JPH0323179B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ultrafiltration device that draws blood from a human body outside the body and circulates it, and removes water in the blood by ultrafiltration at that time.

In this type of ultraviolet device, it is important to determine how accurately the ultraviolet amount is determined. For this reason, conventionally, as shown in FIG. 1, blood in a human body 11 is guided into a blood passage 12 outside the body, and the blood in the blood passage 12 is sent by a pump 13 to be circulated back into the body. It passes through a dialyzer 14. A dialysate tank 1 is provided in the dialyzer 14.
Dialysate is supplied from 5 by a pump 16, and the drained fluid is drawn out from a pipe 17 by a pump 18.
In the dialyzer 14, waste products are transferred to the dialysate side through the dialysis membrane due to the concentration difference between the blood and the dialysate, and the difference between the pressure of the blood and the pressure of the dialysate, that is, the pressure applied to the dialysis membrane, so-called ultrafiltration. Depending on the pressure, water in the blood is discharged to the dialysate side through the dialysis membrane. In this way, water in the blood is removed and the purified blood is returned to the human body 11.

By driving the pump 16 that sends dialysate to the dialyzer 14 and the pump 18 that discharges dialysate from the dialyzer 14 by the same motor 19, and by making these pumps 16 and 18 metering pumps with the same characteristics, the dialyzer 14
By matching the flow rate of the dialysate sent to the dialyzer 14 with the flow rate discharged from the dialyzer 14, excess water from the discharge path 17, that is, excess water taken out from the blood, accumulates in the container 21. Therefore, the amount of liquid that enters the container 21 becomes an ultra-excess amount. The ultra-limit excess amount in this container 21 is measured to control the removal of water during dialysis, and this control is done, for example, by adjusting the opening degree of the valve 22 inserted into the blood pipe to control the pressure on the blood side. , or conversely, the pressure on the dialysate side is controlled to adjust its ultrafiltration.

In this way, ultrafiltration in hemodialysis is an operation in which water accumulated in the body is drawn out of the body by applying an ultraoverpressure to the dialysis membrane, but whether this goal has been achieved is controlled by the difference in body weight before and after dialysis. Normally, when controlling the ultra-excess in hemodialysis and controlling body weight, the ultra-excess amount, that is, the amount of liquid in the container 21 in Fig. 1, is accurately measured, and this measurement value is used to control the ultra-overpressure of the dialysis membrane. (TPM) was being adjusted. However, it has been difficult to accurately measure the ultraviolet excess amount due to the presence of bubbles in the waste liquid. Furthermore, even if the ultraviolet dose can be precisely controlled, the weight of food and drink during hemodialysis, fluid replacement (for example, adding physiological saline to the blood and returning it to the body), the amount of drug administered, and the amount of insensible excretion of the patient. Due to amounts in and out of the patient other than the extreme excess amount, the body weight at the end of dialysis will deviate from the target weight at the start of dialysis by these amounts. This deviation can be prevented by, for example, adjusting the ultra-overpressure while monitoring the patient's weight using a bed with a scale, or by shortening or lengthening the dialysis time. However, such a procedure requires a great deal of effort on the operators, such as doctors and nurses, who are involved in dialysis, and is difficult to carry out clinically.

In order to obtain an ultraoverload close to the target weight just by adjusting the ultraoverload, calculate the amount of food, drink, fluid replacement, etc. in advance before starting dialysis, and set the amount added to the target weight loss as the ultraoverload. It is possible to do so. However, even if various disturbance factors are calculated in advance, there will be variations in the amount of food consumed by each patient, the length of meal times,
The amount of fluid replacement will vary depending on the patient's condition during dialysis.
It cannot be managed in advance.

The purpose of this invention is to correctly manage the weight of a patient regardless of whether the patient is in or out of a patient other than the limit, that is, to easily achieve the initial target limit. The objective is to provide an over-the-counter device.

According to the invention, the patient's weight is measured during the ultraviolet period, while means are provided for generating water in terms of weight and a removal program;
The extreme overpressure is controlled from this removal program and the measured weight. Furthermore, if food or drink is taken or fluid replacement is performed as necessary, the removal program is changed accordingly.

For example, as shown in FIG. 2, a weight scale 24 is used in the present invention. This weight scale 24 is a so-called bed scale, which is capable of measuring the weight of a patient undergoing ultra-extraordinary treatment while the patient is lying on the bed.
Alternatively, if the ultraviolet test is performed with the patient sitting in a chair, a chair is used that is adapted to measure the patient's weight.

Further, a removal program setting device 25 is provided, and this removal program setting device 25 generates a signal indicating an ideal removal amount that changes over time in accordance with the ultraviolet to be removed from the start of the ultraviolet. Moreover, the value is converted to body weight. For example, for a weight W ₀ just before the start of the limit limit, the target weight is W ₃ , the limit limit ends at time t ₃ , and the weight decreases linearly during this time T ₃ = t ₃ - _{t 0} . In this case, the gradient α corresponding to the _line 26 _shown in _FIG . The product αT _t of this α and the count value T _t of the counter 28 indicating the passage of time is output from the calculation unit 27 . Further, the initial weight W ₀ of the patient immediately before dialysis is set in the setting device 29, this initial weight W ₀ and αT _t from the calculation unit 27 are added in the addition circuit 31, and the addition result W ₀ - αT _t is calculated as the time The setting device 25 outputs a weight conversion removal program that changes over time.

The removal program thus obtained and, for example, the weight W ₁ from the scale 24 at time t ₁ are compared in the comparator circuit 32, and the extreme overpressure is controlled in accordance with the difference between them. That is, the output of the comparator 32 is supplied to the controller 33, and an operation signal is output according to the input value. For example, the weight at that time W ₁
If the value of the removal program is small compared to W ₀ −
When αT ₁ < W ₁ , the ultraviolet exceeds more, so the valve 22 is controlled to be closed by the operation signal from the controller 33 to increase the blood pressure, and conversely, when the removal program is larger. When W ₀ −αT ₁ >W ₁ , the ultraviolet amount becomes too large, so the valve 22 is opened in response to an operation signal from the controller 33 and controlled to lower the blood pressure.

In this way, the patient's weight is always automatically measured during the extremity period, and the extremity overpressure is controlled according to the deviation between this and the elimination program converted to the weight at that time, so the patient's weight is always maintained at the target weight value. It is possible to terminate the ultraviolet rays.

By the way, when the patient goes out to eat or drink or replaces fluids during the limit period, the output of the comparator 32 changes significantly. In such a case, for example, when a meal is taken at time _t1 as shown in FIG. 3, the patient's weight increases as indicated by the dotted line 35. If the weight reaches W ₂ at time t ₂ when the eating and drinking is finished, then the deviation of the weight from the previous elimination program will be quite large. Therefore, if the extreme overpressure is significantly increased so as to suddenly reduce the deviation, water in the blood is suddenly drawn away, which may have an adverse effect on the patient. Alternatively, the control system may not be able to follow such a large deviation. Therefore, when the body weight is artificially increased to W ₂ from the outside, the time difference T between the dialysis end time t ₃ initially set in the calculation unit 42 and the time t ₂ when eating and drinking is finished, for example. α' is obtained by dividing W ₂ -W ₃ by ₄ = t ₃ -t ₂ , and a removal program determined by this value α' is generated. In other words, the program is set so that the dialysis ends at time t3 according to the removal program shown in line ₃₆ after the time _t2 when eating and drinking is finished. In other words, the point t ₂ of program line 26 up to that point
The difference ΔW and α′T _t between the value W ₁ and the actual weight W ₂ is given to the calculation unit 27, and the calculation unit 27 calculates α′T _t +ΔW and supplies it to the addition circuit 31. .

To do this automatically, for example, the output of the comparator 32 is supplied to the detection circuit 38, and the maximum deviation set value 39 is adjusted based on the water removal program and body weight, taking into account the influence on the human body or the control system. The maximum allowable deviation is set in advance, and the difference between this and the output of the comparator 32 is taken by the detection circuit 38. If the output deviation of the comparator 32 is smaller than the maximum deviation, control continues as it is; When the output exceeds α', the switch 41 is turned on, and α' calculated in the α' calculating section 42 and ΔW obtained by the comparator 32 are
is supplied to the calculation unit 27. In the α' calculation unit 42, as mentioned above, the elapsed time t ₂ and end time t ₃ from the counter 28, the weight W ₂ from the scale 24, the final weight W ₃ , etc. are input, and α ′ can be obtained by the following operation.

α′=W ₂ −W ₃ /t ₃ −t ₂ =W ₂ −W ₃ /T ₄ In addition to setting such a new program line 36, the modification of the program can be done by changing the maximum permissible value at time t ₂ , for example. It is also possible to reach the current program line 26 with a slope, ie, with a slope as indicated by the line 43 in FIG.
Or a program 4 that reaches the target value W ₃ from time t ₂ on a line 44 with the same slope as the initial water removal program.
It may be set to 4. Switch 46 with manual operation device 45
It is also possible to switch the program by switching the .

Generally, when eating or drinking, for example, the dialyzer 14 sets the extreme overpressure to a state close to open, that is, the valve 22 is set to a state close to open, so that there is almost no pressure difference between the blood and the dialysate. Make sure you don't have to worry about it.
Only the removal of waste products due to the concentration difference between the dialysate and blood is performed, and ultra-excess control is performed again after eating and drinking.

In this way, according to the present invention, the patient's weight is always automatically measured during the overextension, and the extremity overpressure is controlled according to the deviation between this and the removal program converted to the weight at that time. Therefore, you can always end the extreme limit at your target weight value.

Furthermore, since a means for changing the removal program is provided, even when the patient's weight is artificially changed by a relatively large amount, such as when eating or drinking, there is no adverse effect on the patient, and the control system does not perform unreasonable control. Therefore, it is possible to always perform ultra-overpressure control in a preferable state. Moreover, even if you eat and drink in this way, you can correctly perform ultraviolet rays until you reach your initially set target weight.

Although the removal program is set as a straight line in the above, it is not necessarily limited to such a straight line. You can also use it as This has been done in the past with such curve programs, and the same program settings can be made.

Furthermore, in the above, various calculations, program generation and program changes in FIG. 2 can be performed using a so-called microcomputer, and in that case, a keyboard or the like can be used to set the initial initial weight, further set the target weight, For example, the gradient α
The calculations of _αT and α′ are performed internally, and the elapsed time is also managed by a microcomputer. _t + ΔW is calculated, the calculated program is compared with the measured weight, and control according to the result is output from the computer as an operation output, and the comparison operation of the comparator 32 and the preset It is also possible to perform the comparison with the maximum deviation value using a microcomputer. Furthermore, in the above, ultrafiltration was performed by using a dialysate and the pressure difference between the dialysate and blood, but water is removed from the dialysis membrane by simply applying pressure to the blood without using a dialysate. This invention can also be applied to so-called hyperdialysis in which waste products are excreted at the same time.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a conventional ultrapass device, FIG. 2 is a block diagram showing an example of an ultrapass device according to the present invention, and FIG. 3 is a curve diagram showing an example of a water removal program. 11...Blood passage, 12...Blood passage, 13...
... pump, 14 ... dialyzer, 15 ... dialysate tank, 16 ... pump, 22 ... valve, 24 ... scale, 25 ... removal program setting device, 32 ... comparator, 33 ... control device, 38...detection circuit, 39
...Maximum deviation setter, 42...Change program calculation section.

Claims (1)

[Claims] 1 In an ultrafiltration device that circulates human blood extracorporeally and removes water from the blood by ultrafiltration,
a weight measuring means for measuring the weight of the human body during the limit period; a means for setting a removal program converted to body weight; an ultra-overpressure control means comprising: a changing means for changing the slope of the ultra-high pressure; a removal program obtained from the setting means and the changing means; and a control means for controlling the ultra-high pressure from the measured body weight obtained from the weight measuring means. Device.