WO2016161399A2

WO2016161399A2 - Within-breath variable positive airway pressure device

Info

Publication number: WO2016161399A2
Application number: PCT/US2016/025784
Authority: WO
Inventors: Bradley Fuhrman
Original assignee: Texas Tech University System
Priority date: 2015-04-02
Filing date: 2016-04-02
Publication date: 2016-10-06
Also published as: WO2016161399A3

Abstract

A system, method, and apparatus for providing variable expiratory pressure comprises an expiratory chamber in operable communication with an expiratory pathway; a valve within the expiratory chamber wherein the valve comprises an orifice; and a control module configured to alter an area of the orifice wherein the area of the orifice is altered to vary backpressure in the expiratory pathway over the course of expiration.

Description

WITHIN-BREATH VARIABLE POSITIVE AIRWAY PRESSURE DEVICE

FIELD OF THE INVENTION

[0001] Embodiments are generally related to the field of medical devices. Embodiments are also related to methods, systems, and devices for regulating expiratory pressure. Embodiments are further related to expiratory positive airway pressure. Embodiments are further related to methods, systems, and apparatuses for providing within-breath variable positive airway pressure.

BACKGROUND

[0002] Alveolar or airway collapse during the expiratory phase of breathing is a major concern in many medical applications. Expiratory positive airway pressure (EPAP) devices are used to prevent such collapse. EPAP devices are employed in the treatment of patients at risk of airway or alveolar collapse, acute or chronic respiratory disease, to avert or treat hypoxia, for acute or chronic respiratory failure, or by patients requiring mechanical ventilation.

[0003] There are several means of creating EPAP. The expiratory pathway may be pressurized, which produces resistance to externally provided flow such that continuous positive airway pressure (CPAP) is generated in the expiratory path. However, such expiratory air is generally directed through a valve which produces fixed backpressure. Prior art devices thus produce EPAP that is fixed in magnitude throughout expiration.

[0004] Over the course of a single expiration, lung volume decreases. At the end of expiration, alveolar spaces are smallest. Thus, it is at the end of expiration that alveolar collapse occurs most commonly. However, prior art methods do not set adjust backpressure based on the understanding that alveolar collapse most often occurs at the end of expiration.

[0005] Positive End-Expiratory Pressure (PEEP) was introduced in clinical medicine largely in response to the needs of infants with immature lungs prone to collapse toward the end of expiration. While PEEP is known to maintain alveolar patency, excessive PEEP may also impair filling of the heart and impede circulation by creating high backpressure throughout expiration.

[0006] The airway compression seen in patients with Chronic Obstructive Pulmonary Disease (COPD), Emphysema, Asthma, Bronchiolitis, Bronchomalacia, Tracheomalacia, and other such maladies may begin early in expiration, and, if prevented, be inconsequential later in expiration. Accordingly, there is a need in the art for methods and systems that provide EPAP that avoids hyperinflation, which is an unwanted side effect in the use of PEEP, and minimizes the effects of constant expiratory backpressure on circulation.

SUMMARY

[0007] The following summary is provided to facilitate an understanding of some of the innovative features unique to the embodiments disclosed and is not intended to be a full description. A full appreciation of the various aspects of the embodiments can be gained by taking the entire specification, claims, drawings, and abstract as a whole.

[0008] It is, therefore, one aspect of the disclosed embodiments to provide a method, system, and apparatus for regulating expiratory pressure.

[0009] It is another aspect of the disclosed embodiments to provide a method, system, and apparatus for a within-breath variable expiratory positive airway pressure device.

[0010] The aforementioned aspects and other objectives and advantages can now be achieved as described herein. A system and method for providing variable expiratory pressure comprises an expiratory chamber in operable communication with an expiratory pathway, a valve within the expiratory chamber wherein the valve comprises an orifice, and a control module configured to alter an area of the orifice wherein the area of the orifice is altered to vary backpressure in the expiratory pathway over the course of expiration.

[0011] In an embodiment the control module comprises a tensioning member operably connected to a partially obstructing member wherein the tensioning member modulates an obstruction of the orifice. In another embodiment of the system, an airflow velocity module is configured to measure airflow velocity in the expiratory pathway wherein the control module is configured to adjust the orifice area according to the airflow velocity. The airflow velocity module can comprise a pneumotachometer. In another embodiment, the valve further comprises an aperture adjustment member.

[0012] In another embodiment, the control module comprises a computer and an operable connection to the aperture adjustment member wherein an expiration algorithm is executed by the computer to adjust the aperture adjustment member to alter the orifice area in order to thereby create a timed partition of optimal orifice areas during expiration.

[0013] In yet another embodiment, the system further comprises a backpressure module for measuring a backpressure in the expiratory pathway wherein the backpressure module is in operable communication with the computer. The backpressure module can comprise a manometer.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The accompanying figures, in which like reference numerals refer to identical or functionally-similar elements throughout the separate views and which are incorporated in and form a part of the specification, further illustrate the embodiments and, together with the detailed description, serve to explain the embodiments disclosed herein.

[0015] FIG. 1 depicts a block diagram of a computer system which is implemented in accordance with the disclosed embodiments;

[0016] FIG. 2 depicts a graphical representation of a network of data-processing devices in which aspects of the present invention may be implemented;

[0017] FIG. 3 depicts a computer software system for directing the operation of the data-processing system depicted in FIG. 1 , in accordance with an embodiment of the invention;

[0018] FIG. 4 depicts a system for varying positive airway pressure in accordance with an embodiment of the present invention;

[0019] FIG. 5 depicts chart illustrating back pressure as a function of flow rate in accordance with an embodiment of the present invention;

[0020] FIG. 6 depicts a system for varying positive airway pressure in accordance with another embodiment of the present invention;

[0021] FIG. 7 depicts steps associated with a system and method for varying positive airway pressure in accordance with embodiments of the present invention;

[0022] FIG. 8A depicts steps associated with a system and method for varying positive airway pressure in accordance with embodiments of the present invention; and [0023] FIG. 8B depicts steps associated with a system and method for varying positive airway pressure in accordance with embodiments of the present invention.

DETAILED DESCRIPTION

[0024] Subject matter will now be described more fully hereinafter with reference to the accompanying drawings, which form a part hereof, and which show, by way of illustration, specific example embodiments. Subject matter may, however, be embodied in a variety of different forms and, therefore, covered or claimed subject matter is intended to be construed as not being limited to any example embodiments set forth herein; example embodiments are provided merely to be illustrative. Likewise, a reasonably broad scope for claimed or covered subject matter is intended. Among other things, for example, subject matter may be embodied as methods, devices, components, or systems. Accordingly, embodiments may, for example, take the form of hardware, software, firmware, or any combination thereof (other than software per se). The following detailed description is therefore, not intended to be taken in a limiting sense.

[0025] Throughout the specification and claims, terms may have nuanced meanings suggested or implied in context beyond an explicitly stated meaning. Likewise, the phrase "in one embodiment" as used herein does not necessarily refer to the same embodiment, and the phrase "in another embodiment" as used herein does not necessarily refer to a different embodiment. It is intended, for example, that claimed subject matter include combinations of example embodiments in whole or in part.

[0026] In general, terminology may be understood, at least in part, from usage in context. For example, terms, such as "and", "or", or "and/or," as used herein may include a variety of meanings that may depend, at least in part, upon the context in which such terms are used. Typically, "or" if used to associate a list, such as A, B, or C, is intended to mean A, B, and C, here used in the inclusive sense, as well as A, B, or C, here used in the exclusive sense. In addition, the term "one or more" as used herein, depending at least in part upon context, may be used to describe any feature, structure, or characteristic in a singular sense or may be used to describe combinations of features, structures or characteristics in a plural sense. Similarly, terms such as "a," "an," or "the," again, may be understood to convey a singular usage or to convey a plural usage, depending at least in part upon context. In addition, the term "based on" may be understood as not necessarily intended to convey an exclusive set of factors and may, instead, allow for existence of additional factors not necessarily expressly described, again, depending at least in part on context.

[0027] FIGS. 1 -3 are provided as exemplary diagrams of data-processing environments in which embodiments of the present invention may be implemented. It should be appreciated that FIGS. 1 -3 are only exemplary and are not intended to assert or imply any limitation with regard to the environments in which aspects or embodiments of the disclosed embodiments may be implemented. Many modifications to the depicted environments may be made without departing from the spirit and scope of the disclosed embodiments.

[0028] A block diagram of a computer system 100 that executes programming for implementing parts of the methods and systems disclosed herein is shown in FIG. 1 . A computing device in the form of a computer 1 10 configured to interface with sensors, peripheral devices, and other elements disclosed herein may include one or more processing units 102, memory 104, removable storage 1 12, and non-removable storage 1 14. Memory 104 may include volatile memory 106 and non-volatile memory 108. Computer 1 10 may include or have access to a computing environment that includes a variety of transitory and non-transitory computer-readable media such as volatile memory 106 and non-volatile memory 108, removable storage 1 12 and non-removable storage 1 14. Computer storage includes, for example, random access memory (RAM), read only memory (ROM), erasable programmable read-only memory (EPROM) and electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, compact disc read-only memory (CD ROM), Digital Versatile Disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage, or other magnetic storage devices, or any other medium capable of storing computer-readable instructions as well as data including image data.

[0029] Computer 1 10 may include or have access to a computing environment that includes input 1 16, output 1 18, and a communication connection 120. The computer may operate in a networked environment using a communication connection 120 to connect to one or more remote computers, remote sensors, medical devices, hand-held devices, multi-function devices (MFDs), mobile devices, tablet devices, mobile phones, Smartphone, or other such devices. The remote computer may also include a personal computer (PC), server, router, network PC, a peer device or other common network node, or the like. The communication connection may include a Local Area Network (LAN), a Wide Area Network (WAN), Bluetooth connection, or other networks. This functionality is described more fully in the description associated with FIG. 2 below.

[0030] Output 1 18 is most commonly provided as a computer monitor, but may include any output device. Output 1 18 and/or input 1 16 may include a data collection apparatus associated with computer system 100. In addition, input 1 16, which commonly includes a computer keyboard and/or pointing device such as a computer mouse, computer track pad, or the like, allows a user to select and instruct computer system 100. A user interface can be provided using output 1 18 and input 1 16. Output 1 18 may function as a display for displaying data and information for a user and for interactively displaying a graphical user interface (GUI) 130.

[0031] Note that the term "GUI" generally refers to a type of environment that represents programs, files, options, and so forth by means of graphically displayed icons, menus, and dialog boxes on a computer monitor screen. A user can interact with the GUI to select and activate such options by directly touching the screen and/or pointing and clicking with a user input device 1 16 such as, for example, a pointing device such as a mouse and/or with a keyboard. A particular item can function in the same manner to the user in all applications because the GUI provides standard software routines (e.g., module 125) to handle these elements and report the user's actions. The GUI can further be used to display the electronic service image frames as discussed below.

[0032] Computer-readable instructions, for example, program module or node 125, which can be representative of other modules or nodes described herein, are stored on a computer-readable medium and are executable by the processing unit 102 of computer 1 10. Program module or node 125 may include a computer application. A hard drive, CD-ROM, RAM, Flash Memory, and a USB drive are just some examples of articles including a computer-readable medium.

[0033] FIG. 2 depicts a graphical representation of a network of data-processing systems 200 in which aspects of the present invention may be implemented. Network data-processing system 200 is a network of computers or other such devices such as mobile phones, smartphones, sensors, medical devices, MFDs, and the like in which embodiments of the present invention may be implemented. Note that the system 200 can be implemented in the context of a software module such as program module 125. The system 200 includes a network 202 in communication with one or more clients 210, 212, and 214. Network 202 may also be in communication with one or more sensors/actuators 204, servers 206, and storage 208. Network 202 is a medium that can be used to provide communications links between various devices and computers connected together within a networked data processing system such as computer system 100. Network 202 may include connections such as wired communication links, wireless communication links of various types, and fiber optic cables. Network 202 can communicate with one or more servers 206, one or more external devices such as sensors/actuator 204, and a memory storage unit such as, for example, memory or database 208. It should be understood that sensor/actuator 204 may be embodied as a medical device, medical sensor, control module, controller, receiver, or other such device.

[0034] In the depicted example, sensor/actuator 204, server 206, and clients 210, 212, and 214 connect to network 202 along with storage unit 208. Clients 210, 212, and 214 may be, for example, personal computers or network computers, handheld devices, mobile devices, tablet devices, smartphones, personal digital assistants, printing devices, recording devices, MFDs, etc. Computer system 100 depicted in FIG. 1 can be, for example, a client such as client 210 and/or 212.

[0035] Computer system 100 can also be implemented as a server such as server 206, depending upon design considerations. In the depicted example, server 206 provides data such as boot files, operating system images, applications, and application updates to clients 210, 212, and/or 214. Clients 210, 212, and 214 and sensor/actuator 204 are clients to server 206 in this example. Network data-processing system 200 may include additional servers, clients, and other devices not shown. Specifically, clients may connect to any member of a network of servers, which provide equivalent content.

[0036] In the depicted example, network data-processing system 200 is the Internet with network 202 representing a worldwide collection of networks and gateways that use the Transmission Control Protocol/Internet Protocol (TCP/IP) suite of protocols to communicate with one another. At the heart of the Internet is a backbone of high-speed data communication lines between major nodes or host computers consisting of thousands of commercial, government, educational, and other computer systems that route data and messages. Of course, network data-processing system 200 may also be implemented as a number of different types of networks such as, for example, an intranet, a local area network (LAN), or a wide area network (WAN). FIGS. 1 and 2 are intended as examples and not as architectural limitations for different embodiments of the present invention.

[0037] FIG. 3 illustrates a software system 300, which may be employed for directing the operation of the data-processing systems such as computer system 100 depicted in FIG. 1 . Software application 305, may be stored in memory 104, on removable storage 1 12, or on non-removable storage 1 14 shown in FIG. 1 , and generally includes and/or is associated with a kernel or operating system 310 and a shell or interface 315. One or more application programs, such as module(s) or node(s) 125, may be "loaded" (i.e., transferred from removable storage 1 12 into the memory 104) for execution by the data- processing system 100. The data-processing system 100 can receive user commands and data through user interface 315, which can include input 1 16 and output 1 18, accessible by a user 320. These inputs may then be acted upon by the computer system 100 in accordance with instructions from operating system 310 and/or software application 305 and any software module(s) 125 thereof. [0038] Generally, program modules (e.g., module 125) can include, but are not limited to, routines, subroutines, software applications, programs, objects, components, data structures, etc., that perform particular tasks or implement particular abstract data types and instructions. Moreover, those skilled in the art will appreciate that elements of the disclosed methods and systems may be practiced with other computer system configurations such as, for example, hand-held devices, mobile phones, smartphones, tablet devices, multi-processor systems, printers, copiers, fax machines, multi-function devices, data networks, microprocessor-based or programmable consumer electronics, networked personal computers, minicomputers, mainframe computers, servers, medical equipment, medical devices, and the like.

[0039] Note that the term module or node as utilized herein may refer to a collection of routines and data structures that perform a particular task or implements a particular abstract data type. Modules may be composed of two parts: an interface, which lists the constants, data types, variable, and routines that can be accessed by other modules or routines; and an implementation, which is typically private (accessible only to that module) and which includes source code that actually implements the routines in the module. The term module may also simply refer to an application such as a computer program designed to assist in the performance of a specific task such as word processing, accounting, inventory management, etc., or a hardware component designed to equivalent^ assist in the performance of a task.

[0040] The interface 315 (e.g., a graphical user interface 130) can serve to display results, whereupon a user 320 may supply additional inputs or terminate a particular session. In some embodiments, operating system 310 and GUI 130 can be implemented in the context of a "windows" system. It can be appreciated, of course, that other types of systems are possible. For example, rather than a traditional "windows" system, other operation systems such as, for example, a real time operating system (RTOS) more commonly employed in wireless systems may also be employed with respect to operating system 310 and interface 315. The software application 305 can include, for example, module(s) 125, which can include instructions for carrying out steps or logical operations such as those shown and described herein. [0041] The following description is presented with respect to embodiments of the present invention, which can be embodied in the context of, or require the use of a data- processing system such as computer system 100, in conjunction with program module 125, and data-processing system 200 and network 202 depicted in FIGS. 1 -3. The present invention, however, is not limited to any particular application or any particular environment. Instead, those skilled in the art will find that the system and method of the present invention may be advantageously applied to a variety of system and application software including database management systems, word processors, and the like. Moreover, the present invention may be embodied on a variety of different platforms including Windows, Macintosh, UNIX, LINUX, Android, and the like. Therefore, the descriptions of the exemplary embodiments, which follow, are for purposes of illustration and not considered a limitation.

[0042] Expiratory positive airway pressure (EPAP) methods and systems as described in the embodiments herein are used to prevent alveolar and/or airway collapse during the expiratory phase of breathing. Such systems may be applied externally to a patient's face or by way of tubes inserted into the patient's nose, mouth, or trachea. The EPAP devices described herein generally comprise an expiratory breathing pathway, which includes a valve to create backpressure.

[0043] In the embodiments disclosed herein, the expiratory pathway may be pressurized at its exhaust port by a valve which produces resistance to externally provided flow such that continuous positive airway pressure (CPAP) is generated in the expiratory path.

[0044] The EPAP devices disclosed herein may be useful for patients at risk of airway or alveolar collapse during quiet sleep. They may be used to prevent airway or alveolar collapse in the face of acute or chronic respiratory disease, and to avert or treat hypoxia. The embodiments disclosed herein are also useful for patients suffering from acute or chronic respiratory failure who require mechanical ventilation among other things. Given this wide spectrum of patient need, in some embodiments the EPAP devices disclosed herein may be incorporated into mechanical ventilators, attached to mechanical ventilators, or applied to the expiratory pathway of spontaneously breathing patients who are not on ventilators.

[0045] Many clinical situations require variable backpressure during expiration. The airway compression seen in patients with Chronic Obstructive Pulmonary Disease (COPD), Emphysema, Asthma, Bronchiolitis, Bronchomalacia, and Tracheomalacia may begin early in expiration, and, if prevented, be inconsequential later in expiration. Once the lungs have adequately emptied, little backpressure may be required. The embodiments disclosed herein preserve airway patency while minimizing the need for backpressure at end-expiration. In conditions characterized primarily by dynamic airway compression, the methods and systems disclosed herein may also be used to avoid hyperinflation (an unwanted side-effect of the use of PEEP), and minimize the effects of constant expiratory backpressure on circulation.

[0046] In contrast to existing expiratory backpressure devices, the embodiments disclosed herein make use of flow restrictor technology where backpressure is created by restriction of the cross-sectional area of the opening of an orifice in the expiratory pathway. The pressure drop (backpressure) across such an orifice is proportional to the square of the velocity of flow. Thus, generally speaking the pressure drop is greater early in expiration than later in expiration. Accordingly, in various embodiments of such a flow restrictor, the orifice area may further be a function of velocity of airflow. Because backpressure is inversely proportional to the square of the orifice area, in certain embodiments, the orifice area may be subject to either manual or computerized control within the course of the breath.

[0047] FIG. 4 illustrates an exemplary embodiment of a system 400 for within-breath variable positive airway pressure control. The system comprises a nozzle used as a flow restrictor to generate backpressure during expiration 415 by a patient into a mouthpiece 420. In this embodiment, expiratory airflow 415 moves a float 405 against a tensioning device or spring 410 into an orifice 425. A greater velocity of flow, presses float 405 against spring 410 into orifice 425, effectively obstructing orifice 425. The more obstructive float 405 is, the more restrictive the orifice 425 is of airflow. This effectively results in greater backpressure. As the velocity of airflow 415 decreases toward the end of expiration, the float 405 backs away from the spring 410, enlarging the effective size of orifice 425 and reducing the backpressure. For any given orifice 425 area, backpressure is also a direct function of flow rate. This arrangement allows backpressure to vary widely across expiration. There may be large differences in the range of backpressures and flows required by individuals. As such the system 400 allows individualization of the starting distance from float 405 to spring 410.

[0048] The system 400 can comprise two segments, segment 430 and segment 435, respectively, joined by a threaded region 440 which allows the segments 430 and 435 to screw together effectively forming a chamber. The spring 410 may be fixed to an outlet 465. The orifice 425 is incorporated into the proximal segment 430 of the system 400. As the segments 430 and 435 are progressively screwed into one another, the orifice 425 of the nozzle approaches the float 405. The distance between the orifice 425 and float 405 can thus be set by the progressive engagement of the two segments 430 and 435 via threaded region 440. At any given setting, this fixes the orifice area at "no flow". Thus, at each setting, an individualized flow-backpressure relationship is established.

[0049] Segment 430 may further include a mounting bracket 445 and guide assembly 450. The segment 430 may also include a pressure transducer 455 operably connected to a computer system 100 or other such device. Segment 435 may further include a pneumotach 460, which may also be operably connected to computer system 100 and to the chamber formed by segments 430 and 435.

[0050] The system 400 is configured to adjust the size of orifice 425, as a function of the airflow 415 velocity. As the patient exhales, the size of orifice 425, through which the expiratory air 415 is flowing, is automatically adjusted. As the speed of the airflow 415 decreases during expiration the float 405 backs away from the orifice 425 according to spring 410, enlarging the effective size of orifice 425 and reducing the backpressure. Backpressure is a direct function of airflow rate. Thus, by controlling the orifice 425 size the backpressure experienced by the patient is automatically adjusted such that the backpressure experienced by the patient is automatically reduced.

[0051] It should be appreciated that in other embodiments, pneumotach 460 and/or pressure transducer 455 may be used to measure and report the backpressure experienced by the patient to a computer 100 in real time. An actuator may be actuated according to commands from computer 100 to adjust float 405 and thereby adjust the backpressure. The desired backpressure for each instant during expiration may be provided in advance to computer 100, or may be determined algorithmically. Computer 100 may adjust the float according to the information provided by the pneumotach 460 and pressure transducer 455 in real time so that the backpressure matches the desired backpressure provided to the computer 100.

[0052] FIG. 5 illustrates a chart 500 of expiratory backpressure as a function of flow rate. Chart 500 illustrates that as flow rate increases, the backpressure increases dramatically. This is a result of the fact that backpressure is inversely proportional to the square of an orifice area.

[0053] FIG. 6 illustrates another embodiment of a system 600 in which orifice area, or the aperture 610 of an iris 605 may be altered in order to generate backpressure during expiration 415 by a patient. In this embodiment the aperture 610 of iris 605 contained in chamber 435 can be altered electronically or mechanically over the course of expiration. This creates flow, area, and backpressure relationships that may be measured by a sensor, and computed and manipulated by an algorithm implemented with a program module on a computer 100.

[0054] System 600 can include a pneumotach 460 and transducer 455. During expiration the pneumotach 460 and transducer 455 can collect and report measurements of airflow 415 velocity and pressure respectively. The pneumotach output 620 and transducer output 625 can be provided to a computer system such as computer system 100 via wireless or wired communication, as illustrated in FIG. 2, for real time processing. The computer system 100 can be used to algorithmically adjust the iris or aperture 610 area via an iris control module 615. In this way the effective size of aperture 610 is adjusted, increasing or reducing the backpressure in real time over the course of patient expiration. Computer system 100 and/or program module 125 may include a digital select module, curve select module, iris control module, digital display, USB input or output port, etc. for control of the settings, controls, and displays associated with the system 600.

[0055] Any of the embodiments illustrated above may be coupled with measurements of pressure and flow that allow algorithmic control of airway patency via program module 125. The algorithm may be derived from the relationship illustrated in chart 500 so that the patient experiences variable expiratory airway pressure, and in particular experiences reduced airway pressure at the end of expiration.

[0056] FIG. 7 illustrates a set of logical steps 700 associated with a method for providing variable expiratory pressure. The method begins at block 705. At block 710, an apparatus including system 400 and/or system 600, illustrated in FIGS. 4 and 6 respectively, are arranged in an expiratory pathway of a patient. This may include operable connection to the patient directly via a mouthpiece or connection to a ventilator, CPAP machine, or other such machine in line with the patient's expiratory pathway. Next at block 715, the patient begins to exhale. As the patient exhales, the size of an orifice or aperture through which the expiratory air is flowing is adjusted as shown at block 720. Backpressure is a direct function of airflow rate. Thus, by controlling the aperture or orifice size, the backpressure experienced by the patient is also controlled as illustrated by block 725. As the airflow rate decreases naturally during the course of the patient's expiration, the backpressure experienced by the patient is systematically reduced. At block 730, the patient completes expiration. It should be understood that the method steps 715 through 730 illustrated in FIG. 7 may be repeated indefinitely as the patient breaths. The method ends at 735.

[0057] Method step 720 illustrated in FIG. 7 is particularly important. The adjustment of the orifice can be accomplished in multiple ways. FIGS. 8A and 8B illustrate methods of adjusting the orifice or aperture as described in step 720. In FIG. 8A, the method step 720 begins at block 805. At block 810, the patient's expiration pushes the float in the nozzle against the opposing tensioning device. This moves the float toward the orifice as shown at 815 block effectively reducing the orifice size and increasing the backpressure experienced by the patient. As the expiratory airflow velocity decreases at block 820, the opposing force in the tensioning device drives the float back away from the orifice effectively increasing the orifice size and decreasing backpressure experienced by the patient. The method ends at block 825.

[0058] In another embodiment illustrated in FIG. 8B, the method step 720 begins at block 905. At block 910, the patient's expiration creates an airflow velocity and backpressure which are measured in real time. At block 915, the measurements are provided to a computer via wireless or wired communication. At block 920, an algorithm, based in principle on the relationship illustrated in chart 500 in FIG. 5, is used to determine the real time desired backpressure for the patient. The desired backpressure is used to determine the desired orifice size or aperture. At block 925, a signal from the computer system provided by wireless or wired communication to a control module/actuator can be used to adjust the float to effectively reduce or enlarge the orifice size, and by extension the back pressure experienced by the patient. An arrow is provided from block 925 to block 915 to indicate that the steps are dynamic and can be done in real time. Thus, during and after the float is adjusted at block 925, measurements can be taken at block 915 and the method is iterated during the patient's expiration. The method then ends at block 935.

[0059] Alternatively, at block 930 a signal from the computer system provided by wireless or wired communication to a control module can be used to adjust the iris 605 aperture 610 to effectively reduce or enlarge the aperture size, and by extension, the back pressure. An arrow is provided from block 930 to block 915 to indicate that the steps are dynamic and can be done in real time. Thus, during and after the aperture 610 is adjusted at block 930, measurements can be taken at block 915 and method is iterated during the patient's expiration. The method then ends at block 935.

[0060] Based on the foregoing, it can be appreciated that a number of embodiments, preferred and alternative, are disclosed herein. For example, in one embodiment, a system for providing variable expiratory pressure comprises an expiratory chamber in operable communication with an expiratory pathway, a valve within the expiratory chamber wherein the valve comprises an orifice, and a control module configured to alter an area of the orifice wherein the area of the orifice is altered to vary backpressure in the expiratory pathway over the course of expiration.

[0061] In another embodiment, the control module comprises a tensioning member operably connected to a partially obstructing member wherein the tensioning member modulates an obstruction of the orifice.

[0062] In another embodiment of the system, an airflow velocity module is configured to measure airflow velocity in the expiratory pathway wherein the control module is configured to adjust the orifice area according to the airflow velocity. The airflow velocity module can comprise a pneumotachometer. In another embodiment, the valve further comprises an aperture adjustment member.

[0063] In another embodiment, the control module comprises a computer, and an operable connection to the aperture adjustment member wherein an expiration algorithm is executed by the computer to adjust the aperture adjustment member to alter the orifice area in order to thereby create a timed partition of optimal orifice areas during expiration.

[0064] In another embodiment, the system further comprises a backpressure module for measuring a backpressure in the expiratory pathway wherein the backpressure module is in operable communication with the computer. The backpressure module can comprise a manometer.

[0065] In another embodiment, a method for providing variable expiratory pressure comprises inserting an expiratory chamber in an expiratory pathway, accepting an expiration in the expiratory chamber through a valve within the expiratory chamber wherein the valve comprises an orifice, and altering an area of the orifice with a control module to vary backpressure in the expiratory pathway over the course of expiration.

[0066] In another embodiment, the method further comprises modulating an obstruction of the orifice with the control module wherein the control module comprises a tensioning member operably connected to a partially obstructing member.

[0067] In another embodiment, the method further comprises measuring an airflow velocity in the expiratory pathway with an airflow velocity module and adjusting the orifice area according to the airflow velocity with the control module. In another embodiment, the airflow velocity module comprises a pneumotachometer. In another embodiment, the valve further comprises an aperture adjustment member.

[0068] In another embodiment, the method further comprises executing an expiration adjustment algorithm with a computer in order to provide a timed partition of optimal orifice areas during expiration, and altering the orifice area with the aperture adjustment member according to the expiration adjustment algorithm.

[0069] In another embodiment, the method further comprises measuring a backpressure in the expiratory pathway with a backpressure module. The backpressure module can further comprise a manometer.

[0070] In yet another embodiment, a variable expiratory pressure apparatus comprises an expiratory chamber in operable communication with an expiratory pathway, a valve within the expiratory chamber wherein the valve comprises an orifice, and a control module configured to alter an area of the orifice wherein the area of the orifice is altered to vary backpressure in the expiratory pathway over the course of expiration.

[0071] In another embodiment of the variable expiratory pressure apparatus, the control module comprises a tensioning member operably connected to a partially obstructing member wherein the tensioning member modulates an obstruction of the orifice. [0072] In another embodiment, the variable expiratory pressure apparatus further comprises a pneumotachometer configured to measure airflow velocity in the expiratory pathway wherein the control module is configured to adjust the orifice area according to the airflow velocity.

[0073] In another embodiment, the variable expiratory pressure apparatus further comprises a manometer for measuring a backpressure in the expiratory pathway wherein the backpressure module is in operable communication with the computer, wherein the control module comprises a computer, and an operable connection to the aperture adjustment member wherein an expiration algorithm is executed by the computer to adjust the aperture adjustment member to alter the orifice area in order to thereby create a timed partition of optimal orifice areas during expiration.

[0074] It will be appreciated that variations of the above-disclosed and other features and functions, or alternatives thereof, may be desirably combined into many other different systems or applications. Also, it should be understood that various presently unforeseen or unanticipated alternatives, modifications, variations or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims.

Claims

CLAIMS What is claimed is:

1 . A system for providing variable expiratory pressure comprising:

an expiratory chamber in operable communication with an expiratory pathway; a valve within said expiratory chamber wherein said valve comprises an orifice; and

a control module configured to alter an area of said orifice wherein the area of said orifice is altered to vary backpressure in said expiratory pathway over the course of expiration.

2. The system of claim 1 wherein said control module comprises a tensioning member operably connected to a partially obstructing member wherein said tensioning member modulates an obstruction of said orifice.

3. The system of claim 1 further comprising an airflow velocity module configured to measure airflow velocity in said expiratory pathway wherein said control module is configured to adjust said orifice area according to said airflow velocity.

4. The system of claim 3 wherein said airflow velocity module comprises a pneumotachometer.

5. The system of claim 1 wherein said valve further comprises an aperture adjustment member.

6. The system of claim 5 wherein said control module comprises:

a computer; and

an operable connection to said aperture adjustment member wherein an expiration algorithm is executed by said computer to adjust said aperture adjustment member to alter said orifice area in order to thereby create a timed partition of optimal orifice areas during expiration.

7. The system 6 further comprising a backpressure module for measuring a backpressure in said expiratory pathway wherein said backpressure module is in operable communication with said computer.

8. The system of claim 7 wherein said backpressure module comprises a manometer.

9. A method for providing variable expiratory pressure comprising:

inserting an expiratory chamber in an expiratory pathway;

accepting an expiration in said expiratory chamber through a valve within said expiratory chamber wherein said valve comprises an orifice; and

altering an area of said orifice with a control module to vary backpressure in said expiratory pathway over the course of expiration.

10. The method of claim 9 further comprising:

modulating an obstruction of said orifice with said control module wherein said control module comprises a tensioning member operably connected to a partially obstructing member.

1 1 . The method of claim 9 further comprising:

measuring an airflow velocity in said expiratory pathway with an airflow velocity module; and

adjusting said orifice area according to said airflow velocity with said control module.

12. The method of claim 1 1 wherein said airflow velocity module comprises a pneumotachometer.

13. The method of claim 9 wherein said valve further comprises an aperture adjustment member.

14. The method of claim 13 further comprising: executing an expiration adjustment algorithm with a computer in order to provide a timed partition of optimal orifice areas during expiration; and

altering said orifice area with said aperture adjustment member according to said expiration adjustment algorithm.

15. The method of claim 14 further comprising:

measuring a backpressure in said expiratory pathway with a backpressure module.

16. The method of claim 15 wherein said backpressure module comprises a manometer.

17. A variable expiratory pressure apparatus comprising:

18. The variable expiratory pressure apparatus of claim 17 wherein said control module comprises a tensioning member operably connected to a partially obstructing member wherein said tensioning member modulates an obstruction of said orifice.

19. The variable expiratory pressure apparatus of claim 17 further comprising a pneumotachometer configured to measure airflow velocity in said expiratory pathway wherein said control module is configured to adjust said orifice area according to said airflow velocity.

20. The variable expiratory pressure apparatus of claim 19 further comprising: a manometer for measuring a backpressure in said expiratory pathway wherein said backpressure module is in operable communication with said computer, wherein said control module comprises:

a computer; and