Abstract:
A stoma stent with an internal, self-contained flap valve permitting speech. The one-way flap valve is part of the stent.

Description:
BACKGROUND OF THE INVENTION 
   This invention relates to a tracheal device which permits a patient to breath after a tracheotomy, and in particular, to a stoma stent with an integrated speech flap valve. 
   A tracheotomy is a surgical operation in which an incision, or opening, is cut through the front of the neck and into the trachea, or windpipe. A tracheotomy creates an alternate passage to the lungs for air that cannot flow from the nose and mouth through the trachea because of an obstruction. Obstructions may occur when a foreign body lodges in the larynx, or voice box, above the trachea; as a result of swelling or spasm of the larynx or vocal cords; or from infection and swelling of the epiglottis, the thin flap of cartilage covering that keeps food and liquid out of the trachea. 
   After a patient has undergone a tracheotomy, he is often provided with a tubular prosthesis, e.g., a short stationary tube, including air channel means between the trachea and the outside ambient air. A tracheotomy that includes the insertion of a tubular prosthesis into the trachea is called a tracheostomy. The purpose of a tracheostomy is to keep the airway from closing prematurely and to enable the physician to take further measures, if necessary, to ensure that the patient has a patent airway. The prosthesis is held in place in the stoma so that it may be used for long time periods, maintaining patentcy of the tracheostomy. Such prosthesis are known as stoma stents. 
   A tracheostomy prevents patients from using their vocal cords. Once the reason for having a tracheostomy has ended, the tracheostomy is closed and patients are able to breathe and speak normally. However, in some situations, a tracheostomy must remain in place for a period of time, often lengthy. This presents a particular physiological problem associated with prior art stents in that a patient with an open stent cannot use his vocal cords to speak. 
   Human speech is enabled by the passage of expired air from the lungs up though the trachea, passing through the laryngeal cavity and exhaled through the mouth. The laryngeal cavity contains a plurality of adjustable-tensioned mucous membranes, or vocal cords, stretched across the cavity. During such exhalation, these membranes are cause to vibrate and produce audible sounds by a flow of expired air, and differences in pitch are achieved by muscles which adjust the tension of these vibratory membranes. 
   With some stents one-way speech valves are offered as an accessory to the device. The valves close during exhalation thereby forcing air through the laryngeal cavity out through the mouth. During inhalation, the valves open bringing air in through the stent. These valves are designed to allow a patient to speak without physically occluding the stoma opening. With some prior art stents one-way valves are inserted into the stent. While these work, they also reduce air flow. Other types of valves are fitted over the stent and extend well beyond the stoma site. The added weight may require the stent to be tied in place. 
   SUMMARY OF THE INVENTION 
   The present invention is a stoma stent with an internal, self-contained flap valve permitting speech. The stoma stent maintains a stoma site and eliminates the need for a tracheotomy tube. The stoma stent is easily removed by a patient, cleaned and replaced. 
   The present invention addresses the problem of prior art devices by providing a one-way flap valve as part of the stent. As part of the stent itself, air flow through the stent is not reduced. The stent of the present invention also has minimal external protrusions. 
   These together with other objects of the invention, along with various features of novelty which characterize the invention, are pointed out with particularity in the claims annexed hereto and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and the specific objects attained by its uses, reference should be had to the accompanying drawings and descriptive matter in which there is illustrated a preferred embodiment of the invention. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a side elevational view of a stoma stent in accordance with the present invention. 
       FIG. 2  is a proximal end view of the invention. 
       FIG. 3  is a cross-sectional view of the invention embodiment illustrated in  FIG. 1 . 
       FIG. 4  is a cross-sectional view as shown in  FIG. 4  with baffles added thereto. 
   

   DETAILED DESCRIPTION OF INVENTION 
   Referring to the drawings in detail wherein like elements are indicated by like numerals, there is shown a stoma stent  10  constructed according to the principles of the present invention. The stoma stent  10  has a hollow tube  11  having an open first end  12  and an opposite open second end  13 , said first end  12  and second end  13  defining a tube longitudinal axis. In the embodiment shown, the tube  11  is straight. In other embodiments, the tube  11  may be curvilinear to conform to the anatomical needs of a tracheotomy incision. The tube  11  has a smooth exterior surface  14  and smooth interior surface  15 , said interior surface  15  defining a tube interior  16 . The tube second end  13  has a pair of angled flanges  17 ,  18  extending radially outward from the tube exterior surface  14  away from a tube central longitudinal axis. The tube open first end  12  terminates in a frusto-conic forward portion  20 , said tube open first end  12  and forward portion  20  forming a junction  21  with an initial diameter matching the diameter of the tube  11 . The forward portion  20  expands forwardly and outwardly terminating in a rounded rim  22 , said rim  22  defining a stent proximal end. Said forward portion  20  has a longitudinal central axis coincident with the longitudinal central axis of the tube  10 . In the embodiment shown, the diameter of the stent proximal end  22  is approximately twice the diameter  21  of the tube  11 . The tube second end  13  defines a stent distal end. 
   The tube interior  16  has a circular, thin flap  30  molded directly to the tube interior surface  15 , said flap  30  having a diameter slightly less than the diameter of the tube interior  16 , said flap  30  being radially connected along a portion of its perimeter  31  to the tube interior surface  15  adjacent to the tube first end  12 . The flap  30  is nominally positioned so that in a closed position the planes of its surfaces are transverse to the longitudinal axis of the tube  11 . In another embodiment of the invention, the flap  30  may be nominally positioned so that in a closed position the planes of its surfaces are at an acute angle to the longitudinal axis of the tube  11 . The flap  30  is adapted to be in a closed position during patient exhalation and in an open position during inhalation. 
   The forward portion  20  has an inner surface  23  and an outer surface  24 . The forward portion inner surface  23  has a channel  25  formed therein adjacent to the junction  21 . A retaining ring  35  is inserted into the channel  25  and bonded into place. The ring inner opening  36  has a diameter slightly less than the diameter of the tube interior  16 . The retaining ring  35  provides a locking detent for the flap  30  during exhalation. 
   After a tracheostomy, the stoma stent  10  may be inserted into the stoma, i.e. opening between the trachea and outside, with the stent distal end  13  disposed through the incision into the trachea, and the stent forward portion  20  disposed outside and partially into the incision. The frusto-conic shape of the forward portion  20  provides a slidable fit, and thereby a seal, against the patient&#39;s neck. The forward portion  20  may optionally have two opposed holes  26  formed therein near to the rim  22 . The forward portion holes are adapted to hold cotton ties (not shown). 
   In another embodiment of the invention, baffles may be installed in the tube interior  16 , said baffles being comprised of a plurality of staggered posts  19  attached to the tube interior surface  15 . The internal baffles  19  prevent the flap  30  from being ingested if the flap  30  should break free from the tube. 
   It is understood that the above-described embodiment is merely illustrative of the application. Other embodiments may be readily devised by those skilled in the art which will embody the principles of the invention and fall within the spirit and scope thereof.