Patent Abstract:
A method and apparatus for collecting a fluid specimen, locally analyzing the specimen to qualitatively detect specified chemical components at concentrations above threshold levels, and providing machine readable test results for facilitating data collection and reporting. The apparatus includes an assaying device comprised of a cup for collecting a fluid specimen and a cap carrying at least one test strip for visually reacting to one or more specified chemical components in the specimen. The cap also carries an aliquot delivery mechanism for forcing an aliquot of the fluid specimen onto the test strip. The assaying device is preferably configured to interact with a reader device capable of reading the reaction of the test strip to produce a data output.

Full Description:
RELATED APPLICATIONS  
       [0001]    This application is a Continuation -In-Part of U.S. Application 08/832,957 filed Apr. 4,1997 by Murray Lappe. U.S. Applications 08/801,041 filed Feb. 14, 1997; 09/018,487 filed Feb. 13, 1998; and 09/025,559 filed Feb. 18, 1998 are also related. The disclosures of the aforementioned applications are, by reference, incorporated herein. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    This invention relates to a system and components thereof for collecting and locally analyzing fluid specimens, e.g., body fluids such as urine.  
           [0003]    Devices for collecting and locally analyzing body fluids have been described in the patent literature, as exemplified by U.S. Pat. No. 5,403,551. Such devices may be used, for example, by employers to screen employee applicants for illegal drug use. As noted in U.S. Pat. No. 5,403,551, it is desirable for drug screening tests to be locally performed, i.e., at the collection site, for the purpose of quickly determining on a qualitative basis whether specific drugs are present in a fluid specimen, typically, urine. If the results of the screening test are positive, a more complete quantitative analysis is subsequently performed, typically, at a remote laboratory site. Inasmuch as it is extremely important to positively correlate the specimen with the person being tested, U.S. Pat. No. 5,403,551, describes an assaying device that minimizes possible contamination of the specimen after the specimen is first collected. More particularly, U.S. Pat. No. 5,403,551 describes a device which functions to both collect and locally analyze a specimen. The device comprises a container for collecting and storing the specimen, a cap for sealing the container, and an assay means attached to the container for qualitatively analyzing a portion of the specimen. The assay means is described as using a plurality of latex/antibody chromatograph strips. Since the specimen does not have to be transferred out of the container for qualitative testing, if the initial test produces a positive result, the entire device containing the specimen can then be shipped to a laboratory for quantitative analysis.  
           [0004]    The aforementioned Lappe applications variously describe machine readable assaying systems employing test or assaying cards bearing test or analysis strips thereon. The strips are configured such that when wetted by a fluid, they will react to visually indicate the presence of certain detectable substances in the fluid. The format of the visual indications can be of many different types capable of being machine read by a suitable reading apparatus.  
         SUMMARY OF THE INVENTION  
         [0005]    The present invention is directed to a method and apparatus for collecting a fluid specimen and locally analyzing the specimen to qualitatively detect specified chemical components therein. More particularly, the invention is directed to such an apparatus which provides machine readable test results for facilitating the data collection and reporting of the results.  
           [0006]    Apparatus in accordance with the invention includes an assaying device comprised of a cup for collecting a fluid specimen and a cap carrying at least one test strip for visually reacting to one or more specified chemical components in the specimen. The assaying device is preferably configured to interact with a reader device capable of reading the reaction of the test strip to produce an electronic data output.  
           [0007]    One example of a test strip suitable for use with embodiments of the invention comprises membrane strips pre-coated with drug protein conjugates deposited on defined bands of the strip. Such strips are commercially available as the InstaCheck Multi-Drug Screen Panel manufactured by Forefront Diagnostics. Inc. of Laguna Hills, Calif.  
           [0008]    In accordance with a preferred embodiment of the present invention, the assaying device carries one or more test strips which collectively test for multiple characteristics of the fluid specimen including the presence of specific chemical components at concentrations above threshold levels, the authenticity of the specimen (as, for example. whether it is freshly voided urine), and whether or not the specimen has been adulterated.  
           [0009]    A preferred assaying device in accordance with the invention includes an open cup defining an interior volume for accommodating a fluid specimen and an attachable cap configured for mounting on the cup to seal the interior volume. The cap carries at least one test strip and an aliquot delivery mechanism actuatable to wet the test strip with an aliquot derived from the fluid specimen. In a preferred embodiment of the invention, the aliquot delivery mechanism comprises a pump in the form of a plunger for forcing an aliquot of the fluid specimen onto the test strip. The plunger can be actuated either manually or automatically, e.g., by a piston controlled by a compatible reader device.  
           [0010]    In accordance with the preferred embodiment, the aliquot delivery mechanism includes first and second concentric tubular walls descending from the cap into the cup. A passageway is defined between the tubular walls having an inlet at its lower end for contacting the specimen in the cup and an outlet at its upper end for delivering an aliquot onto the test strip.  
           [0011]    In accordance with a significant feature of the preferred embodiment, the descending tubular walls and interior cup floor are cooperatively configured to isolate a portion of the specimen when the cap is installed onto the cup. The plunger acts on this isolated portion to force a small part thereof, i.e., an aliquot, through the passageway onto the test strip.  
           [0012]    Tests strips used in preferred embodiments of the invention provide a visual reaction to chemical components having a concentration in the aliquot greater than a threshold concentration. Preferably, each test strip functions so that a negative test result for one or more components causes a multiple number of visually discernable discrete bands to appear on the strip. The presence of a single component in excess of a threshold suppresses the development of at least one of the bands. Therefore, the absence of a visually discernable band indicates a positive test result for a particular chemical component associated with that band.  
           [0013]    The cap is preferably configured with one or more compartments, each for accommodating a different test strip. The passageway, which may comprise multiple branches, extends to the compartment for delivering an aliquot thereto. The cap preferably also defines one or more catch basins to catch any excess fluid delivered by the aliquot delivery mechanism to the test strip.  
           [0014]    The cap is preferably also configured to define a transparent area or window located relative to the test strip compartment to enable the strip visual reaction to be read by a machine, e.g., a digital camera and image processor, and/or a human.  
           [0015]    In accordance with a preferred embodiment, the cap and cup are provided with cooperating coupling means (e.g., mating threads or a bayonet mount) configured to seal the cup interior volume when key exterior portions of the cap and cup are physically aligned. More particularly, when the cap is fully installed on the cup, a key external portion of the cap, e.g., a flat slotted area, aligns relative to a key external portion of the cup. When these key external portions align, the aforementioned interior tubular walls form an interior chamber for isolating the aforementioned portion of the specimen.  
           [0016]    The exterior of the cap and cup preferably have an irregular periphery to facilitate easy manual handling. The periphery is preferably also shaped to assure its particular orientation in a receptacle of a compatible reader device. When inserted in the receptacle, the cap is properly positioned to enable the test strip in the cap to be read by an imager, e.g. a digital camera, housed in the reader device.  
           [0017]    A preferred reader device in accordance with the invention includes a microprocessor based controller for actuating the aliquot delivery mechanism of an assaying device placed in the reader device receptacle. More particularly, the reader device preferably includes an actuatable piston for pressing the delivery mechanism plunger to deliver an aliquot to the test strip. Preferably, the piston remains engaged with the assaying device for the duration of the test (typically, up to eight minutes) to prevent a person from substituting specimens during the course of a test.  
           [0018]    The reader device preferably includes a camera and image processor controlled by the controller for viewing the test strip of an assaying device to produce a positive or negative test result for the specimen contained therein. The test result data, along with identification data read from a label carried by the assaying device, can then be stored or communicated, e.g., via a modem.  
           [0019]    Embodiments of the present invention are used primarily to perform local on-site screening while preserving an uncontaminated specimen for further analysis if necessary. That is, in typical use, embodiments of the present invention function to perform a qualitative analysis on an aliquot of the specimen to screen for negative results. If a negative result is not achieved, then the sealed assaying device containing the remaining uncontaminated specimen is typically shipped to a remote site for further analysis. 
       
    
    
     BRIEF DESCRIPTION OF THE FIGS.  
       [0020]    [0020]FIG. 1 is an isometric view showing the rear exterior of an assaying device in accordance with the present invention;  
         [0021]    [0021]FIG. 2 is a top plan view of the assaying device of FIG. 1;  
         [0022]    [0022]FIG. 3 is a left side view of the assaying device of FIG. 1;  
         [0023]    [0023]FIG. 4 is a diagrammatic view of a typical test strip used in embodiments of the present invention;  
         [0024]    [0024]FIG. 5A is a sectional view taken substantially along the plane  5 - 5  of FIG. 3 showing the plunger in its actuated up position;  
         [0025]    [0025]FIG. 5B is a sectional view similar to FIG. 5A but showing the plunger in its actuated down position;  
         [0026]    [0026]FIG. 6 is a sectional view taken substantially along the plane  66  of FIG. 5A showing the chamber for isolating a small specimen position;  
         [0027]    [0027]FIG. 7 is a sectional view taken substantially along the plane  7 - 7  of Figure.  2 ;  
         [0028]    [0028]FIG. 8A is a sectional view taken substantially along the plane  8 A- 8 A of FIG. 7;  
         [0029]    [0029]FIG. 8B is an enlarged sectional view of a portion of FIG. 8A;  
         [0030]    [0030]FIG. 9A is an isometric view of the assaying device of FIG. 1 showing the front exterior and FIG. 9B is a right side view of the assaying device;  
         [0031]    [0031]FIG. 10 is an exploded isometric view of the assaying device of FIG. 1;  
         [0032]    [0032]FIG. 11 is an enlarged isometric view of the lower cap member shown in FIG. 10;  
         [0033]    [0033]FIG. 12 is an enlarged isometric view of the upper cap member;  
         [0034]    [0034]FIG. 13 is an isometric view primarily showing the cup interior;  
         [0035]    [0035]FIG. 14 is a schematic representation of a reader device useful in conjunction with the assaying device of FIGS.  1 - 13  for interpreting the visual indications produced by a test strip therein; and  
         [0036]    [0036]FIG. 15 is a functional block diagram depicting the microprocessor based controller of the reader unit of FIG. 14 for executing a test procedure in accordance with the present invention. 
     
    
     DETAILED DESCRIPTION  
       [0037]    FIGS.  1 - 3 ,  9 A,  9 B depict the external configuration of a preferred assaying device  20  in accordance with the present invention. The assaying device  20  includes a housing  22  comprised of a cup  24  and a detachable cap  26 . The cup  24  defines an interior volume for collecting a fluid specimen, e.g., a body fluid such as urine. After the fluid specimen has been deposited into the cup  24 , the cap  26  is mounted thereon to seal the interior volume and prevent the fluid specimen from leaking. In a preferred utilization, each physical assaying device  20  will be used only once, i.e., to collect a single specimen. Accordingly, the assaying device components are all preferably fabricated via relatively low cost plastic molding processes.  
         [0038]    Before proceeding with a discussion of the internal structure and operation, certain exterior characteristics of the housing  22  should be noted in FIGS.  1 - 3 . Initially, note that the cup  24  has an irregular peripheral surface including an enlarged front portion  30  and a reduced rear portion  32 . The reduced rear portion  32  is bounded by flat finger grip sides  34  having raised surface features  36  extending to an oblique wall surface  38 . This irregular configuration of the cup facilitates easy manual handling of the cup enabling it to be readily grasped by the hand of a user and/or administrator.  
         [0039]    The front enlarged portion  30  of the cup preferably includes (FIG. 9A) an area  39  characterized by multiple vertical fins  40 . This area  39 , as will be mentioned hereinafter, functions as a key or registration area to which an index area  50  on the cap must be aligned to assure proper cap/cup sealing.  
         [0040]    Briefly, the cap  22  is comprised of a substantially circular member  41  having a top exterior surface  42  and a depending flange or skirt  44 . The skirt  44  has a primarily knurled outer surface  46  that preferably defines flat areas  48  and an index area  50 . The index area  50 , which may be defined by vertical slots, is preferably used to align with the aforementioned cup area  39  to visually indicate to a user that the cap has been properly installed onto the cup. The cap  26  is preferably installed onto the cup via a mating thread  51 . The cap  26  can carry a stop sooth  52  which rotates into engagement with the end fin  40  to assure proper installation of the cap onto the cup. When properly installed, the cap index area  50  will be aligned with the cup registration area  39 . Alternative mounting mechanisms, e.g., bayonet mount, can be used to couple the cap  26  to the cup  24 .  
         [0041]    The cap top surface  42  is either transparent or at least defines one or more transparent areas, e.g., windows  60  (i.e.,  60 A,  60 B,  60 C,  60 D) for enabling a test strip mounted beneath to be visible therethrough. As will be discussed hereinafter, the cap defines one or more compartments each of which accommodates a test strip which, when wetted by a fluid specimen, reacts to provide a visual indication indicative of a characteristic of the specimen.  
         [0042]    In the exemplary embodiment illustrated, the smaller windows  60 C and  60 D cover test strips intended to detect specimen (1) authenticity and (2) adulteration. As is well known, a freshly voided urine specimen can be authenticated by sensing various characteristics including its temperature and creatinine content. Adulteration of the specimen can be detected by known test strips sensitive to exogenous components. Larger windows  60 A and  60 B cover test strips intended to detect various specific chemical components typically associated with illegal substance abuse. FIG. 4 schematically represents such a test strip  61  showing multiple bands  62  visually represented on an indicator portion  63  extending from an absorbent portion  64 . If the trip is being used to test for the presence of specific chemical components. the presence of such components will suppress the appearance of one or more of the visual bands  62 . If all of the bands visually appear within a certain test interval, e.g. up to eight minutes, after the absorbent portion  64  has been wetted, this will indicate the absence of the specific chemical components sought. However, if any of those specific chemical components are present in concentrations above a certain threshold. their presence will suppress the appearance of one or more of the bands to indicate to an astute observer and/or computer based reader, the presence of such chemical components.  
         [0043]    [0043]FIG. 2 also depicts a central opening  66  formed in the cap top surface  42 . As will be discussed hereinafter, this opening  66  provides access to an aliquot delivery mechanism carried by the cap for delivering an aliquot of the fluid specimen in the cup to the test strips  61  carried beneath the windows  60 . The top surface  42  also defines a “T” shaped area  67  intended to be used for a label preferably carrying bar code information for identification and tracking. Registration knobs  68  are formed in the area  67  to facilitate alignment of the label. The label preferably carries a self-adhesive on a portion of the label which can be adhered to the fins  40  on a cup  24  to create a tamper proof seal.  
         [0044]    Attention is now directed to FIGS. 5A and 5B which comprise vertical sectional views through the assaying device  20  showing its inner construction and operation. FIG. 5A illustrates a plunger  70  in its non-actuated up position whereas FIG. 5B illustrates the plunger  70  in its actuated down position.  
         [0045]    As shown in FIGS. 5A and 5B, the cap  26  may be constructed of an upper cap member  72  and a lower cap member  74  which can be secured together as by welding or an appropriate adhesive. When assembled, the cap  26  defines descending concentric outer and inner tubular walls  76  and  78 . As shown in FIGS. 7 and 8B, at least one passageway  80  extends vertically between the outer and inner tubular walls  76  and  78 . As will be discussed in greater detail hereinafter, the passageway  80  defines a passageway inlet  82  at the lower end of inner tubular wall  78  and a passageway outlet  83  proximate to a test strip  61 . Each test strip is accommodated in a compartment  86  formed in the cap between the cap upper member  72  and lower member  74 . When the test strip absorbent portion  64  is wetted by fluid delivered by outlet  83 , the strip will visually indicate one or more characteristics of the specimen as previously mentioned. A catch basin  88  is located adjacent to the compartment  86  to collect any fluid overflow from the absorbent portion.  
         [0046]    As depicted in FIGS.  5 - 7 , the inner floor  90  of the cup  24  is configured to define spaced first and second arcuate walls  92 A,  92 B, opposed to one another and defining an open well  94  therebetween. When the cap  26  is installed on the cup  24 , as by aforementioned threads  51 , the lower end of the outer tubular wall  76  extends into the well  94 . The lower ends of the wall  76  essentially define partitions  98 A.  98 B which bridge the walls  92 A,  92 B to form a closed chamber  100  for isolating a portion of the fluid specimen. More particularly, initially assume that a fluid specimen has been collected in the open cup  24  to a level  102  (i.e., between the MAXIMUM and MINIMUM level lines depicted in FIG. 1) above walls  92 A,  92 B. When the cap  26  is then installed on the cup, a small portion of the specimen will be captured in the chamber  100  and isolated from the remainder of the specimen in the cup. The plunger  70 , comprised of plunger pin  104  and plunger element  106 , is mounted in inner tubular wall  78  above chamber  100 . The plunger element  106 , is formed of soft conforming material able to seal against the inner surface of inner tubular wall  78 . The opening  66  in the cap upper surface  42  provides access to enable the pin  104  to be depressed either manually or by a machine operated piston.  
         [0047]    As the plunger element  106  is depressed into chamber  100 , the fluid therein is displaced upwardly via inlet  82  through passageway  80 . Note that although passageway  80  has thus far been primarily referred to in the singular, the preferred embodiment depicted in the drawings, particularly FIG. 8B, shows the inclusion of multiple passageways  80 , i.e.,  80 A,  80 B,  80 C,  80 D. These passageways respectively extend to test strip compartments  86  (FIG. 11), i.e.,  86 A,  86 B,  86 C,  86 D respectively located below the aforementioned cap windows  60 A,  60 B,  60 C, and  60 D. Thus, depression of the plunger  70  within the inner tubular wall  78  displaces fluid from the chamber  100  to deliver an aliquot to each of the compartments  86 , each compartment accommodating a separate piece or strip of test material  61 . The device  20  is constructed and dimensioned so that each aliquot comprises a specific volume of fluid, e.g., four drops.  
         [0048]    Attention is now specifically called to FIG. 9 which illustrates an isometric view of the front exterior of the assaying device  20 . Note in FIG. 9 that the slotted portion  50  of the cap  26  is aligned with the finned portion  40  of the cup  22 . This alignment indicates to a user that the cap is properly installed on the cup to seal the specimen therein. FIG. 9 also illustrates a recessed area  120  below the finned area  40 . The recessed area  120  along with the flat areas  48  on the cap  26  are used to properly orient the assaying device cap relative to an automatic reader device, to be discussed hereinafter.  
         [0049]    Attention is now directed to FIG. 10 which illustrates an exploded isometric view of the assaying device  20  of FIG. 1- 9 . More particularly, FIG. 10 shows the lower cap member  74  and upper cap member  72  spaced from one another and ready for insertion into the cup  24 . The cap members  72 ,  74  are preferably joined together at the fabrication stage, e.g., by a suitable weld, prior to being made available for use. FIG. 10 also illustrates the plunger pin  104  and soft plunger element  106  ready for insertion through the opening  66  of cap top surface  42  into the interior of inner tubular wall  78 . The tubular wall  78  then extends into the outer tubular wall  76  descending from the lower cap member  74 .  
         [0050]    [0050]FIG. 11 shows in detail the geometry of the lower cap member  74  which together with the upper cap member  72  (FIG. 12) forms the aforementioned test strip compartments  86  and catch basins  88 . Initially, note in FIG. 7 the passageways  80 A,  80 B,  80 C, and  80 D rising on the inner surface of outer tubular member  76 . These vertical passageways join horizontally oriented passageway branches  82 A,  82 B,  82 C,  82 D shown in FIG. 1  1 . Although not clearly visible in the drawings, the passageways preferably include simple unidirectional leaf valves to prevent backflow through the passageways. The lower cap member  74  defines compartments  86 A,  86 B each for accommodating a different test strip  61 . Each compartment  86 A,  86 B is comprised of a flat bed area  130  and a sloped area  132 . The test strip  61  is placed in the compartment  86  with the strip indicator portion  63  on area  130  and the strip absorbent portion  64  on area  132 . Tabs  133  on the underside of upper cap member  72  press against and hold the test strips in the compartments  86 . The vertical passageways  80 A,  80 B and passageway branches  82 A,  82 B respectively deliver an aliquot to the absorber portions of the test strips respectively in the compartments  86 A,  86 B. The sloped areas  132  formed immediately adjacent to compartment  86 A and  86 B carry excess fluid deposited onto the absorber portions into the catch basins  88 A,  88 B.  
         [0051]    Note that the passageway branches  82 C,  82 D respectively lead to small compartments  86 C,  86 D intended to accommodate small test strips used primarily for authentication and adulteration checks, as previously described. For convenience in fabrication, compartments  86 C,  86 D can in fact be unified into a single physical compartment. Overflow from the compartments  86 C,  86 D flows into catch basin  142 .  
         [0052]    Note in FIG. 11 the configuration of the lower end of outer tube  76 . The tube includes opposed slots  148  in the tubular wall which form the aforementioned partitions  98 A,  98 B discussed in connection with FIG. 6. These partitions cooperate with the arcuate walls  92 A,  92 B shown in plan view in FIG. 6 and in isometric view in FIG. 13 to form chamber  100 .  
         [0053]    Attention is now directed to FIG. 14 which illustrates a reader device  160  for automatically reading the visual indications produced by the test strips in the assaying device  20  to generate data signals representative thereof. The reader device  160  defines a receptacle  162  for receiving the assaying device therein in a particular orientation. More particularly, the receptacle  162  is defined by surfaces intended to mate with key surfaces on the assaying device, e.g., cap flat areas  148  and/or recessed area  120 , in order to compel the assaying device to a particular orientation. This orientation will place the aforementioned cap windows  60 A.  60 B,  60 C, and  60 D within the field of view of a camera  164  carried by the reader device.  
         [0054]    The reader device  160  preferably also carries a reciprocally moveable piston  166  positioned in alignment with the opening  66  in an assaying device  20  properly oriented in the receptacle  162  for the purpose of actuating plunger  70 . The reader device also preferably includes a START switch  167  and display panel  168 .  
         [0055]    [0055]FIG. 15 depicts a functional block diagram of an electronic subsystem  169  utilized in the reader device  160 . The subsystem  169  includes a microprocessor based controller  170 , the camera  164 , and an image processor  176 . Although shown separately from the controller  170 , the function of the image processor  176  could be performed by the microprocessor of controller  170 .  
         [0056]    The reader electronic subsystem  169  further includes a plunger actuator  180  which can, for example, comprise a solenoid for moving the piston  166  against the plunger  70 . Additionally, the reader device can include a label reader module, e.g.. a bar code reader  182 , capable of reading a label adhered to the assaying device housing, for identification purposes. The electronic subsystem preferably further includes the aforementioned display panel  168  and an output module  184  for printing and/or storing data generated by the controller  170 . The data may additionally be communicated. e.g . via modem (not show), to a remote site.  
         [0057]    In the contemplated utilization of the assaying device  20 , a staff person at a local site will give a user, e.g., an employee applicant, a new unused assaying device  20 . The employee applicant will then deposit a fluid specimen into the cup to a level above the walls  92 A,  92 B. The cap  26  will then be installed onto the cup to a stop position which aligns the cap slotted area  50  with the finned area  39  of the cup  20 . By so installing the cup  26  on the cup  24 , the descending outer tubular wall  76  will capture and isolate a small portion of the fluid specimen in chamber  100 .  
         [0058]    The assaying device  20  will then be placed in the receptacle  162  of the reader unit  160  and switch  167  will be pressed to supply a start signal to microprocessor based controller  170 . The controller  170  will then initiate and execute a test procedure which involves initially reading an identification label (not shown) carried by the cap assaying device  20 . The controller  170  will then thrust the piston  166  into the cap opening  66  to drive the plunger  70  downwardly against the fluid specimen portion in chamber  100 . This action will pump an aliquot from the isolated specimen portion via each of the passageways  80  to the test strips in the compartments  86 A,  86 B,  86 C,  86 D. Preferably. the controller will leave the piston  166  within the inner tubular wall  78  for the full duration of the test procedure to thus lock and prevent removal of the assaying device during the test procedure.  
         [0059]    After an appropriate test interval, controller  170  will actuate camera  174  to cause it to generate an electronic representation of the visual indications provided by the respective test strips  61 . The electronic representations generated by the camera  174  are then processed by the image processor  176  to interpret the characteristics of the fluid specimen. The resulting output data can then be displayed, stored, printed and/or communicated to a remote site, e.g. via modem. Unless this test produces a negative result, the entire assaying device  20  containing the uncontaminated specimen is then typically shipped to a remote laboratory for further analysis.  
         [0060]    The foregoing describes applicants&#39; preferred system for collecting and locally analyzing a fluid specimen. The preferred system includes an assaying device comprised of a fluid collection cup and a cap containing a mechanism actuatable to deliver an aliquot of the specimen to a test strip configured to produce a visually discernable reaction to the fluid. The visual reaction can be read by an imager, e.g., digital camera, and interpreted by a processor contained in a reader device to produce electronic data output suitable for data collection and reporting.  
         [0061]    Although a preferred embodiment has been described, it is understood that many modifications and variations will occur to those skilled in the art which fall within the intended scope of the invention as defined by the appended claims.

Technology Classification (CPC): 6