JP5347602B2 - Blood processing equipment - Google Patents

Description

  The present invention is used for extracorporeal circulation in cardiovascular surgery, and is a blood processing apparatus for removing the increased water content into a normal amount of blood while supplying oxygen to the blood and removing carbon dioxide. About.

  In cardiovascular surgery involving extracorporeal circulation, it is common to use a dilute extracorporeal circulation method for the purpose of reducing blood transfusion, improving peripheral circulation, and reducing blood damage. However, when high dilution occurs due to inflow of extracorporeal fluid or myocardial protective fluid into the extracorporeal circuit, edema will occur due to decreased colloid osmotic pressure, and gas exchange capacity will decrease due to decreased hematocrit. If necessary, an operation for discharging (water removal) excess water using a blood concentrator or the like is required.

  Therefore, in order to perform the extracorporeal circulation method, it is necessary to use an oxygenator for performing gas exchange for supplying oxygen to blood and removing carbon dioxide, and a blood concentrator for performing dehydration. An extracorporeal circuit in which both devices are separately arranged has been known. However, since a blood concentrator circuit is required in parallel with the artificial lung circuit, the circuit is complicated and the blood processing operation is complicated. In addition, since the configuration is a parallel loop circuit, there is a disadvantage that the priming amount (blood filling amount) increases and the biological load increases.

  On the other hand, Patent Document 1 describes that the above-described problems are solved by a configuration in which an artificial lung and a blood concentrator are integrated and housed in a common housing. This blood processing apparatus will be described with reference to FIG. This blood processing apparatus A has a configuration in which an artificial lung B and a blood concentrator C are arranged and accommodated in a cylindrical housing 20 in series.

  A blood introduction port 21a serving as an inlet for the untreated blood F1 is provided on the first end side in the longitudinal direction of the housing 20, and a blood outlet port 21b serving as an outlet for the processed blood F2 is provided on the terminal side. In the region where the oxygenator B is housed, a gas outlet port 22a serving as a carbon dioxide outlet is provided at the outer peripheral position in the vicinity of the blood introduction port 21a, and oxygen is provided at the outer peripheral position downstream of the oxygenator B region. A gas inlet port 22b serving as an air supply port is provided. A drainage port 23 serving as a water removal port for the filtrate E is provided at the outer peripheral position of the region where the blood concentrator C is stored.

  The artificial lung B is composed of a large number of first hollow fiber membranes 24 made of a silicone membrane, and both ends thereof are airtightly fixed by a curable resin 25 such as polyurethane. The blood concentrator C is composed of a plurality of second hollow fiber membranes 26 made of a polysulfone membrane having a high water permeation rate and a high protein blocking rate, and both ends thereof are airtightly fixed by a curable resin 25 such as polyurethane.

  With the above configuration, oxygen is supplied from the gas inlet port 22b to the blood flowing in the axial direction in the first hollow fiber membrane 24 of the oxygenator B, and carbon dioxide in the blood gas-exchanged with this oxygen is supplied to the gas outlet port. It discharges from 22a. Further, moisture is permeated in the radial direction from the blood flowing in the second hollow fiber membrane 26 of the blood concentrator C in the axial direction and is discharged from the drain port 23.

  As described above, the first hollow fiber membrane 24 and the second hollow fiber membrane 26 are arranged in series in the housing 20, so that the untreated blood F 1 flowing from the blood introduction port 21 a is oxygenated in the region of the artificial lung B. After the carbon dioxide is discharged, excess water is removed in the region of the blood concentrator C and flows out from the blood outlet port 21b as the processed blood F2.

  Patent Document 2 discloses another configuration in which an artificial lung and a blood concentrator are integrated and housed in a common housing. This will be described with reference to FIG. In the blood processing apparatus A, a large number of first hollow fiber membranes 24 constituting the artificial lung B and a plurality of second hollow fiber membranes 26 constituting the blood concentrator C are mutually connected in a cylindrical housing 20. It has the structure accommodated in parallel. The same elements as those in the blood processing apparatus of FIG. 4 are denoted by the same reference numerals, and the description is not repeated.

  A blood introduction port 21a is provided on the first end side in the longitudinal direction of the housing 20, and a blood outlet port 21b is provided on the end side. On the outer peripheral surface on the side that functions as the oxygenator B, a gas outlet port 22a serving as a carbon dioxide discharge port and a gas inlet port 22b serving as an oxygen supply port are provided. On the outer peripheral surface on the side that functions as the blood concentrator C, a drainage port 23 serving as a water removal port for the filtrate E is provided.

  With the above configuration, oxygen is supplied from the gas inlet port 22b to the blood flowing in the axial direction in the first hollow fiber membrane 24, and the carbon dioxide in the gas-exchanged blood is discharged from the gas outlet port 22a. Further, moisture is permeated in the radial direction from the blood flowing in the second hollow fiber membrane 26 in the axial direction and is discharged from the drain port 23.

JP 62-47369 A JP 62-47368 A

  In the case of the configuration described in Patent Document 1, the axial directions of the artificial lung and the hollow fiber membrane of the blood concentrator are arranged in series, and the path through which blood passes through the hollow fiber membrane becomes long. Therefore, the pressure loss of the blood flow is large. Further, since an internal perfusion system as described later is adopted, it can be used only at a low perfusion rate (or under a low perfusion), and further from the drainage port 23 for water removal by the blood concentrator. There is a problem that it is necessary to apply a negative pressure and the number of elements constituting the apparatus increases.

  Further, in the case of the configuration described in Patent Document 2, since the blood flowing in from the blood introduction port 21a is diverted to the artificial lung region and the blood concentrator region, only a part of the perfused blood volume is gas-exchanged, Moreover, only the remaining part is drained. Therefore, the blood after processing by the blood processing apparatus is mixed with blood having different processing states, which is not preferable. On the blood concentrator side, there is a possibility that the viscosity of the blood increases due to concentration, and the blood does not flow.

  In addition, as shown in Patent Documents 1 and 2, the blood concentrator generally uses a hollow fiber internal perfusion system in the same manner as the blood purifier in terms of efficiency. That is, blood is circulated through the lumen of the hollow fiber membrane, and water is removed to the outer surface side of the hollow fiber membrane. This is because the transmembrane pressure (TMP) can be increased even with low perfusion, and the water removal efficiency can be improved.

  On the other hand, since the pressure loss is high, it is not suitable for use under high perfusion (500 mL / min or less). Therefore, in the case of a heart-lung machine used for high perfusion, it is necessary to provide a blood concentrator in a separate circuit for low perfusion.

  In consideration of the above problems, the present invention is suitable for an artificial lung because the oxygenator and the blood concentrator are housed in a common housing, and can perform gas exchange and water removal with low pressure loss of the blood flow. An object of the present invention is to provide a blood treatment apparatus that can be used under high perfusion.

In order to solve the above problems, the blood treatment apparatus of the present invention comprises a blood concentration module formed by a hollow fiber bundle in which a plurality of hollow fiber membranes for water removal are arranged in a plane and laminated in a plurality of layers, and a gas exchange device. A gas exchange module formed by a hollow fiber bundle in which a plurality of hollow fiber membranes are arranged in a plane and laminated in a plurality of layers, and the blood concentration module and the gas exchange module are arranged in series, each housed in a laminated state A housing having a blood concentration part and a gas exchange part, and an opening at one end of the hollow fiber membrane for water removal is exposed, an opening at the other end is closed, and openings at both ends of the hollow fiber membrane for gas exchange are exposed. Sealing both ends of the blood concentration module and the gas exchange module in a direction intersecting with the axial direction of the dewatering hollow fiber membrane and the gas exchange hollow fiber membrane in an intermediate region between the both ends. Extended A sealing member forming a blood flow path passing through the blood concentration part and the gas exchange part, a blood inflow port and a blood outflow port provided in the housing facing both ends of the blood flow path, a drain port provided in the housing facing the opening of the one end of the dewatering hollow fiber film exposed from the sealing member, both ends of the gas exchange hollow fiber membrane exposed from the sealing member An air supply port and an exhaust port provided in the housing facing the opening, and a space in a region facing the opening of the closed other end of the dewatering hollow fiber membrane by the inner wall of the housing it said that the blockade was.

  In the blood processing apparatus having the above configuration, the blood concentration module and the gas exchange module are housed in a stacked state in the same housing, and are arranged in series with respect to the blood flow path, so that an external perfusion method can be applied. .

  Therefore, the blood flow sequentially passes along the outer surface side of the hollow fiber membrane of the blood concentration module and the gas exchange module, and blood concentration and gas exchange can function in the same housing, and the blood is hollow fiber. Since it flows outside the membrane, there is little pressure loss. Therefore, it can be used under high perfusion suitable for artificial lungs.

Sectional drawing of the blood processing apparatus in Embodiment 1 of this invention The perspective view which showed the principal part of the blood processing apparatus in the partial cross section The perspective view which shows the other form of the principal part of the blood processing apparatus Sectional drawing of the blood processing apparatus in Embodiment 2 of this invention Sectional view of a conventional blood treatment apparatus Sectional drawing of the blood processing apparatus of another conventional example

  The blood processing apparatus of the present invention can take the following aspects based on the above-described configuration.

That is, it is preferable that the gas exchange part is disposed closer to the blood inlet port than the blood concentrating part .

  Further, the blood channel preferably has a circular cross section perpendicular to the channel direction.

  The axial direction of each hollow fiber constituting the blood concentration module and the gas exchange module may be arranged so as to be orthogonal to the flow direction of the blood flow path and the axial directions of the hollow fibers intersect each other. it can.

  Further, the gas exchange hollow fiber membrane is formed using a polypropylene membrane, and the water removal hollow fiber membrane is a polystyrene film, a polyether sulfone film, a polymethyl methacrylate film, or a cellulose acetate film. It can be set as the structure formed.

  Further, the blood concentration part may have a structure in which a plurality of stages are provided on the front and rear sides to concentrate the blood stepwise.

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

(Embodiment 1)
A cross-sectional view of the blood treatment apparatus according to Embodiment 1 of the present invention is shown in FIG. FIG. 2A is a perspective view showing the main part in a partial cross section. This blood processing apparatus has a blood concentration module 1 and a gas exchange module 2. The blood concentration module 1 is formed by a hollow fiber bundle in which a plurality of dewatering hollow fiber membranes 1a that permeate moisture but block proteins are arranged. The gas exchange module 2 is formed of a hollow fiber bundle formed by arranging a plurality of gas exchange hollow fiber membranes 2a having excellent gas exchange performance.

  The housing 3 includes a blood concentration unit 4 that houses the blood concentration module 1 and a gas exchange unit 5 that houses the gas exchange module 2. The water removal hollow fiber membrane 1a and the gas exchange hollow fiber membrane 2a are arranged in a laminated state. That is, in the example of FIG. 1, the axial direction of the water removal hollow fiber membrane 1a and the axial direction of the gas exchange hollow fiber membrane 2a are parallel. However, if the dewatering hollow fiber membrane and the gas exchange hollow fiber membrane have a laminated structure, the axial directions of the hollow fiber membranes do not necessarily have to be parallel to each other. For example, as shown in FIG. 2B, the water removal hollow fiber membrane and the gas exchange hollow fiber membrane are arranged in a state substantially perpendicular to the direction of the blood flow path, and the water removal hollow fiber membrane is used for gas exchange. The aspect which cross | intersected with respect to the hollow fiber membrane may be sufficient. Thereby, the space formed between the hollow fiber membrane bundles can be reduced, which is preferable.

  Both end portions of both modules 1 and 2 are sealed by a sealing member 6 formed of a polymer potting material such as polyurethane, silicone, epoxy resin or the like. A state in which the housing 3 is removed is shown in a partially sectional view in FIG. 2A so that the structure formed by the sealing member 6 can be easily understood.

  In this sealing structure, the opening at one end of the water removal hollow fiber membrane 1a is exposed without being closed, but the opening at the other end is closed. Further, the openings 7 at both ends of the gas exchange hollow fiber membrane 2 a are exposed without being closed by the sealing member 6. Therefore, a gas flow path penetrating both ends of the hollow fiber membrane is secured inside the gas exchange hollow fiber membrane 2a. Furthermore, the sealing member 6 has a through-hole that forms the blood flow path 8 in the middle region between both end portions of both modules 1 and 2. The blood flow path 8 is formed to extend in a direction intersecting the axial direction of the dewatering hollow fiber membrane 1a and the gas exchange hollow fiber membrane 2a and pass through the blood concentration unit 4 and the gas exchange unit 5, The cross-sectional shape orthogonal to the flow path direction is circular.

  The housing 3 further has blood inflow ports 9 and blood outflow ports 10 facing both ends of the blood flow path 8. Further, a drainage port 11 is provided on the side of the blood concentration part 4 so as to face the opening at one end of the water removal hollow fiber membrane 1 a exposed from the sealing member 6. Further, an air supply port 12 and an exhaust port 13 are provided on the side of the gas exchange part 5 so as to face the openings at both ends of the gas exchange hollow fiber membrane 2 a exposed from the sealing member 6.

  Furthermore, a partition wall 14 is provided on the inner wall of the housing 3 at the boundary between the blood concentration unit 4 and the gas exchange unit 5. Thereby, in the blood concentration part 4, a space isolated from others is formed in the region facing the drainage port 11. Further, at both ends of the gas exchange unit 5, spaces isolated from others are also formed in regions facing the air supply port 12 and the exhaust port 13, respectively. Accordingly, the drain port 11, the air supply port 12, and the exhaust port 13 function independently of each other.

  Although not shown in the figure, by incorporating a heat exchanger between the blood concentration unit 4 and the gas exchange unit 5, it is possible to heat or cool the blood immediately after blood concentration, Since the warm / cooled blood can be gas exchanged, it can be heated efficiently and the generation of bubbles can be suppressed.

  As described above, in the blood processing apparatus of the present embodiment, the blood concentration module 1 and the gas exchange module 2 are arranged in a stacked state, and are arranged in series with the blood channel 8. Then, blood circulates on the outer surface side of the hollow fiber membranes 1a and 2a, water is removed through the inside of the water removal hollow fiber membrane 1a, and oxygen-containing gas circulates inside the gas exchange hollow fiber membrane 2a. A so-called external perfusion system is used.

  Therefore, blood concentration and gas exchange can be easily functioned in the same housing, and since blood does not pass through the hollow fiber membrane, pressure loss is small compared to the internal perfusion method. Therefore, it can be used without providing a separate circuit for water removal under high perfusion suitable for an artificial lung. In the external perfusion method, the water removal efficiency is lower than that in the internal perfusion method. On the other hand, since the pressure loss is reduced in the external perfusion method, the decrease in the water removal efficiency is not a problem if used at a high perfusion rate.

  Moreover, when the blood concentration part 4 is arranged on the side closer to the blood inflow port 9 than the gas exchange part 5 as in the present embodiment, there are the following advantages. That is, when the blood flow first passes through the blood concentration unit 4 and then passes through the gas exchange unit 5, a higher TMP is obtained. Moreover, since the gas is exchanged after the blood is concentrated, the gas exchange performance is improved.

  Furthermore, by using the external perfusion method, it is not necessary to apply a negative pressure for water removal in the blood concentration unit 4.

  In addition, the structure of the present embodiment adopting the laminated type can easily form the hollow fiber membranes of different materials in the same housing as compared with the wind type artificial lung in which the hollow fiber is wound around the core. And since it is easy to provide an independent division about the flow path inside a hollow fiber membrane, it is easy to apply an external perfusion system using a blood concentration module and a gas exchange module together.

  As a raw material of the gas exchange hollow fiber membrane 2a used in the gas exchange module 2, for example, a polypropylene membrane can be used.

  Examples of the material for the water removal hollow fiber membrane 1a used in the blood concentration module 1 include PS (polystyrene) resin, PES (polyethersulfone) resin, PMMA (polymethylmethacrylate) resin, CA (cellulose acetate). Resin or the like may be used as it is, or other materials may be used.

  Blood concentrators using hollow fiber membranes made of these materials are most suitable for the internal perfusion system, for example, a structure in which a dense layer is disposed on the inner surface or intermediate layer side of the hollow fiber to maintain water removal efficiency for a long period of time. . Therefore, when the external perfusion method is used as in the present embodiment, if a conventional product is used, blood components may enter the outer surface of the hollow fiber, and the water removal efficiency may be somewhat reduced.

  However, compared with the internal perfusion method, the pressure loss can be reduced with the external perfusion method, so it can be used even at high perfusion rates, and the reduction in water removal efficiency due to the use of the external perfusion method is a problem. Not. For example, compared with the perfusion rate of about 100 to 500 mL in the case of the internal perfusion method, a much higher perfusion rate of about 100 mL to 7 to 8 L / min can be obtained. Of course, a hollow fiber membrane having a structure suitable for external perfusion, for example, a structure in which a dense layer is disposed from the outside may be used.

  The shape of the blood channel may be a straight channel, and the channel cross-sectional shape may be a square. However, if the circular channel is used as in the above embodiment, uneven flow is suppressed and the peripheral portion of the blood channel is also used. Since gas can be exchanged without stagnation (blood flow), high gas exchange efficiency can be obtained.

  Moreover, it is good also as a structure condensed in steps as a structure of three or more layers before and after.

(Embodiment 2)
FIG. 3 shows a cross-sectional view of the blood processing apparatus according to Embodiment 2 of the present invention. This blood processing apparatus has the same constituent elements as those in the first embodiment, and the gas exchange unit 5 is disposed upstream and the blood concentrating unit 4 is disposed downstream of the blood flow direction. However, this is different from the first embodiment. Accordingly, the same elements as those in the first embodiment are denoted by the same reference numerals, and the description will not be repeated.

  As shown in FIG. 3, the gas exchange unit 5 is disposed closer to the blood inflow port 9 than the blood concentration unit 4, and the gas exchange module 2 and the blood concentration module 1 are stacked in the same manner as in the first embodiment. Has been placed. Accordingly, the gas exchange module 2 and the blood concentration module 1 are arranged in series with respect to the blood flow path 8. Then, blood circulates on the outer surface side of the hollow fiber membranes 1a, 1b, oxygen-containing gas circulates inside the gas exchange hollow fiber membrane 2a, and water is removed through the interior of the water removal hollow fiber membrane 1a. The external perfusion method is used.

  As the blood flow first passes through the gas exchanging unit 5 and then passes through the blood concentrating unit 4 as in the present embodiment, the pressure loss in the oxygenator is reduced more than in the case of the first embodiment. is there. However, in the blood concentration unit 4, there is a possibility that a slight gas discharge occurs at the same time as the water-drawing effect. When the oxygen gas taken into the blood by the gas exchange is released, the gas exchange efficiency is substantially reduced.

  According to the blood processing apparatus of the present invention, blood concentration and gas exchange can be functioned in the same housing, and the pressure loss of the blood flow is small, so that it can be used under high perfusion, and is currently performed. This is useful because extracorporeal circulation can be performed without forming a separate circuit for water removal.

DESCRIPTION OF SYMBOLS 1 Blood concentration module 1a Water removal hollow fiber membrane 2 Gas exchange module 2a Gas exchange hollow fiber membrane 3 Housing 4 Blood concentration part 5 Gas exchange part 6 Sealing member 7 Opening 8 Blood flow path 9 Blood inflow port 10 Blood outflow port DESCRIPTION OF SYMBOLS 11 Drain port 12 Supply port 13 Exhaust port 14 Partition 20 Housing 21a Blood introduction port 21b Blood outlet port 22a Gas outlet port 22b Gas inlet port 23 Drain port 24 First hollow fiber membrane 25 Curable resin 26 Second hollow fiber membrane A Blood processing device B Artificial lung C Blood concentrator E Filtrate F1 Untreated blood F2 Treated blood

Claims (6)

A blood concentration module formed of a hollow fiber bundle in which a plurality of hollow fiber membranes for water removal are arranged in a plane and laminated in a plurality of layers ;
A gas exchange module formed by a hollow fiber bundle in which a plurality of gas exchange hollow fiber membranes are arranged in a plane and laminated in a plurality of layers ;
A housing having a blood concentration unit and a gas exchange unit in which the blood concentration module and the gas exchange module are housed in a stacked state and arranged in series ;
One end of the dewatering hollow fiber membrane is exposed and the other end is closed, and both ends of the gas exchange hollow fiber membrane are exposed, and both ends of the blood concentration module and the gas exchange module are exposed. The blood concentrating part and the gas exchange extending in a direction intersecting the axial direction of the dewatering hollow fiber membrane and the gas exchange hollow fiber membrane in an intermediate region between the both ends. A sealing member forming a blood flow path passing through the section;
A blood inflow port and a blood outflow port provided in the housing facing both ends of the blood flow path;
A drain port provided in the housing facing the opening of the one end of the dewatering hollow fiber film exposed from the sealing member,
An air supply port and an exhaust port provided in the housing facing openings at both ends of the gas exchange hollow fiber membrane exposed from the sealing member ;
A blood processing apparatus , wherein an inner wall of the housing seals a space in a region facing the opening of the closed other end of the dewatering hollow fiber membrane . The blood processing apparatus according to claim 1, wherein the gas exchange unit is disposed closer to the blood inlet port than the blood concentrating unit .   The blood processing apparatus according to claim 1, wherein the blood channel has a circular cross section perpendicular to the channel direction.   The axial direction of each hollow fiber which comprises the said blood concentration module and the said gas exchange module is orthogonally crossed with the flow direction of the said blood flow path, and it arrange | positions so that the axial direction of each hollow fiber may mutually cross | intersect. The blood processing apparatus of any one of 1-3.   The gas exchange hollow fiber membrane is formed by using a polypropylene membrane, and the water removal hollow fiber membrane is formed by using a polystyrene film, a polyether sulfone film, a polymethyl methacrylate film, or a cellulose acetate film. The blood processing apparatus according to any one of claims 1 to 4.   The blood processing apparatus according to any one of claims 1 to 5, wherein the blood concentration unit has a structure in which a plurality of stages are provided on the front and rear sides to concentrate blood in stages.

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