Abstract:
A tracheotomy device has a housing configured to guide the device to an appropriate location in a suprasternal notch of a subject and a hollow penetrator associated with the housing. The penetrator resiliently moves from a retracted restrained position to an extended operational position with sufficient force to penetrate a tracheal wall, where the operational position extends a pre-determined distance from the housing. The pre-determined distance is correlated to a distance required to penetrate an anterior side of the tracheal wall without penetrating a posterior side of the tracheal wall. An actuator associated with the housing and the penetrator for releasing the penetrator is configured for use in one hand. The device is simple and disposable and may be used by unskilled caregivers to successfully and safely perform a tracheotomy on a subject with a blocked airway.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of International Patent Application PCT/CA2014/050911, filed Sep. 23, 2014, which claims the benefit of U.S. patent application No. 61/881,100, filed Sep. 23, 2013, the entire contents of which are incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to medical devices, in particular to devices for performing emergency tracheotomies. 
     BACKGROUND OF THE INVENTION 
     An obstruction in a person&#39;s trachea can cause death from asphyxiation, often within minutes before medical help can arrive. When back slaps or the Heimlich maneuver cannot dislodge the obstruction, it may be necessary to perform a tracheotomy. A tracheotomy involves inserting a hollow tube into the trachea below the obstruction so that the person can breathe freely through the tube. Because the trachea is surrounded by stiff cartilaginous material, a scalpel, trocar or other cutting instrument is required to make an incision in the trachea between the cartilaginous rings. This can be difficult without specific knowledge, so tracheotomies traditionally require medical knowledge to perform successfully and safely. Given that the time for trained emergency services personnel to arrive after a subject has begun to choke often exceeds the survival time that someone can survive without breathing, any attempt to save the subject&#39;s life must be considered. Therefore, if trained medical personnel are not present, then it would be useful to have a simple emergency tracheotomy device that can be used safely and successfully by the general public with little or no training. Further, to reduce the possibility of contamination and for simplicity, such an emergency device should be simple to use, inexpensive, sterilizable and amenable to single-use with disposal after use. 
     SUMMARY OF THE INVENTION 
     There is provided a tracheotomy device comprising: a housing configured to guide the device to an appropriate location in a suprasternal notch of a subject; a hollow penetrator associated with the housing, the penetrator resiliently moveable from a retracted restrained position to an extended operational position with sufficient force to penetrate a tracheal wall, the operational position extending a pre-determined distance from the housing, the pre-determined distance correlated to a distance required to penetrate an anterior side of the tracheal wall without penetrating a posterior side of the tracheal wall; and, an actuator associated with the housing and the penetrator and configured for use in one hand for releasing the penetrator to be resiliently moved from the restrained position to the operational position. 
     There is further provided a kit comprising a device of the present invention and instructions for use of the device for performing a tracheotomy. 
     There is further provided a method of performing a tracheotomy comprising positioning a device of the present invention in a suprasternal notch of a subject, and actuating the actuator to release the penetrator into a trachea of the subject. 
     The penetrator preferably comprises a hollow sharp blade that can penetrate skin and the tracheal wall of the subject. The penetrator may be elongated, for example a hollow needle, scalpel or trocar. Hollow trocars are particularly preferred. The penetrator may comprise any medically approved material, for example stainless steel, and is preferably sterilizable. 
     The penetrator is resiliently moveable from a retracted restrained position to an extended operational position with sufficient force to penetrate the tracheal wall. Preferably, the penetrator cannot then be reset back to the retracted restrained position to reduce the possibility that the device will be reused, since reuse could increase the chance of infecting future subjects with pathogens. Preferably, a biasing member is employed to provide the resilient movement and penetrating force. The biasing member may be, for example, a spring. Springs include, for example, leaf springs, torsion springs, compression springs and the like. Compression springs are particularly preferred. 
     The penetrator is associated with a housing. The penetrator may sit within or outside the housing, however, it is preferable that the penetrator is within the housing to reduce the possibility of accidentally causing injury with the penetrator. When the penetrator is in the retracted restrained position it is preferably fully within the housing so that no part of the penetrator is exposed. The housing is preferably a hollow tube with the penetrator housed coaxially within the tube. The tube may have a proximal end and a distal end. The distal end may be configured for placement in the suprasternal notch and may have a discharge aperture through which the penetrator can fully or partially extend when resiliently moved from the restrained position to the operational position. The proximal end of the housing may be configured for blowing air through the penetrator, optionally with the aid of a mouthpiece. The mouthpiece may be unitized with the housing or a separate piece that can be inserted on to the proximal end of the housing. The penetrator may be associated with a sealing element to seal a space between the penetrator and the housing to ensure that air blown into the device passes through penetrator. 
     The housing preferably comprises an inexpensive material, for example a plastic. The material is preferably moldable to form a one-piece or unitized structure and is preferably sterilizable. A one-piece structure provides for more economical construction and assembly and simplifies sterilization of the device. The housing may be opaque, transparent or translucent. A transparent or translucent housing facilitates observing the condition of the elements inside the housing, for example determining the status of a usage indicator. 
     The housing is configured to guide the device to an appropriate location in a suprasternal notch of a subject. Preferably, the penetrator is positioned above tissue between cartilaginous rings of the trachea. Therefore, the housing may comprise guide elements that naturally seat themselves between the cartilaginous rings and are configured on the housing to align the penetrator over the tissue between the cartilaginous rings rather than over the cartilaginous rings themselves. The guide elements may be further configured to reduce slippage of the device during actuation of the penetrator. In one embodiment, the housing may comprise spaced-apart protrusions configured to sit between cartilaginous rings of the trachea to guide the penetrator to a position above tissue between the cartilaginous rings when the device is placed in the suprasternal notch. 
     The housing may further comprise a securement structure for securing the device to the subject when the device is in operation. In one embodiment, the securement structure comprises one or more connections on the housing to which a tying feature, for example a strap, a cord, a string, a chain, etc., may be secured. The tying feature may be looped around the subject&#39;s neck and tightened sufficiently to hold the device in place in the suprasternal notch. In another embodiment, the securement structure may comprise a self-adhesive pad that binds sufficiently strongly to skin of the subject that it will not release too easily. When the housing comprises a tube, the self-adhesive pad is preferably located on the distal end of the housing, preferably as a ring that surrounds the discharge aperture. 
     An actuator is associated with the housing and the penetrator and is configured for use in one hand for releasing the penetrator to be resiliently moved from the restrained position to the operational position. The actuator preferably comprises a depressible structure disposed on a side of the housing whereby pressing the actuator applies a lateral force relative to the direction of motion of the penetrator. The lateral force releases the penetrator to be resiliently moved from the restrained position to the operational position to puncture the skin and tracheal wall to create an opening in the tracheal wall. Depressing the actuator with a lateral force to actuate the penetrator reduces the chance of an inexperienced user bearing down on the device during actuation. Preferably, the actuator comprises two depressible structures disposed on opposed sides of the housing and configured to be simultaneously depressed by one hand, for example by pinching the depressible structures on the housing with thumb and forefinger of one hand. Using two opposed depressible structures advantageously reduces the risk of laterally displacing the device when the penetrator is activated. In one embodiment, the penetrator is restrained in the retracted position by a resiliently deflectable restraint, and the depressible structure is in abutting contact with the resiliently deflectable restraint. Depressing the depressible structure or structures deflects the restraint to release the penetrator for resilient movement to the operational position. 
     The device preferably comprises a depth selector for selecting the distance that the penetrator moves, and therefore selecting the depth into the subject&#39;s body to which the penetrator will go. This is important for reducing the possibility that the penetrator will penetrate the posterior wall of the trachea. It is desired for the penetrator to fully penetrate the anterior wall of the trachea, but penetrating the posterior wall could lead to complications causing death of the subject. While the device may be designed to permit selection of various depths positions, it is preferable for simplicity to have only two or three pre-set positions, one for a human adult, one for a human child, and possibly one for an oversized human adult. The depths to which the penetrator must penetrate in each of these cases are sufficiently different that different pre-determined distances are warranted. The pre-set positions may be marked with indicia to indicate the age/size group for which the position is suited. The indicia may be printed or engraved on the housing and/or ring. The indicia may comprise words, pictures or both. 
     The depth selector can function by altering the position of the penetrator in relation to the housing, by altering the length of the housing or by altering the position of a stop inside the housing. Preferably, the depth selector adjusts a position of a stop that stops the penetrator from extending beyond the pre-determined distance. The stop may be a projection in the housing that may be moved longitudinally in relation to the direction of motion of the penetrator, or that may be removed from inside the housing. 
     In one embodiment, the depth selector comprises a rotatable ring around an exterior of the housing. The ring may be rotatatable on a threaded surface so that rotation of the ring moves the ring axially along the housing. Movement of the ring axially along the house may serve to lengthen the housing. The ring may comprise a projection projecting into the housing that engages the penetrator to stop the penetrator from extending beyond the pre-determined position. The penetrator may comprise a corresponding projection for engagement with the projection on the ring. 
     In another embodiment, the depth selector comprises a first pre-set position defined by a first stop in the housing, which extends through an aperture in the housing and which is configured to be removable from the aperture and therefore from the inside of the housing, for example by pulling the first stop out of the aperture. A pull tab attached to the first stop and extending outside the housing may be used to pull the first stop out of the housing. A second pre-set position defined by a second stop located inside the housing and farther toward the distal end of the housing sets the pre-determined distance once the first stop is removed. The first stop may define the pre-determined distance for a human child while the second stop may define the pre-determined distance for a human adult. 
     In an alternative embodiment, the device may have only one pre-set position specific for a particular age or size group, and several different models of the device constructed, each for use with a different age or size group. 
     The device may comprise a usage indicator that indicates whether the device has been used or is still in a ready-to-use state. This is particularly important as a safety measure to ensure sterility of the device, especially for disposable devices. It may be possible to reload the penetrator after use by pushing the penetrator back into the housing and re-setting the actuator, which comprises sterility and therefore safety. Thus, a non-re-settable usage indicator would be beneficial. The usage indicator may be a visual indicator located inside the housing and visible either through a window in the housing or by virtue of the housing being transparent or translucent. In one embodiment, the usage indicator may be a flag, preferably colored with a bright color (e.g. green, red, orange and the like), whereby operation of the device changes the location of the flag relative to another element of the device. 
     In a particularly preferred embodiment, a disposable tracheotomy device comprises: a spring-loaded hollow penetrator housed within a hollow tube, the penetrator resiliently moveable by a spring from a retracted restrained position to an extended operational position with sufficient force to penetrate a tracheal wall, the operational position extending a pre-determined distance from a distal end of the hollow tube, the pre-determined distance correlated to a distance required to penetrate an anterior side of the tracheal wall without penetrating a posterior side of the tracheal wall; spaced-apart protrusions on the distal end of the hollow tube configured to sit between cartilaginous rings of a trachea to guide the penetrator to a position above tissue between the cartilaginous rings when the device is placed in a suprasternal notch of a subject; and, two depressible actuators disposed on opposed sides on the housing and configured for use in one hand for releasing the spring-loaded penetrator by action of lateral force relative to direction of motion of the penetrator to permit the spring to resiliently move the penetrator from the restrained position to the operational position. 
     A kit of the present invention comprises the device of the present invention together with instructions for use of the device for performing a tracheotomy. The instructions may take the form of printed matter, for example, text, illustrations or both. The device is preferably sterilized and then shrink wrapped in a sealed package to prevent contamination. The instructions may be printed on the shrink wrap or accompany the shrink wrapped device in another packaging material. 
     To use the device in an emergency setting after backslapping and the Heimlich maneuver have failed to dislodge an obstruction in a choking subject&#39;s trachea, the subject is laid on his/her back and any neck-covering clothing is removed. The subject is generally unconscious at this point. The user reviews the instructions accompanying the device if not already familiar with them. The device is then unwrapped, the appropriate pre-set distance is selected and the device is placed in the hollow of the subject&#39;s neck, i.e. in the suprasternal notch. The guide elements naturally position the device in the correct place in the suprasternal notch. The actuator is then pressed to release the penetrator which extends out under the influence of the bias to penetrate the skin and trachea. The subject can now breathe through the hollow penetrator, or air can be blown into the subject&#39;s lungs through the hollow penetrator. The device is secured to the subject until trained medical personnel arrive. 
     The device of the present invention is preferably a single-use device that may be disposed of after use. It is simple to use so that unskilled people or people with only basic first aid training can successfully and safely perform an emergency tracheotomy. The device is particularly useful in military applications, schools, airplanes, restaurants, and similar venues where the likelihood of someone choking on an obstruction is higher. Further, people who are afraid, unwilling or too nervous to push a hollow blade into a subject&#39;s neck are instead able to simply position the device on the subject&#39;s neck and release the penetrator by simply depressing an actuator. The device is preferably used when the subject has lost consciousness after the use of back-slapping and the Heimlich maneuver has been unsuccessful at clearing a blockage in the trachea. 
     Further features of the invention will be described or will become apparent in the course of the following detailed description. It should be understood that each feature described herein may be utilized in any combination with any one or more of the other described features, and that each feature does not necessarily rely on the presence of another feature except where evident to one of skill in the art. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In order that the invention may be more clearly understood, embodiments thereof will now be described in detail by way of example, with reference to the accompanying drawings, in which: 
         FIG. 1  depicts a schematic drawing of a tracheotomy device in accordance with the present invention showing internal and external structures; 
         FIG. 2  depicts a schematic drawing of a tracheotomy device in accordance with the present invention having a mouthpiece and showing internal and external structures; 
         FIG. 3  depicts a schematic drawing of the tracheotomy device of  FIG. 1  rotated 90-degrees about a vertical axis in which release clips and child setting stops are removed; 
         FIG. 4  depicts a schematic drawing of the tracheotomy device of  FIG. 3  showing an alternative embodiment of a release clip mount; 
         FIG. 5  depicts a side view of a first embodiment of a child setting stop; 
         FIG. 6  depicts a side view of a second embodiment of a child setting stop; 
         FIG. 7A  depicts the tracheotomy device of  FIG. 1  set for a child and in a ready-to-use state; 
         FIG. 7B  depicts the tracheotomy device of  FIG. 7A  in an extended used state; 
         FIG. 8A  depicts the tracheotomy device of  FIG. 1  set for an adult and in a ready-to-use state; 
         FIG. 8B  depicts the tracheotomy device of  FIG. 8A  in an extended used state; 
         FIG. 9A  depicts a schematic drawing of another embodiment of a tracheotomy device in accordance with the present invention showing internal and external structures; 
         FIG. 9B  depicts the tracheotomy device of  FIG. 9A  in an extended used state; 
         FIG. 9C  depicts a schematic drawing of a top view of a child setting stop used in the tracheotomy device of  FIG. 9A ; 
         FIG. 9D  depicts a schematic drawing of a side view of the child setting stop of  FIG. 9C ; 
         FIG. 9E  depicts a schematic drawing of a side view of a tube of the tracheotomy device of  FIG. 9A  showing a cut-away in the tube to accommodate child and adult setting stops; 
         FIG. 9F  depicts a side view of a trocar seal and support of the tracheotomy device of  FIG. 9A  showing a usage flag in an unused position in relation to a recess in the seal and support; 
         FIG. 9G  depicts the trocar seal and support of  FIG. 9F  rotated 90°; 
         FIG. 9H  depicts a bottom view of the trocar seal and support of  FIG. 9G ; 
         FIG. 10A  depicts a schematic drawing of another embodiment of a tracheotomy device in accordance with the present invention showing internal and external structures in a ready-to-use state; 
         FIG. 10B  depicts the tracheotomy device of  FIG. 10A  in an extended used state; 
         FIG. 100  depicts a magnified side view of a trocar sleeve used in the tracheotomy device of  FIG. 10A ; 
         FIG. 10D  depicts a magnified top view of a trocar sleeve used in the tracheotomy device of  FIG. 10A ; 
         FIG. 11  depicts the tracheotomy device of  FIG. 1  positioned above a trachea of a person; 
         FIG. 12A  depicts another embodiment of a tracheotomy device in accordance with the present invention in perspective view; and, 
         FIG. 12B  depicts the embodiment of  FIG. 12A  in a cross-sectional perspective view. 
     
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
     Referring to  FIG. 1 , a tracheotomy device  1  includes a housing comprising a hollow open-ended tube  5  containing a trocar  10  supported in a trocar seal and support  15 . The tube  5  may have any suitable cross-sectional shape, for example circular, rectangular, square, hexagonal and the like. The trocar seal and support  15  comprises an annular sealing member having a through aperture through which the trocar  10  extends, the sealing member forming a seal with an outer surface of the trocar  10  so that the trocar  10  cannot move translationally in the trocar seal and support  15 . The trocar seal and support  15  is slidably engaged within the tube  5 . Thus, the trocar  10  moves with the trocar seal and support  15  when the device  1  is activated. The seal may be a friction seal or an adhesive seal. 
     The tube  5  comprises spring retainer  20  inside and proximate a proximal end of the tube  5 . The spring retainer  20  may be an annular protrusion fully or partially around an inner circumference of the tube  5  or it may be two or more separate protrusions extending into the tube  5  from an inner wall of the tube  5 . A coiled spring  25  is located between the spring retainer  20  and the trocar seal and support  15 .  FIG. 1  shows the device in a ready-to-use state so the coiled spring  25  is compressed between the spring retainer  20  and the trocar seal and support  15  biasing the trocar seal and support  15  toward a distal end of the tube  5 . Seal engagement portions  31   a ,  31   b  of release clips  30   a ,  30   b  engage a bottom surface of the trocar seal and support  15  to prevent the coiled spring  25  from moving the trocar seal and support  15  toward the distal end of the tube  5 . The release clips  30   a ,  30   b  are pivotally mounted on release clip mounts  32   a ,  32   b  through pivot pins  33   a ,  33   b  (e.g. rivets). The release clip mounts  32   a ,  32   b  comprise outwardly extending flanges having through apertures for accepting the pivot pins  33   a,    33   b . The pressure exerted on the seal engagement portions  31   a ,  31   b  of the release clips  30   a ,  30   b  by the trocar seal and support  15  as a result of the force exerted by the coiled spring  25  is sufficient to prevent pivoting of the release clips  30   a ,  30   b  unless significant force is applied to lever arms  34   a ,  34   b  of the release clips  30   a ,  30   b . The lever arms  34   a,    34   b  are configured to be actuated simultaneously by one hand of a person using the device  1 . For example, the two lever arms  34   a ,  34   b  may be depressed simultaneously by gripping the device  1  between the thumb and forefinger of one hand such that one lever arm is engaged with the thumb and the other lever arm is engaged with the forefinger. Squeezing the thumb and forefinger together would simultaneously depress the two lever arms  34   a ,  34   b  thereby activating the device  1 . 
     Proximate the distal end of the tube  5  are child setting stops  40   a ,  40   b . The child setting stops  40   a ,  40   b  stop movement of the trocar seal and support  15  and therefore stop movement of the trocar  10  after the device  1  is activated. The child setting stops  40   a ,  40   b  are positioned and sized in relation to a length of the trocar  10  to stop movement of the trocar seal and support  15  when the trocar  10  reaches an extended position appropriate for a trachea of a child. If the device  1  is to be used on an adult, the child setting stops  40   a ,  40   b  may be removed through apertures in the side walls of the tube  5  (see  FIG. 3 ). The child setting stops  40   a ,  40   b  comprise pull tabs  41   a ,  41   b , which allow removal of the child setting stops  40   a ,  40   b  from the inside of the tube  5 . Applying a lateral force to the pull tabs  41   a ,  41   b  results in pulling the child setting stops  40   a ,  40   b  out through apertures in the side walls of the tube  5 . In a variation, only one child setting stop may be used on one side of the trocar as one stop would be sufficient to arrest the movement of the trocar seal and support. Some variations of child setting stops are illustrated in  FIG. 5  and  FIG. 6 . 
     Adult setting stop  45  is provided inside the tube  5  distally from the child setting stops  40   a ,  40   b . The adult setting stop  45  is positioned and sized in relation to the length of the trocar  10  to stop movement of the trocar seal and support  15  when the trocar  10  reaches an extended position appropriate for a trachea of an adult. The adult setting stop  45  may be a protrusion fully or partially around the inner circumference of the tube  5  or it may be two or more separate protrusions extending into the tube  5  from the inner wall of the tube  5 . If the device  1  is to be a three setting device rather than a two setting device, the adult setting stop  45  may be constructed in a manner similar to the child setting stops. 
     The child setting stops  40   a ,  40   b  and the adult setting stop  45  should be sized to permit the trocar  10  to pass unimpeded while stopping the trocar seal and support  15  at the appropriate position. 
     Final retainer  50  is provided inside the tube  5  distally from the adult setting stop  45 . The final retainer  50  provides further support to absorb the force generated by the coiled spring  25  when the trocar seal and support  15  is forced against the child setting stops  40   a ,  40   b  or the adult setting stop  45 . In addition, if the adult setting stop  45  is removable, the final retainer  50  may be positioned and sized in relation to the length of the trocar  10  to stop movement of the trocar seal and support  15  when the trocar  10  reaches an extended position appropriate for a trachea of an extra-large adult. 
     At the distal end of the tube  5 , the tube  5  may comprise an inwardly depending surface  52  narrowing to an aperture  53  that is large enough to permit egress of the trocar  10  out of the tube  5  while small enough to ensure that the trocar  10  maintains linear movement as it passes out of the tube  5 . The inwardly depending surface  52  comprises alignment tabs  55   a ,  55   b  that are positioned, sized and shaped to guide the device  1  naturally to the correct position in a suprasternal notch of a person on which the device  1  is being used. For durability and performance, spring retainer  20 , final retainer  50 , release clip mounts  32   a ,  32   b  and alignment tabs  55   a ,  55   b  may be monolithically molded with the tube  5 . 
     Referring to  FIG. 2 , a tracheotomy device  100  of generally the same construction as the device of  FIG. 1  is shown. The device  100  comprises a mouthpiece  101  at a proximal end of hollow tube  105 . The mouthpiece  100  has a larger diameter than the tube  105  and the diameter of the mouthpiece  100  is sized to fit comfortably in a person&#39;s mouth. The mouthpiece  100  is shown monolithically molded with the tube  105 , but it may alternatively be a separate piece that is fitted on to the tube  105 . Friction fittings, mated screw threads, clips or any other suitable structures may be used to fit the mouthpiece to the tube. 
       FIG. 3  depicts an external surface of the tracheotomy device of  FIG. 1  rotated 90-degrees about a vertical axis in which the release clip  30   a  and the child setting stop  40   a  are removed. As seen in  FIG. 3  with reference to  FIG. 1 , the tube  5  comprises a through aperture  35  through which the seal engagement portions  31   a  extends when the device  1  is in the ready-to-use state. When the lever arm  34   a  of the release clip  30   a  is depressed with sufficient force toward the tube  5 , the release clip  30   a  pivots on pivot pin  33   a  mounted on the release clip mount  32   a  causing the seal engagement portion  31   a  to slide out of the through aperture  35  thereby releasing the trocar seal and support  15  to move under the force of the coiled spring  25 . There is a similar arrangement on the other side of the tube  5  in relation to the release clip  30   b . Simultaneously depressing both of the lever arms  34   a ,  34   b  of both release clips  30   a ,  30   b  permits simultaneous release of the trocar seal and support  15  one both sides of the tube  5  so that the trocar  10  may move in a substantially linear path out of the tube  5  with minimal lateral movement away from the vertical axis. Lateral movement of the trocar  10  is preferably avoided so that the trocar  10  does not jam in the tube  5  and so that the trocar  10  pierces the trachea cleanly between cartilaginous rings of the neck. 
       FIG. 4  depicts the device of  FIG. 3  with an alternative embodiment of the release clip mount  32   a . The release clip mount comprises two substantially parallel outwardly extending flanges  32   a ′,  32   a ″″ having the pivot pin  33   a  mounted therebetween. Providing an addition outwardly extending flange provides greater durability and better support for the release clips. A similar release clip mount may be present on the other side of the tube  5 , although it is possible to use different release clip mounts on each side. 
     Referring again to  FIG. 3 , the tube  5  comprises a through aperture  44  proximate the distal end of the tube  5  through which the child setting stop  40   a  may be removed. There may be a similar arrangement on the other side of the tube  5 . Referring to  FIG. 5  and  FIG. 6 , variations of child setting stops are illustrated. In all cases, the width of the child setting stops should be no larger than the width of the through aperture  44  so that the stop may be pulled out through the aperture  44 . As shown in  FIG. 5 , the child setting stop  40   a  may comprise a rectangular solid portion  42  that extends into the tube  5  through the aperture  44  and a pull tab  41   a  attached to or integrally formed with the rectangular solid portion  42  that protrudes outwardly from the tube  5 . Since the rectangular solid portion  42  rests on the adult setting stop  45  inside the tube  5 , no further support is necessarily required. However, it is possible that the child setting stop  40   a  could move farther inward thereby potentially interfering with movement of the trocar  10 . If further surety is required, a child setting stop  140   a  as illustrated in  FIG. 6  may be employed in which a lip  143  is provided between a rectangular solid portion  142  and a pull tab  141   a . The lip  143  is located exterior to the tube  5  and is dimensioned larger than the aperture  44  to prevent the rectangular solid portion  142  from migrating farther into the tube  5 . 
       FIG. 7A ,  FIG. 7B ,  FIG. 8A  and  FIG. 8B  illustrate the operation of the device  1 .  FIG. 7A  depicts the tracheotomy device  1  in the ready-to-use state for a child, as already described in relation to  FIG. 1 . When the device  1  is in the ready-to-use state, the trocar  10  is fully within the tube  5 . When the lever arms  34   a ,  34   b  are depressed simultaneously, the trocar seal and support  15  is released and the coiled spring  25  biasing the trocar seal and support  15  toward the distal end of the tube  5  is allowed to extend thereby driving the trocar seal and support  15  toward the distal end of the tube  5 . The trocar  10  is driven with the trocar seal and support  15  as the trocar seal and support  15  slides in the tube  5  until the trocar seal and support  15  abuts the child setting stops  40   a ,  40   b  in the extended used state ( FIG. 7B ). In the extended used state, the trocar  10  now protrudes from the distal end of the tube  5  at a distance appropriate for a tracheotomy on a child. As can be seen in  FIG. 7B , the lever arms  34   a ,  34   b  are now up against the side wall of the tube  5  and the seal engagement portions  31   a ,  31   b  of the release clips  30   a ,  30   b  are outside the tube  5 . Further, the trocar seal and support  15  abutting the child setting stops  40   a ,  40   b  provides for a seal so that air being blown into the tube  5  from the proximal end of the tube  5  can pass through the trocar  10  rather escaping between the inner wall of the tube  5  and an outer edge of the trocar seal and support  15 . To further enhance the seal, a sealing element (e.g. an o-ring or a gasket) may be provided on a bottom surface of the trocar seal and support  15 .  FIG. 8A  and  FIG. 8B  illustrate the same operation except that the tracheotomy device  1  in the ready-to-use state for an adult. It can be seen in  FIG. 8A  and  FIG. 8B  that the child setting stops  40   a ,  40   b  have been removed so that the trocar seal and support  15  abuts the adult setting stop  45  in the extended used state. Thus, the trocar  10  extends further out from the tube  1  when the device  1  is used for an adult (compare  FIG. 8B  to  FIG. 7B ). 
     Referring to  FIGS. 9A-9H , another embodiment of a tracheotomy device  200  is depicted comprising many similar features as the device of  FIG. 1  including a housing comprising a hollow open-ended tube  205 , a trocar  210 , a trocar seal and support  215 , a spring retainer  220 , a coiled spring  225 , release clips  230   a ,  230   b , a final retainer  250 , a trocar exit aperture  253  and alignment tabs  255   a ,  255   b . The tracheotomy device  200  is equipped with a mouthpiece  201 . The operation of the tracheotomy device  200  is substantially the same as the operation of the tracheotomy device  1  and  100  of  FIGS. 1-2 . 
     In the tracheotomy device  200  a single-piece child setting stop  240  is provided, the child setting stop  240  comprising a single pull tab  241 . A single-piece adult setting stop  245  on which the child setting stop  240  rests is also provided. The adult setting stop  245  also has only one pull tab  247 . The design of the setting stops  240 ,  245  are substantially the same and is described in relation to the child setting stop  240  as depicted in  FIGS. 9C-9D . The adult setting stop  245  rests on an extra-large adult setting stop  246 . Both the child setting stop  240  and the adult setting stop  245  are removable by pulling on the respective pull tabs  241 ,  247 . The extra-large adult setting stop  246  is not removable and comprises a substantially annular ring resting on the final retainer  250  inside the tube  205 . As shown in  FIG. 9C , the child setting stop  240  (as well as the adult setting stop  245 ) comprises a generally annular disc surrounding a central aperture  242  through which the trocar  210  may pass. The generally annular disc has an arc section cut out therefrom to form a slot  243  of sufficient size so that the trocar  210  will pass through the slot  243  when the pull tab  241  of the child setting stop  240  is pulled to remove the child setting stop  240  from the tube  205 .  FIG. 9E  illustrates how a cut-away  249  is disposed in the tube  205  to provide sufficient clearance for the child and adult setting stops  240 ,  245  to be pulled out of the tube  205 . The child and adult setting stops  240 ,  245  and the cut-away  249  should be sized and constructed so that the setting stops  240 ,  245  cannot simply fall out of the tube  205 , but can be pulled out of the tube  205  without exerting undue force. 
     Referring again to  FIGS. 9A-9B  as well as to  FIGS. 9F-9G , the tracheotomy device  200  also comprises a green usage flag  235  (although other colors may be used) associated with the trocar seal and support  215 . The usage flag  235  may comprise plastic, although any suitable material may be employed. When the device  200  is in the ready-to-use state, the usage flag  235  depends downwardly from the trocar seal and support  215 , and is visible either through transparent/translucent material of the tube  205  or through a window in the tube  205 . The trocar seal and support  215  also comprises a recess  236  so that when the trocar seal and support  215  is driven distally carrying the trocar  210  fixed in aperture  237  of the trocar seal and support  215 , the usage flag  235  is driven into the recess  236  by the force of the impact on one of the setting stops, for example the child setting stop  240  as shown in  FIG. 9B . Thus, when the device  200  is in the used state, the usage flag  235  does not depend below the trocar seal and support  215 . In the event that the trocar  210  is reloaded by forcing the trocar  210  with the trocar seal and support  215  back into the tube  205  and re-setting the release clips  230   a ,  230   b,  the usage flag  235  will remain in the recess  236  indicating that the device  200  has already been used. 
     To provide further security from tampering, the recess  236  may be wholly inside the trocar seal and support  215  except for an exposed bottom into which the usage flag  235  may be driven. Thus, the usage flag  235  would not be visible at all from the sides of the device  200  when the device  200  is in the used state. The visual absence of the usage flag  235  as viewed from the side of the device  200  would then be an indicator that the device  200  has been used. 
     Referring to  FIGS. 10A-10B , another embodiment of a tracheotomy device  300  is depicted comprising many similar features as the device of  FIG. 1  including a housing comprising a hollow open-ended tube  305 , a trocar  310 , a trocar seal and support  315 , a spring retainer  320 , a coiled spring  325 , release clips  330   a ,  330   b , a final retainer  350 , a trocar exit aperture  353  and alignment tabs  355   a ,  355   b . The operation of the tracheotomy device  300  is substantially the same as the operation of the tracheotomy device  1  of  FIG. 1 . 
     However, the tracheotomy device  300  also comprises features beneficial in the event the device is successfully used on an unconscious subject and the subject subsequently regains consciousness. Upon regaining consciousness, the subject is often prone to coughing, panic and/or other vigorous movement. Such activity may dislodge the device. Thus, the tracheotomy device  300  may further comprise a trocar sleeve  370  around the trocar  310 , the trocar sleeve  370  being driven with the trocar  310  when the device  300  is actuated. The trocar sleeve  370  may be driven by a hollow cylindrical spacer  380  between the trocar sleeve  370  and the trocar seal and support  315 , the spacer  380  also surrounding the trocar  310 . The spacer  380  is driven by the trocar seal and support  315  when the coiled spring  325  is released by activation of the release clips  330   a ,  330   b . Alternatively, the trocar sleeve  370  may be sufficiently long that the trocar seal and support  315  drives the sleeve  370  directly. The trocar sleeve  370  and/or hollow cylindrical spacer  380  may comprise any suitable material, for example plastic. 
     Referring to  FIGS. 10C-10D , the trocar sleeve  370  may be of similar shape to the hollow tube  305 , for example cylindrical, and may comprise a sleeve body  375  and a through aperture  374  through the sleeve body  375  through which the trocar  310  extends. The trocar sleeve  370  may comprise a tapered distal edge  372  to facilitate entry into the hole in the trachea created by the trocar  310 . The trocar sleeve  370  may also comprise a radially extending flange  371  toward a proximal end of the sleeve  370  to prevent the sleeve  370  from completely entering the hole in the trachea to avoid loss of the sleeve  370  in the subject&#39;s trachea. The flange  371  has a larger diameter than the body  375  of so that the flange  371  may engage the surface of the subject&#39;s neck around the hole created by the trocar. The sleeve  370  is preferably a monolithic structure. 
     When the device  300  is actuated, the trocar sleeve  370  is driven into the hole in the trachea created by the trocar  310 . In the event the subject regains consciousness and moves vigorously due to coughing, panicking or the like, the trocar  310  may be dislodged from the hole in the trachea and from the through aperture  374  in the trocar sleeve  370 , but the trocar sleeve  370  may remain in the hole to keep the hole open. To help prevent the trocar sleeve  370  from also becoming dislodged, sides of the sleeve body  375  may comprise one or more features that allow easy penetration while resisting removal. Such features may comprise one or more protrusions, screw threads, or the like. For example,  FIG. 100  depicts radially extending ridges  373  (only one labelled) that are angled toward the proximal end to permit easy penetration into the hole while resisting removal from the hole. The trocar sleeve  370  may be removed by medical personnel when the wound in the trachea is treated. The use of a trocar sleeve may also permit deliberate removal of the trocar, if desired, since the subject could breathe through the sleeve rather than the trocar. 
     Referring to  FIG. 11 , in use the tracheotomy device  1  is placed vertically in suprasternal notch  75  of a person  60  lying prone (horizontally). The suprasternal notch  75  is at the top of the sternum (not shown) between the clavicles  80  of the person  60 . The suprasternal notch  75  is colloquially known as the hollow of the throat. At the suprasternal notch  75 , the device  1  is above a trachea  85  (shown in dashed lines) of the person  60 . The alignment tabs  55   a ,  55   b  (drawn in stippled lines) guide and position the device  1  in the suprasternal notch  75  such that the trocar  10  is aligned above a gap  92  between two cartilaginous rings  90   a ,  90   b  of the trachea  85  to facilitate insertion of the trocar  10  into the trachea  85 . Once aligned, the release clips  30   a ,  30   b  are actuated and the trocar  10  springs down under the force of the coiled spring to pierce the trachea  85  in the gap  92  between the cartilaginous rings  90   a ,  90   b . With the proper setting (child or adult, or possibly large adult) the trocar  10  will pierce the anterior wall of the trachea  85  without piercing the posterior wall of the trachea  85 . With the trocar  10  in the person&#39;s trachea, the person may now breathe through the trocar  10 , or another person may blow into the proximal end of the tube  5  and thus into the trocar  10  to assist with the person&#39;s breathing. 
     Referring to  FIGS. 12A-12B , another embodiment of a tracheotomy device  400  is depicted comprising many similar features as the device of  FIG. 1  including a housing comprising a hollow open-ended tube  405 , a trocar  410 , a trocar support  415 , a spring retainer  420 , a coiled spring  425 , release clips  430   a ,  430   b  (not shown in  FIGS. 12A-12B ), a final retainer  450 , and a trocar exit aperture  453 . Alignment tabs  455   a ,  455   b  (not shown in  FIGS. 12A-12B ) may also optionally be provided. The tracheotomy device  400  is equipped with a mouthpiece  401  provided with a removable cap  499 . The operation of the tracheotomy device  400  is substantially the same as the operation of the tracheotomy device  1  and  100  of  FIGS. 1-2 . 
     The housing comprises the mouthpiece  401  at one end, the exit aperture  453  at an opposite end and the hollow tube  405  therebetween. The hollow tube  405  has an exterior threaded surface  498  thereon. The housing further comprises a rotatable ring  497  having an interior threaded surface  496  complementary to the exterior threaded surface  498 , a rounded end  495  configured to guide the device  400  to an appropriate location in a suprasternal notch of a subject and a ring aperture  496  aligned with exit aperture  453 , thereby permitting passage of the trocar  410  therethrough. The rotatable ring  497  functions as a depth selector by altering the length of the housing. Rotation of the ring  497  moves the ring along the complementary exterior and interior threaded surfaces  498 ,  496 , causing it to extend or retract axially along the hollow tube  405 . Movement of the ring axially serves to lengthen or shorten the housing and changes the distance between the exit aperture  453  and the ring aperture  496 . Since the trocar  410  protrudes a fixed length from the exit aperture  453 , lengthening the housing causes the trocar to protrude through the ring aperture  496  a shorter distance from the rounded end of the ring  497 . Since the rounded end  495  of the ring  497  is placed against the throat of the subject, lengthening of the housing effectively causes the trocar  410  to penetrate a shorter distance into the trachea than if the housing were shortened. Thus, depth control of the trocar  410  is possible. Although depth control is infinite, indicia (not shown) on the exterior of the ring  497  can be provided to guide a user of the device  400  to extend the housing to suggested lengths and corresponding trocar penetration depths. 
     The novel features of the present invention will become apparent to those of skill in the art upon examination of the detailed description of the invention. It should be understood, however, that the scope of the claims should not be limited by the preferred embodiments set forth in the examples, but should be given the broadest interpretation consistent with the specification as a whole.