JPH0519070Y2 - - Google Patents

Description

[Detailed description of the invention] "Industrial Application Field" This invention relates to an improvement of a blood circuit side pressure control device in an artificial kidney device.

"Prior Art" A conventional artificial kidney device will be explained with reference to FIG.

Blood is drawn from a patient's artery through a blood tube 1 by a blood pump 2, and is supplied to a dialyzer 4 via a trip chamber 3. This blood comes into contact with the dialysate through the membrane in the dialyzer 4, and water and waste products in the blood move to the dialysate side. This water-reduced blood is returned from the dialyzer 4 to the patient's vein through the blood tube 7 via the drip chamber 5 and the aperture section 6. In this way, a blood circuit is constructed.

On the other hand, dialysate is supplied to the dialyzer 4 from the dialysate supply section 8 through the channel 9 . The dialysate containing water and waste products that have migrated from the blood through the membrane in the dialyzer 4 is returned from the dialyzer 4 to the dialysate supply section 8 through the flow path 10. In this way, a dialysis circuit is constructed.

A pressure sensor 11 is provided in the trip chamber 5 to measure blood circuit side pressure P. Further, a pressure sensor 12 is provided in the flow path 10 near the dialyzer 4, and the pressure Q on the dialysis circuit side is measured. These measured values P and Q are taken into the control unit 13, and the TMP
Differential pressure P-Q called (transmembrane pressure)
is calculated, and a control signal is given from the control unit 13 to the aperture unit 6 so as to reduce the difference between the calculated TMP and a preset TMP control setting value. The throttle section 6 adjusts the pressure on the blood circuit side by varying the cross-sectional area of the flow path in accordance with the control signal. The pressure sensors 11 and 12, the control section 13, and the throttle section 6 constitute a blood circuit pressure control device.

``Problems with the Prior Art'' In the conventional apparatus, when the change in TMP with respect to the elapsed time from the start of dialysis is determined, the characteristics shown in FIG. 11 are obtained. From point A to point B shown in the same figure is
TMP does not change and remains an almost constant negative value. During this period, there is no substantial effect of increasing the pressure in the blood circuit due to the restriction in the restriction part 6, and the pressure P on the blood circuit side is zero, and the dialysate is pressurized by the pressure Q on the dialysis circuit side. TMP increases with waves from point B, becomes zero at point C, that is, the blood circuit side pressure P becomes equal to the dialysis circuit side pressure Q, further increases while making waves, and becomes equal to the control set value at point D. Become. Thereafter, after a large overshoot with waves, small fluctuations around the control set value are repeated.

In this way, with conventional devices, it takes a long time for TMP to equilibrate near the control set value after starting dialysis, the transient vibration at the start-up is large, and the deviation from the control set value during dialysis is large. It was relatively large. For this reason, there was a problem in that the ultraviolet amount (the amount of water transferred from the blood to the dialysate side) corresponding to TMP had a larger error than the expected value.

The purpose of this invention is to eliminate these drawbacks, shorten the time from the start of dialysis until the TMP is controlled closer to the control set value, reduce transient vibrations, and reduce the difference between the control set value and the control set value during dialysis. This is an attempt to reduce the deviation.

As shown in FIG. 12, the conventional aperture section is such that a blood tube 20 is held between a holding member 21 and a head 22, and the head 22 is moved in response to a control signal to collapse the tube. Note that the tube is disposable after each dialysis. An example of the relationship between the moving distance l of the head in the tube direction and the pressure P on the blood circuit side is shown in Figure 13, where the blood pressure does not change within approximately 4 mm from the beginning, and the blood pressure does not change at the point approximately 4 mm from the beginning. It exhibits nonlinear characteristics in which the pressure increases more rapidly. Furthermore, when the tube is replaced, variations in the tube itself and slight changes in the state of contact with the head when the tube is set cause variations in pressure characteristics, as shown by A, B, and C in the same figure. Therefore, it can be seen that there is a large error between the typical aperture characteristics assumed when designing the control section 13 and the actual characteristics. This means that it takes a longer time for TMP to equilibrate near the control set value after starting dialysis with conventional equipment, and transient vibrations are large, and the deviation from the control set value during dialysis is relatively large. This is thought to be one of the causes.

The roller of blood pump 2 has a rotational speed of 0.25 to 1 rotation per rotation.
Since it rotates in about seconds, the pressure P of the blood is as shown in Fig. 9, assuming the condition of the constriction part is constant.
A ripple appears that corresponds to the rotational speed of the blood pump roller. This is the reason why ripples are seen in the control characteristics of TMP in conventional devices as shown in FIG. That is, the response characteristics of the control loop including the control section are extremely slow, and pressure control cannot be performed to follow and eliminate ripple changes. Since the pressure on the dialysis circuit side is approximately constant unless the flow rate is changed, TMP always involves ripples, just like the pressure on the blood circuit side. Controlling the pressure in the blood circuit using rippled blood circuit pressure or each instantaneous value of TMP causes an error in the control signal given to the restrictor, and TMP may not be controlled close to the control set value. This is considered to be one of the reasons why the amplitude and duration of the transient vibration at the time of rise increase as the time required for the vibration to rise increases.

Immediately after the start of dialysis, TMP is as shown in Figure 11.
There is no change between point A and point B. This is because the blood is not pressurized until the head moves considerably, as seen in the throttling characteristics illustrated in FIG. The long time from point A to point B is also a TMP.
This is one of the reasons why it takes time for the control value to be controlled close to the control set value.

``Means for Solving Problems'' According to this invention, during the preparation period before starting dialysis, the degree of restriction of the aperture part, for example, the moving distance of the head or the driving pulse applied to the stepping motor to move the head, can be determined. The relationship between the number of and the blood circuit side pressure is measured by the aperture characteristic measuring means, and the measured aperture characteristic is stored in the aperture characteristic storage means.

During dialysis, depending on the deviation between the differential pressure (TMP) between the blood circuit side pressure and the dialysis circuit side pressure and the control set value,
Based on the stored aperture characteristics, a control signal is applied from the aperture section control means to the aperture section so as to reduce the deviation.

At the start of dialysis, the differential pressure (TMP) pulsates due to the influence of the blood pump. Therefore, in this invention, the average value of the instantaneous values of the fluctuating TMP is determined by an average value means, and this average value is used as necessary.

When dialysis is started, the first deviation calculation means sets an intermediate set value lower than the final set value as the control set value, and also calculates the difference between this intermediate set value and the average value of the differential pressure (TMP) and suppresses it. Find the deviation that should occur.

As described above, the aperture section control means applies a control signal to the aperture section so as to reduce this deviation based on the memorized aperture characteristics. As a result, after the differential pressure (TMP) becomes almost stable, the second deviation calculation means sets the final setting value as the control setting value, and calculates the difference between this final setting value and the average value of the differential pressure (TMP). Find the deviation that should be suppressed.

As before, the aperture section control means applies a control signal to the aperture section so as to reduce this deviation based on the memorized aperture characteristics. This results in differential pressure (TMP)
approaches the final setting value. After the differential pressure (TMP) is almost stabilized, the third deviation calculating means calculates the difference between the differential pressure (TMP) and the final set value at each timing to determine the deviation to be suppressed. As before, the aperture section control means applies a control signal to the aperture section so as to reduce this deviation based on the memorized aperture characteristics.

"Embodiment" The configuration of the pressure control device of this invention is shown in FIG. 1 together with the artificial kidney device.

Portions corresponding to those in FIG. 10 are designated by the same reference numerals, and redundant explanation will be omitted. In this embodiment, the control section 13
This is the case when a microcomputer is used.
A CPU (central control unit) 30 performs pressure control by decoding and executing a system program stored in a ROM (read-only memory) 31. The TMP control setting values are stored in a RAM (random read/write memory) 32. The pressure on the blood circuit side and the pressure on the dialysis circuit side are determined by pressure sensors 11 and 12, respectively.
and these data P and Q are respectively
The AD converter 33 performs AD conversion and stores it in the RAM 32 via the I/O (input/output circuit) 34, and the CPU 30 calculates TMP=P-Q to reduce the deviation from the control setting value. , drive circuit 35
A control signal is given to the diaphragm section 6 via the diaphragm section 6. Conventionally, this control signal was determined by using the standard aperture characteristic of the aperture section, that is, the change characteristic of the blood pressure P with respect to the moving distance l of the head (or the number n of driving pulses corresponding to this). Then, the CPU 30 accurately measures the aperture characteristics of the aperture section that will actually be used during the dialysis preparation period using the program in the ROM 31.
This n-P characteristic is stored in the RAM 32 as a data table. During dialysis, this data table is used to control the motor in the aperture section for accurate control of TMP. Therefore, TMP control errors caused by variations in the aperture characteristics of the aperture section are eliminated.

As shown in FIG. 13, the iris characteristic is that the head movement distance l ₀ is 4 mm (corresponding to the number of drive pulses n ₀ ).
Since the blood pressure P does not change until the blood pressure P reaches 1 mm, the average blood pressure P is approximately ₁ mm before dialysis begins.
It is desirable to apply the total number of pulses that will result in Hg in advance. In this way, the initial movement time of the head can be shortened.

The CPU 30 calculates the average value of the instantaneous values of the pulsating TMP, and uses this average value as necessary to reduce control errors.

In this design, TMP control immediately after the start of dialysis is performed by continuously adjusting the moving distance of the head (integrated value of the number of driving pulses) to reduce the deviation between the TMP control setting value and the measured value, as in the conventional case. Don't always control. That is, at least one intermediate setting value lower than the final setting value is provided, and the CPU 30 first uses the intermediate setting value as the control setting value, calculates the deviation between TMP and the intermediate setting value, and stores a control signal that eliminates the deviation. It is determined from the aperture characteristic (n-P characteristic) obtained and is intensively applied to the aperture section 6 in a short period of time. No control signal is then applied until TMP has stabilized to some extent near the intermediate set point. After TMP has stabilized near the intermediate set value, the CPU 30 uses the final set value as the control set value, calculates the deviation between TMP and this final set value, and calculates the deviation based on the previously memorized aperture characteristics. A control signal that eliminates the deviation is obtained and is intensively applied to the aperture section 6 in a short period of time.
As before, no control signal is applied until TMP has stabilized near its final set point.
After TMP has stabilized to some extent near the final setting value, the CPU 30 uses the memorized aperture characteristics to
The deviation from the final setting value of TMP is calculated at each short interval timing by subdividing the pulsation cycle of the blood circuit.
A control signal is applied to the aperture unit 6 to eliminate the deviation, and small errors from the control set value, including ripples caused by the blood pump, are quickly suppressed. Control at each timing after TMP has been stabilized to some extent near the final setting value is control during steady state (not during rising).

The above-described stepwise control in which an intermediate set value and a final set value are provided can shorten the time until TMP is stabilized near the final set value and reduce the magnitude of transient vibration.

Figure 2 shows an example of the TMP rise characteristic in the embodiment shown in Figure 1, with the intermediate setting value set at 1.
This is the case when one is provided. The waveform A shown by the dotted line in the figure is the case where no intermediate setting value is provided and the final setting value is used as the control setting value from the beginning, and it can be seen that the amplitude and duration of the transient vibration are large.

We will sequentially explain in detail the measurement of aperture characteristics, the control operation at the rise of TMP, and the control operation during steady state after TMP approaches the final setting value to some extent.

(a) Measurement of aperture characteristics Figure 3 is an operation flowchart regarding measurement of aperture characteristics. To measure the squeezing characteristics, physiological saline is supplied from a supply section (not shown) to the blood tube 1 instead of blood (step S ₁ ). The blood pump 2 is turned on (step S ₂ ), and a driving pulse is applied to the stepping motor of the diaphragm 6 to move the head of the diaphragm 6 (step S ₃ ). The CPU 30 monitors the blood pressure data p ₀ of the pressure sensor 11, and p ₀ =
Check whether it becomes 1 mmHg (step _S4 ).
When the CPU 30 detects p ₀ =1 mmHg, it stops applying the drive pulse at that point and stores the total number n ₀ of pulses applied up to that point in the RAM (step S ₅ ). The following measurement cycle i is i=0
(Step S ₆ ) The CPU 30 takes in blood pressure data p _i every 0.05 seconds and stores it in the RAM for 10 seconds.
(Step _S7 ). This data p _i has undulating characteristics due to the influence of the blood pump.
The CPU 30 calculates the average blood pressure _i from the maximum value of the stored blood pressure data p _i to the next maximum value (step S ₈ ), and checks whether the average pressure _i is _i 400 mmHg ( Step _S9 ), _i <400
If it is mmHg, store the average blood pressure _i and the integrated drive pulse value n _i in RAM (step
_S10 ). Next, the measurement cycle is advanced by one, i+1 is set as i (step S ₁₁ ), and one drive pulse is applied to the motor (step S ₁₂ ). Therefore n _i+1 = n _i
+1. Returning again to step _S7 , new pressure data p _i for 10 seconds is taken in and the corresponding data in the RAM is updated. When _i reaches 400mmHg in step _S9 , the measurement operation is completed. In this way ₀
Between (1) and _n (400mmHg), the number of driving pulses
Every time one pulse is applied starting from n ₀ , the average value of the blood pressure data changed due to the squeezing effect _{is 0} , ₁ ,
_{p2 .}

Physiological saline supply section (not shown), pressure sensor 1
1. The aperture section 6 and the control section 13 constitute an aperture characteristic measuring means, the RAM 32 constitutes an aperture characteristic storage means, the control section 13 constitutes an aperture control means, and the AD converter 33 of the control section 13, I /O34, CPU3
0, ROM 31 and RAM 32 constitute an average value means.

(b) Initial control immediately after starting dialysis Immediately after starting dialysis, the intermediate setting value of TMP
The throttle unit 6 is controlled with T _P1 as the target, that is, the control set value, and after TMP has become almost stable (in Fig. 2, after Δt ₀ has passed after the start of dialysis), the throttle unit is controlled with the final set value T _p2 as the target. do. When TMP becomes almost stable (in FIG. 2, after Δt ₀ has passed and further Δt ₁ hour has passed after the start of dialysis in FIG. 2), steady throttling control is performed. Let us explain the control operations during these first and second rising periods Δt ₀ and Δt ₁ with reference to the aperture characteristic diagram in Figure 4 (n-P characteristic measured in (a)) and the operation flowchart in Figure 5. .

In order to pressurize the blood immediately after starting dialysis, the CPU 30 calculates P ₀ = ₀ (1 mm
The number of pulses n ₀ corresponding to Hg) is read from the RAM 32, and Δn pulses are applied to the motor of the aperture section along with a signal instructing forward or reverse rotation so that the total number of applied pulses becomes n ₀ (step S ₁ ). Hereinafter, for the sake of simplicity, it is assumed that Δn>0 in the case of forward rotation and Δn<0 in the case of reverse rotation.

TMP intermediate setting value T _p1 , final setting value T _p2 , first rise period Δt ₀ , second rise period Δt ₁ as necessary
and store these data in RAM (step _S2 ).

When TMP is almost stabilized (Δt ₀ or Δt ₀ +
Δt ₁ ) may be determined by the CPU 30 capturing the blood pressure P every 0.05 seconds and storing it in the RAM 32, and detecting the point in time when the difference between the maximum value and the next maximum value becomes less than a predetermined value, or it may be determined in advance. It may be determined experimentally.

CPU 30 includes blood pump 2 and dialysate supply section 8
and start dialysis (step _S3 ). Capture blood pressure value P every 0.05 seconds and RAM for 10 seconds
Since these data are pulsating due to the blood pump, the average pressure ₀ (i=0) from the maximum value to the next maximum value is calculated and stored in the RAM (step S ₄ ). _Five ). Next, the dialysate pressure Q ₀ (represents an almost constant value in a short period of time)
(step S ₆ ), and the average value of TMP _{is 0.}
= ₀ − Q ₀ , and the deviation Δ ₀ = T _p1 − ₀ between the average value of TMP and the intermediate setting value is determined. Therefore, if the blood pressure is increased by Δ ₀ , this deviation can ideally be reduced to zero, and the new blood pressure required to bring this deviation close to zero is P ₁ = ₀ + Δ ₀ (Step _S7 ) The aperture characteristic (n-p
The integrated value _{N 1} of pulses corresponding to _this blood pressure P ₁ is calculated ₍ step S ₈ ) using
N ₀ =n ₀ ) is calculated and applied to the motor (step S ₉ ). As blood pressure P rapidly increases, TMP (=P-Q) rapidly rises from a negative value to a positive value toward the intermediate set value T _p1 as shown in Figure 2. This causes small transient oscillations above and below T _p1 . The elapsed time since starting dialysis is the first
When the time point when the rising period becomes equal to Δt ₀ is detected (step S ₁₀ ), it is determined whether or not i=1 in the control cycle i (step S ₁₁ ), and if i=1, i=1, that is, Update the subscripts 0 and 1 up to now to 1 and 2, respectively, and return to step _S4 .
The operation during the rising period Δt ₁ is resumed.

In addition, when calculating the average value _i of TMP in step _S7 , we used the instantaneous value of the dialysate pressure and did not use the average value, but if the instantaneous value fluctuates and causes an error, is the blood pressure P
Similarly, it is preferable to use the average value. Also
The average TMP value _i was determined as the difference between the average value _i of blood pressure and the dialysate pressure Q _i (or its average value _i ), but it is calculated from the instantaneous values of each pressure of blood and dialysate.
Find the instantaneous value TMP _i of TMP, and from this calculate the average value
You can also find TMP _i .

Measurement and control operations during the second rising period Δt ₁ are
The operation is exactly the same as the operation in the first rise period described above except that the final setting value T _p2 of TMP is used as the control setting value, so the explanation will be omitted.

(c) Steady state control When control cycle i=1 is detected in step _S11 in FIG. 5, the control operation automatically shifts to the steady state control operation described below. This operation will be explained with reference to the operation flowchart of FIG. During this period, TMP is close to the final set value, so fine control is performed every Δ _t2 (for example, 0.05 seconds) to reduce TMP by the blood pump.
Small errors with the control set value, including ripples, are quickly suppressed. In steady-state control, instantaneous values are used to perform measurements and control much faster than in the past.
However, the operation of each step is similar to the 0th and 1st control cycles of FIG. First, blood pressure P _i ′
(The instantaneous value is used instead of the average value) and the dialysate pressure Q _i are taken in (step S ₂₁ ). Note that the measured blood pressure data is designated as P _i ′ with a “′” added, and the CPU
This is distinguished from the blood pressure data P _i calculated by 30.
Next, the instantaneous value TMP _i =P _i ′−Q _i of TMP is calculated, and the deviation Δ _i =T _p2 −TMP _i between this value and the final setting value T _p2 is calculated. FIG. 7 shows TMP _i , Δ _i, etc. along with the ripple characteristics of TMP. Next, the ideal blood pressure value P _i+1 = to make the TMP deviation Δ _i zero
P _i ′+ _Δi is calculated (step S ₂₂ ). Next, using the aperture characteristics measured in (a), calculate the integrated value N _i+1 of the driving pulses corresponding to P _i+1 (step S ₂₃ ), and from this integrated value N _i+1 Subtract the integrated value N _i of the applied pulses to calculate the number of new pulses ΔN _i to be applied, that is, ΔN _i =N _i+1 −N _i (step
_S24 ). When it is detected that the elapsed time since the start of step S ₂₁ has reached Δt ₂ (for example, 0.05 seconds), that is, when the next timing is detected (step S ₂₅ ), ΔN _i pulses are applied to the motor. (Step S ₂₆ ). The CPU 30 determines the dialysis time t _a (for example, 5 hours) set by the elapsed time t _i since the start of dialysis.
Check whether timer 37 has reached
is checked (step _S27 ), and if the time has not been reached, the control cycle i is advanced by one and i+1→
i (step _S28 ), the process returns to step _S21 and the next control cycle is started. When the total dialysis time reaches the set value _ta in step _S27 , the dialysis is terminated.
In this way, fine and fast control is performed, and ripple fluctuations in TMP due to the influence of the blood pump are suppressed to a sufficiently small level.

As can be seen from the above explanation, the control unit 13
The CPU 30, ROM 31, and RAM 32 constitute first, second, and third deviation calculating means.

Example of Throttle Section FIG. 8 is a schematic diagram showing an example of the throttle section of this invention. The throttle tube 40 is inserted between a tube receiver 41 and a head 42, and a stepping motor 43 is used to move the head 42 forward in the direction of compressing the tube or backward. A rotating shaft 44 of the stepping motor 43 is connected to a screw 46 through a coupling 45, so that when the motor 43 rotates in the normal direction, the head 42 moves forward, and when the motor 43 rotates in the reverse direction, the head 42 moves backward. A control signal consisting of a forward/reverse rotation signal and a drive pulse is applied by the diaphragm control means. A brim-like position detection drum 47 is integrally provided on the circumferential surface of the coupling ring 45, and the position of the head 42 at the time when the circumferential edge of the drum turns on the lower limit switch 48 is the reference position. In other words, it is a position where the moving distance l=0. Also, when the drum 47 moves forward and the upper limit switch 49 is turned on,
Even if a forward control signal is given, the motor will not rotate and the head will not move forward any further. By turning on the lower limit switch 48, the position detection circuit 36 of the control section 13 can detect the position that should be the reference of the head.

This aperture section can follow control signals of up to approximately 1500 drive pulses/second at high speed. The pulse motor rotates, for example, θ=1.8 degrees per pulse.
The pitch P _a of the screw is, for example, 0.5 mm. The relationship between the moving distance l of the head and the total number n of drive pulses is l
It is expressed as = θ/360×n×p _a . In the case of the above numerical example, if n = 100 pulses are applied, l = (1.8/
360)×100×0.5=0.25mm.

``Effect of the invention'' In this invention, the average value of instantaneous values measured as necessary is used as the actual measured value of the blood circuit side pressure or TMP used for pressure control, so the instantaneous value fluctuates due to the influence of the blood pump. However, unlike the conventional case, large errors do not occur in the control signal applied to the aperture section.

Furthermore, even if there are variations in the squeezing characteristics of the aperture section due to irregularities in the disposable blood tube each time, according to this invention, the squeezing characteristics can be accurately measured before the start of dialysis, and the characteristics can be stored in the RAM and used thereafter. Since the control signal calculated based on the stored aperture characteristics is used to control the blood circuit side pressure (or TMP control), the error in the control signal can be significantly reduced compared to the conventional method.

By using the average value of TMP mentioned above and using the aperture characteristics measured and stored before dialysis, it is possible to give a more accurate control signal to the aperture section than before, and the TMP stabilizes near the final setting value. In addition to shortening the time it takes for the vibration to occur, the amplitude and duration of the rising transient vibration can be reduced, and more accurate ultraviolet detection can be performed than in the past.

Furthermore, in this invention, an intermediate setting value lower than the final setting value of TMP is set, and TMP is controlled in stages, so that the amplitude and duration of transient vibrations at the rise can be reduced, making it extremely accurate. It allows for extreme ultraviolet rays,
Its practical effects are enormous.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of this invention, together with an artificial kidney device. Fig. 2 is a diagram showing the TMP rise characteristics of the embodiment shown in Fig. 1;
Figure 3 is an operation flowchart for measuring and storing the throttling characteristics of the throttle section in the embodiment shown in Figure 1, and Figure 4 is an operation flowchart for measuring and storing the throttling characteristics of the throttle section in the embodiment shown in Figure 1. (Number of drive pulses to be applied)
FIG. 5 is an operation flowchart showing the startup operation immediately after the start of dialysis in the embodiment of FIG. 1, FIG. 6 is an operation flowchart showing the operation of the embodiment of FIG. The figure shows the TMP vs. time characteristic at steady state in the embodiment of Fig. 1, Fig. 8 shows the outline of the throttle part of the embodiment of Fig. 1, and Fig. 9 shows the blood circuit side of the artificial kidney device. A diagram showing ripple fluctuations in pressure, Figure 10 is a block diagram of a conventional artificial kidney device, Figure 11 is a diagram showing TMP rise characteristics of the conventional device in Figure 10, and Figure 12 is a diagram of the conventional device in Figure 10. FIG. 13 is a diagram showing the outline of the aperture section, and FIG. 13 is a diagram showing the variation in aperture characteristics when the tube of the aperture section is replaced. 1, 7...Blood tube, 2...Blood pump,
3, 5... Drip chamber, 4... Dialyzer, 6
... Throttle section, 8... Dialysate supply section, 9, 10...
Flow path, 11, 12...Pressure sensor, 13...Control unit, 30...CPU, 31...ROM, 32...
RAM, 33... AD converter, 34... input/output circuit, 35... drive circuit, 36... position detection circuit,
37...Timer.

Claims (1)

[Scope of Claim for Utility Model Registration] Blood circuit side pressure is measured by a blood circuit side pressure measuring means, dialysis circuit side pressure is measured by a dialysis circuit side pressure measuring means, and these measured blood circuit side pressure and dialysis circuit side pressure Calculate the differential pressure (TMP) between
In a blood circuit pressure control device for an artificial kidney device, which controls a constriction section provided in a venous line in the blood circuit according to the deviation between the calculated value and the control set value, so as to reduce the deviation. throttling characteristic measuring means for measuring the relationship between the degree of throttling and the blood circuit side pressure; a throttling characteristic storage means for storing the measured throttling characteristic; throttling part control means for generating a control signal for the throttling part so as to reduce the deviation of the throttling part; averaging means for calculating the average value of the differential pressure (TMP); a first deviation calculation means that sets the set value as the control set value and calculates the difference between this and the average value of the differential pressure (TMP) to obtain the deviation; After the final set value is almost stabilized, the control set value is set as the final set value, and a second deviation calculation means is set as the deviation by calculating the difference between the final set value and the average value of the differential pressure (TMP); After the differential pressure (TMP) is almost stabilized at the final set value, the third deviation calculating means calculates the difference between the differential pressure (TMP) and the final set value at each timing and uses the difference as the deviation. A blood circuit pressure control device for an artificial kidney device, characterized by: