Abstract:
A virtual touchscreen for mobile devices provides a touchscreen area displaced to a side of the display to eliminate problems of a finger blocking the display during normal touchscreen operation. The virtual touchscreen may be monitored by a sensor system looking edgewise from a housing of the mobile device employing as few as two displaced photodetectors and a correspondingly oriented light source constrained to sensitivity within a narrow fan-shaped light-sensing plane. Extraction of the spatial location of a finger touch within this touchscreen area may be performed by a model of reflected light signals of a finger in different locations calibrated to environmental parameters of finger reflectivity and background reflectivity by a simple calibration process.

Description:
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0001]    This invention was made with government support under CNS1318292, CNS1343363, CNS1350039, and CNS1404613 awarded by the National Science Foundation. The government has certain rights in the invention. 
     
    
     CROSS REFERENCE TO RELATED APPLICATION 
     Background of the Invention 
       [0002]    The present invention relates to human machine interfaces and in particular to a touch type interface suitable for providing input to compact mobile devices. 
         [0003]    Mobile devices are shrinking in size for improved portability; however, this reduction in size makes receiving user input increasingly difficult. The transition from desktop and laptop computers to tablet type devices and cell phones has been largely managed by the introduction of touchscreens which allow shared use of the display surface as an input surface. 
         [0004]    Particularly for smaller devices, including wristwatches, this dual use of the display as an input surface can become a problem as the user&#39;s finger obscures increasingly larger portions of the area of the display being manipulated. 
       SUMMARY OF THE INVENTION 
       [0005]    The present invention provides a virtual touch screen displaced to unused space to the side of the display of the device. Photosensors and at least one light source detect and project light respectively along a light-sensing plane extending from the housing of the device and defining the virtual touch screen area. The edgewise orientation of the sensing system to the virtual touch screen area allows the sensor system to be easily incorporated into the frame around the display for convenient simultaneous access to the display and virtual touch screen. 
         [0006]    Specifically, the present invention provides a human interface device having a housing supporting a graphics display screen positionable against a surface. At least two photodetectors supported by the housing receive light along a light-sensing plane substantially parallel to the surface and extending away from the housing over an area offset from the housing and at least one light emitter projects light along the light-sensing plane. An electronic computer communicates with the photodetectors and light emitter and executes a program stored in non-transitory medium to (1) independently measure light signals indicating light received by the photodetectors reflected from the light emitter of a finger within the light-sensing plane; (2) apply values of the light signals to a model converting the light signals to orthogonal coordinates defining points within the light-sensing plane; and (3) control an output on the graphics display screen according to the coordinates. 
         [0007]    It is thus a feature of at least one embodiment of the invention to provide a sensing system providing an improved touchscreen experience by removing the point of touch from the display without substantially increasing the size of the device to support a touchpad or the like. 
         [0008]    The graphics display screen may provide a display surface parallel to the light-sensing plane. 
         [0009]    It is thus a feature of at least one embodiment of the invention to provide an extremely simple interface for convenient use when the housing is resting flat on a surface. 
         [0010]    The housing may provide a greatest dimension along the display surface and a narrowest dimension perpendicular to the display surface and the light-sensing plane is positioned within the narrowest dimension. 
         [0011]    It is thus a feature of at least one embodiment of the invention to provide an interface whose hardware components can he incorporated in the edge of the device without substantially increasing the housing size. 
         [0012]    The housing may be sized to fit atop of an average human wrist and may include a wrist strap for attaching the housing to the wrist in the manner of a wristwatch. 
         [0013]    It is thus a feature of at least one embodiment of the invention to provide a touchscreen interface for watch-size type devices where a finger touch substantially obscures the display. 
         [0014]    The housing may provide a frame surrounding the graphics display screen to support the graphics display screen face upward and parallel to the surface during use. 
         [0015]    It is thus a feature of at least one embodiment of the invention to provide an interface that can work with tablet-type devices when resting on a table with the display upward. 
         [0016]    The device may include a collimator collimating the light from a fan-shaped acquisition region in the light-sensing plane onto the photodetector, the fan-shaped acquisition region having its widest dimension aligned along the light-sensing plane. 
         [0017]    It is thus a feature of at least one embodiment of the invention to improve sensitivity of the interface by reducing extraneous light received outside of the light-sensing plane. 
         [0018]    The fan-shaped acquisition region may have a width measured in the light-sensing plane with at least 20 times the height of the fan measured perpendicularly to the light-sensing plane. 
         [0019]    It is thus a feature of at least one embodiment of the invention to provide a sensing region that closely mimics a touch surface. 
         [0020]    The device may further include a collimator forming the light from the LED into a fan shape having its widest dimension aligned along the light-sensing plane. 
         [0021]    It is thus a feature of at least one embodiment of the invention to provide improved sensitivity by reducing scattered light off of services outside of the light-sensing plane. 
         [0022]    The fan shape may have a width measured in the light-sensing plane with at least 20 times the height of the fan measured perpendicularly to the light-sensing plane. 
         [0023]    It is thus a feature of at least one embodiment of the invention to provide a collimation pattern for the light which closely matches that of the photodetectors. 
         [0024]    The output controls an image location on the graphics display screen or may control a virtual keyboard for entering characters on the graphics display screen. 
         [0025]    It is thus a feature of at least one embodiment of the invention to provide common interface controls needed for electronic devices. 
         [0026]    The motion of the image may have the same orientation as motion of the finger within the light-sensing plane. 
         [0027]    It is thus a feature of at least one embodiment of the invention to provide intuitive operation despite displacement of the control surface from the screen. 
         [0028]    The electronic computer may monitor the measured signals to deduce a presence or absence of the finger to control output on the graphics display according to the presence or absence of the finger in the light-sensing plane. 
         [0029]    It is thus a feature of at least one embodiment of the invention to provide touch sensing in addition to spatial discrimination. 
         [0030]    The electronic computer may further determine a background signal level when a finger is not within the light-sensing plane and compensate the measured light signals according to that measured background signal. 
         [0031]    It is thus a feature of at least one embodiment of the invention to enable edgewise sensing despite variation in background surfaces. 
         [0032]    The light source may be modulated and light signals from the photodetector demodulated to reject ambient light not subject to the modulation. 
         [0033]    It is thus a feature of at least one embodiment of the invention to permit operation of the device in a variety of environments subject to ambient lighting. 
         [0034]    The modulation duty cycle of the light source may be decreased when a finger presence is not detected. 
         [0035]    It is thus a feature of at least one embodiment of the invention to provide a power efficient design compatible with battery-operated devices. 
         [0036]    The electronic computer may further execute to receive measured light signals during a predefined path of motion of a finger within the light-sensing plane to calibrate the model. 
         [0037]    It is thus a feature of at least one embodiment of the invention to provide improved performance of the interface through a simple calibration process. 
         [0038]    The model may be calibrated to an arbitrary area defined by the predetermined path of motion of the finger. 
         [0039]    It is thus a feature of at least one embodiment of the invention to provide a modeling process that does not require precise finger movement by the individual. 
         [0040]    The model may include corrections for angular sensitivity variation of the photodetectors within the light-sensing plane and angular sensitivity variations of the LED light output within the light-sensing plane. 
         [0041]    It is thus a feature of at least one embodiment of the invention to operate with conventional photodetector and light sources subject to angular variation. 
         [0042]    These particular objects and advantages may apply to only some embodiments failing within the claims and thus do not define the scope of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0043]      FIG. 1  is a perspective view of a portable device supported on a table surface or the like providing a virtual touchscreen per the present invention, the virtual touchscreen displaced from the display area of the device; 
           [0044]      FIG. 2  is a perspective view of a wrist mounted portable device in which the virtual touchscreen is displaced from the display over the user&#39;s wrist; 
           [0045]      FIG. 3  is a perspective view of a sensor system for use with the present invention showing a light shroud for use in collimation; 
           [0046]      FIG. 4  is a cross-section along line  3 - 3  of  FIG. 1  showing the operation of the shroud in providing a light grooming producing a limited height, light-sensing plane; 
           [0047]      FIG. 5  is a block diagram of the sensing system of  FIG. 3  as communicating with a processor of the device and the display screen; 
           [0048]      FIG. 6  is an alternative collimation system incorporating anisotropic lenses in the photodetector and light source; 
           [0049]      FIG. 7  is a flowchart executed by the processor  FIG. 5  in deriving finger touch position; 
           [0050]      FIG. 8  is a contour plot of signal strength from the left and right photodetectors showing unique intersections of the curve from each photodetector allowing a functional mapping between signal strength and spatial location forming the basis of a model; 
           [0051]      FIG. 9  is a plot against time of the signal from one photodetector during a calibration procedure allowing adjustment of the model to particular environmental parameters; and 
           [0052]      FIG. 10  is a simplified representation of a model implemented as a lookup table giving pairs of signal strength from the left and right photodetector. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0053]    Referring now to  FIG. 1 , a portable device  10 , such as a tablet or cell phone or the like, may provide for a graphics display screen  12 , for example, an LCD display with or without touchscreen capabilities surrounded by a frame  14  such as form part of a housing  16  for the graphics display screen  12  and other electronics incorporated within the portable device  10  as will be described below. 
         [0054]    The housing  16  may provide for a rear face  18  that may be placed against an upper horizontal surface  20  of the table or the like to support the device  10  such that the graphics display screen  12  has its broad face exposed upwardly and generally parallel to a upper surface  20  of the table to be visible to the user. 
         [0055]    One embodiment of the invention provides a sensor system  22  incorporated into the frame  14  and operating to sense motion of a user&#39;s finger  24  moving within a virtual touchscreen area  26  offset from the frame  14  along an axis  27 . Axis  27  may in one embodiment be generally in a parallel plane to a plane of the display area of the graphics display screen  12  so that the virtual touchscreen area  26  is positioned over an unoccupied portion of the upper surface  20 . The sensor system  22  will be generally sensitive to light within a light-sensing plane  28  extending edgewise from the frame  14  and aligned with and subtending the virtual touchscreen area  26 . 
         [0056]    As will be discussed below, movement of the user&#39;s finger  24  within the virtual touchscreen area  26  may be detected by the sensor system  22  to control output on the graphics display screen  12 , for example, the movement of an image  30  of a cursor or the like, to track movement of the user&#39;s finger  24  within the virtual touchscreen area  26  mapped to the area of the graphics display screen  12 . For a tablet-type device  10 , the virtual touchscreen area  26  may, for example, be nine centimeters by seven centimeters. 
         [0057]    Referring now to  FIG. 2 , the same concept can be applied to a device  10 ′ in the form factor of a wristwatch also having a graphics display screen  12  surrounded by a frame  14  being part of a housing  16 . In this case the housing  16  may be attached to the upper side of the user&#39;s wrist  32 , for example, held by a wrist strap  34  in the manner of a conventional wristwatch, so that the graphics display screen  12  is visible like the face of a wristwatch. The sensor system  22 , in this case, may monitor a light-sensing plane  28  extending back along the upper surface of the user&#39;s wrist  32  toward the user&#39;s elbow to define a virtual touchscreen area  26  over the unoccupied area of the surface of the user&#39;s forearm. 
         [0058]    In either embodiment of  FIG. 1 or 2 , the user may touch a location  36  within the virtual touchscreen area  26  with a finger  24  of the user&#39;s other hand to control the graphics display screen  12 , for example, an image  30  of a cursor as discussed above, and/or to provide input to the device  10 ,  10 ′, for example, by touching locations  36  which map to key buttons of a keyboard image  23  on the graphics display screen  12  (shown in  FIG. 1 ) providing keyboard-type entry. Generally the movement, for example, of an image  30 , will track movement of the location  36  in orientation (e.g., left movement of the image  30  will correspond the left movement of the location  36 ) and in translation by a fixed scale factor relating the size of the graphics display screen  12  to the size of the virtual touchscreen area  26 . 
         [0059]    Referring now to  FIG. 3 , the sensor system  22  in one embodiment may provide for a sensor housing  38  providing three apertures  40   a - 40   c  displaced along an axis  42  perpendicular to axis  27  and together with axis  27  defining a plane generally parallel to the plane of the virtual touchscreen area  26 . Ideally, the separation of apertures  40   a  and  40   c  will be maximized within the space constraints of the frame  14  to provide for maximum resolution in the virtual touchscreen area  26  with aperture  40   b  positioned approximately midway between apertures  40   a  and  40   c.    
         [0060]    Behind each of apertures  40   a  and  40   c  are left and right photodetectors  44   a  and  44   b,  respectively, positioned to receive light through the apertures  40   a  and  40   c  from the light-sensing plane  28 . Behind aperture  40   c  is a light source  46 , for example, a light emitting diode in the near infrared frequency range positioned to project light through the aperture  40 b along the light-sensing plane  28 . 
         [0061]    In one embodiment of the sensor housing  38 , the sensor housing  38  may provide for a collimating shroud around the apertures  40  to provide for light “grooming” of both of the light projected by the light source  46  and the light received by the photodetectors  44   a  and  44   b  within a relatively thin light-sensing plane  28  extending fanlike across the virtual touchscreen area  26 . In this respect, the shroud formed by the housing  38  may provide for a V-notch  47  for each of the apertures  40 , for example, having an angular extent of 90 degrees within the light-sensing plane  28 , thereby limiting the angular extent of the light-sensing plane  28 . Similarly, and referring also to  FIG. 4 , the shroud provided by the housing  38  may likewise constrain a vertical width  21  of the light-sensing plane  28 , for example, to a few degrees measured perpendicularly to the light-sensing plane  28  and less than 10 degrees. 
         [0062]    This light grooming allows better rejection of unwanted light and reflections that might detrimentally affect detection of the finger  24  in the virtual touchscreen area  26 . The light grooming also allows the finger  24  to be easily removed from and inserted into the sensing region defined by the light-sensing plane  28 . Detection of the presence of the finger  24  as well as its spatial location allows not only finger position to be determined within the virtual touchscreen area  26  but also a touch “event” occurring at the introduction of the finger into the virtual touchscreen area  26  with slight movement of the finger toward the surface  20  or the back of the wrist  32 . A touch event may provide for an input signal similar to a mouse “click” or the touch of a touchscreen. 
         [0063]    In some embodiments an infrared filter  49  may be placed over the apertures  40   a  and  40   b  to limit the effect of bright daylight in possibly saturating the photodetectors  44  or otherwise interfering with the measurement of the photodetectors  44 . Other saturation prevention techniques may also be used, for example, including an actively controlled LCD shutter or, for wide dynamic range photodetectors  44 , a change in bias voltage or amplification of the signals received from the photodetectors  44 . 
         [0064]    Referring momentarily  FIG. 5 , it will be appreciated that in an alternative embodiment light-sensing or light-emitting elements  50  associated with either the photodetectors  44  or light source  46  may include an anamorphic lens  52  and opaque stops  55  to provide similar light grooming as described above while improving the sensitivity of the system by reducing light blocking in the grooming process. Generally the anamorphic lens  52  will provide for an expansion of a field of view along axis  42  relative to the field of view perpendicular to axis  42  and axis  27 . The anamorphic lens  52  and opaque stops  55  may be formed into a package integrated with the light-sensing or light-emitting elements  50 . 
         [0065]    Referring no to  FIG. 5 , light source  46  may be driven by a driver circuit  53  under the control output of a microcontroller  54  to modulate the light from the light source  46 , for example, using on-off keying (OOK) at a switching, rate of about 30 hertz, much faster than the typical variation of ambient light sources. Light sensed from either photodetector  44   a  or photodetector  44   b  (for example, being photo transistors) may be measured from base resistances  43  attached to the emitters of the transistors and further received by an analog-to-digital converter in the microcontroller  54 . This light may be synchronously or asynchronously demodulated at the switching rate and phase to discriminate against ambient light that is not so modulated. 
         [0066]    Referring still to  FIG. 5 , the microcontroller  54  may include one or more processors  56  communicating with electronic memory  58  holding a stored program  60  executable by the processors  56  as will be discussed below. Generally, the microcontroller  54  may also communicate with the graphics display screen  12  to provide images thereon associated with the sensing of the present invention. The microcontroller  54  may also communicate with various electronic interfaces  62  such as pushbuttons, microphones, accelerometers, gyroscopes and the like, well known in portable devices. 
         [0067]    When the portable device  10  is a cell phone or the like, the microcontroller  84  may also communicate with wireless communications circuits  64  such as those providing for Wi-Fi, Bluetooth, and cell phone communication as well as GPS communication circuits for GPS navigation. 
         [0068]    Referring now to  FIGS. 1 and 6 , the present invention may be activated by the user, for example, using a variety of input methodologies including electronic interfaces  62  or even the sensor system  22  detecting a momentary finger touch. At this time, as indicated by process block  70 , a calibration may be performed and calibration input indicated by process block  70 . This calibration input is intended to calibrate the sensor system  22  to environmental variables such as background reflection and ambient light. Specifically, these environmental variables include variations in finger reflectivity from different individuals (including that caused by skin differences and finger sizes) and workspace related parameters such as surface reflectivity of the surface  20 . In one embodiment, the calibration process may instruct the user to insert his or her finger  24  into the light-sensing plane  28  at a beginning of the virtual touchscreen area  26  along axis  27  and then to move his or her finger  24  generally along axis  27  from a beginning of the virtual touchscreen area  26  to an end of the virtual touchscreen area  26  and then to lift the user&#39;s finger out of the light-sensing plane  28 . In one embodiment, the user may be instructed to move a precise distance; however, the calibration system may readily accommodate variations in this distance by simply scaling the virtual touchscreen area  26  appropriately to whatever distance the user moves. 
         [0069]    Referring now to  FIG. 8 , during this calibration procedure, for each photodetector  44 , a signal  72  will be detected being reflectance from the light source  46  generally declining with time after an initial increase with a finger insertion at time t i  within the light-sensing plane  28  until a finger extraction at time t e . This signal may be generally modeled for each photodetector  44  as a combination of a variety of factors according to the equation: 
         [0000]        RSS=C g   t    g   d    S   PD (θ r )  S   LED (θ t )   (1)
 
         [0070]    where: 
         [0071]    RSS is the measured signal strength (respectively for the photodetectors  44   a  and  40   b ); 
         [0072]    C is an environmental calibration factor incorporating finger reflectivity and work surface reflectivity discussed above to be determined through the calibration process; 
         [0073]    g t  is a falloff in light intensity from the light source  46  generally observing the inverse square law and will be a function of finger position; 
         [0074]    g d  is a falloff in light intensity detected by the photodetectors  44  generally being an inverse linear relationship caused by a change in the finger&#39;s visible height with distance and will be a function of finger position; 
         [0075]    S PD (θ r ) is an angular variation of the sensitivity of the individual photodetector  44  with an angle in the light-sensing plane  28  and will be a function of finger position; and 
         [0076]    S LED (θ t ) is an angular variation in light output from the light source  46  within the light-sensing plane  28  and will be a function of finger position. 
         [0077]    It will be appreciated that S PD (θ r ) and S LED (θ t ) may be subject to factory determination being intrinsic properties of the photodetectors  44  and light source  46  and the collimation provided as discussed above. The values of g t  and g d  maybe separately determined for each point of the signal  72  between t i  and t e  (and these values averaged together) assuming constant finger motion between entry and exit from the light-sensing plane  28 . The finger position values used for these values of g t  and g d  for each photodetector  44  may be based on actual measured distances or normalized to a reference frame of an arbitrarily sized virtual touchscreen area  26  defined by the normalized distance between the user&#39;s insertion and removal of his or her finger  24  from the light-sensing plane  28 . That is, the user may size the virtual touchscreen area  26  during the calibration process. The slope of the signal  72  may then indicate the value of C for each of the photodetectors  44   a  and  44   b  separately lumping together the environmental considerations discussed above. Generally, the threshold  74  of signal RSS before time t i  and after time t e  may be used to determine background values that may be used to provide an indication of when a finger is and is not in the region as will be used and discussed above, 
         [0078]    As indicated by process block  76 , the values of equation (1) discussed above may be used to create a model relating the signals detected by each of the photodetectors  44   a  and  44   b  as a function of an x and y Cartesian location of a finger touch in the virtual touchscreen area  26  where y is measurement along axis  27  and x is a measurement along axis  42 . In principle, the model takes the measured values of RSS for the photodetectors  44   a  and  44   b  and determines x and y values that would satisfy equation (1). Generally, RSS isostrength lines  80  from a contour plot generated by equation (1) for one photodetector  44   a  will have only one intersection with isostrength lines of the other photodetector  44   b  allowing each location (x, y) to be mapped to a unique pair of RSS values that may be stored in a lookup table  82  shown in  FIG. 9  schematically and stored in the memory  58  of the microcontroller  54  (shown in  FIG. 5 ) as a table built per process blocks  76 . This lookup table  82  avoids the need for complex real-time calculations; however, such calculations can be a viable alternative to look up table storage. 
         [0079]    In one embodiment, the model is used to compute a look-up table that maps every location spot on 1 mm×1 mm grid into an RSS pair. At run-time, the program can look for the RSS pair that matches closely with its measured one, and then reverse it to a location spot. The error metric for matching can be either Euclidean distance or Manhattan distance. 
         [0080]    Each entry in the lookup table  82  includes a pair of measurements of RSS and are related to specific spatial locations x and y by a column and row of the table  82 , for example, each column and row representing a successive displacement by a given distance, for example, in absolute millimeters or m percentages of the size of the virtual touchscreen area  26 . 
         [0081]    Additional detail in one embodiment of building this table is described in the published paper “Extending Mobile Interaction through Near-Field Visible Light-sensing” by Chi Zhang, Joshua Tabor, Jialiang Zhang and Xinyu Zhang, publishing conjunction with MobiCom′15, Sep. 7-11 2015, Paris France ACM ISBN 978-1-4503-3543-0/15/09 DOI: http://dx.doi.org/10.1145/2789168.2790155 hereby incorporated in its entirety in the present application together with the references cited therein. 
         [0082]    It will also be appreciated that this model may be developed empirically by using a set of calibrated finger phantoms moved within the virtual touchscreen area  26  and the calibration process used to select among the different empirically developed submodels by a closest fit process. 
         [0083]    Referring again to  FIG. 6 , at process block  86  sensor signals are periodically acquired from the photodetectors  44   a  and  44   b  with activation of the light source  46 , and at decision block  88  the acquired signals are evaluated to determine whether a finger touch is present (that is the user&#39;s finger  24  newly arriving within the light-sensing plane  28 ). In the simplest embodiment, a finger touch may be determined by measurement signals that exceed a threshold  74  determined during calibration by a fixed given percentage. Other more sophisticated techniques such as the “Temporal Background Modeling” approach described in the above referenced paper may be used. 
         [0084]    If a finger touch is not detected, the program may proceed to process block  90  and the background level  74  updated in preparation for a next reading of sensor signals at process block  86 . If a finger touch is detected at decision block  88  then the values of the signals detected by the photodetectors  44   a  and  44   b  are applied to the table  82  to find a closest match and that closest match value mapped to x and y coordinates per process block  92 . 
         [0085]    At process block  94  this position information together with the implicit touch information of decision block  88  may be used in another application program (for example, by a touchscreen-emulating driver) to control the output on the graphics display screen  12  (shown in  FIG. 1 or 2 ), for example, by moving a cursor or moving an underlying image selecting among multiple virtual buttons displayed on the graphics display screen  12  or identifying a key of the virtual keyboard that has been pressed. Selection of a particular key may be determined, for example, through a two-step process in which a spatial location is determined per table  82  of  FIG. 9  and that spatial location identified to a closest key based on the keyboard&#39;s geometrical outline of each key. A keypress may be determined by a touch event occurring contemporaneously with the spatial location. 
         [0086]    Certain terminology is used herein for purposes of reference only, and thus is not intended to be limiting. For example, terms such as “upper”, “lower”, “above”, and “below” refer to directions in the drawings to which reference is made. Terms such as “front”, “back”, “rear”, “bottom” and “side”, describe the orientation of portions of the component within a consistent but arbitrary frame of reference which is made clear by reference to the text and the associated drawings describing the component under discussion. Such terminology may include the words specifically mentioned above, derivatives thereof, and words of similar import. Similarly, the terms “first”, “second” and other such numerical terms referring to structures do not imply a sequence or order unless clearly indicated by the context. 
         [0087]    The term orthogonal is intended to mean independent and is not limited to perpendicular coordinates but would include coordinates such as polar coordinates or the like. Non-transitory medium should be understood to exclude any program storage elements not meeting the statutory requirements of 35 USC §101. 
         [0088]    When introducing elements or features of the present disclosure and the exemplary embodiments, the articles “a”, “an”, “the” and “said” are intended to mean that there are one or more of such elements or features. The terms “comprising”, “including” and “having” are intended to be inclusive and mean that there may be additional elements or features other than those specifically noted. It is further to be understood that the method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed. 
         [0089]    It is specifically intended that the present invention not be limited to the embodiments and illustrations contained herein and the claims should be understood to include modified forms of those embodiments including portions of the embodiments and combinations of elements of different embodiments as come within the scope of the following claims. All of the publications described herein, including patents and non-patent publications, are hereby incorporated herein by reference in their entireties.