JP2800123B2 - Bypass tube - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a bypass tube, and more particularly to a bypass tube used for transferring air bubbles mixed in an extracorporeal blood circuit using an artificial organ such as an artificial lung. And a blood processing apparatus and an extracorporeal circulation blood circuit device using the same.

[Related Art] In general, in an extracorporeal circulation blood circuit using an artificial organ such as an artificial lung, removal of bubbles in the circuit is a major problem with respect to priming operation and safety during circulation. That is, in open heart surgery, when the blood removal catheter is insufficiently placed in the blood vessel or when blood is removed, air bubbles may be mixed into the blood removal tube. If it cannot be removed sufficiently, the microvessels of each organ, especially the brain, will be blocked, resulting in postoperative brain damage,
You will be at risk of life.

Such an effect of removing air bubbles increases as the capacity of the blood reservoir increases. However, increasing the capacity of the blood reservoir increases the amount of priming of the circuit, which in turn increases the amount of blood transfusion. Therefore, the possibility of occurrence of postoperative hepatitis or the like increases, and it is not preferable in terms of blood saving.

For this reason, conventionally, in an extracorporeal circulation blood circuit, an air trap unit typified by a bubble remover (bubble trap) is used. In the air trap section, usually, a bypass tube is connected to a cardiotomy reservoir or an artery or vein reservoir from an air vent port, and when air accumulates, the bypass is opened to release air.

[Problems to be Solved by the Invention] As described above, in the conventional extracorporeal blood circulation circuit, when the air accumulates, the bypass tube is opened to remove the air bubbles. It is preferable that the user always keeps open.

However, if it is designed to allow enough air to escape,
The inner diameter of the bypass tube is about 3.0 mm, so that the amount of blood flowing through the tube increases, and the efficiency of extracorporeal circulation deteriorates. On the other hand, if the inner diameter of the bypass tube is reduced to about 1.1 mm in order to reduce the amount of bypass blood, the flow of blood and air becomes worse, and there is a problem that it takes time to remove air.

The present invention has been made in view of such a problem, and in an extracorporeal circulation blood circuit using an artificial organ such as an artificial lung, the time required for air removal is greatly reduced without increasing the amount of bypass blood. It is an object of the present invention to provide a bypass tube, a blood processing apparatus using the same, and an extracorporeal circulation blood circuit apparatus using the same.

[Means for Solving the Problems] In order to solve the above problems, a bypass tube according to the present invention is provided between a bubble removing unit and a blood storing unit, and these two units are communicated to remove the bubble. A bypass tube that is used for bypassing blood from the device and guiding the blood to the blood storage device, and for transferring bubbles generated in the blood in the bubble removing device to the blood storage device; The flow path is always kept open, and a throttle having a small-diameter hole is provided in a part of the flow path. In this case, the throttle is preferably provided on the blood inflow side of the bypass tube, and the throttle preferably has a plurality of pores.

Further, the blood processing apparatus according to the present invention is characterized in that the air bubble removing means and the blood storing means are connected by the bypass tube. Furthermore, the extracorporeal circulation blood circuit device according to the present invention includes a first device for storing blood from the blood removal line.
And an artificial lung for performing gas exchange of blood derived from the first blood reservoir, and filtering and defoaming air bubbles in the blood exchanged by the artificial lung, and then returning the blood. An air bubble remover for guiding a part of the blood to a second blood reservoir while guiding the blood to the line, and providing a space between the air bubble remover forming the air bubble removing means and the second blood reservoir forming the blood storing means. It is characterized by being connected by the bypass tube.

[Operation] In the bypass tube configured as described above, since the flow path of the tube is always kept open and the blood flow rate is regulated by the throttle provided in the tube, the inner diameter of the tube is reduced. Even if it is enlarged, a large amount of blood does not flow to the blood storage means side under normal conditions. Further, if only the hole of the constricted portion is filled with air, the flow path portion in the tube thereafter has a large inner diameter, so that blood flows smoothly. Accordingly, the time required for the air to reach the other blood storing means from the one air bubble removing means is greatly reduced, and the air can be reliably removed.

Examples Examples of the present invention will be specifically described below with reference to the drawings.

FIG. 1 shows a bypass tube 1 according to an embodiment of the present invention.
FIG. 2 is a view showing a cross-sectional structure of a main part of the bypass tube 1 of FIG. The bypass tube 1 includes a tube main body 2 formed of a soft resin, for example, vinyl chloride resin, and luer ports 3a and 3b attached to both ends of the tube main body 2, respectively. At the connection of the luer port 3a with the tube main body 2, a throttle 4 for regulating blood flow is provided. As is clear from FIG. 2, the flow path in the tube 1 is always kept open, and the throttle portion 4 provided in a part thereof opens along the longitudinal direction of the bypass tube 1. The tube 1 has pores 5 smaller in diameter than the other flow paths. Although the number of the pores 5 may be one, in the actual blood circulation, there is a possibility that the pores 5 are clogged by foreign substances or the like, so it is preferable to provide a plurality of the pores 5 from the viewpoint of safety.

FIG. 3 shows the configuration of an extracorporeal circulation blood circuit device using the bypass tube 1 described above. That is, in this circuit, the venous blood from the patient P passed through the blood removal line 11 and the blood inlet 12, and the blood from the operative field was filtered and defoamed in the second blood reservoir (cardiotomy reservoir) 13. Thereafter, they flow into the first blood reservoir (venous reservoir) 16 via the cardiotomy line 14 and the blood inlet 15 respectively. The air defoamed in the first blood reservoir 16 is discharged by a vent line tube 17. Further, the blood after defoaming is sent to the oxygenator with heat exchanger 20 by the roller pump 19 via the blood outlet 18, where the gas exchange between carbon dioxide and oxygen is performed. The patient P is returned by a blood return line 22 through a bubble remover (bubble trap) 21
Is returned to. The bypass tube 1 has its luer port 3a side connected to the bubble outlet 21a of the bubble remover 21,
Further, the luer port 3b side is connected to the bubble inlet 13a of the second blood storage tank 13 forming the blood storing means.

That is, in the extracorporeal blood circulation circuit, the blood filtered and defoamed in the bubble remover 21 is returned to the patient P through the blood return line 22 and a part of the blood is restricted in the bypass tube 1. Second blood reservoir 13 through part 4
Is transferred to

Here, air is removed from the bubble eliminator 21 by the bypass tube 1.
When it starts to enter, the inside of the bypass tube 1 is filled with blood, and this blood becomes a resistance to the flow of air. Therefore, all the blood in the bypass tube 1
Until the blood is transferred to the blood reservoir 13 of the second blood reservoir
13 cannot be reached. In other words, the air cannot be completely removed. Therefore, the bypass tube 1
It is necessary to transfer the blood in the tube 1 to the second blood reservoir 13 quickly so that the inside of the tube 1 has a low resistance and the air can easily flow. As described above, the conventional bypass tube having a small inner diameter has a uniform diameter as a whole, so that much time is required until blood is pushed out. On the other hand, in the bypass tube 1 of the present embodiment, since the constricted portion 4 is provided, even if the inner diameter of the tube main body 2 is large and is always kept in the open state, a large amount of blood is always discharged. 2
The flow rate is regulated without flowing to the blood storage tank 13 side. In addition, since the inner diameter of the tube main body 2 is extremely larger than the inner diameter of the pores 5 of the constricted portion 4, the portion through which the blood flows after the constricted portion 4 sharply widens. Therefore, the blood is squeezed 4
After passing through, if there is air bubble mixing, it flows smoothly and quickly,
As a result, the time required for the air flowing into the bypass tube 1 to reach the second blood reservoir 13 is greatly reduced, and the air can be sufficiently removed.

In the above embodiment, the pores 5
Although the configuration is provided with the throttle unit 4 having the
Can be variously modified without changing the gist of the present invention. For example, a large-diameter filter or the like may be used.

Next, the inventor conducted the following experiment in order to confirm the effects of the present invention.

(Example) As shown in FIG. 4 (b), a 10 mm long narrowed portion (pore, φ0.2 mm) is inserted at one end of a tube body having a length of 100 cm and an inner diameter of 3.0 mm.
The blood flow rate when a pressure of 100 mmHg was applied to both ends of the bypass tube provided with × 10) as an example and a bypass tube having a length of 100 cm and an inner diameter of 1.1 mm as shown in FIG. 4 (a) as a comparative example. , Air flow rate, and the amount of air bleeding per second after mixing 50 ml of air during blood circulation. In addition,
4 (a) and 4 (b), luer ports at both ends are omitted for easy comparison. When the entire inside of the bypass tube is blood, the flow rate is 10 ml / min for both the comparative example and the example, and when the entire inside of the bypass tube is air, the flow rate is 1500 ml for the comparative example and the example.
/ min, both seemingly the same. However, considering the pressure gradient and the flow rate in the case where the entire inside of the bypass tube is blood, in the case of the comparative example, the pressure gradient becomes uniform because the tube inner diameter is uniform, and thus the flow rate of the entire tube is uniform and 17 cm / s. Was. On the other hand, in the case of the embodiment, since the inner diameter suddenly increases after passing through the throttle, the pressure difference sharply decreases, and therefore, the flow velocity is 50 cm /
s, 2.4 cm / s after passing through the aperture. Next, when air enters the bypass tube from the bubble remover side, immediately after that (after 1/50 second), in the comparative example, as shown in FIG. In this embodiment, only 10 mm was advanced as shown in FIG. At this point, the throttle is completely filled with air, so that there is no pressure loss at this point. Therefore, pressure loss occurs only in the tube body, but the resistance is small due to the large diameter of the tube. As a result, the blood flow velocity was increased, the blood flow velocity was 100 cm / s, and the flow rate was 450 ml / min.

Further, one second after the air enters the bypass tube, in the comparative example, the air travels only 17 cm as shown in FIG. 6 (a). At this time, since the length of the portion where blood is present becomes shorter as the air advances, the pressure loss gradually decreases, and the flow velocity gradually increases accordingly. On the other hand, in the embodiment, as shown in FIG. 3B, the air passes through the throttle portion and then becomes only a portion having a large tube diameter, so that the amount of air traveling is 119c.
m, and the entire bypass tube (100 cm) was filled with air after one second.

As described above, in the bypass tube of the comparative example, much time was required until the air was pushed out. However, in the bypass tube of the example, a large amount of blood can be prevented from constantly flowing into the second blood reservoir side. Thus, the blood flow became faster after passing through the constriction, and the time until the air was pushed out was greatly reduced.

Although the present invention has been described with reference to the embodiment, the present invention is not limited to the above embodiment, and can be variously modified without departing from the gist of the invention. For example, in the above embodiment, the bypass tube 1 is connected to the bubble remover 21 and the second
In the case where the second blood reservoir 13 is not provided, for example, the first blood reservoir 16 is used as the blood storing means, and the bubble remover which serves as the bubble removing means is provided. twenty one
And the first blood reservoir 16. In addition, the oxygenator with heat exchanger 20 and the second blood reservoir 13 are directly connected by the bypass tube 1 so that the blood outflow port of the oxygenator 20 is used as the air bubble removing means to transfer the air bubbles accumulated in this. Alternatively, the blood outflow portion of the heat exchanger may be used as air bubble removing means, and the space provided therein and the second blood reservoir 13 may be connected by the bypass tube 1. Further, the air bubble remover means and the blood storing means connected by the bypass tube 1 are not limited to those having separate structures, but have a structure integrated with each other, for example, a blood storage tank and an artificial lung are integrated. Of course, it may be a thing.

[Effects of the Invention] As described above, according to the bypass tube of the present invention, the flow path of the tube is always kept open, and a part of the flow path has a smaller diameter than that of the other flow path. The provision of the constricted section having holes prevents a large amount of blood from constantly flowing into this tube, and at the time of air bubbles mixing, the flow of blood and air becomes faster, so that air bubbles can be removed sufficiently in a short time. Therefore, it is suitable for use in a blood processing apparatus or an extracorporeal circulation blood circuit apparatus.

[Brief description of the drawings]

FIG. 1 is a side view of a bypass tube according to an embodiment of the present invention, FIG. 2 is a cross-sectional view showing an essential part of the bypass tube, and FIG. 3 is a diagram of an extracorporeal circulation blood circuit device using the tube. 4 to 6 are explanatory diagrams for comparing the characteristics of the bypass tube with the embodiment of the present invention and the comparative example. 1 ... bypass tube, 2 ... tube body 3a, 3b ... luer port, 4 ... throttle section, 5 ... pore 13 ... second blood reservoir (cardiotomy reservoir) 16 ... first blood reservoir Vessel (venous reservoir) 20 ... oxygenator with heat exchanger 21 ... air bubble remover

Claims (5)

(57) [Claims] 1. A method according to claim 1, wherein said air removing means is provided between said air removing means and said blood storing means. The two means are communicated with each other to bypass blood from said air removing means and to lead to said blood storing means. A bypass tube used for transferring air bubbles generated in blood to the blood storing means, wherein a flow path of the bypass tube is always kept open, and a part of the flow path has a small-diameter hole. A bypass tube having a throttle section. 2. The bypass tube according to claim 1, wherein the throttle portion is provided on the blood inflow side of the tube. 3. The bypass tube according to claim 1, wherein said throttle portion has a plurality of said holes. 4. A blood processing apparatus comprising the air bubble removing means and the blood storing means connected by the bypass tube according to any one of claims 1 to 3. 5. A first blood reservoir for storing blood from a blood removal line, an oxygenator for gas exchange of blood derived from the first blood reservoir, and gas exchange by the oxygenator. An extracorporeal circulation blood circuit device comprising: an air bubble remover that filters and defoams air bubbles in blood, guides the blood to a blood return line, and causes a part of the blood to flow to a second blood reservoir. The said bubble remover serves as the bubble remover and the second blood reservoir serves as the blood storage means, and the two means are connected by the bypass tube according to any one of claims 1 to 3. Extracorporeal circulation blood circuit device characterized by the above-mentioned.