WO2013150313A1

WO2013150313A1 - Tracheostomy tube

Info

Publication number: WO2013150313A1
Application number: PCT/GB2013/050892
Authority: WO
Inventors: John Stephen RUBIN
Original assignee: Rubin John Stephen
Priority date: 2012-04-05
Filing date: 2013-04-05
Publication date: 2013-10-10
Also published as: GB2500933A; GB201206187D0

Abstract

The present application discloses an artificial syrinx for location in the trachea of a patient. Also disclosed is a tracheostomy tube comprising an artificial syrinx, a fenestrated tracheostomy tube comprising an artificial syrinx, an inner cannula for a fenestrated tracheostomy tube comprising an artificial syrinx, a voice prosthesis, methods for manufacturing a tracheostomy tube, methods for performing a tracheostomy and/or returning speech to a patient, and methods for preparing an artificial syrinx for implantation into the trachea of a patient.

Description

TRACHEOSTOMY TUBE

Field of the Invention The present invention relates to an artificial syrinx for location in the trachea of a patient. The invention also relates to a tracheostomy tube comprising an artificial syrinx, a fenestrated tracheostomy tube comprising an artificial syrinx, an inner cannula for a fenestrated tracheostomy tube comprising an artificial syrinx, a voice prosthesis, methods for manufacturing a tracheostomy tube, methods for performing a tracheostomy and/or returning speech to a patient, and methods for preparing an artificial syrinx for location into the trachea of a patient.

Background to the Invention The larynx is an organ in the neck of mammals (including humans) and many other vertebrates involved in breathing, sound production, and protecting the trachea against food aspiration. The larynx houses the vocal folds, which are used for phonation. The vocal folds are situated where the tract of the pharynx splits into the trachea and the oesophagus.

In adult humans, the larynx is found in the anterior neck at the level of the C3-C6 vertebrae. It connects the inferior part of the pharynx with the trachea.

In some patients the vocal folds can become damaged or scarred by disease, surgery and/or trauma to such an extent that they no longer produce a voice. Indeed, as part of the treatment of cancer of the throat, it often occurs that the larynx, or part of the larynx, including the vocal folds, or part of the vocal folds, is removed. Further patients are born with congenital abnormalities affecting the larynx. Still further patients with an intact larynx are unable to develop adequate lung pressure to create a voice. In all of these instances, the lack of voice can be extremely distressing and debilitating for the patient. As such, there is a need for devices and/or methods of treatment which enable speech to be returned or provided to the patient. Traditionally, to enable voice production after total removal of the larynx, it has been usual to place a valve in the wall between the oesophagus and the trachea. Air flowing out of the lungs is then passed from the trachea through the valve to the upper part of the oesophagus. This vibrates the tissue in the oesophagus and enables the patient to generate a voice. The results are however often disappointing because of the unnatural sound produced as a consequence of the oesophagus' fundamental frequency being too low.

Other approaches have included both electronic voice prostheses and alternative exhaled air driven voice prostheses.

Typical electronic voice prostheses include an electronic vibration source which is pressed against the throat. This type of prosthesis suffers from the problem of producing an unnatural, robotic sound.

Other electronic voice prostheses have included an external tone generator, a tracheostomy or nasal intubation tube, and a secondary speaking channel. Drawbacks of this type of prosthesis are the quality of the voice, and the unattractiveness of the tone generator and/or secondary speaking channel leading from the mouth or nose.

Exhaled air driven devices have included a reed, or other tone generating means, which is placed at the back of the mouth or in the pharynx. Again, however, they have previously relied upon the use of a nasal intubation tube, which can be unattractive. As will be apparent, there remains a need for a voice prosthesis which produces a more natural voice, which is aesthetically pleasing, which is simple to use and which is comfortable in individuals with part of the larynx removed or damaged to the point it cannot reliably create a voice. The present invention sets out to address these and other problems with the prior art. Summary of the Invention

In a first aspect, the invention provides an artificial syrinx for location in the trachea of a patient, preferably who still has portion or all of their larynx intact. The artificial syrinx preferably comprises a conduit for aligned intubation in the lumen of the trachea and said conduit preferably comprises means for vibrating exhaled air within the trachea, preferably means for vibrating exhaled air within the trachea to produce an audible sound. Preferably, the vibrating exhaled air is delivered to an intact vocal tract. Preferably, said conduit comprises means for vibrating exhaled air within the trachea at a frequency substantially similar to the frequency of natural human speech. Preferably, the vibrating means is breath-actuated. Once vibrating, the exhaled air travels to the mouth, via the vocal tract, and enables the patient to speak and to take advantage of the relatively intact pharynx and vocal tract to create natural resonance of the voice. In use, preferably a majority, more preferably substantially all, of the audible sound is conveyed through the mouth of the patient. Preferably, the entirety of the vibrating means is located within the trachea of the patient. Preferably, in use, the entirety of the artificial syrinx is located below the larynx of the patient. The means for vibrating air within the trachea may also vibrate in response to an external air or oxygen supply. Preferably, the conduit for aligned intubation in the lumen of the trachea comprises a superior aperture and an inferior aperture wherein, once located in the trachea of a patient, said superior and inferior apertures are in fluid communication with the lumen of the trachea. Typically, the superior and inferior apertures are in fluid communication with superior and inferior portions of the lumen of the trachea, respectively.

Typically, during exhalation, vibrating air leaves the conduit via the superior aperture.

The syrinx is the name for the vocal organ of birds. Located at the base of a bird's trachea, it produces vibrating air for sound production without the need for functioning vocal folds. The syrinx is not found in mammals. The inventor has determined that by locating an artificial syrinx into the trachea of a patient, particularly those whose vocal folds are scarred, or otherwise damaged, to such an extent that they cannot speak; it is possible to deliver vibrating air to the mouth of a patient and recover speech. This has the advantage of not requiring surgery on the larynx itself which may affect swallowing and other functions. It also provides a more natural voice compared to known devices. While not necessarily located in the same place within the windpipe as the syrinx of birds, by being located within the trachea the artificial syrinx of the present invention is able to function in much the same way as that found in birds.

For the purposes of the invention, artificial syrinx is understood to be a device or formation which mimics the syrinx. Typically, an artificial syrinx is a device or formation that produces an audible sound by the passage of gas over or through the device or formation. Audible sound has its usual meaning, i.e. a sound a young human with undamaged hearing can detect. Typically, the audible sound will be audible outside of the patient who has received the artificial syrinx. Typically, the audible sound will have a frequency of 20 Hz - 20,000 Hz and an intensity of 10^"12 - 10 watts/m². Preferably, the frequency of the audible sound produced by the means for vibrating exhaled air within the trachea will be in range typical of natural human speech.

For the purpose of the invention patient is understood to mean any mammal, preferably any human, more preferably any human who has lost their voice as a result of absent or compromised vocal folds.

For the purpose of the invention, trachea is understood to mean the portion of windpipe running from below the larynx to the primary bronchi. The trachea comprises a lumen surrounded by the tracheal wall.

As used herein, the following directional definitions apply. Anterior and posterior mean nearer the front or nearer the back of the body respectively. Superior and inferior mean nearer to or further from the top of the device or body, respectively. Superior and inferior portions of the trachea respectively refer to portions of the trachea above and below the device once in position. As used herein, natural human speech is understood to have a frequency of from about 85 Hz to about 355 Hz.

In an embodiment of the invention, the means for vibrating exhaled air within the trachea comprises at least one membrane. Membrane is understood to mean a planar body having a minor dimension (i.e. thickness) and at least one major dimension (i.e. width or length), although preferably two major dimensions (i.e. width and length). Typically, the means for vibrating exhaled air within the trachea comprises two membranes, although three, four or more membranes are contemplated. In one embodiment, when more than one membrane is present, the membranes are in substantially the same plane and, preferably, approach along a minor surface. Preferably, when not in use, the membranes touch along the minor surface. Typically, when two membranes are used they approximate across a diameter of the conduit. Preferably, the at least one membrane has a major surface, said at least one membrane being arranged such that said at least one membrane vibrates in response to airflow substantially transverse to said major surface.

In alternative arrangements, the at least one membrane is arranged such that said at least one membrane vibrates in response to airflow substantially parallel to a major surface. In said alternative arrangement, when more than one membrane is present, the membranes are arranged such that their major surfaces face one another. Again, two, three, four, or more membranes are contemplated.

By providing at least one membranes of different thicknesses and/or materials, at the same or different tensions, so, by altering the fundamental frequency of the at least one membrane, the pitch of the voice produced by the artificial syrinx may be altered. Preferably, the thickness, material and/or tension of the at least one membrane is such that its fundamental frequency is substantially similar to the frequency of natural human speech. Preferably the material, thickness, and/or tension of the at least one membrane is such that the fundamental frequency of the at least one membrane is from about 85 Hz to about 355 Hz. Typically, the thickness (i.e. the minor dimension) of the at least one membrane is from about 0.1 mm to about 5 mm. Preferably, the thickness is uniform along the length and width of the membrane, although it may vary. The material may be any biocompatible material, although silicone rubbers are particularly preferred. Typically, the silicone rubber is a medical grade silicone rubber; preferably, with a Shore durometer hardness (ASTM D2240, Type A) of from about 40 to about 70. Typically, the silicone rubber is moulded using liquid silicone resin.

In an embodiment, the at least one membrane comprises at least one inflatable bladder. Preferably, the at least one inflatable bladder is inflated and/or deflated in order to alter the fundamental frequency of the at least one inflatable bladder. Preferably, the at least one inflatable bladder may be inflated such that its fundamental frequency is substantially similar to the frequency of natural human speech. Preferably the at least one inflatable bladder may be inflated such that the fundamental frequency of the at least one inflatable bladder is from about 85 Hz to about 355 Hz. Providing a bladder which may be inflated and/or deflated has the advantage of enabling the pitch of the patient's voice to be altered. In a preferred embodiment, the fundamental frequency can be altered during speech.

Being able to alter the pitch of a voice enables the voice to be more realistic, and enables the depth of the voice to be adjusted depending on, for instance, the sex of the patient. Male patients, for instance, will tend to require deeper voices than female patients. Typically, the vibrating means of the artificial syrinx of the invention has a fundamental frequency of from about 85 Hz to about 355 Hz. In another embodiment, the at least one inflatable bladder is inflated and/or deflated in order to allow the airflow to pass unimpeded from the nose to the lungs upon inhalation. This has the advantage that the artificial syrinx does not produce a noise upon inhalation and reduces the inhalation effort required by the patient. It also helps in the case of emergencies.

In a further embodiment, the at least one inflatable bladder comprises a secondary conduit for inflating and/or deflating the at least one inflatable bladder. Typically, inflation and/or deflation of the at least one inflatable bladder is managed by a patient operable external control. Preferred patient operable external controls include a manual or electronic pumping means, or a source of compressed gas. In an embodiment, the artificial syrinx comprises two inflatable bladders, although three, four or more bladders are contemplated. Typically, the two or more inflatable bladders approximate each other. Typically, when two inflatable bladders are present, the inflatable bladders approximate across a diameter of the conduit. Typically, when two or more inflatable bladders are present, they are provided in fluid communication with one another.

Preferably, the at least one inflatable bladder is inflated with a fluid, preferably water, saline or air. Typically, the at least one membrane and/or inflatable bladders comprise a silicone rubber. Typically, the silicone rubber is a medical grade silicone rubber; preferably, with a Shore durometer hardness (ASTM D2240, Type A) of from about 40 to about 70. Typically, the silicone rubber is moulded using liquid silicone resin.

Preferably, the conduit comprises a biocompatible material selected from the group consisting of biocompatible metals and alloys or biocompatible polymers. Preferred biocompatible polymers include polyethylene, polypropylene, polyvinylchloride, polyurethane, and silicone rubber.

Preferably, the conduit for aligned intubation in the lumen of the trachea has a cross- section less than or substantially similar in size to the lumen of the trachea of the patient. More preferably, the conduit for aligned intubation in the lumen of the trachea has an external diameter of from about 4 mm to about 25 mm. Preferably, the conduit for aligned intubation in the lumen of the trachea has an internal diameter of from about 3 mm to about 15 mm; more preferably from about 4 mm to about 10 mm.

Typically, the conduit for aligned intubation in the lumen of the trachea has a cross-section substantially similar in shape to the lumen of the trachea of the patient. More preferably, the conduit for aligned intubation in the lumen of the trachea is substantially circular or elliptical in cross-section. In a second aspect, the invention provides a tracheostomy tube comprising an artificial syrinx according to the first aspect of the invention. Typically, the tracheostomy tube comprises a conduit for aligned intubation in the lumen of the trachea and said conduit comprises means for vibrating exhaled air within the trachea, preferably means for vibrating exhaled air within the trachea to produce an audible sound. Typically, the tracheostomy tube comprises an external cuff for securing the tracheostomy tube in the trachea. Preferably, the external cuff comprises an inflatable bladder. In a third aspect, the invention provides a fenestrated tracheostomy tube comprising an artificial syrinx according to the first aspect of the invention. Typically, the fenestrated tracheostomy tube comprises a conduit for aligned intubation in the lumen of the trachea and said conduit comprises means for vibrating exhaled air within the trachea, preferably means for vibrating exhaled air within the trachea to produce an audible sound.. Typically, the fenestrated tracheostomy tube comprises an external cuff for securing the fenestrated tracheostomy tube in the trachea. Preferably, the external cuff comprises an inflatable bladder.

In an embodiment, the fenestrated tracheostomy tube comprises a superior fenestra and the means for vibrating exhaled air within the trachea is located within said superior fenestra. Within said superior fenestra is not limited to the exact confines of the superior fenestra and, preferably, includes immediately next to, inside or across the superior fenestra. Typically, the means for vibrating exhaled air within the trachea spans the superior fenestra.

An advantage of providing the means for vibrating exhaled air within the trachea within the superior fenestra is that during an emergency a secondary cannula may be intubated into the fenestrated tracheostomy tube without damaging the means for vibrating exhaled air within the trachea. Typically, the secondary cannula does not comprise a fenestra. The secondary cannula may also be introduced when vibrating air in the trachea is not required, such as during sleep. In an alternative embodiment, the secondary cannula may comprise a superior fenestra. Preferably, in use, once intubated in the fenestrated tracheostomy tube, the superior fenestra of the secondary cannula aligns with the superior fenestra of the fenestrated tracheostomy tube so as to be in fluid communication therewith. This has the advantage that the secondary cannula can be maintained within the fenestrated tracheostomy tube to keep it free of secretions whilst allowing the artificial syrinx in the tracheostomy tube to function.

In an alternative embodiment, the fenestrated tracheostomy tube comprises an inferior cannula portion and wherein the artificial syrinx is located in said inferior cannula portion. The inferior cannula portion refers to the portion of the tracheostomy tube below the superior fenestra, which, in use, is intubated in the trachea of the patient.

In embodiments, the tracheostomy tubes or fenestrated tracheostomy tubes further comprise an anterior aperture and an anterior aperture valve. Preferably, the anterior aperture valve is arranged so as to open on inhalation and close on exhalation. By closing on exhalation, substantially all exhaled air is directed through the superior fenestra and the means for vibrating exhaled air within the trachea. Preferably, the anterior aperture valve may be locked in its open position. In the case of the fenestrated tube wherein the means for vibrating exhaled air within the trachea is located within said superior fenestra, this arrangement has the advantage of allowing the patient to switch off the artificial syrinx. This enables them to, for instance, sleep free from vibration. In a fourth aspect the invention provides, an inner cannula for a fenestrated tracheostomy tube. Typically, the inner cannula comprises an artificial syrinx according to the first aspect of the invention. Preferably, the inner cannula is suitable for aligned insertion within a fenestrated tracheostomy tube. Preferably, the inner cannula is removable from said fenestrated tracheostomy tube. Preferably, the fenestrated tracheostomy tube comprises a superior fenestra. Typically, the inner cannula comprises a fenestra which, in use, substantially aligns with the superior fenestra of the fenestrated tracheostomy tube so as to be in fluid communication therewith. Typically, the means for vibrating exhaled air within the trachea is located within the inner cannula fenestra. Within said inner cannula fenestra, is not limited to the exact confines of the inner cannula fenestra and, preferably includes immediately next to, inside or across the inner cannula fenestra. Typically, the means for vibrating exhaled air within the trachea spans the inner cannula fenestra.

An advantage of providing an inner cannula comprising an artificial syrinx is that the artificial syrinx may be inserted and removed without the need for further invasive treatment. This has the advantage of enabling the patient to easily remove the artificial syrinx when it is not required, such as during sleep, or for cleaning or replacement.

In an embodiment, a range of inner cannula having artificial syrinxes comprising vibrating means each with different fundamental frequencies is provided. Thus, an inner cannula can be selected to provide a pitch of voice appropriate for a particular patient. Being able to alter the pitch of a voice enables the voice to be more realistic, and enables the depth of the voice to be adjusted depending on, for instance, the sex of the patient. Male patients, for instance, will tend to require deeper voices than female patients. Typically, the vibrating means of the artificial syrinx of the invention has a fundamental frequency of from about 85 Hz to about 355 Hz. The inner cannula may have vibrating means with a fundamental frequency from with this range.

In an embodiment, a minor cannula for delivering air or oxygen from an external supply is provided within the tracheostomy tube. Typically, the minor cannula is in fluid communication with an outside source of oxygen or air. In use, the minor cannula may act as a pathway for air or oxygen to pass either to the lungs or directly into the prosthesis to act as an external source of air or oxygen and/or as a source of air for vibrating the artificial syrinx's means for vibrating exhaled air within the trachea. This is particularly beneficial to individuals with poor lung capacity and/or who require breath support, such as those with advanced neurological diseases, chronic obstructive pulmonary disease or emphysema, or those in an intensive treatment unit. Typically, the minor cannula is separate from the tracheostomy tube, although in embodiments the minor cannula forms a unitary part of the tracheostomy tube. In still further embodiments, the minor cannula forms a unitary part of an inner cannula. As will be appreciated, a minor cannula as described above may be used with other aspects of invention. In a fifth aspect the invention provides, a voice prosthesis for implantation in the lumen of the trachea comprising an artificial syrinx according to the first aspect of the invention. Typically, the voice prosthesis comprises a conduit for aligned intubation in the lumen of the trachea and said conduit comprises means for vibrating exhaled air within the trachea, preferably means for vibrating exhaled air within the trachea to produce an audible sound.

The voice prosthesis may be fixed in the trachea by means of mechanical fixation, such as suturing or stapling, or by means of an external cuff, such as an inflatable bladder or expandable foam. In an embodiment of the invention, the voice prosthesis comprises an artificial trachea for replacing a portion of the trachea that has been removed and wherein the artificial syrinx is located within said artificial trachea.

In embodiments of the invention, the artificial syrinx allows airflow to pass from the nose to the lungs unimpeded during inhalation.

In a sixth aspect, the invention provides a method for returning speech to a patient comprising the steps of:

a. providing an artificial syrinx comprising a conduit for aligned intubation in the lumen of the trachea, said conduit comprising means for vibrating exhaled air within the trachea, preferably means for vibrating exhaled air within the trachea to produce an audible sound; and

b. intubating said artificial syrinx in the trachea of a patient.

In a seventh aspect, the invention provides a method for performing a tracheostomy comprising the steps of: a. providing a tracheostomy tube or fenestrated tracheostomy tube comprising a conduit for aligned intubation in the lumen of the trachea, wherein said conduit comprises means for vibrating exhaled air within the trachea, preferably means for vibrating exhaled air within the trachea to produce an audible sound;

b. making an incision on the anterior aspect of a patient's neck;

c. opening a direct airway through an incision in the trachea; and

d. inserting the tracheostomy tube or fenestrated tracheostomy tube through the incisions.

In an eighth aspect, the invention provides a method for performing a tracheostomy comprising the steps of:

a. providing a fenestrated tracheostomy tube;

b. making an incision on the anterior aspect of a patient's neck;

c. opening a direct airway through an incision in the trachea;

d. inserting the fenestrated tracheostomy tube through the incisions; e. providing an inner cannula comprising a conduit for aligned inserting in the fenestrated tracheostomy tube, wherein said conduit comprises means for vibrating exhaled air within the trachea, preferably means for vibrating exhaled air within the trachea to produce an audible sound; and f. inserting the inner cannula in the fenestrated tracheostomy tube.

In a ninth aspect, the invention provides a method for returning speech to a patient comprising the steps of:

a. providing a voice prosthesis comprising a conduit for aligned implantation or intubation in the trachea, wherein said conduit comprises means for vibrating exhaled air within the trachea, preferably means for vibrating exhaled air within the trachea to produce an audible sound; and b. implanting or intubating said conduit in the trachea of a patient.

In a tenth aspect, the invention provides a method for manufacturing a fenestrated tracheostomy tube comprising the steps of: a. moulding or otherwise forming a fenestrated tracheostomy tube; and b. affixing means for vibrating exhaled air within the trachea, preferably means for vibrating exhaled air within the trachea to produce an audible sound.

In an eleventh aspect, the invention provides a method for preparing an artificial syrinx for location in the trachea of a patient comprising the steps of:

a. providing a plurality of artificial syrinxes, each comprising a conduit for aligned intubation in the trachea of a patient, said conduit comprising means for vibrating exhaled air within the trachea, preferably means for vibrating exhaled air within the trachea to produce an audible sound; wherein the means for vibrating exhaled air within the trachea of the plurality of artificial syrinxes have fundamental frequencies which are substantially similar to the frequency of natural human speech and which are different; and

b. selecting an artificial syrinx having a means for vibrating exhaled air within the trachea having a fundamental frequency which is appropriate for the patient.

In a twelfth aspect, the invention provides a method for preparing an artificial syrinx for location in the trachea of a patient comprising the steps of:

a. providing an artificial syrinx comprising a conduit for aligned intubation in the trachea of a patient, said conduit comprising means for vibrating exhaled air within the trachea, preferably means for vibrating exhaled air within the trachea to produce an audible sound; and

b. adjusting the means for vibrating exhaled air within the trachea such that its fundamental frequency is substantially similar to the frequency of natural human speech.

All embodiments of the first aspect of the invention may be combined with all other aspects of the invention. Brief Description of the Figures

The above-mentioned and other features and objects of this invention, and the manner of obtaining them, will become more apparent and the invention itself will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein:

Fig.1 is a schematic of a cross-sectional side view of a patient's head throat area. Fig. 2 is a schematic of an artificial syrinx according to the invention comprising one membrane.

Fig. 3 is a schematic of an alternative artificial syrinx according to the invention comprising two membranes.

Fig. 4 is a schematic of an alternative artificial syrinx according to the invention comprising two membranes.

Fig. 5 is a schematic of an alternative artificial syrinx according to the invention comprising two inflatable bladders.

Fig. 6 is a schematic of an alternative artificial syrinx according to the invention.

Fig. 7 is a schematic of a known fenestrated tracheostomy tube.

Fig. 8 is a schematic of a fenestrated tracheostomy tube according to the invention.

Fig. 9 is a schematic of a fenestrated tracheostomy tube according to the invention which has been located in the trachea of a patient.

Fig.10 is a schematic of an inner cannula for aligned intubation in a fenestrated tracheostomy tube. Fig. 11 is a schematic of a fenestrated tracheostomy tube according to the invention which has been located in the trachea of a patient, said tracheostomy tube further comprising a minor cannula in fluid communication with an outside source of oxygen or air.

Although the drawings represent exemplary embodiments of the present invention, the drawings are not necessarily to scale and certain features may be exaggerated to better illustrate and explain the invention. The exemplification set out herein illustrates exemplary embodiments of the invention only.

Detailed Description of the Invention

The invention provides an artificial syrinx for location in the trachea of a patient. The artificial syrinx preferably comprises a conduit for aligned intubation in the lumen of the trachea and preferably comprises means for vibrating exhaled air within the trachea, preferably means for vibrating exhaled air within the trachea to produce an audible sound.

Preferably, the entirety of the vibrating means is located within the trachea of the patient.

Preferably, in use, the entirety of the artificial syrinx is located below the larynx of the patient. The means for vibrating air within the trachea may also vibrate in response to an external air supply. Preferably a majority, preferably substantially all, of the audible sound is conveyed through the mouth of the patient.

Fig. 1 is a schematic diagram showing a cross-sectional side view of a patient's head and throat area. The trachea is the portion of lower respiratory tract running from below the larynx to the primary bronchi. The vocal folds (not shown) stretch horizontally across the larynx.

Fig. 2 is a schematic cross-section of an artificial syrinx for location in the trachea of a patient (21) according to the invention. The artificial syrinx (21) comprises a conduit (22) for aligned intubation in the lumen of the trachea. The conduit (22) comprises means for vibrating exhaled air within the trachea (23). Arrow (A) indicates the direction of exhaled air. As the conduit (22) is intubated in the lumen of the trachea, so the means for vibrating exhaled air within the trachea (23) are able to provide vibrating air to the mouth for speech without the need for a functioning larynx.

In the embodiment illustrated in Fig. 2, the means for vibrating exhaled air within the trachea (23) comprise a membrane (24). Furthermore, in the illustrated embodiment, the membrane (24) is arranged such that the membrane (24) vibrates in response to airflow (A) substantially transverse to its major surfaces (25, 26).

Fig. 3 illustrates a schematic cross-section of an alternative artificial syrinx for location in the trachea of a patient (31) according to the invention. The artificial syrinx (31) comprises a conduit (32) for aligned intubation in the lumen of the trachea. The conduit (32) comprises means for vibrating exhaled air within the trachea (33). Arrow (B) indicates the direction of exhaled air. In the embodiment illustrated in Fig. 3, the means for vibrating exhaled air within the trachea (33) comprise two membranes (34, 35). In the illustrated embodiment, the two membranes approach along minor surfaces (36, 37). In the illustrated embodiment, the approaching minor surfaces (36, 37) are touching one another. Further, the membranes' (34, 35) major surfaces (38, 39, 310, 311), are arranged such that they vibrate in response to airflow (B) substantially transverse to the major surfaces (38, 39, 310, 311).

Fig. 4 shows a further alternative artificial syrinx for location in the trachea of a patient (41) according to the invention. The artificial syrinx (41) comprises a conduit (42) for aligned intubation in the lumen of the trachea. The conduit (42) comprises means for vibrating exhaled air within the trachea (43). Arrow (C) indicates the direction of exhaled air.

In the embodiment illustrated in Fig. 4, the means for vibrating exhaled air within the trachea (43) comprise two membranes (44, 45). In this embodiment, however, the membranes (44, 45) are arranged such that the membranes vibrate in response to airflow (C) substantially parallel to the major surface (46, 47). In said alternative arrangement, the membranes are arranged such that their major surfaces (46, 47) face one another. The membranes (44, 45) are held in place by supporting means (48, 49, 410, 411).

In the embodiments illustrated in Figs. 2 to 4, the material and/or thickness and/or tension of the at least one membrane is such that the fundamental frequency of the at least one membrane is from about 85 Hz to about 355 Hz. The thickness (i.e. the minor dimension) of the at least one membrane may be from about 0.1 mm to about 5 mm. Preferably, the thickness is uniform along the length and width of the membrane, although it may vary. The material may be any biocompatible material, although silicone rubbers are particularly preferred. Typically, the silicone rubber is a medical grade silicone rubber; preferably, with a Shore durometer hardness (ASTM D2240, Type A) of from about 40 to about 70. Typically, the silicone rubber is moulded using liquid silicone resin.

Fig. 5 shows a further alternative artificial syrinx for location in the trachea of a patient (51) according to the invention. The artificial syrinx (51) comprises a conduit (52) for aligned intubation in the lumen of the trachea. The conduit (52) comprises means for vibrating exhaled air within the trachea (53). Arrow (D) indicates the direction of exhaled air. In the embodiment illustrated in Fig. 5, the means for vibrating exhaled air within the trachea (53) comprise two membranes (54, 55). In this embodiment the membranes (54, 55) are in the form of inflatable bladders (56, 57). The inflatable bladders may be inflated with water, saline or air, or any other suitable fluid. The inflatable bladders may be inflated such that their fundamental frequency is substantially similar to the frequency of natural human speech. The inflatable bladders may be inflated such that their fundamental frequency is from about 85 Hz to about 355 Hz.

The thickness (i.e. the minor dimension) of a membrane forming a bladder may be from about 0.1 mm to about 5 mm. Preferably, the thickness is uniform along the length and width of the membrane, although it may vary. The material may be any biocompatible material, although silicone rubbers are particularly preferred. Typically, the silicone rubber is a medical grade silicone rubber; preferably, with a Shore durometer hardness (ASTM D2240, Type A) of from about 40 to about 70. Typically, the silicone rubber is moulded using liquid silicone resin.

Fig. 6 shows a further alternative artificial syrinx for location in the trachea of a patient according to the invention. The artificial syrinx (61) comprises a conduit (62) for aligned intubation in the lumen of the trachea. The conduit (62) comprises means for vibrating exhaled air within the trachea (63). Arrows (E) and (F) indicate the direction of exhaled air. In the embodiment illustrated in Fig. 6 the means for vibrating exhaled air within the trachea (63) is located in a fenestra (64) in a superior wall (65) of the conduit (62). The conduit (62) is curved such that it may be intubated in the lumen of the trachea, while also presenting the fenestra (64) superiorly in order to vibrate the air within the trachea and direct it towards the mouth for speech. The illustrated means for vibrating exhaled air within the trachea (63) is a pair of inflatable bladders, although it may, in other embodiments, be one or more membranes or a single inflatable bladder. Similar or the same materials and/or material thicknesses may be used for the membranes and/or inflatable bladders as described above for the other illustrated embodiments. Fig. 7 is a schematic of a known fenestrated tracheostomy tube (71). The known fenestrated tracheostomy tube (71) comprises a conduit (72) for aligned intubation in the lumen of the trachea. The conduit (72) comprises a fenestra (73) which is located in the superior wall (74) of the conduit (72). In use, exhaled air is able to pass through the fenestra (73) unobstructed to the vocal folds, enabling the patient to speak.

The known fenestrated tracheostomy tube (71) also comprises a retention plate (75) comprising two retention apertures (76, 77) for receiving a retention strap (not shown). The retention plate prevents over-intubation of the conduit (72) into the patient's trachea. The embodiments of the artificial syrinx (21, 31, 41, 51) illustrated in Figs. 2 to 5 may be incorporated within the inferior cannula portion (78) of such known devices. In such arrangements, preferably, the wall of the inferior cannula portion forms the conduit for aligned intubation in the lumen of the trachea.

Fig. 8 shows a fenestrated tracheostomy tube (81) according to the invention. The fenestrated tracheostomy tube (81) comprises a conduit (82) for aligned intubation in the lumen of the trachea and said conduit comprises means for vibrating exhaled air within the trachea. The illustrated fenestrated tracheostomy tube (81) comprises an optional external cuff (84) for securing the fenestrated tracheostomy tube (81) in the trachea. The illustrated optional external cuff (84) is an inflatable external cuff. Such cuffs are well known in the art.

The fenestrated tracheostomy tube (81) comprises a superior fenestra (85) and the means for vibrating exhaled air within the trachea (83) is located within said superior fenestra (85). The means for vibrating exhaled air within the trachea (83) spans the superior fenestra (85). The illustrated means for vibrating exhaled air within the trachea (83) is two inflatable bladders, although it may, in other embodiments, be one or more membranes or a single inflatable bladder. Similar or the same materials and/or material thicknesses may be used for the membranes and/or inflatable bladder membranes as described above for the other illustrated embodiments.

The fenestrated tracheostomy tube (81) also comprises an optional retention plate (86). The external portion of the tracheostomy tube comprises an optional anterior aperture (87) and an optional anterior aperture valve (not shown) located in an anterior valve housing (88). The optional anterior aperture valve opens on inhalation and closes on exhalation in order to better direct air through the superior fenestra (85) and the means for vibrating exhaled air within the trachea (83).

The fenestrated tracheostomy tube (81) also comprises a patient operable external control (89) for managing inflation and/or deflation of the inflatable bladders (83). The patient operable external control (89) comprises a secondary conduit (810), an inflation bladder (811) and a one way valve (812). The patient operable external control (89) is detachable. The inflatable bladders are inflated by squeezing the inflation bladder (811) by hand so that air is pushed along the secondary conduit (810) and into the inflatable bladders (83). When the inflation bladder (811) is subsequently released, air is drawn through the one-way valve (812) and the inflation bladder (811) is refilled. If further inflation is required the process is repeated. In order, to deflate the inflatable bladders (83), the one-way valve (812) is held open. Conveniently, the patient operable external control (89) may also be used to inflate the external cuff (84). In alternative arrangements, the illustrated patient operable external control can be replaced by an electronic pumping system or the use of compressed gas. Preferably, if an electronic pumping system is used the control is situated on the retention plate. In certain embodiments, the electronic pumping system is automatically controlled in order to deflate the bladders for inhalation and inflate them for exhalation. The patient operable external control can be used to deactivate the device during, for instance, sleep; to alter the pitch of the voice; and to deactivate the device during an emergency.

Fig. 9 shows a fenestrated tracheostomy tube (91) according to the invention located in the trachea (90) of a patient. The fenestrated tracheostomy tube (91) comprises a conduit (92) for aligned intubation in the lumen of the trachea and said conduit (92) comprises means for vibrating exhaled air within the trachea (93). The fenestrated tracheostomy tube (91) comprises a superior fenestra (97) located in the superior wall (98) of the conduit (92). The means for vibrating exhaled air within the trachea (93) comprises two inflatable bladders. The fenestrated tracheostomy tube (91) comprises an optional external cuff (94) and an optional retention plate (95).

The arrows 1 to 5 illustrate the movement of air during use. In use, on inhalation [1] air is drawn in through the anterior aperture (96), [2] along the conduit and [3] into the patient's trachea for inhalation. On exhalation, [4] air expelled from the lungs travels up the trachea (90), into the conduit (93), and through the superior fenestra (97). The movement of air through the superior fenestra (97) causes the inflatable bladders (93) to vibrate which, in turn, vibrates the exiting air as it enters the trachea [5]. The vibrating air in the trachea is delivered to the mouth for speech. Air cannot leave through the anterior aperture (96) because the optional anterior aperture valve (not shown) closes during exhalation. The anterior aperture valve may be held open when vibrating air for speech is not required, such as during sleep. In embodiments not including the anterior aperture valve, a digit may be placed over the anterior aperture during exhalation in order to assist the provision of vibrating air to the trachea for speech.

Fig. 10 shows an inner cannula (101) for a fenestrated tracheostomy tube. The inner cannula (101) comprises a conduit (102) for aligned insertion in a fenestrated tracheostomy tube and said conduit (102) comprises means for vibrating exhaled air within the trachea (103). The inner cannula (101) comprises a superior fenestra (104) located in the superior wall (105) of the conduit (102). The means for vibrating exhaled air within the trachea (103) comprises two inflatable bladders. The inner cannula (101) comprises a retention portion (106) for preventing over insertion of the inner cannula (101) in a fenestrated tracheostomy tube. The retention portion (106) preferably comprises a greater diameter than the anterior aperture of the fenestrated tracheostomy tube. The retention portion (106) may optionally comprise a one-way valve (not shown) which opens on inhalation and closed on exhalation, thereby preferentially diverting exhaled air across the means for vibrating exhaled air within the trachea (103). If no one-way valve is present, the patient may produce a similar effect by covering the anterior aperture of the inner cannula with, for instance, their finger.

An advantage of the inner cannula according to the invention is that it may be inserted in prior art fenestrated tracheostomy tubes such as the one shown in Fig. 7. This allows surgeons and caregivers greater freedom of selection when choosing a suitable fenestrated tracheostomy tube. It also aids with cleaning and replacement of the device.

Fig. 11 shows a fenestrated tracheostomy tube (11 1) according to the invention located in the trachea (110) of a patient. The fenestrated tracheostomy tube (111) comprises a conduit (112) for aligned intubation in the lumen of the trachea (110) and said conduit (112) comprises means for vibrating exhaled air within the trachea (113). The fenestrated tracheostomy tube (111) comprises a superior fenestra (117) located in the superior wall (118) of the conduit (112). The means for vibrating exhaled air within the trachea (113) comprises two inflatable bladders. The fenestrated tracheostomy tube (111) comprises an optional external cuff (114) and an optional retention plate (115). The fenestrated tracheostomy tube (111) further comprises a minor cannula (119) for delivering air or oxygen from an external supply. The minor cannula (119) is in fluid communication with an outside source of oxygen or air (not shown). As shown, the minor cannula (119) is intubated through the anterior aperture (116), fed through the fenestrated tracheostomy tube, and exits through the inferior aperture (1110). In this embodiment, the minor cannula (119) acts as a pathway for air or oxygen to pass to the lungs. In alternative embodiments, the minor cannula may act directly as a source of air or oxygen for vibrating the means for vibrating exhaled air with trachea of the artificial syrinx, or both. Typically, the minor cannula is separate from the tracheostomy tube, although in embodiments it forms a unitary part of the tracheostomy tube. In still further embodiments, it forms a unitary part of an inner cannula.

It will be appreciated by those skilled in the art that the foregoing is a description of a preferred embodiment of the present invention and that variations in design and construction may be made to the preferred embodiment without departing from the scope of the invention as defined by the appended claims.

Claims

An artificial syrinx for location in the trachea of a patient comprising a conduit for aligned intubation in the lumen of the trachea; and means for vibrating exhaled air within the trachea to produce an audible sound.

An artificial syrinx according to claim 1 wherein, in use, vibrating exhaled air exiting the artificial syrinx enters a superior portion of the trachea.

An artificial syrinx according to claims 1 or 2 wherein the conduit for aligned intubation in the lumen of the trachea comprises a superior aperture and an inferior aperture wherein, once located in the trachea of a patient, said superior and inferior apertures are in fluid communication with the lumen of the trachea.

An artificial syrinx according to claims 1 to 3 wherein the means for vibrating exhaled air within the trachea to produce an audible sound comprises at least one membrane.

An artificial syrinx according to claim 4 wherein the at least one membrane has a major surface, said at least one membrane being arranged, in use, such that said at least one membrane vibrates in response to airflow substantially transverse to the major surface.

An artificial syrinx according to claim 4 or 5 wherein the at least one membrane comprises at least one inflatable bladder.

7. An artificial syrinx according to claim 6 wherein the at least one inflatable bladder comprises inflation and/or deflation means for altering its fundamental frequency.

8. An artificial syrinx according to claims 6 or 7 wherein the at least one inflatable bladder comprises inflation and/or deflation means for allowing airflow to pass unimpeded from the nose to the lungs upon inhalation.

9. An artificial syrinx according to claims 7 to 8 wherein the inflation and/or deflation means comprises a secondary conduit for inflating and/or deflating the at least one inflatable bladder.

10. An artificial syrinx according to claims 7 to 9 wherein the inflation and/or deflation means is managed by a patient operable external control.

11. An artificial syrinx according to claims 6 to 10 wherein the artificial syrinx comprises two inflatable bladders.

12. An artificial syrinx according to claim 11 wherein the two inflatable bladders approximate each other.

13. An artificial syrinx according to claim 11 or 12 wherein the two inflatable bladders are in fluid communication.

14. An artificial syrinx according to claims 6 to 13 wherein the at least one inflatable bladder is inflated with a fluid, preferably water, saline or air.

15. An artificial syrinx according to claims 4 to 14 wherein the at least one membrane is biocompatible, preferably wherein the at least one membrane comprises a silicone rubber.

16. An artificial syrinx according to any preceding claim wherein the means for vibrating exhaled air within the trachea to produce an audible sound has a fundamental frequency of from about 85 Hz to about 355 Hz.

17. An artificial syrinx according to any preceding claim wherein airflow across the artificial syrinx is generated by exhalation and/or an external air or oxygen supply.

18. A tracheostomy tube comprising an artificial syrinx according to any preceding claim.

19. A fenestrated tracheostomy tube comprising an artificial syrinx according to any of claims 1 to 17.

20. A fenestrated tracheostomy tube according to claim 19 comprising a superior fenestra and wherein the means for vibrating exhaled air within the trachea to produce an audible sound is located within said superior fenestra.

21. A fenestrated tracheostomy tube according to claim 19 wherein the fenestrated tracheostomy tube comprises an inferior cannula portion and wherein the means for vibrating exhaled air within the trachea to produce an audible sound is located in said inferior cannula portion.

22. A tracheostomy tube or fenestrated tracheostomy tube according to any of claims 18 to 21 further comprising an anterior aperture and an anterior aperture valve.

23. A voice prosthesis for aligned implantation in the lumen of the trachea comprising an artificial syrinx according to any of claims 1 to 17.

24. A voice prosthesis according to claim 23 wherein the voice prosthesis comprises an artificial trachea and wherein the artificial syrinx is located within said artificial trachea.

25. A voice prosthesis according to claims 23 or 24 wherein the artificial syrinx allows airflow to pass from the nose to the lungs unimpeded during inhalation. A method for manufacturing a fenestrated tracheostomy tube comprising the steps of:

a. moulding or otherwise forming a fenestrated tracheostomy tube; and b. affixing means for vibrating exhaled air within the trachea to provide an audible sound.

A method for returning speech to a patient comprising the steps of:

a. providing an artificial syrinx according to any of claims 1 to 17; and b. locating said artificial syrinx in the trachea of a patient.

A method of performing a tracheostomy comprising the steps of:

a. providing a tracheostomy tube or fenestrated tracheostomy tube according to any of claims 18 to 22;

b. making an incision on the anterior aspect of a patient's neck;

c. opening a direct airway through an incision in the trachea; and

A method for returning speech to a patient comprising the steps of:

a. providing a voice prosthesis according to any of claims 23 to 25; and b. implanting said voice prosthesis in the trachea of a patient.

An inner cannula for a fenestrated tracheostomy tube comprising an artificial syrinx according to any of claims 1 to 17.

A method for performing a tracheostomy comprising the steps of:

a. providing a fenestrated tracheostomy tube;

b. making an incision on the anterior aspect of a patient's neck;

c. opening a direct airway through an incision in the trachea;

d. inserting the fenestrated tracheostomy tube through the incisions; e. providing an inner cannula comprising a conduit for aligned insertion in the fenestrated tracheostomy tube, wherein said conduit comprises means for vibrating exhaled air within the trachea to provide an audible sound; and f. inserting the inner cannula in the fenestrated tracheostomy tube.

An assembly comprising an inner cannula according to claim 30 and a fenestrated tracheostomy tube.

An assembly comprising a fenestrated tracheostomy tube according to any of claims 19 to 22 and a secondary cannula.

An assembly according to claim 33 wherein the secondary cannula comprises a superior fenestra.

A device, apparatus or method as substantially described in the figures, examples or description.