WO2021210563A1

WO2021210563A1 - Dialysis machine and control method

Info

Publication number: WO2021210563A1
Application number: PCT/JP2021/015262
Authority: WO
Inventors: 尋智長尾; 正岡　勝則
Original assignee: 株式会社ジェイ・エム・エス
Priority date: 2020-04-15
Filing date: 2021-04-13
Publication date: 2021-10-21
Also published as: CN115151283A; JP2021168786A; JP7396180B2

Abstract

Provided are a dialysis machine capable of reducing the burden on a patient in accordance with blood circulatory dynamics following infusion of a replenishing fluid, and a water removal control method. A dialysis machine 100 according to the present invention comprises a blood circuit 110, a blood cleaning means 120, a dialysate circuit 130, a circulating blood volume measurement means 140, a replenishing fluid infusion means for infusing replenishing fluid into the blood circuit 110, and a control unit 150 that controls the replenishing fluid infusion means so as to intermittently infuse a prescribed volume of replenishing fluid into the blood circuit 110 at prescribed intervals. When the blood cleaning means 120 is removing water from the blood, the control unit 150 reduces the water removal rate of the blood cleaning means 120 if the rate of reduction in the post-infusion rate of change in replenishing fluid most recently measured by the circulating blood volume measurement means 140 exceeds a first threshold.

Description

Dialysis equipment and control method

The present invention relates to a dialysis machine and a control method using the dialysis machine.

In dialysis treatment, blood is taken out from the patient's arterial side using a pump and sent to a blood purification means such as a dialyzer or hemodiafilter, and the blood from which waste products and excess water have been removed is sent to the patient's vein side. The return is done.
Generally, in dialysis treatment, blood is purified over a period of about 4 hours in one treatment, and as the dialysis time elapses, the blood is purified and excess water in the body is removed. Since this blood purification reduces the amount of circulating blood flowing through the patient's body, it is not uncommon for patients to exhibit symptoms of decreased blood pressure in the latter half of dialysis treatment.

When the circulating blood volume decreases, in a normal biological reaction, the circulating blood volume on the central side is maintained by constricting peripheral blood vessels by the action of the autonomic nerves. In addition, when blood is concentrated by removing water, plasma refilling occurs in which plasma components move from the interstitium into blood vessels due to the difference in osmotic pressure, and the circulating blood volume is maintained. However, depending on the patient, such a biological reaction may not be performed normally, and it may be difficult to continue dialysis treatment due to a decrease in blood pressure.

In the event of such a symptom of decreased blood pressure, in order to rapidly increase the circulating blood volume, measures such as replacement fluid with physiological saline or purified dialysate in the blood are taken. ..
Further, in recent years, in order to prevent the occurrence of a decrease in blood pressure due to a decrease in circulating blood volume due to water removal, in the treatment of hemodialysis (so-called HD) or hemofiltration dialysis (so-called HDF), for example, 150 mL to 200 mL every 30 minutes. A "intermittent replenishment type hemodialysis filtration method" has been proposed in which the replenishment solution is repeatedly carried out and the water equivalent to the replenishment solution is added to the original amount of water removal to remove water (see Non-Patent Document 1 and Non-Patent Document 2).

As described above, while it is possible to suppress the occurrence of a decrease in blood pressure by systematically performing fluid replacement during dialysis treatment, the amount of water increased by the replacement fluid is added to the original amount of water to be removed to remove water, so no replacement fluid is involved. The rate of water removal is increased compared to dialysis treatment. Since the circulatory dynamics of blood during dialysis treatment (circulating blood volume, plasma refill rate, etc.) differ from patient to patient, if water is removed at an increased water removal rate, the rate of change in circulating blood volume may decrease significantly. There is a risk of burdening the patient.

Therefore, an object of the present invention is to provide a dialysis apparatus capable of reducing the burden on the patient and a method for controlling the water removal rate according to the circulatory dynamics of blood after injection of the replacement solution.

The present invention is a blood circuit, a blood purification means arranged in the blood circuit and capable of removing water in the blood, and a dialysate connected to the blood purification means to introduce and derive a dialysate into the blood purification means. A circuit, a measuring means for measuring the rate of change of the circulating blood volume, a replenisher injection means for injecting a replenisher for recovering the circulating blood volume decreased by water removal into the blood circuit, and a predetermined blood circuit. A dialysis apparatus including a control unit that controls the replenisher injection means so as to intermittently inject a predetermined amount of the replenisher solution at intervals. The control unit is a water content in blood by the blood purification means. When the rate of decrease of the rate of change after the completion of injection of the latest replenisher measured by the measuring means exceeds the first threshold value, the dialysis apparatus that reduces the rate of water removal of the blood purification means. Regarding. The rate of change in circulating blood volume may be determined by measuring the hematocrit value. Then, it is possible to control the blood purification process in the same manner as the circulating blood volume by using the change in the hematocrit value (for example, the rate of increase) as an index.

Further, it is preferable that the blood purification means and the dialysate circuit are used as the replenisher injection means, and the dialysate that is back-filtered by the blood purification means is used as the replenisher.

Further, the present invention is connected to a blood circuit, a blood purification means arranged in the blood circuit and capable of removing water in the blood, and the blood purification means, and introduces and derives a dialysate into the blood purification means. The dialysate circuit, the measuring means for measuring the rate of change of the circulating blood volume, the replenisher injection means for injecting the replenisher for recovering the circulating blood volume decreased by water removal into the blood circuit, and the blood circuit. A method for controlling a water removal rate using a dialysis apparatus including a control unit for controlling the replenisher solution injection means so as to intermittently inject a predetermined amount of the replenisher solution at predetermined intervals. The rate of decrease of the rate of change after the injection of the latest replenisher is calculated using the rate of change measured in, and when the calculated rate of decrease of the rate of change exceeds the first threshold value, the blood purification The present invention relates to a control method for reducing the water removal rate of the means.

Further, the first threshold value is preferably 2% / min.

Further, when the rate of decrease of the rate of change after the completion of injection of the latest replenisher measured by the measuring means after reducing the rate of water removal of the blood purification means is less than the second threshold value, it is described. It is preferable to return the water removal rate of the blood purification means to the speed before the decrease.

Further, the second threshold value is preferably 1% / min.

Further, when the water removal rate of the blood purification means is reduced, it is preferable to control to reduce the injection amount of the next replenisher and / or to extend the injection interval.

According to the present invention, the burden on the patient can be reduced according to the movement of the circulating body of blood by controlling the water removal rate according to the rate of decrease in the rate of change in the circulating blood volume.

It is a figure which shows the schematic structure of the dialysis apparatus. It is a figure which shows the dialysis process performed by a dialysis machine. It is a figure which shows the fluid replacement process performed by a dialysis machine. It is a figure which shows the rate of change of the circulating blood volume at the time of performing fluid replacement during dialysis. It is a flowchart for demonstrating the flow of the dialysis treatment of this invention. It is a flowchart for demonstrating the control method of the water removal rate of this invention.

Hereinafter, preferred embodiments of the dialysis machine and the control method of the present invention will be described with reference to the drawings.
The control method of the present invention can be applied when supplementation is intermittently performed during dialysis treatment such as hemodialysis (so-called HD) or hemodiafiltration (so-called HDF). As an application example of the present invention, a case where intermittent replenishment type hemodiafiltration is performed by using a back-filtered dialysate to intermittently replenish the fluid will be described.

As shown in FIG. 1, the dialysis apparatus 100 controls a blood circuit 110 for flowing blood, a blood purification means 120, a dialysate circuit 130, and a circulating blood volume measuring means 140 arranged in the blood circuit 110. A unit 150 is provided.

The blood circuit 110 has an arterial side line 111, a venous side line 112, a drug line 113, and a priming fluid discharge line 114. The arterial side line 111, the venous side line 112, the drug line 113, and the priming liquid discharge line 114 are all mainly composed of a flexible and soft tube through which a liquid can flow.

One end of the arterial line 111 is connected to the blood inlet 122a of the blood purification means 120, which will be described later. An arterial side connection portion 111a, an arterial side bubble detector 111b, a blood pump 111c, and a circulating blood volume measuring means 140 are arranged on the arterial side line 111.
The arterial side connecting portion 111a is arranged on the other end side of the arterial side line 111. A needle that punctures the patient's blood vessel is connected to the arterial connection portion 111a.
The arterial bubble detector 111b detects the presence or absence of bubbles in the tube.
The blood pump 111c is arranged downstream of the arterial bubble detector 111b in the arterial line 111. The blood pump 111c delivers a liquid such as blood or priming fluid inside the arterial line 111 by squeezing the tube constituting the arterial line 111 with a roller.

One end of the venous line 112 is connected to the blood outlet 122b of the blood purification means 120, which will be described later. The venous side connection portion 112a, the venous side bubble detector 112b, the drip chamber 112c, and the venous side clamp 112d are arranged on the venous side line 112.
The venous side connecting portion 112a is arranged on the other end side of the venous side line 112. A needle that punctures the patient's blood vessel is connected to the venous side connection portion 112a.
The venous air bubble detector 112b detects the presence or absence of air bubbles in the tube.
The drip chamber 112c is arranged on the upstream side of the vein side bubble detector 112b. The drip chamber 112c stores a certain amount of blood in order to remove air bubbles, coagulated thrombi / clots, etc. mixed in the venous side line 112, and to measure venous pressure.
The venous side clamp 112d is arranged on the downstream side of the venous side bubble detector 112b. The venous side clamp 112d is controlled according to the result of detecting air bubbles by the venous side air bubble detector 112b, and opens and closes the flow path of the venous side line 112.

The drug line 113 supplies the drug required during hemodialysis to the arterial side line 111. One end of the drug line 113 is connected to the drug solution pump 113a for delivering the drug, and the other end is connected to the arterial line 111. Further, the drug line 113 is provided with a clamping means (not shown), and the flow path is closed by the clamping means except when the drug is injected. In the present embodiment, the other end side of the drug line 113 is connected to the upstream side of the circulating blood volume measuring means 140 in the arterial side line 122.

The priming liquid discharge line 114 is connected to the drip chamber 112c. A priming liquid discharge line clamp 114a is arranged on the priming liquid discharge line 114. The priming liquid discharge line 114 is a line for draining the priming liquid in the priming step described later.

The blood purification means 120 includes a container body 121 formed in a tubular shape and a dialysis membrane (not shown) housed inside the container body 121, and the inside of the container body 121 is made of blood by the dialysis membrane. It is divided into a side flow path and a dialysate side flow path (neither is shown). The container body 121 is formed with a blood inlet 122a and a blood outlet 122b communicating with the blood circuit 110, and a dialysate inlet 123a and a dialysate outlet 123b communicating with the dialysate circuit 130.

According to the above blood circuit 110 and blood purification means 120, the blood taken out from the artery of the subject (dialysis patient) flows through the arterial side line 111 by the blood pump 111c and flows through the blood side flow path of the blood purification means 120. Introduced in. The blood introduced into the blood purification means 120 is purified by the dialysate flowing through the dialysate circuit 130 described later via the dialysate membrane. The blood purified by the blood purification means 120 passes through the vein side line 112 and is returned to the vein of the subject.

In the present embodiment, the dialysate circuit 130 is composed of a so-called closed capacity control type dialysate circuit 130. The dialysate circuit 130 includes a dialysate supply line 131a, a dialysate drainage line 131b, a dialysate introduction line 132a, a dialysate lead-out line 132b, and a dialysate delivery unit 133.

The dialysate delivery unit 133 includes a dialysate chamber 1331, a bypass line 1332, and a water removal / reverse filtration pump 1333.
The dialysate chamber 1331 is composed of a hard container capable of accommodating a constant volume (for example, 300 ml to 500 ml) of dialysate, and the inside of the container is formed by a soft diaphragm (diaphragm) to provide a liquid feed accommodating portion 1331a and drainage. It is partitioned into the accommodating portion 1331b.
The bypass line 1332 connects the dialysate lead-out line 132b and the dialysate drainage line 131b.

The water removal / reverse filtration pump 1333 is arranged on the bypass line 1332. The water removal / reverse filtration pump 1333 has a direction in which the dialysate inside the bypass line 1332 is circulated to the dialysate drainage line 131b side (water removal direction) and a direction in which the dialysate is circulated to the dialysate discharge line 132b side (back filtration direction). It is composed of a pump that is driven so that the liquid can be sent to the dialysis machine.

The dialysate supply line 131a is connected to the dialysate supply device (not shown) at the proximal end side and to the dialysate chamber 1331 at the distal end side. The dialysate supply line 131a supplies the dialysate to the fluid delivery accommodating portion 1331a of the dialysate chamber 1331.

The dialysate introduction line 132a connects the dialysate chamber 1331 and the dialysate introduction port 123a of the blood purification means 120, and dialysates the dialysate contained in the liquid delivery accommodating portion 1331a of the dialysate chamber 1331 to the blood purification means 120. Introduce into the liquid side flow path.

The dialysate lead-out line 132b connects the dialysate outlet 123b of the blood purification means 120 and the dialysate chamber 1331, and leads the dialysate discharged from the blood purification means 120 to the drainage accommodating portion 1331b of the dialysate chamber 1331. do.

The base end side of the dialysate drainage line 131b is connected to the dialysate chamber 1331, and the dialysate drainage stored in the drainage storage unit 1331b is discharged.

According to the above dialysate circuit 130, by partitioning the inside of the hard container constituting the dialysate chamber 1331 with a soft diaphragm (diaphragm), the amount of dialysate derived from the dialysate chamber 1331 (liquid feeding accommodation). The amount of dialysate supplied to section 1331a) and the amount of drainage collected in the dialysate chamber 1331 (drainage accommodating section 1331b) can be made equal.
As a result, when the water removal / reverse filtration pump 1333 is stopped, the flow rate of the dialysate introduced into the blood purification means 120 and the amount of the dialysate (drainage) derived from the blood purification means 120 are the same. Can be done.

Further, when the water removal / reverse filtration pump 1333 is driven so as to send the liquid in the reverse filtration direction, a part of the drainage discharged from the dialysate chamber 1331 passes through the bypass line 1332 and the dialysate lead-out line 132b. It passes through and is collected again in the dialysate chamber 1331. Therefore, the amount of dialysate derived from the blood purification means 120 is the amount of dialysate collected in the dialysate chamber 1331 (that is, the amount of dialysate flowing through the dialysate introduction line 132a), and the amount of dialysate flowing through the bypass line 1332. The amount is obtained by subtracting the amount of liquid. As a result, the amount of dialysate derived from the blood purification means 120 flows through the dialysate introduction line 132a by the amount of dialysate (drainage) collected again in the dialysate chamber 1331 through the bypass line 1332. It will be less than the flow rate of dialysate. That is, when the water removal / back filtration pump 1333 is driven so as to send the liquid in the back filtration direction, a predetermined amount of dialysate is injected (back filtration) into the blood circuit 110 in the blood purification means 120 (FIG. 3).

As described above, in the present embodiment, the blood purification means 120 and the dialysate circuit 130 (water removal / reverse filtration pump 1333) are used as the replenisher injection means, and the back-filtered dialysate is used as the replenisher. In other words, the dialysate as the replenisher is injected from the dialysate circuit 130 into the blood circuit 110 via the blood purification means 120 by driving the water removal / backfiltration pump 1333 in the backfiltration direction. A replenisher line may be connected to the blood circuit 110 to serve as a replenisher injection means, and physiological saline or the like may be used as the replenisher. Further, a replenisher line provided with a replenisher pump may be connected from the dialysate introduction line 132a to the arterial side line 111 or the vein side line 112 to serve as a replenisher solution injection means, and the dialysate may be used as the replenisher solution.

On the other hand, when the water removal / reverse filtration pump 1333 is driven to send the liquid in the water removal direction, the amount of dialysate flowing through the dialysate lead-out line 132b is the dialysate collected in the dialysate chamber 1331. (That is, the amount of dialysate flowing through the dialysate introduction line 132a) plus the amount of dialysate flowing through the bypass line 1332. As a result, the amount of dialysate flowing through the dialysate lead-out line 132b is the same as the amount of dialysate (drainage) discharged to the dialysate drainage line 131b through the bypass line 1332. It will be larger than the amount of dialysate in circulation. That is, when the water removal / reverse filtration pump 1333 is driven so as to send the liquid in the water removal direction, the blood purification means 120 removes a predetermined amount of water from the blood (see FIG. 2).

The circulating blood volume measuring means 140 is a sensor that measures the hematocrit value of blood flowing in the blood circuit 110. For example, the hematocrit value can be measured based on the light transmittance of blood obtained by irradiating blood with near infrared rays. The rate of change in the circulating blood volume in the patient's body can be calculated based on the hematocrit value measured over time by the circulating blood volume measuring means 140. As shown in FIG. 1, the circulating blood volume measuring means 140 is located on the downstream side of the blood pump 111c in the arterial side line 111 and on the blood purifying means 120 so as not to be affected by the water removal and fluid replacement by the blood purifying means 120. It is located on the upstream side.

The control unit 150 is composed of an information processing device (computer), and controls the operation of the dialysis machine 100 by executing a control program. In addition, the control unit 150 calculates the rate of change in the circulating blood volume based on the hematocrit value measured by the circulating blood volume measuring means 140. In addition, the control unit 150 calculates the rate of decrease in the rate of change in the circulating blood volume after the injection of the replacement fluid is completed.
Specifically, the control unit 150 controls the operations of various pumps, clamps, and the like arranged in the blood circuit 110 and the dialysate circuit 130, and performs various steps performed by the dialyzer 100, such as a priming step and a removal step. Perform blood steps, dialysis steps, replenishment steps, blood return steps, etc.

Various processes will be briefly described with reference to FIGS. 2 and 3.
In the priming step, the blood circuit 110 and the blood purification means 120 are washed and cleaned using a back-filtration dialysate as the priming liquid.
In the blood removal step, the patient's blood is aspirated to fill the arterial line 111 and the venous line 112 with blood. After the blood removal step, a dialysis step is performed to purify the blood and remove water (see FIG. 2). In the dialysis process, excess water of the patient is removed, and the amount of replacement fluid recovered is also removed.
The fluid replacement process is intermittently performed in the middle of the dialysis process (see FIG. 3). After the dialysis process is completed, a blood return process is performed to return the blood to the patient.

Among the various steps performed by the dialysis apparatus 100, the dialysis step and the fluid replacement step related to the change in the circulating blood volume will be described in detail below.

The dialysis process will be described with reference to FIG.
In the dialysis step, the patient's blood introduced from the arterial connection 111a is purified by the blood purification means 120 through the arterial line 111 and returned to the patient from the venous connection 112a through the venous line 112. ..

In the dialysis step, as shown in FIG. 2, the arterial side connection portion 111a and the venous side connection portion 112a are respectively connected to the needle punctured in the patient's blood vessel, and the priming fluid discharge line clamp 114a is closed. State, the venous side clamp 112d is in the open state.

The dialysate supply device (not shown) supplies and discharges dialysate to the dialysate chamber 1331 at an average liquid feed rate of 500 ml / min, and feeds the water removal / reverse filtration pump 1333 in the water removal direction. To operate. By setting the feed rate of the water removal / reverse filtration pump 1333 to 10 ml / min as an example, the blood purification means 120 removes water at 10 ml / min.
The blood pump 111c gradually increases the flow rate from 40 to 50 ml / min at the start of the dialysis process to, for example, about 200 ml / min, and discharges blood from the arterial side connection portion 111a side to the blood purification means 120 side.
Blood flows into the blood purification means 120 at a flow rate of 200 ml / min from the blood inlet 122a, is drained at a flow rate of 10 ml / min, and is drawn out from the blood outlet 122b at a flow rate of 190 ml / min. Further, the dialysate drainage is led out from the dialysate outlet 123b.
In this way, water is gradually removed from the blood in the dialysis step, and the circulating blood volume is gradually reduced accordingly.

Next, the fluid replacement step will be described with reference to FIG.
The fluid replacement step is a step of injecting a reverse filtration dialysate into the blood circuit 110, and in the present embodiment, it is intermittent at predetermined intervals in order to prevent a decrease in blood pressure due to a decrease in circulating blood volume due to water removal. It is done in.

In the fluid replenishment step, as shown in FIG. 3, the arterial side connection portion 111a and the venous side connection portion 112a are each connected to the needle punctured in the blood vessel of the patient as in the dialysis step, and the priming fluid discharge line. The dialysis clamp 114a is in the closed state, and the vein side clamp 112d is in the open state.

The dialysate supply device (not shown) supplies and discharges dialysate to the dialysate chamber 1331 at an average flow rate of 500 ml / min, and sends the water removal / reverse filtration pump 1333 in the reverse filtration direction. To operate. For example, in the case of performing 200 ml of fluid replacement, by setting the feed rate of the water removal / reverse filtration pump 1333 to 150 ml / min as an example, the blood purification means 120 can perform the fluid replacement of 150 ml / min in about 80 seconds. It is said.
The blood pump 111c gradually reduces the flow rate from 200 ml / min to about 50 ml / min during the dialysis process, and discharges blood from the arterial side connection portion 111a side to the blood purification means 120 side.
Blood flows into the blood purification means 120 at a flow rate of 50 ml / min from the blood inlet 122a, the reverse filtration dialysate is replenished at a flow rate of 150 ml / min, and 200 ml of diluted blood is supplied from the blood outlet 122b. Derived at a flow rate of / min. In this way, the dialysate is rapidly replenished into the blood in about 80 seconds in the fluid replacement step.

Next, a specific method for controlling the water removal rate in the present embodiment will be described with reference to FIGS. 4 and 5.

First, the effect of intermittent fluid replacement will be briefly described.
During dialysis treatment, water (plasma) in the blood is removed as the water removal progresses, and the circulating blood volume decreases. When the circulating blood volume decreases and the protein concentration in the blood rises, water (plasma) gradually moves from the interstitium to the inside of the blood vessel due to the difference in osmotic pressure between the inside and outside of the blood vessel (interstitium) ( Plasma refilling), circulating blood volume is restored and blood vessels are maintained. However, when the rate of plasma refilling cannot keep up with the rate of water removal and the circulating blood volume decreases and the blood pressure decreases, the biological reaction that attempts to maintain the blood pressure by constricting peripheral blood vessels by the action of the autonomic nerves. Occurs. Due to the contraction of peripheral blood vessels in this way, the rate of plasma refilling decreases, the rate of plasma refilling is significantly lower than the rate of water removal, the rate of decrease in circulating blood volume increases, and the blood pressure drops sharply. Invite.

In order to prevent such a rapid decrease in blood pressure, fluid replacement is performed intermittently. By performing dialysis while restoring blood circulation by performing fluid replacement, a decrease in blood pressure is prevented, peripheral circulation is improved, and the rate of plasma refilling is maintained. As a result, the rate of decrease in the circulating blood volume after the completion of dialysis can be reduced even at the same water removal rate (excluding the amount of fluid replacement) as compared with the case where fluid replacement is not performed. The increase in the circulating blood volume due to the implementation of the replacement fluid is removed by increasing the water removal rate of the blood purification means 120 from the start to the end of dialysis. Therefore, the total amount of water removed is the sum of the patient's excess water (body weight removal) and the amount of fluid replacement recovered.
INDUSTRIAL APPLICABILITY The present invention makes it possible to carry out a dialysis process in which the burden on the patient is reduced by appropriately controlling the water removal rate after injecting the replacement fluid while obtaining the above-mentioned effects by carrying out the replacement fluid.

Next, the transition of the rate of change in the circulating blood volume when the fluid replacement is performed under general conditions will be described.
FIG. 4 is a diagram showing the transition of the rate of change in the circulating blood volume when replacement fluid is performed under the conditions of an injection volume of 200 ml and an injection interval of 30 minutes, which are generally performed. As shown in FIG. 4, it can be seen that the rate of change in the circulating blood volume increased by performing the replacement fluid every 30 minutes, and started to decrease after the injection of the replacement fluid was completed and the water removal was resumed. .. The slope of the white arrow shown in FIG. 4 indicates the rate of decrease in the rate of change in circulating blood volume. The steeper the slope of the arrow, the larger the rate of decrease of the rate of change, and the gentler the slope, the smaller the rate of decrease. In this embodiment, the average rate of decrease is used as the rate of decrease of the rate of change. Here, the average rate of decrease of the rate of change is calculated from the amount of decrease in the rate of change and the elapsed time at a certain point in time, starting from the time when the rate of change changes from increasing to decreasing after the completion of the injection of the latest replenisher.

As a result of the present inventions examining the rate of decrease of the appropriate rate of change in circulating blood volume, in order to reduce the burden on the patient, the average rate of decrease of the rate of change is set to 2% / min as the first threshold value. It is considered desirable not to exceed. Therefore, the water removal rate is reduced so that the average rate of decrease of the rate of change is equal to or less than the first threshold value. The water removal rate can be increased, for example, to recover the replenisher, or reduced by a predetermined percentage (eg, 50%). Further, when the average decrease rate of the rate of change becomes smaller due to the decrease in the water removal rate and becomes less than the second threshold value smaller than the first threshold value, the plasma refilling rate becomes the water removal rate. Therefore, it is desirable to return the water removal rate to the original rate in order to increase the amount of water recovered due to the increase in the replenisher solution. Here, it is preferable that the second threshold value is 1% / min.

Therefore, the blood purification means so that the rate of decrease in the rate of change in circulating blood volume after the completion of injection of the replacement fluid does not exceed the first threshold value (2% / min) and is less than the second threshold value. The method of controlling the water removal rate in 120 will be specifically described.

(Control method of water removal speed)
In the present embodiment, as an example, a case where the injection interval of the replacement fluid is constant at 30 minutes and the replacement fluid is performed a total of 7 times out of the treatment for 4 hours will be described with reference to FIGS. 5 and 6.

The control unit 150 measures the hematocrit value by the circulating blood volume measuring means 140, and calculates the rate of change of the circulating blood volume over time based on the measured hematocrit value. In addition, after the injection of the replenisher solution is completed, the average rate of decrease in the rate of change is calculated.

The flow of dialysis treatment will be described with reference to FIG.
After the start of dialysis, the dialysis apparatus 100 removes water at a predetermined water removal rate (S100). After a lapse of a predetermined time (S110), replacement fluid is performed with a predetermined injection amount (S120). Here, the predetermined water removal rate in S100 indicates the water removal rate at the start of the dialysis treatment, which is set based on the amount of water (water removal amount) to be removed from the patient by the dialysis treatment.
After the replacement fluid is performed, the water removal rate is controlled until a predetermined time elapses, based on the rate of decrease in the rate of change in circulating blood volume (S130).
Next, it is determined whether or not the predetermined dialysis time has elapsed (S140), repeated until the predetermined dialysis time elapses, replacement fluid is performed with a predetermined injection amount (S120), and the water removal rate is controlled. After the lapse of a predetermined time (S140), the dialysis treatment is terminated. Here, the predetermined dialysis time in S140 similarly indicates the dialysis time at the start of dialysis treatment.
In the present embodiment, as an example, the end of the dialysis treatment is determined by the passage of a predetermined dialysis time, but if the scheduled water removal is not completed within the water removal time scheduled at the start of the dialysis treatment, The dialysis time may be extended until the scheduled water removal is complete.

A method of setting the water removal rate will be described with reference to FIG.
After the injection of the replenisher by the most recent replacement fluid, the water removal rate is increased more than the water removal rate in S100 in order to recover the water corresponding to the injection amount of the replenisher (S131).
Next, it is determined whether or not the average decrease rate of the rate of change exceeds the first threshold value (S132), and if the average decrease rate exceeds the first threshold value, the water removal rate is decreased (S133). If it does not exceed, the water removal rate is maintained (S134).

When the water removal rate is decreased (S133), it is determined whether or not the average decrease rate of the rate of change is less than the second threshold value (S135). When it is determined that the average rate of decrease is equal to or greater than the second threshold value, the rate of water removal is maintained at a reduced rate (S137), and the determination of S135 is repeated until a predetermined time in S138 elapses. When the predetermined time in S138 has elapsed, the control of the water removal rate is terminated. The predetermined time in S138 is the time until the next fluid replacement is performed, and even when the predetermined dialysis time has elapsed, it is assumed that the predetermined time in S138 has elapsed. When it is determined that the average decrease rate is less than the second threshold value, the water removal rate is returned to the original rate before the decrease (water removal rate in S131) (S136).
When the water removal rate is maintained (S134), the determination is made by returning to S132 until a predetermined time elapses (S139). It is determined whether or not the rate of decrease of the average rate of change is less than the second threshold value, which is smaller than the first threshold value (S135). When it is determined that the average rate of decrease is equal to or greater than the second threshold value, the rate of water removal is maintained at a reduced rate (S137), and the determination of S135 is repeated until a predetermined time in S139 elapses. The predetermined time in S139 is the time until the next fluid replacement is performed as in the case of S138, and even when the predetermined dialysis time has elapsed, it is assumed that the predetermined time in S139 has elapsed.

As described above, water is removed at an increased water removal rate for replacement fluid recovery, and the water removal rate is reduced when the average rate of decrease in the rate of change in circulating blood volume exceeds the first threshold value. As a result, the rate of decrease in the average rate of change can be reduced, and the burden on the patient can be reduced.

In addition, if the next replacement fluid or dialysis treatment is completed while the water removal rate is reduced, it will be difficult to recover the water injected as the replacement fluid. Therefore, by reducing the water removal rate, when the average decrease rate of the rate of change is less than the second threshold value, the water removal rate is returned to the rate before the decrease, so that the amount of water corresponding to the increase in the replenisher solution is increased. Uncollected can be reduced. In addition, if there is uncollected water for the increased amount of replacement fluid at the time when the next replacement fluid is scheduled to start, the next replacement fluid may be performed as scheduled while remaining uncollected, but only the uncollected portion of the next replacement fluid is collected. Fluid replacement may be performed by reducing the injection volume. Further, the injection interval may be extended by extending the time until the next fluid replacement is performed until the uncollected water is removed. Further, by performing both of them, the unrecovered water content may be adjusted.

According to the dialysis apparatus 100 of the first embodiment and the first control method described above, the following effects are obtained.

(1) The dialysis apparatus 100 includes a blood circuit 110, a blood purification means 120, a dialysate circuit 130, a circulating blood volume measuring means 140, a replacement liquid injection means for injecting a replacement liquid into the blood circuit 110, and the like. A control unit 150 that controls the replenisher injection means so as to intermittently inject a predetermined amount of the replenisher solution into the blood circuit 110 at a predetermined interval is included, and the control unit 150 is provided with the blood purification means 120. When removing water in the blood, when the rate of decrease in the rate of change after the completion of the injection of the latest replenisher measured by the circulating blood volume measuring means 140 exceeds the first threshold value, the water is removed from the blood purifying means 120. Reduced speed. As a result, the rate of decrease in the rate of change in the circulating blood volume can be set to be equal to or lower than the first threshold value, so that the burden on the patient can be reduced.

(2) After reducing the water removal rate of the blood purification means 120 to the control unit 150, the rate of decrease of the rate of change after the completion of the injection of the latest replenisher measured by the circulating blood volume measuring means 140 is the second. When it became less than the threshold value, the water removal rate of the blood purification means 120 was returned to the speed before the decrease. As a result, it is possible to reduce the amount of unrecovered water due to the increase in the replenishing liquid due to the decrease in the water removal rate.

(3) When the water removal rate of the blood purification means 120 was reduced, the control unit 150 was made to perform a control to reduce the injection amount of the next replenisher and / or a control to extend the injection interval. As a result, it is possible to further reduce the amount of unrecovered water due to the increase in the replenishing liquid due to the decrease in the water removal rate.

(4) The control method using the dialysis apparatus 100 is calculated by calculating the rate of decrease in the rate of change in the circulating blood volume due to the injection of the latest replacement solution using the rate of change measured by the circulating blood volume measuring means 140. When the rate of decrease of the rate of change exceeds the first threshold value, the rate of water removal of the blood purification means 120 is reduced. As a result, the rate of decrease in the rate of change in the circulating blood volume can be set to be equal to or lower than the first threshold value, so that the burden on the patient can be reduced.

Although the preferred embodiments of the dialysis machine and the control method of the present invention have been described above, the present invention is not limited to the above-described embodiments and can be appropriately modified.
For example, in the above-described embodiment, the case of using the back-filtered dialysate as the replenisher has been described, but the present invention is not limited to this. For example, physiological saline may be used as the replenisher, or the dialysate may be replenished from the dialysate line directly connected to the blood circuit without using a blood purification means. If this happens, it is not necessary to stop the water removal in the blood purification means. That is, the replenisher may be injected while maintaining the water removal rate.

Further, in the above-described embodiment, an example is shown in which the water removal rate is increased after the replacement fluid is performed and the water removal rate is controlled so as to recover the water corresponding to the increase in the replacement fluid, but the present invention is not limited to this. For example, the recovery of the increased amount of water in the replacement fluid may be started ahead of schedule before the replacement fluid is carried out. Since the water removal rate is increased, if the rate of decrease in the rate of change in the circulating blood volume exceeds the first threshold value, the water removal rate may be controlled to decrease as in the above-described embodiment.

Further, in the above-described embodiment, the average rate of decrease is used as the rate of decrease in the rate of change in circulating blood volume, but the rate of decrease is not limited to this. For example, as the rate of decrease of the rate of change, the rate of decrease at a certain point in time after the completion of injection of the replenisher may be used. In this case, the feedback control may be performed by increasing or decreasing the water removal rate so that the rate of decrease at the moment of the rate of change becomes equal to or less than the first threshold value. The upper limit of the water removal rate is the original water removal rate (the water removal rate increased to recover the increased amount of replenisher), and the water removal rate is within the range in which the instantaneous decrease rate does not exceed the first threshold value. By controlling the water removal rate so as to approach the original water removal rate, it is possible to reduce the amount of unrecovered water due to the increase in the replenisher solution.

100 Dialysis apparatus 110 Blood circuit 111 Arterial side line 111c Blood pump 112 Vein side line 120 Blood purification means 130 Dialysate circuit 140 Circulating blood volume measuring means (measuring means)
150 control unit

Claims

Blood circuit and
A blood purification means arranged in the blood circuit and capable of removing water in the blood,
A dialysate circuit that is connected to the blood purification means and that introduces and derives dialysate into the blood purification means.
A measuring means for measuring the rate of change in circulating blood volume,
A replenisher injection means for injecting a replenisher into the blood circuit to recover the circulating blood volume decreased by water removal, and
A dialysis apparatus including a control unit that controls the replenisher injection means so as to intermittently inject a predetermined amount of replenisher solution into the blood circuit at predetermined intervals.
When the control unit removes water in the blood by the blood purification means, when the rate of decrease of the rate of change after the completion of the injection of the latest replenisher measured by the measuring means exceeds the first threshold value. , A dialysis apparatus that reduces the water removal rate of the blood purification means.
After reducing the water removal rate of the blood purification means, the control unit reduces the rate of decrease of the rate of change after the completion of injection of the latest replenisher measured by the measuring means, which is smaller than the first threshold value. The dialysis apparatus according to claim 1, wherein when the value is less than the second threshold value, the water removal rate of the blood purification means is controlled to return to the rate before the decrease.
The dialysis according to claim 1 or 2, wherein the control unit controls to reduce the injection amount of the next replenisher and / or to extend the injection interval when the water removal rate of the blood purification means is reduced. Device.
The dialysis apparatus according to any one of claims 1 to 3, wherein the blood purification means and the dialysate circuit are used as the replacement liquid injection means, and the dialysate back-filtered by the blood purification means is used as the replacement liquid. ..
Blood circuit and
A blood purification means arranged in the blood circuit and capable of removing water in the blood,
A dialysate circuit that is connected to the blood purification means and that introduces and derives dialysate into the blood purification means.
A measuring means for measuring the rate of change in circulating blood volume,
A replenisher injection means for injecting a replenisher into the blood circuit to recover the circulating blood volume decreased by water removal, and
A method for controlling a water removal rate using a dialysis apparatus including a control unit that controls the replenisher injection means so as to intermittently inject a predetermined amount of replenisher into the blood circuit at predetermined intervals. ,
Using the rate of change measured by the measuring means, the rate of decrease of the rate of change after the injection of the latest replenisher is calculated.
A control method for reducing the water removal rate of the blood purification means when the calculated rate of decrease of the rate of change exceeds the first threshold value.
The control method according to claim 5, wherein the first threshold value is 2% / min.
After reducing the water removal rate of the blood purification means, when the rate of decrease of the rate of change after the completion of the injection of the latest replenisher measured by the measuring means is less than the second threshold value, the blood purification means. The control method according to claim 5 or 6, wherein the water removal speed of the means is returned to the speed before the reduction.
The control method according to claim 7, wherein the second threshold value is 1% / min.
The control method according to any one of claims 5 to 8, wherein when the water removal rate of the blood purification means is reduced, the control for reducing the injection amount of the next replenisher and / or the control for extending the injection interval is performed.
Blood circuit and
A blood purification means arranged in the blood circuit and capable of removing water in the blood,
A dialysate circuit that is connected to the blood purification means and that introduces and derives dialysate into the blood purification means.
A measuring means for measuring the hematocrit value of blood flowing through a blood circuit,
A replenisher injection means for injecting a replenisher solution for recovering the circulating blood volume decreased by water removal into the blood circuit, and a replenisher solution injection means.
A dialysis apparatus including a control unit that controls the replenisher injection means so as to intermittently inject a predetermined amount of replenisher solution into the blood circuit at predetermined intervals.
When the control unit removes water in the blood by the blood purification means, when the rate of increase in the hematocrit value after the completion of the injection of the latest replenisher measured by the measuring means exceeds a predetermined threshold value, the control unit said. A dialysis machine that reduces the rate of water removal of blood purification means.