Nasal Cannula

Abstract

Nasal cannula device molded of a soft, flexible material includes a tubular member which supports a pair of integral cannula extensions. Openings at each end of the tubular member provide alternative connection points for an oxygen supply tube. An arch-like nose bridge engageable band member integrally attached to the tubular member outwardly of the cannula extensions has a layer of adhesive on its under surface for anchoring the cannula to the patient's nose.

Description

BACKGROUND OF THE INVENTION

This invention relates to a nasal cannula device for delivering oxygen to a patient over a relatively long period of time.

There are many devices for carrying oxygen into the nostrils of a patient which are shown in the prior art. Although each of these prior art devices performs the function of delivering oxygen to a patient, it does so with some degree of discomfort to the patient. Most of the prior art devices rely on the use of elastic bands encircling the wearer's head to provide the support necessary for maintaining the cannula extensions in position within the wearer's nostrils. Others utilize the oxygen supply tubing as a support, sometimes by having a length of tubing extending from each end of the cannula with the two lengths of tubing being adjustably fastened to each other at a point behind the wearer's head. More often, the latter type of device is anchored by looping the lengths of tubing over the wearer's ears and fastening them together under his chin. When such prior art devices are worn for an extended period of time, they generally chafe and irritate the wearer's skin as he moves his head. They also are uncomfortable and often interfere with the wearer's sleep since they press into his flesh as he moves his head on his pillow. U.S. Pat. Nos. 2,735,432, 2,831,487, 2,868,199, 2,931,358 and 3,513,844 are illustrative of the aforementioned types of devices.

In U.S. Pat. No. 3,046,989, a flat ductile metal member is shown which has an adhesive coating on one side and includes a pair of integral tabs which are adapted to encircle a non-integral single nasal tube. The metal member is adhered to a patient's nose and deformed into conforming shape after a nasal tube has been placed into the patient's nostril. The tabs are then bent around the nasal tube to anchor it. Being made of flat metal, the member would be rather difficult to conform to the shape of the wearer's nose so as to achieve good contact with most of the adhesive. In addition, the metal, being a good conductor, would probably feel uncomfortably cold to the wearer when it was initially fastened to him.

SUMMARY

It is an object of this invention to provide a nasal cannula device which is effective for its purpose and more comfortable to the patient than previously known devices while yet being relatively simple and economical to manufacture.

It is a further object of this invention to provide a nasal cannula which may be attached to a source of oxygen located on either side of a patient's bed without having the supply tube pass over the patient's body.

It is another object of the invention to provide a nasal cannula which is shaped so that a single size can be worn comfortably by the vast majority of potential users.

These and other objects are obtained by the present invention wherein a nasal cannula is formed, preferably by injection molding, from a soft plastic material such as vinyl or plastisol or from silicone rubber. Since the cannula is adapted to be adhesively fastened to the wearer's nose, it is within his field of view. Thus, the cannula, like the frames of a new pair of glasses, can be slightly distracting when first worn. However, the patient quickly becomes used to it and forgets he is wearing it. To minimize the initial distraction, the cannula can be molded of a generally clear material which is frosted to reduce glare.

The cannula device basically comprises as open ended curved cannula member which has a pair of spaced integral cannula extensions extending generally radially upwardly from its central region. The cannula extensions are formed generally parallel to the transverse midline of an arched nose bridge engageable band which is integrally connected to the cannula tube near its ends. The cannula extensions are preferably slightly flared at their outer ends. The flaring causes a slight reduction in the velocity of the oxygen as it enters the wearer's nostrils and therefore minimizes the possibility of damage to the mucosa. It has been found that by making the cannula so that the arched band has a width along its transverse midline where it engages the bridge of the nose of about 22 millimeters, the cannula can be comfortably and effectively worn by the vast majority of potential users, even though the sizes and shapes of the noses of the persons in this group vary widely. Preferably, the cannula device is attached to the bridge of the wearer's nose so that the center of the cannula member either touches or is very close to the web separating the wearer's nostrils. For most of these users, the cannula member will be supported by the nose contacting band so as to be spaced slightly from the wearer's lip rather than resting upon it. For small children, a scaled down version of the device may be used. The adhesive used to attach the device to the patient should be hypo-allergenic and may be either coated onto the underside of the arched band portion or applied to it in the form of a double-faced pressure sensitive tape. In either of these forms, the adhesive surface which is to be attached to the patient should be protected with an easily removed protective covering such as plastic coated paper which has little affinity for the adhesive. Rather than manufacture the cannula with the adhesive on it, it would also be possible to apply a piece of double faced tape to either the cannula or the patient at the time the cannula is fitted to the patient. Although the cannula member preferably is open at each end so that the oxygen supply tubing can be attached from either end, depending on the location of the patient relative to the oxygen supply, it would of course be possible to mold the cannula with one closed end to avoid the necessity of placing a plug in the end which is not connected to the oxygen supply.

The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of a preferred embodiment thereof, as illustrated in the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing the cannula of the present invention in exploded relationship with a sealing plug and oxygen supply tube;

FIG. 2 is a side view of the cannula with the oxygen supply tubing removed showing its position relative to a diagrammatic representation of the nasal passages of a human patient;

FIG. 3 is a front view of the cannula with a portion thereof shown in section; and

FIG. 4 is a cross-sectional view taken on the line 4--4 of FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENT

In FIG. 1, a nasal oxygen cannula indicated generally at 10, which is preferably injection molded of a soft flexible plastic or rubber-like material, comprises an elongated cannula member 12 which has an opening or passageway 14 extending throughout its length. A pair of hollow cannula extension members 18, 20 extend radially outwardly from the central region 22 of the cannula member 12. Preferably, the internal diameter of the cannula extensions 18, 20 is greater at the free ends thereof, as shown in FIG. 3, in order to lower the velocity of and slightly diffuse the oxygen delivered by the extensions, so that the oxygen will impinge only lightly upon the mucosa in the nostrils of a patient wearing the cannula. The elongated opening or passageway 14 may be attached to an oxygen supply tube 26 at one of its ends and may be closed off by a plug member 28 at its other end. The end which is to be attached to the oxygen supply tubing 26 is determined by the location of the source of oxygen relative to the location of the patient. Generally, it is desirable that the tubing 26 be connected to the end of the cannula member which is on the same side of the patient as the oxygen supply so as to eliminate the need for the tubing to cross the patient's body, as is often necessary with cannula devices wherein the tubing is non-removably affixed to one end of the cannula.

Attached to the cannula member 12 at opposite end regions 32, 34 thereof is a thin (approximately 2mm thick) arch-like band portion indicated generally at 38 which includes a pair of leg portions 40, 42 which are connected to each other by a generally U-shaped portion 44 which is formed so as to closely approximate the shape of the human nose along the bridge thereof. The legs 40, 42 and the U-shaped portion 44 are relatively flat and much wider than they are thick and have a smooth undersurface where they are to contact the wearer. The legs twist somewhat from their junctures 32, 34 with the cannula member 12 to the region in which they join the U-shaped portion 44 in a manner which approximates the contours of a wearer's face and nose. To anchor the U-shaped portion 44 to a wearer's nose, a layer of adhesive 48 is provided. The adhesive 48 is normally protected by a lightly adhering plastic or paper layer 50 which may be readily removed when the cannula is to be used. In use, the cannula extensions 18, 20 are placed into the nostrils N of a patient P as shown in FIG. 2 so that the cannula member 12 touches or comes close to the lower portion of the patient's nose. The U-shaped portion 44 is then pressed against the nose so as to cause the adhesive 48 to adhere firmly. In this position, the cannula extensions 18, 20 cannot be unintentionally displaced from the nostrils N. However, the flexible nature of the cannula member 12 and legs 40, 42 permits the extensions 18, 20 to be intentionally pulled out of the nostrils N and the cannula member 12 left to rest comfortably on the tip of the nose without unfastening the adhesive 48 from the nose. Thus, the patient can blow his nose or permit it to be examined without rendering the adhesive ineffective. In order to permit the device to accommodate to a large range of nose shapes and sizes, the U-shaped portion 44 should have a width as measured on the line a-b in FIG. 3 which is great enough to provide a sufficient surface to achieve a good adhesive bond to the nose and small enough that it will not extend upwardly past the bridge of the nose on a small-nosed patient. It is also preferable that the U-shaped portion not cover the tip of the nose. It has been found that a dimension a-b of a size greater than the diameter of the cannula extension 18 and less than the distance a-c from the cannula member 12 to the uppermost part of the U-shaped portion 44 will provide satisfactory results although it is preferable that the dimension a-b be about one half of or slightly less than one half of the distance a-c. Line a-b-c defines a midline of U-shaped, or arch-like, portion 44 in a direction transverse to the length of portion 44.

Claims

That which is claimed is:

1. A nasal oxygen cannula formed of soft flexible material and comprising an elongated cannula member, a pair of nasal cannula extension portions integral with and extending generally radially outwardly from a central region of said cannula member, said pair of nasal cannula being in flow communication with said elongated cannula member, an arch-like portion adapted to extend across the bridge of the nose of a user integrally joined at its ends to regions of said cannula member which are spaced away from said central region and toward the respective ends of said cannula member, said arch-like portion extending from said cannula member in generally the same direction as said nasal cannula extension portions and having a width along a midline of the arch in a direction which is transverse to the length of the arch which is greater than the diameter of one of the cannula extension portions and less than the spacing along said midline between the cannula member and the remotest point of said arch-like portion, means on said arch-like portion for attaching same to the nose of a user, and at least one opening in said cannula member for connecting said cannula to a source of oxygen.

2. The nasal oxygen cannula of claim 1 wherein said arch-like portion has a width considerably greater than its thickness and a generally smooth undersurface.

3. The nasal oxygen cannula of claim 2 wherein said means for attaching includes a portion of said undersurface covered by a layer of adhesive.

4. The nasal oxygen cannula of claim 3 wherein said adhesive is of the pressure sensitive type and is protected before use by a layer of easily removed, lightly adherable material.

5. The nasal oxygen cannula of claim 1 wherein said cannula member has openings at each of its ends adapted to receive either a length of oxygen supply tubing or a sealing plug.

6. The nasal oxygen cannula of claim 1 wherein the ends of the cannula extensions which are remote from the cannula member have a greater internal diameter than the remainder of the cannula extensions.

7. The nasal oxygen cannula of claim 1 wherein the cannula extensions have their axes generally parallel to the transverse midline of the arch-like portion.

8. The nasal oxygen cannula of claim 1 wherein said cannula member is curved.

9. The nasal oxygen cannula of claim 1 wherein the width along the midline of said arch-like portion is approximately one half of the distance between the cannula member and the remotest point on the midline of said arch-like portion.

10. The nasal oxygen cannula of claim 9 wherein the width along the midline of said arch-like portion is less than one-half of the distance between the central region of the cannula member and the remotest point on the midline of said arch-like portion.

11. The nasal oxygen cannula of claim 9 wherein said arch-like portion has a width considerably greater than its thickness, is smooth on its undersurface, and is covered over a portion of said undersurface by a layer of pressure sensitive adhesive.

12. The nasal oxygen cannula of claim 11 wherein said cannula is injection molded of a soft vinyl plastic.