JPH0217180B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION This invention relates to a hollow fiber blood processing device having an improved blood inlet header. (Prior Art) Blood processing devices using hollow fibers have conventionally been widely used as hemodialysis devices, artificial liver devices, blood filtration devices, plasma separation devices, or artificial lung devices. As such a blood processing device (blood filtration device), a device in which blood inlet ports are provided at axially symmetrical positions as shown in FIG. 4 is usually used. In FIG. 4, 1a is a blood inlet tube with a circular cross section for guiding blood into the inside of the hollow fiber 5 and isolating it from the outside. be introduced. Reference numeral 1b denotes a blood outlet header having a circular cross section for collecting blood that has passed through the hollow fibers and leading it out from the blood outlet 20b. Reference numeral 2 designates a fixing cap for bringing the blood inlet and outlet headers 1a and 1b into close contact with the partition wall 6, which fixes the hollow fiber bundle, through the packing 12. The housing 3 is usually cylindrical and made of transparent, hard synthetic resin (polypropylene, polycarbonate, etc.), and its interior is filled with hundreds to tens of thousands of hollow fibers 5. The housing 3 is also provided with a filtrate outlet 4. A large number of hollow fibers 5 are packed in the housing 3, and both ends of the hollow fibers 5 are fixed liquid-tightly with partition walls 6 made of polyurethane resin or the like having excellent blood compatibility.
It communicates with the space provided in 1b. Blood is introduced into the device through the blood inlet port 20a of the blood inlet header 1a, and harmful substances in the blood are discharged into the housing 3 through the wall membrane of the hollow fibers. It is returned to the body via On the other hand, harmful substances discharged into the interior of the housing 3 are taken out from the outlet 4. Recently, a blood processing device has been proposed in which blood is introduced tangentially into a space provided in a blood inlet header in order to introduce blood uniformly into each hollow fiber (Japanese Patent Publication No. 60-5308, (Sho 57-86361, etc.) FIG. 5 shows an example of such a device, and common parts in the figure are given the same numbers as in FIG. 1.
In this device, blood is introduced into a blood inlet port 2 which opens tangentially from the outside to the inside of the blood inlet header 1a.
It is introduced from 0a and descends while turning along the blood guide path 10 provided in a spiral shape along the inner wall surface of the upper end of the space provided in the header, and reaches the outer periphery of the cut surface of the hollow fiber bundle. Then, it becomes a spiral flow toward the center and is introduced into each hollow fiber from the cut surface. (Problems to be Solved by the Invention) However, such conventional blood processing devices have the following drawbacks. There are various practical problems in the case of long-term use over several days, such as hemodialysis (non-hepadialysis or reduced hepadialysis), continuous hemofiltration (CAVH), and extracorporeal circulation pulmonary support (ECMO). That is, in the blood processing apparatus shown in FIG. 4, due to the structure, blood introduced from the blood inlet 20a first collides with the center of the end face of the hollow fiber, and then is dispersed into the hollow fiber at the outer periphery. Therefore, the speed of blood flowing in the middle of the header is high near the area immediately below the blood inlet, and decreases toward the periphery. As a result, blood may stagnate within the space of the header, and blood may stagnate on the side of the space provided in the header. As a result, the performance of the blood processing device deteriorates, and when blood is returned, the speed of blood return differs between the center and the periphery, so blood remains inside the hollow fibers near the periphery or in areas where blood stagnates. Causes blood phenomena. On the other hand, in the device shown in FIG.
Blood is guided from the tangential direction to the outer periphery, which occupies a relatively large area on the cut surface of the hollow fiber,
After that, since the thickness of the helical flow path gradually decreases, the velocity of blood flowing into the hollow fiber at the outer and inner circumferences is kept more uniform than in the device shown in Figure 4, and is parallel to the cutting surface. Blood flow velocity can also take on large values. However, the flow of blood in the space provided in the header is not a fixed flow path, and although it takes a helical flow path, the distribution of the hollow fibers accommodated in the housing, the undulations of the cut surface of the hollow fibers, and the Depending on the undulations of the contact surface with the blood, local eddy flow and associated thrombus formation and bubble retention may occur more easily, and the volume of blood filling increases as the head becomes bulkier. There was a problem. (Means for Solving the Problems) Therefore, the object of the present invention is to provide a blood inlet header which has less accumulation of air bubbles, less occurrence of thrombi, and less blood clots, and which does not cause blockage of hollow fibers even when used continuously for a long time. An object of the present invention is to provide a blood processing device having the following features. That is, the present invention is a hollow fiber type blood processing device in which a hollow fiber bundle is housed in a cylindrical housing having a blood inlet header at one end and a blood outlet header at the other end, the blood inlet header having a groove inside. The top of the wall substantially abuts the cut surface of the hollow fiber bundle, and a continuous helical groove extends in front of the center of the header to provide a space in the center of the header, and the continuous helical groove extends in front of the center of the header. A blood inlet opening in the tangential direction is provided at the end of the groove so that blood introduced from the blood inlet into the blood inlet header flows into the space formed in the center of the header along the spiral groove. This is a hollow fiber type blood processing device characterized by the following configuration. (Function) The blood processing device of the present invention is provided with a continuous helical groove extending to the front of the center of the header inside the blood inlet header, so that blood introduced into the header from the blood inlet can be made to flow into the space provided in the central portion of the header while turning in a helical manner along the continuous helical groove. Therefore, when the helical groove is extended to the front of the center of the header, an extreme decrease in the amount of blood at the center of the header is prevented, and blood can be uniformly introduced into all the hollow fibers. Therefore, it is presumed that stagnation that causes accumulation of air bubbles and thrombus formation on the open end surface of the hollow fiber bundle, inhibition of platelet adhesion, and occlusion of the hollow fibers can be eliminated. (Example) Next, an example of the blood processing apparatus of the present invention will be described with reference to the drawings. FIG. 1 is a partial sectional view of the device of the present invention, and FIG. 2 is a perspective view of the blood inlet header 1a in which the depth of the continuous spiral groove gradually decreases toward the center of the header. Common parts are given the same numbers as in FIG. The device shown in FIG. 1 is characterized by its structure centered around the header portion. In the device of the present invention, blood introduced from the blood inlet 20a of the blood inlet header 1a is directed tangentially to the end of a continuous helical groove 8 formed by a continuous helical wall 7 extending from the center inside the header to the periphery. introduced from. As the top of the continuous helical wall 7 substantially contacts the cut surface of the hollow fiber as shown in FIG. while being introduced inside the hollow fiber. Further, the spiral groove 8 extends to the front of the center of the header, and a space 9 is formed in the center of the header.
, which allows blood to flow into the center of the header. The diameter of the space at the center of the header is usually preferably 1/6 to 1/3 of the inner diameter of the header. Therefore, blood is introduced into each hollow fiber almost uniformly. However, since the top of the helical wall abuts the cut surface of the hollow fiber, blood does not flow into the hollow fiber at that portion. Therefore, it is preferable that the top of the helical wall be sharp and narrow. It is preferable to gradually reduce the depth of the helical groove as shown in FIG. 2 because the blood velocity can be kept constant at all locations in the continuous helical groove. Further, it is preferable that the blood outlet header 1b is also provided with the blood outlet 20b in the tangential direction of the header, as in the case of the inlet header 1a, since this makes it possible to reduce the lengthwise dimension of the apparatus, thereby making it more compact. In this case, it is preferable not to provide a helical wall in the recess of the blood outlet header 1b. Next, the performance of the device of the present invention and the conventional device will be compared. As the device of the present invention, the blood inlet header has a continuous helical groove extending to the front of the center of the header as shown in FIG. 1, and the blood outlet header does not have a helical groove. On the other hand, devices shown in FIGS. 4 and 5 were used as conventional devices. (inner diameter
Uses 235μm polysulfone membrane, number of hollow fibers
4300 tubes, effective membrane area 0.5 m ² ) Fresh bovine blood (hematocrit value 38%, total protein concentration 6 g/dl) was used in each of the above blood processing devices, and the blood flow rate was 200 ml/min and the transmembrane pressure difference was 100 mmHg. A filtration test was conducted. Table 1 shows the results of measuring the amount of ultrafiltration after 8-hour hemofiltration and the number of blood remaining after blood return.

[Table] From the above results, it is clear that the device of the present invention has a larger amount of ultrafiltration and an extremely smaller number of residual blood tubes than the conventional device. Furthermore, as a result of visual observation, it was confirmed that in the blood processing apparatus of the present invention, the blood introduced into the header was almost uniformly introduced into each hollow fiber. Therefore, the blood processing device of the present invention can be used for extracorporeal circulation pulmonary support or continuous hemofiltration that is used continuously for a long time.
Alternatively, it is suitably used for reduced heparin dialysis. (Effects of the Invention) As described above, in the blood processing device of the present invention, the continuous spiral groove for guiding blood inside the header is provided such that a space exists at the center of the spiral groove inside the header. Therefore, the blood velocity parallel to the open end surface of the hollow fiber bundle can be suitably maintained. Such a structure can reduce the influence on the blood inflow speed into the hollow fiber, and therefore, in the blood processing device of the present invention, a substantially uniform inflow speed can be obtained, so that air bubbles in the recesses in the head can be reduced. It has a strong effect of inhibiting the retention of blood and the generation of thrombi and blood clots, and enables long-term continuous use and non-hepatodialysis and low-hepadialysis, which was impossible with conventional devices.

[Brief explanation of drawings]

FIG. 1 is a partial sectional view of the blood processing device of the present invention, and FIG. 2 is a sectional view of a header in which the depth of the continuous spiral groove gradually decreases toward the center of the header. , FIG. 3 is an enlarged perspective view of the shape of the header portion of the device of the present invention, and FIGS. 4 and 5 are partial sectional views of a conventional blood processing device. 1a, 1b...Blood inlet, outlet header, 2...
Fixed cap, 3... Housing, 4... Filtrate outlet, 5... Hollow fiber, 6... Partition wall, 7... Continuous helical wall, 8... Continuous helical groove.

Claims (1)

[Claims] 1 A hollow fiber blood processing device in which a hollow fiber bundle is housed in a cylindrical housing having a blood inlet header at one end and a blood outlet header at the other end, the top of the groove wall inside the blood inlet header. substantially abuts the cut surface of the hollow fiber bundle, and extends a continuous helical groove to the front of the center of the header to provide a space in the center of the header, and the end of the continuous helical groove A blood inlet opening in the tangential direction is provided in the blood inlet header, and the blood introduced from the blood inlet into the blood inlet header is configured to flow into a space formed in the center of the header along a spiral groove. A hollow fiber type blood processing device featuring: