JPS6056499B2 - Ultrafiltration rate regulating device - Google Patents

Description

Detailed Description of the Invention The present invention provides a compact and inexpensive device that can accurately measure and adjust the amount of ultrafiltrate without reducing dialysis efficiency when dialysis and ultrafiltration are performed simultaneously. Regarding an external filtration liquid volume regulating device.

For example, an artificial kidney device used for blood purification uses the principles of dialysis and ultrafiltration to remove waste products and water from the blood. dialysis efficiency is required. That is, if the amount of ultrafiltrate is inaccurately controlled and, for example, a large amount of water is removed too quickly, symptoms such as a drop in blood pressure may occur, and in some cases, death may occur. In addition, if the dialysis efficiency is poor, the removal of waste products tends to be insufficient, and in order to remove the waste products sufficiently, it is necessary to perform dialysis treatment for a long time, which is a burden on the patient.

As a device for accurately controlling the amount of ultrafiltrate, for example, Japanese Patent Application Laid-Open No. 48-76393 has been proposed.

That is, for example, as shown in FIG. 1, a sealed container 8 of a certain capacity is prepared on the dialysate side, and the container is connected to the dialysate inlet 5 and the dialysate outlet 7 to form one closed circulation circuit, Dialysis is performed by circulating the dialysate using a dialysate circulation pump 9 provided in the circuit, and for ultrafiltration, an ultrafiltration pump 11 is used to draw out the ultrafiltrate from an ultrafiltrate outlet 10 that is branched from the circuit. The ultrafiltrate is taken out at a constant rate while measuring the amount of ultrafiltrate. In this method, since the amount of ultrafiltrate in the dialyzer 13 and the amount of dialysate extracted from the ultrafiltrate outlet 10 are equal,
The measuring device 12 can directly measure the amount corresponding to the amount of ultrafiltrate, and therefore the amount of ultrafiltrate can be accurately controlled. However, in this method, the dialysate is circulated and used, so the used dialysate, which has a high waste concentration due to the waste removed from the fluid to be treated, is mixed with fresh dialysate in the closed container 8. For,
There is a drawback that the concentration of waste products in the dialysate increases over time during dialysis, and the difference in concentration between the dialysate and the dialysate decreases over time, resulting in a decrease in dialysis efficiency over time.

An object of the present invention is to provide an overflow control device that does not have such drawbacks and can accurately control the amount of overflow overflow.

Another object of the present invention is to provide a compact and inexpensive ultrafiltration control system that can accurately measure and adjust the ultrafiltration rate without reducing dialysis efficiency when dialysis and ultrafiltration are performed simultaneously. The goal is to provide equipment. The present invention provides (a
(b) a serpentine tube having a switching valve mechanism at both ends; (c) a conduit for forming a closed circulation circuit including the dialysate flow path of the dialyzer and the serpentine tube; (d) a device for circulating the dialysate provided in the middle of the closed circulation circuit; (e) a device for quantitatively extracting the dialysate from the closed circulation circuit; (g) The ratio L/D of the length L of the flexible tube to the inner diameter D is 20 or more. This is an ultra-p overload control device.

One embodiment of the present invention will be explained in more detail using FIG. 2.

The dialysate is supplied from the dialysate inlet 2 of a dialyzer 13 whose interior is divided into a dialysate flow path 3 and a dialysate flow path 6 by a permeable semipermeable membrane 1, and the dialysate is subjected to dialysis treatment at the dialysate outlet. Discharge from 4.

On the other hand, by operating the switching valve mechanisms located at both ends of the flexible pipe 16, the following two circuits including the flexible pipe 16 are formed.

That is, one is a closed circulation system that connects one end of the flexible tube 16 to the dialysate inlet 5 of the dialyzer 13 and the other end of the flexible tube 16 to the dialysate outlet 7, and includes the dialysate flow path 6 and the flexible tube 16. forming a circuit, the other one connects one end of the flexible tube 16 and the dialysate supply conduit 14, and the other end of the flexible tube and the dialysate discharge conduit 1.
5 and supply fresh dialysate into the flexible tube. form a brushing circuit for A dialysate circulation pump 9 is provided in the middle of the closed circulation circuit.

In order to carry out dialysis, the inside is filled with fresh dialysate to form the above-mentioned closed circulation circuit, and the dialysate is pumped through the dialysate circulation 5 pump 9 to the dialyzer 13 through the coiled pipe 16, and then from the dialyzer 13 again. Dialysis is performed by circulating through the flexible tube 16.

At this time, if the used dialysate that has returned to the flexible pipe 16 is again supplied to the dialyzer 13, the dialysis efficiency will be significantly reduced due to the above-mentioned reasons. It is important to prevent this as much as possible. The present invention is L/D2
It is suitably carried out using a flexible tube made of a tube with a diameter of 0 or more, preferably L/D50 or more.

If L/D is too small, used dialysate and fresh dialysate will mix in the spiral tube, and the used dialysate will be supplied to the dialyzer again, resulting in a decrease in dialysis efficiency. In the case of using a flexible tube made of a dialysis tube, the degree of mixing is small, and a decrease in dialysis efficiency can be substantially prevented. Furthermore, if dialysis is continued through the closed circulation circuit, the rate at which used dialysate is supplied to the dialyzer increases over time, resulting in a decrease in dialysis efficiency.

Therefore, before the dialysis efficiency decreases to such an extent that it becomes a substantial problem, the dialysis treatment using the closed circulation circuit is temporarily interrupted, the initial changeover valve mechanisms 18 and 19 are operated, and the brushing circuit is closed. Fresh dialysate is supplied from the dialysate supply conduit 14 from one end of the corrugated tube 16, and the used dialysate in the corrugated tube is discharged from the other end of the corrugated tube 16 through the dialysate discharge conduit 15, replacing the dialysate in the corrugated tube. (hereinafter referred to as brushing) is important. After forming the closed circulation circuit and starting dialysis, the average residence time in the coiled tube = (volume inside the coiled tube /
The present invention is achieved by operating the switching valve mechanism as described above and switching from the closed circulation circuit to the brushing circuit after a time period of 0.8 times or more and 1.2 times or less of the dialysate circulation amount) has elapsed. It can be carried out particularly suitably.

If the above-mentioned time is too short, the fresh dialysate will not be sufficiently utilized and will be discharged, which is uneconomical.If the above-mentioned time is too long, the dialysis efficiency will drop significantly for the reasons mentioned above. Dialysis is performed continuously by sequentially repeating dialysis using a closed circulation circuit and brushing using a brushing circuit. If only one meandering tube is used, dialysis is temporarily interrupted.

In such a case, the brushing time is sufficiently shorter than the dialysis time, preferably 1/5 or less. Furthermore, as shown in FIG. 2, dialysis can be performed continuously by preparing a plurality of flexible tubes and alternately and sequentially repeating dialysis using a closed circulation circuit and brushing using a brushing circuit. In this case, instead of the flexible pipe 16, the switching valve mechanism 20, 2
1 is used. When brushing is performed by forming a brushing circuit, if the brushing is insufficient and a large amount of used dialysate remains in the coiled tube, the dialysis efficiency will decrease during subsequent dialysis.

In the present invention, as in the case of dialysis using a closed circulation circuit as described above, the degree of mixing of the used dialysate to be discharged from the corrugated tube and the fresh dialysate to be supplied within the corrugated tube is small;
Therefore, it is possible to carry out effective and sufficient brushing with a relatively small amount of dialysate.

During brushing, the amount of fresh dialysate supplied is 0.00000000000000000000000000000000000000000000000000000000000000000 Particularly suitable is a range of 1.0 times or more and 15 times or less, preferably 1.0 times or more and 15 times or less.

If the fresh dialysate supply amount is less than the above, brushing will be insufficient and the dialysis efficiency will decrease, and if it exceeds the above range, fresh dialysate will be unnecessarily discharged, which may be uneconomical. Undesirable. Operation of the switching valve mechanism from the closed circulation circuit to the brushing circuit or vice versa is performed using a timer when the dialysate circulation volume and fresh dialysate supply volume are set at constant values and relatively stable. It can be operated by receiving signals from

Alternatively, the operation may be performed in response to a signal generated by measuring or calculating each integrated flow rate value and comparing it with a reference value. On the other hand, an ultrafiltrate extraction port 10 branching from the sealed circulation circuit and an ultrap-permeate amount extraction pump 11 for quantitatively extracting a part of the dialysate in the sealed circuit are further provided, as necessary. A correspondingly provided meter 12 is provided, from which a portion of the dialysate in the closed circulation circuit is quantitatively withdrawn in parallel with the dialysis being carried out in the manner described above.

Since the amount of the extracted liquid is equal to the amount of ultrafiltrate in the dialyzer 22, the amount of the extracted liquid can be accurately measured by the measuring device 12, for example, and the discharge amount of the ultrafiltrate amount extraction pump 11 By setting the flow rate to a constant value or by providing another flow rate adjustment device and setting the flow rate to a constant value, the limit offshore overflow amount can be set with high accuracy. As mentioned above, dialyzer 13 and limit? In order for the amount of liquid to be extracted from the excess liquid amount outlet 10 to be equal, it is necessary that the internal volume of the closed circulation circuit does not change.

Therefore, the flexible tubes 16 and 17 need to have sufficiently high rigidity, and are preferably made of metal or glass. On the other hand, it is also important to ensure that the pressure inside the corrugated tube does not change significantly during dialysis and brushing. Furthermore, even if bubbles are generated in the closed circulation circuit due to vaporization of gas dissolved in the dialysate, the same problem occurs as when the internal volume of the closed circulation circuit changes.

In such a case, it is necessary to provide a degasser in the closed circulation circuit, and in some cases, it is necessary to use dialysate from which a certain amount of dissolved gas has been removed in advance as fresh dialysate for brushing. The apparatus of the present invention having the configuration detailed above has the following excellent features.

(b) The ultrafiltrate volume can be accurately measured, set, and adjusted.

(b) Relatively little decrease in dialysis efficiency.

(c) The amount of dialysate used is relatively small.

(d) Since the closed circulation circuit is constructed using flexible pipes, it is compact and inexpensive.

In order to further clarify the features of (a) and (g) above, examples will be described in more detail.

Example 1 Concentration 0.8m9/C in a storage tank with stirring mechanism
Adjust the urea aqueous solution 37f in c, and use the pump to increase the flow rate to 20
At a rate of 0cc/Min, inner diameter 10.5φ = length 5.8
The dialysate is supplied to the inlet 2 of the dialysate of the apparatus according to the invention shown in FIG. 2, which has two flexible pipes made of metal tubes of 500 mm, and is returned to the storage tank through the outlet 4 of the dialysate.

On the other hand, water is supplied from the dialysate supply conduit 14 at 600cc/min.
dialysis and ultrafiltration were performed. Dialysis fluid circulation rate: 500cc/Minl Ultra-overflow filtrate extraction pump output rate: 10cc/Minl Dialysis time/brushing time per corrugated tube: 1min/1mjn1 When dialysis treatment was performed under the conditions, 265% after the start of dialysis. The urea concentration in the dialysate decreased to 0.3 m9/Cc in minutes. In addition, 30 minutes after the start of dialysis, the entire amount of the ultrapure filtrate removed by the pump 11 is measured using a measuring cylinder (measurement cylinder) 12.
The difference between the value received and weighed and the value measured by measuring the decrease in the amount of the aqueous solution in the storage tank using a scale, that is, the error in the amount of ultrafiltrated liquid was 36 g. Example 2 In the apparatus shown in Fig. 2, the length and inner diameter of two flexible pipes made of Teflon (registered trademark) (polytetrafluoroethylene) plate hoses were varied. Dialysis was carried out under the same conditions as in Example 1.

The time required for the urea concentration in the dialysate to become 0.3 m9/Cc or less was as shown in Table 1. Comparative Example: Instead of the two flexible pipes in the device shown in Figure 2, two pipes with an inner diameter of 5.
4.8w0nφ, length 220T! Dialysis was carried out under the same conditions as in Example 1, using an apparatus equipped with a cylindrical container of Rln.

After starting dialysis, the urea concentration in the dialysate was 0.3Tn.
It decreased to 9/CC.

Furthermore, the error in the amount of permeate in the limit of 36 powders after the start of dialysis was 30 g.

[Brief explanation of the drawing]

FIG. 1 is a system diagram showing an example of a conventional limit offshore overflow liquid amount regulating device, and FIG. 2 is a system diagram showing an embodiment of the present invention. 1: Permeable semipermeable membrane, 2: Dialysate inlet, 3: Dialysate flow path, 4: Dialysate outlet, 5: Dialysate inlet, 6: Dialysate flow path, 7: Dialysate outlet, 8 : Sealed container, 9: Dialysate circulation pump, 10: Ultra-deep filtrate extraction port, 11: Ultra-deep filtrate extraction pump, 12: Measuring device, 13: Dialyzer, 14: Dialysate supply conduit, 15: Dialysate discharge conduit, 16, 17: Serpentine pipe, 18, 19, 20, 21: switching valve mechanism.

Claims (1)

[Scope of Claims] 1 (a) a dialyzer, (b) a flexible tube having a switching valve mechanism at both ends, and (c) forming a closed circulation circuit including a dialysate flow path of the dialyzer and the flexible tube. a conduit for (d
) a device for circulating the dialysate provided in the middle of the closed circulation circuit; (e) a device for quantitatively extracting the dialysate from the closed circulation circuit; and (f) a device provided at one end of the flexible tube. (g) the length L of the flexible pipe;
An ultrafiltration rate regulating device characterized in that the ratio L/D between the inner diameter D and the inner diameter D is 20 or more. 2. The ultrafiltration rate regulating device according to claim 1, which includes a plurality of flexible pipes and is switchable.