WO2015046224A1

WO2015046224A1 - Artificial lung with integrated filter and method for producing same

Info

Publication number: WO2015046224A1
Application number: PCT/JP2014/075242
Authority: WO
Inventors: 吉田伸一; 和泉亮平; 泉田秀樹
Original assignee: 株式会社ジェイ・エム・エス
Priority date: 2013-09-24
Filing date: 2014-09-24
Publication date: 2015-04-02
Also published as: JPWO2015046224A1; CN105555333A; JP6135769B2; CN105555333B

Abstract

An artificial lung that is provided with a bundle of hollow fiber membranes (12) loaded in a gas exchange part (3) and a filter (15) loaded in a filter space (14) adjacent to the gas exchange part, wherein a blood channel (4) is formed in such a manner as to transversely pass through the hollow fiber membrane bundle and the filter. At the top end part of the blood channel, an exhaust port (16) for communicating the filter space with the external space is placed. The filter is formed of a sheet-type filtering material (17) having a plurality of parallel pleats (18) and the pleats are oriented in the vertical direction of the blood channel. The filter space is divided into a primary side space (14a) and a secondary side space (14b) by the sheet-type filtering material. The exhaust port is placed at the top end part of the blood channel and provided with exhaust passages (21a, 21b) by which exhausted gases discharged from the primary side and secondary side spaces are output in a state of being separated from each other.

Description

Built-in filter type artificial lung and manufacturing method thereof

The present invention relates to an oxygenator for exchanging gas with respect to blood in extracorporeal circulation, and more particularly to a filter-incorporated oxygenator having a built-in filter device for capturing and discharging foreign substances and bubbles mixed and generated in blood.

In cardiac surgery, an extracorporeal cardiopulmonary circuit for extracorporeal blood circulation is used to stop the patient's heart and perform the breathing and blood circulation functions during that time. The artificial lung constituting the main part of the artificial heart-lung circuit provides a gas exchange function for blood (a function of supplying oxygen to blood and discharging carbon dioxide) in place of a patient's lung. As a structure of the oxygenator, a hollow fiber membrane oxygenator is widely used.

The hollow fiber membrane oxygenator is configured such that a gas containing oxygen and blood flow through a porous hollow fiber membrane, and gas exchange is performed between the blood and the gas. That is, a hollow fiber membrane laminate in which a large number of hollow fiber membranes are laminated is housed in a housing, and a blood flow path that passes across the hollow fiber membrane laminate is formed. When oxygen-containing gas is allowed to flow through the hollow fiber membrane and the blood flowing through the blood flow passage passes through the gaps between the hollow fiber membranes, gas exchange, that is, oxygenation and decarboxylation gas is performed through the hollow fiber membranes.

On the other hand, when using an artificial lung, priming with a priming solution such as physiological saline is performed in advance to remove bubbles and foreign substances from the blood circuit, and to make the hollow fiber membrane of the gas exchange unit compatible with the liquid. After that, it is used for blood circulation. A blood filter device is used to remove bubbles generated during priming and mixed foreign substances. In addition, even after priming, foreign substances and blood clots may be mixed into the circulating blood, so that a blood filter device is often incorporated in the cardiopulmonary circuit.

In general, a blood filter device incorporates a filter formed by folding or winding a sheet-shaped filter medium in a housing, and using the blood flow path in the housing as a blood flow path, when blood passes through the filter medium, It is configured to capture and discharge foreign objects such as bubbles and bubbles. On the other hand, a configuration is also known in which an artificial heart-lung circuit is simplified by being built in and integrated with an oxygenator without providing a blood filter device independently, and a blood filling amount is reduced by shortening a connection tube or the like.

An example of a configuration in which a blood filter function is integrally provided in a hollow fiber membrane oxygenator is disclosed in Patent Document 1, for example. FIG. 13 is a cross-sectional view showing the oxygenator according to the first embodiment of Patent Document 1. As shown in FIG. The artificial lung includes a gas exchange unit 100A configured in the housing 101 and a heat exchange unit 100B configured in the heat exchanger housing 102. The blood that flows in first flows into the heat exchanger 100B, and then flows out through the gas exchange unit 100A.

A cold / hot water port 103 (the other cold / hot water port is hidden) is formed at the lower end of the housing 102 of the heat exchange unit 100B. Further, a blood introduction port 104 is formed in the lower part on the left side of the housing 102. Inside the housing 102, a cylindrical heat exchange body 105 and a cylindrical heat medium chamber forming member (cylindrical wall) 106 disposed along the inner periphery of the heat exchange body 105 are installed. The heat medium flowing in from the cold / hot water port 103 enters a large number of concave portions of the bellows of the heat exchanger 105 and heat exchange is performed with blood flowing on the outer peripheral side of the heat exchanger 105.

The housing 101 has a blood outlet port 107 formed in the lower portion of the side surface on the blood outflow side, a gas port 108 formed in the upper portion, and a gas port 109 and an exhaust port 110 formed in the lower portion. Inside the housing 101, a hollow fiber membrane layer 111 and bubble removing means (consisting of a filter member 112 and an exhaust hollow fiber membrane layer 113) are accommodated. The upper and lower ends of the hollow fiber membrane 111 of the hollow fiber membrane layer 111 are fixed by

partition walls

114 and 115 made of a potting material, respectively. Thus, a blood flow path is formed between the partition wall 114 and the partition wall 115 that passes through the hollow fiber membrane layer 111, the exhaust hollow fiber membrane layer 113, and the filter member 112. The space above the partition wall 114 and below the partition wall 115 is divided by

partition portions

116 and 117.

The exhaust hollow fiber membrane layer 113 is configured by integrating a number of hollow fiber membranes, and has a function of permeating and discharging the gas constituting the bubbles trapped by the filter member 112. The filter member 112 is formed of a substantially rectangular sheet-like member, is provided in contact with the downstream surface of the exhaust hollow fiber membrane layer 113, and covers substantially the entire surface. The filter member 112 captures bubbles in the blood flowing through the blood channel and prevents them from flowing out from the blood outlet port 107. Air bubbles captured by the filter member 112 are discharged from the blood flow path through the exhaust hollow fiber membrane layer 113 and the exhaust port 110.

JP 2007-215992 A

In the artificial lung disclosed in Patent Document 1, when a large amount of air is mixed, the exhaust from the exhaust hollow fiber membrane layer 113 may not be in time, and may flow through the filter member 112 to the blood outlet port 107. There is. Further, since the entire effective area of the filter member 112 needs to be in contact with the exhaust hollow fiber membrane layer 113, the filter shape is limited, and it is difficult to ensure a sufficient filter area (substantially impossible). is there.

That is, in the description of Patent Document 1, it is said that two or more sheets of the artificial lung filter member 112 may be used in an overlapping manner. However, two sheets of blood are sequentially arranged with respect to the blood flow path. It is comprised so that each sheet | seat overlaid above may be passed sequentially. Therefore, although the filter member 112 of Patent Document 1 covers almost the entire downstream surface of the exhaust hollow fiber membrane layer 113, the maximum membrane area of the filter member 112 with respect to the blood flow is that of the blood flow path. The upper limit is the cross-sectional area. For this reason, it is difficult to take a sufficiently large filter membrane area.

It is advantageous to increase the membrane area of the filter member in order to fully exhibit the ability to capture bubbles. That is, having a sufficient membrane area corresponds to a large cross-sectional area of the flow path, substantially lowering the blood flow rate with respect to the membrane surface, and facilitates gas-liquid separation. In addition, if there is a sufficient membrane area, even if some clogging occurs, the influence on the blood flow as a whole can be reduced. However, it is necessary not to increase the cross-sectional area of the blood flow path in order to suppress the blood filling amount to the artificial lung low.

On the other hand, the function of a large filter membrane area to provide sufficient bubble trapping capability, and the ability to effectively discharge trapped bubbles to the outside is necessary to fully demonstrate the ability to remove bubbles from blood. It is.

Accordingly, the present invention provides a filter-embedded artificial lung that allows a substantially sufficiently large filter membrane area to function while suppressing the blood filling amount to be low, and that can effectively discharge trapped bubbles to the outside, and a method for manufacturing the same. The purpose is to provide.

A filter built-in type artificial lung according to the present invention includes a housing forming a gas exchange part and a filter space adjacent to each other, a bundle of a plurality of hollow fiber membranes loaded in the gas exchange part, and a filter space. A filter, a bundle of hollow fiber membranes, a blood flow path provided so as to pass through the filter sequentially, and a gas containing oxygen through the lumen of the hollow fiber membrane are provided in the housing. A gas introduction port, a blood introduction port and a blood outlet port provided on the outer wall of the housing at both ends of the blood flow path, and an exhaust port for communicating the filter space with the external space.

In order to solve the above problems, the filter-embedded artificial lung of the present invention is configured such that the filter is formed of a sheet-like filter medium provided with a plurality of parallel pleats, and the direction of the pleats is the vertical direction of the blood channel. The filter space is separated by the sheet-like filter medium into a primary space on the blood introduction port side and a secondary space on the blood outlet port side, and the exhaust port is connected to the blood flow path. It has an exhaust passage which is arranged at an upper end part and which exhausts exhaust from the primary side space and the secondary side space separately from each other.

A method for producing an oxygenator with a built-in filter according to the present invention is a method for producing an oxygenator having the above-described configuration, wherein the outer peripheral edge of the filter is sealed with a sealing material to form a part of the blood channel. The method includes the steps of producing a filter module, loading the filter module into the filter space, and sealing the outer peripheral edge of the filter module together with the bundle of hollow fiber membranes to form the blood channel.

The step of producing the filter module includes preparing a primary side and secondary side masking block that sandwiches the filter and forms a molding die for molding a sealing portion by the sealing material on an outer peripheral edge thereof. A step of attaching and assembling the primary side and secondary side masking blocks on both sides of the filter, and a mold formed on the outer peripheral edge of the filter by the primary side and secondary side masking blocks; Filling and curing the sealing material, and removing the masking block after the sealing material is cured.

The primary side masking block has a structure in which a group of linear protrusions having a shape corresponding to a valley portion of the pleat facing the primary side space is provided on a substrate, and an outer peripheral edge of the group of linear protrusions The shape of the portion corresponds to the portion belonging to the primary space in the inner wall portion of the blood flow path formed by the sealing material, and the secondary masking block is formed of the pleat facing the secondary space. A group of linear protrusions having a shape corresponding to the valley is provided on the substrate, and the shape of the outer peripheral edge of the group of linear protrusions is the inner wall of the blood flow path formed by the sealing material Among these, in the step of attaching the masking block corresponding to the portion belonging to the secondary side space, each of the linear protrusions is fitted into the valley portion of the pleat.

According to the artificial lung having the above-described configuration, by providing a plurality of pleats, the filter membrane area can be set sufficiently large without being restricted by the cross-sectional area of the blood flow path, and by having the pleats There is a slight increase in blood filling. Further, since the plurality of pleats of the filter are oriented in the vertical direction, the bubbles rise along the pleats in the vicinity of the filter, are easily guided to the exhaust port, and are effectively discharged to the outside. Further, in the exhaust port, the bubbles from the primary side and secondary side spaces are separated and discharged, so that high exhaust ability can be obtained.

Moreover, according to the manufacturing method of the said structure, the process which seals the outer periphery part of the filter which has a pleat by using a primary side and a secondary side masking block, and produces a filter module easily is stabilized. It can be carried out.

FIG. 1 is a perspective view of a hollow fiber membrane oxygenator according to an embodiment of the present invention. FIG. 2 is a cross-sectional view of the oxygenator as viewed from the side. FIG. 3 is a cross-sectional view of the oxygenator as viewed from above. FIG. 4 is a perspective view of a filter included in the oxygenator. FIG. 5 is a perspective view of a filter module formed by sealing the outer peripheral edge of the filter with a sealing material. FIG. 6 is an enlarged cross-sectional view of the upper part of the oxygenator. FIG. 7 is a perspective view showing a section of the filter space 14 of the oxygenator in cross section. FIG. 8 is an enlarged perspective view of a part of FIG. FIG. 9A is a front view showing a specific structure of a filter module included in the artificial lung. FIG. 9B is a bottom view of the filter module. FIG. 9C is a cross-sectional view taken along line AA in FIG. 9A. FIG. 9D (a) is a right side view of the filter module of FIG. 9A, and FIG. 9D (b) is a cross-sectional view taken along line BB of FIG. 9A. FIG. 10 is a front view showing a primary masking block for producing the filter module by insert molding. FIG. 10B is a bottom view of the primary side masking block of FIG. 10A. FIG. 10C is a right side view of FIG. 10A. FIG. 11A is a front view showing a secondary masking block for producing the filter module by insert molding. FIG. 11B is a bottom view of the secondary masking block of FIG. 11A. FIG. 11C is a right side view of FIG. 11A. FIG. 12A is a front view showing a state in which the primary side and secondary side masking blocks are mounted on both surfaces of the filter. 12B is a bottom view of FIG. 12A. 12C (a) is a right side view of FIG. 12A, and FIG. 12C (b) is a cross-sectional view taken along the line CC of FIG. 12A. FIG. 13 is a cross-sectional view showing a conventional hollow fiber membrane oxygenator.

The filter-embedded artificial lung of the present invention can take the following modes based on the above configuration.

That is, the exhaust port is a hollow flow path member, and may include first and second exhaust paths formed by dividing the cross section of the hollow flow path member and separating them from each other. The first exhaust path may be in communication with the primary side space, and the second exhaust path may be in communication with the secondary side space. Thereby, it is possible to provide an exhaust path that separates and exhausts exhaust from the primary side space and the secondary side space with a simple configuration.

Further, a stepped portion can be provided on the inner peripheral wall surface of the blood flow channel in the vicinity of the filter in such a direction that the flow channel cross section on the side close to the filter is smaller than the separated side. A gap for collecting bubbles is formed by the stepped portion, and the bubbles are easily collected in the upper part over the entire circumference of the blood flow path.

In addition, the blood flow path in the filter space may be formed by a sealing material that seals the outer peripheral edge of the filter. An inclined surface corresponding to each of the valley portions of the pleat may be formed on the inner peripheral wall surface of the sealing material at the upper end portion of the pleat. The direction of inclination of the inclined surface can be set so as to go from the shallow part to the deep part of the valley as it goes downward. As a result, the bubbles rising from below along the valley of the pleats are easily introduced into the exhaust port away from the filter while rising along the inclined surface.

Also, the inclination angle of the inclined surface with respect to the horizontal direction can be set within a range of 5 ° to 80 °. If it is this range, it will be easy to remove | bubble and the influence which has on an effective filter membrane area is small. More preferably, the inclination angle is set within a range of 20 ° to 60 °.

Further, the cross-sectional shape of the blood channel may have a vertex that is the highest point of the outer peripheral edge of the cross-section. On both sides of the apex, the direction of the tangent to the outer peripheral edge of the cross section may be inclined downward as viewed from the apex. As a result, the exhaust port provided at the uppermost part (top) of the inner wall surface of the blood channel is located at the apex of the filter space, so that the raised bubbles are likely to collect and the effect of air discharge is great. The cross-sectional shape of the blood channel may be a circle or a rhombus arranged with one corner as a vertex.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<Embodiment>
[Configuration of oxygenator with built-in filter]
FIG. 1 shows a perspective view of a filter built-in oxygenator according to an embodiment of the present invention. FIG. 2 shows a cross-sectional view of the oxygenator as seen from the side, and FIG. 3 shows a cross-sectional view as seen from the top. FIG. 4 is a perspective view showing the shape of a filter included in the oxygenator.

In this oxygenator, as clearly shown in FIG. 2, a space region of the heat exchange part 2 and the gas exchange part 3 is formed in the housing 1, and elements for heat exchange and gas exchange are accommodated, respectively. Yes. A blood channel 4 (shown only in FIGS. 2 and 3) having a circular cross section is formed by penetrating the lumen formed by the heat exchange unit 2 and the gas exchange unit 3 in the horizontal direction. A blood introduction port 5 (see FIGS. 2 and 3) and a blood outlet port 6 (see FIGS. 1 to 3) are provided on the outer shell wall of the housing 1 corresponding to both ends of the blood flow path 4, respectively. The blood introduction port 5 and the blood outlet port 6 are disposed so as to open at the center of the circular cross section of the blood flow path 4.

Cold water / hot water ports 7 and 8 are provided in the outer shell walls of the housing 1 at the left and right ends of the heat exchange unit 2 to allow cold water or hot water (cold / hot water) to flow in and out, respectively.

Gas ports

9 and 10 are provided in the outer shell wall of the housing 1 at the upper and lower ends of the gas exchange unit 3 for inflow and outflow of oxygen-containing gas.

As shown in FIGS. 2 and 3, in the internal space of the heat exchanging unit 2, a bundle of stainless pipes 11 is arranged in a horizontal direction as a heat transfer thin tube through which a heat medium (cold / warm water) for heat exchange flows. It is loaded. Cold / hot water flows through the stainless steel pipe 11 through the cold / hot water ports 7, 8. A bundle of hollow fiber membranes formed by laminating a plurality of hollow fiber membranes 12 is loaded in the internal space of the gas exchange unit 3 with the tube axis of the hollow fiber membranes 12 oriented in the vertical direction. A gas containing oxygen flows through the lumen of the hollow fiber membrane 12 through the

gas ports

9 and 10.

As shown in FIGS. 2 to 3, the outer peripheral area of the heat exchanging portion 2 and the gas exchanging portion 3 in the housing 1 is sealed by a sealing member 13 formed using a sealing material made of polyurethane resin or epoxy resin. Stopped. The internal space of the seal member 13 forms the blood channel 4. The blood flow path 4 extends across the bundle of the stainless pipe 11 and the hollow fiber membrane 12 in the horizontal direction. Thereby, blood can be circulated so as to contact the outer surfaces of the stainless steel pipe 11 and the hollow fiber membrane 12.

A filter space 14 is formed downstream of the gas exchange unit 3, that is, between the side of the bundle of hollow fiber membranes 12 facing the blood outlet port 6 and the inner wall surface of the housing 1. A filter 15 is inserted into the filter space 14 so as to cover the entire cross section of the blood channel 4. The seal member 13 is also provided over the outer peripheral region of the filter space 14, and a part of the peripheral portion of the filter 15 is embedded in the seal member 13.

An exhaust port 16 is provided at the upper part of the housing 1 so as to be positioned at the upper end of the blood flow path. As shown in FIG. 1, the exhaust port 16 is configured by a tubular member extending laterally from the outer surface of the housing 1, and opens to the uppermost portion of the inner peripheral wall surface of the blood flow path 4 located in the filter space 14. ing. Thus, the exhaust port 16 has a function of an exhaust path for discharging the bubbles captured by the filter 15 by communicating the filter space 14 with the external space. The filter 15 and the exhaust port 16 arranged as described above provide a bubble removing function for capturing bubbles in the blood and discharging them to the outside of the housing 1. The exhaust port 16 is not limited to a tubular member, and any member may be used as long as it forms a hollow flow path.

The filter 15 has a function of capturing foreign substances in the blood flowing through the blood flow path 4 and a function of capturing and discharging bubbles. As shown in FIG. 4, the filter 15 is composed of a mesh-like sheet-like filter medium 17 made of, for example, polyethylene terephthalate, and is folded back so as to form a plurality of pleats 18. The pleat 18 has a ridge shape curved in a mountain shape as illustrated. However, the shape is not limited to such a curved ridge line shape, and may be a creased shape, and the pleats in the present embodiment are used in the meaning including any case.

2 and 3, the plurality of pleats 18 are arranged in a plane orthogonal to the blood flow path 4, and the direction of the pleats 18 is oriented in the vertical direction (vertical direction). However, the plurality of pleats 18 are not necessarily arranged in a plane orthogonal to the blood flow path 4, and may be arranged in a plane that “crosses” the blood flow path 4. The filter space 14 is separated into a primary space 14 a on the blood introduction port 5 side and a secondary space 14 b on the blood outlet port 6 side by the sheet-like filter medium 17. The area of the membrane surface of the sheet-like filter medium 17 in contact with the primary space 14a is remarkably wider than that of the flat sheet-like filter medium by repeating the peaks and valleys formed by the plurality of pleats 18.

That is, by providing the pleats 18, the restriction due to the cross-sectional area of the blood channel 4 can be eliminated, and the filter membrane area can be set sufficiently large. Therefore, an effect similar to the fact that the cross-sectional area of the flow path is substantially large is obtained, and the flow rate of the priming liquid / blood with respect to the membrane surface is reduced to facilitate gas-liquid separation and to fully demonstrate the ability to trap bubbles. can do. Moreover, the increase in the thickness of the filter 15 in the direction of the blood flow path 4 due to the provision of the pleats 18 is slight, and the blood filling amount can be sufficiently suppressed.

As shown in FIG. 5, the outer peripheral edge of the filter 15 is sealed with a sealing material 19 to form a filter module 20. 5 is a view seen from the side facing the primary space 14a in FIGS. The inner peripheral wall surface of the sealing material 19 is a cylindrical surface and forms the blood flow path 4 in the region of the filter 15. Further, an end portion of the exhaust port 16 is disposed at a position adjacent to the upper end region of the blood flow path 4 of the sealing material 19, and opens at the upper end of the blood flow path 4.

The filter 15 is loaded in the filter space 14 in the form of such a filter module 20 and sealed together with the stainless pipe 11 and the hollow fiber membrane 12 by the seal member 13. Details of the structure of the filter module 20 and its function will be described with reference to FIGS. FIG. 6 is a cross-sectional view conceptually showing the upper part of the oxygenator according to the present embodiment. FIG. 7 is a perspective view showing a region of the filter space 14 of the oxygenator in a cross section, and FIG. 8 is a perspective view showing a part of FIG. However, for convenience of illustration in FIGS. 6 to 8, the artificial lung is placed in the opposite direction to FIGS. 1 and 2, that is, with the blood introduction port 5 on the left side and the blood outlet port 6 on the right side. It is drawn.

As shown in FIG. 6, the exhaust port 16 includes first and

second exhaust passages

21a and 21b separated from each other. In the illustrated structure, the first and

second exhaust passages

21a and 21b are formed by dividing the inside of one tubular exhaust port 16. However, the present invention is not limited to this. May be. The first exhaust path 21a has an inner end opened to the primary space 14a, and the second exhaust path 21b has an inner end opened to the secondary space 14b. The outer end portions of the first and

second exhaust passages

21a and 21b are opened to the outside of the oxygenator. Therefore, the exhaust from the primary side space 14a and the secondary side space 14b can be separated and led out by the first and

second exhaust passages

21a and 21b.

At the outer end portions of the first and

second exhaust passages

21a and 21b, it is possible to simultaneously open and close the primary and

secondary spaces

14a and 14b by opening and closing a single opening / closing plug provided in one exhaust port 16. You may comprise so that it may exhaust. The operation of the opening / closing plug is performed as necessary to block communication between the filter space 14 and the outside of the housing 1 when priming is completed and extracorporeal blood circulation is started. Thereby, it is possible to prevent blood from leaking from the exhaust port 16 during extracorporeal blood circulation.

As described above, the direction of the plurality of pleats 18 of the filter 15 is oriented in the vertical direction (vertical direction). Therefore, when the priming liquid or bubbles in the blood are trapped by the filter 15 in the primary space 14a, the bubbles rise along the pleats 18. Then, the air enters the first exhaust path 21a and is discharged to the outside. Similarly, in the secondary side space 14b, the bubbles rise along the pleats 18, enter the second exhaust path 21b, and are discharged to the outside.

That is, since the pleats 18 are oriented in the vertical direction, there is an effect that bubbles are easily guided to the exhaust port 16 in the vicinity of the filter 15. Therefore, air bubbles in the filter space 14 can be collected in the exhaust port 16 without requiring an operation of tilting the artificial lung. Further, the air bubbles in the primary and

secondary spaces

14a and 14b are separated and discharged through the first and

second exhaust passages

21a and 21b, so that high exhaust performance can be obtained. By separating the exhaust from each other, it is possible to avoid the possibility that the blood in the primary side space 14a is mixed into the blood in the secondary side space 14b after filtration.

7 and 8, a step portion 22 is provided on the inner peripheral wall surface of the blood channel 4 in the vicinity of the filter 15 over the entire circumference of the circular cross section. In the drawing, the stepped portion 22 facing the primary side space 14a is shown, but the stepped portion 22 is similarly provided on the side facing the secondary side space 14b. The stepped portion 22 is formed in a direction in which the flow path cross section on the side close to the filter 15 is smaller than the separated side. By providing the step portion 22, a gap for collecting bubbles is formed, and the bubbles are easily collected at the upper part over the entire circumference of the circular blood channel 4.

Further, the sealing material 19 forms inclined

surfaces

23 a and 23 b in the region where the blood flow path 4 is formed, that is, in the upper end portion of the pleat 18. The

inclined surfaces

23a and 23b correspond to the valley portions of the pleat 18, the inclined surface 23a is formed in the valley portion 18a facing the primary space 14a (front side in FIG. 8), and the inclined surface 23b is secondary. It is formed in the trough part 18b facing the side space 14b. The direction of inclination of the

inclined surfaces

23a and 23b is set so as to go from the shallow part to the deep part of the valley as it goes downward. As a result, as indicated by the arrows, the bubbles rising from below along the valleys 18a of the pleats 18 are introduced along the inclined surfaces 23a away from the filter 15 and introduced into the first exhaust path 21a. The The operation of the inclined surface 23b is the same. At that time, the bubbles rising along the peripheral pleats 18 are guided to the central portion by the step portion 22 and reach the open ends of the first and

second exhaust passages

21a and 21b.

The inclination angle of the

inclined surfaces

23a and 23b with respect to the horizontal direction has a range in which bubbles can easily escape, and according to experimental results, it functions effectively when set within a range of 5 ° to 80 °. When the inclination angle is smaller than 5 °, the bubbles are difficult to rise, and when it is larger than 80 °, it is difficult to secure a sufficient effective area as the filter membrane area. Further, if it is set within the range of 20 ° to 60 °, it is more preferable as a realistic design range.

When using the oxygenator having the above-described configuration, a priming solution or blood is introduced from the blood introduction port 5, passed through the blood flow path 4 extending from the heat exchange unit 2 to the gas exchange unit 3, and further to the filter space 14. And is derived from the blood outlet port 6. Cold water or hot water, which is a heat exchange liquid flowing in from the cold / hot water inlet port 8, exchanges heat with blood in the heat exchange section 2 while passing through each stainless steel pipe 11. On the other hand, the oxygen-containing gas flowing in from the gas inlet port 9 exchanges gas with the blood in the gas exchange unit 3 while passing through each hollow fiber membrane 12. The blood after the gas exchange reaches the filter space 14 and is mixed into the priming solution / blood. The generated foreign matter and blood clots are trapped by the filter 15, and the priming solution / blood from which bubbles and foreign matter have been removed becomes the blood derivation. It is led out of the housing 1 from the port 6.

When the priming liquid / blood passes through the filter space 14, the bubbles are trapped by the filter 15, rise along the sheet-like filter medium 17, and reach the upper region of the blood flow path 4 in the filter space 14. Since the exhaust port 16 is open in this region, the bubbles are exhausted to the outside through the exhaust port 16.

In the above configuration, the effect of discharging air from the exhaust port 16 is great because the cross section of the blood flow path 4 is circular. This is because the exhaust port 16 provided at the uppermost part (top) of the inner wall surface of the blood flow path 4 facing the filter space 14 is located at the apex of the filter space 14, so that the raised bubbles gather. . However, the cross section of the blood flow path 4 is not limited to a circular shape, and any cross-sectional outer peripheral shape aggregated at the apex may be used. The outer peripheral shape of the cross-section aggregated at the apex has the apex that is the highest point of the outer peripheral cross-section of the blood flow path, and on both sides of the apex, the direction of the tangent to the outer peripheral cross-section is downward when viewed from the apex. Defined as an inclined shape. For example, the case where the outer peripheral edge shape of the cross section is a rhombus and one corner thereof is arranged as a vertex is included.

[Manufacturing method of built-in filter type artificial lung]
The filter built-in artificial lung having the above-described configuration is manufactured by manufacturing the filter module 20 as shown in FIG. It includes a step of forming the blood flow path 4 by sealing the peripheral edge. Other steps are performed using known techniques.

An example of a specific structure of the filter module 20 manufactured by this manufacturing method is shown in FIGS. 9A to 9D. 9A is a front view seen from the side facing the primary space 14a of the filter module 20, and FIG. 9B is a bottom view. FIG. 9C is a cross-sectional view taken along line AA in FIG. 9A. 9D is a right side view of the filter module 20 of FIG. 9A, and FIG. 9D is a cross-sectional view taken along line BB of FIG. 9A. The same reference numerals are given to the same elements as the respective parts of the filter module 20 shown in FIGS. 5 to 8, and the description thereof is omitted.

Hereinafter, steps for manufacturing the filter module 20 will be described with reference to FIGS. 10A to 12C.

10A to 10C show the primary side masking block 24a, and FIGS. 11A to 11C show the secondary side masking block 24b. The primary side and secondary side masking blocks 24a and 24b are used for manufacturing the filter module 20 by insert molding. That is, a molding die for molding a sealing portion by the sealing material 19 is formed on the outer peripheral edge portion by combining the primary side and secondary side masking blocks 24a and 24b with the filter 15 interposed therebetween. The

FIG. 10A is a front view of the primary side masking block 24a, FIG. 10B is a bottom view, and FIG. 10C is a right side view. The primary side masking block 24 a has a structure in which a group of linear protrusions 26 is provided on the substrate 25. The linear protrusion 26 has a shape corresponding to the valley portion 18a of the pleat 18 facing the primary space 14a. Further, the shape of the outer peripheral edge portion of the group of linear protrusions 26 corresponds to a portion belonging to the primary space 14 a in the inner wall portion of the blood flow path 4 formed by the sealing material 19.

At the upper end of the linear protrusion 26, there is provided an inclined surface molding portion 27 for forming the inclined surface 23a of the valley portion 18a facing the primary space 14a shown in FIG. Further, a step forming portion 28 for forming the step portion 22 shown in FIG. 8 is provided outside the peripheral portion of the group of linear protrusions 26. Further, a protrusion 29 for forming a mounting hole for mounting the exhaust port 16 is provided on the upper portion of the group of linear protrusions 26. The protrusion 29 is provided with an engagement hole 29a (see FIG. 10C).

FIG. 11A is a front view of the secondary side masking block 24b, FIG. 11B is a bottom view, and FIG. 11C is a right side view. The secondary side masking block 24b has a structure in which a group of linear protrusions 31 is provided on the substrate 30 in substantially the same manner as the primary side masking block 24a. The linear protrusion 31 has a shape corresponding to the valley portion 18b of the pleat 18 facing the secondary space 14b. Further, the shape of the outer peripheral edge portion of the group of linear protrusions 31 corresponds to a portion belonging to the secondary space 14 b in the inner wall portion of the blood flow path 4 formed by the sealing material 19.

At the upper end portion of the linear protrusion 31, there is provided an inclined surface molding portion 32 for forming the inclined surface 23b of the valley portion 18b facing the secondary space 14b shown in FIG. Further, a step forming portion 33 for forming the step portion 22 shown in FIG. 8 is provided outside the peripheral portion of the group of linear protrusions 31. Further, a protrusion 34 for forming a mounting hole for mounting the exhaust port 16 is provided on the upper portion of the group of linear protrusions 31.

FIGS. 12A to 12C show a state where the primary and

secondary masking blocks

24a and 24b are combined and the mold is assembled. However, when actually molding, both masking

blocks

24a and 24b are assembled with the filter 15 interposed therebetween. 12A is a bottom view of the assembled mold, FIG. 12C (a) is a right side view of FIG. 12A, and FIG. 12C (b) is a cross-sectional view taken along the line CC of FIG. 12A.

Each of the linear protrusions 26 of the primary side masking block 24a is inserted between the adjacent linear protrusions 31 of the secondary side masking block 24b. In other words, each of the linear protrusions 31 is between the adjacent linear protrusions 26. Has been inserted. In a state where the filter 15 is sandwiched therebetween, the

linear protrusions

26 and 31 are fitted into the

valley portions

18a and 18b of the pleat 18, respectively. Further, the projection 34 of the secondary masking block 24b is fitted in the engagement hole 29a of the projection 29 of the primary masking block 24a.

In the process of manufacturing the filter module 20, the primary side and secondary side masking blocks 24a and 24b are assembled as described above with the filter 15 in between. Next, a space formed between the

substrates

25 and 30 on the outer peripheral edge of the filter is filled with a sealing material made of a thermosetting resin such as polyurethane and cured. After the sealing material is cured, the masking blocks 24a and 24b are removed, and the filter module 20 formed by the sealing material is taken out.

However, at this time, only mounting holes are formed at locations corresponding to the protrusions 29 of the primary masking block 24a and the protrusions 34 of the secondary masking block 24b. That is, the separately manufactured exhaust port 16 is mounted in the mounting hole as shown in FIGS. 9A, 9B, and 9D, thereby completing the filter module 20 as shown in FIGS. 9A to 9D.

In order to facilitate assembly with the filter 15 sandwiched therebetween and disassembly after sealing with a sealing material, a hard resin is used for one of the masking blocks 24a and 24b, and a soft resin is used for the other. It is desirable to use it. However, the present invention is not limited to this. For example, any of the masking blocks 24a and 24b can be made using a soft resin.

In the above description, an artificial lung having a configuration in which the heat exchange unit 2 and the gas exchange unit 3 are formed by the housing 1 is shown as an example, but the application of the present invention is not limited to this. That is, even in a hollow fiber membrane oxygenator having only the gas exchange part 3 without the heat exchange part 2, the same effect as described above can be obtained by applying the structure of the bubble removing part by the filter 15 described above. be able to.

The built-in filter type artificial lung of the present invention has a built-in filter device that allows a substantially sufficiently large filter membrane area to function while suppressing the amount of blood filling, and that can effectively discharge trapped bubbles to the outside. Therefore, it is useful as a heart-lung machine for extracorporeal blood circulation.

1, 101, 102

Housing

2, 100B

Heat exchange part

3, 100A Gas exchange part 4

Blood flow path

5, 104

Blood introduction port

6, 107

Blood outlet port

7, 8, 103 Cold /

hot water port

9, 10, 108, 109 Gas Port 11 Stainless steel pipe 12 Hollow fiber membrane 13 Seal member 14 Filter space 14a Primary side space 14b Secondary side space 15 Filter 16 Exhaust port 17 Sheet-like filter medium 18 Pleated 18a, 18b Valley 19 Sealing material (sealing part)
20 Filter module 21a First exhaust passage 21b Second exhaust passage 22 Stepped

portions

23a, 23b Inclined surface 24a Primary side masking block 24b Secondary side masking blocks 25, 30

Substrate

26, 31

Linear protrusions

27, 32 Inclined

surface forming portion

28 , 33

Step forming portions

29, 34 Protruding portions 29 a Engaging holes 105 Heat exchange body 110 Exhaust port 111 Hollow fiber membrane layer 112 Filter member 113 Hollow fiber membrane layers 114 and 115 for

exhaust Separation

116 and 117 Partition

Claims

A housing forming a gas exchange section and a filter space adjacent to each other;
A bundle of a plurality of hollow fiber membranes loaded in the gas exchange unit;
A filter loaded in the filter space;
A blood channel provided to sequentially traverse the bundle of hollow fiber membranes and the filter;
A gas port provided in the housing to circulate a gas containing oxygen through the lumen of the hollow fiber membrane;
A blood inlet port and a blood outlet port provided on the outer wall of the housing at both ends of the blood flow path;
In the filter built-in type artificial lung having an exhaust port for communicating the filter space with an external space,
The filter is composed of a sheet-like filter medium provided with a plurality of parallel pleats, and the direction of the pleat is oriented in the vertical direction of the blood flow path,
The filter space is separated into a primary space on the blood introduction port side and a secondary space on the blood outlet port side by the sheet-like filter medium,
The filter built-in oxygenator, characterized in that the exhaust port is disposed at an upper end portion of the blood flow path, and has an exhaust path that separates and exhausts exhaust from the primary side space and the secondary side space. .
The exhaust port is a hollow flow path member, and includes first and second exhaust paths formed by dividing the cross section of the hollow flow path member and separating them from each other,
2. The filter built-in oxygenator according to claim 1, wherein the first exhaust path communicates with the primary side space, and the second exhaust path communicates with the secondary side space.
The step part is provided in the inner peripheral wall surface of the said blood flow path in the vicinity of the said filter so that the flow path cross section of the side close | similar to the said filter may become smaller than the side which separated. A built-in filter artificial lung.
The blood flow path in the filter space is formed by a sealing material that seals the outer peripheral edge of the filter,
An inclined surface corresponding to each of the valley portions of the pleat is formed on the inner peripheral wall surface of the sealing material at the upper end portion of the pleat, and the inclination direction of the inclined surface is shallower in the valley portion as it goes downward. The oxygenator with a built-in filter according to any one of claims 1 to 3, which is set so as to go from a portion toward a deep portion.
The filter built-in oxygenator according to claim 4, wherein an inclination angle of the inclined surface with respect to a horizontal direction is set in a range of 5 ° to 80 °.
The filter built-in oxygenator according to claim 5, wherein the inclination angle is set within a range of 20 ° to 60 °.
The cross-sectional shape of the blood flow path has a vertex that is the highest point of the outer peripheral edge of the cross section, and the tangent direction of the outer peripheral edge of the cross section is inclined downward as viewed from the apex on both sides of the apex. The filter-embedded oxygenator according to any one of claims 1 to 6.
8. The filter built-in oxygenator according to claim 7, wherein the cross-sectional shape of the blood channel is a circle or a rhombus arranged with one corner as a vertex.
A method for producing a filter built-in oxygenator according to claim 1,
A filter module in which an outer peripheral edge of the filter is sealed with a sealing material to form a part of the blood flow path is manufactured, the filter module is loaded into the filter space, and the filter is bundled with the bundle of hollow fiber membranes. Sealing the outer peripheral edge of the module to form the blood flow path,
The step of producing the filter module includes:
Preparing a primary side and secondary side masking block for forming a molding die for sandwiching the filter in between and forming a sealing portion by the sealing material on the outer peripheral edge thereof;
Attaching and assembling the primary side and secondary side masking blocks on both sides of the filter; and
Filling and curing the sealing material in the mold formed on the outer peripheral edge of the filter by the primary side and secondary side masking blocks;
A step of removing the masking block after the sealing material is cured;
The primary side masking block has a structure in which a group of linear protrusions having a shape corresponding to a valley portion of the pleat facing the primary side space is provided on a substrate, and an outer peripheral edge of the group of linear protrusions The shape of the part corresponds to the part belonging to the primary space among the inner wall part of the blood flow path formed by the sealing material,
The secondary masking block has a structure in which a group of linear protrusions corresponding to the valleys of the pleat facing the secondary space is provided on a substrate, and the group of the linear protrusions The shape of the outer peripheral edge corresponds to the portion belonging to the secondary side space in the inner wall portion of the blood flow path formed by the sealing material,
In the step of attaching the masking block, each of the linear protrusions is fitted into a valley portion of the pleat.