JPS6334698Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a blood reservoir used in an extracorporeal blood circulation circuit using a heart-lung machine.

Conventionally, in order to cope with fluctuations in blood volume during extracorporeal circulation, such as when the amount of blood removed decreases or when it is desired to increase the amount of blood delivered, a certain amount of blood has always been stored in the circuit. The first blood storage tank is used to effectively remove air bubbles generated during
A structure as shown in Fig. 2 has been proposed (Japanese Patent Application Laid-Open No. 58-99968).

Reference numeral 1 in the figure indicates a container body. This container body 1 itself may be made of a flexible material or may be made of a rigid material, but even if the amount of blood stored changes, the amount of blood stored will increase or decrease due to the expansion of the container 1. However, in order to prevent the deterioration of blood proteins due to contact between blood and air without the presence of an air phase inside the container body 1, it is preferable to construct the container body 1 from a flexible material. ing.

Deaeration ports 2, 2 are formed in the upper part of the container body 1. The deaeration ports 2, 2 are for removing air bubbles separated and removed inside the container body 1 to the outside of the system, and can also be used as a chemical solution injection port and a sampling port. .

Further, at the lower part of the container body 1, a tube-shaped blood inflow pipe 3 and a blood outflow pipe 4 each opening into the inside of the container body 1 and a tube for suctioning bleeding from the surgical field are provided.
A connecting tube 5 is attached, which is used for connection with a cardiotomy blood reservoir for storing and then collecting the blood into the blood circuit. The tip 3a of the blood inflow tube 3 is located above the other tubes in the container body 1, and the tip opening 4a of the blood outflow tube 4 is located below the other tubes (inner bottom of the container 1). The distal end opening 5a of the connecting tube 5 is located between the other tubes.

Further, the tip 3a of the blood inflow tube 3 is sealed, and a plurality of side ports 3b are bored in the tube wall near the tip 3a. By providing a plurality of side ports 3b on the tube wall near the tip of the blood inflow tube 3 in this way, the rotational flow or vortex flow of blood flowing into the container body 1 is reduced, and the rotational flow or vortex flow of blood flowing into the container body 1 is reduced. It is said that the currents cancel each other out.

Further, a screen filter 6 is provided inside the container body 1. This screen filter 6 substantially separates the side opening 3b of the blood inflow tube 3 and the opening 4a of the blood outflow tube 4, and allows air bubbles contained in the blood flowing in from the blood inflow tube 3 to be removed from the opening of the blood outflow tube 4. This is to form a floating path for preventing air bubbles from reaching the portion 4a and for causing the thus blocked air bubbles to float to the deaeration ports 2, 2.

By the way, the conventional blood storage tank described above has the following drawbacks, and a solution to these problems is desired.

(a) Although the effect of the screen filter 6 is recognized, providing the screen filter 6 increases material costs and manufacturing man-hours, resulting in an increase in manufacturing costs. Furthermore, the screen filter 6 has the disadvantage that fibrin is easily formed, which causes proteins in the blood to be adsorbed.

(b) The side ports 3b of the blood inflow tube 3 open in a direction perpendicular to the internal flow of the blood inflow tube 3, and the flow path is suddenly changed at this point. A small vortex is generated around the side openings 3b. The presence of vortices is undesirable because it induces hemolysis.

(c) Furthermore, the flow of blood flowing out from the plurality of side ports 3b is substantially perpendicular to the longitudinal direction of the blood inflow tube 3, as described above. Therefore, the blood flow exiting from the side ports 3b of the portion of the container body 1 near which the side wall is located hits the side wall and weakens, but the blood flow opens in the width direction of the container body 1 (to the left of the blood inflow pipe in FIG. 1). Since there is nothing to obstruct the blood flow coming out of the side openings 3b, the blood flows toward the left side in FIG. 1 without being weakened. As mentioned above, some of the blood is sucked into the blood outflow tube 4, so
The blood flow forms a flow path as shown by arrow A in FIG. Therefore, if the screen filter 6 is not present, there is a risk that small air bubbles will be drawn into the blood outflow tube 4 before heading to the degassing ports 2, 2.

(d) In order for blood to flow out evenly from the side ports 3b of the blood inflow tube 3, the large-diameter tip opening must be hooked, but if the tip opening is sealed, This is undesirable because blood may stagnate and swirl inside the sealed portion, or air bubbles may accumulate. Furthermore, all side ports 3b
Since the structure is such that it is difficult for blood to flow out evenly, air bubbles may accumulate in some of the side ports 3b and prevent them from moving.

(e) If air bubbles flow in from the connecting pipe 5, the connecting pipe 5
The opening 5b is located at a lower position than the side opening 3b,
Since it is close to the opening 4b of the blood outflow tube 4, the air bubbles are easily drawn into the blood outflow tube 4.

The inventor conducted extensive research to solve the above drawbacks and came to the following findings.

First, it has been found that if the diameter of the blood inflow tube is gradually increased from near the lower end of the container body 1 to the tip inside the container body 1, the flow can be slowed down without creating a vortex flow.

Furthermore, as described above, a large rotational flow tends to occur within the container body from the opening of the blood inflow tube toward the opening of the blood outflow tube. On the other hand, if the distal end opening of the connecting tube provided next to the blood inflow tube is located near the distal opening of the blood inflow tube, the connecting tube will exert the same effect as a baffle plate, and as a result, It has been found that the generation of the rotational flow can be prevented. Furthermore, it has been found that even if air bubbles flow into the container body from the connecting pipe, it is possible to prevent the air bubbles from flowing into the blood outflow pipe.

This idea was made based on the above findings. That is, in the blood storage tank according to this invention, the blood inflow tube inserted and fixed into the container body and the tip opening of the connecting tube are arranged at approximately the same horizontal position, and the diameter of the blood inflow tube is adjusted from near the lower end of the container body. It is configured so that the diameter gradually increases toward the tip opening inside the container body.

This invention will be explained below with reference to the drawings. FIG. 3 shows an embodiment of this invention. In the figure, reference numeral 10 indicates a container body, and this container body 10 is made of a material with good biocompatibility and high flexibility.
For example, it is formed into a bag shape using polyvinyl chloride, polycarbonate, ethylene-vinyl acetate copolymer, or the like.

The upper end 11 inside this container body 10 gradually rises from one side end 11a (right side end in the figure) toward the other side end 11b, especially the one side end 11a.
The slope is steep in the vicinity. A deaeration port 1 opened to the outside of the container body 10 is provided at the other side end 11b.
2 is formed. A chemical solution inlet 13 is formed to the right of this deaeration port 12, and a sample collection port 14 is formed further to the right.

On the other hand, at the lower end 15 inside the container body 10, one side 15a and the other side 15b are inclined downward toward the center 15c, and the center 15c is horizontal. This central part 15
c has three tubes, namely blood inflow tube 1
6, a connecting pipe 17 and a blood outflow pipe 18 are attached. The blood inflow pipe 16 is connected to the one side 1
5a, the blood outflow pipe 18 is located near the other side 15b, and the connecting pipe 17 is located between the two pipes. The distal end opening 16a of the blood inflow pipe 16 and the distal opening 17a of the connecting pipe 17 are located at the vertical center inside the container body 10, and are substantially at the same horizontal position. Further, the tip opening 18 of the blood outflow tube 18
a is located near the lower end 15.

The blood inflow tube 16 is gradually expanded in diameter twice from the central portion 15c of the lower end 15 to the tip opening 16a. Each enlarged diameter portion has a gentle taper so that no small vortices are generated around it and the flow is laminar.

In the blood storage tank configured as described above, since the blood inflow pipe 16 gradually expands in diameter from the point where it enters the container body 10, the blood flow from the inside of the pipe toward the inside of the container body 10 is formed in a layer that gradually expands. While forming a flow, the flow velocity is gradually slowed down and no vortex flow is generated. In addition, the blood flow discharged from the tip opening 16a of the blood inflow tube 16 into the container body 10 should be reasonably slowed down, and the container body wall with a steep slope at the upper right side (one end 11a (nearby)
The tip opening 17a of the connecting tube 17 is located near the tip opening 16a, and the connecting tube 17 acts as a baffle against the flow toward the left in the figure. A rotating flow toward the tip opening 18a of the blood outflow tube 18 is not formed. Therefore, even if there is no screen filter between the blood inflow pipe 16 and the blood outflow pipe 18,
Air bubbles in the blood that has flowed into the container body 10 are reliably separated and discharged from the system through the deaeration port 12.

Further, in such a blood storage tank, it is desirable that there should be no stagnation of blood in the tank, and that there should be as little non-uniformity of flow as possible.

However, in the present invention, in order to prevent the generation of vortices and facilitate the removal of air bubbles, the diameter of the blood inflow tube 16 is gradually expanded toward the tip, thereby slowing the flow. . Therefore, the container body 10
The overall blood flow within the vessel becomes weak, and blood tends to stagnate between the blood inflow pipe 16 and the right side wall of the container body 10. This is also due to the fact that the connecting tube 17 and the blood inflow tube 16 themselves act as a baffle against the blood outflow from the blood outflow tube 18.

In order to solve this problem, the blood in the vicinity of the tip opening 18a and the upper part of the blood outflow tube 18 is bypassed by the connecting tube 17 and the blood inflow tube 16, so to speak, on the right side of the blood inflow tube 16 and the container body 10. The blood between the wall and the wall must be raised to approach the tip opening 18a of the blood outflow tube 18.

On the other hand, in the blood storage tank of the present invention, as described above, the upper end 11 of the inside of the container body 10 is steeply sloped especially in the vicinity of one side end 11a, and then the side end on the blood outflow tube 18 side is sloped. It is gradually increasing toward 11b. In this way, the upward flow is promoted, and then the blood flow approaches parallel flow, so that the blood flow approaches the distal end opening 18a of the blood outflow tube 18, albeit slowly. The reason why the sides 15a and 15b of the lower end 15 inside the container body 10 are sloped is to make the blood flow smoother.

In this way, according to the blood storage tank having the above structure, the screen filter is not required, so that the material cost and man-hours used for it can be reduced, and the manufacturing cost can be reduced. In addition, the flow of blood flowing into the container body is a gentle laminar flow throughout the entire process, and there is no place where eddies occur, so that hemolysis does not occur. moreover,
The tip opening of the blood inflow tube and the tip opening of the connecting tube are at almost the same horizontal position, and the connecting tube acts as a baffle plate to block the rotational flow that tends to form inside the container. The bubbles can be removed reliably. Furthermore, as mentioned above, even if the blood flow is slowed down to remove air bubbles, the characteristic sloping shape of the upper end of the container body prevents stagnation of blood within the container body, thereby preventing uneven flow. We have been able to correct this as much as possible.

In the above configuration, the diameter of the blood inflow tube is expanded at two locations; however, the diameter of the blood inflow tube is expanded at two locations; however, the diameter of the blood inflow tube is expanded in two places. The diameter may be expanded to .

In addition, in the above configuration, the tubes such as the blood inflow pipe, the connecting pipe, and the blood outflow pipe are not only made of biocompatible materials like the container body, but also made of flexible materials so that they can be clamped in the middle. It is desirable to give gender.

As explained above, in the blood storage tank according to this invention, the blood inflow tube inserted and fixed into the container body and the tip opening of the connecting tube are arranged at approximately the same horizontal position, and the diameter of the blood inflow tube is adjusted to the diameter of the blood inflow tube of the container body. The diameter gradually increases from near the lower end to the tip opening, and the upper end of the inside of the container body has a steep slope, especially near the tip opening of the blood inflow tube, and then at the side end on the blood outflow tube side. Since it is configured to gradually rise toward the target, the structure is simple, and it can reliably remove bubbles without causing hemolysis, prevent blood stagnation inside, and reduce uneven blood flow. It has the excellent advantage that it can be manufactured at low manufacturing cost.

[Brief explanation of the drawing]

Figures 1 and 2 show a conventional blood storage tank, with Figure 1 being a front view, Figure 2 being a sectional view taken along the line shown in Figure 1, and Figure 3 showing an embodiment of this invention. FIG. 3 is a partially sectional front view. 10... Container body, 11... Upper end inside the container body,
11a, 11b... Side part of the upper end inside the container body, 1
2... Deaeration port, 15a... Lower end center part of the container body,
16...Blood inflow tube, 16a...Tip opening, 1
7... Connecting pipe, 17a... Tip opening, 18...
Blood outflow tube.

Claims (1)

[Claims for Utility Model Registration] A blood inflow pipe, a connecting pipe, and a blood outflow pipe are connected to the bottom of a container body provided with a deaeration port at the top thereof, and the connecting pipe connects the blood inflow pipe to the blood inflow pipe. and a blood outflow tube, and the blood inflow tube and the connecting tube have tip openings in the container body at approximately the same vertical position from a lower end position of the container body, and the blood inflow tube The diameter of the tube is gradually increased from near the lower end of the container body to the tip opening in the container body, and the upper end of the inside of the container body is made to have a steep slope, especially near the tip opening of the blood inflow tube. The blood storage tank is also characterized in that it is gradually inclined from the steeply sloped portion to the side end on the side of the blood outflow tube.