JPS58163372A - Apparatus for removing gas bubble in blood - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (I) Background Art (I-1) Technical Field The present invention relates to a blood circuit for extracorporeal circulation such as an artificial heart-lung device, an artificial kidney device, and a device for separating blood cell components and plasma components during open-heart surgery. The present invention relates to a blood bubble removal device that removes bubbles from blood flowing through blood.

(I-2) Prior art and its problems The blood bubble removal device uses a filter system in which air bubbles in the blood are captured by a filter and raised to be removed, and a blood retention space is provided to reduce the blood flow velocity. There is a retention method in which air bubbles in the blood rise due to buoyancy, and a combination method in which a filter and blood retention are used. FIG. 1 and FIG. 2 each show a conventional filtration type blood bubble removal device. In the apparatus shown in FIG. 1, the inside of the container body 1 is made of nylon that easily repels air bubbles, and is vertically divided into a blood chamber 3 to be processed and a blood chamber 4 to be processed by a mesh filter 2. Each chamber is located at the bottom of the container 1. It has a structure in which there is a blood volume 5 and a blood outlet 6 communicating with each other, and furthermore, there is a bubble volume lower at the top of the container body 1 which communicates with both chambers. Therefore, when the blood introduced into the blood chamber 3 to be processed from the blood population 5 passes through the filter 2 due to blood flow pressure, air bubbles larger than the pore diameter of the filter 2 are trapped and enter the blood chamber 4 to be processed, which enters the blood outlet 6. The air bubbles captured by the filter body 2 rise due to buoyancy and flow out from the air bubble lower every time they collect in a certain amount at the upper part of the container body 1.

The apparatus shown in Fig. 2 is made of nylon and is housed in a cylindrical container 8 which has a blood supply 9 in the tangential direction of the lower side, a blood outlet 10 in the center of the lower surface, and a bubble outlet 1 in the upper center. A radial and cylindrical filter body 12 is housed with the cylinder core serving as the vertical axis, and the open end of the soil portion of the filter body 12 is closed with a cover plate 13.

Due to the above mechanism, the blood flowing from the blood population 9 is transferred to the filter body 12.
The swirling flow reduces the pressure caused by the blood flow when the blood passes through the filter body 12 to avoid passing through due to the pressure of microbubbles, and furthermore, the swirling flow is captured by the filter body 12. The bubble separation function is the same filtration method as the device shown in FIG. 1 above. There are two types for adults and children, each with a bubble removal function that corresponds to a predetermined blood flow rate. However, each device shown in FIGS. 1 and 2 has a pore diameter of 200 mm.
If a filter inside or outside μ is used, not only microbubbles easily pass through the filter, but also the air bubbles are broken up into small pieces, resulting in low safety and reliability. In the apparatus shown in FIG. 1, the ability to remove air bubbles is extremely low when a large amount of air is mixed in with the large barrel. In addition, a filter with a pore size of 50 μm to 150 μm generally has a slightly better ability to remove microbubbles than the 200 μm filter described above, so a filter with a pore size of 20 μm to 40 μm, with emphasis on the effect of removing foreign matter and agglomerates,
Arterial filters are used as arterial filters, but arterial filters have the drawbacks of increased blood invasion, such as destruction of platelets and red blood cells, and increased pressure loss. Furthermore, the apparatus shown in FIG. 2 has a priming capacity of approximately 220 m1, which is disadvantageous in that it is large.

FIG. 3 shows a conventional blood retention type blood bubble removal device. This device penetrates the bottom of a container body 14 having a volume that allows the blood flow to become small so that microbubbles can float, and the blood flow 15 is inserted into the container 14 so that the inner end thereof is located in the middle of the container 14 in the vertical direction.
In addition, the container 14 has a blood outlet 16 at the bottom and a bubble outlet 17 at the top of the container 14. Therefore, the blood to be processed introduced into the container main body 14 from the blood population 15 forms a gentle downward flow within the container main body 14 and is allowed to rise due to the buoyancy of air bubbles in the blood, so that air bubbles are removed. The treated blood flows out through the blood outlet 16 and air bubbles rising inside the container body 14 are taken out through the air bubble outlet 17 every time a certain amount accumulates in the upper part. # The device can separate and remove microbubbles to a certain extent by enlarging the container body 14 and increasing the volume. However, this inevitably leads to an increase in the amount of extracorporeal circulating blood and the amount of fluid replacement, leading to a decrease in the amount of blood remaining in the body, which has an adverse effect on the human body. The amount of priming that has been put into practical use is 250-4
00 mJ, which cannot be said to be a sufficient volume to remove even microbubbles, and the miniaturization of the device itself has the disadvantage that it is difficult to put it into practical use due to its function of utilizing blood retention. There is.

FIG. 4(a) shows a conventional filter/blood retention type blood bubble removal device, and FIG. 4(b) shows a filter η housed in its internal space. The device has a blood outlet 19 penetrating the lower surface of the container body 18, a blood outlet in the lower side of the container body 18, and an air bubble outlet 2 in the upper center of the container body 18. Blood population inside is 19
There is a nylon cylindrical filter element η connected to the inner end of the filter.
A guide rod nb is connected to the upper part of the support frame Z3a and hangs down to the center inside the filter body n, and the outer space of the filter body 22 has a volume where the blood flow becomes small so that microbubbles can float. The configuration consists of a row of processing blood chambers. Therefore, the blood to be processed introduced from the blood population 19 is transferred to the guide rod 2.
3b and passing through the filter body n, air bubbles larger than the pore diameter of the p filter body ρ are captured on the inner surface of the filter body and become primary treated blood. The flow becomes a gentle downward flow and allows the microbubbles that have passed through the filter body η to rise due to their buoyancy, resulting in secondary treated blood in which the removal of bubbles is further promoted, flowing out from the blood outlet and rising inside and outside the filter body. Every time a certain amount of bubbles accumulates in the upper part, they are taken out from the bubble outlet 2. However, in this device, even if air bubbles larger than the pore diameter are captured by the filter n, the surface of the filter η is cylindrical as described above, and the guide rod 23b hangs down into the inner space of the filter body. Therefore, as the internal volume of the inner space becomes smaller, the flow rate of blood to be processed rising through the inner space increases. Therefore, there is a risk that the air bubbles trapped in the filter n will be raised by the blood flow and flow out from the upper opening of the filter η along with a downward flow toward the outside of the filter ρ, directly heading toward the blood outlet. Furthermore, it is also possible to prevent the buoyancy of microbubbles that have passed through the filter η from increasing. Therefore, a mechanism can be adopted that increases the internal volume of the treated blood chamber to weaken the flow rate and promote the rise of microbubbles due to the retention effect. This should be avoided because it leads to an increase in the amount of blood and fluid replacement, resulting in unfavorable results for the human body.On the other hand, if the device is made smaller and the priming amount is made smaller than 1901, the disadvantage is that it becomes impossible to remove microbubbles due to the retention effect. There is.

(n) Purpose of the Invention The present invention was devised after intensive research in view of the above-mentioned points, and it is possible to remove air bubbles by the effect of increasing the buoyancy of air bubbles and the centrifugal separation effect caused by the difference in specific gravity between air bubbles and blood. In particular, compared to the conventional device mentioned above, the priming capacity can be made smaller, the device can be made more compact, the amount of extracorporeal circulating blood and fluid replacement can be reduced, and if the priming capacity is the same as the conventional device, the capacity can be improved, and microbubbles can be sufficiently removed. It is safe and reliable as it can be removed quickly, and the burden on the filter body for bubble separation is small, so even if the pore size of the filter body is increased, microbubbles can be removed, thereby reducing pressure loss due to the filter body and improving performance. To provide a blood bubble removing device that reduces blood invasion such as destruction of platelets and red blood cells, and can also eliminate almost all residual blood in the device when returning blood after use.

According to the present invention, this object includes: a container body; a filter body made of a porous material provided so as to divide the container body into an upper space and a lower space; a liquid inlet provided in the container body to allow blood to be processed to be introduced into the upper space as a swirling flow; a liquid outlet provided in the container body to communicate with the lower space and send out the processed blood passing through the filter body; In the blood bubble removal device, the blood bubble removal device includes an air bubble outlet provided in the main body so as to communicate with the upper center of the upper space and for removing air bubbles separated in the upper space, the upper space formed by the container main body. is achieved by a blood bubble removal device characterized in that the upper side of the vertical cross-section passing through the center of the plane of the upper space is flat or has an upward slope toward the center, and has a substantially circular planar shape. be done.

That is, the device for removing air bubbles in blood of the present invention creates a swirling flow of blood containing air bubbles, and collects the air bubbles in the upper center and removes them through the gas-liquid separation effect due to the difference between the buoyancy increasing effect of the air bubbles in the blood flow and the centrifugal force. In addition, the above buoyancy can also be achieved by making the lower part of the swirling flow near the filter body occupied by blood in which bubble removal has been sufficiently promoted, and by making the blood swirl like air bubbles in the blood at the introduction diameter. When the rising action and the gas-liquid separation action do not work sufficiently, some of the microbubbles that approach the filter collide with the filter at a low angle, are repelled in the direction away from the filter, and are collected in the upper center of the filter. The amount of microbubbles smaller than the pore diameter of the filter that passes through the filter is reduced.

According to the device for removing bubbles in blood of the invention, the swirling flow of blood has a high flow velocity at the outer periphery and has a large gas-liquid separation effect, but immediately after the blood is introduced into the soil space from the liquid inlet, air bubbles are formed. The flow becomes a flow in which separation has not progressed, and as it moves toward the center, the buoyancy of the many bubbles, which have a slower flow velocity, has a greater effect on the flow, resulting in a flow in which bubble separation has progressed. Therefore, it is generally necessary to separate the liquid inlet from the filter body, and when the filter body faces the circumferential portion of the swirling blood flow, the liquid inlet is provided above and apart from the filter body.

Therefore, in the present invention, the container body may have a shape that wraps around the circumferential portion of the upper space from above, below, and from the outside so that the circumferential portion of the upper space is not defined by the filter. desirable.

([II) Detailed Description of the Present Invention (m-1) Structure A preferred embodiment of the blood bubble removal device of the present invention is shown in FIGS. 5 and 6. This blood bubble removal device includes a container body δ and an upper space (blood space to be treated) 2 inside the container body δ.
6 and a lower space (processed blood space) 27, a liquid inlet 4 and a bubble outlet I are provided in the container body 5 so as to communicate with the upper space, and a filter body 27 is provided in the container body 5 for each of the lower spaces. It consists of a liquid outlet 31 provided so as to communicate with the liquid outlet 31. The container body is made of polycarbonate, styrene, and acrylic resin.

It can be made using plastics such as AS resin, methyl methacrylate, butadiene, styrene, etc., but it is transparent so that bubbles can be observed, and it is preferable to make it from polycarbonate for biological safety and strength safety. The circumferential portion of the upper space is formed in a shape that wraps around the circumferential portion of the upper space from above, below, and from the outside so that the circumferential portion of the upper space is not defined by the p-shaped body. The filter body is made of a porous mesh made of plastic such as nylon, polyester, polypropylene, etc., and the pore size is selected to be larger than about 50 μm to prevent invasion of blood. The liquid inlet 4 is provided in the container body 6 so that the blood to be treated can be introduced as a swirling flow from the circumference of the upper space. The bubble outlet (9) is provided in the container main body so as to communicate with the upper center of the upper space 3, and includes a bubble release valve 32. The liquid outlet 31 may be provided in the container body δ at an appropriate position relative to the liquid inlet 4 and the filter body as long as it communicates with the lower space. The upper space defined by the container body 5 has a flat shape in which the upper side of the vertical cross section passing through the center of the plane of the upper space slopes upward toward the center. That is, the container body 5 defining the upper space defines the upper side of the upper space with the inner surface of the container body through which floating bubbles can flow toward the bubble outlet (9). Further, the upper space is formed in a substantially circular plane. Therefore, the blood to be treated introduced from the upper space and the liquid inlet 4 occupies the entire volume, forming a disk shape capable of creating a swirling flow. The volume of the upper space, the hole diameter of the liquid inlet 29 and the liquid outlet 31, and the area of the liquid are determined so that the flow rate of the blood to be processed, which becomes a swirling flow, is below a predetermined flow rate that does not prevent the increase in the buoyancy of air bubbles therein. It is determined appropriately in correlation with blood volume. In addition, it is preferable to provide a bubble reservoir 42 in the upper center of the above-mentioned upper space to be able to accumulate a certain amount of bubbles.

(m-2) Effect The above-mentioned blood bubble removing device is preferably installed in the middle of the blood circuit connecting the oxygenator and the aorta in, for example, an artificial heart-lung machine. The blood bubble removing device is primed with a replacement fluid such as physiological saline or lactated Ringer's prior to introducing the blood to be processed. When the blood to be processed is introduced into the upper space from the liquid inlet 4, the upper space inside the container body δ, which is covered with a filter, becomes a flat, circular disk-shaped space, and the liquid inlet 4 is connected to the upper space. Since it communicates tangentially with the upper space, the blood to be processed occupies the entire volume of the upper space and forms a swirling flow.

Generally, when a liquid containing air bubbles in a closed container causes a swirling flow, a difference in centrifugal force occurs due to the difference in specific gravity between the liquid and air bubbles, and the air bubbles gather in the central soil layer with the help of buoyancy, causing the bubbles to self-destruct. A lump of air is formed, and therefore the outer periphery of the swirling flow becomes a liquid flow that does not contain air bubbles.

However, in the blood bubble removal device of the present invention, the blood to be treated is continuously introduced from the liquid input port n9 into the upper space, passes through the filter body, and flows out through the liquid outlet 31, so that the upper space is The swirling flow contains a large number of bubbles at its outer periphery with no progress in bubble separation, while the separation of blood and bubbles is accelerated toward the center.

However, since the filter array is located outside the outer periphery of the swirling flow and located in the center of the lower layer of the swirling flow, the filter array is made of porous material with a pore diameter of 50μ or more to prevent invasion of blood. Even though the blood is composed of blood, only the blood for which bubble separation has been sufficiently promoted passes through the filter array, flows into the lower space 27, and flows out from the liquid outlet 7 and port 31. On the other hand, the air bubbles in the blood to be processed introduced into the upper space as a swirling flow are removed from the air bubble outlet I by opening the air bubble removal valve 32 every time a certain amount of air bubbles collects in the air bubble reservoir 42.

(■) Modification of the present invention (IV-t) First modification The blood bubble removal device shown in FIGS. 7 and 8 is a household item.
- If the vortex of separated air bubbles extends in the direction of the blood outlet 31, unlike the above embodiment, the swirling speed of the air bubbles is abnormally fast and the vortex of separated air bubbles extends in the direction of the blood outlet 31 as the air bubbles move toward the center. It is possible to prevent the vortex from coming into contact with the Okishū body as much as possible, and the bubble separation function is the same as that of the above embodiment.

(IV-2) Second Modification The blood bubble removal device shown in FIG. 9 is different from the above embodiment in that the filter rows are provided in a spherical shape convex to the upper side, and the bubble separation function is There is no difference from the above embodiment.

(TV-3) Third Modified Example The blood bubble removal device shown in FIG. The difference is that the slope slopes upward toward the center.

However, even if the upper surface portion 25a is horizontal toward the center, the bubbles can flow toward the bubble outlet I due to centrifugal force that separates blood and bubbles, so the bubble separation function is different from that of the above embodiment. There is no place.

(IV-4) Fourth Modification The blood bubble removing device shown in FIG. 11 differs from the above embodiment in that the body is provided so as to define the circumference of the upper space. In this case, the liquid reservoir n9 is provided at a required distance above the filter body so that the lower part of the outer periphery of the swirling blood flow in the upper space is occupied by blood whose air bubbles have been sufficiently removed. The bubble separation function is the same as in the above embodiment.

(V) Experimental Results Figure 12 shows an experimental device for confirming the bubble removal ability of the blood bubble removal device of the present invention.
A is a constant temperature bath and an open flask where the water temperature is kept at 25C, and it is filled with a 35% glycerin solution.
．． The viscosity is 5 centiboise, which is the hematocrit value at 37 C ()ict=blood cell volume/blood volume) 35s
corresponds to the blood viscosity of I is a filter that captures dust in the glycerin solution, and 37 is a roller pump that squeezes the tube circuit and sends the liquid, and the amount of liquid sent is 4b-. For fat, a graduated syringe provided as a bubble injection means, 3
Reference numeral 9 denotes a test air trap, and 4o an ultrasonic blood flow meter, which are installed immediately after the test air trap 39.

The ultrasonic blood flow meter 40 uses a model 1935 manufactured by Sanei Sokki Co., Ltd., which has a flat globe attached type 5, has a frequency of 5 MHz, and can record a diagram at a chart speed of 5 wv'B.
The sensitivity is such that it can detect bubbles with a diameter of about 20μ. Reference numeral 41 denotes an observation air trap, which has a structure as shown in FIG. 42 is a cylinder and is 2000
43 and 44 are three-way stopcocks that have the function of changing the direction of the solution flowing in the circuit, and 46 is an observation trap with a capacity of 10,100 O, with a shielding plate 4 inside.
7 is provided. Due to the structure described above, the solution is instantaneously introduced into the cylinder 42 by operating the three-way stopcocks 43 and 44, and when the flow of the solution introduced into the cylinder 42 becomes stable, the rising speed of bubbles in the solution can be observed. The trap 46 accumulates a large number of bubbles due to the retention effect, and the graduated thin tube section 4 at the upper end
The air bubbles accumulated in step 8 can be measured.

This experiment not only confirmed the effect of the present invention by comparing the effect of the present invention with the conventional device mentioned at the beginning, but also confirmed that the device of the present invention can remove bubbles using a different method. This was done based on the recognition that even if the pore size of the filter body is small and the pore size of the filter body is increased, there is an excellent effect of increasing the bubble removal ability. Therefore, for the test air trap 39, the conventional devices shown in FIGS. 2, 3, and 4 and the device of the present invention shown in FIG. 10 were used interchangeably, and experiments were conducted on each. Furthermore, with respect to the device of the present invention, several experiments were conducted by replacing the filters with different pore sizes.

Note that the specific shape and dimensions determining the priming capacity of each device are expressed only by numerical values with negative units in the drawings showing each device.

Table 1111 shows that the device of the present invention can effectively capture medium and small bubbles even though the priming capacity is smaller than that of the conventional device.

It is also found that the device of the present invention can effectively trap medium and small bubbles even when the pore diameter of the filter body is around 260 μm.

FIGS. 14 and 15 show the experimental apparatus shown in FIG. 12, with the conventional device shown in FIG. 4 and the device of the present invention shown in FIG. This diagram is a diagram obtained for each using an ultrasonic blood flow meter 40 after experiments were conducted on each of the two, and the amount of air injected by the bubble injection means 22 was set to 3Q 1rLl.

Both diagrams show that when air is injected in both devices, the needle swings significantly, and the magnitude of the amplitude is almost the same for both devices, but the length of the amplitude disturbance is much greater in the conventional device than in the device of the present invention. It shows that it is a long time.

Note that in both diagrams, the needle disturbances before air injection and after the amplitude disturbance subsides are thought to be noise caused by air bubbles or impurities in the solution used in the experiment.

It can be seen from both diagrams that in the device of the present invention, air bubbles are quickly separated and removed from the blood, whereas in the conventional device, the outflow of air bubbles can be seen over a relatively long period of time. This difference is due to the fact that in the device of the present invention, air bubbles in the blood are actively transferred to the bubble outlet by the action of centrifugal force as the blood turns into a swirling flow, whereas in the conventional device, the air bubbles are removed by the filter. Air bubbles are removed by trapping and trapping microbubbles through the filter, and the air bubbles captured by the filter may pass through the upper part of the filter again when rising, and the microbubbles that have passed through the filter may pass through the upper part of the filter again. It is speculated that this is because the buoyancy of the air bubbles is extremely small, and a large number of air bubbles do not head towards the air bubble outlet, but slowly head towards the liquid outlet along with the downward blood flow, so to speak, the air bubbles in the blood passively migrate to the air bubble outlet. Ru.

Figures 16, 17, and 18 show the experimental setup shown in Figure 12, in which an integral measuring device is connected to the ultrasonic blood flow meter, and the needle deflection of the ultrasonic blood flow meter is measured. This is a diagram recording the respective integral values. In each figure, the lower diagram shows the deflection of the needle of the ultrasonic blood flow meter, and the upper diagram shows the integral curve corresponding to the needle deflection. FIG. 16 shows the case where the test air trap 39 is the conventional device shown in FIG.
This is the case with the conventional device shown in the figure.
This is a case where the present invention apparatus shown in the figure is used.

In this experiment, in the experimental apparatus shown in FIG. 12, the probe of the ultrasonic blood flow meter was connected to a stainless steel plate wrapped around the outside of an acrylic resin tester pipe having an inner diameter of 6III. This is to eliminate blood flow waves so that only waves for air bubbles can be observed.

The conditions for this experiment were that the test solution was an anticoagulant and heparin (
Bovine blood containing 5000 units/); anticoagulant) and ACD 50 ml/n was diluted with physiological saline to obtain a Hct of 35%. The air injection amount was 10 tnl.

In Figures 16, 17, and 18, a perpendicular line is drawn from the apex of each wave of the upper integral curve to the horizontal axis coordinate, and the area surrounded by this perpendicular line, the integral curve, and the horizontal axis coordinate is This is the amount of bubbles that could not be captured by the test air trap 39 of the experimental device shown in FIG. 12 and was measured by an integral measuring device connected to the ultrasonic blood flow meter 40. In these three experiments, the 18th
It can be seen that the wave height of the integral curve shown in the figure is small and the wave convergence is the fastest. Therefore, the blood bubble removal device shown in FIG. 12 according to the present invention is different from the conventional device shown in FIGS. 2 and 4, respectively. It was confirmed that the bubble removal ability was higher than that of

(Vl) Effects As explained above, in the blood bubble removal device of the present invention, the inside of the container body is divided into an upper space and a lower space by a filter, and a liquid inlet is connected to the circumference of the upper space in a tangential direction. In the case where there is a bubble outlet in the upper center of the upper space and a liquid outlet communicating with the lower space, the upper part of the vertical section passing through the horizontal center of the upper space defined by the container body is directed toward the center. It has a flat shape with a horizontal to upward slope and a circular planar shape.

Therefore, the blood bubble removal device of the present invention can introduce the blood to be processed into the upper space from the liquid inlet as a swirling flow with the longest filtration path, and remove the air bubbles in the blood from the upper center of the upper space by the buoyant floating action and the centrifugal separation action. It is possible to actively collect air bubbles and discharge them from the outlet, and also to actively promote the separation of air bubbles from the lower layer near the filter body of the blood to be processed that fills the upper space. The trapping of air bubbles by the function has the effect that air bubbles can be sufficiently removed from the treated blood that passes through the filter, passes through the lower space, and reaches the liquid outlet.

According to the device of the present invention, air bubbles are actively collected in the upper center using swirling flow and buoyancy to trap and remove them.In particular, the buoyancy is extremely small and is easily affected by the flow of blood. It has been fully confirmed by the above-mentioned experiment that even easily-prone microbubbles can be effectively captured and removed, and the device has superior bubble removal ability compared to conventional devices. Therefore, the blood bubble removal device of the present invention can effectively remove even minute bubbles from the blood to be processed, thereby making it possible to extremely reduce the amount of bubbles passing through, thereby improving the safety and reliability of the device.

In addition, the device for removing air bubbles in blood of the present invention actively collects and removes air bubbles in the upper center by creating a swirling flow in the blood to be processed, so that the filtration process can be substantially lengthened, compared to conventional devices. It has been confirmed through the above-mentioned experiment that it is possible to downsize the device so that the priming capacity is small, and therefore the amount of extracorporeal circulating blood and the amount of fluid replacement for priming can be reduced. If the size is made to have the same priming capacity as the conventional device without downsizing, the processing capacity will be improved compared to the conventional device, and the removal of microbubbles will be further promoted than when the device is downsized.

Furthermore, the blood bubble removal device of the present invention uses the blood to be treated as a swirling flow and actively collects the bubbles in the blood in the upper center by buoyancy and centrifugation, and is close to the filter body of the blood swirling flow in the upper space. The lower layer is occupied by blood from which air bubbles have been sufficiently removed, which is different from the conventional system in which air bubbles are captured by a filter;
Even if a filter body made of a porous material with a pore size of around 0μ is used, microbubbles with a diameter of 0.1W or less can be removed effectively, and the safety and reliability of the device will not be compromised.
If a filter with a diameter of around 60μ is used, there is no risk of blood invasion such as destruction of platelets or red blood cells, and the pressure loss in the filter is significantly reduced compared to conventional methods, which in turn improves the performance of the device.
It has the effect of becoming the top.

Further, as an embodiment of the present invention, when the container body has a shape that envelops the circumference of the upper space from above, below, and from the outside so that the circumferential part of the upper space is not demarcated by the filter, the filter can be used to form air bubbles of the swirling blood flow. Facing the central lower layer where removal has been sufficiently promoted, there are fewer microbubbles passing through the filter, and the bubble removal ability is even higher.Also, the liquid inlet is brought closer to the filter, making the upper space thinner, reducing the priming volume and downsizing the device. It has the effect of being able to be converted into

[Brief explanation of the drawing]

1 and 2 are longitudinal sectional front views of a conventional filter type blood bubble removal device, FIG. 3 is a longitudinal sectional front view of a conventional blood retention type blood bubble removal device, and FIG. 4 is a 61) FIG. 4(b) is a front view of a main part of the same device, and FIG. 5 is a preferable one of the present invention. FIG. 6 is a vertical sectional front view of a blood bubble removing device according to an embodiment, FIG. 6 is a sectional view taken along VI-VI of the same as above, and FIG. Figure 8 is a sectional view taken along the line ■--■, and Figures 9, 1(), and 11 are longitudinal sectional front views of blood bubble removal devices according to second, third, and fourth modifications of the present invention, respectively. 12 is an experimental device for confirming the technical effects of the present invention, and FIG. 13 is a longitudinal sectional view of an observation air trap prototyped for use in the above device. FIGS. 14 and 15 are diagrams obtained using an ultrasonic blood flow meter when experiments were conducted on the bubble removal effect using the conventional device and the device of the present invention using the experimental device shown in FIG. 12. FIGS. 16, 17, and 18 show the ultrasonic blood flow meter and the integral measuring device connected to it for the conventional device and the device of the present invention in experiments using the experimental device shown in FIG. 12.
It is an ear graph. 5...Container main body, U...upper space, n...lower space', a...filter body, 4...liquid inlet, I
...bubble outlet, 31...liquid outlet. Patent Applicant: Terumo Co., Ltd. Agent, Patent Attorney Hiroshi Ohnuma Figure 7 Figure 8 Figure 4 Figure 10 Figure No. 12 Figure 14 Figure 3 and λ Rebelling Master

Claims (1)

[Claims] 1. A container body, a filter body made of a porous body provided so as to divide the container body into an upper space and a lower space, and a filter body configured to communicate with the upper space in the container body. a liquid inlet provided in the container body to allow the liquid to be treated to be introduced into the upper space as a swirling flow relative to the filter body; and a liquid inlet provided in the container body to communicate with the lower space to send the treated blood passing through the filter body. A blood bubble removal device comprising: a liquid outlet for removing air bubbles separated in the upper space; and a bubble outlet for removing air bubbles separated in the upper space, the air bubble outlet being provided in the container body so as to communicate with the upper center of the upper space; The formed upper space has a flat shape in which an upper side portion of a vertical cross-sectional shape passing through the center of the plane of the upper space is horizontal or slopes upward toward the center, and has a substantially circular planar shape. , medium bubble removal device. 2. Claim 1, wherein the container body has a shape that wraps around the circumferential portion of the upper space from above, below, and outward so that the circumferential portion of the upper space is not defined by the filter body. The blood bubble removal device described.