JPH09149935A - Dehydration quantity monitoring device for dialyzer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dehydration quantity monitoring device capable of directly monitoring the dehydration quantity and operating an alarm when necessary. SOLUTION: A light sensor containing a pair of a light emission section and a light reception section is provided on a vein side line 6, and the concentration of the blood going out of a dialyzer 3 is measured by the light sensor 4 before reinfusion. The transmittance of the light sent from the light emission section to the light reception section through the vein side line 6 during a dialysis is measured, the concentration of the blood passing through the dialyzer 3 is obtained, and the measured value of the blood concentration during the dialysis is compared with the theoretical value of the blood concentration calculated from the blood concentration measured before the start of the dialysis, the set flow of a blood pump 1, and the set dehydration speed. When the difference between the theoretical value and the measured value of the blood concentration becomes a prescribed value or above, a dehydrating pump 11 is stopped, and an alarm buzzer (not shown in the figure) is rung.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention flows in a blood circuit in order to prevent a change in the patient's physical condition caused by the excessive removal of water during dialysis and the increase in the weight of the patient due to the flow of dialysate into the blood. The change over time in blood concentration is monitored, and when an abnormal blood concentration is detected, water removal is immediately stopped,
The present invention relates to a water removal amount monitoring device for a dialysis machine that performs an alarm operation such as sounding an alarm buzzer.

[0002]

2. Description of the Related Art In recent years, high performance dialyzer (dialyzer)
Has been developed, and a large amount of water can be removed, and water removal can be controlled with high accuracy.On the other hand, if an operation error or trouble of the water removal mechanism occurs, the conditions are Depending on the situation, the situation may occur in which the device continues to operate without the mistake or trouble being discovered.
For example, as can be seen from the configuration shown in FIG. 1, there is no means for measuring the actual amount of water removed from the patient in the liquid circuit of the conventional dialysis machine, and the amount of water removed calculated by the rotation speed of the water removal pump 1 is confirmed. Therefore, if liquid leakage occurs from each component forming the closed circuit such as the three-way solenoid valves 9 and 12 or the silicone tube 8 connecting these components, it is possible to obtain by calculation. A large gap sometimes occurred between the amount of water removed and the actual amount of water removed. In such a case, there is a possibility that the water may be removed more than necessary to endanger the life of the patient, or the water may not be removed sufficiently.

[0003]

With a measuring device equipped in a current dialysis machine, such as a pressure gauge for measuring venous pressure or fluid pressure or a dialysate concentration sensor, it is directly determined whether the amount of water removed is normal or not. Since the measurement cannot be performed, the above-mentioned inconvenience occurs. Therefore, it is desired to develop a safety device that can directly monitor the amount of water removed and activate an alarm when necessary. The applicant of the present invention has conducted intensive studies in view of the above circumstances, and as a result, the blood concentration after water removal was higher than that before water removal.
Theoretically, it should be rising at a certain rate due to the water removal rate, so the blood concentration is directly measured in real time at any point on the venous line from the dialyzer to the patient,
By comparing this with the blood concentration measured before the start of dialysis, it is possible to recognize whether water removal control is being performed under the control conditions at the start of dialysis, and also to monitor changes in blood concentration during dialysis. By doing so, it was conceived that it is possible to recognize whether or not the change in the blood concentration of the patient during dialysis is appropriate.

[0004]

Based on the above recognition, the present invention provides a water removal amount monitor for a dialysis machine, which comprises a pair of a light emitting part and a light receiving part in a vein side line of a blood circuit of the dialysis machine. An optical sensor is provided, and the concentration of blood that has passed through the dialyzer is obtained by measuring the transmittance of light that passes through the blood circuit from the light emitting unit to the light receiving unit during dialysis, and the measured value of the blood concentration during the dialysis. And the blood concentration measured before the start of dialysis, the set flow rate of the blood pump, and the theoretical value of the blood concentration calculated from the set water removal rate, are compared to monitor the water removal amount. ing. In this case, as a monitoring method, it is possible to employ a method in which the water removal pump is stopped and an alarm buzzer sounds when the difference between the actually measured value and the theoretical value of the blood concentration exceeds a predetermined value. As the water removal amount monitoring device, a device is added which further monitors the time-dependent change of the actual measurement value of the blood concentration and stops the water removal pump and sounds an alarm buzzer when the time-dependent change shows an abnormal value. Preferably.

Further, as a water removal amount monitoring device for a dialysis machine,
An optical sensor including a pair of light emitting part and light receiving part is provided on the vein side line of the blood circuit of the dialysis machine, and the transmittance of light from the light emitting part through the blood circuit to the light receiving part is measured during dialysis. It is also possible to employ a configuration in which the change with time of the light transmittance is monitored. In this case, as a monitoring method, it is possible to employ a method in which the water removal pump is stopped and the alarm buzzer sounds when the change with time of the light transmittance shows an abnormal value. As the water removal amount monitoring device, further, the concentration of blood that has passed through the dialyzer is obtained from the transmittance of light, the actual measurement value of the blood concentration during the dialysis, the blood concentration measured before the start of dialysis, and the set flow rate of the blood pump. And the theoretical value of the blood concentration calculated from the set water removal rate are compared, and when the difference between the measured blood concentration and the theoretical value exceeds a specified value, the water removal pump stops and the alarm buzzer sounds. It is preferable to add such a structure.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a liquid circuit flow for explaining a water removal amount monitoring device of the present invention, FIG. 2 is a diagram showing a temporal change pattern of blood concentration in a venous line, and FIG. FIG. 4 is a diagram showing a time-dependent change pattern when physiological saline is injected, and FIG. 4 is a diagram showing a time-dependent change pattern when the blood pump flow rate and the water removal rate are changed in FIG. In the figure, 1 is a blood pump, 2 is an arterial line, 3 is a dialyzer, 4 is an optical sensor, 5 is a venous pressure sensor, 6 is a venous line, 7 is a hydraulic pump, 8 is a silicone tube, 9 and 12. Is a three-way solenoid valve, 10 is a water removing mechanism, 11 is a water removing pump, and 13 is a hydraulic pressure sensor.

As shown in FIG. 1, the blood of the patient is sent by the blood pump 1 to the dialyzer 3 through the arterial line 2 and the blood removed by the dialyzer 3 is passed to the patient through the venous line 6. Although blood is returned, the water removal amount monitoring device of the present invention is provided with an optical sensor 4 including a pair of a light emitting part and a light receiving part in the vein side line 6, and returns the blood concentration after leaving the dialyzer 3. It is designed to be measured by the optical sensor 4 before blood. Then, during dialysis, the concentration of blood that has passed through the dialyzer is obtained by measuring the transmittance of light that passes through the vein side line 6 from the light emitting unit and reaches the light receiving unit.
The amount of water removed by comparing the measured value of the blood concentration during the dialysis with the blood concentration measured before the start of dialysis and the theoretical value of the blood concentration calculated from the set flow rate of the blood pump 1 and the set water removal rate. Is monitored, and this mechanism prevents the error of water removal from becoming large in advance, and as a result,
The deterioration of the patient's condition due to water removal error is prevented.

If water is removed without problems after the start of dialysis, the difference between the blood concentration measured before the start of dialysis and the blood concentration after treatment with the dialyzer 3 depends on the flow rate of the blood pump 1 and the water removal rate. Although it should indicate the calculated value, if liquid leakage occurs, the theoretical value calculated and the measured value will be greatly different. In the water removal amount monitoring device of the present invention, the blood concentration difference between the theoretical value and the actually measured value is detected, and when the blood concentration difference exceeds a predetermined value, the water removal pump 11 stops and an alarm buzzer (not shown). Sounds.

In the water removal amount monitoring apparatus of the present invention, the time-dependent change of the actually measured value of the blood concentration after being processed by the dialyzer 3 (when water removal is normally performed, the slope becomes a constant straight line) is monitored. However, when the change over time in blood concentration shows an abnormal value, that is, when the slope deviates from the theoretical value and the deviation from the straight line becomes large (the blood concentration difference between the theoretical value and the actual measured value exceeds a predetermined value). If the patient's condition or the water removal mechanism of the dialysis machine is abnormal, the water removal pump 11 stops and the alarm buzzer sounds. May be. Further, since the blood concentration can be obtained from the light transmittance, it is possible to adopt a configuration in which the change with time of the light transmittance is monitored. In this case, the blood concentration difference between the theoretical value and the actually measured value may be monitored together.

As a water removing mechanism, the dialysate flow path is a closed circuit, a constant volume chamber is used to equalize the amount of dialysate into and out of the dialyzer, and a water removal pump is used to remove water. Closed-circuit capacity control method or by putting viscous (viscous liquid) in two chambers and controlling the amount of viscous with a viscous pump to control the amount of dialysate supplied to the dialyzer and the amount of dialysate discharged from the dialyzer. In order to maintain the transmembrane pressure (TMP) calculated from the preset water removal rate and the ultrafiltration rate (UFR) of the dialyzer, the closed capacity difference control method that uses the difference as the water removal amount is used. The TMP control method, which is designed to control the liquid by applying negative pressure or positive pressure, is used.
In short, any type of system can be adopted as long as it has a mechanism capable of removing water. The optical sensor 4 may be of any type as long as it is an optical method capable of measuring the transmittance of the light emitted from the light emitting section at the light receiving section.

Next, the water removal mechanism in the water removal amount monitor of the present invention will be described. Since the blood concentration is proportional to the hematocrit value, the blood concentration during dialysis is represented by the hematocrit value, and the pattern of the change over time is shown in FIG.
It looks like 4. Assuming that the blood concentration measured on the arterial line is A, the blood concentration on the venous line 6 is B, the flow rate of the blood pump 1 is Xml / min, and the water removal rate is Yml / min, the theoretical formula (1): Since A: B = 1: X / (X−Y) holds, the theoretical value of the blood concentration can be calculated from the blood concentration measured before the start of dialysis, the flow rate of the blood pump 1, and the water removal rate. The theoretical change in concentration over time is also linear. That is, in FIG. 2, when water removal is normally performed, the blood concentration changes like a linear CDF.
However, in the case of over-removal of water, the blood concentration is
As shown in E, the water-removal operation change point D is bent upward, and when the water-removal is insufficient, the blood concentration changes to the curve CDG.
As described above, the water-removal operation change point D will be bent downwardly.

In actual dialysis treatment, physiological saline may be injected during dialysis. FIG. 3 shows the blood concentration when physiological saline was infused between time points J and K. In such a case, the blood concentration fluctuates (decreases) while physiological saline is infused. Therefore, it is necessary to provide a function to suspend the monitoring function so that the dewatering pump is not stopped or the alarm action is not performed. The flow rate and water removal rate of the blood pump 1 are often changed during dialysis. For example, when the water removal speed is increased, the slope of the straight line increases from the point L when the water removal speed is changed as shown in FIG. 4, so that in this case also, the water removal pump is stopped and the alarm operation is performed. Not to
It is necessary to provide a function to suspend the monitoring function.

[0013]

As is apparent from the above description, by adopting the water removal amount monitoring device of the present invention, the water removal amount can be directly monitored during dialysis, and the alarm can be activated when necessary. Therefore, excessive water removal or insufficient water removal can be prevented in advance.

[Brief description of the drawings]

FIG. 1 is a diagram showing a liquid circuit flow for explaining a water removal amount monitoring device of the present invention.

FIG. 2 is a diagram showing a temporal change pattern of blood concentration in a vein side line.

FIG. 3 is a diagram showing a change pattern with time when physiological saline is injected into the dewatered water in FIG.

FIG. 4 is a diagram showing a temporal change pattern when the blood pump flow rate and the water removal rate are changed during water removal in FIG. 2.

[Explanation of symbols]

 1 blood pump 2 arterial line 3 dialyzer 4 optical sensor 5 venous pressure sensor 6 venous line

Claims (6)

[Claims] 1. A venous line of a blood circuit of a dialysis machine,
An optical sensor including a pair of light emitting part and light receiving part is provided,
By measuring the transmittance of light that passes through the blood circuit from the light emitting unit to the light receiving unit during dialysis, the concentration of blood that has passed through the dialyzer is obtained, and the measured value of the blood concentration during the dialysis,
Monitoring the amount of water removed from the dialyzer by comparing the blood concentration measured before the start of dialysis with the set flow rate of the blood pump and the theoretical value of the blood concentration calculated from the set water removal rate apparatus. 2. The water removal amount monitoring device according to claim 1, wherein the water removal pump stops and an alarm buzzer sounds when the difference between the actually measured value and the theoretical value of the blood concentration exceeds a predetermined value. 3. Monitoring the change over time of the actual measurement value of blood concentration,
The water removal amount monitoring device according to claim 2, wherein the water removal pump stops and an alarm buzzer sounds when the change with time shows an abnormal value. 4. The venous line of the blood circuit of the dialysis machine,
An optical sensor including a pair of light emitting part and light receiving part is provided,
A water removal amount monitoring device for a dialysis device, which measures the transmittance of light that passes through a blood circuit from a light emitting unit to a light receiving unit during dialysis and monitors changes over time in the transmittance of the light. 5. The water removal amount monitoring device according to claim 4, wherein the water removal pump is stopped and an alarm buzzer is activated when the change with time of the light transmittance shows an abnormal value. 6. The concentration of blood that has passed through the dialyzer is obtained from the light transmittance, and the actual value of the blood concentration during the dialysis, the blood concentration measured before the start of dialysis, the set flow rate of the blood pump, and the set water removal are performed. Comparing the theoretical value of the blood concentration calculated from the speed, and when the difference between the measured value and the theoretical value of the blood concentration exceeds a predetermined value, the water removal pump is stopped and the alarm buzzer sounds. The water removal amount monitoring device according to item 5.