JP2003220130A - Dialysis liquid supply system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve reduction in costs and a precise control even in a small amount of removing water by reducing the number of pumps for use in supply and discharge of dialysis liquid, simplifying piping and eliminating valves for switching flow paths. <P>SOLUTION: A dialysis liquid supply system 3S is connected to a dialysis liquid inflow port 2in, and a dialysis liquid discharge system 3D is connected to a dialysis liquid discharge port 2out of the dialyzer 2. The dialysis liquid supply system 3S and discharge system 3D are individually provided with a dialysis liquid supply pump 8S and a dialysis liquid discharge pump 8D, respectively. A flow rate controller 9 drives the flow rate the discharge pump 8D at a flow rate relatively greater than that of the supply pump 8S by the amount of removing water per unit time q to be determined based upon the total amount of removing water Sq to be removed from the blood through dialysis and dialysis time T. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dialysate supplying / discharging device used for an artificial kidney for purifying blood by removing waste products and excess water in blood by artificial dialysis.

[0002]

2. Description of the Related Art At present, about 200,000 patients in Japan alone and about 1 million patients worldwide are treated by artificial dialysis at dialysis facilities such as hospitals and clinics. In patients with renal disease, urine volume decreases as renal function decreases,
In the end, one drop of urine disappeared, and despite severe restrictions on water intake, excessive water accumulated in the body, and if left unattended, congestive heart failure resulted in pulmonary edema and choking. There is danger.

For this reason, artificial dialysis is carried out 2-3 times a week for 3 to 5 hours each time using an artificial kidney to remove water until the water content in the body falls to an appropriate value. The balance of water and electrolytes is maintained, and unnecessary wastes are removed from the body. By doing so, the renal function, which has fallen to 10% or less in healthy subjects, can be restored to about 20 to 25%.

As shown in FIG. 4, the artificial kidney 31 used in this case is a dialysate which supplies unused dialysate to a dialyzer 32 which circulates blood extracorporeally for dialysis and discharges used dialysate. A supply / discharge device 33 is provided.

The dialysate supply / discharge device 33 has a dialysate supply / discharge system 34 for supplying / discharging a dialysate with a flow rate Q to the dialyzer 32, and a flow rate equal to the unit time dewatering amount q to be removed from blood. A water removal amount control system 35 for draining the dialyzer 32 to the outside of the dialysate supply / discharge system 34 is provided.

The dialysate supply / discharge system 34 is driven alternately and two diaphragm pumps 36A and 36B for continuously supplying the dialysate to the dialyzer 32, and the dialyzer 3 are provided.
The dialysate flow rate control pump 37 that supplies fresh dialysate from the diaphragm pumps 36A and 36B by the fluid pressure of the dialysate that is forcibly discharged from 2 and the resting diaphragm pumps 36A and 36B are filled with fresh dialysate. A dialysate filling pump 38 that discharges the used dialysate stored in the diaphragm pumps 36A and 36B by the fluid pressure
, And pipings 39 for alternately driving the diaphragm pumps 36A and 36B, a switching valve 40, and the like. Further, the water removal control system 35 includes a water removal flow rate control pump 41 having the same amount of drainage as the unit time water removal amount q to be removed from blood.

As a result, the dialysate having a flow rate Q is supplied to the dialyzer 32 and the dialysate having a flow rate Q + q is discharged from the dialyzer 32, so that the inside of the dialyzer 32 becomes a negative pressure, and the pressure difference between the dialyzer 32 and the dialysate 32 is excessive. It is designed to remove water.

[0008]

However, the dialysate supply / discharge device 33 of this type includes two diaphragm pumps 36A and 36B and respective pumps 37 for driving them.
In addition to having 38 and 41, many pipes 39 ...
And a large number of switching valves 40 ... Which switch between them. Therefore, there is a problem that the structure is extremely complicated, the cost is increased, and the maintenance at the time of failure or cleaning takes time and effort.

Further, since the switching valves 40 ... Are switching channels during artificial dialysis, they are liable to malfunction, and there is a problem that the service life is exceeded in a short period and frequent replacement is required. It was

Furthermore, the total amount Sq of water to be removed from the blood
Is determined by the flow rate of the dewatering flow rate control pump 41, but normally 300 to 500 cc per one dialysis and the unit time dewatering amount q = 60 to 100 cc / h, which is stable because the flow rate is extremely small. However, there is a problem that it is difficult to finely adjust the flow rate even if a small pump is used.

If an error occurs in the flow rate, even if the error is slight, the total amount of water removed greatly changes when artificial dialysis is performed over 3 to 5 hours, and the amount of water removed per unit time increases, resulting in unreasonable rapid removal. If water is given, there is a risk of abnormally lowered blood pressure and shock.

Therefore, the present invention not only reduces the number of pumps and simplifies the piping, but also reduces the cost without using a valve for switching a flow path, and simplifies maintenance at the time of failure or cleaning. The challenge is to be able to accurately control a small amount of water removal.

[0013]

In order to solve this problem, the present invention supplies fresh dialysate to a dialyzer of an artificial kidney which circulates blood extracorporeally and performs hemodialysis, and at the same time, removes blood waste products. In the dialysate supply / discharge device for discharging together with the dialysate, a dialysate supply pump and a dialysate discharge pump are individually provided in the dialysate supply system and the dialysate discharge system connected to the dialysate inlet and outlet of the dialyzer. At the same time, it is equipped with a flow rate controller that drives the discharge pump by setting the flow rate of the discharge pump to be relatively higher than that of the supply pump by the unit time water removal volume determined based on the total removal volume of water to be removed from blood by dialysis and the dialysis time. Characterize.

According to the present invention, a dedicated dialysate supply pump for supplying fresh dialysate to the dialyzer and a dedicated dialysate discharge pump for discharging blood waste together with the dialysate from the dialyzer are provided. The dialysate can be continuously supplied and discharged by each pump without switching the flow path.

Further, since the flow rate of the discharge pump is set to be higher than the flow rate of the supply pump by a unit time dewatering amount determined based on the total dewatering amount of water to be removed from blood by dialysis and the dialysis time, It is possible to remove an appropriate amount of water by setting a negative pressure inside the dialyzer without providing a pump for removing water.

That is, if the dialysate supply flow rate is Q and the unit time water removal amount is q, the dialysate supply pump flow rate is Q,
The flow rate of the dialysate drain pump is set to Q + q. Therefore, the dialysate discharge pump can be driven at a flow rate capable of stably discharging the dialysate, and a small amount of water removal can be accurately controlled.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be specifically described below with reference to the drawings. FIG. 1 is an explanatory view showing an artificial kidney using the dialysate supply system according to the present invention, FIG. 2 is an explanatory view showing an example of a dialysate supply pump, and FIG. 3 is an explanatory view showing its operation.

As shown in FIG. 1, the artificial kidney 1 supplies a dialyzer 2 which circulates blood extracorporeally for dialysis, and a fresh dialysate to the dialyzer 2 to discharge blood waste together with the dialysate. A dialysate supply system 3 is provided.

The dialyzer 2 has a housing 4 in which a blood purification module 6 consisting of a bundle of hollow fibers 5 formed of a hollow fiber type blood purification membrane is arranged, and blood supplied from the internal circulation system into the module 6. The blood waste permeates into the dialysate flowing from the inside of the hollow fiber 5 to the outside thereof to return the purified blood to the body circulation system.

The dialysate supply system 3 according to the present invention comprises a dialysate supply system 3S and a dialysate discharge system 3D which are connected to the dialysate inlet 2in and the outlet 2out of the dialyzer 2, and the supply system 3S and discharge are provided. A dialysate supply pump 8S and a dialysate discharge pump 8D are individually provided in the system 3D, and the discharge pump 8D corresponds to a unit time removal amount determined based on the total removal amount of water to be removed from blood by dialysis and the dialysis time. A flow rate controller 9 is provided for setting and driving the flow rate higher than the supply pump 8S side.

Each of the pumps 8S and 8D is composed of a positive displacement rotary pump 11 driven by a stepping motor 10, and its rotation speed is accurately controlled by a pulse signal output from a flow rate controller 9. .

The positive displacement rotary pump 11 has a circular pump chamber 1 formed in a housing 12 as shown in FIG.
3, an eccentric cam roller 14 rolling along its inner peripheral surface
And oscillating vanes 15 that are urged to come into contact with the peripheral surface of the eccentric cam roller 14 are arranged, and the eccentric cam roller 14 is rotationally driven by the stepping motor 10 via the reduction gear 16. It is supposed to be done.

The housing 12 has a suction port 11in formed on one side of the pump chamber 13 partitioned by the eccentric cam roller 14 and the swing vane 15, and a discharge port 11out on the opposite side.
Are formed.

Then, as shown in FIG. 3 (a), the suction port 1
When the eccentric cam roller 14 is rotated leftward from the position where 1 in is blocked, the cam roller 14 rolls rightward along the inner peripheral surface of the pump chamber 13, as shown in FIGS. In addition, the volume of the pump chamber 13A communicating with the suction port 11in gradually increases and the dialysate is sucked into the pump chamber 13A, and at the same time, the pump chamber 1 communicating with the discharge port 11out.
The volume of 3B gradually decreases and the dialysate is discharged.

Then, as shown in FIG. 3D, when the discharge port 11out is rotated to a position where it is blocked, the suction port 11in
At the same time that the volume of the pump chamber 13A communicating with the pump chamber 13A is maximized and the inhalation of the dialysate is completed, the volume of the pump chamber 13B communicating with the discharge port 11out is minimized and the discharge of the dialysate is completed.

Further, the eccentric cam roller 14 is shown in FIG.
When it rotates back to the position shown in, the dialysate in the pump chamber 13A starts to be discharged from the discharge port 11out, and the suction port 11in
The dialysate is inhaled from. Therefore, by rotating the eccentric cam roller 14, the dialysate can be continuously sucked / discharged.

The flow rate controller 9 includes pumps 8S and 8S.
The dialysate supply system 3S is controlled by controlling the rotation speed of the stepping motor 10 that drives the eccentric cam roller 14 of D.
And the dialysate delivery rate of each of the dialysate drainage system 3D.

For example, when the eccentric cam roller 14 returns to the same position at one rotation of each of the pumps 8S and 8D, the discharge amount of the pumps 8S and 8D is 14 cc per rotation, and the stepping motor 10 is driven by a pulse signal of 50400 Hz. When the pumps 8S and 8D rotate once per second, and the total dialysate supply amount SQ for 5 hours once is 144 liters,
Since the unit time supply flow rate Q of the dialysate is 28.8 liters / hour, {28800 / (60 × 60)} × (50400/14) ≈28800 Therefore, if each pump 8S, 8D is driven at 28800Hz,
Can supply the dialysate properly.

At this time, the flow rate per 1 Hz is 14/5040.
Since it is 0 (cc / s), when the driving pulse is changed by 1 Hz, the discharge amount of 1 cc can be changed in 1 hour from 3600 × 14/50400 = 1 (cc / h). In this example, the flow rate of the dialysate discharge pump 8D is set slightly higher than that of the dialysate supply pump 8S to cause a flow rate difference, and the outside of the hollow fiber 5 is set to a negative pressure from the inside to remove excess water in blood. To do. The flow rate difference is calculated by inputting the total water removal amount Sq to be removed and the dialysis time T to the flow rate controller 9 to calculate the unit time water removal amount q = Sq / T, and the dialysate supply pump 8S supplies the dialysate supply flow rate. A pulse signal for driving each pump 8S, 8D is output so that the dialysate discharge pump 8D is driven at a flow rate equal to Q and the dialysate discharge pump 8D is driven at a flow rate of Q + q.

For example, when the body weight of a patient having an ideal body weight of 65.0 kg is increased to 65.3 kg by water intake, it is necessary to remove 300 cc of water. If you input the dialysis time T = 5 hours and the total water removal amount Sq = 300 cc, the unit time water removal amount q = 60
cc / h is calculated, dialysate supply pump 8S is 28800H
The pulse signal of z drives the supply flow rate of 28.8 l / h, and the dialysate discharge pump 8D is driven by the pulse signal of 28860 Hz at a discharge flow of 28.86 l / h.
As a result, 144 liters of dialysate can be supplied and discharged in 5 hours, and about 300 cc of excess water can be removed from the blood.

The above is one configuration example of the present invention, and its operation will be described below. The blood purification module 6 of the dialyzer 2 is connected to the internal circulation system 7, and the dialysate inflow port 2in and the outflow port 2out are connected to the dialysate supply system 3S and the dialysate discharge system 3D, respectively, and the flow rate controller 9 is completely removed. The water amount Sq and the dialysis time T are set. When the total amount of water removed is 300 cc and the dialysis time is 5 hours, set the dialysate supply pump 8S to 28800
If it is driven by a pulse signal of Hz, 144 liters of dialysate is supplied in 5 hours and blood waste products are removed. If the dialysate discharge pump 8D is driven by a pulse signal of 28860 Hz, the total discharge amount during the dialysis time will be 144 liters + 300 cc, so all 144 liters of dialysate supplied by the dialysate supply pump 8S will be discharged. At the same time, the excess water 300 cc contained in the blood passing through the hollow fiber 5 is sucked out of the hollow fiber 5 and discharged.

As described above, the dialysate supply system 3S and the dialysate discharge system 3D are respectively provided with the dialysate supply pump 8S and the dialysate discharge pump 8D, respectively.
Since the dialysate is supplied / discharged by S and 8D and the excess water in the blood can be removed by using the difference in flow rate, the number of pumps is as small as two and the piping is simplified. Not only is the dialysate supplied, the dialysate supply pump 8S
Is continuously supplied from the dialysate discharge pump 8D and continuously discharged from the dialysate discharge pump 8D, no flow path switching valve is required, manufacturing cost is reduced, and maintenance at the time of failure or cleaning is simplified. .

In the present invention, if the difference between the flow rates of the pumps 8S and 8D is kept constant, the total supply amount S of dialysate is S.
Since it is not necessary to strictly set Q, the flow rate difference may be generated by keeping the flow rate of the dialysate discharge pump 8D constant and reducing the flow rate of the dialysate supply pump 8S. For example, the same applies when the dialysate discharge pump 8D is driven by a pulse signal of 28800 Hz and the dialysate supply pump 8S is driven by a pulse signal of 28740 Hz, which is 60 Hz less than this.

The case where the positive displacement rotary pump 11 using the eccentric cam roller 14 and the swinging vane 15 is used as the dialysate supply pump 8S and the dialysate discharge pump 8D has been described. The form is arbitrary as long as continuous discharge can be performed.

[0035]

As described above, according to the present invention, the dialysate is supplied / discharged only by the dialysate supply pump and the dialysate discharge pump, and at the same time, the surplus in blood is utilized by utilizing the difference in flow rate. Since the water can be removed, the number of pumps is as small as two, the piping is simplified, and the dialysate is continuously supplied from the dialysate supply pump and continuously from the dialysate discharge pump. Since it is discharged as desired, a valve for switching the flow path is not required at all, the manufacturing cost can be reduced, and maintenance at the time of failure or cleaning can be simplified, which is a very excellent effect.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an artificial kidney using a dialysate supply system according to the present invention.

FIG. 2 is an explanatory diagram showing an example of a dialysate delivery pump.

FIG. 3 is an explanatory diagram showing the operation.

FIG. 4 is an explanatory view showing a conventional device.

[Explanation of symbols]

1 ………… Artificial kidney 2 ………… Dializer 2 in ... dialysis fluid inlet 2out ... dialysate outlet 3 ... Dialysate supply system 3S ... Dialysate supply system 3D ... Dialysate drainage system 4 ………… Housing 8S ... Dialysate supply pump 8D ... Dialysate discharge pump 9 ......... Flow rate controller 10 ... Stepping motor 11 ………… Positive displacement pump 14 ... Eccentric cam roller 15 ………… Swing vane

Continued front page    F term (reference) 4C077 AA05 BB01 DD10 DD28 DD29                       EE03 HH02 HH15 HH19 JJ02                       JJ16 JJ19 KK01 KK11 KK25                       LL05 NN14

Claims (2)

[Claims] 1. A dialysate supply / discharge device for supplying fresh dialysate to a dialyzer (2) of an artificial kidney which circulates blood extracorporeally and performs hemodialysis, and at the same time discharges blood waste together with the dialysate. The dialysate supply system (3S) and the dialysate discharge system (3D) connected to the dialysate inlet (2in) and the outlet (2out) of the dialyzer (2) have a dialysate supply pump (8S) and a dialysate discharge pump. (8D) is provided separately,
Total amount of water removed from blood by dialysis (Sq)
And the flow rate of the discharge pump (8D) by the unit time water removal amount (q) determined based on the dialysis time (T)
A dialysate supply / discharge device comprising a flow rate controller (9) for setting and driving a relatively larger amount than S). 2. A positive displacement rotary pump (11) in which each of said pumps (8S, 8D) is driven by a stepping motor (10) whose rotational speed is controlled by a pulse signal output from said flow rate controller (9). The dialysate supply and discharge device according to claim 1.