GB2329340A - Breathing aid for tracheostomy patients - Google Patents

Abstract

The aid comprises a channel member 1 having a first end defining a cannula 5 for insertion into the stoma of the patient, a body member 4 and a second end adapted to condition inspired air by means of a releasable cap 8 constructed from hydrophilic foam, such cap fitting securely about the inlet port of the channel member. The foam may be a reticulated, open-pored, polyester-based polyurethane foam and may be impregnated with an anti-bacterial agent. The foam cap can be quickly and easily removed when blocked with mucus or particulate material. The aid, which may also be used as a phonation device, maybe secured about the patient's neck by means of attachment rings 7 and a securing thread.

Description

BRICATHING AID The invention relates to a breathing filter for use by tracheostomy patients to condition air before it reaches the lungs.

The human respiratory system comprises the upper respiratory tract which includes the nose, pharynx and larynx and the lower respiratory tract corvising the trachea which divides into the bronchioles and the bronchial tree and terminates in aveoli, the site of respiratory gas exchange.

In mammals air is drawn into a paired nasal cavity through external nostrils.

The nasal cavities contain a series of ridges which increase the surface area of the nasal cavity. The nasal cavity is covered in a mucosa which is well vascularised and contains various mucus glands which function to secrete a 4hickmucopolysaccharide based mucus. This region is also rich in cilia which function to move the mucus to the back of the pharynx where it is either swallowed or expectorated, The mucus functions to remove particulate mateal from ire inspired air to prevent it accumulating in the lungs and it also helps to warm and humidify the incoming air so that when it reaches the lungs it has been fkally conditioned.

A highly specialised region of the respiratory tract is the larynx, more cwly known as the voice box. The larynx is a cartilaginous structure located at the base of the pharynx and at the entrance of the trachea The vocal chords are situated in the larynx and they comprise a pair of lateral folds in the waJls of the larynx. When these folds are apposed, air expired from the lungs vibrate the vocal chords which vibrates the air in the upper pharyngeal region.

This process is termed phonation or the production of vocal sound. The vocal sound is translated into speech by the combined action of the pharynx, mouth, tongue and lips which are co-ordinated by the central nervous system.

The majority of people speak during expiration and therefore the ability to be able to pass air from the lungs to the larynx and pharyngeal region is crucial if a person is to communicate via speech.

It will be apparent that damage to the trachea either as a result of injury or disease will have profound effects on an individuals ability to breath un-aided and to communicate via speech. A tracheostomy is a surgical procedure that results in the removal of part of the trachea. This is most common in cases where tumours are established and the only remedial course of action is the surgical removal of the cancerous tissue. To ensure the complete removal of the cancer tissue large sections of the trachea are removed. In severe cases sections of trachea can be excised thereby separating the lungs from the upper pharyngeal region and so preventing the normal respiratory process.

In these cases gaseous exchange between the air and lungs is via a tube inserted into the neck of the patient and locating in the cavity of the trachea. The tube is adapted to incorporate, amongst other things, a filter and heating means to assist in the removal of particulate material and the humidification and warming of air that passes directly into the trachea before it reaches the lungs.

A number of respiratory aids have been developed that function in the aforedescribed manner. In its simplest form the aid is a bib that covers the tracheal opening. An example of such a bib is described in patent document GB109Q336. The bib contains a hydrophilic filter contained within a meshed network pouch. The hydrophilic filter allows moisture to be retained in the bib and prevents dust, dirt etc from entering the trachea. The air is therefore Edified and notably is also warmed by the radiant heat obtained in the bib from the expired air and the patients own body heat. The bib is not entirely efve as a filter because air can pass around the edges of the bib. Also this aid does not facilitate the passage of air to the larynx to effect speech. The patient has to lift and place a finger/hand over the tracheal opening to redirect the expired air to the larynx to enable phonation.

A further development of a respiratory aid for tracheostomy patients is described in patent document GB 2214089 A. A filter is incorporated into a body member which is placed into the tracheal opening. Air is inspired through a downward projecting outlet so that air close to the patient's body is inspired and is therefore warmer than the ambient temperature of the surrounding enwonment. The filter is located in the body member in such a way that expired air swirls around the body member behind a check valve to humidify the filter. Air passing through the humidified filter acquires both heat and mnist}s during passage through the same. This is a considerable improvement on a bib as expired air can be easily diverted to the larynx by the inclusion of the check valve which opens upon inspiration and closes when the patient exhales thus facilitating speech. However, the filter requires periodic retlaoewt due to the accumulation of mucus and dust in the filter. This procedure is somewhat involved and will cause undue stress to the patient during reement.

A variation on the above device is described in patent document US 5022394.

The device described in this document incorporates a collar to secure the device around the patient's neck. The filter is manufactured from a hygroscopic (water retaining) material which retains moisture and heat from expired air. The retained heat and moisture is utilised to warm and humidify inspired air. The patient can relatively easily prevent expired air escaping via the tracheal opening by placing a hand/ finger over the inlet opening thereby directing airflow to the larynx to effect speech. However, the device described in document US 5022394 suffers from the same disadvantage as the device described in GB2214089A insofar as the filter needs to be periodically exchanged to prevent filter blockage due to particulate material and mucus.

Moreover, the incorporated neck brace assists in securing the valve in the tracheal opening but is somewhat unattractive and is likely to draw attention to the patient's condition.

An attempt to improve the aesthetic appearance of tracheal tubes is described in patent document US 4763645. The basic design of the tracheal tube comprising; an outer inlet aperture, a body member containing a filtration system and ending in a cannula, is additionally designed to appear as an ornamental piece ofjewellery. The objective is to hide the tracheal tube behind an ornamental cap thereby making the tube less obvious to the general public.

A more recent variation on these respiratory aids is described in patent document US 5259378. The device utilises a pair of filtration units attached to a cannula which is inserted into the tracheal opening. The body of the cannula has been further adapted by incorporation of a valve which although enabling the inhalation of air, prevents exhaled air escaping via cannula. The expired air is therefore forced towards the larynx to allow phonation. The filtration units, as with previous embodiments of this type of device do require periodic replacement. The major disadvantage of this device is that expired air is not utilised to humidify and warm the inspired air. By directing airflow from the lungs to the larynx the filters are not moisturised or warmed by the expired air.

Although this may not ordinarily be disadvantageous in certain climates, (e.g.

humid/warm countries), in either arid or cold climates this would be a distinct disadvantage because the air is not conditioned before it contracts the lungs.

The vice is also large and somewhat bulky and protrudes in front of the patient's throat.

Given the above facts it can be seen that there is a need to provide a respiratory aid that overcomes the disadvantages associated with prior art devices.

It-is therefore an object of this invention to provide a effective means of conditioning inspired air for tracheostomy patients that does not require extensive manipulation of the device to remove filters for replacement.

It is afiner object of the invention to provide a tracheostomy device that can be readily blocked by the patient to direct expired air from the lungs to the laaw to facilitate speech.

It is yet a further object of the invention to provide an unobtrusive and comfortable tracheostomy device.

The invention comprises a novel solution to the aforementioned problems relating to respiratory aids. A standard tracheal cannula with a standard 15mum connector ISO number (5356-1) is adapted by the addition of a gas permeable air conditioning cap that fits loosably but securely upon a selected port.

The cap is manufactured from a hydrophilic material that has excellent water retention properties, an effective filtration means, can be easily removed and replaced with little disturbance to the patient and is unobtrusive.

An advantage provided by the current invention is the relocation of the filtration humidification means from an integral site in the body of the cannula to an external location covering an inlet to a channel defining means. Another advantage provided by the current invention is the use of a foam as an air conditioning member for a respiratory aid. It is not necessary to dismantle the respiratory device to remove and replace blocked filters. It is also easy to redirect expired air to the pharyngeal region. The cap can be easily covered or depressed thereby occluding the inlet to the cannula and redirecting expired air to the larynx. Because of the caps unobtrusive nature a patient can simply place a finger onto the cap to enable phonation.

According to a first aspect of the invention there is provided a respiratory aid for tracheostomy patients which comprises: a channel defining means having at least first and second ends, one of which is adapted for insertion into at least the stoma of a patient and the other is adapted for conditioning air to be inspired by way of the releasable attachment thereto of at least one conditioning cap comprising a suitably sized and shaped piece of hydrophilic foam.

According to another aspect of the invention there is provided a respiratory aid for tracheostomy patients which comprises: a channel defining means having at least first and second ends, one of which is adapted for insertion into at least the stoma of a patient, and the other is adapted for conditioning air to be inspired by way of the releasable attachment to an outer end thereof of at least one conditioning cap comprising a suitably sized and shaped piece of foam.

In a preferred embodiment of the invention said first and second ends provide inlet and exit ports of the channel defining means which facilitate the passage of air In yet a ftirther preferred embodiment of the invention said channel defining means is fUrther adapted by inclusion of at least one appendage, appropriately positioned, via which said aid can be reversibly secured in place.

In a yet furier preferred embodiment of the invention said channel defining means is of constant diameter.

Altaniatively, in yet a further preferred embodiment of the invention said inlet port has a greater cross-sectional area than the exit port.

In yet a zither preferred embodiment said inlet port is convergently connected over at least part of its length to said exit port to form the channel defining means.

According to a second aspect of the invention there is provided at least one conditioning cap as herein described.

In a preferred embodiment of the invention said cap is selectively sized and shaped to fit releasably, and ideally resiliently, and securely upon a selected port.

In yet a further preferred embodiment of the invention said cap is manufactured from hydrophilic material, ideally Hydrolox.

Hydrolox is a reticulated, fully open-pored foam, constructed from a flexible polyester based polyurethane having the following physical characteristics: 80110 pores per linear 2.54cm, a density of 30-37kg per cubic metre, hardness of 4-5.0 KPA and a tear strength of 7min.KPA. Moreover, Hydrolox is supplied in a number of flesh-coloured tones and white to allow the constructed cap to merge with a patient's skin colour or tracheostomy tube.

In yet a further preferred embodiment said foam is suitably coloured to merge inconspicuously with the skin tone of the relevant tracheostomy patient.

In a yet further preferred embodiment said foam is white to merge with a patients tracheostomy device.

In yet a further preferred embodiment said air conditioning cap is impregnated with an anti-bacterial agent to prevent bacteria entering the trachea.

According to a third aspect there is provided a respiratory aid or conditioning cap as herein described for use as a phonation device.

It will be apparent the conditioning filter can be quickly and easily removed when blocked with mucus or particulate material. This is a significant improvement on prior art devices since they require the respiratory aid to be dismantled before replacement of an integral filter.

An embodiment of the invention will now be described, by example only, with reference to the following figures.

Figure 1 represents a perspective view of a tracheostomy cannula with the onmg cap removed.

Figure 2 represents a perspective view of a tracheostomy cannula with the conditioning cap in place.

Figure 3 represents a front end view ofthe cannula showing the securing arms attached end rings, and the convergent connection between the inlet port and the body member.

Figure 4 represents a perspective view of the conditioning cap.

Referring to Figure 1: the respiratory aid comprises a channel defining means (1) comprising an inlet aperture (2) and an exit aperture (3). The channel definX means, essentially, comprises two parts, connected there together via an intermediary member (4). The first inlet port, comprises a tube whose logitudinai axis is parallel with a single plane. The second outlet port comprises a flexible or semi-rigid tube that is arranged to curve downwardly with respect to said first port. In the above example the inner side of the first inlet port (2) describes a convergent bore at least to the medially located intermediary member (4). Downstream of the body member (4) the channel defining means (1) extends to the exit aperture (3) the downstream region ofthe respiratory aid defines a cannula (5) which is inserted through the stoma of the patient and into the cavity of the trachea. Body member (4) is further adapted by the attachment of paired appendages (6) symmetrically arranged about a selected diameter of member (4) and terminating in attachment rings (7) for use in the securing of the respiratory aid to a securing thread about the patients neck.

Referring to Figure 2: the respiratory aid described above is adapted by the placement of an air conditioning cap (8) upon the inlet aperture (2). The air conditioning is a one-piece construction generally of conical shape, but may in other embodiments be of any desired shape provided it fits on the end of the respiratory aid. The pliant property of the air conditioning cap (8) enables the cap to fit securely about the inlet port (2) but is so constructed that the filter (8) can be easily removed with a minimum of disturbance to the patient. The dark colouration of the cap is merely for contrast purposes and can be alternatively constructed from flesh coloured or white Hydrolox to merge with the patient's skin tone or tracheostomy device Referring to Figure 3: the respiratory aid is shown as a front end view to illustrate the inner convergent connection (9) between the inlet port (2) and the medially located intermediary member (4). Downstream of the member (4) extends the cannula (5) which has a bore of generally a constant diameter.

It can be seen that the respiratory aid is simple in construction and therefore easy to make and inconspicuous when in use.

Finally referring to Figure 4: an air conditioning filter (10) manufactured from a Hydrolox foam is given. The dimensions/shape of the cap can be adapted for its selected use and can be so coloured to merge unobtrusively with the patient's sE tone also the cap may be impregnated with anti bacterial agents to reduce the threat of microbial infection. Moreover, the upper most surface (11) is sufficiently pliant to enable the patient to easily deform the cap to occlude the inlet port (2) to prevent expired air escaping via the channel defining means (1) and redirecting the air to the larynx to facilitate speech.

During use the channel defining means (1) would be gently inserted into the stoma of a tracheostomy patient. Securing thread is placed through the securing rings (7) and around the patients neck to retain the position of the channel defining means in the stoma. The air conditioning cap is then placed over the inlet aperture (2). During respiration the patient inspires air that is filtered by the air conditioning cap (10). Upon expiration the hydrophilic property of Hydrolox retains both moisture and heat thereby humidifying and warming the conditioning cap. During subsequent cycles of respiration the heat and water rettied in the cap is conducted to the inspired air thus conditioning the air before it reaches the lungs.

After use, the blocked air conditioning cap can be easily removed and replaced with a clean cap as and when required. If the patient wishes to speak, the cap top (11) can be readily depressed to occlude the inlet aperture (2) ofthe channel defining means (1). The expired air cannot thus escape and is redirected to the larynx to facilitate phonation.

It will be apparent that the air conditioning cap represents an efficient means of humidifying and filtering inspired air before it reaches the lungs of a tracheostomy patient. It will also be evident that the cap is a significant improvement on existing respiratory aids since the removal and replacement of the cap can be easily effected with a minimum of disturbance to the aid and consequently to the patient.

Claims (15)

1. A respiratory aid for tracheostomy patients comprising; a channel defining means having at least first and second ends, one of which is adapted for insertion into the stoma of a patient and the other adapted to condition inspired air by way of a releasable air conditioning cap constructed from hydrophilic foam.

2. A respiratory aid for tracheostomy patients comprising a channel defining means having at least first and second ends, one of which is adapted fbr insertion to the stoma of a patient and the other adapted to condition inspired air by way of the releasable attachment to an outer end thereof of an air conditioning cap constructed from hydrophilic foam.

3. A respiratory aid for tracheostomy patients according to Claims I or t-wioin said first and second ends provide inlet and exit ports of the cnel defining means which facilitate the passage of air.

4. A respiratory aid for tracheostomy patients according to Claims 1-3, wherein said channel defining means is adapted by the inclusion of at least one-appendage, appropriately positioned, via which said respiratory aid can be reversibly secured in said stoma

5. A respiratory aid for tracheostomy patients according to Claims 1-4, wherein said channel-defining means is of a constant diameter.

6 A respiratory aid for tracheostomy patients according to Claims 1-4 wherein said channel defining means is of a variable diameter.

7. A respiratory aid for tracheostomy patients according to Claims 1-6 wherein one of said ends is convergently connected over at least part of its length to said other end to form the channel defining means.

8. An air conditioning cap for the releasable attachment to an end of a respiratory aid according to Claims 1-7 for the conditioning of inspired air.

9. An air-conditioning cap according to Claim 8 wherein said cap is selectively sized and shaped to fit releasably and securely upon a selected end.

10. An air conditioning cap according to Claims 8 or 9 wherein said cap is manufactured from hydrophilic material.

11. An air-conditioning cap according to Claims 8-10 wherein said cap is constructed from foam suitably coloured to merge inconspicuously with the skin tone of a tracheostomy patient.

12. An air-conditioning cap according to Claims 8-10 wherein said cap is constructed from white foam to merge with a patient's tracheostomy device.

13. An air-conditioning cap according to Claims 8-12 wherein said cap is impregnated with an anti-bacterial agent.

14. A respiratory aid according to Claims 1-7 and an air conditioning cap according to Claims 8-13 for use as a phonation device.

15. A respiratory aid or conditioning cap or phonation device as substantially herein described and/or with reference to the corresponding figures.