicators 260 with the help of a thorn in the bottles 270 and the chemicals leave the bottles under the action of gravity and run into the interior of the loading platform 250 , As will be described in more detail below, an atomizer 285 the chemicals from the loading platform 250 in the container 202 where the chemicals to form the dialysate solution are dissolved and mixed with the water. In addition, preferred are purge valves for the bottles within the chemical applicator 260 intended. The valves located below the bottles of dry dialysate chemicals inject water into the bottles in a series of short pulses to gradually flush the chemicals out of the bottles. After the chemicals to the loading platform 250 were flushed, the valves rinse remaining, in the bottles 270 remaining chemicals from the bottles in the loading platform 250 , A third chemical applicator 260 and a third container 270 are also preferred above the platform 250 intended. The chemicals contained in the third container are usually either a salt, which may optionally be added to the dialysate solution to adjust the chemical properties of the dialysate solution, or a chemical cleaning or disinfecting agent added to the container during the disinfection cycle. Other conceivable chemicals for the third bottle 270 are drugs and vitamins or other nutritional supplements. As described below, in the device according to the invention preferably hot, pure water without chemical additives for disinfecting and cleaning the fluid circuits of the device 22 used. However, if there are reasons that make disinfection with hot water alone not sufficient, another cleaning process may be initiated in which the disinfectant chemicals are added from the third container into the container and then for cleaning and / or disinfection by the device be circulated. If necessary, of course, other chemical applicators and containers on the loading platform 250 to be ordered.

The container inlet 203 is located at the bottom of the container 202 and is tangent to the walls of the container 202 arranged in a horizontal plane so that the incoming water at the side surfaces of the container in one of the orientation of the inlet 203 corresponding direction is swirled around, so that a vortex is created and that in the container 202 is stirred water. A spray washer 205 , which is essentially comparable to the water atomizer of a dishwasher, is in the upper region of the container 202 provided and is used to clean the container 202 and for mixing the dialysis chemicals in the container 202 used. The power of the spray washer 205 leaving water causes a rotation of the spray washer 205 and water is flowing in one direction into the container 202 sprayed the water flow in through the water inlet 203 produced strudel corresponds. The interaction of spray washer 205 and water intake 203 produces a very good mixing of the contents of the container 202 and contributes to effective dispersion and solution into the container 202 from the loading platform 250 introduced chemicals, so that settling of the chemicals is prevented at the bottom of the container.

The container 202 itself preferably consists of a light, biocompatible, chemically compatible, sterilizable and substantially unyielding (ie, rigid and not readily expandable or contractible due to pressure, temperature, or other conditions) material, and may be as described, for example, in U.S. Pat 2 represented, shaped. Of course, other forms of the container 202 possible. An example of a container that meets the above conditions is a container made of polypropylene whose shell is reinforced on the outside by fiberglass windings. Polypropylene is preferred because it is chemically inert, light in weight and hot for long periods of time Water can be exposed without causing adverse effects occur. Another possible material for the shell is polyvinyl fluoride (PVDF). The reinforcing fiberglass ribbons contribute to a significant improvement in the intransigence (or rigidity) of the container 202 at. As described in more detail below, the intransigence of the container is particularly important in order to improve the real-time measurements of the amount of fluid withdrawn from the patient during dialysis. The fiberglass ribbons are on the outside surface of the walls of the container 202 wrapped in overlapping diagonal layers, with an additional layer covering the central portion of the container 202 surrounds horizontally. A suitable container is available, for example, from Structural North America, Ohio. Other conceivable reinforcing fibers may also be suitable for the stated purpose, for example composite fibers, carbon fibers and Kevlar, which may either be integrated in the shell body or surround it on the outside. Heaters may be installed in the upper portion of the container shell or attached externally to assist the dialysate separation process described below.

A pressure sensor LT (Microswitch, Part No. 26PC X-98494-PC) is at the bottom of the tank 202 in the pipe 206 provided to the water level in the tank 202 to determine. The administration 206 is statically isolated, ie no liquid flows through the line when the NO output of valve V17 for the line 206 closed and the NC output in line 209 is open, so that the level gauge the water level in the container 202 can determine. This is the case, for example, when the container 202 is filled. When filling the container and mixing the contents of the container, water is released from the line 209 to the valves V17 and V9, through the pump 212 , the valves 220 and 232 , The administration 231 to valve V15 and finally via the atomizer 205 back into the container 202 circulates, which also advantageously contributes to the mixing of the container contents.

At the bottom of the container 202 a filter screen FTB (mesh size 130 microns) is provided, which may for example be designed as a flat plate with a polypropylene frame. A pump filter FP2 (mesh size preferably between 50 and 200 μm) is in the degassing line 209 arranged. Air or gas, which may still be present in the dialysate, is removed by pumping the dialysate through the filter FP2. The filter FP2 generates a negative pressure which ensures that dissolved air comes out of the water.

About the container outlet 206 the dialysate solution flows to a pump 212 , If chemicals from the chemical addition subunit 204 are discharged into the container and mixed there with the water, the circulation of liquid through the line 206 , in which case the degassing line 209 is static.

A three-way valve V17 is located at the intersection of the pipes 206 and 209 and determines which of the two lines is static. The pump 212 (For example, Micropump EG series, 0-3 L / min.) Pumps the solution through a pressure sensor 214 (Microswitch PN 26PCT X-98752-PC).

As in particular from 2 can be seen controls a three-way valve 220 the fluid flow through the outlet line 226 and the return line 236 , Water or solution in the pipe 226 gets into a heater 228 directed. When heating 228 For example, it may be a temperature-controlled, 1300-watt flow heating, such. For example, a Heatron # 23925 heater. The heating system 228 It is used to warm the dialysate to body temperature while in the extracorporeal circulation 28 ( 1 ) entry. The heater is also used to heat water to the disinfection temperature of at least 80 ° C and preferably at least 85 ° C and the water for more than one hour during the heating water disinfection of the flow paths of the device 22 to keep at this temperature.

After passing through the heater 228 the water flows through a flowmeter 241 (for example, a Digiflow ^™ unit) which determines the flow rate of the solution in the line. This is followed by a safety thermistor CHS in the line. A second thermistor 230 is used to control the temperature of the fluids in the pipe 226 to control. A three-way valve 232 controls the flow of fluid through the return line 231 to the tank and the outlet pipe 233 , A dialysate filter, such as the ultrafilter / pyrogen filter 234 is intended to remove particles and pyrogenic material from the dialysate. A preferred filter 234 is about the Minntech Renaguard ^TM -yrogen filter. It is ensured that during the dialysis treatment no dialysate solution in the dialysis circuit 402 enters without first passing through the filter 234 to have run. About the condition of the three-way valve 236 it is determined whether fluid through the pipe 238 or from the input line 406 from the ultrafilter or pyrogen filter 234 exit.

Between the lines 238 and 206 there is a check valve CV12. During prefilling the ultrafilter 234 and pumping the dialysate through the ultrafilter 234 and the dialysate cycle 402 allow the lead 238 , the check valve CV13 and the valve V22 the escape of air from the ultrafilter 234 (ie from the outside of the fibers of the filter 234 ).

According to the invention, a test of the pyrogen or ultrafilter before treatment 234 performed on integrity of the fiber bundles. The integrity of the ultrafilter 234 is important to make sure there are no leaks. The pyrogen / ultrafilter will be on the "blood side" of the ultrafilter before dialysis 234 pressurized, ie inside the directly in fluid communication with the dialyzer 404 standing fiber bundles, and the pressure drop rate is measured. A rapid pressure drop or failure to pressurize the pyrogen / ultrafilter triggers an alarm, such as a warm tone, indicating to the patient that the pyrogen / ultrafilter 234 must be replaced. The test is carried out so that first the fluids from the blood side of the pyrogen / ultrafilter 234 be removed by the UF pump 242 is operated in reverse, allowing air through the valve 236 , the bypass valve 412 in the dialysate cycle 402 and through the line 406 into the lumen or the blood side of the pyrogen / ultrafilter 234 is pumped back. Once the water has been removed from the blood side of the pyrogen / ultrafilter, it starts under the condition that the pyrogen / ultrafilter 234 there are no leaks to increase the pressure on the blood side. The ultrafilter pump 242 Pumps until the pressure in the pyrogen / ultrafilter 234 about 500 mm Hg. If there are any leaks, air will enter the dialysate side of the filter 234 , The air pressure is with the pressure sensor 410 in the dialysate cycle 402 measured. Should the pressure sensor 410 show no pressure increase, then there is a significant leak. A slow pressure drop indicates that there is no leak. The pressure drop rate, which already indicates a leak requiring replacement of the pyrogen / ultrafilter, depends essentially on the physical properties of the filter membrane and will vary depending on the filter used. For most commonly used filters 234 The limit of the pressure drop rate, which indicates a malfunction, should be above 10-25 mm Hg / 30 sec, depending on the filter type used.

The pressurization of the pyrogen / ultrafilter 234 can also be correlated with the maximum pore size of the filter. If the pyrogen / ultrafilter 234 is placed under ever higher pressure, a maximum pressure is reached, above which the pressure drops suddenly, indicating that the surface energy of the water in the pores of the filter is less than the force exerted by the pressure force. If the pore size can be deduced from this maximum pressure, the filtration capacity for certain pyrogens and other materials can be determined.

From the in 16 The disclosure of the illustrated diagram will be clear that the analog circuit 614 and the central processor 610 of the central control module, pressure data from the pressure sensor 410 receive. Pressure values indicative of a leak, such as when the pressure drop rate is greater than a predetermined threshold, cause the CPU 610 (or the security CPU 616 ) to give an alarm, for example, a message displayed on the patient interface or an audible or visual indication 604 or a buzzer can be.

When filling the container 202 After chemicals have been added, the device determines 22 by monitoring the fluid sensor 288 in the from the top of the container 202 coming line, when the addition of water should be stopped. Once the fluid sensor 288 Fluid registered, is the influx of water by closing the valve 108 completed ( 5 the published patent application).

The return flow of old solution, ie solution, which has already flowed through the dialyzer, from the dialyzer 404 done by the return 240 , the V18 valve and the dialysate inlet 243 , The valves V19, V15 and V6 are closed and pass the dialysate through the Dialysateinlaß 243 , An integral pressure relief valve with sampling outlet 210 is at the top of the container 202 arranged in the line leading to the valve V6.

According to the invention, a method is provided for old and new dialysate in the container 202 keep separate, with the density differences of the dialysate are used at different temperatures. The inventive method is a further development and improvement in the U.S. Patent 4,610,782 (Terstegen) described method. The preparation and mixing of dialysate in the container 202 takes place at a dialysate temperature between 28 and 30 ° C instead. Compliance with this temperature is in a preferred embodiment of the invention by the temperature-controlled mixing valve 36 in the water pretreatment module 20 guaranteed. During dialysis, the dialysate in the heating element 228 at body temperature, ie heated to 37 ° C and into the dialyzer 404 the extracorporeal circuit 28 directed ( 3 ). New, ie fresh dialysate is from the bottom of the tank 202 removed and old dialysate passes over the top of the container 202 into the inlet 243 wherein it is a temperature of about 37 ° C or one or two degrees less due to heat losses due to radiation and heat conduction in the hoses and components of the dialysate circuit 402 has.

The old dialysate is so carefully from the top into the container 202 derived that no turbulence of the "old" dialysate occur, so that virtually no mixing of old and fresh dialysate takes place in the container. According to the invention a turbulence-free recycling of the spent dialysate in the container 202 preferably achieved in that in the center of the upper part of the container 202 a circular inlet tube is provided, wherein a series of radially inwardly directed small holes are provided in the tube. As the recirculating dialysate reaches the inlet tube, it passes gently through the holes approximately into the center of the tip of the container. In another embodiment, the return of the dialysate with minimal turbulence is achieved in that an inlet 243 slightly upwards and towards the side walls of the container 202 is oriented. The returning dialysate forms an area above the fresh dialysate, wherein a thermocline boundary layer separates the returned and fresh dialysate due to the temperature difference and the resulting density difference between the dialysate in the two areas. In the course of dialysis treatment, this boundary layer migrates in the container 202 down, because the volume of the returned spent dialysate in the upper area increases and the volume of fresh dialysate decreases.

The Method works especially reliable especially if the pressure difference between the upper and the lower area at least 5-7 ° C, where satisfactory results already at a temperature difference of about 3 ° C be achieved. Usually, such a temperature difference easily accessible if the dialysate is heated as described above.

A further improvement of this method is, prior to the start of the dialysis treatment, one or two liters of fresh dialysate, preferably at least 5 ° C. above the temperature of the dialysate in the container 202 to heat and initiate the thus heated dialysate in a substantially non-turbulent manner at the top of the container. Thus, an area with maximum temperature is already defined at the top of the container, so that the used during dialysis, old dialysate when flowing back into the container 202 above this defined range, which further reduces the risk of noticeable mixing of old and new dialysate. The heating of this defined layer can be done by the heater 228 be achieved and the return of the heated dialysate, for example via the valve 232 , the return 231 and the valve V18. To put the heated dialysate in the container 202 should return the valves V6, V15 and the NO outputs of the valves 236 and 232 be closed.

The separation of used, recirculated and fresh dialysate in the container 202 offers numerous advantages. First, the ultrafiltration can take place in a closed circuit. Second, the fluids dialyzed by the patients may be in the reservoir 202 be collected separately from other solutions, so that the spent dialysate can be optically monitored in a container with window or other determinations can be performed on a sample. Third, ultrafiltration in a closed loop allows the device to operate during dialysis without connection to a water source or drain. This means both patient and dialysis machine 22 more mobile, which proves to be particularly beneficial for use at home, in hospitals or nursing homes. Fourth, the separation of old and new dialysate improves the liberation of uremic toxins in a batch system.

An ultrafiltration pump 242 that have a valve 236 with the return 240 dialysate is pumped out of and into the ultrafiltration tank 244 , The flow direction depends on whether the ultrafiltration pump 242 works in forward or reverse direction. The NC output of valve V9 is closed and the NO output of valve V13 is open, providing a flow path for the solution into the bottom of the container 244 provided. The ultrafiltration pump 242 is also used to prefill solution from the extracorporeal circuit 400 back to the ultrafiltration tank 244 to pump.

The level sensor PUH in the ultrafiltration tank ensures an exact measurement of the fluid volume in the ultrafiltration tank 244 , The ultrafiltration tank 244 serves to store fluid which is removed from the dialysis circuit according to the fluid removed from the patient. Thus, the fluid removed from the patient is the difference in fluid volume in the ultrafiltration vessel before and after the dialysis treatment. The rate at which fluid enters the ultrafiltration tank 244 is derived (and thus, considered over the entire time, the total volume) by the pumping rate of the ultrafiltration pump 244 controlled. An atmosphere-open, sterile air barrier filter AF (for example Pall EMFLON II) is at the top of the container 244 appropriate. More detailed descriptions of the prior art ultrafiltration control in hemodialysis are given in the now defunct American patents US 3,974,284 and 3,939,069 by Rhone-Poulenc, which is hereby incorporated by reference.

The pressure sensor PUH is located at the bottom of the ultrafiltration tank 244 , The pressure sensor PUH measures the pressure and thus the fluid level in the tank 244 , The level sensor PUS serves as a safety system and for monitoring the ultrafiltration pump 242 to increase the amount of fluid obtained by ultrafiltration during the dialysis treatment to verify. In particular, the sensor PUH measures the hydrodynamic pressure of the dialysate in the ultrafiltration tank 244 and then generates one to the control module 25 sent measuring signal, the fluid volume in the ultrafiltration tank 244 equivalent. Alternatively, the transport rate of the through the ultrafiltration pump in the ultrafiltration tank 244 pumped fluids are continuously monitored. Another alternative is that the delivery volume of the ultrafiltration pump per revolution and the duration of the dialysis treatment are known. With this information, the central control module 25 ( 16 the published patent application) the expected dialysate volume in the ultrafiltration tank 244 determine. By comparing the signal measured by the sensor PUH with the expected dialyzer volume in the ultrafiltration vessel, the pumping rate of the pump 242 be checked.

In another embodiment of this method, for example, an adjustment of the transport rate of the dialysate into the ultrafiltration tank can be carried out (for example, the pump rate of the pump 242 ). For example, if the sensor PUH has a fluid amount of 350 ml in the container 244 but a calculation of the expected fluid volume in the ultrafiltration tank based on the pump rate and the time past 385 ml corresponds to determine that the pump 242 pumping about 10% too slowly and the pump speed should be increased to reach the given ultrafiltration target in the expected dialysis time.

After the container 202 and the fluid circuits of the dialysis production module 26 are filled with dialysate, a positive pressure with the help of the pump 212 in the pipe 209 generated. This will dialysate from the container 202 through the valve V9, the ultrafiltration pump 242 to the valve 236 down through CV12, the line 206 , the valve 220 , and the valve V8 in the pyrogen / ultrafilter 234 directed. The dialysate is passed through the flowmeter 241 in the dialysate cycle 402 sent where the solution is a bypass valve 412 flows through, through the return 422 and the line 240 back into the container 202 flows. During dialysis, dialysate is removed from the dialysate cycle via the line 240 , the valve 236 and valve V13 corresponding to the ultrafiltration volume to be reached by the patient into the ultrafiltration vessel 244 pumped.

Airways and processes 282 and 280 are in the module 26 provided to optionally fluid or condensate from the container 202 to collect. An optical fluid sensor 288 serves to fill the container 202 determine when the container is full during the dialysis treatment to detect a malfunction of the valve V6 and to determine if there is water or dialysate in the tube section (solid line) between valve V6 and air filter AF.

In the construction according to the invention, the housing of the dialysis production module 26 a floor or a basin for the entire device 22 including the other modules 24 and 28 include. Fluids, such as blood, water or dialysate, leak through the modules 24 . 26 or 28 flow, be in a reservoir 284 collected at the bottom of the entire device. Such leakage currents can flow in any way, which is schematically represented by the dashed lines 280 and 282 is shown. The bottom of the case of the device 22 is not flat horizontally, so that the collection of the fluid is facilitated, as it is known from the oil pan of an engine ago. The bottom of the appliance may be in the shape of a bowl or any other suitable outline, which may be a lower reservoir 284 provides. A fluid sensor 286 is near the collecting basin 284 arranged to prevent the occurrence of fluid in the sump 284 display. When fluid is detected, the user is alerted via an audible or visual signal and the device is checked for leaks.

In 2 is a lead on the left side 283 shown the water to the chemical applicator 260 directs the bottles 270 for the Dialysatchemikalie can be spooled after their opening, as well as for disinfecting the seals of the bottles. The administration 281 is a return from the chemical applicator 260 to valve V13. The administration 291 transports water from the three-way valve 287 to a spray nozzle or atomizer 285 in the chemical loading platform 250 , drain pipes 236A and 236B Provide flow paths for the dialysate or the disinfecting water to make it the extracorporeal circulation 28 over the disinfectant distributor 494 (see also 28 of the published patent application) through the valve V14 and the thermistor 293 can leave. A pressure limiting / sampling outlet 215 is in a drain line 236C arranged with the valve 220 connected is. The pressure limiting / sampling output 215 is a combination of a pressure relief valve and an integrated sampling output constructed as the pressure limiting / sampling output 78 (see. 4 of the laid-open specification) and serves to remove fluid samples from the system. The wires 289 and 289A provide via the valve CV11 for a fluid connection in the extracorporeal circulation 28 , The administration 295 takes care of the line 496 for a connection of the disinfection outlet 495 of the disinfection distributor 494 ( 28 the published patent application). The thermistor 293 monitors the temperature of the out of the extracorporeal circulation 400 during the hot water disinfection cycle returning fluid.

In the present 3 and in 27A The published patent application is the extracorporeal circulation 28 shown. Blood of the patient is in the arterial line 532 in the extracorporeal bloodstream 400 directed. If one, as described below, a bag 448 Used with saline, the salt is transferred to the arterial line 432 introduced via a three-way connector TC, which has a rotating Lueranschlußzapfen and two Lueranschlußbuchsen, such as Haemotronics, part no. B-82, or alternatively a four-way injection site with a rotating luer fitting and a double luer fitting, such as Haemotronics part no. CR-47. The optional salt solution bag 448 is via a saline infusion line S, which optionally a fluid / air sensor 781 and a clamp 779 owns, with the arterial line 432 connected. The salt bag 448 has several possible uses: To pump out the air from the extracorporeal circuit 400 to replace fluid lost during treatment to rehydrate the patient and to direct blood back into the patient. This is achieved by establishing a pressure difference on the membrane of the dialyzer in the extracorporeal circuit 400 introduced reverse osmosis water and ultrapure dialysate are also suitable for these tasks, so that the saline solution bag 448 an alternative method for pumping and rinsing. The fluid sensor 781 Determines when the salt bag is empty and allows this condition to be displayed to the patient so that periodic checks of the saline bag 448 are not necessary. When air passes through the sensor 781 is determined, the clamp 779 closed. Instead of a fluid sensor 781 An in-line infusion filter can also be used, so that no fluid sensor is necessary.

On the line 432 there is a clamp 444 , an air bubble detector 446 , which can operate on ultrasound basis, for example, a pressure gauge 500A and optionally an injection site 556 (for injections with or without needle). The blood pump 558 pumps blood into the tubing through a special tubing in the pumping section (for example, made of Pharmed ^™ material or silicone) 462 , past a possibly provided injection site 460 and a pressure monitor 500B and an expansion chamber (if provided) 466 in the dialyzer 404 , The return of the blood to the patient via the line 470 first in a chamber 472 for separating the air and for pressure monitoring, the top or bottom of an inlet nozzle 471 has, with the upper position is preferred.

As in particular from 3 becomes clear, the Chamber has 472 a chamber section 474 , an upper and a lower sensor 476 respectively. 478 for the blood level in the chamber and optionally one or more injection sites 480 , To monitor and control the blood level is located in the chamber 472 also a third blood level sensor 477 , which is installed at the level of the optimal blood level. About a line 482 there is a communicating air connection of the chamber 474 with a connection 483 in a disinfection distributor 494 that also with a lead 491 connected, which is a pressure sensor 775 , an air pump 777 and having a filter, and finally discharging into the atmosphere. Normally the fluid is in the chamber 474 during dialysis under an overpressure and blood level, if it passes through the level sensor 478 is registered as too low by switching on the pump 777 be increased, as long as the air from the chamber 472 sucks until the level reaches the level sensor 476 reached. Accordingly, the level can be lowered by the occlusive blood pump 458 stopped and the air pump 777 operated so that air into the chamber 472 is given. The bottom of the chamber 474 is with a lead 484 connected to an ultrasonic air bubble detector 486 , a blood sensor 488 and a clamp 490 and with the venous line leading to the patient 492 connected is.

Between the line 482 and the exit 483 is a disc-shaped pressure isolator 493 installed (cf. 28 ). The pressure isolator 493 has a microporous membrane that ensures that only air but no fluid from the line 482 into the pipe 491 can escape. Instead of the air pump 777 can also be a valve for adjusting the air pressure and a terminal in the output 483 leading line 491 be provided, which is open to the atmosphere.

In 13 and in particular in 28 The published patent application is the disinfection distributor 494 shown, the disinfection outputs 495 . 497 and 499 having. The exit 495 is at the back of the distributor 494 with a disinfection line 496 connected, the disinfecting fluids (for example, hot water) in the extracorporeal circuit 400 leads. The exits 497 and 499 take each the end connections of the venous and arterial lines 432 respectively. 492 after completion of the dialysis treatment. The exits 497 and 499 are via a valve V20 ( 2 ) connected with each other. The connections 497 and 495 are via a tee at the back of the disinfectant manifold 494 connected. These ports provide a path of flow for the disinfectant fluid (such as hot water and disinfectant-treated water) throughout the extracorporeal circuit 400 , including the blood side of the membrane in the dialysis gate 404 provided. Between the exit 483 and the other outputs 495 . 497 and 499 however, there is no communicating connection for fluid. After completion of the dialysis treatment, the patient connects the from the connection 483 upcoming manifold for air bubbles 482 with the disinfection output 495 , The disinfection distributor 494 may be formed as a housing, but it may also be merely an arrangement of terminals having the described here or equivalent communicating compounds. As it turned out 2 and 28 of the disclosure, connect the wires 289A and 236A the back of the disinfectant distributor 494 with the outputs 499 and 497 ,

The back of the disinfectant distributor 494 is via the return lines 236A and 289A with the valves V14, V20, the check valve CV 22 and the thermistor 293 connected ( 2 ). If the wires 432 and 492 with the connections 499 and 497 of the disinfection distributor 494 , as in 27A are disclosed in the publication, a connection of the lines 436A and 289A via the disinfectant distributor with the arterial and venous line 432 respectively. 492 the extracorporeal circulation.

Usually In extracorporeal blood circuits are blood filters that both Filter the blood as well as remove air or gas bubbles from it. Typically, such filters become heavier operations used. The blood flow rate, which is needed in such operations is within the range from 3 to 6 liters per minute. The typical blood flow at the hemodialysis however, it is only in the range of 200 to 600 ml per minute.

The operation of the device 22 constituent components is created by a memory in the host CPU 610 controlled resident software program. In the 4 and 5 are in the form of flowcharts the different routines and subroutines of the software (or according to the operations of the device 22 ). These routines and subroutines, the data entered into the CPU and the data output from the CPU, and the operation of the other modules 24 . 26 and 28 of the device 22 will be described in detail below.

First, however, the self-test routines that are performed when the device is described will be described 22 is switched on or if the power is available again after a temporary power interruption.

At power-on, the machine performs self-tests necessary to ensure proper operation. If an error is detected in any area of the device, the user will be notified, for example by a message on the display 600 , the flashing of an indicator or warm light 604 or other appropriate means in accordance with the AAMI / IEC standards. Also preferred is a lamp 604 is provided for the current, so that the distinction between the lack of power and a system error is possible. Preferably, the device also includes other aids, such as a fax and / or modem, to communicate the results of the dialysis treatment to a central monitoring station, a blood pressure cuff, a patient scale, and a heparin infusion device. The self-test routine should also check the status of these features.

After the self-test, the unit performs 22 a cycle status to determine if the system was in the middle of a process (such as cleaning, disinfecting, or dialysis) when power was interrupted and the backup battery was exhausted. If the system is in the middle of such a process and the turn-off time was short, the system will continue this process.

If the disinfection has just been carried out, the CPU can 610 be preprogrammed so that either the process continues or a message is displayed after which the "continue" operator must press. The default is that the system will continue to run and display the status. As the process continues, the temperature of the system must be checked. Preferably, a method is provided, with the help of which you can specify depending on the time passed without electricity and the current temperature of the device, if a heating cycle only continued, extended or, if necessary, with previous flushing, to be completely repeated again. As a result, it must be ensured that after the disinfection cycle, a certain degree of cleanliness of the system, especially with regard to the presence of bacteria, must be achieved.

When the container 202 has been filled, the CPU determines from the no-flow time whether to empty the existing water or to continue refilling from the existing level. Based on the current state, the system allows the filling to continue and the status to be displayed if the system is bacteriologically safe. If the water is not bacteriologically safe, the system is drained and filling starts again. Depending on the past time, it may be necessary to perform the disinfection cycle again.

If when dialysis of the current just dialysate was mixed determined the system, whether due to the time without electricity, the present Batch with regard to bacterial growth and failure of the dissolved Chemicals is "safe". If so is not the case, the operator is notified and the batch must be discarded become. The system is preferably user-programmable insofar as as can be determined, whether it is an audible and / or a visible one To give an alarm. The default setting is "audible" and "visible". If the batch is "safe", the blending process will be under status display continued.

If the extracorporeal circuit has just been prefilled, the system, based on the time without electricity, set whether that pumped material is "safe" in terms of bacterial growth and precipitation. Is not that so, the operator is notified and the sucked material must be disposed of and a completely new dialysis batch are made. In safe condition will the prefilling process continues.

If at the moment of power-off, a clearance test has just been carried out, the system notifies the user that usable clearance test data could not be obtained (this will only be technically savvy Users are interested, but the treatment report sent to the central Center is forwarded, the lack of clearance test.Data Show). If the time since power off was short enough, the system will continue to dialyze against water on the blood side, to a satisfactory electrolyte concentration and temperature on the blood side is ensured. If too much time passed the system notifies the user that the prefilled solution is discarded and a completely new dialysis batch must be prepared.

Should just an initialization process for dialysis took place have the system, starting from the past without electricity Time determines whether the existing aspirated solution with regard to bacterial Growth and fancy chemicals is still useful. If not, the operator is notified that the prefilled solution is discarded and a completely new Dialysatcharge must be made. Should the materials are still "safe", that sets Continue the dialysate run and keep the dialysate on the Target temperature.

If the system interruption occurs during the dialysis treatment itself, the system checks if the blood lines are connected to the device. If the blood lines are connected to the device, the elapsed time since the power was cut is determined. If this period poses no bacterial growth problems in the system, the system will ask the user if a clean cycle should be started or if the user wants to reconnect to continue the dialysis treatment. The system should be set up in such a way that it only allows the patient to be reconnected (and / or removed from the dialysate from the by-pass) if the dialysate has the correct temperature and conductivity. If the temperature gradient no longer allows dialysate separation (if this procedure is used), it must take this into account in the treatment report. However, if too much time has passed that the dialysate can no longer be considered "safe", the system indicates that a cleaning cycle should be performed. It can be programmed to automatically start this cleaning cycle if the blood lines 432 . 492 on the device 495 . 497 are connected ( 3 ). If the blood lines are not connected to the device (for example, because they are connected to the patient), the system asks the patient if he wants to resume dialysis, if blood is to be returned or if he wants to disconnect the blood lines. When resuming or flushing back blood, the system notifies the user that it must be checked that the safety clamps are back in the operating position, ie not open by hand. The system also checks the temperature and conductivity of the dialysate. If the patient continues treatment, it will continue from the interruption point.

If in the course of the interruption the backwashing of the blood was carried out, runs the Continuation of the procedure as described above in the dialysis treatment.

If the system at power interruption just on the separation of the hoses Waiting for the patient checks the system when restarting first, whether the blood lines with the device are connected. If not, the patient is prompted to Separate blood lines. If the blood lines with the device connected, the device prompts to start the cleaning cycle, but it can also be programmed to that the Cleaning cycle is started automatically when the blood lines connected to the machine.

Should when interrupting just the blood pressure will be measured the measurement continues after restarting. The system first checks again the time passed since the power failure. Due to the possible setback in the body However, it may take a few minutes for the patient to get the blood pressure can be measured again.

After performing the initialization tests and checking if the system was interrupted in the middle of the treatment, the system enters a hibernation state 702 , An overview of the operation of the dialysis machine according to the invention is in 4 shown. At rest 702 the device is waiting 22 on user input to begin dialysis treatment. The device 22 monitors the time elapsed since the last dialysis treatment. If the period since the last disinfection is greater than an experimentally verified downtime (perhaps 24 hours), the unit will begin a disinfection sequence 704 , During the disinfection sequence 704 The entire device is disinfected with hot water at a high disinfection temperature (for example, greater than 80 ° C) in a sufficient time for a satisfactory disinfection of the device period, for example, at least one hour at 80 ° C. Once the thermistors in the modules 24 . 26 and 28 for more than one hour higher temperatures than 80 ° C to the two central processors 610 and 616 reported, the machine starts with the Dialysatherstellungsschritt 706 , After filling the extracorporeal circulation, the dialysis sequence begins 710 During the blood and dialysate through the extracorporeal circulation and the dialysate circuits 400 respectively. 402 be circulated. When the parameters given for a dialysis treatment, such as ultrafiltration volume and / or KT / V and / or dialysis time have been reached, the machine starts the backwash sequence 712 in the extracorporeal circulation 410 remaining blood is flushed back to the patient. Upon completion of this sequence, a purge sequence will occur 714 carried out. After sufficient flushing and drainage of the dirty liquids via the drain line from the device, the device returns to the idle state 702 back and wait for a command or until the next scheduled treatment and repeats the entire process.

In another embodiment of the method according to the invention, the disinfection sequence could 704 after the rinsing sequence 714 be carried out so that the device is disinfected directly after completion of the dialysis treatment. In this case, after the disinfection sequence has been completed, the system would return to idle and wait for the start of the next dialysis treatment or perform a new disinfection cycle if the idle time between two treatments is greater than a predetermined period of time.

It should also be noted that after completion of the dialysis treatment, the arterial and venous lines 432 and 492 ( 4 ) with their corresponding nozzles 497 . 499 of the disinfection distributor 494 need to be connected. These compounds provide a flow path for the reverse osmosis water from the dialysate production module 26 that enters the extracorporeal circulation 400 should be initiated because the nozzles 497 . 495 to the lines 289a and 236a ( 2 ) are connected, so that the two modules are connected together. This connection is necessary to perform a number of special extracorporeal circuit functions, which are described below.

Of course, the mentioned temperature of the hot water (80 ° C) and the time indicated with one hour, with the hot water for disinfection in the unit 22 circulating, not the only possible choice. Achieving a high degree of disinfection of the fluid circuits with water generally depends on the water temperature and the duration of the hot water circulation. It can generally be assumed that hotter water requires a shorter circulation time and cooler water a longer time. In practice, a high disinfection temperature is often determined in advance or selected, which then passes through the water heater 228 is controlled in the device and by means of strategically arranged thermistors, while the circulation time by means of a clock in the central processing unit of the control module 25 which simultaneously controls the operation of the pumps and valves of the device.

After completing the disinfection mode, the system starts a sequence 706 for dialysis production, which in 5 is shown in more detail. In step 717 becomes the one in the step above 742 explained process performed. In step 719 becomes the reverse osmosis filter 100 switched to a water production mode. Likewise, the reverse osmosis alarm activates the reverse osmosis conductivity in the cell 106 supervised. The filtered by reverse osmosis water is then in the container 202 directed. The pump 212 is operated at maximum speed in the forward direction. The container 202 is operated in a recirculation continuous mode, in which water through the degassing line 209 , through the valves V9 and 220 from the container 202 out and over the valve 232 , The administration 231 and the valve V15 flows back into the tank. The at the thermistor 230 measured temperature should be about 30 ° C. The ultrafiltration tank 244 is via the ultrafiltration pump 242 charged with about 500 ml of water. The container 202 gets to the level where chemicals enter the container 202 be given, filled with reverse osmosis water. Then the reverse osmosis filter 100 off.

In step 721 the dialysate circuit and the ultrafiltration control system are checked for integrity. After initializing the check, the water level in the tank becomes 202 until the level of the chemical loading platform is raised and the reverse osmosis filter is in an idle mode while the arterial clamp 444 and the venous clamp 490 the extracorporeal circulation 400 are open. The valves of the module 26 are connected so that water from the dialyzer 404 channeled away and the container 202 to be isolated. The fluid lines of the dialysate circuit 402 are completely filled. The fluid circuit is a closed system, with the valves 414 and 416 are closed while the bypass valve 412 is open. In the ultrafiltration tank 244 are still residues of reverse osmosis water. The ultrafiltration pump 242 is operated in reverse to add water to the pipe 240 to pump in the dialysate flow network. This increases the volume of water in the closed system, increasing the pressure. The pressure sensor 410 in the dialysate cycle 402 monitors this pressure increase. A malfunction or the occurrence of leaks in the system may be beyond the rate of pressure drop caused by the sensor 410 is monitored, whereupon an alarm is triggered if necessary. The pressure in the extracorporeal circulation 400 is also monitored and assisted with blood pump 458 slowly reduced.

In step 723 become the pressure sensors 500A -B in the extracorporeal circuit with the pressure sensor 410 calibrated in the dialysate circuit. Pressure variations in the dialyz cycle 402 are achieved by fluid volumes between the container 202 and the ultrafiltration tank 244 are reciprocated, wherein the introduction of fluid into the container 202 causes a pressure increase. Accordingly, the pressure changes in the extracorporeal circulation 400 by introducing additional volumes of fluid via the dialyzer in the extracorporeal circuit conceivable. The calibration test is advantageous because it allows for extracorporeal circulation 400 smaller disposable pressure sensors can be used. It also allows extremely accurate monitoring of blood pressure during dialysis in the extracorporeal circuit 400 , For this purpose, the valves are switched so that fluid from the dialysate side through the dialyzer 404 and the pressure sensor 410 is directed. These valves are connected so that the container 202 isolated from the dialysate flow path. The ultrafiltration pump 242 is operated in reverse, so that fluid from the ultrafiltration tank to the dialyzer 404 and into the extracorporeal circuit, and the dialysate cycle is pressurized to between 400 to 300 mm Hg. If the pressure sensors 500A -B in the extracorporeal circulation 400 show no pressure increase or the pressure drop exceeds a certain limit, an alarm is triggered, indicating that in the extracorporeal circuit 400 a leak has occurred. However, if there is no leak, the readings of the pressure sensor become 410 for calibrating the pressure sensors 500A - 500B in extracorporeal circulation 400 used.

The ultrafiltration pump 242 is operated in the forward direction, wherein fluid from the dialysate 402 is removed and the pressure is stabilized at about 10 mm Hg. Then a second calibration of the pressure sensors 500A . 500B and gain and offset values are determined for the sensors. In the event of a malfunction of the pressure sensor, an alarm is triggered indicating this malfunction. The ultrafiltration pump is operated in the forward direction until a negative pressure is produced, wherein the additional calibration of the pressure sensor is performed. Subsequently, an additional negative pressure is generated and carried out a further calibration. Finally, the ultrafiltration pump 242 operated backwards and the pressure stabilized at about 0 mm Hg. Then the container 202 ventilated.

In step 725 is ensured by means of a pressure drop test, the integrity of the air filter AF. The air filter AF is a sterile membrane barrier which filters all the air entering the fluid flow paths of the device 20 invade or leave. The integrity of the filter is checked by checking that the ultrafiltration tank 244 is filled, the valve V6 is closed and the container 244 via the ultrafiltration pump 242 under a pressure of about 4 Pa (12 psi). The pressure is monitored by means of a safety pressure gauge PUS for the ultrafiltration tank. If the pressure transducer does not indicate sufficient pressure and the pressure drop should be too great, it is assumed that the air filter has failed the integrity test, whereupon the user is alerted and informed that the filter must be replaced.

At step 727 becomes an integrity test of the fibers of the dialyzer 404 performed to ensure that the dialyzer 404 has no leaks. Similar to the ultrafilter / pyrogen filter 234 This test is carried out under atmospheric pressure. To carry out the test, the parenthesis 490 and the valve V14 is closed. Air is using the blood pump 458 from the ultrafiltration tank 244 over the disinfectant distributor 494 into the arterial line 432 pumped, then through the dialyzer 404 to remove any residual fluid through the valve 414 divert up the lumenal side of the dialyzer 404 is substantially free of fluid. The pressure sensor 500B in extracorporeal circulation 400 monitors the pressure of the dialyzer 400 and the pressure drop in the pipe 462 , If the sensor 500B For a long time indicates no adequate pressure, or the pressure drop rate is too large, it is assumed that the extracorporeal circuit failed the test whereby the user is informed of the need to replace the extracorporeal circuit module.

In step 729 becomes the integrity of the pyrogen / ultrafilter 234 tested. This test was discussed above in connection with the description of the dialysate preparation module 26 explained in more detail.

In step 731 becomes the extracorporeal circulation 400 filled with water. The reverse osmosis conductivity and pressure are monitored. The ultrafiltration tank 244 is filled with about 1 liter of water, in addition to the ultrafiltration pump 242 is used. The reverse osmosis filter 100 is then placed in an idle mode. Reverse osmosis water is using the blood pump 458 through the dialyzer 404 from the ultrafiltration tank 244 back into the container 202 promoted. Then water gets through the valve 416 filtered back while the venous clamp 490 is pulsed to the air separation chamber 474 to fill ( 3 ). Valve V13 is pulsed to remove air from the line 432 of the extracorporeal circulatory module. When the ultrafiltration tank 244 is empty, the terminals are 444 and 490 , as well as the blood pump 458 closed.

In step 733 Reverse osmosis water gets out of the container 202 in the dialyzer 404 pumped. The dialyzer 404 is bridged for a short period and then water is poured over the membrane of the dialyzer 404 in the extracorporeal circuit and finally in the container 202 pumped back to the extracorporeal circulation 400 to suck. In these steps, the blood pump 458 operated backward during the bypass and subsequently forward filtered.

In step 735 becomes the extracorporeal circulation 400 rinsed with fresh reverse osmosis water, so that virtually no air or bubbles in the circulation occur more. The automatic prefilling operation can be performed in steps before, during and after dialysis, depending on the most effective and efficient way to meet the requirements for aspiration and dialysis clearance. If it is found that the extracorporeal circulation 400 has a leak, a new extracorporeal circuit is needed immediately. Unacceptable performance of the dialyzer during the clearance test requires replacement of the dialyzer before the next treatment. If the dialyzer becomes blocked during treatment, it will be replaced in the middle of treatment.

In pre-fill mode 735 becomes water with valves closed 412 and 414 and open valves 416 . 232 and V15 through the dialyzer 404 pumped. The lines of the extracorporeal circuit are placed in a recirculation mode with the valve V20 closed. To remove adherent bubbles from the fibers of the dialyzer 404 To remove pressure jumps (or spikes) in the arterial line 432 generated. This happens because the terminals 490 and 444 be opened and closed in rapid succession and the flow direction in the blood pump 458 is varied. The pressure rises in the lines when the clamps are closed and the blood pump 458 continues to pump, and when the clamps are then opened, the sudden pressure drop in the dialyzer wipes 404 the bubbles from the fibers. The valve 416 is also pulsed to produce a back-filtration for stripping the bubbles from the fibers.

In addition, a periodic back-filtering of the water via the dialyzer also contributes to the occurrence 404 at. The back filtration of fluid via the dialyzer is also by the generation of pressure surges in the dialysate 402 accompanied. By the pressure surges when introducing fluid through the membrane causes air bubbles are stripped from the blood side of the dialyzer membrane. The air bubbles are then removed from the blood side of the dialyzer from the extracorporeal circuit 400 over the air line 482 the bubble trap led away. The dialysate is at a high flow rate through the dialysate circuit 402 pumped, wherein a valve in the dialysate circuit is opened and closed to create pressure surges in the fluid. The back filtration can be synchronous to that in the dialysate cycle 402 generated pressure surges done.

The system then starts calibrating the blood pump. Since the section of tubing in the blood pump can undergo a permanent deformation by the heat during the disinfection cycle, the blood pump becomes 458 calibrated prior to each treatment to ensure the correct fluid flow rate for a given rotation rate and fluid pressure of the blood pump. The flow rate is determined by a volume change of the fluid in the ultrafiltration tank 244 determined during the calibration time. The rate of rotation of the blood pump is determined by the speed of the blood pump and directional sensors located above the pressure sensors in the blood tubes. Optionally, a check valve may be required to isolate the line downstream of the valve V14 and the disinfectant manifold on the device side of the nozzle. The fluid flows from the ultrafiltration tank 244 through the valve 236 , the check valve CV12, the valve 220 , The administration 236 to the valve V21 and finally through the valve V14 to the blood pump 458 , The fluid is filtered by the dialyzer and passes over the line 240 back to the dialysate container 202 , The rotation The blood pump rate is set to maintain the inlet pressure of the pump at the specified calibration pressure when the ultrafiltration pump is operating at the set, calibrated flow rate.

In step 737 the reverse osmosis conductivity and pressure are monitored and the dialysate container 202 is filled with reverse osmosis water unless the water level is already above the level of the chemical loading platform 250 , Then the ultrafiltration tank 244 emptied. The water becomes a filter 234 and away from the dialyzer 404 pumped, taking the water through the heater 228 was heated to a temperature of 37 ° C. The return valve V18 of the container is closed and the water is removed from the container 202 through the valve 236 with the help of the ultrafiltration pump 242 in the ultrafiltration tank 244 directed. The ultrafiltration tank 244 will be filled. The return valve V18 of the container is opened.

In step 739 the reverse osmosis conductivity and pressure is monitored and the reverse osmosis water is added to the tank 202 until the intended level for the addition of dialysate chemicals is reached. The powdered chemicals containing bottle 270 is through the chemical applicator 260 Punctured and the chemicals are made by brief, periodic water jolts from the applicator 260 provided nozzle 350 out of the bottle 270 flushed ( 12 the published patent application). The one in the loading platform 250 provided atomizer 285 flushes the chemicals from the plate of the platform 250 in the container 202 , While water through the tank and the outlet 206 circulates, monitors the conductivity sensor 226 the conductivity of the solution. If necessary, additional water can be added to the container 202 are given. The additional dialysis chemicals in the second and third chemical bottles are then activated by operating the chemical applicator 260 into the platform 250 Approved. Liquid chemicals are just before the fluid level is the level of the nozzle 352 in the applicator 260 reached, admitted. The container 202 is then completely filled with water.

In step 741 enters the system in a mixing mode in which the dialysate chemicals in the container 202 be mixed. The mixture takes place by the method described above. During mixed mode, the conductivity sensor monitors 218 the conductivity of the dialysate in the line 206 and supplies the measured values to the central processor 610 , A secured chemical concentration is measured by conductance measurements by the conductivity sensor 426 and / or by taking dialysate samples in the sampler 210 guaranteed. Preferably, the dialysate is during the mixing process from the container outlet via the conductivity sensor 426 and over the atomizer 205 back to the top of the container 202 circulated. If the conductivity of the dialysate has remained constant for a sufficiently long time, one can assume a correct mixture of the solution.

In step 743 a conductivity test is performed, which serves to determine the conductivity in the sensor 426 to check. Dialysate is removed from the container 202 through the ultrafilter 234 and the dialysate cycle 402 via the bypass valve 412 back into the container 202 pumped. If the conductivity readings do not move within a certain range, an alarm is triggered. In addition, the measured values of the thermistors 424 and 408 and an alarm is triggered if the measured values of the dialysate temperature should not be practically identical, indicating a malfunction of one of the thermistors.

In step 745 the clearance test of the dialyzer is performed. Before initiation of dialysis treatment should the integrity of the dialyzer 404 and the diffusion rate through the membrane of the dialyzer can be checked. On average, the extracorporeal circuits 12-15 used again before they have to be thrown away. To determine whether the extracorporeal circuit should be replaced or not, its clearance capability must be tested. According to the invention, the clearance test is performed after the chemicals in the container 202 mixed and the ultrafiltration tank 244 were filled with about 4 liters to a temperature of 37 ± 1 ° C heated reverse osmosis water. The Dialysattempertur is about 30 ° C. The extracorporeal circulation 400 is filled with reverse osmosis water.

The device 22 tests the clearance of the dialyzer 404 by exploiting certain properties of the Na ⁺ ions: Na ⁺ ions are about the same size as urea molecules; Na ⁺ is the dominant cation in a dialysate solution, and solutions with Na ⁺ ions are very conductive, with conductivity being monitored by a conductivity monitor, such as a noninvasive conductivity cell 426 in the dialysate preparation module 26 determined with high precision. The Na ⁺ ion is therefore used as a substitute for urea. The conductivity sensor 426 measures the conductivity of the dialyser 404 coming dialysate.

The blood pump 458 continuously pumps reverse osmosis water through the blood side of the dialyzer 404 (in a single pass). The water flows from the ultrafiltration tank 244 through the valve V13, through the pipe 289 and 289A to the neck 499 of the disinfection distributor 494 ( 3 ) of the extracorporeal circulation 28 , from there into the arteri elle line 432 and through the cycle 400 and the dialyzer 404 from the venous line 492 to the neck 497 of the disinfection distributor 494 and then back to the drain. At the same time the pump is pumping 212 fresh dialysate through the heater 228 where it heats to 37 ± 1 ° C and through the dialysate circuit 402 back into the container 202 is pumped. Upon completion of the clearance mode 745 of the dialyzer remain about 500 ml, 37 ± 1 ° C warm reverse osmosis water in the ultrafiltration tank 244 ,

The conductivity measurements are sent to the central processor 610 of the interface and control module 25 transmitted. The difference in conductivity between an initial condition in which the by-pass valves to the dialyzer are closed and an equilibrium or stability condition in which the by-pass valves are open correlate to the degree of urea clearance of the dialyzer 404 , As in 6 shown, which falls through the conductivity cell 426 measured conductivity when the process is initialized, but soon reaches a stable level at which no further waste takes place. If that through the cell 426 Measured conductivity has reached its constant value, the clearance of the dialyzer 404 in the unit ml of sodium purified per minute by the central processor 610 be calculated. A minimum and maximum conductivity level 759 can for the sensor 426 and if the sensor in a stationary state does not indicate a minimum conductivity below this predetermined level, a failure of the clearance test can be assumed.

In an alternative method for determining whether the dialyzer is to be replaced, the clearance coefficient K of the dialyzer is compared with the value K of the new dialyzer. Let C _in = original conductivity measurement before the test, with closed bypass valves; and C _out = the through the sensor 426 measured conductivity on the outlet side of the dialyzer with open valves. Further, let K _i = [(C _in - C _out) / C _in] x flow rate [in ml / min]. K _init should be the original clearance coefficient of the new dialyzer. Before each dialysis treatment, the value K _i is determined as shown above. If K _i ≤ 0.9 K _init , it can be assumed that the dialyzer should be replaced before the next treatment.

The device performs as a redundant security measure 22 perform the clearance test twice before performing the dialysis. If the dialyzer 404 If the test fails both times, a replacement prompt will be displayed on the user interface informing the user of the need to replace the extracorporeal circuit and dialyzer 404 informed before the next dialysis treatment. The central processor 610 stores the determined uselessness of the dialyzer together with the clearance value and the date on which the error occurred.

In step 747 begins a mixing step, which serves the fluids in the extracorporeal circuit 400 and in the ultrafiltration tank 244 to bring the right conductivity. Dialysate is passed through the ultrafiltration tank 244 circulated at a temperature controlled at 29 ± 2 ° C. After a certain period of time, the conductivity in the ultrafiltration tank becomes stable and an alarm is triggered if the conductivity should be outside of a specified expectancy range. The valves are then switched so that the dialysate from the container 202 through the pyrogen / ultrafilter 234 and the dialyzer 404 is passed through back filtration into the extracorporeal circulation. The Dialysatfluß the extracorporeal circulation is using the blood pump 458 through the disinfectant distributor 494 back into the container 202 directed. If necessary, the fluid level in the container 202 reduced below the valve V6.

A preferred embodiment of the dialysis machine according to the invention 22 has the ability to automatically send treatment reports to a central support or other facility that monitors patient hemodialysis. Depending on the means of communication available, the treatment report can be forwarded during dialysis in real time or after treatment has ended. This can be done by the device 22 for example, having a fax modem connected to a telephone line, the device being programmed to automatically send the fax report of hemodialysis to the fulcrum or other location, for example, to the attending physician's office or to a home computer. The treatment report may include, for example, information such as the patient name, address, telephone number, date and time of the report, weight of the patient before treatment, blood pressure, pulse and temperature, a code for the dialysate used, conductivity measurements and clearance results, information on heparin used, Results of measurements taken regularly during dialysis treatment, such as blood flow rate, dialysate flow rates, arterial pressure, venous pressure, blood pressure, pulse, ultrafiltration rate, total ultrafiltration volume and additional comments. Further information may include, for example, the occurrence of particular events during treatment, for example, if the blood flow has been interrupted, the time of interruption, when the treatment has been continued, and also all the alarm messages that occurred during the treatment. Furthermore, the treatment report Informatio include when the treatment was stopped, how long the entire analysis took, and the KT / V parameters calculated for the treatment. Finally, the treatment report may also include the weight of the patient after the treatment, the post-treatment blood pressure, and the patient's answers to any question of his condition as a result of the post-treatment system. It is also possible to provide weekly overviews of the treatment in numerical and / or graphic form about the body-removed fluid, KT / V and blood pressure. The interface and control module 25 may include an additional data store (eg, a hard disk) to permanently store such information initially present in random access memory (RAM), for example, but at least until the data is later sent to a monitoring center. A printer for printing the treatment report on-site may be another useful accessory for the dialysis machine 22 be.

Preferably, the user interface and control module comprises 25 the dialysis machine 22 also diagnostic and test software that can be accessed via the user interface to the various sensors and components of the dialysis machine 22 to review and change their operating parameters. Ideally, such a diagnostic software, for example via a modem by remote access, so that the device service, if necessary, in a very short time via telephone line query the sensors, error messages and other test data and optionally components of the dialysis machine 22 can adjust. Due to the modular structure of the dialysis machine 22 with the modules 24 . 26 and 28 , Troubleshooting or service of the different modules can be done relatively easily by replacement or replacement.

From the foregoing description it is clear that the method according to the invention, the system components and their subcomponents as well as the flow paths proposed according to the invention can be used for hemofiltration and hemodiafiltration. Hemofiltration with predilution takes place as follows. The outlet of the dialysate container 202 becomes as before also the dialysate filter 234 (Pyrogenic / ultrafilter). The output of the dialysate filter 234 however, now leads to a second depyrogenation filter 404A whose output is via a T-terminal 404T upstream of the blood inlet of the dialyzer 404 in the extracorporeal bloodstream 400 empties. The dialysate line 418 is like in 7 shown, blocked. The principle of closed volume, which allows for the control of ultrafiltration in normal dialysis, is also applied here, so that any in the bloodstream 400 leading solution through the outlet of the dialyzer in the dialysate container 202 is sucked back. The ultrafiltration pump 242 can still be used to remove excess fluid.

In hemofiltration with post-dilution, the procedure largely corresponds to hemofiltration with predilution, but the output of the depyrogenation filter 404A via a T-connection 404T after the blood outlet of the dialyzer 404 is conducted in the bloodstream (see. 8th ).

At the in 9 The hemodiafiltration with predilution is similar to that of hemodiafiltration, with the only difference being that the output of the second depyrogenation filter 404A over the T-connection 404A downstream from the outlet of the dialyzer 404 in the bloodstream 400 empties. In the dialysate line L are a valve 414 and a peristaltic pump 404P arranged. The administration 418 is over the valve 414 open.

Hemodiafiltration with center dilution does not require a second depyrogenation filter. Instead, the ultrafiltration pump 242 used to make ultrapure dialysate in the dialyzer 404 backwash and then remove this excess fluid (see. 25 the published patent DE 196 05 260 A1 ).

In a further embodiment of the device according to the invention, a more concentrated dialysate batch can be prepared, which can then be dosed to the correct dilution during the dialysis treatment with the water obtained via the reverse osmosis. It can be an equal or smaller container 202 be used and also the inventive mixture of chemicals corresponds to the case described above. The preparation of a more concentrated dialysis batch would be particularly useful for longer treatments. The incoming reverse osmosis water is heated and a suitable means is provided to ensure that the concentrated dialysate solution and the inflowing reverse osmosis water are thoroughly mixed. The in-flowing reverse osmosis water can be, for example, by the use of a temperature-controlled mixing valve, as in the water treatment unit 20 to be heated. The means for ensuring that the concentrated dialysate solution and the incoming reverse osmosis water are well mixed are obtainable, for example, by monitoring the conductivity of the solution while concentrating dialysate from the container 202 via the conductivity sensor 226 taken and using the above-described mixing method in the upper tank area such as which enters the container.

From the foregoing description will be apparent to those skilled in numerous other embodiments of the device according to the invention, which will not be described in detail here. As used herein, the terms "modulus" and "unit" are to be understood broadly and encompass a component or group of components that perform a specific function, such as water treatment or dialysate solution manufacture, whether such component or component Group of components physically separated, for example, within a housing, is arranged. Obviously, the selection of the components which make up such a "module" is a matter of the chosen construction of the device according to the invention. For example, in the described embodiment, the dialysate circuit 402 as part of the dialysis production module 26 but it is just as well part of the extracorporeal circuit 28 could be, with suitable connections would be provided in the leading to the dialysate side of the dialyzer lines. The term "pure water" as used in the present specification is understood to mean that impurities have been removed as much as possible. The term should not be limited to a technical or pharmacological definition.

Claims (5)

Procedure for determining if the dialyzer replaces should be, taking the urea clearance of the dialyzer on the Determined sodium clearance by: Containing sodium ions Dialysate through the dialysate side of the dialyzer, which is a membrane having a dialysate and a blood side, circulating, continuous Purified water can flow through the blood side of the dialyzer, wherein the water only passes through the blood side of the dialyzer once the original conductivity of dialysate, the conductivity of the dialysate on the Outlet side measures after the dialysate passed through the dialyzer has been, the sodium clearance coefficient of the dialyzer by means of the conductivity readings of the dialysate calculated, the determined clearance coefficient compared with the predetermined limit, which is 0.9 times the clearance coefficient of the new dialyzer, and the user over the need for an exchange of the dialyzer, when informed the determined clearance coefficient is below the specified limit lies. Method according to claim 1, characterized in that the purified water to a Temperature of 37 +/- 1 ° C warmed before you let it circulate through the blood side of the dialyzer. Method according to one the claims 1 to 2, characterized in that the purified water in a Ultrafiltration tank saved and while the conductivity measurements from the ultrafiltration tank pumped to the dialyzer. Method according to one the claims 1 to 3, wherein the clearance test is performed twice, before passing through a patient's blood during dialysis treatment the dialyzer is passed, whereby the exact calculation of the Ensures dialyzer clearance is. Method according to one the claims 1 to 4, characterized in that by the blood side of the Dialyzer flowed, purified water returned to a dialysate tank becomes.