Abstract:
A bougie for insertion in a patient, the bougie including:
       (i) a main shaft having proximal and distal ends and a bore extending axially therein;   (ii) a movable tip having proximal and distal ends, the proximal end of the movable tip being connected to the distal end of the main shaft;   (iii) a control member having proximal and distal ends, the control member being mounted for sliding movement in the bore of the main shaft; and   (iv) the distal end of the control member being coupled to the distal end of the movable tip, the arrangement being such that an operator can slide the control member relative to the main shaft so as to cause displacement of the tip relative to the axial direction of the main shaft.

Description:
FIELD OF THE INVENTION 
       [0001]    This invention relates to a bougie with a controllable tip. 
       BACKGROUND 
       [0002]    The introduction of an endotracheal tube (ETT) into the trachea is a common medical procedure performed during resuscitation and anaesthesia. It is referred to as “intubation” and is intended to provide a secure airway in patients who are unable to manage their breathing. Greater than 4.5 million intubations occur worldwide per year. 
         [0003]    This is usually performed under direct vision using a laryngoscope. Laryngoscopes come in a variety of patterns but essentially comprise a light source, a blade and a handle. Using the blade as a spatula the laryngoscope is inserted through the mouth behind the base of the tongue and is then placed above the larynx in order to visualise the vocal cords (chords). Once the laryngoscope is in place an endotracheal tube is guided manually under direct vision between the chords and into the upper trachea. Recently a number of video laryngoscopes have become available, these devices are designed to provide a clearer view of the vocal chords and surrounding structures by virtue of a camera being placed close to the tip of the blade. The image from this camera is typically displayed on a screen attached to the handle of the video-laryngoscope, or placed remotely, but within visual range of the operator. 
         [0004]    There are a number of situations that can make intubation difficult and in some cases impossible. These include an inability to sufficiently open the mouth due to trauma, inability to flex or extend the neck due to trauma or pathology in the cervical spine or distortion of the anatomy surrounding the glottis due to tumours, haemorrhage, etc. The inability to intubate a patient can constitute a medical emergency and in some cases can result in death. A number of techniques have been developed to help clinicians overcome some of these difficult situations. 
         [0005]    One technique is the use of a guide or a bougie to negotiate a pathway between the vocal chords. Once a bougie is successfully in place an endotracheal tube can be placed over the bougie and slid down to follow the bougie through the chords, this technique is commonly referred to as “railroading”. 
         [0006]    The advantage of placing the bougie through the chords is that it is of a significantly smaller diameter (typically 4-5 mm) in comparison to the ETT which can range from 5-12 mm. This allows much greater visibility when guiding the bougie through the chords. With both conventional and video laryngoscopes a large diameter ETT can obscure vision of the chords. The ETT is normally moulded with a curve that allows it to follow the curved pathway from the oral opening to the chords. However, in many cases the angle at which the tip of the ETT presents itself to the opening between the chords does not allow the ETT tube to negotiate this space. Furthermore, the bougie can be made from relatively stiff material which is easier to control in terms of guiding it through the chords. Additionally, the end of the bougie may be formed with an angled tip, which provides the capacity to manoeuvre the tip through the chords by rotating the bougie so the tip can be positioned optimally to advance. 
         [0007]    A number of bougies are currently available for this purpose and are designed using different materials, diameters and tip angles. 
         [0008]    There are, however, occasions where the tip angle is insufficient or too great to position these bougies within the chords. 
         [0009]    Additionally, in some circumstance it is helpful to be able to introduce oxygen into the patient&#39;s airway during the intubation process. Therefore some bougies have an internal passageway to channel oxygen from the proximal end to the distal end of the bougie, that is they are hollow. When additional oxygen is used in this way, it may be introduced in a manner that assists in ventilation. This can occur by the entrainment of air into the trachea, a technique known as jet ventilation or the agitation of surrounding air this technique is known as high frequency jet ventilation. 
       SUMMARY OF THE INVENTION 
       [0010]    According to the present invention there is provided a bougie for insertion in a patient, the bougie including:
       (i) a main shaft having proximal and distal ends and a bore extending axially therein;   (ii) a movable tip having proximal and distal ends, the proximal end of the movable tip being connected to the distal end of the main shaft;   (iii) a control member having proximal and distal ends, the control member being mounted for sliding movement in the bore of the main shaft; and   (iv) the distal end of the control member being coupled to the distal end of the movable tip, the arrangement being such that an operator can slide the control member relative to the main shaft so as to cause displacement of the tip relative to the axial direction of the main shaft.       
 
         [0015]    Preferably the tip includes a tip body with lateral formations which, when the body is subject to pulling or pushing by the control rod, causes lateral displacement of the tip in anterior and posterior directions respectively. 
         [0016]    Preferably further the body is tubular and the lateral formations comprise slots extending laterally through the tubular body along one side of the tubular body. 
         [0017]    Preferably further, the control rod extends through the tubular body and its distal end is coupled to the distal end of the tubular body so that:
       (i) when the operator slides the control rod in a proximal direction relative to the main shaft the tip is displaced in the anterior direction; and   (ii) when the operator slides the control rod in a distal direction relative to the main shaft the tip is displaced in the posterior direction.       
 
         [0020]    An additional feature is the addition of a channel running the entire length of the device to allow the passage of oxygen from the proximal end to the distal end. The proximal end may have a removable cover to allow coupling of an oxygen supply tube. The channel may terminate at the tip of the bougie via a concentric port or, alternatively, it may terminate via a side port in the distal end of the main shaft in close proximity to the displaceable tip. 
         [0021]    The oxygen may pass through the existing hollow formation of the main shaft and displaceable tip with an additional channel formed in the lateral aspect of the control shaft opposite to the lateral projections. Alternatively, a specific channel may be formed within the main shaft for this purpose. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0022]      FIG. 1  is a side view of a bougie constructed in accordance with the invention; 
           [0023]      FIG. 2  is a schematic exploded view of the bougie of the invention; 
           [0024]      FIG. 3  is a fragmentary view showing a slot in the main shaft of the bougie; 
           [0025]      FIG. 4  is a fragmentary view of part of the control rod of the bougie; 
           [0026]      FIG. 5  is a fragmentary exploded view of the tip of the bougie; 
           [0027]      FIG. 6  is an enlarged axial cross-sectional view of the tip of the bougie; 
           [0028]      FIG. 7  is a cross-sectional view along the line  7 - 7 ; 
           [0029]      FIG. 7A  is a similar view to  FIG. 7  through an alternative embodiment of the invention; 
           [0030]      FIG. 8  is a cross-sectional view along the line  8 - 8 ; 
           [0031]      FIG. 9  shows operation of the bougie in order to produce deflection in a posterior direction; 
           [0032]      FIG. 10  is a schematic view showing operation of the bougie to produce deflection in an interior direction; 
           [0033]      FIG. 11  is a schematic view showing insertion of the bougie through the chords of a patient; 
           [0034]      FIG. 12  is a schematic view showing insertion of the tip of the bougie into the trachea of a patient; 
           [0035]      FIG. 13  schematically shows railroading of an ETT on the bougie; 
           [0036]      FIG. 14  shows the ETT deployed and the bougie removed from the patient; 
           [0037]      FIG. 15  is a schematic longitudinal view through a modified bougie of the invention having an oxygen port therein; 
           [0038]      FIG. 16  is a cross-sectional view along the line  16 - 16 ; 
           [0039]      FIG. 17  is a schematic view of the oxygen inlet port; 
           [0040]      FIG. 18  is an alternative bougie of the invention with an oxygen port; 
           [0041]      FIG. 19  is a cross-sectional view along the line  19 - 19 ; 
           [0042]      FIG. 20  is a cross-sectional view along the line  20 - 20 ; 
           [0043]      FIG. 21  is a cross-sectional view along the line  21 - 21 ; 
           [0044]      FIG. 22  is a cross-sectional view along the line  22 - 22 ; 
           [0045]      FIG. 23  is a fragmentary longitudinal cross-section through a further alternative embodiment of the invention; 
           [0046]      FIG. 24  is a cross-sectional view along the line  24 - 24 ; and 
           [0047]      FIG. 25  is a cross-sectional view along the line  25 - 25 . 
       
    
    
     DETAILED DESCRIPTION 
       [0048]      FIG. 1  schematically shows a bougie  1  of the invention. It includes a main shaft  2  having a proximal end  4  and a distal end  6 . A displaceable tip  8  is located at the distal end of the main shaft  2 . The main shaft  2  is preferably in the form of a nylon tube having a length of about 600 mm. It is preferred that the outer diameter is about 4 mm and it has an internal bore  10  which is 3 mm in diameter, as seen in  FIG. 6 . The tip  8  can be displaced relative to the longitudinal axis  12  of the main shaft  2 . As will be described in more detail below, the orientation of the tip  8  relative to the axis  12  can be controlled by means of a control rod  14  which is slidably mounted within the bore  10  of the main shaft  2 . 
         [0049]    In the preferred form of the invention, the proximal end  4  of the main tube is closed and a longitudinally extending recess  16  is formed in the shaft  2  in order to permit access by an operator to the control rod  14 . As best seen in  FIG. 2 , the control rod  14  includes lateral projections  18  which are located in the region of the recess  16  so that they are manually accessible to an operator. As best seen in  FIGS. 9 and 10 , an operator can grasp the bougie  1  of the invention and use his or her fingers or thumb to grip the projections  18  on the control rod  14  so that it can be axially moved within the main shaft  2  and this movement can be used to control deflection of the tip  8  relative to the axis  12 .  FIG. 9  shows the axis  13  of the tip deflected through an angle A in a posterior direction.  FIG. 10  shows the axis  13  of the tip deflected through an angle B in the anterior direction. 
         [0050]    As seen in  FIGS. 5 to 8 , the tip includes a tip body  20  which is preferably formed of a relatively short length of nylon tube, the length of which is in the range from 25 to 35 mm and preferably about 30 mm. It is preferred that the outer diameter of the body  20  is intermediate of the outer diameter and bore diameter of the main shaft  2 . In this way, the distal end  6  of the main shaft  2  can be formed with a rebate  21  which can receive the proximal end  24  of the body  20 , as shown in  FIG. 6 . In  FIG. 6 , part of the control rod  14  is not shown for clarity of illustration. The body is formed with a plurality of transversely extending slots  22 . The arrangement is such that when the distal end of the body  20  is subjected to tension, it will tend to distend towards the side in which the slots are formed and in the opposite direction when subjected to compression, as will be described in more detail below. After tension or compression the natural elasticity of the material of the body will return it to a relaxed position in which its axis  13  is aligned with the axis  12  of the main shaft  2 . 
         [0051]    In an alternative arrangement, the tip body  20  could be integrally formed at the distal end of the main shaft  2 . 
         [0052]    The proximal end  24  of the tip body  20  is glued or bonded to the rebate  21  of the main shaft  2  so that the bore  26  of the body  20  is aligned and generally contiguous with the bore  10  of the main shaft  2 , as seen in  FIG. 6  (i.e. the axes  12  and  13  are concentric). 
         [0053]    The control rod  14  is preferably moulded from nylon rod having a diameter of 2.8 mm so that it is freely slidable within the bores  10  and  26 . In the region where the projections  18  are located, the cross-sectional shape of the rod  14  is flattened so that the projections  18  are more prominent. Preferably the outer surface of the shaft  2  adjacent to the recess  16  is roughened or contains projections (not shown) to facilitate the user gripping the main shaft  2  and enabling better control of the movement of the control rod  14 . 
         [0054]    In  FIG. 6  it will be seen that the distal end  30  of the control rod  14  is joined to a closed distal end  32  of the tip body  20 . The tip  8  includes a flexible sheath  34  which is in the form of a sleeve of silicon rubber having a rounded closed distal end  36  and a proximal end  38  which is glued or bonded to the proximal end  24  of the body  20 . It is preferred that the outer diameter of the sheath  34  is the same as or approximately the same as the outer diameter of the main shaft  2 . 
         [0055]    In the illustrated arrangement, the slots are located on one side only of the tip body  20 . The provision of asymmetrically located slots  22  enable the tip body  20  to be rotated, laterally displaced or bent laterally because of expansion or contraction of the slots  22  when subjected to tensile or compressive forces from the control rod  14 . In this arrangement the inner ends  23  of the slots  22  are V-shaped so that each slot has an apex which enhances bending of the tip body  20  when the control rod  14  is moved. A similar effect could also be obtained if the inner ends  23  of the slots  22  were curved or rounded. More particularly, if the control rod  14  moves in a proximal direction (to the left), as seen in  FIG. 6 , the body  20  will be displaced or rotated upwardly relative to the axis  12 . Preferably this displacement in an anterior direction is about 100°. In the illustrated arrangement the control rod has a range of movement of about 3 to 5 mm and preferably about 4 mm either side of a neutral position (in which the tip  8  is aligned with the main shaft  2 ). On the other hand, if the control rod  14  is moved in the distal direction (to the right), the body  20  will be displaced or rotated in the posterior direction preferably by an amount of up to about 90° relative to the axis  12 . Movement of the control rod is limited by the endmost projections  18  engaging the ends of recess  16 . As indicated above, an operator can grip the projections  18  of the main shaft  2  and cause movement of the control rod  14  in either a proximal or distal direction in order to cause displacement in anterior or posterior directions, as diagrammatically illustrated in  FIGS. 9 and 10 . It is to be understood that the terms anterior and posterior are used for convenience and are the normal positions as shown in  FIGS. 9 and 10 . It is to be understood, of course, that the bougie of the invention can be used in any orientation. 
         [0056]    In the preferred embodiment, the portion  27  of the control rod  14  which is located within the bore  26  of the body  20  is flattened so that it has good flexure in the anterior and posterior directions as diagrammatically illustrated in  FIG. 7A . This facilitates in stiffening the body  20  against displacement in directions other than the posterior and anterior directions (i.e. perpendicularly relative to these directions). It will also be appreciated that the shape of the body  20  with the lateral slots  22  also facilitates in providing flexibility in the anterior and posterior directions whilst resisting deflections in directions perpendicular thereto. More particularly, the flattened shape of the portion  27  of the control rod and the orientation of the slots  22  is such that the deflection of the tip  8  occurs most easily in a plane  29  which includes the axis  12  and is transverse to the lateral direction of the slots  22 . It also follows that the tip  8  is more resistant to deflection in a plane  31  which is orthogonal to the plane  29 , as shown in  FIG. 7A . 
         [0057]      FIGS. 11 to 13  diagrammatically illustrate the manner in which the bougie  1  of the invention can be deployed in a patient  40 . In  FIG. 11  it will be seen that the hand  42  of an operator can be used to grip the projections  18  so as to enable control of the orientation of the tip  8  relative to the main axis of the shaft  2 . In  FIG. 11  a laryngoscope  44  is deployed so that the operator has a view of the vocal chords  46  of the patient. During this stage of the deployment, the operator can move the control rod  14  in a proximal or distal direction in order to cause displacement of the tip  8  in an anterior or posterior direction as required in order to best facilitate insertion of the tip through the vocal chords  46 . The operator can rotate the main shaft  2  whilst manipulating the control rod so that the tip  8  can be moved through a wide range of positions relative to the anatomy of the patient. 
         [0058]    In  FIG. 12  it will be seen that the tip  8  has passed beyond the chords  46  and into the trachea  48  of the patient. Once in this position, the operator can then mount an endotracheal tube (ETT)  50  over the proximal end of the main shaft  2  of the bougie and then slide the ETT  50  along the length of the main shaft so that its cuff  52  is guided past the vocal chords  46  of the patient and is correctly located in the trachea  48  of the patient. Once in this position, the cuff  52  of the ETT  50  can be inflated and the bougie  1  of the invention removed, as shown in  FIG. 14 . 
         [0059]      FIGS. 15 to 17  illustrate an alternative bougie  51  of the invention which has provision for supplying oxygen to the tip  8 . The same reference numerals have been used to denote parts which are the same as or correspond to those of the previous embodiment. It will be seen that the main shaft  2  is in the form of a tube, the interior of which constitutes an oxygen channel  53 . The device includes a removable cap  57  which when removed forms an inlet port  62  being the proximal end of the tube which forms the main shaft  2 . In this embodiment, the control rod  14  includes a longitudinally extending oxygen channel  55  to permit oxygen to pass from the port  62  along the length of the tube which forms a main shaft  2  and through the body  20  of the tip. The sheath  34  includes an outlet port  58  at its distal end. It will be appreciated that by connecting an oxygen supply tube  54 , as shown in  FIG. 17 , to the port  62  oxygen can be discharged to a patient from the outlet port  58 . 
         [0060]      FIGS. 18 to 22  diagrammatically illustrate a further bougie  61  constructed in accordance with the invention. The same reference numerals have been used to denote parts which are similar to those of the bougie  51  shown in  FIGS. 15 to 17 . In this embodiment, the main shaft  2  is in the form of a tubular body  65  which is formed with a longitudinally extending partition  67  which defines two channels  56  and  59 . The control rod  14  is slideably mounted in the channel  59  and is generally semi-circular in cross-section so as to neatly fit within the channel  59 . The proximal end of the channel  59  includes a barrier  60  which can be formed from a body of silicon adhesive or the like. The channel  59  can be used for introduction of oxygen at the port  62  and the barrier  60  prevents oxygen entering the channel  59 . The distal end of the tubular body  65  is formed with an outlet port  58  in the sidewall of the tube which forms the main shaft  2 , as shown in  FIG. 18 . Oxygen can be introduced into inlet port  62  via the oxygen supply tube  54  as before. 
         [0061]    It will be appreciated that the bougie  61  of  FIGS. 18 to 22  could be used for suction purposes if a source of vacuum were coupled to the port  62 . The device could therefore be used for removal of mucous, blood or other fluid from a patient. The port  62  could also be used as a passageway for a guidewire or other instrument to be inserted into the trachea of a patient. 
         [0062]      FIGS. 23 to 25  illustrate an alternative bougie  70  constructed in accordance with the invention. The same reference numerals have been used to denote parts which are the same as or correspond to those of previous embodiments. In  FIG. 23  the flexible sheath  34  has been omitted for clarity of illustration. The main difference between the bougie  70  and the previous embodiments is that the distal end  30  of the control rod  14  is not directly connected to the tip body  20  but is coupled thereto by means of a wire  68 . Preferably, the wire  68  is made from stainless steel and has a diameter of about 0.24 mm. In the illustrated arrangement, the wire  68  may have a length of say 49 mm. It will be appreciated that braided wire could also be used. 
         [0063]    The proximal end  72  of the wire  68  is located within a recess  66  formed in the distal end  30  of the control rod. The proximal end of the wire  68  is securely fastened to the control rod by means of a body  69  of adhesive material such as epoxy resin. In the arrangement shown in  FIG. 23 , the tip body  20  is moulded with a thickened portion  74  on one side thereof where the openings to the slots  22  are located, i.e. opposite to the apices of the slots  22 . A bore  76  is formed in the widened portion  74  as best seen in FIG.  25  and the wire  68  can pass through the bore  76  to the distal end  32  of the body  20 . In the illustrated arrangement, the distal end  78  of the wire  68  is bent back in the proximal direction so as to extend within the bore  26  of the body  20 . A body  71  of adhesive such as epoxy resin is then placed in the bore so as to fix the distal end  78  of the wire to the distal end  32  of the body  20 . The bougie  70  operates in a similar manner to the previous embodiments. When the user engages the projections  18  and pulls the control rod in a distal direction, this will be translated into increased tension in the wire  68  which will cause bending of the body  20  laterally owing to the decrease in width of the slots  22 . In the illustrated arrangement, when the control rod is moved proximally, the body  20  will be bent downwardly as shown in  FIG. 23 . On the other hand, if the user pushes the control rod in a distal direction, the wire  68  will be capable of transmitting compressional forces on the end  32  so that it will be bent in the opposite direction, that is to say upwardly as seen in  FIG. 23 . It will be appreciated that the wire  68  and bore  76  function somewhat analogously to a Bowden cable. A prototype of this arrangement has been made and found to exhibit good flexure of the body  20  with relatively small forces being applied by the user to the projections  18 . The ends of the projections  18  can therefore be rounded as shown in  FIG. 23  which makes the bougie  70  more convenient to use. 
         [0064]    As mentioned above, the main shaft  2  is in the form of a nylon tube. The control rod  14  can also be injection moulded from nylon. The body  20  or sheath  34  is preferably coloured green or yellow so that it can better be seen by a user. Preferably further, the tip body or sheath may include fluorescent pigment (glow in the dark pigment) such as those available through Smooth-On, Inc. of Pennsylvania USA. In some applications, the glow in the dark effect enhances placement of the bougie tip and provides a clear indication that the bougie tip has passed through the vocal chords and into the trachea of a patient. The glow in the dark effect can be enhanced by exposure of the tip to ultraviolet light prior to use. 
         [0065]    It will be appreciated that the bougie of the device is simple and inexpensive and can be manufactured as a disposable or single use product. 
         [0066]    Many modifications will be apparent to those skilled in the art without departing from the spirit and scope of the invention. 
         [0067]    The reference in this specification to any prior publication (or information derived from it), or to any matter which is known, is not, and should not be taken as an acknowledgment or admission or any form of suggestion that that prior publication (or information derived from it) or known matter forms part of the common general knowledge in the field of endeavour to which this specification relates. 
         [0000]    
       
         
               
             
               
               
               
             
           
               
                   
               
               
                 LIST OF PARTS 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 bougie 
                 1 
               
               
                   
                 main shaft 
                 2 
               
               
                   
                 proximal end 
                 4 
               
               
                   
                 distal end 
                 6 
               
               
                   
                 displaceable tip 
                 8 
               
               
                   
                 internal bore 
                 10 
               
               
                   
                 longitudinal axis 
                 12 
               
               
                   
                 axis 
                 13 
               
               
                   
                 control rod 
                 14 
               
               
                   
                 recess 
                 16 
               
               
                   
                 lateral projections 
                 18 
               
               
                   
                 tip body 
                 20 
               
               
                   
                 rebate 
                 21 
               
               
                   
                 slots 
                 22 
               
               
                   
                 inner ends 
                 23 
               
               
                   
                 proximal end 
                 24 
               
               
                   
                 bore 
                 26 
               
               
                   
                 portion 
                 27 
               
               
                   
                 plane 
                 29 
               
               
                   
                 distal end 
                 30 
               
               
                   
                 plane 
                 31 
               
               
                   
                 distal end 
                 32 
               
               
                   
                 flexible sheath 
                 34 
               
               
                   
                 distal end 
                 36 
               
               
                   
                 proximal end 
                 38 
               
               
                   
                 patient 
                 40 
               
               
                   
                 hand 
                 42 
               
               
                   
                 laryngoscope 
                 44 
               
               
                   
                 vocal chords 
                 46 
               
               
                   
                 trachea 
                 48 
               
               
                   
                 endotracheal tube 
                 50 
               
               
                   
                 bougie 
                 51 
               
               
                   
                 cuff 
                 52 
               
               
                   
                 oxygen channel 
                 53 
               
               
                   
                 oxygen supply tube 
                 54 
               
               
                   
                 oxygen channel 
                 55 
               
               
                   
                 channel 
                 56 
               
               
                   
                 removable cap 
                 57 
               
               
                   
                 outlet port 
                 58 
               
               
                   
                 channel 
                 59 
               
               
                   
                 barrier 
                 60 
               
               
                   
                 bougie 
                 61 
               
               
                   
                 inlet port 
                 62 
               
               
                   
                 tubular body 
                 65 
               
               
                   
                 recess 
                 66 
               
               
                   
                 partition 
                 67 
               
               
                   
                 wire 
                 68 
               
               
                   
                 body 
                 69 
               
               
                   
                 bougie 
                 70 
               
               
                   
                 body 
                 71 
               
               
                   
                 proximal end 
                 72 
               
               
                   
                 portion 
                 74 
               
               
                   
                 bore 
                 76 
               
               
                   
                 distal end 
                 78