Disposable Swab Unit

Abstract

A swab unit comprising an enclosure, a cap for the enclosure, a hollow stemmed swab secured to the cap and in communication with a flexible walled housing mounted on the cap. A frangible liquid filled ampoule is located in the housing. Upon squeezing of the flexible walls of the housing, the ampoule is broken, permitting the liquid to flow through the hollow stem of the swab to moisten absorbent material secured to the end of the swab.

Description

This invention relates to a disposable swab unit and particularly to a unit for taking a sample from a patient's body and preserving that sample by moistening it with a transport medium until it can be applied as a smear to a slide for a microscope.

While the invention will be described as a unit for obtaining samples of a human body, it should be understood that the structure has other uses, such as applicators for medicaments or applicators for other mediums, such as shoe polish.

In taking samples it has been common practice for the physician to remove a swab from a sterile package, take a sample from a patient's body with the swab, insert the swab into a container holding a transport medium and break off the swab stick, thereby minimizing the possibility of contaminates from the physician's hands of being introduced into the transport medium. The container and remaining portion of the swab unit are sealed and sent to a laboratory for analysis.

That procedure has a number of disadvantages which the present invention eliminates. The two packages, swab and vial, are expensive. The swab stick must be handled by the physician, thereby introducing the possibility of contaminating the transport medium. A wooden stick, which must be used in order to break it off into the medium container, has several disadvantages. The wood dries out and becomes brittle and can result in jabbing a patient's throat, and the wood itself could contain a fungus which, if released in the transport medium, will contaminate it and botch the test to be run on the sample.

To avoid the disadvantages referred to above, attempts have been made to provide disposable swab units wherein the transport medium is contained within the unit. One such unit consists of a two section tube having a swab in one section and a supply of transport medium in the other section with a slitted valve between the two sections, does not appear to have enjoyed any success in the marketplace probably because of the cost of manufacturing it. Another unit consists of a flexible tube having a frangible ampoule in one end, absorbent material adjacent the ampoule and a swab disposed in contact with the absorbent material. In use of the latter unit a sample is taken with the swab, the swab is inserted into the flexible walled container and the area containing the ampoule is squeezed to break the ampoule. The medium contacts the absorbent material which then moistens the tip of the swab in contact with the absorbent material.

The present invention provides an improvement over the unit described above in two major respects. First, the physician is never required to touch the swab stem and thus the possibility of introducing contaminates is greatly minimized. Second, the swab tip is moistened directly rather than through an intermediate absorbent material, thereby providing greater assurance of the moistening of the swab tip.

To attain these advantages, the invention provides a cap for an enclosure, the cap carrying a hollow stemmed swab and a flexible walled housing in communication with the swab stem. A frangible, medium containing, ampoule is mounted in the housing. With this unit, a sample is taken with the physician holding only the cap and not touching the swab stick. After the sample is taken, the physician squeezes the housing to fracture the ampoule. The squeezing of the housing and even repeated squeezing of the housing pumps the medium down the swab stem into contact with the absorbent material in the swab tip.

The invention has a number of advantages. It is economical to manufacture and, hence, economical for the physician in that, except for the cap and flexible housing, it is made of standard components. The cap and housing are easily molded and assembled.

Because the swab is securely mounted in the cap, the swab and stem need not be touched by the physician, for the physician performs all operations by gripping the cap and/or flexible housing. Further, the swab stem is a plastic tube which does not suffer from any of the disadvantages of the wood swab stem discussed above. The device is easily handled by the physician in that the liquid medium and swab are contained in one unit so that the physician does not have to open another package to moisten the swab.

The cap has a sealed relationship to the enclosure for the swab which keeps the transport medium in a liquid condition for a week or more which is ample time for submission to a laboratory for the running of tests.

The structure admits of the use of the two-position cap of U.S. Pat. No. 3,004,681. That cap, in one position, admits gas to the interior of the swab enclosure enabling it to be sterilized as by ethylene oxide gas. Also, in that position the pumping action to drive the liquid medium down the stem is not impeded by the high pressure of a sealed container. In the second position, the enclosure is sealed to keep the transport medium from evaporating.

The several features and objectives of the invention will become more readily apparent from the following detailed description taken in conjunction with the accompanying drawings in which:

FIG. 1 is a cross-sectional view of the device; and

FIG. 2 is a cross-sectional view partly in elevation of an alternative embodiment.

The unit is indicated at 10 and includes a swab 11 mounted in a cap 12, the cap 12 normally being mounted on an enclosure 13. The upper end of the cap 12 has a flexible wall sealed housing 14 secured to it, the housing 14 containing an ampoule 15 within which a transport medium 16 is carried.

The swab 11 has a hollow stem 20 whose internal diameter is, in the illustrated embodiment, approximately 0.055 inch. The swab stem may be made of any suitable plastic, for example, polyethylene or polystyrene. The free end of the swab stem has an absorbent material 21 of known type as, for example, cotton fibers, although rayon or plastic are preferred in that the plastic fibers have no inhbiting characteristics. The absorbent fibers 21 are attached to the end of the swab in a conventional manner.

The other end 22 of the swab is press fitted into a socket 23 which is integral with a top wall 24 of the cap 12. The socket is, of course, hollow and is in communication with a port 25 in the top wall of the cap. The flexible walled housing 14 is mounted on the top surface 26 of the cap 12 surrounding the port 25 so as to be in communication with the port. The housing 14 may be made of any suitable plastic materials as, for example, a low density polyethylene which is thin enough to be relatively easily compressed by the physician. The walls also should have enough resiliency in order to return to their original position upon release of pressure so as to enable the physician to impart a pumping action to the housing where that is desired to drive the liquid medium down the swab stem. The housing is sealed to the surface 26 of the top wall of the cap by means of an annular flange 27, the joint between the flange 27 and the surface 26 being made simply by raising the temperature of the respective surfaces until they are slightly fused and then holding them together. Alternatively, the housing and cap could be molded integrally with the top of the housing left open. Upon insertion of the ampoule, the top of the cap could then be closed and sealed.

The ampoule 15 has a glass wall of about 0.010 -0.015 inch thickness which, due to its thinness, is known in the trade as "onion skin." It is easily broken by squeezing on the housing 14. It contains a known transport medium such as Stuart's transport medium. The transport medium has many formulations, none of which forms a part of the present invention.

The enclosure 13 functions simply as a sheet around the swab to keep it in a sterile condition. The amount of medium in the ampoule is preferably between one-half and 1 ml., being only sufficient to moisten the swab and thus there is no requirement for the enclosure 13 to hold the medium. The enclosure 13 is of a test tube configuration preferably being formed of clear polystyrene. It is closed at one end 30 and has an open end 31. An annular bead 32 is formed around the open end, the bead 32 being engageable by the interior surface of the cap 12.

The cap 12 is formed generally as disclosed in U.S. Pat. No. 3,004,681 to provide two stages of application to the open end of the enclosure 13. The first stage is indicated at 34 and has at its lower end an annular bead 35 with a flared opening 36 to facilitate the introduction of the container into the cap. The bead has two diametrically opposed, axially extending slots 37 to assure passage of gas past the bead. An annular groove 39 is located adjacent the bead, the annular groove being slightly larger than the diameter of the bead 32 so as to provide a slop fit between the two. The slot 37 extends the axial length of the groove 39. The axial length of the groove 39 is approximately twice that of the bead.

Above the groove 39 is a sealing groove 41 defined by an internal bead 42 and a shoulder 43. The relationship between the diameter of the enclosure bead 32 and the diameter of the groove 41 is such as to assure a press fit between the two when the cap is fully placed onto the enclosure 13 as shown in FIG. 1. While the cap as described above is preferred, it is to be understood that a slip fit cap or a screw cap can also be used.

The alternative embodiment of FIG. 2 is substantially identical to that of FIG. 1 except for the fact that the embodiment of FIG. 2 utilizes two ports 45 in the top wall of the cap, two sockets 46 and two hollow stem swabs 47. In the alternative embodiment, a somewhat larger supply of medium may be required in order to moisten both swabs. The two absorbent tips of the swabs are in contact with each other so as to permit wicking of the liquid from one to the other to enable them to be equally moistened even in the event that more liquid goes down one swab stem than the other.

In the operation of the invention, the sterilized swab is removed from the enclosure 13 by the physician simply by pulling the cap off the enclosure. A sample is taken from the patient and the swab is reinserted into the enclosure 13 with the cap being placed upon the bead 32 until the bead resides in the large annular groove 39. The physician immediately squeezes the housing 14 to break the wall of the ampoule 15, thereby permitting the liquid medium to flow through the port 25 down the hollow stem 20 and into contact with the absorbent tip 21. Movement of the medium down the stem can be encouraged by applying a repeated squeezing to the housing 14 which pumps the fluid down the stem. When in contact with the tip, the fluid disperses itself throughout the tip through a wicking action, thereby completely moistening the tip. Thereafter, the cap is fully applied to the bead 32 until it has a tight fitting relationship with the annular sealing groove 41. In this condition, the transport medium will stay liquid for a long period of time, thereby keeping the sample moist until it can be processed in the lab.

While the invention has been described as utilizing a frangible glass ampoule in the housing, it should be understood that the invention also embraces other means for confining a liquid in the housing to block the flow of liquid through the port and into the swab until it is time to use the swab. For example, a rupturable capsule of liquid contained in a plastic film could be employed instead of the frangible ampoule. Alternatively, the liquid could be confined in the housing by a rupturable membrane disposed between the housing and the port. Still further, some type of inexpensive valve in the port could be employed, the valve being openable either upon squeezing the housing or upon manipulation by the user.

Claims

We claim:

1. A swab unit comprising,

an enclosure having an open end,

a cap mounted on the open end of said enclosure,

a port in said cap,

a hollow stemmed swab mounted in said port and extending from one face of said cap,

a flexible walled housing mounted on the opposite face said cap and surrounding said port,

a rupturable ampoule containing a liquid and mounted in said housing,

whereby squeezing said housing will break open said ampoule and permit said liquid to flow through said port and through the stem of said swab.

2. A unit as in claim 1 further comprising at least one socket integral with said cap and extending from said port toward said enclosure,

said swab stem being fitted into said socket.

3. A unit as in claim 1 in which said enclosure has a circular bead at its open end,

said cap having a generally cylindrical interior surface adapted to receive said bead,

said surface having an outward portion which loosely receives said bead to permit air flow into said enclosure,

and said surface having an inward portion forming an airtight fitting relation with said bead.

4. A unit as in claim 1 in which two ports are provided in said cap and two hollow stemmed swabs are mounted in said ports.

5. A disposable swab unit comprising,

an elongated, generally cylindrical enclosure which is closed at one end and open at the other,

a cap mounted on the open end of said enclosure,

said cap having a top wall and port in said wall,

a socket projecting into said cap and being integral with said top wall and aligned with said port,

a hollow stem tightly secured at one end in said socket,

an absorbent material covering the other end of said stem,

a flexible housing on the outside of said cap on said top wall, said housing communicating with said port,

and a rupturable liquid-containing ampoule in said housing adapted to be broken to release said liquid upon squeezing said housing.

6. A swab unit comprising,

an enclosure having an open end,

a cap mounted on the open end of said enclosure,

a port in said cap,

a hollow stemmed swab mounted in said port and extending from one face of said cap,

a flexible walled housing mounted on the opposite face of said cap and surrounding said port,

a liquid in said housing,

means temporarily confining the liquid in said housing to block flow of said liquid into said port and swab,

whereby upon removal of said blocking means, liquid can be caused to flow through said port and through the stem of said swab.