JPS649026B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention provides ultrafiltration pressure (hereinafter referred to as
Regarding artificial dialysis equipment that accurately measures ultrafiltration rate (hereinafter referred to as TMP) and obtains a predetermined ultrafiltration rate (hereinafter referred to as UFR), in more detail, when performing UFR control, the control unit controls the blood circuit of the dialyzer and the dialysate. Cancel dialyzer blood side pressure loss and dialysate side pressure loss, as well as blood side head pressure and dialysate side head pressure, using four signals corresponding to the fluid pressures of the inflow line and outflow line of the circuit and a predetermined signal. The present invention relates to an artificial dialysis device that calculates the TMP and performs control calculations using this as a measured value.

[Conventional technology]

Conventionally, this type of artificial dialysis device has been equipped with a signal from a blood pressure sensor (blood circuit fluid pressure M ₁ ) installed in the inflow line of the blood circuit of the dialyzer and a signal from a dialysate pressure sensor installed in the inflow line of the dialysate circuit. Input the signal (dialysate circuit fluid pressure M ₃ ), perform the prescribed processing, operate the autocleaner installed in the dialysate circuit (adjust the pressure applied to the dialysis membrane, that is, TMP), and adjust the set UFR. Some are equipped with a control section to hold them.

In the above configuration, since there is pressure loss in the blood circuit and dialysate circuit of the dialyzer, TMP does not match the difference between blood circuit fluid pressure M ₁ and dialysate circuit fluid pressure M ₃ , and the relationship is as shown in the following equation: The relationship between UFR and M ₁ −M ₃ is shown in Figure 3.

TMP=M ₁ −M ₃ +ΔP However, ΔP…Offset due to the pressure loss, etc. Therefore, during ultrafiltration operation, the control section calculates M 1 −M ₃ from the signals of each hydraulic pressure sensor, and calculates M ₁ −M 3 from the signal of each hydraulic pressure sensor. corresponds to the value of M ₁ −M ₃ based on the properties of
Find UFR, that is, TMP, and use this as the measured value,
TMP _c (to get UFR configured externally)
Perform control calculations using TMP) as the set value and operate the auto-cleaner to obtain the specified UFR.

By the way, the above offset ΔP is the viscosity of blood,
It has been confirmed through experiments that it varies depending on blood flow rate, dialysate flow rate, etc. For this reason, UFR
In order to control the offset ΔP accurately, it is necessary to accurately know the offset ΔP, but in practice this is avoided because it is a very troublesome task.

[Problems that the invention attempts to solve]

In the conventional artificial dialysis equipment mentioned above, the troublesome measurement of the offset ΔP is avoided and the value determined empirically, that is, the offset ΔP is treated as a fixed value. If ΔP fluctuates, accurate TMP cannot be obtained and the predetermined
The problem is that it is difficult to obtain UFR.

Therefore, the present invention provides an artificial dialysis device that accurately measures TMP and obtains a predetermined UFR with high accuracy.

[Means for solving problems]

The configuration of the present invention is such that a blood inflow line and a blood outflow line are connected between the blood circuit of the dialyzer and the patient, a blood pump is provided in the blood inflow line, and a dialysate inflow line and a dialysate inflow line are connected to the dialyzer's dialysate circuit. A dialysate outflow line is connected, and an ultraoverpressure control means is provided on the dialysate outflow line or the blood outflow line, and the ultraoverpressure between the blood circuit of the dialyzer and the dialysate circuit is below a set limit. In an artificial dialysis apparatus that obtains a target ultraviolet amount by controlling the overpressure to match the overpressure, a first blood pressure sensor provided in the blood inflow line, and a second blood pressure sensor provided in the blood outflow line are provided. a blood pressure sensor; a first calculation means that receives detection signals from the first and second blood pressure sensors and outputs an average value of these blood pressures; and a first dialysis device provided in the dialysate inflow line. Detection signals are given from the fluid pressure sensor, a second dialysate pressure sensor provided in the dialysate outflow line, and the first and second dialysate pressure sensors, and an average value of these dialysate pressures is output. a second calculation means, a signal X _B corresponding to the average value of the blood pressure from the first calculation means, a signal X _D corresponding to the average value of the dialysate pressure from the second calculation means,
A third calculating means is provided to which a signal △P _H for correcting the head pressure error of the dialyzer is applied from the head pressure corrector, and calculates X _n =X _B -X _D +△P _H. Corrector output signal △P _H
is adjusted to cancel the error caused by the head pressure on _the blood circuit side of the dialyzer and _the head _pressure on the dialysate circuit side contained in The reason is that the extreme overpressure control means is controlled so as to match the pressure.

[Effect]

In the artificial dialysis apparatus of the present invention, when performing UFR control, the control unit controls the dialyzer using predetermined signals corresponding to the fluid pressures of the inflow and outflow lines of the blood circuit and dialysate circuit of the dialyzer. Blood side pressure drop and dialysate side pressure drop, and
The TMP is obtained by canceling the blood side head pressure and the dialysate side head pressure, and control calculations are performed using this as the measured value to obtain a predetermined UFR while operating the operating end.

〔Example〕 The present invention will be described below with reference to the drawings.

FIG. 1 is a configuration diagram showing an embodiment of the present invention. The artificial dialysis apparatus is composed of a dialyzer 1, its peripheral devices, and a control section 2 that inputs signals from the peripheral devices, performs predetermined processing, and operates the peripheral devices. The blood inflow line (arterial line) 3 of the dialyzer 1 includes a blood pump (roller tube pump) 4, an arterial chamber 5, and a blood pressure sensor 6 that detects the blood pressure _M1 of the blood inflow line 3 and outputs a signal _M1 . The blood outflow line (venous line) 7 has a venous chamber 9 and a blood pressure sensor 10 that detects the blood pressure M ₂ of the blood outflow line 7 and outputs a signal M ₂ . Further, the dialysate inflow line 11 of the dialyzer 1 is connected to the dialysate supply pump 12.
and a dialysate pressure sensor 13 that detects the dialysate pressure _M3 of the dialysate inflow line 11 and outputs a signal _M3 ,
The dialysate outflow line 14 has a dialysate pressure sensor 15 that detects the dialysate pressure M ₄ in the line 14 and outputs a signal M ₄ , and a negative pressure pump 8 that is operated by an external signal. On the other hand, the control unit 2 receives the signals M ₁ and M ₂
is input to calculate the average blood pressure value M ₁ +M ₂ /2 of the blood circuit consisting of the blood inflow and outflow lines, and _the calculation means ₁₆ outputs the signal X _B. Calculating means 17 calculates the dialysate pressure average value M ₃ +M ₄ /2 of the dialysate circuit consisting of the outflow line and outputs the signal X _D , inputs _the signals X _{B and}
Calculating means 19 which subtracts X _D , performs a correction calculation using a signal value ΔP _H corresponding to the head pressure of the dialyzer 1 (the signal value ΔP _H is given from the head pressure corrector 18), and outputs a signal X _n . and the signal X _n
It has a calculation means 20 that operates the negative pressure pump 8 by performing control calculations using a measured value and a signal X _S corresponding to the UFR set from the outside as a set value.

In the above configuration, the dialysis operation is performed while driving the blood pump 4 to flow blood into the blood circuit, and driving the dialysate supply pump 12 to flow dialysate into the dialysate circuit. A predetermined UFR can be obtained by At this time, the input X _n (measured value of control calculation) to the calculation means 20 of the control unit 2 is the second
The explanation is as follows with reference to the drawings.

FIG. 2 is a diagram showing the hydraulic pressure relationship of the dialyzer 1, each line, etc., and each reference numeral is used to have the same meaning as in FIG. 1. In addition, in Fig. 2, P _B ...the fluid pressure on the blood side, which is the fluid pressure at the 1/2 position in the longitudinal direction of the dialyzer P _D ...the fluid pressure on the dialysate side, at the 1/2 position in the longitudinal direction of the dialyzer. Fluid pressure ΔP _BL …Blood side pressure drop (fluctuation component affected by blood viscosity, blood flow rate, etc.) ΔP _DL …Dialysate side pressure drop (fluctuation component affected by dialysate flow rate, etc.) ΔP _BH1 , ΔP _BH2 …Dializer length Blood side head pressure when the 1/2 position in the longitudinal direction is referenced (fixed component determined by the dialyzer structure) ΔP _DH1 , ΔP _DH2 ... Dialysate side head pressure when the 1/2 position in the longitudinal direction of the dialyzer is referenced (dialyzer (fixed components determined _by the structure _of the
The relationships expressed by equations (1) to (4) hold between P _B and P _D.

M ₁ =P _B −ΔP _BH1 +1/2ΔP _BL (1) M ₂ =P _B +ΔP _BH2 −1/2ΔP _BL (2) M ₃ =P _D +ΔP _DH1 +1/2ΔP _DL (3) M ₄ =P _D − ΔP _DH2 −1/2ΔP _DL (4) Therefore, the outputs of calculation means 16, 17 and 19
X _B , X _D and X _n are expressed as equations (5), (6) and (7).

X _B = M ₁ + M ₂ /2 = P _B - 1/2 (ΔP _BH1 - ΔP _BH2 ) (5) X _D = M ₃ + M ₄ /2 = P _D + 1/2 (ΔP _DH1 - ΔP _DH2 ) (6 ) X _n =X _B −X _D +ΔP _H =P _B −P _D −1/2 {(ΔP _BH1 −ΔP _B
H2 ) + (ΔP _DH1 −ΔP _DH2 )} + ΔP _H (7) As is clear from equations (5) and (6), the signals X _B and X _D include the blood side pressure drop ΔP _BL and the dialysate side pressure drop. ΔP _DL is not included. That is, the calculation means 16 and 1
The processing in step 7 cancels the effects of blood viscosity, blood flow rate, dialysate flow rate, etc. In addition, the setting value of the head pressure corrector 18 is set in advance as (8)
If the formula is determined so that it holds true, the calculation means 19
The output signal X _n of is P _B - P _D.

ΔP _H = 1/2 {ΔP _DH1 − ΔP _DH2 ) + (ΔP _BH1 − ΔP _BH2 )} (8) Furthermore, since ΔP _BH1 , ΔP _BH2 , ΔP _DH1 , ΔP _{DH2 ,} etc. are fixed values, the head Pressure compensator 18
When set, X _n =P _B - P _D is maintained during dialysis operation.

Signal △P _H given from head pressure corrector 18
As a method of adjusting to the relationship of equation (8), the above head pressure error is calculated from the structure of the dialyzer 1 part, and the output △ _PH of the head pressure corrector 18 is adjusted to this value, or There is a method of operating the artificial dialysis machine with TMP set to zero, and adjusting the output △P _H of the head pressure corrector 18 so that the ultraviolet amount becomes zero while measuring the ultraviolet amount at this time. .

Therefore, the input to the calculation means 20 (measured value of control calculation) can be made to correspond accurately to the difference between the blood side liquid pressure and the dialysate side liquid pressure of the dialyzer 1, that is, TMP, and a predetermined UFR can be obtained. be able to.

It should be noted that the present invention is not limited to the above embodiment, and the control section 2 may be configured with a microcomputer, for example. Also, the UFR of dialyzer 1
Control may be performed by an autocleaner installed in the blood circuit.

〔Effect of the invention〕

As explained above, according to the artificial dialysis apparatus of the present invention, when performing UFR control, the control unit uses four signals corresponding to the fluid pressures of the inflow line and outflow line of the blood circuit and dialysate circuit of the dialyzer, respectively, and The specified signal is used to cancel the dialyzer's blood-side pressure loss and dialysate-side pressure loss, as well as the blood-side head pressure and dialysate-side head pressure, so TMP can be accurately measured and the predetermined UFR can be accurately measured. You can get a good deal.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram showing an embodiment of the present invention, Fig. 2 is a diagram showing the hydraulic pressure relationship of the dialyzer and its surrounding lines, and Fig. 3 is a diagram showing the UFR-(M ₁ - M ₃ ) characteristic. be. 1... Dialyzer, 2... Control unit, 3... Blood inflow line, 4... Blood pump, 6, 10...
Blood pressure sensor, 7... Blood outflow line, 8... Negative pressure pump, 11... Dialysate inflow line, 12...
Dialysate supply pump, 13, 15... Dialysate pressure sensor, 14... Dialysate outflow line, 16, 17, 1
9, 20...Calculating means, 18...Head pressure corrector.

Claims (1)

[Scope of Claims] 1. A blood inflow line and a blood outflow line are connected between the blood circuit of the dialyzer and the patient, a blood pump is provided in the blood inflow line, and a dialysate inflow line is provided in the dialysate circuit of the dialyzer. and a dialysate outflow line, and an ultraoverpressure control means is provided in the dialysate outflow line or the blood outflow line,
In the artificial dialysis apparatus that controls the ultra-overpressure between the blood circuit and the dialysate circuit of the dialyzer to match the set ultra-overpressure to obtain the target ultra-overpressure, the blood inflow line is provided with: a first blood pressure sensor provided in the blood pressure sensor; a second blood pressure sensor provided in the blood outflow line; detection signals are provided from the first and second blood pressure sensors, and an average value of these blood pressures is output. a first calculation means for calculating the dialysate pressure; a first dialysate pressure sensor provided in the dialysate inflow line; a second dialysate pressure sensor provided in the dialysate outflow line; a second calculation means that receives detection signals from the dialysate pressure sensor and outputs an average value of these dialysate pressures, and a signal _XB corresponding to the average value of the blood pressure from the first calculation means; A signal X _D corresponding to the average value of the dialysate pressure is output from the second calculation means,
A third calculating means is provided to which a signal △P _H for correcting the head pressure error of the dialyzer is applied from the head pressure corrector, and calculates X _n =X _B -X _D +△P _H. Corrector output signal △P _H
is adjusted to cancel the error caused by the head pressure on _the blood circuit side of the dialyzer and _the head _pressure on the dialysate circuit side contained in An artificial dialysis apparatus characterized in that the ultra-overpressure control means is controlled so as to match the pressure.