Abstract:
An inexpensive, endo-tracheal intubation device is disclosed. Methods of making and using the inexpensive, endo-tracheal intubation device are also disclosed.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a non-provisional application of the earlier filed provisional application, Ser. No. 61/343,413, filed on Apr. 28, 2010, and claims the benefit of priority of the filing date of Apr. 28, 2010, pursuant to 35 U.S.C. Sec. 119(e). 
    
    
     FIELD OF THE INVENTION 
     The present invention relates generally to medical devices designed to improve airway tube placement and, more specifically, to such devices which allow a medical practitioner to insert an airway tube rapidly and properly in a patient&#39;s trachea. 
     BACKGROUND OF THE INVENTION 
     In a medical emergency, it is frequently necessary for the medical practitioner to insert a breathing tube into the patient&#39;s trachea so that he or she can be ventilated. The tube must enter the larynx and pass through the opening between the vocal cords. Care must be taken during insertion to prevent the tube from entering the esophagus. 
     Some patients present more difficult airway access than others. Medical experts have classified airways into four different types. Type I is easily accessible and type IV is the most difficult. Airways need to be protected in unconscious patients, as well as in those of motor vehicle accident victims who may have suffered an unknown fracture of the cervical spine. This presents a special challenge to the medical practitioner. In such situations, if one were to extend the neck in the usual fashion, that is, in such a way that one can visualize the vocal cords by using a direct laryngoscope in order to insert the endo-tracheal tube, one could injure the spinal cord, causing severe paralysis or even death. Moreover, endo-tracheal tube insertion must be accomplished in less than 4 minutes to avoid brain death. Prolonged intubation procedure time can result in various degrees of brain injury. 
     Accidental placement of an endo-tracheal tube, whether it is inserted nasally or orally, in the esophagus rather than in the trachea is a possibility because of the natural curvature of the orpharynx. Such placement can result in patient hypoxia, varied degrees of brain damage and/or death. 
     The shape of a patient&#39;s throat varies widely from one individual to the next. In some patients, the vocal cords can be seen on visual inspection and it is relatively easy to insert ah intubation device. However, in other patients, the vocal cords are completely hidden from view, making insertion of the intubation device difficult. Often it is helpful to extend the patient&#39;s head backward as far as possible to increase the medical practitioner&#39;s view of the vocal cords; but such an approach cannot be used if the patient has suffered a neck injury and has to be made immobile in order to prevent further damage. 
     In practice then, physical and anatomical variations among patients can make it difficult for a medical practitioner to clearly identify a particular individual&#39;s vocal cords. Unless they can be properly identified, however, they may be damaged during ah intubation procedure. To address this heed, Schwartz et al. (U.S. Pat. No. 6,539,942) disclosed a tubular endotracheal device, capable of being flexed into a L-shape and through which a conventional imaging device, such as a nasopharyngoscope, is inserted centrally, so as to allow for direct visualization of the vocal cords. 
     Unfortunately, this prior art combination is too costly to be disposed of after a single patient use; and the probability of infectious materials being transmitted from one patient to another is high—especially during a medical emergency in which more than one airway-compromised patient is involved and the same imaging device must be reused immediately. 
     SUMMARY OF THE INVENTION 
     The object of this invention is to provide a disposable, inexpensive-to-manufacture endo-tracheal tube placement device which includes components useful for visualizing key anatomical structures which a medical practitioner encounters in the course of gently pushing a portion of a tube placement device between a patient&#39;s vocal cords and into his trachea, the portion so pushed being encased in the endo-tracheal tube prior to its insertion into the patient&#39;s airway, said portion being adjustably bendable in such a way that the endo-tracheal tube can be inserted into the patient&#39;s trachea even when visualization of the anatomical structures is difficult because of the shape of the patient&#39;s throat and/or because of injury. 
     A further object is to provide an endo-tracheal intubation device which paramedical personnel, after a brief training exercise in its applications, can safely use to assist a patient experiencing a compromised airway. 
     A still further object is to provide a one-handed endo-trachel intubation device which emergency medical technicians can use in the field, freeing up one of the hands of the individual performing the intubation procedure so that he can use his free hand to support the patient&#39;s head and/or otherwise assist in the intubation process. 
     In combination with an endo-tracheal tube which, like those well-known in the prior art, is typically made of a flexible, medical grade PVC material with substantial resistance to collapse, the improved endo-tracheal intubation device, according to the present invention, includes a stylet with a bendable, substantially tubular element, an elongated stylet holder, and a bell crank pivotally mounted thereon which is connected to the stylet by a flexible wire. Fabricated of a hollow, semi-rigid, medical grade plastic material which is generally circular in transverse cross-section, the tubular element encases a portion of the flexible wire, which not only extends lengthwise through the tubular element but also protrudes therefrom. In assembled relation, one end of the tubular element is slip-fitted, pinched or otherwise firmly held in place within a cylindrically-shaped void defined by interior walls of the stylet holder. Also so defined by its interior walls is a through passageway which communicates with the cylindrically-shaped void and through which the flexible wire passes enroute to its connection with the bell crank. 
     Distal from the stylet holder, the end of the tubular element is covered by a metal cap which preferably also encases a disk to which the flexible wire is affixed and on which a LED light is mounted in such a way that it protrudes outwardly from the stylet&#39;s tip. Bright enough to be seen through the skin of a patient&#39;s neck in a darkened setting, the LED light allows the user to track the endo-tracheal tube&#39;s advancement along the patient&#39;s airway, as well as to visualize his vocal cords. In the preferred embodiment, the LED light is powered by at least one battery housed within the stylet holder and is activated by a sliding, on-and-off switch mounted thereon. 
     Proximate with the metal cap, the stylet&#39;s tubular element is scored in such a way that it can be bent in a controlled manner by tensioning the flexible wire, without disturbing electrical wires, connecting the LED light to the battery, which also run through the tubular element. In the preferred embodiment, the scored portion of the tubular element defines a series of spaced apart, transverse slots so positioned that the mid-section of each slot is disposed on only one side of the unbent stylet&#39;s longitudinal centerline, away from the electrical wires, thereby minimizing their exposure to the slots, each of which is squeezed so as to narrow its width, closing it to a degree, whenever the stylet is flexed. 
     Means for tensioning the flexible wire includes the bell crank which is pivotally mounted on a forked structure situated at the stylet holder&#39;s terminal end distal from the cylindrically-shaped void. The forked structure, which defines a U-shaped channel with opposing side walls, generally straddles the bell crank&#39;s short arm to which the flexible wire is affixed. By rotating the bell crank&#39;s trigger arm toward the stylet holder and, in the process, simultaneously moving the short arm away from the through passageway and its opening into the U-shaped channel—an opening which is located approximately midway between the opposing side walls, one can pull a short portion of the flexible wire outwardly from the through passageway, thereby reducing, while the trigger arm is so rotated, the length of the flexible wire retained within the tubular element and flexing the stylet. Moreover, the further the trigger arm is rotated in a direction toward the stylet holder so as to bring the trigger arm&#39;s longitudinal centerline more nearly into generally parallel alignment with the path which the flexible wire takes, under tension, between the through passageway&#39;s respective junctures with the cylindrically-shaped void and the U-shaped channel, the greater is the flexing of the stylet. 
     In order for the improved endo-tracheal device to be operable using only one hand, spacing between the bell crank&#39;s axis of rotation and an elongated portion of the stylet holder which extends for most of its length and which has a generally cylindrically-shaped exterior is preferably such that the trigger arm not only clears said portion but also is narrow enough that the average medical practitioner can simultaneously grasp such portion and use the finger(s) of his grasping hand to rotate the trigger arm-throughout its full range of motion. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of the endo-tracheal intubation device according to the present invention, showing its tubular stylet in a generally unflexed condition, with the trigger arm of the device&#39;s bell crank rotated outwardly; 
         FIG. 2  is a perspective view of the endo-tracheal intubation device according to  FIG. 1 , showing its tubular stylet in a bent configuration; 
         FIG. 3  is a perspective view, on an enlarged scale, of a fragmentary portion of the endo-tracheal intubation device according to  FIG. 1 , showing the end of its stylet distal from its holder; 
         FIG. 4  is a perspective view of the endo-tracheal intubation device according to  FIG. 1 , showing its stylet encased in an endo-tracheal tube adaptively mounted on the stylet holder; 
         FIGS. 5  depicts, on an enlarged scale, components of the endo-tracheal device according to  FIG. 4 , showing, (i) the first flat wall surface of the first element, of the stylet holder, (ii) the bell crank pivotally mounted on the first element, (iii) a cross-sectional view of the stylet, (iv) a cross-sectional view of the endotracheal tube, and of (v) a cut-out cross-sectional view of the flexible wire connected to the bell crank&#39;s short arm as viewed along line  5 - 5  shown in  FIG. 4 ; 
         FIG. 6  depicts a view of the second flat wall surface of the second element of the stylet holder; 
         FIG. 7  shows a view of the endo-tracheal intubation device according to  FIG. 4  successfully placed orally into a patient&#39;s trachea; 
         FIG. 8  is a side elevation view, on an enlarged scale, of fragmentary portions of the endo-tracheal intubation device according to  FIG. 1 , with its tubular stylet in a bent configuration and encased in an endo-tracheal tube; 
         FIG. 9  is a transverse cross-sectional view of the first and second elements, taken along line  9 - 9  shown in  FIGS. 5 and 6 , respectively, with the first and second elements of the stylet holder being positioned apart from one another; 
         FIG. 10  is an end elevation view of the stylet holder, without the bell crank pivotally mounted thereon; 
         FIG. 11  is an end elevation view of the stylet holder and of the bell crank pivotally mounted thereon; 
         FIG. 12  is a perspective view, on an enlarged scale, of a disk onto which the steering wire is attached, the disk being part of the stylet in the endo-tracheal intubation device according to  FIG. 5 ; and 
         FIG. 13  is an exploded view, on a reduced scale, of the endo-tracheal intubation device according to  FIG. 1  and of an endo-tracheal tube having an adapter mountable on the stylet holder. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     In the drawings, an improved endo-tracheal intubation device is indicated generally by the reference numeral  10 . The device  10 , designed for single use only, provides its own bright, battery-powered LED light  18  to illuminate the vocal cords of a patient&#39;s larynx so that a medical practitioner can visualize them directly in certain individuals—specifically, those whose neck can be hyper-extended in such a fashion that anatomical structures along the patient&#39;s airway are aligned linearly—and, more generally, to enable a trained observer to confirm placement of a conventional endo-tracheal tube  40  in the trachea, as can be determined by observing the position of the device&#39;s light as it shines through the skin of the patient&#39;s neck. Coupled with this low cost visualization tool is a novel mechanism which allows the operator to deflect the tip of the endotracheal tube  40  towards the vocal cords, thereby facilitating its proper placement anteriorly in the trachea. 
     Basic to the device  10  is a stylet having a substantially tubular element  16  ( FIGS. 1-3 ,  5  and  13 ). Fabricated of a hollow, semi-rigid, medical grade plastic material which is generally circular in transverse cross-section, the tubular element  16  preferably measures, at most, approximately 6.0 mm in diameter in order to ease its insertion, while encased in the tube  40 , between the vocal cords. So that the tip of the tube  40  can be deflected towards the vocal cords, the tubular element  16  defines a scored section  11  which can be bent in a controlled manner by tensioning a flexible wire  11  ( FIGS. 1-3  and  5 ). As is best illustrated in  FIG. 5 , the tubular element  16  encases a portion of the flexible wire  11  which not only extends lengthwise through it but also protrudes therefrom. 
     The scored section  17  itself defines a plurality of spaced apart, transverse slots  37  so positioned that the midsection of each slot is disposed on only one side of the unbent stylet&#39;s longitudinal centerline, away from electrical wires  34  which connect the LED light  18 , mounted on a disk  31  at the stylet&#39;s tip, to batteries  14  ( FIGS. 3 ,  5  and  12 ). Preferably, the spacing between the elongated edges of each individual slot  37 , when the stylet is not in a state of flexure, measures, by way of example, approximately 1.5 mm; and the length of each segment of the tubular element  16  which separates proximal edges of each contiguous pair of slots  37  is typically about 7.9 mm, giving the scored section  17 , in a tubular element  16  with a diameter of approximately 4.7 mm, an overall length of about 48.5 mm. 
     Also included in the device  10  is a stylet holder  13  which has two major components: a first element  23  and a second element  33  which, except for structures defined by the first element  23  to accommodate the batteries  14  and an on-and-off switch  15 , are generally mirror images of each other ( FIGS. 5 ,  6  and  13 ). Generally flat first and second walls, namely, first wall  231  and second wall  331 , each of which is interrupted by a plurality of interconnected recesses which divide it into two parts along its entire length, extend longitudinally across the first and second elements  23  and  33 , respectively (see,  FIGS. 5 and 6 ). These interconnected recesses, when the elements  23 ,  33  are fastened together in assembled relation, define a pair of contiguous first and second cylindrically-shaped voids  20 / 30  and  25 / 35  and a through passageway  26 / 36  extending generally longitudinally from its juncture with the second cylindrically-shaped void  25 / 35  to the passageway&#39;s opening into a U-shaped channel  38 , which is defined by open-ended cutouts in the elements  23 ,  33  (see  FIGS. 5 ,  6 ,  9 ,  10 , and  13 ). The interconnected recesses, in the case of the first element  23 , include concavities  20 ,  25 ,  26  and  27 , each of which is approximately semicircular in transverse cross-section, as well as battery compartments  24 ,  28  and a shallow cutout  29  juxtaposed between them. Similarly, the interconnected concavities  30 ,  35  and  36  in the second element  33  are also approximately semi-circular in transverse cross-section, with the radius of curvature of each of the concavities in the first element  23  and the concavity in the second element with which, in assembled relation, it is paired having the same radius of curvature. Moreover, paired concavities  20 ,  30  have a radius of curvature which is greater than that of paired concavities  25 ,  35 , thereby creating a first shoulder  88  between the first and second cylindrically-shaped voids  20 / 30  and  25 / 35 . Likewise, paired concavities  25 ,  35  have a greater radius of curvature than do paired concavities  26 ,  36 , so that a second shoulder  89  is formed at the juncture between the second cylindrically-shaped void  25 / 35  and the through passageway  26 / 36  (see,  FIGS. 5 and 6 ). 
     Abutting the second shoulder in the assembled holder  13  is one end of the tubular element  16 . Preferably during assembly, said end is slideably slip-fitted into the concavity  25  until the tubular element  16  abuts the juncture between concavities  25 ,  26 . Next, in preparation for its being affixed to tensioning means located distal from the concavity  25 , the protruding portion of the flexible wire  11  is stretched across the interconnected recesses in the first element  23 . By following this procedure, the assembler can then simultaneously pinch the tubular element  16  between concavities  25 ,  35 , holding it in place within the second cylindrically-shaped void, and position the protruding portion of the flexible wire  11  so that it traverses the through passageway and extends outwardly therefrom into the U-shaped channel  38 . 
     Means for tensioning the flexible wire  11  includes a bell crank pivotally mounted, with the use of a pin  32 , to the first and second elements  23 ,  33  at their respective ends located distally from the first and second cylindrically-shaped voids in the assembled holder ( FIGS. 5 ,  6  and  11 ). Attached to the bell crank&#39;s short arm  22  by first inserting the wire  11  through a narrow hole formed therein, pulling the wire taut and lastly affixing a metal sleeve  21  thereto so as to secure the sleeve/flexible wire juncture within the narrow hole, the wire  11  can then be tensioned by rotating the bell crank&#39;s trigger arm  12  toward the holder  13 —a process which simultaneously moves the short arm  22  away from the through passageway, as well as its opening into the U-shaped channel  38 , and pulls a short portion of the wire  11  outwardly, thereby reducing, while the trigger arm is so rotated, the length of the flexible wire retained within the tubular element  16  and flexing the stylet. As can be seen in  FIGS. 1 ,  2 ,  5 ,  7  and  8 , the further the trigger arm  12  is rotated in a direction toward the holder  13 , the greater is the flexing of the stylet&#39;s scored section  17 . 
     Distal from the stylet holder  13 , the end of the flexible wire  11  is preferably looped through holes  39  defined by the disk  31 , so as to affix the wire  11  thereto. As illustrated in  FIGS. 3 ,  5  and  13 , both the disk  31  and a portion of the tubular element  16  contiguous with the disk are covered by a stainless cap  19  from which the LED light  18  protrudes outwardly at the stylet&#39;s tip. 
     Prior to use, the stylet, with its tubular element  16  mounted within the holder&#39;s second cylindrically-shaped void, is inserted into an endo-tracheal tube  40  fitted with a conventional adapter  45 ; and the latter is then slip-fitted into the holder&#39;s first cylindrically-shaped void, thereby encasing the stylet within the tube ( FIG. 4 ). 
     During use of this combination endo-tracheal tube/adjustably bendable stylet assembly, the device  10  can be employed to maneuver the tip of its stylet, as well as the overall tip of said assembly past a patient&#39;s tongue and inbetween his vocal cords. After the latter tip has been inserted past them, the bell crank&#39;s trigger arm  12 , if previously engaged, may be released, reducing substantially all of the tension on the flexible wire  11  and relaxing the stylet&#39;s bent configuration, while said assembly is then inserted further into the patient&#39;s airway. Once the assembly is properly placed anteriorly into the trachea, the endo-tracheal tube&#39;s balloon cuff  50  is inflated, locking the tube  40  in place; and the stylet is withdrawn, allowing the patient to breathe/be ventilated. 
     Because of the brightness of the LED light  18 , a trained observer can confirm placement of the tube  40  in the trachea, even under emergency field conditions and in bright sunlight, or in a well-lighted room, by placing a dark coyer (not shown) over the patient&#39;s neck. With the dark cover so placed, the operator can then visualize the position of said assembly&#39;s tip because of the skin illumination of the anterior aspect of the neck which the LED light  18  provides. 
     Other advantages of the improved endo-tracheal intubation device  10  include its affordability. In the preferred embodiment, the stylet holder  13  and the bell crank are fabricated from surgical grade plastics; but they can also be made from a variety of materials, so that device  10  is inexpensive to manufacture. Thus, it is suitable for single patient use only and fills the need for affordable devices which can perform the function of much more costly devices without compromising the quality of patient care.