AN APPARATUS FOR MEASURING THE CONCENTRATION OF A LOW-MOLECULAR COMPOUND IN A COMPLEX MEDIUM, ESPECIALLY WHOLE BLOOD

Abstract: An arrangement for measuring the concentration of a low-molecular compound in a complex medium, especially whole blood. The arrangement comprises means for the dialysis of the complex medium so as to form a dialyzate on which the measurement is to be carried out, possibly after previous passage of the dialyzate through an enzyme bed (37) for the enzymatic conversion of the low-molecular compound to a more readily measurable compound. The arrangement comprises moreover means for the feed and removal respectively of dialyzing solution and possibly further liquids useful for the measurement. The last mentioned means comprises a single container (1) common to the said liquids divided into at least two separate inner chambers (2, 3, 4, 5) which are provided with suitable connections (13, 16, 19, 22) to be connected to corresponding junctions (11, 14, 17, 20) on the arrangement. The container (1) is preferably manufactured from a flexible or readily foldable material, for example plastics, and is in the shape of a substantially rectangular bag with closed outer periphery and with the interior of the bag divided into the required number of chambers (2, 3, 4, 5) by appropriate welding (6, 7, 8). The bag (1) is preferably made of a transparent material.

Description: TITLE AN ARRANGEMENT FOR MEASURING THE CONCENTRATION OF A LOW-MOLECULAR COMPOUND IN A COMPLEX MEDIUM, ESPECIALLY WHOLE BLOOD TECHNICAL FIELD The present invention in general relates to an arrangement for measuring the concentration of a low-molecular compound in a complex medium. The arrangement comprises means for the dialysis of the complex medium so as to form a dialyzate on which the measurement is to be carried out, possibly after previous passage of the dialyzate through an enzyme bed for the enzymatic conversion of the low-molecular compound to a more readily measurable compound. The arrangement comprises moreover means for the feed and removal respectively of dialyzing solution and possibly further liquids required or suitable for the measurement. The invention relates in particular to an arrangement of the type specified for measuring the concentration of a low-molecular compound in whole blood, especially in connection with a medical treatment. An example of such a compound may be glucose. The invention relates moreover to a container for the feed and removal respectively of dialyzing liquid and at least one further liquid, this container being intended to be used, for example, in connection with the above-mentioned arrangement. BACKGROUND ART An arrangement of the above-mentioned type is known, for example, from US patent 4 229 542. The means for the feed and removal of the said liquids in this known arrangement comprises for every one of the liquids used a separate container provided with suitable connections to be connected to corresponding junctions on the arrangement. Similar arrangements are described also in Swedish patent 402 980 as well as in US patents 4 123 353, 4 240 291 and 4 266 021. These known arrangements too have in common that the said means for the feed and removal respectively of the liquids used comprises a separate container for every one of these liquids. It is an object of the present invention, therefore, to provide an advanced and improved arrangement of the known type, according to which it is not necessary to use separate or individual containers for the liquids used, but where it is sufficient to use a single common container for all the liquids. It is a further object to provide a container for the feed and removal respectively of dialyzing liquid and at least one further liquid, this container being intended to be used, for example, so as to form part of the said arrangement. The object is achieved in accordance with the invention in that the common container forming part of the said arrangement is divided into a number of inner separate chambers depending on the number of liquids which are to be used for the measurement. The connection of these inner chambers to corresponding junctions on the arrangement is achieved in a known manner by means of suitable connections. DISCLOSURE OF INVENTION In accordance with the present invention an arrangement for measuring the concentration of a low-molecular compound in a complex medium, especially whole blood, is provided, this arrangement comprising means for the dialysis of the complex medium so as to form a dialyzate on which the measurement is to be carried out, possibly after previous passage of the dialyzate through an enzyme bed for the enzymatic conversion of the low-molecular compound to a more readily measurable compound in the dialyzate, together with means for the feed and removal respectively of dialyzing solution and at least one further liquid useful for the measurement. The arrangement is characterized in that the lastmentioned means comprises a single container common to the said liquids, divided into at least two separate inner chambers which are provided with suitable connections to be connected to corresponding junctions on the arrangement. The fact that the means for the feed and removal respectively of dialyzing liquid and possibly further liquids useful for the measurement in accordance with the invention comprises a single container common to the said liquids instead of separate containers depending on the number of liquids used, as in the prior art, provides the advantage, among other things, that the arrangement becomes easier to install and at the same time the checking and monitoring of the different liquid volumes is made simpler, since the liquids now can be kept more closely together than previously. In connection with whole blood, for example, one of these inner chambers may be adapted so as to contain dialyzing solution, for example a salt solution customary for conventional haemodialysis, whilst a second chamber may be adapted to contain an anticoagulant liquid, e.g. heparin. The container preferably comprises a third inner chamber which is adapted so as to contain a suitable reagent solution, for example a calibrating solution, in case the measurement is performed with the help of some suitable electrode, such as will be described in the following. In accordance with a further advantageous embodiment of the arrangement in accordance with the invention the container comprises a fourth separate inner chamber, which is adapted for the collection of spent liquid. The container may suitably be manufactured from a flexible or readily foldable material, such as plastics, and be in the shape of a substantially rectangular bag with closed outer periphery and with the interior of the bag divided into the required number of chambers by appropriate welding or bonding of the plastic material in the manner described in more detail in the following. This has the advantage that the bag can be folded to a small packet, with the chambers stacked on top of each other or alongside each other as in a bellows, as a result of which the device as a whole can be made less space-demanding. The bag is made preferably of a transparent material, which has the effect that the monitoring and checking of the liquid volumes enclosed in the different chambers of the bag readily take place by visual means. In accordance with the invention a container for the feed and collection respectively of a dialyzing liquid and at least one further liquid is also provided, this container being intended to be used for example in connection with the arrangement in accordance with the invention described above. The container is characterized in that it is divided into at least two separate inner chambers. Preferably the container in accordance with the invention is divided into four inner chambers by welding, each of these chambers separately being adapted to contain dialyzing liquid, anti-coagulant liquid, e.g. heparin, calibrating liquid; and spent liquid from the three first-mentioned chambers. In this manner a compact and therefore space-saving container for the arrangement described is obtained which consequently can be made to be small in size and easy to install. By adapting the container preferably so that it can be folded along two of its welded zones to a substantially bellows-like packet with the chambers located adjoining one another, the container can be made even more compact and consequently still less space-demanding In accordance with a specially preferred embodiment, holes are provided in the welded zones in such a manner that these holes form two through-going holes which are intended for the suspension of the container in a manner which will be described in more detail. BRIEF DESCRIPTION OF DRAWINGS In the following the invention will be described further with reference to the enclosed drawings, wherein fig. 1 is a block diagram of the arrangement in accordance with a first preferred embodiment, fig. 2 is a block diagram of the arrangement in accordance with a second preferred embodiment, and fig. 3 shows schematically a preferred embodiment of the common container forming part as a component of the arrangement in accordance with fig. 1 and fig 2. BEST MODE OF CARRYING OUT THE INVENTION The arrangement in accordance with the invention shown in fig. 1 is intended chiefly to be used in connection with whole blood for measuring the concentration of glucose and will be described therefore with special reference to this application. In the example shown the arrangement comprises a common container 1 for the liquids which are to be used. The container is in the shape of a rectangular elongated bag with the interior of the bag divided preferably into four separate chambers 2, 3, 4, 5 by means of suitable welding, as indicated at 6, 7, 8. Furthermore, the bag Is made of a flexible plastic material in the form of an extruded flexible tube with the ends closed by welding, as indicated at 9, 10. The first chamber 2 in this example is adapted to contain dialyzing solution, e.g. NaCl, and is connected to a corresponding junction 11 on the arrangement via a conduit 12 and connecting nipple 13. The second chamber 3 is adapted to contain for example heparin or a similar anticoagulant liquid and is connected to a junction 14 on the arrangement via a conduit 15 and connecting nipple 16. The third chamber 4 is adapted to contain a calibrating solution for the measurment and is connected to a corresponding junction 17 on the arrangement via a conduit 18 and connecting nipple 19. The fourth chamber 5 is adapted to collect spent liquid from the chambers 2, 3, 4 and is connected to a corresponding junction 20 on the arrangement via a conduit 21 and a connecting nipple 22. The junctions 11, 14, 17, 20 are preferably arranged in a common junction block 23, as shown. The arrangement moreover comprises in a known manner a dialyzer 24 with inlet side for whole blood connected to a source 25 for the whole blood, for example a patient, via a conduit 26, 27. The outlet side for the whole blood is connected to the source 25 via a return conduit 28 comprising an air-trap 29 and clip 30. The inlet side for dialyzing solution of the dialyzer 24 is connected to the junction 11 via a conduit 31 comprising a pump 32. The outlet side for dialyzing solution is connected in a corresponding manner to the junction 20 via a conduit 33 comprising a valve 34 and a measuring apparatus 35, for example an electrode. As can be seen, the conduit 33 comprises a shunt circuit 36 between the valve 34 and the measuring apparatus 35 with an enzyme bed 37. Since these components in themselves do not constitute any part of the invention, but are well known in the field both with regard to design and to operation, they do not require detailed description here. For further information regarding possible and preferred embodiments of these components, reference is made instead to the aforementioned US patent 4 229 542, where an extensive description of them will be found. The arrangement in accordance with the invention shown in fig. 2 is built up essentially in the same manner as that described above in accordance with fig. 1. The same reference numerals have been used therefore for identical components, but with the addition of the letter "a". The arrangement according to fig. 2 differs, however, from that described according to fig. 1 in that the outlet side of the dialyzer 24a lacks a return conduit for the return of the whole blood to its source 25a. Instead the outlet side is connected to the conduit 33a after the measuring apparatus 35a via a conduit 38a for the collection of the whole blood in the fourth chamber 5 via the junction 20a on the junction block 23a, the conduit 21a and the connecting nipple 22a. In fig. 3 is shown a preferred embodiment of the container for the liquids forming part of the arrangement according to fig. 1 and 2. The same reference numerals as in the two foregoing figures have therefore been used for corresponding components, but with the addition of the letter "b". As can be seen in fig. 3, the bag 1b is preferably folded along the welds 6b and 7b to a bellows-like packet with the chambers 2b, 3b (not shown), 4b and 5b arranged next to one another. The first chamber 2b for dialyzing solution is situated between on the one side the chambers 3b (not shown) for heparin and 4 for calibrating solution and on the other side the chamber 5b for the collection of spent liquid. As shown in fig. 1 (fig. 2) holes 39, 40 (39a, 40a) and 41-44 (41a - 44a) are provided in the welded zones 9 (9a) and 10 (lOa) respectively. If the container is folded in the manner as shown in fig. 3, corresponding holes 39b, 40b and 41b - 44b on the bag 1b will form two through-going holes, one of which, 40b, 42b, 44b, is indicated by broken lines at the top in fig. 3. These two through-going holes 40b, 42b, 44b and 39b, 41b, 43b (not shown) respectively are intended to be used for suspending the bag on suspension hooks (not shown) or the like in the arrangement in accordance with the invention. When the arrangement in accordance with the invention is used for measuring the concentration of glucose in whole blood, the procedure is as follows, with reference to figure 1. In the first place the measuring electrode 35 is calibrated by allowing a calibrating solution of known content of the compound to be measured to flow from the chamber 4 of the bag 1 via connecting nipple 19, conduit 18, junction 17 on the junction block 23 and conduit 39, valve 34 and conduit 33 past the measuring electrode. Having passed the measuring electrode the calibrating solution is collected in the chamber 5 via the continuation of the conduit 33, junction 20 on the junction block 23, conduit 21 and connecting nipple 22. Whole blood is pumped from the source 25 with the help of a pump 40 in conduit 26, 27 through the dialyzer 24 for the diffusion of glucose in the whole blood to the dialyzing solution which in a corresponding manner is pumped with the help of the pump 32 in the conduit 31 from the chamber 2 in the bag 1 via connecting nipple 13, conduit 12 and junction 11 in the junction block 23. To prevent coagulation of the whole blood, heparin is pumped at the same time with the help of a pump 41 in a conduit 42, forming part of the arrangement, connected to the junction 14 on the junction block 23 and the conduits 26, 27 at 43 from the chamber 3 of the bag 1 via the connecting nipple 16 and the conduit 15 connected to the junction 14 on the junction block 23. After passage through the dialyzer 24 the whole blood is returned to the source 25 through the conduit 28 via the air trap 29 and the clip 30. The part of the glucose which has diffused over into the dialyzing solution in the dialyzer 24 is conveyed with this solution out of the dialyzer through conduit 33, enzyme bed 37 via valve 34 and subsequently conduit 36 to the measuring apparatus 35 for measurement. After the measurement, spent dialyzing solution is conducted to the chamber 5 of the bag 1 in the same manner as described above in connection with the calibrating solution. To obtain a reference value for the measurement, the dialyzing solution is pumped at times from the dialyzer 24 directly to the measuring apparatus 35 via the valve 34 without passage through the enzyme bed 37. With the help of the value recorded by the measuring apparatus 35 a measure of the glucose concentration in the whole blood is obtained indirectly through proportionality, as the enzymatic conversion reaction involved in the enzyme bed 37 is known. The arrangement in accordance with figure 2 in principle operates in the same manner as that in fig. 1, the only difference being that the whole blood after passage through the dialyzer 24a is collected in the bag 1a instead of being returned to the source 25a. Thus the whole blood is conducted from the dialyzer 24a to the chamber 5a of the bag la via conduit 38a, conduit 33a, junction 20a on the junction block 23a, conduit 21a and connecting nipple 22a. INDUSTRIAL APPLICABILITY The arrangement in accordance with the invention is usable for measuring the concentration of a low-molecular compound in a complex medium through dialysis of the complex medium so as to form a dialyzate on which the measurement is carried out. The arrangement can be used especially for measuring the concentration of glucose in whole blood, in particular in connection with a medical treatment. The container in accordance with the invention is intended to be used for the feed and removal respectively of liquids. The container is intended especially to be used to form part of the arrangement in accordance with the invention described for the supply and removal respectively of dialyzing liquid and at least one further liquid.

Claims: CLAIMS 1. An arrangement for measuring the concentration of a lowmolecular compound in a complex medium, especially whole blood, this arrangement comprising means for the dialysis of the complex medium so as to form a dialyzate on which the measurement is to be carried out, possibly after previous passage of the dialyzate through an enzyme bed (37; 37a) for the enzymatic conversion of the low-molecular compound to a more readily measurable compound in the dialyzate, together with means for the feed and removal respectively of dialyzing liquid and at least one further liquid useful for the measurement, c h a r a c t e r i z e d in that the lastmentioned means comprises a single container (1; la; 1b) common to the said liquids divided into at least two separate inner chambers (2, 3, 4, 5; 2a, 3a, 4a, 5a; 2b, 3b, 4b, 5b) which are provided with suitable connections (13, 16, 19, 22; 13a, 16a, 19a, 22a; 13b, 16b, 19b, 22b)to be connected to corresponding junctions (11, 14, 17, 20; lia, 14a, 17a, 20a; 11b, 14b, 17b, 20b) on the arrangement. 2. An arrangement in accordance with claim 1, c h a r a c t e r i z e d in that the said container comprises a chamber (2; 2a; 2b) for dialyzing liquid and a chamber (3; 3a; 3b) for anticoagulant liquid, e.g. heparin. 3. An arrangement in accordance with claim 1 or 2, c h a r a c t e r i z e d in that the container (1; la; 1b) comprises a chamber (4; 4a; 4b) for a suitable reagent solution, for example a calibrating solution, in the event of the measurement being carried out with the help of a measuring electrode (35; 35a). 4. An arrangement in accordance with claim 3, c h a r a c t e r i z e d in that the container (1; 1a; 1b) also comprises a chamber (5; 5a; 5b) for the collection of spent liquid from the chambers (2, 3, 4; 2a, 3a, 4a; 2b, 3b, 4b). 5. An arrangement in accordance with claim 4, c h a r a c t e r i z e d in that the container (1; la; 1b) is manufactured from a flexible or readily foldable material, for example plastics, and is in the shape of a substantially rectangular bag with closed outer periphery and with the interior of the bag divided into the required number of chambers (2, 3, 4, 5; 2a, 3a, 4a, 5a; 2b, 3b, 4b, 5b) by appropriate welding (6, 7, 8; 6a, 7a, 8a; 6b, 7b, 8b). 6. An arrangement in accordance with claim 5, c h a r a c t e r i z e d in that the bag (1; la; Ib) is made of a transparent material. 7. A container for the feed and collection respectively of dialyzing liquid and at least one further liquid, this container being intended to be used, for example, in connection with the arrangement defined according to claim 1, c h a r a c t e r i z e d in that the said container (1; la; 1b) is divided into at least two separate inner chambers (2, 3, 4, 5; 2a, 3a, 4a, 5a; 2b, 3b, 4b, 5b) for the said liquids. 8. A container in accordance with claim 7, c h a r a c t e r i z e d in that the container (1; la; 1b) is divided into four inner chambers (2, 3, 4, 5; 2a, 3a, 4a, 5a; 2b, 3b, 4b, 5b) by welding (6, 7, 8, 9, 10; 6a, 7a, 8a, 9a, 10a; 6b, 7b, 8b, 9b, 1Ob). 9. A container in accordance with claim 8, c h a r a c t e r i z e d in that the container (ib) is folded along the welded zones (6b, 7b) to a substantially bellows-like packet with the chambers (2b, 3b, 4b, 5b) arranged next to one another (fig. 3). 10. A container in accordance with claim 9, c h a r a c t e r i z e d in that the welded zones (7b, 9b) comprise holes (39b, 40b, 41b - 44b) which are arranged so as to form two through-going holes (40b, 42b, 44b; 39b, 41b, 43b) for the suspension of the container (1b) on corresponding suspension hooks.

Inventors: CLAREN, JAN SEIVERT, OLSSON, LARS-GORAN, PAULSSON, BENGT GORAN, Olsson, Lars-Göran, Paulsson, Bengt Göran
Applicants: GAMBRO LUNDIA AB
Application year: 1982
Main classification: A61M1
IPC codes: G01N33, A61M1, A61B5