JP4097811B2 - Hemodialysis equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a hemodialysis apparatus used for the treatment of patients with renal failure.
[0002]
[Prior art]
Hemodialysis devices are widely used as devices for treating patients with renal failure. Dialysis therapy not only removes waste in the blood, but also plays a role of so-called water removal, which removes the water consumed by dialysis patients who do not produce urine. Therefore, the hemodialysis apparatus is usually provided with a function of removing any amount of water in addition to the function of supplying the dialysate to the dialyzer. FIG. 5 shows the principle of dialysis fluid supply and water removal of a general hemodialysis apparatus. The diaphragm chamber 16 is a non-deformable container divided into a liquid supply chamber 18 and a waste liquid chamber 19 by a displaceable diaphragm 17. First, the supply chamber 18 is filled with fresh dialysate, the diaphragm 17 is displaced to the limit toward the waste solution chamber 19 side, the solenoid valves 12 and 15 are closed, the solenoid valves 13 and 14 are opened, and the feed pump 9 is stopped. Consider the operation when the liquid feed pump 10 is operated. However, here, the water removal pump 11 is not provided. The dialysate in the liquid supply chamber 18 is sucked by the liquid feed pump 10 and moves to the waste liquid chamber 19 through the dialysate chamber 5 of the dialyzer 2. At this time, since the dialysate flow path is a closed circuit when viewed from the dialyzer 2, the dialysate flow rate flows from the supply chamber 18 into the dialysate chamber 5 and the dialysate flow rate flows out from the dialysate chamber 5 and into the waste fluid chamber 19. Are equal. Eventually, all of the dialysate in the liquid supply chamber 18 moves to the waste liquid chamber 19, and the diaphragm 17 is displaced to the limit toward the liquid supply chamber 18 side. Therefore, if the solenoid valves 12 and 15 are opened, the solenoid valves 13 and 14 are closed, the liquid feed pump 9 is operated, and the liquid feed pump 10 is stopped, the supply of dialysate to the dialyzer 2 is interrupted, and the waste liquid chamber 19 As soon as the used dialysate is discarded, the liquid supply chamber 18 is filled with fresh dialysate, and the diaphragm 17 is again displaced to the limit toward the waste liquid chamber 19 side. Thereafter, if this operation is repeated, a certain amount of dialysate can be intermittently supplied to the dialyzer 2, and hemodialysis can be performed while keeping the dialysate 2 in and out of the dialyzer 2 equal. Next, a state where the water removal pump 11 is added will be described. As described above, the dialysate flow path always maintains a closed circuit when viewed from the dialyzer 2, and therefore, when the water removal pump 11 is operated at a predetermined flow rate, the amount of liquid fed is the semipermeable membrane 3 of the dialyzer 2. It will be supplemented from the blood chamber 4 via. That is, water in the blood is discharged from the body by the water removal pump 11. From the above, it is possible to configure a system that can perform a predetermined amount of water removal while supplying a certain amount of dialysate. However, since the dialysate supply to the dialyzer 2 is intermittent in the system shown in FIG. 5, in practice, two diaphragm chambers are connected in parallel as shown in Japanese Examined Patent Publication No. 56-82, and continuous while supplementing each other. In particular, a system for supplying dialysate and a system for continuously supplying dialysate by connecting a buffer in series to a diaphragm chamber as disclosed in Japanese Patent Application Laid-Open No. 5-146506 have been devised.
[0003]
[Problems to be solved by the invention]
However, in the above-described prior art, the closed circuit tends to become negative pressure in order to remove water by the suction force generated by the water removal pump from the closed circuit, and therefore gas dissolved in the dialysate (oxygen) Or carbon dioxide) is generated as air bubbles and adheres to the semipermeable membrane of the dialyzer, leading to a decrease in dialysis efficiency. It is necessary to deaerate upstream of the circuit. Deaeration requires a pump that generates negative pressure and a mechanism that collects the generated bubbles and discharges them to the outside. As a result, the hemodialysis apparatus is complicated and large. Further, by degassing, the carbon dioxide in the dialysate is also removed, the pH of the dialysate is increased, calcium carbonate is likely to precipitate, and there is a disadvantage that the calcium carbonate must be removed complicatedly.
In view of the above points, an object of the present invention is to provide a hemodialysis apparatus which can perform hemodialysis without requiring deaeration of the dialysate and which has improved the problems of the prior art.
[0004]
[Means for Solving the Problems]
The present invention provides a hemodialysis apparatus for supplying dialysate and blood to a dialyzer, bringing the dialysate and blood into contact with each other through a semipermeable membrane provided in the dialyzer, and removing waste and water from the blood. A closed circuit type dialysate supply means for keeping the flow rate of the dialysate flowing into the dialyzer and the flow rate of the dialysate flowing out of the dialyzer, and a predetermined flow rate from the closed circuit portion of the closed circuit type dialysate supply means And a water removing means for discharging the dialysate out of the closed circuit, and a pressure adjusting means for adjusting the blood side pressure of the dialyzer to a predetermined pressure, the blood side pressure adjusted by the pressure adjusting means and the By controlling the dialysate pressure in the closed circuit determined by the pressure loss generated by the water removal means to be positive , the dialysate degassing mechanism is unnecessary .
[0005]
[Action]
By adopting the above configuration, it is possible to suppress the generation of bubbles in the dialysate closed circuit including the dialyzer without using complicated deaeration means, and it is possible to suppress the precipitation of calcium carbonate. .
[0006]
【Example】
Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows the configuration of a first embodiment of the present invention. The dialysate is supplied intermittently by a closed circuit system using a single diaphragm chamber 16 and water removal is performed by suction from the closed circuit by the water removal pump 11, as described above in detail. It is omitted here. The blood of the patient 1 is sent to the dialyzer 2 by the blood pump 20 and returned to the patient 1 again. In this example, a restriction 22 is provided in the blood return path to provide flow path resistance so that the pressure in the blood chamber 4 of the dialyzer 2 can be adjusted. It is assumed that a UFR (water removal amount per unit time when a unit pressure difference is given) of 10 ml / mmHg / h is used for the dialyzer 2 and 1000 ml of water is removed per hour. Then, the differential pressure (hereinafter referred to as TMP) generated between the blood chamber 4 and the dialysate chamber 5 of the dialyzer 2 becomes 100 mmHg. Therefore, if the throttle 22 is adjusted so that the pressure gauge 21 indicates 100 mmHg or more, the pressure in the dialysate chamber 5, that is, the dialysate pressure in the closed circuit can be kept positive.
FIG. 2 shows a second embodiment of the present invention. The dialysate pressure in the closed circuit is measured by the pressure gauge 23. If this value is negative pressure, the controller 24 drives the motor connected to the adjusting shaft of the restrictor 22 to restrict the blood circuit and increase the flow resistance. Let As a result, the blood pressure increases and the dialysate pressure also increases. When the dialysate pressure becomes positive, the throttle 22 is fixed. When the dialysate pressure becomes excessively positive, the restrictor 22 is adjusted in a direction to decrease the flow path resistance of the blood circuit, and is fixed when the dialysate pressure becomes an appropriate positive pressure.
FIG. 3 shows a third embodiment of the present invention. In this example, the pressure adjustment mechanism 25 is provided so that the diaphragm can be adjusted without using a controller. Details of the pressure adjustment mechanism 25 are shown in FIG. The dialysate exiting the dialyzer 2 enters from the dialysate inlet 26 of the pressure adjustment mechanism 25 and exits from the dialysate outlet 27. At this time, the dialysate pressure is applied to the bellows 28, but the inside of the bellows 28 is released to the atmospheric pressure and simultaneously supported by the spring 32. As a result, the perot 28 reaches a position where the dialysate pressure = atmospheric pressure + spring pressure. Move and stop. On the other hand, the contraction of the bellows 28 is transmitted by the shaft 29, and the blood circuit tube 31 is squeezed by the tube presser 30 to change the flow path resistance of the blood circuit. That is, when the dialysate pressure decreases, the bellows 28 moves downward to squeeze the blood circuit tube 31 to increase the pressure in the blood circuit and the dialysate pressure. When the dialysate pressure increases, the blood circuit tube 31 is opened. Therefore, the dialysate pressure can be kept constant at a positive pressure.
These examples are based on a closed circuit type dialysate supply system using one diaphragm chamber, but a system in which two diaphragm chambers shown in Japanese Patent Publication No. 56-82 are connected in parallel, It is easily conceivable that the present invention can also be applied to a system in which a buffer is connected to a diaphragm chamber disclosed in JP-A-5-146506.
[0007]
【The invention's effect】
As described above, in the present invention, the pressure adjustment means is provided on the blood circuit to maintain the pressure in the closed circuit of the dialysate at a positive pressure, thereby eliminating the conventionally required dialysate degassing mechanism, In addition, frequent washing operations can be reduced by suppressing the precipitation of calcium carbonate. As a result, it has become possible to supply a dialysis machine with high reliability, economy, and maintainability.
[Brief description of the drawings]
FIG. 1 is a diagram showing a first embodiment of a hemodialysis apparatus of the present invention.
FIG. 2 is a view showing a second embodiment of the hemodialysis apparatus of the present invention.
FIG. 3 is a view showing a third embodiment of the hemodialysis apparatus of the present invention.
FIG. 4 is a diagram showing details of a pressure adjustment mechanism in a third embodiment of the hemodialysis apparatus of the present invention.
FIG. 5 is a diagram showing a closed-circuit dialysate supply method and a water removal method in a conventional hemodialysis apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Patient 2 Dialyzer 3 Semipermeable membrane 4 Blood chamber 5 Dialysate chamber 6 Dialysate supply line 7 Dialysate waste liquid line 8 Water removal line 9, 10 Liquid feed pump 11 Water removal pump 12, 13, 14, 15 Solenoid valve 16 Diaphragm chamber 17 Diaphragm 18 Supply chamber 19 Waste fluid chamber 20 Blood pumps 21 and 23 Pressure gauge 22 Throttle 24 Controller 25 Pressure adjustment mechanism 26 Dialysate inlet 27 Dialysate outlet 28 Bellow 29 Shaft 30 Tube presser 31 Blood circuit tube 32 Spring

Claims (1)

In a hemodialysis machine that supplies dialysate and blood to a dialyzer, contacts the dialysate and blood through a semipermeable membrane provided in the dialyzer, and removes waste and water from the blood, then flows into the dialyzer A closed circuit type dialysate supply means for keeping the flow rate of the dialysate to be equal to the flow rate of the dialysate flowing out of the dialyzer, and the dialysate at a predetermined flow rate from the closed circuit part of the closed circuit type dialysate supply means A water removal means for discharging out of the closed circuit, and a pressure adjustment means for adjusting the blood side pressure of the dialyzer to a predetermined pressure, and the blood side pressure adjusted by the pressure adjustment means and the water removal means A hemodialysis apparatus characterized by eliminating the dialysate degassing mechanism by controlling the dialysate pressure in the closed circuit portion determined by the generated pressure loss to be positive.

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