JPS6328624B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION I. Background of the Invention (Technical Field) The present invention relates to a blood reservoir (cardiotomy reservoir) used in an artificial heart-lung circuit during extracorporeal circulation associated with open heart surgery.

(Prior art and its problems) In an artificial heart-lung circuit, as illustrated in FIG. and from the pump 3 via the blood reservoir 4 and line 5 to the venous reservoir 7 housed in the volume regulating means 6.
The pump 8 then connects the oxygenator 9 with a heat exchanger.
The oxygenated blood is then returned to the patient's body via a blood supply line 10.

By the way, in addition to defoaming and storing blood aspirated in the operative field such as the thoracic cavity and heart cavity, the blood reservoir has the function of defoaming and storing blood that is aspirated in the operative field. Devices that incorporate a filter to filter out foreign substances such as microaggregates and are configured to perform the three important functions of filtration, defoaming, and blood storage have become widely used. However, it has been pointed out that the blood reservoirs currently in use have the following various problems in the three functions mentioned above.

(1) Problems with filtration function When blood containing many foreign substances such as tissues and microaggregates is passed through a filter, the filter tends to become clogged quickly before it is used effectively. In addition, in the case of pleated filters,
Due to the fact that the filter is arranged in a cylindrical shape, a lumen is created, and therefore blood accumulates in this lumen, making it difficult to accurately determine the amount of blood in the blood reservoir. Therefore,
There is a difference between the scale markings on the housing of the blood reservoir and the actual amount of blood stored, resulting in the problem that the actual amount of blood cannot be read when necessary. In addition, filter performance and the ability to quickly separate blood and valves within the filter conflict, and it is difficult to find a balance between them.

(2) Problems with defoaming function Blood that enters the blood storage tank is filtered and defoamed by a filter and an antifoaming agent, and then stored in the housing. In a structure in which outflowing blood (or priming liquid) is once defoamed and drips onto the blood surface where the blood is stored, bubbles will occur again, which is undesirable. In such a case, blood containing microphone bubbles is also sent to the patient, and there is a risk of brain damage due to peripheral blood vessel occlusion.

Some models have a structure that avoids the above phenomenon by bringing the filtration/defoaming member into contact with the bottom of the housing, but in this type of structure, the air in the blood discharge port at the bottom of the housing and the tube connected to it is discharged. The air block phenomenon of being left behind is likely to occur. For membrane lungs using closed venous reservoirs, this poses a significant risk of air contamination into the venous reservoir, oxygenator, and patient. Air block phenomenon is when the blood surface inside the tube connected to the blood outflow port is clamped, and when a large amount of inflow blood flows in, air cannot be discharged and some of the air remains inside the tube. It means the phenomenon of being put away.

In addition, in blood storage tanks with a built-in filter, due to the resistance of the filter, which has recently become more sophisticated,
Functionally, it is necessary to have a structure that defoams after filtration.
For this reason, positive pressure filtration is performed when filtering the blood mixed with air that flows in. In positive pressure filtration, as the blood flow rate increases, the processing capacity of the defoaming member is exceeded, and the positive pressure air jets out blood from the filter, creating bubbles in the blood, which tends to make subsequent defoaming disadvantageous. In such a case, the pressure increase in the filter is also large, which tends to reduce filter performance. In order to avoid this, some products have adopted a cyclone type air separation structure at the blood inlet, but this cannot be done when a large amount of air is mixed in, which tends to cause a pressure increase, and results in considerably poor defoaming performance. I'm inviting you.

In addition, even if the structure obtains the above merits by separating the filtration and defoaming section and the blood storage section, the blood once defoamed in the filtration and defoaming section is transferred from the filtration and defoaming section to the blood storage section through the guide section between them. There remained a problem that foaming occurs again between the filtration/defoaming section and the guide section or between the guide section and the bottom of the housing.

(3) Problems with blood storage function There are also problems with the shape and structure of the housing in terms of blood storage function. In terms of mold production, it is convenient for the housing to produce flanged halves and bond them together at the middle. However, with such a structure, there is a possibility of blood leakage at the bonded portion, and at the same time, the liquid volume scale table using the label is cumbersome, and the display of the amount of stored blood at the flange portion is likely to be inaccurate. Furthermore, depending on the case of open heart surgery, blood volume is often measured through the vent line in order to ascertain the status of circulatory abnormalities and valve insufficiency. In other words, the heart is in an ischemic state, but if there is abnormal pulmonary venous return, blood accumulates in the left ventricle, and the degree of abnormality can be understood from the amount. Also,
Caval valve insufficiency is also determined by the amount of blood stored in the left ventricle. That is, in order to measure these quantities through the vent line, fine scale display is required. Therefore, the shape of the housing bottom and the blood outflow port is required to be such that the blood volume can be easily read.

Further, even if the area of the filter is the same, it greatly affects the above-mentioned ability of the filter to separate blood from bubbles, and the longer the area, the better the separation ability. For this reason, use a long filter,
Many of them reach near the bottom of the housing.
However, in these types of blood reservoirs, the contact time between the constituent members and the blood is long, which is undesirable due to the fact that complement activation and silicone desorption, which are currently attracting attention, are highly problematic. A typical example of a filter that reaches near the bottom of the housing is:
There are USP 4164468, USP 4209193, etc.

Purpose of the Invention The present invention has been made in view of the above-mentioned current situation.
The purpose of this is to separate the filtration and defoaming section from the blood storage section, to reduce the time during which blood contacts foreign substances in the filtration and defoaming section of the blood storage tank, that is, to only the transit time, and to It is an object of the present invention to provide a blood storage tank configured so that blood once defoamed in the defoaming part does not foam again between the filtration and defoaming part and the guide part or between the guide part and the blood reservoir. .

Structure of the Invention That is, the present invention includes a housing capable of storing blood, which has a blood inlet at the top and a blood outlet at the bottom, and a filtration and defoaming section is provided in the upper part of the housing. The bubble part communicates with the blood inflow port, has a lower end open to form a blood outflow part, and is arranged between a cylindrical body that limits a blood flow path for the introduced blood, and the cylindrical body. It has a filtration and defoaming member that is concentrically arranged with a cylindrical filter that defines a gap for separating and eliminating air bubbles, and a defoaming member that is arranged on the outer periphery of the filter, and further includes a filtration and defoaming member that defines a gap for separating and eliminating air bubbles in the blood filtration and defoaming part. A guide part for guiding the blood flowing out from the outflow part to the bottom of the housing is provided in a shape converging from the filtration/defoaming part toward the bottom of the housing, and the blood outflow part of the filtration/defoaming part and the guide part a trickle plate whose distance from the blood receiving part is equal to or less than the length of the blood droplet, and at the distal end of the guide part the blood stream flowing on the converging inner surface of the guide part is divided into trickles; The present invention provides a blood storage tank characterized by being provided with.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The blood reservoir of the present invention will be described in detail below with reference to preferred embodiments shown in the accompanying drawings.

FIG. 2 is a partial cross-sectional side view of the blood storage tank 20 of the present invention with a portion cut away to reveal the inside, in which a filtration and defoaming section is provided in a substantially cylindrical housing 21 so as to be biased upward. , it can be clearly seen that the blood is guided from there towards the bottom of the housing or the blood reservoir. The housing 21 is a hard transparent material made of polycarbonate, acrylic-styrene copolymer, polyester, polyamide, polyvinyl chloride, acrylic-butadiene.
It is made of a hard plastic material such as styrene copolymer, preferably molded in one piece.

The top of the housing 21 is closed by an upper lid 22 and a housing extension 23, and the upper lid 22
A suction blood inlet port 24, a filtered infusion port 25, a rapid infusion port 26 are provided on the top, and an air vent port 27 is provided on the housing extension 23. The body of the housing 21 is approximately cylindrical and hollow. Housing 21
The bottom part has a slope that slopes toward the eccentrically shaped blood outflow port 29, and a mid-height support part 32 for supporting the filtering and defoaming member 30 and the deflector 31 is formed in the center of the slope. .

Although it is preferable for the housing 21 to be composed of halves in terms of mold production, from the viewpoint of blood leakage, graduations, labels, etc., it is preferable to form the housing 21 seamlessly as one piece except for the top part. In particular, it is necessary to prevent blood from collecting at the bottom, and it is better to have no adhesive parts. The blood outflow port 29 provided at the bottom of the housing 21 is preferably provided eccentrically near the outer periphery of the bottom of the housing 21, since if it is provided at the center of the bottom of the housing 21, visibility of the scale, blood volume, etc. will be poor. Furthermore, depending on the case of open heart surgery, it may be necessary to know the exact amount of blood even if it is a small amount, so it is preferable that the shape of the blood outflow port 29 is funnel-shaped with a smooth curved surface. The scale can be easily read if it has a bulging shape such as a hemisphere.

In this way, when blood flows into the venous reservoir via the tube connected to the funnel-shaped blood outflow port with a smooth curved surface, the blood flows through the blood outflow port 2.
9 and to flow along the wall of the tube,
The air block phenomenon, which is the problem mentioned above, does not occur. This also applies if the blood level rises or falls at the blood outlet due to the vertical movement of the blood reservoir during adjustment operations to optimize the body's blood volume, which is constantly monitored, or fluctuations in blood inflow from the surgical field. , the air block phenomenon is likewise prevented.

The filtering and defoaming member 30 disposed in the upper part of the housing 21 described above is connected to the guide member 28 below.
At the same time, it is supported between an upper support body 33 extending from the top cover 22 and a mid-height support part 32 . The filtering/defoaming member 30 has various functional elements concentrically arranged outward from the center, and sequentially distributes air-mixed blood introduced into the center evenly, separates blood and bubbles, The blood is filtered and defoamed, and the defoamed blood is stored in the blood storage section or the bottom of the housing via the guide member 28 at the bottom of the housing without generating bubbles again.

The filtering/defoaming member 30 has a filter 35 having a lumen 34 and a defoaming member 36 on its outer periphery, and the filter 35 has an upper support 33 and a lower support 37.
The defoaming member 3 is fixed with an adhesive 38 between the
6 fits into the filter 35 and is supported by a lower support member 37. The upper support 33 has a filter 35
A cylindrical body 40 as a cylindrical body that hangs downward by a length shorter than the filter length within the inner cavity 34 composed of
, and defines an annular gap 41 between the filter 35 and this cylindrical body 40. Since a cylindrical body exists in this gap, blood does not directly enter, and therefore the part of the filter corresponding to the gap 41 does not get wet, and the bubble air separated from the blood flows from this part to the filter 35 and the defoaming member. 36 and vent port 27.

The lower support body 37 has a hollow member 42 that rises upward within the inner cavity 34 formed by the filter 35. A lower part 44 of the hollow member 42 is in close contact with the filter 35, but an upper part 43 is reduced in diameter to form a cylinder. It extends upwardly within the body 40 to approximately the position of the upper support 33 .
The hollow member 42 and the cylindrical body 40 are preferably arranged concentrically with the filtering and defoaming member 30, and the gap 45 between the hollow member 42 and the cylindrical body 40 defines a blood flow path. The upper portion 43 of the hollow member 42 is closed and its head is preferably rounded to allow for even distribution of blood.

Conventionally, this blood distribution hollow member 42 was not disposed inside the filter 35 and formed a lumen, which caused a problem in that blood whose amount could not be measured was accumulated in this lumen, but in the present invention, , the placement of the blood distribution hollow member 42 into the lumen 34 of the filter 35 to a considerable height position eliminates unnecessary lumens and ensures even distribution of blood into the filter 35 and between the cylinder 40 and the filter 35. Blood and bubble separation gap 4
By forming No. 1, the filtering surface can be used effectively, and channeling as in the conventional case can no longer occur. The constituent material of the blood distribution hollow member 42 is as follows:
Hard plastics such as polycarbonate, acrylic-styrene copolymer, polyamide, polyester, polyvinyl chloride, acrylic-butadiene-styrene copolymer, polypropylene, etc., which can define the diameter of the inner cavity 34 of the filter 35, are preferable.

There are various types of filters 35 disposed around the blood distribution hollow member 42, but even if a screen type with a mesh with a pore diameter of about 20μ or a depth type with an adsorption effect is used, it is difficult to make it compact and lightweight. A pleated filter is preferred. It is preferable that the filter 35 is not limited to a pleated type, and that it contacts the blood distribution hollow member 42 at equal intervals, with a certain amount of space formed therebetween. This is because the contact between the filter 35 and the blood distribution hollow member 42 at equal intervals can increase the effective area of the filter. Furthermore, the space formed between the filter 35 and the blood distribution hollow member 42 is intended to provide a storage space for substances that hinder the effective use of the filter, such as clogging and channeling caused by foreign substances such as tissues and microaggregates. It's for a reason.

In a blood storage tank with a built-in filter, blood is filtered under positive pressure, but as the blood flow rate increases, the processing capacity decreases, and the blood is ejected from the filter due to positive pressure, generating bubbles, which are then defoamed. As mentioned above, it may be disadvantageous. To prevent this, it is best to treat the filter with an antifoaming agent in advance. The antifoaming agent is generally antifoaming silicone (compound type mixed with silica, oil type), etc., and the filter constituent material is preferably nylon, polyester, polypropylene, etc. The filter is preferably made of these meshes or nonwoven fabrics. By attaching an antifoaming agent to the filter, when blood comes into contact with the filter, the bubbles are defoamed and separated into blood and air, which suppresses the increase in pressure caused by the filter and at the same time improves the filtration performance of the filter. maintained.

The defoaming member 36 on the outer periphery of the filter 35 is for further defoaming the blood that has been filtered or defoamed by the filter 35 on the upstream side, and is made of foamed urethane, stainless steel ribbon, polypropylene mesh, etc. The material is coated with the antifoaming agent mentioned above. The defoaming member 36 is wrapped in a tricot-like bag 46.

Further, in the blood storage tank of the present invention, the filtration and defoaming section is provided biased toward the upper part of the hollow housing. This is to prevent the stored blood from being immersed in the filter 35 or the defoaming member 36 as in the conventional case, as described above, and to avoid contact with foreign matter as much as possible. This is due to the activation of complement by components that are currently attracting attention (complement, a type of protein in animal serum that plays an important oxygen role when antigen-antibody reactions occur in vivo, is activated). activation, causing damage to cell membranes, the body's defense mechanism against infection, and inflammatory responses. In addition, due to activation, complement is consumed, temporarily lowering the body's immune system and increasing the risk of infection, etc.)
To provide a scale that suppresses desorption of silicone, reduces the dead volume of blood in a filter 35 and an antifoaming member 36, and allows accurate grasping of the amount of blood when blood is returned.

In order to achieve such a function, in the present invention, a filter is provided so that the blood that has been filtered and defoamed in the filter and defoamer section can be guided again to the blood outlet 29 at the bottom of the housing 21 without generating bubbles. A guide member 28 is provided at the lower part of the super-defoaming member 30. Guide member 2
8 is preferably configured with a funnel-shaped deflector 31.

The deflector 31 converges to be supported on a rib 39 on a mid-height support portion 32 at the bottom center of the housing 21 . For details of the deflector 31, see
FIG. 4 will be described in detail later. This deflector 31 is preferably configured so as not to contact the body of the housing 21 and the bottom portion adjacent to the body to open the flow path. This is because if the deflector 31 and the housing come into contact as described above, when the blood level is below the contact point, the contact point is likely to be mistaken for the blood level, which may lead to a misunderstanding by the operator.

In addition, since blood is constantly flowing over the deflector, if the deflector is made of a transparent material, it will tend to be difficult to read the blood level, so the deflector should be made of something that does not give the impression of blood color, or is made of an opaque or colored material. It is preferable to do so.

3 and 4, the blood filtered and defoamed by the filtering and defoaming section is shown between the filtering and defoaming member 30 and the deflector 31, and between the deflector 31 and the housing 2.
A preferred configuration example of the deflector 31 that prevents re-foaming between the deflector 31 and the mid-height support section 32 at the bottom of the deflector 31 is shown.

The deflector 31 has a converging funnel shape, and allows the filtered and defoamed blood to flow down onto its inner surface without foaming again.

As shown in FIG. 4, the deflector 31 has a substantially frustoconical body portion 50, the top of which constitutes a blood receiving portion with an overhang portion 51 and a substantially horizontal step portion 52. This blood receiving part is a part that directly receives blood flowing out from the defoaming member 36 wrapped in the tricotty bag 46 of the filtration and defoaming part. If blood from the defoaming member 36 drips into this area, the impact will cause foaming to occur again.

Therefore, in the present invention, this defoaming member 36
The distance between the outer circumferential edge of the foam-defoaming member 36 and the horizontal stepped portion 52 is made smaller than the vertical size of the blood droplets from the tri-chop bag 46 enclosing the defoaming member 36, so that the blood droplets from the defoaming member 36 are to prevent the phenomenon of dripping from occurring. However, if the distance between the antifoaming member 36 and the horizontal step portion 52 of the deflector 31 is made too small, foaming may occur because the blood flow path is narrow when a large amount of blood flows out.

Therefore, it is assumed that the distance between the outer circumferential edge of the tricot bag 46 enclosing the defoaming member 36 and the horizontal step of the deflector 31 is equal to or slightly smaller than the vertical length of the blood droplet. It is preferable to form a continuous flow without dripping. Furthermore, it is preferable to form a plurality of ribs 53 as guide portions that guide blood to the horizontal step portion 52 without dripping. An example of its configuration is shown in FIG.

Further, it is preferable that the blood defoamed by the defoaming member 36 flows out from the outer peripheral end of the tricot bag 46 that encloses the blood as much as possible. For this purpose, it is preferable to have a structure in which the center part of the tri-tight bag 46 enclosing the defoaming member 36 is pushed up and tilted toward the outer periphery.

In the present invention, in order to achieve this objective, eight or more ribs 53 are preferably formed on the horizontal step portion 52 at equal angular intervals.

In this way, the horizontal step portion 5 of the deflector 31 is
The blood that flows out onto the body 50 of the deflector 31 without foaming flows down the inner surface of the inclined body 50 of the deflector 31 along its wall, and finally flows down the body 50 of the deflector 31.
It flows out from the end onto the mid-high support part 32 without dripping in the same way as above.

It is preferable to provide a plurality of guide plates 54 between the body portion 50 of the deflector 31 and form a plurality of blood flow paths to disperse the blood into many flows and to minimize the chances of foaming. Furthermore, in addition to the guide plate 54, ribs 55 as trickle plates are preferably provided at the distal end of the body 50, preferably evenly angularly, so that the blood flow is dispersed into finer flows and flows out from the body 50. Avoid foaming due to pressure or a film that may form during spillage. By providing the trickle plate (rib) 55 in this way, defoaming at the end of the body 50 is ensured. A preferred example of the rib 55 is shown in FIG.

The ribs 55 formed at the end of the body 50 are preferably equally spaced, and in that case, the rib shape and size are such that the outlet at the end of the deflector has an area that ensures a rapid flow of blood flow 5. There is a need for a number of ribs that are spaced so that they are both large and spacing that does not create a blood bubble film. The number of ribs 55 is preferably at least eight. As a result of various tests, it has been confirmed that when the number of ribs 55 is less than 8, the flow becomes non-uniform or the bubble film of blood breaks and microbubbles are generated.

The defoamed blood that has exited the filtering and defoaming member 30 passes through the trough-like passage 47 of the deflector 31 and forms a gentle flow, so that the invasion of the blood is small and no bubbles are generated again.

Now, in a closed system, the amount of blood stored at the bottom of the housing, which does not come into contact with this filtration/defoaming section, is constant.
Since blood storage of 300 to 500 ml is forced, the lower limit is at least 500 ml.Also, as a myocardial protection method performed when the aorta is blocked, cooling fluid is refluxed, so more than 2000 ml of cooling fluid is required, so the upper limit is Approximately 2500ml is required.

The deflector 31 is for guiding the filtered and defoamed blood to the bottom of the hollow housing 21 without foaming again. Many conventional deflectors are configured to allow blood to flow above the blood stored in the lower part of the housing, and as described above, it is easy to mistake the level of blood on the deflector and the level of the stored blood.

In the present invention, the above-mentioned example is shown as the deflector 31 that guides the filtered and defoamed blood from the filtering and defoaming member 30 to the bottom of the hollow housing 21. It is not necessary to have a bottom, nor is it necessary to have a mid-height support part 32. The blood processed in the filtering and defoaming section 30 can also be guided by the deflector 31 that converges toward the blood outlet 29 located in the center of the housing 21 . In this case as well, the blood flows down on the inner surface of the deflector 31, but the color of the blood is not visible unlike in the conventional case where the blood flows down the outer surface, so the liquid level of the blood can be visually observed accurately. measurement becomes easy. Furthermore, it is even more effective if the deflector 31 is made of an opaque or colored material.

Although the hollow housing 21, the cylindrical body 40, and the hollow member 42 have been described as having a cylindrical shape, they may have other suitable shapes such as a polygonal column shape or an irregular cross-sectional shape, and the hollow member may be a solid body. Of course.

Specific effects of the invention Filtration, defoaming, and defoaming during use of the blood storage tank of the present invention
The blood storage function will be explained.

The blood reservoir is constructed and used as shown in FIG. Blood mixed with the pipe suctioned from the surgical field such as the cardiothoracic cavity during open-heart surgery or the like falls onto the upper part 43 of the hollow member 42 through the blood inlet port 24. Blood flows down through the gap blood passage 45 between the upper part 43 of the hollow member 42 and the cylindrical body 40 while avoiding direct contact with the filter 35, and contacts the filter 35 for the first time at the lower part 44 of the hollow member 42. The blood passes through the portion from the upper part to the lower part 44 of the hollow member 42, and by increasing the contact area of the member with the bubble-containing blood before contacting the filter 35, the bubbles and the blood are separated. Since a gap 41 is provided between the filter 35 and the cylindrical body 40, the separated bubbles gather in that area, are swept away by the blood, and are prevented from passing through the filter.

As shown by the solid line showing the flow of blood and the dotted line showing the flow of bubbles, the bubbles are separated from the blood and form a gap 41.
The air is defoamed through the filter 35 and the defoaming member 36 with or without the defoaming agent, and the air is discharged to the outside through the vent port 27. Therefore, air will not accumulate in the filter lumen 34 and increase the internal pressure, and together with the pressure from positive pressure filtration, bubbles will not be ejected from the filter 35 together with the blood.

In addition, the amount of blood conventionally stored in the filter lumen 34 is reduced due to the presence of the hollow member 42 and the rapid and effective separation of blood and bubbles as described above, and the amount of blood in the blood reservoir can be accurately determined. I am now able to grasp it.

Filter 3 arranged around the outer periphery of hollow member 42
5 is a micro-aggregate, which is a tissue contained in blood or transfused blood, in which bubbles are evenly distributed by a hollow member 42 and bubbles are effectively separated by a gap 41 between a filter 35 and a cylindrical body 40. Filter foreign substances such as from blood.

In this manner, the blood that has been filtered or filtered and defoamed by the filter 35 is completely defoamed while passing through the defoaming member 36, and leaks out from the tricot bag 46 enclosing the defoaming member 36. The oozing blood is transferred to the deflector 31 from the outer periphery of the tricot bag 46.
This action is caused by the rib 5 formed on the horizontal step 52.
3, the center part of the tricottle bag 46 is pushed up and the outer periphery thereof is inclined. The blood that has flowed out onto the horizontal stepped portion 52 of the deflector 31 without dripping gently flows down the trough-like passage formed by the guide plate 54 of the deflector 31 and reaches the end of the body portion 50. A large number of ribs 55 are formed at the end of the body 50, which further reduces the blood flow to a trickle, and at the same time prevents the formation of a bubble film at the end of the ribs, allowing the blood to flow into the blood storage space 48 without generating bubbles again. Inflow. The blood in the blood storage space 48 forms a swirling flow around the middle and high support part 32 through the inclined bottom part of the housing 21 and reaches the venous reservoir 7 through the blood outlet 29 and the tube 5 . This also applies to the configuration example shown in FIG.

In addition, if the blood outflow port 29 is not formed at the center of the bottom of the housing 21 but near the outer peripheral edge, and its shape is a bulge having a smooth curved surface such as a spherical shape, it is possible to Even a small amount of blood can be accurately and easily read by the scale attached to the blood outlet 29. In this way, by forming a swirling flow in the exuded blood and also configuring the blood outlet 29 to ensure a smooth flow, the blood is connected to the bottom of the housing 21, the blood outlet 29, and the blood outlet 29. Since the flow follows the walls of the tube, air block phenomena are prevented and there is no possibility of bubbles circulating into the patient's body via the venous reservoir.

The blood storage capacity of the blood storage space 48 at the bottom of the housing is
The volume is 500 to 2,500 ml, and the filter 35 and antifoaming member 36 are not constantly immersed in the pooled blood, so there is little risk of complement activation or silicone elution.
Its blood storage capacity is sufficient even in emergencies.

Specific Effects of the Invention The blood reservoir of the present invention provides many advantages over conventional ones, as listed below.

(1) Since the filtration/defoaming part and the blood storage part are completely separated, the blood storage does not constantly soak foreign substances such as the filtration member and the defoaming member, so complement activation,
There is extremely little risk of silicone elution.

(2) By providing a cylindrical body, a filter, and an antifoaming member concentrically in the filter inner cavity, and forming a gap between the cylindrical body and the filter in particular, separation of blood and bubbles is promoted, and the separation of blood and bubbles is facilitated. Since the bubbles can escape as air through the filter part protected from wetting by the cylindrical body, the bubbles no longer increase the internal pressure and are forced out of the filter along with the blood due to the pressure of positive pressure filtration, as was the case in the past. Ta.

(3) Since the distance between the outer periphery of the tricot bag that encloses the defoaming member and the horizontal step of the deflector is smaller than the length of the blood droplets, there is no dripping of blood and a continuous flow is formed. Therefore, there is no longer any possibility of blood dripping onto the deflector and causing foaming. Further, since the tricotto bag is configured to be pushed up at the center and tilted downward toward the outer periphery, blood flows out only from the outer periphery.

(4) Multiple ribs are installed at the end of the deflector to disperse the blood flow into finer streams to prevent foaming, making defoaming extremely efficient. .

[Brief explanation of the drawing]

FIG. 1 is a diagrammatic perspective view of an example of an artificial heart-lung circuit;
FIG. 2 is a partial cross-sectional side view of a preferred embodiment of the blood reservoir of the present invention, FIG. 3 is a plan view of a deflector used in the blood reservoir of the present invention, and FIG. 4 is a cross-sectional view taken along the line ~ in FIG. 3. 5 and 6 are side views of preferred examples of ribs formed on the upper and lower portions of the deflector, respectively. Explanation of symbols, 1...Blood removal line, 2...Suction line, 3, 8...Pump, 4...Blood storage tank, 5...
Line, 6... Capacity regulating means, 7... Venous reservoir, 9... Oxygenator with heat exchanger, 10... Blood supply line, 20... Blood storage tank of the present invention, 21... Housing, 22... First Upper lid, 23...Second upper lid, 24...
...suction blood inlet port, 25...filter-passing fluid, blood transfusion port, 26...rapid infusion port,
27... Air vent port, 28... Guide member,
29...Blood outflow port, 30...Filtering and defoaming member, 3
1...Deflector, 32...Mid-high support part, 33...
...Upper support, 34...Inner cavity, 35...Filter, 36...Defoaming member, 37...Lower support, 3
8... Adhesive, 39... Rib, 40... Cylindrical body,
41... Annular void, 42... Hollow member, 43...
Upper part, 44...Lower part, 45...Gap, 46...Tricot bag, 50...Deflector body, 51...
Drawer part, 52...Horizontal step part (blood receiving part), 53...
...Rib, 54...Guide plate, 55...Rib (rivulet plate).

Claims (1)

[Scope of Claims] 1. A housing having a blood inlet at the top and a blood outlet at the bottom, capable of storing blood; a filtration and defoaming section provided above in the housing; is a cylindrical body that communicates with the blood inlet, has a lower end open to form a blood outflow part, and defines a blood flow path for the introduced blood; and air bubbles in the blood are separated from the cylindrical body. It has a filtration and defoaming member that is concentrically arranged with a cylindrical filter and a defoaming member arranged on the outer periphery of the filter, and further includes a blood outflow part of the filtration and defoaming part. A guide part for guiding blood flowing out from the filtering and defoaming part to the bottom of the housing is provided in a shape that converges from the filtering and defoaming part toward the housing bottom, and the blood outflow part of the filtering and defoaming part and the blood receiving part of the guide part are connected to each other. The distance between the guide part and the guide part is equal to or smaller than the length of the blood droplet, and a trickle plate is provided at the distal end of the guide part to divide the blood flow flowing on the converging inner surface of the guide part into trickles. A blood storage tank characterized by: