JP7310153B2 - Oxygenator - Google Patents

Description

TECHNICAL FIELD The present invention relates to an oxygenator that removes carbon dioxide contained in blood and adds oxygen to it.

In surgeries performed after the patient's heart has been stopped, such as cardiac surgery, a heart-lung machine is used to replace the function of the stopped heart and lungs. In this artificial heart-lung circuit, the oxygenator plays the role of the lungs.

The oxygenator disclosed in Patent Document 1 includes a housing and a gas exchanger. The housing has a cylindrical shape and is closed at both ends by headers. Further, the housing is arranged upright so that each header is positioned above and below, and the gas exchanger is accommodated therein. A gas exchanger consists of a bundle and a tubular core, and is constructed by winding the bundle around the tubular core. In such an oxygenator, an annular blood passage is formed between the housing and the tubular core.

A diffusing portion is formed at the upper end of the tubular core, and the diffusing portion diffuses the blood introduced into the tubular core into the blood passageway. A bundle wound around a tubular core is interposed in the blood passageway. The bundle is configured by arranging a plurality of hollow fibers in a belt shape, and gaps are formed between adjacent hollow fibers, and the diffused blood advances to the discharge port through the gaps. In addition, the hollow fibers have oxygen flowing through them, and remove carbon dioxide and add oxygen to the blood in contact with the hollow fibers.

Japanese Patent Publication No. 11-508476

The oxygenator described in Patent Document 1 is of a so-called vertical type, but other than such an oxygenator, the following oxygenator has also been developed. That is, it is a horizontal-type oxygenator in which the housing is laid down horizontally. In a horizontal-type oxygenator, the gas exchanger is also horizontally oriented within the housing, and the annular blood passage extends horizontally. Blood flows through this blood passage, and air bubbles may be carried along with this blood.

Such air bubbles are basically absorbed when they come into contact with the hollow fibers, and most of them are removed. However, when a large amount of air bubbles are brought along with the blood, the hollow fibers may not be able to absorb them sufficiently. In that case, the air bubbles that are not absorbed float in the housing toward the ceiling and accumulate near the ceiling. And, if the air bubbles accumulate excessively, they can be carried towards the outlet by the blood flow.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide an oxygenator that can suppress excessive accumulation of air bubbles while removing air bubbles carried by blood.

The oxygenator according to the present invention comprises a cylindrical housing with both ends closed, a blood inflow port and a blood outflow port, and a housing arranged with its axis oriented laterally; a gas exchanger for exchanging gas with the blood on the way from the blood inflow port to the blood outflow port; and a gas guide section for directing the passing gas to the gas exchanger again.

With such a configuration, the gas that has not been absorbed even after passing through the gas exchanger in the oxygenator is directed to the gas exchanger again, so more bubbles can be absorbed by the gas exchanger. . Therefore, it is possible to suppress excessive accumulation of air bubbles while removing the air bubbles in the housing.

In addition, in the oxygenator, the gas exchanger has a columnar shape with its axis oriented laterally in the housing, and the gas guide section extends from the gas exchanger to the blood outflow port. It has a rectifying surface provided across the flow path toward the direction of A first rectifying surface is provided, and is inclined such that a downstream portion thereof is closer to the outer peripheral surface of the gas exchanger than an upstream portion thereof in a blood flow direction; A second straightening surface may be provided which is closer to the outer peripheral surface of the gas exchanger than the upstream portion of the straightening surface and has a different inclination than the first straightening surface.

In this case, on the first rectifying surface in the lower portion of the gas guide section, the air bubbles received in the upstream portion approach the outer peripheral surface of the gas exchanger as they move toward the downstream portion along the blood flow. . Also, the air bubbles received by the first rectifying surface float in the blood and approach the outer peripheral surface of the gas exchanger as they move upward toward the second rectifying surface. Therefore, according to the above configuration, it is possible to make the bubbles exit the gas exchanger, reach the gas guide portion, and be directed to the gas exchanger again.

Further, a filter may be provided on the rectifying surface.

With such a configuration, foreign matter can be removed from the blood received by the rectifying surface.

Further, in the oxygenator, an opening may be formed in the first rectifying surface, and a filter may be provided in the opening.

With such a configuration, foreign matter can be removed from the blood exiting the oxygenator through the blood outflow port. In addition, since the filter is provided on the lower first rectifying surface rather than on the second rectifying surface on which air bubbles tend to gather, it is possible to prevent air bubbles from passing through the filter.

Further, in the oxygenator, the second rectifying surface is separated from the outer peripheral surface of the gas exchanger by a predetermined distance, and the second rectifying surface is positioned between the second rectifying surface and the outer peripheral surface of the gas exchanger. , a gas reservoir may be formed.

With such a configuration, bubbles floating along the rectifying surface can be brought into contact with the outer peripheral surface of the gas exchanger before reaching the second rectifying surface, and when a large amount of bubbles flow, can be temporarily stored in the gas reservoir, which is the space between the second straightening surface and the outer peripheral surface of the gas exchanger. Furthermore, when a certain amount of air bubbles is accumulated in the gas reservoir, the air bubbles can be drawn into the hollow fiber membrane and degassed.

Further, in the oxygenator, at least the second rectifying surface among the rectifying surfaces may be formed by an inner wall surface of the housing.

With such a configuration, it is possible to improve the accuracy of alignment between the second rectifying surface and the outer peripheral surface of the gas exchanger during assembly.

Moreover, in the oxygenator, the blood outflow port may be provided with a filter.

With such a configuration, foreign matter can be removed from the blood at the blood outflow port.

In the oxygenator, the filter may have a columnar shape with a dimension in the blood flow direction of the blood outflow port that is larger than an inner diameter dimension of the blood outflow port.

With such a configuration, the volume of the filter can be increased, so foreign matter can be more reliably removed from the blood.

Further, the oxygenator may have a bubble trap part downstream of the gas reservoir part.

With such a configuration, even if there are bubbles that have been added to the filter, they can be trapped again in the gas reservoir.

Moreover, in the oxygenator, the bubble trap section may have an air vent port.

With such a configuration, the gas accumulated in the gas reservoir can be discharged to the outside through the air vent port.

The oxygenator according to the present invention comprises a cylindrical housing with both ends closed, a blood inflow port and a blood outflow port, and an axial center thereof directed in the lateral direction; a gas exchanger disposed in the blood flow port to perform gas exchange with the blood on the way from the blood inflow port to the blood outflow port; and a rectifying frame having a filter and provided around the gas exchanger. and a gas reservoir provided between the straightening frame and the gas exchanger, wherein the gas reservoir is located above the housing and faces the gas exchanger.

With such a configuration, the bubble reservoir is located on the upper side of the housing and faces the gas exchanger so as to be adjacent to it. Therefore, as bubbles accumulate in the space inside the bubble reservoir, the bubbles can eventually come into contact with the gas exchanger and be taken into the gas exchanger. As a result, it is possible to suppress excessive accumulation of air bubbles in the air bubble reservoir.

Moreover, in the oxygenator, the gas reservoir may include the inner peripheral surface of the straightening frame and the outer peripheral surface of the gas exchanger.

Moreover, in the oxygenator, the rectifying frame may have an inclined rectifying surface adjacent to the gas exchanger.

With such a configuration, the inclined rectifying surface of the rectifying frame allows the gas in the gas reservoir to be smoothly introduced into the gas exchanger and taken in.

According to the present invention, it is possible to provide an oxygenator that can suppress excessive accumulation of air bubbles carried by blood.

FIG. 1 is a front view showing the appearance of the oxygenator of this embodiment. FIG. 2 is a front cross-sectional view of the oxygenator of FIG. 1. FIG. 3 is a perspective view of a straightening frame provided in the oxygenator of FIG. 1. FIG. FIG. 4 is a partial cross-sectional view showing a straightening frame of an oxygenator according to Embodiment 2. FIG. FIG. 5 is a partial cross-sectional view showing a blood outflow port of an oxygenator according to Embodiment 3. FIG.

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of an oxygenator according to the present invention will be described below with reference to the drawings. The oxygenator described below is merely one embodiment of the present invention, and the present invention is not limited to this embodiment, and additions, deletions, and modifications can be made without departing from the scope of the present invention. .

(Embodiment)
FIG. 1 is a front view showing the appearance of an oxygenator 1 of this embodiment, and FIG. 2 is a front cross-sectional view of the oxygenator 1 of FIG. The oxygenator 1 shown in FIGS. 1 and 2 is used to replace the function of the patient's lungs in surgery performed while the patient's heart is stopped. Therefore, the oxygenator 1 has a gas exchange function to remove carbon dioxide contained in the patient's blood and add oxygen to it, and a heat exchange function to adjust the temperature of the blood. The oxygenator 1 having such functions has a so-called horizontal type configuration, and includes a housing 2 , an inner cylinder 3 and a middle cylinder 4 .

The housing 2 is formed in a substantially cylindrical shape with both ends closed, and has an internal space 2a (see FIG. 2) for accommodating the inner cylinder 3 and the middle cylinder 4 therein. Specifically, the housing 2 has a housing body 11 , a hanging portion 13 and two cap portions 14 and 15 .

The housing main body 11 is formed in a substantially cylindrical shape, and has a suspending portion 13 on its upper outer peripheral surface. The hanging portion 13 is arranged in the central portion of the housing body 11 in the direction of the axis 11 a and extends radially outward from the upper outer peripheral surface of the housing body 11 . The suspending portion 13 is formed, for example, in a substantially columnar shape, and its tip side portion is attached to an external suspending device (not shown) so as to be suspended. Therefore, the housing body 11 can be hung via the hanging portion 13, and the suspended housing body 11 is configured so that its axis 11a extends in the horizontal direction.

The housing body 11 has open ends on both sides in the direction of the axis 11a. Among them, the opening end on one side (the left side in FIG. 2) is closed by the cap portion 14 and the opening end on the other side (the right side in FIG. 2) is closed by the cap portion 15 . These cap portions 14 and 15 are formed in a substantially disk shape. For convenience of explanation, the side where the cap portion 14 is positioned is defined as the left side in the direction of the axis 11a of the housing body 11, and the side where the cap portion 15 is positioned is defined as the right side.

As shown in FIG. 1, a gas supply port 18 is formed in the cap portion 14 . The gas supply port 18 is formed in a substantially cylindrical shape and protrudes leftward in the direction of the axis 11a from the vicinity of the outer peripheral edge of the cap portion 14 . The gas supply port 18 is connected to an external gas supply device (not shown) through a gas supply tube, and gas containing oxygen supplied from the gas supply device is supplied from the gas supply port 18 into the housing 2 . led to.

On the other hand, a gas discharge port 19 is formed in the cap portion 15 . The gas discharge port 19 is formed in a substantially cylindrical shape and protrudes from the vicinity of the outer peripheral edge of the cap portion 15 to the right in the direction of the axis 11a. This gas discharge port 19 is connected to an external gas supply device via a gas discharge tube, and the gas supplied from the gas supply port 18 into the housing 2 is discharged and returned to the gas supply device. It has become.

A blood inflow port 16 is formed in the vicinity of the central axis of the cap portion 14 (an axis substantially coinciding with the axis 11a of the housing body 11). The blood inflow port 16 is formed in a substantially cylindrical shape and protrudes obliquely downward to the left from the lower side of the central axis of the cap portion 14 . A venous blood tube (not shown) is connected to the blood inflow port 16 , and venous blood is introduced into the housing body 11 via the venous blood tube and the blood inflow port 16 .

On the other hand, a blood outflow port 17 is formed at the lower part of the outer peripheral surface of the housing body 11 (the part on the opposite side of the hanging part 13) and on the left side of the center of the oxygenator 1 in the direction of the axis 11a. It is More specifically, the blood outflow port 17 includes a port attachment portion 17a and a port body portion 17b. Among them, the port mounting portion 17a is formed in a substantially cylindrical shape, is provided at the lower portion of the outer peripheral surface of the housing body 11, and protrudes downward. The port body portion 17b is inserted into the port attachment portion 17a from below. The port body portion 17b is formed in a substantially cylindrical shape, protrudes downward from the lower end of the port attachment portion 17a, and bends obliquely downward at its tip. An arterial blood tube (not shown) is connected to the blood outflow port 17 (port body portion 17b), and the arterial blood generated in the oxygenator 1 is delivered to the outside through the arterial blood tube.

A medium inflow port 20 and a medium outflow port 21 are provided in the cap portion 15 . The medium inflow port 20 and the medium outflow port 21 are vertically spaced apart from each other with the central axis of the cap portion 15 interposed therebetween. The two ports 20 and 21 do not necessarily need to be separated vertically, but may be arranged horizontally. The two ports 20 and 21 are generally cylindrical and protrude from the cap portion 15 to the right in the direction of the axis 11a. The medium inflow port 20 is connected to a medium supply tube (not shown) and guides a heat medium such as hot water or cold water from the medium supply tube into the housing 2 . The medium outflow port 21 is connected to a medium discharge tube (not shown), and discharges the heat medium inside the housing 2 to the outside of the housing 2 through the medium discharge tube.

The inner cylinder 3 and the middle cylinder 4 are coaxially housed in the internal space 2a of the housing 2, and these form a heat exchange chamber 3c, a gas exchange chamber 45, and the like.

The middle tube 4 has an outer diameter smaller than the inner diameter of the housing main body 11 and is arranged with respect to the housing main body 11 so that their axial centers coincide with each other. As a result, an annular space is formed between the outer peripheral surface of the middle cylinder 4 and the inner peripheral surface of the housing body 11 , and this annular space forms a gas exchange chamber 45 . A hollow fiber body (gas exchanger) 43 is provided in the gas exchange chamber 45 .

The hollow fiber body 43 is formed in a substantially cylindrical shape (or a columnar shape having an internal space) and is composed of a plurality of hollow fibers. Specifically, the hollow fiber body 43 is constructed by winding a mat-like hollow fiber membrane (bundle) formed by laminating a plurality of intersecting hollow fibers around the outer peripheral surface of the middle tube 4. . The hollow fiber membrane is wound until the thickness of the hollow fiber body 43 substantially matches the gap between the middle tube 4 and the housing body 11 . That is, the hollow fiber body 43 is formed along the inner peripheral surface of the housing main body 11 so that the outer peripheral surface thereof contacts substantially the entire inner peripheral surface of the housing main body 11 .

An annular sealing member 50 is provided in the left region of the gas exchange chamber 45 . The seal member 50 forms a gas inflow space 52 together with the inner peripheral surface of the cap portion 14 , and the gas supply port 18 communicates with the gas inflow space 52 . An annular seal member 51 is provided in the right region of the gas exchange chamber 45 . The seal member 51 forms a gas outflow space 53 together with the inner peripheral surface of the cap portion 15 , and the gas discharge port 19 communicates with the gas outflow space 53 .

The hollow fiber body 43 is provided in a state of being sandwiched between the sealing member 50 and the sealing member 51 from the left and right. The seal member 50 seals between the middle cylinder 4 and the housing 2 on the left side of the gas exchange chamber 45 over the entire circumference. In addition, the seal member 51 seals the space between the middle tube 4 and the housing 2 on the right side of the gas exchange chamber 45 over the entire circumference. With such a configuration, the gas inflow space 52 communicating with the gas supply port 18 and the gas outflow space 53 communicating with the gas discharge port 19 are interconnected via the inner holes of the hollow fibers forming the hollow fiber body 43 . are in communication with each other.

In the hollow fiber body 43 , gaps are provided between each of the plurality of hollow fibers constituting the hollow fiber body 43 , and in the gas exchange chamber 45 , blood flows through these gaps. Specifically, the blood introduced to the gas exchange chamber 45 passes through the gaps in the hollow fiber body 43 and flows from the right side to the left side in the direction of the axis 11a while touching the hollow fibers. An oxygen-rich gas is passed through the inner hole of the hollow fiber from an external gas supply device via the gas supply port 18 and the gas inflow space 52 . Therefore, when blood with a high concentration of carbon dioxide comes into contact with the hollow fiber, gas exchange takes place between the blood and the gas inside the hollow fiber. This removes carbon dioxide from the blood and oxygenates the blood. Thus, the blood flows leftward in the direction of the axis 11a in the gas exchange chamber 45 while gas exchange is performed. On the other hand, the gas passing through the inner hole of the hollow fiber flows to the right while gas exchange is performed, and returns to the external gas supply device through the gas outflow space 53 and the gas discharge port 19 .

Here, the downstream (left) portion of the gas exchange chamber 45 is radially outwardly enlarged compared to the remaining portion. Specifically, as shown in FIG. 2, an annular recess 54 is formed in the inner peripheral surface of the left portion of the housing body 11 so as to be recessed radially outward. The left portion of the concave portion 54 has a substantially constant diameter, while the right portion tapers toward the right and is formed in a tapered shape. The seal member 50 is arranged in the central portion of the recess 54, and the portion of the recess 54 on the right side of the seal member 50 is tapered as described above. An outer peripheral space 55 formed between the recess 54 and the hollow fiber body 43 is formed around the hollow fiber body 43 and communicates with the blood outflow port 17 at the bottom. With such a configuration, the blood gas-exchanged in the gas exchange chamber 45 flows into the blood outflow port 17 after being guided to the outer peripheral space 55 .

A ring-shaped rectifying frame 56 is provided in the outer peripheral space 55 along the outer peripheral space 55 . The rectifying frame 56 guides the air bubbles carried with the blood flowing through the gas exchange chambers 45 while exchanging gas to return to the hollow fiber bodies 43 and incorporates them into the hollow fibers, which will be described later in detail.

An air vent port 57 is provided in the upper portion of the housing body 11 to communicate the outer peripheral space 55 with the outside. The air vent port 57 discharges air bubbles accumulated in the upper portion (bubble trap portion) of the outer peripheral space 55 to the outside. The bubble trap section is provided downstream of the gas reservoir section 70, which will be described later, and is provided so as to be able to store bubbles. In this embodiment, such a bubble trap portion is constituted by the recess 54 (in particular, the portion of the recess 54 above the hollow fiber body 43). The outer open end of the air vent port 57 is basically covered with a cap member (not shown) to prevent air bubbles and blood from being discharged from the air vent port 57 except when air bubbles are discharged. ing.

By the way, the middle cylinder 4 described above has a middle cylinder body portion 40 and a bridge portion 41 . The middle cylinder main body 40 is a part that forms a cylindrical shape and forms the above-described gas exchange chamber 45 on the outside thereof, and accommodates the inner cylinder 3 that forms the heat exchange chamber 3c in the inner space. The bridge portion 41 forms a heat medium channel for a heat medium entering and exiting the heat exchange chamber 3c and a blood channel for blood traveling from the heat exchange chamber 3c to the gas exchange chamber 45, which intersect three-dimensionally. do.

As shown in FIG. 2, a tube group 32 is inserted into the heat exchange chamber 3c in the inner cylinder 3 so that the axial direction of the tube group 32 is aligned with the axial direction of the inner cylinder 3. As shown in FIG. The tube bank 32 is an assembly of multiple heat exchange pipes. Each heat exchange pipe is a long, small-diameter tube made of a material with high thermal conductivity such as stainless steel, and blood from the blood inflow port 16 flows in from the left opening.

The inner cylinder 3 has an outer diameter smaller than the inner diameter of the middle cylinder 4 and is positioned with respect to the middle cylinder 4 so that their axes are aligned with each other. As a result, between the outer peripheral surface of the inner cylinder 3 and the inner peripheral surface of the middle cylinder 4, an annular heat medium chamber 35 through which the heat medium flows is formed. The heat medium chamber 35 is partitioned into a first heat medium compartment 33 on the upper side and a second heat medium compartment 34 on the lower side. The upper first heat medium compartment 33 communicates with the medium outlet port 21 through the heat medium flow path of the bridge portion 41 . The second heat medium compartment 34 on the lower side communicates with the medium inflow port 20 via another heat medium flow path of the bridge portion 41 .

As shown in FIG. 2, inside the inner cylinder 3, a pair of disk-shaped tube supports 32a, 32a are provided. The outer diameter of the tube support 32a substantially matches the inner diameter of the inner cylinder 3. As shown in FIG. The left tube support 32 a is inserted through the left end of the inner cylinder 3 , and the right tube support 32 a is inserted through the right end of the inner cylinder 3 . Each heat exchange pipe constituting the tube group 32 has its left end inserted through each of a plurality of holes radially arranged in the left tube support 32a, and its right end passes through the right tube support. It is inserted through each of a plurality of holes radially arranged in 32a.

As a result, the open ends on both sides of the inner cylinder 3 are sealed by the pair of pipe supports 32a, and both ends of the heat exchange pipes of the tube group 32 are open to both ends of the inner cylinder 3. . The left opening of the heat exchange pipes of the tube group 32 communicates with the blood inflow port 16 , and the right opening communicates with the gas exchange chamber 45 via the blood flow path of the bridge portion 41 .

A plurality of through holes are formed in the upper portion and the lower portion of the inner cylinder 3, respectively. In the inner cylinder 3, the inside of the inner cylinder 3 communicates with the upper first heat medium compartment 33 through the upper through hole, and the inside of the inner cylinder 3 and the lower heat medium compartment 33 communicate with the lower through hole. It communicates with the second heat medium compartment 34 . Therefore, the heat medium flowing in from the medium inflow port 20 enters the inner cylinder 3 (heat exchange chamber 3c) from the lower second heat medium compartment 34, passes through the gaps between the heat exchange pipes of the tube group 32, and then It flows out from the medium outflow port 21 through the upper first heat medium compartment 33 .

In such an oxygenator 1, venous blood drawn from a vein enters the housing 2 through the blood inflow port 16 and enters the heat exchange chamber 3c through the left opening of the heat exchange pipes of the tube group 32. As shown in FIG. The blood in the heat exchange chamber 3c enters the gas exchange chamber 45 from the right side through the bridge portion 41 from the right opening of the heat exchange pipe, flows leftward through the gas exchange chamber 45, and is sent out from the blood outflow port 17. .

During this time, in the heat exchange chamber 3 c , heat exchange takes place between the heat medium flowing through the second heat medium compartment 34 from the medium inflow port 20 and the blood flowing through the heat exchange pipes of the tube group 32 . In the gas exchange chamber 45, gas exchange takes place between the blood flowing through the gaps of the hollow fibers 43 and the oxygen-rich gas passing through the inner holes of the hollow fibers. In this way, the blood that has flowed into the oxygenator 1 is adjusted to a predetermined temperature, has its carbon dioxide reduced and is oxygenated, and flows out from the blood outflow port 17 as arterial blood.

By the way, the oxygenator 1 is of a horizontal type, and the blood flowing through the gas exchange chamber 45 is configured to flow in a substantially horizontal direction. The blood flowing through the gas exchange chamber 45 may be mixed with a small amount of air bubbles entering from any part. Such air bubbles are basically absorbed when they come into contact with the hollow fibers of the hollow fiber body 43, and most of them are removed. However, while the blood passes through the hollow fiber body 43 once, it may not be sufficiently absorbed into the hollow fiber. Therefore, the oxygenator 1 according to the present embodiment includes the straightening frame 56 so that the hollow fiber body 43 can absorb more air bubbles.

FIG. 3 is a perspective view of the straightening frame 56 provided in the oxygenator 1. FIG. The rectifying frame 56 serves as a gas guiding portion that directs the gas that has passed through the hollow fiber bodies 43 without being absorbed by the blood flow toward the hollow fiber bodies 43 again. As shown in FIG. 3, the straightening frame 56 has a substantially annular shape and a substantially truncated cone shape.

Specifically, the straightening frame 56 has a left first opening 60 with a relatively small diameter and a right second opening 61 with a relatively large diameter. Both the first opening 60 and the second opening 61 are circular. When the rectifying frame 56 is assembled to the oxygenator 1, the upper end 60b of the first opening 60 and the upper end 61b of the second opening 61 are substantially at the same position in the vertical direction. The lower end 60c of the second opening 61 is located above the lower end 61c. The first opening 60 and the second opening 61 are separated from each other by a predetermined distance in the left-right direction. ing. Therefore, the straightening frame 56 has a truncated cone shape in which the center line 60 a of the first opening 60 is positioned above the center line 61 a of the second opening 61 .

As shown in FIG. 2, the rectifying frame 56 is configured such that the left first opening 60 is fixed to the seal member 50 in the outer peripheral space 55 and the right second opening 61 is in contact with the inner peripheral surface of the housing body 11 . It's set up. As a result, the rectifying surface 62 is provided across the flow path from the gas exchange chamber 45 toward the blood outflow port 17 in the outer space 55 . The straightening surface 62 is provided so as to face the outer peripheral surface of the hollow fiber body (gas exchanger) 43 and surround the hollow fiber body 43 . As shown in FIG. 2, the upper portion of the rectifying frame 56 is positioned substantially directly below the opening of the air vent port 57 on the side of the outer peripheral space 55, and the lower portion of the rectifying frame 56 is positioned on the side of the outer peripheral space 55 of the blood outflow port 17. located almost directly above the opening of the

Further, the straightening surface 62 has a first straightening surface 63 and a second straightening surface 64 . Of these, the first rectifying surface 63 is provided relatively downward, and a downstream portion (left portion in FIG. 2) 63b in the blood flow direction is hollow compared to an upstream portion (right portion in FIG. 2) 63a. It is inclined so as to be close to the outer peripheral surface of the thread body 43 . Also, one or more openings 65 are formed in the first rectifying surface 63 , and filters 66 are provided in the openings 65 . The filter 66 provided on the first rectifying surface 63 is separated from the outer peripheral surface of the hollow fiber body 43 and faces upstream in the blood flow direction. 66 to blood outflow port 17; This filter 66 removes a predetermined foreign substance mixed in the blood passing therethrough, and a known blood filter can be used.

On the other hand, the second straightening surface 64 is provided relatively upward. The second rectifying surface 64 is positioned closer to the outer peripheral surface of the hollow fiber body 43 than the upstream portion 63a of the first rectifying surface 63, and has an inclination different from that of the first rectifying surface 63 with respect to the outer peripheral surface. have. In this embodiment, the second rectifying surface 64 forms a surface substantially parallel to the outer peripheral surface of the hollow fiber body 43 . However, the second rectifying surface 64 is also located apart from the outer peripheral surface of the hollow fiber body 43, and as shown in FIG. is formed with a gas reservoir 70 . Note that no filter is provided on the second rectifying surface 64 .

In the rectifying frame 56 according to the present embodiment, when the rectifying surface 62 is divided into a total of four areas, that is, upper and lower parts and a part between them, filters 66 are provided in the three areas excluding the upper part. shows an example. However, the position where the filter 66 is provided is not limited to this. The filter 66 can be provided at an appropriate position and range except for the upper second rectifying surface 64 .

In the oxygenator 1 having such a straightening frame 56 , the blood that has passed through the hollow fiber body 43 of the gas exchange chamber 45 passes through the filter 66 of the straightening frame 56 toward the blood outflow port 17 . At this time, air bubbles mixed in the blood are received by the straightening surface 62 of the straightening frame 56 . The air bubbles flow from the upstream portion 63a toward the downstream portion 63b along the first straightening surface 63, or rise due to buoyancy. As a result, the air bubbles approach the hollow fibers 43 in the process of moving from the upstream portion 63a to the downstream portion 63b of the first rectifying surface 63, and rise from the first rectifying surface 63 to the second rectifying surface 64 due to the buoyant force. It approaches the hollow fiber body 43 also in the process of doing. Therefore, in the oxygenator 1 , the rectifying frame 56 can direct the air bubbles contained in the blood that have once passed through the hollow fiber bodies 43 toward the hollow fiber bodies 43 , where they can be absorbed by the hollow fiber bodies 43 . .

The oxygenator 1 also has a gas reservoir 70 between the second rectifying surface 64 and the outer peripheral surface of the hollow fiber body 43 . Therefore, even if a large amount of air bubbles flow, it is possible to temporarily store the air bubbles in the gas reservoir 70 . While the first rectifying surface 63 mainly has the function of guiding (directing) bubbles to the hollow fiber body 43, the second rectifying surface 64 temporarily stores the guided bubbles and It has a function of contacting the hollow fiber body 43 . Therefore, the second straightening surface 64 does not have to be exactly parallel to the outer peripheral surface of the hollow fiber body 43 .

(Embodiment 2)
FIG. 4 is a cross-sectional view showing a straightening frame 56A of an oxygenator 1A according to Embodiment 2. As shown in FIG. More specifically, (a) of FIG. 4 is a cross-sectional view of a portion of the oxygenator 1A including the entire rectifying frame 56A, and (b) is a portion of the oxygenator 1A including the upper portion of the rectifying frame 56A. It is a sectional view. The straightening frame 56A of the oxygenator 1A has a second straightening surface 64A at least partially formed by the inner wall surface of the housing body 11. As shown in FIG.

That is, in the first embodiment, the rectifying frame 56 as a whole is configured independently of the housing body 11 as a separate body. However, the rectifying frame 56 is not limited to such a configuration. Specifically, in the oxygenator 1A shown in FIG. 4(b), a wall portion 71 extends from the upper right end of the concave portion 54 of the housing body 11 into the outer peripheral space 55 along the outer peripheral surface of the hollow fiber body 43. is set. An inner peripheral surface 71A of the wall portion 71 forms (a part of) the rectifying surface 62A, and in particular, the upper portion of the inner peripheral surface 71A forms a second rectifying surface 64A.

Further, as shown in FIG. 4(a), the straightening frame 56A has substantially the same width dimension in the left-right direction from the top to the bottom when viewed from the front. The wall portion 71 has a leftward protrusion dimension that decreases from the top to the bottom, and a remaining portion 72 of the rectifying frame 56A other than the portion constituted by the wall portion 71 is separate from the housing body 11. It is made up of body parts. A structure corresponding to the first rectifying surface 63 of Embodiment 1 is mainly formed in the remaining portion 72 , and the filter 66 is also provided in an opening (not shown) formed in the remaining portion 72 .

In the example of FIG. 4(a), the boundary between the portion of the rectifying frame 56A constituted by the wall portion 71 and the remaining portion 72 is set as a boundary line extending in the circumferential direction. It is not limited to this and can be set arbitrarily. Moreover, not only a part of the rectifying frame 56A may be configured by the wall portion 71, but the entire rectifying frame 56A (excluding the filter 66) may be configured by the wall portion 71.

With such a configuration, it is possible to more easily and accurately align the second rectifying surface 64A and the outer peripheral surface of the hollow fiber body 43 when assembling the oxygenator 1A.

(Embodiment 3)
FIG. 5 is a cross-sectional view showing the blood outflow port 17 of the oxygenator 1B according to the third embodiment. Here, a configuration in which a filter is provided at a different location in place of or in addition to the filter 66 of the rectifying frames 56 and 56A shown in the first and second embodiments will be described.

The blood outflow port 17 shown in FIG. 5(a) has a port attachment portion 17a and a port body portion 17b, as in the first and second embodiments. On the other hand, in the port attachment portion 17a, a plate-like filter 66A is provided at the opening on the inner side of the housing body 11 so as to cover the opening. The periphery of the filter 66A may be fixed by a fixing member that is different from the filter 66A and fixes the filter 66A to the housing.

Also, the blood outflow port 17 shown in FIG. 5(b) has a port attachment portion 17a and a port body portion 17b as in the first and second embodiments. On the other hand, a columnar filter 66B is provided inside the port attachment portion 17a. The filter 66B has an outer diameter substantially equal to the inner diameter of the port mounting portion 17a, and is inserted so as to be in contact with the inner peripheral surface of the port mounting portion 17a with substantially no clearance. Filter 66B is configured such that the dimension in the blood flow direction at blood outflow port 17 is larger than the inner diameter dimension of blood outflow port 17 .

Such filters 66A and 66B can remove foreign substances from the blood at the blood outflow port 17 . In addition, since the filter 66B shown in FIG. 5B can easily secure a large volume, it is possible to remove more foreign matter from the blood.

INDUSTRIAL APPLICABILITY The present invention can be applied to an oxygenator that removes carbon dioxide contained in blood and adds oxygen to it.

1 oxygenator 2 housing 20 blood inflow port 21 blood outflow port 43 hollow fiber body (gas exchanger)
54 concave portion (bubble trap portion)
56 rectification frame (gas induction part)
62 rectifying surface 63 first rectifying surface 64 second rectifying surface 66 filter 66A filter 66B filter 70 gas reservoir

Claims (14)

a housing having a cylindrical shape with both ends closed, having a blood inflow port and a blood outflow port, and arranged with its axis directed in the lateral direction;
a gas exchanger disposed within the housing for performing gas exchange with the blood on its way from the blood inflow port to the blood outflow port;
a gas guide section for directing the gas that has passed through the gas exchanger along with the flow of blood to the gas exchanger again in the housing;
with
The gas guide section has a rectifying surface provided across a flow path from the gas exchanger to the blood outflow port, and the rectifying surface faces the outer peripheral surface of the gas exchanger. An oxygenator installed around a gas exchanger. the gas exchanger has a columnar shape and is arranged in the housing with its axis centered in a lateral direction;
The rectifying surface has a first rectifying surface and a second rectifying surface provided above the first rectifying surface,
the first rectifying surface is inclined with respect to the outer peripheral surface so that a downstream portion thereof is closer to the outer peripheral surface of the gas exchanger than an upstream portion thereof in a blood flow direction;
The second rectifying surface is closer to the outer peripheral surface of the gas exchanger than the upstream portion of the first rectifying surface, and is parallel to the outer peripheral surface of the gas exchanger or inclined at an angle to the outer peripheral surface. is different from the first rectifying surface,
The oxygenator according to claim 1. The oxygenator according to claim 2, wherein the rectifying surface is provided with a filter. 4. The oxygenator according to claim 2, wherein an opening is formed in said first rectifying surface, and said opening is provided with a filter. The second rectifying surface is separated from the outer peripheral surface of the gas exchanger by a predetermined distance, and a gas reservoir is formed between the second rectifying surface and the outer peripheral surface of the gas exchanger. The oxygenator according to any one of claims 2 to 4, wherein The oxygenator according to any one of claims 2 to 5, wherein at least the second rectifying surface among the rectifying surfaces is formed by an inner wall surface of the housing. The oxygenator according to any one of claims 1 to 6, wherein the blood outflow port is provided with a filter. 8. The oxygenator according to claim 7, wherein said filter has a columnar shape whose dimension in the blood flow direction at said blood outflow port is larger than the inner diameter dimension of said blood outflow port. 6. The oxygenator according to claim 5, further comprising a bubble trap part downstream of said gas reservoir part. 10. The oxygenator according to claim 9, wherein said bubble trap section has an air vent port. a housing having a cylindrical shape with both ends closed, having a blood inflow port and a blood outflow port, and arranged with its axis directed in the lateral direction;
a gas exchanger disposed within the housing for performing gas exchange with the blood on its way from the blood inflow port to the blood outflow port;
a rectifying frame having a filter and provided around the gas exchanger;
a gas reservoir provided between the straightening frame and the gas exchanger,
The gas reservoir is located above the housing and faces the gas exchanger,
The rectifying frame has an inclined rectifying surface that is close to the gas exchanger, and the downstream portion of the inclined rectifying surface is closer to the outer peripheral surface of the gas exchanger than the upstream portion in the blood flow direction. ,
Oxygenator. 12. The oxygenator according to claim 11, wherein the gas reservoir includes the inner peripheral surface of the straightening frame and the outer peripheral surface of the gas exchanger. 13. The oxygenator according to claim 11 or 12 , further comprising a bubble trap part downstream of said gas reservoir part. 14. The oxygenator according to claim 13 , wherein said bubble trap section has an air vent port.

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