Tracheostomy tube and technique for using the same

A molded tracheostomy tube may provide enhanced comfort for a patient. A unitary molded coating over areas of the tracheostomy tube that come into contact with the patient's skin may prevent irritation. Further, the overmolding manufacturing process may allow the tracheostomy tube assembly to incorporate features that allow for greater ease of movement for a patient, such as features that allow flexing at the connection point of the tracheostomy tube to other medical devices.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to medical devices, and more particularly, to airway devices, such as tracheostomy tubes.

2. Description of the Related Art

In the course of treating a patient, a tube or other medical device may be used to control the flow of air, food, fluids, or other substances into the patient. For example, medical devices, such as tracheal tubes, may be used to control the flow of one or more substances into or out of a patient. In many instances, it is desirable to provide a seal between the outside of the tube or device and the interior of the passage in which the tube or device is inserted. In this way, substances can only flow through the passage via the tube or other medical device, allowing a medical practitioner to maintain control over the type and amount of substances flowing into and out of the patient.

More specifically, tracheal tubes may be used to control the flow of air or other gases through a patient's trachea. Such tracheal tubes may include endotracheal tubes or tracheostomy tubes. While patients may be intubated using endotracheal tubes during emergencies or shorter hospital stays, tracheostomy tubes are more typically used for prolonged ventilation, as the use of a tracheostomy tube is generally more comfortable for a patient.

A typical tracheostomy tube is generally inserted into the trachea via a surgical incision in the neck. After insertion of the tube into the trachea, a portion of tube remains outside the patient. This portion extends outwards from the neck and may connect the tracheostomy tube to a ventilator or other medical device. Generally, this exterior portion of the tube is held in place by a flange that rests on the patient's neck and is further secured by straps to the patient. The inserted portion of the tracheostomy tube is generally mechanically coupled to the flange, typically by a snap or screw mechanism on the underside of the flange, which rests on the patient's neck. As such, the mechanical connection point may display angled edges that may irritate a patient's skin. Certain devices attempt to address this problem by providing pillow or fabric protectors for the neck that may lift the flange slightly off the neck to avoid skin irritation. However, these devices may compromise the secure attachment of the tracheostomy tube to the patient by providing a less stable base for the tube at the patient's neck.

A stable attachment of the tracheostomy tube to the patient is advantageous for preventing motion of the tube within the trachea. Because the exterior portion of the tracheostomy tube is connected to the inserted portion, when the exterior portion of the tube is shifted or moved, these movements may be translated to the interior potion of the tube. These movements may cause some discomfort for the patient if the tracheostomy tube shifts position within the trachea.

SUMMARY

There is provided a tracheostomy tube that includes a cannula including a distal end and a proximal end, the distal end being adapted to be inserted into a patient's trachea; a flange member molded over the proximal end of the cannula; and a conduit disposed on the flange member in communication with the cannula, wherein the conduit is adapted to operatively connect to a medical device.

There is also provided a method of manufacturing a tracheostomy tube that includes providing a cannula comprising a distal end and a proximal end, the distal end being adapted to be inserted into a patient's trachea; molding a flange member over the proximal end of the cannula such that the proximal end of the cannula is coupled to the flange member; and disposing a conduit disposed on the flange member in communication with the cannula, wherein the conduit is adapted to operatively connect to a medical device.

There is also provided a method of sealing a patient's trachea that includes inserting a tracheostomy tube into a patient's trachea, wherein the tracheostomy tube comprises: a cannula comprising a distal end and a proximal end, the distal end being adapted to be inserted into a patient's trachea; a flange member molded over the proximal end of the cannula; and a conduit disposed on the flange member in communication with the cannula, wherein the conduit is adapted to operatively connect to a medical device.

There is also provided a tracheostomy tube mold form that includes: a mold cavity defining a flange member; a mold cavity defining a conduit adapted to be disposed on the flange member in communication with the cannula; and an opening in the mold form adapted to receive a cannula comprising a distal end and a proximal end, wherein the proximal end of the cannula is adapted to be inserted into at least a portion of the mold cavity defining the flange member.

There is also provided a unitary molded tracheostomy tube assembly that includes: a cannula adapted to be inserted into a patient's trachea comprising a distal end and a proximal end; a flange member disposed on the proximal end of the cannula; and a conduit disposed on the flange member in communication with the cannula, wherein the conduit is adapted to operatively connect to a medical device, and wherein the cannula, the flange member, and the conduit comprise a unitary molded structure.

DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS

Provided herein are tracheostomy tubes in which a flange portion is permanently attached to a cannula portion. Such tubes may allow for increased patient comfort. Typical tracheostomy tubes contain a curved cannula portion that is mechanically connected to an outer flange that is designed to rest on a patient's neck. This mechanical connection may include exposed notches or edges that may cause discomfort against a patient's skin. The tracheostomy tubes according to the present techniques may be molded or cast to provide a comfortable coating over the flange/cannula connection point that reduces the chance of such discomfort. Further, the coating results in a more robust tracheostomy tube assembly in which the flange portion is substantially permanently connected to the cannula portion without sacrificing patient comfort for increased durability. In specific embodiments, the tracheostomy tubes may also contain features that reduce the outside forces that may be transferred to inserted portion of the tube, which may cause discomfort if the tube shifts position and contacts the trachea. For example, the exterior flange and other patient exterior assemblies may include regions that allow for flexing or bending of the tracheostomy tube to reduce or eliminate the translation of movement to the interior portion of the tube.

FIGS. 1A and 1Bshow a side perspective view of an exemplary overmolded tracheostomy tube assembly10according to the present techniques. In the depicted embodiment, a portion of a cannula12is permanently embedded in a portion of a flange20member through an overmolding technique, described in detail below. Generally, a region of a preformed cannula12may be inserted into a mold suitably sized and shaped to form the flange member20. A flange material may be injected into the mold so that as the flange material cools and hardens around the cannula12, it permanently attaches itself to any portion of the cannula12that is contained in the mold. Alternatively, as provided herein, a tracheostomy tube assembly10may be formed from a single mold. In any case, a flange member20may be permanently attached to a cannula12, without employing a mechanical coupling, such as a snap or screw.

The tracheostomy tube assembly10may include an arcuate cannula12having a distal end14, which is generally sized and configured to be inserted through a patient tracheostomy. When the tracheostomy tube assembly10is in use, the distal end14as well as the major portion of the length of the cannula12will reside within the trachea, with the proximal end16being generally flush with the anterior surface of the patient's neck. The cannula12may also feature a small lumen (not shown) within the wall, accessed by notches18aand18b. This lumen is an airway that may be used to fill a balloon type sealing cuff13at the patient insertion end. The cuff13may be a urethane balloon bonded to the exterior of the cannula12such that the notch18bis encompassed. A user may inject air into the lumen through its access point at notch18a, which transfers air to the cuff. The cuff13may inflate within the patient airway to provide an additional seal.

The tracheostomy tube assembly10also features a flange20connected to the proximal end16of the cannula12. The flange20is designed to rest on the neck of a patient and may feature openings22aand22bdesigned to accommodate attachment straps that may further secure the tracheostomy tube assembly10to the neck. The flange20may feature a conduit24that is substantially in-line with the proximal end16of the cannula12. Generally, the conduit24may be adapted to connect the tracheostomy tube10to any suitable medical device. For example, the conduit24may serve as an insertion point for a disposable cannula lining17(shown inFIG. 1B) or may be suitably sized and shaped to connect the tracheostomy tube10via medical tubing or other devices to a mechanical ventilator.

In certain embodiments, the flange20may include features that allow the conduit24to move or flex to accommodate outside forces. Because the conduit24may be manipulated by healthcare providers to attach or detach a medical device, it may be advantageous for the conduit24to have some freedom of movement. For example, if a healthcare worker exerts force on the conduit24to connect a medical device, the conduit24may transmit some of that force into a bending or flexing motion so that the cannula12, which is mostly inside the patient's trachea, does not experience the full force exerted on the conduit24. As such, the cannula's12movements may be reduced, which may result in less irritation of the tracheal walls. Additionally, a flexible medical device connection point, i.e. the conduit24, may increase possible patient room layout options. Such a feature may be advantageous in emergency room or operating room settings, where larger medical devices may be difficult and time-consuming to move. As depicted inFIG. 1, an annular notch or recess26that substantially surrounds the conduit24may allow the conduit24to have flexibility in several directions. Further, the conduit24may also feature a grooved region28that may allow additional degrees of freedom to the conduit24. In certain embodiments, the grooved region28may include support ribs30to assist in supporting the conduit24in a substantially orthogonal position relative to the flange20absent any deforming forces applied to the conduit24.

FIG. 2is a cross-section view of the tracheostomy tube10ofFIG. 1. As depicted, a flared portion32of the proximal end16of the cannula12is embedded in the flange member20. The flange member20may also include guides34that may provide additional support to the proximal end16of the cannula12. The conduit24defines a passageway36into which respiratory gases may flow. Passageway36may be connected with a passageway38, defined by the cannula12, to allow flow of respiratory gases into the trachea. Although the conduit24may bend or flex, the passageway36will remain substantially in-line with the passageway38.

The grooved region28may include grooves with a substantially V-shaped cross-section with sloping sides that meet in a point, as shown. In other embodiments, the grooves in the grooved region28may have different configurations. For example, the grooves may include non-sloping sides that are connected by a substantially flat bottom region. In any case, the grooved region28allows the conduit24to bend at the area that includes the grooves. Further, in certain embodiments, the grooved region28may include semi-annular grooves that may allow flexibility only in certain directions where the grooves are located. Similarly, the notch26may also include any suitably shaped annular or semi-annular notch or groove that allows the flange to bend in the area surrounding the conduit.

The flexibility of the conduit24may be altered according to the needs of the patient or healthcare workers by altering the configuration of the flange member20. For example, the flange member20illustrated inFIG. 3includes a grooved region28with support ribs30without a notch26surrounding the conduit24. Such a configuration may provide increased support to a heavier or larger conduit24, which may be appropriate for a larger patient, while maintaining some degree of flexibility. The flange member20depicted inFIG. 4includes a grooved region40substantially surrounding the conduit24. Such an embodiment may confer increased degrees of freedom to the conduit24, which may be advantageous for an active patient. In other embodiments (not shown), a grooved region (e.g.28or40) may contain more or fewer grooves in order to alter the flexibility characteristics of the conduit24. In other embodiments, a flange member20may contain no flexibility features, such as grooves or notches, if a healthcare worker is not particularly concerned about outside forces being transmitted to the tracheal walls. The flange member20may also include a certain degree of flexibility through the choice of an appropriate mold material, such as a thermoplastic elastomer. Such an embodiment may be appropriate for a stable patient in an intensive care setting, where the patient is not being moved very often.

In addition, as depicted inFIG. 5, increased flexibility for the conduit24may be achieved by molding portions of the flange member20into thin or membranous regions of thermoplastic material, such as a membranous region42surrounding the conduit24. Such flexible regions may allow a greater range of motion for the conduit24. In certain embodiments, the membranous region may be 0.03-0.05 inches in thickness, while the outer rim44of the flange member may be 0.1″-0.2″ thick. In an alternative embodiment the conduit24may exhibit an outer wall thickness of 0.07″-0.11″ be internally ribbed and may include ribs or grooves (not shown) molded into the interior passageway. The support ribs30, may be 0.03″-0.1″ inches in thickness depending on material flexural modulus and may, for example, vary in number from 3 to 6.

The proximal end16of the cannula12may include a region that is embedded in the flange member20through an overmolding process. As noted above, in certain embodiments of the present technique, the tracheostomy tube10is overmolded to form a unitary or integral assembly in which the cannula12is integrated into the flange member20during the manufacturing process. Such overmolded embodiments may result in an assembly in which the tracheostomy tube10is completely or partially coated with a thermoplastic material, discussed in more detail herein. For example, the flange member20and conduit24may be formed by an injection molding process. In one example of such a process, the proximal end16of the cannula12may be positioned within a die or mold48, shown inFIG. 6of the desired shape for the flange member20and conduit24. In certain embodiments, the mold48may include cavities defining the guides34on either side of an opening in the mold48designed to accommodate the proximal end16of the cannula12. The mold48may also include an opening50into which the mold material may be injected. The guides34may help properly position the proximal end16of the cannula12in the mold. Additionally, the tracheostomy tube10may also include a second or distal conduit extension (not shown) that may be inserted into the proximal end16of the cannula12and radio-frequency welded to the cannula12.

In certain embodiments, the tracheostomy tube10may be constructed, in whole or in part, from polymeric materials, such as thermoplastics, capable of providing a suitable rigidity or semi-rigidity. Examples of such suitable materials include polyvinylchloride, polyurethane, polypropylene and silicone, though other polymeric materials may also be suitable. In one implementation, the overmolding or coating is a thermoplastic elastomer or other conformable coating or material. In such embodiments, the thermoplastic elastomer may include compositions such as styrenic block copolymers, thermoplastic vulcanizate alloys, silicone, thermoplastic polyurethane, and so forth. Further, many elastomer alloys may be suitable as well. As will be appreciated by those of ordinary skill in the art, the overmolding composition may vary, depending on the varying degrees of conformability, durability, wettability, elasticity, or other physical and/or chemical traits that are desired. For example, in certain embodiments, the thermoplastic elastomer is selected to have a hardness between 30 and 60 Shore A to provide a robust yet comfortable material to rest against a patient's skin. In one embodiment, a suitable material having a hardness between 30 and 60 Shore A is employed to mold the flange member20while another material having a hardness between between 50 and 70 Shore A is employed to form the cannula12. In embodiments in which the flange member20and the cannula12are formed from different materials, these materials may be selected based upon the desirability of a chemical bond between the between the flange member20and the cannula12.

A molten or otherwise unset overmold material may then be injected into the die or mold. For example, in one implementation, a molten thermoplastic elastomer at between about 340° F. to about 430° F. is injected into the mold. The overmold material may then be set, such as by cooling for a period based upon wall thickness where cooling may take place at 30 seconds per 0.100″ thickness of overmold material to form the tracheostomy tube10. In certain embodiments, shear-dependent overmold materials may be advantageous for molding thin or more intricate parts.

In an alternative embodiment, the tracheostomy tube10may be formed from a two-shot injection molding process in which a mold is moved or rotated from one injection barrel to a second injection barrel to allow two materials, which may be the same or different, to be injected one after the other in the same mold. Such a process may allow a first molded part to cool before the second molded part is formed. In certain embodiments, the mold may not move or rotate, but movable components within the mold may allow for molding shots from different barrels. In one embodiment, a two-shot molding process may involve injecting a higher durometer material for the conduit and injecting a softer durometer material for the flange. Additionally, insert injection molding techniques may also be appropriate for forming the tracheostomy tube10.

The cannula12may be a pre-formed assembly that may be molded into the appropriate curved configuration or may be extruded and curved into a “J” shape with heat-setting. The proximal end of the cannula12may be flared using radio frequency energy. In certain embodiments, it may be advantageous to form perforation or depressions (not shown) into the flared region32of the cannula12. In such an embodiment, the overmolding material may flow into the perforations or depressions to create an improved bond with the flared region32.

The tracheostomy tubes10of the present techniques may be incorporated into systems that facilitate positive pressure ventilation of a patient, such as a ventilator. Such systems may typically include connective tubing, a gas source, a monitor, and/or a controller. The controller may be a digital controller, a computer, an electromechanical programmable controller, or any other control system.