Patent Publication Number: US-2023138935-A1

Title: System and method for stimulating airways

Description:
FIELD 
     This invention relates to a system and method for stimulating airways. 
     BACKGROUND 
     Up to 25% of the world&#39;s population is thought to be negatively affected by nasal congestion, a condition of increased breathing resistance often described as ‘stuffiness’ (R1). Nasal congestion is a common symptom of upper airway disorders and is associated with a range of causes (R2). Variable nasal congestion is usually caused by reversible and potentially spontaneously resolving causes such as mucosal inflammation and nasal secretions found during nasal allergy or upper respiratory infection (R1). 
     Normal tidal nasal breathing air flow exert fluctuating pressure and shear stresses against the airway mucosa, stimulating the discharge of airway surface liquid and mucociliary transport via cellular purinergic channels (R3). This mechano-stimulation aids in the regulation and enhancement of mammal airway defence (R4). 
     The paranasal sinuses are a rich endogenous source of nitric oxide (NO) gas (R5) which has been shown to protect and treat bacterial, fungal and viral airway infections, and stimulate mucociliary clearance of entrapped pathogens (R6). NO is considered crucial in airway defence and thought to play an important role in nasal airway resistance, with higher levels of NO being associated with nasal decongestion (R7). This positive association between nasal NO concentration and nasal decongestion has been demonstrated by humming which greatly increases the concentration of inhaled endogenous nitric oxide (R8, R9) while also leading to a reduction in nasal congestion (R10). Humming is thought to also provide additional mechano-stimulation of the airway mucosa purinergic channels, increasing airway hydration and mucociliary transport. 
     NO is a free radical gas signalling molecule which is also produced throughout the human body that plays a variety of important roles. These include assisting oxygen uptake in the lungs, improving circulation through vasodilation, modulating neurological function including depression, memory (R11) and sleep staging, and a variety of other important signalling activities. To maintain good health the concentration of NO needs to remain within certain limits. Low NO levels are associated with poor wellbeing and closely linked to reduced sleep quality (R12) and interruption to the sleep/wake cycle (R13). Low levels of circulating NO are also associated with high blood pressure, poor circulation, low blood oxygen saturation levels, muscle pain and is linked to many long-terms ailments, such as chronic obstructive pulmonary disease (COPD). Smoking, stress, injury, pathology, poor lifestyle choices, as well as nasal abnormalities and aging can lead to a reduction in circulating NO levels. This reduction is linked to an increased risk of cardiovascular disease, poor metabolic disease management, poor circulation and insomnia. High levels of NO are thought to potentially reduce asthma and airway viral infections (R14), COPD (R15), rhinovirus (R16), ischemic stroke and traumatic brain injury (R13). 
     The human paranasal sinuses, including the maxillary sinuses, contain the highest levels of NO found in the body (R17, R18) so unsurprisingly respiratory physiotherapists recommend nasal breathing over mouth breathing for many reasons including the augmentation of inhaled nitric oxide (iNO) (R19). During normal nasal breathing iNO is metered into the inhaled air before passing into the lungs where it assists oxygen uptake before becoming dissolved into the blood to then circulate throughout the body. Many benefits of nasal breathing and augmented iNO level are claimed including prevention and protection from airway infection (R20) through to its role in modulating healthy pulmonary function (R21). 
     NO is considered to be crucial in airway defence (R17, R18, R20) and thought to play an important role in nasal airway resistance, with higher levels of NO being associated with nasal decongestion (R7). This positive association between nasal NO concentration and nasal decongestion has been demonstrated by humming which greatly increases the concentration of inhaled endogenous nitric oxide (R8, R9) while also leading to a reduction in nasal congestion (R48). 
     The status of the nasal cycle, where one nostril normally conducts more tidal airflow, termed ‘patent’, compared to the other, termed ‘congested’, has previously been shown to allow the nose to simultaneously undertaking its air-conditioning and mucociliary roles (R22). A healthy nasal cycle also enables the nose to act as a NO regenerator to maintain a higher mean concentration of iNO compared to a non-cycling nose. This is realised through the NO concentration within the paranasal sinuses on the congested side of the nose increasing as a result of low airflow whereas the NO concentration on the patent side paranasal sinuses are progressively depleted due to the higher airflow. Normal periodic change in the nasal cycle status results in the previously congested airway paranasal sinuses now having available a high concentration of stored NO so when this side of the nose becomes patent (where it conducts the majority of the tidal nasal airflow) there is a high concentration store of NO available to be inhaled. Conversely, the NO storage levels in the previously patent side of the nose, depleted due to the previously higher airflow, start to increase again due to the reduction in airflow when this side becomes congested.  FIG.  1    shows how this nasal cycle NO regeneration effect enables a higher mean level of maximum iNO concentration  170  to be entrained into the lungs compared to the case of the of maximum iNO concentration  270  where there was no nasal cycle, shown by  FIG.  2   , and the maximum iNO concentration  370  when near equal airflow passes down both nasal airways, such as that found during pressurised nasal breathing (R23), shown by  FIG.  3   . 
     In  FIGS.  1  to  3   , the graphs  100 ,  200 ,  300  show internasal airflow apportionment, graphs  130 ,  230 ,  330  show paranasal sinus NO concentration (ppb) and graphs  160 ,  260 ,  360  show and maximum iNO concentration. Time  105 ,  135 ,  165 ,  205 ,  235 ,  265 ,  305 ,  335 ,  365  is shown on the x-axis. The y-axis shows internasal airflow apportionment ( 108 ,  208 ,  308 ), paranasal sinus NO concentration (ppb) ( 138 ,  238 ,  338 ) and maximum iNO concentration (ppb) ( 168 ,  268 ,  368 ). Lines  110 ,  210 ,  310  show the percentage of internasal airflow through the left nostril, lines  120 ,  220 ,  320  show the percentage of internasal airflow through the right nostril. Lines  140 ,  240 ,  340  show the paranasal sinus NO concentration in the left sinus and lines  150 ,  250 ,  350  shows the paranasal sinus NO concentration in the right sinus. Lines  170 ,  270 ,  370  show the mean of maximum iNO concentration. 
     The human autonomic nervous system (ANS) undertakes the unconscious regulation of many body functions associated with the ongoing maintenance of maintaining life (homeostasis) and is closely associated with the hormonal and the immunological systems (R24). The two main branches of the ANS, sympathetic and parasympathetic, jointly regulate a multitude of organ, immune and regulatory systems and have opposing affect. Through brain to body signalling (efference), these two branches periodically alternate in dominance so that the organs and systems they regulate operate between two states; sympathetic dominance ‘fight or flight’ (stressed) or parasympathetic dominance, rest and digest’ (relaxed). Heart rate, blood pressure, alertness, energy levels, blood flows and insulin levels (R25), hunger and digestion, organ activity, hormone release (R26), stress levels (cortisol and adrenaline hormone release), cognitive function, sleep stage, and many more life sustaining functions are all linked to this constant cycling of ANS state dominance that continue throughout the day and night (R24). The ANS system also receives feedback signals from the external environment and physical body (afference) that can change the state of ANS dominance to aid survival and wellbeing. These signals, for example a loud explosion, could change the ANS dominance from parasympathetic (rest &amp; digest) to sympathetic (fight or flight). This change would trigger the release of stress hormones, such as adrenaline and cortisol, and enable more oxygen and blood sugar to be available to the muscles to enable the individual to flee the perceived risk to life. 
     Healthy ANS cyclic regulation is termed ‘sympathovagal balance’, where there is normal distribution of cycling of the ANS between sympathetic and parasympathetic dominant states throughout the day and night. This periodic cycling was first associated with the changing states of the ANS in 1954 by Hess who described the cycling variation in autonomic function between ‘energy’ and ‘restitution’ states (R26). Later, in  1960 , sleep researcher Nathaniel Kleitmann proposed the human body operated on a basic-rest-activity cycle (BRAC), where it alternated between activities associated with activity or rest (R26, R27). This hypothesis proposed these contrasting ultradian (sub 24 hour) ANS cycles occur in varying degrees of dominance and duration during both waking and sleep, as demonstrated by periods of activity or rest during waking and rapid eye movement (REM) and non-REM staging during sleep. 
     Over exposure to sources of stress, such as excessive caffeine intake, late nights, shift work, relationship breakdown, physical trauma and exposure to other forms of excessive ANS stimuli sends a signal back to the brain (afference) that may, if sustained long-term, cause sympathetic over-stimulation and lead to disruption of an individual&#39;s sympathovagal balance (R24). This ANS dysfunction can potentially lead to poor wellbeing, and if persisting longer term, cause chronic disease, cancer, neurological disorder and early morbidity (R24). Autonomic nervous system dysfunction is thought to precede many illnesses and diseases including cardiovascular and metabolic diseases including Type 2 diabetes (R25, R28). 
     The positive effect regulated nostril breathing, commonly known as yoga breathing, has on the ANS has been well published which includes change in heart rate variability (HRV) and cardiovascular risk (R29), cognitive performance (R30), psychiatry treatment (R31) and post stroke language, spatial abilities and anxiety (R32). While the mechanism(s) by which regulated nostril breathing can influence the ANS are poorly understood, iNO is thought to play a major role given NO is known to decrease ANS sympathetic over-excitation (stress) (R33). This change could then affect the ANS sympathetic/parasympathetic balance and potentially restore sympathovagal balance. 
     The status of the nasal cycle, where one nostril normally conducts more tidal airflow compared to the other, has been closely linked to sleep stage(R34) and has previously been used to indicate the status of ANS dominance during waking and sleep (R35, R36). Here the left or right nostril airflow dominance indicates parasympathetic or sympathetic dominance respectively (R31, R37). Previous work has shown the afference signalling influence of regulated nostril breathing (yogic breathing) on the state of ANS dominance (R31, R38, R39) with the right and left nostril influencing sympathovagal balance, heart rate variability and cardiovascular risks (R29) and metabolism (R40). Unilateral forced nostril breathing (UFNB) through the right nostril is associated with ANS sympathetic dominance (stressed) while UFNB through the left nostril is associated with ANS parasympathetic (relaxed) dominance (R31). Abnormal or total lack of patterns of nasal cycling have also been found in studies of neurological disorders and disease (R38, R41, R42), and many other chronic disease states (R43). This associations is suggestive that reduction in iNO levels may play an early role in the development of many neurological and chronic diseases since it serves to suppress ANS sympathetic over-excitation (stress response). 
     Studies have demonstrated that humming at a range of frequencies spanning approximately 100 Hz to 450 Hz augments levels of exhaled NO by up to 15 times the normal value (R44-R46). During humming, augmented NO release from the paranasal sinuses is achieved through slight pressure variations over a broad frequency range, spanning approximately 100 Hz to 450 Hz. While this technique has been shown to rapidly resolve chronic rhinosinusitus (R47) within the nasal cavity, the additional NO does not enter the lower airways as the individual is exhaling during the humming manoeuvre. 
     PCT Application No. PCT/NZ2015/050169 A METHOD AND APPARATUS FOR THE CONTROLLED DELIVERY OF GASES which describes controlling the cycling of the naris is incorporated by reference in full. 
     SUMMARY 
     According to one example embodiment there is provided a method of stimulating airways of a mammal comprising: 
     cyclically occluding a nasal air stream at a frequency rate between 50 Hz to 650 Hz. 
     Preferably stimulating the airways of a mammal improves nasal airflow by decongesting nasal obstruction in the mammal. 
     Preferably stimulating the airways of a mammal improves airway infection by enhancing airway hydration and mucociliary transport. 
     Preferably stimulating the airways of a mammal improves the inhaled Nitric Oxide in the mammal. 
     Preferably the mammal has two nares, a first naris and a second naris and cyclically occluding the nasal air stream comprises simultaneously cyclically occluding the nasal air stream of both nares. 
     Preferably the mammal has two nares, a first naris and a second naris and during a first mode cyclically occluding the nasal air stream comprises cyclically occluding only the nasal air stream of the first naris. 
     Preferably the nasal air stream to the second naris is unrestricted. 
     Preferably the nasal air stream to the second naris is restricted. 
     Preferably the restriction is partial. 
     Preferably the during the first mode the first naris is the congested naris and the second naris is the patent naris. 
     Preferably during a second mode cyclically occluding the nasal air stream comprises cyclically occluding only the nasal air stream of the second naris. 
     Preferably the nasal air stream to the second naris is unrestricted. 
     Alternatively, the nasal air stream to the second naris is restricted. 
     Preferably the restriction is partial. 
     Preferably during the second mode the second naris is the congested naris and the first naris is the patent naris. 
     Preferably the change between the first mode and the second mode is controlled by a controller. 
     Preferably the period of operation of the first mode or the second mode is between 1 and 360 minutes, preferably between 1 and 15 minutes, more preferably between 1 and 5 minutes. 
     Preferably the nasal air stream is cyclically occluded during both inhalation and exhalation. 
     Preferably the nasal air stream is cyclically occluded during inhalation only. 
     Preferably including controlling the occlusion by controlling an average percentage of obstruction of the nasal air stream. 
     Preferably the average percentage of obstruction is between 5 and 95 percent. 
     Preferably controlling the average percentage of obstruction of the nasal air stream includes controlling a percentage of time in a cycle in which the nasal air stream is at least partial obstructed and controlling a maximum percentage of obstruction of the nasal air stream. 
     Preferably the maximum percentage of obstruction of the nasal air stream is between 5 and 95 percent. 
     Preferably the frequency rate is between 100 Hz to 450 Hz. 
     Preferably the mammal is a human. 
     According to a further example embodiment there is provided an apparatus for stimulating airways of a mammal, comprising:
         a fluid connection to each of a first and second naris of the mammal; and   an occluding device configured to cyclically occlude a nasal air stream within each fluid connection at a frequency rate between 100 Hz to 650 Hz.       

     Preferably stimulating the airways of a mammal improves the inhaled Nitric Oxide in the mammal. 
     Preferably stimulating the airways of a mammal improves airway infection by enhancing airway hydration and/or mucociliary transport. 
     Preferably stimulating the airways of a mammal improves nasal airflow by decongesting nasal obstruction in the mammal. 
     Preferably cyclically occluding the nasal air stream comprises simultaneously cyclically occluding the nasal air stream of both nares. 
     Preferably the apparatus in a first mode cyclically occludes only the nasal air stream of the first naris. 
     Preferably in the first mode the nasal air stream to the second naris is unrestricted. 
     Alternatively, in the first mode the nasal air stream to the second naris is restricted. 
     Preferably the restriction is partial. 
     Preferably in the first mode the first naris is the congested naris and the second naris is the patent naris. 
     Preferably the apparatus in a second mode cyclically occludes only the nasal air stream of the second naris. 
     Preferably in the second mode the nasal air stream to the second naris is unrestricted. 
     Alternatively, in the second mode the nasal air stream to the second naris is restricted. 
     Preferably the restriction is partial. 
     Preferably wherein in the second mode the second naris is the congested naris and the first naris is the patent naris. 
     Preferably the change between the first mode and the second mode is controlled by a controller. 
     Preferably the period of operation of the first mode or the second mode is between 1 and 360 minutes, preferably between 1 and 15 minutes, more preferably between 1 and 5 minutes. 
     Preferably the nasal air stream is cyclically occluded during both inhalation and exhalation. 
     Preferably wherein the nasal air stream is cyclically occluded during inhalation only. 
     Preferably the apparatus including controlling the occlusion by controlling an average percentage of obstruction of the nasal air stream. 
     Preferably the average percentage of obstruction is between 5 and 95 percent. 
     Preferably controlling the average percentage of obstruction of the nasal air stream includes controlling a percentage of time in a cycle in which the nasal air stream is at least partial obstructed and controlling a maximum percentage of obstruction of the nasal air stream. 
     Preferably the maximum percentage of obstruction of the nasal air stream is between 5 and 95 percent. 
     Preferably the frequency rate is between 100 Hz to 450 Hz. 
     Preferably the mammal is a human. 
     Preferably further including a flow direction sensor. 
     Preferably the apparatus further includes a pressure sensor. 
     Preferably the apparatus includes a battery and is configured to be worn under the nose. 
     Preferably the apparatus is a standalone device. 
     Preferably the apparatus further comprises an air supply device. 
     Preferably the air supply device is selected from the group comprising CPAP, Bi-PAP, Auto-PAP and other assisted breathing devices. 
     Preferably the occluding device is a linear slide shutter system including a liner solenoid actuator. 
     Alternatively, the occluding device is a linear shutter system with crank actuator. 
     Alternatively, the occluding device is a rotating shutter system. 
     Alternatively, the occluding device is a transverse rotating partially blocking shutter inline in the fluid connection. 
     Preferably the transverse rotating partially blocking shutter is a barrel and the barrel include cut outs. 
     It is acknowledged that the terms “comprise”, “comprises” and “comprising” may, under varying jurisdictions, be attributed with either an exclusive or an inclusive meaning. For the purpose of this specification, and unless otherwise noted, these terms are intended to have an inclusive meaning—i.e., they will be taken to mean an inclusion of the listed components which the use directly references, and possibly also of other non-specified components or elements. 
     Reference to any document in this specification does not constitute an admission that it is prior art, validly combinable with other documents or that it forms part of the common general knowledge. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings which are incorporated in and constitute part of the specification, illustrate embodiments of the invention and, together with the general description of the invention given above, and the detailed description of embodiments given below, serve to explain the principles of the invention, in which: 
         FIG.  1    is a graph illustrating paranasal and iNO concentrations during normal nasal cycling; 
         FIG.  2    is a graph illustrating paranasal and iNO concentrations during absence of nasal cycling; 
         FIG.  3    is a graph illustrating paranasal and iNO concentrations during sustained equal internasal airflow apportionment; 
         FIG.  4    is an example embodiment of a linear slide shutter system with a liner solenoid actuator; 
         FIG.  5    is an example embodiment of a slide linear shutter system with a crank actuator; 
         FIG.  6    is a side view of an example embodiment of a linear shutter system; 
         FIG.  7    is an example embodiment of a rotating shutter system with a motor actuator; 
         FIG.  8    is a side view of an example embodiment of a rotating shutter system; 
         FIG.  9    is an example embodiment of an oscillating shutter system with a 4-bar linkage actuator; 
         FIG.  10    is an example embodiment of an oscillating shutter system with a motor-crank actuator; 
         FIG.  11    is a side view of an example embodiment of an oscillating shutter system; 
         FIG.  12    is a diagram of the example sensors of the system; 
         FIG.  13    is an example embodiment of a rotating barrel shutter; 
         FIG.  14    is a cross section of the rotating barrel shutter inline in an air flow pipe; 
         FIG.  15    is an example embodiment of a rotating partially blocking shutter; 
         FIG.  16    is a cross section of the rotating partially blocking shutter inline in an air flow pipe; 
         FIG.  17    is a front view of a person wearing an example embodiment of the apparatus; 
         FIG.  18    is a side view of a person of  FIG.  17    wearing an example embodiment of the apparatus; 
         FIG.  19 A  is an example embodiment featuring a single rotating shutter, central air inlet/outlet port and side naris manifolds; 
         FIG.  19 B  is a sectional side view of  FIG.  19 A ; 
         FIG.  19 C  is a pictorial view of housing with naris manifolds of an example embodiment featuring a single rotating shutter, central air inlet/outlet port and side naris manifolds; 
         FIG.  19 D  is a top side view of  FIG.  19 C ; 
         FIG.  20 A  is a sectional assembly side view showing air flow paths in an example embodiment featuring a single rotating shutter, central air inlet/outlet port and side naris manifolds; 
         FIG.  20 B  is a pictorial view of the housing of  FIG.  20 A ; 
         FIG.  21 A  is top view of an example embodiment featuring a single rotating shutter, central air inlet/outlet port and side naris manifolds; 
         FIG.  21 B  is a sectional side view of  FIG.  21 A ; and 
         FIG.  21 C  is a pictorial view of the rotating shutter of  FIG.  21 A ; 
     
    
    
     DETAILED DESCRIPTION 
       FIGS.  4  to  11  and  13  to  22    illustrates various shutter systems and an example apparatus according to various example embodiments. 
     The linear slide shutter system  400  illustrated in  FIG.  4   , delivers pressure oscillations into the inhaled air stream path  450  entering the nose to elevate the levels of iNO and/or provide mechanical stimulation to the airway mucosa. In one embodiment this is realised by using an airflow interrupter  460 , such as air airflow shutter, that cyclically partially occludes the incoming air stream at a frequency rate replicating that found during low-frequency humming (100 Hz to 650 Hz, preferably 100 Hz to 450 Hz). Motors  410  are connected to the airflow interrupters  460  using linear actuators  420 . The motors  410  move the airflow interrupters  460  backwards and forwards in a linear motion to partially occlude the incoming air stream. 
       FIGS.  4    though to  11  and  13  to  16  illustrate various potential embodiments of airflow shuttering systems. Other embodiments that occlude the incoming air stream at a frequency rate replicating that found during low-frequency humming (100 Hz to 650 Hz, preferably 100 Hz to 450 Hz) may also be used. 
     Referring to  FIG.  5    motors  510  are connected to the airflow interrupters  560  using rotating  570  disks  530 , that are in turn connected to a link  520 . The disks  530  and link  520  provide a linear motion to the airflow interrupter  560 . The motors  510  move the airflow interrupters  560  backwards and forwards in a linear motion to partially occlude the incoming air stream in the air stream path  550 . 
     Referring to  FIG.  6    a motor  610  is connected to an airflow interrupter  660 . The motor  610  moves the airflow interrupter  660  backwards and forwards in a linear motion to partially occlude the incoming air stream  670  in the air stream path  650 . 
     Referring to  FIG.  7    motors  710  are connected to airflow interrupters  760 . The motors  710  rotate  720  airflow interrupters  770  in a circular motion to partially occlude the incoming air stream in the air stream path  750 . 
     Referring to  FIG.  8    a motor  810  is connected to an airflow interrupter  860 . The motor  810  rotates the airflow interrupters  860  in a circular motion to partially occlude the incoming air stream  870  in the air stream path  850 . 
     Referring to  FIG.  9    rotating  990  motors  910  are connected to the airflow interrupters  960  using links  930 . The links  930  move  920  the airflow interrupters  960  to partially occlude the incoming air stream in the air stream path  950 . 
     Referring to  FIG.  10    a motor  1010  is connected to an airflow interrupter  1060  using links  1090 . The links  1090  move  1020  the airflow interrupter  1060  to partially occlude the incoming air stream in the air stream path  1050 . 
     Referring to  FIG.  11    a motor  1110  is connected to an airflow interrupter  1160  using a rotating disk  1130 , that is in turn connected to a link  1120 . The disk  1130  and link  1120  provide a linear motion to the airflow interrupter  1160 . The motor  1110  moves the airflow interrupters  1160  backwards and forwards in a linear motion to partially occlude the incoming air stream  1170  in the air stream path  1150 . 
     Referring to  FIGS.  13  and  14    a rotating barrel  1410  with alternating slots  1420 ,  1430  and solid portions  1440 ,  1445  to allow airflow could be utilised to partially occlude the incoming air stream  1470  in the air stream path  1450 . 
     Referring to  FIGS.  15  and  16    a rotating shutter  1610  with alternating blocking  1630  and non-blocking  1620  portions to allow airflow could be utilised to partially occlude the incoming air stream  1670  in the air stream path  1650 . 
     A single rotating barrel slide shutter system is illustrated by  FIGS.  19 A to  19 D,  20 A and  20 B and  21 A to  21 C . A single rotating barrel slide shutter  1950 ,  2050 ,  2150  has slots  1955 ,  2055 ,  2155  and solid portions in the barrel. The barrel  1950 ,  2050 ,  2150  delivers pressure oscillations into the inhaled air stream  1970 ,  2070 ,  2170  entering the nose via a common manifold  1990 ,  2090 ,  2190 . The air flowing to each nostril via first  1903 ,  2003 ,  2103  and second  1904 ,  2004 ,  2104  outlets. 
     Airflow shuttering could occur for just the inhalation breath phase or both inhalation and exhalation phases. Breath phase could be sensed via pressure sensors  1210 ,  1215  illustrated in  FIG.  12    detecting low or high pressure during the inhalation or exhalation phases of breathing respectively. Alternatively, the system could use flow sensors  1220 ,  1225  to sense the flow. In a further alternative, if the rotating flow interrupter  1230 ,  1235  had slightly inclined blades, motor torque could be sensed to provide an indication of airflow direction. 
       FIGS.  17  and  18    show the shutter system  1702  being used by a mammal/person  1701 . Each naris  1703 ,  1704  receives a separate airflow. 
     Airflow shuttering could be applied to just one nostril, periodically alternating between either the right or left nostrils or simultaneously to both nostrils. 
     Shuttering of airflow could also be directed to a specific nostril depending upon the status of the user&#39;s nasal cycle where, for example, the paranasal sinuses within the congested nasal airway contain the highest NO levels. In a preferred embodiment airflow shuttering is applied to the congested nostril improving discharge of stored NO. 
     Periodically switching airflow shuttering between each side of the nose enables the NO concentration within the paranasal sinuses on one side to build up while the other is be discharged. 
     In one embodiment the device may be small enough that it could be worn discreetly under the nose and be battery powered. 
     Augmented iNO use assists in restoring sympathovagal balance and when combined with cyclically occluded air flow shear and pressure stresses also may potentially bring a multitude of therapeutic benefits that include:
         1. Treating nasal congestion.   2. Improving airway hydration and mucociliary clearance to assist treating upper airway infection.   3. Post-operative recovery.   4. Pre-event build for high-performance sports.   5. Aid post-event muscle recovery.   6. Aiding sleep homeostasis in the elderly or insomniacs.   7. Aid sleep onset for shift workers.   8. Assist ventilation and blood oxygenation in COPD sufferers.   9. Prevent the onset of metabolic disease and assist in the management of Type-2 diabetes.   10. Assist blood pressure reduction.   11. Long-term benefits in reducing cardiovascular disease.   12. Treat traumatic brain injury.   13. Treat neurological diseases such as Alzheimer&#39;s and Parkinson&#39;s.       

     In an embodiment a method of stimulating airways of a mammal is provided by cyclically occluding a nasal air stream at a frequency rate between 50 Hz to 650 Hz. 
     Stimulating the airways of a mammal can improve nasal airflow by decongesting nasal obstruction in the mammal. Further stimulating the airways of a mammal can improve airway infection by enhancing airway hydration and mucociliary transport. Yet still further stimulating the airways of a mammal can improve the inhaled Nitric Oxide in the mammal. 
     When the mammal has two nares, a first naris and a second naris cyclically occluding the nasal air stream comprises simultaneously cyclically occluding the nasal air stream of both nares. 
     When the mammal has two nares, a first naris and a second naris and during a first mode of operation cyclically occluding the nasal air stream comprises cyclically occluding only the nasal air stream of the first naris. In this mode the nasal air stream to the second naris can be fully or partial restricted or unrestricted. 
     During the first mode the first naris is the congested naris and the second naris is the patent naris and cyclically occluding the nasal air stream comprises cyclically occluding only the nasal air stream of the second naris. In this mode the nasal air stream to the second naris can be fully or partial restricted or unrestricted. 
     During the second mode the second naris is the congested naris and the first naris is the patent naris. The change between the first mode and the second mode can be controlled by a controller. 
     The period of operation of the first mode or the second mode can be between 1 and 360 minutes, preferably between 1 and 15 minutes, more preferably between 1 and 5 minutes. 
     The nasal air stream can be cyclically occluded during both inhalation and exhalation or alternatively the nasal air stream can be cyclically occluded during inhalation only. Controlling the occlusion can be implemented by controlling an average percentage of obstruction of the nasal air stream. The average percentage of obstruction is between 5 and 95 percent. 
     Controlling the average percentage of obstruction of the nasal air stream includes controlling a percentage of time in a cycle in which the nasal air stream is at least partial obstructed and controlling a maximum percentage of obstruction of the nasal air stream. The maximum percentage of obstruction of the nasal air stream is between 5 and 95 percent. 
     In one embodiment the frequency rate is between 100 Hz to 450 Hz. 
     In one embodiment the mammal can be a human. 
     In an embodiment there is provided an apparatus for stimulating airways of a mammal, comprising a fluid connection to each of a first and second naris of the mammal, and an occluding device configured to cyclically occlude a nasal air stream within each fluid connection at a frequency rate between 100 Hz to 650 Hz. 
     Stimulating the airways of a mammal can improve nasal airflow by decongesting nasal obstruction in the mammal. Further stimulating the airways of a mammal can improve airway infection by enhancing airway hydration and mucociliary transport. Yet still further stimulating the airways of a mammal can improve the inhaled Nitric Oxide in the mammal. 
     Cyclically occluding the nasal air stream can comprise simultaneously cyclically occluding the nasal air stream of both nares. 
     The apparatus in a first mode cyclically occludes only the nasal air stream of the first naris and in the first mode the nasal air stream to the second naris can be unrestricted. Alternatively, in the first mode the nasal air stream to the second naris can be partially or fully restricted. 
     In the first mode the first naris can be the congested naris and the second naris can be the patent naris. The apparatus in a second mode can cyclically occludes only the nasal air stream of the second naris. In the second mode the nasal air stream to the second naris can be unrestricted. Alternatively, in the second mode the nasal air stream to the second naris can be partially or fully restricted. 
     Alternatively, in the second mode the second naris can be the congested naris and the first naris can be the patent naris. The change between the first mode and the second mode can be controlled by a controller. 
     The period of operation of the first mode or the second mode can be between 1 and 360 minutes, preferably between 1 and 15 minutes, more preferably between 1 and 5 minutes. The nasal air stream can be cyclically occluded during both inhalation and exhalation. Alternatively the nasal air stream can be cyclically occluded during inhalation only. 
     The apparatus can include a controller for controlling the occlusion by controlling an average percentage of obstruction of the nasal air stream. The average percentage of obstruction can be between 5 and 95 percent. 
     Controlling the average percentage of obstruction of the nasal air stream can include controlling a percentage of time in a cycle in which the nasal air stream is at least partial obstructed and controlling a maximum percentage of obstruction of the nasal air stream. The maximum percentage of obstruction of the nasal air stream can be between 5 and 95 percent. 
     In one embodiment the frequency rate is between 100 Hz to 450 Hz. 
     The mammal can be a human. 
     The apparatus can include a flow direction sensor and/or a pressure sensor. Further the apparatus can include a battery and can be configured to be worn under the nose. The apparatus can be a standalone device or can include an air supply device. The air supply device being selected from the group comprising CPAP, Bi-PAP, Auto-PAP and other assisted breathing devices. 
     The occluding device can be a linear slide shutter system including a liner solenoid actuator. Alternatively the occluding device can be a linear shutter system with crank actuator. 
     The occluding device can be a rotating shutter system. Alternatively, the occluding device can be a transverse rotating partially blocking shutter inline in the fluid connection. The transverse rotating partially blocking shutter can be a barrel and the barrel can include cut outs. 
     While the present invention has been illustrated by the description of the embodiments thereof, and while the embodiments have been described in detail, it is not the intention of the Applicant to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details, representative apparatus and method, and illustrative examples shown and described. Accordingly, departures may be made from such details without departure from the spirit or scope of the Applicant&#39;s general inventive concept. 
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