The invention relates to laryngeal devices, particularly those used for intubation of patients.
Several existing devices are used for facilitating spontaneous breathing in anaesthetised patients; traditionally, the Endotracheal Tube (ETT) and more recently the Laryngeal Mask Airway (LMA). The majority of these devices use an inflatable cuff(s) to create the anatomical seal and as a consequence there is an incidence of co-morbidity associated with their use; both physiological and anatomical. Subsequent refinement of the LMA has resulted in the development and introduction of supraglottic airway devices (SAD) with gastric drainage (GD). The reported advantages being ease of insertion, haemodynamic stability, decreased morbidity, improved respiratory mechanics and reduced incidence of pulmonary aspiration. An alternative development uses a pre-formed and non-inflatable cuff. Disadvantages of SAD with GD primarily relate to the configuration of the distal tip becoming bulbous by the presence of the gastric tube passing through the inflatable cuff and the associated structures employed; to present a flat profile of the distal tip when the inflatable cuff is deflated immediately prior to deployment and; prevent occlusion of the drain tube after the SAD is deployed and inflated in situ.
The visco-elastic characteristics of the materials used for construction of the various SAD's exert significant influence over the ability of the device to deliver the above stated advantages and contribute significantly to the disadvantages. SAD's use the same materials as existing LMA devices. Semi rigid PVC, vinyl elastomers and liquid silicone rubbers are predominant in combinations comprising a more rigid airway with a softer inflatable cuff whilst thermoplastic elastomers (TPE) are used for versions exhibiting a non-inflatable cuff. Those devices using PVC and LSR require the use of adhesives and solvents for bonding and joining the different components during manufacture. SAD's using TPE do not require adhesives as they are essentially a one piece more rigid airway tube covered with TPE material to form the required shape without an inflatable cuff.
In a first aspect the invention provides an airway management device comprising a body having a proximal end for receiving an oxygen supply tube and an distal end for insertion into a trachea of a patient; said body including a linear portion adjacent to the proximal end and a curved portion adjacent to the distal end; said body including an external shell and having a first bore through said shell for receiving the oxygen supply tube; wherein flexural strength for said airway management device is provided by said shell.
It will be appreciated that the first bore will include an adequate internal diameter to accommodate the oxygen supply tube in the form of an endotracheal tube;
In a second aspect the invention provides an airway management device comprising a body having a proximal end for receiving an oxygen supply tube and an distal end for insertion into a trachea of a patient; said body including a linear portion adjacent to the proximal end and a curved portion adjacent to the distal end, and a passage arranged to receive a gastric drain tube; a toroidal shaped membrane having a first and second opposed edged, said first edge moulded to a corresponding portion of the body and the second edge moulded to a corresponding second portion of the body, said first and second portions in spaced relation, the membrane forming an inflatable cuff.
Accordingly, the shell acts as an exoskeleton, protecting the oxygen supply and any other device placed therein during the insertion process. Further, by providing a first bore of sufficient size to receive the oxygen supply tube, the body will include a moment of inertia for the cross-sectional shape to provide a high degree of stiffness. The cross-sectional shape and selection of material may therefore allow considerable scope for selecting the required flexural stiffness for the airway management device. In the current embodiment, the body may simply be referred to as an airway tube.
The first bore may be a non-symmetrical shape having two lobes, having two portions arranged to receive and position the oxygen supply tube in one lobe, or a first passage, and an endoscope in the other lobe or second passage. By shaping the first bore, and in particular, the lobes the oxygen supply tube and endoscope may be confined to the particular lobe and so separate from each other, despite being positioned within an open first bore.
The body may include a second bore for containing a gastric drain tube. In the case of having the first and second passages as mentioned above, the second bore may then be considered a third passage.
The device according to the present invention may use methods of manufacturing that do not require adhesives. Rather, in one embodiment, it may utilise the self-adhesive properties of softer and more elastic TPE to the more rigid polypropylene substrate. In terms of visco-elasticity, a polyolefin material such as polypropylene may be used for the more rigid airway and TPE compound (using the same polypropylene as the base material) may be used for the inflatable cuff which offers superior elastic response and reduced hysteresis. By virtue of doing so, it allows for the introduction of numerous and desirable features for a SAD with GD.
Furthermore, the invention describes a SAD with GD that in addition to maintaining an airway as described, it also provides for blind intubation simultaneous with gastric access and the ability to visually evaluate in situ via endoscopy. Prior art describes LMA and SAD that do not offer such diverse functionality.
A possible application of the device according to the present invention may include where the patient is to be transferred to an intensive care facility. In such instances the LMA may be removed and replaced with an endotracheal tube.
An advantage of this invention may include that the device itself, by virtue of the airway tube structure, guides the ET Tube into position quickly and effectively with minimal trauma and loss of oxygen supply if intubation becomes a necessary requirement toward protecting the wellbeing of the patient. Positioning of the ET Tube may then be confirmed via endoscopy. The device described by the invention may then be removed whilst the ET Tube remains in situ.
It will be convenient to further describe the present invention with respect to the accompanying drawings that illustrate possible arrangements of the invention. Other arrangements of the invention are possible, and consequently the particularity of the accompanying drawings is not to be understood as superseding the generality of the preceding description of the invention.
In the context of this description, the invention is henceforth described as if it were inserted in a supinely positioned patient. The airway management device includes a body, such as the airway tube (
Inserted into the airway tube proximal opening is an adaptor (
Cross section A-A (
Continuing inferiorly from this transition, the airway tube cross section maintains the semi-circular contour of the partial posterior channel 5 until reaching the proximal end 8 of the medial slot 9, a feature congruent with the anterior or ventral opening. When viewed anteriorly toward the frontal plane (
Attached to the posterior of the airway tube is the intermediate strip (
When combined with the elastic properties of the polyolefin material, the ventrally concave curvature parallel to the medial slot 33a and horizontally through 33b the medial slot creates a compound curvature (
In pure mechanical terms, the distal end of the airway tube can be considered as the fixed support, whilst the airway tube by itself can be considered to act as a cantilever beam. Force exerted through the straight proximal portion of the airway tube during insertion concentrates flexion and extension through a horizontal axis coincident with two laterally opposed slots 23. The primary passage being larger in diameter than the secondary passage allows a degree of rotation around the medial axis of the proximal airway tube that can be transferred as torsion through to the distal tip. SAD's using semi-rigid PVC materials for the airway tube behave in a viscous manner i.e. when force is applied they resist shear and exhibit linear strain (relationship between change in length to original length) for the duration of the applied force. However, these forces are dissipated into the PVC material such that when force is released, PVC will not immediately respond and return to its original state. This lost energy, or hysteresis, is a significant disadvantage of prior art based on PVC materials. Polyolefin materials such as polypropylene exhibit a superior visco-elastic response, characterised by elastic rather than viscous response.
During insertion, the forces transferred through the airway tube are manifested by circumduction. As a consequence, hysteresis in the materials used by existing prior may prevent the distal tip being correctly in situ with the upper oesophageal sphincter. Prior art describes the possibility of the distal tip entering the larynx or, the distal tip of the LMA or SAD may fold under, a phenomenon described as down-folding. Unlike other LMA or SAD, this invention uses an airway tube that extends from the proximal end to the distal tip and whose form and function utilise the more immediate visco-elastic response of a rigid polyolefin material. Where other SAD's describe a ventral displacement of the distal tip in relation to a dorsal or posterior reference point on the airway tube to better conform to the anatomy, this invention provides for a wide range of flexional response that obviates the ventral displacement described by prior art.
Protruding from the external surface of the gastric drain tube opening in closest proximity to the adaptor (
As the median axis of the proximal opening (
Proximally, the intermediate strip is attached by 4 latches, 2 per side positioned laterally 18 where the intermediate strip straddles the airway tube. Coinciding at the tangent where the straddling straight section of the airway tube terminates and the curvature 6 begins, the intermediate strip narrows abruptly 19. The supporting structure of ribs 17 follow the curvature of the airway tube 6; opposing ribs 11a integral with the intermediate strip (
Having described the airway tube, intermediate strip and adaptor, any or all of which may be manufactured from polyolefin material; the description now focuses on the inflatable cuff manufactured from a thermoplastic elastomer (TPE) compounded from the same base polyolefin material. This in itself provides the means of assembly for the device described herein. The self-adhering property of TPE, adhere the intermediate strip to the airway tube and create an open thin walled cuff membrane by virtue of an initial injection moulding processes; a subsequent injection moulding process entraps the open membrane and creates an airtight and inflatable cuff, integral to the form and function of the device.
Viewed anteriorly toward the frontal plane (
Horizontal cross sections B-B and C-C (
With reference to
It is a feature of this invention that the distal portion of the gastric drainage tube may not intersect the inflated volume of the cuff (
Furthermore, immediately superior to the distal opening, the anterior of distal airway tube compound curvature 33 defines the internal posterior surface of the third passage or gastric drain tube; the narrow width and curvature of the airway tube; the reducing thickness 26b and; the surrounding contour 34 of self-adhered TPE elastomer, minimise the deflated thickness of the distal tip. The elastic response of the polyolefin airway tube is manifest at the distal tip, now assisted by the softer TPE. This configuration keeps combined thickness of materials to a minimum, a characteristics evident when the cuff is deflated prior to deployment, negating the potentially bulbous nature of the distal cuff and gastric drainage supporting structure.
The contour of TPE adhering 34 to the distal anterior airway tube (
The angle 13 of the tubular feature relative to the adaptor (
The adaptor can be returned to its original position by inserting the distal end 41 into the proximal airway tube opening 42 and pushing it posteriorly. Once the notch 43 in the adaptor encounters the raised step 14 on the tubular feature 12; a moderate increase in pressure will enable the adaptor to snap back into the home position; the mating face 44 of the adaptor (
The subsequent injection moulding process provides a core and cavity that locates the leading edge of the open cuff membrane 27 firmly against an airway portion such as the posterior distal airway tube perimeter 26. TPE interacts with the leading peripheral edges, entrapping them and blending with the already complete distal closed section 28 and conforming to the finished inflatable cuff contour defined by the injection mould core and cavity so as to close the toroidal cuff. A further embodiment (
The finished contour of the distal portion (
The inflatable cuff membrane completes the manufacturing of the device described by this invention, without the need for adhesives or solvents. Using entirely polyolefin based materials achieves a more ecological sustainable alternative to PVC and vinyl elastomers that may contain DEHP plasticisers or, LSR that cannot be recycled and similarly re-processed due to the fact that it is a thermoset material whose cross linking during moulding cannot be reversed.
In a further aspect of the present invention, the arrangement of the passage for receiving gastric drainage tube may be applied to an airway management device of the prior art. Further, the method of manufacturing the cuff in a two part construction may also be applied as an invention separate to the shell arrangement described previously. To this end, the third passage described previously, may be a distinct and discrete addition to an airway management device and consequently may simply be described as a passage when an equivalent first and second passage, as described above is not clearly defined or in fact not present.
Number | Date | Country | Kind |
---|---|---|---|
2014011720 | Feb 2014 | SG | national |
Filing Document | Filing Date | Country | Kind |
---|---|---|---|
PCT/SG2015/000035 | 2/9/2015 | WO | 00 |
Publishing Document | Publishing Date | Country | Kind |
---|---|---|---|
WO2015/119577 | 8/13/2015 | WO | A |
Number | Name | Date | Kind |
---|---|---|---|
4509514 | Brain | Apr 1985 | A |
4995388 | Brain | Feb 1991 | A |
5241956 | Brain | Sep 1993 | A |
5249571 | Brain | Oct 1993 | A |
5282464 | Brain | Feb 1994 | A |
5297547 | Brain | Mar 1994 | A |
5303697 | Brain | Apr 1994 | A |
5305743 | Brain | Apr 1994 | A |
5355879 | Brain | Oct 1994 | A |
5391248 | Brain | Feb 1995 | A |
5513627 | Flam | May 1996 | A |
5584290 | Brain | Dec 1996 | A |
5632271 | Brain | May 1997 | A |
5682880 | Brain | Nov 1997 | A |
5711293 | Brain | Jan 1998 | A |
5896858 | Brain | Apr 1999 | A |
6079409 | Brain | Jun 2000 | A |
6439232 | Brain | Aug 2002 | B1 |
6631720 | Brain | Oct 2003 | B1 |
6705318 | Brain | Mar 2004 | B1 |
6792948 | Brain | Sep 2004 | B2 |
6918388 | Brain | Jul 2005 | B2 |
7004169 | Brain | Feb 2006 | B2 |
7097802 | Brain | Aug 2006 | B2 |
7128071 | Brain | Oct 2006 | B2 |
7134431 | Brain | Nov 2006 | B2 |
7156100 | Brain | Jan 2007 | B1 |
7159589 | Brain | Jan 2007 | B2 |
RE39508 | Parker | Apr 2007 | E |
RE39938 | Brain | Dec 2007 | E |
7305985 | Brain | Dec 2007 | B2 |
7493901 | Brain | Feb 2009 | B2 |
7506648 | Brain | Mar 2009 | B2 |
7694682 | Petersen et al. | Apr 2010 | B2 |
7780900 | Cook | Aug 2010 | B2 |
7784464 | Cook | Aug 2010 | B2 |
7806119 | Nasir | Oct 2010 | B2 |
7896007 | Brain | Mar 2011 | B2 |
7900632 | Cook | Mar 2011 | B2 |
7934502 | Cook | May 2011 | B2 |
8215307 | Nasir | Jul 2012 | B2 |
8449713 | Brain | May 2013 | B2 |
8485188 | Nasir | Jul 2013 | B2 |
8590535 | Dubach | Nov 2013 | B2 |
8622060 | Cook | Jan 2014 | B2 |
8631796 | Cook | Jan 2014 | B2 |
8776797 | Brain | Jul 2014 | B2 |
8778248 | Nasir | Jul 2014 | B2 |
8783256 | Brain | Jul 2014 | B2 |
8887716 | Dubach | Nov 2014 | B2 |
8978657 | Sandmore et al. | Mar 2015 | B2 |
8978658 | Cook | Mar 2015 | B2 |
9027559 | Brain | May 2015 | B2 |
9265904 | Esnouf | Feb 2016 | B2 |
9265905 | Nasir | Feb 2016 | B2 |
9266268 | Nasir | Feb 2016 | B2 |
9271631 | Leeflang et al. | Mar 2016 | B2 |
9320864 | Cook | Apr 2016 | B2 |
9463296 | Stix | Oct 2016 | B2 |
9475223 | Nasir | Oct 2016 | B2 |
9480806 | Brain | Nov 2016 | B2 |
9498591 | Brain | Nov 2016 | B2 |
9522245 | Brain | Dec 2016 | B2 |
9662465 | Brain | May 2017 | B2 |
9675772 | Brain | Jun 2017 | B2 |
9694150 | Brain | Jul 2017 | B2 |
20030037790 | Brain | Feb 2003 | A1 |
20030051734 | Brain | Mar 2003 | A1 |
20030060764 | Dua et al. | Mar 2003 | A1 |
20030131845 | Lin | Jul 2003 | A1 |
20040089307 | Brain | May 2004 | A1 |
20040129272 | Ganesh | Jul 2004 | A1 |
20050103345 | Brain | May 2005 | A1 |
20050133037 | Russell | Jun 2005 | A1 |
20070102001 | Brain | May 2007 | A1 |
20080053455 | Brain | Mar 2008 | A1 |
20080060655 | Brain | Mar 2008 | A1 |
20080092903 | Nash | Apr 2008 | A1 |
20080099026 | Chang | May 2008 | A1 |
20080115783 | Brain | May 2008 | A1 |
20080142017 | Brain | Jun 2008 | A1 |
20080308109 | Brain | Dec 2008 | A1 |
20090007920 | Brain | Jan 2009 | A1 |
20090090356 | Cook | Apr 2009 | A1 |
20090133701 | Brain | May 2009 | A1 |
20090145438 | Brain | Jun 2009 | A1 |
20100147309 | Cuevas et al. | Jun 2010 | A1 |
20100313893 | Brain | Dec 2010 | A1 |
20110203594 | Brain | Aug 2011 | A1 |
20110220117 | Dubach | Sep 2011 | A1 |
20110226256 | Dubach | Sep 2011 | A1 |
20110290246 | Zachar | Dec 2011 | A1 |
20120010467 | Brain | Jan 2012 | A1 |
20120048279 | Brain | Mar 2012 | A1 |
20120090609 | Dubach | Apr 2012 | A1 |
20120145160 | Brain et al. | Jun 2012 | A1 |
20120174920 | Barkai et al. | Jul 2012 | A1 |
20120211010 | Brain et al. | Aug 2012 | A1 |
20120283513 | Leeflang et al. | Nov 2012 | A1 |
20130125897 | Baska | May 2013 | A1 |
20130239959 | Brain | Sep 2013 | A1 |
20130247907 | Brain | Sep 2013 | A1 |
20130247917 | Brain | Sep 2013 | A1 |
20130269689 | Brain | Oct 2013 | A1 |
20130324798 | Molnar | Dec 2013 | A1 |
20140000624 | Miller | Jan 2014 | A1 |
20140323806 | Brain | Oct 2014 | A1 |
20150083138 | Brain | Mar 2015 | A1 |
20150114400 | Dubach | Apr 2015 | A1 |
20150246196 | Hansen et al. | Sep 2015 | A1 |
20150290413 | Dubach | Oct 2015 | A1 |
20160008562 | Sagales Manas et al. | Jan 2016 | A1 |
20160101254 | Hansen et al. | Apr 2016 | A1 |
20160114117 | Cook | Apr 2016 | A1 |
20160136373 | Hansen et al. | May 2016 | A1 |
20160184542 | Esnouf | Jun 2016 | A1 |
20160206841 | Vadivelu | Jul 2016 | A1 |
20160317768 | Nasir et al. | Nov 2016 | A1 |
20170209660 | Cook | Jul 2017 | A1 |
Number | Date | Country |
---|---|---|
202005940 | Oct 2011 | CN |
103203058 | Apr 2013 | CN |
2008-541817 | Nov 2008 | JP |
2012017213 | Feb 2012 | WO |
WO2014166136 | Oct 2014 | WO |
Number | Date | Country | |
---|---|---|---|
20160346493 A1 | Dec 2016 | US |