Patent ID: 12220663

SPECIFIC DESCRIPTION OF THE INVENTION

FIG.1shows an apparatus manufactured according to the invention apparatus for example for exchanging substances between blood and a gas, in particular for oxygenating blood.FIG.1shows an axially elongated housing1with a port1a. This port1ain this embodiment extends radially as a tubular hose-connection fitting from housing1.

A winding core2is inserted into the housing1, here in particular coaxial to the housing1, and has a core opening2a. This core opening2ais an annular gap connected to a hose-connection fitting2b. The winding core2is surrounded by a fiber mat formed by a plurality of joined fiber tubes3, but in this view only a single fiber tube3is shown schematically for clarity. This fiber tube3also is, for the sake of clarity, enlarged and shown at a slight spacing from the core.

At each of axial ends1band1cof the housing1the fiber tubes3are potted in an adhesive body4that also bonds them to the winding core2and to the housing1. The ends1band1cof the housing1are therefore sealed to contain the contents of a chamber5from the outside.

This bonding, which is also called potting in the art, is for example carried out in a centrifuge so that centrifugal forces restrict the adhesive to the axial ends of the housing. The potting or bonding of the fiber tubes3takes place in such a centrifuge for the axial ends1band1caccordingly one after the other, with the end being bonded radially outward of the centrifuge axis.

Manufacture of this type produces the inner chamber5that is delimited axially between the potted ends1band1cand radially between the outer surface of the winding core2and the inner wall surface of the housing1. This chamber5therefore contains the semipermeable fiber tubes3around which the medium flows. It can be seen here that medium supplied through the hose-connection fitting2bof the winding core can enter the chamber5via the core opening2aand then flow s all around all of the fiber tubes of the winding on the outside and after flowing axially through the chamber region5exits through the port1a. The direction of flow is here for example from the chamber opening2ato the port1aand can be reversed.

The axial end of each semipermeable fiber tube3, namely the ends3aand3b, are accessible, and a second medium flows axially through the fiber tubes3, for example in the application as an oxygenator by a gas. This gas can be pumped via an appropriate connection6ain one of two axial end caps6into and out of the interior fiber tubes3.

If necessary, the axial end faces3a,3bof the fiber tubes3are cleared if they get clogged by during potting.

The axial end caps6shown here are identical and each have a central hole6bplugged in the upper cap of the figure, but here is shown in the open state, and that of the lower end cap6the winding core2is fitted with a tapered hose connection2b. In this way, identical axial housing end caps6are used, with the unused hole6bof only one of the end caps closed with an unillustrated plug.

FIG.1shows that the axial spacing between the core opening2aand the port1a, which axially flow is through and which is defined by the length of the chamber area5and by the axial length of the fiber tubes3, so as to define, as it were, the total immersed surface of the fiber tubes3that participates in mass transfer.

FIG.2shows an apparatus according to the invention apparatus that, like the apparatus ofFIG.1, has exactly the same components, i.e. housing, winding core, fiber tubes and end caps.

UnlikeFIG.1, however, the core is shifted during manufacturing according to the invention, to axially move the core opening2a, because here before potting the core2is shifted axially inFIG.2, thereby moving the core opening2aupward further into the interior of the housing1in comparison toFIG.1.

Moving the core opening2afurther into the housing1creates a shorter axial spacing between the core opening2aand the port1aand accordingly also a smaller axial length for flow around the winding formed by the fiber tubes3.

In the manufacture method according to the invention, the manufacture of the apparatus according toFIG.2uses more adhesive4to get a greater fill height at the lower axial end1cof the apparatus. As inFIG.1, inFIG.2the amount of adhesive4to be used when sealing the fiber tubes at the lower end1cof the housing moves the surface4aof the adhesive axially upward in the housing1to raise the core opening2awithout plugging the core opening2awith adhesive.

The invention can provide between the surface4aof the adhesive4and the lower edge of the core opening2aan axial safety spacing, such as 1% to 10% of the spacing between the core opening2aand the lower end face of the end1c.

It can be clearly recognized by the hatching of the adhesive4inFIG.2compared to the adhesive4inFIG.1that the fill height and thus the fill quantity of the adhesive4in the embodiment according toFIG.2is greater than inFIG.1.

In both cases from inside the chamber5viewed areas beyond the core opening2athe adhesive4is excluded from the chamber area5. Consequently both the chamber volume of the chamber5inFIG.2is smaller than inFIG.1as well as the actively active area of the fiber tubes that take part in mass transfer.

It can be seen here that inFIG.2unlike inFIG.1the winding core2projects axially above the upper end face1eof the upper end1b. However, the axial projection above the end face1eis less here than the inner free axial length of the end cap6, so that the projecting end of the winding core2is completely covered by the end cap6.

It can therefore be seen fromFIGS.1and2in comparison that through the simple axial shifting the position of the core opening2aand changing the amount of adhesive4near this core opening2aallows systems with different volumes and the exchange areas to be made with identical components.

FIG.3shows another embodiment of the method or of the apparatus where the winding core2compared to the embodiment inFIGS.1and2is of significantly increased axial length. This ensures that the core opening2ainFIG.3is shifted clearly closer to the port1aduring before sealing and thus provides even significantly smaller sizes for the internal volume of the chamber5or in the case of the active mass transfer surface.

InFIGS.3to6, the fiber tubes are not shown, but also here surround the respective core, as inFIGS.1and2.

Here, too, it can be seen in the comparative consideration ofFIGS.3and4that inFIG.4the amount of adhesive4is greater due to the higher axial position of the core opening2athan inFIG.3. In both figures the surface4aof the facing the interior of the chamber5adhesive is raised to the lower edge of the core opening2a, in particular, however, without the adhesive in the sealing process getting into the core opening2a. Again, a safety spacing as described at the beginning must be observed.

Because of the significantly increased axial length of the winding core2provided at least the projecting axial upper end1bof the winding core2projecting from the housing1can be cut off before a lid6is put on, as indicated schematically by the scissors on the dashed line symbolically above the axial end face1eof the housing1.

Alternatively, however, the invention can also provide that, in use of the housing, end caps6with holes6blarge enough to cover the area of winding core2surround and are sealed thereon, so cutting off is not absolutely necessary so that hereFIGS.3and4also show the axially upper winding core area can projects upward from the end cap6through the opening6b. The invention can provide here that in the hole6bat the lower end, where this hole is in cross section, it surrounds the narrowed hose connection area2bof the winding core2with an additional sealing element.

FIG.5shows a further variant of the method according to the invention in which two nested cores are used. In this embodiment, the here radially outer winding core2has its radial essentially ring-shaped core opening2apointing outward and that core, which in the context of the inventive method is shifted axially, defines the length of the chamber area5. Here, too, the adhesive is 4 is brought up to the lower edge of the core opening2a, so that essentially the axial length of the outer chamber5is defined by the spacing between the opposite and one another assigned surfaces of the adhesive4or the axial spacing between the core opening2aand the port1a.

A further core2′ is provided within the core2, also surrounded by an unillustrated winding of fiber tubes, this core having a core opening2′athat is axially spaced from the core opening2aand that preferably is in this embodiment essentially axially level with the port1a.

The winding core2′ here essentially corresponds to the embodiments of the winding core2ofFIGS.1and2, apart from the position of the core opening.

The method according to the invention here proposes, when comparing the embodiments ofFIGS.5and6, that during manufacture the axial position of the inner winding core2′, as in the various embodiments ofFIGS.5and6, is unchanged, whereas the axial position of the outer winding core2inFIG.6with respect toFIG.5is shifted such that the core opening2aof the outer core2inFIG.6is closer to the port1athan inFIG.5.

This is achieved in that in the case of the procedure as described for the other figures the core2with its core opening2ais pushed further into the housing and then inFIG.6more adhesive is used to attach the fiber tubes to the lower axial end1bof the housing1with one another to glue them to the housing and the cores.

In principle, the inner winding core2′ can move between two maximum positions, like the outer winding core2.

The embodiments ofFIGS.5and6result form two radially nested chamber areas5and5′, the one after the other in the direction of flow from the supplied medium flow through, whereby in these chamber areas5and5′ there are identical or different fiber tubes.

The flow path here will essentially be such that the medium enters through the inlet hose connection2′bof the inner winding core2′ and moves from its core opening2′ainto the inner chamber area5′, thus into the interior of the core2, from whose core opening2ait flows out into the outer chamber area5and flows from there to the outlet port1a.

By shifting the core opening2aof the outer core when performing the method according to the invention, bonding is achieved in that the spacing between the core openings2aand2′aof outer and inner cores can be set variably, which thus affects the mass transfer surfaces of the fiber tubes in the chambers5and5′ has the same effect.

FIG.5shows that the winding core2aprojects downward past the axial end face1eof the housing1, so that according to the invention in which the embodiment ofFIG.5with the higher volume and the larger exchange surface the core2is cut to length in its lower area, whereas in the embodiment ofFIG.6the same external core2with its upper axial end projecting up past the axial end face1eof the housing1has an upper end that can be cut to length, as shown by the schematic cut line.

The also provided end caps, which are shown inFIGS.1to4are not shown inFIGS.5and6, but are basically also used to move gas through the fiber tubes. Here too as in the above-described embodiments, the covers either fit with the larger cross-section of the outer winding core or of the inner connection cross-section of the inner winding core can be adjusted.

All figures make it clear that in spite of the manufacture use of identical components, in particular identical housings and winding cores, apparatuses with different volumes and mass transfer areas can be realized simply by moving the core openings with respect to their axial position and use of different amounts of adhesive4.

FIG.7is a flow diagram for carrying out the method using steps1ato1hof original claim1.

In first step1a, a mat2of fiber tubes is wound around a core2with an outer surface forming at least one core opening2athat has a first medium flowing in or out, as shown inFIG.1.

In following step1b, the winding core2is fitted into an axially extending housing, in particular a cylindrical housing1, preferably arranged coaxially, and having at least one port1afor the inflowing or outflowing medium.

An axial displacement then takes place in step if of the winding core2relative the winding core2surrounded by the fiber-tube winding3and the housing1, whereby an axial spacing between the core opening2aand the port1ais set to a desired value of several possible values. Two setting modes are shown inFIGS.1and2. In these figures the same winding core2has different axial positions relative to the housing1and to the fiber tubes3.

Then in step1c, the axial ends of the housing1are sealed around the fiber tubes3with adhesive4; preference is given to the axial ends1b,1cof the housing1with adhesive4securing the wound fiber tubes3with the core2, one below the other and to the housing1.

Therefore, in this step1c, steps1gand1hare executed, namely according to step1gdepositing adhesive fat the opening to the housing1aat the near side of the housing1and the fiber tubes3and in an area between the axial end face of the housing and the port1aand, according to step1h, putting adhesive the side of the housing1near the core opening2athe fiber tubes3in an area between the axial end face of the housing and the core opening2a, in particular axially up to the core opening2a. TheFIGS.1and2show the final result of the bond for two different axial positions.

According to this, in step1dadhesive is applied between the axial ends1b,1cof the housing1and between at least the fiber tubes3surrounding chamber region5formed between the winding core2and the housing1, so that the core opening2aand the port1acan pass the first medium, in particular blood.

Preferably a second medium, in particular a gas, flows through the fiber tubes3between the axial ends1b,1cof the housing1.