JPH0155008B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to an improved laryngoscope.

A laryngoscope is an instrument used in general anesthesia that is used to expose the larynx to the anesthetist's view, and the larynx is illuminated by a lamp built into the laryngoscope. Normally, the laryngoscope is used by holding the tongue in front of the line of sight so that the larynx is clearly visible in the view. (The term "anterior" refers to the front of the patient throughout the specification.) The anesthetist then inserts the distal end of the rubber tube (i.e., known as the endotracheal tube) into the laryngoscope and connects the proximal end with the anesthetic device. Connecting. This rubber tube is used for general anesthesia, when there is a significant amount of blood or other fluid in the pharynx, or when head or neck surgery is being performed, and also for special surgeries. This is preferable when it is necessary to keep the muscles in a relaxed state. In the latter case, it is necessary for the anesthesiologist to be able to periodically inflate the patient's lungs.

Currently used laryngoscopes can be used to widen the larynx and insert a rubber tube if the patient has bony abnormalities in the neck or jaw, or soft tissue abnormalities in the mouth, tongue, or anterior neck tissue. It can be difficult to do. In these cases, the anesthetist is unable to sufficiently manipulate the patient's head to position the patient's head in the "sword swallow" position, and therefore also typically moves the tongue into the line of sight to bring the larynx into view. Unable to hold forward.

If this difficulty exists, it will be a significant disadvantage,
Approximately 5% of adults have such cases, so
Many attempts have been made to solve this. In some cases, surgical techniques such as tracheostomy (surgical opening in the trachea) and direct insertion of an endotracheal tube have been used. Alternative methods include neck puncture or inserting a thin catheter from the larynx to the mouth and then "trajectling" an endotracheal tube over the catheter into the trachea. It was.

Various other modifications have been made to the conventional laryngoscope, with only limited success. These modifications include the use of mirrors and prisms as indirect methods of viewing the trachea. There are generally two types of conventional laryngoscope blades. One is a curved blade that is inserted in front of the epiglottis and is pulled straight forward to expose the larynx. The other is a straight blade that is inserted under the tip of the epiglottis and the tip of the blade pulls up the larynx to expose it. However, while these conventionally used laryngoscope blades can be used effectively in normal adults, they can be difficult to use in the special 5% range of patients mentioned above.

The most widely used curved laryngoscope blade is probably the blade known as the Macintosh blade, which consists of a handle and a horizontal upper flange attached to the upper end of a vertically extending web or vertical element; and a blade with a lower flange extending from the base of the web on the opposite side of the flange. The blade of a machinist is relatively short compared to a long, straight laryngoscope and has a curved surface that forms a pronounced upward curve or concave surface relative to the handle.

Although the machinist's blade often does not visibly expose the entire glottis, it generally exposes enough of the larynx to see the tracheal landmarks and tube insertion site. Furthermore, the curved shape allows for spacing between its proximal end and the upper teeth, thereby reducing the risk of insertion injury. In general, in practice, this occurs in the trachea when a Jackson-type or straight-type laryngoscope is used, even if the tip of the endotracheal tube is placed close to the larynx at an actual angle to the line of the trachea. There is no effect on that.

However, as previously mentioned, in special cases where difficulties arise due to the above-mentioned anomalies in anatomy, the laryngoscope blade of the machining tool may fail for two main reasons.

First, to properly expose the larynx, the blade must be pulled far enough forward to bring the tip, which is located in the sulcus and obscured by the curvature of the blade, far enough in front of the larynx. It must be held out at a sufficient distance from the glottis, which is visible behind the curve of the blade. If the blade cannot be pulled forward to this extent, the ridge or concave curvature of the blade will obscure direct visibility of the larynx.

Next, if it is difficult to expose the larynx, the anesthetist should “lean toward the corners of the mouth” and insert the laryngoscope blade from the upper incisor side, past the palatoglossal arch of the tonsils, and between the tongue and tonsils. must be inserted into the groove. For many patients, the blade is too wide to properly perform this maneuver. The vertical element of the makintoss blade generally holds the tongue to the left side of the mouth, and along this vertical flange or element the electrical connection to the lamp is usually located. In patients with very small mouths and patients with very prominent teeth, this element has been found to be too high for proper insertion of the laryngoscope.

In 1968, Huffman introduced a prism to solve this problem, which was attached to the machine blade with a steel clip. In some cases, the larynx could be seen indirectly through this prism. However, prisms are usually not necessary when direct endotracheal insertion is possible, and prisms are too bulky to allow sufficient room in the mouth for the endotracheal tube, making it difficult for the patient's anatomy to fit. In special cases with abnormalities, laryngoscopy cannot be performed.

In 1956, Cyker created a laryngoscope blade that was angled or V-shaped with a 135° bevel angle. However, the cross-section of this blade was generally C-shaped with an overhanging roof section, so that the larynx could not be seen directly. Psykers suggested using the blade with a mirror, but the laryngoscope proved impractical.

It is therefore an object of the present invention to provide a laryngoscope which alleviates the above-mentioned related problems and which allows viewing of the larynx and its associated structures even in patients with significant anatomical abnormalities.

The laryngoscope blade of the present invention comprises a first straight inner portion and a second straight outer portion, the inner portion and the outer portion forming a V with an included angle of about 135°.
forming a Z-shape, the ratio of the lengths of said inner and outer portions being between 4:5 and 3:4, and the cross-section of the blade being substantially Z-shaped throughout at least a portion of its length, with the Z upright or the diagonal portion is substantially vertical, and the upper arm of the Z is shorter in length than the lower arm, and in use, it is inserted into the patient's mouth and the back side of the distal end of said outer portion is It is characterized in that it is pressed against the epiglottis and moves the epiglottis forward to allow a direct view of the larynx along said outer part.

Preferably, the base of the straight portion of the blade or the portion proximate the handle forms an included angle with the handle of about 90° to 110°, more preferably 105° to 110°.

Thus, it is a great advantage that the use of a blade with a cross section according to the above design eliminates the roof-like overhang included in the overall C-shaped psyker blade.

According to the invention, the prism for attachment to said laryngoscope blade comprises, viewed from the side, a front surface, a top surface and a rear surface, the front surface being inclined rearward at an acute angle with respect to the horizontal plane. the upper surface slopes rearwardly but at a shallower angle to the horizontal plane before merging with the rear surface, the rear surface slopes downwardly from the upper surface, and the rear surface slopes downwardly from the upper surface; The length of the surface is relatively short compared to the top surface, and the rear surface is characterized in that it is longer than the front surface.

Preferably, the prism has a substantially rectangular front surface which slopes rearwardly at an acute angle to the horizontal and then continues via an edge to an upper surface which also slopes rearwardly. forming a rear surface which is inclined but at a shallower angle with respect to the horizontal plane and which subsequently slopes downwardly so that the prism is shaped with a basal or base surface which is preferably substantially horizontal; There is. Furthermore, the substantially planar side faces facing each other are also provided in a suitable shape.

If desired, the prism may have chamfers at the junction of the front surface, top surface, and adjacent side surfaces.

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

The prism 10 shown in FIGS. 1-3 has a front surface 1
1. Rear surface 12, upper surface 13, opposing side surface 14
and 15 and a chamfered portion 16.

Prism 10 may be attached to the laryngoscope blade in any manner, but is preferably removably attached. The prism may thus be attached to the blade in one form by means of a spring clip 17, which curves inwardly or by means of a U-shaped portion 18 that extends from the vertical web of the blade. mounted on. Clip 17 also includes a support surface 19 for supporting the base of prism 10, as shown in FIG.
The clip 17 is also provided with an auxiliary window 20.

Laryngoscope blade 21 shown in Figures 4, 5, 7 and 8
comprises a tip 22, a web 23 consisting of components 23A and 23B, a base flange 24 and a protector 25 and a ramp 26 consisting of components 24A and 24B. As shown, the blade consists of two straight sections 27 and 28. FIG. 5 shows cross-sectional views taken along lines A to E at each stage from the tip to the rear of the blade 21.

FIG. 6 shows a prism 10 having a ray 29 incident on the front surface of the prism 10 from an object at an angle of 50 DEG 30'. Furthermore, the front surface 1 of the prism 10
Another object 30A is also shown in this figure, emitting a ray 29A which is incident at an angle of 72°30' to 1.
Bright rays 29 and 29A are refracted into refracted rays 31 and 32, which pass through eyepiece sites 33 and 34.
reach respectively.

FIG. 6 thus essentially shows an optical diagram of the prism 10, and also shows that the appearance of the larynx at positions 30 and 30A can be observed at the eyepieces 33 and 34, respectively. be. Also shown in FIG. 6 are surfaces 35 and 36 that correspond to the front surface 11 and the rear surface 12.

FIG. 9 shows the prism 10 attached to the laryngoscope blade 21. Small angular cartilage near the larynx 37
The ray 39 emerging from the prism 10 is refracted by the front surface 11 into a refracted ray 39A, which is then refracted onto the rear surface 12 of the prism 10 and refracted into a refracted ray 39B.
The ocular site 38 is then reached, whereby the cornicular cartilage can be visualized. The path of the refracted ray can then be contrasted with the original path 40 of the bright ray emanating from the cartilage cartilage 37. The laryngoscope blade 21 is inserted into the mouth and positioned with some space left for the upper teeth 41. 4 of the upper bones
Part 2 often blocks the bright light path 40, obscuring the larynx. In such a case, a prism can be used as shown in FIG. 9 to refract the bright light ray 39 exiting the larynx along paths 39A and 39B to reach the ocular site 38.

The laryngoscope blade of the present invention is much narrower and lower in height when compared to the Macintosh blade, with an overall width of less than 16 mm (preferably less than 13 mm) and a maximum height at its highest point of 21 mm (more preferably 17 mm). less than). prism 10
The endotracheal tube also has a very thin shape to allow enough room to insert it into the mouth. The narrow cross-section of the tip or anterior surface 11 of the prism 10 eliminates the possibility of a panoramic view of the glottis and provides sufficient structural visibility to guide the direction of intubation, even in patients with major abnormalities. can be determined.

Although the angled blade of the present invention is easier to insert into the mouth than a straight blade,
The continuously curved blade shown in Figure 15 cannot be inserted as far past the tongue as easily. However, it is not necessary to pull the tongue as hard forward as with a curved blade. Also, there is no curved line that blocks bright light approaching the prism from the glottis.
The prism can be located more proximally so that the laryngoscope blade and prism combination does not project as strongly against the upper incisors.

The laryngoscope blade of the present invention is narrower and has a more slender shape than the Macintosh blade.
It can also be inserted into a much smaller mouth than the makintoshu blade. Furthermore, the narrower width of the blade of the present invention allows it to be drawn deeper between the tongue and tonsils.

The laryngoscope blade of the present invention also does not require force, and there is room to insert the endotracheal tube past the blade and into the larynx, even in patients with major abnormalities.

FIG. 10 shows a handle 43 with a neck 44, a head 45 with a notch 46, and a bolt 48. The base 47 of the blade has a downwardly projecting portion 49 located in the notch 46 . A clip 50 for its fixation is also shown in this figure.

It is also a practical advantage that although the handle of the laryngoscope blade of the invention may be constructed integrally with the blade, it is more preferably removably attached to the blade as in the foregoing description with respect to FIG. Dew.

Other types of attachment and detachment attachments may also be used, such as clip attachment or hook attachment attachments.

One prism variant 10A suitable for use in the present invention is shown in FIGS. 11 and 12, and yet another variant 10B is shown in FIGS. 13 and 16.
In these cases, the prism chamfer 16 as shown in FIGS. 1 to 3 is not provided. However, these chamfers are useful when inserting the endotracheal tube through the mouth, in that they provide greater ease of passage. FIG. 14 shows the state in which the prism 10A is attached to the support clip 17.

FIG. 17 shows the case where the laryngoscope blade 21 of the present invention is used to directly view the cartilage 37 by means of the bright light beam 40 reaching the eyepiece position 40A. In fact, the blade 21 can often directly view the larynx without the use of the prism 10, in contrast to the prior art described above.

The overall length of the straight line portion of the angled laryngoscope blade according to the present invention is
90 to 210 mm is appropriate, and for children, 70 to 85 mm. Components 24 of base flange 24
The length of A is 40 to 120 mm (preferably 60 mm) for adults.
~85mm), 50mm is appropriate for children. On the other hand, the appropriate length of the component 24B is 50 to 90 mm (preferably 60 to 75 mm) for adults and 22 to 32 mm (preferably 27 mm) for children. On the other hand, the width of the flange 24 is suitably in the range of 7 to 16 mm (preferably 11 to 13 mm), the height of the web 23A is suitably in the range of 6 to 14 mm at the junction with the web 23B, and the handle For the distal end near 43, 11 to 21 mm is appropriate. The height of the component 23B close to the tip 22 is suitably between 2 and 8 mm, and gradually increases as it approaches the junction of 23A and 23B, reaching the aforementioned limit value.

The various lengths l ₁ , l ₂ , l ₃ , l ₄ , l ₅ and l ₆ shown respectively in the prisms of FIGS. 2, 12 and 13 are the angles X,
It is drawn as a line forming X ₁ , X ₂ , X ₃ , X ₄ and X ₅ .

l ₁ length is 27-63mm (preferably 43-48mm), l ₂
The length of L3 is 12-22mm (preferably 14-18mm), the length of _L3 is 30-70mm (preferably 40-55mm), and the length of _L4 is 4-11mm (preferably 6-8mm). Appropriate.

In the case of FIG. 13, which shows one variant of the prism with a modified rear surface having components 12A and 12B, a suitable length of l ₅ is 7-13 mm (preferably 9-10 mm) and l ₆ The appropriate length is 5~
9 mm (preferably 6 to 7.5 mm).

Regarding the angle, X is 50~75° (preferably 60~
65°), X ₁ is 115-135° (preferably 122-130°), X ₂
is 85-105° (preferably 92-102°), X ₃ is 65-90° (preferably 70-80°), X ₄ is 165-175° (preferably 168-173°), X ₅ is 78 ~90° (preferably 83-87°)
It is appropriate that

The width of the prism is 5 to 15 mm (more preferably 8 mm).
~10mm). The prisms may be made of, for example, glass or plastic material, such as cast allyl diglycol carbonate monomer known as "CR-39", methyl methacrylate polymer (known as "perspex", "plexiglass" or "oliglass"). ) and polycarbonate materials] may be used.

The refractive index of the transparent material can vary between 1.40 and 1.65, but is preferably between 1.47 and 1.55.

Compared to prior art prisms such as the Huffman prism, the prism of the present invention has anterior and posterior surfaces that refract bright light rays exiting the larynx to a greater extent as shown in FIGS. 6 and 9. It also has the advantage of reducing the deflection of the light ray from the prism when it exits the prism, as also shown in FIGS. 6 and 9. Moreover, its volume is about 1/3 that of the Huffman prism.

Furthermore, in contrast to Huffman's prism,
The prism of the present invention has the great practical advantage of being usable and useful in the clinical treatment of patients for whom intubation is otherwise difficult or impossible.

When compared to the Huffman prism, the prism of the present invention has a much shorter base to refract light rays to a greater extent, making it particularly useful when using angled laryngoscope blades as in the present invention. The smaller size of the prism also allows for better manipulation of both the endotracheal tube and blade. This prism is also lower in height than the Huffman prism, so it is less likely to strain the teeth.

[Brief explanation of drawings]

FIG. 1 is a top view of a suitable prism for use in the present invention. FIG. 2 is a side view of the prism of FIG. 1. Figure 3 shows the illustrations of Figures 1 and 2 in combination with support clips for attachment to the laryngoscope blade.
FIG. 3 is a perspective view of the prism shown in FIG. FIG. 4 is a schematic side view of a laryngoscope blade assembled in accordance with the present invention. Figure 5 shows A in Figure 4,
A series of cross-sectional views taken along lines B, C, D and E are shown. FIG. 6 is a diagrammatic representation of the prism of FIG. 1, showing the refraction of light rays passing through the prism. FIG. 7 is a perspective view of one of the angled laryngoscope blades assembled in accordance with the present invention. FIG. 8 is a side view of a non-chamfered prism attached to a blade having the angle shown in FIG. FIG. 9 is a view showing the laryngoscope of the present invention in use, illustrating a state in which the larynx can be easily seen with the laryngoscope.
FIG. 10 is a detailed view of the handle of the laryngoscope shown in FIG. 7. FIG. 11 is a top view of one modified prism suitable for use in accordance with the present invention.
FIG. 12 is a side view of the prism shown in FIG. 11. FIG. 13 is a side view of another deformed prism used in the present invention. Figure 14 shows the first laryngoscope blade in combination with the support clip attached to the laryngoscope blade.
FIG. 2 is a perspective view of the prism of FIG. 1; FIG. 15 is a perspective view of a conventional machining tool type curved laryngoscope blade. FIG. 16 is an end view of the prism of FIG. 13. FIG. 17 is a diagram showing the laryngoscope of the present invention in use, illustrating a case in which the patient's larynx can be viewed without the need for a prism. 10 is a prism, 21 is a blade, 33 is an eyepiece, 39 is a light beam, and 43 is a handle.

Claims (1)

[Scope of Claims] 1. Consisting of a first straight inner part and a second straight outer part, the inner part and the outer part form a V-shape with an included angle of about 135 degrees, The ratio of the length of the inner part to the outer part is 4:5 to 3:4
a laryngoscope blade having a cross section substantially in Z through at least a portion of its length;
shape, the upright or diagonal portion of the Z is substantially vertical, the length of the upper arm of the Z is shorter than that of the lower arm, and in use,
A laryngoscope blade that is inserted into a patient's mouth, presses the back side of the tip of the outer part against the epiglottis, moves the epiglottis forward, and makes it possible to see the larynx in a straight line along the outer part. 2. The inner portion has an end attachable to a handle, the outer portion has the tip remote from the handle, and a portion adjacent the tip is substantially flat. The laryngoscope blade according to paragraph 1. 3. The linear portion of the inner portion adjacent the handle is substantially L-shaped, and both arms of the L are of substantially equal length.
The laryngoscope blade according to item 1 or 2. 4. The laryngoscope according to any one of claims 1 to 3, wherein the overall length measured along a straight line is 90 to 210 mm for adults and 75 to 85 mm for children. blade. 5. The laryngoscope blade according to claim 4, wherein the length of the inner portion is within the range of 40 to 120 mm. 6. According to claim 5, the height of the L or Z vertical web or vertical element is in the range of 2 to 21 mm, and the width of the L or Z horizontal element or arm is in the range of 7 to 16 mm. laryngoscope blade. 7. Viewed from the side, it has a front surface, a top surface and a rear surface, the front surface sloping rearwardly at an acute angle to the horizontal plane to merge with the top surface, the top surface having an upper surface which, before merging with the rear surface, the rear surface slopes downwardly from the top surface, the length of the front surface being relatively short compared to the top surface; is a laryngoscope prism characterized by being longer than its anterior surface. 8. A patent in which the front surface makes an angle in the range of 50 to 75 degrees with respect to the horizontal plane, the top surface makes an angle of 25 to 45 degrees with the horizontal plane, and the rear surface makes an angle of 65 to 90 degrees with the horizontal plane. A prism according to claim 7. 9. The prism according to claim 7, wherein the maximum length of the prism in the longitudinal direction is within the range of 30 to 70 mm.