JP4889297B2 - Hemodialysis machine - Google Patents

Description

  The present invention relates to a hemodialysis apparatus for purifying the blood of a patient with renal failure in the medical field, and more specifically, it eliminates air bubbles in the blood circuit and prevents air bubbles during blood removal from entering the patient's body. In addition, the present invention relates to a hemodialysis apparatus that can reliably determine completion of blood return.

In general, hemodialysis treatment consists of a priming process, a dialysis preparation stage, a blood removal process after puncture, a dialysis process in which blood purification is performed by extracorporeal circulation, and a return process of purified blood. As the dialysis equipment for the purpose, there are 3 hemodialyzers (dialyzers) for purifying blood by extracorporeal circulation, a blood circuit for extracorporeal circulation of blood arranged across the dialyzer, and a dialysate supply system connected to the dialyzer Consists of two parts.
In hemodialysis medical care, it is important to automate all these steps in order to safely and quickly carry out a series of steps from dialysis preparation to the end of treatment. It is. The inventors of the present invention have also developed an automatic dialysis apparatus shown in Patent Document 1 as a result of various studies and experiments with such aim. In Patent Document 1, a dialyzer that purifies blood by contacting blood and dialysate through a semipermeable membrane, a blood circulation system that circulates blood, and a dialysate supply / drainage system that supplies and discharges dialysate The blood circulation system has an arterial blood circuit that draws blood from the patient and flows into the dialyzer, and a venous blood circuit that returns the blood flowing out of the dialyzer to the patient, and the dialysate supply / drainage system is a dialyzer A dial for supplying and discharging dialysate, connecting a blood pump to at least one of the two blood circuits, a blood chamber and its overflow line to the other blood circuit, and supplying and discharging the dialysate The first and second liquid feeding means are respectively provided in the lines, the bypass line is provided in at least one of the supply and discharge liquid lines, the third liquid feeding means is disposed in the bypass line, and the bypass line is removed. / It has third liquid feeding means that can feed the dialysate in both forward and reverse directions so that the amount of dialysate can be fed for replacement fluid, and the liquid feeding speed of the third liquid feeding means and the blood pump In automatic hemodialysis equipment with automatic priming function that can be adjusted in conjunction with each other, blood circuit blockage detection function at the time of automatic priming, negative pressure elimination reverse filtration function at the time of automatic priming, vein side clamp operation delay function at the start of blood removal, artery It is characterized by having at least one function selected from the group consisting of a side blood loss failure detection function, a rapid fluid replacement function, and a dialyzer replacement function.

On the other hand, in this type of hemodialysis apparatus, bubbles remaining in the circuit at the time of priming become a problem. Since air bubbles cause serious problems when they enter the body (remaining in the dialyzer may cause blood clots and residual blood), they need to be completely removed during priming. Conventionally, during automatic priming, air bubbles remaining in the blood chamber on the venous side are sent to the overflow line by the supplied cleaning liquid (physiological saline or equivalent solution), and an air vent valve provided in the overflow line is used. Air bubbles were removed by opening and closing. In addition to this, various proposals have been made to reliably detect bubbles and prevent their entrainment (for example, Patent Documents 2 and 3).
Furthermore, air mixing becomes a problem not only during priming but also in the blood removal process. When the arteriovenous bypass part of the blood circuit is separated after the priming process and before the start of automatic blood removal, there is a possibility that bubbles may enter the connection part of the blood circuit due to liquid dripping. If blood removal is started in this state, there is a risk that air bubbles may enter the patient side, particularly on the venous side. Therefore, in Patent Document 1, the clamp under the venous chamber is closed before the blood removal is started. The automatic blood removal is started, and the clamp at the lower part of the venous chamber is opened after a certain period of time, and the blood circuit is made negative pressure to prevent air bubbles from entering the patient.
Furthermore, in addition to the above matters, for example, when returning blood, it is important to ascertain the time when blood return has been completed. However, there have been few proposals in the past regarding this point. Patent Document 4 is known as a device that can confirm the type of fluid at the time of blood return, but this device always detects the fluid in the blood return chamber by light detection means including a light emitting element and a light receiving element. Monitor the permeation, detect the transmitted light level when the fluid becomes a mixture ratio or bubble below a certain level of blood and saline, and stop the blood return operation immediately by stopping the closing means and the pump. Yes.
JP 2003-180823 A JP 2005-46404 A JP-A-6-142193 Japanese Patent Publication No. 5-74378

However, in the apparatus of Patent Document 1 described above, the target is almost achieved, but in order to obtain higher safety and reliability, removal of residual bubbles in the circuit in the automatic priming process. On the other hand, there is still room for further improvement in terms of the problem of air bubble suction at the connection part of the blood circuit at the time of blood removal and the uncertainty of the determination of the completion of blood return.
That is, in Patent Document 1, air bubbles are removed in the priming process by opening and closing an air vent valve provided in the overflow line of the venous blood chamber as described above, but air remains only by this valve opening and closing operation. Bubbles could not be completely removed. In addition, Patent Document 2 related to bubble detection is excellent as a bubble detection system, but does not specifically present measures for preventing bubble mixing. Further, Patent Document 3 describes a dialyzer or blood circuit. In order to prevent the air from being caught, when supplying the cleaning liquid in the cleaning operation and the blood return operation, the operation of the blood pump is performed when the integrated liquid volume or weight of the cleaning liquid reaches the set amount by the arithmetic control unit connected to the blood pump. However, the difference in the filling volume due to the difference in the membrane area of the dialyzer becomes the difference in the amount of the washing solution at the time of returning blood, and in all cases, there is a problem that the same level of blood cannot be returned.
Next, in order to prevent air bubbles that have entered the circuit from flowing into the patient when the blood removal process shifts to the dialysis process, blood is removed from the arterial and venous sides almost simultaneously in Patent Document 1, but this The air mixed into the connecting portion with the indwelling needle on the side is not always reliably prevented from moving to or mixing into the chamber due to factors such as poor blood removal.
Furthermore, in the conventional apparatus of Patent Document 4, the equipment is complicated and disadvantageous in terms of cost, and the determination of blood return completion is not necessarily high in accuracy. That is, Patent Document 4 has a problem that blood is returned more than intended and there is a possibility of insufficient water removal.
The present invention has been made to solve the above-described problems of the prior art, and it is possible to remove air bubbles almost completely from the circuit of the dialysis apparatus. It is an object of the present invention to provide a hemodialysis apparatus that can prevent the blood from being mixed, and can reliably determine the completion of blood return by the color and the blood return amount set by the apparatus.

To solve the problem of removing air bubbles from the circuit of dialysis apparatus
(1) In the hemodialysis apparatus of the present invention, an arterial blood circuit having a blood pump is connected to the artery side of the dialyzer, a venous blood circuit having a venous chamber is connected to the venous side of the dialyzer, and the side surface of the dialyzer In addition, in the hemodialysis apparatus constructed by connecting the dialysate supply line and the dialysate discharge line, respectively, the opening / closing operation of the clamp of the overflow line provided in the venous chamber of the venous blood circuit at the stage of the automatic priming process, and in addition to the pulsating operation opening and closing operation of the vein chamber bottom of the clamp and by the blood feeding bubble removing operation and the blood pump by liquid pumps, gas bubbles by utilizing the pulse flow operation by the constant spacing change of the rotational speed of the blood pump Is configured to be discharged from the overflow line via the venous chamber.
(2) The hemodialysis apparatus according to (1), wherein the number of rotations of the blood pump is switched at a constant interval in two steps, slow and rapid.
(3) The hemodialysis according to (1), wherein the blood removal operation after automatic priming is performed such that blood removal from the venous blood circuit precedes blood removal from the arterial blood circuit. apparatus.
(4) The hemodialysis apparatus according to (3), wherein the preceding blood removal operation from the venous blood circuit is performed by stopping the blood pump.
(5) A pressure gauge is provided in the venous chamber provided in the venous blood circuit, and when the pressure of the pressure gauge is maintained at a predetermined pressure (negative pressure) or less, the venous blood removal operation is started. (3) or (4) hemodialysis machine characterized by the above-mentioned.
(6) The present invention is characterized in that the completion of the blood return is determined by determining the transparency or redness of the blood in the blood circuit in or below the venous chamber provided in the venous blood circuit (1). ) Hemodialysis machine.
(7) The blood of the blood circuit according to (6), wherein the blood transparency or redness of the blood circuit is determined by the intensity of light that is incident on the blood circuit and reflects or transmits the light. Dialysis machine.

  According to the hemodialysis apparatus according to the present invention, first, almost all air bubbles in the circuit including microbubbles are concentrated in the venous chamber, and during priming, this is almost completely out of the system by opening and closing the clamp. In addition, air bubbles that may be generated during blood removal can be reliably transferred to the air trap in the circuit, and the risk of air bubbles entering the patient's body can be reduced. Furthermore, in the dialysis apparatus of the present invention, it is possible to know the timing of the return of blood reliably, which helps to improve the efficiency of the entire dialysis process, and at the same time, it is possible to set an appropriate blood return volume, Inflow of excess moisture can be prevented.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic diagram showing an outline of an automatic dialysis apparatus optimal for carrying out the present invention. An arterial blood circuit 2 is connected to an artery side of a dialyzer 1 for purifying blood by extracorporeal circulation of blood, and a vein A venous blood circuit 3 is connected to the side, and a dialysate supply line 4 and a dialysate discharge line 5 are connected to the side surface of the dialyzer 1, respectively. The arterial blood circuit 2 is provided with a blood pump 7 that removes blood from the arterial connection portion 6a of the patient and guides it to the dialyzer 1, and an arterial chamber 8 that has a function of removing air bubbles mixed in the circuit during priming. It has been. In addition, the venous blood circuit 3 for returning blood to the venous side connection portion 6b of the patient has a function of discharging air bubbles and excess dialysate mixed in the circuit to the overflow line 9, and pressure measurement during treatment, A vein side chamber 10 having an air trap function is provided.
A pressure gauge 15 is connected to the venous chamber 10, and the venous pressure of the venous blood circuit 3 is detected by the pressure gauge 15. In addition, the overflow line 9 is provided with a clamp means 16 including a valve for opening and closing the line, and by this opening and closing operation, it is possible to discharge bubbles that have passed through the venous chamber 10. Furthermore, a bubble sensor 17 for detecting bubbles in the venous blood circuit 3 and a clamping means 18 for opening and closing the venous blood circuit 3 are provided below the venous chamber 10. When the bubble sensor 17 detects a bubble, the clamp means 18 is closed to prevent the bubble from being mixed into the patient.

On the other hand, the dialysate supply line 4 and the dialysate discharge line 5 are provided with a first liquid feeding means 11 (dialysate supply side) and a second liquid feed means 12 (dialysate drain side), respectively, and dialysate discharge. A bypass line 13 that connects the upstream side and the downstream side of the second liquid feeding means 12 in the line 5 is provided, and the amount of dialysate for dehydration / replacement fluid can be adjusted in the bypass line 13 in both forward and reverse directions. The 3rd liquid feeding means 14 which can be liquid-fed is provided. In the example shown in the figure, the bypass line capable of feeding in both forward and reverse directions is provided only in the dialysate discharge line 5, but the present invention is not limited to this, and only the dialysate supply line 4 or It can also be provided in both the dialysate supply line 4 and the dialysate discharge line 5.
When actual hemodialysis is performed in the dialysis apparatus having the above-described configuration, a priming process for cleaning the blood circuit and dialyzer before starting treatment, a blood removal process after puncture for drawing blood from the body, and an extracorporeal circulation are performed. Therefore, the dialysis process by diffusion and filtration in the dialyzer, and the blood return process for returning the blood in the blood circuit to the body.
Hereinafter, embodiments of the present invention will be sequentially described with reference to the drawings.

(1) Removal of residual bubbles in the circuit during automatic priming As shown by the arrows in FIG. 1, during automatic priming, priming liquid (usually physiological saline) is supplied from the dialysate supply line 4 into the blood circuits 2 and 3 and the dialyzer 1. Is supplied and fluidized to remove bubbles and solvents in the circuit and the dialyzer, and finally the priming solution is filled in the circuit and the dialyzer to perform a cleaning operation. At this time, bubbles may remain in the circuit, but this was done by opening and closing the clamp means 16 (valve) of the overflow line 9 to evacuate the air. Air (bubbles) remained. Therefore, in the present invention, the bubbles in the circuit are almost completely removed by using the pulsation operation of the blood pump 7.

That is, since the blood pump 7 in the arterial blood circuit 2 shown in FIG. 1 employs a normal roller pump system, it is possible to remove remaining bubbles using the pulsating action of the pump. If so, there is no need to provide a special means separately, which is advantageous in terms of operation and facilities. The pulsating flow operation of the blood pump 7 applied in the present invention is performed by switching the rotation speed of the blood pump (roller pump) to two steps of slow speed and rapid speed at regular intervals. The fluid flowing in the direction of the arrow from the blood pump 7 enters the venous chamber 10 through the connected blood circuit tips 6a and 6b, but this fluid has a unique pulse due to the aforementioned arterial flow operation of the blood pump 7. As a result, the bubbles in the circuit can be discharged to the overflow line 9 via the venous chamber. Such pulsating action of the liquid is also useful for removing microbubbles adhering to the inner surface of the circuit (tube). The trapped bubbles are sent from the venous chamber 10 to the overflow line 9 and are removed by opening and closing a valve 16 provided in the overflow line. As the bubbles are removed, physiological saline or dialysate is injected simultaneously by automatic priming. Finally, forward recirculation is performed.
FIG. 4 shows an example of a pattern in which the blood pump performs a pulsating operation. The vertical axis indicates the pump rotation speed (V), the horizontal axis indicates time (t), and the low speed (50 to 100 mL / min). It is desirable to perform switching at intervals of 5 to 10 seconds between the supply amount) and the high speed (supply amount of 200 to 400 mL / min). In particular, the speed gradient (acceleration) is important in order to perform a suitable pulsating motion based on the present invention, and the pattern shown in the figure is optimal.

(2) Prevention of air inhalation at the time of connection with an indwelling needle at the time of blood removal As shown in FIG. 2, when the priming process is completed and the process proceeds to the blood removal process, the connection parts 6a and 6b of the arterial / venous blood circuit are removed. Release the air present in the connection portion, connect to the puncture needle punctured by the patient, and start the blood removal operation. At this time, if air bubbles are mixed into the patient, there is a risk that the air bubbles that have entered the circuit flow into the patient when the blood removal process shifts to the dialysis process. Blood removal is started from this point, and then blood is also removed from the artery side. Even if air bubbles are mixed by leading blood removal from the venous side in advance, by monitoring the blood removal failure state with a venous pressure gauge, the blood bubbles are discharged to the venous blood chamber 10 by blood removal as scheduled. It can be determined whether it could be moved, and the bubbles are trapped by the venous blood chamber, reducing the risk of contamination to the patient. Here, if poor blood removal is detected by the venous pressure gauge, it can be determined that the mixed air has not reached the chamber. As a method of blood removal in advance from the venous side, if the arterial blood pump is stopped, blood removal starts from the venous side.
Also, the timing of the start of blood removal on the arterial side after blood removal on the venous side is, for example, the pressure in the venous chamber 10 (venous pressure P detected by the pressure gauge 15) does not drop below a certain pressure (not in a poor blood removal state). B) Start when a set amount of blood is removed. When performing both blood removal on the venous side and blood removal on the arterial side, for example, the blood pump 7 may be rotated at a speed half that of the third liquid feeding means 14, and blood removal is performed only from the arterial side. When the blood pump 7 is used, the blood pump 7 may be rotated at the same speed as the third liquid feeding means 14.
The above-mentioned constant pressure is a pressure at which normal blood removal operation is inhibited for some reason, the pressure in the venous blood circuit 3 is lowered, and it is determined that blood removal is poor. Usually, −200 mmHg Degree.

(3) Confirmation of completion of blood return After treatment, blood in the dialyzer and blood circuit must be returned safely and promptly (returning blood). The amount used of redness and physiological saline was determined. However, this determination has individual differences and requires a considerable degree of skill, and is not necessarily accurate. For example, if the return of blood is completed early, the inconvenience that the amount of blood remaining in the circuit increases, and conversely, if it is slow, there is a problem that excessive moisture enters the patient's body. For this reason, a highly accurate means for determining completion of blood return has been demanded.
In order to obtain a dialysis apparatus equipped with a highly accurate blood return completion determining means, in the present invention, as shown in FIG. 3, light of a certain wavelength (red, green, etc.) enters the blood circuit from the light emitting element and receives light. The device received light and measured the intensity of the transmitted light to determine the transparency in the circuit. Instead of transmitting light, reflection may be used. Further, not only the transparency but also the redness may be determined to determine the completion of blood return, and if both are determined and determined, the accuracy is further improved. In addition, it is possible to determine the completion of blood return by determining the color density using a laser sensor system.

  In the specific example of FIG. 3A, an appropriate light source, a signal processing circuit, a control circuit, and the like (not shown) are connected to a distal end portion 21 in which a light emitting side 19 and a light receiving side 20 are integrally incorporated via an optical fiber 22. Connected to the blood circuit 23, the reflected light of the light of a certain wavelength irradiated to the blood circuit 23 is received, the light intensity is measured to determine the transparency, and the completion of the blood return is detected when it enters the preset range Like to do. In FIG. 3B, a tip 21 having a light emitting part and a light receiving part is provided in the groove of the fixture 24, and a blood circuit 23 is set in the groove to complete blood return on the same principle as described above. Is detected. In this case, it is preferable to fix the distal end portion 21 with respect to the blood circuit 23 by offsetting (s). This is because when reflected light is received, unless the amount of received light is adjusted by offsetting, the incident light is reflected on the tube surface, making it difficult to determine the color. Note that the distal end portion 21 is arbitrarily set in a positional relationship with the circuit tube and can be fixed.

Whole showing an embodiment of the engagement Ru hemodialysis apparatus of the present invention is a schematic diagram. Another embodiment of the engagement Ru hemodialysis apparatus of the present invention is an overall schematic view showing a. It is explanatory drawing of the apparatus which determines the transparency or redness of the blood which concerns on this invention. It is explanatory drawing which shows the example of a pattern of the pulsating flow operation | movement employ | adopted in this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Dializer 2 Arterial side blood circuit 3 Vein side blood circuit 4 Dialysate supply line 5 Dialysate discharge line 6a Arterial side connection part 6b Venous side connection part 7 Blood pump 8 Arterial side chamber 9 Overflow line 10 Vein side chamber 11 1st sending Liquid means 12 Second liquid feeding means 13 Bypass line 14 Third liquid feeding means 15 Venous pressure manometer 16 Clamp means (overflow line)
17 Bubble sensor 18 Clamping means (venous blood circuit)
DESCRIPTION OF SYMBOLS 19 Light emission side 20 Light reception side 21 Tip part 22 Optical fiber 23 Blood circuit 24 Fixing tool

Claims (7)

An arterial blood circuit having a blood pump is connected to the artery side of the dialyzer, a venous blood circuit having a venous chamber is connected to the venous side of the dialyzer, and a dialysate supply line and a dialysate discharge line are connected to the side of the dialyzer In the hemodialysis apparatus constructed by connecting each of the above, at the stage of the automatic priming process, the opening / closing operation of the clamp of the overflow line provided in the venous chamber of the venous blood circuit and the opening / closing operation of the clamp below the venous chamber and the blood In addition to the bubble removal operation by pumping liquid, the configuration is such that the bubbles can be discharged from the overflow line via the venous chamber by using the pulsating flow operation by changing the rotation speed of the blood pump at regular intervals. A hemodialysis machine characterized. 3. The hemodialysis apparatus according to claim 2, wherein the number of rotations of the blood pump is switched at a constant interval in two stages of slow and rapid . The hemodialysis apparatus according to claim 1, wherein the blood removal operation after priming is configured such that blood removal from the venous blood circuit precedes blood removal from the arterial blood circuit. The hemodialysis apparatus according to claim 3, wherein the preceding blood removal operation from the venous blood circuit is performed by stopping the blood pump. A pressure gauge is provided in a venous chamber provided in the venous blood circuit, and the blood removal operation on the venous side is started when the pressure of the pressure gauge is maintained below a certain pressure (negative pressure). The hemodialysis apparatus according to claim 3 or 4. The completion of the blood return is determined by determining the transparency or redness of blood in a blood circuit in or below the venous chamber provided in the venous blood circuit. Hemodialysis machine. 7. The hemodialysis apparatus according to claim 6, wherein the blood transparency or redness of the blood circuit is determined by irradiating the blood circuit with light of a certain wavelength and reflecting or transmitting the light intensity.

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