JP3051495B2 - Defoaming device and blood reservoir - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a defoaming apparatus for separating and removing air bubbles in blood and a blood reservoir provided with the same.

[0002]

2. Description of the Related Art In cardiac surgery, for example, a blood pump is operated to remove blood from a patient's vein, gas is exchanged by an artificial lung, and this blood is returned to the patient's artery. Extracorporeal blood circulation is performed. A line is also provided for aspirating blood from the operative field, filtering out and removing foreign matter, and returning blood. Such an artificial lung extracorporeal blood circulation circuit includes a blood reservoir for temporarily storing the blood removed,
A blood reservoir (cardiotomy reservoir) for filtering and temporarily storing blood aspirated from the surgical field is installed.

[0003] Such a blood reservoir has a buffer function for adjusting the amount of blood in the circuit and keeping the amount of blood returned constant.
A defoaming device is installed in the blood reservoir and has a function of removing air bubbles in blood.

In this defoaming apparatus, a cylindrical filter and a filtering member are arranged concentrically from the inside in this order, blood containing air bubbles is supplied to the inside of the filter, and the blood passes through the filter and the filtering member. Japanese Patent Application Laid-Open No. H10-163873 discloses a structure that separates bubbles when passing through and breaks bubbles separated by contact with an antifoaming agent (silicone) carried on a filter and a filter member. Showa 60
-103968 gazette).

[0005] In this defoaming apparatus, the filter and the filter member are coated with an antifoaming agent, but since the blood passes through this portion, the antifoaming agent may be separated and mixed into the blood. Silicone used as an antifoaming agent
It is an inert substance and is not harmful per se, but is not metabolized by the human body, so it is likely to accumulate in the human body, and it may also clog extra-fine capillaries and blood vessels. Should be avoided as much as possible.

In order to prevent the defoaming agent from being mixed into the blood, the defoaming agent is supported only on the upper end of the defoaming element (defoaming member), and the defoaming agent-supporting region is formed in the defoaming agent carrying region. Japanese Patent Application Laid-Open No. 63-21064 discloses a defoaming device which is set above the maximum liquid level to prevent blood from contacting the antifoaming agent.

However, this defoamer has the following disadvantages. That is, since the defoaming element with which blood first comes into contact is formed of a foam such as polyurethane foam, and furthermore, the blood is configured to flow mainly vertically to the defoaming element, Bubbles are pressed by the blood flow and adhere to the inner surface of the defoaming element, and may further enter the pores of the defoaming element, and thus, the clogging of such bubbles reduces the efficiency of removing bubbles. In addition, the pressure loss when blood passes through the defoaming element increases, and the effective area of the defoaming element decreases.

As a result, the blood level of the blood inside the defoaming element rises and exceeds the maximum liquid level to reach the defoaming agent carrying area, so that the blood comes into contact with the defoaming agent and eventually defoams. The agent will be mixed into the blood, and the intended purpose will not be achieved. Further, the occurrence of such a rise in the blood level of blood also causes an increase in the amount of priming in the defoaming device, which is not preferable.

[0009] Once such a situation occurs,
Since no blood bypass is provided, the accumulation of bubbles in the defoaming element is further increased by the blood continuously supplied, and the blood cannot be returned to a normal state.

When the amount of air bubbles mixed into the defoaming device is relatively small, or after the air bubbles have been mixed, the contact with the antifoaming agent due to the rise in blood level does not occur. ,
In this case, the lower end of the defoaming element holding area of the defoaming element is separated from the actual blood liquid level by a predetermined distance, that is, air bubbles always adhere to the area of the defoaming element that does not hold the antifoaming agent. As a result, the ratio of the effective area to the entire area of the defoaming element decreases, and an increase in the priming amount due to an increase in the pressure loss is inevitable.

[0011]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a defoaming apparatus and a blood storage tank which do not mix an antifoaming agent into blood, do not increase the amount of priming, and are excellent in the ability to remove air bubbles. It is in.

[0012]

This and other objects are achieved by the present invention which is defined below as (1) to (7).

(1) A blood flow path is formed between a mesh-shaped first filter for removing air bubbles from blood and the first filter, and the flow of blood is substantially reduced within the flow path. It has a flow path regulating member that regulates so as to be parallel and upward to the first filter, and a defoaming member that is installed above a normal liquid level of blood in the flow path and carries an antifoaming agent. A defoaming device characterized by the above-mentioned.

(2) The defoaming apparatus according to (1), wherein the flow path regulating member regulates the flow of blood substantially vertically upward.

(3) On the blood outflow surface side of the defoaming member, a second bubble for separating and removing microbubbles passing through the defoaming member is provided.
The defoaming apparatus according to (1) or (2), further comprising a filter.

(4) The defoaming device according to any one of (1) to (3), wherein the defoaming member is made of a material having a lower resistance to the passage of blood than the first filter.

(5) The defoaming member is composed of a mesh coarser than the first filter.
The defoaming apparatus according to item 1.

(6) The defoaming device according to (4), wherein the defoaming member is made of a foam or a porous material.

(7) A blood reservoir provided with the defoaming device according to any one of (1) to (6).

[0020]

When blood containing air bubbles passes through the first filter, the air bubbles are separated and removed. That is, the blood passes through the mesh of the first filter and is stored in the blood reservoir, and the air bubbles cannot pass through the mesh and adhere to the inner surface (the surface on the flow path side) of the first filter. At this time, since blood flows substantially parallel to the first filter in the flow path formed between the first filter and the flow path regulating member,
By this liquid flow, air bubbles adhering to the inner surface of the first filter are peeled off and float. This phenomenon is called washout. By such a washout, the first filter functions normally without causing clogging by air bubbles, and excellent air bubble removing ability is maintained.

The bubbles that have floated off the first filter are accumulated near and above the blood surface of the blood in the flow channel. A defoaming member carrying an antifoaming agent is provided above the normal liquid level in the flow channel, and bubbles are accumulated to some extent, and when the defoaming member comes into contact with the defoaming member, it breaks. The broken bubbles are exhausted as air into the reservoir or from the degassing port to the outside.

As described above, since the first filter does not cause clogging due to air bubbles, there is no increase in pressure loss and an abnormal rise in blood level in the flow path due to the pressure loss.
The frequency with which blood comes into contact with the defoaming member provided above the normal liquid level in the flow path is very low. Accordingly, it is possible to prevent the defoaming agent carried by the defoaming member from coming off and entering the blood.

Further, when the defoaming member is made of a material having a lower resistance to the passage of blood than the first filter, for example,
Due to the rapid increase in the amount of blood flowing into the defoaming device, the blood level in the flow path rises, and even if the blood level exceeds the lower end of the defoaming member, the blood quickly passes through the defoaming member and passes through the flow path. And the liquid level in the flow path falls to the lower end of the defoaming member.
Therefore, the time during which the blood contacts the defoaming member is short, and even if the defoaming agent is mixed into the blood, the amount is extremely small.

When a second filter for separating and removing microbubbles passing through the defoaming member is provided on the blood outflow surface side of the defoaming member, the first filter is clogged,
Even if most of the blood passes directly through the defoaming member, the microbubbles which are not separated and removed by the defoaming member are removed by the second method.
It becomes possible to remove with a filter.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a defoaming apparatus and a blood reservoir according to the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.

FIG. 1 is a sectional side view showing an example of the configuration of a blood reservoir having a defoaming apparatus of the present invention, and FIG. 2 is a sectional view taken along line AA in FIG. As shown in FIG. 1, the blood reservoir 1 has a housing 2 including a housing body 3 and a lid 4. Inside the housing 2, a blood storage space 5 for storing blood is formed.

The housing body 3 has a box shape having a protruding portion 31 on the upper right side in FIG. The inner wall of the housing below the protrusion 31 in FIG. 1 is an inclined surface 32 inclined at a predetermined angle with respect to the horizontal plane. Defoaming device 8 to be described later
The blood flowing out of the container flows down along the inclined surface 32.

The inclination angle θ of the inclined surface 32 with respect to the horizontal plane
Is preferably about 1 to 45 °.

The inclined surface 32 is not limited to a flat surface, but may be a curved surface.

A tubular blood outlet 7 communicating with the blood storage space 5 is formed in a lower portion of the housing body 3. The blood outlet 7 is connected to, for example, a tube to an artificial lung or the like in an extracorporeal blood circulation circuit.

The lid 4 is placed so as to cover the upper opening of the housing main body 3, and does not seal the blood storage space 5, but, for example, a gap between the housing main body 3 and the lid 4 or an opening described later. The blood storage space 5 and the outside can be ventilated via 41. Thereby, the amount of blood stored in the blood storage space 5 can be increased or decreased. The housing 2 may be provided with a vent (not shown) for communicating the blood storage space 5 with the outside.

The lid 4 has an opening 41 into which a defoaming device 8 described later is inserted. The opening 41 preferably has a shape corresponding to the insertion portion of the defoaming device 8, and in the illustrated example, has a circular shape similar to the cross-sectional profile of the defoaming member 12 described later.

Although the volume of the blood storage space 5 is not particularly limited,
About 3000-5000ml for adults, 10 for children
It is preferable to use about 00 to 2000 ml.

Although not shown, a heat exchanger may be provided in the blood storage space 5. As this heat exchanger,
For example, one having a heat exchange part in which a plurality of straight metal tubes are arranged in parallel in the blood storage space 5 is preferably used.

The constituent materials of the housing body 3 and the lid 4 are polycarbonate, acrylic resin, polyethylene terephthalate, polyethylene, polypropylene,
Examples include polystyrene, polyvinyl chloride, acryl-styrene copolymer, acryl-butadiene-styrene copolymer, and among them, polycarbonate, acrylic resin, polystyrene, and polyvinyl chloride are particularly preferable.

The housing body 3 and the lid 4 are
It is preferably transparent so that the amount of stored blood can be checked visually.

It is to be noted that a scale (not shown) indicating the amount of stored blood may be provided on the side surface of the housing body 3.

In the blood storage space 5 in the protruding portion 31, a defoaming device 8 for removing bubbles contained in blood flowing from the blood inlet 6 is provided. The defoaming device 8 includes a mesh filter 9 and flow path regulating members 10 and 11.
A defoaming member 12 carrying an antifoaming agent, and a cover member 1
3 is comprised. Hereinafter, each of these components will be described.

The flow path regulating member 10 is a straight tubular member extending in the vertical direction, and has a blood inlet 6 formed at the upper end thereof. The blood inlet 6 is connected to, for example, a tube of a blood removal line in an extracorporeal blood circulation circuit.

The inner diameter of the flow path regulating member 10 is 8 for adults.
It is preferably about 12 mm and about 6 to 10 mm for children.

In the vicinity of the lower end of the flow path regulating member 10, there is provided a flow path regulating member 11 whose inner surface 110 is curved, for example, in a spherical shape.

At the upper end of the flow path regulating member 11, a first cylindrical filter 9 is installed, for example, concentrically with the flow path regulating member 10. Thus, a blood channel 15 is formed between the first filter 9 and the channel regulating member 10. As shown by the arrow in FIG. 1, the blood B flowing from the blood inlet 6 flows vertically downward in the lumen of the flow path regulating member 10 and is inverted along the inner surface 110 of the flow path regulating member 11. Then, it flows substantially vertically upward in the flow path 15.

Here, "substantially vertically upward" does not exclude that the flow has a horizontal component, but means that the main direction of the flow is vertically upward. Therefore, in the flow path 15, stagnation (stagnation), swirling, turbulence, bending toward the first filter 9, and the like of blood may partially occur.

The constituent materials of the flow path regulating members 10 and 11 include polycarbonate, acrylic resin, polyethylene terephthalate, polyethylene, polypropylene, polystyrene, polyvinyl chloride, acryl-styrene copolymer, and acryl-butadiene-styrene copolymer. Polymer materials such as coalescing, various ceramics such as glass, alumina and silica, metals such as stainless steel, aluminum, copper and titanium, various carbon materials and the like, or a combination of two or more thereof can be mentioned. Of these, polycarbonate, polystyrene, stainless steel, and aluminum are particularly preferred.

The first filter 9 is a mesh (net)
It is preferable to be constituted by a shape. This is because a mesh-like material has excellent blood permeability, has high opening accuracy, and can effectively remove bubbles.

Here, the mesh is a sheet-like member having a regularly arranged mesh.
Examples include fiber woven or knitted articles, integrally molded articles, and processed articles.

The constituent material of the mesh constituting the first filter 9 is nylon (polyamide), tetron,
Polyolefins such as rayon, polypropylene, and polyethylene; polymer materials such as polyester such as polyvinyl chloride, PET, and PBT; and metal materials such as aluminum and stainless steel. Among them, polyester, polypropylene, and polyethylene are particularly preferable. , Stainless steel is preferred.

The fiber diameter of this mesh is 10 to 100.
It is preferably about μm, especially about 20 to 80 μm.

The opening of the mesh is 2
It is preferably about 0 to 300 μm, particularly preferably 20 to 200 μm. If it exceeds 300 μm, fine bubbles may pass through the mesh network together with blood, and
If it is less than μm, the blood passage resistance increases and the flow path 15
This is because the blood level in the blood tends to rise.

As long as the blood permeability of the first filter 9 is not impaired, the first filter 9 may be formed by stacking two or more mesh sheets as described above.

The inner diameter of the first filter 9 is 6 to 100 mm
It is preferably about 10 to 100 mm.

The length of the first filter 9 in the vertical direction is 2
It is preferably about 0 to 500 mm, particularly about 50 to 200 mm.

The cross-sectional area of the flow path 15 is 0.2 to 2
0 cm ² or so, particularly preferably set to about ² 0.3～10Cm. If the cross-sectional area of the flow path 15 is less than 0.2 cm ² , the inflow resistance of the blood B increases, and if it exceeds 20 cm ² , the flow rate of the blood B in the flow path 15 decreases, and the first filter This is because the effect of washing out the air bubbles adhered to 9 decreases.

The first filter 9 may be subjected to a hydrophilic treatment such as a plasma treatment or a coating of a hydrophilic polymer, if necessary, in order to further improve the blood permeability. In this case, the hydrophilic treatment such as the plasma treatment may be performed according to a conventional method.

By the first filter 9 as described above, for example, bubbles having a diameter of 20 μm or more can be effectively removed.

At the upper end of the first filter 9, a tubular defoaming member 12 carrying an antifoaming agent described later is installed concentrically with the flow path regulating member 10.

The installation position (height) of the defoaming member 12 is
The lower end surface 120 is set higher than the normal liquid level L ₀ of the blood B in the flow channel 15. Thereby, the flow path 1
The blood B in 5 hardly contacts the defoaming member 12, or even if it does, the frequency is small, and thus the elution of the antifoaming agent into the blood is suppressed.

Here, the normal liquid level L ₀ means the amount of blood flowing out of the first filter 9 and the amount of blood flowing out of the blood storage space 5 when blood flows in at an average amount from the blood inlet 6. Means the liquid level of the blood maintained in the flow path 15 by the balance with the first filter 9
Can be determined theoretically or experimentally according to conditions such as the effective area and blood permeability of the sample, and the amount of blood inflow (variable conditions). Thus, the actual liquid level in the channel 15 varies vertically from the common fluid level L _0. For example,
When the inflow amount of blood from the blood inlet 6 sharply increases, the liquid level of the blood B rises, exceeds the ordinary liquid level L ₀ , and further exceeds the lower end face 120 of the defoaming member 12. Occasionally, however, this happens less frequently.

The installation position of the defoaming member 12 is
The distance (head) H between the fluid level 20 and the regular liquid level L ₀ is the first
It is preferable that the length is about 10 to 80%, particularly about 20 to 70% (specifically, about 10 to 300 mm, particularly about 50 to 200 mm) of the length of the filter 9 in the vertical direction.
If the distance H is less than 10% of the length of the filter, the frequency of contact of the blood with the defoaming member 12 due to the rise of the liquid level increases, and if the distance H exceeds 80%, the first filter 9
This is because the effective area is reduced.

Examples of the material of the defoaming member 12 include foams such as polyurethane foam, polyethylene foam, polypropylene foam, and polystyrene, meshes, woven fabrics, nonwoven fabrics, and sintered bodies such as porous ceramics and resins. Among them, it is preferable to use a material having a lower blood passage resistance than the first filter 9. Thereby, the defoaming member 1
2 serves as a bypass, and even if the blood level of the blood in the flow path 15 rises and exceeds the lower end surface 120 of the defoaming member 12, the blood quickly passes through the defoaming member 12 and is discharged. Therefore, the liquid level in the flow path 15 is
0, thus reducing the time that the blood contacts the defoaming member 12.

When a mesh having a coarser mesh than the filter is used as a material having a lower resistance to the passage of blood than the first filter 9, the opening of the mesh is 30
The thickness is preferably about 500 to 500 μm, particularly preferably about 50 to 200 μm. The other conditions of the mesh forming the defoaming member 12 are the same as described above.

When a foam or a porous material is used as a material having a lower blood passage resistance than the first filter 9, the pore size is about 20 μm to 5 mm, particularly 30 μm.
It is preferably about 2 mm.

The inner diameter of the defoaming member 12 is preferably about 6 to 100 mm, particularly preferably about 10 to 100 mm.

The vertical length of the defoaming member 12 is 5 to 2
It is preferably about 00 mm, especially about 10 to 100 mm.

The defoaming agent carried on the defoaming member 12 has a function of breaking bubbles when air bubbles come into contact with the defoaming agent. As a representative example, silicone (compound type containing silica, Oil type).

As a method of supporting the defoaming agent on the defoaming member 12, for example, a material containing the defoaming agent is impregnated, applied or sprayed on the material of the defoaming member 12, and then dried (for example, 30%). (180 ° C., 180 minutes).

At the upper end of the defoaming member 12, the defoaming member 12
A cup-shaped cover member 13 is attached so as to cover the upper end opening of the cover. Further, the flow path regulating member 10 is fixed to the cover member 13 through the center of the cover member 13.

The outer diameter of the cover member 13 corresponds to the opening 4 of the lid 4.
1, when the defoaming device 8 is inserted into the opening 41 as shown in FIG. 1, the lower end surface of the cover member 13 is locked on the upper surface of the lid 4 around the opening 41, and 8
Are fixed to the housing 2.

The cover member 13 has the deaeration port 1
4 are formed. The air bubbles broken by contacting the defoaming member 12 are exhausted to the outside through the deaeration port 14 as air.

The air vent 14 may not be provided. In this case, the broken air bubbles pass through the defoaming member 12 and the blood storage space 5.
It is exhausted inside.

The constituent material of the cover member 13 is the same as the constituent material of the flow path regulating members 10 and 11.

The flow path regulating members 10 and 11 and the cover member 13 may be separate bodies, or may be connected or integrally formed.

Next, the operation of the defoaming device 8 and the blood reservoir 1 will be described.

As shown by the arrows in FIG. 1, for example, blood B flowing from the blood inlet 6 through the blood removal line flows vertically downward in the lumen of the flow path regulating member 10, and then, Inverts along the inner surface of the flow path regulating member 11, and further,
The air flows vertically upward in the flow path 15.

Although air bubbles are inevitably mixed in the blood B, the blood B passes through the mesh of the first filter 9 and rises in the The bubbles flow out to the outside and cannot temporarily pass through the mesh of the first filter 9, but temporarily adhere to the inner surface (the surface on the side of the flow path 15) of the first filter 9.

The air bubbles that have floated off the first filter 9 are accumulated near and above the blood surface of the blood in the flow channel 15. When air bubbles are accumulated to some extent and come into contact with the defoaming member 12, the air bubbles break, grow and grow by the action of the antifoaming agent carried on the defoaming member 12, and finally become air in the blood storage space 5. Or from the degassing port 14 to the outside.

Normally, the inflow from the blood inlet 6 and the outflow from the first filter 9 (filter permeation) and the outflow from the blood storage space 5 (for example, due to the discharge of a pump) are determined. the balance, the liquid surface of the blood B in the channel 15, even involve some variation, it is maintained in the vicinity of conventional liquid level L _0.

In the flow channel 15, the blood B flows upward in the vertical direction, so that the air bubbles adhering to the inner surface of the first filter 9 are separated and floated (washout) by this liquid flow. As a result, the first filter 9 functions normally without causing clogging by air bubbles, and excellent air bubble removal performance is maintained. Therefore, the liquid level of blood B in the flow path 15 does not rise due to a decrease in blood permeation amount (increase in pressure loss) due to clogging of the first filter 9, and the normal liquid level L ₀ is maintained. The priming amount in the flow path 15 does not increase.

Further, the defoaming member 12 has a normal liquid level L.
_Since it is installed above at a distance H from ₀ , blood B is applied to the defoaming member 12 unless there is a large change in blood inflow.
Are not in contact with each other, and even if blood B comes into contact with the defoaming member 12, the frequency is very low. Accordingly, it is possible to prevent the antifoaming agent carried by the antifoaming member 12 from coming off and entering the blood.

The bubbles are separated and removed in this way, and the first
The blood B flowing out of the mesh of the filter 9 flows down along the outer peripheral surface of the first filter 9, further flows on the inclined surface 32, and is stored in the blood storage space 5.

The blood B stored in the blood storage space 5 flows out of the housing 2 from the blood outlet 7 by, for example, suction of a pump (not shown) installed in a line connected to the blood outlet 7. I do.

FIG. 3 is a sectional side view showing another configuration example of the blood reservoir of the present invention. Regarding the blood reservoir 1A shown in FIG.
The description of the same items as those of the blood reservoir 1 will be omitted, and different points will be described.

In the defoaming device 16 in the blood reservoir 1A, the flow path regulating member 20 has a double pipe structure (a pipe wall is a hollow member) in order to increase the difference between the inside diameter and the outside diameter.

Further, a second filter 18 for separating and removing microbubbles which are not defoamed by the defoaming member 12 is provided on the blood outflow surface side of the defoaming member 12, that is, on the outer peripheral surface side.

As the second filter 18, a mesh having an opening of preferably about 30 to 500 μm is suitably used. The other conditions of the mesh of the second filter 18 are the same as those of the first filter 9.

By providing the second filter 18, even if the first filter 9 is clogged and most of the blood B passes directly through the defoaming member 12, It is possible to remove microbubbles that have not been defoamed. Moreover, this second filter 1
8 has the opening as described above, the blood B that has passed through the defoaming member 12 is quickly discharged, and therefore the blood level in the flow path 15 does not rise excessively.

FIG. 4 is a sectional side view showing another configuration example of the blood reservoir of the present invention. Regarding the blood reservoir 1B shown in FIG.
The description of the same items as those of the blood reservoir 1 will be omitted, and different points will be described.

In the defoaming device 17 in the blood reservoir 1B, the outer peripheral surface 22 of the flow path regulating member 21 has a tapered (conical) shape whose diameter increases upward. The first filter 9 also has a tapered tube structure whose diameter increases upward so as to correspond to the inclination of the outer peripheral surface 22.

With such a configuration, the flow path 1
Although the flow of the blood B flowing in the inside 5 is slightly inclined with respect to the vertical direction, the flow rate of the blood in the flow path 15, particularly the first Since the flow velocity near the lower portion of the filter 9 can be increased, it is possible to efficiently wash out bubbles.

The outer peripheral surface 22 and the first filter 9
Is preferably not more than 45 °, particularly preferably about 0.5 to 30 °.

The blood storage tank of the present invention is, for example, a blood storage tank for temporarily storing the removed blood in an extracorporeal blood circulation circuit, or a method for temporarily filtering foreign substances from blood sucked from an operative field and temporarily removing blood. It can be applied to blood reservoirs (cardiotomy reservoirs) that are stored in

As described above, the defoaming apparatus and the blood reservoir of the present invention
Although the illustrated configuration examples have been described, the present invention is not limited to these. For example, the first and second filters and the defoaming member are not limited to cylindrical ones, and may have a columnar shape or a configuration in which the filter and the defoaming member are installed in the protruding portion 31 of the housing body 3 like a partition plate. There may be.

[0093]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described.

(Example) A blood reservoir having the structure shown in FIGS. 1 and 2 was prepared. The conditions of each part of the blood reservoir are as follows.

<Housing> Housing volume: 5000 ml Housing material: polycarbonate (transparent) Angle of inclined surface: θ = 10 °

<Defoaming device> Flow path regulating member (straight pipe and cup-shaped) Material: polycarbonate Inner diameter of flow path regulating member (straight pipe): 10 mm Outer diameter of flow path regulating member (straight pipe): 30 mm Straight tube) length: 250 mm Cover material: polycarbonate First filter: cylindrical polyester mesh (mesh opening: 32 μm, fiber diameter: 35 μm) First filter inner diameter: 34 mm First filter length: 200 mm Cross-sectional area: 2 cm ² Antifoam member: Cylindrical foamed polyurethane (porosity: 20 ppi (pores per inch)) Inner diameter of defoamer: Same as the first filter Defoamer length: 50 mm Distance H: 110 mm (When blood flow is 6000 ml / min) Antifoaming agent: silicone oil

Comparative Example A defoaming apparatus was the same as the above-described embodiment except that a defoaming member having a structure in which a first filter was superposed on the outer peripheral surface (a defoaming apparatus 8 'having a structure shown in FIG. 3) was used. A similar blood reservoir was made. The main conditions of the defoaming device are as follows.

First filter: cylindrical polyester mesh (mesh opening: 32 μm, fiber diameter: 35 μm) First filter inner diameter: 54 mm First filter length: 200 mm Defoaming member: cylindrical foamed polyurethane (pores) Rate: 20pp
i) Defoaming member inner diameter: 34 mm Defoaming member length: Same as the first filter Defoaming agent: Silicone oil

In each of the blood reservoirs of the above Examples and Comparative Examples, a blood feeding tube was connected to the blood inlet, and bovine blood (Ht = 35%, 37 ° C.) was flowed into the defoaming device from the blood inlet. The blood was supplied at 6000 ml / min, and a tube and a roller pump were connected to the blood outlet side to discharge approximately the same amount of blood as the supplied amount. In this way, the amount of blood stored in the blood storage space was maintained at about 500 ml.

Next, using a bubbler, a bubble (diameter of about 0.03 to 5 m) was introduced into the supplied blood at a rate of 100 ml / min.
m).

Before, immediately after, and 3 from the start of mixing
At 0 seconds, after 5 minutes, and after 30 seconds from the stop of mixing, the pressure loss ΔP at the filter was measured, and air bubbles adhered to the inner surface of the filter (Example) or the defoaming member (Comparative Example). The condition and the liquid level in the defoamer were observed. The results are shown in Tables 1 and 2 below.
And Table 3.

[0102]

[Table 1]

[0103]

[Table 2]

[0104]

[Table 3]

As shown in the above tables, in the blood reservoir of the embodiment of the present invention, almost no air bubbles adhered to the inner surface of the filter, and as a result, the pressure loss was small and the excellent air bubble removing ability was continuously maintained. Since the liquid does not rise and the liquid level rises and does not contact the defoaming member, there is no mixing of the defoaming agent into the blood. In addition, the pressure loss recovered to the level before the bubble mixing immediately after stopping the bubble mixing.

On the other hand, in the blood reservoir of the comparative example, since air bubbles adhered to the inner surface of the defoaming member, the pressure loss increased, the liquid level rose, and the air bubble removing ability decreased. Further, it was extremely difficult to recover the pressure loss after stopping the bubble mixing.

[0107]

As described above, according to the defoaming apparatus of the present invention and the blood reservoir provided with the same, the filter is not clogged by the air bubbles due to the washout of the air bubbles by the vertically upward blood flow. Since it functions normally and maintains excellent air bubble removal capability, there is no increase in pressure loss and no accompanying rise in the level of blood in the flow path. As a result, the amount of priming in the defoaming device does not increase, and the frequency of contact of blood with the defoaming member is extremely reduced, thereby preventing the defoaming agent carried on the defoaming member from being mixed into the blood. Is done.

[Brief description of the drawings]

FIG. 1 is a sectional side view showing a configuration example of a blood storage tank of the present invention.

FIG. 2 is a sectional view taken along line AA in FIG.

FIG. 3 is a cross-sectional side view showing another configuration example of the blood reservoir of the present invention.

FIG. 4 is a cross-sectional side view showing another configuration example of the blood reservoir of the present invention.

FIG. 5 is a cross-sectional side view showing a configuration of a defoaming apparatus of a comparative example for the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1, 1A, 1B blood storage tank 2 housing 3 housing main body 31 projecting part 32 inclined surface 4 lid 41 opening 5 blood storage space 6 blood inflow port 7 blood outflow port 8, 8 'defoaming device 9 first filter 10, 11 flow path Control member 110 Inner surface 12 Defoaming member 120 Lower end surface 13 Cover member 14 Deaeration port 15 Flow path 16, 17 Defoamer 18 Second filter 20, 21 Flow control member 22 Outer peripheral surface B Blood L ₀ Regular liquid level

Continuation of front page (58) Field surveyed (Int. Cl. ⁷ , DB name) A61M 1/14-1/36

Claims (7)

(57) [Claims] 1. A blood flow path is formed between a mesh-shaped first filter for removing air bubbles from blood and the first filter, and the flow of blood is substantially reduced within the flow path in the flow path. (1) A flow path regulating member that regulates the filter so as to be parallel and upward, and a defoaming member that is installed above a normal liquid level of blood in the flow path and carries an antifoaming agent. A defoaming device characterized by the above-mentioned. 2. The defoaming device according to claim 1, wherein the flow path regulating member regulates the flow of blood substantially vertically upward. 3. The defoaming device according to claim 1, wherein a second filter for separating and removing minute air bubbles passing through the defoaming member is provided on the blood outflow surface side of the defoaming member. 4. The defoaming device according to claim 1, wherein the defoaming member is made of a material having a lower resistance to blood passage than the first filter. 5. The defoaming device according to claim 4, wherein the defoaming member is formed of a mesh that is coarser than the first filter. 6. The defoaming device according to claim 4, wherein the defoaming member is formed of a foam or a porous body. 7. A blood reservoir provided with the defoaming device according to claim 1.