JPH0355139B2 - - Google Patents

Description

BACKGROUND OF THE INVENTION (Technical Field) The present invention relates to a blood reservoir (cardiotomy reservoir) used in an artificial heart-lung circuit during extracorporeal circulation associated with open heart surgery. (Prior art and its problems) In an artificial heart-lung circuit, as illustrated in FIG. and from the pump 3 via the blood reservoir 4 and line 5 to the venous reservoir 7 housed in the volume regulating means 6.
The pump 8 then connects the oxygenator 9 with a heat exchanger.
The oxygenated blood is then returned to the patient's body via a blood supply line 10. By the way, in addition to defoaming and storing blood aspirated in the surgical field such as the thoracic cavity and heart cavity, the blood reservoir has the function of defoaming the blood aspirated in the surgical field such as the thoracic cavity and heart cavity. Devices that incorporate a filter for filtering out foreign substances such as aggregates and are configured to perform the three important functions of filtration, defoaming, and blood storage have become widely used. However, it has been pointed out that the blood reservoirs currently in use have the following various problems in the three functions mentioned above. (1) Problems with filtration function When blood containing many foreign substances such as tissues and microaggregates is passed through a filter, the filter tends to become clogged quickly before it is used effectively. Furthermore, in the case of a pleated filter, a lumen is created due to the cylindrical arrangement of the filter, and therefore blood pools in this lumen, making it difficult to accurately determine the amount of blood in the blood reservoir. Therefore, there is a difference between the scale mark marked on the housing of the blood reservoir and the actual amount of blood stored, resulting in the problem that the actual amount of blood cannot be read when necessary. Furthermore, filter performance and the ability to rapidly separate blood and bubbles within the filter conflict, and it is difficult to find a balance between them. Furthermore, when the filter is arranged in a cylindrical shape, if the aspirated blood is not evenly distributed across the filter and concentrates only in a certain part of the filter, channeling will occur, and the filter will not be used efficiently, resulting in less filtration. If it takes a long time to clean the filter, or if the blood contains many of the foreign substances mentioned above, the area where the blood is concentrated may quickly become clogged, which may reduce the filtration efficiency of the filter. Because there is
A blood storage tank that efficiently filters blood is required to uniformly distribute the drawn blood to the filter. (2) Problems with defoaming function Blood that enters the blood storage tank is filtered and defoamed by a filter and an antifoaming agent, and then stored in the housing. Outflow blood (or priming fluid)
In a structure in which the liquid is dropped onto the surface of blood that has been defoamed and stored, bubbles will occur again, which is not desirable. In such a case, blood containing microbubbles is also sent to the patient, and there is a risk of brain damage due to peripheral blood vessel occlusion. There are some structures that avoid the above phenomenon by bringing the filtration and defoaming member into contact with the bottom of the housing.
This type of device tends to cause an air block phenomenon in which the air in the blood discharge port at the bottom of the housing and the tube connected thereto cannot be discharged and is left behind. For membrane lungs using closed venous reservoirs, this poses a significant risk of air contamination into the venous reservoir, oxygenator, and patient. Air block phenomenon is when the blood surface inside the tube connected to the blood outflow port is clamped, and when a large amount of inflow blood flows in, air cannot be discharged and some of the air remains inside the tube. It means the phenomenon of being put away. In addition, in a blood storage tank with a built-in filter, due to the resistance of the filter, which has recently become more sophisticated, it is necessary to have a structure that defoams after filtration. When filtering, positive pressure filtration is used. In positive pressure filtration, as the blood flow rate increases, the processing capacity of the defoaming member is exceeded, and the positive pressure air jets out blood from the filter, creating bubbles in the blood, which tends to make subsequent defoaming disadvantageous. In such a case, the pressure increase in the filter is also large, which tends to reduce filter performance. In order to avoid this, some products have adopted a cyclone type air separation structure at the blood inlet, but this cannot be done when a large amount of air is mixed in, which tends to cause a pressure increase, and results in considerably poor defoaming performance. I'm inviting you. (3) Problems with blood storage function There are also problems with the shape and structure of the housing in terms of blood storage function. In terms of mold production, it is convenient for the housing to produce flanged halves and bond them together at the middle. However, in such a structure,
There is a possibility of blood leakage at the adhesive part, and at the same time, it is troublesome to display the liquid volume scale on the label, and the display of the amount of stored blood at the flange part is likely to be inaccurate. Furthermore, depending on the case of open heart surgery, blood volume is often measured through the vent line in order to ascertain the status of circulatory abnormalities and valve insufficiency. In other words, the heart is in an ischemic state, but if there is abnormal pulmonary venous return, blood accumulates in the left ventricle, and the degree of abnormality can be understood from the amount. Also, if there is caval valve insufficiency, this is also determined by the amount of blood stored in the left ventricle. That is, in order to measure these quantities through the vent line, fine scale display is required. Therefore, the bottom of the housing and the blood outflow port are required to have shapes that allow easy reading of the blood volume. Purpose of the Invention The present invention has been made in view of the above-mentioned current situation.
The objective is to provide a blood storage tank configured such that blood within a filter and bubbles in blood can be separated quickly and efficiently over a long period of time. In addition to the above objects, another object of the present invention is to uniformize the use of the filter over the entire circumference, increase the efficiency of use of the filter, and promote separation of blood and bubbles in the blood within the filter. Another object of the present invention is to provide a blood storage tank in which the dead volume inside the filter is smaller, the amount of blood stored is accurate, and the amount of blood returned is accurate. That is, the present invention includes a housing capable of storing blood, which has a blood inlet at the top and a blood outlet at the bottom, and a filtration and defoaming section is provided in the housing, and the filtration and defoaming section is configured to prevent the blood from flowing. A cylindrical body that communicates with an inlet and is open at the lower end and limits a blood flow path for introduced blood; a cylindrical filter that defines a gap for separating and eliminating air bubbles in the blood between the cylindrical body; and a filtration and defoaming member arranged concentrically with each other, and the lower end of the cylindrical body is placed above the bottom of the filter to prevent the filter from getting wet with blood. The present invention provides a blood storage tank characterized in that: Further, the present invention includes a housing capable of storing blood, which has a blood inlet at the top and a blood outlet at the bottom, and a filtration and defoaming section is provided in the housing, and the filtration and defoaming section is adapted to control the blood flow. a rod-shaped body that evenly distributes the blood introduced from the inlet; a cylindrical body that communicates with the blood inlet and has an open lower end and limits a blood flow path for the blood introduced between the rod-shaped body; A cylindrical filter that defines a gap between the cylindrical body and the air bubbles in the blood to be separated and eliminated, and a filtration and defoaming member arranged concentrically on the outer periphery of the filter. The present invention provides a blood storage tank, characterized in that the lower end of the cylindrical body is disposed above the bottom of the filter so that the upper part of the filter is not wetted by blood. DETAILED DESCRIPTION OF THE INVENTION Hereinafter, the blood reservoir of the present invention will be described in detail with reference to preferred embodiments shown in the accompanying drawings. FIG. 2 is a perspective view of the blood storage tank 20 of the present invention, and FIG. 3 is a longitudinal cross-sectional view taken along the - line in FIG. You can clearly see that it is laid out in a similar manner. The housing 21 is a rigid transparent body made of a hard plastic material such as polycarbonate, acrylic-styrene copolymer, polyester, polyamide, polyvinyl chloride, acrylic-butadiene-styrene copolymer, etc., preferably by integral molding. . The top of the housing 21 is connected to the first upper lid 2.
2 and the second upper lid 23 are preferably rotatable so that they can be freely connected to the extracorporeal circuit.
5. A rapid infusion port 26 is provided, and the second upper lid 2
3, an air vent port 27 and a filter-impermeable infusion port 28 are provided. The body of the housing 21 is approximately cylindrical and hollow. The bottom of the housing 21 forms an inclined surface that slopes toward the eccentrically formed blood outlet 29, and a medium-high support portion 32 for supporting the filtering and defoaming member 30 and the deflector 31 is formed in the center thereof. ing. Although it is preferable for the housing 21 to be composed of halves in terms of mold production, from the viewpoint of blood leakage, graduations, labels, etc., it is preferable to form the housing 21 seamlessly as one piece except for the top part. In particular, it is necessary to prevent blood from accumulating at the bottom, and it is better to have no adhesive parts. The blood outflow port 29 provided at the bottom of the housing 21 is preferably provided eccentrically near the outer periphery of the bottom of the housing 21, since if it is provided at the center of the bottom of the housing 21, visibility of the scale, blood volume, etc. will be poor. Furthermore, depending on the case of open heart surgery, it may be necessary to know the exact amount of blood even if it is a small amount, so it is preferable that the shape of the blood outflow port 29 is funnel-shaped with a smooth curved surface. The scale can be easily read if it has a bulging shape such as a hemisphere. In this way, when blood flows into the venous reservoir via the tube connected to the funnel-shaped blood outflow port with a smooth curved surface, the blood flows through the blood outflow port 2.
9 and to flow along the wall of the tube,
The air block phenomenon, which is the problem mentioned above, does not occur. This also applies if the blood level rises or falls at the blood outlet due to the vertical movement of the blood reservoir during adjustment operations to optimize the body's blood volume, which is constantly monitored, or fluctuations in blood inflow from the surgical field. , the air block phenomenon is likewise prevented. The filtering and defoaming member 30 disposed in the upper part of the housing 21 described above is connected to the deflector 3 below.
1 and an upper support 33 extending from the second top lid.
and the middle-high support part 32. The filtering/defoaming member 30 has various functional elements arranged concentrically outward from the center, and sequentially and selectively distributes the air-mixed blood introduced into the center evenly.
Blood and bubbles are separated, filtered, and defoamed, and the defoamed blood is stored in the blood storage section through the deflector 31 at the lower part of the housing without generating bubbles again. The filtering/defoaming member 30 has a filter 35 having a lumen 34 and a defoaming member 36 on its outer periphery, and the filter 35 has an upper support 33 and a lower support 37.
The defoaming member 3 is fixed with an adhesive 38 between the
6 fits into the filter 35 and is supported between the lower support 37 and the deflector 31. A funnel-shaped deflector 31 is supported between the lower support body 37 and the mid-high support part 32. Upper support 33
In the lumen 34 constituted by the filter 35,
It has a cylindrical body 40 that hangs downward by a length shorter than the filter length, and defines an annular gap 41 between the filter 35 and this cylindrical body 40.
Since a cylindrical body exists in this gap, blood does not directly enter, and therefore the part of the filter corresponding to the gap 41 does not get wet, and the bubble air separated from the blood flows from this part to the filter 35 and the defoaming member. 3
6 and vent port 27. The lower support body 37 includes a rod-shaped hollow member 42 that rises upward within the inner cavity 34 formed by the filter 35.
The lower part 44 of the hollow member 42 has a filter 3
5, but the upper part 43 is reduced in diameter to form a cylindrical body 40.
The inside extends upward to approximately the position of the upper support body 33. The hollow member 42 and the cylindrical body 40 are the filtering and defoaming member 3
It is preferable to arrange the hollow member 4 concentrically with the hollow member 4.
A gap 45 between 2 and the cylindrical body 40 defines the blood flow path. The upper portion 43 of the hollow member 42 is closed and its head is preferably rounded to allow for even distribution of blood. Conventionally, this blood distribution hollow member 42 was not disposed inside the filter 35 to form a lumen, and there was a problem in that blood whose amount could not be measured was accumulated in this lumen, but in the present invention, , the placement of the blood distribution hollow member 42 into the lumen 34 of the filter 35 to a considerable height position eliminates unnecessary lumens and ensures even distribution of blood into the filter 35 and between the cylindrical body 40 and the filter 35. Blood and bubble separation gap 4
By forming No. 1, the filtering surface can be used effectively, and channeling as in the conventional case can no longer occur. The constituent material of the blood distribution hollow member 42 is as follows:
Hard plastics such as polycarbonate, acrylic-styrene copolymer, polyamide, polyester, polyvinyl chloride, acrylic-butadiene-styrene copolymer, polypropylene, etc., which can define the diameter of the inner cavity 34 of the filter 35, are preferable. There are various types of filters 35 disposed around the blood distribution hollow member 42, but even if a screen type with a mesh with a pore diameter of about 20μ or a depth type with an adsorption effect is used, it is difficult to make it compact and lightweight. A pleated filter is preferred. It is preferable that the filter 35 is not limited to a pleated type, and that it contacts the blood distribution hollow member 42 at equal intervals, with a certain amount of space formed therebetween. This is because the contact between the filter 35 and the blood distribution hollow member 42 at equal intervals can increase the effective area of the filter. Furthermore, the space formed between the filter 35 and the blood distribution hollow member 42 is intended to provide a storage space for substances that hinder the effective use of the filter, such as clogging and channeling caused by foreign substances such as tissues and microaggregates. It's for a reason. In a blood storage tank with a built-in filter, blood is filtered under positive pressure, but as the blood flow rate increases, the processing capacity decreases, and the blood is ejected from the filter due to positive pressure, creating bubbles that are later quenched. As mentioned above, foam may be disadvantageous. To prevent this, it is best to treat the filter with an antifoaming agent in advance. The antifoaming agent is generally antifoaming silicone (compound type mixed with silica, oil type), etc., and the filter constituent material is preferably nylon, polyester, polypropylene, etc. The filter is preferably made of these meshes or nonwoven fabrics. By attaching an antifoaming agent to the filter, when blood comes into contact with the filter, the bubbles are defoamed and separated into blood and air, which suppresses the increase in pressure caused by the filter and at the same time improves the filtration performance of the filter. maintained. The defoaming member 36 on the outer periphery of the filter 35 is for further defoaming the blood that has been filtered or defoamed by the filter 35 on the upstream side, and is made of foamed urethane, stainless steel ribbon, polypropylene mesh, etc. The material is coated with the antifoaming agent mentioned above. Further, it is preferable that the blood storage tank of the present invention is separated into a filtration/defoaming section and a blood storage section. This is to prevent the stored blood from being immersed in the filter 35 or the defoaming member 36 as in the conventional case, as described above, and to avoid contact with foreign matter as much as possible. This is due to complement activation by components that are currently attracting attention (complement, a type of protein found in animal serum that plays an important enzymatic role when antigen-antibody reactions occur in vivo, is activated). activation, causing damage to cell membranes, the body's defense mechanism against infection, and inflammatory responses. In addition, due to activation, complement is consumed, temporarily lowering the body's immune system and increasing the risk of infection, etc.) To provide a scale that suppresses desorption of silicone, reduces the dead volume of blood in a filter 35 and an antifoaming member 36, and allows accurate grasping of the amount of blood when blood is returned. In order to achieve such a function, in the present invention, a filter is provided so that the blood that has been filtered and defoamed in the filter and defoamer section can be guided again to the blood outlet 29 at the bottom of the housing 21 without generating bubbles. A funnel-shaped deflector 31 is provided at the lower part of the excessive foam defoaming member 30.
The deflector 31 is converged so as to be supported on a mid-height support portion 32 at the center of the bottom of the housing 21, and as shown in FIG. 3, a trough-like channel 47 is formed by a large number of guide plates 46. This deflector 31
It is preferable to avoid contacting the body portion of the housing 21 and the bottom portion adjacent to the body portion to open the flow path. This is because if the deflector 31 and the housing come into contact as described above, when the blood level is below the contact point, the contact point is likely to be mistaken for the blood level, which may lead to a misunderstanding by the operator. Also,
Since blood always flows over the deflector, if the deflector is made of a transparent material, the blood level tends to be difficult to read. Therefore, it is preferable that the deflector be made of something that does not give the impression of blood color or is made of an opaque material. The defoamed blood that has exited the filtering and defoaming member 30 passes through the trough-like passage 47 of the deflector 31 and forms a gentle flow, so that the invasion of the blood is small and no bubbles are generated again. Although the hollow housing 21, the cylindrical body 40, and the hollow member 42 are cylindrical in the above description, they may have any other suitable shape such as a polygonal prism or irregular cross-sectional shape, and the member 42 may be solid. The gist of the present invention is not to separate the filtration/defoaming section and the blood storage section;
A cylindrical body forms a non-wetted part in the upper part of the filter due to the gap, making it convenient to eliminate air bubbles, and by providing a rod-shaped body such as the hollow member 42, blood is absorbed by the time it reaches the filter. The air bubbles trapped in the blood float to the surface of the blood, making it easier to separate the air bubbles. In the present invention, the hollow member 42, the cylindrical body 40,
The filter 35 and the defoaming member 36 are arranged concentrically, and a blood flow path is provided between the hollow member 42 and the cylindrical body 40, and a gap 41 for separating blood and bubbles is provided between the cylindrical body 40 and the filter 35. It was discovered as a result of examining various configuration examples based on the experiments described below that it is extremely effective to form the following. A structure as shown in FIG. 4 was created. The filters 35 are all made of the same material, have the same shape, and have the same area, and are pleat-like made of nonwoven fabric or mesh of nylon, polyester, polypropylene, or the like. Hollow member 42 and cylindrical body 4
0 were all made of the hard plastic mentioned above. If there is a foam-defoaming member around the outer periphery of the filter 35, the defoaming state will be inaccurately confirmed, so no foam-defoaming member is used. Flow rate of bovine blood (1 day after blood collection) into these configurations
It was flowed at 1000 ml/min and evaluated in terms of performance and pressure loss depending on the foaming state. As is clear from the table below showing the results, in the case of FIG. 4a, the blood mixed with bubbles directly hits the lower adhesive 38, and the bubbles are likely to be pushed out of the filter 35 by the blood before being separated. In Fig. 4b, filter 3
The effective length of filter 3 is shorter than the longer filter shown in Figure 4d.
5. Wetting is fast, the bubble escape area is easily reduced,
The results were similar to those in Figure 4a. In the case shown in Fig. 4c, the pressure increase was smaller than in the cases shown in Figs. 4a and 4b, and good results were obtained. In the invention shown in Figure 4d, the
Even better results were obtained than those shown in Figures 4b and 4c. In the one shown in FIG. 4c, the air gap 41 between the cylindrical body 40 and the filter 35 is
Due to the presence of the filter, the upper part of the filter does not get wet.
Therefore, air can escape easily, and in addition to the above-mentioned function of the gap 41 between the cylindrical body 40 and the filter 35, in the case shown in FIG. This is thought to be due to the fact that the air bubbles in the blood float to the surface, further promoting the separation of the air bubbles from the blood.

[Table] Specific effects of the invention Filtration, defoaming, and
The blood storage function will be explained. The blood reservoir is constructed and used as shown in FIG. Bubble-containing blood sucked from the surgical field such as the cardiothoracic cavity during open-heart surgery or the like falls onto the upper part 43 of the hollow member 42 through the blood inlet port 24. Blood flows down through the blood flow path between the upper part 44 of the hollow member 42 and the cylindrical body 40 while avoiding direct contact with the filter 35, and contacts the filter 35 for the first time at the lower part 43 of the hollow member 42. The blood passes through the portion from the upper part 43 to the lower part 44 of the hollow member 42, and by increasing the contact area of the bubble-containing blood with the member before contacting the filter 35, bubbles and blood are quickly and effectively separated. be able to. Further, the blood flowing down inside the cylindrical body 40 is evenly distributed radially by the hollow member 42 at the lower end opening of the cylindrical body 40 . and,
The evenly distributed blood mainly flows in the direction shown by the solid arrow in FIG. 3 and does not flow into the gap 41 formed between the filter 35 and the cylindrical body 40, so that The area does not become wet with blood and remains wet for a long time. On the other hand, the bubbles separated from the blood are
As shown by the dotted arrow in the figure, the air collects in the void 41 and is defoamed through the filter 35 and the defoaming member 36, which may or may not be impregnated with an defoaming agent, and the air passes through the vent port 27. It is then discharged to the outside. Therefore, air accumulates in the filter lumen 34 and increases the internal pressure, which, together with the pressure from positive pressure filtration, causes bubbles to flow through the filter 3 along with the blood.
There will be no more gushing from 5. In addition, the amount of blood conventionally stored in the filter lumen 34 is reduced due to the presence of the hollow member 42 and the rapid and effective separation of blood and bubbles as described above, and the amount of blood in the blood reservoir can be accurately determined. You will be able to understand it. Filter 3 arranged around the outer periphery of hollow member 42
5, the tissue or microaggregation contained in the blood or transfused blood is distributed evenly by the hollow member 42, and bubbles are effectively separated by the gap 41 between the filter member 35 and the cylindrical body 40. Filter out foreign substances such as gates from blood. In this way, the blood that has been filtered or filtered and defoamed by the filter 35 is completely defoamed while passing through the defoaming member 36, and oozes out from the defoaming member 36. The oozing blood flows gently down the trough-like passage 47 of the deflector 31 and flows into the blood storage space 48 without generating bubbles again. The blood in the blood storage space 48 forms a swirl flow around the middle and high support part 32 at the inclined bottom of the housing 21, and flows through the blood outflow port 2.
9, it passes through the tube 5 and reaches the venous reservoir 7. In addition, if the blood outflow port 29 is not formed at the center of the bottom of the housing 21 but near the outer peripheral edge, and its shape is a bulge having a smooth curved surface such as a sphere, it is possible to Even a small amount of blood can be accurately and easily read by the scale attached to the blood outlet 29. In this way, by forming a swirling flow in the exuded blood and also configuring the blood outlet 29 to ensure a smooth flow, the blood is connected to the bottom of the housing 21, the blood outlet 29, and the blood outlet 29. Since the flow follows the walls of the tube, air block phenomena are prevented and there is no possibility of bubbles circulating into the patient's body via the venous reservoir. Specific Effects of the Invention As detailed above, according to the blood storage tank of the present invention, the filtration and defoaming section includes a cylindrical body that limits the blood flow path of introduced blood, and a cylindrical body that defines the blood flow path of the introduced blood. By forming a gap between the cylindrical body and the filter, the filter in the area above the lower end of the cylindrical body where there is a gap is not wetted by blood, and Therefore, air from bubbles in the blood can be reliably and quickly separated and removed from the wet filter portion and the defoaming member portion, and this state can be maintained for a long time. Therefore, according to the blood storage tank of the present invention, blood wets the entire filter, and air from bubbles in the blood increases the internal pressure, resulting in positive pressure filtration, unlike conventional blood tanks. This eliminates the possibility of forcing out a large number of new air bubbles from the filter along with the blood. Further, according to the blood storage tank of the present invention in which the rod-shaped body is installed concentrically within the cylindrical body, blood is evenly distributed in the radial direction of the filter by the rod-shaped body, so that blood flows through the filter and the extinguisher without channeling. The entire circumference of the foam member can be used evenly, and when blood flows down inside the cylindrical body, it comes into contact with this rod-shaped member and promotes the separation of blood and air bubbles. It can be efficiently, reliably, and quickly separated and removed from the component. Further, since the rod-shaped body is arranged concentrically within the cylindrical body of the filtration and defoaming section of the blood storage tank of the present invention, blood is not stored in the filter lumen of the filtration and defoaming section. The amount of dead volume in the bubble can be reduced, the amount of blood stored can be made accurate, and the amount of blood at the time of blood return can be made accurate.

[Brief explanation of drawings]

FIG. 1 is a diagrammatic perspective view of an example of an artificial heart-lung circuit;
FIG. 2 is a perspective view of a preferred embodiment of the blood reservoir of the present invention;
FIG. 3 is a vertical cross-sectional view taken along the - line in FIG. 2, and FIG. 4 is a diagrammatic partial cross-section of various configuration examples used in experiments to confirm the effectiveness of the configuration of the blood storage tank of the present invention. It is a diagram. Explanation of symbols, 1...Blood removal line, 2...Satsuka line, 3, 8...Pump, 4...Blood storage tank, 5
... line, 6 ... capacity regulating means, 7 ... venous reservoir, 9 ... oxygenator with heat exchanger, 10 ... blood supply line, 20 ... blood storage tank of the present invention, 21 ... housing, 22 ... ...first upper lid, 23...second upper lid,
24... Suction blood inflow port, 25... Filter-passable infusion, blood transfusion port, 26... Rapid infusion port, 27... Air vent port, 28... Filter-non-passable infusion port, 29... Blood outflow port,
30... Filtering and defoaming member, 31... Deflector, 3
2... Middle and high support part, 33... Upper support body, 34...
...Inner cavity, 35...Filter, 36...Defoaming member, 37...Lower support, 38...Adhesive, 40
... Cylindrical body, 41 ... Annular gap, 42 ... Hollow member, 43 ... Upper part, 44 ... Lower part, 45 ... Gap, 46 ... Guide plate, 47 ... Gutter-like channel, 48
...Blood storage space.

Claims (1)

[Scope of Claims] 1. A housing having a blood inlet at the top and a blood outlet at the bottom, capable of storing blood; a filtration and defoaming section is provided in the housing, and the filtration and defoaming section is configured to absorb the blood A cylindrical body that communicates with the inflow port and is open at the lower end to limit the blood flow path for the introduced blood, and a cylindrical body that defines an air space for separating and eliminating air bubbles in the blood between the cylindrical body and the cylindrical body. A filter and a filtration defoaming member each having a filter and a defoaming member arranged concentrically on the outer periphery of the filter,
A blood storage tank characterized in that the lower end of the cylindrical body is disposed above the bottom of the filter so that the upper part of the filter is not wetted by blood. 2. A housing capable of storing blood having a blood inlet at the top and a blood outlet at the bottom, a filtration and defoaming section provided within the housing, and the filtration and defoaming section being introduced from the blood inlet. A rod-shaped body that distributes blood evenly; a cylindrical body that communicates with the blood inflow port and has an open lower end to limit a blood flow path for blood introduced between the cylindrical body and the rod-shaped body; The air that separates and eliminates air bubbles in the blood between
and a filtration/defoaming member concentrically arranged with a cylindrical filter that defines a cylindrical filter and a defoaming member disposed on the outer periphery of the filter, and the cylindrical body A blood storage tank characterized in that a lower end of the filter is disposed above the bottom of the filter.