Patent Publication Number: US-2021177675-A1

Title: Four-dimensional analysis system, apparatus, and method

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 16/227,090, filed Dec. 20, 2018, which is a continuation application of U.S. patent application Ser. No. 15/354,412, filed Nov. 17, 2016, now U.S. Pat. No. 10,201,463, issued on Feb. 12, 2019, claims the benefit of priority to U.S. Provisional Patent Application Ser. No. 62/256,405 filed on Nov. 17, 2015, the contents of which are incorporated by reference herein. 
    
    
     BACKGROUND 
     Studies and research have been undertaken to determine the efficacy of personal care products. For example, in the context of feminine hygiene products, research has been performed to determine the effectiveness of the products in absorbing fluid. 
     The quality of the results that are obtained in connection with the research are influenced by the quality of the test system, apparatus, and methodology that are used. For example, due to the complexity of the imaging technology (e.g., computed tomography (CT) scanning) that is used as well as variations in the products/samples that are being analyzed, it is difficult to determine a grayscale value that best represent those volumetric pixels (voxels) of reconstructed data sets that correspond to fluid entering a given sample. In the context of medical imaging, CT scans can be low resolution and fail to recreate real-time conditions despite successive scans or a series of scans. Further still, in vivo set-ups can be costly and require significant amounts of time to, inter alia, organizing subject populations, creating a test protocol, scheduling the scans and analyzing the results. Accordingly, there is uncertainty that is introduced that is difficult, if not impossible, to account for. Furthermore, due to delays between the capturing of the image and when the associated data set becomes available, events such as an advancement of a fluid-front in association with the sample may be missed or unaccounted for. 
     SUMMARY OF THE PRESENT DISCLOSURE 
     The present disclosure provides a system for determining real-time fluid dynamics within or near a device. The system includes a fixture that simulates an in vivo set-up via at least one characteristic. The fixture simulates bodily pressure exerted against a device. The device is a consumer product such as a hygiene device, an implement, and/or a medical device. The device is an internally worn device or an externally worn (or externally manipulated) device. In some embodiments, the device is dynamic in that it changes in shape, configuration and/or other mechanical properties upon implementation (i.e. upon contacting the body, fluid and/or by its design). In some embodiments, the device is dynamic due to other forces exerted upon it. Such forces could be bodily, such as pressure exerted by the body cavity against an internally worn device. Such forces could be from other objects, such as garments worn adjacent the body, pressure exerted by a bed or a chair when a person is lying or sitting, and/or limbs directing the device&#39;s movement and/or affecting the device&#39;s configuration. 
     The fixture is a somewhat simple structure as exemplified in  FIGS. 1-4 . The fixture accommodates a device (herein referred to as the “sample” or “test sample”). 
     The fixture is a more complex structure as shown in  FIGS. 5-7 . Such fixtures include multiple regions that can be fixed and thus relative movement amongst these regions is limited, or these regions can be separate, attachable and/or movable with respect to each other to create a dynamic in vivo-esque profile. 
     The fixture is a further refined structure as shown in  FIGS. 8 a -8 c   . Such fixtures are formed from human body scans or measurements, both internal and external. Such fixtures are static and/or dynamic (i.e. the one or more leg regions are able to move with respect to the torso or pelvic region). 
     The fixture is radiographically transparent or translucent (“radiotransparent”) such that a scanning means (such as CT or micro-CT) can be employed. Optionally, the fixture is visually transparent. The fixture is attached to a platform that permits rotation about at least one axis, thereby permitting imaging of the sample in real time. The fixture can move about multiple axes to generate different views and/or different configurations to replicate the position and functionality of the sample of the device in simulated conditions. Movement of a fixture in at least one direction, plane and/or along an axis other than to generate an image, can be done with a cadence that simulates in vivo interaction and motion amongst body parts and the device. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present disclosure is illustrated by way of example and not limited in the accompanying figures in which like reference numerals indicate similar elements. 
         FIG. 1  illustrates a diagrammatic representation of one embodiment of the present disclosure&#39;s test fixture apparatus. 
         FIG. 2  illustrates a diagrammatic representation of one embodiment of the present disclosure&#39;s test fixture apparatus. 
         FIG. 3  illustrates a diagrammatic representation of one embodiment of the present disclosure&#39;s test fixture apparatus. 
         FIG. 4  illustrates a diagrammatic representation of one embodiment of the present disclosure&#39;s test fixture apparatus. 
         FIG. 5  illustrates a diagrammatic representation of one embodiment of the present disclosure&#39;s test fixture apparatus. 
         FIG. 6  illustrates a diagrammatic representation of one embodiment of the present disclosure&#39;s test fixture apparatus. 
         FIG. 7  illustrates a diagrammatic representation of one embodiment of the present disclosure&#39;s test fixture apparatus. 
         FIG. 8 a    illustrates a diagrammatic representation of one embodiment of the present disclosure&#39;s test fixture apparatus. 
         FIG. 8 b    illustrates a diagrammatic representation of a back view of one embodiment of the present disclosure&#39;s test fixture apparatus. 
         FIG. 8 c    illustrates a diagrammatic representation of a side view one embodiment of the present disclosure&#39;s test fixture apparatus. 
         FIG. 9  illustrates a diagrammatic representation of a side view one embodiment of the present disclosure&#39;s test fixture apparatus. 
         FIG. 10  illustrates a computing system architecture. 
         FIG. 11  illustrates a system that is configured to represent a fluid or fluid flow associated with a sample. 
         FIGS. 12A-12E  illustrate a flow chart of an exemplary method for representing a fluid or fluid flow associated with a sample. 
         FIG. 13  illustrates a fixture in accordance with aspects of this disclosure. 
         FIG. 14  illustrates a flow chart of an exemplary method for representing a fluid or fluid flow associated with a sample based on the use of a reference. 
     
    
    
     DETAILED DESCRIPTION 
     It is noted that various connections are set forth between elements in the following description and in the drawings (the contents of which are included in this disclosure by way of reference). It is noted that these connections are general and, unless specified otherwise, may be direct or indirect and that this specification is not intended to be limiting in this respect. A coupling between two or more entities may refer to a direct connection or an indirect connection. An indirect connection may incorporate one or more intervening entities. 
     Aspects of the disclosure are directed to systems, apparatuses, and methods for performing an analysis on one more samples. A sample  204  may be associated with a device such as a personal care product, including hygiene products, medical devices, including diapers and feminine hygiene products worn internally and/or externally (e.g., a pledget, an applicator, a menstrual cup, a napkin, a pad, a liner, a pessary, a suppository etc.) for menstrual and/or incontinence purposes. As for suppositories, the disclosure demonstrates the dissolution and/or transition of a suppository as it enters the body and chemically interacts with the body, thereby inducing a change in the suppository&#39;s state or transport of the material contained within or delivered by the suppository. In some embodiments, a fluid may be injected/introduced to the sample  204 , and an analysis may be performed to determine/characterize how the fluid flows in/through the sample  204 . For example, if a flow rate of fluid  246  introduced to the sample  204  is a constant, a grayscale value that best represents volumetric pixels (voxels) of a reconstructed data set that correspond to the fluid  246  entering the sample  204  can be determined heuristically. As one skilled in the art would appreciate, a grayscale value may serve as a representation of an intensity, ranging from black to white, of a voxel. A voxel may be associated with a three-dimensional data structure defined by a grayscale value, a length, a width, a height, and a relative position in space. 
     Referring now to  FIG. 1 , a fixture  202  is shown. The fixture  202 , as at least a part of system  200 , may be used to represent/simulate a fluid flow associated with one or more samples  204 . 
     The fixture  202  may be configured to retain a sample  204  (e.g., a personal care product) that is to be subjected to an analysis in accordance with aspects of the disclosure. The retention of the sample  204  may be facilitated by the fixture  202  and/or use of retaining mechanism  206 . The retaining mechanism  206  may be made of foam or other material such as materials similar to garments, underwear and/or beds, chairs, etc. . . . . The retaining mechanism  206  may also have a hydrophobic layer or portion such as a plastic, film or silicone. The retaining mechanism  206  may exhibit properties, such as pressure, that simulate properties of tissues such that the in vitro set-up mimics an in vivo set-up. The retaining mechanism  206  may include a bore  208  for holding the sample  204  that is in communication with a fluid line  211 , particularly the fluid line end  211   a . In some embodiments, fixture  202  is also a retaining mechanism  206 . Bore  208  may be generally cylindrical and/or have an arcuate or varying geometry. In some embodiments, fixture  202  has a recess  208   a  that further assists in retaining sample  202 . Recess  208   a  is in concert with bore  208  and creates a slightly raised lip such that sample  204  can be more easily positioned within or adjacent to fixture  202 . Bore  208  can be positioned in varying configurations and/or orientations within fixture  202  such that fluid flow can enter or surround sample  204  as per known gravitational forces. 
     Fixture  202  has an upper region  228  and a lower region  230 , and as shown more easily in  FIG. 3 , a middle region  229 . As shown in  FIGS. 1-4 , the upper, lower and middle regions can have a variety of configurations and purposes, depending on the set-up and predetermined goals of the study. Fixture  202  has a bore  208  and an opening  231 . Bore  208  provides access for sample  204  and/or a line  211  transmitting fluid into, around or proximal to the sample  204 . Opening  231  permits further access to the interior volume  234  of fixture  202 , permitting easier insertion and/or removal of sample  204  and other items described throughout the present disclosure. To facilitate opening  231  and thusly access to the interior volume  234 , fixture  202  has one or more hinges  236  that permit an arm  238  of fixture  202  to deflect and/or move about a pivot point, axis, and/or plane. Said differently, arm  238  is hingedly connected to fixture  202  about one or more hinges  236 . Interior volume  234  is defined by interior surface  235 . 
     The bore  208  has a size similar to that of a predetermined sample  204 . For instance, known tampons have a diameter of between about 0.48 inches to about 0.63 inches (or about 12 mm to about 16 mm) and a length of about 1.25 to about 3 inches. Other known internally worn menstrual devices such as cups have a diameter of about 1 inch while others have a diameter of up to 3 inches. As such, bore  208  is sized similarly to samples  204  of these devices. Alternatively, bore  208  is sized to emulate the in vivo environment. By way of example, the bore  208  is suitably configured to receive an internally worn hygiene device, such as a tampon, and as such, is sized and shaped similarly to any known vaginal cavity anatomy and/or mean, median, mode or otherwise representative dimensions. 
       FIGS. 1-4  exemplify a bore  208  generally disposed along the central vertical 240 axis of fixture  202 , but can be in other locations depending on the configuration of the fixture  202 . For instance,  FIGS. 5-7  exemplify fixtures  202  having one or more contoured surfaces  281  and shapes more closely resembling at least one surface of the human body, more specifically, the pelvic region, and even more specifically, between the upper legs (or thighs), the vaginal, urethral, and/or buttocks regions. 
     The bore  208  may be configured to have a size that corresponds to a predetermined pressure that is applied to the sample  204  by the fixture  202 . For example, bore  208  is configured to have a diameter  207  that is slightly smaller than the sample  204  of a device such as a tampon, such that a predetermined bodily pressure is exerted along at least a portion of the sample  204  (and in some embodiments, along the entire axial length of the sample  204 ). For example, the fixture  202  applies at least one of a hydraulic pressure or a pneumatic pressure to the sample  204 . To apply such pressure, a wrapper  212  is provided proximal, adjacent to and/or surrounding the sample  204 . The wrapper  212  is made of a material having a low density that is sufficiently distinct from the fluid  246  density and/or sample  204  density, to avoid any imaging confusion with sample  204 . The wrapper  212  is often positioned in close proximity to sample  204 , so it is critical the wrapper  212  is radiographically discernable from the sample  204  and/or the fluid  246  contained within the wrapper  212 . Such wrapper  212  materials include hydrophobic foams, closed cell foams, polyurethane, plastics, films and laminates, polyethylene, low density polyethylene, linear low density polyethylene, polyester, polypropylene, nylon and other long-chain carbon materials, etc. The system utilizes fluid of a predetermined viscosity. In some embodiments, the fluid has varying viscosity. In some embodiments, the fluid utilized to generate hydraulic or pneumatic pressure is non-Newtonian. The application of the pressure to the sample  204  may be done to simulate an application of bodily pressure to the sample  204  when the sample  204  (or an analogous sample) is inserted in a body cavity. 
     The pressure is preferably between about 0.1 psi to about 5 psi, and more preferably between about 0.25 psi and 1 psi. Such pressure can be exerted by the fixture  202  in its entirety to simulate an overall bodily pressure. Alternatively [or additively], such pressure can be exerted by a single aspect or member of the fixture  202  to simulate certain anatomical features that exude pressure against a sample  204 . Further, other pressures exerted by, for instance, involuntary or voluntary bodily reactions such as hiccups, sneezing, coughing, laughing, etc., can also create dynamic pressure(s). For example, the fixture  202  may provide a pressure of about 0.25 psi to simulate pressure of the body surrounding the vaginal canal, but may have an additional member  209  that adds an additional pressure simulating the pressure applied to the vaginal cavity by a full or partially full bladder. The additional member  209  in the fixture  202  can be located within and/or proximal the bore  208  such that it applies pressure directly to the sample  204  and/or indirectly to the sample  204 . Additional member  209  can comprise a bladder and contain fluid, and can be dynamic (i.e. fluid volume in the bladder increases or decreases). The pressure exerted by the additional member  209  can be dynamic alone or in concert with the fixture  202  (i.e. where the fixture  202  applies dynamic pressure). Dynamic pressure can be described as pressure that changes over time. Dynamic pressure also includes, in certain embodiments, the force exerted outwardly by a consumer product as it absorbs and/or retains fluid (and thus expands or changes in size/shape). 
     Additional member  209  provides fixture  202  the opportunity to have a plurality of different pressures exerted by multiple different objects and/or fluids. For instance, a first pressure  209   a  is exerted on the sample  204  by fixture  202 . A second pressure  209   b  is provided via fluid disposed or dispensed into a wrapper  212  surrounding and/or proximal to the sample  204  situated in or adjacent to the fixture  202  (i.e. in the bore  208  as shown in  FIG. 3 ). A third pressure is provided via additional member  209  situated proximal the fixture  202  such that it exerts an additional force or pressure onto the fixture  202 , causing the simulation of another environmental variable. In this embodiment, the fixture  202  simulates general bodily pressure. The additional member  209  simulates the environment of the vaginal canal. The additional member  209  simulates the pressure exerted within the body against the vaginal canal by the bladder. 
     In one embodiment, the fixture  202  permits expansion to accommodate studies of dynamic systems. The fixture  202  permits expansion to, for instance, permit a significant amount of pressure to be exerted (via the accumulation of fluid  246  in the bladder of additional member  209 ) while keeping the bladder within the fixture  202  and proximal the sample  204 . The fixture  202  can comprise a material that is expandable or extensible or compressible such that it changes shape in response to the, for instance, bladder&#39;s shape. In embodiments where the fixture  202  material is compressible, it must remain radiotransparent upon compression. Advantageously, compressible structures can be structured to maintain the general shape and size of the footprint to ensure the system  200  isn&#39;t altered. 
     In embodiments where the fixture  202  is expandable or extensible, it can be due to the material properties of the fixture  202  itself, and/or the physical structure. For instance, and as exemplified in  FIGS. 1 and 2 , the fixture  202  can have arms  238  that deviate in position upon expansion of the sample  204  and/or due to the expansion of additional member(s)  209 . 
     In further embodiments, the fixture  202  has one or more retaining straps  214 . In a first embodiment, the one or more retaining straps  214  are extensible thereby permitting expansion/deflection after a certain level of force is reached (i.e. a force exceeding the force exerted by the retaining strap(s)  214 ). This can be advantageous in set-ups where deflection is useful for inserting samples  204  into (or adjacent to, or onto the fixture  202 ) and/or modifying the fixture  202  to perform in a certain manner, while ensuring the fixture  202  remains substantially static with respect to the platform  216  during the test. 
     In some embodiments, the one or more retaining straps  214  can be positioned to provide pressure to the fixture  202  to simulate bodily pressures in addition to, in lieu of, or to support pressures exerted by other portions or structures of the fixture  202 . The one or more retaining strap  214  can be placed around a portion of the fixture  202  to exert a specific pressure around a portion of the length, width and/or height of the sample  204 . The one more retaining strap  214  can be placed around a portion of the fixture  202  to exert a specific pressure adjacent a sample  204 , such as proximal to the inferior sample  204  end and/or the superior sample  204  end, the sample forward end, the sample rearward end, etc. . . . . In these embodiments, a pressure adjacent the sample  204  can simulate the sample&#39;s  204  performance in vivo, modeling the pressure applied by external anatomy such as limbs (i.e. arms or legs), by internal anatomy such as the cervical os, the bladder, the vaginal wall, the introitus, and/or by garments such as underwear, pants, etc. . . . . 
     In a second embodiment, the one or more retaining strap  214  are substantially rigid. In this embodiment, the fixture  202  remains substantially static during the test, but permits access or modification to the fixture  202  before and after the test. 
     The one or more retaining straps  214  can be a unitary structure such as an elastomeric band or tape. The one or more retaining straps  214  can also have a clasp  213  permitting adjustment of the one or more retaining straps  214  to modify pressure around at least a portion of fixture  204 . The one or more retaining straps  214  can be attached and/or positioned on or surrounding a portion of fixture  204 , or can be attached to platform  216 , or combinations thereof. 
     The fixture  202  may include a fluid source  210  that is configured to introduce/apply a fluid  246  to the sample  204  by a line  211  coupling the fluid source  210  and the sample  204  in  FIG. 7 . Fluid source  210  is attachable to system  200 , to fixture  202 , and/or to platform  216 . The fluid  246  provided by the fluid source  210  may be of any type or composition, such as water, menses, blood, synthetic menses, glycerin, etc., or a mixture of one or more of the aforementioned fluids. In some embodiments, a dye may be used in the fluid  246 . The fluid  246  may be selected to have a density that is sufficiently distinct from the density of the fixture  202  (in an amount greater than a threshold), such that the fluid  246  and the fixture  202  can be distinguished from one another via imaging technology. In some embodiments, the fluid  246  density is significantly distinct from a density of the fixture  202 . In some embodiments, the fixture  202  may be clear/see-through/translucent to a user&#39;s naked eye (to facilitate a visual inspection of the sample  204  when the sample is retained in the fixture  202 ), such that the fixture  202  may be optically transparent. However, in some embodiments the fixture  202  might only be radiographically transparent/translucent. 
     Starting with a dry sample  204 , the fixture  202  may cause the fluid source  210  to apply fluid  246  to the sample  204  until the sample  204  is saturated. 
     The fixture  202  may include a wrapper  212 . The wrapper  212  may retain the sample  204  in the bore  208  of the retaining mechanism  206 . The wrapper  212  encompasses at least a majority of an outer periphery of said fixture  202 . To the extent fluid  246  escapes the sample  204  and/or is meant to surround sample  204 , the wrapper  212  may prevent fluid  246  from the fluid source  210  leaking onto/into the retaining mechanism  206 /bore  208  by creating a barrier between the bore  208 , the opening  231  and/or the fixture  202  in general that substantially keeps fluid inside the wrapper  212 . 
       FIGS. 5-7  provide an additional aspect of the present disclosure, where the fixture  202  and/or retaining mechanism  206  are configured to more specifically replicate an in vivo set-up. As shown in  FIGS. 5-6 , Fixture  202  includes a first region  280 , a second region  282 , and a third region  284 . The first region  280 , second region  282  and third region  284  can be fixed and stationary (with respect to each other) or movable and dynamic (with respect to each other) The first region  280  and the third region  284  support second region  282 , and/or simulate a portion of the human body. First region  280  and second region  284  provide support for second region  282 , and as such, resemble limbs such as legs in an in vivo setup. Second region  282  provides at contoured surface  281 . Second region  282  has a contoured surface  281  emulating at least one surface of an in vivo setup. First region  280  and/or third region  284  may also have contoured surfaces to further simulate an in vivo setup. 
       FIG. 6  provides a retaining mechanism  206  holding sample  204  adjacent the body. Retaining mechanism  206  optionally includes one or more retaining straps  214  (and optionally one or more clasps  213 ). Barrier  250  is adjacent retaining mechanism  206  on a surface facing fixture  202  which is adjacent sample  204 . Barrier  250  is integral with retaining mechanism  206  and/or attachable to retaining mechanism  206 . Barrier  250  optionally has varying surface topography to simulate vaginal rugae and/or other anatomical features of the body. 
       FIG. 6  provides a bore  208  that is internal to fixture  202 . In this embodiment, bore  208  provides a means for retaining and/or directing line  208  (and line end  211   a ) into a location that simulates the urethra or vaginal cavity. In such embodiments, line  208  and line end  211   a  is positioned with respect to sample  204  to simulate fluid flow in an in vivo setup. In further embodiments, bore  208  extends through fixture  208  such that line  208  runs internally through fixture  202 ; bore  208  has a first opening (not shown) where line  208  enters and a second opening  208   b  where line end  211   a  deposits fluid  246  onto or proximal to sample  204 . In further embodiments, bore  208  simulates an internal body cavity such as the vaginal cavity. In other embodiments, line  208  is positioned external to fixture  202  and attachable at least at a position similar to where the urethra or vaginal opening would be in an in vivo setup such that fluid  246  exits line end  211   a  at an appropriate location proximal to or on sample  204 . 
       FIGS. 8 a -8 c    provide various views of a fixture  202  emulating the midsection of a person. The description provided for  FIGS. 5-7  also holds true with these embodiments exemplified by  FIGS. 8 a -8 c   . Fixture  202  has a first region  280 , second region  282 , and a third region  284 . Fixture  202  replicates human body. Fixture  202  is, for example cut from a radiotransparent material such as foam by a CNC machine that has inputted data from a human body scan. The CNC machine cuts individual slices of the radiotransparent material which are thereafter connected by adhesive, one or more retaining straps, etc. . . . . The CNC machine can optionally create bore  208  such that it also resembles the human body (i.e. the vaginal cavity). In this manner, fixture  202  can simulate both internal and external human anatomy and thus fixture  202  provides the opportunity to have an in vitro setup that even more closely resembles an in vivo one. 
     Referring now to  FIG. 10 , an illustrative system  100  is shown. The system  100  may be associated with one or more computers. The system  100  includes one or more processors (generally shown by a processor  102 ) and a memory  104 . The memory  104  may store data  106  and/or instructions  108 . The system  100  may include a computer-readable medium (CRM)  110  that may store some or all of the instructions  108 . The CRM  110  may include a transitory and/or non-transitory computer-readable medium. 
     The instructions  108 , when executed by the processor  102 , may cause the system  100  (or one or more portions thereof) to perform one or more methodological acts or processes, such as those described herein. As an example, execution of the instructions  108  may cause: one or more images of a sample to be captured based on an introduction/application of a fluid  246  to the sample  204 , a data set to be obtained/generated based on the one or more images, and an analysis to be performed based on the data set to determine a grayscale value that represents a fluid  246  flow. 
     The data  106  may include the images, the data set or additional data based on an analysis of the data. In some embodiments, the data  106  may be associated with one or more programs, such as a modeling or simulation program. For example, the data may be native to or supported by one or more computed aided design or computer aided drawing programs, either one or both of which may be referred to as CAD programs. 
     The system  100  may include one or more input/output (I/O) devices  112  that may be used to provide an interface between the system  100  and one or more additional systems or components. The I/O devices  112  may include one or more of a graphical user interface (GUI), a display screen, a touchscreen, a keyboard, a mouse, a joystick, a pushbutton, a microphone, a speaker, a microphone, a transceiver, a sensor, etc. 
     The system  200  includes an imaging device  222 . The imaging device  222  may take/acquire one or more images of the sample  204 , such as when fluid  246  from the fluid source  210  is applied to the sample  204 . The frequency with which the one or more images are taken can be dependent on the viscosity of the fluid  246  and/or the properties of the sample  204 . In other words, a fluid  246  having a higher viscosity may travel more slowly through the sample  204 , and as such, time between images may be longer without missing meaningful data sets. Alternatively, a sample  204  having greater porosity, permeability, wicking rates, etc. . . . may require more frequent imaging to fully capture data sets that will demonstrate fluid  246  movement within sample  204 . In some embodiments, sample  204  has multiple different materials and/or rates and the configuration of such materials in sample  204  require varying rates with which images are taken. For instance, images may need to be taken more quickly as fluid  246  is introduced into a wicking layer or highly permeable area of the sample  204 , and thereafter, slower time intervals for taking images may be sufficient as the fluid  246  travels more slowly through less permeable absorbent areas of the sample  204 . The skilled artisan understands that time intervals may vary more complexly than described herein. In some embodiments, images are taken less than one minute apart. In further embodiments, images are taken about ten to fifteen seconds apart. In further embodiments, images are taken less than ten seconds apart. 
     In some embodiments, the fixture  202  or a portion thereof (e.g., the retaining mechanism  206 ) may rotate in order to cause the sample  204  to rotate. The rotation may occur at a predetermined rate. The rotation may occur when the images are acquired by the imaging device  222 . Alternatively, or additionally, the imaging device  222  may rotate relative to the fixture  202 /sample  204 . Relative rotation enables capturing multiple views of the sample  204  during the test. In some embodiments, the fixture  202  is placed upon and/or attached to the platform  216 . The platform  216  is a rotatable surface  216   a  (i.e. a turntable) in at least one plane (i.e., the x-y plane, the y-z plane, and/or the x-z plane) and/or optionally in at least two planes (i.e. a shaker table). In other embodiments, the fixture  202  is attached to a gimbal  216   b ,  216   c  (as represented by both solid and dashed lines in  FIG. 9 ) permitting dynamic movement in multiple planes or about multiple axes. The platform  216  (i.e., rotatable surface  216   a  or gimbal  216   b ,  216   c ) assists the imaging device  222  in visually capturing the sample  204 &#39;s performance during the test. 
     As shown in  FIG. 9 , gimbal  216   b ,  216   c  has a first linkage  260 , a second linkage  262  and a third linkage  264 , where the first linkage  260  and second linkage  262  are connected and/or movable about each other at joint  270 . Second linkage  262  and third linkage  264  are connected and/or movable about joint  272 . Gimbal  216   b ,  216   c  is stabilized by base  266 . Gimbal  216   b ,  216   c  is connected directly to base  266  or by shaft  268 . The aforementioned configuration permits rotation amongst first linkage  260  and second linkage  262 , and second linkage  262  and third linkage  264 . In total, it permits angular rotation of platform  216  and thusly fixture  202  and sample  204 . 
     In some embodiments, a partial gimbal  216   b  is provided to permit relative rotation between the sample  204  that is proximal to the fixture  202  (i.e., within or adjacent the fixture  202 ) and the imaging while not obstructing the imaging device  222  or any other features connected to the fixture  202 . A partial gimbal  216   b  is exemplified by the solid lines in  FIG. 9 . For instance, the partial gimbal provides three dimensional rotation in a partial sphere such that other features can be positioned or connected to the test fixture  202  in areas where there is no movement. Although rotation is restricted with a partial gimbal, it still provides the ability to study the sample  204  in simulated conditions (i.e. shifting of a sample  204  during a person&#39;s gait, the sample&#39;s  204  response to one or more dynamic bodily pressures, etc. . . . ). In some embodiments, the partial gimbal is a half gimbal. In other embodiments, a full gimbal is provided (as indicated by the solid and dashed lines in  FIG. 9 ). 
     In some embodiments, rotation about at least one axis simulates relative in vivo movement of a person and the device. For instance, and with respect to products worn on or internally to the body during physical motion, a typical gait for a person is about three miles per hour. As such, depending on the size of the fixture  202 , the fixture  202  rotates about at least one axis at rate of about 52 in/second. As people typically move at speeds between 0.1 mph and about 25 mph, the fixture  202  is capable of rotating at speeds between about 1.7 in/second to about 806 in/second, or perhaps more typical for most people partaking in exercise, speeds between about 52 in/second to about 176 in/second. 
     As shown in  FIG. 7 , dynamic pressure can be applied via additional members  209   a  and  209   b . Additional members  209   a ,  209   b  articulate about joint  248   a ,  248   b , respectively. Additional members are capable of applying a static pressure as well. Additional members  209   a ,  209   b  apply pressure in at least one plane, or by articulating about at least one axis. Such articulation can work in concert with the movement of fixture  202  or retaining mechanism  206  on platform  216 . For instance, additional members  209   a  and  209   b  can simulate rubbing amongst body parts such as limbs and the torso, or more specifically, the legs and the pelvic region, while a sample is being worn externally as shown in  FIG. 7  (or internally as demonstrated throughout the specification). Movement of additional members  209   a ,  209   b  can be done to simulate bodily pressures exerted amongst body parts at a rate similar to that of a person walking, running, or participating in athletics, as described in the present disclosure. In certain embodiments, barrier  250  separates the retaining mechanism  206  (or fixture  202 , in other embodiments) and sample  204  such that any fluid  246  escaping the sample  204  does not saturate and/or soil retaining mechanism  206  (or fixture  202 ). This simplifies cleaning and maintenance. As such, barrier  250  is an impermeable material that is preferably radiotransparent, or at the very least, has a density sufficiently distinct from the sample  204  and/or fluid  246 . Some examples of materials include silicon and other plastics and foams mentioned throughout the present disclosure. Such a barrier  250  can be applied to any of the exemplary fixtures of the present disclosure. 
     A modified syngyna test methodology can be used in ascertaining fluid handling performance and absorbent characteristics of the sample  204 . Such a set-up includes a syringe pump  220  moving fluid  246  from a fluid source  210  such as a beaker, bag and/or graduated cylinder, to a line  211  located proximal to the sample. The line  211  has a line end portion  211   a  that dispenses (i.e. drips) fluid  246  at a predetermined rate controlled by the syringe pump  220 . The components of the line  211  and line end portion  211   a  must be material that will not disrupt the imaging and as such, should be made from a material that is sufficiently distinct from sample  204  and/or fluid  246 . Preferably, the line and end portion are radio transparent. For instance, the rate is between about 10 ml/hr to about 70 ml/hr, or more preferably, between about 20 ml/hr to about 50 ml/r, or even more preferably, about 25 ml/hr for internally worn menstrual products and about 50 ml/hr for externally worn hygiene products such as menstrual or incontinence underwear, diapers, napkins, pads, and/or liners. 
     The imaging device  222  may be operative in accordance with one or more imaging technologies. For example, the imaging device  222  may be operative in accordance with at least one of computed tomography, magnetic resonance imaging, nuclear magnetic resonance imaging, or magnetic resonance tomography. In some embodiments, the imaging device  222  may include an imaging source  224  and an imaging detector  226 . The imaging source  224  and the imaging detector  226  may be operative in accordance with x-ray technology. 
     The system  200  includes a computer  232 . The computer  232 , which may include one or more of the components/devices described above in connection with the system  100  of  FIG. 10 , may be configured to coordinate or synchronize the activities of the fixture  202  and the imaging device  222 . The computer  232  may also perform one or more of the methodological acts described herein. For example, the computer  232  may obtain one or more images from the imaging device  222 , obtain one or more data sets based on the images, and perform an analysis in connection with data set(s) to determine a grayscale value that represents a fluid flow through the sample  204 . 
     In some embodiments, one or more time stamps (e.g., a scanning time) may be associated with the images acquired by the imaging device  222 . The time stamps may be used to generate a four-dimensional data set associated with a fluid flow in the sample  204 . The four-dimensional data set may be obtained by generating a three-dimensional data set based on the images acquired by the imaging device  222  and applying the time stamps to the three-dimensional data set. 
     In some embodiments, one or more radiographs may be acquired by the imaging device  222 . A radiograph may represent a two-dimensional projection as interpreted by a detector of the imaging device  222 . A three-dimensional reconstruction may be generated based on a synthesis of a plurality of radiographs. A four-dimensional reconstruction may be generated based on an application of the time stamps to the three-dimensional reconstruction. 
     The systems  100  and  200  are illustrative. In some embodiments, one or more of the components or devices may be optional. In some embodiments, the components/devices may be arranged in a manner that is different from what is shown in  FIGS. 10 and 11 . In some embodiments, additional components or devices not shown may be included. For example, in embodiments where the system  100  or the system  200  is included as part of one or more networks, one or more switches, routers, and the like may be included. One or more portions of the system  100  or the system  200  may be included in a particular computing device, such as a server, a personal computer, a laptop, a mobile device (e.g., a smartphone), etc. 
     As described above, the systems  100  and  200  may be used to obtain a grayscale value representative of a fluid flow in the sample  204 . Referring to  FIGS. 12A-3E  (collectively referred to as  FIG. 12 ) a flow chart of a method  300  is illustrated for obtaining such a grayscale value. The method  300  may be executed in conjunction with the system  200 , or a portion thereof. 
     In block  302 , a data set may be obtained based on a plurality of images acquired by, e.g., the imaging device  222  of  FIG. 11 . The data set obtained in block  302  may by a four-dimensional data set/reconstruction. 
     In block  306 , an estimate is obtained regarding a grayscale value that is representative of the fluid flow. The estimate may be based on a user input to the system  200  of  FIG. 11 . 
     In block  310 , a theoretical (volumetric) flow rate of the fluid is obtained. The theoretical flow rate may be based on a user input to the system  200  of  FIG. 11 . 
     In block  314 , a “previous grayscale variable” may be defined. As part of block  314 , the previous grayscale variable may be initialized/set to the estimate of the grayscale value obtained in block  306 . 
     In block  318 , a “current grayscale variable” may be defined. As part of block  318 , the current grayscale variable may be initialized/set to the estimate of the grayscale value obtained in block  306 . 
     In block  322 , an “adjustment variable” may be defined. As part of block  322 , the adjustment variable may be initialized/set equal to an “adjustment value”. For reasons that will become more apparent to a skilled artisan in view of the disclosure provided below, the adjustment value may be selected based on a degree of accuracy that is required and may be representative of a time it takes for the method  300  to converge to a final grayscale value representative of the fluid flow. 
     One skilled in the art will appreciate that the labels applied to the variables in connection with the blocks  314 - 322  are merely illustrative and the naming convention used is merely intended to signify the nature or use of the variables. One skilled in the art would appreciate that a more generic naming convention could be used (e.g., first variable, second variable, etc.) without departing from this disclosure. 
     In connection with block  326 , a number of sub-blocks/operations may be iteratively performed to arrive at, or converge to, a final grayscale value representative of the fluid or fluid flow. Block  326  is described in further detail below in connection with  FIGS. 12B-12E . 
     In block  326 - a  (see  FIG. 12B ), a volume may be calculated for the data set of block  302  based on the current grayscale variable. As part of block  326 - a , a determination may be made regarding a volume of what is intended to be the fluid as a function of length (e.g., radial axis) for every data set/reconstruction of block  302 . This may be done by adding up the volume of each voxel in each layer of the reconstruction whose grayscale value is between the current grayscale variable and an upper bound whose value is fixed relative to the current grayscale variable. As an illustrative example, if the current grayscale variable has a value of 1.34, and an upper bound offset is equal to 2.20, the upper bound may be equal to 1.34+2.20=3.54. 
     In block  326 - b , a flow rate may be calculated based on the volume calculated in block  326 - a . As part of block  326 - b , a linear regression may be used to calculate the flow rate. The flow rate may be based on a derivative of a curve formed with: (A) volume as a dependent variable, and (B) imaging (e.g., scanning) time as an independent variable. 
     In block  326 - c , an error may be calculated as a difference between the calculated flow rate of block  326 - b  and the theoretical flow rate of block  310 . The error calculation of block  326 - c  may be conducted on an absolute value basis, such that the sign/polarity in the error may be disregarded. 
     In block  326 - d , a comparison may be made to determine whether the error calculated in block  326 - c  is less than a threshold. The threshold may be based on, or correspond to, the error calculated in block  326 - c  during a previous iteration associated with block  326 . If the error is less than the threshold, flow may proceed from block  326 - d  to block  326 - e  (see  FIG. 12C ). Otherwise (e.g., the error is greater than or equal to the threshold), flow may proceed from block  326 - d  to block  326 - f (see  FIG. 12D ). 
     In block  326 - e  (see  FIG. 12C ), the previous grayscale variable may be set equal to the current grayscale variable. 
     In block  326 - g , the current grayscale variable may be modified based on the adjustment variable. For example, as part of block  326 - g  the adjustment variable may be subtracted from the current grayscale variable to generate an updated current grayscale variable. Flow may proceed from block  326 - g  to block  326 - a.    
     In block  326 - f  (see  FIG. 12D ), a comparison may be made to determine whether the adjustment variable is less than a (second) threshold. This threshold may be based on a resolution associated with the system (e.g., system  200 ) that is used. The threshold may be based on a user input. The threshold may serve as a factor in the time it takes for the method  300  to converge to a final grayscale value representative of the fluid flow; a smaller value of the threshold (representative of a fine resolution) may result in a longer convergence time relative to a larger value (representative of a coarse resolution), all other things being equal. The threshold may correspond to a predetermined value associated with an accuracy resolution. If it is determined in block  326 - f  that the adjustment variable is less than the threshold, flow may proceed from block  326 - f  to block  326 - h . Otherwise (e.g., the adjustment variable is greater than or equal to the threshold), flow may proceed from block  326 - f  to block  326 - i  (see  FIG. 12E ). 
     In block  326 - h , the iteration associated with block  326  may end. Flow may proceed from block  326 - h  to block  330  (see  FIG. 12A ). 
     In block  326 - i  (see  FIG. 12E ), the previous grayscale variable may be set equal to the current grayscale variable. 
     In block  326 - j , the adjustment variable may be modified by reducing the value of the adjustment variable. For example, the adjustment variable may be reduced in half in block  326 - j.    
     In block  326 - k , the current grayscale variable may be modified based on the adjustment variable. For example, as part of block  326 - k  the adjustment variable may be added to the current grayscale variable to generate an updated current grayscale variable. Flow may proceed from block  326 - k  to block  326 - a.    
     In block  330  (see  FIG. 12A ), the previous grayscale variable may be provided as a representation of the fluid or fluid flow. The method  300  may end following block  330 . 
     While some of the parameters described above in conjunction with the method  300  were described in terms of volume, the parameters may be expressed in other terms (potentially in lieu of expressing the parameters in terms of volume). For example, at least some of the parameters may analogously be expressed in terms of mass via one or more factors that may be used to convert between volume and mass, as described further below. 
     In some embodiments, a calibration may be performed in connection with the fixture  202 . For example, and referring to  FIG. 13 , a fixture  402  (which may correspond to the fixture  202  of  FIG. 11 ) may be configured to retain the sample  204  and a reference sample  404  (in  FIG. 13 , details of the retaining mechanism  206 , the bore  208 , and the wrapper  212  are omitted, with the understanding that the same or analogous components may be applied to the sample  204  and/or the reference sample  404  in the fixture  402  of  FIG. 13 ). The reference sample  404  may be used to calibrate the grayscale value due to the fluid in the reference sample  404  being the same as that being introduced into the sample  204 , as well as the mass or volume of the fluid being predetermined/known. 
     If the reference sample  404  is placed/located out of plane with respect to the sample  204 , the likelihood of any other materials with the same grayscale value appearing in-plane with the reference sample  404  is sufficiently low in relation to any potential impact on accuracy (aside from an insignificant amount of noise that may be present). Therefore, if a correct grayscale value is chosen, volume statistics calculated between the planes containing the reference sample  404  may prove accurate. 
     Referring now to  FIG. 14 , a flow chart of a method  500  is shown. The method  500  may be executed to obtain a grayscale value representative of a fluid or fluid flow. The method  500  may be similar to, or incorporate aspects of, the method  300  described above. Aspects of the method  300  and the method  500  may be combined with one another in some embodiments. The method  500  may be executed in conjunction with the system  200  of  FIG. 11 , or a portion thereof. The method  500  may be executed in conjunction with the fixture  402  of  FIG. 13 . 
     In block  502 , a data set/reconstruction (e.g., block  302 ), an estimate of a grayscale value (e.g., block  306 ), a location of a reference sample (e.g., the sample  404 ), and a specification of the actual mass or volume of the reference sample may be obtained. The location of the reference sample may be specified in terms of one or more planes (e.g., two planes). As part of block  502 , an adjustment variable may be obtained/set, similar to block  322 . Similarly, a current grayscale variable may be obtained/set, similar to block  318 . 
     In block  506 , masses or volumes may be calculated for the data set of block  502  based on the current grayscale variable where the reference sample is located. As part of block  506 , a volume may be converted to a mass by multiplying the volume by the fluid&#39;s density. Block  506  may be analogous, or similar, to blocks  326 - a  and  326 - b . As part of block  506 , one or more filtration or averaging techniques (e.g., root-mean-square (RMS)) may be applied. 
     In block  510 , an error may be calculated as a difference between the (average) mass/volume calculated in block  506  and the actual reference sample mass/volume obtained in block  502 . Block  510  may be analogous, or similar, to block  326 - c.    
     In block  514 , the error calculated in block  510  may be compared to a threshold (e.g., the error calculated in block  510  during a previous iteration of the method  500 , which may be stored in a “previous error” variable). If the error of block  510  is less than the threshold, flow may proceed from block  514  to block  518 . Otherwise, flow may proceed from block  514  to block  522 . Block  514  may be analogous, or similar, to block  326 - d.    
     In block  518 , the current grayscale variable may be stored/saved (into a previous grayscale variable) and then the current grayscale variable may be modified using the adjustment variable. Block  518  may be analogous, or similar, to blocks  326 - e  and  326 - g . Flow may proceed from block  518  to block  506 . 
     In block  522 , a determination may be made whether the adjustment variable is less than a (second) threshold. Block  522  may be analogous, or similar, to block  326 - f . If the adjustment variable is less than the threshold, flow may proceed from block  522  to block  526  (and any iteration in connection with the blocks  506 - 526  and  530  may be ended in a manner similar to block  326 - h ). Otherwise, flow may proceed from block  522  to block  530 . 
     In block  530 , the grayscale value may be stored/saved (into the previous grayscale variable) and then the current grayscale variable may be modified on the basis of a modified value for the adjustment variable. Block  530  may be analogous, or similar, to blocks  326 - i ,  326 - j , and  326 - k . Flow may proceed from block  530  to block  506 . 
     In block  526 , the saved/stored (e.g., previous) grayscale value (as reflected in the previous grayscale variable) may be selected to represent the fluid or fluid flow. Block  526  may be analogous, or similar, to block  330 . 
     As described herein, the methodological acts and processes may be tied to particular machines or apparatuses. For example, one or more computers may include one or more processors and memory storing instructions, that when executed, perform the methodological acts and processes described herein. Furthermore, the methodological acts and processes described herein may perform a variety of functions including transforming an article (e.g., a data set) into a different state or thing (e.g., a grayscale value representative of a fluid flow in a sample). In some embodiments, the transformation may take place in accordance with a predefined algorithm or formula. 
     While some of the examples described herein related to personal care products, one skilled in the art would appreciate that aspects of the disclosure may be applied in connection with other types of samples. 
     Technical effects and benefits of this disclosure include an ability to accurately and quickly characterize a fluid flow applied to a sample as the fluid enters and flows through the sample. This characterization may be made available on a substantially real-time basis, providing insight into the progression of the fluid through the sample. 
     Aspects of the disclosure have been described in terms of illustrative embodiments thereof. Numerous other embodiments, modifications, and variations within the scope and spirit of the appended claims will occur to persons of ordinary skill in the art from a review of this disclosure. For example, one of ordinary skill in the art will appreciate that the steps described in conjunction with the illustrative figures may be performed in other than the recited order, and that one or more steps illustrated may be optional in accordance with aspects of the disclosure. One or more features described in connection with a first embodiment may be combined with one or more features of one or more additional embodiments.