Blood storage tank

Abstract

A blood storage reservoir (10) improves the separability of air bubbles in a cardiotomy part (40). The blood storage reservoir (10) comprises: a defoaming member (52) which is provided below an intracardiac blood inflow port (16) and which protrudes toward an internal space (12a); and a bag-shaped filter (50) covering the outside of the defoaming member (52). The defoaming member (52) has: a first guide member (68) having a first tapered part (73) which is connected to a lower end of an introduction part (48) and shrinks in diameter going downward, and an opening (73b) provided to the lower end of the first tapered part (73); a defoaming sponge (70) disposed so as to cover the outer periphery of the first guide member (68); and a second guide member (72) which is provided outside of and separate from the first guide member (68) and supports the defoaming sponge (70).

Description

【Technical Field】 【0001】 The present invention relates to a blood reservoir used in an extracorporeal circulation circuit such as a cardiopulmonary bypass device. 【Background Art】 【0002】 When performing surgery with the heart stopped, an extracorporeal circulation circuit such as a cardiopulmonary bypass device is used for the purpose of temporarily substituting the functions of the heart and lungs. This type of extracorporeal circulation circuit is provided with a blood reservoir for temporarily storing venous blood withdrawn from the patient's vein and surgical field blood (also referred to as intracardiac blood) that has overflowed into the surgical field (for example, Japanese Patent Application Laid-Open No. 2002-204827). 【0003】 The blood reservoir is provided with a cardiotomy section for removing foreign substances and bubbles from the inflowing surgical field blood. Japanese Patent Application Laid-Open No. 2002-204827 shows a cardiotomy section having a defoaming member. 【Summary of the Invention】 【0004】 In the cardiotomy section, a sponge made of a resin material (defoaming sponge) is used as the defoaming member. When blood passes through the defoaming sponge, the separation of blood and bubbles progresses, and the bubbles float upward through the gaps of the defoaming sponge and are separated. However, in a conventional blood reservoir, bubbles in the blood may be finely crushed near the defoaming sponge, resulting in a decrease in the separability of blood and bubbles. Therefore, measures such as restricting the blood flow rate and increasing the size of the bubble removal section are required. 【0005】 Therefore, one embodiment aims to improve the separability of bubbles in the cardiotomy section of the blood reservoir. 【0006】 One aspect of the following disclosure is a blood reservoir comprising: a housing having an internal space for storing blood; an introduction section for introducing intracardiac blood into the housing; an antifoaming member provided below the introduction section and protruding toward the internal space; and a bag-shaped filter covering the outside of the antifoaming member, wherein the antifoaming member comprises: a first guide member connected to the lower end of the introduction section and having a first tapered section that narrows in diameter downward and an opening provided at the lower end of the first tapered section; an antifoaming sponge disposed outside the first guide member; and a second guide member provided spaced apart outside the first guide member and supporting the antifoaming sponge. 【0007】 According to the blood reservoir described above, the part through which the blood flows down from the inlet and within the defoaming material can be separated from the area where the defoaming sponge is placed. This prevents the bubbles accumulated within the defoaming sponge from becoming finer, thus improving bubble separation. [Brief explanation of the drawing] 【0008】 [Figure 1] This is a perspective view of the blood reservoir according to the first embodiment. [Figure 2] Figure 1 is a cross-sectional view of the blood reservoir. [Figure 3] Figure 2 is a partially enlarged cross-sectional view of the cardiotomy area. [Figure 4] Figure 2 is a perspective view showing the arrangement relationship between the first guide member and the second guide member. [Figure 5] Figure 2 is a perspective view of the second guide member. [Figure 6] Figure 5 is a perspective view showing the second guide member cut at the lower end of the second tapered section. [Figure 7] Figure 2 is a perspective view of the second guide member as seen from the partition plate side. [Figure 8] Figure 2 is an explanatory diagram showing the operation of the defoaming component. [Figure 9] This is a cross-sectional view of the blood reservoir near the cardiotomy area according to the second embodiment. [Modes for carrying out the invention] 【0009】 The following describes a preferred embodiment of the blood reservoir, with reference to the attached drawings. Note that the dimensional proportions in the drawings may be exaggerated for illustrative purposes and may differ from the actual proportions. 【0010】 As shown in Figure 1, the blood reservoir 10 according to this embodiment is an integrated blood reservoir that combines a venous reservoir for temporarily storing venous blood drawn from the patient's veins and a blood reservoir (cardiotomy reservoir) for temporarily storing intracardiac blood (also called aspirated blood or surgical field blood) aspirated from the surgical field (outside the heart). 【0011】 The blood reservoir 10 is used, for example, incorporated into an extracorporeal circulation circuit used in cardiac surgery to filter and defoam venous blood and intracardiac blood for temporary storage. 【0012】 The blood reservoir 10 comprises a housing 12 having an internal space 12a for storing blood, a venous blood inflow port 14 located at the top of the housing 12 for introducing venous blood into the internal space 12a, an intracardiac blood inflow port 16 (inflow port) for introducing intracardiac blood into the internal space 12a, and an outflow port 18 located at the bottom 12c of the housing 12 for draining blood from the internal space 12a of the blood reservoir 10. 【0013】 The housing 12 comprises a housing body 20 and a lid 22 that covers the upper part of the housing body 20. The housing body 20 is formed in a box shape with an open top. The upper part of the housing body 20 is a storage section 24 that forms the upper part of the internal space 12a, and below the storage section 24, a protruding section 26 is formed, which is a part of the front side of the storage section 24 that protrudes downward. The storage section 24 forms a blood storage space on the side into which blood flows, and the protruding section 26 forms a blood storage space on the side into which blood flows. 【0014】 The cover 22 is positioned to cover the opening at the top of the housing body 20. The cover 22 is provided with a venous blood inflow port 14 and an intracardiac blood inflow port 16. The cover 22 is also provided with a priming port 28 for priming the internal space 12a, a drug injection port 30 for mixing drug solutions with blood, and an exhaust port 32 for adjusting the internal pressure in the blood reservoir 10. 【0015】 The housing 12 is made of a transparent or translucent resin material, allowing the liquid level of the blood stored in the internal space 12a to be visible from the outside. Examples of resin materials that make up the housing 12 include polycarbonate, acrylic resin, polyethylene terephthalate, polyethylene, polypropylene, polystyrene, polyvinyl chloride, and ABS resin. Multiple scale lines 36 are formed on the outer circumference of the housing 12, extending horizontally to allow for estimation of the volume of stored blood. 【0016】 As shown in Figure 2, the internal space 12a of the housing 12 houses a venous blood filtration unit 38 for filtering venous blood and a cardiotomy unit 40 for filtering intracardiac blood. The venous blood filtration unit 38 is connected below the venous blood inflow port 14 and extends elongated toward the bottom 12c of the housing 12. The venous blood filtration unit 38 comprises a frame-shaped filter frame 42, an air bubble removal filter 44 supported by the filter frame 42, and a conduit 46 that extends to the bottom of the filter frame 42 and discharges venous blood from the bottom of the filter frame 42. The venous blood filtration unit 38 removes air bubbles from the venous blood using the air bubble removal filter 44. 【0017】 The cardiotomy section 40 is connected below the intracardiac blood inflow port 16 and is located in the housing section 24 of the housing 12. The cardiotomy section 40 has an introduction section 48 provided on the lid 22, a bag-shaped filter 50, and an anti-foaming member 52 located inside the filter 50. 【0018】 As shown in FIG. 3, the introduction part 48 is provided with a substantially cylindrical through-hole 56 formed to penetrate the lid body 22 in the vertical direction, and a cap member 58 attached so as to cover the upper part of the through-hole 56. The through-hole 56 is a cylindrical member integrally formed with the lid body 22, and the upper part of the through-hole 56 protrudes above the lid body 22. At the upper end of the through-hole 56, a converging part 60 is formed which slopes gradually downward as it goes inward. The upper surface 60a of the converging part 60 is formed over the entire circumference in the circumferential direction of the through-hole 56, and is composed of a smooth curved surface whose vertical inclination gradually increases as it goes toward the inner peripheral side. The converging part 60 collects the liquid flowing in from the intracardiac blood inflow port 16 and the chemical solution injection port 30 provided at a plurality of locations in the circumferential direction to the center side and flows it downward. 【0019】 At the inner lower end of the converging part 60, an annular shielding plate 62 protruding inward is formed. The shielding plate 62 protrudes radially inward with a width sufficient to reduce the flow velocity of the blood flowing downward along the converging part 60. A central hole 64 through which the blood flows downward is formed in the central part of the shielding plate 62. 【0020】 The cap member 58 is a member that covers the upper part of the through-hole 56, and is joined to the outer peripheral part of the through-hole 56 by a method such as fitting or screwing. As shown in FIG. 1, the intracardiac blood inflow port 16 and the chemical solution injection port 30 are provided protruding at a plurality of locations in the circumferential direction on the cap member 58. Flow path protrusions 66 that are connected to the intracardiac blood inflow port 16 and the chemical solution injection port 30 and extend radially inward are formed on these cap members 58. The flow path protrusions 66 extend toward the center in the radial direction along the upper surface 60a of the converging part 60. Inside the flow path protrusions 66, a flow path 66a whose lower side opens toward the upper surface 60a of the converging part 60 is formed. The flow path 66a is formed along a smooth curve along the upper surface 60a, and can flow along the upper surface 60a without foaming the blood. 【0021】 The defoaming member 52 is provided below the introduction part 48. The defoaming member 52 includes a first guide member 68 joined to the lower side of the collecting part 60, a defoaming sponge 70 disposed to surround the outer peripheral part of the first guide member 68, and a second guide member 72 disposed outside the defoaming sponge 70 to support the defoaming sponge 70. The first guide member 68 is a funnel-shaped member attached to the lower end part of the collecting part 60. As shown in FIG. 4, the first guide member 68 has a first tapered part 73 whose diameter decreases in a tapered shape toward the lower end. As shown in FIG. 3, a cavity part 73a extending downward is formed inside the first tapered part 73. The cavity part 73a opens at an opening 73b at the lower end part of the first guide member 68. 【0022】 The defoaming sponge 70 is a sponge such as a urethane resin, and includes gaps (open pores) through which air bubbles and blood can pass. When blood containing air bubbles comes into contact with such a defoaming sponge 70, the air bubbles in the blood float up through the gaps of the defoaming sponge 70, and the air bubbles are separated and removed from the blood. The defoaming sponge 70 is formed in a funnel shape and is disposed to surround the outside of the first guide member 68. The lower end part 70b of the defoaming sponge 70 is open. The lower end part 70b of the defoaming sponge 70 extends near the bottom plate 86 of the second guide member 72. 【0023】 As shown in FIG. 4, the second guide member 72 is disposed to surround the outside of the first guide member 68, supports the defoaming sponge 70 (see FIG. 3) from the outside, and is a member that allows blood to flow downward without foaming. The second guide member 72 has a cylindrical part 74 formed at the upper end, a second tapered part 76 extending downward while reducing its diameter from below the cylindrical part 74, and an outflow part 78 extending downward from the lower end of the second tapered part 76. 【0024】 As shown in Figure 3, the cylindrical portion 74 of the second guide member 72 is the part that is inserted into the inner circumference of the through portion 56 and connected to the through portion 56, and is formed in a cylindrical shape with an outer diameter slightly smaller than the inner diameter of the through portion 56. As shown in Figure 5, the second tapered portion 76 is a tapered portion that decreases in diameter towards the lower end. In this embodiment, the second tapered portion 76 has a pair of opening windows 80 spaced 180° apart in the circumferential direction, and the second tapered portion 76 has a pair of inclined walls 76a facing each other between the opening windows 80. The defoaming sponge 70 is supported by the inclined walls 76a. The opening windows 80 are covered and sealed with a funnel-shaped defoaming sponge 70. 【0025】 As shown in Figure 5, a groove 82 is formed in the circumferential central part of the inclined wall 76a, which is concave outwards. As shown in Figure 3, the inclined wall 76a is spaced apart from the defoaming sponge 70 at the groove 82, forming a channel for the blood that flows out from the defoaming sponge 70 downwards. 【0026】 The outflow section 78 has a blood concentration section 84 located below the second tapered section 76. The blood concentration section 84 has a horizontally positioned bottom plate 86, a pair of side wall sections 88 extending upward from the periphery of the bottom plate 86 and connected to the lower end of the inclined wall 76a, and a projection 94 projecting upward from the center of the bottom plate 86. Of these, the bottom plate 86 is a long, narrow plate-like section, and its long side direction coincides with the direction in which the opening window 80 is positioned. As shown in Figure 4, near the center of the short side of the bottom plate 86, there are two rows of outflow holes 90 arranged along the long side to allow the blood collected in the blood concentration section 84 to flow downward. The outflow holes 90 penetrate the bottom plate 86 in the vertical direction. 【0027】 The side walls 88 are provided on both sides of the bottom plate 86 in the short-side direction. The upper ends of the side walls 88 are integrally connected to the inclined wall 76a. A notch 92 is formed at the end of the side wall 88 in the long-side direction, and the two side walls 88 are separated by the notch 92. As shown in Figure 3, a portion of the lower end of the defoaming sponge 70 is inserted between the pair of side walls 88, and the area near the lower end of the defoaming sponge 70 is supported by the side walls 88. 【0028】 As shown in Figure 6, the projection 94 has a support column 96 that protrudes from the base plate 86, and the support column 96 protrudes from the base plate 86 to the height of the lower end of the second tapered portion 76. The support column 96 is formed in a cross-shaped rib form to avoid the outflow hole 90. A conical portion 98 is formed at the upper end of the support column 96. The conical portion 98 is formed in a weight-like shape that protrudes upward while decreasing in diameter towards the center, with a highest point, the apex 100, formed at the center. The conical portion 98 has a first curved portion 98a formed near the central apex 100, and a second curved portion 98b provided on the outer circumference of the first curved portion 98a and curved with a different curvature than the first curved portion 98a. The first curved portion 98a has a greater inclination with respect to the horizontal plane, and the second curved portion 98b is curved such that the gradient with respect to the horizontal gradually decreases as it moves outward. As shown in Figure 3, a portion of the conical portion 98 near the top 100 is inserted inside the opening 73b of the first guide member 68. A gap is provided between the conical portion 98 and the opening 73b through which blood can pass, and the flow of blood that flows out from the opening 73b is directed laterally by the conical portion 98. 【0029】 As shown in Figure 7, the outflow section 78 further includes a flow straightening plate 102 protruding downward from the bottom plate 86 and a partition plate 104 protruding from the flow straightening plate 102. The flow straightening plate 102 protrudes from the bottom plate 86 in the portion between the rows of outflow holes 90 arranged in two rows along the long side as shown in Figures 5 and 6, and extends parallel to the long side. As shown in Figure 2, the flow straightening plate 102 extends downward to near the lower end of the storage section 24 of the blood reservoir 10, allowing the blood flowing out from the outflow holes 90 to flow down quietly without foaming. 【0030】 Multiple partition plates 104 are formed to protrude laterally in short lengths from the rectifier plate 102. The partition plates 104 extend downward so as to partition the portion between adjacent outflow holes 90 in the long-side direction, thereby regulating the flow of blood flowing out of the outflow holes 90. 【0031】 As shown in Figure 2, the defoaming member 52 is configured as described above, and a filter 50 is attached in a bag shape to surround the outside of the defoaming member 52. The filter 50 is mainly used to remove foreign matter from the blood, and can be made of resins such as polyester, polyamide, Tetron, rayon, polypropylene, polyethylene, or polyvinyl chloride. The filter 50 is made of a mesh material with a mesh that can remove thrombi and tissue fragments mixed in the blood. 【0032】 The blood reservoir 10 of this embodiment is configured as described above, and its operation will be explained below. 【0033】 In the blood reservoir 10 shown in Figure 2, venous blood flows in through the venous blood inflow port 14, and intracardiac blood flows in through the intracardiac blood inflow port 16. After air bubbles are removed from the venous blood by the air bubble removal filter 44 of the venous blood filtration unit 38, the venous blood flows into the internal space 12a of the blood reservoir 10. 【0034】 As shown in Figure 8, intracardiac blood flows into the cardiotomy section 40. The blood that flows into the cardiotomy section 40 flows along the introduction section 48 and is collected near the center by the collection section 60. By flowing along the smooth upper surface 60a of the collection section 60, the formation of air bubbles can be prevented. 【0035】 The blood flowing on the upper surface 60a is obstructed by the shielding plate 62 provided at the lower end of the collection section 60, causing its flow velocity to decrease. The blood flows into the lower first guide member 68 through the central hole 64. The blood flows down inside the first guide member 68 and flows out from the opening 73b at the lower end of the first guide member 68. 【0036】 In this embodiment, a projection 94 is provided facing the opening 73b, and the curved surface of the cone portion 98 at its upper end causes the blood to flow outward from the opening 73b. By reducing the flow of blood with the cone portion 98, the flow of blood (dynamic pressure) hitting the defoaming sponge 70 is weakened, preventing the crushing (micronization) of air bubbles. 【0037】 The blood (intracardiac blood) that flows out from the opening 73b flows out from near the lower end of the funnel-shaped defoaming sponge 70 and flows upward through the inside of the defoaming sponge 70 and the gap between the opening 73b and the cone 98. Bubbles can easily rise to the surface on this upward flow, further promoting the separation of bubbles from blood. 【0038】 The blood passes through the defoaming sponge 70 and flows along the groove 82 of the second guide member 72 into the lower outflow section 78. The blood then flows downward through the outflow hole 90 of the bottom plate 86. After passing through the outflow hole 90, the blood flows along the rectifier plate 102 of the outflow hole 90. Subsequently, the intracardiac blood passes through the filter 50 of the cardiotomy section 40 and flows into the internal space 12a of the blood reservoir 10. Foreign matter such as thrombi and tissue fragments in the intracardiac blood is removed as it passes through the filter 50. 【0039】 Intracardiac blood that has passed through the cardiotomy section 40 is stored in the internal space 12a, merges with venous blood that has passed through the venous blood filtration section 38, and flows out from the blood reservoir 10 through the outflow port 18 provided at the bottom 12c of the housing 12. 【0040】 The blood reservoir 10 of this embodiment provides the following effects. 【0041】 The blood reservoir 10 of this embodiment includes a housing 12 having an internal space 12a for storing blood, an introduction section 48 (for example, an intracardiac blood inflow port 16) for introducing intracardiac blood into the housing 12, an antifoaming member 52 provided below the introduction section 48 and protruding toward the internal space 12a, and a bag-shaped filter 50 covering the outside of the antifoaming member 52. The antifoaming member 52 includes a first guide member 68 connected to the lower end of the introduction section 48 and having a first tapered section 73 that narrows in diameter toward the bottom and an opening 73b provided at the lower end of the first tapered section 73, an antifoaming sponge 70 positioned outside the first guide member 68, and a second guide member 72 provided spaced apart outside the first guide member 68 and supporting the antifoaming sponge 70. 【0042】 With the blood reservoir 10 configured as described above, the first guide member 68 separates the portion into which the blood falls from the defoaming sponge 70, making it easier for air bubbles inside the defoaming sponge 70 to rise to the surface, and enabling efficient separation of air bubbles and blood. 【0043】 In the blood reservoir 10 described above, the defoaming member 52 may be positioned opposite the opening 73b of the first guide member 68 and may have a projection 94 that directs the direction of the blood flow out of the opening 73b to the side. With this configuration, the fluid velocity can be reduced when the direction of the fluid is changed significantly, and it is possible to prevent bubbles from being crushed by the fluid flow in the part where the fluid comes into contact with the defoaming sponge 70. Furthermore, with this configuration, the miniaturization of bubbles in the blood is suppressed and the bubble separation efficiency is improved. 【0044】 In the blood reservoir 10 described above, the projection 94 may have opposing conical portions 98 that cover the entire area of ​​the opening 73b. With this configuration, all of the fluid passing through the opening 73b can be deflected laterally, and the fluid velocity can be reduced more effectively. 【0045】 In the blood reservoir 10 described above, the cone portion 98 has a top portion 100 that protrudes most upward in the center, and the top portion 100 may be inserted inside the opening 73b. With this configuration, the fluid passing through the opening 73b can be reliably deflected laterally, and the fluid velocity can be reduced more effectively. 【0046】 In the blood reservoir 10 described above, the cone portion 98 may have a first curved portion 98a formed on the central side and a second curved portion 98b formed on the outer circumference of the first curved portion 98a and curved with a different curvature than the first curved portion 98a. With this configuration, the fluid flowing out from the opening 73b flows along the first curved portion 98a to the second curved portion 98b, which allows the fluid flow to be smoothly deflected and prevents the collapse of air bubbles in the blood. 【0047】 In the blood reservoir 10 described above, the defoaming sponge 70 may be positioned to surround the sides of the opening 73b. With this configuration, blood flowing out from the opening 73b can be guided to the defoaming sponge 70. 【0048】 In the blood reservoir 10 described above, the second guide member 72 has a second tapered portion 76 that narrows in diameter downwards, and the second tapered portion 76 may have an inclined wall 76a that is in surface contact with the defoaming sponge 70, and a groove 82 provided on the inclined wall 76a and spaced apart to the outside of the defoaming sponge 70 that guides the blood that flows out of the defoaming sponge 70 downwards. With this configuration, the blood that flows out from the opening 73b flows upwards along the inclined wall 76a of the second guide member 72, so as to be blown upwards, the efficiency of separating the bubbles that float upwards is improved. 【0049】 In the blood reservoir 10 described above, the second guide member 72 may further include a side wall portion 88 extending downward from the second tapered portion 76, and a bottom plate 86 supporting the lower end of the side wall portion 88. With this configuration, the defoaming sponge 70 can be held in the gap between the projection portion 94 and the side wall portion 88. Then, the blood that flows out from the defoaming sponge 70 can be collected near the bottom plate 86. 【0050】 In the blood reservoir 10 described above, the second guide member 72 may further include an outlet hole 90 provided on the bottom plate 86 for draining blood accumulated near the bottom plate 86 downwards, and a flow straightening plate 102 extending downward from the bottom plate 86 near the outlet hole 90 to regulate the flow of blood. 【0051】 In the blood reservoir 10 described above, the inner circumference of the opening 73b of the first guide member 68 is located inside the inner circumference of the central hole 64 of the introduction section. With this configuration, the blood flowing out from the central hole 64 flows along the inner wall of the first guide member 68 to the opening 73b, thus preventing the blood falling from the central hole 64 from falling directly into the opening 73b and preventing the collapse of air bubbles near the opening 73b. 【0052】 In the blood reservoir 10 described above, the inlet 48 may be provided with a resistive member (for example, a shielding plate 62) to reduce the force of the blood flowing out from the inlet port. This reduces the blood flow velocity and prevents the collapse of air bubbles. 【0053】 In the blood reservoir 10 described above, the resistance member may have an inclined surface tilted with respect to the vertical direction or a horizontal surface extending in the horizontal direction. This configuration makes it possible to reduce the blood flow velocity in the introduction section 48. 【0054】 (Second Embodiment) As shown in Figure 9, the blood reservoir 10A of this embodiment differs from the blood reservoir 10 of Figures 2 and 3 in the introduction section 48A. The introduction section 48A has a collection section 60A that does not have a shielding plate 62. A conical first guide member 68A is joined below the collection section 60A. The first tapered section 113 of the first guide member 68A is formed in a conical shape, and the blood that flows down the collection section 60A flows along the inclined inner surface of the first tapered section 113. The blood flows outward through the gap between the opening 73b at the lower end of the first guide member 68A and the conical section 98 of the projection 94. 【0055】 The blood reservoir 10A of this embodiment provides the same effects as the blood reservoir 10 of the first embodiment. 【0056】 Although preferred embodiments of the present invention have been described above, it goes without saying that the present invention is not limited to the above embodiments, and various modifications are possible without departing from the spirit of the invention. 【0057】 For example, in the blood reservoir 10 of the first embodiment, the projection 94 was provided on the second guide member 72 side, but the present invention is not limited thereto, and the projection 94 may be joined to the lower end of the first guide member 68 via a rib structure or the like.

Claims

[Claim 1] A housing having an internal space for storing blood, The housing includes an introduction section for introducing intracardiac blood, A defoaming member provided below the aforementioned introduction section and protruding toward the internal space, The defoaming member comprises a bag-shaped filter that covers the outside of the defoaming member, The defoaming member comprises a first guide member having a first tapered portion that is connected to the lower end of the introduction portion and whose diameter decreases downward, and an opening provided at the lower end of the first tapered portion, A defoaming sponge is positioned on the outside of the first guide member, The first guide member is spaced apart from the first guide member and includes a second guide member that supports the defoaming sponge, A blood reservoir, wherein the second guide member has a second tapered portion that decreases in diameter downward, and the second tapered portion has an inclined wall that is in surface contact with the defoaming sponge, and a groove provided on the inclined wall and spaced apart to the outside of the defoaming sponge for guiding the blood that has flowed out from the defoaming sponge downward. [Claim 2] A blood reservoir according to claim 1, wherein the defoaming member is positioned opposite the opening of the first guide member and has a projection that directs the direction of the blood flow out of the opening to the side. [Claim 3] A blood reservoir according to claim 2, wherein the projection has opposing conical portions that cover the entire area of ​​the opening. [Claim 4] A blood reservoir according to claim 3, wherein the cone portion has a apex that protrudes most upward from the center, and the apex is inserted inside the opening. [Claim 5] A blood reservoir according to claim 3 or 4, wherein the cone portion has a first curved portion formed on the central side and a second curved portion formed on the outer circumference side of the first curved portion and curved with a different curvature from the first curved portion. [Claim 6] A blood reservoir according to any one of claims 1 to 5, wherein the defoaming sponge surrounds the sides of the opening. [Claim 7] A blood storage tank according to claim 1, wherein the second guide member further comprises a side wall portion extending downward from the second tapered portion and a bottom plate supporting the lower end of the side wall portion. [Claim 8] A blood reservoir according to claim 7, wherein the second guide member is further provided on the bottom plate and includes an outlet hole for draining blood accumulated near the bottom plate downward, and a flow straightening plate extending downward from the bottom plate near the outlet hole for regulating the flow of blood. [Claim 9] A blood reservoir according to any one of claims 1 to 8, wherein the inner circumference of the opening of the first guide member is located inside the inner circumference of the central hole of the introduction portion. [Claim 10] A blood reservoir according to claim 9, wherein the inlet is provided with a resistance member for reducing the force of the blood. [Claim 11] A blood storage tank according to claim 10, wherein the resistance member has an inclined surface tilted with respect to the vertical direction or a horizontal surface extending in the horizontal direction. [Claim 12] A blood reservoir according to any one of claims 1 to 11, wherein the first tapered portion of the first guide member is formed in a conical shape.

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