Abstract:
An intra oral dental device and method for recording the 3D envelope of motion of a patient and translating the recording into digital information used to diagnose, computer design and manufacture dental restorations. The dental device is comprised of upper and lower tracing members having tracing pins on one member and complementary recording material on the other. The method includes forming a set of intra oral gothic arch tracings to define the 3D envelope of motion, converting the tracings to a digital data set reproducing the motion, and using the data to create a virtual model of the patient and the jaw motion. The data is used to mill articulator housings to reproduce jaw motion, to virtually position and shape virtual teeth in conformity with the patient&#39;s jaw motion, and to mill the completed dental prosthesis insuring teeth contacting surfaces are in harmony with the patient&#39;s jaw motion.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This original non-provisional application claims priority to and the benefit of U.S. provisional application Ser. No. 61/962,017, filed Oct. 29, 2013, and entitled “Dental Apparatus and Method for the Digital Diagnosis, Computer Design and Manufacture of Dental Devices,” which is incorporated by reference herein. 
     
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0002]    None. 
       BACKGROUND OF THE INVENTION 
       [0003]    1. Field of the Invention 
         [0004]    This invention is related to dental recording devices, and more particularly to an intra oral dental recorder and related method for recording, scanning and digitizing the unique envelope of motion of a dental patient&#39;s jaw for use in the construction of dental devices. 
         [0005]    2. Description of the Related Art 
         [0006]    For over two hundred years, most if not all dental devices have been made by hand using artisan type manual labor. Recently, digital methods of imaging patients using cone-beam computed tomography (CBCT), laser, light and ultra sound scanning and contact digitizing have transformed the process of making these devices. Three dimensional computer numerical control milling and additive manufacturing technologies are used extensively in dentistry and it appears that almost all devices in the future will be manufactured using digital techniques. 
         [0007]    The human jaw is capable of complex motion because it is unique in that the mandible is rigidly attached to two moveable surfaces, or condyles. The movement of the jaw is not just a hinge motion; it can also have translation motion and rotation motion of the condyles in the glenoid fossae, the depression in the temporal bone that articulates with the condyles. This jaw motion is also constrained by ligaments, the meniscus and muscles. Due to these intricate factors, jaw motion is unique to each patient, and, as such, is complex and difficult to record and reproduce. These factors result in a unique three dimensional envelope of motion for any given patient. 
         [0008]    In prior art, intra oral tracing devices have been used to shape moldable material with scribing or tracing pins to create what is known as a gothic arch tracing. A set of at least three such gothic arch tracings can accurately describe the unique three dimensional envelope of movement of a specific patient. These tracings were then used to mold material contacting the condylar surfaces of an articulator or to mold material on other types of cast holding devices to reproduce the patient&#39;s movement. With the advent of digital manufacturing, a physical articulator is not needed but accurate digital recording of a patient&#39;s jaw movement is. 
         [0009]    Several new companies have developed processes to manufacture dentures using milling or additive manufacturing. However, a simple and cost effective method of recording jaw motion and a method of translating that recording into useful digital data have not yet been developed. All present digital recording devices are complex, expensive and do not allow for direct use in the digital manufacture of dental devices, such as dentures. There is a need for an economical device and method that faithfully and digitally records the position of the upper and lower impressions made with traditional impression materials or digital impressions (scans) of the patient and records the movement of the mandible and its neuro-muscular influences in a digital form. 
       BRIEF SUMMARY OF THE INVENTION 
       [0010]    The present invention is an intra oral gothic arch tracing and dental motion recording device and method for recording the three dimensional envelope of motion of a patient and translating the recording into digital information which is used to diagnose, computer design and manufacture dental restorations. The dental device is comprised of upper and lower gothic arch tracing members having scribing or tracing pins on one member and complementary recording material on the other. The method includes forming a set of intra oral gothic arch tracings to define the three dimensional envelope of motion, converting the tracings to a digital data set that faithfully reproduces that motion, and using the data to create a virtual model of the patient and the jaw motion of the patient for constructing dentures. The data may also be used to mill articulator housings to faithfully reproduce jaw motion and to virtually position virtual teeth and shape them in conformity with the patient&#39;s jaw motion. The data can also be used to mill the completed dental prosthesis to insure the contacting surfaces of the teeth are in harmony with the patient&#39;s jaw motion. 
         [0011]    It is an object of this invention to provide an improved method for constructing dentures. 
         [0012]    It is another object of this invention to provide an improved apparatus for constructing dentures, including an intra oral tracing apparatus. 
         [0013]    It is yet another object of this invention to provide a method and apparatus for constructing dentures, wherein movements of the jaw can be recorded and translated into digital data that identically reproduces that movement. 
         [0014]    It is yet another object of this invention to provide a method and apparatus to join digital scan data from different scanning devices and systems to create a virtual computer model of the patient. 
         [0015]    It is yet another object of this invention to use the digital data of a patient&#39;s jaw motion to mill condylar housings for a simple condylar articulator whereby the movement of the articulator may be confined to the envelope of motion, i.e., movement of the lower jaw as recorded in the sagittal (or vertical) and horizontal planes, of the patient. 
         [0016]    It is yet another object of this invention to use the digital data about a patient&#39;s jaw motion to create a virtual upper and lower model of a patient&#39;s jaw that moves in an identical manner as the patient&#39;s jaw recording and to set virtual teeth to create a digital denture in harmony with the patient&#39;s jaw motion. 
         [0017]    It is yet another object of this invention to digitally mill the surfaces of manufactured dentures such that the teeth are in harmony with the patient&#39;s jaw movement and the type of contacting occlusal relationship indicated for the patient. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         [0018]      FIG. 1  is a top view of the lower gothic arch tracing member of the present invention. 
           [0019]      FIG. 2  is a bottom view of the upper gothic arch tracing member of the present invention. 
           [0020]      FIG. 3  is a rear elevated view of the intra oral gothic arch dental motion recording device of the present invention showing upper and lower gothic arch tracing members in an opposing complementary configuration. 
           [0021]      FIG. 4  is an occlusal view of the lower gothic arch tracing member of  FIG. 1  with recording material and illustrating the gothic arch tracings. The lower handle has been removed. 
           [0022]      FIG. 5  shows an occlusal view of a single anterior gothic arch tracing from  FIG. 4  made on the lower gothic arch tracing member. 
           [0023]      FIG. 6  depicts the upper and lower gothic arch tracing members of the present invention in centric relation and the digital scans made therefrom. 
           [0024]      FIG. 7  is a flow chart of the method of the present invention for recording jaw motion and scanning the tracing members. 
           [0025]      FIG. 8A  depicts an anterior gothic arch digital scan of the present invention in an .stl format. 
           [0026]      FIG. 8B  is a cross sectional view of  FIG. 8A  illustrating the channel created by the tracing pin of the present invention in an .stl format. 
           [0027]      FIG. 9  depicts the three gothic arch tracings of  FIG. 4  from the .stl scan of the lower gothic arch tracing member of the present invention. 
           [0028]      FIG. 10  is an occlusal view of upper virtual teeth set in relation to the virtual upper impression of the present invention. 
           [0029]      FIG. 11  is an occlusal view of a mandibular molar denture tooth. 
           [0030]      FIG. 12  is a perspective view of a dental articulator. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0031]    An intra oral gothic arch dental motion recording device  10  according to the present invention is comprised of lower gothic arch tracing member  12  and upper gothic arch tracing member  16 , as shown in  FIGS. 1 and 2 . Referring now to  FIG. 1 , lower gothic arch tracing member  12  has handle  20  removably attached to lower tray  15 . Handle  20  can be used to ideally position lower gothic arch tracing member  12  in a patient&#39;s mouth (not shown). Dental impression material  13  (see  FIG. 3 ) is placed in lower tray  15  and positioned over the lower soft tissues and teeth to retain lower gothic arch tracing member  12  and to record the shape of the lower teeth and tissue. Dental impression material  13  may be polyvinyl siloxane or other suitable material. Handle  20  can easily be removed, if necessary. 
         [0032]    Lower gothic arch tracing member  12  has at least three receiving areas  22  at various locations on and within lower tray  15 . Receiving areas  22  are depressions or recesses within lower tray  15  for the placement of recording material  18  (see  FIG. 4 ). Threaded post  21  is centrally located within and traverses lower tray  15 . Threaded post  21  can be moved up or down to record movement at the correct amount of jaw opening which has previously been determined. At least three radiographic fiducial markers  40  are attached to lower tray  15  at locations adjacent to receiving areas  22 . 
         [0033]    Referring now to  FIG. 2 , upper tray  17  of upper gothic arch tracing member  16  has contact plate  24  which contacts threaded post  21  when upper tray  17  is in the mouth (not shown). The configuration of contact plate  24  may be flat, curved or arched and still be within the contemplated invention. Upper handle  23  removably attached to and extending distally from upper tray  17  is used to position upper tray  17  in the mouth (not shown) with dental impression material  13  to stabilize upper gothic arch tracing member  16  and to record the shape of the upper tissue or teeth. 
         [0034]    Three or more scribing or tracing pins  25  are rigidly attached to upper tray  17  in a triangular configuration. For example, one tracing pin may be located at an anterior position of the mouth while the other two tracing pins are located at posterior positions on either side of the mouth. The plurality of tracing pins  25  are used to cut and shape recording material  18  located on lower intra oral gothic arch tracing member  12  (see  FIG. 4 ) to record the three dimensional border movements, i.e., envelope of motion, of the patient&#39;s mandible. 
         [0035]    In the preferred embodiment, threaded pin  21  is on lower tray  15  and contact plate  24  on upper tray  17 . However, the two components (i.e., threaded pin  21  and contact plate  24 ) can be reversed such that threaded pin  21  is on upper tray  17  and contact plate  24  is on lower tray  15 , if preferred. The same is true for tracing pins  25  and receiving areas  22 . In the preferred embodiment, tracing pins  25  are on upper tray  17  and receiving areas  22  on lower tray  15  but the positions can be reversed with receiving areas  22  on upper tray  17  and tracing pins  25  on lower tray  15 . Finally, radiographic fiducial markers  40  are located on lower tray  15  but can also be on upper tray  17  to accomplish the same purpose. 
         [0036]    Fiducial markers  40  have a shape, e.g., round, that can be precisely located in a digital scan of lower gothic arch tracing member  12  with light, laser, cone-beam computed tomography (CBCT) or contact digitizing. Only fiducial markers  40  are radiolucent and will be detected with radiographic imaging. The remaining portions of upper gothic arch tracing member  16  and lower gothic arch tracing member  12  of intra oral gothic arch dental motion recording device  10  are radiolucent and will not distort radiographic images. In the preferred embodiment, intra oral gothic arch dental motion recording device  10  is made of a radiolucent plastic, such as carbon fiber or other similar material. 
         [0037]      FIG. 3  is a rear view of intra oral gothic arch dental motion recording device  10  illustrating how upper and lower gothic arch tracing members  12 ,  16  would appear and be aligned relative to each other in the mouth. Upper gothic arch tracing member  16  and lower gothic arch tracing member  12  are aligned in centric position relation with respect to each other. Centric relation is the position of the mandible in relation to the maxilla when the condyles are situated as far anteriorly and superiorly as possible within the glenoid fossa. At centric relation, the condyles are both simultaneously seated most superiority in their respective glenoid fossa. 
         [0038]    Upper tray  17  of upper gothic arch tracing member  16  is stabilized in the mouth with impression material  13 , such as polyvinyl siloxane or other suitable material, that conforms to and records the shape of the upper oral tissue. 
         [0039]    Contact plate  24  provides a vertical stop for threaded post  21  at the proper vertical dimension of occlusion (VDO) for any given patient. At the proper VDO, the patent&#39;s teeth are in maximum intercuspation, i.e., where the cusps of the teeth of both the top set and the bottom set of teeth are fully interposed with each other. Adjustments in the vertical contact position may be made by turning threaded post  21  in a manner similar to turning a screw. For example, turning threaded post  21  in a clockwise direction extends threaded post  21  further from lower tray  15 , expanding the distance between upper gothic arch tracing member  16  and lower gothic arch tracing member  12 . Conversely, rotating threaded post  21  in a counterclockwise rotation minimizes the distance between upper gothic arch tracing member  16  and lower gothic arch tracing member  12 . 
         [0040]    Lower tray  15  of lower gothic arch tracing member  12  is also stabilized with impression material  13  which conforms to and records the shape of the lower oral tissues. Upper tracing pins  25  capture the right lateral, left lateral and protrusive mandibular movements, i.e., envelope of motion, in recording material  18 . Recording material  18  is applied at the same locations where receiving areas  22  (not shown) are located (see  FIG. 1 ). Recording material  18  may be methyl-methacrylate resin, dental modeling compound, plaster, wax, light curable composite or any other suitable recording material. 
         [0041]    Intra oral gothic arch dental motion recording device  10  of the present invention is universally sized, e.g., small, medium and large, to accommodate and be used with patients of various ages and sizes from children to adults. 
         [0042]    In a procedure well known in the dental art, the patient is guided in mandibular movements to cut border movements in the recording material. When the dental professional, e.g., a dentist, is guiding the patient in this procedure, the patient is asked to move the jaw forward and backward, as well as to the left and to the right. The result is a gothic arch tracing with the centric relation position at the apex of the gothic arch tracing. It is useful in the process of making dentures to record this centric position by requesting the patient to move back until the apex position is reproduced and a locking material  14 , such as polyvinyl siloxane or other similar bite registration material, is injected into space  29  between upper contact plate  24  and lower threaded post  21 , as shown in  FIGS. 3 and 6 . 
         [0043]    In the preferred embodiment, the patient can have a CBCT scan made with upper gothic arch tracing member  16  and lower gothic arch tracing member  12  locked in this centric position (see  FIG. 6 ). Radiographic fiducial markers  40  can then be located in the CBCT scan as well as in the scanning of upper and lower gothic arch tracing members  12 ,  16  out of the mouth. This makes it possible to join data from the CT scan with the jaw movement recording of upper and lower gothic arch tracing members  12 ,  16 . 
         [0044]      FIG. 4  is a top occlusal view of lower gothic arch tracing member  12  illustrating anterior gothic arch tracing  19   a , right posterior gothic arch tracing  19   b , and left posterior gothic arch tracing  19   c  cut into recording material  18 . Each gothic arch tracing  19   a - c  has an arrowhead shape with the apex being the centric relation position. These gothic arch tracings  19   a - c  are cut into recording material  18  by tracing pins  25  (see  FIGS. 2 and 3 ) and have a complex three dimensional shape that reflects the precise border and protrusive movements of the mandible. 
         [0045]      FIG. 5  is a top view of anterior gothic arch tracing  19   a  cut into recording material  18 . Centric relation point  34  is located at the point where the individual mandibular movements making up the envelope of motion converge, i.e., the apex of the protrusive  28 , right lateral  26  and left lateral  27  movements. 
         [0046]      FIG. 6  illustrates the steps in scanning the tracing members. Physical combination  43  of upper and lower gothic arch tracing members  16 ,  12 —which are locked in centric position using locking material  14 —of intra oral gothic arch dental motion recording device  10  is first scanned (noted by solid arrow  108  pointing right) with contact, CT, laser or light to produce accurate three dimensional digital images (e.g., .stl file) of upper tissue surface  104  from impression material  13  (resulting in virtual upper impression  41 ) and lower tissue surface  106  from impression material  13  (resulting in virtual lower impression  42 ) in centric relation. Various light scanners from, for example, 3Shape, Dental Wings, and MEDIT are commercially available to perform the scan. In additional, other commercially available scanners may also be used. 
         [0047]    Upper gothic arch tracing member  16  from physical combination  43  is then separated and scanned (noted by solid arrow  110  pointing up) separately to create a three dimensional digital image (e.g., .stl file) of upper tissue surface  104  from upper impression material  13  and occlusal surface  100  with tracing pins  25 , resulting in virtual upper tissue surface  44 . Lower gothic arch tracing member  12  from physical combination  43  is also separated and scanned (noted by solid arrow  112  pointing down) to create a three dimensional digital image (e.g., .stl file) of lower tissue surface  106  from lower impression material  13  and occlusal surface  102 , resulting in virtual lower tissue surface  45 , including fiducial markers  40 , threaded post  21 , and the plurality of gothic arch tracings  19   a - c . Once scanning is complete, intra oral gothic arch dental motion recording device  10  is no longer needed and may be discarded. 
         [0048]    Referring now to  FIG. 7 , flow diagram  300  of the method of the present invention is provided illustrating the steps used to record jaw motion and to scan lower gothic arch tracing member  12  and upper gothic arch tracing member  16  of intra oral gothic arch dental motion recording device  10 . Beginning with step  302 , the dental professional inserts upper and lower gothic arch tracing members  16 ,  12  with impression material  13  in the patient&#39;s mouth. The height of threaded post  21  is set to proper vertical dimension of occlusion in step  304 . Proper spacing for tracing pins  25  is checked and recording material  18  is added to lower tray  15 , as indicated in step  306 . The dental professional then guides the patient through protrusive, right lateral and left lateral jaw movements while recording same in step  308 . Once the envelope of motion has been recorded, the dental professional then guides the patient into placing the patient&#39;s jaw into centric relation position. The dental professional then proceeds to inject locking material  14  between the upper and lower gothic tracing members  12 ,  16 , as indicated in step  310 . A cone-beam computed tomography scan is made, if indicated, in step  312 . The dental professional then sends the upper and lower gothic tracing members  12 ,  16  and locking material  14  to a proper facility, such as a laboratory, to be scanned, as indicated in step  314 . The upper and lower gothic tracing members  12 ,  16  are then scanned together in centric relation and then scanned separately to create 3D digital data files (see  FIG. 6 ), as indicated in step  316 . 
         [0049]      FIG. 8A  is an .stl image and digital scan  30  of anterior gothic arch  19   a .  FIG. 8B  is a cross sectional view and .stl image  116  of channel  114  within anterior gothic arch  19   a —across  116 - 116  of FIG.  8 A—created by tracing pin  25  (see  FIG. 2 ) in recording material  18  (see  FIG. 4 ). In  FIG. 8B , .stl image  116  is cut in a cross section along the x-axis to view the .stl file (.stl image  116 ) which describes raw unstructured triangulated surface  118  by the unit normal and vertices (ordered by the right-hand rule) of the triangles using a three-dimensional Cartesian coordinate system. Simple mathematical algorithms can sort all triangle vertices to select only the lowest points, such as low point  31 , which describe the path of tracing pin  25  through recording material  18 . Simple mathematical algorithms can also sort and use the low points, e.g., low point  31 , in channel  114  to create a polyline or spline of the path of the tracing pin in the recording material.  FIG. 8A  illustrates 3D splines  32  of anterior gothic arch tracing  19   a.    
         [0050]    The gothic arch tracing process can very accurately record jaw movement but the exact timing is not known. However, the starting point and the end point of each movement are known. For example, referring to  FIG. 8A , centric relation point  34  is the common starting point for all three mandibular movements (i.e., protrusive, right lateral and left lateral). End point  35  is the end point of the movements, though the end point will be at different locations for each movement. 
         [0051]      FIG. 9  illustrates the three gothic arch tracings  19   a - c  showing right lateral movement  33  created by tracing pin  25  (see  FIG. 2 ) in recording material  18  (see  FIG. 4 ). These three gothic arch tracings  19   a - c  are from the .stl scan of lower gothic arch tracing member  12 . To illustrate the method of the present invention for using scan data to digitally record movement and to create a virtual computer model of the patient, right lateral movement  33  in  FIG. 9  will be used for illustration purposes. However, the same process may be used for the protrusive and left lateral movements. 
         [0052]    Many methods are used in computer science to move one virtual object in relation to another. Since three points define any object in space, they can be used in computer-aided design (CAD) software to move an object in computer space to another position in computer space precisely. 
         [0053]    Still referring to  FIG. 9 , the splines of right lateral movement  33  for each of anterior gothic arch splines A, right posterior gothic arch splines B and left posterior gothic arch splines C are all of a different length. An excellent estimate of the position of the tracing pin along each of right lateral splines A, B, C can be obtained by bisecting each spline and locating midpoint  36  along the spline. This process of mathematically dividing the spline proportionally will generate Cartesian coordinate points to correctly move the virtual upper and lower impressions in computer space. This process may also be used to move virtual denture teeth to reproduce the motion that exists in the patient. This process may further still be used to mill manufactured dentures to be in conformity with a given patient jaw motion. 
         [0054]    Still referring to  FIG. 9 , three gothic arch tracings corresponding to various locations within the patient&#39;s jaw are shown. Centric positions  34  of anterior gothic arch tracing A, right posterior gothic arch tracing B and left posterior gothic arch tracing C—i.e., three points—define the position of virtual upper impression  41  in relation to virtual lower impression  42  (see  FIG. 6 ). To find the position of virtual upper impression  41  in relation to virtual lower impression  42  at the middle of right lateral movement or tracing  33 , centric points  34  at anterior gothic arch tracing A, right posterior gothic arch tracing B and left posterior gothic arch tracing C may be used to make virtual upper impression  41  move from centric points  34  to bisector points  33  of anterior gothic arch tracing A, right posterior gothic arch tracing B and left posterior gothic arch tracing C. If end points  35  of anterior gothic arch tracing A, right posterior gothic arch tracing B and left posterior gothic arch tracing C—i.e., three points—are used to make virtual centric points  34  and virtual upper impression  41  move in computer space to a new position, the movement of the upper jaw to the end of the right lateral recording or movement  33  will be faithfully reproduced. 
         [0055]    Simple moves from centric point  34 , bisector point  33 , and end point  35  have been used to illustrate the method of precisely creating virtual movement of the jaws in computer space. If the splines are divided further into smaller proportional divisions such as ¼, ⅙, 1/50 or 1/100 of the spline, then an even more accurate record of virtual movement may be made. If needed, the points (XYZ) can be translated into data as a sequence of six (6) degrees of freedom (X, Y, Z translations, and Rx, Ry, Rz Euler angles) as measured at some specific point on the mandible or maxillae. 
         [0056]      FIG. 10  is an occlusal view (i.e., toward the biting surface of posterior teeth) of upper virtual teeth set  120  in relation to virtual upper impression  41  (not shown). Virtual teeth  37  are set in centric relation position in relation to virtual lower impression  42  (not shown). Virtual teeth  38  have been moved in computer space to the bisected position along the right lateral spline. Virtual teeth  39  represent a virtual move of the teeth and virtual upper impression  41  to the end of the right lateral spline. 
         [0057]    The arrows in  FIG. 10  represent the direction of movement in the occlusal view, demonstrating that though the teeth travel together the same distance, the teeth do not necessarily travel in the same direction. This recording of movement can also be used to precisely refine the occlusal contacts (i.e., contacts between the upper and lower teeth when the jaw is in a closed position) of the digitally manufactured dentures. 
         [0058]    Teeth that are used in the manufacture of dentures have predetermined contours and contact relationships that may not be in harmony with the patient&#39;s jaw movement. Frequently, in the construction of dentures, it is necessary to have the denture teeth contact in a lingualized relationship with bilateral balance.  FIG. 11  illustrates a left mandibular molar denture tooth  46 . Upper lingual cusp  47  fits properly in the central fossae of lower left mandibular molar denture tooth  46  but has protrusive  48 , right lateral  49  and left lateral  50  interferences when the mandible moves in these border motion positions that have been measured using the dental motion recording device of the present invention. By using the digital information obtained from the dental motion recording device of the present invention, the interferences can be removed using a number controlled mill to create bilateral balance in the molar occlusal relationship. The same process can be used to mill all the teeth in the processed denture to create bilateral balance or any other type of occlusal relationship. 
         [0059]    Referring now to  FIG. 12 , a typical arcon type semi-adjustable articulator  122  used in dentistry is shown. Articulator  122  is called “semi-adjustable” because this type of articulator cannot follow a patient&#39;s jaw motion but is an approximation to that movement. The present invention provides an inexpensive method of reproducing a patient&#39;s exact jaw movement by milling  58  the condylar housing  51  to allow condylar ball  52  of articulator  122  to travel in the same motion as the patient. It is also possible to mill anterior pin stop  57  such that incisal pin  59  of articulator  122  travels along a milled surface that has protrusive contour  54 , right lateral contour  55 , and left lateral contour  56  that will reproduce the exact movement of the patient&#39;s jaw. 
         [0060]    The various embodiments described herein may be used singularly or in conjunction with other similar devices. The present disclosure includes preferred or illustrative embodiments of specifically described apparatuses, assemblies, methods and systems. Alternative embodiments of such apparatuses, assemblies, methods and systems can be used in carrying out the invention as claimed and such alternative embodiments are limited only by the claims themselves. Other aspects and advantages of the present invention may be obtained from a study of this disclosure and the drawings, along with the appended claims.