Abstract:
An apparatus is provided for oral fluid collection from the mouth the apparatus having a fluid resistant shield adjacent one portion or side of the absorbent to support the absorbent after the absorbent is moist with oral fluid and the shield further operating to block the collection or mucosal transudate from the gum and teeth margin. A method of collection saliva while excluding the collection of mucosal transudate is provided wherein blocking of a portion of an absorbent is performed and the blocked portion of the absorbent is placed adjacent the teeth and gums to exclude any direct collection of mucosal transudate.

Description:
FIELD OF THE INVENTION 
     The field of the present invention is devices for collecting oral fluid samples. In particular, the present invention provides a device having an absorbent for collection of oral fluids thereon and the absorbent having a shield layer positioned adjacent to one side of the absorbent. The shield operates to support the absorbent and to prevent adhesion of the absorbent to the oral tissue or the teeth while the absorbent is within the mouth for collection of an oral fluid sample. In one embodiment of the invention the shield operates to insure that the only oral fluid contacting the absorbent during the collection procedure is saliva. A method of collecting saliva from the buccal cavity is provided which avoids the collection of mucosal transudate. 
     BACKGROUND OF THE INVENTION 
     The buccal cavity of the mouth is that portion of the mouth between the inside of the cheek and the teeth and gums. It has long been recognized that the buccal cavity is a convenient location for the collection of saliva from human beings. One prior example of the use of the buccal cavity as a saliva collection area can be found in Immunoradiometric Assay of Salivary Anti-C3 Antibodies, by Challacombe, Journal of Immunological Methods, (1978), pages 53-59. In the Challacombe article, saliva was collected from neonates by means of a small sterile sponge placed in the mouth between the gum and the cheek. Numerous other methods and devices for collecting saliva have been utilized throughout the years. Typically, these methods for collecting saliva have comprised placement of an absorbent pad or a wad chewable material in the mouth to absorb saliva as the material rested in the mouth or was chewed by the subject. 
     Recently, investigators have been attracted to methods and devices for collecting oral mucosal transudate (OMT) for the collection and measurement of various analytes which may be present in a subject. Typically the device used for such mucosal transudate collection has consisted of a cotton fiber pad that is placed between the lower gum and cheek and rubbed back and forth along the gum/teeth margin (the gingival interface) followed by analysis of the material absorbed on the cotton wool swab. An example of this type of collection of material on a cotton wool swab from along the gum/teeth margin can be found in diagnosis of Hepatitis A and B by testing saliva, J. V. Parry, et al., Journal of Medical Virology, 28:255-60 (1989). 
     During the collection of saliva from the mouth, and in particular, the buccal cavity, it is not uncommon for the absorbent to be placed into the buccal cavity or under the tongue and to be allowed to reside there for two or more minutes. During this period of time that saliva is being collected from the mouth, moisture is being removed from the tissue surrounding the absorbent and drawn into the pad. It is not uncommon for this loss of moisture from the tissues adjacent the pad to result in the absorbent pad beginning to adhere or stick to the tissue of the mouth thereby making removal of the absorbent pad difficult or uncomfortable. It is possible for the adhesion of the absorbent pad to the mouth tissue to be sufficiently strong that the attempt to withdraw the absorbent pad from the mouth results in separation of the pad from the handle portion of the apparatus being used to manipulate the absorbent pad. In particular, it is not uncommon that the absorbent pad will be placed in the buccal cavity, and the side of the absorbent pad which is next to the teeth and gums will become stuck to the teeth or the gum tissue. This circumstance is uncomfortable for the patient and can result in separation of the absorbent pad from the handle when removal of the saliva saturated absorbent pad from the mouth is attempted. 
     The present invention solves the problem of adhesion of the absorbent pad to oral tissue and at the same time provides a support structure to prevent un-wanted tearing of the absorbent away from the device handle. Further, the present invention provides investigators with a means of isolating fluid absorption from areas of the mouth from which collection is not desired. In particular, one embodiment of the present invention prevents the absorbent from contacting the gingival interface at the junction of the teeth and gums and thereby prevents collection of OMT or oral mucosal transudate. 
     SUMMARY OF THE INVENTION 
     The present invention eliminates or greatly reduces the instances of adhesion of an absorbent pad to tissues that are adjacent to one side of the pad. Also, the present invention provides additional structural support for an absorbent pad once it has become saturated with an oral fluid such as saliva. A further advantage of the present invention is that one side of the absorbent pad can be shielded from contact with adjacent oral tissues thereby preventing absorption of an oral fluid onto the shielded side of the absorbent pad as a result of direct contact by the pad with the adjacent oral tissue. 
     The above benefits and objectives are accomplished in the present invention by an oral fluid collection device which provides, in one embodiment, a non-absorbent layer or shield which is applied to, or is adjacent to, one side of an absorbent pad. In another embodiment, a different combination of the benefits of the present invention are accomplished by use of a fluid shield or fluid-impervious layer which is provided with voids in the shield layer. The voids allow analytes that are dissolved in saliva to pass through the shield layer and to be absorbed by the pad while the shield prevents adhesion of the absorbent to the adjacent oral tissue. In addition, mouth fluids which must be rubbed off of tissues (e.g., OMT) are not collected by the pad. 
     The foregoing and other objects are intended to be illustrative of the invention and are not meant in a limiting sense. Many possible embodiments of the invention may be made and will be readily evident upon a study of the following specification and accompanying drawings comprising a part thereof. Various features and subcombinations of invention may be employed without reference to other features and subcombinations. Other objects and advantages of this invention will become apparent from the following description taken in connection with the accompanying drawings, wherein is set forth by way of illustration and example, an embodiment of this invention. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     Preferred embodiments of the invention, illustrative of the best modes in which the applicant has contemplated applying the principles, are set forth in the following description and are shown in the drawings and are particularly and distinctly pointed out and set forth in the appended claims. 
     FIG. 1 a  is a top and side perspective view of a first embodiment of the invention and having a shield having side walls and an open front; 
     FIG. 2 a  is a top and side perspective view of a second embodiment of the invention having a shield with a continuous side wall covering the sides and front of the absorbent; 
     FIG. 1 b  is a bottom and side perspective view of the embodiment of FIG. 1 a  and showing a series of voids in the shield to allow passage of liquids to the absorbent; 
     FIG. 2 b  is a bottom and side perspective view of the embodiment of FIG. 2 a  also showing the inclusion of voids in the shield to allow passage of fluids to the absorbent layer; 
     FIG. 1 c  is a front and elevational view of the embodiment of FIG. 1 a;    
     FIG. 2 c  is a front and elevational view of the embodiment of FIG. 2 a;    
     FIG. 1 d  is a side elevational view of the embodiment of FIG. 1 a;    
     FIG. 2 d  is a side elevational view of the embodiment of FIG. 2 a;    
     FIG. 3 a  is an alternative embodiment of the present invention having a shield without side walls; 
     FIG. 3 b  is a front and elevational view of the embodiment of FIG. 3 a;    
     FIG. 4 is a top and side perspective view of the shield portion of the embodiment of FIG. 1 a;    
     FIG. 5 is a top and side perspective view of the shield portion of the embodiment of FIG. 2 a;    
     FIG. 6 is an exploded view of the embodiment of FIG. 3 a;    
     FIG. 7 is a top and side perspective view of the embodiment of FIG. 3 a  showing the separator shaft of the handle extended to break the absorbent away from the handle; 
     FIG. 8 is a top an d side elevational view of the embodiment of FIG. 8 after the extension of the separator shaft shown in FIG.  7  and the subsequent retraction of the separator shaft and showing the separation of the absorbent from capture within the handle to allow removal of the absorbent; and 
     FIG. 9 is a side elevational view of another embodiment of the invention in which the absorbent has a separation line to permit manual breaking-away of a portion of the absorbent, the embodiment of FIG. 9 can comprise a shield that is impervious to fluids on one side with no shield on the other side or it can comprise a shield that is impervious to fluids on one side while having a covering with micro pores on the other side or it can comprise a shield made of a substance having micro pores that completely covers the absorbent. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now FIG. 1 a , oral sample collection device  10  of the present invention is comprised of absorbent layer  12  which is attached to handle  14  by capture of a tail piece or absorbent tongue portion  30  (FIG. 6) between handle  14  and separator shaft  22  which is slidably captured within handle  14 . Absorbent  12  is comprised of any material which is suitable for collection of saliva. Examples of acceptable absorbent materials are cellulose fiber such as paper or cotton or nylon or polyester absorbent pads. Examples of absorbent papers which are appropriate for the present invention include those manufactured by S &amp; S® 903™ manufactured by Schleicher &amp; Schuell, Inc. or equivalent papers from other vendors such as Whatman, Inc. of Clifton, N.J. Still referring to FIG. 1 a , absorbent  12  is generally formed of a sheet of absorbent paper approximately ½ inch wide and 2½ inches long and {fraction (1/16)} inch in thickness. Absorbent is generally comprised of a first or top surface and a second or bottom surface which are joined by absorbent connecting edge  13 . Adjacent the bottom or lower surface of absorbent  12  is plastic guard or shield  16 . In the embodiment of FIG. 1 a , shield  16  is provided with upturned side walls  18  which extend upwardly along edge  13  of absorbent  12 . Shield  1   b  protects one surface of absorbent  12 , in this case, the lower surface, and a portion of absorbent edge  13  from contact with adjacent oral tissues. 
     It is desirable, but not necessary, that shield  16  be comprised of a thin, sheet plastic material which is slightly soft and flexible and safe that damage to oral tissues is avoided. Generally, any fluid impervious material would be satisfactory for use in forming shield  16  as long it is safe to be used in the mouth. It is also contemplated that shield  16  could be formed as part of absorbent  12  by using a plastic coating directly on absorbent  12 . In an alternative embodiment, in which shield  16  encloses absorbent  12  by covering the top and the bottom surfaces and edge  13  of absorbent  12 , shield  16  can be formed from a material that acts as a molecular sieve to differentially permit molecules to pass through shield  16  to absorb on absorbent  12  depending upon the molecule size. A useful material for this embodiment is cellulose acetate. Cellulose acetate is manufactured in several forms by several different manufacturers. The different forms allow passage through the cellulose acetate of molecules of a particular size range while excluding molecules of other sizes. An example of a suitable cellulose acetate material is a molecular porous membrane product called Spectra/Por manufactured by The Spectrum Companies of Gardena, California. An alternative molecular porous membrane material is polyvinylideneflouride (PVDF). 
     Therefore, a form of cellulose acetate can be selected to form shield which allows passage through the cellulose acetate shield  16  of a molecule of interest while excluding other molecules from reaching absorbent  12 . In one particular application, the molecular porous membrane product could be selected to insure the exclusion of selected sizes of proteins from surrounding oral fluid while allowing passage other analytes of interest through the shield  16  for absorption on absorbent  12 . The function of shield  16  will be discussed in further detail hereinafter. 
     Still referring to FIG. 1 a , device  10  can be provided with a means for determining when a sufficient amount of sample has been collected and for determining whether or not the sample collected is, in fact, saliva. The method of determining that the specimen collected is, in fact, saliva and that a sufficient amount of saliva has been collected is the subject of U.S. Pat. No. 5,334,502 and is incorporated herein by reference. In summary, the method of determining that a sufficient quantity of saliva has been collected can be simple as utilizing a colored vegetable dye which will migrate along the absorbent paper as the saliva is absorbed onto absorbent  12  and the saliva migrates toward handle  14 . In such a case, absorbent  12  will extend up into handle  14  past observation window or void  20  which is placed in handle  14 . As the saliva front moves along absorbent  12  and into handle  14  where the tail portion of the absorbent is captured by handle  14 , the colored vegetable dye or other suitable indicator will dissolve in the saliva and be pushed deeper into the interior of handle  14  until it is visible within void or window  20  of handle  14 . When the dye is visible in window  20 , the user of collection device  10  is assured that sufficient saliva has been applied to absorbent paper  12  to wet the absorbent  14  as far as window  20 . If the absorbent has been properly sized, sufficient sample will have been collected to perform the desired subsequent analysis on the saliva. 
     Alternatively, and as explained in U.S. Pat. No. 5,334,502, the simple vegetable dye can be replaced with a chemical compound which is reactive with the component of saliva. Typically, upon contacting the saliva, the chemical component will undergo a change of color in response to a chemical reaction with a component of saliva. In this manner, the observation of the color change in the indicator demonstrates to the operator of collection device  10  that it is, in fact, saliva on the absorbent paper and not a substitute liquid such as water. 
     Referring now to FIG. 1 b , the bottom side of device  10  of FIG. 1 a  is shown. In FIG. 1 b , shield  16  is shown extending from handle  14 . Shield  16  covers the bottom surface of absorbent  12  and sidewalls  18  of shield  16  is shown extending to cover edge of absorbent  12 . In FIG. 1 b , shield  16  of the embodiment shown is further comprised of shield voids  17 . Shield voids  17  are openings within shield  16  which allow fluids, such as saliva, to pass through shield  16  and be absorbed on absorbent  12 . In this manner, shield  16  serves its general purpose of maintaining separation of absorbent  12  from adjacent mouth tissues while allowing saliva to pass through shield  16  to expedite the saturation of absorbent  12  with oral fluids such as saliva. 
     As previously described, the ability of the present invention to maintain separation between oral tissues and absorbent  12  is important for several reasons. As has been described in the background of the invention, it is often the case that during the time an oral fluid collection device is held in the mouth, the absorbent will adhere to oral tissues which are in contact with absorbent  12 . When the collection period is at an end, and the user attempts to withdraw the oral collection device from the mouth the absorbent may continue to adhere to the oral tissues. As the absorbent now has become wetted with saliva and is less resilient, the absorbent will tend to tear off the handle to which it is attached and remain in the mouth due to the adhesion between the absorbent and the oral tissues. 
     Another purpose of shield  16  is to provide additional physical support to absorbent  12  while it is within the mouth and after it has absorbed saliva. When absorbent  12  is in the mouth, it absorbs saliva and becomes heavy and limp. In this state, the absorbent can easily be torn by pressure applied to it. The presence of shield  16  reinforces pad  12  and adds support to the saturated absorbent and assists in preventing undesired tearing of absorbent  12  from handle of oral fluid collection device  10 . Another useful aspect of shield  16  is the separation shield  16  maintains between absorbent  12  and any surface upon which device  10  is placed. While device  10  should not be placed onto a surface prior to being used, it may be necessary, once the device has absorbed saliva and is withdrawn from the mouth to momentarily set device  10  down on a table surface or the like. In the absence of shield  16 , the wetted and flexible absorbent would droop down and contact whatever surface device  10  was set upon. This contact with the surface upon which device  10  was placed would undesirably contaminate absorbent  12 . In this situation, shield  16  acts as a supporting shelf which holds wetted absorbent  12  away from any adjacent surface upon which oral collection device  10  might be placed. Another important feature of shield  16  is the ability of shield  16  to prevent contact between absorbent  12  and particular mouth tissues. In recent years, some investigators have found it useful to rub absorbents against the gum tissues, specifically at the gingival interface, to collect oral muscosal transudate. It is believed that oral muscosal transudate or OMT presents higher concentrations of various analytes of interest than does saliva. However, saliva has been collected for many years from the buccal cavity of the mouth, and a substantial body of evidence and data has been developed over the years which relate to the concentration of various analytes contained in saliva from the buccal cavity. 
     Therefore, it is useful for investigators to be able to conclusively distinguish the collection of saliva from the buccal cavity and to rule out any collection of OMT while collecting at that location within the mouth. This is accomplished with the present invention by use of shield  16  which, in one of its various embodiments, can allow the passage of saliva only to the absorbent such as the embodiment in which void  17  (FIG. 1 b ) are included in shield  16 . Alternatively, any collection of OMT can be eliminated by the use of an embodiment of shield  16  which has no voids  17  within the shield. In this manner, absorbent  12  is completely shielded from any contact with the gum tissue when the device is properly oriented within the mouth so as to place the shield against the gums. In this orientation collection of OMT is absolutely eliminated and only saliva is collected from the non-shielded surface which is adjacent the inside of the subject&#39;s cheek. 
     Referring now to FIG. 1 c , a front end elevational view of the embodiment of FIGS. 1 a  and  1   b  is shown. In FIG. 1 c , it is shown that shield  16  of the embodiment of FIG. 1 a  and  1   b  fully protects the bottom of absorbent  12  and that shield sidewalls  18  extend upwardly to protect the side portions of absorbent edge  13  while leaving the front of absorbent edge exposed. Examination of FIG. 1 d  shows the complete coverage of absorbent edge  13  by shield sidewall  18 . It will be appreciated that the embodiment of the present invention shown in FIGS. 1 a  and  1   b  and the shield  16  shown therein can be provided with shield voids  17  as shown in FIG. 1 b  or shield  16  can exclude the use of shield voids  17  and present a solid and impenetrable surface. This is dependent upon the particular investigator&#39;s wishes and whether the investigator desires to slightly more rapidly collect saliva and saturate absorbent  12  when shield voids  17  are included in shield  16 . In either embodiment, that is, embodiments of shield  16  including shield voids  17  or embodiments of shield  16  which present a solid surface, the collection of OMT is avoided as in both embodiments of shield  16 , prevent contact between absorbent  12  and the interface between the teeth and gums is avoided. 
     Referring now to FIGS. 2 a  and  2   b ; an alternative embodiment of oral fluid collection device  10  is shown. In the embodiment of FIGS. 2 a  and  2   b  and  2   c , shield  16  has a flat protective bottom surface shown in FIG. 2 b  and has a continuous shield sidewall  18  which protects the entirety of absorbent edge  13  of absorbent layer  12 . In the embodiment of FIGS. 2 a ,  2   b  and  2   c , shield sidewall  18  wraps completely around absorbent edge  13  to prevent any contact between the bottom surface of absorbent  12  and absorbent edge  13 . In this manner, the only portion of absorbent  12  which can contact oral tissue is the top surface as shown in FIG. 2 a . In FIG. 2 b , it can be seen that shield  16  is provided with voids  17  to allow absorption of oral fluids such as saliva at the bottom surface of absorbent  12 . It will be appreciated from the previous discussion that shield  16  in the embodiment of FIGS. 2 a  and  2   b  can be provided with either void  17  or shield  16  can be a solid surface which excludes passage of saliva through shield  16  to contact absorbent  12 . FIG. 2 c  shows a front end elevational view of the embodiment of FIGS. 2 a  and  2   b  and shows the shield sidewall  18  covering the front portion of absorbent edge  13  of absorbent  12 . In FIG. 2 d , it can be seen that shield sidewall  18  protects the entire length of absorbent edge  13  of absorbent  12 . 
     Referring now to FIG. 3 a , an alternative embodiment of the present invention is shown wherein a flat, plastic guard or shield  16  is used to protect the lower side of absorbent  12  from contact with adjacent tissue. In the embodiment of FIG. 3 a , shield  16  is comprised of the same materials as is shield  16  of the embodiments shown in FIG. 1 a  and  2   a . However, shield  16  of the embodiment of FIG. 3 a  is a flat sheet and does not have shield sidewalls  18  to protect edge  13  of absorbent  12  from contact with oral tissue. In practice, the embodiment of FIG. 3 a  may be used when there is less concern over the need to exclude the collection of other oral fluids, for example, when the oral fluid sampling is to be conducted under the tongue. When collecting oral fluid from under the tongue, device  10  is placed such that one surface of absorbent  12  is oriented towards the tongue and the other surface of absorbent  12  is placed against the floor of the mouth. In this collection method, edges  13  of absorbent  12  will not contact oral tissue sufficiently to adhere thereto. In this collection method, flat, plastic guard  16  of embodiment FIG. 3 a  is sufficient to protect one of the large surfaces of absorbent  12  from contact with the adjacent oral tissue and adhesion to the tissue is prevented. Upon the absorbent being saturated with saliva, device  10  of FIG. 3 a  can be easily withdrawn from the mouth without damage to absorbent  12 . 
     Referring now to FIGS. 4 and 5, the construction of shield  16  is shown. In FIG. 4, the shield utilized in the embodiment of FIGS. 1 a  and  1   b  is shown, and in FIG. 5, the shield utilized in the embodiment of FIGS. 2 a  and  2   b  is shown. Shield  16  shown in FIGS. 4 and 5 is comprised of shield floor  19  to which shield tongue  24  extends rearwardly. In the embodiment of FIG. 3 a , shield  16  is comprised of these two principal elements and does not have the shield sidewall  18  element. As previously discussed, attached to shield floor  19  is shield sidewall  18  which can be embodied as two straight sidewalls  18  as shown in FIG. 4, or can be embodied as a continuous sidewall  18  as shown in FIG.  5  and which protects both sides and the front of absorbent edge  13  of absorbent layer  12  when the absorbent layer is placed within shield  16  of FIG.  5 . Each embodiment of shield  16  is equipped with shield tongue  24  which extends rearwardly from shield floor  19  and is captured within the structures provided in handle  14  and separator shaft  22 . The utility and purpose of this capturing tongue  24  within handle  14  will be thoroughly described hereinafter. Shield tongue  24  is provided with two voids. A first void is shield tongue securing void  28  which is at the rear of shield tongue  24 . A second void is shield tongue oval or elongate void  26  which is in a forward position on shield tongue  24 . 
     Referring now to FIG. 6, the construction and utility of the various components comprising shield  16  and absorbent  12  will be discussed. FIG. 6 is an exploded view of the present invention and is essentially the same for all embodiments of the invention discussed herein. The exploded view generally shows handle  14 , shield  16  which is fitted within handle  14 , absorbent  12  which is fitted within handle  14  on top of shield  16 , and separator shaft  22  which is press fitted into separator track  36  of handle  14  where it is slidably held in place by compression fit. 
     The assembly and operation of device  10  will now be described. Shield  16  is placed within handle  14  such that securing post  46  of handle  14  projects through shield tongue securing void  28  at the rear of shield tongue  24  of shield  16 . The engagement between securing post  46  and shield tongue securing void  28  ensures that shield  16  cannot be inadvertently pulled away from handle  14 . Once shield  16  is placed within handle  14 , absorbent layer  12  is then placed on top of shield  16  and positioned such that securing post  46  of handle  14  which is projecting through shield tongue securing void  28  of shield  16  captures absorbent tongue securing void  34 . Absorbent securing void  34  serves to hold absorbent  12  in place within handle  14  and avoids absorbent  12  from being inadvertently pulled away from handle  14 . It will be appreciated that absorbent  12  is positioned within handle  14  to affect registration or alignment between absorbent tongue front void  32  and shield tongue oval or elongate void  26 . The desired alignment is that absorbent front void  32  be directly above the rear of shield tongue oval void  26 . The purpose of this alignment will be described hereinafter. 
     After shield  16  and absorbent  12  have been placed in registration and in handle  14  and secured upon securing post  46 , separator shaft  22  can then be press fitted into handle  14 . As separator shaft  22  is fitted into handle  14 , separator shaft rear post is positioned in handle  14  between handle rear stop  42  and handle forward stop  44 . Separator shaft front post  40  extends through absorbent tongue front void  32  and into shield tongue oval void  26 . Once the alignment of separator shaft  22 , which has just been described, is achieved, separator shaft  22  is compressively fitted into handle  14  where it is held in place by separator track edges  36  which are the edges of a void within handle  14  that is designed to receive separator shaft  22  therein. Once separator shaft  22  is fitted within handle  14 , it is to be understood that separator shaft  22  is slidably mounted within handle  14  and can be pushed in a forward direction whereupon forward movement is terminated by separator shaft rear post  38  contacting handle forward stop  44 . In the reverse movement, the sidling of separator shaft  22  within handle  14  is stopped by separator shaft rear post  38  contacting handle rear stop  42 . 
     Referring now to FIGS. 7 and 8, the function and purpose of the slidable mounting of separator shaft  22  within handle  14  will be described. In general, the purpose of the slidable mounting of separator shaft  22  within handle  14  is to accomplish the separation of absorbent  12  from its attachment within handle  14 . The detachment of absorbent  12  from handle  14  is desired once absorbent  12  has become saturated with saliva and it is desired to detach saturated absorbent  12  from handle  14  so that the saliva saturated absorbent may be placed in a preservative solution or utilized in whatever manner to test for analytes in the saliva. To detach absorbent  12  from handle  14 , the operator grasps handle  14  and, using thumb pressure on ridges  48  of separator shaft  22 , slides separator shaft  22  toward absorbent  12 . The forward movement of separator shaft  22  within handle  14  causes separator shaft front post  40 , which is engaged within absorbent tongue front void  32 , to create a forward pressure on the portion of absorbent  12  which is in front of absorbent front tongue void  32 . By contrast, the portion of absorbent tongue  30  which is to the rear of absorbent front tongue  32  is held in place by capture of absorbent tongue securing void  34  by handle securing post  46 . The pressure that is created by the forward movement of separator shaft front post  40  against absorbent tongue front void  32  causes the portion of absorbent  12  which is in front of separator shaft front post  40  to tear away from the portion of absorbent tongue  30  which is to the rear of absorbent tongue front void  32 . The portion of absorbent  12  which has been separated is pushed forward by the movement of separator shaft  22  within separator shaft track  36 . Once the forward movement of separator shaft  22  has been terminated by separator rear post  38  contacting handle forward stop  44  (FIG.  7 ), separator shaft  22  can be pulled rearwardly by thumb pressure on ridges  48  to reposition separator shaft  22  within handle  14 . Repositioning separator shaft  22  within handle  14  is terminated by separator shaft rear post  38  contacting handle rear stop  42 . (FIG. 8.) At the conclusion of the above procedure, the saturated absorbent  12  is separated from absorbent tongue  30  which is contained within handle  14  and the separated portion of absorbent layer  12  is left residing on shield  16  as shown in FIG.  8 . Now that the user has separated absorbent layer  12  from handle  14 , the separated portion of absorbent  12  may be shaken off of shield  16  and into a preservative solution. 
     The method of operation of the present invention is as follows, sample collection device  10  which can contain any of the shield embodiments described herein is removed from a protective packaging and absorbent layer  12  is inserted into the mouth. Absorbent layer  12  can be placed in several different locations within the mouth such as underneath the tongue or in the buccal cavity, or if desired, absorbent  12  can be placed on top of the tongue. Sample collection device  10  is allowed to remain in the selected location of the mouth for sufficient time to permit absorption of saliva. Should an embodiment of sample collection device  10  be used which includes the indicator which has been previously described in U.S. Pat. No. 5,334,502 and which is incorporated here by reference, the operator can simply rely on viewing the appearance of the indicator within window  20  of device  10 . The operation of the indicator is such that as saliva is absorbed onto absorbent  12 , it migrates toward absorbent tongue  30  (FIG.  6 ). Along the length of absorbent tongue  30  and before the portion of absorbent tongue  30  which is viewable through window  20 , an indicator  50  is placed on absorbent tongue  30 . The migration of the saliva along absorbent tongue  30  moves indicator  50  into position to be observed through window  20  when sufficient saliva has been absorbed onto absorbent  12  to achieve migration of indicator  50  along absorbent tongue  30  to reposition indicator  50  within window  20 . Thus, either using the indicator method or by simply timing the length of time the absorbent is in contact within the mouth, the operator determines that sufficient saliva has been collected on absorbent  12  and device  10  is removed from the mouth. The operator then effects separation of the front portion of absorbent  12  from the tongue portion  30  of absorbent  12  by pushing forward on separator shaft  22  to cause separation between the front and rear areas of absorbent  12  at the location of absorbent tongue front void  32  and the portion of absorbent  12  in front of absorbent front void  32  is pushed in a forward direction by separator shaft  22  and is detached from absorbent tongue  30 . The operator may then remove the separated portion of absorbent  12  from collection device  10  and place the detached absorbent into a preservative solution or into such other container as is desired. 
     Referring now to FIG. 9 an alternative embodiment of the present invention is provided which does not rely upon the use of the separator shaft  22  to release the absorbent from capture in handle  14 . In the FIG. 9 embodiment of the invention the absorbent is provided with a separation line  60  which permits manual breaking-away of a portion  58  of absorbent  12  from handle  14  of device  10 . After portion  58  is removed from absorbent  12  by the user applying tearing or shearing force to handle  14  and portion  58  to cause separation of portion  58  at separation line  60 , the user can then insert portion  58  into a preservative solution or use portion  58  separately from handle  14 . It will also be appreciated that is separation line  60  is placed in the middle of absorbent  12 , either parallel to the longitudinal axis of the absorbent or orthogonally to the longitudinal axis, that absorbent  12  can then provide two useful portions for user testing or storage. 
     It should be appreciated that the embodiment of FIG. 9 can further comprise a shield that is of any of the types previously described. For example, the shield can be impervious to fluids on one side with no shield on the other side or it can comprise a shield that is impervious to fluids on one side while having a covering that contains micro pores on the other side or it can comprise a shield made of a substance having micro pores that completely covers the absorbent. FIG. 9 particularly, shows an embodiment having a shield of a substance with micro pores that completely covers the absorbent while the absorbent is provided with separation line  60 . 
     In the foregoing description, certain terms have been used for brevity, clearness and understanding; but no unnecessary limitations are to be implied therefrom beyond the requirements of the prior art, because such terms are used for descriptive purposes and are intended to be broadly construed. Moreover, the description and illustration of the inventions is by way of example, and the scope of the inventions is not limited to the exact details shown or described. 
     Certain changes may be made in embodying the above invention, and in the construction thereof, without departing from the spirit and scope of the invention. It is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative and not meant in a limiting sense. 
     Having now described the features, discoveries and principles of the invention, the manner in which the inventive oral fluid collection device is constructed and used, the characteristics of the construction, and advantageous, new and useful results obtained; the new and useful structures, devices, elements, arrangements, parts and combinations, are set forth in the appended claims. 
     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.