Abstract:
The invention includes a universal transvalvular insertion tool for providing a passage through a multiplicity of differently designed hemostatically valved introducers, each having a valve within a valved body coupled to a cardiac introducer. The tool includes a longitudinally rigid sheath having a lumen and for insertion through the valve of any one of the multiplicity of differently designed hemostatically valved introducers to provide a substantially obstruction free path for delivery of a lead or vascular device through the valve and valved body to the introducer, the sheath having a length selected to extend through the valve without substantial deformation of the lumen of the sheath. A mechanism is provided for separating the rigid sheath to allow removal from the lead or device without removal of the transvalvular insertion tool over either end of the lead or vascular device.

Description:
RELATED APPLICATIONS 
       [0001]    The present application is related to U.S. Provisional Patent Application Ser. No. 61/638,321, filed on Apr. 25, 2012, which is incorporated herein by reference and to which priority is claimed pursuant to 35 USC 119. 
     
    
     BACKGROUND 
       [0002]    1. Field of the Technology 
         [0003]    The disclosure relates to the field of accessories for use with hemostatic cardiac introducers. 
         [0004]    2. Description of the Prior Art 
         [0005]    Prior art Trans-Valvular Insertion (TVI) tools, are typically comprised of peel-away sheaths with a splitting means on the proximal end of the tool as shown in  FIG. 1 . The tool is configured to be inserted into a hemostatic valve. The hemostatic valve is comprised of a splittable valve body and a splittable or peel-away introducer sheath. The sheath peels apart on lines of weakness along its longitudinal length. The valve body is usually rigid and the sheath is a softer material attached to the valve body, both having some means of splitting in half. Inside the valve body is a membrane with a slit, which is normally closed and fluid tight. A tool or pacemaker lead is inserted through the slit in the membrane in the valve body and through the introducer connected to the distal end of the valve body to be delivered to a location in the heart. 
         [0006]    Once the tool or lead is located in the heart, the introducer is pulled out of the vascular system and the introducer and hemostatic valve body are split apart and pulled off the lead. The lead&#39;s proximal connector, which is too large to fit through the introducer or valve, is connected to the pacemaker, which is then inserted into a subdermal chest pocket surgically created in the chest muscles. 
         [0007]    The membrane seals on the lead and prevents air embolism. The embodiment shown in the upper portion of  FIG. 1  is simply a peel-away sheath that has been partially split on its proximal end. The embodiment below is a peel away sheath with a pair of rigid plastic handles bonded to the proximal end of the sheath. The purpose of the TVI tool is to facilitate insertion of the pacemaker lead, which can be quite flexible or delicate, through the membrane valve and valve body. The TVI tool is inserted through the membrane in the valve body to open it to allow a lead to be placed through the membrane without damage to the lead. Some leads have delicate wiring coils or coatings on their exterior that are damaged if forced through the membrane in the process of being introduced through the introducer into the heart or when being pulled back through the membrane. 
         [0008]    Since the introduction of the first splittable hemostatic introducer by Pressure Products Medical Supplies Inc., namely the SafeSheath, and the expiration of the patents thereon, there have arisen now many different designs for different kinds of splittable hemostatic introducers and valves on the market. The various designs are typically differentiated from each other in the details of their internal dimensions and relative placement of the valve with respect to other portions of the hemostatic valve assembly. As a result, the prior art TVI tools in  FIG. 1  may be unusable in many hemostatic introducers, i.e. the TVI tool bottoms out in the valve body, distorts and otherwise pinches or frictionally engages the cardiac tool or lead disposed through the introducer. The distal end of the TVI tool contacts the transition between the introducer and bottom of the valve body and is crushed, bent, closed or otherwise impeded, because the TVI tool no longer “fits” the design or dimensions of each different kind of hemostatic valved introducer. As a result, a lead then placed through the TVI tool is blocked or damaged when forced through the distorted TVI tool. 
         [0009]    Ye et. al. U.S. Pat. No. 7,993,305, incorporated herein by reference, is directed to a splittable valved introducer apparatus that is designed to introduce a medical device such as a lead or catheter into a patient&#39;s vasculature. FIGS. 1 and 2 in Ye explicitly depict the SafeSheath. Furthermore, the introducer assembly is designed to separate easily without disrupting the placement of the medical device during the removal of the introducer. Referring to FIG. 3 et. seq. in Ye, the valved introducer assembly 100 comprises a sheath 102 connected to a valve housing 104 with valve membrane 106. The longitudinal sheath 102 extends into the valve housing 104 while the lumen 110 allows for a medical device such as a lead or catheter to be advanced through the assembly 103. The valve housing 104 has spaced apart wings 112 and 114. 
         [0010]    The proximal sheath section 102B includes perforations 166 which help propagate splitting of the sheath 102. Once the lead or catheter is properly positioned, the valve introducer assembly 100 is split apart for removal from the vasculature. The valve housing 104 including the valve membrane 106 are then separated along score lines 138 running along the lower valve body 104A and the valve cap 104B. 
         [0011]    Helgeson et. al. U.S. Pat. No. 8,043,263 incorporated herein by reference, is directed to a splittable delivery device assembly for the delivery of a cardiac surgical device. The delivery or insertion tool also includes a hemostasis valve, both of which are splittable or could be removed after the cardiac surgical device of interest is introduced. Beginning with FIG. 9 et. seq. in Helgeson, the delivery device 10 may be a catheter or sheath 10 with shaft 20 including a lumen extending the length of the device 10 providing a passageway for a surgical device 5 to enter the body. After the device 5 has been introduced, the delivery device 10 is removed by means of slitting along its length. A hemostasis valve 25 may be integrated into the hub 15 and may be removed by slitting or a cap 30 may be used to retain the valve 25 within the hub 15. There is a transvalvular insertion tool 305 beginning in FIG. 9. 
         [0012]    Nardeo et. al., U.S. Pre-Grant Publication 2010/0292646 incorporated herein by reference, is directed to a tear away sheath assembly with split hemostasis valve seal. The assembly 100 has a splittable sheath 102 along with a splittable hub 110 and a split valve 150, 250. The valve 150, 250 is formed with two separate halves 152A and 152B that are fused or adhered to each other to form a sealed weak bond 154 that is broken during the splitting of the sheath. The tool may be used to insert a catheter as part of a medical procedure and once in place, the introducer along with the valve may be removed. 
         [0013]    Fisher et. al., U.S. Pat. No. 8,105,287 incorporated herein by reference, is directed to a tear away introducer sheath with hemostasis valve. Referring the figures, the catheter introducer sheath assembly 100 comprises a sheath portion 132 with a tear seam defined along the length of sheath 132 and indicated by score lines 130. Score lines 130 allow the sheath portion 132 to be split apart after the catheter (not shown) has been inserted and in place. The sheath hub portion 140 consists of two half-portions 142 and affixed to the sheath portions on each side of the tear seam 130. The sheath hub 140 may include a valve 300 and is sectioned along a plane perpendicular to the plane of separation of the sheath hub as seen in FIGS. 4 and 5 of Fisher. 
         [0014]    Potter et. al., U.S. Pat. No. 7,985,232 incorporated herein by reference, is directed to a detachable hemostasis valve and splittable sheath assembly and provides an alternative to the systems described above but intended to accomplish the same ends. The hemostasis valve is connected to a splittable sheath and when the handles are pulled to split the sheath, the valve is disengaged from the sheath assembly. The coupling system for the hemostasis device 70 and the splittable sheath 100 is seen in FIGS. 1-4 of Potter and includes a valve housing 90. A tool provides for the introduction of a lead or guide wire as well as a dilator or catheter to be inserted into the hemostasis device 70 and splittable sheath 100 for delivery to a particular site in a medical procedure. 
         [0015]    Johnson et. al. U.S. Pat. No. 8,105,315 incorporated herein by reference, is noted for showing an example of a bypass tool, called an actuator 50. 
         [0016]    The prior art designs for splittable valved introducers do not address the problems arising from friction between the valve and intravascular tools, particularly pliable or soft intravascular instruments. What is needed is a universal TVI tool, which is configured to be inserted into a valved introducer to open the hemostasis valve of the introducer and allow an unobstructed passage for a delicate pacing or defibrillator lead or other instrument. 
       BRIEF SUMMARY 
       [0017]    The illustrated embodiments are directed to a transvalvular insertion tool for providing a passage through a hemostatically valved introducer. The tool includes at least one tab, a hub coupled to the tab, a longitudinally rigid sheath for insertion through the valved introducer to provide an obstruction free path for delivery of a lead or vascular device through the valved introducer, and means for separating the hub and rigid sheath to allow removal from the lead or device without removal of the transvalvular insertion tool over either end of the lead or vascular device. 
         [0018]    The means for separating includes longitudinal halves of the rigid sheath and a temporary mechanical coupling for selectively retaining the longitudinal halves together. 
         [0019]    In one embodiment the means for separating includes a longitudinal line of separation of the rigid sheath and a clam-shell mechanism for spreading the longitudinal line of separation of the rigid sheath apart to selectively create a longitudinal gap in the rigid sheath. 
         [0020]    In another embodiment the means for separating includes a longitudinal line of weakness of the rigid sheath. The rigid sheath includes an external stop positioned between the hub and distal end of the sheath. 
         [0021]    The illustrated embodiments of the invention are directed to a universal transvalvular insertion tool for providing a passage through a multiplicity of differently designed hemostatically valved introducers for a lead or vascular device, each valved introducer having a valve within a valved body. The tool includes a longitudinally rigid sheath having a lumen for insertion through the valve of any one of the multiplicity of differently designed hemostatically valved introducers to provide a substantially obstruction free path for delivery of a lead or vascular device through the valve and valved body of each of the valved introducers. The rigid sheath has a length selected to extend through the valve without substantial deformation of the lumen of the rigid sheath. Means for separating the rigid sheath allows removal from the lead or device without removal of the transvalvular insertion tool over either end of the lead or vascular device. 
         [0022]    The tool further includes a hemostatic introducer to provide a kit. 
         [0023]    In one embodiment the sheath and/or hub separate into two equal halves. 
         [0024]    In one embodiment the hub and/or sheath includes a living hinge that separates into two connected equal halves. A living hinge is a thin flexible hinge (flexure bearing) made from the same material as the two rigid pieces it connects, rather than cloth, leather, or some other flexible substance. It is typically thinned or cut to allow the rigid pieces to bend along the line of the hinge. 
         [0025]    In one embodiment the hub and/or sheath is arranged and configured to be separated and put back together with or without an intravascular tool being inserted therethrough at the time of recombination for indefinite repeated usage on each instance of application if desired. 
         [0026]    In one embodiment the hub and/or sheath has a plurality of interlocking angled projections along the sheath to prevent the sheath halves from becoming misaligned from forces exerted thereon by the valved introducers. 
         [0027]    The sheath and/or hub includes a sealing member or gasket between the halves of sheath and/or hub that seals the halves to each other when assembled, which sealing member or gasket is softer than the halves of the sheath and/or hub. 
         [0028]    The sheath need only be rigid to the extent that the sheath will not deform when the distal end of the sheath stops against the inside of the introducer valve housing. 
         [0029]    The tool is arranged and configured to be used in conjunction with any valved introducer to provide a separable unobstructed conduit through the valve. 
         [0030]    The rigid sheath is arranged and configured to bottom out on the valved body, which allows a user to be instructed or directed to push the tool through the valve until it stops. 
         [0031]    The means for separating the rigid sheath and/or hub to allow removal from the lead or device without removal of the transvalvular insertion tool over either end of the lead or vascular device further includes means for allowing reassembly of the transvalvular insertion tool. 
         [0032]    In one embodiment the sheath and/or hub has two opposing portions and the means for separating and allowing reassembly includes fingers with an interference fit into a mating indentation in the opposing hub sheath and/or sheath portions. 
         [0033]    In one embodiment the hub has two opposing portions and the means for separating and allowing reassembly includes a snap peg and hole combination for coupling the two sheath and/or hub portions together. 
         [0034]    In one embodiment the means for separating and allowing reassembly includes a hinged clam shell mechanism having tabs and an opening on an exterior surface of the hub opposing the tabs of the clam shell mechanism. 
         [0035]    In one embodiment the means for separating and allowing reassembly includes an insert disposed in the sheath and/or hub and a tongue and groove combination defined at least in part in the insert disposed in the sheath and/or hub. 
         [0036]    In one embodiment the means for separating and allowing reassembly includes a single split tab with an opposing resilient hub portion having a longitudinal slit and sheath defined inwardly at least in the hub between the split portions of the tab to provide a clam shell mechanism for opening the hub. 
         [0037]    In one embodiment the means for separating and allowing reassembly includes a plurality of snap interlaced fingers and recesses longitudinally defined in opposing portions of the sheath, and a tenon and mortise combination defined in an inner surface of the opposing hub portions. 
         [0038]    In one embodiment the means for separating and allowing reassembly includes a single tab and an opposing split cylinder portion forming the hub and sheath. 
         [0039]    In one embodiment the means for separating and allowing reassembly includes a one-way swing latch combination defined in an inner portion of the sheath and/or hub portions. 
         [0040]    In one embodiment the means for separating and allowing reassembly includes a resealable membrane combination disposed longitudinally along the hub and/or sheath. 
         [0041]    In one embodiment the means for separating and allowing reassembly includes a single tab having a half cylinder defined therein and an opposing half cylinder to form the hub and sheath and with a hinge on one side of the opposing half cylinder coupled to the tab and with a split defined opposing the hinge and extending longitudinally along the sheath. 
         [0042]    In one embodiment the means for separating and allowing reassembly includes a slidable, longitudinal tongue and groove combination defined in the hub and/or sheath. 
         [0043]    In one embodiment the means for separating and allowing reassembly includes a single tab and an opposing cylinder forming the hub and sheath with an open slot longitudinally defined therein and extending along the hub and sheath. 
         [0044]    In one embodiment the means for separating and allowing reassembly includes opposing portions of the hub having opposing sides and a snap finger and recess combination defined in the opposing sides of the sheath and/or hub. 
         [0045]    The illustrated embodiments also include a method of using a transvalvular insertion tool for providing a passage through a hemostatically valved introducer comprising the steps of inserting a longitudinally rigid sheath through the valved introducer to provide an obstruction free path for delivery of a lead or vascular device through the valved introducer, and separating the hub and rigid sheath to allow removal from the lead or device without removal of the transvalvular insertion tool over either end of the lead or vascular device. 
         [0046]    In one embodiment the step of inserting a longitudinally rigid sheath through the valved introducer is performed until the tool is stopped in the valved introducer. 
         [0047]    In one embodiment the method further includes reassembling the hub and sheath after use for a repeated use. 
         [0048]    While the apparatus and method has or will be described for the sake of grammatical fluidity with functional explanations, it is to be expressly understood that the claims, unless expressly formulated under 35 USC 112, are not to be construed as necessarily limited in any way by the construction of “means” or “steps” limitations, but are to be accorded the full scope of the meaning and equivalents of the definition provided by the claims under the judicial doctrine of equivalents, and in the case where the claims are expressly formulated under 35 USC 112 are to be accorded full statutory equivalents under 35 USC 112. The disclosure can be better visualized by turning now to the following drawings wherein like elements are referenced by like numerals. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0049]      FIG. 1  is a perspective view of two prior art TVI tools. 
           [0050]      FIG. 2   a  is a perspective view of one half of an snap-together embodiment of the invention, and  FIG. 2   b  is a perspective view of two halves of the type shown in  FIG. 2   a  combined to form a completed assembly. 
           [0051]      FIG. 3  is a perspective view of a one piece embodiment. 
           [0052]      FIG. 4   a  is a perspective view of a clam-shell embodiment shown in the closed configuration. 
           [0053]      FIG. 4   b  is a perspective view of a dam-shell embodiment shown in the open configuration. 
           [0054]      FIG. 5   a  is a perspective view in enlarged scale of the snap-together embodiment of  FIG. 2   a.    
           [0055]      FIG. 5   b  is a perspective view in enlarged scale of the snap-together embodiment of  FIG. 5   a  where the second half is combined to provide the complete assembly. 
           [0056]      FIG. 6   a  is a side cross-sectional exploded view of a snap peg-and-hole embodiment. 
           [0057]      FIG. 6   b  is a top plan exploded view of the embodiment of  FIG. 6   a.    
           [0058]      FIG. 6   c  is a side plan exploded view of the embodiment of  FIG. 6   a.    
           [0059]      FIG. 6   d  is a perspective exploded view of the embodiment of  FIG. 6   a.    
           [0060]      FIG. 6   e  is end plan view of the embodiment of  FIG. 6   a.    
           [0061]      FIG. 7   a  is a side cross-sectional unexploded view of a snap peg-and-hole embodiment. 
           [0062]      FIG. 7   b  is a top plan unexploded view of the embodiment of  FIG. 7   a.    
           [0063]      FIG. 7   c  is a side plan unexploded view of the embodiment of  FIG. 7   a.    
           [0064]      FIG. 7   d  is a perspective unexploded view of the embodiment of  FIG. 7   a.    
           [0065]      FIG. 7   e  is end plan view of a peg-and-hole embodiment of  FIG. 7   a.    
           [0066]      FIG. 8   a  is a top plan view of the embodiment of  FIGS. 4   a  and  4   b  in a dosed configuration. 
           [0067]      FIG. 8   b  is a side plan view of the embodiment of  FIGS. 4   a  and  4   b  in a closed configuration. 
           [0068]      FIG. 8   c  is a perspective view of the embodiment of  FIGS. 4   a  and  4   b  in a closed configuration. 
           [0069]      FIG. 8   d  is a side plan view of the embodiment of  FIGS. 4   a  and  4   b  in a closed configuration. 
           [0070]      FIG. 9   a  is a top plan view of the embodiment of  FIGS. 4   a  and  4   b  in an opened configuration. 
           [0071]      FIG. 9   b  is a side plan view of the embodiment of  FIGS. 4   a  and  4   b  in an opened configuration. 
           [0072]      FIG. 9   c  is a perspective view embodiment of  FIGS. 4   a  and  4   b  in an opened configuration. 
           [0073]      FIG. 9   d  is a side plan view embodiment of  FIGS. 4   a  and  4   b  in an opened configuration. 
           [0074]      FIG. 10   a  is a top plan view of an embodiment of the invention with a longitudinal tongue and groove defined in the hub shown in the separated configuration. 
           [0075]      FIG. 10   b  is a side plan view of the embodiment of the invention of  FIG. 10   a.    
           [0076]      FIG. 10   c  is a perspective view of the embodiment of the invention of  FIG. 10   a.    
           [0077]      FIG. 10   d  is a side plan view of an embodiment of the invention of  FIG. 10   a.    
           [0078]      FIG. 10   e  is an enlarged perspective view of the insert regional  10 - 10  of  FIG. 10   c.    
           [0079]      FIG. 11   a  is a top plan view of an embodiment of the invention with a tongue and groove structure defined in inserts in the hub shown in the dosed configuration. 
           [0080]      FIG. 11   b  is a side plan view of the embodiment of the invention of  FIG. 11   a.    
           [0081]      FIG. 11   c  is a perspective view of an embodiment of the invention of  FIG. 1   a.    
           [0082]      FIG. 11   d  is a side plan view of an embodiment of the invention of  FIG. 1   a.    
           [0083]      FIG. 11   e  is an enlarged perspective top plan view of the insert region  11 - 11  of  FIG. 11   c.    
           [0084]      FIG. 12   a  is a top plan view of an embodiment of the invention with a single split tab extending from a resilient cylindrical hinge defining one side of the hub shown in the dosed configuration. 
           [0085]      FIG. 12   b  is a side plan view of the embodiment of the invention of  FIG. 12   a.    
           [0086]      FIG. 12   c  is a perspective view of an embodiment of the invention of  FIG. 12   a.    
           [0087]      FIG. 12   d  is a side plan view of an embodiment of the invention of  FIG. 12   a.    
           [0088]      FIG. 13   a  is a top plan view of an embodiment of the invention with a single split tab extending from a resilient cylindrical hinge defining one side of the hub shown in an opened configuration. 
           [0089]      FIG. 13   b  is a side plan view of the embodiment of the invention of  FIG. 13   a.    
           [0090]      FIG. 13   c  is a perspective view of an embodiment of the invention of  FIG. 13   a.    
           [0091]      FIG. 13   d  is a side plan view of an embodiment of the invention of  FIG. 13   a.    
           [0092]      FIG. 14   a  is a top plan view of an embodiment of the invention with a plurality of interlaced snap-fit fingers or angled projections defined in the hub and down the longitudinal axis of the sheath shown in the closed configuration. 
           [0093]      FIG. 14   b  is a side plan view of the embodiment of the invention of  FIG. 14   a.    
           [0094]      FIG. 14   c  is a perspective view of the embodiment of the invention of  FIG. 14   a.    
           [0095]      FIG. 14   d  is a side plan view of the embodiment of the invention of  FIG. 14   a.    
           [0096]      FIG. 15   a  is a top plan view of one half of the hub and sheath of the embodiment of the invention of  FIGS. 14   a - 14   d  with a plurality of snap-fit fingers defined in the hub and down the longitudinal axis of the sheath. 
           [0097]      FIG. 15   b  is a side plan view of one half of the hub and sheath of the embodiment of the invention of  FIG. 15   a.    
           [0098]      FIG. 15   c  is a perspective view of one half of the hub and sheath of the embodiment of the invention of  FIG. 15   a.    
           [0099]      FIG. 15   d  is a side plan view of one half of the hub and sheath of the embodiment of the invention of  FIG. 15   a.    
           [0100]      FIG. 16   a  is a perspective view of the embodiments of  FIGS. 15   a - 16   d  shown in an exploded or fully separated view. 
           [0101]      FIG. 16   b  is an enlarged view of the portion of the embodiment in  FIG. 16   a  within insert region B. 
           [0102]      FIG. 16   c  is a perspective view of the embodiments of  FIGS. 15   a - 16   d  shown in a view where the portions have just begun to become engage or disengaged from each other. 
           [0103]      FIG. 16   d  is an enlarged view of the portion of the embodiment in  FIG. 16   c  within insert region C. 
           [0104]      FIG. 16   e  is a perspective view of the embodiments of  FIGS. 15   a - 16   d  shown in a fully assembled view. 
           [0105]      FIG. 16   f  is an enlarged view of the portion of the embodiment in  FIG. 16   e  within insert region D. 
           [0106]      FIG. 17   a  is a top plan view of an embodiment of the invention with a single tab extending from a separable cylinder defining one side of the hub shown in the closed configuration. 
           [0107]      FIG. 17   b  is a side plan view of the embodiment of the invention of  FIG. 17   a.    
           [0108]      FIG. 17   c  is a perspective view of an embodiment of the invention of  FIG. 17   a.    
           [0109]      FIG. 17   d  is a side plan view of an embodiment of the invention of  FIG. 17   a.    
           [0110]      FIG. 18   a  is a top plan view of an embodiment of the invention with a single tab extending from a separable cylinder defining one side of the hub shown with the cylinder separated along its longitudinal length. 
           [0111]      FIG. 18   b  is a side plan view of the embodiment of the invention of  FIG. 18   a.    
           [0112]      FIG. 18   c  is a perspective view of an embodiment of the invention of  FIG. 18   a.    
           [0113]      FIG. 18   d  is a side plan view of an embodiment of the invention of  FIG. 18   a.    
           [0114]      FIG. 19   a  is a side cross sectional view of an embodiment of the invention with a one way swing latch defined in the hub shown in a fully separated configuration. 
           [0115]      FIG. 19   b  is a top plan view of an embodiment of the invention of  FIG. 19   a.    
           [0116]      FIG. 19   c  is a side plan view of the embodiment of the invention of  FIG. 19   a.    
           [0117]      FIG. 19   d  is a perspective view of an embodiment of the invention of  FIG. 19   a.    
           [0118]      FIG. 19   e  is a side plan view of an embodiment of the invention of  FIG. 19   a.    
           [0119]      FIG. 20   a  is a side cross sectional view of an embodiment of the invention with a one way swing latch defined in the hub shown in a partially engaged configuration. 
           [0120]      FIG. 20   b  is a top plan view of an embodiment of the invention of  FIG. 20   a.    
           [0121]      FIG. 20   c  is a side plan view of the embodiment of the invention of  FIG. 20   a.    
           [0122]      FIG. 20   d  is a perspective view of an embodiment of the invention of  FIG. 20   a.    
           [0123]      FIG. 20   e  is a side plan view of an embodiment of the invention of  FIG. 20   a.    
           [0124]      FIG. 21   a  is a side cross sectional view of an embodiment of the invention with a one way swing latch defined in the hub shown in a fully assembled configuration. 
           [0125]      FIG. 21   b  is a top plan view of an embodiment of the invention of  FIG. 21   a.    
           [0126]      FIG. 21   c  is a side plan view of the embodiment of the invention of  FIG. 21   a.    
           [0127]      FIG. 21   d  is a perspective view of an embodiment of the invention of  FIG. 21   a.    
           [0128]      FIG. 21   e  is a side plan view of an embodiment of the invention of  FIG. 21   a.    
           [0129]      FIG. 22   a  is a top plan view of an embodiment of the invention with a longitudinal sealing or adhesive membrane defined through the hub and sheath shown in a fully unsealed configuration. 
           [0130]      FIG. 22   b  is a side plan view of the embodiment of the invention of  FIG. 22   a.    
           [0131]      FIG. 22   c  is a perspective view of an embodiment of the invention of  FIG. 22   a.    
           [0132]      FIG. 22   d  is a side plan view of an embodiment of the invention of  FIG. 22   a.    
           [0133]      FIG. 23   a  is a top plan view of an embodiment of the invention with a longitudinal sealing or adhesive membrane defined through the hub and sheath shown in a fully sealed configuration. 
           [0134]      FIG. 23   b  is a side plan view of the embodiment of the invention of  FIG. 23   a.    
           [0135]      FIG. 23   c  is a perspective view of an embodiment of the invention of  FIG. 23   a.    
           [0136]      FIG. 23   d  is a side plan view of an embodiment of the invention of  FIG. 23   a.    
           [0137]      FIG. 24   a  is a top plan view of an embodiment of the invention with a single tab extending from a cylinder defining one side of the hub, which cylinder is separable on one side edge of the cylinder or both shown in an attached configuration. 
           [0138]      FIG. 24   b  is a side plan view of the embodiment of the invention of  FIG. 24   a.    
           [0139]      FIG. 24   c  is a perspective view of an embodiment of the invention of  FIG. 24   a.    
           [0140]      FIG. 24   d  is a side plan view of an embodiment of the invention of  FIG. 24   a.    
           [0141]      FIG. 25   a  is a top plan view of an embodiment of the invention with a single tab extending from a cylinder defining one side of the hub, which cylinder is separable on one side edge of the cylinder or both shown in a detached configuration. 
           [0142]      FIG. 25   b  is a side plan view of the embodiment of the invention of  FIG. 25   a.    
           [0143]      FIG. 25   c  is a perspective view of an embodiment of the invention of  FIG. 25   a.    
           [0144]      FIG. 25   d  is a side plan view of an embodiment of the invention of  FIG. 25   a.    
           [0145]      FIG. 26   a  is a top plan view of an embodiment of the invention with a tongue and groove attachment longitudinally defined through the hub and sheath in which the two opposing portions longitudinally slide together and apart from each other and shown in a detached configuration. 
           [0146]      FIG. 26   b  is a side plan view of the embodiment of the invention of  FIG. 26   a.    
           [0147]      FIG. 26   c  is a perspective view of an embodiment of the invention of  FIG. 26   a.    
           [0148]      FIG. 26   d  is a side plan view of an embodiment of the invention of  FIG. 26   a.    
           [0149]      FIG. 26   e  is a top plan view in enlarged scale of the insert region A of  FIG. 26   a.    
           [0150]      FIG. 27   a  is a top plan view of an embodiment of the invention with a tongue and groove attachment longitudinally defined through the hub and sheath in which the two opposing portions longitudinally slide together and apart from each other and shown in a partially detached or partially assembled configuration. 
           [0151]      FIG. 27   b  is a side plan view of the embodiment of the invention of  FIG. 27   a.    
           [0152]      FIG. 27   c  is a perspective view of an embodiment of the invention of  FIG. 27   a.    
           [0153]      FIG. 27   d  is a side plan view of an embodiment of the invention of  FIG. 27   a.    
           [0154]      FIG. 27   e  is a top plan view in enlarged scale of the insert region A of  FIG. 27   a.    
           [0155]      FIG. 28   a  is a top plan view of an embodiment of the invention with a tongue and groove attachment longitudinally defined through the hub and sheath in which the two opposing portions longitudinally slide together and apart from each other and shown in a fully assembled configuration. 
           [0156]      FIG. 28   b  is a side plan view of the embodiment of the invention of  FIG. 28   a.    
           [0157]      FIG. 28   c  is a perspective view of an embodiment of the invention of  FIG. 28   a.    
           [0158]      FIG. 28   d  is a side plan view of an embodiment of the invention of  FIG. 28   a.    
           [0159]      FIG. 28   e  is a top plan view in enlarged scale of the insert region A of  FIG. 28   a.    
           [0160]      FIG. 29   a  is a top plan view of an embodiment of the invention with a single tab wherein an open slot is defined an opposing cylinder portion of the hub and continues longitudinally along the longitudinal axis of the sheath. 
           [0161]      FIG. 29   b  is a side plan view of the embodiment of the invention of  FIG. 29   a.    
           [0162]      FIG. 29   c  is a perspective view of an embodiment of the invention of  FIG. 29   a.    
           [0163]      FIG. 29   d  is a side plan view of an embodiment of the invention of  FIG. 29   a.    
           [0164]      FIG. 30   a  is a top plan view of an embodiment of the invention with an opposing snap finger and mating recess is defined in the mid portion of the hub and shown in a separated configuration. 
           [0165]      FIG. 30   b  is a side plan view of the embodiment of the invention of  FIG. 30   a.    
           [0166]      FIG. 30   c  is a perspective view of an embodiment of the invention of  FIG. 30   a.    
           [0167]      FIG. 30   d  is a side plan view of an embodiment of the invention of  FIG. 30   a.    
           [0168]      FIG. 31   a  is a top plan view of an embodiment of the invention with an opposing snap finger and mating recess is defined in the mid portion of the hub and shown in a fully assembled configuration. 
           [0169]      FIG. 31   b  is a side plan view of the embodiment of the invention of  FIG. 31   a.    
           [0170]      FIG. 31   c  is a perspective view of an embodiment of the invention of  FIG. 31   a.    
           [0171]      FIG. 31   d  is a side plan view of an embodiment of the invention of  FIG. 31   a.    
           [0172]      FIG. 32   a  is a top plan view of an embodiment of the invention with an opposing line of weakness defined in the mid portion of the hub and shown in a fully assembled configuration. 
           [0173]      FIG. 32   b  is a side plan view of the embodiment of the invention of  FIG. 32   a.    
           [0174]      FIG. 32   c  is a perspective view of an embodiment of the invention of  FIG. 32   a.    
           [0175]      FIG. 32   d  is a side plan view of an embodiment of the invention of  FIG. 32   a.    
           [0176]      FIG. 32   e  is a cross sectional view of the embodiment of  FIG. 32   a.    
           [0177]      FIG. 33   a  is a top plan view of an embodiment of the invention with an opposing line of weakness defined in the mid portion of the hub and shown in a fully assembled configuration. 
           [0178]      FIG. 33   b  is a side plan view of the embodiment of the invention of  FIG. 33   a.    
           [0179]      FIG. 33   c  is a perspective view of an embodiment of the invention of  FIG. 33   a.    
           [0180]      FIG. 33   d  is a side plan view of an embodiment of the invention of  FIG. 33   a.    
           [0181]      FIG. 33   e  is a cross sectional view of the embodiment of  FIG. 33   a.    
       
    
    
       [0182]    The disclosure and its various embodiments can now be better understood by turning to the following detailed description of the preferred embodiments which are presented as illustrated examples of the embodiments defined in the claims. It is expressly understood that the embodiments as defined by the claims may be broader than the illustrated embodiments described below. 
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0183]    One embodiment of the invention is a transvalvular insertion tool (TVI tool)  10  is characterized by a rigid construction of the bypass sheath  12  that will not collapse when it is pushed up against the introducer housing, yet is still able to be separated from the lead after being used. The need for the rigid construction is to allow the TVI tool  10  to work with all existing hemostasis valved introducers where the distal tubular end  14  of the TVI tool  10  needs to be long enough to completely extend through some hemostasis valve introducers yet will “bottom out” on the housing of a shorter introducer, whereby the rigid construction prevents the distal tubular end from collapsing. 
         [0184]    The TVI tool can be fabricated in numerous ways including machining, molding, casting, or forging and can be comprised of one or more materials including metal, plastic, ceramic, composite, rubber or elastomer, but preferably from a rigid plastic such as acetal, polycarbonate, polyester, polypropylene, polyurethane, nylon, PEBA, or ABS. 
         [0185]      FIGS. 2   a  and  2   b  are perspective views of an embodiment, which is a two-piece, snap-together design. Hub  22  is fabricated in two halves and has a pair of radially extending fingers or male snap moldings  16  on the upper portion of one half of hub  22 . Each half hub  22  includes a horizontally oriented tab  20  radially extending from the upper portion of half hub  22 . The embodiment of  FIGS. 2   a  and  2   b  is shown in enlarged scale in  FIGS. 5   a  and  5   b . The bypass sheath  12  is provided with an integrally molded tab  20  on its proximal hub end  22 , a male snap molding  16  on one side of the proximal portion of sheath  12  and a female snap molding  18  on opposing side of the proximal portion of sheath  12 . An identical TVI tool half is provided and mated with the first half to form a combined assembly  24  shown in  FIG. 5   b  where the second half is depicted in phantom shadow outline. The lower portion of the same half hub  22  had defined therein receiving cavities or female snap moldings  18  into which corresponding male snap moldings  16  from the opposing half hub  22  are disposed. Detent protrusions may be defined in female snap moldings  18  over which male snap moldings  16  ride and then snap into place once the detent protrusions are cleared. The matching and opposing half of hub  22  has a mating arrangement, namely male snap moldings  16  extending radially from the lower portion of half hub  22  with female snap moldings (not shown) defined into the upper portion of half hub  22  for receipt of male snap moldings  16  from the opposing half hub  22 . 
         [0186]    The other embodiments include a slotted embodiment shown in perspective view in  FIG. 3 , and a clamshell/clothespin design shown in perspective view in  FIGS. 4   a  and  4   b . The slotted embodiment of  FIG. 3  is formed as an integrally molded half with a longitudinal slot  26  defined along sheath  12  of the half provided. The slotted embodiment has a single horizontally oriented tab  20  integrally formed with a half hub  22  and with half cylindrical sheath  12 . The width of the slot  26 , i.e. the extent to which a full cylindrical enclosure is not provided can be varied according to the application at hand, namely the maximal diameter of the transvascular tool to be accommodated by TVI tool  10 . 
         [0187]    The clam shell embodiment of  FIGS. 4   a  and  4   b  includes a rigid sheath  12 , but is composed of a resilient material which can be torqued open and dosed or at least includes a longitudinal living hinge  30  of resilient material or weakening opposite slit  28 , which allows it to be opened and closed as vertically oriented tabs  20  are squeezed together as shown in  FIG. 4   b  to open slit  28  or allowed to separate under the resilience of sheath  12  and hinge  30  as shown in  FIG. 4   a . The sheath  12  of the TVI tool  10  in  FIGS. 4   a  and  4   b  is stiff and will not collapse, distort or bend when abutted against an obstruction in the valve body, introducer or the transition between them. 
         [0188]    The rigid or at least longitudinally stiff TVI tool  10  of any of the embodiments can be forced through any obstruction or at least forced up against an obstruction to allow a delicate lead to pass through without a friction fit or interference with the TVI tool  10  or from valve membrane of the hemostatic introducer. In all embodiments the TVI tool  10  can be separated to open, or into at least two parts, or otherwise manipulated to allow it to be taken off the pacemaker lead or intravascular device without being slid off the proximal end of the lead or device, which is impossible in any case since there is a large electrical connector or other obstruction at the proximal end of the tool or lead. 
         [0189]    Note that one preferred embodiment of the universal TVI tool  10  does not peel like a conventional splittable/peel away sheath, along lines of weakness or molecular oriented material of sheath  12 , which cannot be rejoined and reused. Nor is the conventional TVI tool, which is sliced open, available for reassembly or reuse. Rather the TVI tool  10  of the illustrated embodiments separates into two portions or has a structure so that it can be reassembled, if necessary or desired, and reused. The Universal TVI tool  10  may be separated and put back together or rejoined with or without an intravascular tool being inserted therethrough at the time of recombination for indefinite re-sterilization and repeated usage on each instance of application if desired. 
         [0190]    Many embodiments may be devised to allow the intravascular tool to be inserted therethrough at the time of recombination for indefinite repeated usage on each instance of application.  FIGS. 2   a - 4   b  illustrate three embodiments, which are shown in greater detail along with a plurality of additional embodiments in  FIGS. 6   a - 32   d . A plurality of different coupling mechanisms or schemes are illustrated in these embodiments. It is to be understood that although the illustrated embodiment may show the mechanism or scheme used to join and separate the hub  22 , in many cases the same or similar mechanism or scheme can be extended to the sheath  12 , if desired, and vice versa. This collection of illustrated embodiments does not exhaust the number of possible mechanisms for providing for the TVI tool  10  of the invention, which may be realized in many other ways without departing from the spirit and scope of the invention. 
         [0191]    For example  FIG. 6   a  is a side cross-sectional exploded view of a snap peg-and-hole embodiment with  FIG. 6   b  a top plan exploded view,  FIG. 6   c  a side plan exploded view and  FIG. 6   d  is a perspective exploded view. The views of  FIGS. 6   a - 6   e  are views in which the two halves of TVI  10  are shown in the separated configuration. Hub  22  of TVI  10  is formed to two opposing portions or halves  22  with a mating peg  24  provided on one side and on the opposing side of the same half or portion is a mating hole  26 , best seen in  FIG. 6   d , into which peg  28  snaps or can be reversibly force fit. Peg  28  is provided with an slightly expanded distal end or head  29  to provide for a compression fit into hole  26 . The proximal end of sheath  12  is coupled to the bottom of corresponding portions of hub  22  and is formed into two longitudinal halves or portions which freely or flushly join or meet with each other.  FIGS. 7   a - 7   d  show the portions in an assembled configuration. 
         [0192]    The clam shell embodiment of  FIGS. 4   a  and  4   b  are shown in more detail in the closed and open configurations in  FIGS. 8   a - 8   d  and  FIGS. 9   a - 9   d  respectively. In the embodiment of  FIGS. 9   a - 9   d , the tabs  20  provide a surface which is oriented in a direction generally parallel to the axis of hub  22  and sheath  12  as opposed to the generally perpendicular surfaces presented by the embodiment in  FIGS. 6   a - 7   e  for example. Hub  22  is thus integral with tabs  20  and shares a continuous surface with tabs  20 . 
         [0193]      FIGS. 10   a - 10   e  show an embodiment with a longitudinal tongue and groove combination  31  defined in the hub  22  in an open configuration and  FIGS. 11   a - 11   e  in a closed configuration. A tongue  32  is provided longitudinally down one side of the inner surface  36  of hub  22 . On the opposing surface  38  of the opposing hub portion is a mating groove  34  defined in a longitudinal insert  33  disposed into hub  22 . Insert  33  may be a selected resilient or softer material than that used for hub  22  to provide a smooth and positive snap or clasping attachment for the combination  31 . Again the proximal end of sheath  12  is coupled to the bottom of corresponding portions of hub  22  and is formed into two longitudinal halves or portions which freely or flushly join or meet with each other. Sheath  12  mates freely and flushly together along a longitudinal access. 
         [0194]      FIGS. 12   a - 12   d  show an embodiment of the invention with a single horizontally oriented split tab having halves  20   a  and  20   b  extending from a resilient cylindrical hinge  22   a  defining one side of the hub  22 .  FIGS. 13   a - 13   d  show the embodiment in an opened configuration where hinge  22   a  has been flexed to open an opposing slot  35  in sheath  12  beginning at the base of tabs  20   a  and  20   b  and extending along the longitudinal length of sheath  12 . The embodiments of  FIGS. 12   a - 13   d  are characterized by the openable slot  35  being located at the tab-to-hub connection of the split tab halves  20   a  and  20   b.    
         [0195]      FIGS. 14   a - 14   d  show an embodiment of the invention with a plurality of interlocking or interlaced angled projections  37  defined in the hub  22  and down the longitudinal axis of the sheath  12 . A pair of fingers  38  are formed on the inner surface of a hub portion  22  as best shown in  FIG. 15   a  which provide an interference fit into a mating indentation  40  partially shown in  FIG. 16   a  in the opposing inner surface of the opposing hub portion. The fit of the mating fingers  38  with the indentations  40  determine the force which is required to separate the TVI for a given material or combination of materials. Similarly, interlocking angled projections  36  on sheath  12  mate into conforming angled indentations  42  defined in the edge of the opposing surface of sheath  12  as shown in  FIGS. 16   b ,  16   d  and  16   f . These interlocking angled projections  36  and angled indentations  42  in the sheath  12  serve to keep the sheath from becoming misaligned when the two halves are assembled together. The interlocking sections also keep the sheath  12  from becoming misaligned when it is inserted into and through an introducer hemostatic valve. The number of interlocking projections can be as few as one or as many as can fit along the length of the sheath  12 . The interface between the interlocking sections is angled so as to prevent the two halves of the sheath  12  from sliding and misaligning in any plane perpendicular to the assembled direction. It is important that the sheath  12  stays aligned when assembled so as to maintain an obstruction free path for delivery of a lead or vascular device through the valved introducer. A longer and more flexible sheath  12  will need the interlocking feature more than a shorter more rigid sheath  12  that is held in alignment by the hub  22 . Alternate embodiments are also contemplated for the sheath  12  that prevent misalignment of the sheath in order to maintain an obstruction free path for delivery of a lead or vascular device through the valved introducer. Mechanical means such as tabs, angled surfaces, keyways, detents, fingers, frictional and temporary adhesive, magnets, static attraction, joined edges, and or any other known means of preventing the two opposing sheath surfaces from freely sliding on each other when assembled. 
         [0196]    Any of the discussed embodiments for the sheath  12  that prevent misalignment of the sheath in order to maintain an obstruction free path for delivery of a lead or vascular device through the valved introducer can be added to any of the TVI embodiments provided in this disclosure to prevent the sheath  12  from becoming misaligned. 
         [0197]      FIGS. 17   a - 17   d  are directed to an embodiment of the invention with a single horizontally oriented tab  20  extending from a separable cylinder defining one side of the hub  22   b . In the preferred embodiment a slit  44  is defined longitudinally down the midline of portion  22   b  and extending into sheath  12 .  FIGS. 18   a - 18   d  show the embodiment of  FIGS. 17   a - 17   d  with slit  44  opened, which may be accomplished, for example, by pulling the intravascular tool through slit  44  as TVI  10  is removed from the hemostatic valve. It is also contemplated that slit  44  be angled or stepped to prevent the hub  22   b  from collapsing and obstructing the free path formed by the hub  22   b  and the sheath  12 . Slit  44  may be entirely cut through or may be partially cut through leaving a very thin membrane which is easily ruptured when the intravascular tool is pull through it. 
         [0198]      FIGS. 19   a - 19   e  are directed to an embodiment of the invention with a one way swing latch  46  defined in the hub  22  shown in a fully separated configuration. A curved latching finger  46  on each hub portion extends into a mating curved cavity  48  defined into the inner surface of the opposing hub portion like a curved tenon and mortise combination. The hub portions are engaged by rotating them together so that the curved fingers  46  are fully inserted into cavities  48  as shown in  FIGS. 20   a - 20   e  in a partially assembled configuration as the swing latch is partially still open but is being closed and in  FIGS. 21   a - 21   e  in the fully assembled configuration after the swing latch is fully closed. The two portions of sheath  12  will flushly and freely be disposed adjacent to each other. 
         [0199]      FIGS. 22   a - 22   e  are directed to an embodiment of the invention with a longitudinal resealable or adhesive membrane  50  disposed on the inner surfaces of the hub  22  and sheath  12  shown in a fully unsealed configuration. Membrane  50  can being sealed or joined together by pressure and then easily pulled apart with the capability of being rejoined an indefinite number of times. The two portions of the hub  22  and sheath  12  are flushly and freely disposed adjacent to each and temporarily join together by virtue of the adhesive quality of the membrane  50 .  FIGS. 23   a - 23   e  show the embodiment when joined together by bringing the membrane-bearing portions into contact with each other. 
         [0200]      FIGS. 24   a - 24   d  show an embodiment of the invention with a single horizontally oriented tab  20  extending from a cylinder  22   c  defining one side of the hub  22 , which cylinder  22   c  is separable on one side edge  23  of the cylinder  22   c  sheath  12  or both shown in an attached configuration. Cylinder  22   c  attaches on one side of the cylinder  22   c  to the inner surface of the opposing hub portion. A separable slit or edge  23  may be defined on the detachable side or the slit  23  may be defined through cylinder  22   c  and retained in the closed configuration by the resiliency of the material composing cylinder  22   c . The slit  23  extends longitudinally along the entire hub length and continues to the distal end of the sheath  12 .  FIGS. 25   a - 25   d  show the embodiment in the opened configuration. 
         [0201]      FIGS. 26   a - 26   e  are directed to an embodiment of the invention with an edge defined tongue and groove attachment which is longitudinally defined through the hub  22  and sheath  12  and in which the two opposing portions longitudinally slide or snap together and apart from each other and shown in a detached configuration. A longitudinally extending tongue  52  slides longitudinally in or snaps into a longitudinally extending groove  54  as best seen in the detailed enlarged view of  FIG. 26   e . Tongue  52  has a bulbous or cylindrical distal end to provide a captured configuration when slid or snapped into a mating and conforming groove  54 .  FIGS. 27   a - 27   e  show the embodiment partially assembled or disassembled and  FIGS. 28   a - 28   e  show the embodiment fully assembled. 
         [0202]      FIGS. 29   a - 29   d  are directed to an embodiment of the invention with a single horizontally oriented tab  20  wherein an open slot  56  is defined in an opposing cylinder  22   d  portion of the hub  22  and continues longitudinally along the longitudinal axis of the sheath  12 . The slot  56  continues along the longitudinal length of hub  22  and sheath  12  to its distal end. 
         [0203]      FIGS. 30   a - 30   d  show an embodiment of the invention with a pair of opposing male snap fingers  58  and mating female recesses  60  defined in the mid portion of the hub  22  and shown in an unassembled configuration. Finger  58  is illustrated in  FIG. 30   c  as being integrally formed at opposing sides of a middle position of hub  22  disposed over a portion of the upper and lower halves of hub  22  and extending below the plane of tabs  20 , however, it is to be understood that other positions on hub  22  could be utilized. The embodiment is shown in a fully assembled configuration in  FIGS. 31   a - 31   d . The sheath  12  is formed into two portions which are flushly and freely disposed together along their longitudinal length. 
         [0204]      FIGS. 32   a - 32   e  are directed to an embodiment of the invention with an edge defined line of weakness, which is longitudinally defined through the integrally molded hub  22  and integrally molded sheath  12  and in which the two opposing portions are longitudinally attached and tear apart from each other. In this embodiment, sheath  12  has a completely smooth exterior surface along its entire length. Distal end  62  is intended to provide the mechanical stop against the bottom or other portion of the hemostatic valve capable of serving as a stop, thereby preventing TVI  10  from being inserted any further into the mating hemostatic valve. In the embodiment of  FIGS. 32   a - 32   e  TVI  10  is an integrally molded piece, and the weakening through hub  22  and sheath  12  is provided by a pair of opposing molded V-grooves  64  which are defined in both hub  22  and sheath  12 . V-groove  64  is deep enough to leave only a thin easily tearable membrane connecting the halves of the TVI  10 , but not so deep as to completely penetrate the material into which it is defined. The line of weakening in sheath  12  may also be provided by any other means known to the art as discussed above. 
         [0205]      FIGS. 33   a - 33   e  are directed to an embodiment of the invention with an edge defined line of weakness which is longitudinally defined through the hub  22  and sheath  12  and in which the two opposing portions are longitudinally attached and tear apart from each other. The embodiment of  FIGS. 33   a - 33   e  is similar in all respects to that embodiment shown in  FIGS. 32   a - 32   e  with the exception that a molded shoulder  66  is defined in sheath  12 . Shoulder  66 , extending from hub  22  to a predetermined position down sheath  12 , has an external diameter slightly larger than the more distal remaining portion of sheath  12 . As shown in  FIG. 33   e  sheath  12  has a proximal portion  68   a  of a first external diameter and a more distal remaining portion  68   b  having a second smaller diameter. Shoulder  66  is designed then to serve as a stop against an corresponding stop structure in the mating hemostatic valve into which TVI  10  is intended to be inserted. In such a case, distal end  62  would then not necessarily serve as the stop element. 
         [0206]    It is to be clearly understood that TVI tool  10  need only be rigid to the extent that sheath  12  will not deform when the distal end of the sheath  12  stops against the inside of the introducer valve housing. 
         [0207]    TVI tool  10  can be used in conjunction with any valved introducer to provide a separable unobstructed conduit through the valve. One of the unique features is the ability of TVI tool  10  to bottom out on the introducer valve housing, which allows the user to be generically instructed or directed to push the universal TVI tool through the introducer valve until it stops. 
         [0208]    Many alterations and modifications may be made by those having ordinary skill in the art without departing from the spirit and scope of the embodiments. Therefore, it must be understood that the illustrated embodiment has been set forth only for the purposes of example and that it should not be taken as limiting the embodiments as defined by the following embodiments and its various embodiments. 
         [0209]    Therefore, it must be understood that the illustrated embodiment has been set forth only for the purposes of example and that it should not be taken as limiting the embodiments as defined by the following claims. For example, notwithstanding the fact that the elements of a claim are set forth below in a certain combination, it must be expressly understood that the embodiments includes other combinations of fewer, more or different elements, which are disclosed in above even when not initially claimed in such combinations. A teaching that two elements are combined in a claimed combination is further to be understood as also allowing for a claimed combination in which the two elements are not combined with each other, but may be used alone or combined in other combinations. The excision of any disclosed element of the embodiments is explicitly contemplated as within the scope of the embodiments. 
         [0210]    The words used in this specification to describe the various embodiments are to be understood not only in the sense of their commonly defined meanings, but to include by special definition in this specification structure, material or acts beyond the scope of the commonly defined meanings. Thus if an element can be understood in the context of this specification as including more than one meaning, then its use in a claim must be understood as being generic to all possible meanings supported by the specification and by the word itself. 
         [0211]    The definitions of the words or elements of the following claims are, therefore, defined in this specification to include not only the combination of elements which are literally set forth, but all equivalent structure, material or acts for performing substantially the same function in substantially the same way to obtain substantially the same result. In this sense it is therefore contemplated that an equivalent substitution of two or more elements may be made for any one of the elements in the claims below or that a single element may be substituted for two or more elements in a claim. Although elements may be described above as acting in certain combinations and even initially claimed as such, it is to be expressly understood that one or more elements from a claimed combination can in some cases be excised from the combination and that the claimed combination may be directed to a subcombination or variation of a subcombination. 
         [0212]    Insubstantial changes from the claimed subject matter as viewed by a person with ordinary skill in the art, now known or later devised, are expressly contemplated as being equivalently within the scope of the claims. Therefore, obvious substitutions now or later known to one with ordinary skill in the art are defined to be within the scope of the defined elements. 
         [0213]    The claims are thus to be understood to include what is specifically illustrated and described above, what is conceptionally equivalent, what can be obviously substituted and also what essentially incorporates the essential idea of the embodiments.