WO2015138924A1

WO2015138924A1 - Device for the emulation of a cough in ventilated patients

Info

Publication number: WO2015138924A1
Application number: PCT/US2015/020478
Authority: WO
Inventors: Jan Lee; Matthew PETNEY; Eric ASHUCKIAN; Pankti SHAH; Tiffany TSENG
Original assignee: The Johns Hopkins University
Priority date: 2014-03-14
Filing date: 2015-03-13
Publication date: 2015-09-17

Abstract

Provided is an airway restrictor. The airway restrictor can include a body, an airway comprising at least one of a primary airflow channel a»d an airflow diversion channel, an actuator, and a valve manipulated by the actuator to: (i) prevent or reduce airflow through either of the primary airflow channel and the airflow diversion channel, (ii) divert airflow from, the primary airflow channel to the airflow diversion channel, (iii) allow air from an external air source to reduce air flow out of the airway, or any combination of (i), (ii) and (iii).

Description

DEVICE FOR THE EMULATION OF A COUGH VENTILATED PATIENTS

10001] This applications claims priority to U.S. Provisional Patent Application Ser.

No. 61/953/408 filed March 14, 2014. the entirety of which is incorporated herein by reference.

10002} This invention relates generally to the field of healthcare, particularly the healthcare of patients who receive mechanical ventilation delivered through a breathing tube, nd specifically to the mobilization a d remo val of mucus and secretions in intubated patients or patients with receiving invasive ventilation. aekgro und of the jn\ ¾ntio«

100 31 Patients may require a ventilator for various reasons, such as trauma, cardiopulmonary failure, or stroke. They rely on mechanical ventilation (MVj delivered through a breathing tube (also known as an endotracheal tube) to survive. Coughing is the body's main defense against respiratory infection. However, the breathing tube can prevent patients from coughing effectively because it does not allow sufficient pressure to build up in the lungs. Thus, over time, the presence of a breathing tube prevents the elimination of mucus and bacteria that build up in the ^'lungs. Within a matter of days, patients on ventilators who are unable to cough properly can develop secondary infections that worsen their condition.

(0004} Conventional devices and .methods that are targeted to the removal of mucus from the lower respiratory system include the COUGHASSiST™ (available from. J.H. Emerson, Co., Cambridge, MA) and the 1PV-2C& (Intrapulrnonary Percussive Ventilation) (available from PERCUSSION AIRE& Corporation, Sagie, .ID), The COUGHASSIST™ forces air into the lungs and quickly reverses the flow to suction out secretions. The iPY- 2C® is attached in line with the mechanical ventilator, it delivers short hursts of air that loosen secretions in the lower airways and move them out of the lungs.

(0005) However, such conventional devices are limited because of their prohibitively expensive costs and because the devices require thai healthcare providers are present while in use. What is needed in the art, therefore, is a secretion management solution thai cm meet the needs of patients and healthcare providers in a critical care setting by providing an alternative secretion management solution.

SUMMARY

(0006) In an embodiment, there is a system for generating and releasing air pressure in intubated patients. The system can include at least one sensor tor sensing air pressure in an airway, air flow n the airway, or another physiological parameter.. The system can also include an electronic control unit (ECU) in communication with the at least one sensor and can be powered by a power source. The system can also include an airway restrietor in communication with the ECU. The airway restrietor can include a body, an airway disposed in the body comprising at least one of a primary airflow channel and an airflow diversion channel, an actuator, and a valve that can be manipulated by the actuator to: (i) prevent or reduce airflow through either of the primary airflow channel and the airflow diversion channel, (ii) divert airflow from the primary airflo channel to the airflow diversion channel, (iii) allow air from an external air source to reduce air flow out of the airway, or any combination of (I), (ii) and (iii). The ECU can include at least one memory to store data and instructions, and at least one processor configured to access the at least one memory and to execute instructions. The instructions can include: comparing at least one of value comprising at least one of a change in air pressure, air velocity and physiological activity detected by the at least one sensor to at least one predetermined value indicative of a cough even The instructions cm also include activating the airway resirictor to prevent or reduce airflow out of the patient, and deactivating the airway resirictor to restore airflow out of the patient.

|0 07| In another embodiment there is an airway resirictor. The airway resirictor can include a body, an airway comprising at least one of a primary airflow channel and an airflow diversion channel, an actuator, and a valve that can be manipulated by the actuator to: (i) prevent or reduce airflow through either of the primary airflow channel and the airflow diversion channel, (ii) divert airflow from the primary airflow channel to the airflow diversion channel, (iii) allow air from an external air source to reduce air flow out of the airway, or any combination of (i), (ii) and (iii ).

| II08| In yet another embodiment, there is a method for reducing patency of an airway. ^'The method can include monitoring at least one of a value corresponding to an airway air pressure, an airway airflow or a physiological parameter. The method can also include comparing the at least one value to a respective one of a predetermined value, determining the onset of a cough event in a patient, activating an airway resirictor to temporarily generate a pressure gradient in the patient's airway, and deactivating the airway resirictor to release the pressure gradient. The airway resirictor can include a body, an airw y disposed in the body comprising at least one of a primary airflow channel and an airflow diversion channel, an actuator and a valve thai can be manipulated by the actuator to (i) prevent or reduce airflow through either of the primary airflow channel and the airflow diversion channel, (ii) divert airflow from the primary airflow channel to the airflow diversion channel, (iii) allow air from an external air source to reduce air flow out of the airway, or any combination of (i), (ii) and (iii). in the method, deactivating the airway resirictor can include moving the valve to allow airflow through the airway channel

|0009| An advantage of an embodiment includes a device that allows intubated patients who require mechanical ventilation to cough and expel secretions from their lungs, [00101 Additional advantages of the embodimen s will be set forth in part in the description which follows, and in part will be understood from the description, or may be learned by practice of the invention. The advantages will be realised and attained by means of the elements and combinations particularly pointed out in the appended claims.

1_.0011] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.

1 0121 The accompanying drawings, which are incorporated in and constitute a part, of this specification, illustrate embodiments of the invention and together with the description, serve to explain the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

1 013) FIG, J A is a 3 -dime si nal rendering of an embodiment of an air restrictor.

10014] FIG. IB is a perspective vie of an embodiment, for example, of a system for generating and releasing air pressure,

|0Θ15] FIG. 2A is a cross section, of an. air restrictor embodiment.

1_.0016] FIG, 2B is a fop-view of the embodiment shown in FIG. 2A,

(00171 FIG, 2C is a side-view of the embodiment shown In FIG. 2 A.

100181 FiG. 3A is an alternative embodiment of an air restrictor.

(0019) FiG, 3B is an alternative embodiment of an air restrictor.

[0020] FIG 4 is a flow chart of an algorithm for operating an embodiment, for example, the system of FiG. 1A, DESCRIPTION OF THE EMBODIMENTS

{0621} Reference will now be made in detail to the present embodiments, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.

f0822J Notwithstanding that the .numerical ranges and parameters setting forth the broad scope of the invention are approximations, the numerical values set forth in the specific examples are reported as precisel as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements. Moreover, all ranges disclosed herein are to be understood to encompass any and all sub-ranges subsumed therein. For example, a range of "less than 10" can include any and all sub-ranges between (and including) the minimum value of zero and the maximum value of 10, that Is, any and all sub-ranges having a minimum value of equal to or greater than zero and a maximum value of equal to or less than 10, e.g., 1 to 5. In certain eases, the numerical values as stated for the parameter can take on negative values. In this case, the example value of range stated as 'less that. 10" can assume negative values, e.g. 4, -2, -3, - 10, -20, -30, etc.

100231 The following embodiments are described for illustrative purposes only with reference to the Figures. Those of skill in the art will appreciate that the following description is exemplary in nature, and that various modifications to the parameters set forth herein could be made without departing from the scope of the present invention. It is intended that the specification and examples be considered as examples only. The various embodiments are not necessarily mutually exclusive, as some embodiments can be combined with one or more other embodiments to form new embodiments.

0024] Shown in fig. I A is a device, for example, an airway restrictor 100, that can be used for the emulation of a cough, in ventilated patients. In an embodiment, the restrictor 100 ears assist patients who require mechanical ventilation, for example, through an endotracheal tube, to cough and remove secretions from their lungs. Accordingly, it can be integrated in a ventilation circuit and can be connected in series with a mechanical ventilator (not shown). For example, as shown in FIG. 1 A₅ an end (such as at opening 104) of the restrictor 100 can be connected to and placed in gaseous communication with a ventilator tubing 108 which is connected on the other end to a mechanical ventilator (not shown), in an embodiment the airway restrictor can. be connected at another end (such as at opening 102) to endotracheal tube 1 6 connection, such as a wye connector.

|0§251 The airway restrictor can be configured as a ventilator attachment device that can ^"be integrated into the endotracheal tube (ETT). integrated into the patient wye, integrated into any other element of the ventilator circuit, or incorporated rnto the mechanical ventilator (MV) itsel As a ventilator attachment, the airway restrictor m ght attach between the patient wye connector and ETT. to the exhale port of the MV, the MV inlet for exhaled gas, or any other location on the ventilator circuit Lastly, the airway restrictor can be configured to wrap around a flexible section of the standard ventilator circuit, for example, rather than comprise its own airway as described below.

(0O26| Under normal circumstances, air passes through an airway that extends from the ventilator to the patients lungs. For example, air can pass from the ventilator tubing 10S, through an airway (not visible in. FIG, i.A) disposed within a body 1 1 1 of the airway restrictor 1 0, and through an endotracheal tube 106 to the patient's lungs, in addition to the endotracheal or tracheostomy tube, the ventilator circuit can include nebulizers, humidifiers, percussive ventilation devices, the ventilator itself or any other attachments that come in. contact with breathable air provided to the patient rid air exhaled by the patient.

[0027) The airway restrictor 1 0 can be incorporated as part of a system 200 as shown in FIG. 18. Generally, the system can monitor physiological parameters, among other variables, to identify when a patient is likely to cough or exhale forcefully. For example, after the patient inhales, the system can activate the airway restrictor to briefly restrict airflow out of the patient^* s lungs, and then quickly release the restriction to create a spike in exhalation velocity, which can result in the mobilization and removal of mucus or other secretions from the patient's lungs.

(0028) As described further below, the system can first detect when a patient is initiating a cough (a cough event), The system can then be operated such that the airway restrictor is activated as pressure builds in the patient's lungs. At an appropriate time, the restrictor can be deactivated to provide for the release of the built up pressure in a way that creates a similar profile to that of a natural cough. Accordingly, in an embodiment, the entire system or just the airway restrictor can be integrated into a ventilator directly rather than being provided as a ventilator attachment

(0 29} Returning to FIG, I B, the system 200 can be a system for generating and releasing air pressure in a patient. The system can include at least one sensor 107 for sensing air pressure in an airway 105, air flow in the airway 105, or a physiological parameter of a patient The system can also include an electronics control unit (ECU) 1 10 in communication with the at least one sensor 107 and powered by a power source 120. The system can .also include airway restrictor 100 in communication with the ECU, The power source can he batteries, a standard wall outlet, or the mechanical ventilator. Alternatively, the system can be pneumatically powered, for example, by a C02 canister or other pressurized storage method for producing power. Powering the air .restrictor with pneumatics may also require supplemental battery power to control the electronics, whereas the other power sources are not so limited. Additionally, the system can be powered by the mechanical ventilator, for example, airflow or heat source within the ventilator circuit. (0030] As shown in FIG, 2 A, the airway reslrictor 100 can include a body I I I, an airway 105 disposed within the body and comprising at least one of a primary airflow channel 1.03 and an airflow diversion channel .10.1 , an actuator 109 and a valve 109'. Valve 109' can he manipulated by the actuator 10.9 to: (i) prevent or reduce airflow through either of the primary airflow channel and. the airflow diversion channel, (ii) divert airflow from the primary airflow channel to the airflow diversion channel, (Hi) allow air from an external air source to red ce air flow out of the airway (as described further below), or a combination of (i), (si_.) and (in).

[ 031J in an embodiment, the airway reslrictor 100 functions to emulate the purpose of the glottis in a cough. The glottis is a physiological structure that blocks the airway briefly io allow a person to effectively cough. Accordingly, in an embodiment, the closure and release of an airway is accomplished via activation and deactivation, respectively, of the airway restrictor 100 to manipulate the airway .105, such that, it creates a similar profile to that of a natural cough. That is, the actuator 109, which can be a pneumatic or electric actuator, ^'can be activated to, for example, open and close valve 109^".

|0032| In an embodiment, the airflow diversion channel 101 can include a portion of the primary airflow channel 1 3 and can be made of a material tha is more flexible than that of the primary airflow channel. In an embodiment, the airflow diversion channel 101. is in gaseous aim nmi cation with the primary airflow channel, but can provide lower-pressure and/or lower gas flow relative to a pressure and/or gas flow, respectively, through the primar airflow channel. The airway restrieior 100 may also include a port (not shown), in communication with the airway 105, through which bodily fluid can be expelled from the airway, such as upon a cough being emulated via activation and deactivation of the airway restrictof. The airway reslrictor 100 may also inelade a chamber (not shown), into which bodily fluid can be captured for later removal. {8033| The ECU 1 10 can include at least one memory 1 12 to store data and instructions, and at least one processor 11.4 configured to access the at least one memory and to execute instructions. The instructions can include: comparing at feast one of value comprising at least one of a change in air pressure, air velocity and physiological activity detected by the at least one sensor to at least one predetermined value indicative of a cough event. The instructions can also, include activating the airway restrictor to prevent or reduce airflow out of the patient, and deact vating the airway restrictor to restore airflow out of the patient. In other words, the ECU can he utilized to constantly monitor airway parameters to predict when a cough or forced exhalation will occur. It may utilize signals provided by pressure sensors, velocity sensors, flow sensors, or electrornyograms (EMG) to determine when to initiate an airway restriction.

| 834j The exact parameters for glottal closure (i.e., ^restriction parameters") can be determined by elrnieians/earegivers and inputted into the ECU memory, or the parameters can be fixed within the device memory so thai they are the same for all patients. Alternatively, as discussed further below, the parameters can be calculated by the ECU, can be inputted patient parameters, or can be parameters thai are learned by the device after several cough attempts. The ECU may include fail-safe controls that prevent the device from harming the patient. The system may include a user input system thai allows an operator to input values such as, but not limited to, sex, age, and weight of the patient. In other words, the system can also include a user interface that allows users to input information such a specific duration of valve closure, or patient parameters like sex, age, weight, or the like. Alternatively, the processor can execute instructions for an algorithm that allows the system to "lear " from values thai are monitored during prior cough attempts. For example, during an attempted cough, the ECU can monitor airway pressure to identify exactly when the patient is expiring with maximum force. The time from the beginning of exhale to maximum airway pressure can then be used to determine the eration of airway restriction for subsequent coughs.

(0035) The airway 105 may extend through the primary air flow channel 103, from one opening 102 to another opening 104. The airway 105 may extend from opening 102, through a portion of the primary air flow channel, and through the airflow diversion channel 101 to the other opening 1 4, In an embodiment, the airflow diversio channel 101 is a bypass channel that bypasses a portion of the primary airflow channel. Thus, in. an embodiment, instruction, for activating the airway restrictor can he executed by causing the valve 109^' to divert air through the airflow diversion channel.

|β036] The airflow diversion channel. 101 may include a portion of the primary airflow channel 103 through which airflow can be restricted. For example, airflow diversion channel 101 can be a flexible portion of primary airflow channel 1.03 thai can be kinked by the actuator directly or by a valve. Thus, in an embodiment, the step of activating the airway restrictor can include causing the valve to reduce airway 105 patency, such as by creating a kink in a portion of airflow channel 103 to form the airflo diversion channel 101 , and the step of deactivating the airway restrictor can. include restoring airway 105 patency_*

(0037] The actuator ca be an electrically powered linear actuator, servo motor or solenoid that, when activated, changes the shape of the airway to form the kink as described above. Otherwise, when the actuator is not activated, the airway tubing is unmolested and allows air to flow unimpeded. In an embodiment, the airway 105 may be the patient's own airway, such as in an embodiment in which the airway restrictor is configured to wrap around a patient's neck rather than being configured as an attachment to a ventilator circuit.

(00381 The ECU 1 10 may supply power to the actuator, such as for a requisite amount .of time to appropriately increase lung pressure in the patient, or allow the patient to increase lung pressure. For example, the ECU can slow charge a capacitor. Then, after sensing the patient's need to cough, the ECU can discharge the capacitor to power the actuator. The capacitor size determines the duration of closure of the device, and the delay to charge the capacitor prevents constant open-close cycling of the valve, In an embodiment the ECU provides one closure of the airway during exhalation for all patients, but is not so limited and can activate the airway restricior several times if needed to simulate other coughing patterns.

[0039] The ECU 1 10 may be the electronics control unit of a ventilator, and the at least one sensor 10? may be a pressure sensor or flow meter of a ventilator and/or may be a sensor attached to the patient to measure a physiological parameter such as voltage or temperature. Accordingly, the at least one sensor 107 can function as a cough detection element. For example, the sensor ! 07 can be used, to monitor changes in air pressure, air velocity, and/or a physiological parameter such as a parameter related to muscle activ ty (of the patient), to predict a cough. Appropriate sensors, such as pressure sensors, flow meters, and/or electromyograms (E Gs) can be used for the at least one sensor 107,

(01)401 The instructions executed by processor 1 14 can include steps in an algorithm.

For example, in one step of the algorithm, signals provided by the at least one sensor 107, such as signals corresponding to measured voltages, pressures, and/or gas flow velocities, can be converted to numeric values stored in the memory, which in torn can be used by the processor to determine, through additional calculations, the likelihood of an oncoming cough (i.e., a cough event). In an embodiment, the algorithm can he utilized to determine a cough event by comparing a combination of values, such as those deteraiined/measured by the at least one sensor from known locations and known times at which they are measured to predetermined values,

|9041J As described above, the ECU 1 10 may be the electronics control unit of a ventilator. Accordingly, an algorithm similar to that described above can be integrated as a set of instructions stored in a memory of the ventilator's electronics. The ventilator's processor can execute the set of instructions which cm include steps for monitoring airway or physiological parameters to detect an oncoming cough. When a coug is detected, the ventilator can. be placed in a "cough mode" such that the ventilator's ventilation parameters are altered to support cough efforts of the patient. For example, in the cough mode, the ventilator can provide additional pressure or volume support to the patient during inhalation to reach a higher than average inspiratory volume, restrict the airflow (such as by activating the airway restrictor as described herein to allow pressure to build in the patient's .lungs, and i can support the exhale of the patient to generate a pressure gradient and subsequent high velocities to mobilize and remove secretions. During this cough mode the ventilator can also provide oscillatory pressure to further mobilize secretions.

(9042) As shown in FIG. 3 A, in an alternative embodiment 300 of an airflow restrictor, an ECU 1 10 and at least one sensor 1 ? can be disposed in. the airway restrictor body 1 1 1. FIG. 38 shows an alternative embodiment for an airway restrictor 350. ^'The airway restrictor 350 can be configured with a T-shaped airway 105^° as shown disposed in the body H i . The T-shaped airway can comprise the primary airflow channel 103 that extends from the first opening 102 to the second opening 104. Upon activation of the airway restrictor 350. actuator 109 can manipulate valve 109' to allow air through opening 104' and from, for example, an external air source (not shown) into the ventilator circuit. The air from the external air source works to slows air that is leaving the lungs through the airway 105. }9043) FIG. 4 is a flow chart of an algorithm 400 for operating an embodiment, for example, the system of FIG, 2. The algorithm 400 can be a set of instructions retrieved from a memory and executed by a processor such, as the instructions described above. The algorithm can comprise method for restricting patency of an airway. The method can include a repeating sub-process 410^° for continuously monitoring at least one value corresponding to an airway air pressure, an airway airflow and/or a. physiological parameter. For example, a flow meter can be used to determine a patient inhale velocity 401. The flow sensor could be a hot wire mass airflow sensor, pneumotachograph, orifice plate, venture tube, or any other form of flow meter,

\ilM4] In 402 an inhalation volume can he determined from the inhalation velocity and a moving average of the inhalation volume can he detennined in 403. Additionally, a pressure sensor can be used to determine a patient airway pressure as in 405,. A moving average of the patient pressure during exhalatio can be detennined in 407. The moving average of inhalation volume 403 can be used as a set point, or predetermined value, for a volume threshold as in 403'. Likewise, the moving average patient pressure can be used as a set point, or predetermined value, for a pressure threshold as in 40?\

{0Θ45) As shown in step 410, a single breath inhalation volume can be detennined in step 410, which cars be the volume measured in step 402. The method can also include a step of comparing the patient inhalation velocity determined in 410 and/or 401 to the predetermined value, such as the volume threshold determined in 403 \ Likewise, as shown in step 413, an instantaneous exhalation pressure can be detennined, which can he the patient airway pressure collected in step 405. The method can also include a step of comparing the exhalation pressure determined in 413 and/or 405 to the predetermined value, such as the pressure threshold determined in 407'. In an example the pressure measured in 413 can instead be a difference in pressure between a patient-side air pressure (i.e., the pressure in an airway on the patient-side of the air restrictor) and a ventilator-side air pressure (i.e., the pressure in an airway on the ventilator-side of the air restrictor).

1_.0046] The onset of a cough event a patient can be detennined by the comparisons performed in steps 41. 1 and 415. For example, the ECU can monitor for abnormally high flow rates during inspiration by calculating and comparing signals generated by the flow sensor. That is, the ECU calculates the inspiratory volume from the flow rate to identify an abnormally high inspiratory volume. Both high flow rates and high inspiratory volumes are indicative of an oncoming cough. Thus, a measured inhalation volume greater than the volume threshold and/or a measured instantaneous exhalation pressure greater than the pressure threshold can indicate the onset of a cough event. Likewise, the value of the measured single breath inhalation volume, the value of the measured instantaneous exhalation pressure, other physiological parameters, or a combination of the volume, pressure and parameters, can indicate of a cough event if they fall within a predetermined percentage of corresponding predetermined values, such as previously determined values that have been experimentally shown to correspond with a cough event

|0047f It is noted that in ventilated patients, there can be a sharp decrease in airway pressure before a cough that is more pronounced than in healthy patient because of the conflicting actions of the mechanical ventilator. Therefore, a pressure sensor within the airway in cooperation with the ECU can be used for monitoring/detemiming an impending cough. Additionally, a velocity sensor can be utilized to allow the ECU to monitor inhalation velocities, which can indicate an oncoming cough because the inhalation velocity increases during inspiration. The velocity sensor could be a pitot tube (current embodiment), calorimetnc velocity sensor, or any other form of velocity sensor, If a device, like air restrictor 300, is incorporated into the exhale port of the ventilator circuit or ventilator, then a detected/calculated sharp spike in exhalation velocity could he used to indicate a cough. In this case, the air restrictor could be activated several milliseconds after the beginning of the exhale,

[#0 81 During inhalaiion, the sealenes, sieraoclidomastoid, upper trapezius, levator cosiorum, paraspinals and subclavian muscles are activated to increase the inspiratory volume. Accordingly, E G signals generated while monitoring such muscles can be used to identify the onset of a cough or forced exhale for mechanically ventilated patients. That is, the EMG signals generated by these muscles can be used to activate the device, like the air restrictor, for the spec fied closure time.

(00491 Upon determining that a cough event is likely or imminent, the airway restrictor can be activated. Thus, as a patient attempts to cough, pressure can build in the patient-side airway by causing the airway restrictor to restrict the airway as discussed above. In other words, once a cough is detected, the electronic control unit can automatically close an actuation circuit which causes the actuator to energize. The energized actuator can manipulate the valve to close or constrict the airway. The natural contraction of the patient's abdominal and other accessory muscles generates pressure within the lungs. By restricting the airway, for example, for about. 200 to about 500 milliseconds as shown in step 417, a pressure gradient in the patient's airway can be generated. That is, after a specific amount of time, such as a time range that allows sufficient pressure to build in the patient's lungs to produce a cough, the electronic control unit can then re-open the actuation circuit which de- energizes the actuator. The actuator then returns to a powered-off position, which then causes the valve to return to an open or inactive state. In other words, the airway restrictor can be deactivated to release the pressure gradient which results in the emulation of a cough. It is here that mucus and other material may be expelled from the patient^' s lungs and can be suctioned out by a clinician, or alternatively, can be caught via a port portion of the air restrictor. Upon execution of a deactivation step, or if the measured values are not indicative of a cough event, the method cycles again back to step 410.

(OOSOj While the steps for the method described above can be activated automatically via continuous monitoring, the activation of she ai w y restrictor, such as that in step 417, can be initiated manually. For example, upon sensing an impending cough event, the patient may depress a trigger that closes an actuation circuit and energizes actuator 109 of the airway restricior. The patient may then release the trigger which opens the actuation circuit and de- energizes the actuator 109. Of course, a patient can also indicate an impending cough event to another person, such as a clinician, and the clinician can manually trigger the activation of the airway resirictor.

{0651 f While the invention, has been illustrated with respect to one or more implementations, alterations and/or modifications can be made to the illustrated examples without, departing from the spirit and scope of the appended claims. In addition, while a particular feature of the invention may have been disclosed with respect to only one of several implementations, such feature may be combined with one or more other features of the other implementations as may be desired and advantageous for any given or particular function.

[0052] For example, the embodiments described herein are capable of being integrated seamlessly into an intensive care unit (I.CU). Additionally, by allowing patients to safel eliminate mucus from, their lungs, embodiments described herein can improve respiratory function and reduce the risk of secondary infections.

I_.0053J Embodiments described herein can be implemented to monitor airflow and pressure to determine when a patient is about to cough. Thus, when a cough is predicted, an airway for providing breathable air to a patient can be briefly restricted to allow pressure to build in the lungs. A valve can be utilized to restrict, the airway and can then be released to cause a rapid change in pressure that moves mucus out of the lungs,

{0054] In embodiments, the airflow restricior may include a pressure release valve that diverts air from the inlet to the outlet if the airway pressure is above a threshold. The ECU may also trigger the diversion valve if airflow is not detected for a specified amount of time. The diversion air path is a second path for the air to travel. 00S5| Furthermore, to the extent that the terms " nclud ng^", -includes", "having",

"has", "with", or variants thereof are used in either the detailed description, and the claims, such terms are intended to be inclusive in a manner similar to the term "comprising." As used herein, the phrase "One or more of, for example. A, 8, and C means any of the following; either A, 8, or C alone; or combinations of two, such as A and 8, 8 and C, .and A and C; or combinations of three A, B and C.

[ΘΘ56| Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the follo wing claims.

Claims

WHAT IS CLAIMED IS:

1. A system for generating and releasing air pressure, the system comprising;

at leas one sensor for sensing air pressure in an airway, air flow in the airway, of a physiological parameter,

an electronic control unit (ECU) in communication with the at least one sensor and powered by a power source,

an airway restrictor in communication with the ECU, the airway restrictor comprising: a body;

an airway disposed i the body and comprising at least one of a primary airflow channel and an airflow diversion channel,

an actuator, and

a valve manipulated by the actuator to; (i) prevent or reduce airflow through cither of the primary airflow channel and the airflow diversion channel., (ii) divert airflow from the primary airflow channel to the airflow diversion channel, (ill) allow air from an external air source to .reduce air flow out of the airway, or any combination of (i), (ii) and (in),

wherein the ECU comprises at least, one memory to store data and instructions, and at least one processor configured to access the at least one memory and to execute instructions, the instructions comprising:

comparing at least one of value comprising at least one of a change in air pressure, air velocity and physiological activity detected by the at least one sensor to at least one predetermined value indicative of a cough event ,

activating the airway restrictor to prevent or reduce airflow out of the patient, and

deactivating the airway restrictor to restore airflow oat of the patient.

2. The system of claim L wherein activating the airway restrictor comprises causing the valve to divert air through the airflow diversion channel.

3. The system of claim t, wherein activating the airway restrictor comprises causing the valve to reduce airway patency and wherein deactivating the airway restrictor comprises restoring airway patency.

4. The system of claim 3, wherein the airway comprises the patient's airway or the primary a flow channel.

5. The system of claim h further comprising a port in communication with the airway and through which bodily fluid can be expelled.

6. The system of claim 1 , wherein the at least one sensor comprises a pressure sensor, a flo w meter or an dectromyogram (EMG),

7. The system of claim 1 , wherein the airway restrictor is integrated into an endotracheal tube, an external air tube, a patient wye, or a mechanical ventilator.

8. The system of claim I, wherein the airway restrictor is incorporated into an airway circuit of a mechanical ventilation system,

9. The system of claim L wherein the power source comprises a wall, outlet or batteries.

10. The system of claim 1 _f wherein the power source is connected to a. pneumatic power source comprising a pressurized storage vessel

1 1. An airway restrictor, comprising:

a body;

an airway disposed, in the body and comprising at least one of a primary airflow channel and an airflow diversion channel;

an actuator; and

a valve manipulated by the actuator to: (i) prevent or reduce airflow through either of the primary airflow channel and the airflow diversion channel, (ii) divert airflow from the primary airflow channel to the airflow diversion channel, (iii) allow air from an external air source to reduce air flow out of the airway, or any combination of ( i), (ii) and (iii).

12. The airway restrictor of claim 1 L further comprising at least one sensor for sensing air pressure in an airway, air flow in the airway, or a physiological parameter.

13. The airway restrictor of claim 1 .1 , further comprising a port in communication with the airway and through which bodily fluid can he expelled.

14. The airway restrictor of claim 1 1 , further comprising an actuator for controlling the valve, wherein the actuator comprises an electronic or a pneumatic actuator.

15. The airway restrictor of claim 1 1 , wherein the airflow diversion channel comprises a section of the primary airflow channel that is made of a material that is more flexible than that of the primary airflow channel.

16. A. method for reducing patency of an airway, comprising;

monitoring at least one of a value corresponding to an airway an pressure, an airway airflow or a physiological parameter;

comparing the at .least one value to a respective one of a predetermined value;

determining the onset of a cough event in a patient;

activating airway restrictor to temporarily generate a pressure gradient in the patien s airway; and

deactivating the airway restrictor to release the pressure gradient;

wherein the airway restrictor comprises

a body,

an airway disposed in. the body and comprising at least one of a primary airflow channel and an airflow diversion channel,

an actuator, and

a valve thai can be manipulated by the actuator, and

wherein activating the airway restrictor comprises energizing the actuator to manipulate the valve tor: (i) preventing or reducing airflow through either of the primary airflow channel and the airflow diversion channel, (is) diverting airflow from the primary airflow channel to the airflow diversion channel, (in) allowing air from an external air source to reduce air flow out of the airway, or perform any combination of (i). (is) and (Hi), and

wherein, deactivating the airway restrictor comprises moving the valve to allow airflow through the airway channel.

17. The method of claim 15, wherein determining the onset of a cough event comprises calculating that the at least one value is within a predetermined percentage of the respective one of the at least one predetermined value,

18. The method of claim 15, wherein a time between the activating and the deactivating is selected from the range of about 200 to about 500 milliseconds,

1 . The method of claim 15, wherein the airway air pressure comprises a difference between a patient-side air pressure and a ventilator-side air pressure.

20. The method of claim 15, wherein determining the onset of a cough event comprises manually closing an actuation circuit to energise the actuator.