US3640282A

US3640282A - Tracheal tube with normally expanded balloon cuff

Info

Publication number: US3640282A
Application number: US61586A
Authority: US
Inventors: Jack M Kamen; Carolyn J Wilkinson
Original assignee: Individual
Current assignee: Individual
Priority date: 1970-08-06
Filing date: 1970-08-06
Publication date: 1972-02-08
Anticipated expiration: 1989-02-08
Also published as: DE2127589B2; CA1004940A; DE2127589A1; GB1308882A; JPS4939799B1

Abstract

A tracheal tube for use in intubation of a trachea, and embodying a resilient, yieldable cuff for effecting an air seal between the tube and the trachea. The cuff contains a resilient member, such as a rubber sponge, which resiliently maintains the cuff in an expanded position away from the tube. The cuff may be contracted by means of a vacuum applied thereinto by a secondary tube mounted on the tracheal tube. The cuff in its normal expanded position within the trachea affords a good seal and at the same time prevents injury to the tracheal wall by virtue of its yieldable contact therewith.

Description

[ Feb. 8, 1972 llnited States Patent amen et al.

[54] TRACHEAL TUBE WITH NORMALLY n O h m 0 7 9 H 4 6 7 4 0 3 3,529,596 9/1970 Garner....

EXPANDED BALLOON CUFF n. U h S & n m P m 0 h T m e fi m 1K o mt m D PM e 4 y w W 1m mm W mm mlw .m M mm 4C ly h 0 mam 846 K m M m .mmnw h hGC m m n e v .m H .U

tleff [73] Assignee: said Kamen, by said Wilkinson [22] Filed:

[ ABSTRACT A tracheal tube for use in intubation of a trachea, and em- Aug. 6, 1970 [21] Appl. No.: 61,586

bodying aresilicnt, yieldable cuff for effecting an air seal 128/351, 128/344, 123/349 B between the tube and the trachea. The cuff contains a resilient 25/00 member, such as a rubber sponge, which resiliently maintains 128/348 349 349 the cuff in an expanded position away from the tube. The cuff [52] US. [51] Int. Cl. [58] Field of may be contracted by means of a vacuum applied thereinto by a secondary tube mounted on the tracheal tube. The cuff in its normal expanded position within the trachea afiords a good seal and at the same time prevents injury to the tracheal wall by virtue of its yieldable contact therewith.

[56] References Cited UNITED STATES PATENTS 10 Claims, 5 Drawing Figures Greenburg.....,.........

t S 5 6 9 1 l 0 1 2 5 l l 1 3 TRACHEAL TUBE WITH NORMALLY EXPANDED BALLOON CUFF BACKGROUND OF THE INVENTION The present invention relates to tracheal tubes and, more particularly, to tracheal tubes of the type embodying a cuff for effecting a seal between the tube and a trachea.

The primary object of the present invention is to afford a novel tracheal tube.

Another object is to enable an effective seal between a tracheal tube and a trachea to be effected in a novel and expeditious manner.

A further object of the present invention is to afford a novel cuff on a tracheal tube.

Tracheal tubes, as that term is used herein, may be of different types, such as, for example, orotracheal tubes, nasotracheal tubes and tracheostomy tubes. Also, such tubes may be flexible, the main body portion thereof being made of flexible material such as, for example, rubber or a suitable plastic material, such as, for example, polyethylene, or the like, or they may be stiff or rigid, being made of material such as stainless steel, or the like, the latter type of tubes being primarily useful as tracheostomy tubes. The present invention is intended for use in the construction of all such tracheal tubes.

As is well known in the art, tracheal tubes are commonly inserted into a persons trachea for various purposes, such as, for example, to enable the person to breathe, or to enable intermittent positive pressure ventilation of the respiratory tract to be carried out. Often, it is highly important, particularly in such instances as when positive pressure ventilation of the respiratory tract is to be carried out, that an airtight or substantially airtight seal be provided between the tracheal tube and the trachea. I-Ieretofore, various attempts have been made to effect such seals between tracheal tubes and the trachea, such as, for example, by using large tubes which completely fill the trachea, or using cuffs which are inflatable by forcing air or other working fluid thereinto. However, each of the methods of sealing heretoforeknown in the art have presented certain difficulties and complexities. It is an important object of the present invention to overcome such difficulties and complexities.

In the cuffed tubes heretofore known in the art, cuffs in the form of elastic diaphragms or tubes made of elastic material, such as latex rubber, have been mounted on the main tube in sealed surrounding relation thereto, with the cuff normally, and when being inserted into the trachea, being in uninflated or deflated condition. With such devices, after the incubation device has been inserted into the trachea, the cuff is inflated,

like a balloon, by feeding air or other working fluid thereinto at a positive pressure to thereby expand the cuff into engagement with the inner wall of the trachea. However, it has been found that such devices have several inherent disadvantages, the primary disadvantage being that they commonly cause injury to the trachea, causing lesions such as tracheal stenosis, tracheal malacia and localized erosion, and the like, particularly if it is necessary for the tube to remain in the trachea for prolonged periods of time. Various attempts have been made to prevent such injuries from occurring with the cuffs heretofore known in the art, such as, for example, by using alternately inflated double-cuffed tubes; using intermittently inflated cuffs; and by serial adjustment of the level of the cuffed tubes. However, these attempts have met with only limited success. It

. is another important object of the present invention to eliminate such injuries to the trachea, or at least to substantially reduce the likelihood and incidence of their occurring.

Another object of the present invention is to enable a seal to be effected in a novel and expeditious manner between a tracheal tube and a trachea by volume occlusion as distinguished from the pressure occlusion heretofore afforded by the aforementioned inflatable cuffs heretofore known in the art.

A tracheal tube constructed in accordance with the present invention comprises an elongated tube, which may be either flexible or stiff, for insertion into the trachea for feeding air, or the like, into and out of the respiratory tract of a patient. A cuff is mounted on the elongated tube for efiecting a seal between the tube and the trachea, after the tube has been inserted into operative positioned in the trachea. The cuff comprises a flexible, air impervious cover disposed in surrounding relation to a portion of the tube and hermetically sealed thereto, and a preferably porous resilient body portion, made of suitable material, such as, for example, sponge rubber, mounted around the elongated tube, within the cover for yieldingly urging the cover outwardly away from the tube. The tracheal tube also includes an auxiliary tube extending into the cover, in hermetically sealed relation thereto. With this construction air may be withdrawn from the cover through the auxiliary tube, to thereby cause the cuff to collapse to facilitate the insertion thereof into a trachea, and, after the cuff is in the desired position in the trachea, the auxiliary tube may be opened to the atmosphere and thereby permit the cuff to expand into yielding, sealing engagement with the trachea.

Other and further objects of the present invention will be apparent from the following description and claims and are illustrated in the accompanying drawings which, by way of illustration, show a preferred embodiment of the present invention and the principles thereof and what we now consider to be the best mode in which we have contemplated applying these principles. Other embodiments of the invention embodying the same or equivalent principles may be used and structural changes may be made as desired by those skilled in the art without departing from the present invention and the purview of the appended claims.

DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. 1 is a fragmentary side elevational view of a tracheal tube embodying the principles of the present invention;

FIG. 2 is a longitudinal sectional view taken substantially along the line 22 in FIG. 1, and showing the tracheal tube disposed in operative position in a trachea, which is shown diagrammatically;

FIG. 3 is a transverse sectional view taken substantially along the line 33 in FIG. 2;

FIG. 4 is a transverse sectional view taken substantially along the line 4-4 in FIG. 5; and

- FIG. 5 is a view similar to FIG. 2, but showing certain parts disposed in different operative positions.

DESCRIPTION OF THE EMBODIMENT SHOWN HEREIN A tracheal tube or intubation device 1, embodying the principles of the present invention, is shown in the drawings to illustrate the presently preferred embodiment of the present invention.

The tracheal tube 1 embodies, in general, an elongated tube 2 having a cuff 3 mounted on one portion thereof, with a tube 4 extending into the cuff 3 for a purpose which will be described in greater detail presently. The tube 2 may be of any suitable construction and is for the purpose of feeding air, or the like, into and out of the respiratory tract of a patient into whose trachea the tracheal tube or intubation device I has been inserted. Commonly, when the tracheal tube 1 is to be used as an endotracheal tube, such as, either an orotracheal or nasotracheal tube, the tube 2 thereof is preferably flexible and may be made of any suitable material such as, for example, rubber or a suitable plastic, such as polyethylene, or the like. However, in other instances, such as, for example, when the tracheal tube 1 is to be used as a tracheostomy tube, it may be desired to have the tube 2 thereof be rigid in construction and made of suitable material such as, for example, stainless steel, or the like.

In the drawings, the tube 2 is shown as having a distal end 5, which is cut on a slope or bevel 6, FIG. 1, extending across the end opening of the tube 2 so as to facilitate insertion of the tube 2 into the trachea. The end portion 5 also has a transverse opening 7, FIG. 2, formed therein, such construction for tracheal tubes being common as is well known in the art. The other, or proximal end 8 of the tube 2 may be of any suitable configuration, such as that shown in FIG. I. It will be understood by those skilled in the art that the tube 2 may be of any suitable length, such tubes, commonly being in the nature of nine to fourteen inches in length, when used in an endotracheal tube, and commonly being considerably shorter when used as a tracheostomy tube.

The cuff 3, FIGS. 3 and 5, includes an air impervious cover 9 and a body portion 10 disposed within the cover 9. Both the body portion 10 and the cover 9 are disposed around a portion of the tube 2 is spaced relation to the ends 5 and 8 thereof. In practice, the wit 3 will normally be disposed substantially closer to the end 5 of the tube 2 than to the end 8 thereof, such as, for example, being spaced from the end portion 6 a distance in the nature of one-half to three-fourths of an inch on a tube having an overall length of 14 inches. However, as will be appreciated by those skilled in the art, the cuff 3 may be disposed at any suitable location along the tube 2, the particular location thereof depending upon the intended use of the intubation device 1. For example, normally, when the end S of the tube is to be inserted into the windpipe or trachea, only, the cuff 3 preferably will normally be spaced a relatively short distance from the end portion 6, such as, for example, the aforementioned one-half to three-fourths of an inch. However, if the intubation device 1 is to be inserted further than the trachea, such as, for example, into the bronchia, the cuff 3 preferably would be spaced a greater distance from the end portion 6 so that it would remain in the trachea when the end portion 5 was inserted into the bronchia.

The cover 9 is flexible and may be made of any suitable material such as, for example, latex rubber or a suitable plastic sheet material, such as, polyethylene, or the like. Preferably, it also is elastic for reasons which will be discussed in greater detail presently, and, of course, under such circumstances it would be made of a suitable elastic material such as the aforementioned latex rubber.

The cover 9 is tubular in form, and the

end portions

11 and 12 thereof are hermetically sealed to the outer surface of the tube 2 by suitable means, such as, for example, being vulcanized thereto or by a suitable cement such as rubber cement, or the like. In the preferred form of the intubation device 1 shown in the drawings, reinforcing rings 13 are mounted on the

end portions

11 and 12 of the cover 9 to insure the maintenance of any effective seal between the

end portions

11 and 12 and the tube 2. The reinforcing rings 13 may be made of any suitable material such as rubber or a suitable plastic such as polyethylene and may be secured to the outer faces of the

end portions

11 and 12 by suitable means such as vulcanization or a suitable cement.

The body portion 10 affords a resilient mass which preferably completely fills the cover 9 between the

end portions

11 and 12 thereof and, when the intubation device 1 is disposed in normal inoperative position, outside the trachea, preferably is effective to yieldingly hold the cover 9 in fully expanded position, as shown in FIG. 1. The body portion 10 may be made of any suitable resilient material, but, preferably, is made of a spongelike resilient material having a multitude of interstices spread therethrough, such as, for example, sponge rubber or a suitable resilient plastic material, such as, for example, foamed polyurethane, or the like, for a purpose which will be discussed in greater detail presently.

The tube 4 has one end portion 14 extending into the cuff 3. As shown in the drawings, the tube 4 extends along the tube 2, and, preferably, the tube 4 is formed integrally with the tube 2 and terminates in a free end portion 15 which extends outwardly beyond the end 8 of the tube 2. However, as will be appreciated by those skilled in the art, the tube 4 may be formed separately from the tube 2 and inserted into the cuff 3 in a suitable manner without departing from the purview of the broader aspects of the present invention.

In the intubation device shown in the drawings, wherein the tube 4 extends along tube 2, FIG. 2, the tube 4 extends through the end portion 11 of the cover 9 and the latter is hermetically sealed thereto in the same manner as it is so sealed to the tube 2. With this construction, it will be seen that when the tube 4 is open to the atmosphere at the end portion 15 thereof, and the intubation device 1 is disposed outside of a trachea, the body portion 10 is effective to yieldingly hold the cover 9 in fully outwardly extended position, as shown in FIG. 1. However, by the application of a vacuum to the end portion 15 of the tube 4, air may be withdrawn from within the cover 9 through the tube 4 to thereby afford a partial vacuum within the cuff 3 and cause it to collapse from the position shown in FIG. 1 to a position such as that shown in FIG. 5, because of the imbalance between the pressures within the cover 9 and the atmospheric pressure exteriorly thereof. It will be seen that by making the body portion 10 of a resilient material having interstices therein, such as, for example, the aforementioned foam rubber or foamed polyurethane, the withdrawal of air from within the cover 9 may be substantially uniform throughout the entire area between the

end portions

11 and 12 thereof, so as to effect a relatively uniform, substantially complete collapse of all portions of the cover 9 throughout the length thereof.

With the intubation device 1 constructed in the aforementioned manner, when it is desired to insert it into a trachea, such as the trachea l6 diagrammatically shown in FIGS. 2-5, a partial vacuum may be applied to the end portion 14 of the tube 4 to thereby cause the cuff 3 to move from its normal expanded position shown in FIG. 1 to a collapsed position such as that shown in FIG. 5. While maintaining the vacuum on the tube 4, the tracheal tube 1 may be inserted into a trachea, such as the trachea 16, the cuff 3 being disposed in the aforementioned collapsed position to thereby facilitate such insertion. Thereafter, when the tracheal tube 1 has been inserted into the desired position in the trachea 16, the vacuum on the tube 4 may be released to thereby permit the cover 9 to be expanded outwardly by the yielding expansion of the resilient body member 10, the expansion of the cover from the collapsed position being to a position wherein it is yieldingly held by the body portion 10 in engagement with the inner wall 17 of the trachea 16, FIGS. 2 and 3. Such expansion, it will be seen, is caused by the resiliency of the body portion 10 and is a direct result of the volumetric expansion thereof. This is to be distinguished from the expansion of the aforementioned cuffs heretofore known in the art, which cuffs are expanded by the application of a positive pressure, by the introduction of air or other working fluid thereinto under pressure.

It will be remembered that the cuff 3 may be made of any suitable flexible material, but that preferably it is made of an elastic material, such as, for example, latex rubber. The latter is true because with the cover made of a suitable elastic material it may be so constructed that no wrinkles are formed therein in any position thereof between the fully expanded position shown in FIG. 1 and the collapsed position shown in FIG. 5, whereas with some materials which are flexible but do not have this degree of elasticity such as, for example, certain plastic sheet materials, and the like, wrinkles could be formed when the cover 9 is disposed in a position wherein it was extended outwardly less than that which it occupies when in fully extended position. Although it is of little or no importance whether the cover 9 is wrinkled when the cuff 3 is in fully collapsed position, as shown in FIG. 5, and it is not essential or an absolute requirement that no wrinkles be .formed in the cover 9 when the cuff 3 is disposed in operative engagement with a trachea, such as is shown in FIG. 2, it is preferred that no such wrinkles be present when the cuff 3 is in operative engagement with a trachea. Therefore, to insure against such wrinkles, we prefer that the cover 9 be made of a suitable elastic material such as, for example, the aforementioned latex rubber.

As will be appreciated by those skilled in the art, the size of the cuff 3 in its nonnal, fully expanded state, as shown in FIG. I, and the characteristics of the cover 9 and the body portion are factors in the determination of the pressure with which the cuff 3 presses outwardly on the trachea such as the trachea 16, when it is disposed in operative engagement with the inner wall 17 of such a trachea. Preferably, the size of the cuff 3 and the characteristics of the cover 9 and the body portion 10 are such that the outward pressure of the cuff 3 on a trachea is no greater than fourteen centimeters of water, when the intubation device 1 is in normal operative position in the trachea and the cuff 3 is in effective sealing engagement with the latter. However, as will be appreciated by those skilled in the art, this is set forth merely by way of illustration of the preferred embodiment of the present invention and not by way of limitation and variations in the size and characteristics of the cuff 3 may be made by those skilled in the art without departing from the purview of the present invention.

From the foregoing it will be seen that the present invention affords a novel intubation device embodying a cuff which is constructed and operates in a novel and expeditious manner.

Also, it will be seen that the present invention affords a novel intubation device for use in tracheas wherein effective sealing between the intubation device and the trachea may be afforded in a novel and expeditious manner.

In addition, it will be seen that the present invention affords a novel intubation device which is practical and efi'rcient in operation and which may be readily and economically produced commercially.

Thus, while we have illustrated and described the preferred embodiment of our invention, it is to be understood that this is capable of variation and modification, and we therefore do not wish to be limited to the precise details set forth, but desire to avail ourselves of such changes and alterations as fall within the purview of the following claims.

We claim:

1. A tracheal tube comprising a. an elongated tube having an outer surface, proximal end and distal end,

b. a cuff mounted on said elongated tube adjacent to said distal end and in spaced relation to said proximal end,

c. said cuff comprising 1. a flexible tubular cover a. disposed on said elongated tube in surrounding rela tion thereto, and

b. having its ends secured to said outer surface, and

2. a resilient body portion mounted in said cover,

d. said body portion having I. normally an expanded position, wherein it is effective to hold a portion of said cover outwardly away from said elongated tube, and

2. a collapsed position, wherein the outer surface thereof is disposed closer to said elongated tube than in said expanded position to thereby permit said portion of said cover to assume a position closer to said elongated tube, and

e. means connected to said cuff for creating and releasing a vacuum in said cover to thereby cause said body portion to move toward said collapsed and expanded positions, respectively. 1

2. A tracheal tube comprising i an elongated tube having a longitudinally extending opening for feeding working fluid therethrough, a proximal end and a distal end,

b. a cufi' mounted on said elongated tube adjacent said distal end and in spaced relation to said proximal end for effecting a seal between said elongated tube and a trachea in which it is disposed,

c. said cuff including resilient means for normally holding said cuff in expanded position wherein it extends outwardly from said elongated tube under atmospheric conditions, and

d. means operatively connected to said cuff for l. creating a vacuum therein and thereby move said cuff inwardly from said expanded position for movement of said cuff through such a trachea, and

2. releasing such a vacuum in said cuff to thereby permit said cuff to move outwardly toward said expanded position under urging of said resilient means into position to effect said seal with such a trachea in which said tube is disposed in operative position.

3. A tracheal tube as defined in claim 2, and in which a. said cuff includes a cover member, and

b. said resilient means comprises a resilient body portion disposed in said cover member for yieldingly urging said cover member outwardly away from said elongated tube.

4. A tracheal tube for use in intubating the trachea and comprising a. an elongated tube for insertion into operative position into a trachea for feeding air into and out of the latter and having a proximal end and a distal end, b. a cuff mounted on the distal end portion of said elongated tube in spaced relation to said proximal end thereof in position to be disposed within such a trachea when said elongated tube is disposed in said operative position therein, c. said cufi' having 1. a normal position wherein it is disposed in radially outwardly expanded position relative to said elongated tube, and

2. another position wherein it extends a lesser distance, radially, from said elongated tube than in said normal position,

d. said cuff including resilient means for normally yieldingly holding said cuff in said normal position,

c. said cuff being movable 1. into said other position for movement through such a trachea, and

2. toward said normal position from said other position into a position for effecting a seal between said elongated tube and said trachea within which said cuff is so disposed, and

means operatively connected to said cuff for creating and releasing a vacuum therein and thereby causing said cuff to move toward said other and normal positions, respectively.

. A tracheal tube as defined in claim 4 and in which a. said cuff comprises 1. a flexible cover secured to said elongated tube, and 2. a resilient filler mounted in said cover for holding the latter in said normal position when said vacuum is completely released and said cuff is completely free to expand.

6. A tracheal tube as defined in claim 5 and in which a. said filler has interstices spread therethrough.

7. A tracheal tube as defined in claim 4 and in which a. said cuff comprises 1. a flexible tube a. disposed in surrounding relation to said elongated tube, and b. having end portions hermetically sealed to said elongated tube, and 2. a spongelike elastic mass mounted in said flexible tube for yieldingly urging the latter outwardly.

8. A tracheal tube as defined in claim 7 and in which a. said flexible tube is elastic, and

b. said elastic mass comprises foam rubber.

9. A tracheal tube as defined in'claim 4 and in which a. said last mentioned means comprise another tube,

b. said cuff comprises 1. a flexible cover a. disposed in surrounding relation to said elongated tube and to said other tube, and b. hermetically sealed to said last mentioned tubes, and 2. a spongelike elastic body portion disposed around said elongated tube within said cover for yieldingly urging the latter outwardly away from said elongated tube. 10. A tracheal tube as defined in claim 4 and in which a. said elongated tube is flexible,

one of said ends of said elastic tube hermetically sealed to said other tube, and

2. a resilient foam rubber body portion mounted around said elongated and other tubes within said elastic tube in position to yieldingly urge said elastic tube outwardly away from said elongated and other tubes between said ends of said elastic tube.

Claims

1. A tracheal tube comprising a. an elOngated tube having an outer surface, proximal end and distal end, b. a cuff mounted on said elongated tube adjacent to said distal end and in spaced relation to said proximal end, c. said cuff comprising 1. a flexible tubular cover a. disposed on said elongated tube in surrounding relation thereto, and b. having its ends secured to said outer surface, and 2. a resilient body portion mounted in said cover, d. said body portion having 1. normally an expanded position, wherein it is effective to hold a portion of said cover outwardly away from said elongated tube, and 2. a collapsed position, wherein the outer surface thereof is disposed closer to said elongated tube than in said expanded position to thereby permit said portion of said cover to assume a position closer to said elongated tube, and e. means connected to said cuff for creating and releasing a vacuum in said cover to thereby cause said body portion to move toward said collapsed and expanded positions, respectively.

2. a collapsed position, wherein the outer surface thereof is disposed closer to said elongated tube than in said expanded position to thereby permit said portion of said cover to assume a position closer to said elongated tube, and e. means connected to said cuff for creating and releasing a vacuum in said cover to thereby cause said body portion to move toward said collapsed and expanded positions, respectively.

2. A tracheal tube comprising a. an elongated tube having a longitudinally extending opening for feeding working fluid therethrough, a proximal end and a distal end, b. a cuff mounted on said elongated tube adjacent said distal end and in spaced relation to said proximal end for effecting a seal between said elongated tube and a trachea in which it is disposed, c. said cuff including resilient means for normally holding said cuff in expanded position wherein it extends outwardly from said elongated tube under atmospheric conditions, and d. means operatively connected to said cuff for

2. a resilient body portion mounted in said cover, d. said body portion having

2. another position wherein it extends a lesser distance, radially, from said elongated tube than in said normal position, d. said cuff including resilient means for normally yieldingly holding said cuff in said normal position, e. said cuff being movable

2. toward said normal position from said other position into a position for effecting a seal between said elongated tube and said trachea within which said cuff is so disposed, and f. means operatively connected to said cuff for creating and releasing a vacuum therein and thereby causing said cuff to move toward said other and normal positions, respectively.

2. a resilient filler mounted in said cover for holding the latter in said normal position when said vacuum is completelY released and said cuff is completely free to expand.

2. a spongelike elastic mass mounted in said flexible tube for yieldingly urging the latter outwardly.

2. a spongelike elastic body portion disposed around said elongated tube within said cover for yieldingly urging the latter outwardly away from said elongated tube.

3. A tracheal tube as defined in claim 2, and in which a. said cuff includes a cover member, and b. said resilient means comprises a resilient body portion disposed in said cover member for yieldingly urging said cover member outwardly away from said elongated tube.

4. A tracheal tube for use in intubating the trachea and comprising a. an elongated tube for insertion into operative position into a trachea for feeding air into and out of the latter and having a proximal end and a distal end, b. a cuff mounted on the distal end portion of said elongated tube in spaced relation to said proximal end thereof in position to be disposed within such a trachea when said elongated tube is disposed in said operative position therein, c. said cuff having

5. A tracheal tube as defined in claim 4 and in which a. said cuff comprises

7. A tracheal tube as defined in claim 4 and in which a. said cuff comprises

8. A tracheal tube as defined in claim 7 and in which a. said flexible tube is elastic, and b. said elastic mass comprises foam rubber.

9. A tracheal tube as defined in claim 4 and in which a. said last mentioned means comprises another tube, b. said cuff comprises

10. A tracheal tube as defined in claim 4 and in which a. said elongated tube is flexible, b. said last mentioned means comprises another tube secured to said elongated tube and extending into said cuff c. said cuff comprises