US3610247A - Surface-anesthetizing medical appliance - Google Patents

Surface-anesthetizing medical appliance Download PDF

Info

Publication number
US3610247A
US3610247A US803717A US3610247DA US3610247A US 3610247 A US3610247 A US 3610247A US 803717 A US803717 A US 803717A US 3610247D A US3610247D A US 3610247DA US 3610247 A US3610247 A US 3610247A
Authority
US
United States
Prior art keywords
anesthetic
surface
tube
film
solid
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US803717A
Inventor
Richard R Jackson
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
RICHARD R JACKSON
Original Assignee
Richard R Jackson
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Richard R Jackson filed Critical Richard R Jackson
Priority to US80371769A priority Critical
Application granted granted Critical
Publication of US3610247A publication Critical patent/US3610247A/en
Anticipated expiration legal-status Critical
Application status is Expired - Lifetime legal-status Critical

Links

Images

Classifications

    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61LMETHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION, OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS, OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS, OR SURGICAL ARTICLES
    • A61L29/00Materials for catheters, medical tubing, cannulae, or endoscopes or for coating catheters
    • A61L29/14Materials characterised by their function or physical properties, e.g. lubricating compositions
    • A61L29/16Biologically active materials, e.g. therapeutic substances
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61MDEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M16/00Devices for influencing the respiratory system of patients by gas treatment, e.g. mouth-to-mouth respiration; Tracheal tubes
    • A61M16/04Tracheal tubes
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61MDEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M16/00Devices for influencing the respiratory system of patients by gas treatment, e.g. mouth-to-mouth respiration; Tracheal tubes
    • A61M16/04Tracheal tubes
    • A61M16/0434Cuffs
    • A61M16/0445Special cuff forms, e.g. undulated
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61MDEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M16/00Devices for influencing the respiratory system of patients by gas treatment, e.g. mouth-to-mouth respiration; Tracheal tubes
    • A61M16/04Tracheal tubes
    • A61M16/0434Cuffs
    • A61M16/0454Redundant cuffs
    • A61M16/0459Redundant cuffs one cuff behind another
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61MDEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M16/00Devices for influencing the respiratory system of patients by gas treatment, e.g. mouth-to-mouth respiration; Tracheal tubes
    • A61M16/04Tracheal tubes
    • A61M16/0475Tracheal tubes having openings in the tube
    • A61M16/0477Tracheal tubes having openings in the tube with incorporated means for delivering or removing fluids
    • A61M16/0481Tracheal tubes having openings in the tube with incorporated means for delivering or removing fluids through the cuff wall
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61MDEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M19/00Local anaesthesia; Hypothermia

Abstract

Medical devices, endotracheal tubes, having on outside a solid layer comprised of surface-effective anesthetic and solid substance physically securing the anesthetic. The outer surface of the layer has a prolonged anesthetizing effect. Semipermeable flexible adhesive film and semipermeable sheet film across which the anesthetic travels are specifically shown.

Description

United States Patent Richard R. Jackson 8 Trinity Road, Marblehead, Mass. 01947 803,7 17

Mar. 3, 1969 Oct. 5, 1971 lnventor Appl. No. Filed Patented SURFACE-ANESTHETIZING MEDICAL APPLIANCE 15 Claims, 9 Drawing Figs.

U.S. Cl 128/351, 128/260, 128/272 Int. Cl A6lm 25/00, A61m 31/00, A6lj 1/00 Field of Search 128/260, 262, 265, 272, 35]; 424/16, 18, 19, 22

References Cited UNITED STATES PATENTS 10/1967 Jackson 2,803,582 8/1957 Cherney 424/19 3,363,624 l/1968 Fishman 128/260 X 3,363,629 1/1968 Kuhn 128/351 3,375,828 4/1968 Sheridan 128/351 FOREIGN PATENTS 998,794 7/1965 Great Britain 3/1 215,350 10/1909 Germany 128/3 Primary Examiner-Channing L. Pace Attorney.lohn Noel Williams ABSTRACT: Medical devices, endotracheal tubes, having on outside a solid layer comprised of surface-effective anesthetic and solid substance physically securing the anesthetic. The outer surface of the layer has a prolonged anesthetizing effect. semipermeable flexible adhesive film and semipermeable sheet film across which the anesthetic travels are specifically shown.

PATENTEDncT 51911 1610247 FiG. 2

Illllllllllllllllllllllllll 5 IO I5 20 25 NUMBING EFFECT SURFACE-ANESTI'IETIZING MEDICAL APPLIANCE This invention relates generally to medical appliances and specifically to endotracheal tubes.

During surgical procedures the depth of general anesthetization is often determined by the need to block the response of the patient to the endotracheal tube that is present in his trachea. In other words the tendency for the patient to buck (tightening of the stomach muscles and tendency of the unconscious patient to sit up) in response to the endotracheal tube is greater that the patients response to the pain at the site of the incision or the need for maintaining a state of amnesia. This particularly so is cases where administration of muscle relaxants is inadvisable.

Since it is desirable to maintain body functions as close as possible to normal during surgery, and since these functions are progressively affected with deeper levels of anesthetization, it has long been desired to reduce the patients reaction to endotracheal tube throughout the surgical procedure. Prior tracheal anesthetizing measures are objectionable for various reasons, e.g. being effective only for short periods requiring repeated dosage, or being complicated and introducing new steps or conditions in the procedure of handling the patient.

It is also desirable to remove from the awakening and fully awake patient the gag and coughing reflexes caused by the presence of the endotracheal tube. This permits the tube to be tolerated and remain in place in the awake patient, enabling continued support of respiration by means of the endotracheal tube and respirator. Likewise it permits respiratory support to be administered immediately should this suddenly become necessary. The endotracheal tube also gives better assurance against blockage of the airway by tongue or tissues than do other airway devices.

More generally it has long been desirable to provide means for decreasing sensations caused by medical tubes and similar appliances residing in mucous passages of patients over periods in the range of l to 20 hours in a manner requiring no change in the appearance of the tubes or the steps required in their administration.

The objects of the present invention are to meet these various needs in a simple and practical way.

The invention employs an endotracheal or other medical tube which may be of conventional construction in being comprised of a flexible material such as latex rubber or polyvinyl chloride of a thickness sufficient to ensure that the fluid passage will not be closed by the flexing action attendant to the entubation and use of the tube. The tube may include one or more cuffs in the form of extensible balloons or in the form of large, highly flexible floppy cuffs formed of thin film material. Featured therewith is a solid layer or coating having a relatively thin effective thickness and comprised of surface effective anesthetic and solid substance physically securing the anesthetic. The outer surface of this layer has a nontoxic (i.e. within nonharmful dosage limits) surface anesthetizing characteristic extending over a period of at least 1 hour, preferably over periods of or hours. Advantageously the initial level of anesthetic availability is relatively high to achieve quick onset of surface anesthetization.

The invention also features a semipermeable membrane or securing material disposed between the surface effective anesthetic in the solid state and the body tissue, the anesthetic being progressively transported thereacross.

The invention also features as the effective layer a matrix formed by an adhesive substance containing a dispersion of solid aggregates or crystals of surface-effective anesthetic, the substance having a diffusion characteristic for body fluids and for body fluids in which are dissolved minor quantities of the anesthetic from the matrix.

The invention also features such a matrix layer and layers of other makeups as integral with tubes and their flexible cuffs, and also as part of flexible and distensible sleeves applied to preexisting tube and cuff assemblies.

These and other objects and features will be revealed in the following description of preferred embodiments taken in conjunction with the drawings wherein:

FIG. 1 is a side view partly in cross section and partly diagrammatic, of an endotracheal tube engaging tissue of a patient;

FIG. 2 is a diagrammatic representation of the availability curve of a typical device according to the invention;

FIGS. 3 and 4 are magnified cross sections taken on lines 33 and 4-4 of FIG. 1, respectively;

FIG. 4a is a greatly magnified view, partly diagrammatic, of a portion of FIG. 4;

FIG. 5 is a perspective view, partly cut away of a sleeve member according to the invention;

FIG. 6 and 7 are views of an endotracheal tube with which the sleeve of FIG. 5 is combined;

FIG. 8 is a cross-sectioned view of a tube having a wrapping of a diffusion membrane, securing in the inside a deposit of solid anesthetic.

Referring to FIG. 1 an endotracheal tube 10 has'a conventional air passage 12, an angular-cut distal end 14, a proximal end provided with a connector for the anesthetic machine, respirator or oxygen line, and an inflatable cuff 20 together with an inflating lumen.

The particular tube shown is made of plastic such as polyvinyl chloride of a wall thickness 1, of approximately one sixteenth inch. The cuff is constructed of any suitable flexible film such as extremely thin latex e.g. of less than 0.002 inch thickness and is of a diameter substantially larger than the trachea, e.g. being 1% inch diameter in comparison with a trachea of inch diameter. Such floppy cuffs are disclosed in my copending patent applications Ser. Nos. 427,60l and 719,994, and require very low pressure to inflate, thus effectively combatting the necrosis problem. Such cuffs flex to the shape shown when the lung pressure exceeds atmospheric pressure.

Combined with this device, on the exterior surfaces exposed to the tissue of the patient, is a layer 26 comprised on surface effective anesthetic and bonding material physically securing the anesthetic in place.

The layer 26 has the characteristic of presenting at its outer surface, to tissue 28 in contact therewith, surface-effective anesthetization of nontoxic levels extending over a period of at least 1 hour, preferably over periods of ID or 20 hours, in accordance with the curve of FIG. 2 which will be discussed further below.

In this preferred embodiment the layer comprises an elastomeric adhesive coating applied to the outer surfaces of a previously formed endotracheal tube and cuff assembly.

In the preferred embodiment of FIG. 5 there is shown a distensible sleeve member 30 formed of resilient material which is supplied in a rolled-up shape.

On its outer surface is a layer 32 similar to layer 26 of the preceding figures, of such flexibility and resiliency to remain coherent when the tube is convoluted in the roll 30a.

FIGS. 6 and 7 show an endotracheal tube 36 with two cuffs 38, 40 and corresponding inflation lumens 42. 44. In FIG. 6 the distensible sleeve is shown partly applied to endotracheal tube 3, the two dotted line positions showing progressive positions during application. In FIG. 7 the sleeve is shown fully applied, with the distal cuff 40 inflated, that portion of the sleeve distending therewith and exposing its outer surface to scaling contact with the tracheal wall.

FIG. 8 shows a section of bendable tube 50 to which has been attached a film wrapping 52 upon the inside surface of which is deposited solid anesthetic particles diffusable through the film upon wetting the outside by secretions.

EXAMPLE I A conventional endotracheal tube with a balloon cuff similar to one of the cuffs of FIG. 7 was coated on surfaces exposed to mucous tissue with medical grade silicone adhesive containing a dispersion of solid particles of a surface effective anesthetic. In preparation, a quantity of tetracaine anesthetic in solid particle form (Pontocaine," Winthrop Drug Company), was ground by a mortar and pestle until a powder of solid particles was obtained. The particles were greenish-blue in color. 20 milligrams of the powder were mixed with 1 cc. of medical grade silicone adhesive (Vivosil" medical adhesive Silicone-Type A, Becton, Dickinson and Company). The adhesive was water-white in color, a nonflowing soft paste. The adhesive with the 2 percent concentration of dispersed anesthetic particles had a uniform greensh-blue cast. The prepared quantity (i.e. 20 mg. of tetracaine) was required to provide the layer (26, FIG. I) over the tube and cuff. The coating was allowed to cure at humidity conditions in excess of 20 percent at 77 F., penetration of the atmospheric water through the silicone adhesive causing its setup. The resulting layer was estimated to be between a 0.003 and 0.005 inch thickness, and provided a shiny, smooth surface. In the cured state the layer appeared clear, however under close examination the anesthetic particles can be observed (particles did not dissolve in the adhesive). The layer was flexible with the underlying endotracheal tube and cuff, the layer remaining coherent upon normal bending of the tube and distension of the cuff.

The thus-prepared endotracheal tube was'administered to an age 45 female, gall bladder excision, under a normal level of general anesthetic. Three hours after the operation began the patient awoke in the recovery room and looked around, with endotracheal tube in place. There were no coughing or gaging reflexes, swallowing being the only reaction of the patient even when the tube was jiggled by the attending physician. When asked if she felt pain she shook her head no. After the patient was awake 1 hour the endotracheal tube was removed, with no spasm or coughing observed during removal, indicating anesthetization of the upper airway as well as the tracheal tissue in contact with the tube.

An endotracheal tube of identical construction was soaked in water for 24 hours, after which anesthetic particles could still be seen in the layer. After a total soaking of 72 hours the physician placed the tube in his mouth and was able to detect numbing on the tip of his tongue, after minute exposure. Prior to soaking, numbing of his tongue was detected with shorter exposure.

In other procedures in which the patients recovered from anesthesia in substantially less than 4 hours, the patients tolerated the endotracheal tubes well, but moderate coughing occurred during initial recovery.

EXAMPLE 2 A dispersion of tetracaine particles and silicone adhesive was prepared as in Example 1, with 30 mg. tetracaine per cc. of adhesive (3 percent concentration). This mixture was diluted by 3 cc. of ether and the resulting dilute suspension was painted on the endotracheal tube in two coatings to form layer 26 of FIG. 1. The overall thickness of the layer was estimated to be between 0.002 and 0.004 inch in thickness. When setup the layer presented a smooth, shiny surface.

This tube was placed in a patient having glaucoma, undergoing lridentasis. Twenty minutes after anesthetization the patient awoke with the tube in place and with no reaction.

A similar tube was employed in a patient undergoing gall bladder removal (cholecystectomy). The patient was maintained on a respirator (assisted breathing) for 4 hours after awakening. After cessation of the respirator the tube was left in the awake patient for 1 hour. After this period the tube was jiggled by the attending physician with no reaction whatever by the patient.

Similar tubes were employed in procedures of short duration(e.g. a carotid arteriogram procedure) and in longer circumstances (e.g. the tube was maintained in an unanesthetized patient for 18 hours while his breathing was assisted by a respirator). In these cases the tubes were welltolerated in the awakening patient.

EXAMPLE 3 A sleeve of distensible latex rubber of 4 inch length, inch internal diameter, was coated on its exterior with a mixture of silicone adhesive containing a 2 percent concentration of tetracaine particles slightly diluted with ether. After solidification of the adhesive layer the physician, by applying the outer surface of the the to his tongue and lips, detected numbness within 2 minutes.

The sleeve was slipped over an endotracheal tube having s single balloon cuff, using liquid soap as lubricant. The tube was inserted and the cuff inflated with air, distending he sleeve in the manner ofcuff40 in FIG. 7.

The operation, surgery on the abdominal wall of an age 83 female, was conducted without muscle relaxants with an unusually light level of anesthesia:

4 liters per minute nitrous oxide 2 liters per minute oxygen 1% halothane (Fluothane, Ayerst Co.).

EXAMPLE 4 An endotracheal tube cuff was formed by a 19/16 inch diameter, approximately 0.002 inch wall thickness, cellophane tube (Weck Sterilizing tubing," Edward Weck & Co., division of Sterling Precision Corp.) applied over an endotracheal tube, and tied to the endotracheal tube at opposite ends spaced approximately 2 inches apart. An inflating lumen was connected to the cuff volume. The cuff was filled with 10 cc. of a 2 percent solution (water base) lidocaine hydrochloride surface-effective anesthetic (xylocaine," Astra Pharamaceutical Products). The cuff was exposed to air for 4 days until the liquid had dried within the cuff, forming a deposit of 200 milligrams solid anesthetic on the inner surfaces of the cuff assembly. The deposit was not observable through the cellophane and was not friable. The exterior of the cuff was moistened with a slight amount of saline solution, to restore the flexibility of the cellophane, and the endotracheal tube was inserted into a patient and the cuff was inflated by introduction of air through the lumen. The patient awoke after 4 hours. The tube was jiggled in the trachea of the conscious patient without causing cough.

The procedure was repeated with a number of patients with same results.

EXAMPLE 5 A loose wrapping was formed using the cellophane tubing of example 4 along a portion of the endotracheal tube proximal to the inflatable cuff. 20 cc. of 2 percent lidocaine hydrochloride, water base, was dried within this wrapping forming a coating on the inner surface of the cellophane. The cellophane wrapping was collapsed upon the endotracheal tube in irregular folds.

The endotracheal tube was inserted with the wrapping located proximal of the trachea. The attending physician observed that the gas reflex of the awake patient was obtunded for 8 hours.

Referring now to FIG. 3, a magnified cross-sectional view along line 3-3 of FIG. 1, mucous tissue 29 lying proximal of the trachea contacts the outer surface of the layer 26. It has been observed that the gag reflex caused by such contact is obtunded over an extended period by anesthetic passing from the layer 26. The physical securement of the anesthetic prevents its being washed away by normal secretions, indeed in important instances it is believed that the secretions play an important part in progressive transport of the surface-effective anesthetic to the tissue. It should be observed that the effective thickness of the layer t, is only a small fraction of the remaining thickness of the tube wall t, which defines the passage in a manner which permits bending without closingoff the passage.

Referring to FIG. 4, a magnified view along line 44 of FIG. 1, it is seen that the cut? 20, inflated by air 24, seals against the tissue of trachea, with direct contact between layer 26 and the tracheal tissue. It has been observed that the coughing and bucking reflexes caused by such contact are obtunded over an extended period by anesthetic passing from the layer 26. Here again the physical securing of the anesthetic prevents its being washed away by normal secretions, the secretions in important instances believed to be effective in causing progressive transport of the anesthetic to the tissue.

The relationship of the effective thickness 1, of the layer and the remaining thickness t of the cuff corresponds to cuffs of the balloon type such as are shown in FIG. 6. As was shown above in example 4, however, where thinner flexible cuffs are employed, the wall thickness of the cuff can comprise the layer in or to which the anesthetic is secured.

Referring to FIG. 4a, a diagrammatic highly magnified cross-sectional view of the layer 24 in action, there are shown three anesthetic particles a, b and 0. Particle a is spaced distance I, away from the tissue, corresponding with the distance all of the anesthetic was spaced from the tissue in examples 4 and 5, and some of the anesthetic in the other examples.

Secretions travel from the tissue 28 through the layer to particle a and upon dissolving slightly, the anesthetic passes through the semipermeable thickness to tissue 28.

Advantageously some of the anesthetic is positioned closer to the effective surface, as for instance particles b and c. Particle c, near or at the surface, can, with proper selection of the anesthetic, provide immediate onset of anesthetization, or, if relatively insoluble in water (and therefore insoluble in the secretions) many maintain anesthetization for a substantial period. Particle b enables an intermediate condition to be achieved.

it will be seen that choice of the particular components of the layer will depend upon the desired characteristics of the device. Using materials available currently, it is most preferred to employ a solid coating in which the anesthetic is distributed from the outer surface to a depth of at least 0.001 inch as illustrated by each of the tiny particles a, b and c, with the inner particles masked with semipermeable material as in the foregoing examples. By this means rapid onset is achieved, but also the layer (being of semipermeable material or rendered so) has an impeding effect that ensures the availability of the anesthetic over an extended period.

It is preferred to employ silicone adhesive diluted with ether or the like, dilution not only enabling smoother and thinner coatings but also believed to increase the permeability of the coating to such anesthetics as tetracaine which, being water and not oil soluble, has very low solubility in silicone.

Suitable semipermeable substances presently known to the inventor, in addition to silicone adhesive and sheet films, are regenerated cellulose (cellophane) and cellulose nitrate. The cellulose thickness in important instances is less than 0.005 inch.

Whatever the type of construction of the layer chosen, a requirement is that the outer surface of the layer have a nontoxic surface anesthetizing characteristic extending over a period of at least 1 hour and preferably over periods of or 20 hours. FIG. 2 is a curve of the characteristic of a typically acceptable embodiment. The horizontal line denotes the threshold of anesthetizing effectiveness, established by a detectable numbness of the tongue after contact with the surface of the layer for 5 minutes. For the examples above the nontoxicity of the quantities of anesthetic is shown by the fact that accepted prior practice has been to apply to the tracheal tissue at a single instant equivalent or greater quantities of the anesthetic by means of spray or ointment (with however only short lasting affect). No toxic reactions were observed for the examples described above.

The required anesthetizing characteristic can be achieved through simple tests with variation of the constituents and their relationship to one another. For instance, for the preferred embodiment variable parameters include the nature of the semipermeable membrane or adhesive material, the

chemical nature of the anesthetic with regard to such factors as solubility in water and secretions, the thickness of the membrane and the distribution and concentration of the dry anesthetic.

Numerous variations within the spirit and scope of the claims will occur to those skilled in the art.

What is claimed is: t

l. A medical tracheal tube constructed for insertion into a body passage for prolonged exposure to mucous tissue of the patient, and having on its outside a solid layer comprised of solid surface effective anesthetic and solid substance physically securing the anesthetic with respect to the tube, both said anesthetic and said substance being solid at body temperature, the outer surface of said layer having a nontoxic surface anesthetizing characteristic extending over a period of at least 1 hour.

2. The tracheal tube of claim 1 wherein said solid substance is at least in part semipermeable to secretions of mucous tissue and to solutions of said anesthetic in said secretions whereby said anesthetic can be gradually dissolved and flow in solution into contact with some mucous tissue over a prolonged period of time.

3. The tracheal tube of claim 2 wherein said solid substance comprises an adhesive forming a coating on said tube with anesthetic distributed therethrough.

4. The tracheal tube of claim 3 wherein said solid substance comprises semipermeable silicone adhesive and said anesthetic is present in said adhesive in the form of solid particles.

5. The tracheal tube of claim 2 wherein as least part of said solid anesthetic is spaced from the outer surface of said layer by said semipermeable solid substance.

6. The tracheal tube of claim 1 wherein said tube is formed of resilient material, adapted to bend during insertion into the patient, and said layer is flexible and adapted to conform to said medical tube.

7. The tracheal tube of claim 6 wherein said layer comprises an elastomeric substance integrally united to said tube.

8. In a tracheal tube for introducing air into the lungs of a patient, said tube having means on its exterior surface for applying surface effective anesthetic to the tissue of the trachea by means of diffusion through a thickness of material having a diffusion characteristic, the improvement wherein said exterior surface is defined by film exposed for contact with body tissue to be anesthetized, said film carrying substantially dry surface-effective anesthetic spaced inwardly from said exterior surface, said film material and said surface-effective anesthetic being solid at body temperature and semipermeable by a liquid compatible with said body tissue to mobilize said anesthetic to diffuse to said exterior surface.

9. The tracheal tube of claim 8 including an inflatable cuff secured adjacent the distal end of said tube, wherein said cuff is formed by said film material, and at least one air passage adapted to introduce air into said cuff to cause said cuff to seal against tracheal tissue.

10. The tracheal tube of claim 9 wherein said film material and said surface effective anesthetic are semipermeable by water.

11. The tracheal tube of claim 10 wherein said cuff is comprised of semipermeable cellophane of a thickness less than 0.005 inch and said surface-effective anesthetic is in the form of a deposit adhered to the inner surface of said cuff, whereby said anesthetic can diffuse through said cuff to the tracheal tissue.

12. A means for applying surface effective anesthetic by diffusion through a thickness of material having a diffusion characteristic wherein the material comprises a film having a surface exposed for contact with body tissue to be anesthetized, the film carrying substantially dry surface-effective anesthetic spaced inwardly from said surface, said film material being permeable to and said surface anesthetic being dissolvable by a liquid compatible with said body tissue to mobilize said anesthetic to diffuse to said surface.

posite to said surface that is exposed for contact with body tissue.

15. The means of claim 12 wherein said surface-effective anesthetic is dispersed through the mass of said film.

Claims (15)

1. A medical tracheal tube constructed for insertion into a body passage for prolonged exposure to mucous tissue of the patient, and having on its outside a solid layer comprised of solid surface effective anesthetic and solid substance physically securing the anesthetic with respect to the tube, both said anesthetic and said substance being solid at body temperature, the outer surface of said layer having a nontoxic surface anesthetizing characteristic extending over a period of at least 1 hour.
2. The tracheal tube of claim 1 wherein said solid substance is at least in part semipermeable to secretions of mucous tissue and to solutions of said anesthetic in said secretions whereby said anesthetic can be gradually dissolved and flow in solution into contact with some mucous tissue over a prolonged period of time.
3. The tracheal tube of claim 2 wherein said solid substance comprises an adhesive forming a coating on said tube with anesthetic distributed therethrough.
4. The tracheal tube of claim 3 wherein said solid substance comprises semipermeable silicone adhesive and said anesthetic is present in said adhesive in the form of solid particles.
5. The tracheal tube of claim 2 wherein as least part of said solid anesthetic is spaced from the outer surface of said layer by said semipermeable solid substance.
6. The tracheal tube of claim 1 wherein said tube is formed of resilient material, adapted to bend during insertion into the patient, and said layer is flexible and adapted to conform to said medical tube.
7. The tracheal tube of claim 6 wherein said layer comprises an elastomeric substance integrally united to said tube.
8. In a tracheal tube for introducing air into the lungs of a patient, said tube having means on its exterior surface for applying surface effective anesthetic to the tissue of the trachea by means of diffusion through a thickness of material having a diffusion characteristic, the improvement wherein said exterior surface is defined by film exposed for contact with body tissue to be anesthetized, Said film carrying substantially dry surface-effective anesthetic spaced inwardly from said exterior surface, said film material and said surface-effective anesthetic being solid at body temperature and semipermeable by a liquid compatible with said body tissue to mobilize said anesthetic to diffuse to said exterior surface.
9. The tracheal tube of claim 8 including an inflatable cuff secured adjacent the distal end of said tube, wherein said cuff is formed by said film material, and at least one air passage adapted to introduce air into said cuff to cause said cuff to seal against tracheal tissue.
10. The tracheal tube of claim 9 wherein said film material and said surface effective anesthetic are semipermeable by water.
11. The tracheal tube of claim 10 wherein said cuff is comprised of semipermeable cellophane of a thickness less than 0.005 inch and said surface-effective anesthetic is in the form of a deposit adhered to the inner surface of said cuff, whereby said anesthetic can diffuse through said cuff to the tracheal tissue.
12. A means for applying surface effective anesthetic by diffusion through a thickness of material having a diffusion characteristic wherein the material comprises a film having a surface exposed for contact with body tissue to be anesthetized, the film carrying substantially dry surface-effective anesthetic spaced inwardly from said surface, said film material being permeable to and said surface anesthetic being dissolvable by a liquid compatible with said body tissue to mobilize said anesthetic to diffuse to said surface.
13. The means of claim 12 wherein said film is comprised of material from the group consisting of silicone, cellulose nitrate an regenerated cellulose.
14. The means of claim 12 wherein said film is less than about 0.005 inch thick and said surface-effective anesthetic is in the form of a deposit adhered to the surface of said film opposite to said surface that is exposed for contact with body tissue.
15. The means of claim 12 wherein said surface-effective anesthetic is dispersed through the mass of said film.
US803717A 1969-03-03 1969-03-03 Surface-anesthetizing medical appliance Expired - Lifetime US3610247A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US80371769A true 1969-03-03 1969-03-03

Publications (1)

Publication Number Publication Date
US3610247A true US3610247A (en) 1971-10-05

Family

ID=25187257

Family Applications (1)

Application Number Title Priority Date Filing Date
US803717A Expired - Lifetime US3610247A (en) 1969-03-03 1969-03-03 Surface-anesthetizing medical appliance

Country Status (3)

Country Link
US (1) US3610247A (en)
CA (1) CA971847A (en)
DE (1) DE2009968A1 (en)

Cited By (41)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4979505A (en) * 1989-06-06 1990-12-25 Cox Everard F Tracheal tube
DE4316920A1 (en) * 1993-05-20 1994-11-24 Michael Dr Med Hartmann endotracheal tube
WO1995008305A1 (en) * 1993-09-24 1995-03-30 Jackson Richard R Medical devices and methods of manufacture
WO1997018849A1 (en) * 1995-11-23 1997-05-29 Alec Douglas Bangham Endotracheal tubes with pulmonary medicaments
US5707355A (en) * 1995-11-15 1998-01-13 Zimmon Science Corporation Apparatus and method for the treatment of esophageal varices and mucosal neoplasms
US5709657A (en) * 1989-06-28 1998-01-20 Zimmon Science Corporation Methods for placement of balloon tamponade devices
WO1999045991A1 (en) * 1998-03-09 1999-09-16 Goebel Fred G Tracheal breathing apparatus
US6146358A (en) * 1989-03-14 2000-11-14 Cordis Corporation Method and apparatus for delivery of therapeutic agent
US6679262B1 (en) * 1996-03-11 2004-01-20 Orlando Morejon Endotracheal tube cleaning apparatus
US6716895B1 (en) 1999-12-15 2004-04-06 C.R. Bard, Inc. Polymer compositions containing colloids of silver salts
US20040116551A1 (en) * 1999-12-15 2004-06-17 Terry Richard N. Antimicrobial compositions containing colloids of oligodynamic metals
EP1428544A3 (en) * 1998-03-09 2004-07-14 Dr. Fred Göbel Patentverwaltung GmbH Tracheal breathing apparatus
US7060135B2 (en) 1996-03-11 2006-06-13 Orlando Morejon Endotracheal tube cleaning apparatus and method
US20060130847A1 (en) * 1996-03-11 2006-06-22 Orlando Morejon Endotracheal tube cleaning apparatus
US7487778B2 (en) 2003-08-11 2009-02-10 Breathe Technologies, Inc. Tracheal catheter and prosthesis and method of respiratory support of a patient
US7533670B1 (en) * 2005-09-20 2009-05-19 Breathe Technologies, Inc. Systems, methods and apparatus for respiratory support of a patient
US7588033B2 (en) 2003-06-18 2009-09-15 Breathe Technologies, Inc. Methods, systems and devices for improving ventilation in a lung area
US7631642B2 (en) 2006-05-18 2009-12-15 Breathe Technologies, Inc. Tracheostoma spacer, tracheotomy method, and device for inserting a tracheostoma spacer
US20100012130A1 (en) * 2006-09-22 2010-01-21 Romano Guerra Tracheostomy apparatus and device
US20100186748A1 (en) * 1996-03-11 2010-07-29 Orlando Morejon Endotracheal tube cleaning apparatus
US7820284B2 (en) 2001-12-03 2010-10-26 C.R. Bard Inc. Microbe-resistant medical device, microbe-resistant polymeric coating and methods for producing same
US20110186052A1 (en) * 2010-02-01 2011-08-04 Orlando Morejon Cleaning assembly for an endotracheal tube
US20110197894A1 (en) * 2010-02-18 2011-08-18 Orlando Morejon Endotracheal tube cleaning apparatus
US8136527B2 (en) 2003-08-18 2012-03-20 Breathe Technologies, Inc. Method and device for non-invasive ventilation with nasal interface
US20130000650A1 (en) * 2006-06-22 2013-01-03 Nellcor Puritan Bennett Llc Endotracheal cuff and technique for using the same
US8381729B2 (en) 2003-06-18 2013-02-26 Breathe Technologies, Inc. Methods and devices for minimally invasive respiratory support
US8567399B2 (en) 2007-09-26 2013-10-29 Breathe Technologies, Inc. Methods and devices for providing inspiratory and expiratory flow relief during ventilation therapy
USD699348S1 (en) 2010-01-27 2014-02-11 Orlando Morejon Handle
US8677999B2 (en) 2008-08-22 2014-03-25 Breathe Technologies, Inc. Methods and devices for providing mechanical ventilation with an open airway interface
US8770193B2 (en) 2008-04-18 2014-07-08 Breathe Technologies, Inc. Methods and devices for sensing respiration and controlling ventilator functions
US8776793B2 (en) 2008-04-18 2014-07-15 Breathe Technologies, Inc. Methods and devices for sensing respiration and controlling ventilator functions
US8925545B2 (en) 2004-02-04 2015-01-06 Breathe Technologies, Inc. Methods and devices for treating sleep apnea
US8939152B2 (en) 2010-09-30 2015-01-27 Breathe Technologies, Inc. Methods, systems and devices for humidifying a respiratory tract
US9032957B2 (en) 2006-06-22 2015-05-19 Covidien Lp Endotracheal cuff and technique for using the same
US9132250B2 (en) 2009-09-03 2015-09-15 Breathe Technologies, Inc. Methods, systems and devices for non-invasive ventilation including a non-sealing ventilation interface with an entrainment port and/or pressure feature
US9180270B2 (en) 2009-04-02 2015-11-10 Breathe Technologies, Inc. Methods, systems and devices for non-invasive open ventilation with gas delivery nozzles within an outer tube
US9962512B2 (en) 2009-04-02 2018-05-08 Breathe Technologies, Inc. Methods, systems and devices for non-invasive ventilation including a non-sealing ventilation interface with a free space nozzle feature
US10058668B2 (en) 2007-05-18 2018-08-28 Breathe Technologies, Inc. Methods and devices for sensing respiration and providing ventilation therapy
US10099028B2 (en) 2010-08-16 2018-10-16 Breathe Technologies, Inc. Methods, systems and devices using LOX to provide ventilatory support
US10252020B2 (en) 2008-10-01 2019-04-09 Breathe Technologies, Inc. Ventilator with biofeedback monitoring and control for improving patient activity and health
US10279137B1 (en) 2014-06-27 2019-05-07 Orlando Morejon Connector assembly for a medical ventilator system

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE215350C (en) *
US2803582A (en) * 1956-07-16 1957-08-20 Leonid S Cherney Local anesthetic composition
GB998794A (en) * 1962-08-28 1965-07-21 Dow Corning Carrier for controlled release of drugs
US3348542A (en) * 1964-12-02 1967-10-24 Richard R Jackson Anesthetic articles
US3363629A (en) * 1963-08-17 1968-01-16 Willy Rusch Fa Endotracheal catheter
US3363624A (en) * 1964-08-14 1968-01-16 Fishman Sam Prophylactic device
US3375828A (en) * 1965-04-15 1968-04-02 Brunswick Corp Suction catheter

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE215350C (en) *
US2803582A (en) * 1956-07-16 1957-08-20 Leonid S Cherney Local anesthetic composition
GB998794A (en) * 1962-08-28 1965-07-21 Dow Corning Carrier for controlled release of drugs
US3363629A (en) * 1963-08-17 1968-01-16 Willy Rusch Fa Endotracheal catheter
US3363624A (en) * 1964-08-14 1968-01-16 Fishman Sam Prophylactic device
US3348542A (en) * 1964-12-02 1967-10-24 Richard R Jackson Anesthetic articles
US3375828A (en) * 1965-04-15 1968-04-02 Brunswick Corp Suction catheter

Cited By (73)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6146358A (en) * 1989-03-14 2000-11-14 Cordis Corporation Method and apparatus for delivery of therapeutic agent
US6616650B1 (en) 1989-03-14 2003-09-09 Cordis Corporation Method and apparatus for delivery of therapeutic agent
US4979505A (en) * 1989-06-06 1990-12-25 Cox Everard F Tracheal tube
US5709657A (en) * 1989-06-28 1998-01-20 Zimmon Science Corporation Methods for placement of balloon tamponade devices
US5417671A (en) * 1990-05-23 1995-05-23 Jackson; Richard R. Medical devices having local anesthetic effect and methods of their manufacture
US5725510A (en) * 1993-05-20 1998-03-10 Hartmann; Michael Endotracheal tube
DE4316920A1 (en) * 1993-05-20 1994-11-24 Michael Dr Med Hartmann endotracheal tube
EP0722302A1 (en) * 1993-09-24 1996-07-24 Richard Robert Jackson Medical devices and methods of manufacture
EP0722302A4 (en) * 1993-09-24 2000-02-23 Richard Robert Jackson Medical devices and methods of manufacture
WO1995008305A1 (en) * 1993-09-24 1995-03-30 Jackson Richard R Medical devices and methods of manufacture
US5810786A (en) * 1993-09-24 1998-09-22 Richard R. Jackson Tissue-numbing anesthetic articles
US5906587A (en) * 1995-11-15 1999-05-25 Zimmon; David S. Apparatus and method for the treatment of esophageal varices and mucosal neoplasms
US5707355A (en) * 1995-11-15 1998-01-13 Zimmon Science Corporation Apparatus and method for the treatment of esophageal varices and mucosal neoplasms
WO1997018849A1 (en) * 1995-11-23 1997-05-29 Alec Douglas Bangham Endotracheal tubes with pulmonary medicaments
US7669600B2 (en) 1996-03-11 2010-03-02 Orlando Morejon Endotracheal tube cleaning apparatus
US8557054B2 (en) 1996-03-11 2013-10-15 Orlando Morejon Endotracheal tube cleaning apparatus
US20060130847A1 (en) * 1996-03-11 2006-06-22 Orlando Morejon Endotracheal tube cleaning apparatus
US20100186748A1 (en) * 1996-03-11 2010-07-29 Orlando Morejon Endotracheal tube cleaning apparatus
US7060135B2 (en) 1996-03-11 2006-06-13 Orlando Morejon Endotracheal tube cleaning apparatus and method
US6679262B1 (en) * 1996-03-11 2004-01-20 Orlando Morejon Endotracheal tube cleaning apparatus
US6526977B1 (en) 1998-03-09 2003-03-04 Goebel Fred G. Tracheal breathing apparatus
EP1428544A3 (en) * 1998-03-09 2004-07-14 Dr. Fred Göbel Patentverwaltung GmbH Tracheal breathing apparatus
US6802317B2 (en) 1998-03-09 2004-10-12 Fred Goebel Patentvarwaltung Gmbh Tracheal ventilating device
WO1999045991A1 (en) * 1998-03-09 1999-09-16 Goebel Fred G Tracheal breathing apparatus
US20030066532A1 (en) * 1998-03-09 2003-04-10 Gobel Fred G. Tracheal ventilating device
AU748342B2 (en) * 1998-03-09 2002-06-06 Avent, Inc. Tracheal breathing apparatus
US7179849B2 (en) 1999-12-15 2007-02-20 C. R. Bard, Inc. Antimicrobial compositions containing colloids of oligodynamic metals
US8034454B2 (en) 1999-12-15 2011-10-11 C.R. Bard, Inc. Antimicrobial compositions containing colloids of oligodynamic metals
US20040116551A1 (en) * 1999-12-15 2004-06-17 Terry Richard N. Antimicrobial compositions containing colloids of oligodynamic metals
US6716895B1 (en) 1999-12-15 2004-04-06 C.R. Bard, Inc. Polymer compositions containing colloids of silver salts
US20090293882A1 (en) * 1999-12-15 2009-12-03 C.R. Bard, Inc. Antimicrobial compositions containing colloids of oligodynamic metals
US7820284B2 (en) 2001-12-03 2010-10-26 C.R. Bard Inc. Microbe-resistant medical device, microbe-resistant polymeric coating and methods for producing same
US8381729B2 (en) 2003-06-18 2013-02-26 Breathe Technologies, Inc. Methods and devices for minimally invasive respiratory support
US8955518B2 (en) 2003-06-18 2015-02-17 Breathe Technologies, Inc. Methods, systems and devices for improving ventilation in a lung area
US7588033B2 (en) 2003-06-18 2009-09-15 Breathe Technologies, Inc. Methods, systems and devices for improving ventilation in a lung area
US8418694B2 (en) 2003-08-11 2013-04-16 Breathe Technologies, Inc. Systems, methods and apparatus for respiratory support of a patient
US7487778B2 (en) 2003-08-11 2009-02-10 Breathe Technologies, Inc. Tracheal catheter and prosthesis and method of respiratory support of a patient
US8136527B2 (en) 2003-08-18 2012-03-20 Breathe Technologies, Inc. Method and device for non-invasive ventilation with nasal interface
US8573219B2 (en) 2003-08-18 2013-11-05 Breathe Technologies, Inc. Method and device for non-invasive ventilation with nasal interface
US8925545B2 (en) 2004-02-04 2015-01-06 Breathe Technologies, Inc. Methods and devices for treating sleep apnea
US7533670B1 (en) * 2005-09-20 2009-05-19 Breathe Technologies, Inc. Systems, methods and apparatus for respiratory support of a patient
CN101454041B (en) 2005-09-20 2012-12-12 呼吸科技公司 Systems, methods and apparatus for respiratory support of a patient
US8631797B2 (en) * 2005-09-20 2014-01-21 Breathe Technologies, Inc. Systems, methods and apparatus for respiratory support of a patient
US20090255533A1 (en) * 2005-09-20 2009-10-15 Breathe Technologies Systems, methods and apparatus for respiratory support of a patient
US7631642B2 (en) 2006-05-18 2009-12-15 Breathe Technologies, Inc. Tracheostoma spacer, tracheotomy method, and device for inserting a tracheostoma spacer
US8985099B2 (en) 2006-05-18 2015-03-24 Breathe Technologies, Inc. Tracheostoma spacer, tracheotomy method, and device for inserting a tracheostoma spacer
US10076623B2 (en) 2006-06-22 2018-09-18 Covidien Lp Endotracheal cuff and technique for using the same
US20130000650A1 (en) * 2006-06-22 2013-01-03 Nellcor Puritan Bennett Llc Endotracheal cuff and technique for using the same
US9289567B2 (en) 2006-06-22 2016-03-22 Covidien Lp Endotracheal cuff and technique for using the same
US9032957B2 (en) 2006-06-22 2015-05-19 Covidien Lp Endotracheal cuff and technique for using the same
US8757161B2 (en) * 2006-09-22 2014-06-24 Romano Guerra Tracheostomy apparatus and device
US20100012130A1 (en) * 2006-09-22 2010-01-21 Romano Guerra Tracheostomy apparatus and device
US10058668B2 (en) 2007-05-18 2018-08-28 Breathe Technologies, Inc. Methods and devices for sensing respiration and providing ventilation therapy
US8567399B2 (en) 2007-09-26 2013-10-29 Breathe Technologies, Inc. Methods and devices for providing inspiratory and expiratory flow relief during ventilation therapy
US8776793B2 (en) 2008-04-18 2014-07-15 Breathe Technologies, Inc. Methods and devices for sensing respiration and controlling ventilator functions
US8770193B2 (en) 2008-04-18 2014-07-08 Breathe Technologies, Inc. Methods and devices for sensing respiration and controlling ventilator functions
US8677999B2 (en) 2008-08-22 2014-03-25 Breathe Technologies, Inc. Methods and devices for providing mechanical ventilation with an open airway interface
US10252020B2 (en) 2008-10-01 2019-04-09 Breathe Technologies, Inc. Ventilator with biofeedback monitoring and control for improving patient activity and health
US9675774B2 (en) 2009-04-02 2017-06-13 Breathe Technologies, Inc. Methods, systems and devices for non-invasive open ventilation with gas delivery nozzles in free space
US10046133B2 (en) 2009-04-02 2018-08-14 Breathe Technologies, Inc. Methods, systems and devices for non-invasive open ventilation for providing ventilation support
US9180270B2 (en) 2009-04-02 2015-11-10 Breathe Technologies, Inc. Methods, systems and devices for non-invasive open ventilation with gas delivery nozzles within an outer tube
US9227034B2 (en) 2009-04-02 2016-01-05 Beathe Technologies, Inc. Methods, systems and devices for non-invasive open ventilation for treating airway obstructions
US9962512B2 (en) 2009-04-02 2018-05-08 Breathe Technologies, Inc. Methods, systems and devices for non-invasive ventilation including a non-sealing ventilation interface with a free space nozzle feature
US10232136B2 (en) 2009-04-02 2019-03-19 Breathe Technologies, Inc. Methods, systems and devices for non-invasive open ventilation for treating airway obstructions
US9132250B2 (en) 2009-09-03 2015-09-15 Breathe Technologies, Inc. Methods, systems and devices for non-invasive ventilation including a non-sealing ventilation interface with an entrainment port and/or pressure feature
US10265486B2 (en) 2009-09-03 2019-04-23 Breathe Technologies, Inc. Methods, systems and devices for non-invasive ventilation including a non-sealing ventilation interface with an entrainment port and/or pressure feature
USD699348S1 (en) 2010-01-27 2014-02-11 Orlando Morejon Handle
US20110186052A1 (en) * 2010-02-01 2011-08-04 Orlando Morejon Cleaning assembly for an endotracheal tube
US20110197894A1 (en) * 2010-02-18 2011-08-18 Orlando Morejon Endotracheal tube cleaning apparatus
US10099028B2 (en) 2010-08-16 2018-10-16 Breathe Technologies, Inc. Methods, systems and devices using LOX to provide ventilatory support
US8939152B2 (en) 2010-09-30 2015-01-27 Breathe Technologies, Inc. Methods, systems and devices for humidifying a respiratory tract
US9358358B2 (en) 2010-09-30 2016-06-07 Breathe Technologies, Inc. Methods, systems and devices for humidifying a respiratory tract
US10279137B1 (en) 2014-06-27 2019-05-07 Orlando Morejon Connector assembly for a medical ventilator system

Also Published As

Publication number Publication date
DE2009968A1 (en) 1970-09-24
CA971847A (en) 1975-07-29
CA971847A1 (en)

Similar Documents

Publication Publication Date Title
Striker et al. Prolonged nasotracheal intubation in infants and children
Rees et al. A technique of pulmonary ventilation with a nasotracheal tube
GROB The manifestations and treatment of poisoning due to nerve gas and other organic phosphate anticholinesterase compounds
Branson Secretion management in the mechanically ventilated patient
US5417671A (en) Medical devices having local anesthetic effect and methods of their manufacture
US6609515B2 (en) Sealed backpressure attachment device for nebulizer
JP3782123B2 (en) Throat luminal cavity airway
US5233979A (en) Methods and apparatus for a micro-tracheal catheter hub assembly
CA1175727A (en) Multi-purpose tracheal tube
Jacoby et al. Transtracheal resuscitation
JP5603371B2 (en) Obstructive sleep apnea and snoring treatments and devices
US5029580A (en) Medical aspirating apparatus with multi-lumen catheter tube and methods
US3734100A (en) Catheter tubes
EP0104287A1 (en) Emergency medical apparatus
EP0613696B1 (en) Medico-surgical tube including improved means for administering liquid or gas treatment
US6792943B2 (en) Intubating ventilatory face mask
US5329921A (en) Endotracheal tube
US4821715A (en) Nasopharyngeal airway
US6402735B1 (en) Medical tube collar
Maltby et al. The laryngeal mask airway: clinical appraisal in 250 patients
US5199427A (en) Multi-layered transtracheal caatheter
US6668821B2 (en) Laryngeal mask airway
US5230332A (en) Methods and apparatus for a micro-tracheal catheter hub assembly
Young et al. Leakage of fluid past the tracheal tube cuff in a benchtop model.
Lomholt A NEW TRACHEOSTOMY TUBE: I. Cuff with Controlled Pressure on the Tracheal Mucous Membrane