JPS5812655A - Capillary type blood treating apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a blood processing device using a permselective capillary membrane, for example, two artificial kidneys, one artificial liver, and one artificial lung.

Artificial pancreas 1 relates to improved technology in an artificial reticuloendothelial system device or plasma separator.

Recently, artificial organs that purify blood using selectively permeable membranes have been developed, and these have become effective therapeutic means in the medical field. -6 In blood processing devices that use such membranes, capillary membranes have the advantage that the total surface area of the membrane that can be accommodated within the housing of the processing device is large relative to the amount of blood filled, making them suitable for dialysis and r. . This capillary-type blood processing device must meet the following three conditions (it must be round).The first is that it has the function of blood purification or blood processing (filtration, plasma separation, etc.).The second is that the blood Compatibility and smooth extracorporeal circulation of blood.The third is biological.

Be chemically safe (e.g. free of leachables and sterile).

The present invention relates to improvements in capillary blood processing devices under the second condition. As shown in FIG. 1, a conventionally known capillary blood processing device has a housing 1 filled with a plurality of capillary bundles 2, both ends of which are supported by partition walls 3, and blood chambers 4 and 2 inside the capillaries. The processing chamber 5 is separated from the processing chamber 5. Furthermore, a blood distribution section 6 and a blood collection section 7 are attached to each outer side of the partition wall end. As shown in an enlarged view in FIG. 2, in the known device, the shape of the end of the capillary tube 2 embedded in the septum and opened at its end is different from the end plane A of the septum and the shape of the capillary tube. The aperture ends form the same plane, and the inner diameter of the capillary is substantially equal to the diameter at the center of the capillary and the diameter at the aperture end (partition end surface A). That is, capillary tubes of equal thickness are embedded in the partition wall in parallel, and holes are opened at the end surface of the partition wall. Further, in the prior art, even when the capillary protrudes from the partition wall as shown in FIG. 3, the film thickness at the tip of the capillary tube is the same as that at the partition support portion. In the case of a capillary membrane having fine pores 8, as shown in FIG. 4, there is no substantial difference from that in FIG. 2.

When blood is circulated outside the body, sufficient consideration must be given to the flow of blood to avoid disturbing blood flow and damaging blood cells.

Disturbances in blood flow and resistance and stagnation caused by obstacles promote the formation of plugs, which block the blood flow path. In addition, damage to blood cells promotes hemolysis or blood cell aggregation, which has a chain reaction of adverse effects on the blood and the living body.

In the device of FIG. 1, the blood flows from the distribution part in such a way that it spreads along the septum and then falls at right angles into the capillary tube. In Figure 2, which shows the prior art, there are local (1) where the blood bends at right angles, and (1) Figure 3 or 4, where the blood tends to collide with obstacles, receive resistance, and stagnate. The cause is thrombus formation and hemolysis, 1.
As a result of intensive research into the shape of a capillary that does not cause thrombus formation or hemolysis, it was discovered that the above problems could be solved by creating a trumpet-like curved surface in the shape of the part where blood is introduced into the capillary and into the tube, and the present invention. has been reached.

That is, the present invention provides a plurality of capillaries made of selectively permeable membranes,
In a capillary type blood processing device consisting of a partition wall and a casing that support both end portions of the capillary tube, each capillary tube has a substantially constant outer diameter at both end portions, and the inner diameter thereof is an open end. This capillary type blood processing device is characterized in that the capillary type blood processing device is characterized in that it forms a curved surface such that the inner diameter is the largest at the inner diameter of the partition wall and continuously decreases from the end surface of the partition wall along the inner surface of the capillary tube.

The present invention will be explained.

The present invention provides a capillary type surface liquid treatment device, as illustrated in FIG. 7th
This is an improved version as shown in the embodiment shown in the figure.

The capillary tube of the present invention has a substantially constant outer diameter and a curved surface whose inner diameter widens at the open end. These curved surfaces have a maximum inner diameter at the end and gradually and continuously decrease along the inner surface of the capillary (the center of the capillary).
q-) (funnel) shape or trumpet shape. This curved surface, in the longitudinal section in the capillary axis direction,
For example, it may be a parabola, hyperbola, transition curve, etc. FIG. 5 shows a transition curve connecting the partition wall end surface A to the capillary inner surface B.

In FIG. 6, a circular curve is interposed between A and B, and in FIG. 7, a curve is interposed between A and B.

51 The shape of the end of the capillary tube of the present invention may be a simple curved surface or a complex curved surface.

If the capillary material is inorganic, electrical discharge machining is used.

The shape of the present invention can be finished by electrical etching, chemical etching, laser beam processing, etc.

Furthermore, if there are pores in the capillary wall, it is necessary to fill or reorganize them so that the A-B curve becomes smooth. On the other hand, when the capillary material is an organic polymer, it can be finished into the shape of the present invention by solvent treatment, local melting, laser beam processing, etc.

If necessary, the curved cross-sectional shape of the present invention may extend to the peripheral portion of the capillary at the end face of the partition (as illustrated in FIG. 6). Further, the end portion of the capillary tube and/or the end surface of the partition wall or the inner surface of the capillary tube having the shape of the present invention may be treated or coated with an anticoagulant.

The term "capillary" in the present invention refers to one having an inner diameter of about 10 microns to 511 microns, and includes hollow fibers and tubes.

Due to the shape of the capillary tube of the present invention, the blood flow path becomes smooth, and there is no resistance or stagnation caused by obstructions. In other words, there are no bends at right angles to the blood flow line, and the blood flux changes continuously, so that the blood flows without turbulence (or stagnation). The effect is to provide a blood processing device with capillary channels suitable for blood flow, improving blood compatibility in a broad sense.

The device of the present invention has two artificial kidneys, two artificial livers, and two artificial lungs.

Artificial reticuloendothelial system device 2 can be widely applied to artificial pancreas, plasma separator, etc.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of a known capillary blood processing device. 2-4 are longitudinal cross-sectional views of the capillary end of a conventional device. 5-7 are longitudinal cross-sectional views of the capillary end of the device of the invention. 1... Housing 2... Capillary (or capillary bundle) 3
... Partition wall 4 ... Blood chamber 5 ... Processing chamber 6 ... Blood distribution section 7 ... Collection section 8 ... Hole A ... Partition end surface B ... Capillary inner surface 7-

Claims (1)

[Claims] In a capillary blood processing device consisting of a plurality of capillaries made of selectively permeable membranes, a partition wall supporting both end portions of the capillary tubes, and a casing, each capillary tube has a substantially constant outer diameter at both end portions. A capillary type characterized in that the inner diameter is maximum at the open end and forms a curved surface such that the inner diameter continuously decreases from the end face of the partition wall along the inner surface of the capillary. Blood processing equipment.