ORAL FLUID COLLECTION DEVICE

TECHNICAL FIELD This invention relates to an oral fluid collection device for safely collecting oral fluid.

BACKGROUND OF THE INVENTION

Several matrices are available for routine diagnostic and forensic testing of biological samples from human subjects. Among these are blood, serum, urine, hair, and saliva or oral fluid. Drug concentrations in saliva or oral fluid are related to the concentration of the drag or its metabolites in the bloodstream which makes it perhaps the most attractive matrix for drug screening. It is the least invasive matrix to collect, it requires little specialized training to collect, and there is no need to provide privacy as when collecting a urine sample. The sample can be collected in almost any environment under the complete observation of the person overseeing the collection process. This minimizes the inconvenience for the donor and greatly reduces the possibility of the sample being adulterated. Oral fluid may also contain active or degraded pathogens and somatic cells which makes it a useful matrix for diagnostic and genetic testing.

For diagnostic and drug testing, biological specimens are often collected at one site and sent to a centralized laboratory for testing. Samples being screened for illicit drug use often undergo two levels of testing, and it is desirable that a single aliquot of approximately 1 ml or more from a sample be available for each level of testing. The different levels of testing include an initial semi-quantitative test using a high throughput technique such as a micro plate immunoassay test, liquid reagent homogeneous assay, or strip test to identify clearly negative samples. The presumptive positive samples from this first round of testing are then subjected to the second level of testing which is a confirmatory test such as GC-MS before being definitively labeled as positive or negative for a particular analyte.

An appropriate collection device is necessary to prevent several potential problems from arising when testing oral fluid. Oral fluid is capable of transmitting human pathogens. A sanitary means of collecting oral fluid samples must be provided. The device should isolate the sample and minimize or prevent contact of the sample with the person supervising its collection. It should provide an adequate volume of sample for initial screening and for archiving or for confirmation of presumptive positive samples, and it is preferable that a uniform sample be split at the time of collection for these purposes.

Many oral fluid collection devices have been described which rely on a sponge, pad, or similar absorbent medium. This absorbent material is placed in the mouth until it is saturated with fluid. After it is removed from the mouth, a means is provided to compress the absorbent material, and the fluid is recovered in a tube or similar sample vial. The use of an absorbent medium has several shortcomings when testing the recovered samples for low concentrations of analytes. The amount of oral fluid recovered is relatively small and may not be of adequate volume for initial screening and subsequent confirmatory testing. Dilution of the sample may provide an adequate volume, but this in turn places greater demands on the limit of detection of the testing methods. Furthermore, the absorbent medium provides a large surface area that may selectively adsorb some drugs and result in low recoveries of these particular drugs. Alternately, an elution buffer or another solvent could be used to wash the absorbent and improve the recovery of the drugs, but this results in dilution of the sample, and an organic co-solvent may not be desirable in an immunochemical screening test. As the pad is transferred from the mouth to the storage or processing vessel, the sample is exposed to the environment and, any persons present are exposed to the sample. Finally, some people may find the sensation of holding a sponge or pad in their mouth for several minutes objectionable.

More specialized oral fluid collectors based on a sponge, pad, or similar absorbent medium have been developed specifically for use with strip testing devices for the screening of oral fluid samples. In some cases, these devices simply provide a means of expressing the oral fluid from the absorbent material and in the same action, applying the oral fluid to the appropriate location on the strip device housing. In other cases, the absorbent medium is intimately attached to the strip device, and the oral fluid is drawn directly into the strip device. In general, these devices restrict the initial testing of the sample to the tests contained in the strip device and eliminate the option of screening the same sample by other means or confirming the initial result. If a fluid sample is available from these devices, it is comparable to and suffers from the same problems as samples collected from any absorbent medium.

Other specimen collection devices which have been optimized for the collection of sputum and that do not use an absorbent medium are available. These designs are based on relatively large conical centrifuge tubes as the collection receptacles with removable funnels at the open end of the tube. They may be graduated to indicate the volume of the sample that has been collected. After the sample is collected, the funnel is replaced by a secure cap to seal the tube for transportation and storage. Use of industry standard-sized tubes in these devices facilitates initial processing of samples in the collection tube as the tubes will fit in standard-sized laboratory tube racks and centrifuges. However, these collectors are larger than required for diagnostic testing of oral fluid for many applications, have relatively large open ends which could allow contamination of the sample or loss of sample, and make no provision for simultaneous collection of multiple samples without manually subdividing the single collected sample into aliquots.

Bifurcated saliva collectors are known in the art which resembles the above described sputum collectors. Such a bifurcated saliva collector includes a divided receptacle closed at one end and with a flared funnel at the open end, which allows

collection of two samples in the device. This type of collector lacks a means for sealing the tube or for separating the samples without transferring the samples to new vessels.

Other saliva collection systems employ a transfer pipette, which is used to directly withdraw a sample of oral fluid from the mouth of the donor. Typically the oral fluid is transferred into a separate tube or vial that contains a preservative solution for storage after collection. Those skilled in the art appreciate shortcomings of such a system because the sample is diluted by the preservative solution. Ih addition, the oral fluid does not remain contained during the collection event. Accordingly, there is potential for loss of sample and spread of pathogens during the transfer of the sample from the mouth to the container.

Another type of oral fluid sampling device includes a vented collection chamber connected to a hollow tube. Oral fluid is expelled by the donor through the tube and into the collection chamber. This device makes no provision for collection of a split sample. Obtaining a split sample requires the separation of aliquots from the original sample of oral fluid whenever a second portion of the sample is required for confirmatory testing or archiving.

It is apparent to one skilled in the art that each of the described collection systems are inadequate. Thus, there is a need for an oral fluid collection device that divides the sample into more than one aliquot while the sample is being collected. Such a device should not require the sample to be diluted or necessitate the sample to be transferred from the collection device. The present invention provides a novel means of satisfying these and other requirements.

SUMMARY OF THE INVENTION

This invention relates to an oral fluid collection device. The device includes a housing and a mouthpiece which communicates an oral fluid sample into a sample

distributor within the housing. A pair of sample collection vessels are detachably mounted on the housing, and a pair of passages extend through the housing. One of the passages communicates the sample distributor with one of the vessels, and the other passage communicates the sample distributor with the other vessel, thereby dividing the sample between the vessels.

The invention allows the use of raw saliva which can be collected in quantities not limited by the amount of an absorbent material which is a limitation with other oral fluid collection devices that use a sponge or pad. No dilution of the sample is required due to elution buffers or solvents; however the option of adding preservatives, buffers, diluents, or other modifiers to the sample remains available. The sample is collected into standard-sized labware to facilitate required manipulations and processing after collection. Collection of the sample is straightforward and does not require anything to be held in the mouth for an extended period. The oral fluid is contained within the collection device with minimum potential for exposure to contamination. With transparent tubes, collection of the sample can be directly observed and volume adequacy determined from graduations such as an indicator mark on the tube. The tubes are sealable for storage or shipping and in the preferred embodiments are large enough to hold clearly legible identification labels. Finally, a split sample of adequate volume is available for screening and confirmatory testing or archiving without requiring additional processing steps to subdivide a single sample into multiple aliquots.

BRIEF DESCRIPTION OF THE DRAWINGS FIGURE 1 is a view in perspective of an oral fluid collection device illustrating the present invention;

FIGURE 2 is a fragmentary view in perspective of the oral fluid collection device illustrated in FIGURE 1, taken from below;

FIGURE 3 is a top plan view of a housing which is a component of the oral fluid collection device illustrated in FIGURES 1 and 2;

FIGURE 4 is a side view of the housing illustrated in FIGURE 3;

FIGURE 5 is a bottom view of the housing illustrated in FIGURES 3 and 4;

FIGURE 6 is a longitudinal cross sectional view of the oral fluid collection device illustrated in FIGURES 1 and 2; FIGURE 7 is an enlargement of the circumscribed portion of FIGURE 6; and

FIGURE 8, FIGURE 9 and FIGURE 10 are schematic illustrations of alternate embodiments of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings, an oral fluid collection device generally indicated by the numeral 10 includes a housing 12 supporting a mouthpiece 14 and a pair of collection vessels 16 and 18, which will be described in detail hereinafter. The mouthpiece 14 is a cylindrical member which includes a tapered section 19 at one end thereof which is adapted to be placed to the lips of the donor. The tapered section 19 terminates in an opening 20 to receive the sample of oral fluid. The other end of the mouthpiece 14 defines an open end. Although the mouthpiece may be made integral with the housing 12, the mouthpiece 14 is illustrated as being joined to the housing 12 through a snap connection (Figure 7) defined by a circumferentially extending rim 22 on the mouthpiece 14 which engages a corresponding circumferentially extending rim 24 on a ring 26 on the housing 12. The volume circumscribed by the ring 26 and mouthpiece 14 defines a sample distribution chamber and flow splitter 28 which receives the sample and splits the sample into two portions, which are independently communicated to the vessels 16 and 18 through tubes 30 and 32 defining separate passages, each of which penetrates the housing to receive oral fluid in the sample distribution chamber. Each of the tubes 30, 32 also project into their corresponding storage vessels a short distance to minimize the chance that oral fluid will escape the sample collection vessels when they are removed from the junctions, and terminate in a tapered edge 33 to assist in directing sample flow. Since caps or plugs are necessary to close the collection vessels 16, 18 as will hereinafter be described, caps 34, 36 are made integral with

the housing 12 and are connected thereto by a short tab which is easily broken to remove the caps when the oral fluid sample has been collected. However, the preferred embodiment may use various sizes of tubes necessitating the use of commercially-available caps that are independent from the housing and may be supplied as distinct components.

Many materials are suitable for the construction of the sample distribution chamber and flow splitter, but it is preferred to have these components molded from plastic such as polyethylene. The volume of the sample distribution chamber should be as small as possible while allowing the sample adequate space to collect and flow into the sample collection vessels with approximately equal probability. Preferably the size of these passages should be as large as possible given the dimensions of the sample distribution chamber and the sample collection vessels. It is preferred that the length of this protrusion should be less than or equal to one quarter of the depth of the sample collection vessels to maximize the volume of oral fluid that can be collected.

The collection vessels 16 and 18 are secured to the housing 12 by corresponding rings 38 and 40 that receive a corresponding vessel with a force fit. Since the housing is made of a material that yields, the vessels may be detached from the housing by pulling on the vessels, to thereby force the rim 70 circumscribing the open end of the vessels to slip past the rim 72 on the rings 38 and 40. While the preferred embodiment utilizes rings that engage the outside of the collection vessels, the rings may also be configured such that they are of smaller diameter than the vessels and engage the inside of the vessels to produce a secure attachment. The use of multiple tube sizes with a single housing may be achieved by placing additional smaller-diameter rings within the rings 38 and 40 or by use of a stepped or tapered mount that engage tubes of different diameters. Alternatively, a threaded connection may be provided to join the vessels to the housing. Each of the rings 38 and 40 circumscribe areas on the lower side (viewing the drawings) of the housing 12 that

partially overlap the ring 26 defining the sample distribution chamber on the opposite or upper side (viewing the drawings) of the housing 12. The tube 30 penetrates the area of the housing 12 common to the areas defined by the rings 38 and 26, and the tube 32 penetrates the area of the housing 12 common to the areas defined by the rings 40 and 26. As with any closed system, it is necessary to provide a means to relieve the build-up of pressure as fluid is introduced into the system. Pressure relief outlets or vents 42 and 44 are provided in the area defined by the rings 38 and 40 that are not common with the area defined by the ring 26. It is desirable that a vent be provided for each of the vessels 16 and 18, and that the vents be located where it will be unlikely that they will come in contact with the oral fluid. La some cases, the vents may be covered or plugged with a semi-permeable barrier which allows the passage of gases to equalize pressure within the device with ambient conditions but which prevents the passage of sample, pathogens, or external contaminants.

The storage vessels 16 and 18 have an open end and a closed end and are preferably conventional test tubes which are commonly available commercially. It is preferred to have volume graduations 46 or at least minimum volume indicator marks 46 on the sides of the sample collection vessels to aid in identifying when an adequate volume of sample has been collected. The size of the sample collection vessels is dictated by the amount of sample that is required. It is preferred that the vessels be 2 to 5 times larger in volume than the desired sample size to allow for the presence of bubbles which readily form in the oral fluid during collection. The volume of the vessels may range from a fraction of a milliliter up to approximately 50 ml or larger depending on the intended testing application. The preferred volume of the sample collection vessels is in the range 5 to 15 ml for collection of samples and vessels of different sizes may be used simultaneously. Many materials are acceptable for these vessels, however preferred materials are transparent or translucent such that the amount of the specimens in the sample collection vessels can be directly observed without disassembly of the apparatus. It is also preferred that the material be a plastic which is less likely to break than glass. In a preferred

embodiment, the collection vessels are 17 x 100 mm polypropylene test tubes of 14 ml volume. This is an industry standard-sized tube that is commonly used in laboratories. It is available from multiple sources with volume graduation marks and the size provides adequate area for labels or bar codes required to identify the oral fluid sample. The material is nearly transparent, and the volume of the sample can easily be observed as it is collected.

Typically, the sample collection vessels 16 and 18 are supplied as distinct components separated from the remainder of the oral fluid collection device 10. Assembly of new, unused sample collection vessels to the housing 12 is required. Fluid is allowed to collect in the donor's mouth, the mouthpiece 14 is placed to the mouth, and the fluid is expelled through the sample inlet opening 20 and into the sample distribution chamber 28. If the housing 12 is held such that the vessels 16 and 18 are nearly vertical, the fluid will collect in the bottom of the sample distribution chamber and pass into the collection vessels in approximately equal quantities either solely under the influence of gravity or with some additional pressure created by exhalation of the donor through the mouthpiece and into the sample distribution chamber.

The relative sizes of the samples can be manipulated. If unequal quantities of oral fluid are desired for the samples, the apparatus can be tilted or rotated to favor filling one sample collection vessel at the expense of the other, with the lower vessel collecting more fluid than the higher vessel. In the extreme case, the apparatus can be held such that the tubes are aligned in a manner to fill the lower vessel almost exclusively. Thus the sample collection vessels can be filled simultaneously or sequentially. After the required amount of oral fluid has been collected, the collection vessels are removed from the junctions and the remainder of the apparatus is then discarded in an appropriate manner. The sample collection vessels containing the samples of oral fluid may then be sealed with the caps 34 and 36 and labeled for transportation or storage, or if desired, may be manipulated to modify the samples in

desirable ways. This processing may include the addition of preservatives, pH buffers, organic solvents or other diluents, or it may entail centrifugation or some other treatment.

Referring now to the alternate embodiment of FIGURE 8, the mouthpiece is a simple tube 48 which communicates the oral sample into the sample distribution chamber 28. A filter or strainer 50 is preferably located in the sample distribution chamber as illustrated, but may be located anywhere in the flow-path between the sample donor and the vessels. The filter or strainer 50 removes aggregates from the oral fluid without absorbing any of the fluid.

Referring now to the alternate embodiment of FIGURE 9, the mouthpiece is a tube 52 which is connected to tubes 54 and 56 which extend into corresponding collection vessels 16 and 18 by a "T" connection 58, the "T'connection being the sample distribution chamber.

Referring now to the alternate embodiment of FIGURE 10, one of the vessels is a rapid testing device 60, which is attached to the housing 12 via one of the rings 38 or 40. The mouthpiece and sample distribution chamber are as described in the embodiment of FIGURE 8. Rapid testing devices are well know in the art. One such rapid test device is called a strip test. One feature of the present invention is to allow substitution of a collection vessel with a rapid testing device. The strip interface 60 communicates oral fluid to a strip device 62, which supports a test strip 64. Accordingly, an initial screen can be read from the test strip, while a confirmatory sample is collected in the vessel 18.