Abstract:
An endotracheal tube which facilitates rapid intubation of the trachea, especially in situations where anatomical variation creates difficult intubating conditions, includes a portion that can be bent during placement to control the position of the distal end of the tube. The distal end of the endotracheal tube may be selectively curled or bent by a mechanism or fluid passage accessible from the proximal end of the endotracheal tube. The endotracheal tube provides for manipulation of the insertion end without occluding the lumen of the tube, to facilitate placement of the tube.

Description:
[0001]    This application is a continuation-in-part of U.S. application Ser. No. 08/405,750, filed Sep. 27, 1999, U.S. Pat. No. 6,321,749 which is hereby incorporated by reference in its entirety into the present disclosure. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    This invention generally relates to endotracheal tubes, and more particularly, to endotracheal tubes having a bendable portion designed to facilitate intubation of difficult airways (tracheal inlet opening) caused by anatomical variation, trauma and the like.  
           [0004]    2. General Background and State of the Art  
           [0005]    An endotracheal tube generally comprises a cylindrical tube used as an air passage to administer oxygen and anesthetic gases directly to the patient. The cylindrical tube terminates in an open distal end configured for insertion into the trachea and has an opposite open proximal end configured to be coupled to a gas source. The endotracheal tube typically has an inflatable cuff on the exterior of the cylindrical tube for forming a seal with the interior walls of the trachea. (See U.S. Pat. No. 3,460,541 to Doherty). The cuff functions to occlude the trachea which protects the trachea and lungs against aspiration of foreign substances. In particular, food, foreign bodies or digestive system contents are prevented from entering the lungs. The endotracheal tube is used primarily in surgery, but is also frequently used in emergency rooms and emergency in-the-field situations.  
           [0006]    In surgical procedures requiring general anesthesia, the patient is rendered unconscious by administration of anesthetic agents including drugs and/or gases. The patient is also given a muscle relaxant/paralyzing agent to minimize the patient&#39;s gagging response to the insertion of the endotracheal tube. A laryngoscope is placed in the mouth of the patient. The blade portion of the laryngoscope is used to push the tongue laterally and the intubating practitioner applies a lifting force to the laryngoscope handle in order to visualize the anatomical structures of the mouth and airway. A specific target area of the tracheal tube is the glottis, which is the opening between the vocal cords and the inlet to the trachea. The distal end of the endotracheal tube is inserted into the glottis and the inflatable cuff (balloon) is filled with air to create an airtight seal between the cuff walls and the interior walls of the trachea. This airtight seal allows for delivery of the oxygen and anesthetic gases with positive pressure directly to the air passages below the tip and the balloon.  
           [0007]    Patient anatomies differ greatly and fall into specific categories that are grouped according to potential difficulty of tube insertion. In a patient with an anterior glottis or target orifice (the vocal cords and opening positioned high in the patient&#39;s neck and to the front of the neck), placing the insertion end of the endotracheal tube through the opening can be extremely difficult, and can lead to serious injury and even death from lack of oxygen. Although careful evaluation by the anesthesiologist or healthcare practitioner may suggest difficulty, the condition is usually undetectable until the orifice and vocal cords are visualized with a laryngoscope and blade apparatus. When this occurs, the practitioner must remove the laryngoscope, and the insert a metal or plastic stylette (semi-rigid wire) into the lumen of the endotracheal tube, bend the tube and stylette into an appropriate configuration to aid in placing the insertion tip in its proper location and to act as a placement guide. A small bend, resembling the shape of a hockey stick, is made in the stylette and the end of the endotracheal tube, while the main body of the tube remains unchanged. Once this is accomplished, another attempt is made by the practitioner to visualize the vocal cords and inlet. The bent shape of the insertion tip improves the chances of passing the tip through the tracheal orifice. An example of early endotracheal tube including a stylette for curvature is described in U.S. Pat. No. 2,458,305 to Sanders.  
           [0008]    Although this method of using a stylette to bend the insertion end of the endotracheal is widely used, it has many shortcomings. The steps of bending the tube in the correct configuration, subsequent visualizing the path of insertion, and then removing the stylette from the lumen of the endotracheal tube wastes valuable time in completing the intubation procedure. Time is of the utmost importance in an unconscious patient who is not breathing, particularly where the patient may have a full stomach with an increased chance for aspiration of foreign substance.  
           [0009]    Also, the use of a stylette is usually employed after an initial attempt has been made with the laryngoscope in place. Further, because of there intended use stylettes must be semi-rigid, capable of being easily bent and, once bent, and shape retaining. This inherent characteristic places a patient at risk of an injury from the stylette to the airway with potential for bleeding in the airway as well. In the past, puncture of soft tissue and vocal cord damage has been attributed to the use of stylettes.  
           [0010]    None of the prior devices have succeeded in the elimination of the use of a stylette to properly configure an endotracheal tube and successfully intubate a patient.  
           [0011]    Many devices have been designed to assist in the placement of the tracheal tube in the target orifice. For example, laryngoscopes have been developed to aid in insertion. However, these devices do not provide any mechanism for controlling the curvature of the insertion end of the endotracheal tube itself.  
           [0012]    U.S. Pat. No. 4,589,410 to Miller, U.S. Pat. No. 4,150,676 to Jackson and U.S. Pat. No. 4,685,457 to Donenfeld each show an endotracheal tube with at least one pull cord in the wall along a portion of the length of the tube. Applying tension on the cord causes the tube at a position proximal to the balloon to curl, apparently due to the compressibility of the material of construction. However, the tip of the tube does not bend, the bending being distributed along the whole length of the pull cord. These devices do not employ a hinge or spring-type mechanism or altered tube wall, nor do they use a locking device. As a result, these prior devices do not allow selected movement at the tip of the tube. In these prior devices, the body of the tube is moved by a pulley mechanism which bends a considerable portion of the tube, thus creating problems due movement of the tube within the mouth.  
           [0013]    Other devices employing tube bending mechanism include U.S. Pat. No. 5,255,668 to Umeda is directed to a bendable endoscope used for broncoscopy which includes a bendable distal portion spaced between two coils in the wall of the tube, the bendable portion is caused to bend by pulling on a wire in the wall of the tube. U.S. Pat. No. 4,911,148 to Sosnowski et al. is directed to small diameter (diameter of 0.15 mm or less) endoscopes which have a series of radial notches spaced along the length of the tube and a pull wire through the notched wall. Pulling on the wire causes the tube to bend along the portion containing the notches, which in turn causes the tip to deflect. U.S. Pat. No. 5,304,131 to Paskar shows an arterial or venous catheter with an area of weakness along one side of the catheter. The weakness is the result of gaps cut through the wall of the catheter. Bending of the weakened portion is provided by a wire running through the wall on the side of the gaps. To aid in returning the weakened portion to its original straight orientation that portion may be surrounded by a spring and, to seal the weakened portion, a jacket can cover the spring and the weakened portion.  
           [0014]    U.S. Pat. No. 4,353,358 to Emerson is directed to a flexible sigmoidoscope which has notches and a pull wire similar to Sosnowski et al. Other flexible tipped endoscopes and catheters with hinged portions and a pull wire are also shown in U.S. Pat. No. 5,772,578 to Heimberger, et al. and U.S. Pat. No. 5,448,989 to Heckele. U.S. Pat. No. 5,306,245 to Heaven shows a bendable tubular device which includes a cutaway wall opposite a flexible stainless steel hinge with a pull wire in the tube wall opposite to the hinge. At least the cut-out portion is covered by an outer plastic material. This plastic cover may also cover the pull wire, as well as the full length of the tube. A balloon may be added distal to the bendable portion. These devices do not include an occlusion balloon such as is required on an endotracheal tube. While Heaven includes a balloon, it is distal to the bendable portion and used for cholangiographic purposes and is not intended to seal a trachea.  
           [0015]    None of these devices in the preceding two paragraphs are intended to operate in the manner of an endotracheal tube. They do not incorporate features of the invention, such that a portion of the tube near the insertion tip articulates, while the main portion of the tube remains in its original preset shape.  
           [0016]    While there have been various changes, improvements and developments in endotracheal tubes, there still remains a need for a device that can bend only at the tip and has a mechanism to temporarily lock the position in place. Such an endotracheal tube would facilitate one-handed manipulation of the tube while the other hand is free to manipulate other devices, such as a laryngoscope. Also, this should be accomplished without having to compromise the lumen of the tube.  
         INVENTION SUMMARY  
         [0017]    The endotracheal tube of the present invention has a distal end configured to be inserted into a human trachea that can be manipulated, without the use of a stylette or other guiding device, while the tip of the tube is approaching the glottis. The main tube body remains in its original configuration, while allowing the distal end to be independently curved or bent and maintained in a desired position during placement of the endotracheal tube. The lumen of the endotracheal tube remains unoccluded during the curving of the distal tip so as not to block the patient&#39;s airways. Creating the desired distal tip curvature is accomplished by the use of various designs, all contemplated as within the scope of the invention, in combination with one or more mechanisms for manipulating the distal end of the tube. In accordance with one specific, exemplary embodiment of the invention, these include:  
           [0018]    1) locating a spring between distal tip and main tube body;  
           [0019]    2) using ultrasound, heat, solvent treatment or like methods, to modify the molecular structure or composition of the polymer forming the portion of the tube to be bent so as to increase flexibility of that portion;  
           [0020]    3) using of a polymer baffle between the distal tip and main tube body;  
           [0021]    4) surrounding the portion to be bent by a polymer spring; or  
           [0022]    5) providing a thin, notched or cutout area between distal tip and main body tube with or without the support spring.  
           [0023]    All of the above mechanisms may be applied to the outside of the endotracheal tube, incorporated in the wall of the tube, or inserted within the lumen of the tube. The endotracheal tube of the present invention also contemplates a control mechanism for causing movement of the tip and temporary locking of the bend which is imposed on the distal end tube. This can be accomplished by the use of a friction lock mechanism, a single axis lock, a sliding trigger with catch, a detent system, or a similar locking device which cooperates with a pull wire. This locked position permits the practitioner to have at least one hand free to manipulate other devices. In its preferred operation, one hand holds the endotracheal tube while the laryngoscope is operated with the other hand. After the curved end of the tube is inserted in its desired position, the trigger mechanism can be easily released and the tube allowed to assume its original configuration. An endotracheal tube incorporating features of the invention preferably does not have an occluded tube lumen, allows the practitioner to have superior tip control, and allows rapid achievement of airway control. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0024]    The following invention will become better understood with reference to the specification, appended claims, and accompanying drawings, where:  
         [0025]    [0025]FIG. 1 is a partial cutaway view of an endotracheal tube incorporating features of the invention;  
         [0026]    [0026]FIG. 1A is an enlarged cutaway view of the balloon shown in FIG. 1;  
         [0027]    [0027]FIG. 2 is a partial cutaway view of the endotracheal tube of FIG. 1 with the tip bending function activated;  
         [0028]    [0028]FIG. 3 is an enlarged, partial cutaway view of the distal portion of the endotracheal tube of FIG. 2 showing the bent portion of the device;  
         [0029]    [0029]FIG. 4 is an enlarged, partial cutaway view of the distal portion tube of FIG. 2 showing the control portion of the device in the tip retracted position;  
         [0030]    [0030]FIG. 5 is an end view taken along line  5 - 5  of FIG. 4 showing the proximal end of the endotracheal tube;  
         [0031]    [0031]FIG. 6 is an enlarged, partial cutaway view of the distal portion of a second embodiment of an endotracheal tube incorporating features of the invention showing the bendable portion of the device;  
         [0032]    [0032]FIG. 7 is an enlarged, partial cutaway view of the distal portion of the endotracheal tube of FIG. 6 showing the bendable portion of the device in its bent configuration;  
         [0033]    [0033]FIG. 8 is an enlarged, partial cutaway view of the distal portion of a third embodiment of the endotracheal tube incorporating features of the invention showing the bendable portion of the device;  
         [0034]    [0034]FIG. 9 is an enlarged, partial cutaway view of the distal portion of the endotracheal tube of FIG. 8 showing the bendable portion of the device in its bent configuration;  
         [0035]    [0035]FIG. 10 is an enlarged, partial cutaway view of a fourth embodiments of the distal portion of the endotracheal tube incorporating features of the invention showing the bendable portion of the device;  
         [0036]    [0036]FIG. 11 is a cross sectional view taken along line  11 - 11  of FIG. 10;  
         [0037]    [0037]FIG. 12 is a side view of the proximal end of an endotracheal tube in accordance with a fifth embodiment of the invention;  
         [0038]    [0038]FIG. 13 is a top view of the proximal end of the endotracheal tube shown in FIG. 12;  
         [0039]    [0039]FIG. 14 is a side view of the proximal end of an endotracheal tube in accordance with a sixth embodiment of the invention;  
         [0040]    [0040]FIG. 15 is a top view of the proximal end of the endotracheal tube shown is FIG. 14;  
         [0041]    [0041]FIG. 16 is a side view of an endotracheal tube in accordance with a seventh embodiment of the invention;  
         [0042]    [0042]FIG. 17 is a cross section view of the endotracheal tube of FIG. 16 as seen along the line  17 - 17 ;  
         [0043]    [0043]FIG. 18 is a side of view of a portion of the endotracheal tube of FIG. 16 showing certain details thereof;  
         [0044]    [0044]FIGS. 19 and 19A comprise, respectively, a cross section view and a side view of a portion of an endotracheal tube in accordance with an eighth embodiment;  
         [0045]    [0045]FIGS. 20 and 20A comprise, respectively, a cross section view and a side view of a portion of an endotracheal tube in accordance with a ninth embodiment;  
         [0046]    [0046]FIGS. 21 and 22 are side views of the proximal end of an endotracheal tube in accordance with a tenth embodiment, showing the proximal end in its unbent and bent configurations, respectively;  
         [0047]    [0047]FIGS. 23 and 24 are side views of the proximal end of an endotracheal tube in accordance with an eleventh embodiment of the invention, showing the proximal end in its unbent and bent configurations, respectively;  
         [0048]    [0048]FIG. 25 is a perspective view of a pair of flexible membranes used in the embodiment of FIGS. 23 and 24;  
         [0049]    [0049]FIG. 26 is a perspective view of the pair of membranes of FIG. 25 shown in their nested or assembled configuration;  
         [0050]    [0050]FIGS. 27 and 28 are enlarged side views of the proximal end of the endotracheal tube of FIGS. 23 and 24, respectively;  
         [0051]    [0051]FIGS. 29 and 30 are side views of the proximal end of an endotracheal tube in accordance with a twelfth embodiment of the invention, showing the proximal end in its unbent and bent configurations, respectively;  
         [0052]    [0052]FIG. 31A is a side elevational view of an endotracheal tube with the inflatable cuff of FIG. 1 replaced by membranes;  
         [0053]    [0053]FIG. 31B is a vertical cross-sectional view of the endotracheal tube taken along the line  31 B- 31 B of FIG. 31A;  
         [0054]    [0054]FIG. 32 is a side elevational view of the endotracheal tube of FIG. 31A with the cable pulled back to create a bend in the tube;  
         [0055]    [0055]FIG. 33 is a side elevational view showing an embodiment of the invention utilizing multiple notches; and  
         [0056]    [0056]FIG. 34 is a side elevational view of an endotracheal tube having a notch disposed distally of the cuff.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0057]    A first embodiment of a tracheal tube  10 , alternatively referred to as an endotracheal tube, incorporating features of the invention is shown in FIGS.  1 - 5 . Tracheal tube  10 , has a hollow tubular body  12  with an inflatable balloon  14 , also referred to as a cuff, mounted on the external surface of tubular body  12  near the distal end  16  thereof. Connected to the space between tubular body  12  and cuff  14 , or the inflatable portion of the cuff in a multi-walled balloon, is a conduit  18  which runs from the proximal end  20  of tubular body  12  to the distal end  16  of tubular body  12 . Conduit  18  is used to inflate balloon  14  to a desired occluding diameter once tubular body  12  is placed in its desired location in the air passage of a patient. Conduit  18  is typically a small diameter tube  22  which runs through a passageway  24  within wall  26  of tubular body  12 , or along the inner or outer surface of wall  26 . Alternatively, passageway  24  in wall  26  can constitute conduit  18  with the small diameter tubular body  12  sealed into the proximal end of passageway  24 . On the proximal end of the small diameter tube  22  is a valve  28 , which acts to retain the inflation air in balloon  14  and, typically, a pilot balloon  30  which inflates when cuff  14  meets resistance from the trachea to further inflation. While the drawings show a cuff  14  with a diameter greater than the outer diameter of tubular body  12 , the Figures all show cuff  14  and pilot balloon  30  in a deflated configuration, the cuff and balloon being further enlarged when inflated.  
         [0058]    On proximal end  20  of tubular body  12  is an adapter  32  for connecting tracheal tube  10  to a source of air, oxygen, or gaseous anesthetic mixture, such as a respirator or wall mounted air supply (not shown). Distal end  16  of tubular body  12  is open to allow gas fed into the tube to flow without obstruction into the patient&#39;s air ways. In FIG. 1, distal end  16  shows an alternative tip design comprising two side openings and a protected tip end so that a smooth leading surface is presented to the tissue of the air passage to minimize trauma to the tissue during placement of the tracheal tube  10 .  
         [0059]    Tracheal tube  10  includes a flexible portion  34  in the wall of tubular body  12  covered by cuff  14 , a cable  36  extending from proximal end  20  to distal end  16  of tubular body  12 , and a control mechanism  38  attached to proximal end of the cable  36 . In a first embodiment, flexible portion  34  is created by removing some or all of wall  26  in the area under cuff  14 . If a portion of the wall is retained, retained portion  40  is along the side of tubular body  12  opposite where cable  36  is located as shown in the embodiment of FIGS.  6 - 7 . Retained portion  40  bends acting as a hinge. In the first embodiment, to provide support and integrity for flexible portion  34  and to bring the bent tube back to its initial shape once the deforming force is released, a coil spring  42  is located within flexible portion  34  of tubular body  12 .  
         [0060]    Where a portion of tube wall  26  is removed, a self-contained cuff  14 , such as shown in FIG. 1A, is provided so that the air space within the cuff is completely isolated from the gas stream flowing through the tracheal tube  10 . The self-contained cuff  14  then has an outer membrane  70  which is expanded against the trachea and an inner membrane  72  facing the open area in the tube wall. The end portions  74  are provided to seal cuff  14  to the outside surface of tubular body  12 . Conduit  18  is used to inflate balloon  14 .  
         [0061]    Cable  36  is threaded through a hole  44  in wall  26  of tubular body  12  near proximal end  20  of tubular body  12 , as best shown in FIG. 4. Cable  36  may run through the lumen of tubular body  12  or through a second passageway  46  in the wall of tubular body  12  to the vicinity of cuff  14  where it exits through wall  26  into space  48  enclosed by cuff  14 . The distal end  50  of cable  36  is then attached to wall  26  of the tubular body  12  at a point  52  more distal from the exit point, but still within the space  48 . Attachment may be by adhesives, clips, rings or other attachment devices or techniques known to those skilled in the art. Cable  36  may be formed from various materials. For example, it may be a thin wire, such as piano wire or surgical stainless wire, a plastic filament such as nylon monofilament, multifilament braided structures or sutures, or any other variety of materials typically used as sutures or tensioning cords.  
         [0062]    Mounted on proximal end  20  of tubular body  12  is a handle or trigger  54  movable longitudinally within a slide channel  56  (FIGS. 4 and 5). The proximal end of cable  36  is attached to trigger  54  so that when an operator retracts the trigger  54  in the direction indicated by the arrow in FIG. 1, the pulling force is transmitted to distal point  52  of cable attachment, causing tubular body  12  to bend in the area covered by cuff  14  and spring  42  to flex as shown in FIGS. 2 and 3. When the trigger is released, spring  42  causes tubular body  12  to return to the unbent configuration as shown in FIG. 1. The trigger  54  and slide channel  56  may be so dimensioned that sufficient friction exists between these elements to retain the trigger  54  in its retracted position.  
         [0063]    [0063]FIGS. 6 and 7 show a modification of the first embodiment where a stretchable but substantially non-expandable membrane  58  covers flexible portion  34  to separate cable  36  and lumen of tubular body  12  from spring  42  and to prevent gas flowing through tubular body  12  from creating an expanding or pulsatile force on cuff  14 . In this instance, the membrane  58  acts as the inner membrane  72  of cuff  14  in FIG. 1A and the cable passes through cuff  14  rather than between balloon inner membrane  72  and spring  42 . Otherwise, the modification of FIGS. 6 and 7 functions in the same manner as the first embodiment.  
         [0064]    [0064]FIGS. 8 and 9 show a further embodiment where flexible portion  34  is created by providing one or more notches  60  in wall  26  with bottom  62  of the notch  60  functioning as a hinge. While this embodiment does not show the use of the spring  42 , a spring can be used within that portion of the tube for the same purposes as set forth above. A membrane  58  is shown covering the notch  60  and forming the inner membrane  72  of cuff  14 .  
         [0065]    [0065]FIG. 10 shows a cutaway view and FIG. 11 shows an end view of an alternative embodiment of the endotracheal tube of the present invention having a distal end with an inner membrane  58  covering the spring  42 .  
         [0066]    [0066]FIGS. 12 and 13 show a fifth embodiment of the present invention including a mechanism  80  for retaining the handle or trigger  82  in its fully retracted position. The embodiment of FIGS. 12 and 13 includes a universal connector  84  received by the proximal end of the endotracheal tube  12 . The handle or trigger is attached to a cable  86  and is movable within a longitudinally extending slide channel  88  to bend or flex the distal end  90  of the endotracheal tube  12  as already explained. Mounted on the proximal end  92  of the tube  12  is a pair of longitudinally extending, flexible retention members  94 ,  96  having opposed recesses  98 , 100  for receiving and retaining the trigger  82  when the trigger is in its fully retracted position, as shown in FIGS. 12 and 13. This retention mechanism allows one-handed manipulation of the trigger as previously described.  
         [0067]    [0067]FIGS. 14 and 15 show a sixth embodiment of the invention which includes an alternative retention mechanism for holding the cable trigger  82  in its fully retracted position. In this embodiment, a hook  110  rotatable about a vertical axis  112  is movable between a latched and unlatched position. In the latched position, shown in FIGS. 14 and 15, the trigger  82  is held by the hook  110  in its fully retracted position. The trigger is released when the hook  110  is rotated clockwise, as seen in FIG. 15.  
         [0068]    FIGS.  16 - 18  show a seventh embodiment of the invention which includes a curved, relatively rigid, sliding bar or flattened wire  120  to actuate the flexible distal tip  122 . The bar or wire  120  is slidably disposed within a longitudinally extending groove or channel  124  formed in the wall of the tube  12 , as best seen in FIGS. 17 and 18. A hook  126  on the proximal end of the bar or wire  120  is used to actuate the distal tip between its bent and unbent configurations.  
         [0069]    [0069]FIGS. 19 and 19A show an eighth embodiment of the invention in which, instead of a single cable for bending the distal tip, a pair of cables  130 ,  132  disposed within passageways  134 ,  136  within the wall  138  of the endotracheal tube  12  are used to flex or bend the distal tip in either of two directions along a y-axis shown in FIG. 19. An alternative to this arrangement, providing for even greater versatility, is shown in the ninth embodiment of the invention in FIGS. 20 and 20A. In this case, four cables  140 ,  142 ,  144  and  146 , disposed within passageways  148 ,  150 ,  152  and  154  spaced at 90° intervals within the wall  156  of the endotracheal tube  12  can be used to flex the tip in either direction along an x-axis, a y-axis or anywhere in between, thus providing the greatest degree of options so as to permit more precise control of the direction of the bending of the distal tip.  
         [0070]    [0070]FIGS. 21 and 22 show a tenth embodiment of the invention in which flexibility of the distal tip of the endotracheal tube is provided by a bellows section  160  within the cuff  162 . Such a flexible bellows section allows movement of the distal tip in any direction while preserving the airtight integrity of the tube without any additional covering. The embodiment of FIGS. 21 and 22 includes a small baffle chamber  164  disposed along the underside of the bellows section  160  of the distal tip of the endotracheal tube. Air or fluid forced into this chamber by way of a small diameter tube  166  causes expansion of the small baffle chamber  164  against a fixed projection  168  extending from the underside of the bellows section. FIG. 22 shows the distal tip of this embodiment in its flexed or bent configuration upon the introduction of air or other fluid under pressure into the small baffle chamber  164 .  
         [0071]    FIGS.  23 - 28  show an eleventh embodiment of the present invention. In this embodiment, flexibility of the distal tip is provided by a V notch  170  formed in the underside of the distal end of the endotracheal tube  12 . This V-shaped cutout or notch  170  is covered by a dual membrane, details of which are shown in FIGS. 25 and 26. A first flexible, inner membrane  172  including laterally oriented corrugations  174  is configured to nest within a similar, outer flexible membrane  176  also including laterally disposed corrugations  178 . The corrugations allow expansion of the membranes. The membranes are bonded together along their edges  180 ,  182  so as to define an enclosed space  184  therebetween. Air or fluid under pressure is supplied to this space by means of a small diameter tube  186 . FIGS. 27 and 28 show the distal tip of the endotracheal tube of this embodiment in its unflexed or unbent configuration and in its bent or flexed configuration when air or other fluid is forced into the space  184  between the inner and outer membranes.  
         [0072]    [0072]FIGS. 29 and 30 show a twelfth embodiment of the invention comprising an endotracheal tube having a distal end including a cuff, as already described. A V-shaped cutout or notch  190  is formed in the distal end of the endotracheal tube  12  within the confines of the cuff. Inserted into the lower end of the V-shaped notch  190  is an expandable balloon  192  having a distal extremity  194  and a proximal extremity  196 . The distal extremity  194  is sealed while the proximal extremity receives the distal end of a small diameter tube  198 . The distal end of the tube  198  is bonded or otherwise secured in fluid-tight fashion within the proximal end  196  of the balloon. Air or other fluid forced into the balloon causes expansion thereof and flexing or bending of the distal end of the endotracheal tube, as best seen in FIG. 30.  
         [0073]    The embodiments of FIGS.  21 - 30  show the small diameter tubes  166 ,  186  and  198  for supplying air or other fluid to the baffle chamber  164 , dual membrane  172 ,  176 , and balloon  192 . The small diameter tubes are illustrated as co-extruded to the exteriors of the primary tubular bodies. However, the small diameter tubes can also be co-extruded to the interiors of the primary tubular bodies. Alternatively, the small diameter tubes can extend within the passageways in the walls of the primary tubular bodies in a similar fashion to the conduit  18  illustrated in FIG. 1. Also, the passageways in the walls themselves can constitute the air-tight or fluid-tight small diameter tubes in which case the small diameter tubes are sealed into the proximal ends of passageways.  
         [0074]    Although the present invention has been described in considerable detail with reference to certain preferred versions and uses thereof, other versions and uses are contemplated by the invention. For example, it is not necessary to purposely provide a flexible portion to the wall nor is it necessary that the distal portion of the cable be placed between the cuff and the tube outer wall. The bending action can be obtained using a standard cuffed endotracheal tube with the cable run through the lumen of the tube or in the wall of the tube. The cable then exits through the wall just proximal of the cuff and is attached to the wall just distal of the cuff (i.e., external to the cuff). Pulling on the cable in the manner described above causes the tube to bend in the region covered by the cuff.  
         [0075]    Further, it is not necessary to limit the flexible portion  34  to the cuff area. Any portion of the tube can be caused to bend by providing a cable exiting through the tube wall before the desired bendable section and attaching the cable proximal thereto. Pulling on the cable bends the tube within that portion where the cable is external to the tube.  
         [0076]    Other variations contemplated within the general scope of the device described above include other means of creating a flexible portion such as by providing the tubular body a corrugated tube wall or making the distal end portion of the tubular body of a material that is more flexible than the remainder of the tubular body.  
         [0077]    In some applications the inflatable cuff in neither needed nor desirable. For example, when used with some children, the endotracheal tube forms a seal with the interior walls of the trachea without use of the inflatable cuff, and elimination of the cuff reduces the thickness of the device for easier insertion and manipulation. Also, the cuffless device of the present embodiment can be used for applications other than as an endotracheal tube, for example, as a cannula for insertion into a human or animal body.  
         [0078]    [0078]FIGS. 31 a ,  31   b  and  32  show a further embodiment in which one or two membranes are used rather than the inflatable cuff as described above. In this embodiment, a flexible portion  202  of the tube is created by providing one or more notches  204  in a wall  206  with a bottom  208  of the notch functioning as a hinge. An outer membrane  210  covers the notch  204 . An inner membrane  212  may be placed inside the tube in which case a cable  214  of the pulling mechanism is located between the outer membrane  210  and the inner membrane  212 . The outer membrane  210  protects the walls of the body passage into which the tube is inserted from coming into contact with the cable. The outer membrane  210  can be sealed to the outer surface of the tube forming a fluid-tight seal. Alternatively or additionally, the inner membrane  212  can be sealed to the inner surface of the tube to form a fluid-tight seal.  
         [0079]    [0079]FIG. 32 shows the cable  214  creating a temporary bend in the flexible portion of the tube covered by the membrane. The cable  214  extends from the proximal end  216  of the tube through a proximal end of the portion of the tube covered by the membrane, extending between the flexible portion  202  and the outer membrane  210 . The distal end of the cable  214  is attached to the wall  206  distal to the notch  204 . The cable  214  can be attached to the wall  206 , for example, at a position distal to (as illustrated in FIG. 31 a ) or below (as illustrated in FIG. 34) the outer membrane  210 . A pulling force is applied to the proximal end of the cable  214  at the proximal end  216  of the tube.  
         [0080]    As explained above with respect to other embodiments, the flexible portion  202  of the tube need not include a notch, but can formed in other ways. For example, the tube can be formed from a polymeric material with the portion of the tube forming the flexible portion  202  being a polymer of different chemical properties having a greater flexibility than surrounding portions of the tube. Also, the flexible portion  202  can be heat, ultrasound or UV radiation treated to create flexibility greater than surrounding portions of the tube.  
         [0081]    While this embodiment does not show the use a spring, a spring can be used within the tube for the same purposes as set forth in other embodiments.  
         [0082]    As shown in FIG. 34, an inflatable cuff  228  can be used with the embodiment of FIG. 31 a . Thus, the flexible portion of the tube  202  need not be within the inflatable cuff  228 . The inflatable cuff  228  can be positioned proximate to the flexible portion  202  (as illustrated FIG. 34), can be positioned distal to the flexible portion  202 , or can surround the flexible portion  202  (as illustrated in FIG. 8).  
         [0083]    [0083]FIG. 33 shows flexible portions created by a plurality of notches  220 - 226 . FIG. 33 shows the notch  226  oriented 180 degrees from the notches  220 ,  222 ,  224  relative to the axis of the tube. This allows bending of the tube in directions within a plane. Additionally, the notches can be oriented anywhere 360 degrees around the axis of the tube allowing the bending of the tube in directions outside of the plane. The multiple notches can be controlled by multiple cables oriented similarly to those shown in FIGS. 19, 19 a ,  20  and  20   a.  Each notch can have a cable that exits through the wall at the proximal end of the notch which then attaches to the wall just distal of the notch. As explained above with respect to other embodiments, the flexible portion of the tube need not include a notch, but can formed in other ways.  
         [0084]    In the embodiments of the present invention described above and shown in the figures, some of the mechanisms for bending the primary tubular body, including the cables and the small diameter air/fluid supplying tubes, are shown extending within the walls of the primary tubular body from the proximate end of the body to the flexible region. Other of the mechanisms for bending the body are shown co-extruded to the exteriors of the primary tubular bodies. However, it is also intended that in all the described embodiments the mechanisms for bending the tubular body can extend within the walls of the body and/or can be co-extruded to the exterior and/or interior of the primary tubular body.  
         [0085]    It is believed that the operation and construction of the present invention will be apparent from the foregoing description and, while the invention shown and described herein has been characterized as particular embodiments, changes and modifications may be made therein without departing from the spirit and scope of the invention as defined in the following claims.