DE3827527A1 - Method of producing a capillary dialyser and capillary separators - Google Patents

Abstract

In the production of capillary dialysers for haemodialysis with distribution of the casting compound at the ends of the capillary bundle 90 by centrifugation, a displacement liquid 160 which has a higher specific weight than the casting compound and is not miscible or reactive with the latter, is included in the centrifugation process, and this forms a layer into which the ends of the capillary tubes 110 project on the bottom 50 of the cylindrical housing 100. The capillary bundle 90 need not be cut off. The ends of the capillary tubes 110 have no ridges but remain open (Fig. 5). In the production of capillary dialysers the ends of the capillary bundles 90 are sealed relative to the surrounding housing 100 by means of a casting compound 160 which is applied by centrifuging the housing 100 about an axis 140. In order to apply the same amount of casting compound 160 to both ends of the housing 100 to avoid unbalanced masses, the metering aid 200 is provided with two identical metering chambers 250, 260 from which the identical amounts of casting compound 160 present therein can be transferred to the housing 100 of the capillary dialyser via overflows 330, 340 at the start of centrifuging. <IMAGE>

Description

The invention relates to a method of the preamble of claim 1 corresponding Art.

Furthermore, the invention relates to an auxiliary device Preamble of claim 9 corresponding type.

Capillary dialyzers are in various embodiments from the DE-OS 30 39 336, 34 09 000 and 28 51 929 known. They include one cylindrical housing in which a loose cylindrical bundle of, for example, 3 cm diameter made of fine capillary fibers is not. At the head ends of the housing are the connections for the Blood circulation provided. The blood enters at an inlet, flows through the inside of the fibers and leaves the dialyzer at an off leave at the opposite end.

Near the ends, the capillary fibers are in one radially extending layer of, for example, 1 cm thick from a embedded liquid and then solidifying potting compound, which the space between the individual capillaries and the space between the capillary bundle and the inner circumference of the cylindrical Fills the housing completely and seals.  

Inside the potting compounds provided on both ends are radial connections for the dialysis fluid see that is introduced at one end, the space between the capillaries and at the other end again exit. So the capillaries are on one essential Part of its length is washed by the dialysis fluid, see above that there dialysis, d. H. the withdrawal of pollutants from the blood flowing through the capillaries through the Capillary walls into the dialysis fluid can be done.

Care must be taken to ensure that the Circulation of the dialysis fluid and blood circulation stay separated. The tightness of the sealing compound and the compact filling of the around the capillaries remaining cross-section are therefore high requirements deliver. In the manufacture of capillary dialyzers the necessary amounts of liquid at both ends Potting compound introduced and the cylindrical housing, which is about 25 cm to 30 cm in length an axis perpendicular to its axis in rapid Rotation offset, for example at 5000 rpm. Through the the casting compound against the high centrifugal effect this spinning process still closed ends of the Ge driven out and in all gaps except pushed in half of the capillaries. A high arises Pressure that causes the potting compound to capillary tightly encloses and also against the inner circumference of the Ge seals the house. The spinning continues as long as until the potting compound has solidified enough, what either by pure timing of responsive approaches or with the help of heat or radiation. The technique of adding potting compounds to dialyzers is flung by DE-OS 34 09 000 and 34 02 336 known.  

After solidification, the capillary bundle is at the end closed because the capillaries are not exactly to the bottom range and the space between the end the capillaries and the bottom are filled with potting compound and because the casting compound is also less than that when spinning standing pressure a little into the end of the capillaries has penetrated.

To expose the ends of the capillaries, it is common to the housing with the one already in it and already set Capillary bundle in the area of the outer end of the sealing compound layers with a saw or other mechanical Cutting device in a radial plane to the cylinder axis cut off.

Then the ends of the cylindrical Ge housed end caps, the axial in the middle Have connections for the blood circulation.

When the capillary bundle is separated by a mechanical cutting device must be accepted, that part of the capillary cross section through burr formation is closed, be it that with a single capillary a partial occlusion takes place, be it that part the capillaries are completely closed. It suffers the throughput of the capillary dialyzer because of the pressure of the flowing blood cannot be increased significantly.

The high speed when spinning the capillary dialyzer during Introducing and solidifying the casting compound means that even small ones Differences in the amount of casting compound lead to disturbing imbalances. A dose of brin to both ends of the capillary dialyzer quantities of the liquid potting compound by means of metering valves or metering pumping is not possible because the potting compound solidifies what for longer operating times with the metering devices mentioned Malfunctions. Also the effort for such dosing devices considerably.

The invention has for its object the full capillary cross section for the flow of blood in the manufacture of the capillary dialyzer to obtain. This object is represented by the one in claim 1 Invention solved.  

The effect of the invention is that when spinning the Area of the ends of the capillaries is artificially occupied, so that the potting compound cannot penetrate in this area, and that then the cast is canceled again. In this way, the endbe keep the capillaries free of the sealing compound and the otherwise necessary radial separation of the capillaries bundle in a radial plane is unnecessary. There is no mechanical attack on the capillaries by a cutting process and there is therefore no annoying ridge education. The full capillary cross section remains open.

The displacement liquid and the potting compound in their liquid state should not be mutually exclusive influence chemically or physically, but separately stay. Due to the higher specific weight of ver urging fluid pushes it forward when spinning outside and the potting compound remains as a layer on the ver urgent fluid, d. H. with respect to the spin axis stand radially further inside.

The displacement liquid and the potting compound can in a first embodiment of the method simultaneously be filled and flung (claim 2).

The quantities required are simultaneously or successively filled in the ends of the housing and then the housing is rotated, whereby the Centrifugal action of the two liquids over the floor of the housing in two superimposed layers broad.

An alternative embodiment is the subject of Claim 3. This is first by spinning on the Bottom of the case formed a layer on which during the spinning by a suitable device the Ver Casting compound is given up, which then becomes one from the end the layer removed from the capillaries.

The primary displacement fluid is one heavy organic liquid into consideration (claim 4), which remains liquid during the spin cycle and after the  Spin just runs off. What liquid it is acts depends on the chemical nature and the specific Weight of the potting compound.

According to claim 5, it is also possible to Ver pushing fluid to choose at normal temperature is solid and in a liquid state at elevated temperature is introduced. For example, it may be wax act like substances. After skidding and that The solidified displacement solidifies the sealing compound liquid melted away. It is understood that this still substances with a relatively low melting point in Be costumes, whose melting temperature is neither the capillaries nor the sealing compound nor the material of the housing pregnant.

According to claim 6, a displacement liquid can be used, which can be introduced liquid and solidifies when spun, but with a solvent is easily removable. So here is the removal of the displacement liquid after spinning Effect of temperature, but by a dissolution process.

Another option is to use it of a molten metal as a displacement liquid (Claim 7).

Low-melting metals such as lead come here or tin and especially low-melting alloys with such metals, some of which are enamel have points below 100 ° C, which the capillaries, the Ver Do not endanger the casting compound and the housing.

The use of a metal as a displacement liquid has the additional advantage that the layer of ver urgent contactless inductive liquid during spinning can be heated, creating heat in the immediate vicinity Shaft of the potting compound layer is created and in this can pass over, causing the hardening of many types of casting compounds is accelerated.  

Furthermore, the invention is based on the object of an auxiliary metering device to create the purpose that can be derived from the generic term, by means of which is a simple and exact allocation of equal amounts of casting compound at the two ends of the capillary dialyzer and with which longer, trouble-free operating times can be achieved.

This object was achieved by the invention reproduced in claim 9 solved.

The dosing device contains two identical dosing chambers, in which the liquid potting compound is contained in equal amounts. The equality the quantities is due to the symmetrical design of the dosing chambers and the in the horizontal position of the dosing device the same height as the over runs determined. When the dosing device is on the capillary housing dialyzer is placed and this is rotated, so the two amounts of potting compound ge by the centrifugal force driven and get into the outlets or in via the outer overflows the capillary dialyzer housing. The middle overflow web holds the separate the two quantities so that each outlet is exactly the one in the outlet Dosing chamber contained amount of potting compound is supplied.

The dosing chambers are powered by the strong centrifugal almost completely from the casting compound when spinning emptied, so that hardly anything remains, which is in the Dosage aid could solidify. But otherwise also the dosing device is a simple plastic part, which is discarded after one or more uses or can be replaced by another dosing device, with which continues to work while from the first dose auxiliary device the solidifying remnants of the sealing compound be washed out by a solvent.

In principle, the dosing device already works with the features described so far, d. H. if the Both dosing chambers are open at the top. But that would be assume that the acceleration when spinning too next must be very low so the two servings the potting compound not from the open dosing chambers be thrown out.

In order not to have to take this into account, are covers the dosing chambers according to claim 10, d. H. related Lich the longitudinal axis of the dosing device in the circumferential direction closed all around and only at the two axial ends the through the column on the overflow web or the two äus open to our overflows.  

So that in the horizontal spin position of the auxiliary device in the two dosing chambers up to the level of the outer overflows Potting compound is not higher than the top of the overflow web and thus in the first phase of acceleration when expelling the ver casting compound according to the two sides, the distribution is undefined, recommends the design according to claim 11.

An important feature is the subject of claim 12. This Ausge design allows the dosing device to be simply moved from the top to the one in the rotatable holder of the centrifugal capillary plug the analyzer and thereby the holder of the dosing aid device and the fluid connection with the connection piece of the Kapil Manufacture lardialysators, through which the sealing compound in the housing of the Capillary dialyzer is introduced.

Exemplary embodiments of the invention are shown in the drawing.

Fig. 1 shows a longitudinal section through the housing of a capillary dialyzer before the introduction of the sealing compound.

Fig. 2 to 7 in each case 1 the production of the capillary dialyzer show the right end of FIG. Ver in different phases.

FIG. 8 shows a longitudinal section through a metering aid device which is placed on the housing of a capillary dialyzer and is in the centrifugal position.

FIG. 9 shows a view corresponding to FIG. 8 from above.

FIG. 10 shows a cross section along the line III-III in FIG. 8.

Fig. 11 shows a phase of handling the dosing device.

The designated as a whole by 10 in FIG. 1 the housing of the capillary dialyzer consists of a trans parten plastic and comprises a central cylindrical housing part 1, at both ends thereof to short zylin-cylindrical coaxial housing parts 2, 3 Close slightly larger diameter, which at the ends are closed by ver in a radial plane floors 4, 5 and have circumferential radial connections 6, 7 through which the dialysis fluid is passed during operation of the finished capillary dialyzer.

In the housing 10 there is a bundle of thin capillary fibers, designated as a whole by 9 , which are not packed very tightly, but nevertheless essentially fill the clear cross section of the cylindrical part 1 . The capillaries are shown in Fig. 1 by parallel lines, but do not run so evenly in the longitudinal direction in practice. The individual capillaries 11 of the capillary bundle 9 are open at the ends and end at a short distance from the inside of the bases 4 and 5 . The end faces of the capillary bundle 9 are denoted by 12 and 13 respectively. The capillaries 11 consist of a semipermeable organic material.

The housing 10 is fixed in a holder, not shown in Fig. 1, which can be rotated about a perpendicular to the axis of the cylindrical part 1 of the housing through the center of the housing 1 Ge centrifugal axis 14 in the direction of arrow 15 in rotation at considerable speeds .

The centrifugal axis 14 thus passes through the axis of the cylindrical part 1 in the middle of the length of the housing 10th

In the Fig. 2 of the completion of the manufacture of the capillary dialyzer is shown in different phases.

In Fig. 2 there is still no spinning around the spin axis 14th It has been introduced through the port 7 a displacement liquid 16 . In Fig. 3 the closing phase is shown during the spinning, in which the displacement liquid 16 is distributed over the bottom 5 of the housing and forms a layer with a mirror 17 which, according to FIG. 3, is located to the left of the end face 13 of the capillary bundle 9 is. In other words: the ends of the capillaries 11 are all immersed in the layer of the displacement liquid 16 .

The next phase is shown in FIG. 5. The spinning is continued and a liquid potting compound 18 is introduced during the spinning through the connection 7 , which pours out under centrifugal action to form a layer with a mirror or a surface 19 and all the spaces between the capillaries 11 and between the capillary bundle 9 and the Fills the inner circumference 20 of the enlarged housing part 3 . The displacement liquid 16 is specifically heavier than the casting compound 18 and does not mix with it. These properties give the layer structure shown in FIG. 5.

In FIG. 4, an alternative to the Fig. 2 and 3 Ver drive is as shown, are filled in at once at the beginning, that is at a standstill, both the displacement fluid 16 and the potting compound 18th If the housing 10 is then set in rotation about the centrifugal axis 14 , the same state as in FIG. 5 results as it also occurs after the phases shown in FIGS. 2 and 3.

When the spinning continues, the potting compound 18 solidifies, which is indicated in FIG. 6 by the additional hatching. The consolidation can be supported by an external heating, which is represented very schematically by the dashed conductor loop 21 . If the displacement liquid is a molten, low-melting metal, it can also be an inductive conductor loop, by means of which the displacement liquid 16 is heated in order to assist the hardening of the casting compound 18 .

After the phase according to FIG. 6 has ended, the base 5 is separated off and the displacement liquid 16 is removed, as a result of which the openings in the end face 13 of the capillaries 11 are exposed. It is then placed on the housing 10, an end cap 22 with a connection 23 for the blood circulation tight. When the capillary dialyzer is in operation, the blood enters the capillaries 11 from the end chamber 24 formed in front of the end face 13 of the capillary bundle 9 and flows through them lengthways. The left of the potting compound 18 interior of the housing parts 1, 2, 3 outside of the capillaries 11 is flowed through by the dialysis fluid which exits at the circuit 7 .

The whole designated in Fig. 8 with 100 housing of the capillary dialyzer consists of a transparent plastic and comprises a central cylindrical Ge housing part 10 at its two ends short cylindri cal to the housing part 10 coaxial housing parts 20, 30 connect with a slightly larger diameter, the are closed at the ends by extending in a radial plane floors 40, 50 and have circumferential radial connecting pieces 60, 70 through which the dialysis fluid is passed during operation of the finished capillary dialyzer.

In the housing 100 there is a bundle of thin capillary fibers, designated as a whole by 90 , which are not packed very tightly, but nevertheless essentially fill the clear cross section of the cylindrical part 10 . The capillaries 110 are shown in FIG. 8 by parallel lines, but in practice do not run so uniformly in the longitudinal direction. The individual capillaries 110 of the capillary bundle 90 are open at the ends and end at a short distance in front of the inside of the bottoms 40 and 50 . The end faces of the capillary bundle 90 are designated 120 and 130 , respectively. The capillaries 110 consist of a semiper meable organic material.

The housing 100 is fixed in a Fig. 8 not Darge bracket, which can be rotated about a perpendicular to the axis of the cylindrical part 10 of the housing through the center of the housing 10 centrifugal axis 140 in the direction of arrow 150 in rotation with considerable speeds . The centrifugal axis 140 thus passes through the axis of the cylindrical part 10 in the middle of the length of the housing 100 .

To introduce equal amounts of potting compound 100 through the two connecting pieces 60/70 during centrifugation, the metering aid, designated as a whole with 200, is used, which in the exemplary embodiment has a housing 180 made of plastic with a rectangular outline and a rectangular outer cross section, which is aligned with the longer sides extends parallel to the housing 180 of the Ka pillardialysators at least over the distance between the connecting piece 60/70 . When spinning, the connecting pieces 60 point upwards. The dosing device 200 has at the bottom near its ends cylindrical recesses 210/220 with which the dosing device 200 is plugged onto the connecting piece 60, 70 , which thus form the holder for the dosing device. In the recesses 210, 220 open outlets 230, 240 through the potting compound from the interior of the Dosierhilfsge device, the connecting piece 60, 70 is supplied.

Inside the dosing device 200 , two different dosing chambers 250, 260 are formed, the side walls 250 ' and 260' of which have the dashed line in FIG. 9 and which are separated in the middle by an overflow web 300 . The overflow web extends from one side wall 250 ' or 260' to the other and be at the top a narrow gap 270 to the in the embodiment flat bottom 280 of the upper wall 290 of the metering device 200 which forms the ceiling of the metering chambers 250, 260 to a certain extent .

The metering chambers 250, 260 have their greatest depth near the overflow web 300 . Their bottoms 310, 320 rise, starting from the overflow web 300 , steadily, in the exemplary embodiment evenly, to the outside up to overflows 330, 340 which are in the horizontal centrifugal position of the metering device 200 at the same height. Gaps 350, 360 remain between the apexes of the overflows 330, 340 and the underside 280 of the wall 290 . Via the overflows 330, 340 via pouring potting compound, the column 350, 360 led into the outlets 230, 240 . The upper edge of the overflow web 300 is at least as high as the overflows 330, 340 .

The metering device 200 is in the state shown in FIG. 8, ie horizontally and with metering chambers 250, 260 filled with potting compound 160 , placed on the housing 100 , which in turn is located in the holder of the centrifugal device. When accelerating, the still liquid potting compound in the metering chambers 250, 260 is driven outward and flows over the overflows 330, 340 , the outlets 230, 240 and the connecting pieces 60, 70 into the ends of the housing 100 of the capillary dialyzer and then becomes there driven radially outwards and to a capillary 110 tightly surrounding and against the housing 100 sealing layer on the bottoms 40, 50 of the housing 100 ge, which solidifies ver during the spinning process. The dosing device 200 remains on the housing 100 of the capillary dialyzer during the entire spinning process. By spinning practically the entire amount of the potting compound from the metering chambers 250, 260 is driven out. Any residues can be washed out with a solvent.

It is understood that in practice the metering device 200 is composed of several easy-to-form parts and is formed symmetrically to the centrifugal axis 140 , so that unbalances, which are to be avoided at the casting compound, are now caused by the rotating Dosing device 200 occur.

In Fig. 11 the filling of the dosing device 200 with liquid potting compound 160 is indicated. It is supplied at the lower end through a hose or the connecting piece of a container or a mixing device and rises from below through the entire inner volume of the metering device 200 , the gap 270 covering the overlap from the lower metering chamber 260 shown in the illustration to the upper one Dosing chamber 250 allowed. If casting compound appears at the top, the filling is finished. The feed is interrupted and the dosing device is first placed on its back so that the upper wall 290 points downward, and then rotated through 180 ° about the longitudinal axis, the orientation remaining horizontal. This is conveniently done in a suitable device. Excess potting compound 160 then runs out of the outlets 230, 240 until the level of the overflows 330, 340 is reached. In this state, which is shown in Fig. 8, the dosing device 200 is placed on the upright connecting piece 60, 70 of the capillary dialyzer, whereupon the spinning begins.

Claims (12)

1. A method for producing hemodialysis serving capillary dialyzers, which comprise a cylindrical, closed at the ends of the housing and extending in the longitudinal direction of the housing therein and substantially filling capillary bundle, which is sealed at the ends by a solidified potting compound and festge is set, the housing after a successful near the ends insertion of the still liquid potting compound is thrown around its axis at high speed to drive the potting compound against the ends of the housing, characterized in that one opposite the liquid potting compound inert and with this immiscible, compared to the potting compound heavier displacement liquid is thrown in such an amount that the ends of the capillaries are in the displacement liquid in the centrifugal state. 2. The method according to claim 1, characterized in that the displacement supply liquid and the potting compound simultaneously filled and ge to be hurled. 3. The method according to claim 1, characterized in that first the Ver and filled with throwing liquid and spinning the sealing compound can be refilled. 4. The method according to any one of claims 1 to 3, characterized in that as a displacement liquid, a heavy organic liquid is used. 5. The method according to any one of claims 1 to 3, characterized in that as a displacement liquid an easily meltable and after the remeltable substance is used for hardening. 6. The method according to any one of claims 1 to 3, characterized in that as a displacement liquid solidifies when spinning after spinning with a solvent soluble substance is used. 7. The method according to any one of claims 1 to 3, characterized in that a molten metal is used as the displacement liquid becomes.   8. The method according to claim 7, characterized in that the metal is heated inductively during the spin cycle. 9. dosing device for the production of for hemodialysis serve the capillary dialyzers, which comprise a cylindrical, closed at the ends of the housing and extending in the longitudinal direction of the housing in this and it essentially filling capillary bundle, which at the ends by a solidified potting mass is sealed and fixed, the housing after a near-end insertion of the still liquid potting compound is flung at high speed about an axis perpendicular to its axis, going through the center of the housing to the casting compound against the Ver To drive ends of the housing, characterized in that the dosing device 200 comprises an elongated housing 180 which can be placed on the housing 100 of the capillary dialyzer, which at the ends with the insertion openings of the potting compound into the housing 100 of the capillary dialyzer in liquid connectable outlets Sse 230, 240 and which contains in the interior two in the longitudinal direction of the housing 180 one behind the other, separated by an overflow web 300 , overflow web 300 dosing chambers 250, 260 , the bottom 310, 320 of the overflow web 300 rises steadily and at the outer ends are in fluid communication with the respective outlets 230, 240 via overflows 330, 340 of equal height in the horizontal centrifugal position. 10. dosing device according to claim 9, characterized in that the dosing chambers 250, 260 are covered with gaps 270 on the overflow web 300 and 350, 360 at the overflows 330, 340 are covered. 11. dosing device according to claim 9 or 10, characterized in that in the horizontal centrifugal position of the dosing device 200 of the overflow web 300 is at least as high as the overflows 330, 340 . 12. dosing device according to one of claims 9 to 11 for capillary dialyzers with radial connecting piece for the dialysis liquid, characterized in that the dosing device 200 has recesses 210, 220 with which on the lower side in the horizontal centrifugal position around the outlets 230, 240 around it can be plugged onto the connecting pieces 60, 70 of the capillary dialyzer located in the centrifuge.