Abstract:
An extendable lighted intubation stylet enables a clinician or emergency medical personnel to introduce a breathing tube into a person&#39;s trachea. The extendable lighted intubation stylet includes a handle, a switch, a sheath, an extension member, and a light source. The extension member can be extended or retracted relative to the sheath thereby increasing or decreasing the length of the extendable lighted intubation stylet. The light source provides for superior visualization of the airway compared to a standard laryngoscope bulb. In its extended configuration, the extendable intubation stylet is immediately available in the case of an unanticipated difficult airway and can be used as a bougie. The extendable stylet is lightweight and convenient because it can be folded and placed in a pocket or in a space critical location such as a field kit or portable airway bag.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application is based on and hereby claims the benefit under 35 U.S.C. §119 from U.S. Provisional Application No. 60/831,825, entitled “Extendable Lighted Intubation Stylet,” filed on Jul. 19, 2006, the subject matter of which is incorporated herein by reference. 
     
     BACKGROUND INFORMATION 
       [0002]    In the course of medical care, healthcare providers often have to place an endotracheal tube into a person&#39;s airway. This process, intubation, may be necessary for artificial ventilation, protecting the airway from aspiration of stomach contents or for the delivery of anesthetics. Intubation may be performed by paramedics or military personnel in the field, in emergency departments, hospitals or in the operating room. 
         [0003]    An endotracheal tube  34  is shown in  FIG. 1 . An endotracheal tube has a tubular shaft  17  with a distal end  14 , a proximal end  15 , an inflatable cuff  12  and an inflation lumen  10 . During intubation the distal end  14  of the endotracheal tube is inserted into a person&#39;s mouth and slidably positioned into the person&#39;s trachea such that proximal end  15  projects outward from person&#39;s mouth. Inflatable cuff  12  is then used to secure the endotracheal tube  34  in the trachea. Inflatable cuff  12  is inflated by supplying air at inflation lumen  10 . Oxygen and/or anesthetics are then supplied to the person by supplying them utilizing proximal end  15  of endotracheal tube  34 . 
         [0004]    In many situations a person&#39;s glottis is not visible to the physician such as when obstructed by blood, secretions, swelling, abnormal anatomy, or when person is obese. This is termed the “difficult airway” and in these situations proper intubation may be difficult and ventilation of the person may fail if endotracheal tube  34  of  FIG. 1  is incorrectly inserted into the person&#39;s esophagus rather than the person&#39;s trachea. To facilitate proper intubation, a variety of introducers are utilized. 
         [0005]      FIG. 2  is a drawing of a standard stylet  30 . To facilitate intubation of the person, a plastic coated metal stylet is frequently used to stiffen endotracheal tube  34  of  FIG. 1  by inserting standard stylet  30  within the endotracheal tube. A distal end  24  of standard stylet  30  is inserted into the endotracheal tube such that a proximal end  20  of the standard stylet  30  extends outward from proximal end  15  of endotracheal tube  34  of  FIG. 1 . The standard stylet  30 , together with the endotracheal tube can then be bent to form a shape that facilitates insertion into the trachea of a person. 
         [0006]      FIG. 3  shows a standard stylet  30  placed within an endotracheal tube  34  and disposed within a person&#39;s airway. The distal end of the endotracheal tube is disposed within a person&#39;s trachea  32 . Once an endotracheal tube  34  containing standard stylet  30  is properly positioned as indicated in  FIG. 3 , standard stylet  30  is then removed leaving endotracheal tube  34  disposed in the trachea. A source of oxygen can then be coupled to the proximal end of endotracheal tube  34 . 
         [0007]    Since visibility is often partially or fully obstructed in the case of a difficult airway, intubation utilizing a standard stylet is not optimal. The distal end  14  of endotracheal tube  34  of  FIG. 1  is many millimeters in diameter and decreases the operator&#39;s visibility of the airway. The large diameter of endotracheal tube  34  makes it difficult to slip under the epiglottis such to access to the trachea. Therefore, since visibility is not optimal and since the relatively large diameter of the endotracheal tube further frustrates intubation, other devices or introducers are often utilized in the difficult airway situation. 
         [0008]    One of these introducers is shown in  FIG. 4 , a drawing of a gum elastic bougie  40  or “bougie.” The bougie  40  is used in combination with a laryngoscope to first locate a person&#39;s epiglottis or vocal cords and then as a guide for insertion of the endotracheal tube. 
         [0009]    The bougie  40  is approximately 70 centimeters long and includes a distal end  44  and a proximal end  42 . Both the proximal end  42  and distal end  44  are rounded such for prevention of trauma to the person during insertion of bougie  40  into the airway. Commercially supplied bougies are marketed and sold in varying diameters, and some are approximately 5 millimeters in diameter. This relatively small diameter of the bougie compared to the diameter of an endotracheal tube increases the possibility of proper insertion since it fits into smaller openings and allows for increase visibility during intubation. However, the bougie is approximately 70 centimeters in length and is cumbersome and is also not immediately disposed to operator&#39;s use. 
         [0010]      FIG. 5  shows a bougie  40  disposed within a person&#39;s airway. When bougie  40  is correctly guided into the airway, distal end  44  will enter a person&#39;s trachea  32 . The trachea  32  is composed of C-shaped cartilaginous rings known as tracheal rings  39 . An esophagus  57  is devoid of tracheal rings and is shown in  FIG. 5  adjacent trachea  32 . During intubation, distal end  44  of bougie  40  glides over tracheal rings  39  and the physician or operator will feel a vibration or tapping sensation at a proximal end  42 . This is known as “tracheal clicking.” The operator is then assured that bougie  40  is correctly located in the airway and not in the person&#39;s esophagus. If tracheal clicking is not felt at proximal end  42 , bougie  40  is likely disposed within esophagus  57  and must be withdrawn and replaced. 
         [0011]    Bougie  40  finds use in the difficult airway situation since it is smaller in diameter than the endotracheal tube and allows for greater operator visibility and since distal end  44  is easier to slip under the epiglottis and into the airway when compared to the endotracheal tube. Bougie  40  is also manufactured with an angled or “Coude tip” which facilitates tracheal clicking as a result of improved contact with tracheal rings  39 . 
         [0012]    Once the bougie has been correctly placed within the person&#39;s trachea, endotracheal tube  34  can be inserted over the proximal end  42  of bougie  40  and slidably positioned into the person&#39;s trachea using bougie  40  as a guide. Bougie  40  is then slidably removed from the person leaving endotracheal tube  34  disposed within the trachea for ventilation or delivery of anesthetics. Although a bougie may offer improved performance over the standard stylet, there remains a need for improved visibility and bougie  40  is also prone to twisting during use making proper handling less than ideal. 
         [0013]    Another introducer, a lightwand  60 , is shown in  FIG. 6 . The lightwand has a handle  52  located at the proximal end of a shaft  54  and a light source  56  located at the distal end of shaft  54 . A switch  58  disposed on handle  52  of lightwand  60  and allows the operator to control light source  56 . 
         [0014]    To intubate a person using a lightwand, an endotracheal tube is slipped over the light source  56  at the distal end of shaft  54  and is positioned on shaft  54  between handle  52  and light source  56 . A bend is then placed at the distal portion of the light wand such that the distal end containing light source  56  is at an approximate 90 degree angle relative to the axis of shaft  54 . The light source is then switched on using switch  58  and the distal portion of the lightwand is then inserted into person&#39;s throat and advanced until an external glow is seen emanating from the person&#39;s suprasternal notch. This glow is externally visible to the operator and indicates that the lightwand is properly positioned in the trachea of a person. If a glow is not seen than the lightwand is incorrectly positioned in person&#39;s esophagus and must be withdrawn and reinserted until proper placement is achieved. 
         [0015]      FIG. 7  shows a lightwand  60  and an endotracheal tube  34  disposed within a person&#39;s trachea. A light source  56  is viewable externally when lightwand  60  is properly positioned in the airway as shown. If lightwand  60  were incorrectly positioned within an esophagus  57 , light source  56  would not be externally visible. Lightwand  60  is smaller than other introducers such as a bougie and can easily store in situations where space is limited such as a field kit or portable airway bag. However lightwand  60  is not adaptable to standard orotracheal techniques since it calls for the use of a guide or a metal stylet that is removable such to prevent trauma. Additionally, lightwands do not produce the tracheal clicking as evidence of proper intubation thus depriving the operator of an effective manner of validating proper placement. 
         [0016]    In a trauma situation, the aforementioned introducers and similar commercially available devices are problematic since they are either quite lengthy, cumbersome or not readily adaptable to standard orotracheal techniques. In addition, where one introducer may have been initially selected to intubate a person, if physician subsequently desires a different introducer, he will waste precious time as he must remove the introducer that was initially selected and replace it with the more desirable alternative. An optimal introducer is thus desired which eliminates the combined disadvantages of the aforementioned introducers. 
       SUMMARY 
       [0017]    An extendable lighted intubation stylet has been invented to enable a clinician or emergency medical personnel to easily introduce a breathing tube into a person&#39;s trachea. The extendable lighted intubation stylet includes a sheath member, an extension member and a light source. 
         [0018]    The extension member can be extended or retracted relative to the sheath such to increase or decrease the length of the extendable lighted intubation stylet. When utilized in retracted form, the extendable stylet is compact and may be used as a replacement for the standard stylet for routine intubations. The light source of the extendable lighted intubation stylet provides for superior visualization of the airway compared to a standard laryngoscope bulb. In extended configuration, the extendable intubation stylet is immediately available in the case of the unanticipated difficult airway and the need to look for another device in this time critical period is obviated. The extension member can be quickly extended similar to a bougie. It is then retractable in the case where the practitioner decides to use it as a bougie and then as a standard stylet or a lightwand. The extension member contains a stiffening wire and can be bent at a 90 degree or a preferred angle when in use as a lightwand. The extendable lighted intubation stylet is compact and is thus ideal for pre-hospital use such as by paramedics or in military use. It can be folded and placed in a pocket or in space critical locations such as a field kits or portable airway bags. 
         [0019]    When used similar to a bougie, the distal end containing the light source will be placed under a person&#39;s epiglottis and advanced. As the light source passes into the trachea the operator will first see light emanating from person&#39;s suprasternal notch. Upon further advancement of the extendable stylet the operator will then experience vibratory sensations from the distal end of the extendable stylet bumping the cartilaginous rings of the trachea indicating that the stylet is properly positioned in the trachea. 
         [0020]    When used in this manner, the operator has two indications that the extendable stylet is correctly positioned in the airway, the light seen externally at person&#39;s suprasternal notch and the vibratory sensations produced by the distal end of the extendable stylet bumping into the cartilaginous tracheal rings. 
         [0021]    If this is not successful, the extension member can be quickly retracted and the device may be used similar to a lightwand. When used similar to a lightwand, light from the light source will be seen externally at person&#39;s suprasternal notch indicating that the extendable stylet is properly positioned in the trachea and not in the person&#39;s esophagus. If a glow is not seen then the extendable stylet is in the esophagus and must be repositioned. 
         [0022]    Further details and embodiments and techniques are described in the detailed description below. This summary does not purport to define the invention. The invention is defined by the claims. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0023]    The accompanying drawings, where like numerals indicate like components, illustrate embodiments of the invention. 
           [0024]      FIG. 1  is a drawing of an endotracheal tube. 
           [0025]      FIG. 2  is a drawing of a standard stylet. 
           [0026]      FIG. 3  is a cross sectional side elevation view of the standard stylet and endotracheal tube disposed within a person&#39;s airway. 
           [0027]      FIG. 4  is a drawing of a bougie. 
           [0028]      FIG. 5  is a cross sectional side elevation view of the bougie and endotracheal tube disposed within a person&#39;s airway. 
           [0029]      FIG. 6  is a drawing of a lightwand. 
           [0030]      FIG. 7  is a cross sectional side elevation view of the lightwand and endotracheal tube disposed within a person&#39;s airway. 
           [0031]      FIG. 8  is a cross sectional side elevation drawing of an extendable lighted intubation stylet. The extendable lighted intubation stylet is shown in its fully retracted position. 
           [0032]      FIG. 9  is a cross sectional side elevation drawing of an extendable lighted intubation stylet. The extendable lighted intubation stylet is shown in its fully extended position. 
           [0033]      FIG. 10  is a cross sectional side elevation diagram showing displacement of handle portion of an extendable lighted intubation stylet. 
           [0034]      FIG. 11  is a drawing of an extendable lighted intubation stylet in its fully retracted position. 
           [0035]      FIG. 12  is a drawing of an extendable lighted intubation stylet in its fully extended position. 
           [0036]      FIG. 13  is a drawing of an endotracheal tube mounted upon an extendable lighted intubation stylet in its fully retracted position. 
           [0037]      FIG. 14  is a cross sectional side elevation diagram of another embodiment of an extendable lighted intubation stylet with conductive tracks disposed along the inner aspect of the sheath member. 
           [0038]      FIG. 15  is a cross sectional side elevation diagram of another embodiment of an extendable lighted intubation stylet with conductive tracks only partially disposed along the inner aspect of the sheath member. 
           [0039]      FIG. 16  is a cross sectional drawing of an extendable lighted intubation stylet. 
           [0040]      FIG. 17  is a cross sectional drawing of another embodiment of an extendable lighted intubation stylet. 
           [0041]      FIG. 18  is a cross sectional side elevation diagram showing an extendable lighted intubation stylet and endotracheal tube in extended position, the endotracheal tube has not yet been advanced into the airway of a person. 
           [0042]      FIG. 19  is a cross sectional side elevation diagram showing an extendable lighted intubation stylet in its fully extended position with an endotracheal tube disposed within a person&#39;s trachea. 
           [0043]      FIG. 20  is a cross sectional side elevation diagram showing an extendable lighted intubation stylet in its fully retracted position and an endotracheal tube disposed within a person&#39;s airway. 
           [0044]      FIG. 21  is a flowchart of a novel method of using an extendable stylet to intubate a person. 
       
    
    
     DETAILED DESCRIPTION 
       [0045]      FIG. 8  is a drawing of an extendable lighted intubation stylet  69  in accordance with one novel aspect. Extendable lighted intubation stylet  69  includes a sheath member  74 , an extension member  76 , and a light source  78 . In one embodiment, light source  78  is a light emitting diode (LED). 
         [0046]    Sheath member  74  has a proximal end  61 , a tube section, a distal end portion  85 , and a distal end  81 . Sheath member  74  also has a handle portion  72  which is coupled to a T-shaped grip  70  at proximal end  61  of sheath member  74 . Extension member  76  is slidably coupled to sheath member  74  and has a proximal end  88 , a distal end portion  65 , and a distal end  77 . Light source  78  is disposed upon the distal end portion  65 . 
         [0047]    Also shown in this  FIG. 8  is a power supply  82 . The positive terminal of power supply  82  is connected to one terminal of a switch  71 . The opposite terminal of switch  71  is connected to a terminal of a resistor  87 . The opposite terminal of resistor  87  is connected to one of two insulated wires within a coiled wire pair  83  which is further connected to a first conductor  84 . First conductor  84  then extends to the positive terminal of light source  78 . The negative terminal of power supply  82  is connected to the second of the two insulated wires within coiled wire pair  83  which further connects to a second conductor  89  which in turn further connects to the negative terminal of light source  78 . Power supply  82  can be batteries disposed in series such to provide at least 3.6 Volts to light source  78 . In other embodiments, power supply  82  is a single 6 Volt medical battery. 
         [0048]    A stiffening wire  85  is disposed within extension member  76  and permits the distal end portion of extension member  76  to be more formable than sheath member  74 . 
         [0049]    It is desirable that the extendable lighted stylet is disposable after a single use and therefore be made of inexpensive materials and is easily manufactured. The extension member should be flexible to eliminate it as a source of trauma during intubation but must be of sufficient stiffness to permit an operator to locate the airway and facilitate insertion. 
         [0050]    The hardness of plastics and similar material is measured by a Shore or durometer test and is often used as a proxy for flexibility (flexural modulus). Extension member  76  may be made from aliphatic polyurethane of varying hardness although generally the range of 50 Shore A to 90 Shore D is satisfactory. Sheath member  74  and extension member  76  are hollow and the material is selected such to increase the hardness. Materials that create a hardness of approximately 90 Shore D are used in embodiments wherein both sheath  74  and extension member  76  are tubular. Additional materials that could yield the desired degree of both rigidity and flexibility include polyvinyl chloride (PVC) materials, gum elastic materials, polyurethane materials, polyethylene materials, fluorinated hydrocarbon polymer materials, polytetrafluoroethylene (PTFE) materials, silicone rubber materials, nylon materials, flexible silicone compositions, polyamide materials, and polyesther block amide materials. 
         [0051]    The desired stiffness of the extension member  76  is about 20-50 MPa as measured with a Tinius Olsen stiffness tester. 
         [0052]    Sheath  74  is approximately 4 millimeters to 5.5 millimeters in diameter and is sized to fit within endotracheal tubes of standard sizes. The length of sheath  74  is approximately 40 centimeters to 60 centimeters. Extension member  76  is approximately 10 centimeters to 30 centimeters in length. This small diameter of extension member  76  provides for greater visibility when intubating persons and be easily insterted under the epiglottis. 
         [0053]    Light source  78  can be a light emitting diode “LED” and is used as supplementary light to the standard laryngoscope bulb. The light is also usable to indicate the correct placement of the extendable stylet in the airway when the extendable stylet is being used as a lightwand. 
         [0054]    In this  FIG. 8 , extension member  76  is shown in its retracted position relative to sheath  74 . In this configuration, the overall length of the extendable stylet is approximately 50 centimeters. In the retracted position, the extendable stylet can be operated as either a lightwand or as a standard stylet. Extension member is 10 centimeters to forty centimeters in length. 
         [0055]    The handle portion  72  of sheath member  74  is coupled to a T-shaped grip  70 . T-shaped grip  70  allows the operator to control the axial rotation of the extendable stylet. This design eliminates unintended axial rotation of the inducer thus eliminating the potential for the extendable stylet to cause trauma. 
         [0056]    Stiffening wire  85  is disposed within extension member  76  from a proximal end  88  of extension member  76  to a distal end  77  of extension member  76 . The stiffening wire  85  allows the distal end portion  65  of extension member  76  to be formed into an angle with respect to the axis of sheath member  74 . During use as a lightwand, stiffening wire  85  allows the tip to be bent at a 90 degree angle such that a glow can be more readily seen at person&#39;s suprasternal notch indicating correct placement in the trachea. The stiffening wire is of such rigidity that it will flex back such to allow its withdrawal from the endotracheal tube  34  of  FIG. 10  when the extendable stylet is being retracted after successful intubation. 
         [0057]      FIG. 9  is a cross sectional side elevated view of the extendable stylet in its fully extended position. In this extended position, a coiled wire pair  83  has flexed to allow electrical connections to be maintained as an extension member  76  has been slidably extended from a sheath member  74 . Friction between the outer wall of extension member  76  and inner surface of sheath member  74  is such that it will overcome the force caused by flexion of coiled wire pair  83  thus preventing inadvertent retraction of extension member  76 . In other embodiments sheath member and extension member  76  each have threaded portions and are rotatably coupled such that extension member  76  must be axially rotated to telescopically extend it relative to sheath member  74 . In other embodiments, the extension and retraction of extension member  76  relative to sheath member  74  is effectuated by a spring. 
         [0058]    In its fully extended position the extension member  76  has been slidably extended from sheath member  74  such to increase the length of the extendable stylet to approximately 70 centimeters. In this configuration the device may be used similar to a bougie, wherein the light source  78  is positioned under the epiglottis and advanced until the operator feels a slight vibratory sensations or tracheal clicking thus indicating the light source is bumping the cartilaginous tracheal rings and the device is correctly positioned in the trachea. If no vibratory sensation is felt than the extendable stylet is in the esophagus and the should be removed and repositioned. 
         [0059]      FIG. 10  displays the extendable stylet in its fully retracted position. To retract an extension member  76  relative to a sheath member  74 , a handle portion  72  is pulled from sheath member  74  such to exert tension on a coiled wire pair  83  and further tension on a first conductor  84  and a second conductor  89 . The force caused by removal of handle portion  72  is such to overcome the friction between the outer surface of extension member  76  and inner surface of sheath  74  thus permitting extension member  76  to slidably retract relative to sheath member  74 . In some embodiments handle portion  72  and a tube section of sheath member  74  are threaded and handle portion  72  must be axially rotated with respect to tube section of sheath member  74  in order to detach handle portion  72  from the tube section of sheath member  74 . 
         [0060]      FIG. 11  is a drawing of an extendable lighted intubation stylet in accordance with one novel aspect. In this figure a light source  78  is coupled to an extension member  76  and extension member  76  is slidably coupled to a sheath member  74 . The T-shaped grip of a handle portion  72  of sheath member  74  is also present in this figure. A light source  78  is controlled by a switch  71 . 
         [0061]    The extendable intubation stylet  90  is fully retracted in this figure and may be used in a similar fashion as a lightwand or a standard stylet. When used similar to a lightwand, an endotracheal tube is slidably mounted on sheath member  74  and a distal end portion  65  of extension member  76  is bent relative to the axis of sheath member  74 . Light source  78  is switched on using switch  71  and the light source  78  and a distal end  77  of extension member  76  are inserted into the throat of a person and advanced. Light from light source  78  will be externally viewable when extendable intubation stylet is properly positioned in the airway of the person. During insertion, light from light source  78  also provides supplementary light such to aid the operator in initially locating the airway. After insertion, if light is not seen emanating from the suprasternal notch of the person, than the extendable stylet is in the person&#39;s esophagus and must be withdrawn and replaced. In its fully retracted position, extendable lighted intubation stylet  90  is also used similar to a standard stylet  30  of  FIG. 2  to shape an endotracheal tube such to permit insertion into a person&#39;s airway. 
         [0062]    In this  FIG. 11 , extension member  76  is fully retracted relative to sheath member  74 , and in this configuration the overall length of the device is approximately 50 centimeters. 
         [0063]      FIG. 12  is a drawing of the extendable intubation stylet in its fully extended position. In this position, an extension member  76  has been slidably extended from a sheath member  74  to increase the length of the extendable stylet to approximately 70 centimeters. In this configuration the device may be operated similar to a bougie, wherein a light source  78  is positioned under the epiglottis of a person and advanced until the operator feels a slight vibratory sensation indicating that the device is correctly positioned in the trachea. If no vibratory sensation or tracheal clicking is felt, the extendable intubation stylet is in the esophagus and must be removed and repositioned. In some embodiments light source  78  will be controlled by a switch  71  of  FIG. 11  such that it may remain on when extendable intubation stylet is extended position. In those embodiments, when the extendable intubation stylet is extended and light source  78  is on, light will be seen emanating from the suprasternal notch of the person similar to a lightwand. This provides additional validation, in addition to the tracheal clicking, that the extendable intubation stylet is correctly positioned in the person&#39;s airway. 
         [0064]      FIG. 13  shows an endotracheal tube  34  disposed upon an extendable stylet. To mount an endotracheal tube  34  onto the extendable stylet, the endotracheal tube is slidably moved over a light source  78 , over an extension member  76 , and a sheath member  74  until it abuts a handle portion  72 . In this figure, the extendable stylet is shown in its fully retracted position. Once the extendable intubation stylet is correctly positioned in the airway of a person, endotracheal tube  34  may be held in place while the extendable stylet is slidably removed from the person, leaving the endotracheal tube disposed within the trachea. Oxygen and/or anesthetics may then be applied to the person via endotracheal tube  34 . 
         [0065]      FIG. 14  is another embodiment of an extendable lighted intubation stylet  90  which obviates the need for the coiled wire pair  83  of  FIG. 8 . In  FIG. 14 , a first conductor  101  connects to a terminal of resistor  87  of  FIG. 8 . The opposite end of first conductor  101  is connected to a conductive track  103  which is disposed along an inner surface of a sheath member  74 . A sliding contact  105  is conductive and is slidably coupled to conductive track  103 . A third conductor  107  further connects sliding contact  105  to one terminal of a light source  78 . The opposite terminal of light source  78  is connected to a fourth conductor  108  shown disposed within an extension member  76 . At a proximal end  88  of extension member  76 , fourth conductor  108  is connected to a sliding contact  106  which is conductive and is slidably coupled to a conductive track  104  which is disposed along the interior surface of sheath member  74 . The opposite end of conductive track  104  is connected to the negative terminal of power supply  82  of  FIG. 8 . 
         [0066]    In this embodiment of  FIG. 14 , extension member  76  can be slidably extended and retracted relative to sheath member  74  while still maintaining electrical connectivity such to permit electrical control of light source  78 . Conductive tracks  103  and  104  can be metal tracks or can be alternatively constructed of electroconductive tape or similar material. 
         [0067]      FIG. 15  displays yet another embodiment of an extendable lighted intubation stylet  92 . In this embodiment, a conductive track  103  and a conductive track  104  do not extend the entire length of a sheath member  74  thus permitting a light source  78  to be electrically controlled when the extendable lighted intubation stylet  92  is in its fully retracted position. When the extendable lighted intubation stylet  92  is in the fully extended position, electrical connectivity to light source  78  is not maintained and light source  78  will be electrically disabled. In this embodiment, the extendable stylet may be used similar to a lightwand when it is in its fully retracted position and similar to a bougie when it is extended. In yet another embodiment, conductive tracks  103  and  104  make electrical contact with sliding contacts  105  and  106  only when the extendable stylet is in its fully retracted position and light source  78  will not turn on if extendable stylet is extended from its fully retracted position. 
         [0068]      FIG. 16  is a cross sectional diagram of an extendable lighted intubation stylet.  FIG. 16  displays a sheath member  74 , an extension member  76 , a stiffening wire  85 , a light source positive terminal  114  and a light source negative terminal  112 . In order to control distal end portion  65  of extension member  76  of  FIG. 8 , and to prevent it from inadvertently rotating and becoming a source of trauma, both sheath member  74  and extension member  76  are oval in shape. This oval construction prevents extension member  76  from rotating within sheath member  74  and potentially causing trauma to the person. 
         [0069]    A cross sectional diagram of one alternative embodiment is shown in  FIG. 17 .  FIG. 17  displays a sheath member  74 , an extension member  76 , a stiffening wire  85 , a light source positive terminal  114 , a light source negative terminal  112  and a notch  116 . In order to control the distal end portion  65  of extension member  76  of  FIG. 8 , and to prevent it from inadvertently rotating and becoming a source of trauma, sheath member  74  has notch  116  which is filled by a corresponding raised section disposed upon the outside surface of extension member  76 . The notch  116  thus prevents extension member  76  from axially rotating relative to sheath member  74  thereby reducing the possibility of trauma from inadvertant rotation. 
         [0070]      FIG. 18  shows an extendable lighted intubation stylet and endotracheal tube  34  before the endotracheal tube  34  is slidably positioned within person. The extendable lighted intubation stylet is shown with an extension member  76  fully extended relative to sheath member  74 . In this manner, when the extendable lighted intubation stylet is advanced into a trachea  32 , light from a light source  78  can be seen emanating from the suprasternal notch of a person indicating correct placement. Additionally, the operator will also feel vibratory sensations or tracheal clicking at the handle portion of the extendable intubation stylet as it is further advanced and the distal portion of extension member  76  bumps the cartilaginous rings located in the person&#39;s trachea  32 . In this manner the operator has two sources of verification that they have correctly placed the extendable stylet into the person&#39;s trachea. Once correct placement has been validated, the endotracheal tube can be slidably moved along the a sheath member  74  towards an extension member  76  into the person using the extendable stylet as a guide. Once the endotracheal tube  34  is properly positioned in the person&#39;s trachea, the extendable stylet could then be withdrawn leaving endotrachial tube  34  in place for administration of oxygen or anesthetics. 
         [0071]      FIG. 19  is a drawing showing extendable lighted intubation stylet  90  and endotracheal tube  34  disposed within a person. Extendable lighted intubation stylet is shown with an extension member  76  in a fully extended position. 
         [0072]      FIG. 20  is a drawing showing an extendable lighted intubation stylet  90  and endotracheal tube  34  disposed within a person&#39;s airway. In this drawing, light from a light source  78  is emanating from the person and is viewable externally at the suprasternal notch of the person. In this figure, the extendable lighted intubation stylet  90  is properly positioned in the airway and extends into a trachea  32  of a person. The light from light source  78  permits the operator to validate that the extendable lighted stylet is in the airway and is not disposed in an esophagus  57 . 
         [0073]      FIG. 21  is a simplified flowchart diagram of a novel method in accordance with one embodiment. In the initial step  200 , an endotracheal tube  34  is mounted onto an extendable lighted intubation stylet.  FIG. 13  shows an endotracheal tube  34  disposed upon the extendable stylet. To mount endotracheal tube  34  onto the extendable stylet, endotracheal tube  34  is slidably moved over light source  78 , over extension member  76 , and a sheath member  74  until it abuts handle portion  72 . 
         [0074]    Next, in step  201 , the extension member  76  of  FIG. 13  is inserted into the airway of a person. The light source  78  and extension member of  FIG. 13  are slipped underneath the person&#39;s epiglottis and slidably advanced through the airway and into the trachea. The light source  78  may be on and externally viewable to the operator through the suprasternal notch of the person. This is one method of verifying that the extension member  76  is correctly positioned in the airway. Additionally, tracheal clicking can also be felt at handle portion  12  of proximal end  61  of sheath member  74  of  FIG. 13  when extension member  76  is further advanced into the airway of a person. This further validates that the extendable stylet has been properly inserted into the trachea rather than in the person&#39;s esophagus.  FIG. 18  shows the extendable lighted intubation stylet after extension member  76  has been advanced through the airway and into the trachea  32 . The endotracheal tube  34  is disposed upon the sheath member  74  of extendable lighted intubation stylet  90  of  FIG. 18 . 
         [0075]    In a third step  202 , the endotracheal tube is moved relative to the sheath member such that the endotracheal tube is moved into the trachea.  FIG. 19  shows the endotracheal tube  34  after it has been slidably advanced along sheath member  74  of the extendable lighted intubation stylet  90  and into the trachea of a person. During intubation, endotracheal tube  34  is slidably moved along sheath member  74  in a direction towards extension member  76 . The extendable intubation stylet guides endotracheal tube  34  into its proper position in the trachea. Once properly in place, the inflation lumen  10  may be used to inflate inflatable cuff  12  thus securing the endotracheal tube  34  within the person&#39;s trachea. 
         [0076]    In the fourth step,  203 , the extendable lighted intubation stylet is removed from the mouth while the endotracheal tube remains disposed within the trachea of the person. Once the extendable intubation stylet has been removed, the person is successfully intubated and oxygen or anesthetics can be applied to the person via the endotracheal tube  34  of  FIG. 20 . 
         [0077]    Although certain specific embodiments are described above for instructional purposes, the teachings of this patent document have general applicability and are not limited to the specific embodiments described above. Accordingly, various modifications, adaptations, and combinations of various features of the described embodiments can be practiced without departing from the scope of the invention as set forth in the claims.