JPH0345735Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION BACKGROUND TECHNICAL FIELD OF THE INVENTION The present invention relates to a material or heat exchange device for body fluids. More specifically, the present invention relates to improvements in body fluid inlet ports, particularly in artificial dialyzers, artificial lungs, heat exchangers, etc., in which body fluids flow through thin tubes to perform mass exchange or heat exchange through the thin tubes. Prior art and its problems Conventionally, in an artificial dialysis machine, a bundle of thin tubes made of multiple porous hollow fibers arranged in parallel inside a housing is supported liquid-tightly by partition walls made of potting material at both ends of the housing. However, a housing is known in which a body fluid inlet port and a body fluid outlet port are provided at both ends of the housing, and a body fluid inlet chamber, a body fluid outlet chamber, a body fluid inlet port, and a body fluid outlet port are formed outside the partition wall. In such an artificial dialyzer, body fluid flows from the body fluid inflow chamber through each hollow fiber through the body fluid inlet of the body fluid inlet port, and between each hollow fiber in the housing and between the hollow fiber and the housing. Substances are exchanged with the dialysate introduced into the dialysate flow space formed between the inner wall and the hollow fiber membrane, thereby purifying the body fluid. In such a case, the body fluid inflow direction is at the center of the bulkhead hollow fiber bundle, so the flow of body fluid introduced into the body fluid inflow chamber from the body fluid inlet port is generally directed toward the center of the hollow fiber bundle, In the periphery, where the number of threads is large and therefore the mass exchange capacity is high, the flow rate decreases and body fluid tends to accumulate. In addition, in the dialysate circulation space, a certain amount of space must be provided around the hollow fiber bundle, so structurally, a certain amount of space must be provided around the bulkhead on the body fluid inflow side.
There are regions where there are no hollow fibers. For this reason, body fluid retention increases at the outer periphery of the partition wall of the body fluid inflow chamber.
A residual liquid will be produced. Furthermore, if a flexible tube is connected to the body fluid inflow port and body fluid is passed through it, if the tube is bent, the flow direction of the body fluid will be skewed, causing partial blood flow within the body fluid inflow chamber. Retention or residual liquid is likely to occur. In an attempt to solve this problem, if the body fluid inlet port is made longer, the entire device becomes larger. As described above, in conventional artificial dialyzers, the flow rate of body fluid in the body fluid inflow chamber is uneven, and blood stagnation or residual fluid occurs, which prevents the effective use of the hollow fiber membrane and also reduces the overall efficiency of the device. Exchange efficiency is reduced, and performance stability is also adversely affected. Particularly when the body fluid contains solid components, the mass exchange efficiency is further reduced due to the retention of the body fluid around the hollow fiber bundle. Although the explanation above has been about an artificial dialysis machine, this phenomenon also occurs in oxygenators and heat exchangers equipped with thin tube bundles such as hollow fibers and tubular bodies, and is a practical problem. It's summery. Purpose of the invention The present invention was developed in view of the above-mentioned circumstances, and its main purpose is to create a material for body fluids that has improved exchange efficiency, with less accumulation or residual fluid in the vicinity of tubule bundles. Or to provide heat exchange equipment. The inventors of the present invention have conducted various studies for this purpose and have come up with the present invention. A device that achieves the above object includes a cylindrical housing with both ends open, a bundle of thin tubes for heat exchange and a plurality of substances provided along the longitudinal direction within the housing, and a bundle of thin tubes for heat exchange provided at both ends of the housing. a pair of partition walls that liquid-tightly support each capillary so as not to block the inside thereof; and a body fluid inflow chamber or body fluid connected to each end of the housing and communicating with the inside of each capillary outside the partition wall. In a body fluid substance or heat exchange device having a body fluid inlet port and a body fluid outlet port forming an outflow chamber and having a body fluid inlet port or a body fluid outlet port communicating with each of the chambers, the body fluid inlet The section is located at the center of the body fluid inlet port and has a substantially cylindrical passage section with an inner diameter of 2 to 3 mm formed along the central axis direction, and the body fluid outlet section is located at the center of the body fluid inlet port. The substance or heat exchange device for body fluids has a minimum inner diameter larger than the passage portion, and further has a region in the center portion of the partition wall in which no capillary tube having a diameter larger than the inner diameter of the passage portion is present. Furthermore, the cylindrical passage has a length such that the value obtained by dividing the length of the cylindrical passage by the distance from the opening end of the body fluid inlet to the body fluid inflow chamber side partition is 0.75 to 0.9. It is preferable that Furthermore, the body fluid inflow port has an inner wall that is substantially parallel to an outer wall surface on the body fluid inflow chamber side of the body fluid inflow chamber side partition wall, and the wall surface forms a cylindrical passage portion of the body fluid inflow port. It is preferable that the inner wall surface of the body fluid inflow port is connected with a curvature. Further, it is preferable that the body fluid inflow port has a tapered shape in the vicinity of the opening end of the body fluid inflow port such that the inner diameter increases toward the open end. Further, it is preferable that the body fluid inflow chamber-side partition wall has a central portion thereof protruding toward the body fluid inflow port. Preferably, the thin tube is a hollow fiber for dialysis, and the body fluid substance or heat exchange device is an artificial dialysis machine. Specific Structure of the Invention Hereinafter, the specific structure of the invention will be explained in detail with reference to the drawings. The embodiment of the present invention shown in FIG. 1 is an example in which the present invention is applied to a disposable artificial dialysis machine. As shown in the figure, this artificial dialyzer 1 includes a cylindrical housing 2 made of, for example, acrylonitrile-styrene copolymer resin, with both ends open. In the internal space defined by the peripheral wall 21 of the housing 2, a plurality of thin tubes 3, for example, 6,000 to 6,000 thin tubes 3 made of hollow fiber membranes for dialysis with a membrane thickness of about 16 μm are arranged in parallel in the longitudinal direction of the housing 2. 50000
This arrangement constitutes a bundle of tubules. The hollow fiber membrane constituting the thin tube 3 is made of copper ammonium cellulose, for example, and has a flat pore diameter of about 30 to 60 Å. Such a bundle of thin tubes made of hollow fiber membranes etc. is supported by a pair of partition walls 41 and 45 within both ends of the housing 2 without blocking the internal space of the thin tubes 3 of each hollow fiber membrane etc. There is. These partition walls 41 and 45 are made of a polymeric potting material, for example polyurethane. These partition walls 41 and 45 define a dialysate flow space 5 between each thin tube 3 such as a hollow fiber membrane and the peripheral wall 21 of the housing 2. The housing 2 is provided with a dialysate inlet 61 and a dialysate outlet 65 in communication with the dialysate flow space 5 on the peripheral wall 21 near both ends thereof. On the other hand, body fluid inlet portions 711 for blood inflow and outflow are provided at both end surfaces of the housing 2, respectively.
A body fluid inlet port 71 having a body fluid outlet part 751 and a body fluid outlet part 75 are attached. These body fluid inflow ports 71 and body fluid outflow ports 75 are connected to annular tightening members 81 and 85, respectively.
It is fixed to the housing 2 by screwing and tightening. The body fluid inflow port 71 and the body fluid outflow port 75 have a body fluid inflow chamber 9 for blood inflow and outflow between the partition walls 41 and 45, respectively.
1 and a body fluid outflow chamber 95, and the body fluid inflow port 711 and body fluid outflow port 751 communicate with the internal space of each hollow fiber membrane 3 via the body fluid inflow chamber 91 and the body fluid outflow chamber 95, respectively. are doing. Note that when an oxygenator is used, a hydrophobic porous hollow fiber membrane made of polypropylene or the like is used as the hollow fiber membrane, and the dialysate inlet 61 and dialysate outlet 65 are connected to the gas inlet and the gas flow, respectively. Gas may be allowed to flow as an outlet. When a heat exchanger is used, a thin tube made of stainless steel or the like may be used, and hot water or the like may be passed through the dialysate inlet 61 and dialysate outlet 65. Based on this premise, in this invention,
The minimum inner diameter a of the body fluid inlet portion 711 is made smaller than the minimum inner diameter b of the body fluid outlet portion 751. In this case, for example, in a conventional dialysis machine, a and b are about 4 mm;
When it is larger than 4 mm, as mentioned above, there is a lot of blood stagnation and residual blood, and the exchange efficiency is low. On the other hand, according to the present invention, if a is made smaller than b, the flow rate of body fluids such as blood becomes faster, and the accumulation of blood or residual blood at the outer periphery of the partition wall 41 where no tubules are present in the body fluid inflow chamber 91 is reduced. Moreover, the amount of inflow into the thin tube 3 at the outer periphery of the partition wall 41 is increased, and the exchange efficiency is improved. However, taking into consideration the dimensions of the device normally used and the flow rate of body fluids to be circulated, it is preferable that a be 3 mm or less. Note that it is only necessary that a be smaller than b, but if a becomes too small, the pressure within the device will increase, leading to damage to body fluids such as blood.
Under normal conditions, a is preferably 2 mm or more. On the other hand, if b is made larger than a, it has the effect of reducing the pressure increase (pressure loss) caused by making a small, and as a result of reducing the flow velocity within the body fluid outflow port, the outflow from the entire tubule bundle is made even. This reduces the amount of blood stagnation in the body fluid outflow port. In such a case, b is preferably 4 mm or more, particularly 4 mm to 5 mm under normal conditions. The body fluid inlet part 711 and the body fluid outlet part 751 having such a relationship of a<b are, as shown in the figure,
Along the central axis direction of the body fluid inlet port 71 or the body fluid outlet port 75 (that is, the longitudinal direction of the housing at the radial center of the ports 71, 75), it is concentric with the opening end of the body fluid inlet port or the body fluid outlet port. Preferably, it is formed as a passage. As a result, the unevenness of the flow within the body fluid inflow chamber 91, the thin tube 3, and the body fluid outflow chamber 95 is further reduced, retention and residual blood are further reduced, and exchange efficiency is improved. In such a case, the body fluid inlet portion 711
The body fluid outflow port 751 is formed along the longitudinal direction of the housing 2 and has an inner diameter a or b.
Even more favorable results can be obtained if the passage portion is substantially cylindrical. At this time, in particular, since the body fluid inlet port 711 has a cylindrical passage, the directionality of the body fluid whose inflow speed has been increased becomes stronger, and the body fluid inlet port 711
Even if the flexible tube for supplying body fluids is bent, the inflow direction of the body fluids is corrected, residual blood and stagnation are reduced, and the drop in exchange efficiency is lessened. As shown in FIG. 1, the length of the cylindrical passage of the body fluid inlet 711 is c, the length of the cylindrical passage of the body fluid outlet 751 is e, and the body fluid inlet 7
11 When the distance from the opening end to the body fluid inflow chamber side partition wall 41 is d, and the distance from the body fluid outflow port 751 opening end to the body fluid outflow chamber side partition wall 45 is f, c/d>
If it is e/f, even more preferable results will be obtained. At this time, within the body fluid outflow chamber 91, the directionality of the flow toward the outer periphery of the partition wall becomes stronger, and on the other hand, the body fluid outflow chamber 91
Within 5, the directionality of outflow blood is weakened,
Inside the body fluid inflow chamber 91 at the outer periphery of the tubule bundle, the tubule 3
Retention of body fluid inside and inside the body fluid outflow chamber 95 is extremely reduced, and the exchange efficiency is further improved. In addition, in order to further enhance the effectiveness of this effect, under normal conditions, c/
It is preferable that d is 0.75 to 0.9 and e/f is 0.5 to 0.7. Furthermore, in the present invention, the tubule density of the tubule bundle of the septum located in the body fluid inflow direction (the extension direction of the body fluid inlet portion 711) must be smaller than the tubule density in other parts (generally the outer periphery thereof). . With this configuration, there are fewer thin tubes located in the extending direction (body fluid inflow direction) of the body fluid inflow port 711, so that the number of thin tubes located in the body fluid inflow port 711 toward the outer periphery of the partition wall 41 is reduced by the above configuration. Body fluid with a high flow rate effectively flows into the thin tubes 3 on the outer periphery of the thin tube bundle, and retention or residual liquid on the outer periphery of the partition wall 41 in the body fluid inflow chamber 91 is reduced, improving exchange efficiency. . In addition, since the inner diameter of the body fluid outflow port 751 is wide,
The flow velocity within the body fluid outflow chamber 95 is decreasing,
Moreover, as described above, by increasing the density of the tubules at the outer periphery, the outflow of body fluid from the outer periphery of the tubule bundle is increased, the flow from the entire tubule bundle is equalized, and the flow of body fluid in the body fluid outflow chamber 95 is increased. Retention is reduced, which further improves exchange efficiency. In such a case, as described above, it is preferable that the body fluid inlet port 711 and the body fluid outlet port 751 be provided along the central axis direction of the body fluid inlet port 71 or the body fluid outlet port 75. , it is preferable that the density of tubules is smaller than that of the peripheral part. In general, in the body fluid inflow direction (preferably at the center of the septum), the density (%) of the region having the aforementioned minimum inner diameter a is 0, or the density (%) of the outermost portion of the tubule bundle is 0. It is preferable to set it to about 0.2 or less. In such a case, a region where no capillary exists is provided in the center of the partition wall (the radial center of the capillary bundle), as shown in the figure, with a diameter g larger than the above a (usually 5 to 15 mm). and obtain even more favorable results. Furthermore, the inner wall surface 715 of the body fluid inflow port 71, which forms the body fluid inflow side wall surface of the body fluid inflow chamber 91, is formed to be approximately parallel to the body fluid inflow chamber side outer wall surface 411 of the partition wall 41, which is normally formed flat. It is preferable. As a result, the body fluid that forms a vortex and stays between the partition wall 41 and the inner wall surface 715 is reduced, and the exchange efficiency is further improved. In this case, in order to make the two substantially parallel as described above, the inner wall surface 71 of the body fluid inflow port 71 that forms the wall surface on the body fluid inflow side of the body fluid inflow chamber 91 must be
5 is inclined at an angle α (see Fig. 1) within 10°, particularly within 5°, with respect to the direction p (see Fig. 1) parallel to the side wall surface 411 of the body fluid inflow chamber of the partition wall 41, so as to prevent the flow of body fluid. It is preferable that the inner wall surface 717 of the body fluid inflow port 71 forming the cylindrical passage portion of the inlet portion 711 be connected to the inner wall surface 717 . Furthermore, a wall surface on the body fluid inflow side of this body fluid inflow chamber 91 is formed, and an outer wall surface 41 on the body fluid inflow chamber side of the partition wall 41 is formed.
Inner wall surface 71 of body fluid inflow port 71 substantially parallel to 1
5 and the inner wall surface 717 of the body fluid inlet port forming the cylindrical passage section of the body fluid inlet portion 711, it is preferable that the inner wall surface 719 be connected to both with a curvature. This inner wall surface 719 and the inner wall surface 7 connected thereto
15, 717, body fluids tend to accumulate at the corners and the exchange efficiency tends to decrease. Note that on the inner wall of the body fluid outflow port 75,
These conditions may or may not be satisfied. In the exchange device of the present invention configured in this manner, the inner diameter of the body fluid inlet portion 711 is smaller than usual, and as a result, in order to connect with a normal body fluid supply tube, it is necessary to It is necessary to increase the thickness of the portion of the port 71 that forms the body fluid inlet portion 711. In such a case, the supplied body fluid will collide with the thick part of the body fluid inlet port 71 on the end face of the body fluid inlet portion 711. Therefore, in order to further reduce damage to the body fluid, the method shown in FIG. It is preferable to form a taper 7115 near the opening end of the body fluid inlet portion 711 so that the inner diameter becomes thicker toward the opening end. Furthermore, although the body fluid inflow chamber side wall surface of the partition wall 41 is normally formed flat, in order to further strengthen the body fluid flow toward the outer circumference of the tubule bundle within the body fluid inflow chamber 91,
As shown in FIG. 3, the outer surface of the body fluid inflow chamber side partition wall 41 (preferably the partition wall 4
It is preferable to form the protrusion 415 integrally or by bonding, etc. Specific effects of the invention The exchange device of the invention connects tubes for body fluid supply and body fluid discharge, and transfers body fluids such as blood to the body fluid inlet port 711, the body fluid inlet chamber 91, the thin tube 3, and the body fluid outflow chamber 95. , body fluid outflow port 751 in this order. At this time, after dialysis, gas, hot water, etc. are
Flows in contact with body fluids to exchange substances or heat in body fluids. In such a case, according to the present invention, the minimum inner diameter a of the body fluid inlet 711 is smaller than the minimum inner diameter b of the body fluid outlet 751, so that the inflow speed of the body fluid becomes faster. At the same time, since the density of the tubules in the tubule bundle of the partition wall located in the body fluid inflow direction is smaller than the density of tubules in other parts, the fluid flows into the tubules 3 at the outer periphery of the tubule bundle with sufficient flow rate and velocity. For this reason,
Retention in body fluid inflow chamber 91 and thin tube 3 is reduced. In addition, since the region on the outer periphery of the partition where the thin tube 3 does not exist has a sufficient flow velocity, there is little accumulation or residual fluid on the outer periphery of the body fluid inflow chamber 91. Moreover, the minimum inner diameter b of the body fluid outflow port 751 is
Since it is larger than the minimum inner diameter a of the body fluid inflow port 711, the flow velocity in the body fluid outflow chamber 95 is slowed down, and at the same time, the amount of outflow from the thin tube 3 on the outer periphery of the partition increases, so that retention in the body fluid outflow chamber 95 is also reduced. do. Therefore, the accumulation or residual fluid of the body fluid is extremely reduced, and as a result, the mass exchange efficiency or the heat exchange efficiency is improved. Furthermore, since the inner diameter of the body fluid outlet portion 751 is large, the pressure loss of the body fluid is small, the damage to the body fluid is small, the trans membrane pressure (TMP) is reduced, and the ultraviolet flow rate (UFR) can be easily controlled. . These effects become significant when the minimum inner diameter a of the body fluid inlet is set to 2 to 3 mm. Moreover, according to the above-mentioned embodiments, such effects are even more excellent when the configurations of the above-mentioned embodiments are adopted. The present inventors conducted various experiments to confirm such effects. An example is shown below. Experimental example: Using a housing with an outer diameter of 64 mm and an inner diameter of 61 mm, the first
An artificial dialyzer 1 as shown in the figure was manufactured. In this case, 9900 hollow fibers of copper ammonium cellulose with an average thickness of 16 μm were used. Minimum inner diameter a of the body fluid inlet 711, cylindrical passage length c, distance d from the opening end of the body fluid inlet to the partition wall, minimum inner diameter b of the body fluid outlet 751, cylindrical passage length e, body fluid outlet opening. The distance f from the end to the partition wall was changed to Table 1, and five types of samples Nos. 1 to 5 were obtained. In this case, in samples No. 2 to 5, a region where no capillary with a diameter of 8 mm does not exist (center capillary density ρc = 0) is provided in the radial center of the partition wall, and the capillary density ρo in the area around the periphery is 55%. did. On the other hand, in sample No. 1, the tubule distribution of the tubule bundle was uniform, and the tubule density was 55%. (ρc=ρo=55%). Then, the supply tube and the discharge tube were connected, and the bovine blood and dialysate were flowed at 200 ml/min and 500 ml/min, respectively, and the amount of nitrogen in blood urea (BUN) was measured to evaluate the dialysis efficiency. It was measured. In this case, the supply tubes were connected without bending. The results are shown in Table 1. Note that for each port, the angle α shown in Figure 1 is 0° when c/d is 0.85;
When d or e/f was 0.64, it was set to 10°. In addition, in order to confirm the degree of blood retention, the above sample No.
1 to 5, bovine blood with Ht=3.5 was circulated at 100 ml/min, and physiological saline was circulated at 100 ml/min for 2 minutes, and blood retention was observed. The results are shown in Table 1.

[Table] From the results shown in Table 1, it can be seen that according to the present invention, retention of body fluids is extremely reduced and exchange efficiency is improved. In addition, bend the supply tube and connect it in the same way.
When the BUN value was measured, almost the same values were obtained for Nos. 2 to 5, whereas the BUN value for No. 1 was significantly reduced. Additionally, in No. 5, there was a tendency for excessive water removal.

[Brief explanation of the drawing]

FIG. 1 is a front view, partially in section, showing an embodiment in which the body fluid substance or heat exchange device of the present invention is applied to an artificial dialysis machine. FIG. 2 is a sectional view showing another example of the body fluid inflow port of the present invention. FIG. 3 is a partially omitted sectional view showing another embodiment of the present invention. 1...Artificial dialysis machine, 2...Housing, 3...
Thin tube, 41, 45...Partition wall, 71...Body fluid inflow port, 711...Body fluid inlet port, 75...Body fluid outflow port, 751...Body fluid outflow port, 91...Body fluid inflow chamber, 95...Body fluid Outflow chamber.

Claims (1)

[Claims for Utility Model Registration] (1) A cylindrical housing with both ends open, a plurality of substance or heat exchange thin tube bundles provided along the longitudinal direction within the housing, and a pair of partition walls that liquid-tightly support each capillary so as not to block the inside of each capillary at both ends; and a body fluid inflow connected to each end of the housing and communicating with the inside of each capillary to the outside of the partition. A body fluid substance or heat exchange device having a body fluid inlet port and a body fluid outlet port forming a body fluid inlet port or a body fluid outlet port and having a body fluid inlet port or a body fluid outlet port communicating with each of the chambers, wherein the body fluid The inlet portion is located in the center of the body fluid inlet port and is substantially cylindrical and has an inner diameter of 2 to 3 mm formed along the central axis direction.
the body fluid outlet has a minimum inner diameter larger than the passage of the body fluid inlet;
Furthermore, the substance or heat exchange device for body fluids is characterized in that the partition wall has a region in the center thereof in which no thin tube having a diameter larger than the inner diameter of the passage portion is present. (2) The cylindrical passage has a length such that the value obtained by dividing the length of the cylindrical passage by the distance from the opening end of the body fluid inlet to the partition wall on the body fluid inflow chamber side is 0.75 to 0.9. Scope of claims for utility model registration No. 1
Substances or heat exchange devices for body fluids as described in Section. (3) The body fluid inflow port has an inner wall that is substantially parallel to an outer wall surface on the body fluid inflow chamber side of the body fluid inflow chamber side partition wall, and the wall surface extends through the cylindrical passage portion of the body fluid inflow port. The body fluid substance or heat exchange device according to claim 1 or 2, which is connected with the inner wall surface of the body fluid inflow port to be formed with a curvature. (4) The body fluid inflow port has a tapered shape near the opening end of the body fluid inflow port so that the inner diameter increases toward the opening end. Substances or heat exchange devices for body fluids as described in . (5) The body fluid inflow chamber side partition wall is for use in body fluids according to any one of claims 1 to 4, wherein the central part of the partition wall protrudes toward the body fluid inflow port. material or heat exchange equipment. (6) The device for body fluids according to any one of claims 1 to 5, wherein the thin tube is a hollow fiber for dialysis, and the substance or heat exchange device for body fluids is an artificial dialysis machine. material or heat exchange equipment.