Blood storage tank

Abstract

To provide a blood storage tank capable of preventing the clogging of a defoaming member with blood or bubbles and preventing the leakage of the blood or the bubbles from the defoaming member by maintaining the defoaming performance of the defoaming member.SOLUTION: A blood storage tank 10 includes: a housing 12 having an internal space 12a for storing blood inside; a filter part arranged in the internal space 12a and filtering the inflow blood; and a flow passage 36 for guiding the blood from the upper part of the housing to the inside of the filter part. The filter part includes: a filter frame 32 having a frame shape; a filter 34 held by the filter frame 32; and a sponge-like defoaming member 38 filled in the upper end of the filter frame 32. The defoaming member 38 has: a second part 38a filling a space between the filter frame 32 and the flow passage 36 without any clearance; and a first part 38b overlapping the inside of the filter 34.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a blood reservoir used in an extracorporeal circulation circuit of an artificial heart-lung machine or the like. [Background technology]

[0002] For the purpose of life support during cardiac surgery, an extracorporeal circulation circuit is used to temporarily perform the functions of the heart and / or lungs. This type of extracorporeal circulation circuit uses a blood reservoir that stores blood drawn from the patient's veins (for example, Patent Document 1). This type of blood reservoir is equipped with a filtering section that removes foreign matter and air bubbles from the blood. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6132137 Summary of the Invention [Problem to be solved by the invention]

[0004] Conventional blood reservoirs have a sponge-like defoaming member in the filtration section that removes air bubbles from the blood. However, as the number of air bubbles in the blood increases, the defoaming member can become clogged with the blood and air bubbles, causing the blood and air bubbles to overflow the defoaming member and flow into the blood reservoir without passing through the filter.

[0005] An object of the present invention is to solve the above-mentioned problems. [Means for solving the problem]

[0006] One aspect of the following disclosure resides in a blood reservoir comprising: a housing having an internal space for storing blood; a filtration section disposed in the internal space for filtering the blood; and a flow path for guiding blood into the filtration section, wherein the filtration section has a frame-shaped filter frame, a filter held by the filter frame, and a sponge-like defoaming member packed into an upper end of the filter frame, and the defoaming member has a first portion whose outer peripheral surface abuts and overlaps with the filter, and a second portion extending above the first portion and filling the space between the filter frame and the flow path with no gaps. [Effects of the Invention]

[0007] The blood reservoir according to the above aspect allows the liquid inside the defoaming member to easily drain, thereby preventing clogging of the defoaming member with blood or air bubbles, and by maintaining the defoaming performance of the defoaming member, preventing leakage of blood or air bubbles from the defoaming member. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a cross-sectional view of a blood reservoir according to an embodiment. [Figure 2] FIG. 2 is a perspective view of the second filter portion of FIG. [Figure 3] 3 is a partially enlarged cross-sectional view of the vicinity of the upper end of the second filter portion taken along line III-III in FIG. [Figure 4] FIG. 4 is a diagram illustrating the function of the second filter unit in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0009] The blood reservoir 10 according to this embodiment shown in FIG. 1 is an integrated blood reservoir that combines a venous reservoir that temporarily stores venous blood drawn from a patient's veins and a blood reservoir (cardiotomy reservoir) that temporarily stores intracardiac blood (aspirated blood) aspirated from the surgical field (outside the heart).

[0010] The blood reservoir 10 is incorporated into an extracorporeal circulation circuit used in cardiac surgery, for example, and is used to filter and defoam venous blood or intracardiac blood and temporarily store the blood.

[0011] The blood reservoir 10 comprises a housing 12, a venous blood port 14, an intracardiac blood port 16, and an outflow port 18. The housing 12 has a main body 20 and a lid 22. The main body 20 has an internal space 12a for storing blood therein. The lid 22 covers an opening at the top of the main body 20. The venous blood port 14 and the intracardiac blood port 16 are formed in the lid 22. The venous blood port 14 introduces venous blood into the internal space 12a. The intracardiac blood port 16 introduces intracardiac blood into the internal space 12a. The outflow port 18 is located at the bottom 25 of the housing 12. The outflow port 18 allows blood to flow out of the internal space 12a of the blood reservoir 10.

[0012] The housing 12 is formed of a transparent or translucent resin material, allowing the level of blood stored in the internal space 12a to be visually confirmed. The main body 20 has a blood storage section 24 and a cardiotomy section 26. The cardiotomy section 26 is a portion that bulges in the first and second directions in FIG. 1 . The cardiotomy section 26 has a first filter section 28 therein that filters intracardiac blood. The first filter section 28 has a sponge filter 28b and an outer filter 28c disposed inside a funnel-shaped inlet section 28a. The intracardiac blood port 16 communicates with the inside of the sponge filter 28b. The first filter section 28 has an outlet section 28d below the inlet section 28a. The outlet section 28d guides blood that has passed through the sponge filter 28b toward the bottom 26a of the cardiotomy section 26.

[0013] On the other hand, the blood storage section 24 is a long, narrow portion that protrudes downward from the cardiotomy section 26. The blood storage section 24 has a flat shape that is narrow in the first and second directions and wide in the third and fourth directions. The third direction is the direction perpendicular to the paper surface of FIG. 1 and extending toward the back, and the fourth direction is the direction perpendicular to the paper surface of FIG. 1 and extending toward the front. A second filter section 30 that filters venous blood is disposed in the blood storage section 24. The second filter section 30 includes a filter frame 32, a filter 34, a flow path 36, and a defoaming member 38. The filter frame 32 is disposed below the venous blood port 14 of the cover 22. As shown in FIG. 2, the filter frame 32 includes a cylindrical portion 32a and a frame portion 32b. The cylindrical portion 32a is located above the frame portion 32b. The cylindrical portion 32a has an elliptical cylindrical wall without an opening. The cylindrical portion 32a is fitted and attached to the lid 22.

[0014] The frame portion 32b has multiple beams arranged along the contour of an ellipse and extending in the vertical direction. The frame portion 32b has windows 32c between the multiple beams. The filter frame 32 has a closed bottom portion 32d. The bottom portion 32d has an uneven shape (not shown) that directs the flow of blood flowing out of the flow path 36 sideways or upward.

[0015] The filter 34 is made of a filter material such as a mesh or a screen. The filter 34 is held by the filter frame 32. The filter 34 covers the window portion 32c of the filter frame 32. Although not particularly limited, the filter 34 is attached to the filter frame 32 from the outside. The filter 34 and the filter frame 32 are joined to each other by a method such as insert molding, adhesive, or fusion bonding.

[0016] The flow path 36 has an oval-shaped cylinder 36a disposed inside the filter frame 32. The upper end of the flow path 36 communicates with the venous blood port 14. The cylinder 36a of the flow path 36 extends downward. The lower end of the cylinder 36a opens near the bottom 32d of the filter frame 32. The flow path 36 ejects blood from near the lower end of the filter frame 32.

[0017] The space between the outer periphery of the flow path 36 and the filter frame 32 and filter 34 forms a passage for blood to be filtered. Venous blood passes through the filter 34 and is stored in the blood reservoir 24. Inside the filter frame 32, the level of the venous blood fluctuates up and down depending on the flow rate.

[0018] The defoaming member 38 is located at the upper end of the second filter section 30. The defoaming member 38 is formed of a sponge material with open pores, such as urethane resin. The defoaming member 38 has a structure in which an antifoaming agent, such as a silicone agent, is applied to the microstructured surface of the sponge material. The defoaming member 38 breaks down bubbles in the blood, separating it into a liquid phase and a gas phase.

[0019] As shown in FIG. 3 , the defoaming member 38 has a second portion 38a and a first portion 38b. The second portion 38a is disposed in the cylindrical portion 32a and does not contact the filter 34. The first portion 38b extends into the frame-shaped portion 32b and is in surface contact with the inside of the filter 34. In the second portion 38a, the defoaming member 38 is packed without leaving any gaps between the cylindrical portion 32a and the flow path 36. The second portion 38a prevents blood from flowing upward. The second portion 38a prevents blood that does not pass through the filter 34 from flowing out. In other words, the second portion 38a prevents blood from flowing out through the gap between the filter frame 32 and the lid 22.

[0020] The first portion 38b is filled between the flow path 36 and the filter 34. A part of the first portion 38b overlaps with the window portion 32c. The first portion 38b and the second portion 38a may be formed integrally and connected, or may be formed as separate defoaming members 38 adjacent to each other with no gap between them.

[0021] The blood reservoir 10 of this embodiment has the above-described configuration. The blood reservoir 10 operates as follows.

[0022] 1, blood flows into the blood reservoir 10 from the venous blood port 14 and the intracardiac blood port 16. The blood flowing in from the intracardiac blood port 16 is filtered by the first filter section 28 of the cardiotomy section 26 and stored in the blood reservoir section 24.

[0023] Meanwhile, blood flowing in from the venous blood port 14 is filtered by the second filter section 30. The blood that has flowed into the second filter section 30 flows through the flow path 36 toward the lower end of the filter frame 32. The blood is discharged from the lower end of the flow path 36 into the inside of the filter frame 32. The discharged blood changes direction and moves upward through the gap between the filter frame 32 and the flow path 36. As the blood flows between the filter frame 32 and the flow path 36, most of the blood flows out of the filter 34 and into the blood reservoir 24, where it is stored.

[0024] As shown in Figure 4, the blood containing many air bubbles continues to rise upward and comes into contact with defoaming member 38. The air bubbles in the blood enter defoaming member 38 and are broken down by contact with the defoaming agent in defoaming member 38. As a result, the air bubbles are separated into blood and air. Inside defoaming member 38, the separated blood flows by gravity toward filter 34 and is quickly discharged from defoaming member 38 through filter 34.

[0025] Therefore, the separated air is discharged from the upper end of the defoaming member 38 through the pores of the defoaming member 38. This prevents an increase in the pressure inside the defoaming member 38, and the blood reservoir 10 can prevent blood from leaking from the upper part of the defoaming member 38.

[0026] The blood reservoir 10 of this embodiment can be summarized as follows.

[0027] One aspect is a blood reservoir 10 comprising: a housing 12 having an internal space 12a for storing blood therein; a filtration section disposed in the internal space for filtering the blood; and a flow path 36 for guiding blood into the filtration section, wherein the filtration section has a frame-shaped filter frame 32, a filter 34 held by the filter frame, and a sponge-like defoaming member 38 packed into the upper end of the filter frame, and the defoaming member has a first portion 38b whose outer peripheral surface abuts and overlaps with the filter, and a second portion 38a extending above the first portion and packing the space between the filter frame and the flow path without any gaps.

[0028] The blood reservoir according to the above aspect allows the liquid inside the defoaming member to easily drain, thereby preventing clogging of the defoaming member with blood or air bubbles and preventing leakage of blood or air bubbles from the defoaming member. As a result, the blood reservoir can prevent air bubbles from mixing into circulating blood.

[0029] In the blood reservoir of the above aspect, the first portion of the defoaming member may overlap and contact the filter from the inside of the opening of the filter frame. This blood reservoir can effectively prevent clogging of the defoaming member because blood in the defoaming member is quickly discharged through the filter.

[0030] In the above blood reservoir, the second portion of the defoaming member may be located above the first portion. This blood reservoir allows the liquid inside the defoaming member to smoothly move to the first portion by gravity, making it possible to more effectively discharge blood from the defoaming member.

[0031] In the above blood reservoir, the housing includes a main body 20 that defines the internal space and has an open upper end, and a lid 22 that closes the opening at the upper end of the main body, the filter frame includes, at its upper end, a tubular portion 32a that fits into the lid, and a frame-like portion 32b that extends below the tubular portion and has a plurality of windows, and the defoaming member fills the tubular portion without any gaps and may also extend into the frame-like portion. In this blood reservoir, the defoaming member can prevent blood from leaking through the tubular portion.

[0032] In the above blood reservoir, the defoaming member may be a urethane sponge having open pores and a coating of an antifoaming agent formed on the surface thereof. In this blood reservoir, the defoaming member can efficiently break down bubbles in the blood.

[0033] The blood reservoir described above may have a second filter section 30 for filtering venous blood and a cardiotomy section 26 for filtering intracardiac blood, and the filtering section may be the second filter section. This blood reservoir improves the reliability of the second filter section.

[0034] The present invention is not limited to the above-described embodiment, and various configurations can be adopted without departing from the gist of the present invention. [Explanation of symbols]

[0035] 10...blood reservoir 12...housing 12a...Internal space 20...Main body 22...lid body 26...cardiotomy part 30... Second filter portion 32... Filter frame 32a...Cylindrical portion 32b...Frame-shaped portion 32c...Window 34...Filter 36...flow path 38...defoaming member 38a...Second part 38b...First part

Claims

1. a housing having an internal space for storing blood therein; a filtering section disposed in the internal space and filtering blood; a flow path that guides blood into the filtration unit, The filtration section is A frame-shaped filter frame; a filter held in the filter frame; a sponge-like defoaming member filled in the upper end of the filter frame, The filter frame is a frame-shaped portion extending in the extension direction of the flow channel and having a plurality of window portions; a cylindrical portion located on the frame-shaped portion and having a diameter larger than that of the frame-shaped portion through a step portion, the defoaming member has: a first portion inserted into the frame-shaped portion; and a second portion extending above the first portion, filled between the cylindrical portion and the flow path, the second portion having a cross-sectional area perpendicular to an extension direction of the flow path that is larger than that of the first portion through the step portion.

2. 2. The blood reservoir according to claim 1, wherein the first portion of the defoaming member overlaps and contacts the filter from the inside of the window portion of the filter frame.

3. 3. The blood reservoir according to claim 1, wherein the housing comprises a main body portion that defines the internal space and has an open upper end, and a lid body that closes the opening at the upper end of the main body portion; The filter frame has an upper end of the cylindrical portion fitted to the lid.

4. 4. The blood reservoir according to claim 1, wherein the defoaming member is a urethane sponge having open pores and a coating of an antifoaming agent formed on the surface thereof.

5. 5. The blood reservoir according to claim 1, further comprising: a second filter section for filtering venous blood; and a cardiotomy section for filtering intracardiac blood, wherein the filtering section is the second filter section.

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