Abstract:
A laryngoscope ( 1 ) includes a socket ( 3 ) that is mountable on a hand grip, a spatula blade ( 2 ) that is coupled with the socket ( 3 ) and a light guide tube ( 4 ) that has proximal and distal end portions, with the proximal end portion of the light guide tube ( 4 ) being releasably mounted in a cavity ( 11 ) that extends completely through the socket ( 3 ) while the distal end portion engages in a snap-in device on the spatula blade ( 2 ). The light guide tube ( 4 ) has a completely uniform permanent cross section that improves the laryngoscope spatula ( 1 ) since the light guide tube ( 4 ) can be manufactured and serviced in an uncomplicated manner.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    This application claims a priority based on German Applications DE 100 60 645.8, filed on Dec. 6, 2000 and DE 101 25 389.3, filed on May 23, 2001 and the contents of these priority applications are incorporated by reference herein.  
           [0002]    This invention concerns a laryngoscope with a socket mountable on a handle, a spatula blade attached to the socket and a light conductor tube having proximal and distal end portions, with the proximal end portion of the light conductor tube being removably mounted in a cavity extending through the socket, while the distal end portion engages in a snapping attachment on the spatula blade.  
           [0003]    Laryngoscopes serve particularly for introducing tubes for artificial breathing in air pipes of patients. For illumination of the throat cover area and the vocal chords, apparatus having fiber optic light guides are preferred. So that durability of the entire laryngoscope spatula is not determined by the relatively short lifespan of the light guides contained therein, laryngoscope spatulas with changeable light guide parts have been developed. These have the advantage that if, because of aging, light transmission of the light guide bundle falls below a particular threshold, the light guide tube is simply replaced by a new light guide tube. Such a laryngoscope spatula is disclosed in European Patent EP 0 586 972 B1.  
           [0004]    According to European Patent EP 0 586 972 B1, a narrow side opening is provided in a socket of a laryngoscope spatula into which a light guide tube can be laterally placed. A sideward release of the light guide tube is, in this regard, prevented in that an enlarged area of the light guide tube engages in an enlarged area of the opening, with a breadth of the side opening being smaller than the breadth of the enlarged area of the light guide tube. The light guide tube has, in this regard, at an end of the enlarged area a tube flange, which serves as a stop during an insertion movement. Such an embodiment of the light guide tube is installed, according to European Patent EP 0 586 972 B1, by one first moving a small breadth area sidewardly through the small side opening and then inserting it lengthwise until engagement of the tube flange, and then by pivoting approximately 90 degrees to fix it in an end position. a proximal facing end of the light guide tube extends, in this regard, out from the socket.  
           [0005]    It is detrimental that for such a laryngoscope spatula the construction of the part of the light guide tube to be mounted in the side socket opening, which has a step-wise structure with three breadths, is so expensive; and also, that there is a relatively complicated learning-intensive procedure for mounting the light guide tube. Further, the sensitive proximal facing end of the light guide, which extends out of the socket, is exposed to mechanical loads during fabrication and disassembly of the structure, which could lead to a damaging of the facing surface of the light guide.  
           [0006]    It is an object of this invention to provide a laryngoscope with a changeable light guide tube of the type set forth in the opening paragraph above that avoids the disadvantages set forth above and therefore allows a particularly uncomplicated replacement procedure for replacing the light guide tube.  
         SUMMARY OF THE INVENTION  
         [0007]    According to principles of this invention, the light guide tube has, throughout its length, a substantially uniform permanent breadth, which allows a particularly uncomplicated fabrication of the light guide tube. This also allows the proximal facing end of the light guide to be held within the socket, which assures better mechanical protection for the facing end. Additional advantages and advantageous embodiments of a laryngoscope according to this invention are described and claimed herein. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]    Embodiments of the invention are described in more detail using the following drawings. In the drawings:  
         [0009]    [0009]FIG. 1 a  is a side view of a general laryngoscope of this invention with a light guide;  
         [0010]    [0010]FIG. 1 b  is a simplified plan view of the distal end of a laryngoscope with a bowed light guide tube;  
         [0011]    [0011]FIG. 1 c  is a simplified plan view of a distal end of a laryngoscope with a skewed-angled cut light guide tube;  
         [0012]    [0012]FIG. 2 a  is a side view of the distal end of a laryngoscope of this invention with a snapped-in light guide tube (embodiment 1);  
         [0013]    [0013]FIG. 2 b  is a plan view of a spatula portion of the device of FIG. 2 a;    
         [0014]    [0014]FIG. 2 c  is a cross-sectional view taken on line II-II in FIG. 2 a;    
         [0015]    [0015]FIG. 3 a  is a side view of the distal end of a laryngoscope of this invention with a snapped-light guide tube (embodiment 2);  
         [0016]    [0016]FIG. 3 b  is a plan view of a spatula portion of the device of FIG. 3 a;    
         [0017]    [0017]FIG. 3 c  is a cross-sectional view of the spatula portion taken on line III-III in FIG. 3 a;    
         [0018]    [0018]FIG. 4 a  is a side view of a distal end of a laryngoscope of this invention with a snapped-in light guide tube (embodiment 3);  
         [0019]    [0019]FIG. 4 b  is a plan view of a spatula portion of the device of FIG. 4 a;    
         [0020]    [0020]FIG. 4 c  is a cross-sectional view of the spatula portion taken on line IV-IV in FIG. 4 a;    
         [0021]    [0021]FIG. 5 a  is a side view of a distal end of a laryngoscope of this invention with a snapped-in light guide tube (embodiment 4);  
         [0022]    [0022]FIG. 5 b  is a plan view of a spatula portion of the device of FIG. 5 a;    
         [0023]    [0023]FIG. 5 c  is a cross-sectional view of the spatula portion taken on line V-V in FIG. 5 a;    
         [0024]    [0024]FIG. 5 d  is a side view of the distal end of a laryngoscope of this invention with a snapped-in light guide tube (embodiment 5);  
         [0025]    [0025]FIG. 5 e  is a plan view of a spatula portion of the device of FIG. 5 d;    
         [0026]    [0026]FIG. 5 f  is a cross-sectional view taken on line V′-V′ in FIG. 5 d;    
         [0027]    [0027]FIG. 6 a  is a side view of a socket for this invention with an inserted light guide tube (variant 1);  
         [0028]    [0028]FIG. 6 b  is a plan view of the socket with the light guide tube of FIG. 6 a;    
         [0029]    [0029]FIG. 7 a  is an exploded, partially cross-sectional, view illustrating an insertion movement of a light guide tube into a socket (variant 1);  
         [0030]    [0030]FIG. 7 b  is a plan view illustrating a pivotal movement of the light guide tube in the socket (variant 1);  
         [0031]    [0031]FIG. 8 a  is a side view of a socket with an inserted light guide tube (variant 2);  
         [0032]    [0032]FIG. 8 b  is a plan view of the socket with the light guide tube of FIG. 8 a;    
         [0033]    [0033]FIG. 8 c  is an exploded side view illustrating a bending pivoting movement of the light guide tube upon its being mounting into the socket (variant 2);  
         [0034]    [0034]FIG. 8 d  is a plan exploded view of the socket with the light guide tube of FIG. 8 c;    
         [0035]    [0035]FIG. 9 a  is a side view of a socket with an inserted light guide tube (variant 3);  
         [0036]    [0036]FIG. 9 b  is a plan view of the socket with the light guide tube of FIG. 9 a;    
         [0037]    [0037]FIG. 9 c  is a side view of the socket (variant 3);  
         [0038]    [0038]FIG. 9 d  is a plan view of the socket (variant 3);  
         [0039]    [0039]FIG. 9 e  is a view illustrating a pivotal movement of the light guide tube upon its mounting in the socket (variant 3);  
         [0040]    [0040]FIG. 10 a  is a side view of a socket with an inserted light guide tube (variant 4);  
         [0041]    [0041]FIG. 10 b  is a plan view of the socket with the inserted light guide tube of FIG. 10 a;    
         [0042]    [0042]FIG. 10 c  is a side exploded view illustrating a bending pivoting movement of the light guide tube upon its mounting in the socket (variant 4);  
         [0043]    [0043]FIG. 10 d  is a plan exploded view of the socket with the light guide tube of FIG. 10 c;    
         [0044]    [0044]FIG. 11 a  is a side view of a socket with an inserted light guide tube (variant 5);  
         [0045]    [0045]FIG. 11 b  is a plan view of the socket with the light guide tube of FIG. 11 a;    
         [0046]    [0046]FIG. 11 c  is a side view of the socket (variant 5); and  
         [0047]    [0047]FIG. 11 d  illustrates a movement of the light guide tube upon its being mounted in the socket (variant 5). 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0048]    [0048]FIG. 1 a  shows a laryngoscope  1  that includes a spatula blade  2  and a socket  3  with a light guide tube  4  mounted in a snap-in catch. The socket  3  that is affixed to the proximal end of the spatula blade  2  serves as a base part of the laryngoscope  1  that is fastened by a cavity  5  to a handle with a battery and a miniature incandescent light (not shown) and is affixed therein with the help of an indexing, or snapping, ball  6 . The light guide tube  4  is formed as a fiberglass bundle covered with a metallic mantel that is elastically springy, and accordingly bowed. The light guide tube  4  extends directly adjacent to and substantially parallel to a side portion of the spatula blade  2 . An optimal illumination of an operational area at the distal end of the laryngoscope  1  therefore requires a change in a dispersion direction of a light beam, which can result in the suggested variants of FIGS. 1 b  and  1   c.  The light guide tube  4  can either be laterally bowed in a direction away from the spatula blade  2 , as is shown in FIG. 1 b  wherein it has a square cut distal facing end, or the distal facing end can be cut at a skewed angle as is shown in FIG. 1 c  so that it causes a light deflection at the distal facing end of the light guide tube. It should be noted that the embodiments of the distal end of the light guide tube shown in FIGS. 1 b  and  1   c  can be used in all of the embodiments disclosed herein.  
         [0049]    [0049]FIGS. 2 a  through  2   c  depict a first embodiment of attachment of the light guide tube  4  at the distal end of the laryngoscope spatula  1 . As can be seen in FIG. 2 c,  the spatula blade  2  has a clamp-like cross section with a flanged spatula backside  7 . The distal end portion of the light guide tube  4  is therefore affixed in a snap-in catch  8   a  formed by a fold-back  9   a  at a distal edge of the spatula backside  7 . Because of the elastic springy characteristics of the light guide tube  4 , it can be snapped under the fold-back by a light finger pressure. For unsnapping the light guide tube  4 , a grip-trough opening  10   a  is provided in the fold-back  9   a  that forms the snap-in catch at the spatula backside  7 .  
         [0050]    [0050]FIGS. 3 a  through  3   c  show a second snap attachment variant for the light guide tube  4 . Also here the snap-in attachment  8   b  is formed by a fold-back  9   b  of the spatula backside  7  near the distal end of the laryngoscope spatula  1 . The elastically springy light guide tube  4 , in this embodiment, is unlatched by a light finger pressure on the distal end of the light guide tube  4  that extends out from under the spatula backside  7 .  
         [0051]    [0051]FIGS. 4 a  through  4   c  show a distal end of the laryngoscope  1  that has a third snap attachment variant according to this invention. In this case, the affixing is accomplished by a bead  9   c  that is positioned close to the distal end of the laryngoscope, arranged in the lower inside portion of the spatula backside  7 . Also here the affixing is accomplished through the elastically springy characteristics of the light guide tube  4  that is snapped in by a horizontal pivoting movement after overcoming the part  9   c  that is formed out of the plane of the spatula backside  7 . The unlatching can be accomplished in this embodiment through a grip-trough opening  10   c  arranged distal to the snap-in catch  8   c  at a bend area of the spatula backside  7 . In this embodiment, a light finger pressure on the light guide tube  4  through the grip-trough opening  10   c  is sufficient to achieve unlatching.  
         [0052]    [0052]FIGS. 5 a  through  5   c  show a fourth snapping variant of the distal end of the laryngoscope  1  that represents a cross between the variants shown in FIGS. 3 and 4. Similarly as in FIGS. 4 a  through  5   c,  the affixing is accomplished via a bead  9   d  which lies near the distal end of the laryngoscope  1  and which is arranged in the lower portion of the spatula backside  7 . The affixing comes about because of the elastically springy characteristics of the light guide tube  4  that snaps in upon a horizontal pivoting movement following overcoming the part  9   d  of the spatula backside  7  that is out of the plane of the spatula backside  7 . The unlatching can, in this embodiment, be caused by a light finger pressure on the end of the light guide tube  4  extending out from under the spatula backside  7 .  
         [0053]    Upon the affixing of the light guide tube  4  under the spatula backside  7 , a contacting of the light guide tube  4  with an area of the spatula backside  7  in front of the bead  9   d  by a person using the laryngoscope can be perceived as a final affixed position. FIGS. 5 d  through  5   f  show a fifth snapping attachment variant of the distal end of the laryngoscope  1  in which a danger of confusing a final attachment position of the light guide tube  4  under the spatula backside  7  is ruled out because of rubbing between these two parts, or because of an optical partial covering of the light guide tube  4  by the spatula backside  7  in front of the bead  9   c.  This is achieved because a lowest position of the bead  9   e  simultaneously serves as the first and only obstacle in the affixing path of the light guide tube  4 . The spatula backside  7  extends to converge in a wedge-shape in the direction of the distal end with the fold-back edge intersecting the lowest position of the bead  9   e.  Because of the elastically springy characteristics of the light guide tube, after overcoming the part  9   e  extending out of the plane of the spatula backside  7  a final arresting is accomplished by a light finger pressure on the distal end of the light guide tube  4 . The uncoupling can be caused in this embodiment by a light finger pressure and a rotational, pivotal movement of the light guide tube  4  in an opposite direction. This embodiment relates to each of the four previously described snap-in variations. This variant has the substantial benefit that the “cutaway” portion, contrary for example to FIGS. 5 a - 5   c,  of the spatula backside is not an obstacle to viewing in the throat of a patient.  
         [0054]    [0054]FIGS. 6 a  and  6   b  show the socket  3  of the laryngoscope  1  with an inserted proximal end of the light guide tube  4  in accordance with a first variant of the attachment of the proximal end of the light guide tube  4  in a guided-in catch. At the proximal end of the light guide tube  4  there is preferably a shape without a cross-sectional change. A cavity  11   a  having a form corresponding to that of the light guide tube  4  and extending through the socket  3  thereby prevents a sideward falling out of the light guide tube  4  and assures a stable seating position of the light guide tube  4  in the socket  3 . As can be seen in FIG. 6 a,  the proximal end of the light guide tube  4  is positioned at a cross sectional constriction  12 , that amounts to a step transition of the cross section of the cavity  11   a  from a first cross section that corresponds substantially to the cross section of the light guide tube  4  to a smaller cross section. The smaller cross section can be so chosen that the light guides are not covered within the light guide tube  4 . Because the proximal facing end of the light guide tube  4  is positioned within the cavity  11   a  of the socket  3 , a mechanical protection of this sensitive facing end is assured.  
         [0055]    [0055]FIGS. 7 a  and  7   b  show a preferred manner in which the light guide tube  4  is placed and affixed in the laryngoscope  1  of the embodiment of FIGS. 6 a  and  6   b.  The first step includes insertion of the proximal end of the light guide tube  4  in the socket cavity  11  until contact against the cross-sectional constriction  12 . Thereafter, a rotational movement of the light guide tube  4  to below the spatula backside  7  affixes the light guide tube  4 . The rotational movement can also be less than 90 degrees if the light guide tube  4  is mounted at an acute angle to the spatula blade  2 , which is possible according to this invention.  
         [0056]    This invention is not limited in its embodiments to the above given shape of the cross-sectional constriction  12 . Rather, many different variations will occur to those of ordinary skill in the art that basically differ from the above described solution by making use of other types of cross-sectional changing shapes for the cross-sectional constriction (for example, conical, round and so forth).  
         [0057]    For each of the above described embodiments for affixing the light guide tube  4  to the distal end of the laryngoscope  1 , the below described variations of placing the proximal end of the light guide tube  4  in the socket  3  can also be used.  
         [0058]    [0058]FIGS. 8 a  through  8   d  show a further embodiment for attaching the proximal end of the light guide tube  4 , without the cross sectional change, in the socket  3 . The socket  3  has, in this regard, a side opening  11   b  whose inclination angle to vertical changes from the edge area to the middle of the socket  3 . The angle between the access of the opening  11   b  and a normal to the socket in its operational position has thereby a maximum value at the edge, or outer surface, area of the socket  3  and is minimal or equal to zero in the center of the socket  3 . An opposite arrangement in which the minimal angle is in the edge area of the socket and the maximum angle is in the center of the socket  3  is also possible. Upon mounting the light guide tube  4  in the opening  11   b  of the socket  3  the light guide tube  4  makes a pivot bending movement which is required by the change in the inclination angle of the opening  11   b,  as can be seen in FIG. 8 c.  In a mounted position (see FIG. 8 b ) the light guide tube  4  is held tightly in the middle of the socket  3  by a protrusion caused by angling the side opening  11   b,  on the one hand, and by the affixing of the distal end of the light guide tube  4 , on the other hand.  
         [0059]    A further embodiment of the attachment of the light guide tube  4  in the socket  3  of the laryngoscope  1  is shown in FIGS. 9 a  through  9   d.  A characteristic of this embodiment is the presence of a cavity  14   a  in an upper edge area of the straight side opening  11   c  near the middle of the socket  3 . The cavity  14   a,  in this regard, has a geometric shape that form-locks with a portion of the light guide tube  4  lying on the socket  3  that, after a sideward insertion into the opening  11   c  and a horizontal pivoting (see FIG. 9 e ), is affixed in the socket  3 . This embodiment sets a limit on movement of the light guide tube  4  in a mounted position toward the top, for example that the upper edge of the light guide tube  4  lies against the spatula backside  7  or is affixed in the snapping apparatus on the spatula tube  2 . In this attached positioned (see FIG. 9 b ) the light guide tube  4  that engages in the snapping apparatus on the spatula blade (not shown) is, with the help of the cavity  14   a,  prevented from falling out sidewardly through the opening  11   c.    
         [0060]    [0060]FIGS. 10 a  through  10   d  show a further embodiment of the attachment of the light guide tube  4  in the socket  3  that is a cross between the embodiments depicted in FIGS. 8 a - 8   d  and FIGS. 9 a - 9   d.  Similarly as in FIGS. 8 a  through  8   d,  the affixing of the light guide tube  4  and the socket  3  is carried out by insertion of the light guide tube  4  in a side opening  11   d  that has an inclination angle that changes along a path through the socket  3 . Further, the light guide tube  4 , similarly as in FIGS. 9 a  through  9   d,  is fixed by a cavity  14   b  in the opening  11   d.  Also, here the cavity  14   b  is geometrically shaped to lock with a corresponding part of the light guide tube  4 .  
         [0061]    The attachment of the light guide tube  4  and socket  3  shown in the embodiment of FIGS. 11 a  through  11   d  includes a snapping ball  16  provided in the socket  3  with an elastic spring  17  which prevents the light guide tube  4  from falling out of the opening  11   e  sidewardly. This embodiment allows a particularly uncomplicated mounting and affixing of the light guide tube  4  in the socket  3  by a simple sideward insertion movement (see FIG. 11 d ) and thereafter a light finger pressure in the insertion direction without a rotation of the light guide tube  4  whose displacement in the vertical direction is prevented by a horizontally extending protrusion  18  in the sideward opening  11   e  and a correspondingly-shaped cavity  20  in the light guide tube  4 . A flattened surface  19  at the proximal end of the light guide tube  4  allows one to completely eliminate a snapping apparatus on the spatula blade, which leads to a further simplification of the construction and therefore to a corresponding reduction in manufacturing costs.