JPS59181162A - Control of dialytic apparatus and automatic dialytic apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Object of the Invention, Field of Industrial Application) The present invention relates to a method for controlling a dialysis machine and an automatic dialysis machine used in hemodialysis. It is used for manufacturing.

(Prior art) Hemodialysis, which is performed using an artificial kidney device (dialysis device), purifies the blood by eliminating waste products from the body or taking in what is needed in place of the kidneys when the human body suffers from renal failure. It is widely used to carry out.

FIG. 1 shows an example of a conventional dialysis device, which uses a positive pressure method. In FIG. 1, cannulas Ia and lb are inserted into blood vessels in the extremities of body A to serve as entrances and exits for extracorporeal circulation of blood. The blood pump 2 supplies a constant flow of blood flowing out from the cannula la to the dialyzer 3, and the constrictor 4 creates a constriction in the tube 5 to generate positive pressure in the blood within the dialyzer 3. Air chambers 6a, 6b and pressure gauges 7a, 7b are provided at the blood inlet/outlet of the dialyzer 3, and are used as a guide for knowing the ultrafiltration pressure. A supply path 8a and a discharge path 8b are connected to the dialyzer 3, and a separately prepared dialysate is supplied thereto. To perform hemodialysis using this conventional dialysis device, after rotating the blood pump 2, the diaphragm 4 is squeezed to generate positive pressure, and the pressure gauge 7a
, 7b and adjust the ultrafiltration pressure to an appropriate value.

By the way, the main function of the kidneys is to produce urine, and most of this urine is water, so in hemodialysis, it is important to remove water from the blood, so-called water removal. Water in the body moves into the blood through the cells, between cells, and blood vessels, and it is necessary to remove water at a rate commensurate with this transfer rate, and this rate varies depending on the patient. The factors that determine water removal are extremely difficult to understand as they vary from day to day even for the same patient.The factors that determine water removal include ultrafiltration pressure, dialysis area and membrane type of the dialyzer, and dialysis time. , blood flow rate and osmotic pressure difference between dialysate and blood.

Among these factors, the area of the dialyzer and the type of membrane of the dialyzer are determined by the dialyzer used, and the most suitable dialyzer may be selected from among various dialyzers. The osmotic pressure difference between dialysate and blood actually does not work very effectively for water removal. The longer the dialysis time is, the greater the amount of water removed, but since the patient must be restrained during the dialysis and the person caring for the patient must monitor and perform necessary treatment, it is better to keep the dialysis time short.

Therefore, in actual hemodialysis, it is necessary to adjust the ultrafiltration pressure and blood flow rate to make the water removal rate as fast as possible, and to remove a desired amount of water within a certain amount of time. To achieve this, it is a major premise that a stable extracorporeally circulating blood volume can be obtained from the patient, but each patient has a limit to this blood flow rate, and this is also due to a lack of internally circulating blood volume due to rapid water removal. It is extremely difficult to obtain a stable extracorporeally circulating blood volume over a long period of time due to a drop in blood pressure or trouble with the blood access device (blood access) for performing extracorporeal circulation. In particular, patients who experience a drop in blood pressure due to dehydration may experience unpleasant symptoms such as vomiting, as well as spasm of the limbs, which can last for a long time if left untreated, and in the worst case, can lead to death due to shock. Because there is
Great care must be taken to prevent a drop in blood pressure. However, if the water removal rate is made too slow for fear of blood loss, water will not be removed sufficiently and will remain in the body, placing a heavy burden on the circulatory system.

Conventionally, in order to speed up water removal and prevent a drop in blood pressure, even in patients in a stable phase who have undergone long-term dialysis and whose condition is known, treatment was performed every 15 to 30 minutes immediately after the start of dialysis, and every 30 to 60 minutes midway through dialysis. Blood pressure is measured every 15 to 30 minutes before the end of each session, and blood pressure is measured every 15 to 30 minutes before the end of each session. For patients who are likely to fall into an insufficiency state, blood pressure measurements must be performed more frequently than regular blood pressure measurements, and the water removal rate is adjusted according to the results of each measurement. Generally, these tasks are performed by nurses, who are busy with the above-mentioned frequent blood pressure measurements and adjusting the water removal rate, and in the event that a patient's blood pressure drops, they may need to inject fluids or drugs. , they will be busy with post-treatment such as applying warm compresses and disposing of filth. Considering the current situation where one nurse is in charge of 4 to 5 patients,
These tasks account for a very high proportion of the total nursing work, resulting in heavy labor for nurses.

In this way, conventional methods of using dialysis machines and dialysis machines rely on the human power of nurses and others to carry out the multiple tasks necessary to perform hemodialysis under good conditions, which naturally leads to the occurrence of human error. Problems included increased opportunities for hemodialysis, heavy workload and shortage of nurses, and increased costs for hemodialysis.

(Objective of the Invention) The present invention was achieved as a result of long years of research by the inventor in view of the above-mentioned circumstances, and eliminates most of the frequent blood pressure measurements of patients and the adjustment of the water removal rate each time. Therefore, the first object of the present invention is to provide a control method for a dialysis machine and an automatic dialysis machine that can significantly save labor.

A second object of the present invention is to provide a highly efficient control method for a dialysis apparatus and an automatic dialysis apparatus that can prevent a drop in blood pressure due to excessive water removal and can sufficiently increase the water removal rate.

(Structure of the Invention) The method of the present invention is suitable for performing hemodialysis using a dialyzer.
i, sending blood to the dialyzer via a blood pump, and detecting the blood pressure upstream of the blood pump;
It is characterized in that when the pressure falls below a certain value, the ultrafiltration pressure of the dialyzer is reduced or made zero.

The device of the present invention is a device that performs hemodialysis using a dialyzer, and includes a blood pump that sends blood to the dialyzer, a pressure sensor that detects the pressure of blood on the upstream side of the blood pump, and a blood pump that sends blood to the dialyzer. It is characterized by having a control means for reducing or zeroing the ultrafiltration pressure when the pressure detector detects that the pressure is below a certain level.

(Example) To explain the principle of the present invention, instead of conventional blood pressure measurement during dialysis, in the present invention, the pressure of blood on the upstream side of the blood pump 2 is detected by a pressure detector.

That is, in FIG. 2 for explaining the principle of the present invention, the inside of the venous blood vessel B normally has a positive venous pressure b, and a blood pump is pumped through the cannula la and tube 5a punctured into the venous blood vessel B. When blood is aspirated with 2, cannula 1
a causes a pressure drop C which is approximately inversely proportional to the effective area of the cannula 1a and approximately proportional to the blood flow rate, ie the rotational speed of the blood pump 2. Therefore, the pressure of the blood in the tube 5a is (b-c), which is generally a negative pressure and remains approximately constant during normal dialysis. As water removal progresses, the amount of blood in the blood vessels decreases, but blood pressure is normally maintained so as not to drop due to arterial contraction. However, when water is removed beyond the capacity of the blood vessels to contract, the venous pressure b decreases to zero or negative pressure. Therefore, the pressure inside the tube 5a (b-C) becomes more negative, so
By reducing or zeroing the ultrafiltration pressure and stopping water removal when this pressure falls below a certain value, it is possible to prevent a drop in blood pressure throughout the lm body.

A first embodiment of the invention is shown in FIG. This is an example of performing ultrafiltration using a positive pressure method. In FIG. 3, an air chamber 68 is provided in the middle of a tube 5a connecting between the cannula 1a and the blood pump 2, and a pressure detector 9 is connected to the air chamber 6a via a pressure monitor tube 5e. has been done. As shown in FIG. 4, this pressure sensor 9 has a measuring needle 11 that moves across a scale plate 10 having graduations ranging from appropriate negative pressure to positive pressure in response to the pressure applied by a pressure monitor tube 5e. It moves and has a first setting hand 12, a second setting hand 13, a first indicator light 12a, and a second indicator light 13a. The first setting needle 12 and the second setting needle l3 can be set at any position on the scale plate 10,
When each setting position matches the position of the measuring needle 11, the first detection signal R or the second detection signal S is outputted, and the first indicator light 12a or the second indicator light 13a lights up. . The tube 5a used here,
Since negative pressure is applied to the material 5e, it is preferable to use a material that is hard enough not to be deformed even by negative pressure so that pressure plaster can be detected accurately.

The dialyzer 3 is a conventional and well-known device, and the blood pump 2 is connected to the blood inlet via a tube 5b, and the air chamber is connected to the blood outlet via a tube 5c.
6b, a pressure gauge 7b, and further connected to the cannula 1b via a tube 5d. Positive pressure is applied to the part of the tube 5d near the dialyzer 3 outlet to press the tube 5d to create a stenosis or release the pressure to eliminate the stenosis! i
A t-regulator 14 is attached.

In FIG. 5, two guide brackets 16.17 are attached to the L-shaped pedestal 15, and slide holes 16a and 1 are coaxially provided in both guide brackets 16.17.
A slide bead 18 is slidably inserted into 7a. The right side of the slide piece 18 has a small diameter rod portion 18a.
The tip of the rond part 18a is provided with a screw and is fixed to a connector 19 with a naso l-20.20, and this connector 19 is connected to a solenoid 22 fixed to the frame 15 via a pin 21. It is connected to the plunger 22a. The left side of the slide bead 18 is a pressing portion 18b having a substantially triangular cross section for pressing the tube 5d to create a stenosis. A compression spring 23 and a compression spring 23 are provided in the rond part 18a.
The slide bead 18 is urged to the left by the compression spring 23.

Referring also to FIG. 6, a guide screw 26 is installed coaxially on the left side of the pressing part 18b, and is screwed into a screw hole of a bracket 25 fixed to the pedestal 15 and fixed by a rotary screw 26a. A threaded rod 27 having a head 27a is screwed into the threaded hole of the guide screw 26. The above-mentioned head 27a fits into the recess 28a provided in the center of the pedestal 28 disposed opposite to the pressing part 18b, and the head 2'l
A stopper 29 having a hole smaller than the outer diameter of a is loosely fitted onto the threaded rod 27 and fixed to the pedestal 28. pedestal 2
8 has two guide bars 30.3 parallel to the threaded rod 27.
0 is attached, and a guide bar 3 (1.30) slidably passes through the hole provided in the bracket 25, thereby preventing the pedestal 28 from rotating. This is a knob for rotating.

This positive pressure regulator 14 sandwiches the tube 5d between the pedestal 28 and the pressing part 18b, and rotates the knob 27b to move the pedestal 28 in the left-right direction in FIG. 5, thereby preventing constriction in the tube 5d. You can create it and adjust its size. When the solenoid 22 is energized in this state, the plunger 22a is attracted and moves the slide piece 18 to the right through the pin 2l and the connector 19 against the compression spring 23, so that the tube 5d is no longer pressed. Stenosis disappears. When the energization of the solenoid 22 is stopped, the slide bead 18 is urged by the compression spring 23 and returns to its original state, and the same constriction is created in the tube 5d again. The tube 5b used here is preferably thick in order to reduce the flow rate of blood flowing into the dialyzer 3 and distribute the blood evenly within the dialyzer 3, and the tube 5d is preferably thick to reduce the flow rate of blood flowing into the dialyzer 3 and to prevent the creation of stenosis or interference with the equipment. A soft material is preferable in order to facilitate the bonding. Again, in FIG. 3, electromagnetic wires are placed in the middle of the dialysate supply path 31 and the dialysate discharge path 32 of the dialyzer 3 at positions close to the connection to the dialyzer 3. On-off valves 33, 3i are provided. A well-known flow rate adjustment valve 35 and a flow meter 36 are connected to the upstream side of the electromagnetic on-off valve 33 in the supply path 31, and an electromagnetic on-off valve 37 is connected in parallel with the flow rate adjustment valve 35 and flow meter 36.
A high-speed bus route 38 is connected thereto. The electromagnetic on-off valves 33, 34, and 37 used here have a well-known structure that opens and closes the flow path by turning on and off electricity, and are preferably made of chemical-resistant material such as stainless steel. The bypass path 38 is used when exchanging the dialysate in the dialyzer 3 in a short time, and preferably has a flow path resistance as low as possible.

Next, the relationship between the detection signal of the pressure detector 9 and the operating states of the blood pump 2, positive pressure regulator 14, and electromagnetic on-off valves 33, 34, and 37 will be explained. While proper dialysis is being performed, there is no detection signal from the pressure detector 9, the blood pump 2 rotates at a constant rotation speed, and the solenoid 22 of the positive pressure regulator 14 is turned off to create a regulated stenosis. A positive pressure is generated, the electromagnetic on-off valves 33 and 34 are opened, and the electromagnetic on-off valve 37 is closed, and a constant flow of dialysate is supplied to the dialyzer 3, which is a water removal state.

When the pressure decreases and the first detection signal R is output by the first setting needle l2, the solenoid 22 is turned on, the stenosis is released, and the ultrafiltration pressure decreases to near zero, and the electromagnetic on-off valve 33. 34 is closed and the supply of dialysate is stopped, resulting in a water removal stop state. This water removal stop state is maintained even if the pressure drops further below the set value of the first setting needle 12, and is maintained for a certain period of time ( For example, it is configured to be held for 10 minutes to prevent the occurrence of a chattering state and to ensure the patient's complete listening time. There are two ways to start counting this certain period of time: after the first detection signal R is output and after the output stops. When water removal is stopped, water is not removed, but substances are moved by osmotic pressure, so it is preferable to replace the dialysate at appropriate intervals. For this purpose, the electromagnetic on-off valves 33, 34.
37 is open. The shorter the time required for exchanging the dialysate, the better; this is determined by the amount of priming on the dialysate side of the dialyzer 3 and the flow rate at the time of exchange, and is approximately one to several seconds. Now, when water removal is stopped, the blood pressure increases and the first detection signal R is no longer output, and after a certain period of time has passed, the solenoid 22 is turned off, and the electromagnetic on-off valve 33.
34 is opened and normal dialysis resumes.

By the way, it is conceivable that the pressure suddenly decreases due to some abnormality during dialysis. For example, the tip of the cannula 1a may stick to the inner wall of a blood vessel, resulting in a state where blood flow is occluded. In this case, the pressure inside the cannula 1a and the tube 5a drops rapidly, and if this state is left for a long time, the inner wall of the blood vessel will be damaged, so it is necessary to stop the blood pump 2.

The second setting needle 13 is used to detect this pressure drop, and the second detection signal S caused by this causes the blood pump 2 to be stopped and other devices such as the electromagnetic on-off valves 33 and 34 to operate on the safe side. The system will be configured to generate an alarm sound and turn on indicator lights, etc. This second detection signal S allows the nurse to know that an abnormality has occurred, and it becomes possible to take prompt and appropriate measures to prevent accidents.

A method of using the apparatus configured as described above will be explained. First, the electromagnetic on-off valves 33 and 34 are opened and the electromagnetic on-off valve 37 is closed to appropriately adjust the flow rate of the dialysate using a well-known method. The shunt pressure P1 at rest is measured by the pressure detector 9 while the blood pump 2 is stopped. P1 is a positive pressure and is usually several tens of grams.

The order of adjusting the dialysate and measuring P1 may be reversed or may be performed simultaneously. Next, rotate the blood pump 2 and
The rotational speed is set so as to provide the blood flow rate necessary for the dialysis, and at this time, the shunt pressure P2 during circulation is measured by the pressure detector 9. P2 is the value obtained by subtracting the pressure drop due to the cannula 1a from P1, and is usually a negative pressure. The first setting needle 12 of the pressure detector 9 is set to a value of Pa=P2-Pt, and the second setting needle 13 is set to a value of P4=Ps-(50 to 100
). Therefore, P8 is the shunt pressure during circulation P
2, the resting shunt pressure P1 is lower, and P4 is 50 to 100 naHg lower than P8. Next, the tube 5d is
The ultrafiltration pressure is set using a well-known method while observing the pressure gauge 7b. For example 2. 'If 4Il of water is removed in 6 hours, the UFR of dialyzer 3 is 4mj2/hr/
When wHg, the required ultrafiltration pressure is 100vnHg. Also, as a matter of course, the patient's blood pressure and other conditions should be measured and examined.

In the device adjusted as described above, normal dialysis is performed by a constant amount of blood circulation and ultrafiltration pressure by the blood pump 2, and water removal also progresses. As water removal progresses, the patient's blood volume decreases, but blood pressure is maintained to some extent by constriction of the arteries. However, as water removal progresses further and the pressure of blood in the blood vessel punctured by the cannula 1a decreases, the pressure in the tube 5a also decreases, and the measuring needle 11 of the pressure detector 9 moves downward, causing the first When it becomes equal to the set value P8 of the setting hand 12, the first detection signal R is output. When the first detection signal R is output, the solenoid 22 is turned on, the constriction of the tube 5d is released, and the ultrafiltration pressure is reduced to near zero, and at the same time, the electromagnetic on-off valves 33 and 34 are closed, and the dialysate is removed. Since the supply of water stops, the progress of water removal stops.

Also, at this time, the first indicator light 12a lights up. In this water removal stopped state, the solenoid on-off valve 3
3, 34, and 37 are opened, a large flow of dialysate flows, and the dialysate in the dialyzer 3 is replaced in a very short time.

When the water in the patient's body moves into the blood and the blood volume increases and the pressure in the blood vessels is restored, the first detection signal R is no longer output, and if a certain period of time has elapsed, the solenoid 22 is turned off. Solenoid on-off valves 33 and 34 open, solenoid on-off valve 3
7 is closed and the current dialysis is resumed. Therefore, the patient is able to continue normal dialysis without any adverse drop in blood pressure. If the pressure inside the tube 5a suddenly decreases due to some abnormality during dialysis, the second setting needle 13 detects this and outputs the second detection signal S, stops the blood pump 2, and issues an alarm sound and display. A light will alert the nurse.

Therefore, according to this embodiment, water removal can be safely performed as initially set without having to frequently measure the patient's blood pressure or adjusting the ultrafiltration pressure and water removal rate each time. It will be held on. In this embodiment, as water removal progresses, the blood concentration increases, fluid resistance within the cannula la increases, and the pressure drop increases. Therefore, the pressure within the tube 5a is further reduced, and the first detection signal R is output before the pressure of blood within the blood vessel reaches zero, which is safer. If this increase in blood concentration cannot be expected depending on the patient, or if a margin is desired on the safety side due to various circumstances, the first setting needle 12 may be set to a value of about 90 to 95% of P3.

In addition, to obtain P8, we actually measured the shunt pressure P2 during circulation and the shunt pressure P1 at rest and calculated the difference between them, but as a simple method, we calculated the blood hematocrit value and blood flow rate in advance for cannulae of various inner diameters. Calculate the amount of pressure drop using values, etc. as parameters and make a list or graph. During dialysis, use the list or graph to calculate the pressure drop.
It is also possible to find 8. The inventor of this invention is P3
We have implemented both methods to find the results and confirmed that they almost match.

In this embodiment, as the pressure sensor 9, a pressure sensor 9 that obtains a detection signal by moving a setting needle is used as described above, but the pressure sensor 9 is not limited to this in any way.

For example, the pressure may be converted into an electrical signal using a strain gauge or a semiconductor, and the electrically set value and the pressure signal value may be electrically compared to output a detection signal.

Further, at this time, it is also possible to directly attach the sensor portion of the pressure detector 9 to the tube 5a, cannula 1a, blood pump 2, etc.

In this embodiment, a pressure gauge 7b having an upper limit setting needle may be used, and the configuration may be configured to output necessary signals such as stopping the blood pump 2 when a pressure higher than the set pressure is generated due to some abnormality. good.

In this embodiment, the positive pressure regulator 14 is used as the control means, but the control means is not limited to this. For example, the tube 5d may be provided with a branch path, one of which may be constricted using a conventional constrictor, and the other may be opened and closed by opening or pressing with a solenoid or the like.

In addition to this example, if a heater is provided to heat the dialysate, the heater should be turned off when the dialysate supply is stopped, or the heater should not be turned off and the dialysate should be dialyzed in order to prevent overheating of the dialysate. A bypass circuit may be provided in which the fluid flows outside the dialyzer 3.

A second embodiment of the invention is shown in FIG. This is an example of ultrafiltration using the negative pressure method, but the same reference numerals are used for parts that have the same effects as the device using the positive pressure method described above, or that are well known and do not require explanation. The explanation will be omitted.

In FIG. 7, the blood coming out of the dialyzer 3 is transferred to the tube 5d.
is connected to cannula 1b by.

A pressure gauge 39 and a pump 40 for dialysate are connected to the downstream side of the dialysate discharge path 32, and a high-speed bus equipped with an electromagnetic shut-off valve 41 is connected between the supply path 31 and the discharge path 32. 42 is connected. The pump 40 is in operation during dialysis, and the pressure on the suction side is measured by the pressure gauge 39. The electromagnetic on-off valve 41 is closed when dialysis is performed normally and water is removed, and when the first detection signal R is output and the electromagnetic on-off valves 33 and 34 are closed, the dialysate is bypassed. Therefore, the electromagnetic on-off valve 41 is opened. Also, in order to replace the dialysate, the electromagnetic on-off valve 33. ．． 34 and 37 are open, the electromagnetic on-off valve 41 is closed.

To use the device constructed in this way, the pressure sensor 9 is adjusted in the same manner as in the positive pressure method described above, and the pump 40 is adjusted.
The rotational speed of the dialyzer 3 and the flow control valve 35 are adjusted to supply the required amount of dialysate, and the ultrafiltration pressure due to the negative pressure inside the dialyzer 3 is adjusted. When the first detection signal R is output during dialysis/water removal with this device, the electromagnetic on-off valve 3
3.34 is closed, the electromagnetic on-off valve 41 is opened, and the dialysate flows through the bypass path 42 without being supplied to the dialyzer 3. Therefore, the ultrafiltration pressure decreases to near zero, and water removal is stopped.

Furthermore, when exchanging the dialysate in the dialyzer 3, the electromagnetic on-off valves 33, 34, and 37 are opened, and the electromagnetic on-off valve 41 is closed, and the exchange is completed within a short time.

In this embodiment, when the supply of dialysate is stopped, the dialysate is bypassed to the high-pass path 42, but the bypass path 42 may be omitted by stopping the pump 40. The downstream side of
The electromagnetic on-off valve 34 may be connected downstream of the first electromagnetic on-off valve 33, and the electromagnetic on-off valve 34 may be omitted.

In both the first and second embodiments, there is no need for frequent blood pressure measurements of patients or adjustment of the water removal rate each time, which is required in the conventional art, resulting in substantial labor savings. In addition, a drop in blood pressure due to excessive water removal is prevented, and the water removal rate is sufficiently increased to the limit to obtain high efficiency in both clearance and water removal. In the event of an abnormality due to a problem with the cannula 1a, the blood pump 2 is stopped, etc., to ensure the safety of the patient, and the degree of monitoring can be relaxed, and the shunt can be protected and its lifespan can be extended. Even when water removal is stopped, the dialysate is replaced at regular intervals, so dialysis other than water removal continues as usual.

Furthermore, since the time required to replace the dialysate is extremely short, almost no water is removed during the replacement.

Naturally, this device can also be used to remove a small amount of water, and in that case, stable dialysis and water removal can be performed safely.

In both the first and second embodiments, the ultrafiltration pressure is reduced to near zero by the output of the first detection signal R, but the pressure inside the tube 5a, that is, the pressure detector 9
The ultrafiltration overpressure may be adjusted according to changes in the pressure detected by the filter.

For example, a microcomputer may be used to store in advance a program for obtaining the optimal ultrafiltration overpressure based on data regarding the patient, data regarding the equipment used in the device, pressure values within the tube 5a, and various other data. Then, the safest and most efficient dialysis may be performed by operating a servo motor, a servo valve, etc. according to the pressure inside the tube 5a.

(Effects of the Invention) According to the present invention, it is possible to omit frequent blood pressure measurements of patients and adjustment of the water removal rate each time, and moreover, it is possible to prevent a drop in blood pressure due to excessive water removal, resulting in stable dialysis. In addition, the water removal rate can be made sufficiently high to obtain high efficiency. Therefore, it has great practical effects, such as shortening the patient's detention time by shortening the dialysis time, increasing patient safety by reducing the occurrence of human error, and significantly reducing dialysis costs by saving labor and time. .

[Brief explanation of drawings]

FIG. 1 is a diagram showing an example of a conventional dialysis device, FIG. 2 is a diagram showing a blood vessel and a cannula for explaining the principle of the present invention,
FIG. 3 is a diagram showing the first embodiment of the present invention, FIG. 4 is a front view showing the embodiment of the pressure detector, FIG. 5 is a front view showing the embodiment of the positive pressure regulator, and FIG. 6 is the front view showing the embodiment of the positive pressure regulator. The figure is an enlarged view of a portion of FIG. 5 taken in the direction of arrow . A...11, 1a+lb...cannula, 2...
Blood pump, 3...Dylyzer, 9...Pressure detector, 1
4...Positive pressure regulator (control means'), 33,'34...
- Solenoid on-off valve (control means) 40...pump. , -384-

Claims (2)

[Claims] (1) When performing hemodialysis using a dialyzer, blood is sent to the dialyzer via a blood pump, and the blood is pumped upstream of the blood pump. 1. A method for controlling a dialysis machine, comprising: detecting pressure; and reducing or zeroing the ultrafiltration pressure of the dialyzer when the pressure falls below a certain value. (2) A device that performs hemodialysis using a dialyzer, including a blood pump that sends blood to the dialyzer, a pressure detector that detects the pressure of blood on the upstream side of the blood pump, and the pressure detector an automatic dialysis device comprising a control means for reducing or zeroing the ultrafiltration pressure when it is detected that the ultrafiltration pressure is below a certain pressure.