Patent Publication Number: US-2021187224-A1

Title: Ventilation tubes with inflatable cuffs

Description:
FIELD 
     The present invention relates, generally, to systems and methods for airway ventilation tube products, such as tracheal tubes and tracheostomy tube comprising inflatable cuffs. 
     BACKGROUND 
     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. 
     In the course of treating a patient with artificial ventilation, a ventilation tube may be used to control the flow of air into the patient. It is desirable to provide a seal between the outside of the tube or device and the interior walls of the trachea passage in which the tube or device is inserted. For example, tracheal tubes may be used to control the flow of air or other gases through a patient&#39;s trachea. To seal these types of tracheal tubes, an inflatable cuff may be associated with these tubes. When inflated, the cuff generally expands into the surrounding trachea to seal the tracheal passage around the tube. In order to create a good seal, it was found by practitioners that the cuff pressure should commonly be higher than 20 cm H2O. Yet, in order to avoid tracheal tissue ischemia, the cuff pressure is desired to be maintained at a pressure below 30 cm H2O. Hence, proper cuff pressure is limited to a narrow range of 20-30 cm H2O. The trachea is not an even tube and therefore slight movements of the ventilation tube may shift the cuff to more constricted or more open locations within the trachea—resulting in alteration of the original setting of the balloon pressure when first inflated. Unfortunately, in the present art of ventilation cuff balloons, the clinical pressure variation due to such movements range far beyond the desired range of 20-30 cm H2O. 
     Moreover, human anatomy varies significantly between individuals. One prior art device is disclosed in U.S. Pat. No. 9,032,957. 
     SUMMARY OF EMBODIMENTS 
     The present invention relates, generally, to systems and methods for airway ventilation tube products, such as tracheal tubes and tracheostomy tube comprising inflatable cuffs. In particular, various embodiments are directed to efficient methods of improving the sealing properties and pressure stability of the inflated cuff when in use. 
     Embodiments of the invention relate to a ventilation device comprising: a. a ventilation tube having proximal and distal ends; and b. an inflatable cuff having a proximal bulge portion and a distal neck portion disposed distal to the bulge portion, the inflatable cuff being mounted around the ventilation tube to define proximal and distal cuff attachment locations which are both fixed on an outer surface of the ventilation tube. 
     In some embodiments, (i) when the tube-mounted cuff is deployed within a human trachea sized for the ventilation tube so that (A) the ventilation tube is co-axial with the human trachea and (B) the tube-mounted cuff is uninflated or inflated to a pressure of 5 cm H2O, a widest portion of the bulge portion of the mounted cuff is in wrinkled contact with the trachea. 
     In some embodiments, when the tube-mounted cuff is deployed within a human trachea sized for the ventilation tube so that (A) the ventilation tube is co-axial with the human trachea and (B) the tube-mounted cuff is uninflated or inflated to a pressure of 25 cm H2O, a widest portion of the bulge portion of the mounted cuff is in wrinkled contact with the trachea. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A presently preferred embodiment of the invention will be described in detail, in conjunction with the accompanying drawings, in which: 
         FIGS. 1A-1B, 2A-2E, 3A-3B, 4A-4B and 6A-6B  illustrate an exemplary ventilation device of component(s) thereof. 
         FIG. 5  illustrates contact length as a function of pressure. 
         FIGS. 7A-7B and 8A-8B  relate to experiments performed on an exemplary cuff. 
         FIG. 9  illustrates a relationship between a volume parameter and a pressure parameter. 
         FIGS. 10A-10C  illustrate tables and graphs which exemplify the relationship between selected ventilation tube sizes and associated human trachea sizes characterized by their diameter dimension. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     The invention is herein described, by way of example only, with reference to the accompanying drawings. With specific reference now to the drawings in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of the embodiments of the exemplary system only and are presented in the cause of providing what is believed to be a useful and readily understood description of the principles and conceptual aspects of the invention. In this regard, no attempt is made to show structural details of the invention in more detail than is necessary for a fundamental understanding of the invention, the description taken with the drawings making apparent to those skilled in the art how several forms of the invention may be embodied in practice and how to make and use the embodiments. 
     For brevity, some explicit combinations of various features are not explicitly illustrated in the figures and/or described. It is now disclosed that any combination of the method or device features disclosed herein can be combined in any manner—including any combination of features—any combination of features can be included in any embodiment and/or omitted from any embodiments. 
     There is a need for ventilation tubes with inflatable cuff that have improved pressure stability and/or good contact even at low pressure (e.g. to handle the fact that the trachea is not a perfect cylinder). Embodiments of the present invention relate to apparatus and methods for achieving a relatively stable cuff pressure, within the range of 20-30 cm H2O, under varying volume on the order of 10% of the cuff volume. Tracheal tubes cuff volume within the trachea is about 5 cc to 10 cc and tracheostomy tube cuff volumes are even smaller 3 cc to 5 cc. Previously known art of ventilation tube cuffs, a volume difference of 0.4 cc already takes the cuff pressure significantly out of range. 
     The present invention introduces ventilation tubes with new cuffs purposefully engineered to have a pressure/volume inflation curve that is providing for unprecedented pressure stability when inflated within a human trachea. Unlike previously known art of ventilation tube cuffs, the present invention introduces cuffs that behave significantly different when inflated within an enclosing tube compared with free space inflation. The cuffs pressure curve is different when inflated within different tube diameters. Ventilation tubes and associated cuffs are sized according to intended human user, as summarized in the tables shown in  FIGS. 810 to 10C . In particular, the cuffs size, shape, and elastic properties are configured to achieve the specific desired safe pressure range of 20-30 cm H2O when inflated within an enclosing tube of similar dimensions to the associated human trachea. 
     It helps to highlight from the outset certain distinguishing feature of the present invention embodiments in comparison with known art. For ease of reference the following numbers in the figures are meant to refer to as follows
       100 —ventilation device comprising a ventilation tube  106  and an inflatable cuff  200       106 —catheter tube or ventilation tube (e.g. ETT or tracheostomy tube)     102 —proximal end of ventilation tube  106       107 —distal end of ventilation tube  106       130 —central axis of ventilation tube  106       200 —inflatable cuff (e.g. balloon cuff) mounted around the ventilation tube  106       211 —proximal cuff attachment location of cuff  200  on outer surface of tube  106       212 —distal cuff attachment location of cuff on outer surface of tube  106       203 —cuff balloon wall     104 —inflation lumen for inflating the inflatable cuff  200       109 —proximal inflation inlet of inflation lumen  104       105 —distal inflation inlet into cuff  200       287 —proximal bulge portion of cuff  200       289 —distal neck portion of cuff  200       901 —proximal direction defined according to proximal end  102  of the ventilation tube  106       951 —distal direction defined according to distal end  107  of the ventilation tube  106       108 —enclosing tube
 
which is either (i) a human trachea that is sized for the ventilation tube  106  to which cuff  200  is mounted; and/or (ii) an external ‘in vitro’ rigid straight (i.e. perfectly cylindrical) test tube whose interior width matches that of a human trachea that is ‘sized for’ the ventilation tube  106  to which cuff  200  is mounted and/or an in vitro’ rigid straight (i.e. perfectly cylindrical) test tube whose interior width/diameter matches is between 18 mm and 22 mm (e.g. between 18 mm and 21 mm or between 18 mm and 20).
   

     For the present disclosure and as shown in all drawings, it is assumed that when ventilation tube  106  is in enclosing tube  108  (i.e. either a human trachea or an in-vitro enclosing tube), the ventilation tube is co-axial with the enclosing tube  108 . For the present disclosure, any feature disclosed with respect to a human trachea (e.g. a trachea that is ‘sized for’ tube  106 ) may also be provided with respect to an external ‘in vitro’ rigid straight enclosing (i.e. perfectly cylindrical) test tube whose interior width matches that of a human trachea that is ‘sized for’ the ventilation tube  106  to which cuff  200  is mounted and/or an in vitro’ rigid straight (i.e. perfectly cylindrical) test tube whose interior width/diameter is between 18 mm and 22 mm (e.g. between 18 mm and 21 mm or between 18 mm and 20 mm). 
     Any reference to ‘hyper-elastic material’ may also relate to ‘elastic’ material as well. 
     Inflation of a cuff without specifying conditions refers to (i) inflation with air and (ii) at ambient conditions (i.e. standard room conditions of 20 degrees and one atmosphere ambient pressure). 
     Whenever a cuff is in free space, this is understood to require that the cuff is not disposed in any trachea or any enclosing tube. 
     The length of the cuff LENGTH CUFF  is the longitudinal displacement between the proximal  211  and distal  212  cuff attachment locations. Generally, the LENGTH CUFF  is independent of inflation conditions. 
     An X % lengthwise portion (i.e. segment) of the cuff is a portion of the cuff whose length is X % of LENGTH CUFF . Any longitudinal cut of the cuff may be specified by as a X % lengthwise portion of the cuff by specifying (i) a value of X; and (ii) a center longitudinal-location on the ventilation tube around with the X % lengthwise portion of the cuff is longitudinally centered. 
     A X % length fraction of the cuff is a portion of the cuff whose length (i.e. along the central axis of the tube) is X % of the length of the cuff. 
     A most distal X % of the cuff is a X % length fraction of the cuff which is distally bound by the distal  212  cuff attachment location. a most distal X % of the cuff is a X % length fraction of the cuff which is proximally bound by the proximal  212  cuff attachment location. 
     FIGS.  1 A- 1 B 
       FIGS. 1A-1B  illustrate an example ventilation device  100  comprising (A) a ventilation tube  106  (i.e. typically an endo-tracheal type (ETT) or a tracheostomy tube) and an inflatable cuff  200  mounted thereto. The ventilation tube has proximal  102  and distal  107  ends which define the proximal  901  and distal  951  directions shown in  FIG. 1 . 
     As shown in  FIGS. 1A-1B , cuff  200  has a proximal bulge portion  287  and a distal neck portion  289  disposed distal to the bulge portion. As will be discussed below, one salient feature provided by embodiments of the invention is the deformation of the distal neck portion as gas (e.g. air) is forced into cuff  200 . 
     The ventilation tube  106  is intended for use within a human trachea of a particular size according to requirements of the medical community—i.e. the ventilation tube  106  is intended for use in a human trachea that is ‘sized for’ the ventilation use. 
     When the tube-mounted cuff  200  is (i) deployed within a human trachea sized for the ventilation tube (i.e. so a portion of the ventilation tube  106 , around which cuff  200  is mounted, is co-axial with the human trachea) and (ii) is uninflated or inflated to a pressure of 5 cm H2O, a widest portion of the bulge portion  287  of the mounted cuff is in wrinkled contact with the trachea. 
     Thus, one salient feature of ventilation device  100  is that there is no need to ‘stretch’ (i.e. via inflation) the ventilation tube into contact with the human trachea sized for ventilation tube  106 . Thus, even at low pressures (e.g. at 5 cm H2O or even less) cuff  200  has sufficient volume to contact the inner wall of the human trachea—in this sense, ventilation device  100  may be said to belong to a class of devices informally known as ‘high volume low pressure devices. 
     Typically, the mounted cuff  200  is disposed, adhesively or otherwise, towards the distal end  107  of the endotracheal tube  106 . The cuff  200  may be inflated and deflated through a proximal inflation inlet  109  via a lumen  104  in fluid communication with the cuff  200 , typically through a distal inflation inlet hole  105  in the inflation lumen  104 . 
     The cuff  200  has a proximal opening  201  and a distal opening  202  formed in the cuff walls  204  sized to accommodate the endotracheal tube  106 . The proximal opening  201 , located closer to the “ventilation machine end”  102  of the tube  106 , and a distal opening  202 , located closer to the “patient end”  107  of the tube  106 , are typically used to mount the cuff  200  to the tube  106 . 
     Material—In different embodiments, cuff  200  is constructed of a relatively soft material. One example inflatable cuff  200  is referred to as SIL  20 . This cuff  200  (i.e. SIL  20 ) is constructed of silicone, has a Shore A hardness of about A20, and a thickness of between 0.2 mm and 0.4 mm—e.g. 0.2 mm A discussion of some properties of SIL  20  is provided below—see, for example, curves  261 ,  262  of  FIG. 9 . 
     Another example inflatable cuff  200  is referred to as Ultra-Soft and is constructed of thermoplastic elastomer (TPE) having a Shore OO hardness of OO38 and a thickness of between 0.4 mm and 0.7 mm—e.g. about 0.4 mm A discussion of some properties of Ultra-Soft is provided below—see, for example, curves  259 ,  272  of  FIG. 9 . 
     In different embodiments, the material and/or thickness of the material from which cuff  200  is constructed provides sufficient deformability and/or elasticity to provide one or more features (e.g. related to stretching) disclosed herein. 
       FIG. 2A  illustrates cuff  200  in free space when inflated to 5 cm H 2 O of pressure. The radius of the cuff is shown as RB(free, 5 cm) where RB is the largest radius of the cuff  200  (e.g. balloon cuff  200 ) in bulge  287  portion thereof. Also shown in  FIG. 2A  are: (i)  211 —proximal cuff attachment location of cuff  200  on outer surface of tube  106 ; (ii)  212 —distal cuff attachment location of cuff on outer surface of tube  106 ; and (iii)  130 —central axis of ventilation tube  106 . 
     As shown in  FIGS. 2B-2D , the ‘length’ inflatable cuff (L or LENGTH CUFF ) is the longitudinal displacement between the proximal  211  and distal  212  cuff attachment locations. Generally, the length is independent of inflation conditions. Also illustrated in  FIG. 2B  is the longitudinal centerline  299 , which is disposed longitudinally halfway between proximal  211  and distal  212  cuff attachment locations.  FIG. 2D  shows the 2 cm-central portion  298  of cuff  200 . 
       FIG. 3A  illustrates the same cuff  200  of  FIGS. 2A-2E . In  FIGS. 2A-2E  the cuff  200  is in free space. In  FIG. 3A , the cuff  200  is disposed within enclosing tube  108  which is either (i) a human trachea that is sized for the ventilation tube  106  to which cuff  200  is mounted; and/or (ii) an external ‘in vitro’ rigid straight (i.e. perfectly cylindrical) test tube whose interior width matches that of a human trachea that is ‘sized for’ the ventilation tube  106  to which cuff  200  is mounted and/or an in vitro’ rigid straight (i.e. perfectly cylindrical) test tube whose interior width/diameter matches is between 18 mm and 22 mm (e.g. between 18 mm and 21 mm or between 18 mm and 20 mm). In  FIGS. 3A-3B , the cuff  200  (i.e. which is disposed within enclosing tube  108 ) is inflated to a pressure of 5 cm H 2 O. 
     The reader is invited to compare  FIG. 2A  to  FIG. 3A .  FIG. 2A  shows RB(free, 5 cm) where RB is the largest radius of the cuff  200  (e.g. balloon cuff  200 ) in bulge  287  portion thereof. However, the radius of enclosing tube  108  is less than RB(free, 5 cm). Thus, when cuff  200  is inflated to a pressure of 5 cm H 2 O, there is contact between cuff  200  (e.g. in a bulge portion of cuff  200 ) and enclosing tube  108 . 
     TCP stands for “Tube Contact Portion” where the “Tube” of TCB is enclosing tube  108 . TCP refers to a longitudinal potion of cuff  200  that is in contact with enclosing tube  108  under specified conditions. The portion of TCP that is in wrinkled contact with enclosing tube  108  under specified conditions is TCP WRINKLED . 
       FIG. 3A  shows the TCP which is the tube contact portion of cuff  200  when (i) cuff  200  is disposed within enclosing tube  108  and (ii) cuff  200  is inflated to a pressure of 5 cm H 2 O. In different embodiments, at least 10% or at least 20% or at least 50% or at least 75% of TCP(5 cm H 2 O) is characterized by a presence of wrinkles—i.e. wrinkled contact between cuff  200  and enclosing tube  108 . In the particular example of  FIG. 3B , 100% of TCP is in wrinkled contact—i.e. the lengths of TCP(5 cm H 2 O) and TCP WRINKLED  (5 cm H 2 O) are identical. This is not a requirement. 
     The reader is invited to compare  FIG. 3A  to  FIG. 2E . In  FIG. 2E  cuff  200  is shown in free space where the location of enclosing tube  108  is shown in ghost or broken lines (i.e. it is not present in  FIG. 2E ). Clearly, RB&gt;RT. 
     Reference is made, once again to  FIG. 3A . The most distal location of TCP(5 cm H 2 O) is labelled as  349  and this is known as the leading distal edge (LDE) of TCP(5 cm H 2 O) and is labelled as LDE_TCP(5 cm H 2 O). NOTE—once LDE_TCP(5 cm H 2 O) is defined by cuff  200  within the enclosing tube  108  (i.e. a human trachea 108 sized for ventilation tube  106  or any in vitro tube disclosed herein), it is noted that LDE_TCP(5 cm H 2 O)  349  is a property of cuff  200  (i.e. for an appropriate enclosing tube  108 ) and has a longitudinal location that is fixed relative to  211  and  212 . 
     For the situation where cuff  200  is within enclosing tube  108  and inflated to a pressure of 5 cm H 2 O, the contour of cuff  200  in locations (e.g. locations of neck portion  289  of cuff  200 ) distal to labelled as  432 . Cuff counter  432  is particular for the cuff pressure of 5 cm H 2 O and is shown in  FIGS. 3A-3B . 
       FIGS. 3A-3B  versus  FIGS. 4A-4B : In  FIGS. 3A-3B , the cuff  200  (i.e. which is disposed within enclosing tube  108 ) is inflated to a pressure of 5 cm of H 2 O. In  FIGS. 4A-4B , the cuff  200  (i.e. which is disposed within enclosing tube  108 ) is inflated to a pressure of 30 cm of H 2 O. 
     Comparing  FIGS. 3A-3B  to  FIGS. 4A-4B , it is possible to make the following observations: 
     (i) in both  FIGS. 3A-3B  and  FIGS. 4A-4B , at least a portion of cuff  200  is in contact with enclosing tube  108 . When cuff is inflated to 5 cm of H 2 O, the portion of cuff  200  in contact with enclosing tube  108  is shown as TCP(5 cm H 2 O) in  FIG. 3A . When cuff is inflated to 30 cm of H 2 O, the portion of cuff  200  in contact with enclosing tube  108  is shown as TCP(30 cm H 2 O) in  FIG. 4A . 
     (ii) Clearly LENGTH(TCP(30 cm H 2 O))&gt;LENGTH(TCP(5 cm H 2 O)). This is because inflation of cuff  200  deforms the cuff  200 , in particular in neck portion  289  thereof. For example, cuff  300  is constructed of material having specific elasticity and thickness. 
     (iii) leading distal edge of TCP(5 cm H 2 O) is LDE_TCP(5 cm H 2 O) is labelled as element  349 . Leading distal edge of TCP(30 cm H 2 O) is LDE_TCP(30 cm H 2 O) is labelled as element  399 —because LENGTH(TCP(30 cm H 2 O))&gt;LENGTH(TCP(5 cm H 2 O)), element  399  is located distal to element  349 . Similar to LDE_TCP(5 cm H 2 O)  349 , is LDE_TCP(30 cm H 2 O)  399  a property of cuff  200  (i.e. for an appropriate enclosing tube  108 ) and has a longitudinal location that is fixed relative to  211  and  212 . 
     (iv) the contour of cuff  200  that is distal to LDE_TCP(30 cm H 2 O)  399  is labelled as  433   FIG. 4A  shows both the contour  432  (i.e. relevant when cuff  200  is inflated to 5 cm H 2 O) and contour  433  (i.e. relevant when cuff  200  is inflated to 30 cm H 2 O. 
     (v) comparing contours  432  and  433  shows the deformation of the neck portion  289  of cuff  200 . Clearly, inflation of cuff from 5 cm H 2 O to 30 cm H 2 O serves to significantly increase the volume within cuff  200 . Thus can be observed in  FIG. 9 —curves  261  and  262 . The increase in volume may afford a location for ‘spillover’ gas which enters into cuff  200 , 
     (vi) as shown in  FIG. 4B , TCP(30 cm H 2 O) may be divided into two portions—TCP WRINKLED  (30 cm H 2 O) which is the portion of cuff  200  in wrinkled contact with enclosing tube  108  and TCP UNWRINKLED  (30 cm H 2 O) which is the portion of cuff  200  in unwrinkled contact with enclosing tube  108 . At least some of TCP UNWRINKLED  (30 cm H 2 O) may because inflation from 5 cm H2O to 30 cm H2O deforms neck portion  289  of cuff  200  to stretch at least a portion of cuff  200  into contact with enclosing tube  108 . 
     (vii) comparing  FIG. 3A  to  FIG. 4A , it is quite clear that the contact length LENGTH(TPC) between cuff  200  and enclosing tube  108  increases as pressure increases, even quite significantly—e.g. due to inflation-driven deformation of neck portion  289 . 
     Reference is made to  FIG. 5  which shows how contact length LENGTH(TPC) between cuff  200  and enclosing tube  108  increases as pressure increases for a specific example of a straight in-vitro enclosing (i.e. perfectly cylindrical) test tube  108  having a tube diameter (i.e. inner diameter) of 20 mm Curves  271  and  272  refer to embodiments of the invention—in contrast, MICRO and COV cuff (Covidien cuff) are prior art cuffs. 
     From  FIG. 5 , it is possible to observe the following: 
     (i) even at low pressures of at most 5 cm H2O, the contact is length is non-zero; 
     (ii) a ratio between the contact length at relatively ‘high pressures’ and the contact length at relatively low pressures&#39; is significantly greater than can be observed in the MICRO or COV cuff prior art cuffs. 
       FIG. 6A  shows the cuff  200  when it is (i) in free space and (ii) inflated to 5 cm H2O.  FIG. 6B  shows the cuff  200  when it is (i) in free space and (ii) inflated to x cm H2O, where x is a ‘larger’ number (e.g. 40 or 50 or 60). As noted above, both  349  and  399  are properties of cuff  200  (i.e. for an appropriate enclosing tube  108 ) and has a longitudinal location that is fixed relative to  211  and  212 . 
     Thus, comparing  FIG. 6B  to  FIG. 6A , it is shown that the width of cuff  200  at location  399  is significantly larger in  FIG. 6B  than in  FIG. 6A , even as the longitudinal location is fixed. 
       FIGS. 7A-7B and 8A-8B  relate to an experiment performed where the enclosing tube  108  is a perfectly straight cylindrical enclosing in-vitro test tube having a diameter of 20 mm First, cuff  200  is inflated (see  FIGS. 7A and 8A ) to 30 cm H2O in order to establish the leading distal edge  389  of contact portion TCP of cuff  200  with tube  108  at 30 cm H2O. Subsequently, cuff  200  is removed from enclosing tube  108 —due to the material properties of cuff  200  (e.g. of the neck portion thereof), it is possible to inflate cuff so the width at location  389  (i.e. which was defined in  FIGS. 7A  and A) increases significantly—according to this experiment, to about 41 mm which in this experiment is about double the width of tube  108 . 
       FIG. 9  illustrates results of an experiment where both prior-art and cuff according to embodiments of the invention are either (i) in free space or (ii) disposed within a perfectly straight cylindrical enclosing in-vitro test tube having a diameter of 20 mm Each of the cuffs are inflated to various pressures. For various pressures, it is possible to measure the volume V of the cuff. The x axis of  FIG. 9  is not V but rather VD which is the difference between (i) the volume of the cuff at any particular pressure and (ii) the volume of the cuff when inflated to a particular initiation pressure. 
     Observing curve  259 , we note that for the ultra-soft free embodiment, the inflatable cuff  200  is incapable of being air-inflated to a pressure of 30 cm of H 2 O or incapable of being air-inflated to a pressure of 28 of cm H 2 O incapable of being air-inflated to a pressure of 25 of H 2 O—the maximum of curve  259  is below 25 cm of H2O. 
     Curve  261  relates to the SIL  20  embodiment when in free space. As shown in curve  261  of  FIG. 9 , after reaching a pressure of 20 cm of water an additional 2 cc or 3 cc or 4 cc or 5 cc or more of air is required in order to reach the pressure of 35 cm of water. 
     Curve  272  relates to the ultra-soft free embodiment when in the perfectly straight cylindrical enclosing in-vitro test tube  108  having a diameter of 20 mm. 
     Curve  262  relates to the SIL  20  embodiment when in the perfectly straight cylindrical enclosing in-vitro test tube  108  having a diameter of 20 mm. 
     FIGS.  10 A- 10 Cs 
     Taken from the literature—the skilled artisan will understand how this specifies when a ventilation tube  106  is ‘sized for’ a particular human trachea. When a particular ventilation tube  106  is sized for a trachea (i.e. according to the art), we may say that the human trachea is ‘sized for’ that particular ventilation tube  106 . 
     Ventilation tubes and associated cuffs are sized according to intended human user, as summarized in the tables shown in  FIGS. 10A to 10C . For the sake of clarity of presentation, an explicit example embodiments discussion may be done in terms of intended adult male user of assumed trachea size of diameter size of 20 mm and associated ventilation tube size 8.0. Yet, it should be understood that the diameters and lengths would scale proportionally to the ventilation tube diameter. But, the discussed pressure values do not change. For example, the statement “at pressure of 20 cm H2O there must be a contact between the cuff and the bounding testing tube wall” remains valid when a ventilation tube size 7.0 (with associated attached cuff) is tested with a bounding testing tube of diameter of 17 mm, or a ventilation tube size 6.0 (with associated attached cuff) is tested with a bounding testing tube of diameter of 14 mm 
     First Additional Discussion 
     A ventilation device comprising:
         a. a ventilation tube having proximal and distal ends; and   b. an inflatable cuff having a proximal bulge portion and a distal neck portion disposed distal to the bulge portion, the inflatable cuff being mounted around the ventilation tube to define proximal and distal cuff attachment locations which are both fixed on an outer surface of the ventilation tube, wherein:
           (i) when the tube-mounted cuff is deployed within a human trachea sized for the ventilation tube so that (A) the ventilation tube is co-axial with the human trachea and (B) the tube-mounted cuff is uninflated or inflated to a pressure of 5 cm H2O, a widest portion of the bulge portion of the mounted cuff is in wrinkled contact with the trachea; and   (i) when the tube-mounted cuff is deployed within a human trachea sized for the ventilation tube so that (A) the ventilation tube is co-axial with the human trachea and (B) the tube-mounted cuff is uninflated or inflated to a pressure of 25 cm H2O, a widest portion of the bulge portion of the mounted cuff is in wrinkled contact with the trachea.
 
In some embodiments, wherein the ventilation tube is sized for an adult human trachea.
 
In some embodiments, wherein a length of the inflatable cuff is at least 2 cm.
 
In some embodiments, wherein the length of the inflatable cuff is at most 6 cm.
 
In some embodiments, wherein the cuff is unstretched at the wrinkled contact with the trachea.
 
In some embodiments, wherein inflation of the human-trachea-deployed and tube-mounted cuff (i.e. so the ventilation tube is coaxial with the trachea) to a pressure of x cm H 2 O defines a trachea-contact portion TCP(x) of the cuff and a leading distal edge LDE_TCP(x) thereof.
 
In some embodiments, wherein when the ventilation device is in free space, upon inflation of the inflatable cuff to a pressure of at most 60 cm H 2 O, a width of the inflatable cuff at the LDE(TCP(25 cm H 2 O)) reaches at least 40 mm and/or at least 1.5 times the width of the human trachea sized for the ventilation tube.
 
In some embodiments, wherein when the ventilation device is in free space, upon inflation of the inflatable cuff to a pressure of at most 40 cm H 2 O, a width of the inflatable cuff at the LDE(TCP(25 cm H 2 O)) reaches at least 40 mm and/or at least 1.5 times the width of the human trachea sized for the ventilation tube.
 
In some embodiments, wherein when the ventilation device is in free space, upon inflation of the inflatable cuff to a pressure of at most 60 cm H 2 O, a width of the inflatable cuff at the LDE(TCP(30 cm H 2 O)) reaches at least 40 mm and/or at least 1.5 times the width of the human trachea sized for the ventilation tube.
 
In some embodiments, wherein when the ventilation device is in free space, upon inflation of the inflatable cuff to a pressure of at most 40 cm H 2 O 50, a width of the inflatable cuff at the LDE(TCP(30 cm H 2 O)) reaches at least 40 mm and/or at least 1.5 times the width of the human trachea sized for the ventilation tube.
 
In some embodiments, wherein the neck portion is sufficiently deformable such that a ratio between a length of TCP(35 cm) and a length of TCP(5 cm) is at least 1.5 or at least 2.
 
In some embodiments, wherein when the tube-mounted cuff is deployed coaxially within the ventilation-tube-sized human trachea and is inflated to a pressure of 5 cm H 2 O, a ratio between:
   
           (i) a length of a band of the cuff in wrinkle-free contact with the ventilation-tube-sized human trachea [defined as zero if none of the cuff contact perimeter [perimeter line of a cut perpendicular to the cuff center axis] is in wrinkle-free contact with the ventilation-tube-sized human trachea]; and   (ii) a length of a band of the cuff in wrinkled contact with the ventilation-tube-sized human trachea
 
is defined as Contact_Length_Ratio[Wrinkle-free:Wrinkeed](5 cm H 2 O).
 
In some embodiments, wherein a value of Contact_Length_Ratio[Wrinkle-free:Wrinkeed](5 cm H 2 O) is at most 0.01 or at most 0.1 or at most 0.2.
 
In some embodiments, wherein when the tube-mounted cuff is deployed within the ventilation-tube-sized human trachea and is inflated to a pressure of 25 cm H 2 O, a ratio between:
   (i) a length of the cuff in in wrinkle-free contact with the ventilation-tube-sized human trachea [defined as zero if none of the cuff in in wrinkle-free contact with the ventilation-tube-sized human trachea]; and   (ii) a length of the cuff in in wrinkled contact with the ventilation-tube-sized human trachea
 
is defined as Contact_Length_Ratio[Wrinkle-free:Wrinkeed](25 cm H 2 O).
 
In some embodiments, wherein a value of Contact_Length_Ratio[Wrinkle-free:Wrinkeed](25 cm H 2 O) is at least 0.3 or at least 0.5 or at least 1.
 
In some embodiments, wherein: (i) a fraction {i.e. between 0 and 1} of TCP(5 cm) that is wrinkle-free is defined as Fract_Wrinkle-free[TCP(5 cm)]; (ii)) a fraction {i.e. between 0 and 1} of TCP(25 cm) that is wrinkle-free defined as Fract_Wrinkle-free[TCP(25 cm)], and wherein a ratio between Fract_Wrinkle-free[TCP(25 cm)] and Fract_Wrinkle-free[TCP(5 cm)] is at least 2 or at least 5 or at least 10.
 
In some embodiments, wherein when the tube-mounted cuff is deployed within the ventilation-tube-sized human trachea and is inflated to a pressure of 35 cm H 2 O, a ratio between:
   (i) a length of the cuff in in wrinkle-free contact with the ventilation-tube-sized human trachea [defined as zero if none of the cuff in in wrinkle-free contact with the ventilation-tube-sized human trachea]; and   (ii) a length of the cuff in in wrinkled contact with the ventilation-tube-sized human trachea
 
is defined as Contact_Length_Ratio[Wrinkle-free:Wrinkeed](35 cm H 2 O).
 
In some embodiments, wherein a value of Contact_Length_Ratio[Wrinkle-free:Wrinkeed](25 cm H 2 O) is at least 1 or at least 1.5.
 
In some embodiments, wherein when the ventilation device is in free space, the inflatable cuff furthermore is incapable of being air-inflated to a pressure of 30 cm of H 2 O.
 
In some embodiments, wherein when the ventilation device is in free space, the inflatable cuff furthermore is capable of being air-inflated to a pressure of 35 cm of water such that during a pressure ramp-up, after reaching a pressure of 20 cm of water an additional 4 cc (or an additional 5 cc or more) or more of air is required in order to reach the pressure of 35 cm of water.
 
A method of treating a human patient having a human trachea, the method comprising:
   a. providing a ventilation device comprising:
           i. a ventilation tube having proximal and distal ends; and   ii. an inflatable cuff having a proximal bulge portion and a distal neck portion disposed distal to the bulge portion, the inflatable cuff being mounted around the ventilation tube to define proximal and distal cuff attachment locations which are both fixed on an outer surface of the ventilation tube, wherein:   
           b. deploying at least a portion of the ventilation tube within the human trachea of the patient so that the inflatable cuff is deployed therein so that: (A) the cuff is uninflated or inflated to a pressure of 5 cm H2O and (B) a widest portion of the bulge portion of the mounted cuff is in wrinkled contact with the trachea.
 
In some embodiments, further comprising inflating the cuff to a pressure of 25 cm H 2 O so that a widest portion of the bulge portion of the mounted cuff is in wrinkled contact with the trachea.
 
In some embodiments, wherein a length of the inflatable cuff is at least 2 cm.
 
In some embodiments, wherein the length of the inflatable cuff is at most 6 cm.
 
In some embodiments, further comprising inflating the tube to a pressure of x cm H 2 O so to define a trachea-contact portion TCP(x) of the cuff and a leading distal edge LDE_TCP(x) thereof.
 
In some embodiments, wherein a value of x is 25, and when the ventilation device is in free space, upon inflation of the inflatable cuff to a pressure of at most 60 cm H 2 O, a width of the inflatable cuff at the LDE(TCP(25 cm H 2 O)) reaches at least 40 mm and/or at least 1.5 times the width of the trachea to which the device is deployed.
 
In some embodiments, wherein a value of x is 25, and when the ventilation device is in free space, upon inflation of the inflatable cuff to a pressure of at most 40 cm H 2 O, a width of the inflatable cuff at the LDE(TCP(25 cm H 2 O)) reaches at least 40 mm and/or at least 1.5 times the width of the trachea to which the device is deployed.
 
In some embodiments, wherein further comprising inflating the tube to a pressure of x cm H 2 O so to define a trachea-contact portion TCP(x) of the cuff and a leading distal edge LDE_TCP(x) thereof, and the neck portion is sufficiently deformable such that a ratio between a length of TCP(35 cm) and a length of TCP(5 cm) is at least 1.5 or at least 1.75 or at least 2 or at least 2.25 or at least 2.5 or at least 2.75 or at least 3.
 
In some embodiments, wherein when the tube-mounted cuff is deployed coaxially within the ventilation-tube-sized human trachea and is inflated to a pressure of 5 cm H 2 O, a ratio between:
   (i) a length of a band of the cuff in wrinkle-free contact with the ventilation-tube-sized human trachea [defined as zero if none of the cuff contact perimeter [perimeter line of a cut perpendicular to the cuff center axis] is in wrinkle-free contact with the ventilation-tube-sized human trachea]; and   (ii) a length of a band of the cuff in wrinkled contact with the ventilation-tube-sized human trachea
 
is defined as Contact_Length_Ratio[Wrinkle-free:Wrinkeed](5 cm H 2 O).
 
In some embodiments, wherein a value of Contact_Length_Ratio[Wrinkle-free:Wrinkeed](5 cm H 2 O) is at most 0.01 or at most 0.1 or at most 0.2
 
In some embodiments, wherein when the tube-mounted cuff is deployed within the ventilation-tube-sized human trachea and is inflated to a pressure of 25 cm H 2 O, a ratio between:
   (i) a length of the cuff in in wrinkle-free contact with the ventilation-tube-sized human trachea [defined as zero if none of the cuff in in wrinkle-free contact with the ventilation-tube-sized human trachea]; and   (ii) a length of the cuff in in wrinkled contact with the ventilation-tube-sized human trachea
 
is defined as Contact_Length_Ratio[Wrinkle-free:Wrinkeed](25 cm H 2 O).
 
In some embodiments, wherein a value of Contact_Length_Ratio[Wrinkle-free:Wrinkeed](25 cm H 2 O) is at least 0.3 or at least 0.5 or at least 1.
 
In some embodiments, wherein: (i) a fraction {i.e. between 0 and 1} of TCP(5 cm) that is wrinkle-free is defined as Fract_Wrinkle-free[TCP(5 cm)]; (ii)) a fraction {i.e. between 0 and 1} of TCP(25 cm) that is wrinkle-free defined as Fract_Wrinkle-free[TCP(25 cm)], and wherein a ratio between Fract_Wrinkle-free[TCP(25 cm)] and Fract_Wrinkle-free[TCP(5 cm)] is at least 2 or at least 5 or at least 10.
 
In some embodiments, wherein when the ventilation device is in free space, the inflatable cuff furthermore is incapable of being air-inflated to a pressure of 30 cm of H 2 O.
 
In some embodiments, wherein when the ventilation device is in free space, the inflatable cuff furthermore is capable of being air-inflated to a pressure of 35 cm of water such that during a pressure ramp-up, after reaching a pressure of 20 cm of water an additional 4 cc or more, or an additional 5 cc or more of air is required in order to reach the pressure of 35 cm of water.
 
A ventilation device comprising:
   a. a ventilation tube having proximal and distal ends; and   b. an inflatable cuff having a proximal bulge portion and a distal neck portion disposed distal to the bulge portion, the inflatable cuff being mounted around the ventilation tube to define proximal and distal cuff attachment locations which are both fixed on an outer surface of the ventilation tube, wherein:
           (i) when the tube-mounted cuff is deployed within a rigid in-vitro enclosing tube having an inner diameter between 18 mm and 21 mm so that (A) the ventilation tube is co-axial with the rigid in-vitro enclosing tube and (B) the tube-mounted cuff is uninflated or inflated to a pressure of 5 cm H2O, a widest portion of the bulge portion of the mounted cuff is in wrinkled contact with an inner wall of the rigid in-vitro enclosing tube and   (i) when the tube-mounted cuff is deployed within a rigid in-vitro enclosing tube having an inner diameter between 18 mm and 21 mm so that (A) the ventilation tube is co-axial with the rigid in-vitro enclosing tube and (B) the tube-mounted cuff is uninflated or inflated to a pressure of 25 cm H2O, a widest portion of the bulge portion of the mounted cuff is in wrinkled contact with an inner wall of the rigid in-vitro enclosing tube.
 
In some embodiments, wherein the ventilation tube is sized for an adult human trachea.
 
In some embodiments, wherein a length of the inflatable cuff is at least 2 cm.
 
In some embodiments, wherein the length of the inflatable cuff is at most 6 cm.
 
The device of any preceding claim wherein inflation of the rigid-enclosing-tube-deployed and tube-mounted cuff (i.e. so the ventilation tube is coaxial with the rigid in-vitro enclosing tube) to a pressure of x cm H 2 O defines a enclosing-tube-contact portion ETCP(x) of the cuff and a leading distal edge LDE_[(]ETCP(x) thereof.
 
In some embodiments, wherein when the ventilation device is in free space, upon inflation of the inflatable cuff to a pressure of at most 60 cm H 2 O, a width of the inflatable cuff at the LDE(ETCP(25 cm H 2 O)) reaches at least 40 mm and/or at least 1.5 times the internal width of the rigid in-vitro enclosing tube.
 
In some embodiments, wherein when the ventilation device is in free space, upon inflation of the inflatable cuff to a pressure of at most 40 cm H 2 O, a width of the inflatable cuff at the LDE(ETCP(25 cm H 2 O)) reaches at least 40 mm and/or at least 1.5 times the internal width of the rigid in-vitro enclosing tube.
 
In some embodiments, wherein when the ventilation device is in free space, upon inflation of the inflatable cuff to a pressure of at most 50 cm H 2 O, a width of the inflatable cuff at the LDE(ETCP(30 cm H 2 O)) reaches at least 40 mm and/or at least 1.5 times the internal width of the rigid in-vitro enclosing tube.
 
In some embodiments, wherein when the ventilation device is in free space, upon inflation of the inflatable cuff to a pressure of at most 40 cm H 2 O, a width of the inflatable cuff at the LDE(ETCP(30 cm H 2 O)) reaches at least 40 mm and/or at least 1.5 times the internal width of the rigid in-vitro enclosing tube and/or wherein the neck portion is sufficiently deformable such that a ratio between a length of ETCP(35 cm) and a length of ETCP(5 cm) is at least 1.5 or at least 1.75 or at least 2 or at least 2.25 or at least 2.5 or at least 2.75 or at least 3.
 
In some embodiments, wherein when the tube-mounted cuff is deployed coaxially within the in vitro enclosing tube and is inflated to a pressure of 5 cm H 2 O, a ratio between:
   
           (i) a length of a band of the cuff in wrinkle-free contact with the in vitro enclosing tube [defined as zero if none of the cuff contact perimeter [perimeter line of a cut perpendicular to the cuff center axis] is in wrinkle-free contact with the in vitro enclosing tube]; and   (ii) a length of a band of the cuff in wrinkled contact with the in vitro enclosing tube is defined as Contact_Length_Ratio[Wrinkle-free:Wrinkeed](5 cm H 2 O).
 
In some embodiments, wherein a value of Contact_Length_Ratio[Wrinkle-free:Wrinkeed](5 cm H 2 O) is at most 0.01 or at most 0.1 or at most 0.2
 
In some embodiments, wherein when the tube-mounted cuff is deployed within the in vitro enclosing tube and is inflated to a pressure of 25 cm H 2 O, a ratio between:
   (i) a length of the cuff in in wrinkle-free contact with the in vitro enclosing tube [defined as zero if none of the cuff in in wrinkle-free contact with the in vitro enclosing tube]; and   (ii) a length of the cuff in in wrinkled contact with the in vitro enclosing tube is defined as Contact_Length_Ratio[Wrinkle-free:Wrinkeed](25 cm H 2 O).
 
In some embodiments, wherein a value of Contact_Length_Ratio[Wrinkle-free:Wrinkeed](25 cm H 2 O) is at least 0.3 or at least 0.5 or at least 1.
 
In some embodiments, wherein: (i) a fraction {i.e. between 0 and 1} of TCP(5 cm) that is wrinkle-free is defined as Fract_Wrinkle-free[TCP(5 cm)]; (ii)) a fraction {i.e. between 0 and 1} of TCP(25 cm) that is wrinkle-free defined as Fract_Wrinkle-free[TCP(25 cm)], and wherein a ratio between Fract_Wrinkle-free[TCP(25 cm)] and Fract_Wrinkle-free[TCP(5 cm)] is at least 2 or at least 5 or at least 10.
 
In some embodiments, wherein when the ventilation device is in free space, the inflatable cuff furthermore is incapable of being air-inflated to a pressure of 30 cm of H 2 O.
 
In some embodiments, wherein when the ventilation device is in free space, the inflatable cuff furthermore is capable of being air-inflated to a pressure of 35 cm of water such that during a pressure ramp-up, after reaching a pressure of 20 cm of water an additional 4 cc or 5 cc or more of air is required in order to reach the pressure of 35 cm of water.
 
In some embodiments, wherein when the ventilation device is in free space, the inflatable cuff furthermore is capable of being air-inflated to a pressure of 35 cm of water such that during a pressure ramp-up, after reaching a pressure of 20 cm of water an additional 4 cc or 5 cc or more of air is required in order to reach the pressure of 35 cm of water.
 
In some embodiments, wherein throughout a 2 cm-central-portion of the cuff whose longitudinal center is halfway between the proximal and distal cuff attachment locations and whose length is 2 cm, (i) a Shore A value of material of the cuff is at most Shore_A_Max; (ii) a value of Shore_A_Max at most 30.
 
In some embodiments, wherein a value of Shore_A_Max is at most 20 or at most 15 or at most 10.
 
In some embodiments, wherein (i) throughout the 2 cm-central-portion of the cuff, the Shore A value of material of the cuff has a value of at least Shore_A_Min; (ii) a value of Shore_A_Max at least 4 or least 5.
 
In some embodiments, wherein throughout the 2 cm-central-portion of the cuff, a wall thickness of the cuff is at least 0.1 mm or at least 0.25 or at least 1 mm.
 
In some embodiments, throughout the 2 cm-central-portion of the cuff, a wall thickness of the cuff is at most 0.8 mm.
 
In some embodiments, wherein the cuff is constructed from at least one of silicone, or Thermoplastic Rubber (TPR) Compounds, or alternatively thermoplastic elastomers (TPE), or combinations thereof.
       

     Second Additional Discussion 
     A ventilation device comprising:
         a. a ventilation tube  106  having a proximal  102  and distal  107  ends; and   b. an inflatable cuff  200  constructed of an elastic material and mounted around the ventilation tube  106  to define proximal  211  and distal  212  cuff attachment locations which are both fixed on an outer surface of the ventilation tube, the inflatable cuff having a proximal bulge portion  287  and a distal neck portion  289  disposed distal to the bulge portion.
 
In some embodiments, when the mounted cuff  20  is disposed in free space and is inflated with air, a pressure within the cuff  200  first reaches a free-space-inflation peak pressure (FSPIPP) and then decreases upon further inflation, a value of the FSPIPP being between 12 and 35 cm H 2 O.
 
3. In some embodiments, wherein the value of the FSIPP is at most 30 cm H 2 O.
 
4. In some embodiments, wherein the value of the FSIPP is at most 25 cm H 2 O.
 
5. In some embodiments, wherein the value of the FSIPP is at most 21 cm H 2 O.
 
6. In some embodiments, wherein the value of the FSIPP is at most 19 cm H 2 O.
 
7. In some embodiments, wherein the value of the FSIPP is at least 12 cm H 2 O.
 
8. In some embodiments, wherein the value of the FSIPP is at least 15 cm H 2 O.
 
9. In some embodiments, wherein the value of the FSIPP is at least 17 cm H 2 O.
 
10. In some embodiments, wherein the value of the FSIPP is at least 18 cm H 2 O.
 
11. In some embodiments, wherein a length of the mounted cuff is at least 2 cm, the length being defined as a longitudinal displacement between the proximal  211  and distal  212  cuff attachment locations.
 
12. In some embodiments, wherein a length of the mounted cuff is at least 2.5 cm, the length being defined as a longitudinal displacement between the proximal  211  and distal  212  cuff attachment locations.
 
13. In some embodiments, wherein a length of the mounted cuff is at least 3 cm, the length being defined as a longitudinal displacement between the proximal  211  and distal  212  cuff attachment locations.
 
14. In some embodiments, wherein a length of the mounted cuff is at most 6 cm, the length being defined as a longitudinal displacement between the proximal  211  and distal  212  cuff attachment locations.
 
15. In some embodiments, wherein a length of the mounted cuff is at most 5 cm, the length being defined as a longitudinal displacement between the proximal  211  and distal  212  cuff attachment locations.
 
16. In some embodiments, wherein a length of the mounted cuff is at most 4 cm, the length being defined as a longitudinal displacement between the proximal  211  and distal  212  cuff attachment locations.
 
17. In some embodiments (e.g. see  FIG. 6A ) wherein (I) when the mounted cuff  20  is disposed in free space, inflation of the cuff with air is incapable of causing an interior of the cuff to reach a pressure of 25 cm H 2 O; and (ii) when the mounted cuff  20  is disposed within a straight rigid bounding testing tube (SRBTT DIAMETER=20 mm ) that has a diameter of 20 mm and that is co-axial with the ventilation tube, inflation of the cuff with air causes an interior of the cuff to reach a pressure of at least p2 cm H 2 O, a value of p2 being equal to at least 30.
 
18. In some embodiments, wherein a value of p2 is at least 35.
 
19. In some embodiments (e.g. see  FIG. 6A ) wherein (I) when the mounted cuff  20  is disposed in free space, inflation of the cuff with air is incapable of causing an interior of the cuff to reach a pressure of 30 cm H 2 O; and (ii) when the mounted cuff  20  is disposed within a straight rigid bounding testing tube (SRBTT DIAMETER=20 mm ) that has a diameter of 20 mm and that is co-axial with the ventilation tube, inflation of the cuff with air causes an interior of the cuff to reach a pressure of at least p2 cm H 2 O, a value of p2 being equal to at least 35.
 
20. In some embodiments, wherein a value of p2 is at least 40.
 
21. In some embodiments wherein when the mounted cuff  20  ( i ) is disposed within a straight rigid bounding testing tube (SRBTT DIAMETER=20 mm ) that has a diameter of 20 mm and that is co-axial with the ventilation tube and (ii) is inflated with air to a pressure of 20 cm H 2 O, then in order to further inflate the mounted cuff to a pressure of 30 cm H 2 O, at least Vol ADD  of air must be forced into the cuff, a value of being Vol ADD  at least 1 cc.
 
22. In some embodiments, wherein a value of Vol ADD  is at least 2 cc.
 
23. In some embodiments, wherein a value of Vol ADD  is at least 3 cc.
 
24. In some embodiments, wherein a value of Vol ADD  is at least 5 cc.
 
25. In some embodiments (e.g. see  FIG. 6A ) when the mounted cuff  20  ( i ) is disposed within a straight rigid bounding testing tube (SRBTT DIAMETER=20 mm ) that has a diameter of 20 mm and that is co-axial with the ventilation tube and (ii) is inflated with air to a pressure of 15 cm H 2 O, then in order to further inflate the mounted cuff to a pressure of 25 cm H 2 O, at least Vol ADD  of air must be forced into the cuff, a value of being Vol ADD  at least 1 cc.
 
26. In some embodiments, wherein a value of Vol ADD  is at least 2 cc.
 
27. In some embodiments, wherein a value of Vol ADD  is at least 3 cc.
 
28. In some embodiments, wherein a value of Vol ADD  is at least 5 cc.
 
29. In some embodiments, wherein throughout a 2 cm-central-portion of the cuff whose longitudinal center is halfway between the proximal  211  and distal  212  cuff attachment locations and whose length is 2 cm, (i) a Shore A value of material of the cuff is at most Shore_A_Max; (ii) a value of Shore_A_Max at most 30.
 
30. In some embodiments, wherein a value of Shore_A_Max is at most 20.
 
31. In some embodiments, wherein a value of Shore_A_Max is at most 15.
 
32. In some embodiments, wherein a value of Shore_A_Max is at most 10.
 
33. In some embodiments, wherein a value of Shore_A_Max is at most 20.
 
34. In some embodiments, wherein (i) throughout the 2 cm-central-portion of the cuff, the Shore A value of material of the cuff has a value of at least Shore_A_Min; (ii) a value of Shore_A_Max at least 4.
 
35. In some embodiments, wherein a value of Shore_A_Min is at least 5.
 
36. In some embodiments, wherein a value of Shore_A_Min is at least 6.
 
37. In some embodiments, wherein throughout the 2 cm-central-portion of the cuff, a wall thickness of the cuff is at least 0.1 mm.
 
38. In some embodiments, wherein throughout the 2 cm-central-portion of the cuff, a wall thickness of the cuff is at least 0.25 mm.
 
39. In some embodiments, wherein throughout the 2 cm-central-portion of the cuff, a wall thickness of the cuff is at most 1 mm.
 
40. In some embodiments, wherein throughout the 2 cm-central-portion of the cuff, a wall thickness of the cuff is at most 0.8 mm.
 
41. In some embodiments, wherein the cuff is constructed from at least one of silicone, or Thermoplastic Rubber (TPR) Compounds, or alternatively thermoplastic elastomers (TPE), or combinations thereof.
 
42. In some embodiments, (e.g. see  FIG. 6B ) wherein when the mounted cuff  20  is disposed within a straight rigid bounding testing tube (SRBTT DIAMETER=20 mm ) that has a diameter of 20 mm and that is co-axial with the ventilation tube and (i) is inflated to 5 cm H 2 O, a contact length of the cuff is CL_5, (ii) is inflated to 10 cm H 2 O, a contact length of the cuff is CL_10; (iii) is inflated to 15 cm H 2 O, a a contact length of the cuff is CL_10; (iii) is inflated to 15 cm H 2 O, a contact length of the cuff CL_15; (iii) is inflated to 20 cm H 2 O, a contact length is CL_20; (iii) is inflated to 25 cm H 2 O, a contact length of the cuff is CL_25; and (iii) is inflated to 30 cm H 2 O, a contact length of the cuff CL_30.
 
44. In some embodiments, wherein a ratio between CL_5 and the length of the cuff LENGTH CUFF  is at most 0.1.
 
45. In some embodiments, wherein a ratio between CL_25 and CL5 is at least 1.5 or at least 2 or at least 3 or at least 5 or at least 10.
 
46. In some embodiments, (e.g. see  FIG. 6B ) wherein a ratio between CL_25 and CL10 is at least 1.25.
 
47. In some embodiments, wherein a ratio between CL_25 and CL10 is at least 1.5.
 
48. In some embodiments, wherein a ratio between CL_25 and CL10 is at least 1.75.
 
49 In some embodiments, wherein a ratio between CL_25 and CL10 is at least 2.
 
50. In some embodiments, wherein a ratio between CL_30 and CL10 is at least 1.5.
 
51. In some embodiments, wherein a ratio between CL_30 and CL10 is at least 1.75.
 
52. In some embodiments, wherein a ratio between CL_30 and CL10 is at least 2.
 
53 In some embodiments, wherein a ratio between CL_30 and CL10 is at least 2.25.
 
54. In some embodiments, wherein a ratio between CL_30 and CL10 is at least 2.5.
 
55. In some embodiments, wherein when the mounted cuff  20  is disposed within a straight rigid bounding testing tube (SRBTT DIAMETER=20 mm ) that has a diameter of 20 mm and that is co-axial with the ventilation tube, after inflating to a pressure of 15 cm H 2 O so that a contact-portion of the cuff (a length of the contact-potion is a contact-length) is in contact with the straight rigid bounding testing tube (SRBTT DIAMETER=20 mm ), further inflation of the mounted cuff to a pressure of 30 cm H 2 O causes a proximal extreme of the contact-portion to move proximally by prox_15_30, wherein a value of prox_15_30 is positive—for example, a value of prox_15_30 is at least 0.5 mm or at least 1 mm or at least 2 mm and/or at most 5 mm.
 
56. In some embodiments, wherein when the mounted cuff  20  is disposed within a straight rigid bounding testing tube (SRBTT DIAMETER=20 mm ) that has a diameter of 20 mm and that is co-axial with the ventilation tube, after inflating to a pressure of 15 cm H 2 O so that a contact-portion of the cuff is in contact with the straight rigid bounding testing tube (SRBTT DIAMETER=20 mm ), further inflation of the mounted cuff to a pressure of 30 cm H 2 O causes a distal extreme of the contact-portion to move distally by dist_15_30, wherein a value of dist_15_30 is positive—for example, a value of dist_15_30 is at least 3 mm or at least 5 mm or at least 7.5 mm or at least 10 mm.
 
57. In some embodiments, (e.g. this relates to shape-deformation of the cuff when inflated) wherein a ratio between dist_15_30 and prox_15_30 is at least 1.25 or at least 1.5 or at least 3 or at least 5 or at least 10.
 
58. In some embodiments, wherein when (i) the mounted cuff  20  is disposed within a straight rigid bounding testing tube (SRBTT DIAMETER=20 mm ) that has a diameter of 20 mm and that is co-axial with the ventilation tube, and (ii) the mount cuff is inflated to a pressure of 25 cm H 2 O, a contact-portion CP(25) of the cuff is in contact with the straight rigid bounding testing tube (SRBTT DIAMETER=20 mm ).
 
59. The ventilation device of claim  58  wherein a ratio between (i) a length of the contact-portion CP(25) which is wrinkle-free and (ii) a length of the contact-portion CP(25) which exhibits wrinkles, at least 1.2 or at least 1.3 or at least 1.4 or at least 1.5 or at least 1.6 or at least 1.8 or at least 2.
 
61. In some embodiments, wherein:
   A. when (i) the mounted cuff  20  is disposed within a straight rigid bounding testing tube (SRBTT DIAMETER=20 mm ) that has a diameter of 20 mm and that is co-axial with the ventilation tube, and (ii) the mount cuff is inflated to a pressure of 20 cm H 2 O, a wrinkle-free-contact-portion WF_CP(20) of the cuff is both in contact with the straight rigid bounding testing tube (SRBTT DIAMETER=20 mm ) is free of wrinkles;   B. upon further inflation to a pressure of 30 cm H 2 O, a wrinkle-free-contact-portion WF_CP(20) of the cuff is both in contact with the straight rigid bounding testing tube (SRBTT DIAMETER=20 mm ) is free of wrinkles;   C. a proximal extreme of WF_CP(30) is located proximal to a proximal extreme of WF_CP(20).
 
62. In some embodiments, wherein when (i) the mounted cuff  20  is disposed within a straight rigid bounding testing tube (SRBTT DIAMETER=20 mm ) that has a diameter of 20 mm and that is co-axial with the ventilation tube, and (ii) the mount cuff is inflated to a pressure of 25 cm H 2 OL
   i. a contact-portion CP(25) of the cuff is in contact with the straight rigid bounding testing tube (SRBTT DIAMETER=20 mm );   ii. at least a portion WF_CP(25) of the contact-portion CP(25) is wrinkle fee.
 
63. In some embodiments, of wherein another portion WRINKLED_CP(25) of the contact-portion CP(25) is wrinkled, and wherein a ratio between (i) a length of WF_CP(25) and (ii) a length of WRINKLED_CP(25) is at least 1.2 or at least 1.4 or at least 1.5 or at least 1.6 or at least 1.8 or at least 2 or at least 2.5 or at least 3 or at least 5.
 
64. In some embodiments, wherein a most-distal-contact-at-25 cm location of the ventilation tube is defined as follows:
   A. when (i) the mounted cuff  20  is disposed within a straight rigid bounding testing tube (SRBTT DIAMETER=20 mm ) that has a diameter of 20 mm and that is co-axial with the ventilation tube, and (ii) the mount cuff is inflated to a pressure of 25 cm H 2 O, a contact-portion CP(25) of the cuff is in contact with the straight rigid bounding testing tube (SRBTT DIAMETER=20 mm );   B. the most-distal-contact-at-25 cm location of the ventilation tube is defined as a proximal extreme of the contact-portion CP(25).
 
65. In some embodiments, wherein the most-distal-contact-at-25 cm is located in the proximal half (e.g. in the proximal third) of the cuff.
 
66. In some embodiments, wherein when the mounted cuff  20  is in free space, the cuff is inflatable so that a width of the cuff CUFF_WIDTH(most-distal-contact-at-25 cm) at a location on the cuff longitudinally corresponding to the most-distal-contact-at-25 cm location of the ventilation tube is at least 22 mm or at least 25 mm or at least 30 mm or at least 35 mm or at least 40 mm.
 
67. In some embodiments, wherein when the mounted cuff  20  is in free space, all locations in the central 30% of the cuff are inflatable to a width of at least 22 mm or at least 25 mm or at least 30 mm or at least 35 mm or at least 40 mm.
 
68. In some embodiments, wherein when the mounted cuff  20  is in free space, all locations in the central 50% of the cuff are inflatable to a width of at least 22 mm or at least 25 mm or at least 30 mm or at least 35 mm or at least 40 mm.
 
69. In some embodiments, wherein when the mounted cuff  20  is in free space, all locations in the central 7-% of the cuff are inflatable to a width of at least 22 mm or at least 25 mm or at least 30 mm or at least 35 mm or at least 40 mm.
 
Another discussion of how inflation of the cuff induces deformation/change of the cuff shape is now provided.
 
70. In some embodiments, wherein the mounted cuff  20  is geometrically dividable by length to four equal portions that are (i) a most distal 25% MD_25; (ii) a second most distal 25% SMD_25; (iii) a second most proximal 25% SMP_25; and (iv) a most proximal 25% MP_25. (e.g. see  FIGS. 3A-3B )
 
71. In some embodiments, wherein when the mounted cuff  20  is in free space and inflated to a pressure of 5 H 2 O, (i) an average width of the mounted cuff over the most distal portion is WIDTH_AVG(MD_25,5,free space); (ii) an average width of the mounted cuff over the most second distal portion is WIDTH_AVG(SMD_25,5,free space); (iii) an average width of the mounted cuff over the most second proximal portion is WIDTH_AVG(SMP_25,5,free space); and (iv) an average width of the mounted cuff over the most proximal portion is WIDTH_AVG(MP_25,5,free space).
 
72. In some embodiments, wherein when the mounted cuff  20  is in free space and inflated to a pressure of 26 H 2 O, (i) an average width of the mounted cuff over the most distal portion is WIDTH_AVG(MD_25,26,free space); (ii) an average width of the mounted cuff over the most second distal portion is WIDTH_AVG(SMD_25,26,free space); (iii) an average width of the mounted cuff over the most second proximal portion is WIDTH_AVG(SMP_25,26,free space); and (iv) an average width of the mounted cuff over the most proximal portion is WIDTH_AVG(MP_25,26,free space).
 
73. In some embodiments, wherein a ratio between WIDTH_AVG(MD_25,26,free space) and WIDTH_AVG(MD_25,5,free space) is at least 1.5 or at least 2 or at least 3. This may relate to neck ‘lift-off’ when the cuff is inflated.
 
74. The ventilation device of any one of claims  72 - 73  wherein a ratio between WIDTH_AVG(SMD_25,26,free space) and WIDTH_AVG(SMD_25,5,free space) is at least 1.5 or at least 2 or at least 2.5 or at least 3. This may relate to neck ‘lift-off’ when the cuff is inflated—e.g. significant lift-off in a distal 25% of the cuff.
 
75. In some embodiments, wherein a ratio between (i) a ratio between WIDTH_AVG(SMD_25,26,free space) and WIDTH_AVG(SMD_25,5,free space) and (ii) a ratio between WIDTH_AVG(SMP_25,26,free space) and WIDTH_AVG(SMP_25,5,free space) is at least 1.2 or at least 1.4 or at least 1.6 or at least 1.8 or at least 2.
 
76. In some embodiments, wherein a ratio between (i) a ratio between WIDTH_AVG(SMD_25,26,free space) and WIDTH_AVG(SMD_25,5,free space) and (ii) a ratio between WIDTH_AVG(MP_25,26,free space) and WIDTH_AVG(MP_25,5,free space) is at least 1.2 or at least 1.4 or at least 1.6 or at least 1.8 or at least 2.
 
77. In some embodiments, wherein the cuff further has most-proximal and most-distal half-height geometric-locations whose position relative to the ventilation tube varies as a function of inflation pressure of the inflatable cuff.
 
78. In some embodiments, wherein the cuff outer diameter is measured along an axis that is substantially orthogonal to the axis of the ventilation tube.
 
79. In some embodiments, wherein when the cuff is fully inflated with air in free space so that the cuff is inflated while unbounded and not inserted in a patient trachea, to and beyond 5 cm H 2 O initiation pressure:
   A. a volume of the cuff at a 5 cm H 2 O initiation pressure is V 1  and its outer cuff diameter at the widest location is CD5.   B. a pressure within the cuff reaches a free-space-inflation peak pressure PPFS whose value is between 18 and 35 cm H 2 O;   C. at the free-space-inflation peak pressure PPFS a volume of the cuff is VP;   D. upon further inflation a pressure decreases after reaching the free-space-inflation peak pressure PPFS; and   E. when the cuff is inflated from 5 cm H 2 O to peak pressure PPFS, a ratio between an axial displacement of the most-distal half-height location and an axial displacement of the most-proximal half-height location is at least two.
 
80. In some embodiments, wherein when the cuff placed within a straight rigid bounding testing tube (SRBTT DIAMETER=20 mm ) that has a diameter of 20 mm and that is co-axial with the ventilation tube, inflation of the cuff to a pressure of 30 cm H 2 O, forms a wrinkle-free band of length LF against the testing tube wall, such that at least 50% or at least 75% or at least 85% or at least 90% of the cuff contact length with testing tube wall is wrinkle-free.
 
81. In some embodiments, wherein when the cuff placed within a straight rigid bounding testing tube of a diameter that is larger than CD5 by 1 mm and that is co-axial with the ventilation tube, and when the cuff is inflated to a volume V 3  that is less than VP, the pressure within the cuff exceeds the free-space-inflation peak pressure PPFS by at least 5 cm H 2 O.
 
82. In some embodiments, wherein a length of the wrinkle-free band is at least 5 mm.
 
83. In some embodiments, wherein a length of the wrinkle-free band is at least 10 mm.
 
84. In some embodiments, wherein when the cuff placed within a straight rigid bounding testing tube (SRBTT DIAMETER=20 mm ) that has a diameter of 20 mm and that is co-axial with the ventilation tube, and the cuff is inflated to a pressure of 30 cm H2O, the diameter of the cuff at a majority of points along the wrinkled free band is smaller by at least 5% than when the cuff is inflated with air in unbounded free space, to a pressure of 30 cm H2O or to the free-space-inflation peak pressure PPFS less than 30 cm H2O.
 
85. In some embodiments, wherein the proximal bulge portion  201  and the distal neck portion  202  are such that
   a. the proximal bulge portion  201  is extending from the most-distal half-height location  204  proximally up to the proximal attachment  211  of the cuff to the tube  106 ;   b. the distal neck portion  202  is extending from the most-distal half-height location  204  distally up to the distal attachment  212  of the cuff to the tube  106 ;   c. the proximal bulge portion  201  is convex in the cuff section between the most-distal half-height location  204  and most-proximal half-height location  205 .
 
86. In some embodiments, wherein, the distal neck portion  202  is concave, in the sense that a tangent sphere of finite radius is tangent to the cuff at two non-attached locations, a distal tangent point at a distal location on the cuff and a proximal tangent point at a location on the cuff more proximal than the distal tangent point; such that when held in free space,
   d. at initiation pressure P 1  of 5 cm H2O the largest tangent sphere has a radius R 1 , at mid-pressure P 2  equal to 15 cm H2O the largest tangent sphere has a radius R 2 , at a mid-pressure P 3  higher than P 2 , P 3 &gt;P 2 , the largest tangent sphere has a radius R 3 ; and   e. R 1 &gt;R 2 &gt;R 3 .
 
87. In some embodiments, wherein, the cuff having most-proximal and most-distal half-height locations whose position relative to the ventilation tube varies as a function of inflation pressure of the inflatable cuff such that: when inflated inside a testing tube of 20 mm diameter, the axial distance between locations of the half-height distal cuff edge  234  at pressure P 1  of 5 cmH2O, and half-height distal cuff edge  236  at pressure P 5  of 35 cm H 2 O is greater than the axial distance, when inflated in free space, between locations of the half-height distal cuff edge  224  at pressure P 1  of 5 cmH2O and the half-height distal cuff edge  226  at free-space peak pressure PPFS, by at least 30%, or by at least 50%.
 
88. In some embodiments, wherein when a cuff  200  is inflated within the testing tube  108 , there is a central holding position such that: (a) there is no contact between the cuff and the bounding testing tube wall at initiation pressure of 5 cm H2O; and (b) at pressure of 30 cm H2O there must be a contact between the cuff and the bounding testing tube wall.
 
89. In some embodiments, wherein when a cuff  200  is inflated within the testing tube  108 , there is a central holding position at which as inflation pressure grows, the cuff contact section  240  length grows such that: (a) at a pressure P 4  of 20 cm H2O, having a contact section  240  of axial length L 20  greater than 2 mm between the cuff and the testing tube wall, there is distance D 2  between distal cuff attachment location  215  and most-distal contact location of the cuff with the bounding tube wall; and (b) at a pressure of 40 cm H 2 O, having a contact section  240  of axial length L 40  greater that 5 mm between the cuff and the testing tube wall, there is distance D 3  between distal cuff attachment location  215  and most-distal contact location of the cuff with the bounding tube wall, and (c) L 40  is greater than L 20  by at least 25%.
 
90. In some embodiments, wherein at an inflation pressure of 15 cm H2O, the cuff is having a contact section  240  of axial length that is less than 30% of the distance between the proximal cuff attachment  211  and the distal cuff attachment  212 .
 
91. In some embodiments, wherein the cuff  200  is attached to the ventilation tube  106  at a proximal cuff attachment  211  and at a distal cuff attachment  212 , where the attachment is in the form of glue or welding or elastic compression with a material of shore value at least twice larger than the shore value of the cuff bulge wall material.
 
92. In some embodiments, wherein when the mounted cuff is disposed in free space and inflated with air to 5 cm H 2 O, further inflation of the mounted cuff to the FSPIPP:
   1) axially displaces the most distal half-max-elevation location in the distal direction by a first displacement; and   (2) axially displaces the most proximal half-max-elevation location in the proximal direction by a second displacement; and   B. a ratio between the first and second displacements is at least two or at least 3.
 
93. In some embodiments, wherein the cuff is single-layered.
 
94. In some embodiments, wherein the ventilation tube is selected from the group consisting of a endotracheal tube (ETT), tracheostomy tube; and a multi-cuff (e.g. dual cuff) laryngeal device tube (e.g. the cuff is a proximal cuff around the multi-cuff tube).
 
95. In some embodiments, wherein an outside diameter of the ventilation tube is at least 6 mm.
 
96. In some embodiments, wherein an outside diameter of the ventilation tube is at least 7 mm.
 
97. In some embodiments, wherein an outside diameter of the ventilation tube is at least 8 mm.
       

     All publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety. In case of conflict, the patent specification, including definitions, will prevail. In addition, the materials, methods, and examples are illustrative only and not intended to be limiting. 
     The present invention has been described using detailed descriptions of embodiments thereof that are provided by way of example and are not intended to limit the scope of the invention. The described embodiments comprise different features, not all of which are required in all embodiments of the invention. Some embodiments of the present invention utilize only some of the features or possible combinations of the features. Variations of embodiments of the present invention that are described and embodiments of the present invention comprising different combinations of features noted in the described embodiments will occur to persons of the art.