JP2014151115A - Hollow fiber membrane oxygenator with built-in filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an oxygenator with a built-in filter device in which a large filter membrane area is made to function with a limited blood filling amount and the captured air bubbles are efficiently discharged outside.SOLUTION: A bundle of hollow fiber membranes 12 is stored in a gas exchange unit 3, and a gas containing oxygen is circulated through a lumen. A blood flow path 4 is provided which circulates blood by crossing the hollow fiber membranes, and a filter space 15 adjacent to a blood derivation side of the bundle of the hollow fiber membranes is inserted with a filter 16. An exhaust port unit 17 is provided which forms an exhaust path and brings the filter space into communication with an outer space and enables exhaust of air bubbles. The filter is constituted by a sheet filtering medium 18 folded back in multiple leaves, and mounted by providing membrane surface gaps between membrane surfaces of respective folded leaves. Edge line gaps are formed between an edge line 19 of pleats and an inner circumferential surface of the blood flow path, and the circumferential edge part other than the edge lines of the pleats in the sheet-like filtering medium is brought into close contact with an inner circumferential surface of the blood flow path. The exhaust path is configured to come into communication with the membrane surface gaps, and an opening/closing plug for operating the opening/closing of the exhaust path is provided.

Description

  The present invention relates to a hollow fiber membrane oxygenator that performs gas exchange with respect to blood in extracorporeal circulation, and more particularly to a hollow fiber membrane oxygenator that incorporates a filter device that excludes foreign substances and blood clots that are 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 act as a substitute for breathing and blood circulation 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 examples of the oxygenator, a bubble oxygenator and a hollow fiber membrane oxygenator are known.

  The hollow fiber membrane oxygenator is configured such that a gas containing oxygen and blood are flowed 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. The hollow fiber membrane oxygenator is widely used because it has advantages such as less blood damage and a smaller priming amount than the bubble oxygenator.

  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.

  Such a configuration in which the function of a blood filter is integrally provided in a hollow fiber membrane oxygenator is disclosed in Patent Document 1, for example. FIG. 14 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 that exchanges gas with blood, and a heat exchange unit (heat exchanger) 100B. The gas exchange unit 100A is configured in the housing 101, and the heat exchange unit 100B is configured in the heat exchanger housing 102. The inflowing blood flows out first through the heat exchanger 100B and then through the gas exchange unit 100A.

  At the lower end of the housing 102 of the heat exchanging unit 100B, a tubular cold / hot water inflow port 103 for allowing cold / warm water as a heat medium to flow in, and a cold / warm water outflow port for discharging cold / warm water (hidden in the figure). Is formed. In addition, a tubular blood introduction port 104 is formed at the lower part on the left side of the housing 102. Inside the housing 102, a heat exchanger 105 having a cylindrical shape as a whole and a cylindrical heat medium chamber forming member (cylindrical wall) 106 disposed along the inner periphery of the heat exchanger 105 are installed. ing.

  The heat medium flowing in from the cold / hot water inflow port 103 flows into the heat medium chamber forming member 106 and enters a large number of concave portions of the bellows of the heat exchanger 105. As a result, the heat exchanger 105 in contact with the heat medium is heated or cooled, and heat exchange (warming or cooling) is performed with the blood flowing on the outer peripheral side of the heat exchanger 105.

  In the housing 101 of the gas exchange part 100A, a blood outlet port 107 is formed in the lower part of the side surface on the blood outflow side. A gas inflow port 108 is formed in the upper part of the housing 101, and a gas outflow port 109 and an exhaust port (exhaust port) 110 are formed in the lower part. Inside the housing 101 are housed a hollow fiber membrane layer 111 in which a large number of hollow fiber membranes are integrated, and a bubble removing means comprising a filter member 112 and an exhaust hollow fiber membrane layer 113.

  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 through which blood passes through the hollow fiber membrane layer 111 and the exhaust hollow fiber membrane layer 113. The space above the partition 114 and below the partition 115 is partitioned by partition portions 116 and 117 provided at the boundary between the hollow fiber membrane layer 111 and the exhaust hollow fiber membrane layer 113.

  The exhaust hollow fiber membrane layer 113 is configured by integrating a number of hollow fiber membranes, and has a function of permeating and exhausting gas constituting bubbles captured 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 flow path and prevents them from flowing out from the blood outlet port 107. Bubbles captured by the filter member 112 are removed from the blood flow path through the exhaust port 110 by the exhaust hollow fiber membrane layer 113 located on the upstream side.

JP 2007-190217 A

  It is said that the artificial lung filter member 112 disclosed in Patent Document 1 may be a single sheet-like member or may be used by superposing two or more sheets. However, even in such a case, the blood is sequentially arranged with respect to the blood flow path, and the blood is configured to sequentially pass through the two or more stacked sheets. This is described in paragraph 0056 of Patent Document 1 “For example, when two meshes having different openings are used as the filter member 112 in a stacked manner (a mesh having a large opening is arranged on the upstream side), a mesh having a large opening is used. It is clear from the description that "a relatively large bubble can be captured first, and fine bubbles that have passed through the mesh can be captured with a mesh having a small mesh size."

  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. It is difficult to make the filter membrane area sufficiently large with the cross-sectional area as the upper limit.

  Increasing the membrane area of the filter member is advantageous in order to sufficiently exhibit the ability to trap 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.

  For example, a filter device having a structure in which filter members (mesh, filter medium) are arranged in a cylindrical shape can secure a sufficient filter membrane area as compared with the above-described sheet-like filter member. However, in this case, the blood filling amount in the filter portion must be increased.

  In addition, even if a filter device capable of functioning a large filter membrane area is configured and has sufficient ability to capture air bubbles, it must be captured in order to fully demonstrate the ability to remove air bubbles from blood. It is necessary to have a function of efficiently discharging bubbles to the outside.

  Accordingly, the present invention provides a hollow fiber membrane having a built-in filter device that allows a substantially sufficiently large filter membrane area to function while maintaining a low blood filling amount and that can efficiently discharge trapped bubbles to the outside. An object is to provide a type oxygenator.

  The hollow fiber membrane oxygenator of the present invention includes a housing having a space region in which a gas exchange part is formed, a bundle of a plurality of hollow fiber membranes housed in the gas exchange part, and an inner part of the hollow fiber membrane. A gas port provided in the housing so as to circulate a gas containing oxygen through a cavity, a blood flow path for circulating blood so as to cross the bundle of hollow fiber membranes and contact the outer surface of the hollow fiber membranes; A blood inlet port and a blood outlet port provided on the outer wall of the housing at both ends of the blood channel; a filter space provided adjacent to the blood outlet side of the bundle of hollow fiber membranes; A filter that covers the entire cross-section and is inserted into the filter space; and an exhaust port portion that forms an exhaust path that allows the filter space to communicate with the external space and allows air bubbles to be discharged.

  In order to solve the above-mentioned problems, the hollow fiber membrane oxygenator of the present invention is configured such that the filter is constituted by a sheet-like filter medium folded back into a plurality of leaves, and the membrane surface of each leaf of the folded-up sheet-like filter medium. A ridge line gap is formed between a ridge line of the pleat formed by the folding and an inner peripheral surface of the blood flow path, and the pleat in each leaf of the sheet-like filter medium Peripheral portions other than the ridge line are in close contact with the inner peripheral surface of the blood flow path, and the exhaust passage is configured to communicate with the gap between the membrane surfaces, and operates to open and close the external space of the exhaust passage. An opening / closing plug is provided for this purpose.

  According to the hollow fiber membrane-type artificial lung having the above-described configuration, the priming liquid or blood flowing into the filter space passes through the ridge line gap between the pleat ridge line and the inner peripheral surface of the blood flow path, and further, the sheet-like filter medium. It flows into all the membrane surfaces of the sheet-like filter medium via the membrane surface gap between the membrane surfaces. Thereby, the entire area of the sheet-like filter medium located in the blood flow path functions as a filter membrane surface substantially simultaneously. Therefore, it is possible to increase the membrane area by increasing the number of turns, and the membrane area can function a substantially sufficiently large filter membrane area without being restricted by the cross-sectional area of the blood flow path. . Moreover, even if a clearance is secured between the leaves of the sheet-like filter medium, the volume of the filter space is only slightly increased, and the blood filling amount can be kept sufficiently low.

  In addition, the exhaust passage of the exhaust port portion is configured to communicate with the gap between the membrane surfaces, and an open / close plug for operating the external space of the exhaust passage to open and close is provided, so that trapped bubbles can be efficiently It is possible to discharge to the outside.

The perspective view of the hollow fiber membrane type artificial lung in one embodiment of this invention Front view of the artificial lung Side view of the oxygenator Cross section viewed from the side of the oxygenator Cross-sectional view of the oxygenator seen from above A perspective view showing a cross section of the artificial lung Front view showing a sheet-like filter medium constituting a filter included in the artificial lung The front view which shows the form after performing insert molding to the sheet-like filter medium The perspective view which shows the state in the middle of the process of producing a filter using the sheet-like filter medium The perspective view which shows the state at the time of completion | finish of the manufacturing process of the filter The principal part perspective view shown with the partial cross section which shows the structure and operation | movement of the exhaust port part in the oxygenator of embodiment of this invention The principal part perspective view shown with the partial cross section which shows the operation state different from FIG. 11A of the exhaust port part The perspective view which shows the structure of the ring-shaped rib provided in the sheet-like filter medium in the artificial lung of embodiment of this invention Side view showing the structure of the ring-shaped rib Sectional drawing which shows the hollow fiber membrane type artificial lung of a prior art example

  The hollow fiber membrane oxygenator of the present invention can take the following aspects based on the above configuration.

  That is, the exhaust port portion forms an internal opening that opens in the filter space at a position facing the blood outlet side surface of the filter, and is orthogonal to the sheet-like filter medium outwardly from the internal opening. It has a tubular horizontal trunk portion having an extending lumen, and an external opening that communicates the lumen with an external space is provided in a side portion of the horizontal trunk portion, and the sheet-like filter medium is folded back. A pipe wall forming a through hole having a circular cross-section penetrating each leaf is provided, and the through hole is continuous with the inner lumen of the horizontal trunk portion and spans a certain angular range in the circumferential direction of the pipe wall. A vent slit communicating with the gap between the membrane surfaces is provided, and the opening / closing plug includes a tubular inner tube portion mounted from the horizontal basic portion of the exhaust port portion to the through hole of the sheet-like filter medium. The lumen of which forms the exhaust passage The inner pipe portion has a vent hole that can communicate with the vent slit of the sheet-like filter medium at a tip portion located in the through hole, a rear end is sealed, and the external opening is formed on a peripheral surface near the rear end. A control hole capable of communicating with the external pipe, and the communication state and the closed state between the control hole and the external opening are switched according to the rotation angle of the inner tube portion, and the external space of the exhaust passage is When the opening and closing are operated, and the communication state thereof is established, the communication between the vent hole of the tip and the vent slit of the duct wall can be established.

  In another aspect, when the gap between the control hole and the external opening is in a closed state, the gap between the vent hole of the opening / closing plug and the vent slit of the sheet-like filter medium is also closed. ing. Thereby, a closed state can be maintained reliably.

  In yet another aspect, a through-hole is provided for each folded leaf of the sheet-shaped filter medium, a ring-shaped rib is provided to cover the through-hole, and the sheet-shaped filter medium is folded, The said pipe wall is formed by combining the said ring-shaped rib for every leaf integrally. Thereby, the through-hole of the circular cross section which penetrated each folded-back leaf can be formed easily.

  In still another aspect, the sheet-like filter medium has side edge ribs protruding from the membrane surface along side edges in the longitudinal direction, and the side edge ribs of each folded leaf are in contact with each other. The film surface gap is provided, and the ring-shaped rib is formed of the same material as the side edge rib. Thereby, the formation of the film surface gap can be easily performed by the same process as the formation of the through hole.

  In still another aspect, the exhaust port portion is provided so as to open to the uppermost portion of the inner wall surface of the blood flow channel facing the filter space. Thereby, it is possible to discharge bubbles captured by the filter with a simple configuration without providing suction means.

  In still another aspect, the filter is arranged such that the ridge line of the pleat extends in the vertical direction at the left and right positions of the housing.

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

<Embodiment>
FIG. 1 is a perspective view of a hollow fiber membrane oxygenator according to an embodiment of the present invention. A front view of this oxygenator is shown in FIG. 2, and a side view thereof is shown in FIG. FIG. 4 shows a cross-sectional view taken along line AA in FIG. 2, that is, a cross-sectional view seen from the side of the oxygenator. FIG. 5 shows a cross-sectional view taken along the line BB in FIG. 2, that is, a cross-sectional view seen from the upper surface of the artificial lung. FIG. 6 is a perspective view showing a cross section of the oxygenator.

  In this oxygenator, as clearly shown in FIGS. 3 and 4, space regions of the heat exchange unit 2 and the gas exchange unit 3 are formed in the housing 1, and elements for heat exchange and gas exchange are respectively formed. It is stored. A blood channel 4 (shown only in FIGS. 4 to 6) having a circular cross section is formed by penetrating through 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. 3 to 6) and a blood outlet port 6 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 is disposed so as to open at the center of the circular cross section of the blood flow path 4. On the other hand, the blood outlet port 6 is disposed so as to open adjacent to the bottom of the circular cross section of the blood channel 4.

  A cold / hot water inflow port 7 for allowing cold water or hot water (cold / warm water) to flow downward, and a cold / hot water outflow port for causing the outer wall of the housing 1 at the left and right ends of the heat exchange portion 2 to flow downward. 8 is provided. The outer shell wall of the housing 1 at the upper and lower ends of the gas exchange part 3 is provided with a gas inflow port 9 for inflow of oxygen-containing gas and a gas outflow port 10 for outflow, respectively.

  As shown in FIGS. 3 and 4, a bundle of stainless steel pipes 11 in the lumen of the heat exchanging section 2 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 arranged toward. The cold / hot water flows through the stainless steel pipe 11 through the cold / hot water inflow port 7 and the cold / hot water outflow port 8. A bundle of hollow fiber membranes formed by laminating a plurality of hollow fiber membranes 12 is arranged in the lumen 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 inflow port 9 and the gas outflow port 10.

  As shown in FIGS. 4 to 6, the seal is located in the outer peripheral area of the heat exchanging portion 2 and the gas exchanging portion 3 in the housing 1, and the stainless pipe 11 and the hollow fiber membrane 12 are exposed and exposed at both ends. A member 13 is provided. The lumen of the seal member 13 forms the blood channel 4, and the blood channel 4 extends across the bundle of the stainless pipe 11 and the hollow fiber membrane 12 in the horizontal direction. Thereby, the blood can be circulated so as to cross the bundle of the stainless steel pipe 11 and the hollow fiber membrane 12 and to be in contact with the outer surfaces of the stainless steel pipe 11 and the hollow fiber membrane 12. As shown in FIGS. 1 and 6, a circular transparent window 14 is provided on the front side of the housing 1.

  A filter space 15 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 16 is inserted into the filter space 15 so as to cover the entire cross section of the blood flow path 4. The seal member 13 is also provided over the outer peripheral region of the filter space 15, and a part of the peripheral portion of the filter 16 is embedded in the seal member 13. In addition, an exhaust port portion 17 is provided in the upper portion of the housing 1, and the filter space 15 communicates with the external space to form an exhaust path that allows the air bubbles captured by the filter 16 to be discharged. The filter 16 and the exhaust port portion 17 arranged as described above constitute a bubble removing unit for discharging bubbles in the blood to the outside of the housing 1.

  The filter 16 has a function of removing bubbles in the blood flowing through the blood flow path 4 and a function of capturing bubbles. As shown in FIGS. 4 and 5, the filter 16 is composed of a mesh-like sheet-like filter medium 18, which forms a pleat and is folded back into a plurality of leaves. In the present embodiment, as clearly shown in FIG. 5, the pleat ridge lines 19 are arranged so as to extend in the vertical direction (vertical direction) at the left and right positions of the housing 1.

  The duct of the lumen of the exhaust port portion 17 opens at the uppermost part of the inner wall surface of the blood flow path 4 located in the filter space 15, and forms an exhaust path that allows the filter space 15 to communicate with the outside of the housing 1. doing. The exhaust port portion 17 forms a tubular horizontal trunk portion extending laterally from the outer surface of the housing 1 and has a branched outer end portion 17a branched upward. The horizontal trunk forms an area where the opening / closing stopper 20 is mounted. The open / close plug 20 is provided for operating the opening and closing of the exhaust passage, and provides a function of blocking the communication between the filter space 15 and the external space of the housing 1 as needed during extracorporeal blood circulation. Specific structures and functions of the exhaust port portion 17 and the opening / closing plug 20 will be described later.

  The filter 16 is mounted in the filter space 15 with a membrane surface gap 21 (see FIG. 5) between the membrane surfaces of the leaves formed by the folded sheet-shaped filter medium 18. A ridge line gap 22 is provided between the pleat ridge line 19 and the inner peripheral surface of the blood flow path 4. Peripheral portions other than the pleat ridge line 19 in each leaf of the sheet-shaped filter medium 18, that is, the longitudinal sides of the front and rear surfaces of each folded leaf and the lateral sides of all the leaves are the blood flow path 4. It is in close contact with the inner peripheral surface. Here, “adhesion” means that the blood is sealed so as not to flow between the peripheral edge of the sheet-like filter medium 18 and the inner peripheral surface of the seal member 13 forming the blood flow path 4. To do. As described above, as described above, the peripheral portion of the sheet-like filter medium 18 may be embedded in the seal member 13 or may be bonded to the inner peripheral surface of the seal member 13.

  In the above configuration, at the time of priming, a priming solution is introduced from the blood introduction port 5, passes through the blood flow path 4 extending from the heat exchange unit 2 to the gas exchange unit 3, and further passes through the filter space 15 to the blood outlet port 6. Derived from During extracorporeal blood circulation after priming, 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 passed through the filter space 15. The blood is discharged 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, enters the lumen from one end of each stainless steel pipe 11 and flows out from the cold / hot water outlet port 7 via the other end of each stainless steel pipe 11. . Meanwhile, heat exchange is performed with the blood in the heat exchange unit 2. On the other hand, the oxygen-containing gas flowing from the gas inlet port 9 enters the lumen from one end of each hollow fiber membrane 12 and flows out from the gas outlet port 10 via the other end of each hollow fiber membrane 12. In the meantime, gas exchange is performed with the blood in the gas exchange unit 3. The blood after the gas exchange reaches the filter space 15, and the foreign matter and blood clots that are mixed and generated in the blood are trapped by the filter 16, and the blood from which bubbles and foreign matter are removed is removed from the blood outlet port 6 to the outside of the housing 1. To be derived.

  When the priming liquid or blood passes through the filter space 15, bubbles in the priming liquid are captured by the filter 16 and rise along the sheet-like filter medium 18 to reach the upper region of the blood flow path 4 in the filter space 15. Since the exhaust port portion 17 is open in this region, the bubbles are exhausted to the outside through the exhaust port portion 17.

  When passing through the filter space 15, the priming solution / blood passes through all of the folded membrane surfaces of the sheet-like filter medium 18. This is because there are ridge line gaps 22 between the plurality of pleat ridge lines 19 and the inner peripheral surface of the blood flow path 4, and between the film surfaces of the folded sheet-shaped filter medium 18, the film surface gaps. This is because 21 exists. That is, the priming solution / blood passes through the ridge line gap 22 between the pleat ridge line 19 and the inner peripheral surface of the blood flow path 4 and further passes through the film surface gaps 21 between the respective film surfaces of the sheet-like filter medium 18. Then, it flows into all the membrane surfaces of the sheet-like filter medium 18.

  Thereby, the entire area of the sheet-like filter medium 18 located in the blood flow path 4 can be made to function substantially simultaneously as a filter membrane surface for the priming solution / blood. Therefore, the membrane area can be set sufficiently large without being restricted by the cross-sectional area of the blood flow path 4, and an effect similar to that of a substantially large cross-sectional area of the flow path can be obtained. That is, the flow rate of the priming liquid / blood with respect to the membrane surface can be reduced to facilitate gas-liquid separation, and the ability to capture bubbles can be sufficiently exhibited.

  The operation of the opening / closing plug 20 is performed to shut off the communication between the filter space 15 and the outside of the housing 1 when priming is completed and extracorporeal blood circulation is started as necessary. Thereby, it is possible to prevent blood from leaking from the exhaust port portion 17 during extracorporeal blood circulation.

  As described above, during the extracorporeal blood circulation, the entire area of the sheet-like filter medium 18 located in the blood flow path 4 functions as a membrane surface for filtering blood. Thereby, even if clogging occurs in a part of the sheet-like filter medium 18, the influence on the blood flow can be reduced as a whole.

  In addition, according to the above configuration, even if the sheet-like filter medium 18 is folded back and secured with a gap, the volume of the filter space 15 for forming the bubble removing portion is little increased. That is, it is possible to allow a substantially sufficiently large filter membrane area to function while keeping the blood filling amount sufficiently low.

  In the above configuration, since the exhaust port portion 17 is provided so as to open at the uppermost portion of the filter space 15, the air bubbles rising along the sheet-like filter medium 18 are easily discharged. Therefore, natural exhaust is possible, and suction for exhaust from the exhaust port portion 17 is unnecessary. However, by providing the exhaust means, the exhaust port portion 17 can be arranged at another position depending on the specifications.

  In addition, the blood outlet port 6 is disposed so as to open adjacent to the bottom of the circular cross section of the blood flow path 4, thereby effectively separating bubbles from the blood led out of the housing 1. . However, the blood outlet port 6 can be provided in other manners.

  Further, since the cross section of the blood flow path 4 is circular, the effect of exhausting air from the exhaust port portion 17 is great. This is because the exhaust port portion 17 provided at the uppermost portion of the inner wall surface of the blood flow path 4 facing the filter space 15 is located at the apex of the filter space 15, so that the raised bubbles gather. However, the circular flow path cross section is an example of the outer peripheral edge shape concentrated in the exhaust port portion 17. The outer peripheral shape aggregated in the exhaust port portion 17 is that the intersection of the vertical plane including the flow path center axis and the outer peripheral edge of the cross section of the flow path is the uppermost peripheral edge, and the tangential direction of the outer peripheral edge is on both sides of the uppermost peripheral edge. It is defined as the shape going down.

  Next, the shape of the sheet-like filter medium 18 constituting the filter 16 and the filter manufacturing process will be described with reference to FIGS. FIG. 7 is a front view showing the sheet-like filter medium 18 used for the configuration of the filter. FIG. 8 is a front view showing a form after the sheet-shaped filter medium 18 is subjected to insert molding. FIG. 9 is a perspective view showing a state in the middle of the production process of the filter 16, and FIG. 10 is a perspective view showing a state at the end of the production process.

  As shown in FIG. 7, the sheet-like filter medium 18 is provided with through holes 23 along the side edges in the longitudinal direction. As shown in FIG. 8, the sheet-shaped filter medium 18 is provided with side edge ribs 24 and ring-shaped ribs 25 integrated with the side edge ribs 24 by resin insert molding. The side edge rib 24 protrudes from the membrane surface along the side edge in the longitudinal direction of the sheet-like filter medium 18. The ring-shaped rib 25 is provided by the same material as the side edge rib 24 so as to surround and cover the through hole 23. The side edge rib 24 is provided with a cut 26 corresponding to a fold when the sheet-shaped filter medium 18 is folded back. The through hole 23 is arranged so as to be located at the center in the width direction of each leaf formed by folding at the cut line 26.

  The sheet-like filter medium 18 is folded at the position of the cut 26 by forming a pleat ridge line 19 as shown in FIG. 9 (folded twice in the figure). Finally, as shown in FIG. 10, it is folded until the folded side edge ribs 24 of each leaf come into contact with each other. When the side edge ribs 24 of each leaf come into contact with each other, a membrane surface gap 21 (see FIG. 5) between the membrane surfaces of each leaf is provided and reliably maintained. Further, the ring-shaped ribs 25 of the respective leaves are integrally combined in a state where the sheet-shaped filter medium 18 is folded, thereby forming a pipe wall of a through hole 27 having a circular cross section that crosses each folded leaf. The Providing such side edge ribs 24 along the side edges in the longitudinal direction of the sheet-like filter medium 18 is effective in maintaining the shape of the folded sheet-like filter medium 18.

  The rib for forming the membrane surface gap 21 between the leaves of the sheet-like filter medium 18 is not limited to the shape provided along the side edge in the longitudinal direction, such as the side edge rib 24. For example, a radial rib may be provided at the center of each folded leaf.

  Next, the structure and operation of the exhaust port portion 17 and the opening / closing plug 20 will be described with reference to FIGS. 11A and 11B. FIG. 11A is a perspective view showing a part of the vicinity of the exhaust port portion 17 in a state where the filter space 15 and the external space of the housing 1 communicate with each other via the exhaust port portion 17. FIG. 11B is a perspective view in a state where communication through the exhaust port portion 17 is closed by the opening / closing plug 20.

  The exhaust port portion 17 forms an internal opening 28 that opens into the filter space 15 at a position facing the blood outlet side surface of the filter 16, and is orthogonal to the sheet-like filter medium 18 outwardly from the internal opening 28. A tubular horizontal backbone 29 is formed. The branch outer end portion 17a communicates with the port main body portion 29 and branches upward, and the tip opens to the external space. Therefore, the side part (peripheral wall part) of the horizontal trunk | drum 29 is provided with the external opening which is a through-hole which connects the internal cavity with external space via the branch outer end part 17a. However, the branch outer end portion 17 a is not necessarily provided, and may have a structure in which an external opening is simply formed on the side portion of the horizontal trunk portion 29.

  A through hole 27 formed by a pipe wall made of an assembly of a plurality of ring-shaped ribs 25 in the sheet-like filter medium 18 is arranged so as to be continuous with the inner cavity of the horizontal trunk portion 29. A ventilation slit 30 that communicates with the membrane surface gap 21 over a certain angular range in the circumferential direction of the pipe wall is provided at the lower part of the pipe wall made of the ring-shaped rib 25.

  The structure of the ventilation slit 30 is shown in detail in FIGS. FIG. 12 is an enlarged perspective view showing the ring-shaped rib 25. FIG. 13 is a side view showing the ring-shaped rib 25 in a form integrated with the sheet-like filter medium 18 by insert molding.

  A membrane surface gap 21 is formed by the sheet-like filter medium 18 extending from the lower end of each of the ring-shaped ribs 25. The ring-shaped rib 25 has a lower thickness compared to the upper portion, and a step 31 is formed. The step 31 forms a ventilation slit 30 in the duct wall made up of a plurality of ring-shaped ribs 25, so that the membrane surface gap 21 and the ventilation slit 30 communicate with each other.

  As shown in FIGS. 11A and 11B, the opening / closing plug 20 has an inner tube portion 32 on the front end side and a grip portion 33 on the rear end side, and the inner tube portion 32 extends from the horizontal trunk portion 29 of the exhaust port portion 17. The sheet-shaped filter medium 18 is mounted over the through hole 27. The inner pipe portion 32 forms a part of the exhaust passage, and has a vent hole 34 a and 34 b that can communicate with the vent slit 30 of the sheet-like filter medium 18 at the tip 34 positioned in the through hole 27. The rear end is sealed, and has a control hole 35 that can communicate with the branched outer end portion 17a on the peripheral surface near the rear end. With the opening / closing plug 20, the outer branch end 17 a and the ventilation slit 30 can communicate with each other via the inner pipe portion 32.

  That is, by rotating the inner tube portion 32 via the grip portion 33, the communication state and the closed state between the control hole 35 and the branch outer end portion 17a are changed according to the rotation angle of the inner tube portion 32. It is switched and the opening and closing of the external space of the exhaust passage is operated. In this communication state, the vent holes 34 a and 34 b at the tip of the opening / closing plug 20 and the vent slit 30 in the duct wall are in communication with each other, so that the exhaust path communicates with the membrane surface gap 21.

  Further, when the space between the control hole 35 and the branch outer end portion 17a (external opening) is in a closed state, the space between the vent holes 34a and 34b of the opening / closing plug 20 and the vent slit 30 of the sheet-like filter medium 18 is also closed. It is comprised so that it may be in a state. However, this condition is not essential. That is, when the membrane surface gap 21 is closed with respect to the external space, it is possible to obtain a practical effect if at least one of the control hole 35 or the vent holes 34a and 34b is closed.

  The hollow fiber membrane oxygenator of the present invention has a built-in filter device that allows a large filter membrane area to function with a limited blood filling amount and efficiently discharges 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, 103 Cold / warm water inflow port 8 Cold / warm water outflow port 9, 108 Gas Inflow ports 10 and 109 Gas outflow port 11 Stainless steel pipe 12 Hollow fiber membrane 13 Seal member 14 Transparent window 15 Filter space 16 Filter 17 Exhaust port portion 17a Branched outer end portion 18 Sheet-like filter medium 19 Pleated ridgeline 20 Opening plug 21 Membrane surface gap 22 Ridge gap 23 Through hole 24 Side edge rib 25 Ring-shaped rib 26 Cut 27 Through hole 28 Internal opening 29 Horizontal trunk 30 Ventilation slit 31 Step 32 Inner tube portion 33 Grip portion 34 Tip portion 34a, 34b Vent hole 35 Control hole 105 Heat Exchanger 110 Exhaust port 111 Hollow fiber membrane layer 112 Filter member 11 Exhaust hollow fiber membrane layers 114 and 115 partition wall 117 partitioning portion

Claims (7)

A housing having a space region in which a gas exchange part is formed;
A bundle of a plurality of hollow fiber membranes housed in the gas exchange part;
A gas port provided in the housing to circulate a gas containing oxygen through the lumen of the hollow fiber membrane;
A blood flow path for circulating blood so as to cross the bundle of hollow fiber membranes and to contact the outer surface of the hollow fiber membranes;
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;
A filter space provided adjacent to the blood outlet side of the bundle of hollow fiber membranes;
A filter that covers the entire cross-section of the blood flow path and is inserted into the filter space;
In the hollow fiber membrane oxygenator comprising an exhaust port portion that forms an exhaust passage communicating the filter space with an external space and enables discharge of bubbles,
The filter is composed of a sheet-like filter material folded back into a plurality of leaves, and is attached with a membrane surface gap provided between the membrane surfaces of each leaf of the folded sheet-like filter material,
A ridge line gap is formed between a ridge line of the pleat formed by the folding and an inner peripheral surface of the blood flow path, and a peripheral part other than the ridge line of the pleat in each leaf of the sheet-like filter medium is formed in the blood flow. Close contact with the inner peripheral surface of the road,
The hollow fiber membrane oxygenator, wherein the exhaust passage is configured to communicate with the gap between the membrane surfaces, and is provided with an open / close stopper for operating opening and closing of the external space of the exhaust passage. The exhaust port portion forms an internal opening that opens in the filter space at a position facing the blood outlet side surface of the filter, and extends perpendicularly to the sheet-like filter medium outward from the internal opening. An external opening that communicates the lumen with an external space is provided on a side portion of the horizontal backbone,
The sheet-like filter medium is provided with a duct wall that forms a through-hole having a circular cross section that penetrates each folded leaf, and the through-hole is continuous with the lumen of the horizontal trunk portion, A ventilation slit is provided in communication with the film surface gap over a certain angular range in the circumferential direction,
The open / close plug has a tubular inner tube portion mounted from the horizontal basic portion of the exhaust port portion to the through hole of the sheet-like filter medium, and the lumen forms the exhaust passage,
The inner pipe portion has a vent hole that can communicate with the vent slit of the sheet-like filter medium at a tip portion located in the through hole, a rear end is sealed, and the external opening is formed on a peripheral surface near the rear end. A control hole that can communicate with
The communication state and the closed state between the control hole and the external opening are switched according to the rotation angle of the inner tube part, and the opening and closing of the exhaust passage with respect to the external space are operated, and the 2. The hollow fiber membrane oxygenator according to claim 1, wherein in the communication state, a communication state is established between the vent hole in the tip and the vent slit in the duct wall.   3. When the space between the control hole and the external opening is in a closed state, the space between the ventilation hole of the opening / closing plug and the ventilation slit of the sheet-like filter medium is also closed. Hollow fiber membrane oxygenator. A through hole is provided for each folded leaf of the sheet-like filter medium, and a ring-shaped rib is provided to cover the through hole,
The hollow fiber membrane oxygenator according to claim 2, wherein the pipe wall is formed by integrally combining the ring-shaped ribs for each leaf in a state where the sheet-like filter medium is folded. The sheet-like filter medium is formed with side edge ribs protruding from the membrane surface along the longitudinal side edges thereof, and the side edge ribs of each folded leaf come into contact with each other so that the membrane surface gap is reduced. Provided,
The hollow fiber membrane oxygenator according to claim 4, wherein the ring-shaped rib is made of the same material as the side edge rib.   The hollow fiber membrane oxygenator according to any one of claims 1 to 5, wherein the exhaust port portion is provided so as to open to an uppermost portion of an inner wall surface of the blood flow channel facing the filter space. .   The hollow fiber membrane oxygenator according to any one of claims 1 to 6, wherein the filter is arranged such that a ridge line of the pleat extends in a vertical direction at a left and right position of the housing.

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