DE1928052A1 - Method and device for blood preparation - Google Patents

Description

Patent attorneys
Dr. Ing.Walter Abitt
'Dr. Dieter F. Morf

8 Munich 86, Pieflzenauerstr. 28

Dr. IiOY LAVIOH S '/ ANK'"-

4400 pp. /. Plaice Jerry hoacl, ■ June 2, 1369 PortlariG, Oregon, V.L't.A. '.... 1193-1

" Method and equipment for blood testing -

Blood is routinely used for blood transfusions and cardiac surgery these days

used by the blood bank. The blood taken from the donor is immediately taken with Loaded with heparin or another preservative. Until the invalid Use the blood is stored under carefully controlled conditions.

In some patients, transfusions or cardiac surgery were subsequently performed Circulation arrest and other reactions were observed, but these were not caused by any incorrect blood group determinations. The exact The cause of these unfortunate results is unknown, but the process has been recognized as a function of "blood retention time. Therefore it has been." made a rule to discard blood from the blood bank after a set retention period.

The present invention is concerned with a method and the corresponding one Device for preparing blood to be used for transfusions and cardiac surgery in such a way as to avoid the complications mentioned above. the The likelihood of transfusion reactions, such as circulation arrest and similar complications, should be reduced; Blood from the blood bank should be kept usable with this method even after a long period of storage.

To the drawings:,

Fig. 1 shows a longitudinal section through the blood preparation device described here.

> Fig. 2 + 3 show the floor plans for the assembly as shown in the device in Fig. was used. ,

Fig. 4 + 5: The curves illustrate the relationship between fiber diameter and filter density in relation to the filter performance. # Ό9 # 5 0/1911

. 4th

ORIGINAL INSPECTED

As already known, the composition of leukocytes and blood cells changes of blood bank blood during storage; the changes it causes are responsible for the transfusion complications mentioned above. the Change is noticeable in two ways: First, some of the platelets become adhesive. Tentens, some of the platelets form with some of the leukocytes Aggregates. These aggregates are primarily responsible for the poor results of using old blood for blood transfusions.

In view of the close relationship between the blood changes and the occurrence From transfusion complications it becomes clear how important it is to have these altered To remove components from the blood before the transfusion.

The present invention describes an effective method and what is required to do so Device for removing such components.

As shown in the drawings, the device consists of a tube 10, which are either made of hard material, such as glass, or better of a non-fever-inducing, sterilizable and elastic material, such as polyethylene plastic, can exist. With the latter material, the tube takes on the character of a hand pump; by slowly compressing the side walls of the tube, the The speed at which the blood flows through the apparatus can be increased (as in Fig. 1 is indicated by the dashed lines).

Since the blood flows through the device in the most favorable direction in the direction of gravity, the tube is most conveniently set up in the vertical direction, whereby at the upper end of the inflow channel and at the lower end of the outflow channel.

In order to enable the use of the device for blood transfusions to the inflow channel has to be adjusted, including the closure (14) of the bottle (16), the blood from the blood bank, pierced a hollow, sharp spur (12).

0008 50/108 δ

The spur 12 should extend into the interior of the bottle 10 so that it looks like a Dosing device can work, with which one can monitor a blood flow drop by drop can. A cap (18) with a built-in valve chamber (20) and a short outlet tube (22) is attached to the open lower end of the stirrer 10. It is We recommend installing a ball valve £ 24) in the valve chamber in order to control the flow of blood that is generated by pumping the tube 10. However, the ball valve assembly is unnecessary if the pressure of the blood in the bottle 16 is sufficient, to prevent the blood from flowing back.

A rubber hose or other tube (26) is attached to the short discharge tube 22 attached to deliver the blood to the patient. Usually there is another Inlet valve interposed.

Stirrer 10 thus offers space for filter components which the undesired Hold on to modified components from the stored blood.

To attach these filters, an upper holder (28), a middle holder (30) and a lower holder (32) are either welded or otherwise attached to the inner side wall of the lower part of the tube below the pumping zone. Details of the upper holder 28 are shown in detail in FIG. 2, while the lower holders 30 4 x 32, which may be substantially the same, are illustrated in FIG. All three holders can be made of rigid plastic. "... ■ -.-.. '; ■: _; ^: ; - -:. \' ■ _: ■

The holder 28 holds a stainless steel or blood clot filter screen (34) another suitable material. The sieve size is selected so that all Clots that may be in the blood are collected.

In addition, the holder 28 supplies the blood to the center of the stirrer. To this Purpose is a ring (36) that is glued to the inner wall of the stirrer 10 or is attached in another way, and an inwardly protruding, annular

009850/1985

The flange has inwardly reaching Flange included in the holder. The flange has to tear inwards Protrusions, the particular ones shown in Fig. 2.

The holders 30 and 32 are only used to support the filter components. Everyone consists of a ring (42) which frames a characteristic crossbar pattern (44). Ring 42, like ring 36, is glued to the inner wall of the tube or otherwise attached.

In this way, the three support rings form three chambers (46, 48, 50) with steps decreasing volume. These chambers contain the filter material that determines the desired filter performance.

The chambers 46 and 48 contain the filter material 52, which is used to remove the Blood aggregates and the altered leukocytes and blood platelets are used. To do this must the filter material: selectively retain these components that have changed due to storage; approve the other blood components free pass; have a large absorption area; must not show any febrile properties; must not develop clump together; must not collapse or clog; and must not be harmful even through repeated exposure to heat and chemical sterilization to be influenced.

To meet these requirements, the filter material consists of fibers, which can be modeled into an elastic matrix; this in turn is ever Can be compressed as required to create paths and channels in the most favorable size to accomplish. The diameter or cross-sectional area of the individual particles the material is of fundamental importance in determining its Usefulness.

In general, as will be explained later, the material is said to be from Fasarn exist whose length is not less than 100 microns and whose diameter is less

009850/1199 '

than 60 microns, preferably even less than 3C microns. Such fibers are large enough not to pass through the filter and into the patient's bloodstream. The diameter is small enough that the elongated through Retaining altered aggregates with their overlapping particles, the stick to each other, the fibers can completely enclose and thereby with be anchored to the fibers.

Materials suitable for this purpose are, for example, fibrous or thread-like polyesters Resins (Dacron + Kodel), fibrous polyamide resin (nylon), fibrous polyacrylic Resin (Orion), glass wool, steel wool, cotton and cellulose (paper). However, other fibrous or thread-like materials mentioned above can also be used Requirements.

In order to achieve the purpose of this invention, the upper portion of the filter material must rather loosely packed so that the large aggregates can seep through and distributed over the entire filter, increasing the capacity of the filter. At the bottom, the filter material should be packed relatively tightly. This creates a large surface area for the selective absorption of the smaller particles, which fail when the blood is stored.

Chamber 46, and to some extent the interior of the dome-shaped Blood clot filter 34, take in the loosely packed filter material * on. The central opening and inward projections (40) of the holder 28 allow the filter material to loosen up above the holder, but without to be able to escape unhindered from the lower chamber.

Chamber 48 contains the more densely packed filter material. Usually it is Advantageously, this filter material is 2-4 times more dense than that in chamber 46 pack, i.e. up to a density of 0.1-0.4 g / cm.

Chamber 50 contains a sponge filter (54), the task of which is to prevent

that fragments of the filter material from the chambers overlying the tube and thus reach the patient's bloodstream. The sponge filter should preferably have a porosity of 10-16 pores / approx. It is recommended, make the filter out of porous polyurethane or other porous plastic material, however, it can also be made from a stainless steel screen or sponge.

Experiaentell was the importance of the diameter of the filter components, wow how also the level of pressure in chamber 48 is determined. The results are in Fig. 4+ shown.

In order to determine the influence of the filter material diameter, the device was (Fig. 1) with filter materials of different characteristics and cross-sectional dimensions filled. Blood from the blood bank, which was several weeks old, gravitated below room temperature through the device.

The blood thus treated was then checked for the presence of any remaining Deposition products, i.e. adhesive blood cells, leukocytes and their aggregates, checked. For this purpose, the blood was tested by the pressure test device, which is in the Patent to Roy L. Swank, U.S.A. No. 3,256,299, directed and the the resulting filtration pressure was measured. The results follow in Table 1 and are shown graphically in Fig. 4.

T A F 2 L 1

Material. average filtration pressure

Fiber diameter (microns) (mm Hg)

Nylon 58 ± 6 180

Nylon 42 L 4 56

Nylon 26 t 2 ² ? ·

Nylon 20 t 2 ^lo

Nylon 14 ± 1 ²⁰

Dacron 13 2 1 23

Dacron 17i 1 ²⁵

Dacron 20 ± 4 39

Glass wool 10 ± 2 24

Steel wool 28 ± 4 36

loat-free steel wool 50 t 10 ¹²⁰

20th t 'i 33 20th i 5 25th 20th - 5th 25th 30th and smaller 40

Verel
Code
cellulose
(Paper broken down into its fibrous components).

From the table and the curve it can be seen that the performance of the Treatment depends noticeably on the diameter of the packing fibers. To be good To be effective, the fiber diameter must be less than 60 microns, preferably less than 30 microns. The efficiency decreases with decreasing diameter the method increases dramatically.

To determine the effect of compression to check Filtsrssaterials in chamber 48 was allowed samples of clot-free blood through the filter at different packing densities gravitate. The same amount of blood was used for each sample and the filter passage time was noted in each case. The results are shown in Fig. 5

At a density of around 0.2 g / cc, a clear turning point can be noticed: In general, the best results are obtained if the density of the filter material in the Range is 0.1-0.4 g / cc. A lower density does not give a complete one Filtration. The higher the density, the higher the rate of filtration too slow to be practical.

If the filter is now used, the stored blood first flows out of the bottle 16 through the hollow spur 12, which forwards it drop by drop into the elastic tube 10. There it flows over the blood clot filter 34, which holds back the blood clots, to the flange 38 of the holder 28, which feeds the blood to the center of the tube.

The blood now comes within the blood clot filter 34 and to a large extent also within the chamber 46, through which the blood then flows, with the loosely packed filter material 52 of the chamber 46 in contact. The larger aggregates are then removed.

9850/1985

t) OPY

The blood then flows through the more densely chopped filter material 52 of Chamber 48, which contains the leukocytes and smaller aggregates changed by storage selectively removed.

The blood then flows through the sponge or mesh filter 54, thereby preventing that particles of the filter material leave the device and into the Get into the patient's bloodstream.

During these processes, the upper elastically deformable part of the hose 10 are compressed lengthways, after which the hose expands again. Through this the blood is pumped through the filter, and transfusions are accelerated in emergency situations are thereby made possible.

Ownership or patent privilege is made based on the following points:

1. The new method makes it possible to prepare stored human blood, which contains blood cells-leukocyte aggregates, for medical use. The method includes:
a) Passage of the blood through a mesh screen, which consists of fibrous material, has a large surface, the blood does not decompose and which is characterized by its ability to hold aggregates electively.

The mean diameter of the braided fibers should be smaller than

Be 60 microns,
b) Contact of the Bluptfi with the fiber braid under such temperature conditions that the Blp ^ retains a liquid viscosity, without, however, undesirable

To be exposed to changes
c) 5 contact of the blood with the fiber network Over a sufficiently long period of time so that a substantial proportion of the aggregates is selectively removed during a

009850/1985

COPY

Claims (10)

Dr. Hoy Laver Swank 1193-1 fe-e patent claims Method of removing γόη from stored blood components that have been changed by storage, characterized in that that the stored blood is kept for a sufficiently long time at a temperature at which the blood is fluid, but is not thermally changed, passes through a mesh made of a fibrous filter material, welohes a large one Oberflieh ”and blood does not decompose, and that Air dry fibers with an average diameter of less than 60 microns. 2. The method naoh claim 1, characterized in that one A mesh of fibrous filter material is used, the fibers of which have a mean diameter of less than 30 microns exhibit· 3 * Method according to claim 1 or 2, characterized in that that one uses a mesh of fibrous filter material with a density of 0.1 to 0.4 g / cm ^. 4. The method according to claim 1 to 3 »characterized in that that nan uses a mesh of fibrous filter material, the fibers of which are polyester. , Polyamide, polyacrylic resin, Glass wool or steel wool are made. 5. Device star implementation of the procedure naoh claim 009850/1985 - J - BAD ORIGINAL COPY 1 to ή, characterized by a vessel at one end an inflow channel and an outflow channel at the other end has a mesh arranged within the vessel of fibrous filter material, the fibers of which have an average diameter of less than 60 microns, and Devices for introducing blood into the inflow channel, xur carrying the blood through the plexus and for removing the blood from the outflow channel. 6. Apparatus according to claim 5, characterized in that the vessel has elastically deformable side walls. 7. Apparatus according to claim 5 or 6, characterized in that the lower part of the Gsf3ssea is divided into two chambers, both of which are filled with the mesh of fibrous filter material, the filter material of the upper Kaaner being more loosely packed than that of the lower Kasner. 8. Apparatus according to claim 5 to 7 »characterized in that below the braid of fibrous filter material a filter for retaining constituents of the fibrous filter material is arranged » 9. Apparatus according to claim 5 to 8, characterized in that above the braid of fibrous filter material a blood clot filter screen is arranged. 10. The device according to claim 5 to 9, characterized in that the inflow channel of the Gefflssas old a hollow spur is provided to penetrate the wall of a blood reservoir. SAD ORIGINAL - COPY