JP2008228783A - Laryngoscope - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laryngoscope easily spreading a larynx with less force compared to conventional laryngoscope, securing a visual field of a laryngeal part, and facilitating intubation in a respiratory tract. <P>SOLUTION: The laryngoscope 1 has a blade 10 having a curved portion 20, the curved portion 20 has a first concave curved portion 21 curved along a first curved line E1 curved in one direction, a second concave curved portion 22 curved along a second curved line E2 curved in the same direction as the above direction, and a convex curved portion 23 curved along a third curved line E3 curved in a reverse direction of the above direction in series from the proximal end P to the distal end D of the blade 10, ratio of a segment length d1 between both the ends of the first curved line E1 relative to the curved line length e1 of the first curved line E1 is larger than the ratio of a segment length d2 between both the ends of the second curved line E2 relative to the curved line length e2 of the second curved line E2, the segment length d1 of the first curved line E1 is longer than the segment length d2 of the second curved line E2, and the segment length d2 of the second curved line E2 is longer than the segment length d3 between both the ends of the third curved line E3. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a laryngoscope that performs laryngeal deployment to perform tracheal intubation, pharyngeal or laryngeal foreign body removal, and in particular, in the case of unexpected intubation difficulties, the larynx can be operated with less force than conventional laryngoscopes. The present invention relates to a laryngoscope that can be easily deployed.

  Traditionally, rigid laryngoscopes have been used to expose the glottis to the anesthesiologist's operator's field of view when inserting a tracheal tube into the trachea or removing foreign objects attached to the pharynx or larynx. Yes. The basic design concept of such a laryngoscope is a curved laryngoscope developed by Macintosh and a direct laryngoscope developed by Miller. For example, as shown in FIG. 7, the Macintosh laryngoscope 70 mainly includes a blade 71, a handle 76 connected to the blade 71, and a light source 77 that irradiates the tip direction of the blade 71 (for example, Patent Document 1). Further, the blade 71 includes a curved portion 72 called a spatula curved along a monotonous curve, and a flange 73 extending from one edge along the curved portion of the curved portion 72.

  Using such a Macintosh laryngoscope 70, the operator grasps the handle 76 and inserts the blade 71 from the patient's mouth. Then, the operator guides the distal end of the bending portion 72 between the base of the tongue and the epiglottis (the epiglottis valley) while pushing the tongue with the flange 73 of the blade 71 so as to hold the patient's tongue on the left side. The tongue base is lifted secondarily by pushing up the tongue base toward the front of the patient while pressing the curved surface of the tongue toward the front of the patient to perform pharyngeal deployment.

  As another laryngoscope, a McCoy laryngoscope 80 as shown in FIG. 8 may be used. The McCoy-type laryngoscope 80 mainly includes a blade 81, a handle 86, and a light source 87 that irradiates the tip of the blade 81, like the Macintosh laryngoscope described above. The blade 81 is called a spatula. A curved portion 82 and a flange 83 are provided. Furthermore, for the purpose of performing the laryngeal deployment more reliably, as shown in FIG. 8, in the McCoy laryngoscope 80, the blade distal end portion 84 pivots toward the proximal end side of the blade 81 by the lever operation of the operator. It is configured as follows.

JP 2005-46565 A

  However, if the soft tissue around the patient's cervical larynx is less flexible or movable (soft tissue abnormality), even if the curved surface is pressed against the tongue base using a Macintosh laryngoscope, May not be pushed up well, and laryngeal deployment may not be sufficient. As a result, it became difficult to insert the tracheal tube into the trachea, and there was a risk of damaging the larynx. Further, using a Macintosh type laryngoscope to press the tongue base until the epiglottis is lifted (deployed in the larynx), the operator requires a great deal of force and advanced technical training.

  On the other hand, when the McCoy type laryngoscope is used, the blade tip is pivoted toward the proximal end as compared with the Macintosh type laryngoscope, so that the tongue base can be locally compressed. However, when there is a soft tissue abnormality as described above, even if the blade tip is turned by lever operation, the tongue base cannot be pushed up as well as the Macintosh laryngoscope. In addition, when the McCoy laryngoscope is used, the blade end may block the operator's field of view after turning the blade tip, and even if the airway is secured by deploying the larynx, it is difficult to confirm the airway and it works well. In some cases, the tube could not be intubated.

  The present invention has been made in view of such a problem, and the object of the present invention is that even if the patient has a decrease in flexibility and mobility of soft tissue around the neck or larynx. It is an object of the present invention to provide a laryngoscope capable of performing laryngeal deployment with a smaller force than that of other laryngoscopes, ensuring a good visual field by the laryngeal deployment, and easily performing tracheal intubation.

  As a result of intensive studies to solve the above-mentioned problems, the present inventor has found that a patient with the soft tissue abnormality has an absolute or relatively larger tongue base than a normal patient. As a laryngoscope that compresses the tongue base more effectively, a laryngoscope that specifies the shape of the curved part of the laryngoscope using a plurality of curves so as to move the tongue base along the direction of such muscle fibers. By using it, the tongue base can be pushed up well, and the new knowledge that laryngeal deployment can be performed easily was obtained.

  The present invention is basically based on the above-mentioned new knowledge, the laryngoscope according to the present invention is a laryngoscope having a blade having at least a curved curved portion, the curved portion, A first concave curved portion that curves along a first curve curved in one direction, a second concave curved portion that curves along a second curve curved in the same direction as the direction, and a direction opposite to the direction A curved portion that curves along the curved third curve, sequentially from the proximal end of the curved portion of the blade to the distal end of the curved portion, and the first curved line has a length corresponding to the curved length of the first curved line. The ratio of the line segment length between both ends is larger than the ratio of the line segment length between both ends of the second curve to the curve length of the second curve, and the line segment length of the first curve is The line length of the second curve is longer than the length of the line segment of the second curve, and the length of the line segment of the second curve is the third curve. It is characterized in longer than the line length across.

  The laryngoscope configured in this way has a first concave curved portion, a second concave curved portion, and a convex curved portion that satisfy the above-mentioned relationship in order, thereby arranging the tongue base in the oral cavity along the direction of the muscle fiber of the tongue base. And the tongue base can be easily pushed up. As a result, the laryngeal visual field can be easily secured.

  Specifically, the laryngoscope includes a convex curved portion that curves along a third curve curved in a direction opposite to the curved direction of the first concave curved portion and the second concave curved portion, thereby The tongue base can be pressed on the surface of the convex curve so that the tongue base can move along the muscle fibers. Furthermore, the ratio of the line segment length between the two ends of the first curve to the curve length of the first curve is made larger than the ratio of the line segment length between the both ends of the second curve to the curve length of the second curve. That is, by curving the second curve to a greater extent than the first curve, the tongue base pressed by the convex curve portion can be moved to the space formed by the curvature of the second concave curve portion. As a result, the tongue can be securely pressed with a smaller force than when a conventional laryngoscope is used, and the pharynx can be easily deployed. Intubation is possible.

  Further, the line segment length between both ends of the first curve is longer than the line segment length between both ends of the second curve, and the line segment length between both ends of the second curve is between the both ends of the third curve. By making it longer than the line segment length, a curved portion matched to the shape of the tongue can be obtained.

  In the laryngoscope according to the present invention, it is more preferable that the tip portion of the blade including the convex curved portion is branched into two, and a smooth raised portion is formed at each branched tip portion. Examples of the shape of the smooth raised portion include a streamline shape, a circular shape, an elliptical shape, and a dome shape, and a streamline shape is particularly preferable. The laryngoscope having the raised shape as described above can lift the epiglottis more efficiently by pressing the tongue base. That is, the laryngoscope has a bifurcated valley at the tip of the laryngoscope between the tongue base and the epiglottis by bifurcating the tip of the blade including the convex curved portion into two. The tip of the blade can be guided and placed at an appropriate position to enter the hyoid epiglottis ligament. Further, by forming a streamlined bulge at each tip of the blade, the frictional force of the tongue and oral mucosa can be reduced when the blade is inserted, and tissue damage can be suppressed. In addition, the epiglottis mucous membrane is formed between the tongue base and the epiglottis (the epiglottis valley), and by providing a streamlined ridge, the contact area of the convex curve with the epiglottis mucosa is increased. It becomes possible. As the degree of mucous membrane tension increases due to the increase in the contact area, the larynx can be lifted more efficiently when the tongue base is pushed up while pressing the blade against the tongue base, and the larynx can be easily deployed.

In the laryngoscope according to the present invention, the angle at the base point between the straight line connecting the two end points of the first curve and the curve connecting the two end points of the first curve is considered in consideration of mechanical rationality and operability. It is preferable that the angle is approximately 10 °, and a first extension line extending a line segment between both end points of the first curve, a first extension line extending from the end point of the first curve, and a tip of the bending portion are extended. More preferably, the angle at which the two extension lines intersect is at least an acute angle and in the range of 38 to 42 °.
The laryngoscope configured in this way can easily move the tongue base along the direction of the muscle fiber of the tongue base, and lift (press) the tongue and epiglottis even in patients with the soft tissue abnormality The larynx can be deployed. When the angle is smaller than 38 °, it is difficult to sufficiently press the tongue base. When the angle is larger than 42 °, the entire curved portion is too large to be suitably guided from the blade tip to the epiglottis.

The laryngoscope according to the present invention includes _an intersection _{of a perpendicular from the distal end of the curved portion with respect to a first extension line obtained by extending a line segment between both end points of the first curve and the first extension line, and} a tip of the first curve. The second line segment length is 0.62 ± 0 of the line segment length of the first curve when the line segment length between the end point on the side is the second line segment length More preferably, it is 0.03 times. The laryngoscope configured in this way has a so-called golden ratio, so that the operator can more naturally see the curvature of the laryngoscope and easily insert it into the oral cavity.

  According to the laryngoscope of the present invention, even a patient with soft tissue abnormality in the tissue of the neck or anterior neck can perform laryngeal deployment with a smaller force than conventional laryngoscopes. Furthermore, sufficient laryngeal deployment ensures a good field of view for airway confirmation and can be easily intubated.

  Hereinafter, embodiments of the laryngoscope according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a perspective view of a laryngoscope according to the present embodiment. 2 is a side view of the laryngoscope viewed from the line II-II in FIG. 1, and FIG. 3 is a diagram showing a curve serving as a base of the shape of the bending portion in the side view of the laryngoscope in FIG. is there. 4 is an enlarged view showing the tip of the blade of the laryngoscope shown in FIG. 1, where (a) is a top view of the tip, and (b) is a view taken along the line BB in FIG. FIG.

  As shown in FIG. 1, the laryngoscope according to the present embodiment mainly includes a blade 10, a handle 50 connected to the blade 10, and a light source 30 that irradiates the tip direction of the blade 10. Further, the blade 10 includes a bending portion 20 called a spatula curved along a curve obtained by combining a plurality of curves to be described later, and a flange 40 extending from one edge portion along the curved curve of the bending portion 20. ing.

  As shown in FIGS. 2 and 3, the curved portion 20 of the blade 10 includes a first concave curved portion 21, a second concave curved portion 22, and a convex curved portion 23, and the curved portion extends from the curved portion proximal end P of the blade. These portions 21 to 23 are formed toward the tip D. The first concave curved portion 21 is curved along a first curve E1 curved in one direction (the direction of the handle 50). The second concave curved portion 22 is curved along a second curve E2 that is curved in the same direction as the bending direction of the first curve E1.

  Furthermore, as shown in FIGS. 2 and 3, the relationship between the first concave curved portion 21 and the second concave curved portion 22 is a line between both ends of the first curve E1 with respect to the curve length el of the first curve E1. The ratio R1 of the segment length d1 is larger than the ratio R2 of the segment length d2 between the both ends of the second curve E2 with respect to the curve length e2 of the second curve E2.

  As shown in FIGS. 2 and 3, the curve length el of the first curve E <b> 1 is the end point (base end of the blade) P of the first curve E <b> 1 constituting the first concave curved portion 21, and the first curve E <b> 1. The curve length of the first curve E1 between the end point A that is the boundary point between the curve E1 and the second curve E2 is referred to, and the line segment length d1 between both ends of the first curve E1 is the first curve E1. The distance between the two end points P and A. Further, the curve length e2 of the second curve E2 refers to the end point A of the second curve E2 constituting the second concave curved portion 22 and the end point B which is a boundary point between the third curve E3 and the second curve E2. The length of the second curve E2 between them is the length of the segment d2 between both ends of the second curve E2, and the distance between the end points A and B of the second curve E2.

  And by satisfy | filling the relationship mentioned above, the 2nd curve E2 will be curved more largely than the 1st curve E1, and the 2nd concave curved part 22 will become a shape curved more largely than the 1st concave curved part 21. FIG. . Further, the end point A is a boundary point between the first curve E1 and the second curve E2, and is an inflection point that connects curves having different shapes.

  The convex curve portion 23 is curved along a third curve E3 that is curved in a direction opposite to the bending direction of the first curve E1 and the second curve E2. Further, as shown in FIGS. 2 and 3, the relationship between the convex curve portion 23 and the second concave curve portion 22 is that the line segment length d2 of the second curve E2 is a line between both ends of the third curve E3. The relationship is longer than the minute length d3.

  Note that, as shown in FIGS. 2 and 3, the line segment length d3 between both ends of the third curve E3 is the end point B that is the boundary point between the third curve E3 and the second curve E2, and the tip of the curved portion ( This is the distance from the end point D. Furthermore, it is preferable that the length of the curved part (spatella) from the curved part front-end | tip (end point) D to the vertex of the convex part of the convex curved part 23 is the range of 10-20 mm. The end point B is a boundary point between the second curve E2 and the third curve E3, and is an inflection point connecting the curves E2 and E3 having two different shapes. In addition, it is preferable that an angle δ formed by the base end point P between the straight line connecting the two end points P and A of the first curve and the curve e1 connecting the two end points P and A of the first curve is about 10 °.

  Further, as shown in FIGS. 1 and 4A and 4B, the tip portion 11 of the blade 10 including the convex curved portion 23 is branched into two, and each branched tip portion 11a has a streamline shape. The raised portion 12 is formed. Further, as shown in FIG. 4A, the length n of the raised portion 12 in the direction along the bending portion distal end D from the bending portion proximal end P of the bending portion 20 is in the range of 8 to 10 mm, and the distal end portion It is more preferable that the valley depth q from the bent portion tip to the valley portion 11b due to the branching of 11 is in the range of 2 to 4 mm, and the distance r between the centers of the two raised portions 12 is in the range of 5 to 10 mm. Moreover, as shown in FIG.4 (b), the peak height t of the curved part 20 to the protruding part 12 is the range of 2-4 mm, and the valley height u of the curved part 20 to the raised part 12 is the range of 1-2 mm. More preferably.

  Further, as shown in FIGS. 2 and 3, the relationship from the first curve to the third curve constituting the bending portion 20 is as follows: a first extension line L1 that extends a line segment between both end points of the first curve E1, and The angle θ at which the end point A on the distal end side of the first curve E1 intersects with the second extension line L2 extending from the bending portion distal end D is at least an acute angle in the range of 38 to 42 °.

  As shown in FIGS. 2 and 3, the relationship from the first curve E1 to the third curve E2 constituting the bending portion 20 is that the perpendicular VL from the bending portion tip D to the first extension line L1 and the first curve The line segment length between the intersection point X with the extension line L1 and the bending portion tip D is defined as a first line segment length d4, and between the intersection point X and the end point A on the tip side of the first curve E1. The second line segment length d5 is 3 to 7 mm longer than the first line segment length d4. The first line segment length d4 is more preferably 15 to 45 mm, and the second line segment length d5 is more preferably 18 to 52 mm in consideration of the relationship of the lengths. Further, the second line segment length d5 is 0.62 ± 0.03 times the line segment length d1 of the first curve.

  Hereinafter, the laryngeal deployment using the laryngoscope according to the present embodiment will be described with reference to FIGS. 5 and 6 and FIG. 2 described above.

  First, the operator grasps the handle 50 and inserts the blade 10 through the patient's mouth. Next, while pushing the tongue with the flange 73 of the blade 71 so as to hold the patient's tongue on the left side, the bending portion tip D is moved toward the tongue base M, and between the tongue base M and the epiglottis G (the epiglottis valley). The tip portion 11 (curved portion tip D) of the blade 10 is guided.

  At this time, as shown in FIG. 6, the laryngoscope 1 divides the distal end portion 11 of the blade 10 including the convex curved portion 23 into two parts, so that it is between the tongue base M and the epiglottis G (the epiglottis valley). The tip portion 11 of the blade 10 can be guided and arranged at an appropriate position such that the branched valley portion 11b of the tip portion 11 of the laryngoscope 1 enters the hyoid epiglottis ligament H. Further, since the streamlined raised portions 12 are formed at the respective distal end portions 11a of the blade 10, the frictional force between the tongue and the oral mucosa can be reduced when the blade is inserted, and tissue damage can be suppressed. .

  And after arrange | positioning the front-end | tip part 11 of the braid | blade 10 in a predetermined position, by pushing up the tongue base M to the front side of a patient while pressing the curved surface of the curved part 20 against the tongue base M, the epiglottis is lifted secondarily. Perform pharyngeal deployment.

  At this time, by pressing the tongue base M with the surface of the convex curved portion 23 curved along the third curve E3 curved in the direction opposite to the curved direction of the first concave curved portion 21 and the second concave curved portion 22. The tongue base M is easily moved along the muscle fibers of the tongue base M. Further, since the second curve E2 is greatly curved as compared with the first curve E1, the tongue base M pressed by the convex curve portion 23 is moved to the space formed by the curvature of the second concave curve portion 22. be able to.

  Furthermore, as shown in FIG. 6, the angle θ at which the first extension line L1 and the second extension line L2 intersect is an acute angle in the range of 38 to 42 °, and the second line segment length d5 is set to the first line segment. By making the length 3 to 7 mm longer than the length d4, even in patients with the soft tissue abnormality, the tongue base is moved more reliably along the direction of the muscle fiber of the tongue base, and the tongue and epiglottis are lifted (pressed down) ) Easy laryngeal deployment.

  Furthermore, a laryngeal valley mucous membrane m is formed between the tongue base M and the epiglottis G (the epiglottis), and by providing a streamlined ridge 12, the convex portion 23 contacts the epiglottis mucosa m. The area can be increased. Since the tension of the mucous membrane is increased by increasing the contact area, the epiglottis G can be lifted more efficiently when the tongue base M is pushed up while pressing the blade against the tongue base M, and the pharynx can be easily deployed. .

  This embodiment will be described by the following examples.

(Example)
The significance of the present invention was explained for subjects with intubation difficulty and this example was performed after obtaining permission for X-ray photography. As the laryngoscope according to the example, the laryngoscope according to the above embodiment was prepared. Specifically, as a laryngoscope, the ratio of the segment length d1 between both ends of the first curve E1 to the curve length el of the first curve E1 is the second curve E2 with respect to the curve length e2 of the second curve E2. The line segment length d1 is set to 65 mm, the line segment length d2 is set to 42 mm so as to satisfy the relationship greater than the ratio of the line segment length d2 between the both ends of the curved portion, and the convex portion 23 from the bending portion tip (end point) D The length of the curved portion (spatula) to the top of the convex portion is 15 mm, the angle θ is 40 °, the first line segment length d4 is 40 mm, the second line segment length d5 is 45 mm, and the second line segment length d5 Was prepared with a laryngoscope having 0.62 times the line length d1 of the first curve. And the larynx deployment was performed with respect to the test subject, and the radiograph was image | photographed in that case. The subject's Cormack grade (see Cormack, RS & Lehane, J .: Difficult tracheal intubation in obstetrics. Anaesthesia. 39: 1105-1111, 1984) was confirmed. The results are shown in Table 1.

<Evaluation method>
The following measurements were performed from the X-ray photograph.

  Measurement point 1: The angle α at which the extension line between the subject's front teeth and the lower edge of the curved portion of the blade, that is, the operator's line of sight (upper limit of line of sight) AB and the subject's tracheal axis CD intersects was measured (see FIG. 5). ). In addition, it means that intubation to a trachea is easy, so that this angle (alpha) is small.

  Measurement location 2: The angle β between the line connecting the third cervical vertebra C3 and the fourth cervical vertebra C4 and the tracheal axis CD was measured (see FIG. 5). In addition, it means that the mobility of the larynx and the trachea improved, so that this angle (beta) was large.

  Measurement location 3: The distance S1 from the third cervical vertebra C3 to the blade of the laryngoscope was measured (see FIG. 5). The larger this distance S1, the wider the upper limit of the operator's field of view.

  Measurement location 4: The distance S2 from the fourth cervical vertebra C4 to the blade of the laryngoscope was measured (see FIG. 5). The larger this distance S1, the wider the upper limit of the operator's field of view.

  Measurement location 5: The distance from the hyoid bone F to the hypopharyngeal posterior wall K was measured. A wider distance means that the tongue base M and the pharynx N are spread.

Measurement location 6: The opening width of the subject was measured. The smaller this width is, the more the subject has opened the larynx with the mouth opening being small.
The measurement results at these measurement points 1 to 6 are shown in Table 1 below.

(Comparative Example 1)
Using the Macintosh type laryngoscope shown in FIG. 7 (size 3), laryngeal deployment was performed on the same subject. While confirming the subject's Cormack grade, radiography was performed in the same manner as in the example, and measurement locations 1 to 6 were measured from the photograph in the same manner as in the example. The results are shown in the following table.

(Comparative Example 2)
Using the McCoy type laryngoscope (size 3) shown in FIG. 8, the larynx was developed for the same subject. While confirming the Cormack grade of the test subject, X-ray photography was performed in the same manner as in the example, and measurement points 1 to 6 were measured from the photograph in the same manner as in the example. The results are shown in the following table.

(Results and discussion)
<Result 1 and discussion>
From the results in Table 1, the Cormack grade of the example was II, the Comparative Example 1 Cormack grade was III, and the Cormack grade of Comparative Example 2 was IV. From this result, it can be said that when the larynx is deployed using the laryngoscope of the embodiment, the visibility of the larynx is good.

<Result 2 and discussion>
From the result of the measurement location 1, the angle α of the example is smaller than those of the comparative examples 1 and 2. From this, when the laryngoscope of an Example is used, compared with the thing of the comparative examples 1 and 2, it is thought that intubation to a trachea is easy. Further, from the result of the measurement result 2, the angle β of the example is larger than those of the comparative examples 1 and 2. From this, when the laryngoscope of an Example is used, it is thought that the mobility of the larynx and the trachea improved compared with the thing of the comparative examples 1 and 2.

  Also, from the results of measurement results 3 and 4, the distances S1 and S2 of the example are larger than those of comparative examples 1 and 2. From this, when the laryngoscope of an Example is used, compared with the comparative examples 1 and 2, it is thought that the upper limit of an operator's visual field spreads. Further, the distance from the hyoid bone F to the hypopharyngeal posterior wall K of the example is larger than those of Comparative Examples 1 and 2. From this, when the laryngoscope of an Example is used, it is thought that the tongue base M and the pharynx N can be expanded compared with the thing of the comparative examples 1 and 2.

  Furthermore, the opening width of the example is smaller than the opening widths of Comparative Examples 1 and 2 from the result of the measurement location 6. Therefore, when the laryngoscope of the example is used, the field of view of the larynx at the time of laryngeal deployment is compared with those of Comparative Examples 1 and 2, without greatly opening the mouth (see the result of measurement point 6). It is thought that can be expanded.

  In addition, it was confirmed that the laryngeal deployment using the laryngoscope of the example can perform the laryngeal deployment with a smaller force than the laryngeal deployment using the laryngoscope of Comparative Examples 1 and 2. .

The perspective view of the laryngoscope which concerns on this embodiment. The side view of the laryngoscope seen from the II-II arrow line of FIG. The figure which showed the curve used as the base of the shape of the curved part in the side view of the laryngoscope of FIG. It is the enlarged view which showed the front-end | tip part of the blade of the laryngoscope shown in FIG. 1, (a) is a top view of a front-end | tip part, (b) is sectional drawing seen from the BB arrow line of (a). The figure for demonstrating the usage method of the laryngoscope shown in FIG. FIG. 6 is a sectional view taken along the line VI-VI in FIG. 5. The side view of the conventional Macintosh type laryngoscope. The side view of the conventional McCoy type laryngoscope.

Explanation of symbols

  1: laryngoscope, 10: blade, 11: tip of blade, 11a: branched tip, 11b: valley, 12: raised portion, 20: curved portion, 21: first concave portion, 22: second Concave part, 23: Convex part, 40: Flange, 50: Handle, 70: Macintosh type laryngoscope, 71: Blade, 72: Curved part, 73: Flange, 76: Handle, 77: Light source, 80: McCoy type Laryngoscope, 81: Blade, 82: Curved part, 83: Flange, 84: Blade tip, 86: Handle, 87: Light source, AB: Line of sight (upper limit of line of sight), CD tracheal axis, C3: Third cervical vertebra, C4 : Fourth cervical vertebra, E1: first curve, D: tip of curved portion, d1 to d3: length of line segment, d4: length of first line segment, d5: length of second line segment, e1: of first curve Curve length, E2: second curve, e2: curve length of the second curve, E3: Three curves, e3: curve length of the third curve, G: epiglottis, F: hyoid bone, H: hyoid epiglottis ligament, K: posterior wall of hypopharynx, L1: first extension line, L2: second extension line, M: tongue base, m: epiglottis mucosa, N: pharynx, θ: angle of intersection of the first extension line and the second extension line, P: base of the curved portion, X: intersection of the perpendicular and the first extension line, VL: perpendicular

Claims (4)

A laryngoscope (1) comprising a blade (10) having at least a curved bend (20),
The curved portion (20) includes a first concave curved portion (21) curved along a first curve (E1) curved in one direction,
A second concave curved portion (22) curved along a second curve (E2) curved in the same direction as the direction;
A convex curved portion (23) curved along a third curve (E3) curved in a direction opposite to the direction from the curved portion base end (P) of the blade (10) to the curved portion distal end (D). We have sequentially toward
The ratio of the line segment length (d1) between both ends of the first curve (E1) to the curve length (el) of the first curve (E1) is the curve length (e2) of the second curve (E2). ) Greater than the ratio of the segment length (d2) between both ends of the second curve (E2) to
The line segment length (d1) of the first curve (E1) is longer than the line segment length (d2) of the second curve (E2) and the line segment of the second curve (E2). The laryngoscope is characterized in that the length (d2) is longer than the length (d3) between both ends of the third curve (E3).   The tip (11) of the blade (10) including the convex curved portion (23) is branched into two, and a smooth raised portion (12) is formed at each branched tip (11a). The laryngoscope according to claim 1.   A first extension line (L1) obtained by extending a line segment between both end points of the first curve (E1), an end point (A) on the distal end side of the first curve (E1), and a distal end (D) of the bending portion are extended. The laryngoscope according to claim 1 or 2, wherein an angle (θ) at which the second extended line (L2) intersects is at least an acute angle in a range of 38 to 42 °. Intersection of _{a perpendicular (VL) from the distal end (D) of the curved portion with respect to a first extension line (L1) obtained by extending a line segment between both end points of the first curve (E1) and the first extension line (L1)} ( X) and the second segment length (d5) when the segment length between the end point (A) on the tip side of the first curve (E1) is the second segment length (d5) The laryngoscope according to any one of claims 1 to 3, wherein the length (d5) is 0.62 ± 0.03 times the line segment length (d1) of the first curve.

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