JP2011156022A - Column for hemocatharsis - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve uniform flow rate of blood flowing in a column for hemocatharsis. <P>SOLUTION: The column 10 for hemocatharsis includes adsorption particles 18 contained in a column main body 12 in a cylindrical form, and an inflow side and an outflow side filters 20 and 22 disposed on both ends of the column main body to prohibit them from flowing out. The filters 20 and 22 have resistance for blood to pass through that is greater around a center part, and smaller around circumferential edge parts. Blood flowing from an inflow port 34 located on an axial center of the column main body is restricted from flowing into the column main body around the center part of the inflow side filter 20, and blood prohibited from flowing into the column main body is guided to the circumferential edge parts. Flow rate distribution of blood in the column main body is thus equalized. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a blood purification column used when a treatment method for removing blood from the body and purifying it and returning the purified blood to the body is performed.

  A treatment method called apheresis therapy is known in which a patient's blood is once taken out of the body, a pathogenic substance in the removed blood is removed by adsorption, filtration, and the like, and then the blood is returned to the patient's body. This apheresis therapy is used to treat drug addiction, food poisoning, familial hypercholesterolemia, autoimmune diseases such as ulcerative colitis, Crohn's disease, and rheumatoid arthritis, and is considered to cause these diseases. It is used to remove substances such as drugs, toxins, cholesterol, and inflammatory cells such as white blood cells and platelets from the patient's blood.

  This apheresis treatment uses a primary membrane to separate plasma from the blood, and then passes this plasma through to the secondary membrane, or direct treatment of the patient's bodily fluid (DFPP: Double Filtration Plasmapheresis) Direct blood perfusion therapy (DHP: Direct Hemo Perfusion) is known. Direct blood perfusion therapy has been rapidly spreading in recent years because it is easy to process.

  In direct blood perfusion therapy, blood is passed through a column containing an adsorbent inside, and the target component in the blood is adsorbed and removed by the adsorbent. The column has a hollow cylindrical column body in which bead-shaped adsorbents (adsorbed particles) such as fine spheres are accommodated. In order to keep the adsorbent in the column main body, a filter having a large number of fine openings is arranged at the end of the column main body where blood flows and at the end where the blood flows. The opening of the filter is sized to allow blood to pass but not adsorbent.

  Patent Documents 1 and 2 below describe a net-like filter for holding an adsorbent in a column.

Japanese Patent No. 4150838 JP-A-6-54905

  If the flow rate of blood flowing in the column is non-uniform in the cross section of the flow path, the contact time with the adsorbent also becomes non-uniform, and the adsorption efficiency of the target component decreases. In particular, when the flow rate is increased in order to shorten the treatment time or prevent blood coagulation in the column, the flow rate tends to be non-uniform.

  An object of the present invention is to make the blood flow rate uniform within the cross section of the flow path in the column.

  The present invention changes the resistance of the filter provided for holding the adsorbed particles in the column when the blood passes for each part of the filter so that the blood spreads widely in the cross section of the flow path in the column. To. Specifically, in the inflow side filter arranged at the end of the inflow side of the column body in which the adsorbed particles are accommodated, the resistance of the portion of the inflow side filter that faces the inflow port that feeds blood into the column body is increased. On the other hand, the resistance is reduced at a portion away from the portion facing the inlet, and the resistance is monotonously decreased toward a portion away from the portion opposite the inlet. As a result, blood is guided from the vicinity of the inflow port to a portion away from the inflow port, and the blood flow is not concentrated in the vicinity of the inflow port. The resistance when blood passes through the filter refers to the resistance per unit area on the filter. The same applies hereinafter. In addition, here, “monotonically” of monotonously decreasing is used to include a fixed case. In other words, monotonously decreasing means “does not increase”. Similarly, monotonously increasing includes a certain case and does not decrease.

  For simplicity, it can be divided into two parts, a part near the inlet and the other part, and different resistances can be set for each part. That is, the resistance value is set in two stages. Three or more steps can be set, and it is possible to change gradually, that is, smoothly instead of stepwise.

  The resistance per unit area can be set by the aperture ratio. Here, the aperture ratio is defined as the ratio of the total area of the openings present in a certain area of the filter to the area of the area. If the aperture ratio is large, blood easily passes through the portion, and the resistance becomes small. On the other hand, if the aperture ratio is small, blood hardly passes and resistance increases. By changing the aperture ratio for each part of the filter, the resistance for each part can be changed.

  The resistance per unit area can be set by the dimensions of the individual openings. The dimension can be represented by the dimension in the shortest direction of the opening, such as the diameter if the shape of the opening is circular, and the width if the shape is elongated (slit shape). Compared to the case where a large size opening is provided in a certain area so that the total area of the opening is equal, and a case where a small size opening having a similar shape is provided, a small size opening is provided. In the case of the case, the resistance becomes larger. By changing the size of the opening for each part of the filter, the resistance for each part can be changed.

  The resistance per unit area can be set by the density of the openings. When a large number of openings having the same shape (same size) are arranged in a certain region and when a small number of openings are arranged, the resistance increases when the openings are arranged in a small number.

  The outflow filter also has a large resistance at the part facing the outlet, decreases at a part away from the part facing the outlet, and monotonously decreases toward a part away from the part opposite the outlet. Can be. The setting of this resistance can be selected from the setting method of the inflow side filter.

  The opening of the inflow filter can be a slit. Each slit can have an arc shape extending along a concentric circle centering on the axis of the inlet, and the width of each slit is small at the part facing the inlet and large at the part away from the part facing the inlet. And monotonously increasing toward a portion away from the portion facing the inlet.

  The opening of the inflow filter can be a slit. Each slit has an arc shape extending along a concentric circle centering on the axis of the inlet, and the radial arrangement pitch of the slits is large at a portion facing the inlet and at a portion away from the portion facing the inlet. It is small and can be decreased monotonically toward a portion away from the portion facing the inlet.

  The opening of the inflow side filter can be a communication hole. The number of communication holes per unit area is small at a portion facing the inlet, large at a portion away from the inlet, and monotonously increasing toward a portion away from the portion facing the inlet.

  The opening of the inflow side filter can be a communication hole. The opening area of each communication hole is small at the part facing the inlet, large at the part away from the part facing the inlet, and monotonously increasing toward the part away from the part facing the inlet. Can be.

  The outflow filter can have the same shape as the inflow filter.

  The inflow side filter and the outflow side filter described above can each be a molded product formed of the same material at the same time.

  In the portion of the inflow filter that faces the inlet, the resistance when blood passes is greater than the portion that is away from the portion that faces the inlet, so that the flow from the portion facing the inlet into the column body occurs. Restrict blood to be introduced and direct at least a portion thereof to the remote portion. Variation in the flow rate of blood flowing in the column in the cross section of the flow path can be reduced. For this reason, since the variation in the contact time with the blood adsorption particles is reduced, the adsorption efficiency of the target component can be increased.

It is a disassembled perspective view which shows schematic structure of the column for blood purification of this embodiment. It is sectional drawing of the column for blood purification of this embodiment. It is the schematic which shows the example of an inflow side filter and an outflow side filter. It is the schematic which shows the other example of the inflow side filter and the outflow side filter.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an exploded perspective view showing a schematic configuration of a blood purification column 10 according to the present embodiment, and FIG. 2 is a sectional view thereof. The blood purification column includes a column-shaped column body 12, preferably a cylindrical column body 12, and an inflow side cap 14 and an outflow side cap 16 that are mounted so as to cover the end surface of the column body. The column main body 12, the inflow side and outflow side caps 14, 16 form a container for storing the adsorbed particles 18. An inflow filter 20 is arranged at the end of the cylinder of the column body 12, and as shown in FIG. 2, the inflow filter 20 is supported by being sandwiched between the column body 12 and the inflow side cap. Yes. Similarly, the outflow side filter 22 is supported and disposed at the other end portion of the column main body 12 so as to be sandwiched between the column main body 12 and the outflow side cap 14. The inflow side and outflow side filters 20 and 22 have a large number of openings large enough to allow blood to pass but not adsorbed particles 18. Thus, the adsorbed particles 18 are accommodated in the space in the column main body 12 and are held so as not to flow out on the blood flow.

  The inflow side cap 14 has a bottom surface 24 that covers the end surface of the column body 12, and a side surface 26 that extends perpendicularly from the bottom surface 24, receives the side surface of the column body 12, and surrounds the periphery thereof. A step is attached to the inner periphery of the side surface 26, thereby forming a shoulder portion 28 extending in the circumferential direction. The inflow filter 20 is sandwiched and fixed between the shoulder 28 and the end surface of the column body 12. Between the inflow side filter 20 and the bottom surface 24, a space (hereinafter referred to as an inflow side cap inner space 30) having a cross section substantially equal to the cross section perpendicular to the axis of the column body 12 is formed. The bottom surface 24 is provided with an inflow pipe 32 connected to a tube (not shown) that sends blood extracted from the patient to the blood purification column 10. The inflow pipe 32 opens toward the inflow side cap inner space 30, and this opening is hereinafter referred to as an inflow port 34. The inflow pipe 32 is preferably arranged coaxially with the cylindrical axis of the column body 12.

  The outflow side cap 16 has the same configuration as the inflow side cap 14. That is, the outflow side cap 16 has a bottom surface 36 and a side surface 38, and a shoulder portion 40 is formed on the side surface. The outflow filter 22 is sandwiched between the shoulder 40 and the end surface of the column body 12. An outflow cap inner space 42 is formed between the outflow filter 22 and the bottom surface 36. The bottom surface 36 is provided with an outflow pipe 44 to which a tube (not shown) that returns blood after treatment in which a predetermined component is adsorbed by the adsorbed particles in the column main body 12 to the patient is connected. The outflow pipe 44 opens toward the outflow side cap inner space 42 (hereinafter, referred to as an outflow port 46). The outflow pipe 44 is preferably arranged coaxially with the cylindrical axis of the column body 12.

  The material of the column body 12, the inflow side and outflow side caps 14, 16 can be, for example, polycarbonate, polysulfone, polypropylene, or the like. The column body 12 and these caps 14 and 16 can be screwed together, and a joining method such as ultrasonic fusion can also be adopted. Further, an O-ring may be disposed between the column body 12 and these caps 14 and 16 to prevent leakage of fluid such as blood from the gap. It is desirable to provide slopes for pressing the O-rings on the inner surfaces of the caps 14 and 16 and to generate a force that causes the filters 20 and 22 and the O-rings to be in close contact with each other when screwed.

  The material of the inflow side filter 20 and the outflow side filter 22 may be a polymer compound such as polyester, polyethylene, or polypropylene, or a metal. Moreover, it is preferable that the mesh part and the frame part are integrally formed, that is, the whole filter is formed at the same time using the same material.

  The blood that has flowed into the blood purification column 10 from the inflow pipe 32 flows from the inflow side cap inner space 30 through the inflow side filter 20 to the space containing the adsorbed particles 18 in the column main body 12. The blood flows toward the outflow side through the gap between the adsorbed particles while contacting the adsorbed particles 18 in the column main body 12 and passes through the outflow side filter 22. The blood that has passed through the outflow filter 22 flows out from the outflow pipe 44 through the outflow side cap inner space 42, the outflow port 46, and the like.

  The blood flowing into the blood purification column 10 from the inflow pipe 32 flows toward the portion of the inflow side filter 20 facing the inflow port 34 due to the inertia at the time of inflow, while being separated from the portion corresponding to the inflow port. There is a tendency for the flow toward the part to decrease. For this reason, the velocity distribution in the cross section of the flow channel in the column main body 12 tends to be fast at a portion facing the inlet 34 and slow at a portion away from this. In order to eliminate this tendency, in this blood purification column 10, the resistance of the inflow filter 20 when blood passes is large at a portion facing the inflow port of the inflow side filter and small at a portion away from this. is doing. As a result, the blood that has flowed into the inflow-side cap inner space 30 also flows in a portion away from the portion facing the inlet, and the uneven velocity distribution in the column body 12 is improved. The “resistance” mentioned here refers to a resistance when blood passes through a region of a unit area on the inflow side filter. The same applies to the resistance relating to the outflow filter described later.

  Even in the flow from the column main body 12 through the outflow filter 22 toward the outflow pipe 44, the portion facing the outflow port 46 tends to flow, and the portion facing the outflow port 46 in the column main body 12 is separated from here. There is a tendency for the flow velocity to be faster than the part. In order to solve this problem, in the outflow side filter 22, as in the inflow side filter 20, the resistance when blood passes is increased in the portion facing the outflow port 46, and the resistance is decreased in a portion away from this. And improving the non-uniform velocity distribution.

  FIG. 3 schematically shows an example of the inflow filter 20 and the outflow filter 22. The filters 20 and 22 have the same shape as the cylindrical axis-orthogonal cross section of the column main body 12, and in the illustrated example, they correspond to the case where the column main body 12 is cylindrical, and are circular. Further, this corresponds to the case where the positions of the inlet 34 and the outlet 46 are arranged coaxially with the cylindrical axis of the column body 12. In addition, what is shown in the figure is 1/4 of the whole, and the other part has the same shape as the part shown in the figure.

  A circular outer ring portion 50 for maintaining the strength of the filter is provided on the outer periphery of the filters 20 and 22, and a beam 52 extending along the diameter and coupled to the outer ring portion 50 is provided on the inner side thereof. ing. Furthermore, the filters 20 and 22 are provided with a large number of slits 48 extending along the circumferential direction of a concentric circle centering on the center of the filter, that is, the point through which the cylindrical axis of the column body 12 passes. The slit 48 on one concentric circle is interrupted by the beam 52 extending in the radial direction, but is formed in an annular shape as a whole. The arrangement pitch p in the radial direction of the slits 48, that is, the interval between the center lines in the width direction of the adjacent slits 48 is constant. On the other hand, the width of the slit, that is, the dimension in the radial direction is narrow (w1) in the slit 48-1 closer to the center and wide (w3) in the slit 48-3 in the peripheral portion. The slit 48-2 near the middle has a middle width w2. By making the arrangement pitch p constant, the width w of the slit 48 is narrow at the center portion and wide at the peripheral portion, thereby increasing the resistance of the central portion and decreasing the resistance of the peripheral portion. Due to this difference in resistance, the flow rate of blood flowing from the inflow port 34 toward the peripheral portion in the inflow side cap inner space 30 is increased. Thereby, the velocity distribution of the blood flow in the column main body 12 is made uniform, and variations in the time during which the blood contacts the adsorbed particles are reduced.

  In FIG. 3, the width w of the slit 48 is shown enlarged so as to be able to be illustrated. The adsorbent particles 18 used in the blood purification column 10 are spheres having a diameter of about 1 mm, and the width of the slit is such that adsorbent particles do not pass through. The width of the slit is 100 μm (= w1) at the central portion and 750 μm (= w3) at the peripheral portion, and gradually increases in steps of 25 μm from the central portion toward the peripheral portion.

  As described above, in this blood purification column 10, by changing the slit width by making the slit arrangement pitch constant, the aperture ratio (the area of the slit in the region with the filter is the area of the entire region). (Value divided by) is changed. In other words, the aperture ratio is low when the slit width is narrow and high when it is wide. Blood is guided from a low opening ratio to a high opening ratio, that is, from the central portion to the peripheral portion.

  The slit width can be changed in two steps or more, and may be gradually increased toward the peripheral portion. In addition, blood can be returned to the central portion in the column main body 12 with no slit in the central portion.

  In the above example, the aperture ratio is changed by changing the slit width. However, the aperture ratio may be changed by changing the arrangement pitch. For example, the slit width may be constant, and the arrangement pitch may be increased at the center portion and decreased toward the peripheral portion. The change in the arrangement pitch may be two steps or more, and may be gradually reduced toward the peripheral portion. In addition, blood can be returned to the central portion in the column main body 12 with no slit in the central portion.

  Furthermore, the resistance of the central portion and the peripheral portion can be changed by changing the slit width and the arrangement pitch without changing the aperture ratio. For example, if the slit width and the arrangement pitch are each halved, the aperture ratio does not change. However, when the slit width is halved, the contact area between the filter and blood passing through the filter increases, and the resistance increases. By utilizing this, the resistance of the central portion and the peripheral portion may be changed.

  If the inflow side filter 20 and the outflow side filter 22 are made the same, it is preferable in terms of sharing parts. However, the inflow side filter 20 and the outflow side filter 22 may have different shapes. The velocity distribution of blood flow in the column main body 12 is considered to have a large influence on the inflow side through which blood flows. Therefore, only the inflow side filter 20 is used, and the resistance of each part is changed. A combination using conventional resistors with uniform resistance may be used.

  FIG. 4 is a diagram illustrating another example of the filter. The filter 54 has a structure that can be used in place of the aforementioned inflow side and outflow side 20, 22. As in FIG. 3, ¼ is shown. The filter 54 is provided with a number of communication holes 56 that communicate the front and back of the filter. In the illustrated example, the communication holes 56 are all circular with the same size. However, the shape may be a square, a polygon such as a hexagon, or a star. In the filter 54, the density (number per unit area) of the communication holes 56 is reduced at the central portion and increased at the peripheral portion. By using this filter 54 as an inflow filter, the aperture ratio is small at the central portion and large at the peripheral portion, and the resistance is large at the central portion and large at the peripheral portion. As a result, the flow rate of blood that attempts to pass through the central portion facing the inlet of the filter 54 is limited, the blood flows toward the peripheral portion, and the blood flow distribution in the column body 12 is made uniform.

  The change in the density of the communication holes can be two steps or more, and may be gradually increased toward the peripheral portion. Alternatively, blood that has passed through the filter may be returned to the central portion in the column body with no communication hole in the central portion.

  The aperture ratio can be changed depending on the size of the communication hole 56. For example, assuming that the density is constant, the opening area of the communication hole in the central portion may be reduced and increased in the peripheral portion. The change in the size of the communication hole can be two steps or more, and may be gradually increased toward the peripheral portion. Alternatively, blood that has passed through the filter may be returned to the central portion in the column body with no communication hole in the central portion.

  Further, even if the aperture ratio is made uniform, the opening area of each communication hole is reduced in the central portion, and the resistance in the central portion can be increased even if it is increased in the peripheral portion.

  The filter may be a mesh filter. Since the opening of the mesh is substantially square, if this is regarded as a communication hole, the resistance of each part can be set similarly to the circular hole filter 54 shown in FIG.

  In the above description, the column main body is exemplified by a cylindrical shape, but is not limited thereto, and may be a rectangular or polygonal square tube cross section, or an oval or oval cross section. Further, the inflow port and the outflow port are not limited to the example in which the inflow port and the outflow port are disposed on the cylindrical axis line of the column body, and may be disposed at positions offset from the axis line.

  Preferred embodiments of the present invention are described below.

  The column for blood purification according to one embodiment of the present invention has a cylindrical shape, and a column main body having a storage space for storing adsorbed particles inside the cylinder, and disposed at one end of the column main body. Is placed at the other end of the cylinder of the column body, and the blood flowing out from the column body is allowed to pass through the blood flowing into the column body, and the adsorbed particles are put into the column body. An outflow side filter to be held; an inflow side cap which is attached to the one end of the column main body and has an inlet for feeding blood into the column main body on the axis of the column main body; and the other end of the column main body And an outflow side cap provided with an outflow port for delivering blood from within the column body, and the inflow side filter has a number of slits through which blood passes, The lit has an arc shape extending along a concentric circle with the cylindrical axis of the column body as the center, the widths of the slits are equal, and the radial arrangement pitch of the slits is large at the radial center portion of the accommodating space. , Small at the peripheral portion and monotonously decreasing from the central portion toward the peripheral portion.

  The column for blood purification according to one embodiment of the present invention has a cylindrical shape, and a column main body having a storage space for storing adsorbed particles inside the cylinder, and disposed at one end of the column main body. Is placed at the other end of the cylinder of the column body, and the blood flowing out from the column body is allowed to pass through the blood flowing into the column body, and the adsorbed particles are put into the column body. An outflow side filter to be held; an inflow side cap which is attached to the one end of the column main body and has an inlet for feeding blood into the column main body on the axis of the column main body; and the other end of the column main body And an outflow side cap provided with an outflow port for delivering blood from within the column body, and the inflow side filter has a number of slits through which blood passes, The lit has an arc shape extending along a concentric circle centering on the cylindrical axis of the column main body, the arrangement pitch in the radial direction of these slits is constant, and the width of each slit is the center in the radial direction of the housing space It is large at the part, small at the peripheral part, and monotonously decreases from the central part toward the peripheral part.

  The column for blood purification according to one embodiment of the present invention has a cylindrical shape, and a column main body having a storage space for storing adsorbed particles inside the cylinder, and disposed at one end of the column main body. Is placed at the other end of the cylinder of the column body, and the blood flowing out from the column body is allowed to pass through the blood flowing into the column body, and the adsorbed particles are put into the column body. An outflow side filter to be held; an inflow side cap which is attached to the one end of the column main body and has an inlet for feeding blood into the column main body on the axis of the column main body; and the other end of the column main body And an outflow side cap provided with an outflow port for sending out blood from within the column body, and the inflow side filter has many communication holes of the same shape through which blood passes The number of communication holes per unit area is less in the radial center portion of the accommodating space, much in the peripheral portion, and monotonically increases from the central portion to the peripheral portion.

  The column for blood purification according to one embodiment of the present invention has a cylindrical shape, and a column main body having a storage space for storing adsorbed particles inside the cylinder, and disposed at one end of the column main body. Is placed at the other end of the cylinder of the column body, and the blood flowing out from the column body is allowed to pass through the blood flowing into the column body, and the adsorbed particles are put into the column body. An outflow side filter to be held; an inflow side cap which is attached to the one end of the column main body and has an inlet for feeding blood into the column main body on the axis of the column main body; and the other end of the column main body And an outflow side cap provided with an outflow port for sending out blood from within the column body, and the inflow side filter has a large number of communication holes through which blood passes. The number per unit area of the through holes is uniform, and the opening area of each communication hole is small at the central portion in the radial direction of the housing space, large at the peripheral portion, and from the central portion toward the peripheral portion. Monotonically increasing.

  In the outflow side cap used simultaneously with the inflow side cap provided with the inflow port on the cylinder axis of the column body, the outflow port can be provided on the axis of the column body cylinder. And an outflow side filter can be made into the same shape as an inflow side filter.

  As shown in FIG. 3, the flow of the passing liquid was observed in an example in which a filter having a circular shape as a whole and having a slit extending in the circumferential direction of a concentric circle was adopted for the inflow side filter and the outflow side filter. The outer diameter of the filter was 60 mm, and the slit width was 100 μm at the central portion and 750 μm at the peripheral portion, and was increased stepwise from the central portion to the peripheral portion in increments of 25 μm. Moreover, the diameter of the inflow port 34 and the outflow port 46 which were each provided in the inflow side cap 14 and the outflow side cap 16 is (phi) 4 mm. The column body 12 has an inner diameter of 54 mm and a length of 150 mm, and the adsorbed particles to be accommodated are spherical bodies having a diameter of about 1 mm.

  As a comparative example of the above embodiment, there is an apparatus in which a grid-like filter formed by linear members arranged vertically and horizontally is used for an inflow side and an outflow side filter. The wire member has a wire diameter of 71 μm and the wire member has an interval of 292 μm, and a uniform mesh is formed on the entire filter. The material of the line member constituting the mesh is PET (polyethylene terephthalate), and the outer ring part is made of polypropylene. The outer diameter of the filter, the diameters of the inlet and outlet, and the inner diameter of the column main body are the same as in the above embodiment.

  The colored liquid was allowed to flow through the columns of the above examples and comparative examples at a flow rate of 100 mL / min, and the flow inside the column outlet was observed. In the column of the example, the colored liquid flowed uniformly, while in the column of the comparative example, the flow at the peripheral edge of the column was slightly slow and the flow at the center was fast.

  10 blood purification column, 12 column body, 14 inflow side cap, 16 outflow side cap, 18 adsorbed particles, 20 inflow side filter, 22 outflow side filter, 34 inflow port, 46 outflow port, 48 slit, 54 filter, 56 communication hole.

Claims (11)

A column for blood purification,
A column body having a storage space for storing adsorbed particles therein;
An inflow filter that is disposed at the blood inflow side end of the column body and holds adsorbed particles in the accommodation space;
An outflow filter disposed at the blood outflow side end of the column body and holding adsorbed particles in the accommodation space;
An inflow side cap mounted on the inflow side end of the column body and provided with an inflow port for feeding blood into the accommodation space;
An outflow side cap mounted on the outflow side end of the column body and provided with an outflow port for sending blood out of the storage space;
Have
The inflow filter has a large number of openings through which blood passes, and the resistance per unit area when blood passes through the filter is determined for each part of the filter. The resistance per unit area is applied to the inflow port. Large at the facing part, small at the part away from the part facing the inlet, and monotonously decreasing toward the part away from the part facing the inlet,
Blood purification column.   2. The blood purification column according to claim 1, wherein the resistance per unit area of the inflow filter is reduced in at least three stages or gradually as the distance from the portion facing the blood inlet is increased. column.   The blood purification column according to claim 1 or 2, wherein the inflow filter has a difference in resistance per unit area for each portion of the inflow filter determined by an aperture ratio. .   3. The blood purification column according to claim 1, wherein in the inflow side filter, a difference in resistance per unit area for each portion of the inflow side filter is determined by the number of openings per unit area. , Blood purification column. The blood purification column according to any one of claims 1 to 4,
In the outflow side filter, the resistance per unit area when blood passes through the filter is determined for each part of the filter, and the resistance per unit area is large in the part facing the outflow port and facing the outflow port. Small at the part away from the part and monotonously decreasing toward the part away from the part facing the outlet,
Blood purification column. The blood purification column according to claim 1 or 2,
The opening of the inflow filter is a slit, and each slit has an arc shape extending along a concentric circle centered on the axis of the inflow port,
The width of each slit is small at the part facing the inlet, large at the part away from the part facing the inlet, and monotonically increasing toward the part away from the part facing the inlet.
Blood purification column. The blood purification column according to claim 1 or 2,
The opening of the inflow filter is a slit, and each slit has an arc shape extending along a concentric circle centered on the axis of the inflow port,
The radial arrangement pitch of the slits is large at the part facing the inlet, small at the part away from the part facing the inlet, and monotonously decreasing toward the part away from the part facing the inlet.
Blood purification column. The blood purification column according to claim 1 or 2,
The opening of the inflow side filter is a communication hole,
The number of communication holes per unit area is small at the part facing the inlet, large at the part away from the inlet, and monotonously increasing toward the part away from the part facing the inlet.
Blood purification column. The blood purification column according to claim 1 or 2,
The opening of the inflow side filter is a communication hole,
The opening area of each communication hole is small at the part facing the inlet, large at the part away from the part facing the inlet, and monotonously increasing toward the part away from the part facing the inlet.
Blood purification column.   The blood purification column according to any one of claims 6 to 9, wherein the outflow filter has the same shape as the inflow filter.   The blood purification column according to any one of claims 1 to 10, wherein each of the inflow side filter and the outflow side filter is a molded product formed of the same material at the same time. .

Images