DE102014008546A1 - Haemofiltration device, hose set and its use and method of operating a haemofiltration device - Google Patents

Abstract

The invention relates to a hemofiltration apparatus having a hemofilter (3), a supply line (1) for supplying a blood stream from a patient to the hemofilter (3), and a return line (6) for returning the bloodstream to the patient, upstream of the patient Haemofilters (3) a first addition point for a substituate to the bloodstream is arranged, and wherein downstream of the Haemofilters (3) a second addition point for a substituate to the bloodstream is arranged, and with a feed device for supplying the substituate from a supply (9) to the first and / or to the second addition point, wherein the feed device has a branched hose line (13) with a first line section (10) running from the supply (9) to a branching point and with a first and second line branch extending from the branching point (7, 8), wherein at the first line section (10) a hose pump (11) for conveying de s substituent, and wherein the first leg (7) extends from the branch to the first upstream point of addition, and the second leg (8) extends from the branch to the second downstream point of addition, and is characterized a check valve (18) is arranged in only one of the two line branches (7, 8) of the hose line (13), and in that only in the other of the two line branches (7, 8) of the hose line (13) a shut-off valve (316), in particular, a hose clamp valve is arranged. Furthermore, the invention relates to a hose set for a Haemofiltrationsgerät and its use. Finally, the invention relates to a method for operating a Haemofiltrationsgeräts.

Description

The invention relates to a Haemofiltrationsgerät with a Haemofilter, with a supply line for supplying a blood stream from a patient to the Haemofilter, and a return line for returning the blood stream to the patient, wherein upstream of the Haemofilters a first addition point for a substituate (= substitution liquid) to the Blood stream is provided, and wherein downstream of the Haemofilters a second addition point is provided for a substituate to the bloodstream, and with a supply means for supplying the Substituats from a supply to the first and / or to the second addition point, wherein the supply means is a Y-shaped branched hose having a line extending to a branch point line section and extending from the branch point first and second line branch, wherein on the first line section a hose pump for conveying the substituate is arranged, and wherein the first leg extends from the branch to the first upstream point of addition and the second leg branches from the branch to the second downstream point of addition.

The invention further relates to a hose set for a Haemofiltrationsgerät, consisting of a Y-shaped branched hose of flexible material, and its use.

The invention further relates to a method for operating a haemofiltration device.

Extracorporeal therapies based on the principle of haemofiltration filter out some of the blood, eliminating dissolved urine-containing substances or toxins in the broadest sense while leaving the cellular blood components in the bloodstream. In order not to cause unwanted volume losses, a sterile substituate with a suitable electrolyte composition and with the desired volume is returned to the extracorporeal blood circulation during the treatment. The medically required balancing accuracy in this addition of substituents is mostly achieved by electronic control devices using control and control systems, such as gravimetric or volumetric measuring devices and processor-controlled pumps. If such a therapy method is used in patients with kidney failure, in addition to the elimination of urinary substances and the required volume reduction can be achieved by more liquid withdrawn from the circuit than substituted. Such devices for renal replacement therapy are known as artificial kidney, z. B. from the DE 25 52 304 A1 ,

The delivery of the substituate to the extracorporeal bloodstream may be accomplished downstream of the hemofilter using a standard drip chamber. The filtered blood and the substituate then pass back to the patient via the return line. Since the blood concentrated in the passage through the haemofilter is diluted again behind the filter during this process, this admixing process is referred to as postdilution.

In the course of a mostly several hours, sometimes even several days Haemofiltrationsbehandlung increases because of the filtration of liquid, the percentage of cellular components in the blood. This increase in hematocrit causes an increase in the viscosity of the blood and often leads to a reduction in the effectiveness of the haemofilter or even to complete blockage of the filter membranes. This effect is also referred to as clotting. By using anticoagulant substances, such as. As heparin or citrate solution, the unwanted coagulation effect can indeed be reduced, however, for medical reasons, the anticoagulation so caused can not be increased arbitrarily.

An alternative to post-dilution is the supply of the substituate before the hemofilter. This admixing process is known as predilution. It has advantages and disadvantages compared to classical postdilution. It is advantageous that due to the blood dilution before entering the Haemofilter the Clottingeffekte can be significantly reduced or avoided altogether. The disadvantage is that a large part of the added substituate in the filtration process is immediately lost again. On the one hand, this reduces the effectiveness of the entire filtration process, on the other hand, the treatment costs increase significantly, because a significant increase in the demand for expensive substitutes can arise.

Often medically and technically useful as well as economically viable is a combined procedure that allows both post and predilution. It is usually switched in the course of a longer treatment of initial postdilution from reaching a measurable increased Haematokritwertes or based on experience on predilution.

The simplest form of switching between post and predilution is to manually shut off the typically used tubing of the substituate using temporary shutoff valves, release it from the postdilution port, and connect it to a port intended for predilution. This manual intervention interferes with the operation and poses an additional risk of contamination. In addition, only 100% Postdilution or 100% Predilution can be used with this method become. A short-term change between the operating modes is therefore not possible.

Technical arrangements are also known in which the hose line for the transport of the substituate is divided into two branches in a Y-shape, each leading to the point of addition for mail or for predilution. Several commercially available haemofiltration devices offer such a solution, wherein two peristaltic pumps for the independent, defined liquid transport are connected in the two branch lines after the Y-shaped division. These two peristaltic pumps arranged in the branch lines cause a selectively controllable ratio of post- and predilution, as well as a desired closure of a single one of the line branches or both line branches at standstill.

Another technical option uses only a peristaltic pump in front of the Y-shaped tubing and two separate tubing clamp valves downstream of the manifold for selective closure of one of the two branches after branching. By opening or closing the typically electrically controllable shut-off valves, post or predilution is made possible. Since, in principle, there is the possibility in this embodiment variant of blood flowing through the hose line when the hose clamping valves are open at the same time, check valves must be provided in both line branches. A defined relation of pre- to postdilution with simultaneous opening of both shut-off valves is not possible because the delivery rates in the two transport branches are counter-pressure-dependent and this back pressure is influenced by the changing filter state and the blood flow rate. The synchronization of the opening and closing operations requires careful timing and is fraught with the risk of unwanted pressure spikes. Since the peristaltic pump usually runs continuously, the pressure in the hose increases immediately when the first shut-off valve is already closed and the second shut-off valve is not yet open. Such an arrangement with correspondingly complex pressure sensor and control is z. B. in the US 7,744,553 described.

The object of the invention is to provide a hemofiltration apparatus and a corresponding hose set, which allow a simple and safe switching of the addition of a substituate between pre- and post-dilution. Furthermore, the object of the invention is to provide an improved method for operating a Haemofiltrationsgeräts.

The object is achieved according to the invention by a Haemofiltrationsgerät with a Haemofilter, a supply line for supplying a blood stream from a patient to the Haemofilter, as well as with a return line for returning the blood stream to the patient, upstream of the Haemofilters a first addition site for the substituate the blood stream is arranged, and wherein downstream of the Haemofilters a second addition point for the Substituat is arranged to the bloodstream, and with a supply means for supplying the substituate from a supply to the first and / or the second addition point, wherein the supply means is a Y-shaped branched hose having a line extending to a branch point line section and extending from the branch point first and second line branch, wherein on the first line section a hose pump for conveying the substituate is arranged, and wherein the the first leg extends from the branch to the first point of addition, and wherein the second leg extends from the branch to the second point of addition, which is further developed in that only in one of the two branches a check valve is arranged, and that only in the other of the two Line branches a shut-off valve, in particular a hose clamp valve, is arranged.

In this embodiment of the invention Haemofiltrationsgeräts manual switching to the device is no longer required for switching between pre- and post-dilution. At the same time only one shut-off valve must be switched while the check valve automatically opens or closes by switching the shut-off valve from the open to the closed state and vice versa. The control and sensor effort is low. In addition, the required equipment is reduced, since only one check valve and only one shut-off valve is needed. Compared to embodiments with two peristaltic pumps and a significant reduction in size can be achieved.

For the purposes of the invention, a Y-branched hose line is understood to mean any hose line whose lumen splits from a lumen leading to the branching into two lumens leading away from the branching. The branch may also be T-shaped or asymmetric, without departing from the invention.

In an advantageous development of the invention, an infusion heating is arranged along the first line section of the hose line. This allows the substituate to preheat to body temperature or slightly higher so as to avoid hypothermia of the patient.

In a particularly advantageous embodiment of the invention, the hose in the region of the hose pump and / or the check valve, a higher load capacity, for. B. a higher elasticity than in the remaining hose area. As a result, the hose can be designed to be optimally optimized for the stress in its particularly stressed area, without the entire hose being made of such a material, which is adapted to the stresses required only in regions. The increased elasticity may, for. B. be achieved by the use of a silicone material, a modified PVC material and / or by changing wall thicknesses of the hose. A particularly stressed area is z. B. the impact area of the peristaltic pump. There, the hose must be walkbar and reliably withstand the replacement of the hose set of the sometimes several days of stress. This applies analogously to the Einwirkbereich the shut-off valve, z. B. a pinch valve.

The check valve is designed to be spring-loaded according to a particularly advantageous embodiment of the invention, that is, the closed position is left only after concerns a spring force exceeding the opening force, and the valve automatically returns to the closed position, when the spring force is higher than the applied opening force again. This ensures that the check valve is not unintentionally opened by the back pressure of the substituent flowing through the opened shut-off valve. The spring load is preferably set so that the peristaltic pump can open the check valve with closed shut-off valve against the pressure in the filtration circuit problem-free. Typical opening pressures at which the check valve should open, are z. In the range of 200-500 mbar. The term "spring-loaded" is to be interpreted broadly here. So z. As well as plastic or rubber diaphragms with spring action or lip valves are used with appropriate shape and sufficient bias in a convenient installation structure.

The first leg of the tubing, which is connected to the first addition point, is provided in a preferred embodiment of the invention with the shut-off valve. In this embodiment, the predominant in typical treatment course postdilution is carried out by the preferably in the de-energized state opening shut-off valve, while the rarer predilution takes place through the check valve, which is arranged in the second leg, leading to the second addition point.

In a particularly advantageous embodiment of the invention, the first point of addition and / or the second point of addition are designed as drip chambers. This allows a bubble-free and visually verifiable addition of the substituate.

The object is further achieved by a hose set for a Haemofiltrationsgerät according to one of the embodiments described above, consisting of a Y-shaped branched hose of flexible material, wherein in only one of the line branches behind the Verzeigung the hose, in particular a spring-loaded check valve is arranged.

In a particularly advantageous embodiment of the hose set according to the invention, the first line section of the hose line and / or the line branch, in which the check valve is not arranged, an area with increased strength, z. B. with increased elasticity.

According to a further aspect of the invention, the stated object is achieved by the use of a hose set according to the invention in a Haemofiltrationsgerät.

According to an additional aspect of the invention, the stated object is further achieved by a method for operating a hemofiltration apparatus comprising the steps of providing a hemofiltration apparatus according to the invention, performing haemofiltration with addition of a substituate through the Y-shaped branched tubing at the first addition site or at the second addition point, and switching the addition of the Substituats between the first addition point and the second addition point by opening or closing the shut-off valve.

The invention is explained below with reference to exemplary embodiments, which are illustrated in the schematic drawings. Show it:

1 : a hemofiltration apparatus according to the prior art,

2 another haemofiltration apparatus according to the prior art, and

3 : a hemofiltration device according to the invention.

1 shows a hemofiltration device 100 according to the prior art. A supply line 1 directs a blood flow from the patient, not shown, through a first drip chamber 2 through to a haemofilter 3 , in which unwanted blood components filtered out and a Filtratleitung 4 be dissipated. The purified blood stream is passed through a second drip chamber 5 through and over a return line 6 fed back to the patient.

The transport of the blood stream through the Haemofiltrationsgerät 100 is typically done using a blood pump, not shown here, wherein the blood is removed from a vein and also returned to a vein.

To compensate for the volume removed by filtration, a substituate is added to the bloodstream. This is from a supply 9 via a Y-shaped branched hose line 13 by means of two peristaltic pumps 14 . 15 the first drip chamber 2 or the second drip chamber 5 fed and added there to the bloodstream. The drip chambers 2 . 5 serve the bubble-free mixing and the visual inspection by the treatment staff.

At a first line section 10 the hose line 13 from the stock 9 runs to the branching point, is an infusion heater 12 arranged to preheat the substituate. The infusion heater 12 can z. B. be designed as a biocompatible heat exchanger, infrared radiator or as a hot plate heater bag combination.

A first line branch 7 the hose line 13 leads from the branching point to the first drip chamber 2 , At this first line branch is a first peristaltic pump 15 placed the substituate over the first drip chamber 2 to supply to the bloodstream. The first peristaltic pump 15 is put into service if a predilution is desired, and put out of service if post-dilution is required. When put out of operation first peristaltic pump 15 is the first leg of the line 7 the hose line 13 locked.

A second line branch 8th the hose line 13 leads from the branching point to the second drip chamber 5 , At this second line branch 8th is a second hose pump 14 placed the substituate over the second drip chamber 5 to supply to the bloodstream. The second hose pump 14 will be put into service if post-dilution is desired and put out of service if a pre-dilution is required. When put out of service second peristaltic pump 14 is the second leg 8th the hose line 13 locked.

2 shows another Haemofiltration device 200 according to another prior art, which is similar to the Haemofiltrationsgerät 100 gem. 1 is constructed. A repeated description of the same components is therefore omitted here.

Unlike in the embodiment according to 1 is in the first line section 10 the hose line 13 a hose pump 11 Both in postdilution and in predilution, the promotion of Substituats from the stock 9 causes.

Both in the first leg 7 as well as in the second leg 8th the hose line 13 are shut-off valves 16 . 17 arranged, which to avoid an unwanted bypass flow of the blood on the filter 3 are each carried out with associated check valves. The shut-off valves 16 . 17 Thus, in the opened state, the substituate only leaves in the direction of the drip chambers 2 . 5 flow, but not in the opposite direction.

During operation of the haemofiltration device 200 First, the shut-off valve is used to work with post-dilution 17 closed and the shut-off valve 16 open. The substituate is through the peristaltic pump 11 from the stock 9 through the pipe sections 10 and 8th the hose line 13 to the second drip chamber 5 promoted, where it is mixed with the bloodstream.

If you want to switch to predilution because of an increased hematocrit value, the shut-off valve will be activated 16 closed and the shut-off valve 17 open. The substituate is then passed through the conduit sections 10 and 7 the tubing to the first drip chamber 2 promoted and mixed there with the bloodstream.

Switching the shut-off valves 16 and 17 must be synchronized. If z. B. the shut-off valve 17 open too late after the shut-off valve 16 is already closed, then builds in the tubing between the peristaltic pump 11 and the shut-off valves 16 . 17 a pressure peak, which after opening the shut-off valve 17 on the supply line 1 and the hemofilter 3 acts and damage the Haemofilters 3 can lead. If, however, the shut-off valve 17 opened before the shut-off valve 16 is closed, then both shut-off valves are short term 16 . 17 opened and it can short term a bypass flow through the line branches 7 and 8th at the hemofilter 3 pass by, the first through the shut-off valves 16 . 17 provided check valves is interrupted.

In 3 is a haemofiltration device 300 represented according to the invention. The hemofiltration device 300 again comprises a supply line 1 receiving a blood stream from the patient, not shown, through a first drip chamber 2 to a haemofilter 3 conducts in which unwanted blood components are filtered out and filtered through a filtrate line 4 be dissipated. The purified blood stream is passed through a second drip chamber 5 via a return line 6 fed back to the patient.

The transport of the blood stream through the Haemofiltrationsgerät 300 is again typically done by a separate, not shown, blood pump, wherein the blood is removed from a vein and returned to a vein.

The substituate is from the stock 9 via a Y-shaped branched hose line 13 by means of a peristaltic pump 11 the first drip chamber 2 or the second drip chamber 5 fed and mixed there with the bloodstream.

At the first line section 10 the hose line 13 from the stock 9 runs to the branching point, as already described to the previous figures, an infusion heater 12 arranged to preheat the substituate.

A first line branch 7 the hose line 13 leads from the branching point to the first drip chamber 2 , In this first leg of the line 7 is a check valve 18 arranged. A second line branch 8th the hose line 13 leads from the branching point to the second drip chamber 5 , At this second line branch 8th is a shut-off valve 316 arranged, which in this illustrated embodiment of the invention does not have to have a check function and is therefore designed as a simple hose clamp valve.

The mode of action of this Haemofiltration device according to the invention 300 is as follows:
At the beginning of the Haemofiltrationsbehandlung the blood of the patient has a normal Haematokritwert, so that it can be used because of a low risk of clotting with post-dilution. This is the shut-off valve 316 open. Since this is the predominant operating condition, the shut-off valve is 316 designed as a passively opening valve, which closes when energized.

In this operating state promotes the peristaltic pump 11 the Substituat with low pressure and monitored by a controller, not shown, flow rate through the second leg 8th and the second drip chamber 5 through into the blood flowing back to the patient. Because of the low delivery pressure and because of the same time over the Haemofilter 3 prevailing pressure gradient remains the check valve 18 securely closed. By using a spring-loaded check valve 18 the security against unwanted opening is additionally increased.

Increasing Haematokritwert the blood increases the risk of clotting, so that should be switched from a certain time of post-dilution on predilution. At this time, the shut-off valve 316 closed by energizing.

Since the substituate is no longer through the second leg 8th which can flow through the shut-off valve 316 is closed, builds in the tubing 13 behind the hose pump 11 successively an increasing delivery pressure, z. B. from about 200-500 mbar. This pressure is sufficient to the check valve 18 to open against the spring tension, so that the substituate is now through the first leg of the line 7 the hose line 13 through to the first drip chamber 2 promoted and mixed there with the bloodstream.

This described arrangement is without additional pressure sensor and associated software control. However, the provision of sensors can be done to z. B. provide additional pressure monitoring and safety precautions,

By electrical actuation of the shut-off valve 316 In sufficiently short time intervals, quasisimultaneous predilution and postdilution can also be achieved with a variable duty cycle to each other. Swapping the positions of the check valve 18 and the shut-off valve 316 is possible and may be useful for technical reasons. However, since in practice the postdilution mostly outweighs the predilution in terms of time and volume, the illustrated arrangement is to be preferred for energetic reasons, because the typically electromagnetically actuated shut-off valve 316 consumes no energy in the normally open state and thus generates no loss-related heat.

The advantage of the invention described lies in particular in the special technical simplicity. In particular, only one peristaltic pump is used for dilution control 11 and only one shut-off valve 316 needed as machine components. This has the consequence that the so-equipped Haemofiltrationsgerät 300 can be produced more cost-effectively than conventionally equipped devices due to the reduced number of components. Furthermore, there is a significant weight and volume reduction, which contributes to the desired reduction of the devices. From the omission of a pump segment in the hose line 13 also results in easier handling of the device, as only one pump segment in the associated peristaltic pump 11 whereas in the prior art it was two pump segments. Another advantage is that existing devices that z. B. allow only post-dilution, can be retrofitted in a simple way.

The hose line, which is typically designed as a disposable article, is also technically simpler and thus less expensive. Instead of a second pump segment, only one miniaturized one of the two line branches check valve 18 integrated. Such components are available in the field of medical technology industrial mass products and as inexpensive, sterilizable disposable items.

The dilution control according to the invention has in addition to the previously known arrangements in addition the advantage that they can work independently and thus can be implemented as a separate retrofit unit for such Haemofiltrationsgeräte, which were originally designed only for post-dilution. Since, in particular, the safety-related fluid balance of the devices is not affected, no change in the device software and no control-technical electrical intervention is required. Only the tubing, which is usually designed as a disposable item anyway, must be integrated by integrating the check valve 18 be modified.

LIST OF REFERENCE NUMBERS

1

feed

2, 5

drip chamber

3

haemofilters

4

filtrate

6

Return line

7, 8, 10

Line sections, first and second line branch

9

stock

11, 13, 14

peristaltic pump

12

infusion Heating

13

hose

16, 17, 316

shut-off valve

18

check valve

100, 200, 300

hemofiltration

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 2552304 A1 [0004]
• US 7744553 [0011]

Claims (9)

Haemofiltration device with a Haemofilter ( 3 ), with a supply line ( 1 ) for delivering a blood stream from a patient to the hemofilter ( 3 ), as well as with a return line ( 6 ) for returning the bloodstream to the patient, upstream of the haemofilter ( 3 ) is arranged a first addition site for a Substituat to the bloodstream, and wherein downstream of the Haemofilters ( 3 ) is arranged a second addition site for a substituate to the bloodstream, and with a feed device for supplying the substituate from a supply ( 9 ) to the first and / or the second point of addition, wherein the feed device is a branched hose line ( 13 ) with one of the stock ( 9 ) extending to a branch point first line section ( 10 ) and with a starting from the branch point extending first and second line branch ( 7 . 8th ), wherein at the first line section ( 10 ) a peristaltic pump ( 11 ) is arranged for conveying the substituate, and wherein the first line branch ( 7 ) from the branch to the first upstream addition point, and wherein the second line branch ( 8th ) runs from the branch to the second, downstream addition point, characterized in that only in one of the two line branches ( 7 . 8th ) of the hose line ( 13 ) a check valve ( 18 ) is arranged, and that only in the other of the two line branches ( 7 . 8th ) of the hose line ( 13 ) a shut-off valve ( 316 ), in particular a hose clamp valve, is arranged. Haemofiltration device according to claim 1, characterized in that along the first line section ( 10 ) of the hose line ( 13 ) an infusion heating ( 12 ) is arranged. Haemofiltration device according to one of the preceding claims, characterized in that the hose line ( 13 ) in the area of the peristaltic pump ( 11 ) and / or the shut-off valve ( 316 ) has a higher strength, in particular a higher elasticity than in the remaining hose area. Haemofiltration device according to one of the preceding claims, characterized in that the check valve ( 18 ) is designed spring-loaded. Haemofiltration device according to one of the preceding claims, characterized in that the shut-off valve ( 316 ) in the first line branch ( 7 ) of the hose line ( 13 ), wherein the shut-off valve is preferably designed to energize energized switching, wherein the shut-off valve is further preferably designed so that it is without current in the open position. Haemofiltration device according to one of the preceding claims, characterized in that the first addition point and / or the second addition point as a drip chamber ( 2 . 5 ) is executed or are. Hose set for a Haemofiltrationsgerät according to any one of the preceding claims, consisting of a branching hose line ( 13 ) made of flexible material, wherein the hose line ( 13 ) extending to a branch point first line section ( 10 ) and from the branch point extending first and second line branches ( 7 . 8th ), wherein at the first line section ( 10 ) a peristaltic pump ( 11 ) can be arranged to convey the substituate, and wherein in only in the first or only in the second line branch ( 7 . 8th ) of the hose line ( 13 ) a particular spring-loaded check valve ( 18 ) is arranged. Hose set according to claim 7, characterized in that at least one line region of the hose line ( 13 ), in which the check valve ( 18 ) is not arranged, a higher resistance, in particular a higher elasticity than the rest of the hose region, namely the intended for the action of a peristaltic pump and / or a shut-off valve hose area. Use of a tubing set according to claim 7 or claim 8 in a hemofiltration device.

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