Blood storage tank

Abstract

This prevents clogging of the defoaming material by blood and air bubbles, and maintains the defoaming performance of the defoaming material, thereby preventing leakage of blood and air bubbles from the defoaming material. [Solution] The blood reservoir 10 comprises a housing 12 having an internal space 12a for storing blood, a filtration unit disposed in the internal space 12a for filtering the incoming blood, and a flow path 36 for guiding the blood from the upper part of the housing into the filtration unit. The filtration unit has a frame-shaped filter frame 32, a filter 34 held by the filter frame 32, and a sponge-like defoaming member 38 filled at the upper end of the filter frame 32. The defoaming member 38 has a second portion 38a that fills the space between the filter frame 32 and the flow path 36 without any gaps, and a first portion 38b that overlaps the inside of the filter 34.

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] For the purpose of maintaining life during heart surgery, an extracorporeal circulation circuit that temporarily substitutes the functions of the heart and / or lungs is used. A blood reservoir that stores blood withdrawn from a patient's vein is used in this type of extracorporeal circulation circuit (for example, Patent Document 1). This type of blood reservoir includes a filtration unit that removes foreign substances and air bubbles in the blood.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Conventional blood reservoirs have a sponge-like defoaming member in the filtration unit, and the defoaming member removes air bubbles in the blood. However, when the air bubbles contained in the blood increase, the defoaming member may become clogged with blood or air bubbles, and there is a risk that blood and air bubbles may overflow from 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-described problems.

Means for Solving the Problems

[0006] One aspect of the following disclosure is a blood reservoir comprising: a housing having an internal space for storing blood; a filtration unit disposed in the internal space for filtering blood; and a flow path for guiding blood into the filtration unit, wherein the filtration unit comprises a frame-shaped filter frame; a filter held by the filter frame; and a sponge-like defoaming member filled at the upper end of the filter frame, the defoaming member having a first portion whose outer surface abuts against and overlaps the filter; and a second portion extending above the first portion and filling the space between the filter frame and the flow path without any gaps. [Effects of the Invention]

[0007] In the blood reservoir described above, the liquid inside the defoaming member can be easily drained, thus preventing clogging of the defoaming member by blood and air bubbles, and maintaining the defoaming performance of the defoaming member, thereby preventing leakage of blood and air bubbles from the defoaming member. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a cross-sectional view of a blood reservoir according to an embodiment. [Figure 2] Figure 2 is a perspective view of the second filter section of Figure 1. [Figure 3] Figure 3 is a partially enlarged cross-sectional view of the area near the upper end of the second filter section along the line III-III in Figure 2. [Figure 4] Figure 4 is a functional diagram of the second filter section in Figure 2. [Modes for carrying out the invention]

[0009] The blood reservoir 10 according to this embodiment, shown in Figure 1, 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 (aspirated blood) drawn from the surgical field (outside the heart).

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

[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. The lid 22 covers the upper opening 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 made of a transparent or translucent resin material, allowing the liquid level of the blood stored in the internal space 12a to be seen. The main body 20 has a blood storage section 24 and a cardiotomy section 26. The cardiotomy section 26 is the portion that bulges in the first and second directions in Figure 1. The cardiotomy section 26 has a first filter section 28 inside for filtering intracardiac blood. The first filter section 28 has a sponge filter 28b located inside a funnel-shaped inlet section 28a and an outer filter 28c. 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 the 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, slender portion that protrudes downward from the cardiotomy section 26. The blood storage section 24 has a flattened shape, narrow in the first and second directions and wide in the third and fourth directions. The third direction is perpendicular to the plane of Figure 1 and towards the back, and the fourth direction is perpendicular to the plane of Figure 1 and towards the front. A second filter section 30 for filtering venous blood is arranged in the blood storage section 24. The second filter section 30 has a filter frame 32, a filter 34, a flow path 36, and an antifoaming member 38. The filter frame 32 is located below the venous blood port 14 of the lid 22. As shown in Figure 2, the filter frame 32 has a cylindrical portion 32a and a frame-shaped portion 32b. The cylindrical portion 32a is located above the frame-shaped 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-shaped portion 32b is arranged along an elliptical contour and has multiple beams extending in the vertical direction. The frame-shaped portion 32b has window portions 32c between the multiple beams. The filter frame 32 has a closed bottom portion 32d. The bottom portion 32d has an unillustrated uneven shape that directs the flow of blood flowing out of the channel 36 to the side or upward.

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

[0016] The flow path 36 has an elliptical cylindrical body 36a positioned inside the filter frame 32. The upper end of the flow path 36 communicates with the venous blood port 14. The cylindrical body 36a of the flow path 36 extends downward. The lower end of the cylindrical body 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] Between the outer peripheral side of the flow path 36 and the filter frame 32 and the filter 34, there is a passage for the blood to be filtered. The venous blood passes through the filter 34 and is stored in the blood storage part 24. Inside the filter frame 32, the liquid level of the venous blood is displaced up and down according to the flow rate.

[0018] The defoaming member 38 is located at the upper end of the second filter part 30. The defoaming member 38 is formed of a sponge material having open pores made of, for example, urethane resin or the like. The defoaming member 38 has a structure in which an antifoaming agent made of a silicone agent or the like is applied to the surface of the fine structure of the sponge material. The defoaming member 38 defoams the bubbles in the blood and separates them into a liquid phase and a gas phase.

[0019] As shown in FIG. 3, the defoaming member 38 has a second part 38a and a first part 38b. The second part 38a is the part disposed in the cylindrical part 32a and does not contact the filter 34. The first part 38b extends to the frame-shaped part 32b and is the part that contacts the filter 34 in surface contact from the inside. In the second part 38a, the defoaming member 38 is filled without a gap between the cylindrical part 32a and the flow path 36. The second part 38a blocks the outflow of blood upward. The second part 38a blocks the outflow of blood that does not pass through the filter 34. That is, the second part 38a blocks the outflow of blood from the gap between the filter frame 32 and the lid body 22.

[0020] The first part 38b is filled between the flow path 36 and the filter 34. A part of the first part 38b overlaps the window part 32c. The first part 38b and the second part 38a may be integrally formed or may be formed by adjacently arranging separate defoaming members 38 without a gap.

[0021] The blood storage tank 10 of the present embodiment has the above configuration. The blood storage tank 10 operates as follows.

[0022] As shown in FIG. 1, blood flows into the blood storage tank 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 storage section 24.

[0023] On the other hand, the blood flowing in from the venous blood port 14 is filtered by the second filter section 30. The blood flowing 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 its flow direction and moves upward through the gap between the filter frame 32 and the flow path 36. Most of the blood flows out from the filter 34 during the process of flowing between the filter frame 32 and the flow path 36, flows into the blood storage section 24, and is stored therein.

[0024] As shown in FIG. 4, the blood containing a large amount of bubbles further rises upward and contacts the defoaming member 38. The bubbles in the blood enter the inside of the defoaming member 38 and are defoamed by contacting the defoaming agent of the defoaming member 38. As a result, the bubbles are separated into blood and air. Inside the defoaming member 38, the separated blood flows toward the filter 34 by gravity and is quickly discharged from the defoaming member 38 through the 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 storage tank 10 can prevent leakage of blood from the upper part of the defoaming member 38.

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

[0027] One perspective is a blood reservoir 10 comprising a housing 12 having an internal space 12a for storing blood, a filtration unit disposed in the internal space for filtering blood, and a flow path 36 for guiding blood into the filtration unit, wherein the filtration unit comprises a frame-shaped filter frame 32, a filter 34 held by the filter frame, and a sponge-like defoaming member 38 filled at the upper end of the filter frame, the defoaming member having a first portion 38b whose outer surface abuts and overlaps with the filter, and a second portion 38a extending above the first portion and filling the space between the filter frame and the flow path without gaps.

[0028] In the blood reservoir described above, the liquid inside the defoaming member can be easily drained, thus preventing clogging of the defoaming member by blood and air bubbles, and preventing leakage of blood and air bubbles from the defoaming member. As a result, the blood reservoir can prevent air bubbles from entering the circulating blood.

[0029] In the blood reservoir according to the above viewpoint, the first portion of the defoaming member may overlap contact with the filter from the inside of the opening of the filter frame. In this blood reservoir, the blood in the defoaming member is quickly discharged through the filter, so clogging of the defoaming member can be effectively prevented.

[0030] In the blood reservoir described above, the second portion of the defoaming member may be located above the first portion. In this blood reservoir, the liquid inside the defoaming member can smoothly transfer to the first portion due to the action of gravity, and the blood can be discharged from the defoaming member more effectively.

[0031] In the blood storage tank described above, the housing comprises a main body portion 20 that forms the internal space and has an open upper end, and a lid portion 22 that closes the opening at the upper end of the main body portion. The filter frame comprises a cylindrical portion 32a at its upper end that fits into the lid portion, and a frame-shaped portion 32b that extends below the cylindrical portion and has a plurality of window portions. The defoaming member may fill the cylindrical portion without any gaps and extend to the frame-shaped portion. In this blood storage tank, leakage of blood through the cylindrical portion can be prevented by the defoaming member.

[0032] In the blood reservoir described above, the defoaming member may be a urethane sponge having open pores on which a film of defoaming agent is formed. This blood reservoir can efficiently break air bubbles in the blood with the defoaming member.

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

[0034] Furthermore, the present invention is not limited to the embodiments described above, and various configurations can be taken without departing from the spirit of the invention. [Explanation of Symbols]

[0035] 10... Blood reservoir 12... Housing 12a...Internal space 20...Main body 22...Lid 26...Cardiotomy 30...Second filter section 32...Filter frame 32a...Cylindrical part 32b...Frame-shaped part 32c...Window section 34...Filter 36…Flow channel 38…Defoaming component 38a...Second part 38b...First part

Claims

[Claim 1] A housing having an internal space for storing blood, The internal space is arranged to include a filtration unit for filtering blood, The filtration section includes a channel for guiding blood inside, The aforementioned filtration section is A frame-shaped filter frame, The filter held in the aforementioned filter frame, The filter frame has a sponge-like defoaming member filled at its upper end, The defoaming member has a first portion whose outer surface abuts against and overlaps the filter, and a second portion that extends above the first portion and fills the space between the filter frame and the flow path without any gaps, in a blood reservoir.

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