JPH0450037Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a device for measuring the amount of water removed per unit time in hemodialysis, and is used attached to a hemodialysis machine.

(Prior art) Hemodialysis, which is performed using an artificial kidney device (hemodialysis device), is a method that eliminates waste products from the body or takes in necessary substances to replace the kidneys when the human body suffers from renal failure. It is widely used for purification. The main function of the kidneys is to make urine, but
Most of this urine is water, so in hemodialysis, water is removed from the blood.
An important issue is to perform so-called water removal.

This water removal method involves creating negative pressure on the dialysate side of the hemodialysis machine to suck out body fluids from the blood from the dialysis membrane surface, or contrary to the previous method, applying pressure to the blood side and sucking body fluids from the dialysis membrane surface. There are two methods for pushing out body fluids; the former is generally called the negative pressure water removal method, and the latter is called the positive pressure water removal method.

In one embodiment of the present invention, the latter positive pressure water removal method will be described as described below, but the invention is of course not limited to this.

First, the operating principle of a commonly used hemodialysis device will be explained with reference to a drawing showing an embodiment of the present invention.
1b is punctured to serve as an inlet/outlet for extracorporeal circulation of blood, a blood pump 2 supplies a constant flow of blood flowing out from the cannula 1a to the hemodialysis apparatus 3, and a squeeze device (clamp) 4 is used to connect the tube to the hemodialyzer 3. A stenosis is created in the dialyzer 5 to generate positive pressure in the blood inside the dialyzer 3. Air chambers 6a, 6b and a pressure gauge 7 are installed at the blood inlet and outlet of the dialysis device 3.
a and 7b are provided as a guide to know the ultrafiltration pressure. The dialysis device 3 has a fluid supply port 8a and a fluid drain port 8b.
and a separately prepared dialysate is supplied. To perform hemodialysis using this general dialysis device, after rotating the blood pump 2, the diaphragm 4 is squeezed to generate positive pressure, and the pressure gauges 7a and 7b are checked to determine the appropriate ultrafiltration pressure, e.g. Adjust to 140mmHg.

By the way, dialysis machines naturally have a water removal capacity value, that is, an ultrafiltration coefficient (UFR), but for example, if you use a dialysis machine whose water removal capacity value is 4.0ml/mmHg/hr If dialysis is performed for 5 hours and the target total amount of water removed is 2800 ml, then 2800 ÷ 4.0 ÷ 5 = 140 mmHg (ultrafiltration pressure), and ultrafiltration of 140 mmHg is obtained by checking the pressure gauge mentioned above on the blood circuit side of the dialysis machine used. Calculated water removal volume should be 2800 ml if the pressure is set to 2,800 ml, but in reality, there are many cases where only about 80% of the target water removal volume can be removed, and even with a dialysis machine of the same standard, the water removal volume is ±7. The current situation is that there is a difference in water removal capacity of 1.5%.

The cause of this is based on the functional evaluation standards for dialysis machines (dialyzers) set by the Japanese Society for Artificial Organs.
Manufacturers measure the performance of their own dialysis machines, and there are three measurement methods (A,
Methods B and C), but both use only degassed ion-exchanged water in the blood circuit and dialysis circuit, so when used in an actual living body, small to small particles such as protein-like substances and lipids may be present. This is thought to be due to various changes in the performance of the dialysis membrane due to the relationship between blood mixed with intermediate molecular weight waste products and relatively pure dialysate.

For this reason, when using a dialysis machine, doctors and nurses frequently measure blood pressure to prevent excessive water removal or insufficient water removal, while at the same time being careful to monitor the patient's condition. They are forced to do work such as handing out information and changing pressure settings. Even so, the exact amount of water removed can only be determined by measuring the patient's weight immediately after the hemodialysis procedure is completed, so the effort required during the dialysis procedure is immeasurable. The current situation is that it is not surprising that we have fallen into this situation.

(Problem that the invention aims to solve) As mentioned above, in the past, the target amount of water removed was obtained by inspecting the UFR specified on the dialysis machine and the pressure gauge on the blood circuit side. Therefore, the present invention has the following drawbacks:
To eliminate the above-mentioned difficulties by making it possible to directly measure the amount of water removed per unit time during actual use of a dialysis machine, without being based on calculated values from UFR and a pressure gauge. With the goal.

(Technical Means for Solving the Problems) In order to solve the above problems, the present invention provides on-off valves 13 in each of the dialysate supply circuit 11 and the dialysate discharge circuit 12, as shown in the embodiment diagram. .
This system adopts a configuration in which a

(Example) Reference numeral 10 indicates a water removal amount measuring device, which includes the following components. Namely, as shown by arrow a, there is a dialysate supply circuit 11 to which dialysate is supplied from an external dialysate tank, etc., and as shown by arrow b, a dialysate discharge circuit to discharge dialysate after its work to the outside. 12, and each circuit is provided with an on-off valve, specifically normally open solenoid valves 13 and 14. Note that the on-off valve is not limited to a normally open solenoid valve, and may be a simple electromagnetic on-off valve or a manual solenoid valve, but as described below, according to a normally open solenoid valve,
Simultaneous operation can be easily performed as described below. And in each circuit, the above-mentioned on-off valve 1
3 and 14, that is, in the dialysate supply circuit 11, a fluid supply side circuit 11a on the way from the on-off valve 13 to the dialyzer 3, and a dialysate discharge circuit 12.
In this case, a drain side circuit 12a in the middle of the circuit for discharging from the on-off valve 14 to the outside is branched and connected by a branch circuit 15 having a smaller diameter than these circuits.
Also, this branch circuit 15 includes a well-known flow rate measuring device 1.
6. For example, an area flowmeter, a positive displacement flowmeter, a differential pressure flowmeter, etc. are interposed and connected. Note that this branch circuit 1
Also on the downstream side of the flow rate measuring device 16 in No. 5,
A normally closed solenoid valve 17 that operates in the opposite direction to the solenoid valve is interposed as an on-off valve, but in this case, as will be described later, the tube diameter of the branch circuit 15 is the same as that of the liquid supply/drainage circuit 11a, If the diameter is sufficiently smaller than 12a, for example, if the former is about 2 mmφ and the latter is about 8 mmφ, there is no need to provide the above-mentioned on-off valve. 18 is a switch lever for operating the on-off valves 13, 14, 17, all at once; 19 is the on-off valve 1;
This is an energization indicator lamp that indicates that power is applied to 3, 14, and 17.

This water removal amount measuring device 10 is connected to a dialysate circuit on the way to the dialysis device 3 using a well-known connection adapter. This method of use involves operating the blood pump 2 to send blood from the living body A through the blood circuit 5a to the dialysis machine 3, as described in the prior art section, and then pumping the dialyzed (water removed) blood into the dialyzer 3. While returning blood to the living body A again, operate the diaphragm 4 according to the target water removal amount and the UFR specified on the dialysis machine 3, and perform ultrafiltration inside the dialysis machine 3 while checking the pressure gauges 7a and 7b. Set the pressure to, for example, 140 mmHg. As a result, the dialysate from the dialysate supply circuit 11 passes through the normally open solenoid valve 13 and the liquid supply side circuit 11a, flows into the dialyzer 3 from its liquid supply port 8a, and the dialysate (body fluid) that has finished its work is transferred to the dialyzer 3. is discharged from the drain port 8b through the dialysate drain circuit 12 and the normally open solenoid valve 14 to the drain side circuit 12a. In this case, as mentioned above, the branch circuit 15 is branched and connected to the liquid supply side circuit 11a, but if the tube diameter of the branch circuit is sufficiently smaller than that of the liquid supply side circuit 11a, Branch circuit 15 by resistor
When the dialysate does not flow into the branch circuit 15 and the diameters of both circuits 11a and 15 are close to the same, the normally closed solenoid valve 17 provided in the branch circuit 15 closes the branch circuit 1.
5 is blocked, no dialysate will flow in. In this dialysis work, the dialysis machine
As mentioned above, when the UFR is 4.0 ml/mmHg/hr, dialysis for 5 hours should result in a calculated amount of water removal of 2800 ml.

In order to check whether the above calculated values are accurate in actual dialysis work, the present invention switches the switch lever 18 and energizes the solenoid valves 13, 14, 17 all at once to the input state. All you have to do is let it happen.

By energizing each solenoid valve, each solenoid valve 13, 14 in the liquid supply/drainage side circuit 11a, 12a
is switched to the closed position, and the flow state of both circuits 11a and 12a is cut off, while the solenoid valve 17 of the branch circuit 15 is switched to the open position, and the circuit 15 is placed in the flow state. Therefore, the dialysate in the dialyzer 3 flows back to the branch circuit 15 from the open liquid supply port 8a through the liquid supply side circuit 11a due to the ultrafiltration pressure, and the flow rate measuring device 16
The liquid is sent out from the drain side circuit 12a via the electromagnetic valve 17. As the dialysate passes through the flow rate measuring device 16 in this way, the flow rate per unit time hr is naturally measured, and if the pointer 16a of the measuring device 16 indicates a position of, for example, 0.45/hr as shown in the figure, then the flow rate per unit time hr is measured. , 0.45 x 5 = 2250ml for 5 hours dialysis
It is read to obtain a dialysis amount of 2800, which is the target value.
ml, so operate the wringer 4 to set the pointer 16a of the measuring device 16 to the desired position, e.g.
It can be determined that the ultrafiltration pressure should be increased until it reaches the 0.56 position. In addition, if the measured water removal amount per unit time is 450ml, the actual UFR is 450ml ÷ 140mmHg ≒ 3.2ml/mmHg/hr
It is converted to be . Therefore, this actual measurement
Based on the UFR, it is possible to preset the exact ultrafiltration pressure before use.

Incidentally, it is possible in principle to measure the amount of water removed by connecting the branch circuit 15 with the flow rate measuring device 16 to the dialysate discharge circuit 12 via the branch with the on-off valve 14 in between. The dialysate flowing through the discharge circuit 12 has come into contact with blood in the dialyzer 3 and contains waste substances such as protein-like substances and lipids, and these substances are absorbed into the glass tube of the flow rate measuring device in a short period of time. It adheres to measuring equipment components such as float valves, making them no longer accurate and requiring frequent disassembly and cleaning.

On the other hand, according to the present invention, the dialysate supply circuit 1
By connecting the branch circuit 15 to the 1 side, clear dialysate that has not yet come into contact with blood is introduced into the flow rate measuring device 16. Contamination is less likely to occur and the equipment is easy to maintain. Furthermore, during measurement, the dirty dialysate in the dialysate discharge circuit 12 does not flow back into the dialyzer 3 because this circuit is shut off by the on-off valve 14, and the dialysate in the dialysate supply circuit 11 is Only the water removed by hemodialysis in the device 3 is pushed out from the liquid supply port 8a, and the amount of water removed can be accurately measured. Furthermore, in the dialysate supply circuit 11, a relatively large amount of dialysate is accumulated in the fluid supply side circuit 11a extending from the fluid supply port 8a to the branch circuit 15. It takes a considerable time for the filtrate) to reach the measuring device 16 of the branch circuit 15, and therefore the unit flow rate with clear dialysate must be measured by the measuring device 16 before this reaches the measuring device 16 of the branch circuit 15. Therefore, if the measurement time is not too long, there is little chance of contamination of the measuring device 16.

(Effects of the invention) According to the invention, it is possible to maintain the blood pressure of patients by freeing them from various tasks and worries such as frequent blood pressure measurements, which were caused by conventionally being able to perform dialysis work only by groping. The amount of water removed per unit time, which is most important for medical treatment, can be directly read using a measuring device, which is great news not only for doctors and nurses but also for the patients themselves.

Further, according to the present invention, since the structure is very simple, it can be manufactured at low cost, and its operation is also extremely easy.

Furthermore, according to the present invention, on-off valves are provided in each of the dialysate supply circuit and the dialysate discharge circuit, and the feed side circuit and the drain side circuit, which are circuits downstream of these on-off valves, are connected by a branch circuit. Since a flow rate measuring device is installed in the branch circuit, by closing both of the on-off valves at the time of measurement, the dialysate remaining in the dialysate supply circuit flows back into the branch circuit and prevents it from coming into contact with blood. Since the clear dialysate that has not been used is first introduced into the flow measuring device, contamination of the flow measuring device is less likely to occur and maintenance of the device is easy.

Furthermore, during measurement, the supply of dialysate from the dialysate supply circuit to the dialyzer is shut off by the on-off valve installed in that circuit, and the dirty dialysate in the dialysate discharge circuit is removed by the on-off valve installed in the circuit. Because it is shut off by a valve, there is no backflow into the dialysis machine, and therefore only the removed water that has been hemodialyzed in the dialysis machine is pushed out from the dialysate supply circuit to the branch circuit and introduced into the flow rate measuring device. Therefore, the amount of water removed can be accurately measured.

Furthermore, by being able to actually measure the amount of water removed per unit time, it becomes possible to convert it into an actual UFR, thereby making it possible to accurately achieve the target amount of water removed.

[Brief explanation of the drawing]

The drawings are explanatory diagrams of one embodiment of the present invention. DESCRIPTION OF SYMBOLS 10... Water removal amount measuring device, 11... Dialysate supply circuit, 11a... Liquid supply side circuit, 12... Dialysate discharge circuit, 12a... Drainage side circuit, 13, 14...
Opening/closing valve, 15...branch circuit, 16...flow measuring device.

Claims (1)

[Scope of utility model registration request] An on-off valve is provided in each of the dialysate supply circuit and the dialysate discharge circuit, and the downstream circuit of these on-off valves, that is, the supply side circuit and the drain side circuit, are connected by a branch circuit, and a flow rate measuring device is installed in this branch circuit. A device for measuring the amount of water removed in hemodialysis using an intervening device.