DE2251644B2 - Device for treating blood - Google Patents

Description

The invention relates to a device for treating blood with a hollow cylindrical rotor with a die Jacket surface of the same surrounding permeable membrane, with one in the interior of the rotor opening inlet for a blood treatment fluid and with a stator housing in which the rotor is mounted and into which a blood inlet and a blood outlet open.

Devices of this type are already known for loading blood with oxygen and for washing blood. A Typical oxygenator comprises a horizontal hollow cylinder rotatable in a stator housing, the The outer surface is surrounded by a semipermeable membrane. This dips into the blood on the outside

so containing a tub, wherein the blood is then taken from the cylinder surface and thereby the Oxygen gas is exposed, which from the interior of the rotating cylinder through the In addition, tubular spray devices are provided to spray blood onto the membrane To spray the outer wall of the cylindrical membrane, thereby increasing the loading speed (U.S. Patent 3,026,871). Such a device requires additional pumping equipment and has only one limited loading capacity. In addition, this device tends to foam.

In another known device, a series of concentric wires made of wire mesh are used Cylinders rotatable in a horizontal axis about an eccentrically arranged in a horizontal cylinder Container arranged, the cylinders are set in rotation and the horizontal container only that with oxygen in its lower area

Contains satiating blood Although this device has a higher loading capacity than the previous one described, but can only be cleaned extremely cumbersome and also requires an additional pump (AT-PS 2 39 956).

Finally, an oxygenator is known in which around a stationary cylinder provided with longitudinal grooves on the surface a suitable membrane circulates here, too, there is no pump effect (Med. & Biolog. Engng. VoL 9, pp. 237-245. Pergamon Press, 1971, Printed in Great Britain).

The invention is based on the object of creating a device of the type mentioned at the outset which is simple is constructed and at the same time acts as a pump

The solution to this problem is to be seen in the fact that the rotor is mounted eccentrically to the interior of the stator housing that the eccentricity and the speed of the rotor are selected such that in the area of the blood-filled annular space between the rotor and stator housing with the smallest gap thickness einr. Laminar flow prevails that in the area of the annular space having the greatest thickness there is an at least partially turbulent flow, that the blood inlet and the blood outlet open into the laminar flow area and that the cylindrical rotor has a number of grooves on its outer surface through which the treatment fluid is passed.

Advantageous further developments are given in the subclaims.

The invention is supplemented below with reference to schematic drawings of an exemplary embodiment described.

F i g. 1 is an axial section through the device for treating blood;

F i g. FIG. 2 is a sectional view of the FIG. 1 circled area 2, and

F i g. Figure 3 is a section taken along line 3-3 of Figure 3. 1.

The device 10 shown in the figures comprises a tubular WtUe 11, which extends centrally over practically the entire length of the device 10 extends. The shaft 11 is provided with a concentric bore 12 provided and wedged on one shaft end 16 with a V-belt pulley 13 via a split pin 13a. Around A first seal 14 is placed on this shaft end and a second seal 15 is placed around the other shaft end 17. Tubular retaining nipples 18 and 19, which also serve to hold a blood treatment fluid, are seated on these seals to lead into the device 10. The direction of flow of the blood treatment film is indicated by arrow 20 In the vicinity of the shaft ends 16 and 17 there is a shaft bearing 21 and 22, respectively, which are shown in FIG exact positions are fixed on the shaft 11 and are locked detachably from this in the usual way. The device further comprises a solid, tubular housing part 23 with an exactly maintained inside diameter 35, which forms the stator housing. The housing part 23 has precisely cut threaded bores 28 and 29, are screwed into the precision screws 24 and 25, which are used to attach the Shaft bearings 21 and 22 are used. A second set of screws, which is not visible in the figure, is used for Fasten the shaft bearings on the opposite face.

An eccentricity compensation part is located between the shaft bearings 21 and 22 and the housing part 23 30 and 31, which are held by the precision screws 34 and 35 and an exact eccentric deviation 32 of the shaft 11 parallel to the axis of symmetry 33 of the interior of the housing part 23 allow to adjust. Metal disks can be used as eccentricity compensation parts other known bodies. The axis of the shaft 11 is located above the axis of the stator housing, but can be any other in the same way Have height position. Instead of the metal disks, fastening pins, for example, can also be used, exactly machined protrusions or grooves, etc. are used

ίο be.

A solid, cylindrical rotor sleeve sits on the shaft 34, which has an outer diameter 108 which is smaller than that by a precisely defined amount Inner diameter 35 of the housing part 23. In the rotor sleeve 34 in the outer jacket surface 37 are a Incorporated a number of flat grooves 36 that extend from the input end area 38 to the output end area 39 the rotor sleeve extend. The grooves 36 run parallel to the longitudinal axis of the shaft 11 and are through Projections 105 separated from each other

The outer circumferential surface 37 of the rotor sleeve 34 is permeable by a thin, for the blood treatment fluid Surrounding membrane 40 completely. This membrane forms a cover for the grooves 36 and is according to FIG F i g. 2 stretched over the front ends of the rotor sleeve 34 and clamped by means of compression rings 41 and 42 respectively the rotor sleeve 34, the membrane 40 and the compression rings 41 and 42 existing subassembly forms a fabrication-like assembly Unit that can be easily replaced in the device

Each press ring 40, 41 tightens the membrane 40 on the relevant end region 38, 39 of the rotor. Instead of the pressure rings shown, other fastening devices for the membrane can of course also be used be used.

At the end regions 38 and 39 each has a detachable end plate 44 and 45, which are in the Interior of the rotor sleeve are precisely fitted and extend inside through the compression rings 41 and 42, respectively. The end disks are screwed into flow guide disks by means of locking screws 46 and 47 or 48 and 49 62 and 63, which are explained below. For sealing the end disks 44 and 45 against the escape of blood during operation, a pair of fluid seals 50 and 51 are provided, the inside rest on the housing part 23 and pressed against the end disks by means of clamping devices 52 and 53, respectively are. The clamping devices 52 and 53 comprise a support ring 54 and 55, respectively, which is supported by a removable Snap ring 56 or 57 is held in the correct position

so and spring guide pins 58 and 59, on each of which a compression spring 60 and 61 is seated

The stationary end disks 44 and 45 and the flow guide disks 62 and 63 are permanently coaxial to the axis of the shaft 11 and result in a pair of precisely defined reference locations. The fixed flow guide disc 62 lies in the input end region 38, and the fixed flow guide disk 63 in that Exit end area 39. Both flow guide disks are connected to the shaft 11 by welds 64 and 65, respectively tied together. The flow guide 62 has at least a radial channel 66, which is used as a fluid inlet for the blood treatment fluid from the hollow Shaft 11 through at least one bore 67 in the same is used up to a distributor groove 68 in the rotor sleeve 34.

The entirety of the grooves 36 forms a flow path 74, from which the blood treatment fluid in a Distributor groove 71 and then via at least one radial channel 69 in the flow guide disk 63 and

flows through a bore 70 in the shaft 11 into the concentric bore 12 of the same. The annular space 74 surrounding the membrane 40 can lead to a flow in opposite directions.

According to FIGS. 1 and 3, the housing part 23 is surrounded by a heat exchange jacket 82 which is traversed by a plurality of passage channels 83 which end radially on the inside in the annular space 74 and radially on the outside in the space delimited by the distributor jacket 81. A blood inlet port 80 ι α is attached to the distributor jacket 81. The blood flowing into the blood inlet port 80 is distributed through the distributor jacket 81 to the individual passage channels 83 and from these into an inlet groove 108 , from where the blood enters the annular space 74 as shown in FIG. When the rotor block 43 rotates in the direction of arrow 77 , a laminar flow 76 is generated via the laminar flow sector 75 between the nozzles 80 and 86 over the length of the rotor block 43, since the annular space 74 is relatively narrow in the laminar flow sector 75 due to the eccentricity of the shaft 11 is. The flow layer at this point has a thickness t which is given by the outside diameter of the rotor block 43, the inside diameter 35 of the housing part 23 and by the eccentricity. The Reynold number for the flow in this space can be replaced more precisely by the Reynold Couette number for a coaxial cylinder viscometer, which is:

30th

where ρ is the blood density, ω is the angular velocity of the rotor block, t is the gap thickness of the laminar flow sector 75 and μ is the effective dynamic viscosity of the blood. At low values of R _c , the flow between the rotor block 43 and the housing part 23 is laminar. With high values of R _c local eddy currents occur in a part of the annulus. This results in an intimate swirling of the blood in the angular region 78. The thickness 79 of the annular space in the angular region 78 is approximately 1.27 mm and the thickness of the laminar flow sector is approximately 0.25 mm.

The Laminarströmungssektor 75 is still continued in the laminar flow area 113, at the transition regions 111 and 112 adjacent, in which the flow state is not defined exactly in Figure 3 the pressure profile 110 is illustrated in the region of Blutauslaßstutzens 86 as curve it can be seen the situation , which the blood outlet port 86 must have so that the highest possible pressure occurs at the same. With this outlet port a distributor channel 87 is connected, which runs axially parallel along the outer surface of the heat exchange jacket 82 and corresponds in structure to the distributor jacket 81. There are also passage channels 88 which extend through the heat exchange jacket 82 from the manifold 87 into an outlet groove 109 . Attached to the heat exchange jacket 82 is an inlet connection 89 and an outlet connection 90 which allow a heat transfer medium to circulate in the heat exchange jacket.

In the flow guide disk 62, annular grooves 91 and 92 are provided for receiving sealing rings 93 and 94 , respectively, which prevent the blood treatment fluid from leaking. A retaining ring 95 is seated in a retaining groove 96 and ensures that the rotor block is positioned precisely. At the opposite end of the device 10 there are annular grooves 97 and 98 in the flow guide disk 63, in which there are sealing rings 99 and 100 , which also serve to prevent a leakage flow. A snap ring 101, which forms the second axial fixation for the rotor block, is seated in a retaining groove 102. Sealing rings 103 and 104 are also provided in the fluid seals 50 and 51, respectively.

The housing part 23 merges into a stator housing extension 106 , which can be made long enough to allow easy assembly and disassembly of the device. The inner surface of the housing part 23 with the inner diameter 35 can be provided with a blood-compatible coating, for example with polyurethane. A device stand 107 is attached to the device.

The device shown can be used for oxygen loading of blood or alternatively for blood dialysis use.

When the device 10 is used for loading blood with oxygen, a membrane which is permeable to oxygen and carbon dioxide is used for the thin membrane 40

When the device is used as a blood dialysis device, a thin membrane 40 is used which is permeable to aqueous dialysis solutions and to waste products from the blood.

For both types of application, the membrane usually has a thickness of 0.05 to 0.08 mm.

The rotor sleeve 34, the desired membrane 40 and the compression rings 41 and 42 are already assembled in the factory as a rotor block. This rotor block 43 can then easily be inserted into a stator housing and, if necessary, replaced by another rotor block.

When using the pump as a blood dialysis device, a membrane 40 made of cellulose acetate is used. The arterial blood withdrawn from the hand, arm or leg of a patient enters the blood inlet port 80 in the manner described above by the suction at this point of the device and exits the blood outlet port 86 and is passed back into the patient's body. The blood which is in contact with the membrane 40 in the device is subjected to diffusion washing by means of a blood treatment fluid serving as dialysis fluid, which flows through the annular space 74. Blood dialysis fluids known per se can be used as treatment fluid to remove the pollutants in the patient's blood. The dialysis procedure can be carried out for a required amount of time. The device is maintained at a temperature of 37.degree. C., which is achieved by a thermoregulating fluid sent through the heat exchange jacket 82. It can be cooled for storage between successive dialysis sessions so that the device does not have to be cleaned again after each use.

When using the device for oxygen loading a conventional semipermeable silicone rubber membrane is used for blood, which is used for oxygen and unc Carbon dioxide is permeable. Other materials can also be used for the membrane, such as a dimethyl silicone polycarbonate block copolymer. Oxygen is commonly used as the blood treatment fluid gas used with a proportion of carbon dioxide. De: Blood circulation through the device takes place in the same way as with hemodialysis. As the membrane for oxygen and carbon dioxide gas is freely permeable, oxygen enters

through the membrane into the blood, and carbon dioxide is released therefrom into the annulus 74.

With a rotor block 43 of about 10 cm in diameter and 20 cm in length, one results Sufficient membrane area to achieve a carry out continuous blood washing.

Such a large machine can be used in preparation for oxygenation of blood Use transplants, such as a heart or kidney. If necessary, the blood can with Water or freon chilled to usually 28 ° C

will. Of course, warmer water can also be used to restore the blood if necessary to warm up. The device stores small amounts of a patient's blood, which is beneficial because it allows

-) the blood loss is kept low in critical situations will. One can also squeeze out the permeable membrane 40 at the end of a treatment in order to protect the Further reduce blood loss.

The device according to the invention can be through

in swapping the rotor sleeve 43 quickly for different ones Prepare areas of application and at the same time act as a pump.

For this 2 sheets of drawings

Claims (16)

Patent claims: 1. Device for treating blood, with a hollow cylindrical rotor, with a permeable membrane surrounding the outer surface of the same, with an inlet for a blood treatment fluid opening into the interior of the rotor and with a stator housing in which the rotor is mounted and in which “in Blood inlet and a blood outlet open, characterized in that the rotor (43) is mounted eccentrically to the interior of the stator housing (23, 35) that the eccentricity and the speed of the rotor are selected such that in the area of the blood-filled annular space between Rotor and stator housing with the smallest gap thickness there is a laminar flow, that in the area of the annular space with the greatest thickness there is an at least partially turbulent flow, that the blood inlet (80, 81, 83, 118) and the blood outlet (86, 87, 88 , 109) open into the laminar flow area and that the cylindrical rotor (43) has a number of grooves (36) on its outer surface through which the loading treatment fluid is passed. 2. Apparatus according to claim 1, characterized in that the grooves are designed as longitudinal grooves. 3. Apparatus according to claim 2, characterized in that the rotor comprises a rotor sleeve (34) in the outer surface of which the grooves (36) are incorporated, and that in the region of the ends of the grooves Flow guide disks (62, 63) are connected to the rotor sleeve (34) in a sealing manner and on a shaft (11) are attached and that the flow guide disks at least one with one to the outside have leading bore (12) in the shaft (11) communicating radial channel (66, 69) and that the bores form the inlet or outlet for the blood treatment fluid. 4. Apparatus according to claim 3, characterized in that the flow guide disks (62,63) carry on their outer circumference sealing rings (93, 94; 97, 98) which bear against the inside of the rotor sleeve (34). 5. Apparatus according to claim 3 or 4, characterized in that an end disk (44 or 45) is attached to the outside of each flow guide disk (62, 63) and rests firmly against the end edge of the rotor sleeve (34). 6. Apparatus according to claim 5, characterized in that the membrane (40) over the end regions (38, 39) of the end disks (44, 45) tensioned and fitted into the inner wall of the rotor sleeve (34) Press rings (41 or 42) is tightened 7. Apparatus according to claim 6, characterized in that the seat for the compression rings (41, 42) from the Wall of the rotor sleeve (34) is cut out and that the inner surface of the press rings (41, 42) is flush with the inner surface of the rotor sleeve (34) 8. Device according to one of claims 3 to 7, characterized in that the shaft (U) as Hollow shaft is formed, which is provided with a barrier wall (72,73) at at least one point. 9. Apparatus according to any one of claims 1 to 8, characterized by fluid seals (50, 51) which in a plane of the diameter of the rotor bear with pressure on the adjoining end regions of the rotor and with its outer surface against the statorge seal the housing. 10. Apparatus according to claim 9, characterized in that the lateral surface of the fluid seal (50,51) carries a sealing ring (103,104) 11. Apparatus according to claim 9 or 10, characterized in that the fluid seals (50, 51) Via springs (60,61) each on a removable support ring (54 or 55) fixed to the housing Tension are maintained. 12. Apparatus according to claim 11, characterized in that the support rings (54, 55) through Snap rings (56,57) are held in place. 13. Apparatus according to any one of claims 1 to 12, characterized in that the stator housing of a heat exchange jacket (82) is surrounded with an inlet and an outlet for a Heat transfer means is provided 14. Device according to one of claims 1 to 13, characterized in that the inner surface of the stator housing (23) is provided with two axially parallel distributor grooves (118,109) and that one distributor groove (118) with a blood inlet port (80) and the other distributor groove (109 ) is connected to a blood outlet port (86) 15. Apparatus according to claim 14, characterized in that the distributor grooves (118, 109) are connected to a distributor channel (81 or 87) via a plurality of pipe sockets (83 or 88). 16. Device according to one of claims 1 to 15, characterized by adjusting devices (24, 26, 28.30) for the eccentricity of the rotor.