Abstract:
A device with a vessel for saliva that has one or more optical indicators to show the volume of saliva in the container. The optical indicators use the principle of total internal reflection together with the difference in refractive index between saliva and air. In embodiments, suitable visual indicators are either visible or invisible, when reflecting surfaces are either not immersed or immersed in saliva or vice versa. The device may comprise a vessel with a saliva pathway, a saliva containment region defining a saliva reservoir, the reservoir having a desired fill level, and an optical viewing window adjacent an angled reflective surface for level indication and/or validating a fill level. The device may include patient interface components and chemical test strips.

Description:
RELATED APPLICATION 
     The present application claims the benefit of U.S. Provisional Application No. 61/827,272, filed May 24, 2013, which is incorporated herein by reference in its entirety. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to devices for collecting saliva. In particular, the present invention relates to a saliva collection container with an optical indicator of the volume of saliva collected. 
     BACKGROUND OF THE INVENTION 
     Bodily fluids are collected for various reasons, including diagnosing illness, simple therapeutic removal, determining pregnancy, confirming or establishing levels of therapeutic agents, determining drug abuse, and profiling DNA composition. Blood, urine, and saliva are among the commonly collected bodily fluids for some or all of these purposes. Among these, saliva has an advantage over other fluids for ease of collection. This is especially true for drugs-of abuse-testing and for DNA testing. 
     Screening for drugs of abuse is performed by health professionals, law enforcement personnel, and government or private employers, among others. Substances of abuse that are commonly screened for include alcohol, cannabis, barbiturates, opiods, cocaine, amphetamines, and hallucinogens. For many such tests and testing environments, blood or urine collection is difficult, if not impossible, making saliva collection an appealing alternative. Saliva is less invasive to obtain than either blood or urine, and does not invoke privacy concerns to the same extent as does urine. 
     DNA testing is used for purposes of paternity, genealogy, disease susceptibility, and forensics, among others. Blood samples, buccal swabs, and saliva are commonly used for DNA tests. Collecting saliva is less invasive than collecting blood, and saliva collection can provide a larger, and therefore perhaps more reliable sample than buccal swabs. 
     Saliva samples are commonly collected by one of two methods: intra-oral sponge absorption and direct expectoration. An example of the first is U.S. Pat. No. 4,580,577 to O&#39;Brien, et al., which discloses an absorbent mass that is masticated by the donor until saturated. The mass is placed in a squeezing device to expel saliva into a holding chamber, out of which a test aliquot can be removed. Sponge or sponge-like absorption methods are disclosed in numerous other patents, teaching variations such as added reagents, salivation promoters, preservatives, flavorings, chemical stabilizers, and a plurality of samples, among others. 
     A flaw of many saliva collection devices that use a sponge for collection is the inability to ascertain adequate sample size. Instructing a donor to “saturate” the sponge is ambiguous and not quantitative. Not only can this result in too little saliva for the intended subsequent use, but also in an unknown amount, even if above a minimum. For some uses such as, for example, chemical assay, a known volume is preferred over a “minimum” volume because the assay may require a relatively accurate volume. Just as important, collecting saliva is a relatively slow process. Unlike urine or blood, for example, saliva is not “cached” by the donor, and must be collected as it is produced. Therefore, it is extremely important not to collect more saliva than is required for subsequent use because this wastes time and adds stress to the persons involved in the collection process. 
     A volume adequacy indicator for use in sponge-type saliva collectors is disclosed in several prior art patents. U.S. Pat. No. 5,260,031 to Seymour, for example, discloses an integrated indicator that provides a visual cue that the sponge is adequately saturated. Another, similar device is disclosed in U.S. Pat. No. 6,423,550 to Jenkins, et al. Several commercially available devices include volume adequacy indicators that use dyes that either change color or are transported to a visually different place upon contact with saliva, which is read by the user as a volume adequacy indicator. One example of a commercially available device is the Quantisal™ device from Immunalysis, which corresponds to U.S. Pat. No. 5,260,031 to Seymour. Another example is the Oral-Eze® device from Quest Diagnostics®, which corresponds to U.S. Pat. No. 5,334,502 to Sangha. 
     The prior art volume indicators employed by sponge-type saliva collection devices require additional substituent components, including coloring dyes. These components add cost and, potentially, contaminate the collected specimen. Moreover, they often indicate only that a minimum volume has been collected, and not a specifically desired volume. 
     Just as important, sponge-based saliva collection itself has significant drawbacks. The sponge or sponge-like materials can adsorb saliva constituents, which may cause errors in subsequent analysis. The absorbent materials can cause discomfort for the donor, perhaps even precipitating a biological reaction. Placing and holding the sponge and sponge assembly into and in the mouth can be unpleasant for donors. 
     An example of a sample collection device based on direct expectoration is disclosed in U.S. Pat. No. 3,518,164 to Andelin, et al. This device includes a tube-like collector, an attached funnel, a stabilizing base, and a threaded sealing cap. The donor spits into the funnel, saliva collects in the tube, the funnel is removed, and the donated sample is sealed with the cap. In this invention, the collected volume is determined by reading the fluid meniscus against inscribed markings on the tube, similar to an ordinary graduated cylinder. 
     Other prior art example patents, which teach variations of direct saliva expectoration collection, and with sample volume indicators include:
     U.S. Patent App. No. 20090216213 to Muir et al.   U.S. Pat. No. 4,283,498 to Schlesinger   U.S. Pat. No. 4,589,548 to Fay   U.S. Pat. No. 4,761,379 to Williams, et al.   U.S. Pat. No. 4,768,238 to Kleinberg, et al.   U.S. Pat. No. 4,932,081 to Burns   

     All of these devices have inscribed markings on the container analogous to a graduated cylinder. 
     While container gradations are relatively common as volume indicators, and are usually accurate enough, reading them correctly can challenge device users. Proper technique requires that the fluid meniscus be discerned and aligned with the gradations, but discerning a fluid meniscus is not always simple, especially in challenging situations (low light, high stress, time-constrained). A consequence can be an erroneous volume reading, either too little or too much. 
     Therefore, there is a need for a saliva container that is a receptacle for neat saliva, and that has an unambiguous, easy-to-read indicator of saliva volume. 
     SUMMARY OF THE INVENTION 
     An embodiment of the present invention comprises a container for oral fluid (saliva) that employs one or more optical indicators to show the volume of saliva in the container. The optical indicators use the principle of total internal reflection together with the difference in refractive index between saliva and air. In embodiments, suitable visual indicators are either visible or invisible, when reflecting surfaces are either not immersed or immersed in saliva (or vice versa). 
     In embodiments, the device comprises a vessel with a saliva entry port, a saliva conduit defining a saliva pathway, a saliva containment region defining a saliva reservoir, the reservoir having a desired fill level, and an optical viewing window adjacent an angled reflective surface in the interior, and visual markings positioned to be reflected off the angled reflective surface for level indication and/or validating a fill level. Embodiments are useful as sub-components of known saliva collection devices and point-of-collection drugs-of-abuse test devices. 
     A feature and advantage of embodiments of the invention is that certainty is provided in whether or not there is an adequate amount of sample. 
     A feature and advantage of embodiments of the invention is that enhanced visual verification of the adequacy of the volume of saliva in the device is provided utilizing conventional materials and can be provided exclusively or partially by the molded configuration of the vessel. 
     A feature and advantage of embodiments is that a plurality or multiple reflective surfaces at different fill levels may be provided. 
     A feature and advantage is that the properties of the polymer forming the molded container are utilized to provide the visual indicator. 
     A feature and advantage of embodiments is that several levels of fill may be identifiable, provide information such as how much more saliva is needed if the current level is not adequate, 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       The invention can be understood in consideration of the following detailed description of various embodiments of the invention in connection with the accompanying drawings, in which: 
         FIG. 1  is a perspective view of saliva container assembly, according to an embodiment of the invention; 
         FIG. 1A  is a cross-sectional view taken at line I-I of  FIG. 2B ; 
         FIG. 1B  is a cross-sectional view taken at line I-I of  FIG. 2B ; 
         FIG. 1C  is a cross-sectional view taken at line I-I of  FIG. 2B ; 
         FIG. 1D  is a further embodiment of a cross sectional view taken at line I-I of  FIG. 2B ; 
         FIG. 1E  is a view of a window of a vessel in accord with the invention with an image of an “insufficient saliva” marking. 
         FIG. 1F  is a view of a window of a vessel in accord with the invention with an image of a “sufficient saliva” marking. 
         FIG. 2A  is an orthogonal cross section view of the saliva container assembly of  FIG. 1 , showing the optical volume indicator without saliva; 
         FIG. 2B  is the same view as  FIG. 2A , but with the optical volume indicator immersed in saliva; 
         FIG. 3  is an orthogonal cross-section view showing an alternate embodiment of the present invention showing a plurality of optical volume indicators; 
         FIG. 3A  is an orthogonal cross-section view showing an alternate embodiment of the present invention showing a plurality of optical volume indicators; 
         FIGS. 4A and 4B  are perspective views of a saliva collection device, according to an embodiment of the invention; 
         FIG. 5  is an orthogonal cross-section view of the saliva collection device of  FIGS. 4A and 4B ; 
         FIG. 6  is an orthogonal cross-section view showing an alternate arrangement for the optical volume indicator of the invention; 
         FIG. 7  is an orthogonal cross-section view showing a plurality of optical volume indicators configured like the alternate arrangement of  FIG. 6 ; 
         FIG. 8  is a perspective view of a point-of-collection drugs-of-abuse test device, according to an embodiment of the invention; 
         FIG. 9  is an exploded perspective view of the device in  FIG. 8 ; and 
         FIG. 10  is an orthogonal cross-section view of the device of  FIGS. 8 and 9 . 
     
    
    
     DETAILED DESCRIPTION 
     Referring now to  FIGS. 1-1C , there is shown a saliva container  100  that includes a collection vessel  101  and a cap  103 , which is releasably attached to saliva vessel  101 . Collection vessel  101  may be made from a suitable optically clear material, such as, for example, polypropylene, polystyrene, poly methyl methacrylate, or glass. In embodiments, portions may be formed of the optically clear material and other portions opaque or translucent. Such separate portions may be joined by welding or overmolding, for example. Saliva container  100  includes a visual marking  105 . Visual marking  105  can be a letter or other indicia, figure, or, as illustrated in  FIG. 1 , a simple printed or dyed color splotch applied to collection vessel  101 . Additional marking  102  may be applied to the region  104  where the light will be transmitted from when the saliva is to a level that covers the reflective surface such as is illustrated in  FIG. 2B . The vessel may be generally cylindrical shaped with respect to the exterior surface  107 , and have interior structure  109 , including the reflective surface  201 , formed during molding such that said interior structure is unitary with the rest of the vessel. Vessel structure includes a mouth  110 , a conduit region  111 , and a saliva reservoir region  112 . Exterior surface structure  114  may additionally include defined viewing structure  120 , including exterior optical structure  121  which may have alternative configurations, including but not limited by, those illustrated by the cross sections of  FIGS. 1A-1C . Such structure can guide the user to the correct viewing window  122  and can provide enhanced optics such as focused, enhanced, magnified, and/or widened image, as well as ribs  126  or other indicia or structure  127  to define or identify the location of the window. Such exterior structure can extend to the bottom of the container for molding simplicity. The interior optical structure  128  can complement the exterior optical structure  121  to create the desired enhanced imaging such as shown in particular in  FIG. 1A . The vessel can have an internal diameter of about 0.4 to 0.6 inches in an embodiment with a saliva reservoir sized for about 1.0 ml. “Sized” meaning the positioning of the optical structure and markings positioned to indicate when the saliva is at least 1.0 ml. In other embodiments, the structure and markings are positions to indicate a saliva fill level of 0.8 to 1.2 ml. In other embodiments, the structure and markings are positions to indicate a saliva fill level of 0.5 to 1.5 ml. 
     In embodiments the saliva conduit can define a saliva flow path with a cross sectional area of 0.10 inches square to 0.30 inches square and a reservoir cross sectional area that changes depending on the level and whereby changes are associated with reflective surfaces. In embodiments the reservoir may be cylindrical with an inside diameter of 0.4 to 0.7 inches. In embodiments the reservoir may be cylindrical with an inside diameter of 0.6 to 0.9 inches. In embodiments the reservoir may be cylindrical with an inside diameter of 0.4 to 0.7 inches. In embodiments the reservoir may be cylindrical with an inside diameter at an upper portion thereof of 0.3 to 0.8 inches. In embodiments, the reservoir has steps associated with different indicating levels. 
       FIGS. 2A and 2B  show reflective surface  201 , which is a functional element of the optical volume indicating feature of the claimed invention. The functioning of the optical volume indicator is as follows: Observer  203  looks toward reflective surface  201  in the spatial configuration shown. In the absence of saliva, reflective surface  201  is a solid/gas interface and, due to the principle of total internal reflection, will reflect the visual marking  105  to observer  203 . However, if a liquid such as saliva  205  covers reflective surface  201  ( FIG. 2B ), the respective refractive index combination of the two interface materials no longer exhibits total internal reflection, and visual marking  105  is no longer reflected to observer  203 . 
     The principle of total internal reflection is a well-known optical phenomenon whose basis is the difference in the speed of light in various transmission media. This difference causes light beams to change direction, or refract, at the interface of two different media. However, if the angle of incidence of light to the interface is beyond a critical angle, governed by the indices of refraction for the two media, all light is reflected rather than refracted. Because of the different refractive indices of the materials involved (e.g. clear plastic, saliva, and air), the critical angle is different enough between the two conditions, saliva and air, to make the necessary geometry convenient to construct. This general principle has been employed in numerous prior art liquid level sensing devices and is described in suitable detail throughout the patent literature. Examples include U.S. Pat. No. 1,883,971 to Kryzanowsky, U.S. Pat. No. 2,943,530 to Nagel, and U.S. Pat. No. 4,353,252 to Jeans. Said patents are incorporated herein by reference. 
       FIGS. 1E and 1F  illustrate a visual indication a user might see of an insufficient quantity of saliva, such as provided by an empty container of  FIG. 2A  and an adequate supply of saliva as illustrated in  FIG. 2B . 
       FIG. 3  shows an additional embodiment of the claimed invention in which a plurality of reflective surfaces (reflective surface A  301 , reflective surface B  303 , and reflective surface C  305 ) of saliva container  100  are depicted. In this embodiment, observer  203  can discern multiple saliva volume levels through three viewing windows or regions  207 ,  208 ,  209 . 
       FIG. 3A  illustrates an arrangement where the optical surfaces may be configured such that the vessel does not have to be repositioned for viewing the separate reflective surfaces in that the reflective angles are different to converge the respective indicating images. Although not illustrated, exterior optical structure may be modified as well to provide this feature. 
     The claimed invention can be used in conjunction with, or as part of any type of saliva collection device, although it is best suited to the spongeless types. One suitable saliva collector example that uses the present invention is the saliva collection device  401 , shown in  FIG. 4 . Collection vessel  101  has been relieved of cap  103 , which has been replaced with header assembly  403 . Header assembly  403  includes a mouthpiece  405 , which includes a saliva inlet  407 . Header assembly  403  also includes a vent  409  (or vents). An embodiment of a header assembly  403  is also described in US Patent Application No. 20120046574, which is herein incorporated by reference in its entirety. 
       FIG. 5  shows the internal components of saliva collection device  401 , including a header housing  501  attached to the aforementioned mouthpiece  405 , and a valve  505 , which is in fluid communication with the saliva inlet  407 , and a vent  409  integrated into an outer wall of header housing  501 . Vent  409  can be covered by a vent membrane (not shown), which prevents escape of saliva through the vent, yet permits escape of air during saliva donation. Collection vessel  101  is removably attached to header housing  501 . 
     To use the saliva collection device  401 , a saliva donor places mouthpiece  405  into the mouth and spits and blows. Saliva enters saliva inlet  407 , flows through valve  505 , and into header housing  501 . Air expelled by the donor is vented out of saliva collection device  401  through vent  409 , whereas saliva flows downward into collection vessel  101 . Observer  203 , who can also be the donor, watches for the expected optical effect to determine when the desired saliva volume has accumulated. This corresponds to a volume that just covers reflective surface  201 , which makes visual marking  105  invisible to observer  203 . So if, for example, visual marking  105  is a blue stripe or patch, observer  203  will initially see a corresponding blue patch reflection when looking straight on as shown in  FIG. 4 . This blue reflection disappears once the predetermined saliva volume is accumulated, and observer  203  will know to stop the donation. After the donation is complete, header assembly  403  can be removed, and a seal such as cap  103  can be reapplied so that the saliva sample can be stored or transported for subsequent use. 
     The alternate embodiment of the present invention shown in  FIG. 6  uses two reflecting surfaces disposed within collection vessel  101 . Reflective surface A  601  serves as the volume indicating surface, whereas reflective surface B  603  allows a different pathway for incident light. This arrangement, is particularly-well suited for electronically reading the optical volume indicator. So, for example, rather than the human eye being observer  203 , a photosensor  605  can be the observer, and a light emitting diode  607  can replace the visual marking  105 . Moreover, because the signal strength can be calibrated to a corresponding percentage of immersion of reflective surface A  601 , it is also possible using this scheme to discern a percentage of a fill volume as well. 
     This principle can be extended to a plurality of optical indicators by disposing a bank of discrete optically reflective surfaces within collection vessel  101  as shown in  FIG. 7 . In this example, a single light source, light emitting diode  607 , is used to illuminate three reflective surfaces  701  by being reflected by reflective surface B  603 . As each surface is immersed in saliva, the corresponding electronic signal changes state. 
     A common use for collected saliva is in drugs-of-abuse screening tests. These tests often use lateral flow immunoassay reagent strips to test for the presence of drugs of abuse such as barbiturates, opioids, methamphetamine, THC, and so on. By using lateral flow immunoassay strips, an immediate, albeit preliminary, result can be obtained at the point-of-collection, avoiding the need to transport the screening sample to a laboratory. 
     The present invention can be incorporated into a saliva collection device that also includes lateral flow immunoassay strips. One such device embodiment is shown in  FIG. 8 . A saliva collection and screening device  801  includes a mouthpiece  405 , a header assembly  403 , and a collection vessel  803 , and also includes the herein described optical volume indicator. 
     Referring now to  FIG. 9 , header assembly  403  is analogous to the already-described header assembly  403  shown in  FIGS. 4 and 5 , and accepts collection vessel  803 . An insert  805  is positioned within collection vessel  803 , and a plurality of immunoassay strips  807  is disposed into slots  809  of insert  805 . Insert  805  includes reflective surface  201  (shown in  FIG. 10 ), as well as visual marking  105 , which in this case is a color splotch. A possible alternate embodiment places visual marking  105  on either the inside or outside bottom of collection vessel  803 . Other visual markings may be on the side of the vessel. 
     The function of screening device  801  is described, with reference to  FIG. 10 , as follows. A donor spits and blows saliva into mouthpiece  405  as before. Air flows out vent  409 , and saliva flows downward into collection vessel  803  as before. Insert  805  is, in this embodiment, a hollow cylinder that directs the saliva to the bottom of collection vessel  803 , and also isolates immunoassay strips  807  from the downward flowing saliva. Once the saliva reaches the bottom (saliva  205  not shown), it can be taken up by the bottom ends of immunoassay strips  807 , which is the prescribed test method for these immunoassay strip elements. The saliva donation continues until observer  203 , which in this case could be a drug-test administrator, sees the optical volume indicator change state as previously described. This confirms that an adequate volume of saliva has been collected to run the immunoassay strip tests to completion, regardless of the test progress. Saliva donation can then be terminated, yet still letting the tests run to completion. This embodiment offers a clear advantage for oral drugs-of-abuse testing wherein the needed collected volume is minimized, thus speeding and simplifying the test methodology. 
     The embodiments above are intended to be illustrative and not limiting. Additional embodiments are within the claims. In addition, although aspects of the present invention have been described with reference to particular embodiments, those skilled in the art will recognize that changes can be made in form and detail without departing from the spirit and scope of the invention, as defined by the claims. 
     Persons of ordinary skill in the relevant arts will recognize that the invention may comprise fewer features than illustrated in any individual embodiment described above. The embodiments described herein are not meant to be an exhaustive presentation of the ways in which the various features of the invention may be combined. Accordingly, the embodiments are not mutually exclusive combinations of features; rather, the invention may comprise a combination of different individual features selected from different individual embodiments, as understood by persons of ordinary skill in the art. 
     Any incorporation by reference of documents above is limited such that no subject matter is incorporated that is contrary to the explicit disclosure herein. Any incorporation by reference of documents above is further limited such that no claims included in the documents are incorporated by reference herein. Any incorporation by reference of documents above is yet further limited such that any definitions provided in the documents are not incorporated by reference herein unless expressly included herein. 
     The above references in all sections of this application are herein incorporated by references in their entirety for all purposes. 
     All of the features disclosed in this specification (including the references incorporated by reference, including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive. 
     Each feature disclosed in this specification (including references incorporated by reference, any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features. 
     The invention is not restricted to the details of the foregoing embodiment (s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any incorporated by reference references, any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed The above references in all sections of this application are herein incorporated by references in their entirety for all purposes. 
     Although specific examples have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that any arrangement calculated to achieve the same purpose could be substituted for the specific examples shown. This application is intended to cover adaptations or variations of the present subject matter. Therefore, it is intended that the invention be defined by the attached claims and their legal equivalents, as well as the following illustrative aspects. The above described aspects embodiments of the invention are merely descriptive of its principles and are not to be considered limiting. Further modifications of the invention herein disclosed will occur to those skilled in the respective arts and all such modifications are deemed to be within the scope of the invention. 
     For purposes of interpreting the claims for the present invention, it is expressly intended that the provisions of Section 112, sixth paragraph of 35 U.S.C. are not to be invoked unless the specific terms “means for” or “step for” are recited in a claim.