Patent Application
20070012317
1. Field of the Invention
The present disclosure, according to one embodiment, relates to medical device tubes, e.g., tracheostomy tubes, used in medical applications and, more particularly, to attaching together a cannula and connector of the medical device tube.
2. Description of the Related Art
This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present invention, which are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present invention. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.
A medical device tube, such as a tracheostomy tube, may be comprised of an outer cannula (slender tube that may be inserted into a body cavity) attached to a head base connector. The tracheostomy tube may be generally “L” shaped and the head base connector may be attached to a swivel neck plate/flange. Because the tracheostomy tube provides an artificial airway for access to the patient's airway for airway management, the tracheostomy tube may be introduced into a tracheotomy incision in the patient's neck that provides access to the trachea. The tracheostomy tube may be secured by means of the swivel neck plate/flange that may be connected to a tracheostomy tube holder or neck strap, thus securing this artificial airway for spontaneous or mechanical ventilation of the patient.
The head base connector and outer cannula are adapted for insertion of a disposable inner cannula. The inner cannula may be inserted into the head base connector and outer cannula after the tracheostomy tube has been placed into the patient's trachea.
This inner cannula typically includes a connector for quick removal of the inner cannula from the outer cannula, e.g., the inner cannula connector removably attaches to the head base connector, so that the inner cannula may be removed quickly if an obstruction, e.g., plug of mucus, sputum, etc., is formed. A mechanical ventilator hose may be coupled to the inner cannula connector for assisting the patient in breathing.
Certain aspects commensurate in scope with the originally claimed invention are set fort below. It should be understood that these aspects are presented merely to provide the reader with a brief summary of certain forms of the invention might take and that these aspects are not intended to limit the scope of the invention. Indeed, the invention may encompass a variety of aspects that may not be set forth below.
There is provided a medical device tube that includes: a cannula having a formed end; and a connector comprised of a first portion and a second portion, wherein the cannula and the connector are coupled together by the formed end of the cannula being held between the first and second portions of the connector.
There is also provided a tracheostomy air passage system that includes: a tracheostomy tube comprising, a cannula having a formed end; a connector comprising a first portion and a second portion, wherein the formed end of the cannula is held between the first and second portions of the connector; a ventilator hose coupled to the connector; and a ventilator coupled to the ventilator hose.
A more complete understanding of the present disclosure may be acquired by referring to the following description taken in conjunction with the accompanying drawings wherein:
While the present disclosure is susceptible to various modifications and alternative forms, specific example embodiments thereof have been shown in the drawings and are herein described in detail. It should be understood, however, that the description herein of specific example embodiments is not intended to limit the disclosure to the particular forms disclosed herein, but on the contrary, this disclosure is to cover all modifications and equivalents as defined by the appended claims.
One or more specific embodiments of the present invention will be described below. In an effort to provide a concise description of these embodiments, not all features of an actual implementation are described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure.
Strengthening the attachment of a cannula to a head base connector is important. Ease in manufacture and reliability of attachment between the cannula and head base connector may also be important. Maintaining a precise inner diameter of an outer cannula for ease of insertion and proper sealing of an inner cannula may also be desirable.
As discussed in detail below, according to a specific example embodiment of this disclosure, a tracheostomy tube has a formed end, e.g., flare-shaped or flute-shaped portion, located at a proximal end (hereinafter “formed end”) of an outer cannula. The formed end of the outer cannula may be placed between first and second portions of a head base connector. The first portion (e.g., top portion) of the head base connector may be similar in shape to the second portion (e.g., bottom portion) of the head base connector. The first and second portions may clamp the formed end when placed together. The first and second portions of the head base connector may be held together, e.g., by adhesive, bonding, welding, etc. Welding together of the first and second portions of the head base connector may be, for example but not limited to, ultrasonic, radio frequency, laser, hot plate, spin, etc. The first and second portions of the head base connector may also be adapted for snapping together, screwing together, clamping together, etc.
The formed end of the outer cannula may also comprise: 1) filleting the outer cannula tube end to lay open two or more flats that may be captured by the first and second portions of the head base connector, 2) heat forming a circumferential bead that may be captured in a corresponding pocket in the first and second portions of the head base connector. This circumferential bead may provide a thick (strong) transition from the formed end to the cylindrical tube of the outer cannula, 3) in place of a formed end cannula tube radius, use a chamfer that substantially matches a chamfer on the first and second portions of the head base connector, e.g., chamfer in a thicker portion of the wall of the outer cannula toward its end. And/or 4) a mating component that may be attached to the end of the outer cannula to fit/lock with the first and/or second portions of the head base connector.
In addition, the first and/or second portions of the head base connector may have ridges, e.g., circumferential rings, on the inner faces thereof that may be in contact with the formed end of the outer cannula, and capture, e.g., clamp, the formed end between the inner faces of the first and second portions of the head base connector. These circumferential rings may comprise ridges and valleys that may be paired or otherwise aligned so as to promote portions of the formed end being received within at least one valley. The rings may be continuous and/or non-continuous, e.g., broken or dashed. The circumferential rings clamping the formed end may also be used for maintaining an appropriate inner diameter of the outer cannula.
The formed end may be captured between the inner faces of the first and second portions of the head base connector by attaching the formed end to the inner face(s) of the first and/or second portions of the head base connector by using adhesive, bonding, welding, etc. This provides for a far superior connection, and/or reliable continuous connection between the outer cannula and the head base connector then does a simple lap weld, butt joint (weld) or a mere adhesive connection. A portion of the outer surface of the outer cannula, e.g., a portion of the formed end may have adhesive holding it proximate to an inner face of the head base connector. The adhesive may be applied to the outer surface portion wherein a line normal to the outer surface portion is not perpendicular to the central axis of the outer cannula proximate the surface portion, e.g., an acute angle may be formed or it may be substantially parallel.
Within the wall of the outer cannula, including the formed end thereof, there may be a small hollow area, e.g., lumen, that may be used to pass air for inflating a flexible collar located over an outer portion of this cannula. The flexible collar may be inflated so as provide a seal in the patient's airway to air from positive pressure ventilation, and may also stabilize the outer cannula in the trachea of the patient. More than one lumen may be in the wall of the outer cannula and the additional lumens therein may be used for various other purposes.
The inside of the formed end of the outer cannula may be configured for insertion of an inner cannula. The formed end of the outer cannula may be arranged between the first and second portions of the head base connector so as to maintain a uniform inside diameter of the outer cannula for precise and uniform insertion of the inner cannula into the outer cannula. The formed end of the outer cannula may be tapered to provide a natural lead in for the ease of insertion of the inner cannula therein.
An inner ridge or ring of the head base connector may aid in aligning a central axis of the outer cannula with the head base connector. The head base connector may be used, with or without an inner ridge or ring, as a port for insertion of the inner cannula.
Testing for separation between the head base connector and the outer cannula has been made on various combinations of locking mechanisms between the head base connector and the outer cannula. A strain rate of 2 inches per minute was used. Testing conditions where at both room and body temperatures and humidity levels. A plurality of sizes of tracheostomy tubes were used in conducting the following separation tests.
Pull forces were determined using 1) a completed assembly and adhesive of the connector with the formed end of the outer cannula (adhesive and clamping compression of the formed end between the connector portions), 2) the formed end attached to a portion of the head base connector with adhesive only, 3) a complete assembly without adhesive, only clamping compression of the formed end between the head base connector portions, and 4) the formed end in frictional cooperation with only the lower portion of the head base connector.
A separation force was observed such that the failure mode was tube wall failure for the complete assembly and adhesive on the connector portion and formed end as described in 1) above, and the formed end attached to a portion of the head base connector with adhesive only as described in 2) above. A substantial separation force was necessary for bond separation between the formed end and head base connector portions as described in 3) above. The separation force was the lowest where the failure mode was bond separation between the formed end and head base connector portion as described in 4) above.
The proximal end of the outer cannula may be formed by various methods, e.g., heating of the proximal end material. The formed proximal end when pulled toward a smaller diameter opening in a portion of the head base connector may create a locking mechanism that effectively captures the outer cannula in the head base connector and substantially aides in preventing pull out of the outer cannula from the head base connector.
An ultrasonic shear weld around the perimeter of the head base connector may be used to couple together the first and second portions thereof. The head base connector portion proximate to the patient may also be referred to herein as the “bottom portion” or “bottom component” of the head base connector, and the head base connector portion distal from the patient may also be referred to herein as the “top portion” or “top component” of the head base connector. The top and/or bottom portion(s) may have at least one groove adapted for engaging (e.g., gripping) the formed end of the outer cannula. The bottom and/or top portion(s) of the head base connector may provide a compression force (e.g., result of the ultrasonic shear weld geometry) to the formed end into the at least one groove of the top and/or bottom portion(s).
For example, the ultrasonic shear weld may start by welding plastic material of the top and bottom portions together for about approximately 0.025 inches. The shear weld continues to compress, forming the clamping force. The ultrasonic shear welding and compression of the top and bottom portions together may continue, e.g., for about another 0.015 inches. The top and/or bottom portion(s) may “bite” (e.g., with barbs, pins, bumps, etc.) into the formed end of the outer cannula and may be held with the ultrasonic shear weld. An adhesive, e.g., medical grade cyanoacrylate 4161, commercial trade name—LOCTITE® (a registered trademark of the Henkel Corporation, 2200 Renaissance Boulevard, The Triad, Suite 200, 200 Gulph Mills, Pa. 19406), may be used to further secure the formed end of the outer cannula to the bottom portion (component) of the head base connector.
Referring now to the drawings, the details of specific example embodiments are schematically illustrated. Like elements in the drawings will be represented by like numbers, and similar elements will be represented by like numbers with a different lower case letter suffix.
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An inflation collar 112 may be located proximate to the outer wall of the outer cannula 104, and an inflation lumen 120 may be within the wall of the outer cannula 104 or proximate thereto. An air valve port 122 may be used in combination with the inflation lumen 120 and the inflation collar 112 for inflating the inflation collar 112 to create a seal between the inflation collar 112 and the trachea 116 air passage. The inflation collar 112 may also position the outer cannula 104 in the trachea 116. The inflation collar 112 may be inflated with a fluid, e.g., air, nitrogen, saline, water, etc. It should be understood that more than one lumen may be in the wall of the cannula 104 and that the additional lumens therein may be used for various other purposes.
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The outer cannula 104 may be made by extrusion or injection molding processes using, for example but not limited to, polyvinyl chloride, flexible, rigid or semi-rigid, of a variety of durometers. The formed end 204 may be formed by heating or molding a proximal end of the outer cannula 104. The connector 212 may be fabricated by injection molding using material suited for a desired application.
The inner face of first portion 216 and/or inner face of the second portion 214 may be used to hold the head base connector 212 to the formed end 204 of the outer cannula 104. The inner face(s) of the first portion 216 and/or the second portion 214 may have gripping ridges 218 that may improve the holding strength between the head base connector 212 and the formed end 204 of the outer cannula 104. The formed end 204 may be attached to the inner face(s) of the first portion 216 and/or the second portion 214 by, for example but not limited to, adhesive, bonding and/or welding, etc. This attachment may provide additional holding strength between the head base connector 212 and the outer cannula 104. The second portion 214 may be tapered about where the outer cannula 104 transitions to the formed end 204 so as to relieve stress pressure on the wall of the outer cannula 104.
The head base connector 212 may be configured to fit into a neck flange 106, and the head base connector 212 may be configured for coupling to a ventilator hose 108 (
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While embodiments of this disclosure have been depicted, described, and are defined by reference to example embodiments of the disclosure, such references do not imply a limitation on the disclosure, and no such limitation is to be inferred. The subject matter disclosed is capable of considerable modification, alteration, and equivalents in form and function, as will occur to those ordinarily skilled in the pertinent art and having the benefit of this disclosure. The depicted and described embodiments of this disclosure are examples only, and are not exhaustive of the scope of the disclosure.
