Abstract:
A laryngeal mask airway installation kit includes a laryngeal mask airway having a gastric access tube and includes a stylet capable of being inserted into the gastric access tube from the inlet end. When bent, the stylet changes the original shape of the laryngeal mask airway, thus facilitating the installation of the laryngeal mask airway.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a medical instrument. More particularly, the present invention relates to an improved laryngeal mask airway (LMA). 
     2. Description of the Related Art 
     In the case of anesthesia and apnea patients, the top priority is the provision of pulmonary gas by emergency medical personnel. Among the various respiration sustaining instruments, the LMA, due to its ease of operability, is a common alternative to endrotracheal intubation. 
     Please refer to  FIG. 1  for the structure of a conventional LMA  10 P. Basically, the LMA  10 P comprises a flexible tubular portion  11 P, an inflatable sealing cuff  13 P, and an inflation tube  15 P. The flexible tubular portion  11 P comprises a first opening part  111 P and a second opening part  112 P. The inflatable sealing cuff  13 P is disposed surrounding the first opening part  111 P. The inflation tube  15 P has one end connected to the inflatable sealing cuff  13 P and the other end directing gas into the inflatable sealing cuff  13 P. 
     Please refer to  FIGS. 2 to 4  for illustrative diagrams showing the conventional laryngeal mask  10 P in use. First, a user may insert the LMA  10 P into a patient&#39;s mouth by the end having the inflatable sealing cuff  13 P, which is in a deflated condition. When the inflatable sealing cuff  13 P reaches a deeper part of the mouth, the user will then have to insert his/her finger into the patient&#39;s mouth to bend the front end of the LMA  10 P to make the structure of the LMA  10 P conform with the structure of the patient&#39;s upper jaw. In addition, due to the softness of the LMA  10 P, the user may not exert force thereby. Thus, the user has to push aside the tongue with his/her finger to bend the first opening part  111 P and the flexible tubular portion  11 P to such an extent that they can reach past the upper jaw to the opening of the trachea, as shown in  FIG. 3 . In  FIG. 4 , when the LMA  10 P gets to a specific position, the user may then aerate the inflatable sealing cuff  13 P from the inflation tube  15 P so as to form a sealing mask in the patient&#39;s throat. The sealing mask may encompass the opening of the trachea and form an air passage thereby. After that, the user may direct gas, such as oxygen, from the second opening part  112 P to maintain the patient&#39;s respiration. 
     Accordingly, during the installation of an LMA  10 P, users always have to insert their finger(s) (especially their index fingers) into a patient&#39;s mouth to pass the soft, inconvenient LMA  10 P through the upper jaw because of the obstruction of the patient&#39;s tongue. In general, this displacement by fingers may cause two problems. First, there is the risk that the user may be bitten by the patient during the installation of an LMA  10 P. Second, in a case where a patient&#39;s oral space is overly small, which may be caused by an overly small mouth, an overly tight tooth joint, or an overly thick tongue, a user may encounter difficulty inserting his/her finger(s) into the patient&#39;s mouth, resulting in failure to install the LMA  10 P. 
     In addition to the LMA  10 P mentioned above, an LMA with a gastric access tube has also been disclosed in the pertinent art, such as the one disclosed in U.S. Pat. No. 5,241,956. The major function of the gastric access tube is that it that allows for easy passage of a gastric tube or can serve as an escape conduit for regurgitant fluid, thus preventing aspiration and pulmonary contamination. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a stylet usable with an LMA having a gastric access tube in order to enable users to install the LMA without having to insert their fingers into the patient&#39;s mouth. 
     It is another object of the present invention to provide an LMA installation kit which may be assembled by a user easily to facilitate the installation of an LMA. 
     It is still another object of the present invention to provide an LMA with a stylet. When the stylet in the LMA is bent by a user to a certain curvature, the stylet, which is relatively more rigid than the LMA, may keep the relatively softer LMA in the curvature and provide some rigidity to the LMA, enabling the user to exert force to the farther end of the LMA. Accordingly, the LMA with a stylet of this invention may not only facilitate the installation of the LMA into a patient&#39;s upper airway but also enable users to conduct the installation without inserting their fingers. 
     To achieve the aforementioned objects, this invention provides an LMA installation kit comprising: an LMA comprising a gastric access tube which comprises an inlet end and an outlet end; and a stylet capable of being inserted into the gastric access tube from the inlet end and, when bent, changing the original shape of the LMA. 
     In addition, this invention provides an LMA with a stylet comprising: an LMA comprising a gastric access tube; and a stylet inserted in the gastric access tube, with said stylet, when bent, being capable of changing the original shape of the LMA. 
     Moreover, this invention provides a stylet usable with an LMA with a gastric access tube, with the stylet comprising a substantially elongated main part capable of changing the original shape of the LMA when bent. 
     In some situations to ensure that the stylet will not penetrate the outlet end of the gastric access tube, the present invention provides a clasp mountable on the stylet. When the length of the stylet in the gastric access tube exceeds a predefined length, the stylet will be restrained by the clasp. The clasp may be installed adjustably so that a user may adjust the insertable length. 
     In some situations, the opening at the outlet end of the gastric access tube is of a specific size. More specifically, the size of the opening is large enough to permit the passage of a gastric tube for extracting regurgitant fluid while small enough to prevent the stylet from penetrating therefrom and thus harming the patient by direct contact or by causing contamination. 
     In addition, the stylet may be used with an image system so that a user may observe the patient&#39;s upper airway during the installation of the LMA. For example, video-recording and image-capturing functions may be obtained by the use of an image-capturing unit. The image captured by the image-capturing unit may be shown with the use of a display unit. The image captured by the image-capturing unit may be transmitted to an external display wirelessly with the use of a signal emission unit. In short, various units may be integrated with this invention whenever needed. 
     Furthermore, in the LMA installation kit and the LMA with a stylet, the penetration of the gastric access tube by the stylet may be prevented by different ways. For example, the clasp may be installed at the inlet end of the gastric access tube. In addition, special design features of the LMA may also have similar effects. For example, the formation of indentations close to the outlet end of the gastric access tube and modification of the opening of the gastric access tube to make it smaller are both viable solutions. 
     It should be noted that even though several objects are described herein, they are just enumerated as examples and not presented as a complete list. In other words, the objects of this invention are not limited thereto. Any practices of the present invention, even if not directed to fulfill the objects mentioned above, shall still fall within the scope of this invention. Meanwhile, the selection of wordings focuses on revealing the invention as simply as possible so that readers may understand the invention without extra effort. Thus, the interpretation of the wordings shall be done broadly without unnecessary limits. 
     Other objects, advantages, and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other objects and advantages of the present invention will become apparent from the following description of the accompanying drawings, which disclose several embodiments of the present invention. It is to be understood that the drawings are to be used for purposes of illustration only, and not as a definition of the invention. 
       In the drawings, wherein similar reference numerals denote similar elements throughout the several views: 
         FIGS. 1 to 4  are illustrations of the LMA used in the prior art. 
         FIG. 5  is an illustration of one embodiment of the LMA installation kit of this invention. 
         FIG. 6  is a sectional view of one embodiment of the LMA installation kit of this invention. 
         FIG. 7  is an illustration of one embodiment of the LMA with a stylet of this invention. 
         FIGS. 8 to 11  are illustrations of different embodiments of the LMA installation kit of this invention. 
         FIG. 12  is an illustration of one embodiment of the LMA with a stylet of this invention in use. 
         FIG. 13  is an illustration of one embodiment of the stylet of this invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Please refer to  FIG. 5  for an illustration of one embodiment of the LMA installation kit  50  of this invention. The LMA installation kit  50  mainly comprises an LMA  20  comprising a gastric access tube  21  which comprises an inlet end and an outlet end; and a stylet  30  capable of being inserted into the gastric access tube  21  from the inlet end and, when bent, changing the original shape of the LMA  20 . To prevent the stylet  30  from penetrating the gastric access tube  21  and injuring the patient, a soft cap  31 , which may be made of any biocompatible material, may selectively be mounted on the stylet  30 . Alternatively, the end of the stylet  30  insertable into the gastric access tube  21  may be made of soft material in some situations so as to prevent injury. 
     In addition, the material of the stylet  30  may be chosen from any substance that is not completely rigid so that the stylet  30  may be bent by the user to a specific curvature suitable for the installation of the LMA  20 . 
     Refer to  FIG. 6  for a sectional view of one embodiment of the LMA installation kit  50  of this invention. As shown, the stylet  30  may be inserted into the gastric access tube  21  of the LMA  20 . Because the gastric access tube  21  of the LMA  20  may bear the force directed from the stylet  30 , the user may use this characteristic to change the curvature of the LMA  20  when the stylet  30  is inserted into the gastric access tube  21  and bent. Thus, the present invention allows users to assemble the LMA installation kit  50  and to bend the stylet  30  to a desirable curvature in light of the physical characteristics of a patient so as to facilitate the installation of the LMA  20 . 
     To prevent users from penetrating the gastric access tube  21  with the stylet  30  and thus contaminating the patient&#39;s upper airway, the LMA installation kit  50  of this invention may selectively contain a clasp  33  mountable on the stylet  30  for controlling the length of the stylet  30  insertable into the gastric access tube  21 . In certain situations, the clasp member  33  is adjustably installed. Therefore, users may adjust the length of the stylet  30  insertable into the gastric access tube  21  according to existing conditions. 
     Refer to  FIG. 7  for an illustration of one embodiment of the LMA with a stylet  60  of this invention. The LMA with a stylet  60  mainly comprises: an LMA  20  which comprises a gastric access tube  21 ; and a stylet  30  inserted into the gastric access tube  21 . Said stylet  30 , when bent, is capable of changing the original shape of the LMA  20 . 
     Similarly, to prevent users from penetrating the gastric access tube  21  with the stylet  30  and thus contaminating the patient&#39;s upper airway, the LMA with a stylet  60  of this invention may selectively contain a clasp  33  mountable on the stylet  30  for controlling the length of the stylet  30  insertable into the gastric access tube  21 . In certain situations, the clasp member  33  is adjustably installed. Therefore, users may adjust the length of the stylet  30  insertable into the gastric access tube  21  according to need. As shown in  FIG. 7 , corresponding threads complementary to that of the stylet  30  may be formed on the clasp  33 , enabling users to move the stylet  30  back or forth by rotation. 
     Undoubtedly, different designs may be applied to the stylet, LMA, or gastric access tube to keep the stylet from penetrating the gastric access tube. Please refer to  FIGS. 8 to 11  for illustrations of different embodiments of the LMA installation kit  50  of this invention. In  FIG. 8 , an indentation  23  capable of restraining the stylet  30   a  may be formed adjacent to the opening of the gastric access tube  21  of the LMA  20 . In that case, the stylet  30   a  will be kept in position when the front end of the stylet  30   a  enters the indentation  23 , effectively preventing the stylet  30   a  from causing any contamination or injury. In addition, different designs may be applied to the stylet  30   b  so that it may be directed into the indentation  23  more easily. 
     In  FIG. 9 , the stylet  30   b  has a fork structure which can be easily fitted into the indentation  23  to prevent the stylet  30   b  from penetrating the gastric access tube  21 . Similarly, as shown in  FIG. 10 , two indentations  23  are formed close to the opening of the gastric access tube  21  of the LMA  20 . The design shown in  FIG. 10  is especially suitable for a stylet  30   c  with another fork structure. In addition, the LMA  20  of this invention may be selectively made of transparent material so as to allow the stylet  30   c , which has an image-capturing unit  35 , to capture images. It should be noted that, due to the high costs of the transparent material, the use of the transparent material in the LMA  20  may be limited only to the area around the image-capturing unit  35 . Also, the image-capturing unit  35  is not limited to use with only one certain type of stylet  30 , but various types of stylet  30  are applicable. 
     In  FIG. 11 , a gastric access tube  21  with a smaller opening is used to restrain the stylet  30   d  from penetrating the gastric access tube  21 . In this case, the size of the opening is large enough to permit the passage of a gastric tube for extracting the regurgitant fluid while small enough to prevent the stylet  30   d  from protruding therefrom and thus harming the patient by direct contact or causing contamination. 
     Please refer to  FIG. 12  for an illustration of one embodiment of the LMA with a stylet  60  of this invention in use. Before being applied to a patient, the LMA with a stylet  60  is bent in advance to a specific curvature. Therefore, a user may easily pass the LMA  20  through the patient&#39;s upper jaw without having to insert a finger into the patient&#39;s mouth to bend the LMA  20 . Then, the LMA  20  may resume its original shape after the user withdraws the stylet  30 . The installation may be completed  20  by the inflation of the LMA  20 . 
     Finally, refer to  FIG. 13  for an illustration of one embodiment of the stylet  30  of this invention. As shown, the stylet  30  comprises an image-capturing unit  35  for capturing an image from a patient&#39;s upper airway. The image may then be directly shown on a display unit  37  installed at one end of the stylet  30 , enabling a user to determine the position of the LMA  20  in the upper airway. In addition, a signal emission unit  39  may be selectively used to wirelessly transmit the image captured by the image-capturing unit  35  to an external display. However, it should be noted that each unit mentioned above may be applied to the stylet  30  either individually or collectively. 
     Accordingly, the stylet  30  of the present invention, when used in an LMA  20 , may not only facilitate the installation of the LMA  20  but may also provide a precise condition assessment capability by enabling users to observe the installation process. 
     Although the present invention has been explained in relation to its preferred embodiments, it is to be understood that many other possible modifications and variations can be made without departing from the spirit and scope of the invention as hereinafter claimed.