Patent Publication Number: US-2022233240-A1

Title: Microwave ablation catheter, handle, and system

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 16/779,861, filed on Feb. 3, 2020, which is a continuation of U.S. patent application Ser. No. 15/870,850, filed on Jan. 12, 2018, now U.S. Pat. No. 10,561,463, which is a continuation of U.S. patent application Ser. No. 14/479,482, filed on Sep. 8, 2014, now U.S. Pat. No. 9,867,665, which claims the benefit of the filing date of provisional U.S. Patent Application Nos. 61/874,881, filed on Sep. 6, 2013; 61/974,611, filed on Apr. 3, 2014; and 62/041,424, filed on Aug. 25, 2014. 
    
    
     FIELD 
     This disclosure relates to surgical instruments and, more specifically, to handles for moving an outer tubular member relative to an inner tubular member inserted therethrough. 
     BACKGROUND 
     A common interventional procedure in the field of pulmonary medicine is bronchoscopy, in which a bronchoscope is inserted into the airways through the patient&#39;s nose or mouth. The structure of a bronchoscope generally includes a long, thin, flexible tube that typically contains three elements: an illumination assembly for illuminating the region distal to the bronchoscope&#39;s tip via an optical fiber connected to an external light source; an imaging assembly for delivering back a video image from the bronchoscope&#39;s distal tip; and a lumen or working channel through which instruments may be inserted, including but not limited to placement (e.g., guide wires), diagnostic (e.g., biopsy tools) and therapeutic (e.g., treatment catheters or laser, cryogenic, radio frequency, or microwave tissue treatment probes) instruments. The distal tip of a bronchoscope is steerable. Rotating a lever placed at the handle of the bronchoscope actuates a steering mechanism that deflects the tip in one or more directions. 
     Bronchoscopies are performed by pulmonologists, also known as bronchoscopists, and are used routinely in the diagnosis and treatment of conditions such as lung cancer, airway stenosis, and emphysema. Bronchoscopies are typically performed by a staff of at least two persons: the bronchoscopist and at least one assistant, usually a nurse. During a typical procedure, the bronchoscopist holds the bronchoscope handle with one hand and the bronchoscope tube with the other hand. The bronchoscopist manipulates the distal tip of the bronchoscope inside the lung by rotating a deflection lever and by pushing and pulling the tube. Once the tip is brought to a target, an instrument can be inserted into the working channel to perform a diagnostic or therapeutic procedure. 
     During insertion and operation of the instruments, the distal tip of the bronchoscope should be held steady at the target. Two hands are needed to secure the bronchoscope in place and one to two more hands are needed for inserting and actuating the instrument. Generally, the bronchoscopist releases the bronchoscope to insert and actuate the instrument. Performing a procedure that requires two people is generally more expensive and the potential for error is increased. Hence, it is desirable to modify a procedure so that it may be performed with one or two hands, if possible. 
     Additionally, because all of the instruments used with a bronchoscope are necessarily long and slender, the instruments do not retain shape when unsupported. Thus, inserting an instrument into a bronchoscope can be difficult or impossible to do quickly with one hand. While this problem can be addressed easily by holding the end of the sheath in one hand and the instrument in another, this would again require additional free hands during performance of the procedure. 
     During particular procedures (e.g., microwave ablation and biopsy) a catheter or extended working channel may be inserted through a working channel to enable navigation to sites too remote and having luminal diameters too small for the bronchoscope. An instrument may be inserted through the catheter or extended working channel in order to perform a biopsy or ablation procedure. Current systems and methodologies for extending the surgical instrument from the catheter or retracting the catheter from the placement of the surgical instrument require at least two people to manipulate all the elements of the system including the bronchoscope. 
     Accordingly, there is a need for an apparatus that would facilitate one-handed actuation of the catheter and surgical instrument leaving one hand to manipulate the bronchoscope. In addition, there is a need for a support for use with a bronchoscope that would facilitate operation of a bronchoscope and associated tools by a single practitioner. It would also be advantageous to provide a support for the probe and the catheter to allow a single practitioner to manipulate a catheter, a probe, and a bronchoscope during the procedure. 
     SUMMARY 
     In an aspect of this disclosure, a handle for longitudinal movement of a first tubular member over a second tubular member includes a handle body, a nose cone, a locking mechanism, and a retraction control. The nose cone has a sleeve and an outer wall defining a control channel therebetween. The nose cone is moveable over the handle body between extended and retracted positions. The locking mechanism has locked and unlocked positions for selectively fixing the nose cone in the extended and retracted positions. The retraction control includes a finger positioned within the control channel of the nose cone and has first and second positions relative to the nose cone for transitioning the locking mechanism between the locked and unlocked positions and for moving the nose cone between the extended and retracted positions. 
     In aspects, when the nose cone is in the extended position and the retraction control is in the first position, the locking mechanism is in the locked position to fix the nose cone in the extended position. 
     In some aspects, when the nose cone is in the extended position and the retraction control is in the second position, the locking mechanism is in the unlocked position such that the nose cone is moveable relative to the handle body. When the nose cone reaches the retracted position, the locking mechanism transitions to the locked position to fix the nose cone in the retracted position. 
     In certain aspects, when the nose cone is in the retracted position and the retraction control is in the second position, the locking mechanism is in the locked position to fix the nose cone in the extended position. 
     In particular aspects, when the nose cone is in the retracted position and the retraction control is in the first position, the locking mechanism is in the unlocked position such that the nose cone is moveable relative to the handle body. When the nose cone reaches the extended position, the locking mechanism may transition to the locked position to fix the nose cone in the extended position. 
     In aspects, the second position of the retraction control is proximal to the first position of the retraction control. The locking mechanism may be disposed within a slot defined in the housing body. The locking mechanism may include a locking pin that has a retention plate. The locking pin may be biased out of the slot defined in the housing body such that the retention plate retains the locking pin within the slot. The sleeve of the nose cone may define first and second openings such that when the nose cone is in the extended position and the locking pin is in the locked position, the locking pin is disposed within the first opening. In addition, when the nose cone is in the retracted position and the locking pin is in the locked position, the locking pin may be disposed within the second opening. 
     In another aspect of this disclosure, a surgical system includes an extended working channel having proximal and distal ends, a handle defining a through passage, a retraction control, and a catheter assembly disposed within the through passage of the handle. The handle includes a housing body defining a proximal portion of the through passage, a nose cone coupled to the proximal end of the extended working channel, a locking mechanism, and a retraction control. The nose cone has a sleeve and an outer wall defining a control channel therebetween. The nose cone defines a distal portion of the through passage in communication with the extended working channel. The nose cone is longitudinally moveable over the housing body between extended and retracted positions. The locking mechanism has locked and unlocked positions for selectively fixing the nose cone in the extended and retracted positions. The retraction control includes a finger positioned within the control channel of the nose cone. The retraction control has first and second positions relative to the nose cone for transitioning the locking mechanism between the locked and unlocked positions and for moving the nose cone between the extended and retracted positions. The catheter assembly includes a catheter hub positioned within the proximal portion of the through passage and an ablation probe extending from the catheter hub through the nose cone of the handle and through the extended working channel. The ablation probe has a distal end that is disposed within the extended working channel when the handle is in the extend position and that is position positioned distal to the distal end of the extended working channel when the handle is in the retracted position. 
     In aspects, the catheter hub combines coolant tubes and an antenna into the ablation probe. The catheter hub may include an adjustment nut that is positioned over an outer surface of the catheter hub. The housing portion may define a nut recess for receiving the adjustment nut to longitudinally fix the ablation probe to the housing portion. The adjustment nut is threaded to cooperate with threads on the outer surface of the catheter hub to allow fine adjustment of the length of the ablation probe relative to the housing portion. The distal end of the ablation probe may be positioned within the distal end of the extended working channel when the nose cone is in the extended position. The distal end of the ablation probe may be positioned distal to the distal end of the extended working channel when the nose cone is in the retracted position. 
     In another aspect of this disclosure, a method of assembly of a surgical system includes positioning a catheter assembly within a half of a first portion of a passage defined within a first half of a housing body of a handle, securing a second half of the housing body of the handle to the first half of the housing body with the catheter assembly that is positioned in a half of the first portion of the passage defined within the second half of the housing body to form the housing body, sliding a nose cone of the handle over a distal portion of the housing body, and inserting a finger of a retraction control within a control channel defined between a sleeve and outer wall of the nose cone. The nose cone defines a second portion of the passage that receives a probe of the catheter assembly therethrough. 
     In aspects, the positioning of the catheter assembly within the first half of the first portion of the passage that is defined within the first half of the housing body includes position an adjustment nut within a nut recess defined in the housing body to adjust the length of the probe extending distally from the housing body. The method may further include rotating the adjustment nut about a threaded portion of the catheter hub to fix the length of the probe that extends distally from the housing body. Securing the second half of the housing body to the first half of the housing body may prevent adjustment of the length of the probe extending distally from the housing body during use of the surgical system. 
     In another aspect of this disclosure, a support system includes a rail, a lower support, and an instrument support. The rail has upper and lower ends that define a longitudinal axis therebetween. The lower support is configured to receive a portion of a bronchoscope and to selectively fix the bronchoscope relative to the rail. The instrument support is slidably disposed on the rail and is selectively lockable to the rail. The instrument support is configured to releasably couple to a surgical instrument inserted through the bronchoscope to fix the position of a portion of the surgical instrument relative to the bronchoscope. 
     In aspects, the instrument support includes a clamp arm and a clamp arm collar. The clamp arm collar may be slidably disposed over the rail. The clamp arm may include instrument fingers that extend from the clamp arm collar. The instrument fingers may define an instrument passage that is configured to releasably couple to the surgical instrument. The instrument support may include a locking arm that has a locking cam. The clamp arm collar may include a camming surface and the locking cam may be configured to compress the camming surface of the clamp arm collar against the rail when the locking arm is in the locked position to lock the instrument support to the rail. In the locked position, the instrument support may be radially locked relative to the rail. 
     In some aspects, the lower support defines a rail opening that is configured to receive the lower end of the rail. The support system may include a collar positioned within the rail opening that includes a threaded portion. The support system may include a securement member that is threaded over the threaded portion of the collar to compress the collar over the lower end of the rail to fix the rail to the lower support. 
     In certain aspects, the lower support includes a pair of support fingers that extend orthogonally from the rail. The support fingers may define a support opening therebetween. The support fingers may be configured to compress the support opening about the bronchoscope to fix the lower support relative to the bronchoscope. 
     In another aspect of this disclosure, a surgical system includes a bronchoscope, an extended working channel that extends through the bronchoscope, an elongated surgical instrument that is inserted through the extended working channel, and a support system for supporting the elongated surgical instrument relative to the bronchoscope. The support system includes a rail, a lower support, and an instrument support. The rail has upper and lower ends that define a longitudinal axis therebetween. The lower support is fixed to the lower end of the rail and to the bronchoscope to fix the rail to the bronchoscope. The instrument support is slidably disposed on the rail and is selectively lockable to the rail. The instrument support is releasably coupled to a first portion of the elongated surgical instrument to fix the position of the first portion of the elongated surgical instrument relative to the bronchoscope. 
     In aspects, a second portion of the elongated surgical instrument is moveable relative to the bronchoscope. The second portion of the elongated surgical instrument may be fixed to a proximal end of the extended working channel such that the extended working channel is moveable relative to the bronchoscope and the first portion of the elongated surgical instrument. The first portion of the elongated surgical instrument includes an ablation probe that extends through the second portion of the elongated surgical instrument and the extended working channel. 
     In some aspects, the extended working channel includes a telescopic extended working channel handle that is fixed to the bronchoscope. When the telescopic extended working channel handle is manipulated, the bronchoscope and the elongated surgical instrument that is fixed to the bronchoscope by the support system move in concert with the telescopic extended working channel handle. 
     In another aspect of this disclosure, a method of positioning an elongated surgical instrument adjacent targeted tissue includes inserting the elongated surgical instrument into an extended working channel, securing a support system to the bronchoscope, coupling a portion of the elongated surgical instrument to the support system to fix the portion of the elongated surgical instrument to the bronchoscope, and manipulating a portion of the extended working channel such that the bronchoscope, the elongated surgical instrument, and the support system move in concert with the portion of the extended working channel. The elongated surgical instrument may have a locatable guide adjacent a distal end thereof. The extended working channel passes through a bronchoscope positioned in an airway of a patient. 
     In aspects, manipulating a portion of the extended working channel includes manipulating a telescopic extended working channel handle of the extended working channel that is connected to the bronchoscope. 
     In some aspects, securing the support system to the bronchoscope may include fixing a lower support of the support system to a portion of the bronchoscope. Securing the support system to the bronchoscope may include inserting a lower end of a rail of the support system into the lower support. 
     In certain aspects, coupling a portion of the elongated surgical instrument to the support system includes coupling the portion of the elongated surgical instrument in an instrument support of the support system. The method may include locking the instrument support to a rail of the support system to fix the portion of the elongated surgical instrument relative to the bronchoscope. 
     Further, to the extent consistent, any of the aspects described herein may be used in conjunction with any or all of the other aspects described herein. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Various aspects of this disclosure are described hereinbelow with reference to the drawings, which are incorporated in and constitute a part of this specification, wherein: 
         FIG. 1  is a perspective view of an exemplary surgical system including a retraction handle and a rail system in accordance with the disclosure; 
         FIG. 2  is a perspective view of the retraction handle of  FIG. 1 ; 
         FIG. 3  is an exploded perspective view showing the components of the retraction handle of  FIG. 1 ; 
         FIG. 3A  is a cross-sectional view taken along the section line  3 A- 3 A shown in  FIG. 3 ; 
         FIG. 4  is a longitudinal cross-sectional view of the retraction handle of  FIG. 1  taken along the longitudinal axis thereof; 
         FIG. 5  is an enlarged view of the indicated area of detail of  FIG. 4 ; 
         FIG. 6  is a longitudinal cross-sectional view of the retraction handle with the retraction control in a second position and the nose cone in an extended position; 
         FIG. 7  is an enlarged view of the indicated area of detail of  FIG. 6 ; 
         FIG. 8  is a longitudinal cross-sectional view of the retraction handle with the retraction control in the second position and the nose cone in the retracted position; 
         FIG. 9  is an enlarged view of the indicated area of detail of  FIG. 8 ; 
         FIG. 10  is a longitudinal cross-sectional view of the retraction handle with the retraction control in the first position and the nose cone in the retracted position; 
         FIG. 11  is an enlarged view of the indicated area of detail of  FIG. 10 ; 
         FIG. 12  is a perspective view of a distal end of the catheter of  FIG. 2 ; 
         FIG. 13  is a perspective view of the distal end of the catheter of  FIG. 12  when the retraction handle is in the retracted position; 
         FIG. 14  is an enlarged view of the indicated area of detail of  FIG. 1 ; 
         FIG. 15  is a side cross-sectional view of taken along the section line  15 - 15  of  FIG. 14 ; 
         FIG. 16  is an enlarged view of the indicated area of detail of  FIG. 1 ; 
         FIG. 17  is a top view of a device support taken along the line  17 - 17   FIG. 16  illustrating a locking arm in an unlocked position; 
         FIG. 18  is a top view of a device support taken along the line  18 - 18  of  FIG. 16  illustrating a locking arm in a locked position; 
         FIG. 19  is a perspective view of the surgical system of  FIG. 1  in use with an electromagnetic navigation system  400  provided in accordance with the disclosure; 
         FIGS. 20A-20C  are side views of distal ends of instruments that may be used with the surgical system of  FIG. 1   
         FIG. 21  is a perspective view of another rail system provided in accordance with the disclosure; 
         FIG. 22  is an enlarge perspective view of the area of detail indicated in  FIG. 21 ; 
         FIG. 23  is a cross-sectional view taken along the section line  23 - 23  of  FIG. 22 ; 
         FIG. 24  is a perspective view of the lower support of  FIG. 22  with the support arm in an open configuration positioned about a portion of a bronchoscope; 
         FIG. 25  is a perspective view of the lower support of  FIG. 24  with the portion of the bronchoscope removed; 
         FIG. 26  is a cross-sectional view taken along the section line  26 - 26  of  FIG. 21  illustrating the instrument support in an unlocked configuration; 
         FIG. 27  is a cross-sectional view of the instrument support of  FIG. 27  in a locked configuration; and 
         FIG. 28  is a perspective view of the rail system of  FIG. 21  with another instrument support provided in accordance with the disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     According to aspects of this disclosure, a support system mounts to a bronchoscope to support instruments inserted through and associated with the bronchoscope. In one embodiment, the support system is configured to separately support a retraction handle and a catheter inserted through the retraction handle and the bronchoscope. The retraction handle is coupled to an extended working channel that passes through the bronchoscope and into the anatomy of a patient. The catheter is inserted through the extended working channel to a position adjacent targeted tissue. When the catheter is positioned adjacent the targeted tissue, the retraction handle is moved to a retracted position to expose the distal end of the catheter adjacent the targeted tissue such that the catheter can treat the targeted tissue. The retraction handle may be moved to the retracted position with one hand of a clinician as detailed herein. 
     Embodiments of this disclosure are now described in detail with reference to the drawings in which like reference numerals designate identical or corresponding elements in each of the several views. As used herein, the term “clinician” refers to a doctor, a nurse, or any other care provider and may include support personnel. Throughout this description, the term “proximal” refers to the portion of the device or component thereof that is closest to the clinician and the term “distal” refers to the portion of the device or component thereof that is farthest from the clinician. 
     Referring now to  FIG. 1 , a surgical system  10  includes a bronchoscope  11 , a telescopic extended working channel (EWC) handle  15 , an ablation catheter assembly  100 , including a cable  18 , a probe  19 , a retraction handle  20 , and a connector  21  for connection to an energy source such as a microwave generator (not shown). A portion  18   a  of the cable  18  may extend from the connector  21  to a coolant source (not shown) for providing a cooling fluid to the ablation catheter assembly  100 .  FIG. 1  also depicts a rail system  300  including a support rail  312  supported on the bronchoscope  11  by a lower support member  320  and includes a device support  330  that supports the retraction handle  20  as detailed below. The support rail  312  may include an additional a device support  330  that supports the cable  18  above the retraction handle  20 . The rail system  300  is disclosed in greater detail below. 
     The telescopic EWC handle  15  connects to the bronchoscope  11  and is in communication with an EWC  96 , formed internally therein, such that instruments passed through the telescopic EWC handle  15  pass through the EWC  96 . The proximal end  16  of the telescopic EWC handle  15  includes a mating feature that is engaged by the retraction handle  20 . The retraction handle  20  mates with the proximal end  16  of the telescopic EWC handle  15  ( FIG. 1 ) enabling movement of the EWC  96  relative to the ablation probe  19 , as described below. The retraction handle  20  may include an engagement feature  27  ( FIG. 2 ) for engaging the mating feature of the proximal end  16  of the telescopic EWC handle  15 . The engagement feature  27  may be a clip that is received within an opening defined in the proximal end  16  of the telescopic EWC handle  15 . 
     With reference to  FIGS. 2 and 3 , the ablation catheter assembly  100  includes an ablation probe  19  and a catheter hub  180  positioned within a through passage  23  ( FIG. 4 ) formed in the retraction handle  20 . The ablation probe  19  extends distally from the catheter hub  180 , through the telescopic EWC handle  15  ( FIG. 1 ) and the EWC  96  formed internal therein, and to a distal end  96   a  ( FIGS. 12 and 13 ) of the EWC  96 . The catheter hub  180  includes coolant channels  183  and a connector  186  enabling electrical connection of cable  18  with an antenna  187 , described below. One of the coolant channels  183   a  is an inflow channel and the other coolant channel  183   b  is an outflow channel. The coolant channels  183   a ,  183   b , the connector  186 , and the antenna  187  are coupled together within the catheter hub  180  into the ablation probe  19 . 
     With particular reference to  FIG. 3A , the ablation probe  19  includes a microwave antenna  82  electrically connected to cable  18  and sized be received within an outer sheath  84  of the ablation probe  19 . An inner sheath  86  is formed within the outer sheath  84  and surrounds the microwave antenna  82 , the inner sheath  86  separates the interior of the ablation probe  19  into inflow and outflow coolant paths  83   a  and  83   b  such that coolant flows through the inflow channel  183   a , along the microwave antenna  82  in the inflow coolant path  83   a  to a distal end of the ablation probe  19 , and returns via the outflow coolant path  83   b  separating the inner sheath  86  from the outer sheath  84  to the outflow channel  183   b . In this manner the ablation probe  19 , and more particularly the microwave antenna  82 , is actively cooled. Examples of microwave antenna construction may be found in commonly assigned U.S. patent application Ser. No. 13/835,283 entitled “Microwave Energy-Device and System,” and Ser. No. 13/836,519 entitled “Microwave Ablation Catheter and Method of Utilizing Same,” the entire contents of each is incorporated herein by reference. 
     Referring back to  FIG. 3 , the catheter hub  180  includes a threaded portion  189  adjacent a distal end thereof. The threaded portion  189  receives an adjustment nut  182  that adjusts the length of the ablation probe  19  extending from the retraction handle  20 . The adjustment nut  182  may be used by the manufacturer of the retraction handle  20  to finely adjust the length of the ablation probe  19  extending from the retraction handle  20  when the retraction handle  20  is assembled over the cable  18 . Such an adjustment mechanism may allow the manufacturer to employ increased tolerances in the length of the ablation probe  19  during manufacture and to finely adjust the length of the ablation probe  19  during assembly. It will be appreciated that once the retraction handle  20  is assembled over the catheter hub  180 , the adjustment nut  182  is not accessible by a clinician using the retraction handle  20  (i.e., once the length of the ablation probe  19  is set during assembly, the length of the ablation probe is fixed). 
     With additional reference to  FIG. 4 , the retraction handle  20  includes a nose cone  22 , a retraction control  24 , a sleeve  124  ( FIG. 3 ), a handle body  26 , a spindle cap  28 , and a locking mechanism  30 . The components of the retraction handle  20  (e.g., the nose cone  22 , the retraction control  24 , the handle body  26 , and the spindle cap  28 ) may be rotatable relative to one another to allow the components to rotate without applying a rotational force to the cable  18  or the EWC  96 . 
     The handle body  26  includes first and second body sections  131 ,  132  ( FIG. 3 ) that are secured together to define a second portion  23   b  ( FIG. 4 ) of the through passage  23  therethrough. As shown in  FIG. 3 , the distal end of the handle body  26  defines a ring groove  133  in an outer surface thereof that receives a ring  134  that secures the first and second body sections  131 ,  132  together. The distal end of the handle body  26  is received in the first portion  23   a  of the through passage  23  defined by the nose cone  22 . The second portion  23   b  of the through passage  23  defined by the handle body  26  includes a nut recess  135  that is positioned adjacent a distal end thereof and a cable recess  136  that is positioned adjacent a proximal end thereof. 
     The outer surface of the handle body  26  includes mating tabs  137  positioned at a proximal end thereof. The spindle cap  28  is disposed over the proximal end of the handle body  26  and includes retention tabs  29  that engage the mating tabs  137  of the handle body to secure the spindle cap  28  to the handle body  26  and to secure the proximal end of the first and second body sections  131 ,  132  together. 
     Referring to  FIGS. 4 and 5 , the nose cone  22  defines an outer wall  122  and receives a sleeve  124 . The sleeve  124  defines a first portion  23   a  of a through passage  23  that receives the handle body  26  and a portion of the probe  19  therewithin. The outer wall  122  of nose cone  22  and the sleeve  124  define a control channel  123  therebetween that slidably receives the retraction control  24 . The distal end of the control channel  123  includes a control stop  125  that may limit the proximal displacement of the retraction control  24  relative to the nose cone  22 . 
     The sleeve  124  includes a first opening  126  and a second opening  128  positioned distal to the first opening  126 . The sleeve  124  may optionally define a slot  127  in communication with the first and second openings  126 ,  128  parallel to the longitudinal axis. The sleeve  124  includes a retention ring  129   a  disposed about the inner wall  124  adjacent a proximal end thereof that prevents the retention control  24  from disengaging the sleeve  124  of (i.e., sliding proximally off of the sleeve  124 ). The sleeve  124  is formed separately from the nose cone  22  and joined thereto by a distal retention ring  129   b . It is also within the scope of this disclosure that the sleeve  124  may be integrally formed with the nose cone  22 . 
     The retraction control  24  includes a proximal flange  141  and a distal finger  145  extending therefrom. The proximal flange  141  includes an inner angled surface  142  and a shoulder  143 . The distal finger  145  includes a ramped surface  146  adjacent the inner wall  124  of the nose cone  22 . The distal finger  145  is positioned over the inner wall  124  of the nose cone  22  such that the distal finger  145  is disposed substantially between the sleeve  124  and the outer wall  122  of the nose cone  22 . 
     Referring in particular to  FIG. 4 , a locking mechanism  30  selectively locks the nose cone  22  in each of an extended position and a retracted position as detailed below. The outer surface of the handle body  26  defines pin slots  138  positioned adjacent a distal end thereof which may be positioned proximal to the nut recess  135 . The locking mechanism  30  includes a locking pin  32  disposed within each of the pin slots  138  and a pin biasing member  37  supported within each of the pin slots  138  between a respective locking pin  32  and the housing body  26 . Each locking pin  32  includes a shaft  33 , a retention plate  34 , and a locking surface  35  and is disposed substantially within a respective pin slot  138 . The shaft  33  may pass through the pin biasing member  37 . Each pin biasing member  37  engages the retention plate  34  of a respective locking pin  32  to urge the respective locking pin  32  out of pin slot  138 . 
     The locking pins  32  are moveable between a locked position and an unlocked position. In the locked position, the locking surface  35  of the locking pin  32  protrudes from the pin slot  138  and through one of the first and second openings  126 ,  128  of the sleeve  124 . In the locked position, the retention plate  34  engages the inner surface of the sleeve  124  adjacent one of the first and second openings  126 ,  128  to prevent the locking pin  32  from passing entirely through the first or second openings  126 ,  128 . In the unlocked position, the locking pin  32  is moved towards the longitudinal axis of the handle  20  against the pin biasing member  37  such that the locking surface  35  of the locking pin  32  is deflected within the inner surface of the sleeve  124 . In the unlocked position ( FIG. 6 ), the locking surface  35  of the locking pin  32  is engaged by the inner surface of sleeve  124  between the first and second openings  126 ,  128 . 
     When the locking pins  32  are in the locked position and positioned to protruded through the first openings  126  ( FIGS. 4 and 5 ), the nose cone  22  is in the extended position. When the locking pins  32  are in the locked position and positioned to protrude through the second openings  128  ( FIGS. 7 and 8 ), the nose cone  22  is in the retracted position. The retraction control  24  engages the locking surface  35  of the locking pins  32  to move the locking pins  32  from the locked position to the unlocked position to permit the nose cone  22  to move between the extended and retracted positions as detailed below. 
     Referring to  FIGS. 4-9 , the retraction control  24  moves the nose cone  22  along the longitudinal axis from an extended position ( FIG. 4 ) to a retracted position ( FIG. 8 ). It will be appreciated that the extended and retracted positions refer to the location of the distal end  96   a  of the EWC  96  relative to the distal end  19   a  of the probe  19  as shown in  FIGS. 12 and 13 . In  FIGS. 4 and 12 , the EWC  96  is extended beyond the distal end  19   a  of the probe  19 , and in  FIGS. 5 and 13  the EWC  96  is retracted, exposing the distal end  19   a  of probe  19 . In part this orientation of movement is necessary when, as shown in  FIG. 1 , the housing body  26  of handle  20  is secured to the rail system  300  by device supports  330 . The retraction control  24  has a first position ( FIG. 4 ) relative to the nose cone  22  such that the retraction control  24  (i.e., the distal finger  145 ) is positioned over the second openings  128  formed in the sleeve  124  leaving the first openings  126  unobstructed and a second position ( FIG. 6 ) relative to the nose cone  22  such that the retraction control  24  (i.e., the proximal flange  141 ) is positioned proximal to the first openings  126  leaving the second openings  128  unobstructed. Initially referring to  FIGS. 4 and 5 , the nose cone  22  is in the extended position, the retraction control  24  in a first position relative to the nose cone  22 , and the locking pins  32  are in the locked position within the first openings  126 . 
     Referring now to  FIGS. 6 and 7 , the nose cone  22  remains in the extended position and the retraction control  24  is moved to the second position relative to the nose cone  22  that is proximal to the first position. As the retraction control  24  is moved to the second position, the inner angled surface  142  of the proximal flange  141  engages the locking surface  35  of the locking pins  32  to move the locking pins  32  from the locked position to the unlocked position. When the locking pins  32  are in the unlocked position, the nose cone  22  is free to move towards the retracted position ( FIG. 8 ). 
     With reference to  FIGS. 8 and 9 , additional retraction of the retraction control  24  stops when the inner angled surface  142  of the retraction control  24  engages retention ring  129   a  fixed to the inner wall  124  stopping the movement of the nose cone  22  proximally over the housing body  26 . As the nose cone  22  is retracted, the retraction control  24  remains in the second position relative to the nose cone  22  and the locking surface  35  of the locking pins  32  slide along the inner surface of the sleeve  124  between the first and second openings  126 ,  128 . When the nose cone  22  reaches the retracted position ( FIG. 8 ), the locking surface  35  of the locking pins  32 , being urged by the pin biasing members  37 , extend through the second openings  128  such that the locking pins  32  are in the locked position to fix the nose cone  22  in the retracted position. 
     Now with reference to  FIGS. 4, 5, and 8-11 , the movement of the nose cone  22  from the retracted position ( FIG. 8 ) to the extended position ( FIG. 4 ) will be described in accordance with this disclosure. Referring initially to  FIGS. 8 and 9 , the nose cone  22  is in the retracted position, the retraction control  24  is in the second position, and the locking pins  32  are disposed in the locked position within the second openings  128  formed in the sleeve  124 . 
     With particular reference to  FIGS. 10 and 11 , the nose cone  22  remains in the retracted position as the retraction control  24  is moved to the first position relative to the nose cone  22  to unlock the locking pins  32 . When the retraction control  24  is moved from the second position to the first position, the ramp  146  of the distal finger  145  engages the locking surface  35  of the locking pins  32  to move the locking pins  32  against the pin biasing member  37  and towards the unlocked position. The distal finger  145  engages the control stop  125  to limit the distal translation of the retraction control  24  relative to the nose cone  22 . Additionally or alternatively, the shoulder  143  of the proximal flange  141  may engage the proximal end of the outer wall  122  to limit the distal translation of the retraction control  24  relative to the nose cone  22 . 
     Referring back to  FIGS. 4 and 5 , continued distal movement of the retraction control  24  moves the nose cone  22  distally relative to the housing body  26  to move the nose cone  22  to the extended position. The distal finger  145  may engage the control stop  125  or the shoulder  143  of the proximal flange  141  may engage the proximal end of the outer wall  122  to move the nose cone  22  to the extended position. As the nose cone  22  is extended, the retraction control  24  remains in the first position relative to the nose cone  22  and the locking surface  35  of the locking pins  32  slide along the inner surface of the sleeve  124  between the first and second openings  126 ,  128 . When the nose cone  22  reaches the extended position, the locking surface  35  of the locking pins  32 , being urged by the pin biasing members  37 , extend through the first openings  126  such that the locking pins  32  are in the locked position to fix the nose cone  22  in the extended position. 
     With reference to  FIGS. 1 and 14-18 , the rail system  300  mounts to a bronchoscope (e.g., bronchoscope  11 ) to support instruments inserted through and associated with the bronchoscope (e.g., ablation catheter assembly  100 ). The rail system  300  is configured to separately support each instrument inserted through the bronchoscope and associated cabling, where necessary. While the rail system  300  detailed herein is described for use with a bronchoscope and associated instruments, it is contemplated that the support system may be used with other devices and associated instruments. 
     Referring now to  FIGS. 1, 14, and 15 , the rail system  300  includes a rail  312 , a lower support  320 , and a device support  330 . The lower support  320  includes a support body  322  that mounts to a bronchoscope  11  to support the rail  312 . The rail  312  has a lower end  316  and an upper end  318  and defines a longitudinal axis therebetween. 
     The support body  322  includes support fingers  324  and defines a rail opening  327  that is sized and configured to receive the lower end  314  of the rail  312 . The support fingers  324  extend from the rail opening  327  in a direction orthogonal to the rail opening  327  and around a portion of the bronchoscope  11 . The support fingers  324  define a support opening  323  therebetween that mates with the portion of the bronchoscope  11 . Each support finger  324  defines a through locking hole  325  aligned with the locking hole of the other finger  324 . A locking member  326  is inserted through the locking holes  325  to compress the support opening  323  about the portion of the bronchoscope  11  which secures the support body  322  to the bronchoscope  11 . It is contemplated that the support opening  323  may compress about the telescopic EWC handle  15 . 
     With reference to  FIGS. 14 and 15 , a collar  316  is disposed over the lower end  314  of the rail  312  and within the rail opening  327 . The rail opening  327  and the collar  316  may be threadably coupled to one another. A thread portion of the collar  316  extends from the rail opening  327 . A securement member  317  is threaded over the threaded portion of the collar  316  extending from the rail opening  327 . The securement member  317  radially compresses the collar  316  against the rail  312  to secure the rail  312  within the rail opening  317 . It is also contemplated that the distal end  314  of the rail  312  may be threaded and configured to thread directly into the lower support  320  without the collar  316 . In such embodiments, the securement member  317  may be a lock nut to 
     The rail  312  extends vertically from the lower support  320  towards the upper end  318 . The rail  312  may be fully supported by the lower support  320  or a support (not shown) may be releasably coupled adjacent the upper end  318  to provide additional support to the rail  312 . The rail  312  may be constructed of any suitable material including, but not limited to, surgical steel, fiberglass, and plastic. 
     Referring to  FIGS. 16-18 , one or more device supports  330  are positioned along the rail  312  and configured to support instruments (e.g., handle  20 , cable  18  of ablation catheter  100 ) inserted through the bronchoscope  11 . The device support  330  includes a clamp arm  331  having a clamp arm collar  332 , which defines a rail passage  333  therethrough. The clamp arm collar  332  is sized and configured to slide over the rail  312  in an unlocked configuration and to engage the rail  312  in a locked configuration to fix the device support  330  in position along the rail  312 . In the unlocked configuration the rail passage  333  is sized and configured to freely slide over the rail  312  and in the locked configuration the rail passage  333  is sized and configured to engage the rail  312 . In the locked configuration, the device support  330  may be longitudinally and/or radially fixed to the rail  312 . 
     The device support  330  includes instrument fingers  334  extending from the clamp arm collar  332  in a direction orthogonal to the longitudinal axis of the rail  312 . The instrument fingers  334  define an instrument passage  335  therebetween that is sized and configured to releasably couple to and to support an instrument (e.g., handle  20 , ablation catheter assembly  18 ). 
     The device support  330  further includes a locking arm  336  that transitions the clamp arm collar  332  between the locked and unlocked configurations. The locking arm  336  includes a locking arm collar  337  that is disposed over a portion of the clamp arm collar  332  and includes a locking cam  338 . The locking cam  338  extends from the locking arm collar  337  substantially parallel to the longitudinal axis of the rail  312  and towards the clamp arm  331 . A portion of the clamp arm collar  332  includes a radial camming surface  339 . The camming surface  339  forms a radial ramp such that as the locking arm  336  is rotated from an unlocked position ( FIG. 17 ) towards a locked position ( FIG. 18 ), the locking cam  338  engages the camming surface  339  to compress the clamp arm collar  332  towards the locked position. The locking cam  337  may engage the clamp arm  331  in one of the locked or unlocked positions of the locking arm  336  to prevent the locking arm  36  from excessive rotation about the clamp arm collar  332  and to provide indicia (e.g., tactile, visual, or audible indicia) that the device support  330  is in the locked or unlocked position. 
     In embodiments, the locking arm collar  337  may include two locking cams  338  radially disposed about the locking arm collar  337  about 180° apart as shown in  FIGS. 17 and 18 . One of the locking cams  337  may engage the clamp arm  331  in the locked configuration and the other of the locking cams may engage the clamp arm  331  in the unlocked configuration to prevent the locking arm  336  from excessive rotation about the clamp arm collar  332  and to provide indicia (e.g., tactile, visual, or audible indicia) that the device support  330  is in the locked and unlocked configuration. 
     In use, the support fingers  324  of the lower support are slid over a portion of the bronchoscope  11  such that the portion of the bronchoscope  11  is positioned within the opening  323 . A locking member  326  is inserted through the locking holes  325  of the support fingers  324  and tightened to lock the lower support  320  to the bronchoscope  11 . 
     The lower end  314  of the rail  312  is inserted into the rail opening  327  defined in the lower support  320 . The lower end  314  may be inserted into the collar  316  disposed within the rail opening  327 . The securement member  317  is tightened over the threaded portion of the collar  316  to secure the rail  312  to the lower support  320 . The upper end  318  of the rail  312  may be coupled to a support (not shown) to provide additional support to the bronchoscope  11 . It is contemplated that the support may be a support stand supported on from the floor, a support hanging from a ceiling, or a support extending from a wall. 
     A catheter (e.g., ablation catheter assembly  100 ) is then inserted through the telescopic EWC handle  15  and the EWC  96 . A proximal end of the ablation catheter assembly  100  may include a catheter collar (not shown) positioned on the outer surface of the cable  18  for engagement with a device support  330  or the device support  330  may clamp directly to an outer surface of the cable  18 , as shown. 
     A first device support  330  is positioned along the rail  312  such that the instrument passage  335  of the first device support  330  is adjacent a portion of ablation catheter assembly  100  (e.g., the catheter collar or the cable  18 ). The portion of the ablation catheter assembly  100  is then coupled to the clamp arm  332  by urging the portion of ablation catheter assembly  100  into the instrument passage  335 . The first device support  330  is then locked in position on the rail  312  by moving the lock arm  336  of the first device support  330  to the locked position. When the portion of the ablation catheter assembly  100  is secured within the instrument passage  335  with the device support  330  in the locked configuration, the portion of the ablation catheter assembly  100  is supported by the first device support  330 . It is contemplated that the first device support  330  may be locked prior to urging the portion of the ablation catheter assembly  100  into the instrument passage  435 . 
     With reference to  FIG. 19 , an electromagnetic navigation (EMN) system  400  is provided in accordance with this disclosure.  FIG. 19  also depicts the ablation catheter assembly  100 , the cable  18  (which connects on one end to a microwave generator (not shown) and on the other end to) the handle  20 , and the rail system  300  of  FIG. 1  for use with the EMN system  400 . One such EMN system is the ELECTROMAGNETIC NAVIGATION BRONCHOSCOPY® system currently sold by Covidien LP. Among other tasks that may be performed using the EMN system  400  are planning a pathway to target tissue, navigating a catheter guide assembly to the target tissue, deploying an instrument adjacent or into the target tissue to treat or capture the target tissue, digitally marking the location of the target tissue in a data file related to the planned pathway, and placing one or more echogenic markers at or around the target tissue. 
     The EMN system  400  generally includes an operating table  410  configured to support a patient; the bronchoscope  11  configured for insertion through the patient&#39;s mouth and/or nose into the patient&#39;s airways; a tracking system  470  including a tracking module  472 , a plurality of reference sensors  474 , and an electromagnetic field generator  476 ; and a workstation  480  including software and/or hardware used to facilitate pathway planning, identification of target tissue, navigation to target tissue, and digitally marking the biopsy location. 
     Before an ablation procedure can be performed, a locatable guide (LG) catheter  492 , including an electromagnetic (EM) sensor  494 , is inserted into the telescopic handle  15 , and connected to rail system  300 . Upon insertion into the telescopic EWC handle  15 , the LG catheter  492  enters the EWC  96  and is locked into position such that the sensor  494  is positioned slightly beyond the distal end  96   a  of the EWC  96  during placement of the EWC  96 . The location of the EM sensor  494 , and thus the distal end  96   a  of the EWC  96 , within an electromagnetic field generated by the electromagnetic field generator  476  can be derived by the tracking module  472 , and the workstation  480 . During insertion and placement of the distal end  96   a  of the EWC  96 , the telescopic EWC handle  15  and the LG catheter  492  inserted therein can be manipulated by rotation and compression to steer and position the LG catheter  492 . An example of a similar catheter guide assembly is currently marketed and sold by Covidien LP under the name EDGE′ Procedure Kits. For a more detailed description of the use of the catheter guide assembly reference is made to commonly-owned U.S. Provisional Patent Application Ser. No. 62/020,240 filed on Jul. 2, 2014 and entitled System and Method for Navigating within the Lung, the entire contents of which are hereby incorporated by reference. 
     Once the LG catheter  492  and EM Sensor  494  are navigated to a target within the patient, the LG catheter  492  is removed from the EWC  96 , bronchoscope  11 , and telescopic EWC handle  15 , and an ablation catheter system  100  may be inserted to treat the tissue at the target. When the EWC  96  is positioned, the bronchoscope  11  is held steady as the LG catheter  492  and the EM sensor  494  are withdrawn from the EWC  96  and the ablation catheter assembly  100  is inserted through the EWC  96  until the distal end  19   a  of the ablation probe  19  is adjacent the distal end of the EWC  96 . In this configuration the ablation catheter assembly  100 , handle  20 , and rail system  300  have substantially the orientation depicted in  FIG. 1 . The handle  20  is then manipulated to retract and extend the EWC  96  as detailed above to permit the clinician to treat the target. The ablation catheter assembly  100  is then withdrawn from the EWC  96  permitting additional instruments to be inserted through the EWC  96 , the EWC  96  to be relocated to another target, or the EWC  96  to be removed from the airway of the patient. 
     In one embodiment, the EM sensor  494  may be disposed on a distal end  19   a  the ablation probe  19 . During insertion and positioning of the ablation probe  19  and EM sensor  494 , the handle  20  is in the extended position ( FIG. 4 ) such that the distal end  19   a  of the ablation probe  19  is substantially within the EWC  96  as shown in  FIG. 12 . In addition, ablation probe  19  and the handle  20  may be secured to the bronchoscope  11  with the rail system  300 , as detailed above, such that as a clinician manipulates the telescopic EWC handle  15 , the ablation probe  19   c  and the handle  20  move in concert together with the telescopic EWC handle  15  permitting one-handed manipulation of the bronchoscope  11 , the telescopic EWC handle  15 , the ablation catheter assembly  18 , and the handle  20 . 
     When the EM sensor  494  is positioned adjacent the target, the handle  20  is moved to the retracted position ( FIG. 10 ) to retract the EWC  96  such that the distal end  19   a  of the ablation probe  19  is exposed as shown in  FIG. 13 . With the distal end  19   a  of the ablation probe  19  exposed, the ablation probe  19  may be activated to treat the target. After the target is treated, the handle  20  is returned to the extended position such that the distal end  19   a  of the ablation probe  19  is substantially within the EWC  96  ( FIG. 12 ). The ablation catheter assembly  100  may then be removed from the EWC  96  leaving the distal end of the EWC  96  adjacent the target. Additional instruments may then be passed through the EWC  96  to treat the target, the EWC  96  may be relocated to another target, or the EWC  96  may also be removed from the airway of the patient. 
     As described above, the rail system  300  and EMN system  400  may be used in combination with an LG catheter  492  or an ablation catheter  100 . However, other instruments may also benefit from the rail system  300 . Examples of additional instruments that may be inserted through the EWC  96  to treat and/or sample the target are shown in  FIGS. 20A-20C , depicting biopsy forceps  670 , a biopsy brush  675 , and a biopsy needle  680 . As shown in  FIG. 20 , each instrument includes an EM sensor  494  disposed thereon in accordance with this disclosure, however, instruments without EM sensors  494  may also be employed without departing from the scope of this disclosure. A proximal end of the instruments  670 ,  675 ,  680  may include a handle  20  similar in construction to what is shown in  FIGS. 1-11 , enabling the retraction and extension of the EWC  96 . 
     Referring to  FIGS. 21-27 , another rail system  500  is provided in accordance with this disclosure and includes a rail  512 , a lower support  520 , and a device support  530 . The rail system  500  is similar in structure and function to the rail system  300  detailed above, as such only the differences will be detailed herein for reasons of brevity. The lower support  520  includes a support body  522  that is coupled to a lower or distal end  514  of the rail  512  and defines a rail opening  529  ( FIG. 23 ) that receives the lower end of the rail  512  therein. The lower support  520  may include a collar  516  positioned in or adjacent to the rail opening  529  that engages an outer surface of the rail  512  to secure the lower support  520  to the rail  512 . 
     The support body  522  of the lower support  520  extends from the rail opening  529  to a support arm  524  that has a clamped configuration ( FIGS. 22 and 23 ) and an open configuration ( FIGS. 24 and 25 ). The support arm  524  and the support body  522  define a support opening  523  that is configured to receive and clamp to a bronchoscope  11  ( FIG. 1 ) using a bronchoscope adapter  511  to secure the lower support  520  to the bronchoscope  11 . The bronchoscope adapter  511  may be threaded to a working channel port on the bronchoscope  11  as is known in the art. The support arm  524  pivots about a pivot pin  528  to transition between the clamped and open configurations thereof. The support arm  524  includes a clip  526  and the support body  522  defines a clip detent  525  ( FIG. 25 ) that is configured to selectively receive the clip  526  to secure the support arm  524  in the clamped configuration. The clip  526  may provide tactile feedback when the clip  526  is secured in the clip detent  525 . The bronchoscope adapter  511  may include an annular ring  511   a  and the inner surface of the support opening  523  may define an annular groove  527  that is sized to receive the annular ring  511   a  to longitudinally fix the lower support  520  to the bronchoscope adapter  511  when the support arm  524  is in the clamped configuration. It is contemplated that the cooperation of the annular ring  511   a  and the annular groove  527  may assist in aligning the lower support  520  with the bronchoscope  11  ( FIG. 1 ). 
     It is also contemplated that the annular ring  511   a  and the annular groove  527  may only be defined along a portion of the support opening  23 . In such embodiments, the cooperation of the annular ring  511   a  and the annular groove  527  may radially fix the lower support  520  to the bronchoscope adapter  511 . 
     With particular reference to  FIGS. 26 and 27 , the device support  530  includes a support collar  532  slidably disposed over the rail  512 , instrument fingers  534  extending therefrom, and a locking mechanism  540  disposed therein. The locking mechanism  540  includes a locking arm  541  having locking cams  542 . The locking arm  541  is pivoted between an unlocked position ( FIG. 26 ) and a locked position ( FIG. 27 ) to actuate the locking mechanism  540  between an unlocked configuration and a locked configuration. It will be appreciated that the locking arm  541  includes a passage that permits support collar  532  and the locking mechanism  540  to slide on the rail without engaging the rail  512  when the locking arm  541  is in the unlocked position. As shown, the locking mechanism  540  has upper and lower mechanisms that are substantially similar to one another and function in concert with one another; however, it is contemplated the locking mechanism  540  may only include either the upper or lower mechanism or that the each of the upper and lower mechanisms may be independently actuated. 
     The locking mechanism  540  further includes an outer member  544  and an inner member  548  coaxially positioned with one another about the rail  512 . The outer member  544  and the inner member  548  are moveable relative to one another between an unlocked position ( FIG. 26 ) and a locked position ( FIG. 27 ). The outer member  544  may be biased towards the unlocked position by a biasing member  546 . The outer member  544  includes a camming surface  549  that is engaged by the locking cam  542  of the locking arm  541 . 
     To fix the device support  530  to the rail  512 , the locking arm  541  is pivoted from the unlocked position ( FIG. 26 ) to a locked position ( FIG. 27 ). As the locking arm  541  is pivoted, the locking cams  542  cam the outer member  544  against the biasing member  546  and over the inner member  548  such that inner angled surfaces of the outer member  544  engage outer angled surfaces of the inner member  548  such that the inner member  548  is radially compressed into the rail  512  to engage the rail  512 . It is contemplated that the inner member  548  may include teeth  548   a  that engage the rail  512  to fix the inner member  548  to the rail  512 . The inner member  548  is coupled to the support collar  532  such that when the inner member  548  is fixed to the rail  512 , the support collar  532  and thus the device support  530  is fixed to the rail  512 . It is contemplated that the inner member  548  may be integrally formed with the support collar  532 . 
     As described above, the rail system  500  may include device support  530 . However, other device supports may be used in combination with the rail system  500  which are configured to support a variety of instruments inserted through the EWC  96 . For example, as shown in  FIG. 28  an additional device support  550  is illustrated in use with rail system  500 . The device support  550  includes a support collar  532  and instrument fingers  554  extending therefrom. The instrument fingers  554  are substantially similar to the instrument fingers  354  detailed above with respect to device support  330 . 
     While the use of the handle  20  and the rail system  300 ,  500  are detailed herein for use in the airway of a patient, it is contemplated that the handle  20  and/or the rail system  300  may be used in a variety of surgical procedures utilizing elongated surgical instruments with extended working channels. For example, the handle  20  and or rail system  300 ,  500  may be used to stabilize a guide wire or catheter during various endovascular procedures such as cardiac interventions, general vascular interventional procedures, cerebral interventions, etc. These procedures may include, but are not limited to, balloon dilations, stent placements, percutaneous valve replacement, percutaneous valve repair, pacing lead placement, cardiac ablation procedures, and electrical mapping procedures. 
     While several embodiments of the disclosure have been shown in the drawings, it is not intended that the disclosure be limited thereto, as it is intended that the disclosure be as broad in scope as the art will allow and that the specification be read likewise. Any combination of the above embodiments is also envisioned and is within the scope of the appended claims. Therefore, the above description should not be construed as limiting, but merely as exemplifications of particular embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the claims appended hereto.