Abstract:
A trocar and cannula assembly with improved conical valve that incorporates a plurality of ribs to restrict and/or otherwise influence valve movement, and a plurality of improved convolutes and bumps to enhance performance characteristics.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation application of U.S. patent application Ser. No. 12/901,393, filed Oct. 8, 2010, currently pending, which claims the benefit of U.S. Provisional Application No. 61/250,194, filed Oct. 9, 2009, now abandoned, the entire disclosures are incorporated herein by reference in their entirety. 
     
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0002]    Not Applicable. 
       REFERENCE TO A MICROFICHE APPENDIX 
       [0003]    Not Applicable. 
       BACKGROUND OF THE INVENTION 
       [0004]    1. Technical Field 
         [0005]    The present disclosure relates generally to medical devices, and more particularly to trocar systems, cannulas, valves, and methods related thereto. 
         [0006]    2. Background 
         [0007]    Numerous trocar systems have been developed for various endoscopic applications in the field of medicine. These trocar systems conventionally include a cannula, through which a trocar or obturator or other endoscopic-related tool extends. In such systems, one or more valves is necessarily positioned within or connected to the proximal end of the cannula. Many such valves are disadvantageously bulky and awkward to use, and complex, multi-component mechanical valves can be difficult and costly to manufacture, and can have increased risk of failure relative to non-mechanical counterparts. Moreover, mechanical valves typically have little or no flexibility. 
         [0008]    Valve improvements can serve to enhance handling of trocar systems by medical professionals, facilitating better performance and improving patient surgical experience. Therefore, it is readily apparent that there is a need for an improved conical valve and related trocar and cannula assembly, and methods related thereto, where performance is enhanced, risk of failure is mitigated, and cost-effective production and manufacture is available. 
       BRIEF SUMMARY OF THE INVENTION 
       [0009]    Briefly described, in a preferred embodiment, the present assembly overcomes the above-mentioned disadvantages and meets the recognized need for such a device by providing a trocar and cannula assembly with improved conical valve, and methods related thereto, wherein an improved single-piece valve design allows for easier stretch of the body of the valve, reduces friction, and promotes retention of original shape of the distal center hole, thereby providing improvement, at least in the ability to seal during aggressive manipulation of instruments through the port. 
         [0010]    According to its major aspects and broadly stated, in its preferred form, the present system is a trocar and cannula assembly with improved conical valve that incorporates a plurality of ribs to restrict and/or otherwise influence valve movement, and a plurality of improved convolutes and bumps to enhance performance characteristics. 
         [0011]    Embodiments of the present invention advantageously provide a valve having a design to provide a secured seal around a plurality of tools that individually and separately extend through the valve, providing for ease of insertion and retraction of various laparoscopic surgical instruments, as well as other surgically-related items with varying diameters, wherein the present system is configured to advantageously accept a broad range thereof. Further, problematical instruments do not get obstructed or caught, such as may occur in some disadvantageous multi-component valve assemblies. Embodiments of the present disclosure also advantageously provide a trocar system having relatively low costs associated with the manufacturing of components of the system, e.g., valves, and thereby reduce the costs associated with the trocar system. 
         [0012]    Embodiments of the present disclosure additionally advantageously provide a more flexible trocar system which is effective during various endoscopic surgical procedures. Embodiments of the present invention further advantageously provide enhanced methods of forming a seal around tools and of using a trocar system during surgical procedures. 
         [0013]    Embodiments of the present further advantageously provide a valve having peripheries fixedly connected to a valve housing, such that the valve may operate like a membrane, and embodiments of the valve advantageously allow one type of valve, cannula, or trocar system to be readily used for various types and diameters of tools used by medical personnel. Moreover, embodiments of the present disclosure further provide a valve having advantageously improved anti-friction features that facilitate insertion and removal of instruments therethrough. Still further embodiments of the present disclosure may provide for the formation of these anti-friction features according to a new multi-shot liquid silicone rubber process, wherein liquid silicone rubber and traditional thermoplastic elements may be combined in a single molded part. In such an embodiment, for example, plurality of bump features may be molded as a thermoplastic material, with a very low coefficient of friction. 
         [0014]    More specifically, the system of the present disclosure in its preferred form is a trocar system comprising a cannula having an elongate cannula body, with medial and distal portions having a first diameter. The cannula body has a proximal portion, connected to the medial portion and opposingly positioned relative to the distal portion, wherein the proximal portion has a second diameter, wherein the second diameter is greater than the first diameter. According to a preferred embodiment of the trocar system, a valve housing is detachably connected to the proximal portion of the cannula body, with an axis and first opening at a proximal end of the valve housing, a second opening at a distal end of the valve housing, and an axially downward facing shoulder. The first opening of the valve housing is preferably defined by a plurality of sidewalls extending in a substantially axial direction, and has a first opening diameter. 
         [0015]    According to embodiments of the present disclosure, the trocar system also includes a cap assembly which includes at least one valve positioned within the valve housing. According to an embodiment of the cap assembly, the at least one valve can include a valve body having an annular-shaped valve opening adapted to individually and separately receive a plurality of different elongate tools. Each of the tools have a different diameter therethrough so that when any one of the plurality of elongate tools is positioned through the valve opening, a septum seal is maintained between peripheries of the valve body surrounding the valve opening and abuttingly contacting outer peripheries of the any one of the plurality of elongate tools extending therethrough. 
         [0016]    The valve body preferably has a periphery valve section connected to and extending radially outwardly from peripheries of the valve body. The periphery valve section includes an outer ring with an outer perimeter thereof defining an outer perimeter of the septum valve, the outer ring engaging the axially downward facing shoulder of the valve housing, and convolutes defined between the outer ring and the valve body. The periphery valve section also has a plurality of rib members, each radially extending at least a portion of the distance between an outer perimeter of the valve body and the outer perimeter of the periphery valve section, and symmetrically positioned spaced-apart from each other. The periphery valve section may have a greater flexibility than the valve body. 
         [0017]    The trocar system also preferably includes a compression ring positioned in the valve housing adjacent the septum valve. The compression ring compresses the outer ring of the septum valve against the axially downward facing shoulder of the valve housing in order to fixedly position the septum valve within the valve housing. The compression ring has a compression ring opening substantially aligned with the first opening of the valve housing. The trocar system further comprises a plurality of tools each having an elongate body for extending through the valve housing, the valve opening, and the cannula. 
         [0018]    Further, more particularly and preferably, the cap assembly of the trocar system may include, but is not limited to, a valve housing having at least one opening formed in line with an axis of the valve housing, with the at least one opening being defined by a plurality of sidewalls extending in a substantially axial direction. The cap assembly also may include at least one valve positioned adjacent to the at least one opening of the valve housing. The at least one valve includes a valve body having an annular-shaped valve opening adapted to individually and separately receive a plurality of different elongate tools. Each of the elongate tools can have a different diameter so that when any one of the plurality of elongate tools is positioned through the valve opening, and when the valve is abuttingly contacting outer peripheries of any one of the plurality of diameter elongate tools extending therethrough, a septum seal is maintained between peripheries of the valve body surrounding the valve opening. The valve body also has a periphery valve section connected to and extending radially outwardly from peripheries of the valve body. The periphery valve section has one or more convolutes within the periphery valve section. The periphery valve section also has a plurality of rib members radially extending at least a portion of the distance between an outer perimeter of the valve body and an outer perimeter of the periphery valve section, and may have a circumferential baffle defined between the plurality of convolutes and the inner perimeter of the outer ring. 
         [0019]    According to another embodiment of the trocar system, the system may include a valve housing adapted to detachably connect to a cannula and characterized by having a proximal end housing portion, a distal end housing portion, and a medial housing portion connected therebetween having a proximal valve housing inner perimeter surface and a distal valve housing inner perimeter surface which can be of the same or different diameters. The proximal end housing portion can include a first opening having a first opening diameter defined by portions of an inner valve housing sidewall extending distally in a substantially axial direction. The proximal end housing portion can also include an annular valve ring recess adapted to receive an annular valve ring which surrounds the first opening. The distal end housing portion can include a second opening diameter defined by a distal valve housing sidewall extending in a substantially axial direction. 
         [0020]    According to an another embodiment of the cap assembly, the at least one valve positioned within a valve housing may include a first valve having a valve body which includes a proximal valve section fixedly positioned within the valve housing and a distal valve section extending axially from the proximal valve section and into the proximal portion of the cannula. The proximal valve section can include a valve ring positioned in the valve ring recess of the valve housing. The valve ring has a proximal surface, a distal surface, an inner perimeter surface, and an outer perimeter surface defining an outer perimeter of the valve body. 
         [0021]    The proximal surface and the distal surface of the periphery valve section are each preferably further defined by two sub-element surfaces, wherein the first sub-element surface of the proximal surface is defined in a first plane and proximate the inner perimeter of the periphery valve section, and the second sub-element surface of the proximal surface is defined in a second plane and proximate the outer perimeter of the periphery valve section. A similar relationship exists between the two sub-element surfaces of the distal surface of the periphery valve section, wherein the first sub-element surface of the distal surface is defined in a first plane and proximate the inner perimeter of the periphery valve section, and the second sub-element surface of the distal surface is defined in a second plane and proximate the outer perimeter of the periphery valve section. Accordingly, neither the proximal surface of the periphery valve section nor the distal surface of the periphery valve section is flat. 
         [0022]    The periphery valve section may include a circumferential baffle element related to the proximal valve section of the valve body, wherein the circumferential baffle element may preferably be defined in the second plane proximate the outer perimeter of the periphery valve section. The proximal valve section of the valve body can also include a plurality of convolutes, each preferably having a first sidewall extending radially inwardly from a portion of the circumferential baffle and a second sidewall extending axially from the first sidewall substantially parallel to the inner perimeter surface of the valve ring and forming an inner radial periphery of the proximal valve section. 
         [0023]    The inner perimeter surface of the periphery valve section, the first sidewall, and the second sidewall of each of the plurality of convolutes preferably form a respective convolute recess for each of the plurality of convolutes. The proximal valve section of the valve body can also include a plurality of rib members, each radially extending at least a portion of the distance between the inner radial periphery of the proximal valve section and inner perimeter surface of the valve ring and can be symmetrically positioned spaced-apart from each other. 
         [0024]    Preferably, each of the plurality of rib members extends radially from the inner radial periphery of the proximal valve section to the circumferential baffle element, wherein the circumferential baffle element extends radially from the plurality of convolutes to the inner perimeter surface of the valve ring. 
         [0025]    The distal valve section of the valve body can include a valve extension extending axially from the plurality of convolutes. The valve extension can include a proximal end portion substantially connected to a distal portion of each of the plurality of convolutes, a distal end portion, and a substantially conically shaped medial portion connected to and extending therebetween. An annular-shaped valve opening is positioned in the distal end portion of the valve extension and is adapted to individually and separately receive therethrough any one of a plurality of different elongate tools, each having a different diameter so that when any one of the plurality of elongate tools is positioned through the valve opening, a seal, e.g., septum seal, is maintained between peripheries of the valve extension surrounding the valve opening and outer peripheries of any one of the plurality of elongate tools extending therethrough. 
         [0026]    The first valve may also include a compression ring positioned in the valve housing abuttingly contacting an axially facing distal surface of the valve ring to hold the valve ring in the valve ring recess and to compress the valve ring against an axially facing inner surface of the proximal end housing portion of the valve housing adjacent the valve ring recess in order to fixedly position the valve within the valve housing. The compression ring may include a compression ring opening substantially aligned axially with the first opening of the valve housing to allow extension of the plurality of elongate tools therethrough, an outer perimeter surface having a radial diameter sized so that the compression ring substantially abuttingly contacts the distal valve housing inner perimeter surface when positioned within the valve housing, and an annular flange extending into each one of the plurality of convolute recesses to individually and separately engage a corresponding one of the plurality of convolutes to further enhance positioning and securing of the first valve within the valve housing. 
         [0027]    The cap assembly can also include a second valve to advantageously help ensure inter-cavity sealing. The second valve can include an annular flange portion spaced axially from the valve ring of the first valve and having a radial diameter sized so that the annular flange portion substantially abuttingly contacts both the distal valve inner housing perimeter surface and an axially facing distal surface of the compression ring adjacent the compression ring opening to enhance positioning of the second valve at least partially within the valve housing. The second valve can also have a second valve opening positioned within the annular flange portion and substantially aligned axially with the first opening of the valve housing to allow extension of the plurality of elongate tools therethrough, an annular-shaped sidewall connected to the annular flange and extending distally in a substantially axial direction when positioned in the valve housing, and a pair of valve flaps connected to and extending inwardly from the annular-shaped sidewall and having at least one slit along common peripheral edges thereof through which the plurality of tools extend individually and separately. The second valve can be held in place through use of a cap seal ring positioned at least partially within the valve housing and positioned to abuttingly contact a distal surface of the annular flange portion of the second valve when the second valve is positioned in the valve housing. The cap seal ring can have an axially extending annular-shaped flange axially spaced apart from the compression ring to provide a slot or recess to releasably receive the annular flange portion of the second valve. The cap seal ring can also include a plurality of radially extending flanges each adapted to engage other peripheries of a separate one of the plurality of radially extending flanges of the cannula to slidably detachably connect the valve housing to the cannula. 
         [0028]    Embodiments of the present disclosure also preferably include methods of using a trocar system. For example, one method embodiment may include the step of providing a cap assembly in a trocar system. The cap assembly has a septum valve including a valve body having an annular-shaped valve opening positioned in a medial portion of the valve body adapted to receive individually and separate a plurality of tools therethrough so that when any one of the plurality of tools is positioned through the valve opening abuttingly contacting outer peripheries of the any one of the plurality of tools extending therethrough, a septum seal is maintained between peripheries of the valve body surrounding the valve opening. The valve body can include a periphery valve section connected to and extending radially outwardly from peripheries of the valve body and having an outer perimeter thereof adapted to be fixedly connected to the valve housing. The periphery valve section can also have a plurality of rib members each radially extending at least a portion of the distance between an outer perimeter of the valve body and the outer perimeter of the periphery valve section and symmetrically positioned spaced-apart from each other. The periphery valve section can also have a circumferential baffle member defined proximate the outer perimeter of the periphery valve section, wherein the plurality of rib members preferably extend between the outer perimeter of the valve body and the circumferential baffle member. The periphery valve section can have a greater flexibility than the valve body. 
         [0029]    The method of using a trocar system can also include the step of inserting a tool through the septum valve and cap assembly comprising the septum valve thereof. During the inserting step, the periphery valve section may be deformed temporarily so that the valve body extends distally by contact pressure from the tool and so that a distal end of the tool is guided toward the valve opening and then the periphery valve section is refracted to its selected biased position upon the complete insertion of the tool. The method of using a trocar system can also include the step of guiding the tool to the septum valve with a substantially cylindrical-shaped cap assembly opening when the tool is being inserted through the cap assembly. The method of using a trocar system can further include the steps of extending the tool through a cannula body matingly connected to the cap assembly at a proximal portion thereof, detaching the cap assembly from the proximal portion of the cannula body, and removing tissue or other specimen from the cannula body. 
         [0030]    According to another embodiment of the method of using a trocar system, the method can include the step of providing a cap assembly in a trocar system including a valve positioned at least partially within a valve housing. The valve can include a valve body having a proximal valve section positioned within the valve housing and a distal valve section extending axially from the proximal valve section and including a valve extension having a proximal end portion, a distal end portion, and a substantially conically shaped medial portion connect to and extending therebetween. A valve opening is positioned in the distal end portion of the valve extension and is adapted to individually and separately receive therethrough any one of a plurality of different elongate tools. The method can also include the step of inserting a tool through the cap assembly including the valve extension and a valve opening thereof, during which the valve extension guides the distal end of the tool to the valve opening and upon reaching the valve opening, the valve opening is deformed temporarily by contact pressure from the tool so that upon the complete insertion of the tool, a seal is formed around outer peripheries of the tool. The method further includes the steps of guiding the tool to the valve extension with a substantially cylindrical- shaped cap assembly opening when the tool is being inserted through the cap assembly, extending the tool through a cannula body matingly connected to the cap assembly at a proximal portion thereof, detaching the cap assembly from the proximal portion of the cannula body, and removing tissue or other specimen from the cannula body. 
         [0031]    The valve also preferably includes a plurality of closely and symmetricallyspaced friction-reduction features to advantageously minimize electrostatic forces between instruments and the valve. A reduction in electrostatic adhesion can be realized from the friction-reduction features, preferably protrusions formed on the inner and outer surfaces of the conically shaped medial portion, proximate the distal end and the valve opening. Preferably, a first circumferential row of protrusions is defined proximate the valve opening in a closely-spaced conformation, whereafter a second circumferential row of protrusions is defined in a position of greater distance relative to the valve opening, wherein the same total number of protrusions is preferably defined in the second row as the first row, but given the increased diameter of the conical valve at the location of the second row relative to that of the first row, the second row protrusions are less closely-spaced. Thereafter, further rows are defined in similar fashion. The positioning of the protrusions of each adjacent circumferential row may also be juxtaposed, such that a radial twist pattern may be defined by the protrusions about the conical valve proximate the distal end and the valve opening. The friction-reduction features essentially serve to create a gap between an instrument surface and a flat area of the valve, beneficially decreasing the total area of contact in the trocar system otherwise potentially faced with a relatively large surface of contact area, high pressure contact, and high shear stress deformation. The protrusions thus function to reduce undesirable pressure contact between the instrument and the valve. Moreover, as noted hereinabove, embodiments wherein the protrusions may be formed from a thermoplastic material with a low coefficient of friction may serve to limit frictional forces even further by effectively changing the coefficient of friction acting on the entire valve system. 
         [0032]    A further improvement proximate the distal end of the valve relates to the definition of the plurality of friction-reduction features definition on both a distal surface and a proximal surface of the distal end of the valve, wherein each protrusion preferably forms a cone, wherein the shape and placement of friction- reduction features enhances friction reduction. That is, kinetic friction between the valve and related instruments is advantageously minimized as the valve opening is deformed temporarily by contact pressure from the tool, wherein contact area between the valve and the instruments is reduced. Moreover, elongation or other reactive force redirection by the circumferential baffle element serves to minimize deformation of the valve opening as well. The friction-reduction features, especially with the circumferential baffle, can reduce the resistive forces between the contact surfaces of an inserted instrument and the valve without compromise to the septum seal or to the inherent flexibility and adaptability of the valve of the present invention, wherein a broad endoscopic instrument diameter range, from about 5 mm to 15 mm diameter, can be successfully accepted. The friction-reduction features, both the plurality of protrusions, or cones, are preferably defined proximate the apical end of the valve, in anticipation of contact with the plurality of elongate tools extended therethrough, and are further preferably defined on both opposing surfaces in order that advantageous minimization of electrostatic forces may be realized also during contact between the valve body and the second valve. Again, these friction-reduction features may be formed from material with a low coefficient of friction relative to the material of the valve body, such as a thermoplastic, wherein further friction-reduction benefits may be realized. 
         [0033]    Embodiments of the present invention also include methods of forming a valve for a trocar system. For example, a method of forming a valve for a trocar system can include first inserting a valve having a valve body into the valve housing. A compression ring, for example, coated with an ultraviolet bonding agent, is then placed into the valve housing adjacent and abuttingly contacting the valve in a “stacked” fashion. Following this, the second valve is inserted into the valve housing adjacent and abuttingly contacting the compression ring, and a cap seal ring coated with an ultraviolet bonding agent is placed into the valve housing abuttingly contacting outer peripheries of the second valve. Both the compression ring and cap seal ring can be coated with an ultraviolet bonding agent, along with the outer peripheries thereof abuttingly contacting the inner peripheries of the valve housing. Once each of the components is in its place, the entire cap assembly is placed in a compression system, wherein each component is compressed to its desired depth into the valve housing. At that point, an ultraviolet light is exposed to the ultraviolet bonding agent to cure the materials. Upon the completion of the curing, the cap assembly is formed as one unit. Beneficially, the second valve can be readily removed and exchanged for a replacement. 
         [0034]    When constructing a trocar system, the cap assembly is abuttingly and releasably connected to a cannula. The proximal end portion of the cannula body has at least one valve housing mating portion associated therewith, and the cap seal ring positioned in the valve housing also has at least one cannula body mating portion or flange associated therewith so that the cap assembly matingly attaches to the cannula body in a secured position and whereby movement of the cap assembly, e.g., rotation, by a hand of a user, releases, e.g., unsecures or unlocks, the respective mating portions for ready removal of the cap assembly by the user with the valve and second valve and so that specimens, e.g., tissue, can be readily removed from the cannula body without damage by the first and second valve. Advantageously, the extraction of large tissue samples and/or gauze packs can be accomplished without removing the cannula from the area where various endoscopic procedures take place. 
         [0035]    There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are additional features of the invention that will be described hereinafter and which will form the subject matter of the claims appended hereto. 
         [0036]    It is noted the purpose of the foregoing abstract is to enable the U.S. Patent and Trademark Office and the public generally, especially the scientists, engineers and practitioners in the art who are not familiar with patent or legal terms or phraseology, to determine quickly from a cursory inspection the nature and essence of the technical disclosure of the application. The abstract is neither intended to define the invention of the application, which is measured by the claims, nor is it intended to be limiting as to the scope of the invention in any way. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
         [0037]    The novel features believed to be characteristic of this invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and method of operation, together with further objects and advantages thereof, may best be understood by reference to the following description taken in connection with the accompanying drawings in which: 
           [0038]      FIG. 1  is a perspective environmental view of a trocar system positioned within a layer of epidermis of a patient, according to a prior art embodiment; 
           [0039]      FIG. 2  is a fragmentary sectional view of a trocar system having first and second valves, according to a prior art embodiment; 
           [0040]      FIG. 3  is a side elevational view of a trocar system according to an embodiment of the present disclosure; 
           [0041]      FIG. 4  is a top plan view of a cap assembly of a trocar system according to an embodiment of the present disclosure; 
           [0042]      FIG. 5  is an exploded view of a cap assembly of a trocar system according to a prior art embodiment; 
           [0043]      FIG. 6  is an environmental perspective view of a valve, valve mold, and a slab illustrating the formation of a valve according to a prior art embodiment; 
           [0044]      FIG. 7  is a perspective view of a valve of a trocar system according to a prior art embodiment; 
           [0045]      FIG. 8  is a magnified, cut-away surface view of a valve of a trocar system according to a prior art embodiment; 
           [0046]      FIG. 9  is a cross-sectional, cut-away view, taken along line  26 - 26  of the valve of  FIG. 7 , according to a prior art embodiment; 
           [0047]      FIG. 10  is a graphical representation of the parabolic relationship between frictional force and roughness; 
           [0048]      FIG. 11  is a perspective view of a valve according to an embodiment of the present disclosure; 
           [0049]      FIG. 12  is a proximal view of the valve of  FIG. 11 ; 
           [0050]      FIG. 13  is a cross-sectional view, taken along line A-A of the valve of  FIG. 11 , according to an embodiment of the present disclosure; and 
           [0051]      FIG. 14  is a magnified, cut-away surface view of the valve of  FIG. 13 , according to an embodiment of the present disclosure. 
       
    
    
       [0052]    Those skilled in the art will appreciate that the figures are not intended to be drawn to any particular scale; nor are the figures intended to illustrate every embodiment of the invention. The invention is not limited to the exemplary embodiments depicted in the figures or the shapes, relative sizes or proportions shown in the figures. 
       DETAILED DESCRIPTION OF THE INVENTION 
       [0053]    The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which a preferred embodiment of the invention is shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiment set forth herein. Rather, this embodiment is provided so that this application will be thorough and complete, and will fully convey the true scope of the invention to those skilled in the art. Like numbers refer to like elements throughout the figures. 
         [0054]    The illustrations of the embodiments described herein are intended to provide a general understanding of the structure of the various embodiments. The illustrations are not intended to serve as a complete description of all of the elements and features of apparatus and systems that utilize the structures or methods described herein. Many other embodiments may be apparent to those of skill in the art upon reviewing the disclosure. Other embodiments may be utilized and derived from the disclosure, such that structural and logical substitutions and changes may be made without departing from the scope of the disclosure. Additionally, the illustrations are merely representational and may not be drawn to scale. Certain proportions within the illustrations may be exaggerated, while other proportions may be minimized. Accordingly, the disclosure and the figures are to be regarded as illustrative rather than restrictive. 
         [0055]    One or more embodiments of the disclosure may be referred to herein, individually and/or collectively, by the term “present invention” merely for convenience and without intending to voluntarily limit the scope of this application to any particular invention or inventive concept. Moreover, although specific embodiments have been illustrated and described herein, it should be appreciated that any subsequent arrangement designed to achieve the same or similar purpose may be substituted for the specific embodiments shown. This disclosure is intended to cover any and all subsequent adaptations or variations of various embodiments. Combinations of the above embodiments, and other embodiments not specifically described herein, will be apparent to those of skill in the art upon reviewing the description. 
         [0056]    The Abstract of the Disclosure is provided to comply with 37 C.F.R. § 1.72(b) and is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. In addition, in the foregoing Detailed Description, various features may be grouped together or described in a single embodiment for the purpose of streamlining the disclosure. This disclosure is not to be interpreted as reflecting an intention that the claimed embodiments require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter may be directed to less than all of the features of any of the disclosed embodiments. Thus, the following claims are incorporated into the Detailed Description, with each claim standing on its own as defining separately claimed subject matter. 
         [0057]    The below disclosed subject matter is to be considered illustrative, and not restrictive, and the appended claims are intended to cover all such modifications, enhancements, and other embodiments which fall within the true scope of the present invention. Thus, to the maximum extent allowed by law, the scope of the present invention is to be determined by the broadest permissible interpretation of the following claims and their equivalents, and shall not be restricted or limited by the foregoing detailed description. 
         [0058]    In describing the preferred and alternate embodiments of the present invention, as illustrated in the figures and/or described herein, specific terminology is employed for the sake of clarity. The invention, however, is not intended to be limited to the specific terminology so selected, and it is to be understood that each specific element includes all technical equivalents that operate in a similar manner to accomplish similar functions. 
         [0059]    Referring now to  FIGS. 1-2  and  5 - 9 , it is instructive to reference prior art embodiments, as previously disclosed in commonly-owned U.S. patent application Ser. No. 11/503,314 and U.S. patent application Ser. No. 11/807,202, wherein the presently disclosed trocar and cannula assembly  400  having improved conical valve  450  may include one or more features in common therewith. That is, prior art non-planar valves  150  and  150 ′ are first referenced and instructively described relative to use with cannula  40  and common features of cap assembly  130  shared with prior trocar system  120  and the presently disclosed trocar system  420 . Thereafter, embodiments of improved conical valve  450  are described, with preferred particularity. 
         [0060]    In general, improved conical valve  450  and non-planar valves  150  and  150 ′ may each be used with cannula  40 . Cap assembly  130  of prior art trocar system  120 , as well as of presently disclosed trocar system  420 , preferably comprises valve housing  132 , wherein valve housing  132  may have, for example, a substantially annular shape, with proximal end housing portion  171 , distal end housing portion  173 , and medial housing portion  175 . Proximal end housing portion  171  preferably includes first opening  131  having a first opening diameter defined by portions of inner valve housing sidewall  177  and extending distally in a substantially axial direction Inner valve housing sidewall  177 , forming first opening  131 , extends substantially axially downward toward a valve opening, referenced prior art valve opening  151 ,  151 ′ of prior art valve  150 ,  150 ′, respectively, or valve opening  451  of improved conical valve  450 . The upper portion of the first opening  131  can be rounded so as not to have any right angle edges at the first opening  131 , but with the resulting cross-section forming a substantially cylindrical first opening  131  extending along the same axis as that for the prior art valve opening  151 ,  151 ′ or improved conical valve opening  451 . The proximal end housing portion  171  can also include an annular valve ring recess  179  for retaining the prior art valve  150 ,  150 ′ or improved conical valve  450 . The distal end housing portion  173  can include a second opening  133  having a second opening diameter defined by a distal valve housing sidewall  181  extending in a substantially axial direction. The medial housing portion  175  can includes a first proximal valve housing inner perimeter surface  183  and a second distal valve housing inner perimeter surface  185  which can have a perimeter size or circumference the same or slightly larger than that of the first proximal valve housing inner perimeter surface  183 . 
         [0061]    Cap assembly  130  may also include compression ring  136  positioned in valve housing  132  at a medially axial position between first and second openings  131 ,  133  of valve housing  132 , abuttingly contacting axially facing distal surface  199  of valve ring  195 . Compression ring  136  includes compression ring opening  137 , substantially aligned axially with first opening  131  of valve housing  132  to allow extension of the plurality of elongate tools therethrough. Compression ring opening  137  can also be sized to allow at least portions of inner valve housing sidewall  177  and valve  150 ,  150 ′ or  450  to extend therethrough. Compression ring  136  also includes outer perimeter surface  217  having a radial diameter sized so that compression ring  136  substantially abuttingly contacts proximal valve housing inner perimeter surface  183  when positioned within valve housing  132  and includes annular flange  219  extending preferably into each one of the plurality of convolute recesses  411 . 
         [0062]    Compression ring  136  is positioned to compress valve ring  195 ,  195 ′ or  495  against an axially facing inner surface and an axially facing shoulder of proximal end housing portion  171  of valve housing  132  which together, along with a portion of first proximal valve housing inner perimeter surface  183  of medial housing portion  175 , form valve ring recess  179  and/or compress the valve ring  195  against first proximal valve housing inner perimeter surface  183  of medial housing portion  175 , to hold valve ring  195  in valve ring recess  179  to fixedly position the valve  150 ,  150 ′ or  450  within valve housing  132 . That is, compression ring  136  is positioned so that proximal valve housing inner perimeter surface  183 , surfaces forming valve ring recess  179 , and annular flange  219  of compression ring  136  rigidly hold valve ring  195 ,  195 ′ or  495  within valve housing  132 . 
         [0063]    Annular flange  219  of compression ring  136  can include a plurality of notches  221  symmetrically positioned spaced-apart from each other so that each of the notches  221  aligns with and receives a separate one of the plurality of rib members  459  to thereby rotationally align the compression ring  136  with the valve ring  495  when positioned in contact therewith. Alternatively, the annular flange  219  can include a plurality of separate spaced apart flanges (not shown) having a gap between each pair of flanges defining the notch  221  and aligned with the plurality of rib members  459  to thereby enhance positioning of the valve ring  195 . To further enhance positioning of the valve ring  195 , according to an embodiment of the valve housing  132  and valve ring  195 , the axially facing inner surface of the proximal end housing portion  171  of the valve housing  132  can include one or more protuberances  205  extending at least partially along the length of the valve ring recess  179 , and the proximal surface  197  of the valve ring  195  can include one or more recesses  206  or can deform to form a recess  206 , as illustrated, to receive the one or more protuberances  205  to thereby enhance positioning of the valve ring  195  within the valve housing  132 . 
         [0064]    Cap assembly  130  can also include second valve  160 . Second valve  160  is advantageously positioned adjacent second opening  133  of valve housing  132 , abuttingly contacting compression ring  139 . Second valve  160  advantageously has annular flange portion  162  spaced axially from the valve ring of the first valve  150 ,  150 ′ or  450 . Annular flange portion  162  can have a radial diameter sized so that annular flange portion  162  substantially abuttingly contacts the distal valve inner housing perimeter surface  185  and axially facing distal surface of compression ring  136  adjacent compression ring opening  137  to enhance the positioning of second valve  160  within valve housing  132 . Second valve  160  includes second valve opening  223  positioned within annular flange portion  162  and, when positioned within valve housing  132 , is substantially aligned axially with first and second openings  131 ,  133 , of valve housing  132  to allow extension of the plurality of elongate tools therethrough. 
         [0065]    Annular-shaped sidewalls  164  are connected to annular flange portion  162  and extend distally in a substantially axial direction when positioned in valve housing  132 . At least one pair of valve flaps  166  is connected to and extends inwardly from sidewalls  164  and flange portion  162 . Sidewalls  164 , for example, can extend distally of the end of valve housing  132  so that flange portion  162  retains only portions of second valve  160  within valve housing  132  and yet slidably or in a spaced-apart relation have other portions which are positioned within proximal portion  48  of cannula body  42 . Similarly, portions of the valve extension  452  and/or the valve opening  451  of the first valve  450  can extend within the proximal portion  48  of the cannula body  42 . The pair of valve flaps  166  has at least one opening or slit  168  along common peripheral edges thereof through which the tools  22 ,  23 ,  24 ,  25 , can individually and separately extend. Second valve  160  also advantageously can have ribs or rib members (not shown), e.g., formed integrally therewith as a single piece, and connected to sidewalls  164  to reduce drag as will be understood by those skilled in the art. Second valve  160  can also be advantageously impregnated with a lubricant such as an oil material to enhance performance thereof. It should be noted that the illustrated sidewalls  164  can be replaced with other forms of extension extending from annular flange portion  162  of second valve  160 . Further, valve opening  168  can take other forms, such as an annular shaped opening or other known to those skilled in the art. 
         [0066]    Second valve  160 , in general, and the portion of sidewalls  164  surrounding opening  168 , in particular, can be formed of a flexible material similar to that used in forming the first valve  450 . For example, the flexible material advantageously can include a silicon material coated in paralene to enhance the strength of valve  160  and to enhance sliding and/or sealing of the plurality of tools. 
         [0067]    In order to enhance positioning of second valve  160 , a proximal surface of annular flange portion  162  of second valve  160  can include an at least partially annular recess  227  or can deform to form recess  227 , as illustrated, to receive an at least partially annular protuberance  225  extending from a distal surface of compression ring  136  to thereby enhance positioning of second valve  160  at least partially within valve housing  132 . 
         [0068]    A distal surface of annular flange portion  162  of second valve  160  can further include a second valve annular-shaped recess  229  adapted to receive an axially extending annular-shaped flange  272  of proximal portion  48  of cannula  40  to thereby enhance positioning of at least part of proximal portion  48  of cannula  40  within valve housing  132 . 
         [0069]    Cap assembly  130  can also include cap seal ring  138  positioned at least partially within valve housing  132  and having an axially extending flange  274  positioned to abuttingly contact a distal surface of annular flange portion  162  of second valve  160  when positioned in valve housing  132 . Cap seal ring  138  can include a plurality of radially extending flanges  135 , each adapted to engage outer peripheries of a separate one of the plurality of radially extending flanges  34  of cannula  40  to slidably detachably connect valve housing  132  to cannula  40 . Cannula  40  can also include an annular shaped axially extending flange adapted to engage annular-shaped recess  229  of second valve  160  to thereby enhance positioning of cannula  40  securely against second valve  160  when positioned in engagement with radially extending flanges  135  of cap seal ring  138 . 
         [0070]    Improved conical valve  450 , as with prior art valve  150 ,  150 ′, is advantageously fixedly secured to valve housing  132 .  FIG. 6  illustrates an exemplary construction process of a prior art cap assembly  130 , as instructive of the similar construction process of the presently disclosed cap assembly  430 . To provide secure sealing, prior art valve  150  (or similarly improved conical valve  450 , as may be so read throughout this and the immediately following exemplary cap assembly construction process paragraphs) is first inserted into valve housing  132 . Then compression ring  136 , for example, coated with an ultraviolet bonding agent, is placed into valve housing  132  adjacent and abuttingly contacting valve  150  in a “stacked” fashion. Following this, second valve  160  is inserted into valve housing  132  adjacent and abuttingly contacting compression ring  136 , and cap seal ring  138  coated with an ultraviolet bonding agent is placed into valve housing  132  and abuttingly contacting outer peripheries of second valve  160 . Both compression ring  136  and cap seal ring  138  can be coated with an ultraviolet bonding agent along the outer peripheries thereof abuttingly contacting the inner peripheries of valve housing  132 . 
         [0071]    Once each of the components is in its place, the entire cap assembly is placed in a compression system, wherein each component is compressed to its desired depth into valve housing  132 . At that point, an ultraviolet light is exposed to the ultraviolet bonding agent to cure the materials. The curing takes place in about 8 seconds. Upon the completion of the curing, cap assembly  130  is formed as one unit. Beneficially, second valve  160  can be readily removed and exchanged for a replacement. 
         [0072]    When constructing a trocar system  120 , cap assembly  130  is then abuttingly connected to cannula  40 . Proximal end portion  48  of cannula body  42  has at least one valve housing mating portion  34  associated therewith and cap seal ring  138  positioned in valve housing  132  also has at least one cannula body mating portion or flange  135  associated therewith so that cap assembly  130  matingly attaches to cannula body  42  in a secured position and whereby movement of cap assembly  130 , e.g., rotation, by a hand of a user releases, e.g., unsecures or unlocks, the respective mating portions  34 ,  135  for ready removal of cap assembly  130  by the user with the first and second valves  450 ,  160 , and so that specimens, e.g., tissue, can be readily removed from cannula body  42  without damage by the first and second valves  450 ,  160 . The extraction of large tissue samples and/or gauze packs can be accomplished without removing cannula  40  from the area where various endoscopic procedures take place. 
         [0073]    As perhaps best shown in  FIGS. 2 and 5 , the prior art valve  150 ,  151 ′, as with improved conical valve  450 ′, can include valve body  155 ,  155 ′ or  455 , respectively, positioned at least partially within valve housing  132 , axially aligned with the first opening  131  of the valve housing  132 . Valve body  155 ,  155 ′ or  455  includes proximal valve section  191 ,  191 ′ or  491 , respectively, fixedly positioned entirely within valve housing  132 , and distal valve section  193 ,  193 ′ or  493  extending axially from proximal valve section  191 ,  191 ′ or  491 . These common general features relative to prior art valve  150 ,  150 ′ and improved conical valve  450  are related to facilitate general understanding relative to common interaction within cap assembly  40 , but should not be understood to indicate similarity of specific structure or performance between prior art valve  150 ,  150 ′ and improved conical valve  450 , or to impart any limitation to the presently disclosed improved conical valve  450  other than as specifically described herein. 
         [0074]    Valve  450  has periphery valve section  456  connected to and extending radially outwardly from peripheries of the base of valve extension  452 . Periphery valve section  456  includes valve ring  495 , defining an outer perimeter of valve  450 , and preferably has plurality of convolutes  458 , plurality of rib members  459 , and circumferential baffle  494 . Plurality of rib members  459  each preferably extend radially at least a portion of the distance between peripheries of the base of valve extension  452  and valve ring  495 , preferably symmetrically positioned spaced-apart from each other. Preferably, plurality of rib members  459  preferably extends between the base of valve extension  452  and circumferential baffle  494 . 
         [0075]    Thus, the proximal valve section  191  or  491  includes valve ring  195  or  495 , respectively, positioned in the valve ring recess  179  ( FIG. 2 ) or  479  of the valve housing  132 . Referring now to  FIG. 11 , valve ring  495  has proximal surface  497 , distal surface  499 , inner perimeter surface  501 , and an outer perimeter surface  503  defining an outer perimeter of valve body  455 . Proximal valve section  491  preferably has circumferential baffle  494  extending radially inwardly from inner perimeter surface  501  of valve ring  495  to outer sidewall  510  of plurality of convolutes  458 . Proximal valve section  491  can include plurality of convolutes  458 , each having outer sidewall  510  extending from circumferential baffle  494 , first sidewall  507  extending axially and radially inwardly from outer sidewall  510 , and a second sidewall  509  extending axially from first sidewall  507 , substantially parallel to or slightly angled from inner perimeter surface  501  of valve ring  495 , and forming an inner radial periphery of proximal valve section  491 . 
         [0076]    Proximal surface  498  and distal surface  500  of periphery valve section  456  are each further defined by two sub-elements surfaces, wherein first sub-element surface  502  of proximal surface  498  is defined in a first plane and proximate the inner perimeter of periphery valve section  456 , and second sub- element surface  504  of proximal surface  498  is defined in a second plane and proximate the outer perimeter of periphery valve section  456 . A similar, but opposing relationship exists between two sub-element surfaces of distal surface  500 , wherein first sub-element surface  506  of distal surface  500  is defined in a first plane and proximate the inner perimeter of periphery valve section  456 , and second sub-element surface  508  of distal surface  500  is defined in a second plane and proximate the outer perimeter of periphery valve section  456 . Accordingly, neither proximal surface  498  nor distal surface  500  of periphery valve section  456  is flat. 
         [0077]    Periphery valve section  456  may include circumferential baffle element  494 , wherein second sub-element surface  504  of proximal surface  498  and second sub-element surface  508  of distal surface  500  are components thereof. That is, circumferential baffle element  494  is preferably related to proximal valve section  491  of valve  450 , wherein circumferential baffle element  494  is defined in the second plane proximate the outer perimeter of periphery valve section  456 . Proximal valve section  491  of valve  450  can also include plurality of convolutes  458 , each having outer sidewall  510  extending axially from the second plane and circumferential baffle element  494  to the first plane and first sidewall  507 . Outer sidewall  510 , first sidewall  507 , and the second sidewall  509  of each of the plurality of convolutes  458  form a respective convolute recess  511 . The proximal valve section  491  can also include a plurality of rib members  459 , each radially extending from circumferential baffle element  494  to inner perimeter surface  501  of the valve ring  495  and symmetrically positioned spaced-apart from each other. 
         [0078]    The distal valve section  493  can extend axially from proximal valve section  491  and can include valve extension  452  extending axially from the plurality of convolutes  458 . The valve extension  452  can have a proximal end portion  512  substantially connected to a distal portion of each of the plurality of convolutes  458 , a distal end portion  513 , and a medial portion  515  connected to and extending therebetween. According to an embodiment of the valve extension  452 , medial portion  515  can have a substantially frusta-conical or other similar conical-form shape, as illustrated. The distal valve section  493  includes valve opening  451  positioned in distal end portion  513  of valve extension  452 , which can have, for example, an annular shape. The valve opening  451  is adapted to individually and separately receive therethrough any one of the plurality of different elongate tools (not shown) each having a different diameter so that when any one of the plurality of elongate tools is positioned through valve opening  451 , a septum-type seal is maintained between peripheries of distal end portion  513  of valve extension  452  surrounding valve opening  451  and outer peripheries of any one of the plurality of elongate tools when extending therethrough. As noted previously, the plurality of tools each have an elongate body for extending through valve housing  132 , valve opening  451  of valve  450 , and the cannula  40 . 
         [0079]    The plurality of convolutes  458  are each positioned between and connected to any two adjacent rib members  459 . According to an embodiment of the convolutes  458 , each convolute  458  can be in a selected biased position before and after each of the plurality of different elongate tools, individually and separately, extends through the valve opening  451 . According to an embodiment of the present invention, the combination of the convolutes  458 , circumferential baffle  494  and valve extension  452  allow for axial movement of the tools without a corresponding movement within valve opening  451  with respect to outer peripheries of the tools. 
         [0080]    The valve body  455 , in general, and the portion of valve extension  452  surrounding opening  451 , in particular, can be formed of a flexible material to provide the elastic range necessary to accommodate the plurality of elongate tools. According to an embodiment of valve body  155 , the flexible material advantageously can include a silicon material coated with paralene, available through various manufacturers, including Dow Corning Corp., to enhance the strength of the valve  450  and to enhance sliding and sealing of the plurality of tools. 
         [0081]    A method of forming a trocar system  420 , as constructed, for example, the valve  450  advantageously has a stretching or elastic range to readily accommodate, e.g., auto-reduction, tools or other instruments having a diameter of about 5 millimeters to about 15 millimeters as understood by those skilled in the art while still maintaining pneumoperitoneum. The valve opening  451  of the valve body  455  has a diameter less than the diameter of each of the tools that extend through valve  450  so that a secured seal is provided around outer peripheries of each of the tools. The second valve  160  advantageously has this range as well, but individually can even have a greater range, e.g., 1 millimeter to 13 or 14 millimeters. Accordingly, with valve  450  and second valve  160 , in combination, the trocar system  420  advantageously can receive different diameter instruments without the necessity of switching cannulas or valve systems. 
         [0082]    Embodiments of the present invention also include a method of using a trocar system  420 , as with prior art trocar system  120 , including the steps of providing a cap assembly  130 , which includes valve  450 , or  150 , as described above, and inserting a tool through the valve  450 , or  150 , and cap assembly  130 . During the insertion through improved valve  450 , circumferential baffle  494 , convolutes  458  and valve extension  452  flex so that valve body  455  extends distally by contact pressure from the tool and so that a distal end of the tool is guided through valve opening  451 . The circumferential baffle  494  and symmetric rib structure reinforces the movement of convolutes  458  and the recovery of convolutes  458  once the tool is extended through valve opening  451 . Because valve  450  is constructed in a thin and relatively conical shaped profile, valve  450  functions like a thin elastic membrane that flexes inwardly and outwardly along a fairly wide range of tool positions, without requiring valve opening  451  to “slide” along the outer peripheries of the respective tool once positioned through valve opening  451 , and does not float or rotate in the valve housing  132 . This method also includes extending the tool through a cannula body  42  matingly connected to the cap assembly  130  at a proximal portion  48  thereof. The method further includes the steps of detaching the cap assembly  130  from the cannula body  42  and removing tissue or other specimen as understood by those skilled in the art from the cannula body  42 . Because various types and diameters of tools can be used by medical personnel, embodiments of a valve advantageously allow one type of valve, cannula, or trocar system to be readily used for all of these various sizes and types of tools. 
         [0083]    As noted, valve body  455 , in general, and the portion of valve extension  452  surrounding opening  451 , in particular, can be formed of a flexible material to provide the elastic range necessary to accommodate the plurality of elongate tools. According to an embodiment of valve body  455 , the flexible material advantageously can include a silicon material coated with paralene, available through various manufacturers including Dow Corning Corp., to enhance the strength of valve  450  and to enhance sliding and sealing of the plurality of tools. Because ease of insertion and removal of the instruments is an important aspect during use of cannula  40 , and because even small measures of improvement can translate into realized enhancement of performance, coatings and other measures directed toward improving lubricity can be advantageously supplemented, wherein a reduction in electrostatic adhesion between valve  450  and the plurality of tools can serve to further enhance the ease of insertion and removal. 
         [0084]    The relationship between frictional force and roughness is parabolic, as depicted in  FIG. 10 , wherein frictional forces are increased between both very smooth, as well as very rough surfaces, and wherein at the vertex of the parabola, a target roughness quality is represented that results in little or no frictional force. The smoothness of valve extension  452 , therefore, can be specifically adjusted relative to previously described valve extension  152 ′, such as seen in  FIGS. 7-9 , wherein plurality of friction-reduction features  300  were defined, but, as will be further discussed, are presently improved. That is, prior valve body  155 ′, in general, and the portion of the valve extension  152 ′ proximate opening  151 ′ included plurality of friction-reduction features  300  to advantageously minimize electrostatic forces between instruments and the valve  150 ′. The plurality of friction-reduction features  300  was configured to increase roughness of valve extension  152 ′ in such a manner that movement toward the vertex along the demonstrated parabolic curve relating frictional force and roughness can be realized, wherein plurality of friction-reduction features  300  was comprised of plurality of protrusions  302 , defined on outer surface  304  and inner surface  306  of valve extension  152 ′, generally over an area defined proximate and between medial portion  215 ′ and distal end portion  213 ′ of valve  150 ′. The friction-reduction features  300  were defined proximate the apical end of the valve  150 ′ in anticipation of contact with the plurality of elongate tools extended therethrough, and were further defined on both opposing surfaces  304 - 306  in order that advantageous minimization of electrostatic forces may be realized also during contact between the valve body  155 ′ and the second valve  160 . The plurality of protrusions  302  were tear-drop shaped, to functionally improve the prior manufacturing process, as well as serving to reduce the resistive forces between the contact surfaces of an inserted instrument and the valve  150 ′ without compromise to the septum seal or to the inherent flexibility and adaptability of the valve  150 ′. 
         [0085]    Referring now to  FIGS. 11-14 , improved conical valve  450  preferably has plurality of closely and symmetrically spaced friction-reduction features  600 , wherein increased concentration and relative proximity of friction-reduction features  600  was empirically determined to enhance minimization of electrostatic forces between instruments and valve  450 . Friction-reduction features  600  are preferably protrusions formed on inner and outer surfaces,  504  and  506 , respectively, of conical valve  450 , proximate distal end  413  and valve opening  451 . Preferably, first circumferential row  602  of protrusions  604  is defined proximate valve opening  451  in a closely-spaced, essentially abutting conformation, whereafter second circumferential row  606  of protrusions  604  is defined in a position of greater distance from valve opening  451  relative to first circumferential row  602 , wherein the same total number of protrusions  604  is preferably defined in second row  606  as first row  602 , but given the increased diameter of conical valve  450  at the location of second row  606  relative to that of first row  602 , protrusions  604  of second circumferential row  606  are less closely- spaced than those of first circumferential row  602 . Thereafter, further plurality of rows  608  are defined in similar fashion. The positioning of the protrusions  604  of each adjacent circumferential row  608  may also be juxtaposed, such that a radial twist pattern may be defined by the protrusions  604  about conical valve  450  proximate distal end  413  and valve opening  451 . 
         [0086]    Protrusions  604 , as noted, may be formed in essentially any shape capable of maintaining the preferred functionality of creating additional space between valve  450  and an instrument inserted therein, and thereby reducing surface area for frictional contact therebetween. Moreover, protrusions  604  may be formed according to a multi-shot liquid silicone rubber process, wherein liquid silicone rubber may be utilized for formation of valve body  455  and traditional thermoplastic elements may be utilized for formation of protrusions  604 , thus combining materials of differing coefficients of friction in a single molded part. In such manner, protrusions  604  may perform with action similar to that of ball bearing elements. 
         [0087]    A further improvement proximate distal end  413  of valve  450  relates to the definition of the plurality of friction-reduction features  600  definition on both inner surface  504  and outer surface  506  of the distal end  413  of valve  450 , wherein each of the plurality of protrusions  604  is preferably shaped as a round-tipped cone  610 , wherein the position and shape of friction-reduction features effectively and measurably enhances friction reduction. That is, kinetic friction between valve  450  and related instruments is advantageously minimized as valve opening  451  is deformed temporarily by contact pressure from the tool, wherein contact area between valve  450  and the instruments is reduced. 
         [0088]    Moreover, elongation or other reactive force redirection by circumferential baffle  494  serves to minimize deformation of the valve opening as well. The friction-reduction features  600 , especially with circumferential baffle  494 , ribs  459 , and convolutes  459 , can reduce the resistive forces between the contact surfaces of an inserted instrument and valve  450  without compromise to the septum seal or to the inherent flexibility and adaptability of valve  450  of the present invention, wherein a broad endoscopic instrument diameter range, from about 5 mm to 15 mm diameter, can be successfully accepted. The friction-reduction features  600  are preferably defined proximate the apical end of valve  450 , in anticipation of contact with the plurality of elongate tools extended therethrough, and are further preferably defined on both opposing surfaces  504  and  506  in order that advantageous minimization of electrostatic forces may be realized also during contact between valve  450  and second valve  160 . 
         [0089]    Each protrusion  604  is thus preferably shaped with a generally circular base and extending outward from inner and outer surfaces  504  and  506 , respectively, of valve  450 , to form cone  610 , preferably with a rounded tip  612 . This preferred shape also serves to facilitate the manufacturing process, wherein successful formation and ejection of valve  450  from a mold is achieved more readily. Thus, while it is recognized that other shapes could be utilized, the preferred round-tipped cone shape is preferred. Further, while the arrangement of plurality of protrusions  604  is depicted and described according to the preferred configuration, wherein a particular enhanced roughness quality is achieved, with measurable improvements over previous configurations, relative to frictional force, other arrangements could be utilized, including more rows, aligned rows, non-rows and/or an arrangement of protrusions with even closer relative proximity, even approaching or achieving an essentially solid configuration, such as an annular rib; however, resulting modification to the roughness and/or related electrostatic nature of the surface could influence the achieved performance enhancement relative to the preferred configuration. 
         [0090]    While the invention has been described with respect to a certain specific embodiment, it will be appreciated that many modifications and changes may be made by those skilled in the art without departing from the spirit of the invention. It is intended, therefore, by the appended claims to cover all such modifications and changes as fall within the true spirit and scope of the invention. In particular, with respect to the above description, it is to be realized that the optimum dimensional relationships for the parts of the present invention may include variations in size, materials, shape, form, function and manner of operation.