JP2000126284A - Blood dialysis apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to execute water removal with high accuracy and reliability and to improve reliability and cost effectiveness without the need for laborious maintenance work by adopting water removing means composed of a metering vessel consisting of two chambers isolated by a diaphragm. SOLUTION: This apparatus removes wastes and moistures from blood by supplying the dialyzate and the blood to a dialyzer 2 and bringing the dialyzate and the blood into contact with each other via a semipermeable membrane disposed in the dialyzer. In such a case, the apparatus has closed circuit system dialyzate supply means 16, 6 and 7 for maintaining the flow rate of the dialyzate flowing into the dialyzer and the flow rate of the dialyzate flowing out of the dialyzer equal to each other, the water removing means for discharging the dialyzate at a prescribed flow rate from the closed circuit sections of the closed circuit system dialyzate supply means to the outside of the closed circuits. The water removing means are composed the metering vessel 201 consisting of the two chambers 205 and 206 separated by the diaphragm 202.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hemodialysis apparatus used for treating patients with renal failure.

[0002]

2. Description of the Related Art Hemodialysis apparatuses are widely used as apparatuses for treating patients with renal failure. Dialysis therapy not only removes waste products in the blood, but also plays a role in removing water that has been eaten and consumed from dialysis patients who do not produce urine. Therefore, a hemodialysis apparatus usually has a function of removing an arbitrary amount of water in addition to a function of supplying a dialysate to a dialyzer. FIG. 2 shows the principle of dialysate supply and water removal of a general hemodialysis apparatus. The diaphragm chamber 16 has a displaceable diaphragm 17 and a liquid supply chamber 18 and a waste liquid chamber 19.
This is a non-deformable container divided into two. First, the electromagnetic valves 12 and 15 are closed in a state where the liquid supply chamber 18 is filled with fresh dialysate and the diaphragm 17 is displaced to the waste liquid chamber 19 side to the limit.
3 and 14 are opened, the liquid feed pump 9 is stopped, and the liquid feed pump 1 is stopped.
Consider the operation when driving 0. However, here, it is assumed that there is no water removal pump 11. The dialysate in the liquid supply chamber 18 is sucked by the liquid pump 10 and moves to the waste liquid chamber 19 through the dialysate chamber 5 of the dialyzer 2. At this time, the flow path of the dialysate is a closed circuit when viewed from the dialyzer 2, so that the flow rate of the dialysate flowing from the liquid supply chamber 18 into the dialysate chamber 5 and the flow rate of the dialysate flowing out of the dialysate chamber 5 and flowing into the waste liquid chamber 19. Are equal. Eventually, all the dialysate in the liquid supply chamber 18 moves to the waste liquid chamber 19, and the diaphragm 17 is displaced to the liquid supply chamber 18 side to the limit. Therefore, if the electromagnetic valves 12 and 15 are opened, the electromagnetic valves 13 and 14 are closed, the liquid supply pump 9 is operated, and the liquid supply pump 10 is stopped, the supply of the dialysate to the dialyzer 2 is interrupted, and the waste liquid chamber 19 At the same time that the used dialysate is discarded, the supply chamber 18 is filled with fresh dialysate, and the diaphragm 17 is again displaced to the waste liquid chamber 19 side to the limit. Thereafter, by repeating this operation, a constant amount of dialysate can be supplied to the dialyzer 2 intermittently.
Hemodialysis can be performed in a state where the amount of dialysate in and out of the dialysis fluid is kept equal. Next, a state in which the water removal pump 11 is added will be described. As described above, the flow path of the dialysate always keeps a closed circuit when viewed from the dialyzer 2. From the blood chamber 4 via the That is,
The water in the blood is discharged out of the body by the water removal pump 11. From the above, it is possible to configure a system capable of performing a predetermined amount of water removal while supplying a constant amount of dialysate. However, in the system shown in FIG. 2, the supply of the dialysate to the dialyzer 2 is intermittent, so in practice,
As shown in JP-A-5-146506, two diaphragm chambers are connected in parallel and a dialysate is continuously supplied while supplementing each other, or a buffer is connected in series to the diaphragm chamber as shown in JP-A-5-146506. Systems have been devised to connect and continuously supply dialysate. In these systems, water removal is an important parameter affecting the life of the patient. Therefore, a plunger sliding type fixed amount pump, which is generally said to have high accuracy, has been used as a water removal pump. FIG. 3 shows an example of a plunger sliding type metering pump. The rotation of the motor 104 is converted by the link 103 into sliding of the plunger 102. When the plunger 102 moves rightward, the volume of the liquid chamber 110 increases, the check valve 105 opens, and liquid flows in from the liquid inlet 108. When the plunger 102 moves to the left, the volume of the liquid chamber 110 decreases, the check valve 106 opens, and the liquid is discharged from the liquid discharge port 109. By repeating the above, the liquid can be sent quantitatively. The plunger 102 is sealed with a seal 107, and the plunger 10
The liquid is prevented from leaking from a gap between the cylinder 2 and the cylinder 101.

[0003]

However, in the above-mentioned prior art, problems such as leakage due to abrasion of the seal material, sticking of the plunger due to adhesion of calcium carbonate generated in waste products of the patient and dialysate and defective valves are caused. There is
In order to avoid adverse effects on patients such as interruption of dialysis treatment and errors in water removal, complicated maintenance work such as frequent replacement of seals and cleaning work was required. In view of the above, an object of the present invention is to provide a hemodialysis apparatus having a water removal mechanism that can maintain high accuracy and reliability without performing complicated maintenance work.

[0004]

SUMMARY OF THE INVENTION According to the present invention, a dialysate and blood are supplied to a dialyzer, and the dialysate and the blood are brought into contact with each other through a semi-permeable membrane provided in the dialyzer. In a hemodialysis apparatus for removing dialysate, a closed-circuit dialysate supply means for keeping the flow rate of dialysate flowing into the dialyzer equal to the flow rate of dialysate flowing out of the dialyzer, and the closed-circuit dialysate supply Water removing means for discharging the dialysate at a predetermined flow rate from the closed circuit portion of the means to the outside of the closed circuit, wherein the water removing means is constituted by a measuring container comprising two chambers separated by a diaphragm. It is assumed that.

[0005]

With the above construction, there can be realized a water removing means capable of maintaining high water removing accuracy without leakage due to abrasion of the seal, fixation by waste or calcium carbonate, and defective valves.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows the configuration of an embodiment of the present invention. The supply of the dialysate is performed intermittently by a closed circuit system using one diaphragm chamber 16, but the details have been described above and thus will not be described here. In the water removal line 8, a measuring vessel 201 separated into two chambers by a diaphragm 202 instead of a plunger pump.
And a three-way solenoid valve 203, 204. The branch point between the dialysate waste liquid line 7 and the water removal line 8 is maintained at a constant positive pressure by a constant pressure valve 208.
Now, the three-way solenoid valve 204 is opened to the first chamber 205 of the measuring container 201 by a command from the controller 207.
Is opened to the second chamber 206, the dialysate waste liquid is discharged to the constant pressure valve 20.
The liquid flows into the first chamber 205 of the measuring container 201 due to the positive pressure by 8 and stops flowing when the first chamber 205 becomes full. Next, when the three-way solenoid valve 204 opens to the second chamber 206 of the measuring container 201 and the three-way solenoid valve 203 opens to the first chamber 205, the dialysate waste liquid flows into the second chamber 206, The dialysate waste liquid in 205 is discharged outside,
Stop when the second chamber 206 is full. Therefore, by repeating the above operation, the measuring container 20
1 is V (ml), and the switching frequency of the solenoid valve is N (times /
Minute), V × N (ml) of water can be removed every minute. However, when the switching time interval of the solenoid valve is 1 / N minutes,
The condition is that each of the rooms is sufficiently filled. This depends on the pressure adjusted by the constant pressure valve 208 and the flow resistance of the piping and the solenoid valve. Further, since the volume of the measuring container 201 itself is the minimum unit of water removal, it is necessary to make the volume equal to or less than the required water removal accuracy. For example, usually 3000
In order to remove the water in the order of 2 ml and to keep the error within 2%, the volume of the measuring container 201 must be 60 ml or less. The above embodiment is based on a closed-circuit type dialysate supply system using one diaphragm chamber.
It is easily conceivable that the present invention can be applied to a system in which two membrane chambers are connected in parallel as disclosed in JP-A-6-82 or a system in which a buffer is connected to a membrane chamber disclosed in JP-A-5-146506. is there.

[0007]

As described above, according to the present invention, water removal can be performed with high accuracy and reliability without requiring complicated maintenance work. As a result, it has become possible to supply a highly reliable, economical and maintainable dialysis machine.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of an embodiment of a hemodialysis apparatus according to the present invention.

FIG. 2 is a diagram showing a closed-circuit type dialysate supply method and a water removal method in a conventional hemodialysis apparatus.

FIG. 3 is a view showing the structure of a water removal pump in a conventional hemodialysis apparatus.

[Explanation of symbols]

 Reference Signs List 1 patient 2 dialyzer 3 semi-permeable membrane 4 blood chamber 5 dialysate chamber 6 dialysate supply line 7 dialysate waste liquid line 8 water removal line 9,10 liquid sending pump 11 water removal pump 12,13,14,15 solenoid valve 16 Diaphragm chamber 17 Diaphragm 18 Liquid supply chamber 19 Waste liquid chamber 20 Blood pump 101 Cylinder 102 Plunger 103 Link 104 Motor 105, 106 Check valve 107 Seal 108 Liquid inlet 109 Drain outlet 110 Liquid chamber 201 Measuring container 202 Diaphragm 203, 2043 One-way solenoid valve 205 first chamber 206 second chamber 207 controller 208 constant pressure valve

Claims (1)

[Claims] Claims: 1. A dialysate and blood are supplied to a dialyzer, and the dialysate and the blood are brought into contact with each other through a semi-permeable membrane provided in the dialyzer.
In a hemodialysis apparatus for removing waste and water from blood, a closed circuit dialysate supply means for keeping the flow rate of dialysate flowing into the dialyzer equal to the flow rate of dialysate flowing out of the dialyzer, and Water removing means for discharging dialysate at a predetermined flow rate from the closed circuit portion of the closed circuit type dialysate supply means to the outside of the closed circuit, wherein the water removing means is a measuring container comprising two chambers separated by a diaphragm. A hemodialysis apparatus characterized by being constituted.