JP5861342B2 - Hollow fiber oxygenator - Google Patents

Description

  The present invention relates to a hollow fiber oxygenator for performing gas exchange (supply of oxygen, discharge of carbon dioxide) to blood in extracorporeal circulation, and in particular, to collect blood for testing from a blood flow that flows after gas exchange. It relates to the improvement of the sampling port.

  In cardiac surgery, a heart-lung machine is used to stop the patient's heart and perform the respiratory and circulatory functions during that time. Artificial lungs provide an extracorporeal blood circulation by supplying oxygen to blood instead of a patient's lungs and discharging carbon dioxide. As examples of the oxygenator, a bubble oxygenator and a hollow fiber oxygenator (membrane type) oxygenator are known. The hollow fiber type artificial lung is configured such that a gas containing oxygen and blood are made to flow with a porous hollow fiber membrane interposed therebetween, and gas exchange is performed between blood and gas. Since the hollow fiber oxygenator has advantages such as less blood damage and a smaller priming amount than the bubble oxygenator, the hollow fiber oxygenator is becoming popular in recent years.

  In a hollow fiber type artificial lung, a sampling port for sampling blood flowing out after gas exchange is often attached to a blood outlet port connected to an outlet of a blood flow path. When using an oxygenator, a part of the blood after gas exchange derived from the oxygenator is collected through a sampling port and sent to a blood gas measuring device. Measure the pressure. By this measurement, it is determined whether or not the blood to be delivered to the patient has a sufficient oxygen partial pressure, and the setting of the apparatus is adjusted so that the oxygen partial pressure is appropriate.

  However, in the blood collected from the sampling port having the conventional configuration, the measurement result of the oxygen partial pressure may not always indicate an appropriate value. Since the blood after gas exchange that has passed through the hollow fiber laminate linearly reaches the outlet of the blood channel, the blood that has passed through each part of the gas exchange chamber flows out of the blood outlet without being sufficiently mixed. On the other hand, since the oxygen concentration in the gas changes between the inflow side and the outflow side of the oxygen-containing gas in the gas exchange chamber, the oxygen partial pressure of blood passing through each part of the gas exchange chamber varies. Therefore, the blood collected from the sampling port does not have an average oxygen partial pressure in the blood flowing out from the artificial lung, and it is difficult to ensure the validity of the measurement result.

  An example of a configuration for solving this problem is disclosed in Patent Document 1. This will be described with reference to FIGS. 11 to 12C. FIG. 11 is a perspective view showing a configuration of the oxygenator 101 in a partial cross section. The artificial lung 101 has a configuration in which a housing 102 is provided with a blood gas exchange chamber 103 in which a laminate 103A of hollow fiber sheets is housed, and a heat exchange unit 110 provided continuously therebelow.

  A blood inlet port 104 is provided on the lower side of the housing 102, and a blood outlet port 105 is provided on the upper side to lead out blood that has undergone gas exchange. A gas inlet port 106 for introducing an oxygen-containing gas is provided on one side surface of the housing 102, and a gas outlet 107A is provided on the gas outlet cover 107 on the other side surface. In the blood gas exchange chamber 103, gas exchange is performed between blood and oxygen-containing gas via a hollow fiber membrane.

  The heat exchange unit 110 is provided with a heat exchange water inlet port 111 on one side surface of the housing 102 and a heat exchange water outlet port 112 on the other side surface so that the introduced heat exchange water flows through a number of pipes. It is configured. The blood introduced from the blood inlet port 104 flows upward through the pipe through which the heat exchange water flows, and the blood is adjusted to a desired temperature by exchanging heat with the heat exchange water.

  A head portion 113 made of synthetic resin is provided on the upper portion of the housing 102. A bottom view of the head portion 113 is shown in FIG. 12A, and a front cross-sectional view is shown in FIG. 12B. FIG. 12C is a perspective view seen from the bottom surface side of the head portion 113. As shown in FIG. 12A, a blood outlet 115 is provided in the center of the head portion 113, and the blood outlet port 105 communicates with the blood outlet 115. The blood outlet port 105 is provided with a sampling port 108 and a blood temperature measurement port 109 in a branched state on the way. Sampling port 108 is connected to a circuit that collects a small amount of blood in order to measure oxygen partial pressure, carbon dioxide partial pressure, oxygen saturation, etc. in the blood. A temperature sensor is inserted into the blood temperature measurement port 109.

  As shown in FIGS. 12B and 12C, around the blood outlet 115 provided at the center of the head portion 113, four plate-like convex portions 116 are formed to project as mixing portions. The plate-like convex portion 116 is formed along a direction that is obliquely separated from the blood outlet 115 from one end in the longitudinal direction located in the vicinity of the blood outlet 115.

  By providing the plate-like convex portion 116, blood that has undergone gas exchange flows while being guided by the plate-like convex portion 116 when flowing into the blood outlet 115, and flows into the blood outlet 115 from an oblique direction. Thereby, the blood is mixed in the vicinity of the blood outlet 115. As a result, the blood gas concentration derived from the blood outlet port 105 is made uniform, and variations in blood gas analysis results such as oxygen partial pressure in blood collected from the sampling port 108 can be reduced. In this way, by mixing the blood derived from the blood outlet, the validity of the measured value of the oxygen partial pressure can be ensured and the oxygen partial pressure in the blood can be managed appropriately.

JP 2005-192780 A

  However, by adopting the hollow fiber type artificial lung disclosed in Patent Document 1, the plate-like convex portion 116 protruding from the inner surface side of the head portion 113 ensures that the blood flowing out from the blood outlet 115 is reliably averaged. It is considered difficult to make a state. This is because the mixing of blood by the plate-like convex portion 116 formed on the inner surface side around the blood outlet 115 is an operation in a very short time, and in order to sufficiently perform the mixing operation, the plate-like convex portion is used. This is because it is considered that the height of the portion 116 needs to be sufficiently large. However, if the height of the plate-like convex portion 116 is sufficiently increased, the volume of the housing 102 increases, resulting in an inconvenience that the blood filling amount increases. Further, depending on the shape and size of the plate-like convex portion 116, there is a risk that the priming property and the bubble removing property are lowered.

  Therefore, the present invention provides an average gas partial pressure (oxygen partial pressure, carbon dioxide) in blood flowing out from the blood outlet port by simply improving the sampling port portion without changing the structure of the inner surface of the housing in the blood outlet header. It is an object of the present invention to provide a hollow fiber oxygenator capable of appropriately measuring (partial pressure) and ensuring the appropriateness of gas partial pressure management.

  The hollow fiber oxygenator of the present invention includes a hollow fiber bundle formed by a plurality of hollow fiber membranes, a housing forming a gas exchange chamber in which the hollow fiber bundles are accommodated, and an inner portion of the hollow fiber membranes. Blood that circulates through the gas port provided in the housing so as to flow in and out oxygen-containing gas through the cavity and the hollow fiber bundle in the gas exchange chamber so as to contact the outer surface of the hollow fiber membrane A blood flow path, a blood inlet port and a blood outlet port respectively provided in the housing so as to face the central part of both ends of the blood flow path, and a sampling port branched from the blood outlet port.

In order to solve the above problems, the hollow fiber oxygenator of the present invention protrudes from the root portion of the sampling port formed on the side wall of the blood outlet port toward the central axis of the blood outlet port, and the tip thereof is A nozzle located in the blood outlet port, and an inner diameter d of the tip of the nozzle is smaller than an inner diameter F of the blood outlet port at a position where the tip of the nozzle is located in the axial direction of the blood outlet port. And a part of the blood flowing out from the blood outlet port can be collected through the nozzle.

  According to the hollow fiber oxygenator having the above-described configuration, an average of the blood flowing out from the blood outlet port can be obtained by collecting a part of blood using a nozzle whose tip is located at the center of the blood outlet port. Blood having a gas partial pressure can be collected, and the gas partial pressure can be appropriately measured. Therefore, it is possible to ensure the appropriateness of the oxygen partial pressure management by simply improving the sampling port portion without changing the structure of the inner surface of the housing in the blood outlet header.

Side view of hollow fiber oxygenator in embodiment 1 Front view of the hollow fiber oxygenator Sectional drawing which shows the cross section which looked at the same direction as FIG. 1 of the hollow fiber type artificial lung Sectional view showing the vicinity of the sampling port of the hollow fiber oxygenator in an enlarged manner Sectional drawing for demonstrating the desirable conditions about the principal part of the sampling port of the hollow fiber type artificial lung Diagram showing the system used in the experiment to investigate desirable conditions for the main part of the sampling port The figure which shows the experiment which investigated the desirable condition about the principal part of the same sampling port Sectional drawing which shows the vicinity of the sampling port which is the principal part of the hollow fiber type artificial lung in Embodiment 2 Sectional view of another embodiment near the sampling port of the hollow fiber oxygenator Sectional drawing which shows the structure of the nozzle of the hollow fiber oxygenator The perspective view which showed the structure of the hollow fiber type oxygenator of a prior art example with a partial cross section Bottom view showing the head of the hollow fiber oxygenator Front sectional view showing the head The perspective view seen from the bottom side of the head part

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

  That is, the nozzle is formed by extending the end of the sampling port on the blood outlet port side toward the center of the blood outlet port, and at the boundary between the nozzle and the sampling port, The inner diameter may be set so that no step is formed on the inner peripheral surface. By taking such a configuration, it is possible to suppress the retention and remaining of bubbles.

  Alternatively, the nozzle may be formed separately from the sampling port and mounted in the sampling port. Thereby, it is possible to obtain the effect of blood collection through the nozzle without changing the structure of the sampling port.

  In this case, a fitting portion coupled to the base end portion of the nozzle is provided, and the fitting portion is an outer periphery of the outer end portion of the sampling port in a state where the nozzle is fitted in the lumen of the sampling port. The fitting portion is positioned by the outer end portion of the sampling port, and the tip of the nozzle is positioned in the lumen of the blood outlet port via the positioning. A tube for transferring blood to a measuring device or the like can be connected to the portion. As a result, the nozzle can be reliably positioned while maintaining a simple configuration, and the average value of the gas partial pressure can be measured appropriately. The nozzle and the fitting portion may be integrally formed.

  The nozzle is attached to the tip of a tube connected to the sampling port, and the tip of the nozzle is positioned at the center of the lumen of the blood outlet port with the tube connected to the sampling port. It can be set as the structure which has.

  Further, when the protrusion amount at the center of the tip of the nozzle from the inner peripheral surface of the blood outlet port is L, the ratio L / F of the protrusion amount L to the inner diameter F of the blood outlet port satisfies the following condition. It is preferable that the range is satisfied. As a result, blood having an oxygen partial pressure sufficiently close to the average value of the total gas partial pressure can be appropriately collected from the blood flowing out from the blood outlet port.

0.2 ≦ L / F ≦ 0.5
In addition, when the inner diameter of the nozzle tip is d, the ratio d / F of the inner diameter d to the inner diameter F of the blood outlet port is preferably set in a range that satisfies the following conditions. Thereby, blood having a gas partial pressure sufficiently close to the average value of the total gas partial pressure can be easily collected from the blood flowing out from the blood outlet port.

0.1 ≦ d / F ≦ 0.2
Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
FIG. 1 shows a side view of the hollow fiber oxygenator according to Embodiment 1 of the present invention. This artificial lung has a structure in which a heat exchange part 2 and a gas exchange part 3 are formed by a housing 1 and elements for heat exchange and gas exchange are accommodated therein. FIG. 2 is a front view seen from the gas exchange unit 3 side. 3 is a cross-sectional view taken in the same direction as FIG.

  A blood channel 4 (shown only in FIG. 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. The outer shell walls of the housing 1 corresponding to both ends of the blood flow path 4 form a blood inlet header provided with a blood inlet port 5 and a blood outlet header provided with a blood outlet port 6, respectively. Cold / hot water headers provided with cold / hot water ports 7 and 8 (see FIG. 2) for allowing cold water or hot water as heat exchange liquid to flow in and out of the outer shell walls of the housing 1 at the left and right end portions of the heat exchange part 2, respectively. Is forming. The outer shell walls of the housing 1 at the upper and lower ends of the gas exchange part 3 form gas headers provided with gas ports 9 and 10 for introducing and deriving oxygen-containing gas.

  At the base end of the blood outlet port 6, a sampling port 11 for sampling blood flowing out after gas exchange and a temperature measuring port 12 are provided in a branched state. A support portion 13 is formed on the upper surface portion of the outer shell wall of the housing 1 of the heat exchange portion 2 in order to support the artificial lung in a desired state. As shown in FIG. 2, ribs 14 extending radially outward from the vicinity of the blood inlet port 5 are formed on the inner surface of the outer shell wall of the housing 1 forming the blood outlet header on the gas exchange unit 3 side. Yes.

  As shown in FIG. 3, a bundle of stainless pipes 15 for heat exchange is disposed in the inner cavity of the heat exchange unit 2. Cold / hot water flows into and out of the stainless steel pipe 15 via the cold / hot water ports 7 and 8. A hollow fiber bundle formed by a plurality of hollow fiber membranes 16 is disposed in the lumen of the gas exchange unit 3. A gas containing oxygen flows into and out of the lumen of the hollow fiber membrane 16 through the gas ports 9 and 10. The outer edge region of the heat exchange unit 2 and the gas exchange unit 3 is filled with a potting material so that the both ends of the stainless pipe 15 and the hollow fiber membrane 16 are exposed to form a potting unit 17. The lumen of the potting portion 17 forms the blood channel 4 described above, and extends across the stainless steel pipe 15 and the hollow fiber membrane 16 in the horizontal direction. Thereby, blood flows in contact with the outer surfaces of the stainless steel pipe 15 and the hollow fiber membrane 16. Here, the blood inlet port 5 and the blood outlet port 6 are provided so as to correspond to the central portion which is a part of the cross-sectional shape of the blood flow path 4. A temperature sensor 18 is inserted into the temperature measurement port 12.

  The blood flowing in from the blood inlet port 5 passes through the blood flow path 4 extending from the heat exchange unit 2 to the gas exchange unit 3 and flows out 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 15, and flows out from the cold / hot water outlet port 7 via the other end of each stainless steel pipe 15. . 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 16 and flows out from the gas outlet port 10 via the other end of each hollow fiber membrane 16. In the meantime, gas exchange is performed with the blood in the gas exchange unit 3.

  The present embodiment is characterized by an improved configuration for collecting a part of blood flowing out from the blood outlet port 6 through the sampling port 11. The cross-sectional view of FIG. 4 is an enlarged view of the vicinity of the sampling port 11. As shown in this figure, a nozzle 20 is provided at the proximal end of the sampling port 11, and the tip of the nozzle 20 extends toward the center of the blood outlet port 6. A tube 21 is connected to the outer end of the sampling port 11 via a connection member 22. Note that the connection member 22 and the tube 21 are not shown in section but in appearance.

  FIG. 5 is a cross-sectional view for explaining desirable conditions for the main part of the sampling port 11, and only elements formed as a part of the housing 1 are shown. As shown in FIG. 5, the nozzle 20 is formed by extending the end of the sampling port 11 on the blood outlet port 6 side toward the center of the blood outlet port 6. At the boundary between the nozzle 20 and the sampling port 11, the inner diameters of both are set so that no step is formed on the inner peripheral surface, and therefore the inner peripheral surface of the nozzle 20 is smoothly continuous with the inner peripheral surface of the sampling port 11. ing.

  On the other hand, the inner diameter d of the nozzle tip 20 a that is the tip of the nozzle 20 is sufficiently smaller than the inner diameter F of the blood outlet port 6. However, the inner diameter F of the blood outlet port 6 is a value at a position where the nozzle tip 20a is positioned in the axial direction of the blood outlet port 6. The inner diameter d of the nozzle tip 20 a is set to be thinner than the inner diameter of the sampling port 11, and is equal to the inner diameter of the sampling port 11 at the boundary with the sampling port 11. Accordingly, the inner diameter of the nozzle 20 gradually increases from the front end toward the rear end.

  With the above configuration, a part of the blood flowing out from the blood outlet port 6 is collected through the nozzle 20. A small amount of blood collected from the nozzle 20 is transferred through a tube 21 to a circuit for measuring oxygen partial pressure, carbon dioxide partial pressure, oxygen saturation, etc. in the blood.

  Assuming that the inner diameter d of the nozzle tip 20a is smaller than the inner diameter F of the blood outlet port 6, the amount of protrusion L (see FIG. 5) at the center of the nozzle tip 20a from the inner peripheral surface of the blood outlet port 6 is There is a desirable range. That is, when the center of the nozzle tip 20 a is disposed at an appropriate position with respect to the central axis of the lumen of the blood outlet port 6, the gas partial pressure or the like of the collected blood is extracted from the nozzle 20. It becomes close to the average value of the total gas partial pressure. Practically, there is a desirable range of the ratio L / F of the protrusion amount L with respect to the inner diameter F of the blood outlet port 6, and this range will be described below.

  In addition, the inner diameter d of the nozzle tip 20a is more reliably the blood in the region having a gas partial pressure sufficiently close to the average value of the gas partial pressure, as the ratio d / F to the inner diameter F of the blood outlet port is sufficiently small. Sampling becomes possible, variation in measured values of gas partial pressure is suppressed, and accuracy is improved. Here, since there is a desirable range of the ratio d / F that can be practically used, the range will be described below.

  The experimental results obtained by examining a practically desirable setting range by a gas exchange test regarding the protrusion amount L at the center of the nozzle tip 20a and the inner diameter d of the nozzle tip 20a will be described below. In the experiment, a system as shown in FIG. 6 was used. That is, with respect to the hollow fiber type artificial lung Ox having the sampling port 11 according to the present embodiment, blood is introduced from the blood inlet port 5 and part of the blood flowing out from the blood outlet port 6 is passed through the sampling port 11. Collected. In addition, the spilled blood was passed through the line filter Lf, and a part of the blood was collected by the line filter Lf. The carbon dioxide partial pressure of the collected blood was measured, and it was evaluated whether or not the blood collected from the sampling port 11 could appropriately approximate the average value of the gas partial pressure of the whole blood flowing out.

  The parameters applied to each element for the experiment are as follows.

Protrusion L: 0, 1, 2, 3, 4, 5 [mm]
Inner diameter d of nozzle tip 20a: 1.0, 1.5, 2.0 [mm]
Inner diameter F of blood outlet port 6: 10 [mm]
The carbon dioxide partial pressure measured for blood collected through the sampling port 11 is P1, the carbon dioxide partial pressure measured for blood collected in the line filter Lf is P2, and the carbon dioxide partial pressure difference = (P1-P2) is obtained. The result of the experiment is shown in FIG.

  In FIG. 7, the horizontal axis indicates the protrusion amount L (mm), and the vertical axis indicates the carbon dioxide partial pressure difference. When the inner diameter d of the nozzle tip 20a is 1.0 [mm], it is a black triangle ▲, when it is 1.5 [mm] is a black square ■, and when it is 2.0 [mm] It shows with.

  From FIG. 7, regarding the protrusion amount L at the center of the nozzle tip 20a, the gas partial pressure of the blood collected from the sampling port 11 is practically set by setting the ratio L / F within a range that satisfies the following conditions. Can be seen to approximate the average value sufficiently.

0.2 ≦ L / F ≦ 0.5
The above shows the difference in gas partial pressure between the actual blood flowing out from the blood outlet port and the blood collected from the sample port using carbon dioxide partial pressure as an index. On the other hand, the same tendency is shown when oxygen partial pressure is used as an index. Therefore, the difference between the actual blood value and the sampled value can be reduced by adopting the configuration of the present invention regardless of the oxygen partial pressure or the carbon dioxide partial pressure.

  Therefore, it is desirable to satisfy this condition, set the center position of the nozzle tip 20a, and measure the gas partial pressure of blood collected from the nozzle 20. As a result, a practically close value can be obtained as a measured value with respect to the average value of the gas partial pressure in the blood flowing out from the blood outlet port 6.

  As for the inner diameter d of the nozzle tip 20a, if the experimental range, that is, the ratio d / F is set to a range that satisfies the following conditions, the gas partial pressure of blood collected from the sampling port 11 is: It can be seen that the average value is sufficiently approximated in practice.

0.1 ≦ d / F ≦ 0.2
Therefore, it is desirable to set the inner diameter d so as to satisfy this condition. Thereby, blood having a gas partial pressure sufficiently close to the average value of the entire gas partial pressure can be easily collected from blood flowing out from the blood outlet port 6 in practice.

  In the above description, the hollow fiber oxygenator having a configuration in which the heat exchange part 2 and the gas exchange part 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 the case of a hollow fiber type artificial lung having only the gas exchange unit 3 without the heat exchange unit 2, the same effect as described above can be obtained by applying the configuration of the sampling port 11 described above. The same applies to the following embodiments.

(Embodiment 2)
8 and 9 are enlarged cross-sectional views of the vicinity of the sampling port 11 of the hollow fiber oxygenator according to Embodiment 2 of the present invention. The overall structure of the oxygenator is the same as that of the first embodiment shown in FIGS. The present embodiment is characterized in that the nozzle is formed separately from the sampling port 11. The nozzle dimensions, arrangement, function, and the like are the same as those of the nozzle 20 in the first embodiment.

  In one mode shown in FIG. 8, a configuration in which a chip-like nozzle 23 formed separately from the sampling port 11 is mounted in the sampling port 11 is used. The sampling port 11 is formed on the outer shell wall of the housing 1 forming the blood outlet header together with the blood outlet port 6 and the temperature measuring port 12 as in the conventional case. The outer diameter of the chip-like nozzle 23 is set so as to fit and closely contact the inner peripheral surface of the sampling port 11. Similar to the configuration shown in FIG. 4, the tube 21 is connected to the outer end portion of the sampling port 11 via the connection member 22.

  In another embodiment shown in FIG. 9, a nozzle member 26 in which the nozzle 24 and the fitting portion 25 are coupled is used. A connecting portion 25 a is provided at the outer end portion of the fitting portion 25, and the tube 21 is connected via the connecting member 22. In addition, although the nozzle 24 is shown by the cross section, the fitting part 25 and the connection part 25a are not a cross section but the external appearance is shown.

  A cross-sectional structure of the nozzle member 26 is shown in cross section in FIG. The fitting portion 25 is coupled to the proximal end portion of the nozzle 24. In this configuration, the nozzle 24 is formed integrally with the fitting portion 25. However, the nozzle 24 may be formed in a chip shape, and the fitting portion 25 may be formed separately and then joined to each other. The fitting portion 25 is fitted to the outer peripheral surface of the outer end portion of the sampling port 11. In this state, the nozzle 24 is mounted and fitted in the lumen of the sampling port 11.

  The fitting portion 25 is attached to the outer end portion of the sampling port 11 and positioned by the outer end portion, whereby the tip of the nozzle 24 is positioned in the lumen of the blood outlet port 6 through the positioning. .

  As yet another embodiment, although not shown, the nozzle may be coupled to a connection member attached to the tip of a tube connected to the sampling port 11. In this case, the nozzle tip is set so as to be positioned at the center of the blood outlet port 6 with the tube 21 connected to the sampling port 11.

  Also in the case of the hollow fiber oxygenator of the present embodiment, for the nozzles 23 and 24, the ratio L / F of the protruding amount L to the inner diameter F of the blood outlet port 6 and the ratio of the inner diameter d to the inner diameter F of the blood outlet port 6 It is desirable that d / F be within the same setting range as in the first embodiment.

  The configuration of the oxygenator shown in the above embodiment is an example, and the configuration of the sampling port 11 of the present embodiment can be applied to any other configuration. The heat exchange unit 2 and the gas exchange unit 3 may be combined in another form or may be relatively movable. In addition, the artificial lung 2 is not limited to the heat exchange unit 2 and the gas exchange unit 3, and the configuration of the sampling port 11 according to the present embodiment is applied even if the artificial lung 2 is composed of only the gas exchange unit. Thus, similar effects can be achieved. Therefore, in the present invention, the term “artificial lung” is used to mean a device that includes only a gas exchange unit.

  According to the hollow fiber oxygenator of the present invention, it is possible to appropriately measure the average gas partial pressure in the blood flowing out from the blood outlet port by simple improvement of the sampling port portion, and the extracorporeal blood circulation. It is useful as an artificial heart-lung machine.

DESCRIPTION OF SYMBOLS 1 Housing 2 Heat exchange part 3 Gas exchange part 4 Blood flow path 5 Blood inlet port 6 Blood outlet port 7, 8 Cold / hot water port 9, 10 Gas port 11 Sampling port 12 Temperature measurement port 13 Support part 14 Rib 15 Stainless steel pipe 16 Hollow fiber membrane 17 Potting part 18 Temperature sensor 20, 24 Nozzle 20a Nozzle tip 21 Tube 22 Connection member 23 Chip-shaped nozzle 25 Fitting part 25a Connection part 26 Nozzle member

Claims (8)

A hollow fiber bundle formed by a plurality of hollow fiber membranes;
A housing forming a gas exchange chamber in which the hollow fiber bundle is accommodated;
A gas port provided in the housing so that a gas containing oxygen flows in and out through the lumen of the hollow fiber membrane;
A blood flow path for circulating blood so as to traverse the hollow fiber bundle in the gas exchange chamber and to contact the outer surface of the hollow fiber membrane;
A blood inlet port and a blood outlet port respectively provided in the housing so as to face the central part of both ends of the blood flow path;
In a hollow fiber oxygenator provided with a sampling port branched from the blood outlet port,
A nozzle that protrudes from the base portion of the sampling port formed on the side wall of the blood outlet port toward the central axis of the blood outlet port, and has a nozzle that is located in the blood outlet port;
The inner diameter d of the tip of the nozzle is smaller than the inner diameter F of the blood outlet port at the position where the tip of the nozzle is located in the axial direction of the blood outlet port,
A hollow fiber oxygenator configured to collect a part of blood flowing out from the blood outlet port through the nozzle.   The nozzle is formed by extending the end of the sampling port on the blood outlet port side toward the center of the blood outlet port, and the inner diameter of both at the boundary between the nozzle and the sampling port is The hollow fiber oxygenator according to claim 1, which is set so that no step is formed on the inner peripheral surface.   The hollow fiber oxygenator according to claim 1, wherein the nozzle is formed separately from the sampling port and is mounted in the sampling port. A fitting portion coupled to the base end of the nozzle;
With the nozzle fitted in the lumen of the sampling port, the fitting portion is fitted to the outer peripheral surface of the outer end portion of the sampling port, and the fitting portion is the outer end portion of the sampling port. Through which the tip of the nozzle is positioned in the lumen of the blood outlet port,
The hollow fiber oxygenator according to claim 3, wherein a tube for transferring blood to a measuring device or the like can be connected to the fitting portion.   The hollow fiber oxygenator according to claim 4, wherein the nozzle and the fitting portion are integrally formed.   The nozzle is attached to the tip of a tube connected to the sampling port, and the tip of the nozzle is positioned at the center of the lumen of the blood outlet port with the tube connected to the sampling port The hollow fiber oxygenator according to claim 3. When the protruding amount at the center of the tip of the nozzle from the inner peripheral surface of the blood outlet port is L, the ratio L / F of the protruding amount L to the inner diameter F of the blood outlet port satisfies the following condition. The hollow fiber oxygenator according to any one of claims 1 to 6, which is set in a range.
0.2 ≦ L / F ≦ 0.5 The ratio d / F of the inner diameter d to the inner diameter F of the blood outlet port is set in a range satisfying the following conditions, where d is the inner diameter of the nozzle tip. The hollow fiber oxygenator according to Item.
0.1 ≦ d / F ≦ 0.2

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