Blood storage tank

Abstract

This blood storage tank (10) has an introduction part (46), and the introduction part (46) includes: a through part (54) provided through a lid body (22); a funnel-shaped guide part (60) which is provided so as to cover the upper section of the through part (54) and curves such that the inclination angle thereof gradually increases from the outer periphery to the inner periphery; a cap member (56) which is disposed facing the upper side of the guide part (60) and forms a blood flow path (86a) with the guide part (60); and a defoaming sponge (78) which is connected to the lower section of the through part (54) and receives blood that has flowed out from an opening in the guide part (60).

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This type of extracorporeal circulation circuit is provided with a blood reservoir for temporarily storing venous blood withdrawn from the patient's vein and surgical field blood (also referred to as intracardiac blood) that has overflowed into the surgical field (for example, Japanese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 Laid-Open No. 2008-194386).

[0003] The blood reservoir is provided with a cardiotomy section for removing foreign substances and air bubbles from the inflowing surgical field blood. Japanese Patent Laid-Open No. 2008-194386 discloses a cardiotomy section having a bag-shaped filter and a funnel-shaped defoaming member provided inside the filter.

Summary of the Invention

[0004] In the cardiotomy section, a sponge made of a resin material (defoaming sponge) is used as the defoaming member. The intracardiac blood flowing in from the cap member is guided to the funnel-shaped defoaming sponge and is separated into blood and air bubbles by passing through the defoaming sponge.

[0005] However, in a conventional blood reservoir, when the flow rate of the inflowing intracardiac blood is too fast, the air bubbles are finely crushed by the kinetic energy of the fluid, and there is a problem that the air bubbles are miniaturized. When the air bubbles are miniaturized, it becomes difficult to remove the air bubbles with the defoaming sponge, and there is a risk that the air bubbles will remain in the blood.

[0006] Therefore, an object of one embodiment is to provide a blood reservoir capable of preventing the crushing of air bubbles in the cardiotomy section.

[0007] One aspect of the following disclosure is a blood reservoir comprising a housing having an internal space formed therein, a lid covering the upper part of the internal space of the housing, and a cardiotomy section for introducing intracardiac blood into the internal space, wherein the cardiotomy section has a through portion provided through the lid, a funnel-shaped guide portion provided so as to cover the upper part of the through portion and curved such that the angle of inclination gradually increases from the outer circumference to the inner circumference, a cap member positioned opposite to the guide portion and forming a blood flow path between itself and the guide portion, and an antifoaming sponge connected to the lower part of the through portion to receive the blood flowing out from the opening of the guide portion.

[0008] According to the blood reservoir described above, it is possible to prevent the collapse of air bubbles in the cardiotomy area. [Brief explanation of the drawing]

[0009] [Figure 1] This is a perspective view of a blood reservoir according to an embodiment. [Figure 2] Figure 1 is a perspective cross-sectional view of the blood reservoir. [Figure 3] Figure 1 is a perspective view of the lid of the blood reservoir. [Figure 4] Figure 1 is an enlarged perspective cross-sectional view of the inlet of the blood reservoir. [Figure 5] Figure 1 is a perspective view of the inner surface of the cap member. [Figure 6] Figure 1 is a cross-sectional view showing the function of the cardiotomy area. [Modes for carrying out the invention]

[0010] 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.

[0011] 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).

[0012] 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.

[0013] 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 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.

[0014] 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.

[0015] 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 solution port 30 for mixing drug solutions with blood, and an exhaust port 32 for adjusting the internal pressure in the blood reservoir 10.

[0016] 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 34 are formed on the outer wall of the housing 12, extending horizontally to allow for the estimation of the volume of stored blood.

[0017] As shown in Figure 2, the internal space 12a of the housing 12 houses a venous blood filtration section 36 for filtering venous blood and a portion of a cardiotomy section 38 for filtering intracardiac blood. The venous blood filtration section 36 is connected below the venous blood inflow port 14 and extends elongated toward the bottom 12c of the housing 12. The venous blood filtration section 36 comprises a frame-shaped filter frame 40, an air bubble removal filter 42 supported by the filter frame 40, and a conduit 44 that extends to the lower end of the filter frame 40 and discharges venous blood from the lower end of the filter frame 40. The venous blood filtration section 36 removes air bubbles from the venous blood using the air bubble removal filter 42.

[0018] The cardiotomy section 38 is located in the internal space 12a of the housing 12. The cardiotomy section 38 includes an introduction section 46 provided on the lid 22, a bag-shaped filter 50, and an anti-foaming member 52 located inside the filter 50.

[0019] The introduction section 46 has a through section 54 that penetrates the lid 22 and a cap member 56 that covers the through section 54. The through section 54 has an outer cylindrical section 58 that protrudes from the lid 22 and a guide section 60 that protrudes inward from the upper end of the outer cylindrical section 58. The outer cylindrical section 58 and the guide section 60 are integrally formed with the lid 22.

[0020] The outer cylinder part 58 is a cylindrical part that protrudes so as to penetrate the lid body 22 in the thickness direction. As shown in FIG. 4, the outer cylinder part 58 has an outer peripheral wall 62 and an inner peripheral wall 64 formed concentrically. The outer peripheral wall 62 is connected to the lid body 22 at its outer peripheral part 62a. An engaging protrusion 62b for engaging the cap member 56 and a packing accommodation groove 62c are provided on the outer peripheral part 62a of the outer peripheral wall 62. An annular packing 66 such as an O-ring is accommodated in the packing accommodation groove 62c. The packing 66 seals the gap between the cap member 56 and the outer peripheral wall 62 in an airtight and liquidtight manner.

[0021] An upper end part 68 parallel to the lid body 22 is formed at the upper end of the outer peripheral wall 62. The upper end part 68 is formed over the entire circumference of the outer peripheral wall 62. The inner peripheral wall 64 is connected to the outer peripheral wall 62 through the upper end part 68. The inner peripheral wall 64 is separated from the lid body 22 and is supported by the upper end part 68. The inner peripheral wall 64 extends downward in a cylindrical shape from the upper end part 68. The inner peripheral wall 64 is separated inward from the outer peripheral wall 62, and an annular gap is formed between the outer peripheral wall 62 and the inner peripheral wall 64. A filter frame 70 for holding the filter 50 is fitted into the gap. A through hole 72 is formed inside the inner peripheral wall 64.

[0022] As shown in FIG. 4, the guide part 60 is connected to the inner peripheral side of the upper end part 68 of the outer cylinder part 58 and extends out to the inner peripheral side of the inner peripheral wall 64. The guide part 60 covers a part of the outer peripheral side of the through hole 72. The guide part 60 has a curved part 74 that extends horizontally and smoothly curves downward from the outer peripheral side connected integrally with the upper end part 68 toward the inner peripheral side, and a cylindrical skirt part 76 continuous with the lower end of the curved part 74. The curved part 74 has a cross section curved in an arc shape and curves so that the downward inclination angle gradually increases toward the inner periphery. The curved part 74 is formed rotationally symmetric with respect to the central axis of the through part 54 and is formed in a funnel shape.

[0023] As shown in FIG. 4, the skirt portion 76 is a cylindrical portion extending from the lower end of the curved portion 74 and extends below the cap member 56. The skirt portion 76 is tapered so that its diameter gradually decreases downward. The lower end portion of the skirt portion 76 is disposed in the vicinity of the defoaming sponge 78 as shown in FIG. 2. The skirt portion 76 may abut against the defoaming sponge 78.

[0024] As shown in FIG. 1, the introduction portion 46 has a circular cap member 56 that covers the through portion 54, an intracardiac blood inflow port 16, a priming port 28, and a chemical solution port 30. A plurality of intracardiac blood inflow ports 16 and chemical solution ports 30 are provided, respectively, and are arranged at regular intervals in the circumferential direction of the cap member 56.

[0025] The cap member 56 is formed in a disk shape having a diameter that covers the entire area of the through portion 54. As shown in FIG. 4, a fitting wall 56a that protrudes in a circular wall shape is formed on the outer peripheral portion of the cap member 56. An engaging piece 56b is provided on the inner peripheral side of the fitting wall 56a. As shown in FIG. 4, the fitting wall 56a fits on the outer peripheral side of the outer peripheral wall 62 of the through portion 54. The engaging piece 56b of the fitting wall 56a engages with the engaging protrusion 62b of the outer peripheral wall 62, so that the cap member 56 and the through portion 54 are fixed in a non-detachable manner. A reduced diameter portion 只要縮径部56cは、パッキン66と密着して封止する。

[0026] It should be noted that there is an incorrect expression "只要縮径部56cは" in the original text for item , which is likely a typo. The translation is based on the best understanding of the overall context.As shown in Figure 4, a top plate portion 82 is formed on the inside of the fitting wall 56a of the cap member 56. The top plate portion 82 has a curved surface portion 84 that follows the upper end portion 68 of the through portion 54 and the curved portion 74 of the guide portion 60. The curved surface portion 84 is curved such that the angle of inclination gradually increases from the outer circumference toward the center. A flow channel groove 86 is formed in the curved surface portion 84, which communicates with the intracardiac blood inflow port 16 and the drug solution port 30. The outer end of the flow channel groove 86 is connected to the intracardiac blood inflow port 16 and the drug solution port 30. The flow channel groove 86 is formed in a groove shape so as to be recessed relative to the curved surface portion 84 and extends radially from the outer circumference of the cap member 56 toward the center of the cap member 56. As shown in Figure 6, the flow channel groove 86 and the guide portion 60 form a blood flow channel 86a. As shown in Figure 2, the flow channel groove 86 has a pipe portion 86b that protrudes to the outside (upper side) of the cap member 56.

[0027] As shown in Figure 5, a spacer portion 88 is formed in the central part of the cap member 56, below the priming port 28. The spacer portion 88 has a cylindrical spacer wall 88a coaxial with the central axis of the cap member 56 and a cavity portion 88b formed inside the spacer wall 88a. The cavity portion 88b communicates with the priming port 28. The spacer portion 88 defines the inner circumferential end of the flow channel groove 86. That is, the flow channel groove 86 (pipe portion 86b) is formed to the extent that it abuts against the spacer wall 88a, and all flow channel grooves 86 (pipe portions 86b) are spaced radially outward from the spacer portion 88. The spacer wall 88a and the top plate portion 82 are connected via a flat portion 90. The flat portion 90 is formed along a plane perpendicular to the central axis of the cap member 56. As shown in Figure 5, when the cap member 56 is viewed from the inside, the inner circumferential end of the flow channel groove 86 is open at the flat portion 90.

[0028] As shown in Figure 2, the filter 50 is connected below the introduction section 46 via a filter frame 70. The filter 50 surrounds the outside of the defoaming member 52. The filter 50 mainly consists of a mesh material capable of removing thrombi and tissue fragments mixed in the blood. For example, resins such as polyester, polyamide, Tetron, rayon, polypropylene, polyethylene, and polyvinyl chloride can be used as materials for the filter 50.

[0029] The defoaming member 52 is located below the introduction section 46. The defoaming member 52 includes a defoaming sponge 78 positioned below the guide section 60, and a guide member 100 positioned outside the defoaming sponge 78 to support the defoaming sponge 78.

[0030] The defoaming sponge 78 is a sponge made of, for example, urethane resin, and contains gaps (open pores) through which air bubbles and blood can pass. When blood containing air bubbles comes into contact with such a defoaming sponge 78, the air bubbles in the blood float up through the gaps in the defoaming sponge 78, and the air bubbles are separated and removed from the blood. The defoaming sponge 78 is formed in a funnel shape. An open lower end opening 78a is provided at the lower end of the defoaming sponge 78. The lower end opening 78a of the defoaming sponge 78 extends near the bottom plate 106 of the guide member 100.

[0031] The guide member 100 is positioned to surround the outside of the defoaming sponge 78 and supports the funnel shape of the defoaming sponge 78 from the outside. The guide member 100 has a mounting ring 96 formed at its upper end, a tapered portion 98 that extends downward from below the mounting ring 96 while decreasing in diameter, and an outflow portion 101 that extends downward from the lower end of the tapered portion 98.

[0032] The mounting ring 96 of the guide member 100 is inserted inside the inner circumferential wall 64 of the through-hole 54. The mounting ring 96 is formed to have approximately the same diameter as the inner diameter of the inner circumferential wall 64, and the guide member 100 is fitted inside the through-hole 54 when the mounting ring 96 is fitted into the inner circumferential wall 64. The tapered portion 98 is a tapered portion that decreases in diameter towards the lower end.

[0033] The guide member 100 has a blood concentration section 110 located below the tapered section 98. The blood concentration section 110 has a horizontally positioned bottom plate 106 and a pair of side wall sections 108 that extend upward from the periphery of the bottom plate 106 and are connected to the lower end of the tapered section 98. The bottom plate 106 is connected to the tapered section 98 via the side wall sections 108. The bottom plate 106 is provided with a plurality of outlet holes 112 that allow the blood collected in the blood concentration section 110 to flow downward.

[0034] Below the bottom plate 106, a rectifier plate 114 and a partition plate 116 that protrudes briefly in the thickness direction of the rectifier plate 114 are provided. The rectifier plate 114 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 hole 112 to flow down quietly without foaming. The partition plate 116 extends downward and finely partitions the flow of blood flowing out from the outflow hole 112, thereby regulating the blood flow and preventing foaming.

[0035] The blood reservoir 10 of this embodiment is configured as described above, and its operation will be explained below.

[0036] 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 42 of the venous blood filtration unit 36, the venous blood flows into the internal space 12a of the blood reservoir 10.

[0037] Meanwhile, intracardiac blood flows into the cardiotomy section 38 through the intracardiac blood inflow port 16 shown in Figure 6. The cap member 56 is provided with a flow channel groove 86, and a flow channel 86a is formed between the cap member 56 and the guide section 60. Therefore, the blood flowing in from the intracardiac blood inflow port 16 flows into the flow channel 86a. Since the gap α between the top plate portion 82 of the cap member 56 and the curved portion 74 of the guide section 60 is 0.3 mm or less, most of the blood flowing in from the intracardiac blood inflow port 16 flows through the flow channel 86a. It has been confirmed that when blood flows into the gap α between the top plate portion 82 of the cap member 56 and the curved portion 74 of the guide section 60, air bubbles in the blood are crushed and miniaturized. However, by making the gap α between the top plate portion 82 and the curved portion 74 of the guide section 60 0.3 mm or less, the miniaturization of air bubbles can be prevented.

[0038] The flow path 86a is smoothly curved from horizontal to approximately vertical along the upper end 68 and curved portion 74 of the guide portion 60. The blood flows along the curved portion 74. At this time, the blood encounters flow resistance within the flow path 86a, and the blood flow velocity decreases. The blood flows out from the opening of the flow path 86a at the lower end of the cap member 56. After that, the blood flows along the skirt portion 76 and into the defoaming sponge 78.

[0039] Since the cap member 56 is provided with a spacer portion 88, the opening at the lower end of the flow path 86a is spaced away from the central axis. As a result, the vertical drop between the outlet of the flow path 86a and the defoaming sponge 78 is narrowed. This prevents an increase in the blood flow velocity in the skirt portion 76, and prevents the crushing and miniaturization of bubbles due to the kinetic energy of the fluid.

[0040] Blood that flows into the defoaming sponge 78 has its air bubbles separated inside the sponge 78. The blood flows downward along the guide member 100 and merges with the blood stored in the internal space 12a after passing through the filter 50. The blood stored in the blood reservoir 10 flows out through the outflow port 18 at the bottom 12c.

[0041] The blood reservoir 10 of this embodiment provides the following effects.

[0042] The blood reservoir 10 of this embodiment comprises a housing 12 having an internal space 12a formed inside, a lid 22 covering the upper part of the internal space 12a of the housing 12, and a cardiotomy section 38 for introducing intracardiac blood into the internal space 12a. The cardiotomy section 38 includes a through-hole 54 provided through the lid 22, a funnel-shaped guide section 60 provided to cover the upper part of the through-hole 54 and curved such that the angle of inclination gradually increases from the outer circumference to the inner circumference, a cap member 56 positioned above and opposite the guide section 60 and forming a blood flow path 86a between itself and the guide section 60, and an anti-foaming sponge 78 connected to the lower part of the through-hole 54 and receiving the blood flowing out from the opening of the guide section 60.

[0043] With the above configuration, intracardiac blood flows along the funnel-shaped guide section 60, which is curved so that the angle of inclination gradually increases from the outer circumference to the inner circumference, causing it to flow along the curved section 74 and reducing the blood flow velocity. This prevents the collapse of air bubbles in the defoaming sponge 78.

[0044] In the blood reservoir 10 described above, the cap member 56 may have an intracardiac blood inflow port 16 protruding outward from the cardiotomy portion 38, a flow channel groove 86 communicating with the intracardiac blood inflow port 16, curving along the guide portion 60 and extending toward the center of the cardiotomy portion 38, forming a flow channel 86a inside, and a top plate portion 82 covering the guide portion 60 other than the flow channel groove 86. With this configuration, blood can flow through the flow channel 86a inside the flow channel groove 86 along the curved portion 74 of the guide portion 60, and the fragmentation of air bubbles in the intracardiac blood can be prevented.

[0045] In the blood reservoir 10 described above, the cap member 56 may have a cylindrical spacer portion 88 that moves the inner end of the flow path 86a radially outward. With this configuration, the part from which blood flows out of the flow path groove 86 can be moved away from the outer circumference of the cap member 56. This reduces the height difference between the flow path groove 86 and the defoaming sponge 78, and prevents the collapse of air bubbles.

[0046] In the blood reservoir 10 described above, the gap α between the top plate portion 82 and the curved portion 74 of the guide portion 60 may be 0.3 mm or less. With this configuration, it is possible to prevent air bubbles (and blood) from entering the gap α between the top plate portion 82 and the curved portion 74, thereby preventing the bubbles from becoming micronized.

[0047] In the blood reservoir 10 described above, the flow path 86a formed between the guide portion 60 and the cap member 56 may be configured to allow intracardiac blood to fall onto the defoaming sponge 78 from a position radially outward from the center of the cardiotomy portion 38. With this configuration, the drop to the defoaming sponge 78 is reduced, which prevents the bubbles from becoming finer.

[0048] In the blood reservoir 10 described above, the guide portion 60 may have a cylindrical skirt portion 76 that protrudes below the flow path 86a and extends toward the defoaming sponge 78. With this configuration, the intracardiac blood flows along the skirt portion 76, which prevents an increase in the kinetic energy of the fluid and prevents the collapse of air bubbles in the defoaming sponge 78.

[0049] 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.

Claims

1. A housing with an internal space formed inside, A cover that covers the upper part of the internal space of the housing, It comprises a cardiotomy section for introducing intracardiac blood into the internal space, The cardiotomy portion is, The through portion provided that penetrates the aforementioned lid, A funnel-shaped guide portion is provided to cover the upper part of the aforementioned through-hole, and is curved so as to gradually increase in inclination angle from the outer circumference to the inner circumference, A cap member is positioned above the guide portion, facing the guide portion, and forms a blood flow path between itself and the guide portion. It includes an anti-foaming sponge positioned opposite the guide portion below it, which receives blood that flows out from the opening of the guide portion, A blood concentration section is located below the defoaming sponge, has a horizontally positioned bottom plate, and temporarily stores the blood that has flowed down the defoaming sponge, The bottom plate of the blood concentration section is provided with a plurality of outlet holes that allow blood to flow out downwards, The aforementioned cap member is The intracardiac blood inflow port protruding outward from the cardiotomy site, A flow channel groove that communicates with the intracardiac blood inflow port, curves along the guide portion and extends toward the center of the cardiotomy portion, and forms the flow channel inside, A top plate portion that covers the guide portion in a part other than the flow path, A fluid port is provided in the center of the cap member and protrudes upward, A blood reservoir having a cylindrical spacer portion provided in the lower part of the fluid port, which causes the inner end of the flow path to be further radially outward than the outer circumference of the fluid port.

2. A blood reservoir according to claim 1, wherein the gap between the top plate and the guide portion is 0.3 mm or less.

3. A blood reservoir according to claim 1 or 2, wherein the flow path formed between the guide portion and the cap member causes intracardiac blood to fall onto the defoaming sponge from a position radially outward from the center of the cardiotomy portion.

4. A blood storage tank according to claim 3, wherein the guide portion has a cylindrical skirt portion that protrudes below the flow path and extends toward the defoaming sponge.

5. A blood reservoir according to claim 1, The defoaming sponge is provided with a guide member that supports it so as to surround its outer surface. The blood concentration section is a blood reservoir located below the guide member.

6. A blood reservoir according to claim 1 or 5, A flow straightening plate extending downward from below the bottom plate, which allows the blood flowing out from the outflow hole to flow down without foaming, A blood storage tank comprising a partition plate that protrudes briefly in the thickness direction of the rectifier plate and finely divides the flow of blood that has flowed out from the outflow hole.

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