Dialyzing Liquid-collecting Container

Abstract

A liquid container, pumpable to aspirate liquid into it via an inlet passage, has a dialyzing membrane forming first and second compartments within the container on either side of the membrane. The inlet passage feeds into only one of the two compartments and that one compartment, at least, includes pumpable walls of the container.

Description

BACKGROUND

This invention relates to a container for use in the collection and storage of liquids that are to be subjected to chemical analysis or other processing that includes dialysis. More particularly, the invention provides a collection and storage container pumpable to aspirate liquid into it and which feeds the aspirated liquid into a compartment separated from another compartment by a semipermeable membrane.

This invention is particularly suited for use in a clinical sample container as described in the copending Pat. application Ser. No. 884,924, filed Dec. 15, 1969 and assigned to the assignee hereof. Accordingly, the invention is here described in that context, although it is not limited to such a construction or use.

The chemical analysis of dialysis fractions, i.e., of the crystalline and/or amorphous constituents of liquid samples, such as of blood, has conventionally required that the dialysis be performed with equipment separate from the container in which the sample is collected or stored. Further, the samples typically are dialyzed only at the time of the chemical analysis and with equipment separate from that used for the analysis.

These prior practices are costly in terms of equipment and time. Further, the repeated handling of the samples and repeated transfer of the samples from one container to another subjects the samples to leakage, spillage and contamination.

Also, prior dialyzing containers, such as the one disclosed in U.S. Pat. No. 3,485,751 of Herrmann and Spadoni, are not capable of aspirating the liquid into a compartment out of which the crystalline constituents are to diffuse for collection in a further compartment.

Accordingly, an object of this invention is to provide portable container equipment for the collection of liquid samples, such as of animal body fluid, and for the removal of crystalline portions thereof into a separate compartment commencing immediately upon collection of the sample.

Another object of the invention is to provide container equipment of the above character that aspiratively collects the liquid sample.

Other objects of the invention will in part be obvious and will in part appear hereinafter.

SUMMARY OF THE INVENTION

In accordance with the invention, a pumpable liquid container normally closed except for an inlet tubing or other passage is provided with a dialyzing membrane that forms two compartments on either side thereof within the container. The inlet to the container feeds into only one of these two compartments. Also, the other walls of this one compartment include, at least in part, the pumpable walls of the container.

With this construction, the container walls are readily collapsed and released to aspirate liquid into the one compartment, and crystalline constituents of the collected liquid diffuse into the other compartment. Thus, shortly after a liquid is collected in this container, a portion of the crystalline constituents thereof are available for analysis or other processing separate from the noncrystalline or amorphous constituents of the liquid.

Further, the container is readily constructed so that the liquid portions in each compartment can be delivered directly from the container to analysis equipment.

Notwithstanding the seemingly simple construction of the new sample and specimen container, its use greatly simplifies the collection, transportation, storage and preparation of a liquid for analysis or other processing. The capability for in situ dialysis in the new container preserves the sample purity and saves time and equipment.

The invention accordingly comprises the features of construction, combination of elements, and arrangement of parts exemplified in the construction hereinafter set forth, and the scope of the invention is indicated in the claims.

BRIEF DESCRIPTION OF DRAWINGS

For a fuller understanding of the nature and objects of the invention, reference should be had to the following description taken in connection with the accompanying drawings in which:

FIG. 1 is a pictorial view, partly broken away, of a container embodying the invention disposed for collecting a blood sample from a dermal puncture in a finger; and

FIG. 2 is a cross-sectional view of the container of FIG. 1 taken along line 2--2 thereof.

DESCRIPTION OF ILLUSTRATED EMBODIMENT

With reference to the drawings, a container 10 constructed in accordance with the aforementioned application Ser. No. 884,924 and further embodying the invention has a graduated passage 12 feeding from an input opening 14 into a donor compartment 16 of a collapsible chamber 18. A dialyzing membrane 20 forms the donor compartment 16 within the chamber alongside a recipient compartment 22 on the other side of the membrane. The two compartments are sealed from each other except for the porosity of the membrane 20.

A liquid reagent 28 for preserving and/or diluting the sample can be placed in the chamber 18 prior to the collection of the sample. Also, as described in the above-noted copending application, a record panel 30 bearing identification of the sample being collected and other pertinent information can be provided on the container to extend along the side of the chamber 18 and serves, together with the coiled collection passage 12 and the chamber 18, as a handle for the secure holding of the container during the sample collection process.

The opposed chamber walls 24 and 26 are shown in FIG. 1 slightly collapsed into the chamber, as the medical technician or other operator normally would do during the sample-collecting process simply by squeezing the walls together prior to placing the input opening 14 into the liquid being collected. Upon being released, the resiliency of the chamber walls 24-26 restores the chamber to an uncollapsed condition and thereby draws the liquid into the passage 12 under positive pressure conditions. The operator controls the expansion of the chamber walls until he has collected the desired volume of sample in the passage 12, at which point he simply removes the input opening 14 from the liquid source and fully releases the chamber walls. This allows them to resume their normal uncollapsed condition shown in FIG. 2 and thereby to aspirate the collected sample from the passage 12 into the donor compartment 16 of the chamber. After the desired volume of sample is collected in this manner, the passage 12 can be sealed closed, either at the opening 14 or along the length thereof, in a conventional manner.

As soon as the sample enters the donor compartment 16, crystalline constituents of it commence to diffuse through the membrane 20 to the recipient compartment 22. After a relatively brief time, typically between one-half hour and a few hours, depending on factors such as the membrane porosity, the amount of container agitation and the nature of the dialyte, the dialysis is complete. During this time the filled container 10 can simply be stored or can be transported to a laboratory for the analysis or other processing of the sample.

The fluid in each compartment can be withdrawn by way of a needle puncturing the outer wall of 24 or 26 of the compartment of interest. Alternatively, the container can be cut open, as along the dashed line 32, or otherwise, to expose the compartment contents. As a further alternative, the chamber 18 can be provided with one or more initially sealed outlet tubes leading from each compartment.

The chamber 18 is thus seen to be a pouchlike vessel with opposed resiliently collapsible sidewalls 24 and 26. The passage 12 feeds into the container adjacent a top end thereof and the principal volume of the chamber is below this entry point when the container is in the normal upright orientation. This is normally the orientation in which the container is held during the collection of the sample, and is shown in FIG. 1 for the illustrated container, which has the passage entry 14 at the container bottom. Further, the illustrated chamber is fluidtight except for the entry of the passage 12 into it.

The chamber volume is tailored to the maximum volume of sample which is to be collected. To aspirate this volume of sample first into the graduated passage 12 and then into the donor compartment, the chamber should have a donor compartment with a volume, in excess of the volume of reagent 28 therein, that is at least two and preferably three or more times larger than the volume of sample to be collected. And as noted, the opposed chamber walls 24, 26 can be depressed inward to reduce the volume of the donor compartment 16 by at least twice the volume of the graduated passage 12. Upon being released, the container walls restore automatically to their normal concave shape, FIG. 2, with sufficient resilient force to aspirate the sample liquid into the passage 12 and then into the donor compartment 16.

The illustrated container 10 is constructed as a laminate of two casing panels 34 and 36. Panel 34, which includes the chamber wall 24, is recessed with a channel that forms walls of the passage 12. The other panel 36 is basically identical to the panel 24 except that it has no channel. Instead panel 36 has a flat surface opposite the passage-forming channel of panel 34 and which closes the channel to form the passage 12. Also the casing panel 36 includes the chamber wall 26. The record panel 30 of the illustrated container is provided entirely by the casing panel 36.

The two casing panels 34 and 36 are bonded together as shown, with the dialyzing membrane 20 sealed between their mating faces continuously along the juncture of the chamber wall 26 with the adjoining portions of the casing panel 36. The membrane 20 thus divides the bulbous space between the walls 24 and 26 into the two compartments 16 and 22, and the passage 12 feeds only into the donor compartment 16. The casing panels 34 and 36 can, by way of example, be made of polyethylene. The chamber wall portions thereof can be thinner than the other portions thereof as illustrated, to provide the desired flexible resiliency for these walls. Also, the casing panel 36 can have a different thickness along the record panel 30 than along the nonchamber wall portions; it is illustrated as forming a thinner record panel. In the illustrated container 10, the two casings together have sufficient overall rigidity so that the container normally maintains the overall upright shape as shown.

Further by way of illustration, the dialyzing membrane can be made of conventional material for semipermeable membranes such as regenerated cellulose, nitrocellulose or radiation-drilled plastic. A typical membrane 20 has a thickness of 0.0005 to 0.0009 inch and has pores between 40 and 60 angstroms in diameter.

The foregoing dimensions for the semipermeable membrane and illustrated construction for the container are for collecting blood and separating the protein-free filtrate from the proteinatious constituents. However, the invention can be used to provide other separations of micromolecular constituents from a mixture with larger, macromolecular constituents. In each instance, of course, the semipermeable membrane 20 is selected with pores of the diameter corresponding to the desired separation of molecule sizes.

It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are efficiently attained. The invention provides a pumpable liquid-aspirating container having two compartments therein separated by a dialyzing membrane such that the liquid is aspirated into one compartment only and that crystalline constituents thereof diffuse into the other compartment. The container is thus well adapted for the initial collection of a liquid sample, for storing the sample as long as needed and throughout whatever transportation is involved. After the storage time, a portion of the crystalline constituents of the sample are available to be withdrawn from the container free from the amorphous constituents.

One alternative construction for the container 10 is that the wall 26, which together with the membrane 20 forms the recipient chamber 22, be stiff relative to the opposed wall 24. With such a stiff wall 26, when the two walls are squeezed together for aspirating a sample, the wall 26 will collapse only slightly, if at all. The opposed wall 24 of the donor compartment, however, will collapse as desired. It should hence be understood that only the donor compartment 16 needs to be pumpable for aspirating a sample.

Inasmuch as other changes may be made in the above construction without departing from the scope of the invention, all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense. It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.

Claims

Having described the invention, what is claimed as new and secured by Letters Patent is:

1. Liquid container apparatus comprising

A. liquid-impervious wall means forming a chamber with at least a collapsible and resiliently restoring externally accessible wall portion,

B. a dialyzing membrane within said chamber dividing the chamber interior into at least first and second compartments arranged with said collapsible wall portion forming at least part of the wall of said first chamber, and

C. inlet tubing means feeding into only said first of said first and second compartments, and said first compartment being closed except for said inlet tubing means and the porosity of said membrane.

2. Container apparatus as defined in claim 1 in which

A. said wall means forms said chamber with at least two opposed collapsible and resiliently restoring externally accessible wall portions, and

B. said dialyzing membrane is disposed in said chamber between said two opposed wall portions such that each wall portion forms a portion of a different one of said first and second compartments.

3. Container apparatus as defined in claim 1 in which said chamber extends along a first axis and said inlet tubing means feeds into said first compartment adjacent an extreme end thereof along said first axis.

4. A container for the collection, storage and dialysis of a liquid, said container comprising

A. a tubelike collection passage having first and second ends and a first storage volume therein between said ends,

B. a first chamber compartment connected with said first end of said passage to receive liquid therefrom, said first compartment resiliently maintaining a normal uncollapsed shape and being resiliently collapsible to expel fluid therefrom by way of said passage and resiliently recovering said normal uncollapsed shape when said second end of said passage is open to aspirate fluid thereinto,

C. a semipermeable dialysis membrane forming part of the wall of said first chamber compartment, and

D. a second chamber compartment contiguous with said first compartment and having said semipermeable dialysis membrane forming also a portion thereof for the passage of dialyzate between said first and second compartments through said membrane, and forming with said first compartment an enclosure normally fluidtight except for the entry of said passage into said first compartment.

5. A container as defined in claim 4 in which said first chamber compartment is sufficiently large and sufficiently resiliently collapsible to diminish the storage volume thereof by at least twice said first storage volume.

6. A container as defined in claim 5 further comprising a volume-indicating scale arranged along said passage for indicating the volume of liquid in said passage measuring from said second end thereof.

7. A container for the collection, storage and dialysis of liquid, said container comprising

A. a manually holdable body casing sufficiently rigid to be self-supporting,

B. means forming a tubular passage on said casing with an openly accessible inlet end, an outlet end, and a storage length therebetween,

C. means forming on said casing a pouchlike chamber

(1) having at least first and second compartments therein separated by a semipermeable dialysis membrane having a peripheral portion sealed to the walls of said chamber, and with said first compartment connected with said outlet end of said passage to provide fluid communication from the interior of said first compartment through said passage to the said inlet end thereof, and

(2) having a resilient wall forming at least part of said first compartment and collapsible to diminish the volume of said first compartment and resiliently resuming a normal uncollapsed position.

8. A container as defined in claim 7 further comprising means forming a record panel on said casing for bearing readable indicia.

9. A container as defined in claim 7 further comprising a reagent liquid disposed in said chamber compartments.