JPS5854831B2 - Ketsuekirokasouchi - Google Patents

Description

[Detailed description of the invention] The present invention relates to blood filtration.

There are many examples of filtering blood in medical, sanitary, and surgical procedures (eg, extracorporeal blood circuits used during blood transfusions, dialysis procedures, and certain surgical procedures).

Filters used for blood filtration must meet stringent requirements.

Hemofilters must be sterile and therefore easily sterilized.

The filter must be effective and must remove undesirable substances without removing desirable substances or having harmful effects.

The filter must be constructed so as not to create air bubbles in the blood flowing to the patient.

The filter must be free of any foreign matter that could be released into the blood to be filtered.

In view of the problems in cleaning and sterilizing reusable filters, disposable filters have gained considerable acceptance in blood filtration.

The disposable filter is generally comprised of a number of parts, such as a housing, a core that holds the filtration media, and the filtration media or Kerr 1-IJ threaded filter.

These parts must be assembled and sealed or secured together to form a filtration device, which must be cleaned, washed, and sterilized prior to use.

This filter is used once and then discarded.

This means that the filter must not be expensive and must meet strict specifications.

Improved devices have now been developed for filtering blood.

This novel hemofilter can be easily washed and medically cleaned prior to final assembly.

This new device is easily assembled and completely sterilized by steam, gas or radiation sterilization.

Additionally, this new filter does not harm the blood being filtered and has excellent air bubble removal properties.

This new filter has low blockage characteristics and improved flow characteristics.

According to the invention, a novel device for blood filtration consists of a cartridge-type filter support, a cartridge-type filter and their housing.

The housing and the support can be fixedly assembled to each other in a leak-tight manner.

In a preferred embodiment, the housing is screwed to the support as described below.

The support of the cartridge-type filter has a permeable cylindrical core.

A head cap is attached to one end of the core and seals this end with the filtration media located around the core.

At the other end of the core is a bottom element that extends outwardly from the filtration media support core.

This configuration leaves the center of the core open to serve as an outlet for spent blood.

The outer edge of the bottom element can be provided with a thread for attaching the support to the housing.

The filtration media extends around the core from the top cap to the bottom element.

The core and the filtration media are intermittently in contact only at minimal, spaced apart portions that are spaced longitudinally and circumferentially of the core.

In one embodiment of the novel filtration device of the invention, the distance between the filtration media and the core is greatest adjacent the bottom element and least adjacent the top cap.

In one preferred embodiment of the device of the invention for filtering blood, the housing is tapered and cylindrical.

This housing has a small diameter at the top and a large diameter at the bottom.

The distance between the inner wall of the housing and the filtration media is at a minimum adjacent the bottom element and at a maximum adjacent the head cap.

The frame has a blood inlet and an exhaust port at the top for letting air escape.

The filtration media used are convoluted
It may be in the form of a cartridge.

In this pleated structure, the pleats span the entire length of the cartridge.

When using such pleated cartridges, it has been found that it is preferable for the pleats to have a greater density at the top of the filter body than at the bottom, i.e., for the pleats to be closer together at the top of the filter body than at the bottom. Ta.

With this configuration, it is believed that substances removed from the blood will easily sink to the bottom of the filter and will not be trapped in the folds and therefore will not block parts of the filter.

The invention will be described in more detail with reference to the accompanying drawings.

FIG. 1 is a sectional view of the blood purification device of the present invention, and FIG. 2 is a sectional view taken along line 2--2 in FIG.

FIGS. 1 and 2 show a blood filtering device 10 comprising a support 1L of a cartridge-type filter, a cartridge-type filter 12, and a housing 13.

The support 11 has a cylindrical permeable core 14 .

The core has a number of longitudinal struts 15 held in spaced apart relationship by a number of surrounding rings 16.

For ease of manufacture and ease of assembly of the sifter, the core is preferably conical.

The filtration media is in the form of a cartridge 12 having a convoluted sliding structure and surrounding the periphery of the core.

The medium is compressed into the core only in the pleats that are in contact with the outwardly projecting annulus, such that contact between the core and the medium occurs only in the areas located longitudinally and circumferentially at intervals. is in contact with.

Contact between the substantial portion of the core and the filtration media is kept to a minimum to reduce blockage of the filtration section.

The use of vertical folds of the filtration media and rings forming horizontal rings as the only contact support structures minimizes the contact between the core and the media, i.e., only at spaced discrete portions. do.

This configuration reduces adverse effects on the blood caused by obstructions in the flowing blood.

This is because obstacles are minimized.

Covering the core and filter media head is a head cab 18.

The filtration media is sealed to the head cap by hot melt adhesive 19.

Attached to the bottom of the core is a bottom element 20 that extends outwardly from the periphery of the core.

With this configuration, the center of the core 21 is open and forms the outlet of the filter body.

The filtration media is sealed to the bottom element by hot melt adhesive 23.

The outer rim of the bottom element is threaded and has a suitable gasket 25.

This makes it possible to securely attach the bottom element to the housing 13 of the filter body and obtain a tight leak-tight seal in the gasket area.

The above structure allows the support and cartridge to be washed and medically cleaned before being inserted into the housing, sealed and sterilized.

The support and the cartridge can be washed from both directions to ensure that all foreign particles and impurities present are removed and the possibility of foreign matter being present in the filter during use is eliminated.

In use, blood to be filtered flows from the outside of the filtration medium, passes through the filtration medium, the core, and exits through an outlet located in the center of the core.

It can be theorized that due to the space between the filtration media and the core, and the slight contact between the two, there will be less negative effects on the blood.

The smaller the area of filtration media occluded by the core, the more
The pressure drop during the filtration operation is small.

Moreover, the above-mentioned spatial structure between the filtration medium and the core facilitates the elimination of gas ingress into the blood to be filtered.

A housing 13 surrounds the cartridge type filter.

The bottom open end of this housing is threaded so that it can be connected to the bottom element of the support.

The housing is cylindrical and, in the preferred embodiment of the invention, has tapered side walls as shown in FIG. Evacuation of trapped gas or air is facilitated.

A blood inlet 26 is provided at the head of the filter.

As shown, this inlet is essentially centered in the head of the housing.

However, as previously mentioned, it can be offset, ie moved towards the side of the housing.

Furthermore, there is an outlet 27 at the top point of the filter body, which allows air to escape when filling the filter body with blood, and also allows continuous escape of gases that are removed from the filtered bovine blood.

In use, blood enters the central inlet 26 of the head, flows downwardly over the head cap 18 and along the side walls of the housing, filling the housing and forcing air out of the head outlet 27.

Blood passes through the filtration media into the space between the core and the media, and the filtered blood passes through the permeable core and exits through the central bottom outlet 22.

This flow is shown by arrows in FIG. The preferred spacing between the inner wall of the housing and the media is shown in FIG.

This spacing is greater at the top A than at the bottom B of the media.

This structure facilitates the escape of gas from the housing, ie the degassing of the blood to be filtered.

This structure also improves blood flow properties and reduces harmful blood agitation, or undesirable agitation.

Furthermore, the above structure eliminates the need to provide a secondary flow zone in the filter body, i.e. a zone of immobility in which the blood remains for a while.

The above structure allows blood to move continuously through the filter body.

The presence of quiescent zones in the filter body can cause sedimentation and can be harmful and eliminate or reduce the filtration efficiency of the device.

Furthermore, unexpectedly, this configuration eliminates the problem of unloading the filtration media.

Many hemofiltration devices have a problem where the filtration media begins to become clogged.

This blockage increases the pressure drop of the medium.

If conditions are right, at certain times the filter will remove and pass back substances that may be harmful to the patient.

As previously discussed and shown in FIG. 1, the appropriate shape of the inner wall of the housing relative to the upstream filtering surface of the media unexpectedly minimizes the obstruction clearance problem.

The filter housing and support can be made from a variety of plastic and metal materials that are inert to the action of blood.

This material can be opaque, translucent, or transparent as desired.

Suitable materials include polyolefins (e.g. polypropylene,
polyethylene), butadiene-styrene polymers, polycarbonates and the like.

In the case of a two-part structural support as described above, each piece should be thoroughly washed to ensure that it is medically clean and free of foreign particles that may remain in the parts as a result of fabrication or handling prior to assembly. Everything can be removed.

After thorough cleaning and washing, the parts are assembled as described above and the resulting device is sterilized by gas or radiation sterilization.

The media used in the improved filter of the present invention may be depth-type media such as synthetic fiber felt or synthetic foam, or sieve-type media such as polyester woven fabric or nylon woven fabric.

The media used will depend on how the filtration device is operated.

In one particular embodiment, the filtration media has a pleated structure with pleats throughout.

As seen in the drawings, the number of pleats in the cartridge 12 is uniform throughout, but the distance between the pleats is greater in the bottom end cap 20 than in the head cap 18.

This means that the spaces between the pleats become smaller going up and that adjacent pleats move away from each other going from the top cap to the bottom cap.

Therefore, the filtered material trapped between the head folds will easily settle to the bottom of the filter body and the tendency of the filter media to become clogged is reduced.

Although the present invention has been described above, the present invention is capable of many variations and modifications without departing from its scope.

The invention is limited only by the scope of the claims that follow.

The present invention can be summarized as follows.

1. A blood filtration device, comprising: an assembly support for a cartridge-type filter, a cartridge-type filter, and a housing for the support and the filter.
The housing has an inlet for the saturated blood and an air vent, the housing and the support can be fixed to each other, and the support of the cartridge type filter has a permeable cylindrical shape. a core, a head cap attached to one end of the core and sealing it, and a head cap attached to the other end of the core, extending outward from the periphery of the core and having an opening such that the center of the core acts as a filtration outlet; The cartridge-type filtration body is comprised of a bottom element, and the cartridge-type filtration body is comprised of a filtration medium extending around the core between a head cap and a bottom element, the filtration medium being sealed to the top cap and the bottom element. , a filtration device in which the spacing between the housing and the filtration media increases uniformly from the bottom element toward the head cap, thereby increasing uniformity of filtration media utilization.

2. The hemofiltration device according to paragraph 1, wherein the filtration medium is in a pleated structure with pleats distributed throughout the cartridge-type filter, the density of the pleats being greater closer to the head cap than to the bottom element. .

3. The blood filtration device according to item 1, wherein the filtration medium is a woven fabric in a pleated structure with pleats distributed throughout the cartridge-type filter body.

4. The blood filtration device according to item 1, wherein the filtration medium is a nonwoven fabric in a pleated structure with pleats distributed throughout the cartridge-type filter body.

5. The blood bypass device according to item 1, wherein the permeable cylindrical core has a conical structure.

6. The blood filtration device of claim 1, wherein the blood inlet is located substantially in the center of the head of the housing, and the housing has an air outlet at its top.

7. The hemofiltration device of clause 1, wherein the filtration media is sealed to the head cap and the bottom element by a hot melt adhesive.

8. A blood filtration device, comprising a support for a cartridge-type filter, a cartridge-type filter, and a housing (case) for the support and the filter, and the housing has an inlet for blood to be filtered. the housing and the support can be fixed to each other, the support having a permeable cylindrical core, a head cap attached to and sealing one end of the core, and a head cap attached to the other end of the core; Spreading outward from around the core,
a bottom element having an opening in the center of the core to serve as a filtration outlet; the cartridge-type filtration body comprises a filtration medium extending around the core between the head cap and the bottom element; A hemofiltration device, wherein the filtration media is sealed to the top cap and the bottom element, and the core and the filtration media are in contact only at discontinuities spaced longitudinally and longitudinally around the core.

9. The blood filtration device according to clause 8, wherein the permeable cylindrical core has a conical structure.

10. The hemofiltration device of clause 8, wherein the spacing between the filtration medium and the core is greater closer to the bottom element than closer to the head cap.

11. The filtration medium is in a pleated structure with pleats distributed throughout the Kerr 1-IJ lachrymal membrane, the density of the pleats being greater closer to the head cap than closer to the bottom element. blood filtration device.

12. The hemofiltration device of item 8, wherein the filtration medium is a woven fabric in a pleated structure with pleats distributed throughout the cartridge-type filter body.

13. No. 8, wherein the filtration medium is a nonwoven fabric in a pleated structure with pleats distributed throughout the cartridge-type filter body.
Hemofiltration device as described in Section 1.

14. The sides of the housing are tapered and the bottom of the housing has a larger diameter than the top of the housing;
The blood filtration device according to item 8.

15. The hemofiltration device of clause 14, wherein the distance between the housing and the filtration media is a minimum adjacent the bottom element and a maximum adjacent the head cap.

16. The filtration media is in a pleated structure with pleats distributed throughout the cartridge-type filter body, the pleat density being thicker closer to the head cap than closer to the bottom element;
The blood filtration device according to item 5.

17. A pleated cartridge-type filtration body used for blood filtration, characterized in that the density of the pleats is increased at one end of the filter body to aid in the deposition of substances to be filtered.

18. The cartridge type filter according to item 17, wherein the filter is cylindrical and the pleats are distributed throughout the filter.

19. The cartridge type filter or filtration medium according to item 18, wherein the distance between adjacent pleats becomes gradually and uniformly smaller from one end of the filter to the other end.

[Brief explanation of drawings]

FIG. 1 is a sectional view of the hemofiltration device of the present invention. FIG. 2 is a cross-sectional view taken along line 2--2 in FIG. 10...Filtering device, 11...Cartridge type filter support, 12...Car 1-I
J Tsuji type filter, 13...Housing, 27.
...Air vent.

Claims (1)

[Claims] 1. A blood filtering device, comprising: a cartridge-type filter, an assembly support for the cartridge-type filter, and a housing for the support and the filter. , the housing has a tapered cylindrical shape and has an inlet for blood to be filtered and an air vent at the tapered tip, the housing and the support can be fixed to each other, and the housing has a tapered cylindrical shape. The support includes a permeable cylindrical core, a head cap attached to one end of the core and sealing it, and a support attached to the other end of the core and extending outwardly from the periphery of the core such that the center of the core has a filtration rest. a bottom element having an opening to serve as an outlet; the cartridge-type filtration body comprises a filtration medium extending around the core between the head cap and the bottom element; the cap is sealed to the bottom element, the filtration media and the core are in contact only at discontinuities spaced longitudinally around the core, and the spacing between the housing and the filtration media is from the bottom element to the filtration media; It becomes uniformly larger towards the head cap, and the internal openings for the filtration media gradually widen from the head cap to the bottom element, thereby increasing the uniformity of filtration media utilization.
device.