AU2021103415A4 - Training Model for Upper Airway Intubation - Google Patents

Abstract

A three-dimensional model of a human airway for use in the training of oral and/or nasal tracheal intubation and fiberoptic intubation and examination, the model comprising: at least nasal and/or oral structures connected to at least a portion of an upper airway through which an intubation tube and/or fiberscope may pass, a tongue located within the oral structures and/or vocal chords located within the at least portion of an upper airway, wherein a motorised apparatus can move the tongue and/or vocal chords in the airway model. 5/12 Figure 5 2 30 32 10 34 86 84 80 70 50 22 84 72 52 84 38 42 6040 74 76 36 6 14

Description

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Training model for Upper Airway Intubation

Technical Field

[0001] The present invention relates to training models for use in training users with fiberoptic examination and intubation of the upper airway. More particularly, the present invention relates to training models that mimic natural movements of the tongue, vocal chords and other structures of the upper airway for users to circumvent when training and practicing fiberoptic examination and intubation including nasal intubation of the upper airway.

Background Art

[0002] The training of medical practitioners, particularly anaesthetists, emergency medical personnel and others commonly involves considerable practice using teaching models so that they will be sufficiently trained before being allowed to assist human patients in real life scenarios.

[0003] This is specifically the case with training persons around intubation, whether of adults, children or infants, and many such models have since been produced and available for this purpose.

[0004] Intubation models commonly comprise the upper body or at least the head of a manikin with basic through to detailed, anatomically correct and visually accurate airway tracts and associated organs and internal features, including bronchi down to fourth generation.

[0005] Some of these models may be used to train tracheal intubation while other, more detailed models have been created for training and practicing the more difficult fibreoptic guided nasotracheal examination and intubation.

[0006] Some models even provide options of more difficult airways for more advanced training with swollen tongues, bronchoconstriction to simulate asthma, and other such pathologies the trainee may encounter in real situations.

[0007] While intubation through the mouth is generally preferred due to the ease of passing the tube through the mouth and down into the trachea, in some cases oral pathology makes intubation and ventilation through the mouth to be avoided. Examples include severe angioedema of the tongue, and mechanical obstructions to mouth opening from mandibular fixation or other oral pathology, fixed neck contracture, and limited mouth opening, amongst others. In such a situation, nasal intubation may be used for gaining an emergency airway for a patient. Also, nasotracheal intubation by the anaesthetist allows the oral field to be left free and unimpeded for oral surgery under general anaesthetic.

[0008] The basic anatomical structures to navigate through and around during intubation includes the nasal cavity which is situated above the oral cavity and hard palate, and below the skull base and intracranial compartment. It is separated in the midline by the cartilagenous nasal septum into a right and left side. The left and right nasal cavities become continuous in the back of the nose via the opening to the nasopharynx, termed the choana. The lateral nasal walls include three structures called turbinates. Beneath each turbinate is a meatus, named according to the turbinate just above it. The inferior turbinate is the largest of the three paired turbinates and runs along the entire length of the lateral nasal wall, adjacent to the nasal floor. The middle turbinate projects into the central nasal cavity and resides next to the nasal septum. The superior turbinate is the smallest of the turbinates. It resides just above and behind the middle turbinate, and also attaches to the skull base superiorly and nasal wall laterally (Gray's anatomy (2008) The anatomical basis of clinical practice; nose, nasal cavity and paranasal sinuses, 14th edn. Churchill Livingstone, London, pp 549-551).

[0009] There are two pathways along which a tube can be introduced through the nasal cavity namely the lower and upper pathway. The lower pathway lies along the floor of the nose and is safer and preferred for nasal intubation. The upper pathway lies between the inferior turbinate and middle turbinate.

Intranasal abnormalities are also common and may include anatomical variations like concha bullosa, septal deviations, spur, nasal polyps which can cause unilateral obstructions and thereby affect intubation (Smith JE, Reid AP. Asymptomatic intranasal abnormalities influencing the choice of nostril for nasotracheal intubation. B J Anaesth. 1999;83:882-886).

[0010] Intubation tubes generally are classed as oral tubes and nasal tubes. The nasal tubes are longer and of smaller diameter than the oral tubes. The proximal end of these tubes is placed either in the nasal or oral cavity and the distal end of the tube enters the trachea. Nasotracheal intubation involves usage of nasal tube with the proximal end, for example, connected to an anaesthetic circuit. The tube commonly comes with an attached cuff. This cuff (pilot balloon) in the tube when inflated seals the tube against the tracheal wall. This helps in preventing aspiration of fluids into the lungs and ensures that tidal volume ventilates lungs rather than allowing escape of air and gases.

[0011] The more difficult nasal intubation of a patient commonly involves the following steps or variations thereof (Prasanna D, Bhat S. Nasotracheal Intubation: An Overview. J Maxillofac Oral Surg. 2014;13(4):366-372):

1. Examine both nostrils and determine which is larger;

2. Spray the nasal passages and back of the throat with an appropriate topical anaesthetic and vasoconstrictor in order to numb the mucosa and reduce bleeding;

3. Check the balloon on an appropriately sized nasotracheal tube. Firmly seat the 15 mm adapter in the proximal end of the tube and lubricate the distal 4 cm with a numbing medication;

4. Position the patients head in midline neutral position if possible;

5. With gentle, steady pressure, insert the tube directed towards the occipital protuberance on the back of the skull with the bevel turned towards the nasal septum. If the tube will not pass on one side, try the other. Some resistance may be encountered when the tube reaches the posterior nasopharynx. At this point some gentle manipulation may ease passage past the resistance. It may assist to turn the tube 1/4 turn after reaching the nasopharynx.

6. When the tube has reached the oropharynx, manipulation of the tube with Magill's forcep and laryngoscope may be done to facilitate its movement into the trachea. Listen at the end of the tube for air moving in and out with each respiration. This verifies a location above the laryngeal inlet;

7. Spray anesthetic once through tube again. The patient will likely cough and buck;

8. Pass tracheal tube through vocal chords during inhalation by the patient; and

9. Confirm placement of the tracheal tube, then sedate, and administer muscle relaxants to the patient as required.

[0012] Fibreoptic laryngobronchoscopic intubation (fibreoptic intubation) may be used in nasal and oral intubations (either in the awake or anesthetized patient), evaluation of the airway, verification of accurate placement of single or double-lumen endotracheal tubes and laryngeal mask airways (LMA), endotracheal tube exchange, placement of bronchial blocker devices, and for other diagnostic and therapeutic uses.

[0013] Special skills are required to have a high degree of success with fiberoptic intubation. Many of the concepts and mechanical skills required for successful use of the fiberoptic bronchoscope (FOB) used in the technique in clinical practice can be learned through the use of airway models. The FOB is composed of an eyepiece, a control section, the insertion cord, and a universal cord.

[0014] The mechanical skills involved include (Stackhouse RA. Fiberoptic airway management. Anethesiology Clin N Am. 2002; 20:933-951:

• Developing an appropriate grip on the FOB to achieve 360 degrees of rotation by the use of both directions of flexion.

• Rotating the FOB while remembering to keep the scope taut. If the scope is lax, the torque is not optimally translated to the tip, which results in a lesser change in the view through the eyepiece than would be attained if tension were maintained on the insertion cord. • Moving the scope longitudinally. One should advance toward the object or back off and readjust the channel if the target is not achievable with the current orientation. • Manipulating the channel. In clinical practice, the endotracheal tube (ETT) generally serves as the channel for nasal intubations. An intubating airway is used for oral intubations. The model allows for all the same manipulations of the channel that are possible or necessary for actual intubations. The channel can be rotated to adjust for aiming laterally. It can be advanced toward the object or pulled back to regain a broader field of view. It also can be aimed in a more anterior direction. In the clinical setting, this can be accomplished by inflating the cuff of the ETT to lift it off the posterior pharyngeal wall and aim it at the trachea, which has been described for facilitating blind nasal intubation [6-8]. Alternatively, anterior displacement of the tip of the ETT can be accomplished by traction on the pulley of an Endotrol tube.

[0015] The visual skills required areas follows:

• Realizing that to adjust the fiberoptic view, the FOB must be manipulated rather than one's own position, because the image is generated from the distal end of the optical fibers in the insertion cord of the FOB. • Deciphering the fiberoptic image. The view is upright, upside-down, or sideways depending on whether one is at the head of the bed or in front of the patient and the orientation of a camera attached to the FOB (optional). • Determining field of view through the FOB. It can be difficult to identify structures when too close to them and only a small portion is visible. It may be necessary to withdraw the FOB a certain distance to identify landmarks before advancing again.

• Re-establishing a view if the FOB becomes obscured by secretions or the tip fogs. Options include wiping the tip on the pharyngeal wall, injecting through the channel, or removing the scope from the airway and cleaning the tip. • Learning to manipulate the channel to advance toward the airway based on the view seen through the FOB.

[0016] Thus, while intubation airway models maybe useful in practicing certain aspects of oral and nasal intubation including fibreoptic laryngobronchoscopic intubation through the mouth or nostril and down into the trachea past the epiglottis and vocal chords, the user does not experience the issues with the live patient reacting against the movement of the tube through this passage and other related issues.

[0017] In this respect, the epiglottis is a cartilaginous flap that extends in front and above the laryngeal inlet, or more specifically the rima glottidis (glottis). The function of the epiglottis is to close the laryngeal inlet during swallowing and so to prevent the passage of food and liquid into the lungs (aspiration). The epiglottis is located in the larynx and attached to the thyroid cartilage and hyoid bone. Its movements are regulated by the passive pressure from the tongue as it pushes the food down the pharynx, as well as by the contractions of the aryepiglottic muscle. Thus, the epiglottis creates a block for an intubation tube during the time when the patient is swallowing.

[0018] It would therefore be of benefit to provide new, even more realistic models to assist in the training and practice of intubation, and particularly nasotracheal intubation and nasally directed fibreoptic examination for medical practitioners, anaesthetists, emergency personnel, and others.

[0019] The preceding discussion of the background art is intended to facilitate an understanding of the present invention only. It should be appreciated that the discussion is not an acknowledgement or admission that any of the material referred to was part of the common general knowledge as at the priority date of the application.

Summary of the Invention

[0020] The invention provides a three-dimensional (3D) model of a human airway for use in the training of oral and/or nasal tracheal intubation and fiberoptic intubation and examination, the model comprising:

at least nasal and/or oral structures connected to at least a portion of an upper airway through which an intubation tube and/or fiberscope may pass,

a tongue located within the oral structures and/or vocal chords located within the at least portion of an upper airway,

wherein the tongue and/or vocal chords can move in the airway model.

[0021] In a preferred embodiment, a motorised apparatus moves the tongue and/or vocal chords. The movement of the tongue and/or vocal chords by the motorised apparatus preferably simulates human movement of the tongue and/or vocal chords.

[0022] Various body parts are described herein in the process of describing the model of the invention. Unless otherwise stated, reference to these body parts refers to models of these parts of human organs which may be constructed from a variety of different materials comprising resilient or hard plastic, metal and silicone, amongst others, as is useful for the operation of a model according to the invention.

[0023] The tongue and the at least nasal and/or oral structures are preferably located within a head or at least a portion of a head, wherein the head preferably comprises a skull. The head or at least portion of the head is preferably attached to a neck or at least a portion of a neck which comprises the at least portion of the upper airway and the vocal chords.

[0024] The at least portion of the neck is preferably attached to shoulders and at least a portion of an upper chest. The at least portion of the upper chest is preferably attached to a baseplate. The baseplate preferably closes the model to prevent access and potential damage to internal parts by users and act as a bottom surface to which parts of the model may be attached.

[0025] The at least portion of the upper airway preferably attaches to at least a portion of a trachea. The trachea may also comprise primary and secondary bronchi and a left and right lung.

[0026] The head or the at least portion of the head preferably comprises a moveable jaw and a mouth. The jaw is preferably hingedly connected to the skull. The hinged connection of the jaw to the skull preferably comprises slots enabling the jaw to move back and forward and some rotation relative to the skull. The mouth preferably comprises the oral structures.

[0027] In a preferred embodiment of the model of the invention, the tongue moves within the mouth. The movement of the tongue is preferably backwards which blocks the upper airway or movement forwards which unblocks the upper airway.

[0028] In a preferred embodiment of the model of the invention, an epiglottis formed from a resiliently flexible material is located at the rear of the mouth and in an unbiased open configuration does not block the upper airway when the tongue is forward,

wherein the tongue comprises a biasing means and movement of the tongue backwards pushes on the epiglottis into a closed configuration which blocks the upper airway, and

wherein movement of the tongue forward releases the epiglottis to unblock the upper airway and return to the unbiased open configuration.

[0029] In a preferred embodiment of the model of the invention, movement of the tongue is controlled by gears. The tongue is preferably attached to a rack of a rack and pinion mechanism and turning the pinion moves the rack and the attached tongue backwards or forwards in the mouth. The rack and pinion mechanism are preferably contained within a cassette limiting the movement of the rack and pinion mechanism and therefore the movement of the tongue backwards and forwards a limited distance. The cassette is preferably located within the jaw.

[0030] A first drive axle preferably attaches at a first end to the pinion and turning the first drive axle turns the pinion. The first drive axle preferably comprises a first gear cable at the first end. A second end of the first drive axle is preferably attached to a first axle gear. The first axle gear is preferably round and comprises cogs. The cogs of the first axle gear preferably mesh with the cogs of a first motor gear. The first drive axle, first axle gear and first motor gear preferably comprise a first transmission.

[0031] A first motor preferably turns the first motor gear and the first motor is preferably a servo motor. The servo motor is preferably controlled by a computer controller to control when, how far, how fast, and the direction the first motor gear turns.

[0032] The servo motor is preferably powered by a power supply and the power supply preferably comprises a 12-volt battery. The power supply preferably comprises at least one connector for recharging the battery and/or accessing the computer controller.

[0033] At least a portion of the first drive axle is preferably resiliently flexible. The first drive axle preferably comprises a flexible metal and a resiliently flexible plastic portion. At least a portion of the first drive axle is preferably located within a casing and the first drive axle can preferably rotate within the casing. The casing is preferably cylindrical.

[0034] In a preferred embodiment of the model of the invention, at least a portion of the first transmission is located within a gearbox housing. The gearbox housing is preferably attached to the baseplate. The gearbox housing is preferably attached to the baseplate by at least one support and the gearbox housing can at least partially rotate about the at least one support. The at least one support preferably comprises two A-frame supports around which the top of the A-frame supports the gearbox housing can rotate.

[0035] The head or at least portion of the head can preferably move relative to the airway and trachea by tilting backwards or forwards. The rotation of the gearbox housing preferably enables the position and angle of the first drive axle to change when the head and rack and pinion is tilted back and forth relative to the base during use of the model.

[0036] In a preferred embodiment of the model of the invention, the vocal chords can move between an open and a closed configuration. In the closed configuration the vocal chords can preferably block movement of an intubation tube and/or fiberscope from passing through the at least portion of the upper airway. In the open configuration the vocal chords preferably do not block movement of an intubation tube and/or fiberscope from passing through the at least portion of the upper airway.

[0037] The vocal chords preferably comprise a left vocal chord and a right vocal chord.

[0038] The left vocal chord preferably comprises a left arm that rotates about a left arm pivot point adjacent an end of the left arm to move the left vocal chord between the open and closed configuration. The left arm preferably resides in a slot within the left vocal chord so it remains hidden.

[0039] The right vocal chord preferably comprises a right arm that rotates about a right arm pivot point adjacent an end of the right arm to move the right vocal chord between the open and closed configuration. The right arm preferably resides in a slot within the right vocal chord so it remains hidden.

[0040] Rotational movement of the left arm and right arm is preferably controlled by gears.

[0041] A second drive axle can preferably rotate the left arm about the left arm pivot point. A first end of the second drive axle preferably connects to the left arm at the left arm pivot point. The second drive axle preferably comprises a second gear cable at the first end. A second end of the second drive axle is preferably attached to a second axle gear. The second axle gear is preferably round and comprises cogs. The cogs of the second axle gear preferably mesh with the cogs of a second motor gear.

[0042] A third drive axle can preferably rotate the right arm about the right arm pivot point. A first end of the third drive axle preferably connects to the right arm at the right arm pivot point. The third drive axle preferably comprises a third gear cable at the first end. A second end of the third drive axle is preferably attached to a third axle gear. The third axle gear is preferably round and comprises cogs.

[0043] The cogs of the third axle gear mesh preferably with the cogs of the second axle gear. The direction of rotation of the third axle gear is preferably opposite to the direction of the second axle gear when the second motor gear turns the second axle gear. The second drive axle, second axle gear, third drive axle, third drive gear, and second motor gear preferably comprise a second transmission. At least a portion of the second transmission is preferably located within the gearbox housing

[0044] A second motor preferably turns the second motor gear and similarly to the first motor, the second motor is preferably a servo motor. The servo motor is preferably controlled by a computer controller to control when, how far, how fast, and the direction the second motor gear turns.

[0045] The servo motor is preferably powered by a power supply and the power supply preferably comprises a 12-volt battery. The power supply preferably comprises at least one connector for recharging the battery and/or accessing the computer controller.

[0046] At least a portion of the second drive axle and/or third drive axle is preferably resiliently flexible. The second drive axle and/or third drive axle preferably comprises a flexible metal and a resiliently flexible plastic portion. At least a portion of the second drive axle and/or third drive axle is preferably located within a casing and the second drive axle and/or third drive axle can preferably rotate within the casing. The casing is preferably cylindrical.

[0047] In another preferred embodiment, the invention provides use of a model as described herein for training or practicing intubating or inserting a fiberscope. The intubation is preferably nasal intubation. The fiberscope preferably comprises a flexible fiberoptic bronchoscope.

[0048] In a further preferred embodiment, the invention provides a process for the manufacture of a model as described herein.

[0049] In another preferred embodiment, the invention provides a method of training a user in intubation, fiberoptic nasal intubation and/or examination, the method comprising use of a model as herein described.

Brief Description of Figures

[0050] The present invention will now be described, by way of example, with reference to the accompanying drawings, in which:

Figure 1. 3D rendered illustration of (A) front, (B) rear, (C) side, (D) bottom, and (E) top, view of an airway model according to a preferred embodiment of the invention.

Figure 2. 3D rendered illustration of a front perspective view showing the internal workings of an airway model according to a preferred embodiment of the invention.

Figure 3. 3D rendered illustration of a front perspective view showing a portion of the internal workings of the gearbox of an airway model according to a preferred embodiment of the invention.

Figure 4. 3D rendered illustration of a front perspective view showing a portion of the internal workings of the gearbox and neck of an airway model according to a preferred embodiment of the invention.

Figure 5. 3D rendered illustration of a front view showing the internal workings of an airway model according to a preferred embodiment of the invention.

Figure 6. 3D rendered illustration of a front perspective view from above showing the internal workings of an airway model according to a preferred embodiment of the invention.

Figure 7. 3D rendered illustration of a side view showing the internal workings of an airway model according to a preferred embodiment of the invention.

Figure 8. 3D rendered illustration of a top view showing the internal workings of an airway model according to a preferred embodiment of the invention.

Figure 9. 3D rendered illustration of a cross-sectional top view through the mouth showing the internal workings of an airway model according to a preferred embodiment of the invention.

Figure 10. 3D rendered illustration of a cross-sectional top view through the throat showing the internal workings of an airway model according to a preferred embodiment of the invention.

Figure 11. 3D rendered illustration of a rear perspective view from above showing a portion of the internal workings of an airway model according to a preferred embodiment of the invention.

Figure 12. 3D rendered illustration of a side view showing a portion of the internal workings of an airway model according to a preferred embodiment of the invention.

Description of Preferred Embodiments

[0051] Those skilled in the art will appreciate that the invention described herein is susceptible to variations and modifications other than those specifically described. It is to be understood that the invention includes all such variations and modifications. The invention also includes all of the steps, features, compositions and compounds referred to or indicated in the specification, individually or collectively and any and all combinations or any two or more of the steps or features.

[0052] The present invention is not to be limited in scope by the specific embodiments described herein, which are intended for the purpose of exemplification only. Functionally equivalent products, compositions and methods are clearly within the scope of the invention as described herein.

[0053] Other definitions for selected terms used herein may be found within the detailed description of the invention and apply throughout. Unless otherwise defined, all other scientific and technical terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which the invention belongs.

[0054] It will be appreciated that the indefinite articles "a" and "an" are not to be read as a singular indefinite articles or as otherwise excluding more than one or more than a single subject to which the indefinite article refers.

[0055] Reference to cited material or information contained in the text should not be understood as a concession that the material or information was part of the common general knowledge or was known in Australia or any other country.

[0056] Each document, reference, patent application or patent cited in this text is expressly incorporated herein in their entirety by reference, which means that it should be read and considered by the reader as part of this text. That the document, reference, patent application, or patent cited in this text is not repeated in this text is merely for reasons for conciseness.

[0057] Throughout the specification and claims, unless the context requires otherwise, the word "comprise" or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.

[0058] Features of the invention will now be discussed with reference to the following preferred embodiment.

[0059] Figure 1 shows the external configuration of a preferred embodiment of the airway model 2 according to the invention comprising a bust of a human upper body from the shoulders 4 up to, and including the neck 6 and the head 8 comprising the jaw 20. The airway model 2 comprises a full scale model representation of a human head and shoulders, comprising within it a silicone model of a human airway. The skin is made from silicone cast in a mold and attempts to mimic human skin in terms of colour, texture and density. The shoulders 4 comprise vacuum formed plastic created from a mold generated from digital data of the human upper torso. The mouth 10 and nostrils 12 comprise apertures forming the start of passageways into the airway model. The baseplate 14 of the airway model is made from flat acrylic sheet in the shape of a section of the human body, cut through at chest height. The baseplate 14 is flat allowing the airway model 2 to be placed on the baseplate 14 in an upright position or lying down resting on the occipital region 16 of the head and the back 18. A base rim 15 cast in polyurethane rubber from a mold connects the shoulders 4 to the baseplate 14 by way of forming a rubbery seal to the perimeter edge of the shoulders 4 and the baseplate 14 simultaneously. It seals the shoulders 4 and the baseplate 14 together.

[0060] Figure 2 shows the internal workings of the airway model 2 beneath the skin comprising formed silicone. A hard skull 30 of acrylonitrile butadiene styrene (ABS) plastic molded to shape, holds the shape of the skin. A jawbone of molded ABS plastic is in the shape of a human lower jawbone. The jawbone 35 comprises spigots at the point where it meets the skull 30. The spigots are inserted into slots in the skull 30 such that the jaw 35 can rotate in similar movements to a human jaw and also move back and forward similarly to a real human jaw.

[0061] The skull 30 comprises softer resilient materials of rubber imitating the nasal cartilages 32 and lower face 34 surrounding the mouth 10. The resilient materials comprise rubber or silicone.

[0062] A molded plastic gearbox housing 36 comprising part of the movement apparatus for the airway model 2 is attached to the baseplate 14 by gearbox mounts 38. The gearbox mounts 38 comprise plastic molded vertical A-frame mounts at a first end and a second end of the gearbox housing 36. The gearbox mounts 38 comprise an aperture at the top of the A-frame into which spigots are inserted such that the gearbox housing 36 is suspended and is able to swing back and forth, effectively rotating to follow the angle of the flexible axles as the head is tilted back and forth during use. An electronics housing 40 attached to the baseplate 14 comprises circuit boards programmed to control servo motors powered by a 12-volt power supply with a barrel connector, to control the gears within the gearbox housing 36. The electronics housing 40 comprises internal mounts to which the circuit boards are attached.

[0063] Figure 3 shows the inner mechanism of the gearbox housing 36. At the first end of the gearbox housing 36, a first motor 42 comprising a servo motor is mounted which is connected to turn a round first motor gear 44 via a first gear shaft.

[0064] At the second end of the gearbox housing 36, a second motor 60 comprising a servo motor is mounted which is connected to turn a round second motor gear 62 via a second gear shaft.

[0065] The first motor gear cogs 46 of the first motor gear 44 are meshed with cogs (i.e. the teeth are aligned) of a round first axle gear 48 to form a first transmission. A flexible plastic hexagonal first drive axle 52 is connected to the top of the first axle gear 48. A flexible metal first gear cable 50 emanates from the top of the plastic flexible first drive axle 52. The purpose of the first transmission is to move the tongue within the jaw 20 and the head 8 of the airway model 2. The first drive axle 52 is located within a cylindrical plastic molded first drive sleeve 54.

[0066] The second motor gear cogs 64 of the second motor gear 62 are meshed with cogs of a round second axle gear 66, and the cogs of the second axle gear 66 are in turn meshed with cogs of a round third axle gear 68 in a gear train to form a second transmission. The purpose of the second transmission is to move the vocal chords within the neck 6 of the airway model 2.

[0067] A flexible metal second gear cable 70 emanates from a flexible plastic hexagonal second drive axle 72 connected to the top of the second axle gear 66. The second drive axle 72 is located within a cylindrical plastic molded second drive sleeve 73.

[0068] A flexible metal third gear cable 74 emanates from a flexible plastic hexagonal third drive axle 76 connected to the top of the third axle gear 66. The third drive axle 76 is located within a cylindrical plastic molded third drive sleeve 78.

[0069] The first, second, and third drive sleeves form protective casings for the drive axles. The sleeves maintain the position of the hexagonal drive axles to be engaged for rotation by the respective gears, but still allow a range of movement for the flexible drive axles to be able to move up and down vertically as the head 8 is tilted back and forth during operation.

[0070] Thus, the first motor 42 turns the first motor gear 44, therein turning the first axle gear 48 and the connected first drive axle 52 and first gear cable 50.

[0071] The second motor 60 turns the second motor gear 62, therein turning the second axle gear 66 and the connected second drive axle 72 and the second gear cable 70; and the second axle gear 66 therein turns the third axle gear 68 and the connected third drive axle 76 and the third gear cable 74 in the opposite direction to the direction of the turning second axle gear 66.

[0072] Figure 4 shows the internals of the first drive axle 52 in the first drive sleeve 54, second drive axle 72 in the second drive sleeve 73, and third drive axle 76 in the third drive sleeve 78.

[0073] Figure 4 also shows the first gear cable 50 entering a first housing 56 under the jaw 20. The second gear cable 70 and third gear cable 74 enter a second housing 80 within the region of the neck 6, the second housing attached to a collar 82 encircling where the airway 98 meets the trachea 22.

[0074] A front view of the internal workings of the airway model 2 beneath the skin is shown in Figure 5. Two steel support bolts 84 are at one end connected to a shoulder support plate 86 comprising the collar 82, and at the other end connected to the baseplate 14, providing structural support for the airway model 2 between the shoulders 4 and baseplate 14. The tongue 90 can be seen within the mouth 10.

[0075] Figure 5 also shows the gearbox housing 36 suspended above the baseplate 14 by the gearbox mounts 38 enabling it to swing back and forth, effectively rotating to follow the angle of the flexible axles as the head is tilted back and forth during use.

[0076] The perspective internal workings view of Figure 6 shows the shape and configuration of the shoulder support plate 86 in forming the top shape of the shoulders 4. A gap between the collar 82 and the outer circumference of the shoulder support plate 86 can be seen which allows the movement of the head 8 to tilt back. Teeth 92 in gums 94 are visible in the mouth 10. The teeth 92 comprise polyurethane resin cast from a mold. The gums 94 comprise silicone cast from a mold and the teeth 92 are included in the mold to become attached to the gums. The gums 94 are then glued into the mouth 10.

[0077] The side internal workings view of Figure 7 shows the connection of the jawbone 35 to the skull 30 by the jaw hinge spigots 94 located in slotted holes in the skull 30. The slotted holes enable movement of the jaw hinge spigots 94 within the slots so that the jawbone 35 can move back and forward as well as some rotation.

[0078] At the rear of the electronics housing 40 and accessible from the outer surface of the skin is a connector for connecting the electronics housing 40 to a power supply and for control of the programming of the circuit boards.

[0079] A spine 96 is constructed using a flexible metal gooseneck similar to the flexible coil steel hose commonly used in desk lamps. An end of the gooseneck is fixed to a base which attaches to the baseplate 14. The other end of the gooseneck is attached to a top plate to which the skull 30 is fixed by screws. The metal gooseneck of the spine 96 provides support within the airway model 2 between the baseplate 14 and skull 30 and also allows movement of the skull 30 to different angles relative to the baseplate 14.

[0080] The airway 98 also comprising the mouth 10 and nasal cavity situated above the trachea 22 is cast in silicone from a mold created from human CT scan digital data. This includes the nasal and oral cavities, larynx, pharynx, trachea to the first bronchial branch and esophagus. The colour, texture and polymer density of the internal surfaces are similar to that of a real human airway. The skull 30 is formed around the airway 98 such that it holds the airway 98 in place.

[0081] The circuit boards within the electronics housing 40 powered by a 12v power supply are programmed to control the servo motors to move the flexible axles in a way that simulates a swallowing motion by moving the tongue and vocal chords simultaneously.

[0082] The skull 30 and other internal workings including the electronics housing 40 and gearbox mounts 38 are shown from above in Figure 8.

[0083] Part of the mechanism for moving the tongue is shown in Figure 9. The first gear cable 50 comprising a flexible steel cable connects via a rectangular end into an first gear cable attachment aperture 100 in a round first pinion gear 102, as part of a rack and pinion arrangement located in a chin cassette 103 in the chin 21 between the jawbone 35. The flexibility of the first gear cable 50 enables the head 8 to be tilted in any direction, without affecting the operation of the tongue 90 movement.

[0084] The chin cassette 103 comprises an acrylic housing mounted inside the chin 21 on a mounting plate on the jawbone 35 and under the tongue 90 (not shown in Figure 9). The chin cassette 103 is concealed from view under the tongue 90 and is configured to hold the rack and pinion arrangement comprising the first pinion gear 102 and rack 108 within a formed space but enables rotational movement of the first pinion gear 102, and linear movement of the rack 108 forwards and backwards.

[0085] The rack 108 comprises a semi-flexible plastic rail with one edge saw toothed. Positioned under the tongue 90 and a tongue mount, it extends along its length from the interior of the chin 21 to the back underside of the tongue 90. Movement of the rack 108 backwards towards the spine 96 moves the tongue backwards to simulate swallowing, and movement of the rack 108 forwards towards the mouth 10 returns the tongue 90 to a non-swallowing, normal position. The flexibility of the rack 108 allows some resilience to pressure exerted on the tongue 90 by the user's hands to provide a more 'organic' and realistic feel when a user is using the airway model 2.

[0086] The tongue 90 is cast in silicone from a mold created from human CT scan digital data. A cavity is created under the tongue 90 to allow a tongue mount cast in a semi-flexible plastic to be inserted for attaching the tongue 90 to the rack 108.

[0087] The first pinion gear cogs 104 mesh with the rack teeth 106 of the rack 108 to translate rotational motion of the first pinion gear 102 into linear motion by the rack 108. Thus, when the first motor 42 turns the first motor gear 44, the first axle gear 48 is turned by the first motor gear 44, therein also turning the first drive axle 52 and first gear cable 50, wherein the turning first gear cable 50 also turns the first pinion gear 102 which moves the rack 108 forwards or backwards depending on the direction of the turning first pinion gear and first motor gear 44.

[0088] The mechanism for moving the vocal chords is shown in Figures 9 to 12.

[0089] The vocal chords are cast in silicone from a mold created from human 3D CT scan digital data. The colour, texture, and polymer density of the internal surfaces are adjusted to get as close as possible to that of real human organs.

[0090] A right vocal chord motion arm 110 comprising molded plastic is attached to a right rotating barrel 112. The third gear cable 74 is attached by glue to the underside of the right rotating barrel 112. When cast, a sleeve is formed in the right vocal chord 114 to accommodate the right vocal chord motion arm 110.

[0091] A left vocal chord motion arm 116 comprising molded plastic is attached to a left rotating barrel 118. The second gear cable 70 is attached by glue to the underside of the left rotating barrel 118. When cast, a sleeve is formed in the left vocal chord 120 to accommodate the left vocal chord motion arm 116.

[0092] Figure 10 shows the vocal chords practically touching in a closed configuration therein blocking the airway 98. Thus, when the second motor 60 turns the second motor gear 62, the second axle gear 66 is turned by the second motor gear 62, therein also turning the second drive axle 72 and second gear cable 70; wherein the turning second gear cable 70 turns the left rotating barrel 118 and therefore the left vocal chord motion arm 116 in a counter-clockwise direction. The second axle gear 68 also turns the third axle gear 68 turning the third drive axle 76 and the third gear cable 74; wherein the turning third gear cable 74 turns the right rotating barrel 112 and therefore the right vocal chord motion arm 110 in a clockwise direction.

[0093] The action of the left vocal chord motion arm 116 turning in a counter clockwise direction moves the left vocal chord 120 towards the left side of the airway 121, and the right vocal chord motion arm 110 turning in a clockwise direction, separates the left vocal chord 120 from the right vocal chord 114 into an open configuration therein opening the airway 98.

[0094] The second housing 80 shown in Figure 4 and Figure 11 houses the vocal chord chassis which serves three functions. The first is that it houses the left rotating barrel 118 and right rotating barrel 112 so that they are held in position and can rotate about a first plane. The second is that it holds the left vocal chord 120 and right vocal chord 114 in a fixed position in relation to the spine 96. The third is that the second housing 80 and collar 82 holds the silicone airway 98 in a fixed position at this location in relation to the spine 96.

[0095] The epiglottis 130 shown in Figure 12 is cast in silicone from a mold created from human 3D CT scan digital data. The epiglottis 130 is flexible enough to be pushed down into the closed position by the tongue 90 moving backwards to block the airway 98 and simulate a real life swallowing motion.

Claims (5)

The Claims Defining the Invention are as Follows

1. A three-dimensional model of a human airway for use in the training of oral and/or nasal tracheal intubation and fiberoptic intubation and examination, the model comprising:

at least nasal and/or oral structures connected to at least a portion of an upper airway through which an intubation tube and/or fiberscope may pass,

a tongue located within the oral structures and/or vocal chords located within the at least portion of an upper airway,

wherein a motorised apparatus can move the tongue and/or vocal chords in the airway model.

2. A model according to claim 1, wherein the tongue and the at least nasal and/or oral structures are located within at least a portion of a head, and wherein the at least portion of the head is attached to at least a portion of a neck which comprises the at least portion of the upper airway and the vocal chords,

wherein the at least portion of the neck is attached to shoulders and at least a portion of an upper chest, and wherein the at least portion of the upper chest is attached to a baseplate,

wherein the at least portion of the upper airway attaches to at least a portion of a trachea,

wherein the head comprises a moveable jaw and a mouth, and

wherein the movement of the tongue backwards blocks the upper airway and movement forwards unblocks the upper airway.

3. A model according to claim 2, wherein an epiglottis formed from a resiliently flexible material is located at the rear of the mouth and in an unbiased open configuration does not block the upper airway when the tongue is forward, wherein the tongue comprises a biasing means and movement of the tongue backwards pushes on the epiglottis into a closed configuration which blocks the upper airway, and wherein movement of the tongue forward releases the epiglottis to unblock the upper airway and return to the unbiased open configuration.

4. A model according to any one of the preceding claims, wherein movement of the tongue is controlled by gears and the tongue is attached to a rack of a rack and pinion mechanism and turning the pinion moves the rack and the attached tongue backwards or forwards in the mouth.

5. A model according to any one of the preceding claims, wherein the vocal chords can move between an open and a closed configuration,

wherein in the closed configuration the vocal chords can block movement of an intubation tube and/or fiberscope from passing through the at least portion of the upper airway, and

wherein in the open configuration the vocal chords do not block movement of an intubation tube and/or fiberscope from passing through the at least portion of the upper airway,

wherein the vocal chords comprise a left vocal chord and a right vocal chord,

wherein the left vocal chord comprises a left arm that rotates about a left arm pivot point adjacent an end of the left arm to move the left vocal chord between the open and closed configuration, and

wherein the right vocal chord comprises a right arm that rotates about a right arm pivot point adjacent an end of the right arm to move the right vocal chord between the open and closed configuration.