JPH0217179B2 - - 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 as shown in FIG. 4 in which blood inlet ports are provided at axially symmetrical positions is usually used. In FIG. 4, reference numeral 1a denotes a blood inlet header 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 liquid 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, JP-A-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 passed through a blood inlet 20 which opens tangentially from the outside of the blood inlet header 1a to the inside.
It is introduced from a and descends while turning along the blood guide path 10 provided in a spiral 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 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 hemodialysis (CAVH), and extracorporeal circulation lung 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 velocity of blood flowing through the internal space 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 around 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, the thickness of the helical flow path gradually decreases, so that the velocity of blood inflow into the hollow fibers at the outer and inner circumferences reaches the fourth level.
The blood flow velocity is maintained more uniformly than in the device shown in the figure, and the blood flow velocity parallel to the cutting surface can also take on a large value.
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) Accordingly, 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 period of time. An object of the present invention is to provide a blood processing device having the following features. The present invention provides 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. forming a continuous helical groove in the recess by extending a continuous helical wall whose apex substantially contacts the cut surface of the hollow fiber bundle from the center to the periphery of the recess; This hollow fiber type blood processing device is characterized in that a blood inlet opening tangentially toward the outside is provided at the end of the continuous helical groove. (Function) The blood processing device of the present invention is provided with a continuous helical wall that substantially contacts the cut surface of the hollow fiber bundle in the recess formed in the blood inlet header, and the continuous helical groove is formed in the helical wall. By forming a groove, the blood guided from the blood inlet into the recess provided in the header circulates in a helical manner along the continuous helical groove and is directed to the cut surface of the hollow fiber bundle, that is, the hollow fiber be introduced inside. At this time, blood pressure is uniformly applied to each cut surface of the hollow fibers, so that blood is uniformly introduced into the interior of 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;
FIG. 2 is a perspective view of the blood inlet header 1a, and common parts in the figure are given the same numbers as in FIG. 4. The device shown in FIG. 1 has a dynamic structure centered around the header portion. In the device of the present invention, the blood inlet header 1
The blood introduced from the blood inlet 20a of a is introduced tangentially to the end of a continuous helical groove 8 formed by a continuous helical wall 7 extending from the center of the recess in the header to the periphery. be done. 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. Therefore, blood is introduced into each hollow fiber almost uniformly. However, since the top of the helical wall contacts the cut surface of the hollow fiber, blood does not flow into the hollow fiber in that area. Therefore, it is preferable that the top of the helical wall be sharp and narrow. Further, a small gap may be provided within the helical groove to prevent blood from passing into the adjacent groove. Gradually reducing the depth of the helical groove as shown in FIG. 3 is a preferred method because the blood velocity can be kept constant at all locations in the continuous helical groove. Similarly to the inlet header 1a, the blood outlet header 1b also has the advantage of being compact by providing the blood outlet 20b in the tangential direction of the header, since the longitudinal dimension of the device can be reduced. 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 apparatus of the present invention, an apparatus was used in which the blood inlet header had a continuous helical wall as shown in FIG. 1, and the blood outlet header had no helical wall. On the other hand, as a conventional device, the devices shown in FIGS. 4 and 5 were used. (A polysulfone membrane with an inner diameter of 235 μm is used, the number of hollow fibers is 4300, and the effective membrane area is 0.5 m ² ) Fresh bovine blood (hematocrit value 38%, total protein concentration 6 g/dl) is used in each of the above blood processing devices, and the blood flow rate is 200 ml. /min, and a transmembrane pressure difference of 100 mmHg. Table 1 shows the results of measuring the ultraviolet excess amount after 8 hours of blood flow and the number of remaining blood after blood return.

[Table] As described above, compared to the conventional device, the device of the present invention has a large amount of ultraviolet excess, and the number of remaining blood is extremely small.Furthermore, as a result of visual observation, the blood processing device of the present invention It was confirmed that the blood introduced into each hollow fiber was almost uniformly introduced into each hollow fiber. Therefore, the blood processing apparatus of the present invention is suitably used for extracorporeal circulation pulmonary support, continuous blood perfusion, or reduced heparin dialysis that is used continuously for a long period of time. (Effects of the Invention) As described above, the blood processing device of the present invention has a continuous helical groove for guiding blood into the recess in the header, thereby increasing the blood velocity parallel to the open end surface of the hollow fiber bundle. can be maintained. Such a structure has little effect on the blood inflow speed into the hollow fiber, and a nearly uniform inflow speed can be obtained.
It has a strong effect of inhibiting the accumulation of air bubbles in the recesses within the header and the generation of blood clots 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 apparatus of the present invention, FIG. 2 is a perspective view of the header, and FIG. 3 is a sectional view showing the shape of the header part of another embodiment.
FIGS. 4 and 5 are partial cross-sectional views of a conventional blood processing apparatus. 1a, 1b...Blood inlet, outlet header, 2...
Fixed cap, 3... Housing, 4... Liquid outlet, 5... Hollow fiber, 6... Partition wall, 7... Continuous helical wall, 8... Continuous helical groove.

Claims (1)

[Claims] 1. In 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, in a recess formed in the blood inlet header, A continuous helical wall whose apex substantially abuts the cut surface of the hollow fiber bundle extends from the center to the periphery of the recess to form a continuous helical groove within the recess, and A hollow fiber type blood processing device characterized in that a blood inlet opening tangentially toward the outside is provided at an end of a spiral groove.