Blood storage tank

Abstract

To provide a blood storage tank capable of efficiently preventing occurrence of air bubbles.SOLUTION: A blood storage tank comprises: a cardiotomy part 26 into which sucked blood flows; a blood storage part 24 which protrudes downward in an elongated shape from the cardiotomy part, and stores venous blood and the sucked blood; and a connection part which is connected so as to descend smoothly from a bottom of the cardiotomy part toward a first side wall 24a of the blood storage part adjacent to the cardiotomy part. The connection part comprises: a flow channel surface part 36 which is formed of a surface parallel to a longitudinal direction of the blood storage part, and is continuous to the first side wall of the blood storage part; multiple ribs 40 which protrude inward from the flow channel surface part, and extend downward in parallel toward a lower end of the blood storage part; and flow guide parts 37 which are formed on opposite sides of the flow channel surface part and guide the sucked blood to the multiple ribs.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a blood reservoir for use 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 that temporarily substitutes for the functions of the heart and / or lungs. This type of extracorporeal circulation circuit uses a blood reservoir that can store both venous blood drawn from the patient's veins and intracardiac blood (also called aspirated blood) that has overflowed into the surgical field (for example, Patent Document 1). This type of blood reservoir has a wide cardiotomy section into which intracardiac blood flows in, and a blood reservoir section that protrudes downward in an elongated shape to store venous blood and intracardiac blood. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 4952232 Summary of the Invention [Problem to be solved by the invention]

[0004] In the blood reservoir of Patent Document 1, blood that has passed through the cardiotomy section flows down toward the liquid surface in the blood reservoir while increasing in momentum, which creates a problem in that there is a high possibility that air bubbles will be generated when the blood that has flowed down hits the liquid surface, and that the air bubbles will flow out from the outflow port.

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

[0006] One aspect of the disclosure below is a blood storage tank comprising: a cardiotomy section into which drawn blood flows; a blood storage section that protrudes downward from the cardiotomy section and stores venous blood and the drawn blood; and a connecting section that connects a bottom of the cardiotomy section to a lower end of the blood storage section, the connecting section having a flow path surface section that extends smoothly downward from the bottom to the lower end of the blood storage section, a plurality of ribs that protrude inward from the flow path surface section and extend downward parallel to each other at horizontal intervals toward the lower end of the blood storage section, and flow guiding sections formed on both sides of the flow path surface section that guide the drawn blood to the plurality of ribs. Effect of the Invention

[0007] According to the blood reservoir of the above-mentioned aspect, the multiple ribs regulate the flow of the drawn blood, and fluid friction generated by the ribs suppresses the flow speed of the drawn blood, thereby preventing the generation of air bubbles due to air being drawn in. Furthermore, by having a flow guide portion, the blood reservoir can prevent the flow of drawn blood that falls with force, bypassing the multiple ribs, and therefore more effectively prevents the generation of air bubbles. [Brief description of the drawings]

[0008] [Figure 1] FIG. 2 is a cross-sectional view of a blood reservoir according to the embodiment. [Diagram 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. [Diagram 3] 2 is a perspective see-through view showing the blood reservoir in FIG. 1 from diagonally above on the left side. [Figure 4] FIG. 4A is a cutaway perspective view of a blood reservoir according to a comparative example, and FIG. 4B is a cutaway perspective view of a blood reservoir according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[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 and intracardiac blood and temporarily store the blood.

[0011] The blood reservoir 10 comprises a housing 12, a venous blood port 14, a blood suction 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 blood suction port 16 are formed in the lid 22. The venous blood port 14 introduces venous blood into the internal space 12a. The blood suction 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, and the level of blood stored in the internal space 12a can 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 direction and the second direction in FIG. 1. The cardiotomy section 26 has a first filter section 28 therein for filtering intracardiac blood. The first filter section 28 has a sponge filter 28b and an outer filter 28c arranged inside a funnel-shaped introduction section 28a. The suction blood port 16 communicates with the inside of the sponge filter 28b. The first filter section 28 has an outlet section 28d below the introduction section 28a. The outlet section 28d guides the blood that has passed through the sponge filter 28b toward the bottom section 26a of the cardiotomy section 26.

[0013] On the other hand, the blood storage section 24 is a portion that protrudes downward from the cardiotomy section 26 in an elongated manner. 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. A second filter section 30 that filters venous blood is disposed in the blood storage section 24. The second filter section 30 has an elliptical cylindrical lattice-shaped filter frame 30a and an outer filter 30b supported by the filter frame 30a. The filter frame 30a and the outer filter 30b have an elliptical cylindrical shape with a long axis in the third direction perpendicular to the paper surface of FIG. 1 when viewed from above. The lower end of the filter frame 30a abuts against the bottom 25 of the blood storage section 24. The venous blood port 14 communicates with the inside of the outer filter 30b.

[0014] As shown in FIG. 2 and FIG. 3, the housing 12 has a connection portion 34 that smoothly connects the bottom portion 26a of the cardiotomy portion 26 and the first side wall 24a on the first direction side of the blood storage portion 24. The connection portion 34 has a flow path surface portion 36 and a flow guide portion 37. The flow path surface portion 36 has a surface parallel to the third direction and the fourth direction. The flow path surface portion 36 extends from below the outlet portion 28d toward the first side wall 24a while increasing the downward inclination angle. The flow path surface portion 36 has a bent portion 36a where the inclination angle increases sharply on the way from the cardiotomy portion 26 to the first side wall 24a. The bent portion 36a is located at the boundary between the cardiotomy portion 26 and the blood storage portion 24.

[0015] The housing 12 has a plurality of ribs 40 on the flow path surface portion 36 that protrude toward the upper internal space 12a. The ribs 40 extend downward in a direction parallel to the second direction and the vertical direction. The plurality of ribs 40 are arranged at regular intervals in the third and fourth directions. The plurality of ribs 40 are arranged parallel to each other.

[0016] The flow guide section 37 is a section that guides blood to the flow path surface section 36, and has an inclined surface 38 in this embodiment. The inclined surface 38 is disposed on a side portion on the third direction side of the flow path surface section 36 and a side portion on the fourth direction side of the flow path surface section 36. The inclined surface 38 inclines upward as it moves away from the flow path surface section 36. Such an inclined surface 38 serves to collect blood in the cardiotomy section 26 to the flow path surface section 36 by inclination. The inclined surface 38 extends to the tip of the bent section 36a and is connected to the second side wall 24b and the third side wall 24c of the blood storage section 24. Note that the connection portion between the inclined surface 38 and the side walls 26b and 26c of the cardiotomy section 26 may have an R shape having a smooth curved surface in front view, as shown in FIG. 2. Alternatively, the connection portion between the inclined surface 38 and the side walls 26b and 26c may have a C-surface shape having an inclined flat connection surface.

[0017] The second side wall 24b of the blood storage section 24 is a side wall adjacent to the third direction side of the first side wall 24a. The third side wall 24c is a side wall adjacent to the fourth direction side of the first side wall 24a. The second side wall 24b and the third side wall 24c are inclined with respect to the third direction and the fourth direction.

[0018] The blood reservoir 10 of this embodiment is configured as described above. The blood reservoir 10 functions as follows.

[0019] Venous blood flows into the blood reservoir 24 through the second filter section 30, and aspirated blood flows into the blood reservoir 24 through the cardiotomy section 26. Blood is stored in the blood reservoir 24, and a blood level is formed at a predetermined position.

[0020] The blood that has flowed into the cardiotomy section 26 is collected on the flow path surface section 36 due to the inclination of the inclined surface 38, and flows along the flow path surface section 36 into the blood storage section 24. Since a plurality of ribs 40 are formed on the flow path surface section 36, the ribs 40 regulate the flow of blood. In addition, the fluid resistance of the plurality of ribs 40 suppresses the flow rate of the blood. Therefore, the blood that flows along the ribs 40 flows into the blood storage section 24 without entraining air bubbles.

[0021] 4B, in the housing 12 of this embodiment, the inclined surface 38 adjacent to the flow path surface 36 extends beyond the bent portion 36a. Therefore, the housing 12 can efficiently guide blood to the multiple ribs 40 even in the vicinity of the bent portion 36a where the downward inclination angle of the flow path surface 36 increases rapidly. Therefore, the inclined surface 38 can reliably prevent the occurrence of a blood flow that bypasses the multiple ribs 40, which have a large fluid resistance.

[0022] In contrast, the housing 120 according to the comparative example in FIG. 4A does not have an inclined surface 38 on the side of the flow path surface portion 36. In the housing 120 of this comparative example, blood flows along the portion where the multiple ribs 40 are not provided. The surface of the portion where the ribs 40 are not provided has relatively small fluid resistance. Therefore, the flow rate of blood increases in the portion where the ribs 40 are not provided, and the blood flows into the liquid surface of the blood storage portion 24 at a relatively high flow rate while being accompanied by turbulence. As a result, air is entrained at the liquid surface, and the frequency of air bubbles increases.

[0023] According to the blood reservoir 10 of this embodiment shown in FIG. 4B, the problem of the comparative example can be solved, and the generation of air bubbles can be suppressed.

[0024] (Modification) The blood reservoir 10 of the present embodiment is not limited to the above example. The flow guiding section 37 may be configured with an uneven structure that collects blood on the flow path surface section 36, other than the inclined surface 38. The flow guiding section 37 may also have a surface tension gradient that repels blood toward the flow path surface section 36.

[0025] The blood reservoir 10 of this embodiment is summarized as follows.

[0026] The blood storage tank 10 comprises a cardiotomy section 26 into which the drawn blood flows, a blood storage section 24 that protrudes downward from the cardiotomy section and stores venous blood and the drawn blood, and a connection section 34 that connects a bottom 26a of the cardiotomy section to a bottom 25 of the blood storage section, and the connection section has a flow path surface section 36 that extends smoothly downward from the bottom to the lower end of the blood storage section, and has a plurality of ribs 40 that protrude inward from the flow path surface section and extend downward parallel to each other with horizontal gaps between them toward the lower end of the blood storage section, and flow guiding sections 37 that are formed on both sides of the flow path surface section and guide the drawn blood to the plurality of ribs.

[0027] According to the blood reservoir of the above-mentioned aspect, the multiple ribs regulate the flow of the drawn blood, and fluid friction generated by the ribs suppresses the flow speed of the drawn blood, thereby preventing the generation of air bubbles due to air being drawn in. Furthermore, by having a flow guide portion, the blood reservoir can prevent the flow of drawn blood that falls with force, bypassing the multiple ribs, and therefore more effectively prevents the generation of air bubbles.

[0028] In the above blood reservoir 10, the flow guiding portion may have an inclined surface 38 that gradually inclines upward as it moves away from the flow path surface portion toward the side. This blood reservoir can guide the drawn blood to a plurality of ribs by utilizing the inclination of the inclined surface.

[0029] 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]

[0030] 10...Blood storage tank 24...Blood storage part 24a...first side wall 26...cardiotomy section 25, 26a...Bottom 34...Connection 36...Flow path surface section 37...Direction section 38...Inclined surface 40...Rib

Claims

1. a cardiotomy section into which suctioned blood flows; a blood reservoir portion that protrudes downward from the cardiotomy portion and stores venous blood and the aspirated blood; a connecting portion that connects a bottom portion of the cardiotomy portion and a bottom portion of the blood storage portion, The connection portion is a flow path surface portion extending smoothly downward from the bottom to the lower end portion of the blood reservoir, a plurality of ribs protruding inward from the flow path surface portion and extending downward parallel to each other at intervals in the horizontal direction toward a lower end of the blood storage portion; a flow guide portion formed on both sides of the flow path surface portion and guiding the sucked blood to the plurality of ribs.

2. 2. The blood reservoir according to claim 1, wherein the flow guide portion has an inclined surface that gradually inclines upward as it moves away from the flow path surface portion toward a side.

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