Abstract:
Apparatuses useful in and methods for positioning of an endotracheal tube within an airway by allowing manual articulation of the endotracheal tube while a patient is being intubated. The apparatuses and methods are of particular use in intubating patients with unique anatomical conditions that make standard stylets inadequate for intubation. In one embodiment, an apparatus may comprise a stylet having a first end and a second end, with the second end of the stylet being insertable within a lumen of the endotracheal tube. First and second articulatable portions of the stylet may be independently articulated into respective primary and secondary arcuations to bend the endotracheal tube in conformance therewith as desired during the intubation procedure.

Description:
RELATED APPLICATION INFORMATION 
       [0001]    This application claims priority from U.S. Provisional Application Ser. No. 61/609,442, entitled “MANUALLY ARTICULATED INTUBATION STYLET, INTUBATION DEVICE AND INTUBATION METHOD” filed on Mar. 12, 2012, which is incorporated by reference herein in its entirety. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates generally to endotracheal intubation, and more particularly to apparatuses and methods useful in the positioning of an endotracheal tube within the airway of a patient. 
       BACKGROUND OF THE INVENTION 
       [0003]    Anesthesiologists and other medical care providers are often required to intubate patients in order to provide an adequate airway for the patient during receipt of medical care. One manner of intubating a patient involves positioning an endotracheal tube into the patient&#39;s trachea. 
         [0004]    Various implements can be used to assist in the process of positioning endotracheal tubes including, for example, Macintosh blades, Miller blades and intubation stylets. Macintosh blades generally comprise a curved-bladed implement and are typically used to lift a patient&#39;s vallecula out of the way providing the medical care provider a better view of the patient&#39;s airway. Miller blades generally comprise a straight-bladed implement and are typically used to trap the patient&#39;s epiglottis to better expose the patient&#39;s glottis and vocal cords. An intubation stylet may be inserted within the lumen of an endotracheal tube. The stylet may be used with or without other implements (e.g. Macintosh blades and/or Miller blades) to help guide the tube into the patient&#39;s trachea. After the endotracheal tube is properly positioned in the patient&#39;s airway, the stylet is removed from the lumen of the endotracheal tube allowing a ventilator or the like to be attached to the tube to ventilate the patient. 
         [0005]    Despite the availability of various stylets and other implements, the insertion of endotracheal tubes can be difficult even for skilled providers, particularly in patient&#39;s having anterior tracheas and other conditions that make it challenging to guide the distal end of the endotracheal tube into past the vocal cords and into the trachea. In some instances where an endotracheal tube cannot be properly positioned at all or within a timely enough manner, the patient may need to have a tracheotomy. 
       SUMMARY OF THE INVENTION 
       [0006]    Accordingly, apparatuses and methods useful in the positioning of an endotracheal tube within an airway during an intubation procedure are provided. The apparatuses and methods described herein are useful in assisting the intubation of patients in both routine and emergency procedures. The apparatuses and methods described herein are particularly suited for intubating a human patient. However, the apparatuses and methods described herein may also be applicable to the intubation of non-human patients as well. 
         [0007]    The apparatuses and methods provide, for example, the ability to more readily insert an endotracheal tube into the trachea of a patient and desirably avoid the need for a tracheotomy. The apparatuses and methods further provide, for example, the ability to bend the endotracheal tube in more than one direction while the tube is being positioned in a patient&#39;s airway. The ability to bend the endotracheal tube in two directions (e.g. a clockwise bend over a middle portion of the tube and a counter-clockwise bend over a distal end portion end of the tube) helps a medical care provider advance the distal end of the tube past the vocal cords and into the trachea of the patient, particularly in a patient having an anterior trachea or other challenging anatomy. The apparatuses and methods further provide, for example, the ability to bend one portion of the endotracheal tube (e.g. the distal end portion) in one direction independent of a different portion of the endotracheal tube (e.g. a portion preceding the distal end portion) being bent in another direction. The ability to independently bend different portions of the tube affords the medical provider the ability to readily manipulate the endotracheal tube as needed to accomplish positioning of the tube in a patient with challenging anatomy. 
         [0008]    Advantages of the apparatuses and methods described herein further include, without limitation, the ability to control the shape of an endotracheal tube, the ability to respond to unique anatomical differences in trachea location and shape, and the ability to utilize a disposable stylet while continuing to use other portions of the apparatus. 
         [0009]    These and other features and advantages are achieved by various aspects of the apparatuses and methods described herein. In one aspect, an apparatus useful in the positioning of an endotracheal tube within an airway comprises a stylet having a first end and a second end. The second end of the stylet may be insertable within a lumen of the endotracheal tube such that at least a portion of a longitudinal extent of the stylet is received within the lumen of the endotracheal tube. A first filament may extend substantially parallel with a longitudinal axis of the stylet. The first filament may be connected to the stylet at a first location between the first and second ends. A second filament may extend substantially parallel with the longitudinal axis of the stylet. The second filament may be connected to the stylet at a second location farther from the first end than the first location. A first tensioning mechanism may be operable to put the first filament under tension to articulate the stylet into a primary arcuation that may extend from the first location toward the first end. A second tensioning mechanism may be operable to put the second filament under tension to articulate the stylet into a secondary arcuation that may extend from the second location toward the first location. 
         [0010]    In another aspect, an apparatus useful in the positioning of an endotracheal tube within an airway may comprise a stylet having a first end and a second end. The second end of the stylet may be insertable within a lumen of the endotracheal tube such that at least a portion of a longitudinal extent of the stylet is received within the lumen of the endotracheal tube. The stylet may comprise at least a first articulatable portion extending toward the first end from a first location along a longitudinal extent of the stylet and a second articulatable portion extending toward the first location from a second location along the longitudinal extent of the stylet farther from the first end than the first location. The first articulatable portion of the stylet may be articulatable into a primary arcuation and the second articulatable portion of the stylet may be articulatable into a secondary arcuation. In this regard, the first and second articulatable portions of the stylet may be independently articulatable into respective primary and secondary arcuations. 
         [0011]    In a further aspect, a method for positioning an endotracheal tube within an airway may comprise coupling a first end of a stylet with a handle body including first and second articulating mechanisms. The stylet may include a first articulatable portion extending toward the first end from a first location along a longitudinal extent of the stylet and a second articulatable portion extending toward the first location from a second location along the longitudinal extent of the stylet farther from the first end than the first location. In this regard, the first and second articulating mechanisms may be independently operable. The method may further comprise inserting a second end of the stylet within a lumen of the endotracheal tube such that at least a portion of the longitudinal extent of the stylet is received within the lumen of the endotracheal tube. The method may additionally comprise, concurrent with positioning the endotracheal tube within the airway, operating the first articulating mechanism to articulate the first portion of the stylet into a primary arcuation and/or operating the second articulating mechanism to articulate the second portion of the stylet into a secondary arcuation. 
         [0012]    Various apparatuses and methodologies are provided herein. Such apparatuses and methodologies may be employed separately and in combination. Various refinements exist of the features noted in relation to the various aspects, and further features may also be incorporated in the various aspects. These refinements and additional features may exist individually or in any combination, and various features of the various aspects may be combined. These and other aspects and advantages will be apparent upon review of the following Detailed Description when taken in conjunction with the accompanying figures. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]      FIG. 1  is a perspective exploded view of one embodiment of a manually articulatable intubation apparatus. 
           [0014]      FIG. 2  is a side view of the manually articulatable intubation apparatus in which a stylet thereof is shown without any arcuations. 
           [0015]      FIG. 3  is a side view of the manually articulatable intubation apparatus in which the stylet thereof is shown with a primary arcuation. 
           [0016]      FIG. 4  is a side view of the manually articulatable intubation apparatus in which the stylet thereof is shown with a primary arcuation and a secondary arcuation. 
           [0017]      FIG. 5  is a side view of the manually articulatable intubation apparatus in which the stylet thereof is shown with a secondary arcuation. 
           [0018]      FIG. 6  is an exploded perspective view of one embodiment of a stylet of the manually articulatable intubation apparatus. 
           [0019]      FIG. 7  is a perspective cross-sectional view of one-half of one embodiment of a handle body of the manually articulatable intubation apparatus. 
       
    
    
     DETAILED DESCRIPTION 
       [0020]      FIG. 1  shows one embodiment of a manually articulatable intubation apparatus  10 . The manually articulatable intubation apparatus  10  includes a handle body  20  that may be held in an upright position as illustrated. The manually articulatable intubation apparatus  10  also includes an articulating stylet  50 . The stylet  50  includes a first end  50 A proximal to the handle body  20  and a second end  50 B distal from the handle body  20 . When assembled, the first end  50 A of the stylet may be seated against a stylet seating surface  20 A (not shown in  FIG. 1 ) formed at the bottom of a stylet changing opening  30  (not shown in  FIG. 1 ) in the base of the handle body  20 . The stylet seating surface  20 A and stylet changing opening  30  may be seen in  FIG. 7 . 
         [0021]    A major handle lever  22  and a minor handle lever  24  mount freely to the handle body  20  on an axle pin  26 . Major handle lever  22  may also be referred to herein as first lever  22  and minor handle lever  24  may also be referred to herein as second lever  24 . Axle pin  26  is received in axle pin holes  28  formed in the handle body  20 , the major handle lever  22  and the minor handle lever  24  to mount the major and minor handle levers  22 ,  24  on the handle body  20  in a pivotable manner about a fulcrum provided by the axle pin  26 . In other embodiments, the major and minor handle levers  22 ,  24  may be pivotably mounted on the handle body  20  in other manners including, for example, by separate axle pins. 
         [0022]    A first filament  74  and a second filament  76  extend from the first end  50 A of the stylet  50  and through the stylet changing opening  30  (shown in  FIG. 7 ) into the open interior of handle body  20 . The first filament  74  also extends parallel with a longitudinal axis  52  of the stylet  50  through a first longitudinal passageway  54  formed within the stylet  50  to a first location  64  along a longitudinal extent of the stylet  50 . The first filament  74  is connected to the stylet  50  at the first location  64 . The first filament  74  may be connected with the stylet  50  at the first location  64  in a variety of manners including, for example, by soldering the first filament  74  to the stylet  50  at the first location  64 . In this regard, the first filament  74  may comprise a metallic wire (e.g. a piano wire) and the stylet  50  may be comprised of metal at the first location  64 . The second filament  76  also extends parallel with the longitudinal axis  52  of the stylet  50  through a second longitudinal passageway  56  formed within the stylet  50  to a second location  66  along the longitudinal extent of the stylet  50 . The second filament  76  is connected to the stylet  50  at the second location  66 . The second filament  76  may be connected with the stylet  50  at the second location  66  in a variety of manners including, for example, by soldering the second filament  76  to the stylet  50  at the second location  66 . In this regard, the second filament  76  may comprise a metallic wire (e.g. a piano wire) and the stylet  50  may be comprised of metal at the second location  66 . In other embodiments, the first and second filaments  74 ,  76  may comprise materials other than metallic wire and/or may be connected to the stylet  50  at the respective first and second locations  64 ,  66  thereof in manners other than soldering. 
         [0023]    The first and second filaments  74 ,  76  exit the interior of the handle body  20  through a top slot  32  formed in an upper portion of the handle body  20 . The first filament  74  is connected to a first threaded tensioning screw  34  and the second filament  76  is connected to a second threaded tensioning screw  36 . The first filament  74  may be connected with the first threaded tensioning screw  34  in a variety of manners including, for example, by soldering the first filament  74  to the bottom of the first threaded tensioning screw  34 . In this regard, the first filament  74  may comprise a metallic wire (e.g. piano wire) and the first threaded tensioning screw  34  may be comprised of metal. The second filament  76  may be connected with the second threaded tensioning screw  36  in a variety of manners including, for example, by soldering the second filament  76  to the second threaded tensioning screw  36 . In this regard, the second filament  76  may comprise a metallic wire (e.g. piano wire) and the second threaded tensioning screw  36  may be comprised of metal. In other embodiments, the first and second threaded tensioning screws  34 ,  36  may be comprised of non-metallic materials, and/or the first and second filaments  74 ,  76  may comprise materials other than metallic wire and/or may be connected to the respective first and second threaded tensioning screws  34 ,  66  in manners other than soldering. Regardless of the material comprising the first and second filaments  74 ,  76 , the first and second filaments  74 ,  76  may desirably have sufficient yield strength in order to avoid undesirable deformation during use of the manually articulatable intubation apparatus. In this regard, the first and second filaments  74 ,  76  may, for example, have a yield strength of about 20,000 pounds per square inch or greater. 
         [0024]    The first threaded tensioning screw  34  is threaded into a first tensioning thumb nut  38 . The first tensioning thumb nut  38  sits freely in a first gimbal  40 . The first gimbal  40  is pinned freely to the major handle lever  22  via laterally extending gimbal pins  46  received in gimbal pin holes  48  formed in the major handle lever  22 . In this regard, the first threaded tensioning screw  34 , first tensioning thumb nut  38  and first gimbal  40  may together comprise a first gimbal and tension adjustment assembly connecting the first filament  74  to the major handle lever  22 . The second threaded tensioning screw  36  is threaded into a second tensioning thumb nut  42 . The second tensioning thumb nut  42  sits freely in a second gimbal  44 . The second gimbal  44  is pinned freely to the minor handle lever  24  via laterally extending gimbal pins  46  received in gimbal pin holes  48  formed in the minor handle lever  24 . In this regard, the second threaded tensioning screw  36 , second tensioning thumb nut  42  and second gimbal  44  may together comprise a second gimbal and tension adjustment assembly connecting the second filament  76  to the minor handle  20 . 
         [0025]    The first and second gimbal and tensioning adjustment assemblies allow for an initial tension in the first filament  74  and/or the second filament  76  to be adjusted independently of one another. The first tensioning thumb nut  38  sits freely in the first gimbal  40  allowing the first tensioning thumb  38  to be turned in order to adjust an initial tension on the first filament  74 . For example, as the first tensioning thumb nut  38  is turned in one direction (e.g., clockwise), threads on the first tensioning thumb nut  38  engage threads on the first threaded tensioning screw  34  moving the first threaded tensioning screw  34  up relative to the major handle lever  22  thereby increasing an initial tension in the first filament  74  between the first gimbal  40  and the first location  64  of the stylet  50 , and as the first tensioning thumb nut  38  is turned in an opposite direction (e.g., counter-clockwise), threads on the first tensioning thumb nut  38  engage threads on the first threaded tensioning screw  34  moving the first threaded tensioning screw  34  down relative to the major handle lever  22  thereby decreasing an initial tension in the first filament  74  between the first gimbal  40  and the first location  64  of the stylet  50 . The second tensioning thumb nut  42  sits freely in the second gimbal  44  allowing the second tensioning thumb  42  to be turned to adjust an initial tension on the second filament  76 . For example, as the second tensioning thumb nut  42  is turned in one direction (e.g. clockwise), threads on the second tensioning thumb nut  42  engage threads on the second threaded tensioning screw  36  moving the second threaded tensioning screw  36  up relative to the minor handle lever  24  thereby increasing an initial tension in the second filament  76  between the second gimbal  44  and the second location  66  of the stylet  50 , and as the second tensioning thumb nut  42  is turned in an opposite direction (e.g. counter-clockwise), threads on the second tensioning thumb nut  42  engage threads on the second threaded tensioning screw  36  moving the second threaded tensioning screw  36  down relative to the minor handle lever  24  thereby decreasing an initial tension in the second filament  76  between the second gimbal  44  and the second location  66  of the stylet  50 . In this regard, the first tensioning thumb nut  38  and the second tensioning thumb nut  42  may each include a knurled texture on outside surfaces thereof to facilitate gripping of the tensioning thumb nuts  38 ,  42  when turning. 
         [0026]    The first and second gimbal and tensioning adjustment assemblies also help reduce lateral forces on the first and second filaments  74 ,  76  when the major and minor handle levers  22 ,  24  are pivoted on the axle pin  26 . In this regard, the first and second gimbals  40 ,  44  pivot on their gimbal pins  46  relative to the respective major and minor handle levers  22 ,  24  as the respective major and minor handle levers  22 ,  24  are pivoted. This allows the first and second gimbal and tensioning adjustment assemblies to move up and down in response to pivoting of the major and/or minor handle levers  22 ,  24  while maintaining the first and second threaded tensioning screws  34 ,  36  to which the first and second filaments  74 ,  76  are respectively connected to maintain a generally vertical orientation thereby minimizing lateral forces on the first and second filaments  74 ,  76 , particularly at the point of connection to the first and second threaded tensioning screws  34 ,  36 . 
         [0027]    The handle body  20  of the manually articulated intubation apparatus  10  may be shaped and contoured such that the handle body  20  rests comfortably against the palm of a single hand, right or left, allowing the major handle lever  22  and/or the minor handle lever  24  to be readily pulled by the fingers against the handle body  20  thereby pivoting on the axle pin  26 . The handle body  20  may be constructed of a sufficiently rigid material so that the handle body  20  does not excessively deform during use of the manually articulated intubation apparatus  10 , such as, for example, a rigid plastic or a metal (e.g. stainless steel). 
         [0028]    The portions of the major and minor handle levers  22 ,  24  engaged by the fingers to pull the major and minor handle levers  22  toward the handle body  20  may be sufficiently long to provide leverage when pulled toward the handle body  20  so that the first and second filaments  74 ,  76  can be comfortably put under sufficient tension. The minor handle lever  24  may be provided with a sufficiently larger radius curved configuration in comparison to the major handle lever  22  to allow the minor handle lever  24  to be pulled toward the tighter radius curved configuration of the major handle lever  24  without requiring movement of the major handle lever  22  toward the handle body  20 . The major and minor handles  22 ,  24  may be constructed of a sufficiently rigid material so that the major and minor handles  22 ,  24  do not excessively flex during use of the manually articulated intubation apparatus  10 , such as, for example, any plastic or metal sufficiently strong and rigid to maintain their contour during use. 
         [0029]    The first and second threaded tensioning screws  34 ,  36  may be made from a material sufficiently rigid enough to maintain their threads while under tension such as, for example, a metal (e.g., steel). The first and second tensioning thumb nuts  38 ,  42  may be made of any material sufficiently rigid to maintain their outer surface knurl texture and their threads such as, for example a metal (e.g. steel). The first and second gimbals  40 ,  44  may be made from any sufficiently strong material to withstand forces applied thereto by the initial tension on the first and second filaments  74 ,  76  and upon pivoting of the major and minor handles  22 ,  24  such as, for example, a metal (e.g., steel). The axle pin  26  may be made of a material sufficiently hard and strong (e.g. a metal) to withstand repeated rotation of the major and minor handle levers  22 ,  24  as well as the forces applied to the axle pin  26  as the fulcrum about which the major and minor handle levers  22 ,  24  pivot. 
         [0030]    The second end  50 A of the articulating stylet  50  is insertable within the lumen of an endotracheal tube. The articulating stylet  50  has a sufficient longitudinal extent or length such that when fully inserted within the lumen of an endotracheal tube, the second end  50 B of the stylet  50  reaches the internal tip of a standard endotracheal tube, and not beyond. However, it may be possible to utilize the stylet  50  with an endotracheal tube that is shorter than standard length by not fully inserting the stylet  50  into the lumen of the shorter endotracheal tube or by having the second end  50 B of the stylet  50  extend beyond the internal tip of the shorter endotracheal tube. It may also be possible to utilize the stylet  50  with an endotracheal tube that is longer than standard length by having second end  50 B of the stylet  50  extend not quite to the internal tip of the longer endotracheal tube. Furthermore, it is possible that different length stylets  50  may be provided for use with different length endotracheal tubes. The articulating stylet  50  can be made of any material sufficiently hard and strong to withstand the compressive forces applied thereto by tension in the first and second filaments  74 ,  76  such as, for example, a plastic material (e.g., DELRIN® available from DuPont corporation). 
         [0031]    Referring now in particular to  FIGS. 2 ,  3 ,  4 , and  5 , the manually articulatable intubation apparatus  10  is shown with the articulating stylet  50  in various stages of articulation. An exemplary endotracheal tube  80  represented by the dashed lines in  FIGS. 2 ,  3 ,  4  and  5  is shown with the stylet  50  being disposed within a lumen of the endotracheal tube  80 . Various features that may be included in an endotracheal tube such as, for example, a cuff and an inflation tube, are not illustrated as part of the endotracheal tube  80  shown in the figures. 
         [0032]      FIG. 2  shows the stylet  50  in a non-articulated state. In this regard, both the major handle lever  22  and the minor handle lever  24  are in static, neutral positions without being pulled toward the handle body  20 . Further, the first and second tensioning thumb nuts  38 ,  42  have been adjusted so that that an initial tension in the first and second filaments  74 ,  76  is minimal. Thus, the stylet  50  extends straight below the handle body  20  without any significant arcuation present in the stylet  50 , and thus there is no bending of the endotracheal tube  80 . 
         [0033]      FIG. 3  shows the stylet  50  in a first articulated state. In this regard, the major handle lever  22  has been pulled toward the handle body  20  while the minor handle lever  24  remains in a static, neutral position without being pulled toward the handle body  20 . Pulling the major handle lever  22  toward the handle body  20  pivots the major handle lever  22  on the axle pin  28  lifting the first gimbal and tensioning assembly connecting the first filament  74  to the major handle lever  22  thereby placing the first filament  74  under tension (or increased tension if already under initial tension as a result of adjustment to the first tensioning thumb nut  38 ). The tension (or increased tension) in the first filament  74  places the stylet  50  under compression (or increased compression) from the first location  64  toward the first end  50 A. The compressive forces result in the stylet  50  acquiring a primary arcuation  90  extending from the first location  64  toward the first end  50 A of the stylet  50 . The degree of curvature of the primary arcuation  90  may be varied by varying the position of the major handle lever  22  as well as turning the first tensioning thumb nut  38 . Releasing the major handle  22  to return to its static, neutral position allows the primary arcuation  90  to be released from the stylet  50 , for example, during withdrawal of the stylet  50  from the lumen of the endotracheal tube. When articulated into the primary arcuation  90 , portions of the stylet  50  corresponding with the primary arcuation  90  press against the interior sidewall of the endotracheal tube  80  forcing the endotracheal tube  80  to conform with the primary arcuation  90 . 
         [0034]      FIG. 4  shows the stylet  50  in a second articulated state. In this regard, both the major handle lever  22  and the minor handle lever  24  have been pulled toward the handle body  20 . As more fully described elsewhere herein, pulling the major handle lever  22  articulates the stylet  50  into the primary arcuation  90 , with the endotracheal tube  80  bending in conformance with the primary arcuation  92 . Pulling the minor handle  24  toward the handle body  20  pivots the minor handle lever  22  on the axle pin  28  lifting the second gimbal and tensioning assembly connecting the second filament  76  to the minor handle lever  24  thereby placing the second filament  76  under tension (or increased tension if already under initial tension as a result of adjustment to the second tensioning thumb nut  42 ). The tension (or increased tension) in the second filament  76  places the stylet  50  under compression (or increased compression) from the second location  66  toward the first location  64 . The compressive forces result in the stylet  50  acquiring a secondary arcuation  92  extending from the second location  66  toward the first location  64  of the stylet  50 . The degree of curvature of the secondary arcuation  92  may be varied by varying the position of the minor handle lever  24  as well as turning the second tensioning thumb nut  42 . Releasing the minor handle  24  to return to its static, neutral position allows the secondary arcuation  92  to be released from the stylet  50 , for example, during withdrawal of the stylet  50  from the lumen of the endotracheal tube. When articulated into the secondary arcuation  92 , portions of the stylet  50  corresponding with the secondary arcuation  92  press against the interior sidewall of the endotracheal tube  80  forcing the endotracheal tube  80  to conform with the secondary arcuation  92 . 
         [0035]      FIG. 5  shows the stylet  50  in a third articulated state. In this regard, only the minor handle lever  24  has been pulled toward the handle body  20  while the major handle lever  22  remains in a static, neutral position without being pulled toward the handle body  20 . As more fully described elsewhere herein, pulling the minor handle lever  24  articulates the stylet  50  into the secondary arcuation  92 , with the endotracheal tube  80  bending in conformance with the secondary arcuation  92 . 
         [0036]    Depending upon which of the major and minor handle levers  22 ,  24  are pulled, the stylet  50  may be varied among a non-articulated state without any arcuation, the first articulated state with only the primary arcuation  90  present, the second articulated state with both the primary arcuation  90  and secondary arcuation  92  present, and the third articulated state with only the secondary arcuation  92  present. Further, the degree of curvature of both the primary and secondary arcuations  90 ,  92  can be varied as desired, and the stylet  50  can be provided with the secondary arcuation  92  independent of the presence of the primary arcuation  90  and with the primary arcuation  90  independent of the presence of the secondary arcuation  92 . 
         [0037]      FIG. 6  shows one embodiment of the articulating stylet  50  in an exploded view. The articulating stylet  50  is comprised of a plurality of individual beads  100 . Beads  100  in different positions along the longitudinal extent of the stylet  50  may have different configurations. For example, some of the beads  100  may be configured like the individual bead  100  shown in the enlarged view outlined by box  102 , other beads  100  may be configured like the individual bead  100  shown in the enlarged view outlined by box  104 , and other beads  100  may be configured like the individual bead  100  shown in the enlarged view outlined by box  106 . 
         [0038]    Regardless of their configuration, each individual bead  100  may have the first and second longitudinal passageways  54 ,  56  formed therethrough permitting passage of the first and second filaments  74 ,  76  within the stylet  50 . The first passageway  54  and second passageway  56  may be formed at first and second radial locations near the outer surface of an individual bead  100 . In this regard, the first and second radial locations of the first and second passageways  54 ,  56  may be separated by about  180  degrees measured around the circumference of the bead  100  resulting in the first and second filaments  74 ,  76  being near the outer surface of the stylet  50  but on opposite sides of a cross-sectional diameter of the stylet  50 . In other embodiments, one or more of the individual beads  100  may be provided with only a single passageway through which both of the first and second filaments  74 ,  76  extend. 
         [0039]    The stylet  50  may be comprised of various series of differently configured individual beads  100 . For example, there may be a first series  110  of beads  100  configured like the beads  100  shown in box  102 , a second series  112  of beads  100  configured like the beads  100  shown in box  104 , and a third series  110  of beads  100  configured like the beads  100  shown in box  106 . The first series  110  of beads  100  may comprise a portion of the stylet  50  that may be articulated into the primary arcuation  90 , the second series  112  of beads  100  may comprise a portion of the stylet  50  that may be articulated into the secondary arcuation  92 , and the third series  112  of beads  100  may comprise a non-articulated portion of the stylet  50  between the primary arcuation  90  and the first end  50 A of the stylet  50 . 
         [0040]    As illustrated in the enlarged view of box  106 , each bead  100  included in the third series  114  of beads  100  includes flat top and bottom end surfaces  100 A,  100 B that are perpendicular or near perpendicular to the side surface  100 C of the bead  100 . As illustrated in the enlarged view of boxes  102  and  104 , each bead  100  included in the first series  110  and second series  112  of beads  100  includes top and bottom end surfaces  100 A,  100 B that are at non-perpendicular angles with respect to the side surface  100 C of the bead  100 , providing the beads  100  of the first series  110  of beads  100  and second series  112  of beads  100  with angled or beveled end surfaces  100 A,  1008 . In this regard, angling or beveling of the top and bottom end surfaces  100 A,  100 B of the beads  100  in the first and second series  110 ,  112  of beads  100  facilitates articulation of the stylet  50  into the respective primary and secondary arcuations  90 ,  92  in response to tension in the respective first and second filaments  74 ,  76  received in the respective first and second passageways  54 ,  56  by providing the stylet  50  with portions where compressive forces resulting from tension in the first and second filaments  74 ,  76  effectively shorten the length of the stylet  50  (on the inside of the curve of the respective primary and secondary arcuations  90 ,  92 ) by bringing the top and bottom end surfaces  100 A,  100 B of adjacent beads  100  in closer proximity. Further, the degree to which the end surfaces  100 A,  1008 , of the beads in the first series  110  of beads  100  and the second series  112  of beads  100  are angled with respect to the side surfaces  100 C of the beads  100  may be varied to control the amount of curvature in the primary and secondary arcuations  90 ,  92 . For example, the end surfaces  100 A,  1008  of the beads  100  included in the first series of beads  110  may be angled such that the stylet  50  may be articulated into a primary arcuation  90  having a radius of approximately 2.5 inches. 
         [0041]    In other embodiments, such as for example where the stylet  50  is not comprised of individual beads  100  but rather a continuous longitudinal extent of material, notches or the like formed in the side surface of the stylet  50  may be provided to achieve a similar result. Additionally, in other embodiments, one or more of the beads  100  in the first and/or second series  110 ,  112  of beads  100  many have only one or no angled or beveled end surfaces  100 A,  1008 . 
         [0042]    As can be seen by comparing the enlarged views of boxes  102  and  104 , the end surfaces  100 A,  1008  of the beads  100  in the first series  110  may be angled such that the length of the side surface  100 C of the bead  100  proximal to the first passageway  54  is shorter in length than the side surface  100 C of the bead  100  proximal to the second passageway  56 , and the end surfaces  100 A,  1008  of the beads  100  in the second series  112  may be angled such that the length of the side surface  100 C of the bead  100  proximal to the second passageway  56  is shorter in length than the side surface  100 C proximal to the first passageway  54 . Essentially, the angled end surfaces  100 A,  100 B of the beads  100  included in the second series of beads  112  may be oriented in an opposite direction to that of the end surfaces  100 A,  1008  in the first series of beads  110 . Angling of the end surfaces  100 A,  100 B of the beads  100  included in the second series of beads  112  in an orientation opposite that of the end surfaces  100 A,  1008  in the first series of beads  110  facilitates the secondary arcuation  92  of the stylet  50  being oriented in an opposing direction to that of the primary arcuation  90 . 
         [0043]      FIG. 7  shows a perspective cross-sectional view of one-half of one embodiment of a handle body  20  of the manually articulatable intubation apparatus  10 . The other half of the handle body  20  may be configured in a similar manner. 
         [0044]    The handle body  20  includes an endotracheal tube slot  82  at the base of the handle body  20 . The endotracheal tube slot  82  may be configured to receive an endotracheal tube adaptor on the proximal end of an endotracheal tube  80  to secure a proximal end of the endotracheal tube  80  to the handle body  20  during use of the manually articulatable intubation apparatus  10  such as depicted in  FIG. 2 ,  3 ,  4 , or  5 . In this regard, the endotracheal tube slot  82  may be large enough to accept a standard endotracheal tube adaptor, and small enough to hold it fixed. In this regard, a width of the endotracheal tube slot  82  may be such that the endotracheal tube adaptor may be press fit into the slot  82  to retain the tube  80  in proximity with the handle body  20  during insertion of the tube  80  into a patient&#39;s airway while articulating the stylet  50  disposed within the lumen of the tube  80 . Upon proper positioning of the endotracheal tube  80  within the patient&#39;s airway, the endotracheal tube adaptor may be removed from the endotracheal tube slot  82  of the handle body  20  as the stylet  50  is withdrawn from the interior of the tube  80 . 
         [0045]    The handle body  20  also includes a stylet changing opening  30  at the base of the handle body  20 . The first and second filaments  74 ,  76  (not shown in  FIG. 7 ) extend through the stylet changing opening  30 . In this regard, the stylet changing opening  30  may be smaller in diameter than a diameter of the first end  50 A of the stylet  50 . The stylet seating surface  20 A extends outwardly from the bottom edge of the stylet changing opening  30  and provides the surface against which the first end  50 A of the stylet  50  may be seated during using of the manually articulated intubation apparatus  10 . The handle body  20  may extend below the stylet seating surface  20 A to provide an opening that receives a portion of the proximal end of the stylet  50  thereby stabilizing the first end  50 A of the stylet  50 . 
         [0046]    The stylet changing opening  30  provides an opening in the handle body  20  to feed the first and second threaded tensioning screws  34 ,  36  for initial assembly and future replacement of the stylet  50 . In this regard, the stylet changing open  30  may have a diameter that is sufficient for passage of the first and second threaded tensioning screws  34 ,  36  therethrough. This allows for changing of the stylet  50 . In this regard, the first and second filaments  74 ,  76  may be disconnected from the respective major and minor handle levers  22 ,  24  (e.g., by loosening the first and second tensioning thumb nuts  38 ,  42  until disengaged from the threads of the first and second threaded tensioning screws  34 ,  36 ) and the stylet  50  may be pulled away from the handle body  20  until the first and second threaded tensioning screws  34 ,  36  pass through the stylet changing opening  30 . Thereafter, first and second threaded tensioning screws  34 ,  36  connected to first and second filaments  74 ,  76  of another stylet  50  may be passed through the stylet changing opening  30 , through the open interior of the handle body  20 , out of the top slot  32  of the handle body  20 , through the respective first and second gimbals  40 ,  42  and connected to the respective major and minor handle levers  22 ,  24  by tightening the respective first and second tensioning thumb nuts  38 ,  42  onto the respective first and second threaded tensioning screws  34 ,  36 . 
         [0047]    The handle body  20  also includes a plurality of snap hooks  84  along the inside perimeter of the handle body  20  half. During assembly, the snaps hooks  84  may be received in corresponding snap hook retainers on the other half of the handle body  20  in order to retain the two halves of the handle body  20  together. The snap hooks  84  and their corresponding snap hook retainers may be made of the same material as the rest of the handle body  20 . In this regard, the handle body  20  may be prepared by a single casting, by injection molding, and/or by machining. The material comprising the handle body  20  may be sufficiently hard to withstand the forces of repeated use and shall be elastic enough to inhibit cracking during normal use. 
         [0048]    Deviations may be made from the specific embodiments disclosed in the specification without departing from the spirit and scope of the invention. The illustrations and discussion herein has only been provided to assist the reader in understanding the various aspects of the present disclosure. While this disclosure contains many specifics, these should not be construed as limitations on the scope of the disclosure or of what may be claimed, but rather as descriptions of features specific to particular embodiments of the disclosure. Certain features that are described in this specification in the context of separate embodiments and/or arrangements can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable subcombination. Moreover, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a subcombination or variation of a subcombination. 
         [0049]    Additionally, the foregoing description of the present invention has been presented for purposes of illustration and description. Furthermore, the description is not intended to limit the invention to the form disclosed herein. Consequently, variations and modifications commensurate with the above teachings, and skill and knowledge of the relevant art, are within the scope of the present invention. The embodiments described hereinabove are further intended to explain best modes known of practicing the invention and to enable others skilled in the art to utilize the invention in such, or other embodiments and with various modifications required by the particular application(s) or use(s) of the present invention. It is intended that the appended claims be construed to include alternative embodiments to the extent permitted by the prior art.