Abstract:
An endotracheal tube flow control device includes a hollow tubular member, a selectively adjustable surface, and an endotracheal tube. The proximal end of the tubular member is connected to the endotracheal tube. The selectively adjustable surface is connected to the distal end of the tubular member. By selecting the position of the adjustable surface, the area of the air flow opening of the tubular member can be increased or decreased. The endotracheal tube flow control device allows a patient to control breathing by selectively adjusting the breathing area of the endotracheal tube.

Description:
FIELD OF THE INVENTION 
     The present invention relates to devices for use with an endotracheal tube, and in particular to a selectively adjustable device for regulating air flow through an endotracheal tube. 
     BACKGROUND INFORMATION 
     Intubation involves the insertion of a conduit into the trachea of a patient. One of the most commonly used conduits is an endotracheal, tracheotomy, or similar tube (herein collectively referred to as endotracheal tubes). For intubation, the proximal end of the endotracheal tube is extended into the trachea of a patient and the distal end protrudes from the patient&#39;s neck. The patient may then breathe through the tube. However, patients often find it difficult to control their breathing through an endotracheal tube. The functions performed by the mouth and nose in regulating the flow of air to the lungs are not provided for in a standard endotracheal tube which often has a constant cross-sectional area and therefore allows a constant flow of air. 
     Devices have been created to allow a patient to control their breathing through an endotracheal tube, but these have shortcomings. For example, some devices only allow a patient to select an open or closed position of the distal opening of the endotracheal tube. Patients find these devices inadequate when they wish to decrease their breathing but not to discontinue breathing through the endotracheal tube. Other devices are complicated or awkward, and may be prone to malfunction. Still other devices may be large and unwieldy, and thus may restrict movement or cause embarrassment by calling unnecessary attention to the patient&#39;s physical condition. 
     SUMMARY OF THE INVENTION 
     The present invention provides an endotracheal tube flow control device, which includes a hollow longitudinal member and a selectively adjustable valve mechanism. One end of the longitudinal member may be connected to an endotracheal tube. The selectively adjustable valve mechanism is connected to a second end of the longitudinal member. By selecting the position of the adjustable valve mechanism, the air flow through the longitudinal member can be gradually increased or decreased. The endotracheal tube flow control device allows a patient to control breathing by selectively adjusting the breathing area of the endotracheal tube. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an assembly diagram of an exemplary endotracheal tube flow control device according to the present invention. 
     FIG. 2 is a front view of a longitudinal member of the flow control device of FIG.  1 . 
     FIG. 3 is a cross-sectional side view of the flow control device of FIG.  1 . 
     FIG. 4 is a second cross-sectional side view of the flow control device of FIG.  1 . 
     FIG. 5 is a top view of a second exemplary endotracheal tube flow control device according to the present invention. 
     FIG. 6 is a cross-sectional side view of the flow control device of FIG.  5 . 
     FIG. 7 is a second cross-sectional side view of the flow control device of FIG.  5 . 
     FIG. 8 is another cross sectional view of the flow control device of FIG.  5 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1 illustrates a flow control device  8  according to the present invention which includes a longitudinal member  10 , and a valve mechanism that is selectively and gradually positionable between a fully open position and a fully closed position. Flow control device  8  may include an air conduit  40  such as an endotracheal tube or a connecting element for an endotracheal tube. In general, the valve mechanism is capable of continual adjustment between a fully open position and a fully closed position, so that the user can receive a desired flow of air. Gradual actuation of the valve towards the fully open position gradually increases the flow of air, while gradual actuation towards the fully closed position gradually reduces the flow of air. 
     Longitudinal member  10  preferably includes a longitudinal bore  15 , a proximal end  12 , a distal end  14 , an outside surface  16  and an inside surface  18 . Preferably, longitudinal member  10  is tubular with a circular cross section, although any suitable geometry of longitudinal member could be used. In use, longitudinal member  10  connects air conduit  40  with the valve mechanism, and so in general longitudinal member  10  should be shaped to allow a flow of air and to support a selectively and gradually adjustable valve mechanism. Preferably longitudinal member  10  is constructed of a rigid or semi-rigid plastic but could alternatively be constructed of any suitable material. 
     In the exemplary embodiment illustrated in FIG. 1, longitudinal member  10  includes a flange  20 . Flange  20  includes a proximal flange surface  22 , a distal flange surface  26 , and a recess  14 , which is preferably semi-circular as illustrated in FIG.  2 . As discussed below, recess  14  cooperates with an end cap  28  to form the valve mechanism of this embodiment. Flange  20  extends radially outward from the distal end  14  of longitudinal member  10 , providing a shoulder which may abut the distal surface  46  of the air conduit  40  when longitudinal member  10  and air conduit  40  are joined. 
     Recess  24  may be disposed on the distal end  26  of flange  20 . In the illustrated embodiment material has been removed concentrically outward on one side of the distal surface  26  of flange  20 . Preferably recess  24  does not extend to the outer edge of flange  20 . This preferred geometry is best illustrated in FIG.  2 . In general, recess  24  provides a selectively available breathing passage to end cap  28 , as discussed below, and so may be shaped in any matter suitable for this purpose. 
     In an exemplary embodiment end cap  28  includes an end face  29  having at least one aperture  30  therethrough, a depending skirt  31 , and a lip  32 . Preferably a plurality of apertures  30  are provided, and these are preferably grouped toward one side of end face  29 . This placement allows the rotation of end cap  28  to provide a range of selectable breathing areas between a fully open position (see FIG. 3) and a fully closed position (see FIG.  4 ). As end cap  28  is gradually rotated, for example, towards the fully open position, air flow through device  8  gradually increases. While the exemplary embodiment contains multiple apertures  30 , a single aperture  30  could also be provided. 
     Skirt  31  may depend from end face  29 . Preferably, an inner diameter of skirt  31  is slightly larger than an outer diameter of flange  20 . This allows end cap  28  to rotate concentrically around the outside of flange  20 . At a proximal edge of skirt  31  is a lip  32  protruding concentrically inward. Lip  32  may have a smaller inner diameter than the outer diameter of flange  20 , thereby allowing end cap  28  to remain secured on flange  20  in, for example, a snap-fit relationship. Preferably end cap  28  is made from a hard plastic that is adequately rigid and smooth to allow easy rotation of the cap yet is also adequately flexible to allow for snap-fitting to flange  20 . 
     As noted above, air conduit  40  may be integral with an endotracheal tube or could be constructed for connection to an existing endotracheal tube. The distal end  46  of air conduit  40  is coupled to the proximal end  12  of longitudinal member  10 . In particular, the inner surface of conduit  40  preferably fits in frictional interference with the outside surface  16  of longitudinal member  10 , with the distal surface  46  of conduit  40  abutting the proximal surface  22  of flange  20 . In this embodiment, air conduit  40  engages the outside surface  16  of longitudinal member  10 . In an alternative assembly, however, air conduit  40  could fit inside longitudinal member  10 . This coupling could likewise be achieved with frictional interference, which generally allows easy separation for cleaning or other purposes, but any suitable connection may be employed. 
     FIG. 5 illustrates a second exemplary embodiment of a device  8  according to the present invention, in which the valve mechanism takes the general form of a throttle or butterfly valve. In this embodiment, longitudinal member  10  includes a valve plate  50  which is pivotable between a fully open position (see FIG. 6) and a fully closed position (see FIG.  7 ). Valve plate  50  is preferably a thin disk with an outer edge  60  which contacts the inside surface  18  of longitudinal member  10  when valve plate  50  is in the fully closed position. Alternatively, valve plate  50  could take any shape suitable to selectively and gradually pivot between a fully open position that allows the free flow of air and a fully closed position which minimizes the flow of air. 
     When in the fully open position, valve plate  50  is positioned so that it presents a minimal cross-section in the direction of air flow through longitudinal member  10 . Thus air flow is maximized. When in the fully closed position, the illustrated valve plate  50  preferably contacts the inside surface  18  of longitudinal member  10  to create a seal which effectively blocks the flow of air through longitudinal member  10 . It is understood that valve plate  50  need not create a perfect seal against the inner surface  18 , and the term “seal” should be read to include an imperfect seal as may often be formed by valve plate  50 . In this exemplary embodiment, both valve plate  50  and longitudinal member  10  may be constructed of a flexible rubber material, although any material or combination of materials may be used. 
     Valve plate  50  preferably pivots on a pin  52 . Pin  52  may be inserted through valve plate  50  and through the walls of longitudinal member  10  (see FIG.  8 ). Pin  52  may engage valve plate  50  in frictional interference such that when the pin  52  is pivoted, valve plate  50  also pivots. Alternatively, pin  52  may be fused, glued, or otherwise rigidly attached to valve plate  50 . Pin  52  preferably protrudes through the outside surface  16  of longitudinal member  10 . In this manner, pin  52  may also maintain frictional interference with longitudinal member  10  such that when valve plate  50  is rotated to a desired position, it will remain in that position until further manipulated by the user. It is understood that while the illustrated embodiment shows valve plate  50  and pin  52  as distinct elements, the two could be formed integrally. 
     One protruding end  64  of pin  52  may be bent to prevent pin  52  from retracting through the wall of longitudinal member  10 . A second protruding end of pin  52  may be shaped to form a handle  54 , which may be manipulated to selectively position valve plate  50  between the fully open and fully closed positions. While handle  54  is shown integral with pin  52 , handle  54  could be formed separately and attached to pin  52 . 
     The device according to the present invention has been described with respect to two exemplary embodiments. It can be understood, however, that there are many other variations of the above-described embodiments which will be apparent to those skilled in the art, even where elements have not explicitly been designated as exemplary. For example longitudinal member  10  could be constructed integrally with an endotracheal tube, removing the need for a separate air conduit  40 . It is understood that this and other modifications are within the teaching of the present invention, which is to be limited only by the claims appended hereto.