Patent Publication Number: US-2007106122-A1

Title: Intubation assistance apparatus

Description:
BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention relates to an intubation assistance apparatus for use in inserting a distal end of an intubation tube into a target site such as a trachea of a patient.  
      2. Description of the Prior Art  
      It is sometimes necessary to practice artificial respiration, as a first-aid lifesaving treatment for a patient who is suffering from unconsciousness caused by an accident or the like. Although the artificial respiration may be practiced without having to use any instrument or apparatus, it is often the case that a respirator is used for that purpose.  
      In the event that a respirator is utilized to conduct artificial respiration, an intubation tube whose proximal end is connected to the respirator is inserted into the trachea of a patient to supply air into the trachea from the respirator via the tube.  
      In the meantime, if a patient loses consciousness, the root of a tongue is retracted to thereby block up a respiratory tract (air passage) because of the relaxation of muscles of the pharynx and the larynx and/or the gravity caused loosening of a lower jaw.  
      Therefore, in the case where the afore-mentioned intubation tube is to be inserted into the trachea or a target area, it is essential to first open the blocked respiratory tract and secure an air passage by pulling up the tongue.  
      As an instrument for use in securing the air passage, there is known what is called an oral airway (see, e.g., US-A 2005-0150500).  
      Such an oral airway is an elongated member with a curved distal end and can be inserted through the mouth of a patient who has lost consciousness, whereby an appropriate portion on the side of the distal end comes into contact with and lifts up a tongue root portion of the patient, thus securing the air passage.  
      As described in the above-mentioned prior art, the oral airway (intubation assistance instrument) is normally used in a state that the proximal end of the intubation assistance instrument is coupled to a main body of an intubation assistance apparatus (hereinafter, this state will be referred to as “coupling state”). The intubation assistance apparatus includes an imaging means (image pick-up device) for taking an image of an observation site at a distal end portion of the intubation assistance instrument as an electronic image, and a display for displaying the electronic image taken by the imaging means.  
      The above-described intubation assistance apparatus in the coupling state is configured so that the display is positioned on the left side of the intubation assistance instrument at the time when the intubation assistance apparatus is used in a state shown in  FIG. 1  of the prior art. Therefore, the center of the screen of the display is dislocated from the center line of the intubation assistance instrument on the left side thereof.  
      When such an intubation assistance apparatus is used, an operator inserts the intubation assistance instrument into the trachea of a patient through the mouth of the patient with monitoring the display. Therefore, in the prior art intubation assistance apparatus, the operator is likely to operate the apparatus with undesirable recognition that the center of the screen of the display is aligned with the center line of the intubation assistance instrument. For this reason, in the prior art intubation assistance apparatus, there is a problem in that an operator excessively moves the intubation assistance instrument with respect to the observation site due to the dislocation between the center of the screen and the center line of the intubation assistance instrument, thus resulting in the case that the manipulability of the apparatus when the intubation assistance instrument is inserted into the trachea of a patient is lowered.  
     SUMMARY OF THE INVENTION  
      It is therefore an object of the present invention to provide an intubation assistance apparatus having a superior manipulability when an intubation assistance instrument is inserted into an air passage of a patient.  
      In order to achieve this object, the present invention is directed to an intubation assistance apparatus which includes a main body having a proximal end portion; an insertion instrument having an elongated insertion section for insertion into a trachea or its vicinity of a patient from a mouth cavity of the patient, the insertion instrument having a central axis; and imaging means for taking an image of an observation site at a distal end portion of the insertion instrument as an electronic image, wherein the intubation assistance apparatus is adapted to be used in an assembled state where the main body, the insertion instrument and the imaging means are assembled together. The main body includes a display having a screen for displaying the electronic image taken by the imaging means in the assembled state, and the display is arranged on the proximal end portion of the main body so that the center of the screen is located on the central axis of the insertion instrument when the display is viewed from the side of the screen in the assembled state.  
      The intubation assistance apparatus of the present invention having the above structures can exhibit superior manipulability when the insertion instrument is inserted into the trachea of a patient.  
      In the intubation assistance apparatus according to the present invention described above, it is preferred that the screen of the display has a rectangular shape having a center line which is in parallel with the long side of the rectangular shape, and wherein the display is arranged on the proximal end portion of the main body so that the center line is located on the central axis of the insertion instrument when the display is viewed from the side of the screen in the assembled state.  
      This makes it possible to exhibit more superior manipulability when the insertion instrument is inserted into the trachea of a patient.  
      Further, in the intubation assistance apparatus according to the present invention described above, it is preferred that the screen is inclined with respect to the central axis of the insertion instrument.  
      According to this configuration, though depending on the posture of the operator during the insertion operation, it is possible to direct the display to the operator during the insertion operation so that the display can be monitored easily.  
      Furthermore, in the intubation assistance apparatus according to the present invention described above, it is preferred that the display is rotatably provided on the proximal end portion of the main body so as to be movable between a first position where the display is close to the main body and a second position where the display is far away from the main body, and wherein the center of the screen is located on the central axis of the insertion instrument regardless of the rotation angle of the display when the display is viewed from the side of the screen in the assembled state.  
      This makes it possible for an operator to carry out the intubation operation reliably irrespective of the positional relationship between the operator and the patient when inserting the insertion instrument into the trachea of the patient.  
      Moreover, in the intubation assistance apparatus according to the present invention described above, it is preferred that the screen of the display has a rectangular shape having a center line which is in parallel with the long side of the rectangular shape, and wherein the display is arranged on the proximal end portion of the main body so that the center line is located on the central axis of the insertion instrument regardless of the rotation angle of the display when the display is viewed from the side of the screen in the assembled state.  
      This also makes it possible for an operator to carry out the intubation operation reliably irrespective of the positional relationship between the operator and the patient when inserting the insertion instrument into the trachea of the patient.  
      In the above modifications, it is preferred that the screen is inclined with respect to the central axis of the insertion instrument when the display is in the first position.  
      According to this configuration, though depending on the posture of the operator during the insertion operation, it is possible to direct or face the display to the operator during the insertion operation so that the display can be monitored easily.  
      In the intubation assistance apparatus according to the present invention, it is preferred that the main body includes a grip section which is to be grasped by an operator when the intubation assistance apparatus is used.  
      According to this configuration, an operator can grasp the intubation assistance apparatus in the assembled state easily and reliably, thus exhibiting superior manipulability when inserting the insertion instrument into the trachea of a patient.  
      In the modification described above, it is preferred that the grip section has an outer profile of a column-like shape, and the central axis of the grip section is substantially aligned with the central axis of the insertion instrument.  
      According to this configuration, since the hand of the operator who grasps the grip section is positioned near the screen of the display, it is possible to manipulate the insertion instrument accurately.  
      Further, in the intubation assistance apparatus according to the present invention, it is also preferred that the insertion instrument has a straight portion extending linearly and a curved portion continuously extending from the distal end of the straight portion and having a curved form.  
      According to this configuration, the insertion operation of the insertion instrument into the mouth of a patient can be carried out easily.  
      In the modification described above, it is preferred that the distal end of the curved portion is directed to a direction which is substantially in parallel with a normal line of the screen in the assembled state.  
      This also makes it possible to exhibit more superior manipulability when the insertion instrument is inserted into the trachea of a patient.  
      Furthermore, in the intubation assistance apparatus according to the present invention, it is also preferred that the insertion instrument has guide means for removably holding an intubation tube and for leading the intubation tube to the trachea or its vicinity of the patient.  
      This makes it possible to lead the intubation tube to the target site such as the trachea of the patient reliably.  
      Moreover, in the intubation assistance apparatus according to the present invention, it is also preferred that the imaging means includes an image pick-up device provided in the main body and leading means provided in the insertion instrument for leading an image of an object to be taken to the image pick-up device.  
      This makes it possible to take an electronic image of the observation site where the distal end of the insertion instrument is positioned, and the thus obtained electronic image can be monitored by the screen.  
      These and other objects, structures and results of the present invention will be apparent more clearly when the following detailed description of the preferred embodiments is considered taken in conjunction with the appended drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a perspective view which shows a first embodiment of an intubation assistance apparatus according to the present invention.  
       FIG. 2  is another perspective view which shows the first embodiment of an intubation assistance apparatus according to the present invention.  
       FIG. 3  is an illustration which shows the intubation assistance apparatus shown in  FIG. 1  viewed from the direction indicated by the arrow A in  FIG. 1 .  
       FIG. 4  is a cross-sectional view taken along line B-B in  FIG. 1 .  
       FIG. 5  is a perspective view which shows a main body of the intubation assistance instrument of the intubation assistance apparatus shown in  FIGS. 1 and 2 .  
       FIG. 6  is a perspective view which shows an insertion instrument of the intubation assistance instrument of the intubation assistance apparatus shown in  FIGS. 1 and 2 .  
       FIG. 7  is another perspective view which shows an insertion instrument of the intubation assistance instrument of the intubation assistance apparatus shown in  FIGS. 1 and 2 .  
       FIG. 8  is a perspective view of an intubation tube which is used in combination with the intubation assistance apparatus shown in  FIGS. 1 and 2 .  
       FIG. 9  is a perspective view which shows a second embodiment of an intubation assistance apparatus according to the present invention.  
       FIG. 10  is a perspective view of a main body of intubation assistance apparatus shown in  FIG. 9 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
      Hereinbelow, preferred embodiments of an intubation assistance apparatus according to the present invention will be described in detail with reference to the accompanying drawings.  
     First Embodiment  
       FIG. 1  is a perspective view which shows a first embodiment of an intubation assistance apparatus according to the present invention;  FIG. 2  is another perspective view which shows the first embodiment of an intubation assistance apparatus according to the present invention;  FIG. 3  is an illustration which shows the intubation assistance apparatus shown in  FIG. 1  viewed from the direction indicated by the arrow A in  FIG. 1 ;  FIG. 4  is a cross-sectional view taken along line B-B in  FIG. 1 ;  FIG. 5  is a perspective view which shows a main body of the intubation assistance instrument of the intubation assistance apparatus shown in  FIGS. 1 and 2 ;  FIG. 6  is a perspective view which shows an insertion instrument of the intubation assistance instrument of the intubation assistance apparatus shown in  FIGS. 1 and 2 ;  FIG. 7  is another perspective view which shows an insertion instrument of the intubation assistance instrument of the intubation assistance apparatus shown in  FIGS. 1 and 2 ; and  FIG. 8  is a perspective view of an intubation tube which is used in combination with the intubation assistance apparatus shown in  FIGS. 1 and 2 . Note that in  FIG. 3  an intubation tube is omitted. Further, in the following description, the upper side and the lower side in FIGS.  1  to  4  will be referred to as “proximal end” and “distal ends”, respectively, for the purpose of clarity.  
      The intubation assistance apparatus  100  shown in  FIGS. 1 and 2  includes a main body  10 , an insertion instrument  11  and an image taking means  70 , and the intubation assistance apparatus  100  is used in a state that these components are assembled together.  
      As will be described later, the intubation assistance apparatus  100  is used in combination with an intubation tube  200  which is to be inserted into the trachea of a patient through the mouth (mouth cavity) thereof. In this regard, please note that although the main body  10  and the insertion instrument  11  are separate components in the followings embodiments, the main body  10  and the insertion instrument  11  may be formed into an integral body.  
      Hereinbelow, detailed descriptions will be made with regard to each of these components.  
      The insertion instrument  11  shown in  FIGS. 6 and 7  is formed from an elongated member which constitutes an elongated insertion section, and it is used by being inserted into the trachea of a patient or its vicinity who has lost consciousness from the mouth (mouth cavity) of the patient. An air passage for the patient is secured by bringing an appropriate portion on the side of a distal end of the insertion instrument  11  into contact with the root of a tongue of the patient.  
      As illustrated in  FIGS. 6 and 7 , the insertion instrument  11  has a straight portion  11 A and a curved portion  11 B which is curved and extends from the distal end side of the straight portion  11 A continuously. The outer circumferential surface of the straight portion is rounded to form a substantially column-like shape.  
      Further, the proximal end part of the straight portion  11 A is formed with a male thread  111 . The male thread  111  is adapted to be threaded with a female thread  102  formed in a coupling member  101  of the main body  10  (see  FIG. 4 ). When the male thread  111  is threaded with the female thread  102 , the insertion instrument  11  is mounted to the main body to provide the intubation assistance apparatus  100  in the assembled state.  
      Further, by disengaging the male thread  111  of the straight portion  11 A from the female thread  102  of the main body  10 , the insertion instrument  11  is removed from the main body  10 . Therefore, by removing the insertion instrument  11  which has been used for a patient from the main body  10 , it is possible to attach a new insertion instrument  11  to the main body  10 .  
      As described above, the curved portion  11 B extends from the distal end side of the straight portion  11 A in a continuous manner. The curved portion  11 B is curved so that the distal end thereof is directed to a direction inclined with respect to the straight portion  11 A. The inclined angle θ (see  FIG. 7 ) is not particularly limited, but it is preferably in the range of 70 to 140°, and more preferably in the range of 90 to 120°.  
      By constructing the insertion instrument  11  from the straight portion  11 A and the curved portion  11 B so that the entire shape thereof forms an L-shape, the insertion instrument  11  can be inserted into the mouth of a patient easily to thereby secure an air passage of the patient reliably.  
      Further, on the distal end of the curved portion  11 B, a plate-shaped protruding portion (tongue piece)  112  is integrally formed. The protruding portion  112  is used for pushing up or lifting up the epiglottis or the root of tongue of the patient when securing the air passage of the patient.  
      As shown in  FIG. 6 , on the side portion of the insertion instrument  11 , a groove (guide means)  15  is formed from the midway of the straight portion  11 A to the distal end portion of the curved portion  11 B along the central axis O 1  of the insertion instrument  11 . This groove  15  has a function of guiding or leading an intubation tube  200  which is inserted from the mouth of a patient to the trachea of the patient after the air passage thereof has been secured by the insertion instrument  11 .  
      In more details, the intubation tube  200  is inserted into the groove  15  as shown in  FIG. 2  after the air passage of the patient has been secured, and then advanced toward the distal end of the insertion instrument  11 . At this time, the intubation tube  200  is slidably advanced within the groove  15  with being guided by the inner wall of the groove. Then, the distal end of the intubation tube  200  protrudes from the distal end of the insertion instrument  11  and further advanced toward the rima glottidis or its vicinity of the patient which is located back of larynx thereof.  
      In this regard, it is to be noted that the cross-section of the groove  15  shown in the drawings has a substantially C-shape, but the cross-sectional shape there of is not limited thereto and it may be formed into a U-shape.  
      Further, it is preferred that the width (maximum width) of the groove  15  is set to be slightly larger than the outer diameter of the intubation tube  200 . This makes it possible that the intubation tube  200  is stably held within the groove  15 , that is, the intubation tube  200  can be smoothly advanced within the groove  15 .  
      As shown in  FIGS. 4 and 7 , a first internal bore  12 A is formed inside the insertion instrument  11  along the central axis O 1  of the insertion instrument  11 . The first internal bore  12 A has a substantially circular cross-section.  
      As shown in  FIG. 4 , the first internal bore  12 A is opened at the proximal end of the insertion instrument  11  (that is, the straight portion  11 A), and closed at the distal end of the insertion instrument  11  (that is, the curved portion  11 B). In this regard, it is to be noted that a blockage portion for closing the distal end of the internal bore  12 A is formed into a substantially transparent portion.  
      Inside the first internal bore  12 A, there are provided a bundle of optical fibers  13 A which constitutes a part of the image taking means and an objective lens  13 B which is located in front of the bundle of optical fibers  13 A.  
      Further, a second internal bore  12 B having a diameter smaller than the diameter of the first internal bore  12 A is also formed inside the insertion instrument  11 . The second internal bore  12 B is formed along the central axis O 1  of the insertion instrument  11  in the same manner as the first internal bore  11 A. In other words, the second internal bore  12 B is arranged in parallel with the first internal bore  12 A.  
      Both the ends of the second internal bore  12  are opened at the proximal and distal ends of the insertion instrument  11 , respectively, that is, the second internal bore  12 B is formed into a through hole. By using such a second internal bore  12 B, it is possible to aspirate substances inside the air passage, for instance, by means of a suction means such as a pump (not shown in the drawings) connected to the intubation assistance apparatus  100  in the assembled state.  
      The constituent material of the insertion instrument  11  is not particularly limited, but various polymer materials such as polycarbonate and the like are preferably used.  
      As shown in FIGS.  1  to  3  and  5 , the main body  10  includes a grip section  103 , a display  20 , a coupling portion  104  for coupling the grip section  103  to the display  20 , and a coupling member  101 .  
      The grip section  103  is a portion of the intubation assistance apparatus  100  which is to be grasped by an operator with his one or both hands when the intubation assistance apparatus  100  in the assembled state is actually used (see  FIG. 3 ). Note that  FIG. 3  shows a state that the grip section  103  is grasped by an operator with his one hand.  
      The outer profile of the grip section  103  has a roughly column-like shape. Due to this shape, it is possible to grasp the grip section  103  easily and reliably, whereby enabling the insertion instrument  11  to be inserted into the trachea of a patient easily and reliably by manipulating the intubation assistance apparatus  100  in the assembled state.  
      On the distal end portion of the grip section  103 , the coupling member  101  is mounted so that the coupling member  101  is rotatable about the central axis O 2  of the main body  10  (the grip section  103 ). The coupling member  101  is formed from an annular member.  
      Further, as described above, the female thread  102  is formed on the inner circumferential surface of the coupling member  101 . As shown in  FIG. 4 , the female thread  102  is adapted to be threaded with the male thread formed on the proximal end portion of the insertion instrument  11 .  
      On the proximal end portion of the grip section  103 , the coupling portion  104  is provided so as to extend from the grip section  103 . The display  20  is provided on the coupling portion  104 .  
      As shown in  FIGS. 1 and 2 , the display  20  is provided on the coupling portion  104 , that is, on the proximal end portion of the main body  10 .  
      The display  20  is formed into a plate-like shape having a rectangular outer peripheral shape, and includes a screen  21  for displaying an electronic image taken by the image taking means  70  in the assembled state of the intubation assistance apparatus  100 .  
      The screen  21  is constructed from a liquid crystal device or an organic EL device or the like, and displays an image (electronic image) based on image light taken by the image taking means  70 . The screen  21  also has a rectangular shape corresponding to the rectangular outer peripheral shape of the display  21 .  
      The display  20  is rotatably supported on the main body  10  through a rotational mechanism  30  with one of the short sides  212  of the screen  21  being used as a rotation axis thereof. As a result, the display  20  is rotatable with respect to the main body  10  along a plane extending from the side surface  105  of the main body  10 .  
      Specifically, the display  20  is rotatable between a first position where the display  20  makes contact with the main body  10  (this position of the display  20  is shown by a solid line in  FIGS. 1 and 2 ) and a second position where the display  20  is far away from the main body  10  (this position of the display  20  is shown in a two-dot chain line).  
      The rotational mechanism  30  may be constructed so that the display  20  is stopped at each of the first and second positions. Alternatively, the rotational mechanism  30  may be constructed so that the display  20  can be stopped at any desired position between the first and second positions in a nonstep manner, or so that the display  20  can be stopped at one of the predetermined positions (e.g. one of five steps) between the first and second positions in a stepwise manner.  
      As described above, since the display  20  is rotatable with respect to the main body  10 , it is possible to direct the display  20  to a desired direction despite the direction of the insertion instrument  11  in the assembled state of the intubation assistance apparatus  100 . As a result, an operation for inserting the insertion instrument  11  into a patient (hereinafter, this operation will be simply referred to as “insertion operation”) can be carried out easily and reliably. Further, since the insertion operation can be carried out without bending the cervical region of a patient rearwardly, high safeness can be realized.  
      Further, normally, during the insertion operation of the intubation assistance instrument  11  into the trachea of a patient, the direction and posture of the intubation assistance instrument  11  is changed or rotated variously. According to the present embodiment, by rotating the display  20  to an appropriate angle during the insertion operation, it is possible to monitor the display  20  at an optimum angle.  
      As shown in  FIG. 5 , the intubation assistance apparatus  100  of the present invention is configured so that the screen  21  is inclined with respect to the central axis O 2  of the insertion instrument  11  even when the display  20  is in its first position. Therefore, though depending on the posture of the operator during the insertion operation, it is possible to direct the display  20  to the operator without rotating the display  20  during the insertion operation. Namely, the display  20  can be monitored easily during the insertion operation.  
      Next, a description will be made with regard to the image taking means  70 .  
      The image taking means  70  shown in  FIG. 4  is provided to take an image of an observation site where the distal end of the insertion instrument  11  is positioned as an electronic image. The image taking means  70  includes an image guide  13 , an enlargement optical system  17 , a CCD (image pick-up device), and a controller  18 , and these components are arranged in this order along the longitudinal direction of the insertion instrument  11 .  
      In the assembled state, the image guide  12  is arranged inside the first internal bore  12 A. The image guide  13  is composed from a bundle of optical fibers  13 A and an objective lens  13 B provided in front of the bundle of optical fibers  13 A.  
      The image guide  13  takes reflected light (image light) reflected from the observation site where the distal end of the insertion instrument  11  is positioned through the objective lens  13 B, and the thus obtained image light (image of an object) is transmitted to the CCD through the bundle of optical fibers  13 A. With this structure, when the air passage of the patient is secured by the insertion instrument  11 , it is possible to acquire image light (electronic image) of the rima glottidis or its vicinity (that is, a region from the larynx to the rima glottidis) of the patient.  
      Namely, in this embodiment the image guide  13  constitutes means for leading image light of an observation site (image of an object) to the image pick-up device.  
      The bundle of optical fibers  13 A is constructed by bundling a number of optical fibers made of quartz, multi-component glass, plastics or the like.  
      The CCD  16  is provided inside the main body  10 . In the main body  10 , the CCD  16  is disposed at a position facing the proximal end of the image guide in the assembled state of the intubation assistance apparatus  100 , and an image is formed thereon based on the image light acquired by means of the image guide  13 . Namely, an image of the observation site where the distal end of the insertion instrument  11  is positioned is formed by the CCD  16 .  
      The enlargement optical system  17  is composed from magnifying lenses  17 A and  17 B and a diaphragm  17 C, and the enlargement optical system  17  is arranged between the proximal end of the image guide  13  and the CCD  16 . With this arrangement, an image based on the image light is formed on the CCD  16  with being enlarged. Note that the enlargement optical system that can be used in this embodiment is not limited to the optical system described above.  
      The controller  18  for displaying the electronic image on in the display  20  (on the screen  21 ) is also provided inside the main body  10 . The screen  21  of the display  20  displays the electronic image formed by the CCD  16  under the control of the controller  11 .  
      Examples of the image that is to be displayed on the screen  21  of the display  20  include an image showing the rima glottides of a patient in a state that the air passage of the patient is secured by the insertion instrument  11 .  
      Next, a description will be made with regard to an intubation tube  200  that is used in combination with the intubation assistance apparatus  100 .  
      As shown in  FIG. 8 , the intubation tube  200  is composed from a tube main body  201  and a connector  202  affixed to one end portion of the tube main body  201 .  
      The tube main body  201  is made of an elastic material such as elastomer, rubber and the like. Further, the tube main body  201  has a substantially circular cross-section.  
      The connector  202  is used by being connected to a respirator when artificial respiration is carried out using the respirator. By using the intubation tube  200  having the above structure, it is possible to feed air into the trachea of a patient from the respirator with the state that the intubation tube  200  is being inserted into the trachea of the patient.  
      Hereinbelow, a description will be made with regard to the steps for assembling the intubation assistance apparatus  100 .  
      In assembling the intubation assistance apparatus  100 , the proximal end of the image guide  13  (bundle of optical fibers  13 A) is first connected to the main body  10 .  
      Thereafter, the image guide  13  which has been connected to the main body  10  is inserted into the first internal bore  12 A of the insertion instrument  11 .  
      Next, the male thread  111  of the insertion instrument  11  is threaded with the female thread  102  of the main body  10 . In this regard, it is to be noted that the method for coupling the insertion instrument  11  to the main body  10  is not limited to the method mentioned above, and other various methods can be employed. Examples of such methods include a ratchet mechanism method, a bayonet mounting method, a cam method, a locking claw method and a magnetic method.  
      In the intubation assistance apparatus  100  assembled as described above, the center C of the screen  21  is located on (coincided with) the central axis O 1  of the insertion instrument  11  and further the central axis O 3  of the screen  21  which is in parallel with the long side of the rectangular screen  21  is also located on the central axis O 1  of the insertion instrument  11  regardless of the rotation angle of the display  20 , when the display  20  is viewed from the side of the screen  21 .  
      For example, as shown in  FIG. 3 , in the case where the display  20  is in the first position, the center C of the screen  21  is located on the central axis O 1  of the insertion instrument  11  and further the central axis O 3  of the screen  21  is also located on the central axis O 1  of the insertion instrument  11 , when the display  20  is viewed from the direction of the arrow A in  FIG. 1 .  
      Further, even in the case where the display  20  is in the second position, the center C of the screen  21  is located on the central axis O 1  of the insertion instrument  11  and further the central axis O 3  of the screen  21  is also located on the central axis O 1  of the insertion instrument  11 , when the display  20  is viewed from the side of the screen  21 .  
      Furthermore, even in the case where the display  20  is in the arbitral position between the first and second positions, the center C of the screen  21  is located on the central axis O 1  of the insertion instrument  11  and further the central axis O 3  of the screen  21  is also located on the central axis O 1  of the insertion instrument  11 , when the display  20  is viewed from the side of the screen  21 .  
      As described above, since the display  20  is arranged so that the center C of the screen  21  is located on the central axis O 1  of the insertion instrument  11 , the dislocation of the center C of the screen  21  from the central axis O 1  of the insertion instrument  11  which is involved by the prior art intubation assistance apparatus described above can be overcome. As a result, it is possible for an operator to manipulate the insertion instrument  11  (that is, the intubation assistance apparatus  100 ) on the basis of the visual recognition of the operator for the image displayed on the screen  21  during the insertion operation.  
      Further, in this embodiment, when the insertion instrument  11  (that is, the intubation assistance apparatus  100 ) is manipulated, the insertion instrument  11  is pivotally displaced with the grip section  103  grasped by an operator being a center of the pivotal motion (which is shown by the arrow C in  FIG. 1 ). As a result, the distal end of the insertion instrument  11  is also pivotally swung in a substantially predetermined direction. Therefore, the image displayed on the screen  21  moves roughly along the central axis O 1  of the insertion instrument  11  (that is, along top and bottom directions in  FIG. 3 ). In this embodiment, since the display  20  is arranged so that the central axis O 3  of the screen  21  is located on the central axis O 1  of the insertion instrument  11 , it is possible to widen a region (that is, an observation region or a field of view) in the direction (that is, top and bottom directions in  FIG. 3 ) along which the image displayed on the screen  21  can move rather than a region in the direction (that is, left and right directions in  FIG. 3 ) along which the image displayed on the screen  21  can hardly move. As a result, the manipulability of the intubation assistance apparatus  100  during the insertion operation can be made excellent.  
      Further, as shown in  FIGS. 1 and 2 , in the assembled state of the intubation assistance apparatus  100 , the distal end portion of the insertion instrument  11  (that is, the distal end portion of the curved portion  11 B) is directed to a direction which is substantially in parallel with a normal line of the screen  21  of the display  20  at the first position thereof.  
      With this structure, since the direction in which the observation site can be seen through the objective lens  13 B is substantially the same as the direction through which the operator monitors the screen  21  of the display  20 , the operator can manipulate the intubation assistance apparatus  100  based on the image displayed on the screen  21  of the display  20 . Further, according to this embodiment, the intubation assistance apparatus  100  in the assembled state has a roughly straight configuration, and therefore when the intubation assistance apparatus  100  is placed on a table (not shown in the drawings), the intubation assistance apparatus  100  can be placed on the table in a stable manner.  
      Furthermore, the intubation assistance apparatus  100  may be provided with a direction regulating means for regulating the coupling direction of the insertion instrument  11  with respect to the main body  10  so that the distal end portion of the insertion instrument  11  in the assembled state is directed to a direction which is substantially opposite to the direction that the screen  21  of the display  20  faces at the first position thereof. The structure of such regulating means is not limited to a specific one, but as one examples thereof, it is possible to mention a structure in which a rib-shaped convex portion (guide pin) is formed on the distal end surface of the grip section  103  and a concave portion (guide hole) is formed on the distal end surface of the insertion instrument  11  so that the convex portion is engaged with the concave portion in the assembled state of the intubation assistance apparatus  100 .  
      As shown in  FIGS. 1 and 3 , in the assembled state of the intubation assistance apparatus  100 , the central axis O 2  of the grip section  103  of the main body  10  is located on the central axis O 1  of the insertion instrument  11 . With this structure, since the hand of the operator who grasps the grip section  103  is positioned near the lower part of the display  21 , it is possible to manipulate the insertion instrument  11  accurately.  
      Next, a description will be made with regard to one exemplary use (operation) of the intubation assistance apparatus  100  in the assembled state.  
      The intubation assistance apparatus  100  is used in such an instance that a patient has lost consciousness and a need exists to insert the intubation tube  200  into the trachea of the patient.  
      [1] First, the intubation assistance apparatus  100  is assembled in preparation for insertion of the intubation tube  200 , and then confirmation is made as to whether or not the LED for illumination (not shown in the drawings) and the liquid crystal image are properly operated.  
      [2] Next, the insertion instrument  11  of the intubation assistance instrument  100  is inserted (pushed) into the trachea of the patient through the mouth of the patient. More specifically, the insertion instrument  11  is inserted into the mouth of the patient, while allowing the inner side of the curved portion  11 B of the insertion instrument  11  to extend along the root of the tongue. As a result, an appropriate area on the distal end side of the insertion instrument  11  is brought into contact with the tongue root portion of the patient, thus securing an air passage of the patient.  
      As described above, in the intubation assistance instrument  100  of the present invention, since the display  20  is arranged so that the center C of the screen  21  is located on the central axis O 1  of the insertion instrument  11 , it is possible for an operator to manipulate the insertion instrument accurately with monitoring the screen  21  of the display  20 , and thus it is possible to insert the insertion instrument  11  into the trachea of the patient reliably.  
      Further, as described above, the display is provided on the main body  10  in a rotatable manner. Although the direction and posture of the insertion instrument  11  is changed or rotated variously during the insertion operation of the insertion instrument  11  into the trachea of a patient, it is possible to monitor the display  20  at an optimum angle by rotating the display  20  to an appropriate angle during the insertion operation.  
      Furthermore, as described above, the image displayed on the screen  21  moves roughly along the central axis O 1  of the insertion instrument  11  during the insertion operation of the insertion instrument  11 . However, since the display  20  is arranged so that the central axis O 3  is located on the central axis O 1  of the insertion instrument  11 , it is possible to monitor the image being displaced in the screen  21  over a relatively wide region along the moving direction of the image. This also makes it possible to carry out the insertion operation of the insertion instrument  11  easily.  
      [3] Once the air passage is secured by the distal end of the insertion instrument  11 , an image of the rima glottidis and its vicinity of the patient (that is, the observation site) is taken  
      [4] Then, data of the image of the object obtained in the previous step is sent to the display  20  through the controller  18 , and an electronic image of the rima glottidis and its vicinity of the patient is displayed on the screen  21  of the display  20 .  
      [5] Then, the intubation tube  200  is inserted into the groove  15  from the proximal end portion of the insertion instrument  11  and continues to be pushed forward. In this process, the intubation tube  200  is guided by the groove  15  and advanced or moved forward along the groove  15  to protrude out of the groove  15  at the distal end of the insertion instrument  11 . Observing the image displayed on the screen  21  (including the image of the distal end portion of the intubation tube  200 ), the operator inserts the distal end portion of the intubation tube  200 , which protrudes from the groove  15 , into the rima glottidis so that it can reach the trachea.  
      [6] Under the state that the intubation tube  200  remains inserted into the trachea, the intubation tube  200  is deformed and detached from the groove  15 . While maintaining this condition, the insertion instrument  11  is removed or taken out from the mouth of the patient so that only the intubation tube  200  remains being inserted into the mouth of the patient.  
      In the manner as described above, the intubation tube  200  can be intubated into the trachea of the patient.  
      In this regard, it is to be noted that in general the proximal end of the intubation tube  200  is connected to an artificial respirator, and air is fed into the trachea of a patient from the respirator through the intubation tube  200  which is inserted into the trachea of the patient through the rima glottidis thereof.  
     Second Embodiment  
       FIG. 9  is a perspective view which shows a second embodiment of an intubation assistance apparatus according to the present invention, and  FIG. 10  is a perspective view of a main body of intubation assistance apparatus shown in  FIG. 9 .  
      Hereinbelow, the second embodiment of the intubation assistance apparatus according to the present invention will be described based on these drawings, but the description will focus on the different portions from the first embodiment and a description on the common portions is omitted.  
      The structure of the second embodiment is the same as that of the first embodiment excepting that the arrangement of the display with respect to the main body is different that of the first embodiment.  
      As shown in  FIGS. 9 and 10 , in the intubation assistance apparatus  100 A of the second embodiment, the display  20 A is fixedly mounted on the proximal end portion of the main body  10 . The position in which the display  20 A is fixedly mounted may be the same position as the first position of the display  20  of the first embodiment.  
      Therefore, in substantially the same manner as the fist embodiment, the center C of the screen  21  is located on the central axis O 1  of the insertion instrument  11  and further the central axis O 3  of the screen  21  which is in parallel with the long side of the rectangular screen  21  is also located on the central axis O 1  of the insertion instrument  11 , when the display  20 A is viewed from the side of the screen  21  in the assembled state of the intubation assistance apparatus  100 A.  
      As described above, since the display  20 A is arranged so that the center C of the screen  21  is located on the central axis O 1  of the insertion instrument  11 , the dislocation of the center C of the screen  21  from the central axis O 1  of the insertion instrument  11  which is involved by the prior art intubation assistance apparatus described above can be overcome due to the same reasons as the first embodiment. As a result, it is possible for an operator to manipulate the insertion instrument  11  (that is, the intubation assistance apparatus  100 A) on the basis of the visual recognition of the operator for the image displayed on the screen  21  during the insertion operation. Further, it is also possible to prevent erroneous manipulation. For example, it is possible to prevent the insertion instrument  11  from being manipulated toward improper directions or from being moved excessively.  
      Further, as is the same with the first embodiment described above, when the insertion instrument  11  (that is, the intubation assistance apparatus  100 A) is manipulated, the insertion instrument  11  is pivotally displaced with the grip section  103  grasped by an operator being a center of the pivotal motion. As a result, the distal end of the insertion instrument  11  is also pivotally swung in a substantially predetermined direction. Therefore, an image displayed on the screen  21  is displaced roughly along the central axis O 1  of the insertion instrument  11 . In addition, since the display  20 A is arranged so that the central axis O 3  of the screen  21  is located on the central axis O 1  of the insertion instrument  11 , it is possible to widen a region (that is, an observation region or a field of view) in the direction along which the image displayed on the screen  21  can move rather than a region in the direction along which the image displayed on the screen  21  can hardly move. As a result, the manipulability of the intubation assistance apparatus  100 A during the insertion operation can be made excellent.  
      Furthermore, the screen  21  of the display  21 A is inclined with respect to the central axis O 1  of the insertion instrument  11 . Therefore, though depending on the posture of the operator during the insertion operation, it is possible to direct the display  20 A to the operator during the insertion operation. Namely, the display  20 A can be monitored easily during the insertion operation.  
      While the intubation assistance apparatus of the present invention has been described hereinabove in respect of the illustrated embodiments, this is not intended to limit the scope of the present invention. Instead, each component or element of the intubation assistance apparatus may be replaced with other one that exhibits the same or similar function. Furthermore, other arbitrary components than disclosed above may be added thereto.  
      Finally, it is also to be understood that the present disclosure relates to subject matters contained in Japanese Patent Applications No. 2005-309152 filed on Oct. 24, 2005 and 2006-202369 filed on Jul. 25, 2006 which are expressly incorporated herein by reference in their entireties.