Patent Publication Number: US-2015059750-A1

Title: Apparatus and method for maintaining airway patency and pressure support ventilation

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The instant application is a continuation-in-part of application Ser. No. 12/897,809, now U.S. Pat. No. ______, filed Oct. 5, 2010, which claimed benefit of provisional application Ser. No. 61/249,323 filed Oct. 7, 2009 and provisional application Ser. No. 61/258,257 filed Nov. 5, 2009, the disclosures of all of which are incorporated herein by reference. 
    
    
     BACKGROUND 
     1. Field of the Invention 
     The invention relates to the modification of pre-existing airflow generation means to produce a pressurized airflow burst or flow of air directed into the nasopharyngeal airway or trachea of the patient as a patient&#39;s inhalation action continues or is caused to occur. 
     2. Description of the Related Art 
     Breathing disorders or respiratory related problems widely exist for conditions such as sleep apnea, ventilation support, pharmaceutical delivery systems, and manual resuscitation. A new study suggests that CPAP therapy reduces nightmares in veterans with post-traumatic stress disorder (PTSD) and obstructive sleep apnea (OSA), and CPAP machines could indeed become an alternative treatment for those with asthma. Each of these conditions requires a system, method and apparatus for treatment. Several of these markets are sustained today by a related line of products each having one thing in common, namely pressurized ventilation support referred to as Positive Airway Pressure (PAP). In most cases conditions are treated by a continuous positive pressure air source or a continuous positive pressure gas source. At times there may be variations such as a bi-level positive pressure air or gas source delivered by a self contained product for comfort. Unfortunately there are several circumstances where a continuous positive pressure air or gas source is not comfortable, reasonable or useful and a standard bi-level product is cost prohibitive. 
     In the case of Obstructive Sleep Apnea or OSA, the gold standard remains to be a continuous positive pressure of air, which is uncomfortable to say the least. Many patients cannot tolerate the application of continuous positive airway pressure, particularly because of the discomfort associated with exhalation against a continuous positive pressure or the dryness that accompanies this type of delivery. A solution has been developed to alleviate this problem by the addition of a method and apparatus, to an existing continuous positive pressure of air, which converts a substantially constant elevated airway pressure to the patient&#39;s airway, with periodic short term reductions of the elevated airway pressure to a pressure of lesser magnitude. A further advance in such treatment involves the application of alternative high and low-level positive airway pressure wherein the low-level pressure coincides with the breath exhalation of the patient&#39;s breathing cycle. 
     Although more expensive devices may be available that provide relief upon exhalation, they are cost-prohibitive, designed for a single use and tightly regulated by insurance companies. In some cases no device is available at all. By providing a limited reuse/disposable add on or in some cases a durable add on regulating device, the cost, hygiene and comfort for these patients become palatable. 
     In addition, when different drugs, including oxygen, are delivered to a patient via continuous pressure the drug amount is difficult to regulate because breathing rates differ from patient to patient. Take the case of a comatose or mentally handicapped patient. Coordinating inhalation of drug delivery with the breathing cycle is impossible. Yet, with a bi-level attachment to oxygen or a continuous air delivery system, an appropriate treatment amount is delivered and waste is minimized. 
     There are several bi-level apparatus devices available. Each has a specific use and is self-contained. Some are manually manipulated. However, there is no method or device that can be added to an existing continuous positive air or gas source which will convert them for the application and delivery of bi-level positive airway pressure to a patient. 
     The systems, methods and apparatus disclosed in the prior art for treating patients afflicted with such maladies as sleep apnea, snoring, ventilation support and pharmaceutical delivery present a number of problems which need to be addressed. The equipment utilized in such treatment is far too limiting. In the case of sleep apnea, the air stream delivered to the patient tends to dehydrate the nasopharyngeal tissue. The unnatural sensation and discomfort experienced by the patient in overcoming the positive pressure during exhalation results in many patients abandoning the use of a system that is in all other respects quite beneficial. An alternative, much more expensive device is rejected by many insurance companies. By supplying a device as a simple add-on product it is possible to convert these devices to a comfortable useful source of treatment, as follows. 
     SUMMARY 
     It is the objective of the instant invention to provide a device which may be added to any continuous positive air pressure (CPAP) or gas source be it in the home, hospital or via emergency medical treatment. 
     It is further the objective of the invention to lessen the unnatural sensation and discomfort experienced by the patient in overcoming the traditional positive pressure during breath exhalation. 
     It is further the objective of the invention to supply the device as a simple add-on product to convert these traditional CPAP units to a useful source of treatment without considerable expense. 
     Accordingly, what is provided is an assembly for modifying airflow into a nasopharyngeal airway or trachea of a patient, comprising a valve assembly adapted to attach to an airflow generator, wherein the airflow generator is a continuous blower of a type producing a constant head of pressurized air, the valve assembly having two ends, an inlet and an outlet defined between each of the ends, and an interior feed tube, the valve assembly further comprising a motor means signaled by the airflow disposed at one of the ends and underlying the inlet. A valve seal is connected to and operable by the motor means, the valve seal underlying the outlet and adapted to cycle within the interior feed tube between the motor means and across the outlet. A controller circuit is connected to the motor means for operating the motor means incrementally; and, wherein upon activation of both the airflow generator and the controller circuit, pressurized air from the airflow generator continuously enters the interior feed tube from the inlet but passes out of the outlet only when the motor means causes the valve seal to move in relation to the exit tube to at least partially unblock the outlet such that the pressurized air is converted into a single, repeatable burst exiting the outlet. 
     In one embodiment the feed tube is axially aligned with the inlet and the outlet, and in an alternative embodiment the feed tube underlies both the inlet and the outlet to form the valve assembly as generally U-shaped. 
     Instead of a motor, the valve assembly can include a shaft at the proximal end within the feed tube, the shaft having a bottom shaft end and a top shaft end, the top shaft end terminating exterior to a top of the feed tube and the bottom shaft end terminating exterior to a bottom of the feed tube to form the shaft perpendicular to the feed tube. A butterfly valve seal is attached to the shaft within the feed tube. A nickel titanium wire is in conductive communication with the shaft. A switch is programmed by a controller circuit, the switch signaled by the airflow and connected to the nickel titanium wire for incrementally charging and contracting the nickel titanium wire upon voltage being applied thereto; and, wherein upon activation of both the airflow generator and the controller circuit, pressurized air from the airflow generator continuously enters the feed tube but passes out of the feed tube only when the nickel titanium wire causes the butterfly valve seal to partially rotate within the feed tube to at least partially unblock the outlet such that the pressurized air is converted into a single, repeatable burst exiting the outlet. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a schematic representation and partial elevational view of the instant invention. 
         FIG. 2  shows an elevational view in partial section illustrating an alternative embodiment of the valve of the present invention. 
         FIGS. 3 and 4  show elevational views in vertical section illustrating further embodiments of the apparatus valve of the present invention. 
         FIG. 5  shows an elevational view in vertical section illustrating still another alternative form of the system. 
         FIG. 6  shows perspective views of certain components intended for other valve embodiments. 
         FIG. 7  shows an elevational view in vertical section illustrating a valve assembly in which a parallel tube is utilized for exiting exhalation air. 
         FIG. 8  shows an elevational view in vertical section illustrating a valve assembly in which a single, straight tube is utilized for both inhalation and exhalation such that the motor means for controlling the valve seal is external to the tube. 
         FIG. 9  shows an elevational view in vertical section of an alternative embodiment of a valve assembly in closed position and the butterfly valve in an open position allowing pressurized air to advance to the patient, and wherein the motor means excludes a solenoid and alternatively takes the form of Nitinol wire. 
         FIG. 10  shows an elevational view in vertical section of the same embodiment of  FIG. 9  but in a valve-open position. 
         FIG. 11  shows an elevational view in vertical section of a similar embodiment of  FIGS. 9 and 10  but wherein a variation of the exhalation valve takes the form of a thin tube section within a tube. 
         FIG. 12  shows a blown-up elevational view of the slip clutch shown in  FIG. 9  used to open and close the valve. 
         FIG. 13  shows a blown-up elevational view of an alternative embodiment of the slip clutch. 
         FIG. 14  shows a blown-up elevational view of an even further embodiment of the slip clutch used to open and close the valve. 
         FIG. 15  shows a blown-up elevational view of an embodiment of the Nitinol wire in communication directly with the shaft of the butterfly valve and coupled to a return spring. 
         FIG. 16  shows a blown-up elevational view in vertical section of an embodiment similar to  FIG. 10  with the valve in an open position but further including, for exhalation, multiple, funnel-shaped vents used to reduce exhalation noise. 
     
    
    
     Dotted line arrows are shown to depict the direction of patient exhaled breath flow. Solid line arrows mark the air stream flow path of air drawn into the apparatus. 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The invention will now be described in detail in relation to a preferred embodiment and implementation thereof which is exemplary in nature and descriptively specific as disclosed. As is customary, it will be understood that no limitation of the scope of the invention is thereby intended. The invention encompasses such alterations and further modifications and applications as would normally occur to persons skilled in the art to which the invention relates. This detailed description of this invention is not meant to limit the invention, but is meant to provide a detailed disclosure of the best mode of practicing the invention. 
     With reference then to  FIGS. 1-6 , illustrated is an assembly  10  which includes valve assembly  16 , a programmable controller circuit  12  encoded by programmer  8 , a normally-open electrical switch/sensor  18 , and a patient interface device  20  such as a mask, tracheal tube, nasal cannula or similar patient interface, and an optional drug delivery port  19 . 
     Valve assembly  16  has two ends  16   c ,  16   d , an inlet  16   a , an outlet  16   b , and an interior feed tube  7 . Valve assembly  16  further includes an electromagnetic solenoid  14  typically disposed proximate end  16   c , opposite exit tube  4 , which is defined at end  16   d . Instead of a solenoid  14  any type of motor means may be implemented such a stepping motor. Motor means as used herein therefore encompasses any type of motor, but preferably a solenoid  14 . 
     The airflow generator  9 , which is separate from and later attached to the device, may be in the form of a blower or fan of the type used to produce a pressurized airflow, hospital wall air or compressed bottled air or gas. Airflow generator or airflow generator means therefore is used herein to define any type of blower, fan, hospital wall air, compressed air, or any traditional positive airway pressure (PAP) device, including oxygen, already attached to the same. The solid line arrows mark the air stream flow path, beginning with air drawn into the apparatus from the airflow generator  9  as indicated by arrow  22 . 
     The electric current to operate the apparatus is supplied through conductors  24  and  26 , which also supply current to solenoid  14  and switch  18 . The airflow generator  9  is intended to operate continuously whereby a constant head of pressurized air is maintained. However, the solenoid  14  is at rest and will permit full air passage there through to the valve assembly  16  only when the solenoid  14  is charged by switch  18 . 
     The valve assembly  16  of  FIG. 1  further includes a flexible or rigid valve seal  28  such as a circular disc, ball or joined split ball, with the flexible valve mounted to the plunger rod  11  of solenoid  14  plunger rod  11 . In alternate, the use of a slotted tube within two additional separated tubes may act as a valve (not shown). Valve seal  28  is preferably seated within the interior feed tube  7  and is operable by solenoid  14 , adapted to cycle within the feed tube  7  between solenoid  14  and exit tube  4 , across outlet  16   b . Valve seal  28  can alternatively be placed directly within exit tube  4 , which would place valve seal  28  more proximate to end  16   c , so use of “within feed tube  7 ” is meant to encompass any location throughout the interior of valve assembly  16  since exit tube  7  is formed within the interior of valve assembly  16 . In its relaxed position (shown), the valve seal  28  will at least partially cover and seal the outlet  16   b  or aperture of the therapy airflow or end  16   d  of the exit tube. The valve seal  28 , in this case, is a member which normally seals against the inside surface of the feed tube  7  but will open in response to airflow passing the switch (an attempt to inhale) which signals solenoid  14  to charge (not shown) and seal against the exit tube  4  which allows the airflow to pass through the valve arrangement out of outlet  16   b , the switch and thence into the patient via a patient interface device  20 . “Member” as used herein can mean any shape, e.g. circular, square, etc. depending on the inside surface of the feed tube  7  as long as the seal closes against the feed tube  7 . 
     It should be noted that the patient interface  20  and valve assembly  16  will allow unassisted inhalation and exhalation by the patient to permit entry of ambient air when the valve is in the “at rest” position. The patient interface  20  is meant to be worn in sealed relation to a patient whereby ambient air during inhalation will pass into the patient interface past valve seal  28 . Exhaled breath will pass through switch  18  whereby the breath flow will be in the direction of the dotted line arrow  38 , and into the valve assembly  16 . Exhaled breath pressure entering the valve assembly  16  passes by the valve seal  28  which is now closed and seated against the feed tube  7 , and through exit tube  4  to ambient. A return spring  40  allows the solenoid plunger rod  11  to return to its original position upstream from said outlet  16   b  (towards inlet  16   a ). This return action of the solenoid sets the switch internally whereby, as the solenoid  14  relaxes, the valve seal  28  will return back to its original position and at the same time close off the release of pressurized air or gas to complete the electrical circuit to the solenoid  14 . The solenoid  14  is thereby caused to cycle open and then re-close after having permitted a “burst” of pressurized air to move into the valve assembly  16  and past the valve seal  28  out of outlet  16   b  and past the switch  18  and into the patient interface  20 . The pressurized airflow burst is directed into the nasopharyngeal airway or trachea of the patient as the patient&#39;s inhalation action occurs, and ambient air moves through valve  16  to allow the patient to complete the breath intake voluntarily. The subsequent exhalation by the patient repeats the described process whereby a pulse, burst of pressurized air is delivered to the patient interface  20  and thence to the patient&#39;s airway as a function of each breathing cycle. An additional feature triggers the pressurized gas flow by way of an adjustable timing device should the patient not attempt to inhale himself. It should be understood that “burst” used herein and in the claims refers to a burst or flow of air of any duration and degree. For example, the produced burst can emulate that of an MPAP, or Metered Positive Airway Pressure device, wherein the burst terminates and slowly dissipates in pressure. The burst can also emulate that of a bi-level design wherein the burst has two levels of constant pressure, namely a higher level of constant therapeutic pressure upon inhalation along with a constant lower level of therapeutic pressure upon exhalation. 
     The pressurized airflow burst is adjustable by way of the controller circuit  12  which is encoded by way of the programmer  8 . The adjustments include, but are not limited to, ramp up time, length of burst, sensitivity of the switch/sensor, timed release of burst or any combination of these settings, should they be required. The programmer  8  is linked to the control circuit by way of a cable  3  which is rigidly connected to the programmer  8  but which is detachable from the control circuit  12 . Once the preferred settings have been programmed into the control circuit they will remain fixed until changed by reconnecting the programming box  8  and the settings are adjusted to alternate values. The values appear on a viewing screen  6  and are set via a navigation button  5 . An additional embodiment allows the programmer  8  and control circuit  12  to be combined into a single enclosure or with cable  3  rigidly connected to both the program box and the control circuit  12  for hospital use, EMS use, testing, etc. The valve assembly  10  is attached to a traditional CPAP unit or traditional constant airflow generator  9  as above, which will convert that traditional CPAP unit or traditional airflow generator into a device providing an intermittent and adjustable air stream (gas), into a therapeutic burst, puff, bolus or flow of air to a patient during inhalation. By this means the patient is able to receive an air supply or concentration of gas, given as a single, but repeatable dose to achieve an immediate effect in transit through assembly  10  and by way of patient interface  20 . The system and method thus can be utilized with pre-existing airflow generation means already implemented in homes, centers and hospitals, thereby varying the traditional constant airflow with use of the instant accessory. An assisted burst of gas given during inhalation or inspiration at the beginning of each breath will prevent collapse or maintain the upper airway, reduce inspiratory WOB (work of breathing), reduce expiratory WOB and reduce or prevent the dryness related to continuous positive airway pressure. The assisted burst itself raises the concentration in the body to a therapeutic level while allowing comfort to the patient. This is accomplished to allow the patient to finish inspiration himself and to exhale against little or no therapeutic pressure. The bolus provided is adjustable and tapers off over a period of time during the inspiration cycle, thus allowing it to maintain positive pressure throughout most of the inhalation process which will promote gas exchange in the alveoli and also keep open smaller airways. A certain amount of natural resistance experienced upon exhale through the exhalation circuit. There may be times when a greater or therapeutic pressure upon exhale is desired or required, the use of devices such as a positive end-expiratory pressure (PEEP) valve may be added to tube  4  or by the addition of a similar restrictive device being incorporated or added into the breathing circuit. As above, should it be desirable, a continuous therapeutic flow of positive pressure air upon inhalation along with a lower level of therapeutic positive pressure airflow during exhalation could result. 
     In some cases additional medication is required. The installation of the optional drug delivery port  19  allows the introduction of inhalable medication. Because of the assembly  10  configuration, the delivery port can be added instantly without harm to the patient or alternatively it can be applied initially and with the entry port  21  being capped until needed. 
     As opposed to CPAP or continuous ventilation this method allows an infinite control of therapeutic air or gas flow during non invasive ventilation which is critical, especially in neonates. Assembly  10  provides the clinician a means of providing safety and comfort for those who cannot speak for themselves. 
     Although  FIG. 1  broadly illustrates the underlying system and method of the present invention, the use of different valves, sensors and components are possible. In lieu of solenoid  14  a stepping motor or similar control (not shown) may be used to control the pressurized air/gas delivery by rotating a seal within valve assembly  16 . However, additional components similar to those shown in  FIG. 2  would be required. 
       FIG. 2  shows a sliding tube valve seal  17 , whereby it replaces the above mentioned valve seal  28  with a slotted, hollow tube. The sliding tube valve seal  17  is connected to the solenoid valve  14  by way of plunger rod  11  and closes off air pressure when the solenoid  14  is relaxed as shown. At least one slot  17   a  is defined within the outer shell of the hollow tube. A seal or wall  15  positioned beyond slot  17   a  and within the sliding tube valve seal  17  directs the flow of air to the patient when the tube is pushed forward by the solenoid valve. In addition, the sliding tube valve seal  17  directs the flow of exhaled air from the patient through exit tube  4  to atmosphere. An additional hole or exhalation slot  17   b  or other means to allow the exhaled air to re-enter the hollow tube and proceed to exit tube  4  is defined on the other side of wall  15 . The placement of the slots  17   a ,  17   b  in the tube may be adjustable or fixed in order to control both the inhalation and exhalation pressures. The sliding tube valve seal  17  slides freely within the feed tube  7  and exit tube  4  and is controlled by way of the solenoid  14 . 
     In alternate, a second method and device for converting a constant airflow generator to a multi-level therapeutic device by way of assembly  10  attached to a CPAP unit or traditional constant airflow generator,  12  will convert a traditional CPAP unit or traditional airflow generator into a device providing an adjustable air stream or gas, into multiple pressurized therapeutic air flows and delivering them to a patient. 
     The device is able to deliver bi-level or multiple levels of therapeutic flows of air or gas to a patient. A patient may receive one or more levels of pressurized air upon inhalation and one or more lower levels of pressurized air upon exhalation. This may be accomplished in several ways such as by leaving valve  28  open or partially open at all times and regulating the distance between valve  28  and feed tube  7  during inhalation. Thus one or more elevated pressures is delivered to patient through assembly valve  16 , switch  18  and patient interface  20  upon inhalation while bleeding off the excess air and pressure through tube  4 . The valve  28  would then partially adjust to a predetermined position or predetermined positions for exhale creating a lower exhalation pressure or multiple lower exhalation pressures. This could allow a bleed off of air by way of tube  4 . Although not necessary, for a split second valve  28  could close against feed tube  7  and start the cycle over or the-add on device could just switch back to the higher level upon inhalation. 
     As a third method and device, seal  28  could close off or partially close off against tube  4  during inhalation and then open the exit port for exhalation to release a predetermined amount of air flow and pressurized air to cause the required pressure drop. The process would then repeat itself as described previously. 
       FIG. 3  and  FIG. 4  illustrate smaller versions of the assembly  16  in that the airflow is controlled in a straight tube and components are more compact. 
       FIG. 5  shows a fourth method and device wherein the return spring  40  may be positioned between the solenoid  14  and valve seal  28  and will be of sufficient strength to control the flow of air or gas coming from the constant air flow generator. In this embodiment the spring is compressed when the solenoid  14  is charged allowing the air flow and pressure to increase to a therapeutic level. When the solenoid  14  is at rest the air flow is restricted to a lower level or may be shut off completely. Ventilation holes  33  or slots, allow exhalation of the patient and provide ambient air should a power failure occur. In addition, these ventilation holes  33  may be restricted or sealed in order to regulate inhalation and/or exhalation pressure. As an alternate, (not shown) the return spring may be positioned within the solenoid itself between the back end of the solenoid and the tip of the plunger  11 . Accordingly, “attached to” as used in relation to the spring and solenoid means the spring can be attached to the exterior of the solenoid or be integrated within the solenoid. As previously stated seal  28  could close off or partially close off against tube  4  during inhalation and then increase open the exit port for exhalation to release a predetermined amount of air flow and pressurized air to cause the required pressure drop. The process would then repeat itself as described previously. 
     In any of the apparatuses and methods above, the use of sliding tube valve seal  17  (slotted tube of  FIG. 2 ) in place of the seal  28  is possible. Furthermore, with reference to  FIG. 6 , several controlling configurations as shown may be used in place of the sliding tube valve seal  17  in  FIG. 2  or in place of valve seal  28  on  FIG. 5 . Any of the valve seals can be keyed by use of a slot  34  and guide. The guide may be a pin, key, roller or any variation of these. Accordingly, “tube valve seal” as defined herein means any shape of tube shown and described above and by the alternative embodiments of  FIG. 6  and their obvious variations, the critical feature of which require some form of wall  28  or solid end to act as a seal and a defined slot  17   a  ( FIG. 2 ) or opening to allow airflow to pass out of the tube valve seal. As in the first method the valve seal  28  can be a circular soft or rigid member which normally seals against the inside surface of the feed tube  16  on  FIG. 5 . The seal mates against or close to the face of a now split or two piece tube (not shown) but will respond to airflow passing the switch (an attempt to inhale) which signals solenoid  31  to charge (not shown) which allows the airflow to pass through the valve arrangement out of outlet  16   b , the switch  18  and thence into the patient via a patient interface device  20 . In alternate, solenoid  14  may also be made to respond to exhalation when continuous airflow during inhalation is present. In such a case valve  28  is will regulate the airflow in relation to exit tube  4 . 
     In the above embodiments it can be seen that the valve assembly  16  can take on various shapes, depending on the type of housing (not shown), valve seal  28 , and other characteristics. In one embodiment, and as shown by  FIG. 7 , the air flow  22  can be allowed to make right turns into an exit tube  4  which is parallel to feed tube  7 . Such may be desirable for generally rectangular housing shapes, and an open fiber type muffler material can be placed near the end of the valve seal  28  if desirable. Here, the motor means or solenoid  14  is still disposed at or near the proximal end  16   c  of the valve assembly  16  but the valve seal  28  and solenoid  14  both are situated underlying the exit tube  4  and entry chamber  70 . In this embodiment the outlet is formed as exit tube  4  and inlet is formed as entry chamber  70 . Namely, shown is valve assembly  16  including solenoid  14  and valve seal  28  within feed tube  7  underlying both an entry chamber  70  near the proximal end  16   c  and the exit tube  4  (outlet) near the distal end  16   d  to form the assembly generally as being U-shaped. “Underlying” therefore means the feed tube  7  containing therein the solenoid  14  is not in line with the center axes of the exit tube  4  (outlet) and entry chamber  70  (inlet). 
     In the above embodiments the “motor means” includes some type of mechanical motor, e.g. a solenoid. The solenoid  14  can be placed at various locations. As shown in the above embodiments the solenoid  14  is at the end of the valve assembly  16  but inside the valve assembly  16  feed tube  7 . In an alternative embodiment and as shown by  FIG. 8 , it is possible to place the solenoid  14  outside the feed tube  7 . Omitted then are in-line exit tubes and entry chambers, wherein outlet  4  is the exit defined as a hole. Whereas above an in-line piston or in-line plunger rod  11  is attached to the solenoid  14  in a U-shaped fashion when combined with the tubing, shown by  FIG. 8  is a “straight-through” design of the valve assembly  16 . In order to accomplish this the solenoid  14  is moved outside the tubing or feed tube  7 . Generally then the solenoid  14  is outside of the air circuit. The plunger rod  11  is still used as a sliding piston or valve on the solenoid  14  but the solenoid  14  is disposed outside of the straight tubing with the valve seal  28  extending upward from the solenoid  14 . The plunger rod  11  extends upward perpendicularly from the motor means then bends to align with the motor means such the valve seal  28  moves above the motor means in alignment with the feed tube  7  such that it can still be situated to move laterally within the tubing. The straight-through design enhances pressure control, requires fewer parts, is easier to assemble, easier to clean and more cost-effective to manufacture. 
     In the above embodiments the valve seal and tube valve seal move laterally within or against the feed tube (or the exit tube). It should be understood that another seal embodiment may be a butterfly valve intended to accomplish the same results, however in this embodiment the valve would move an approximate quarter-turn rotationally. Therefore, in either instance of the valve seal, tube valve seal, or butterfly valve, as used in the claims, the valve will cycle back and forth in relation to the outlet and exit tube and “cycle” either laterally or rotationally. 
       FIGS. 9-16  show rotational sealing using a butterfly valve  71  as the valve seal. Additionally, in the aforementioned embodiments, although the tube arrangement and motor placement can vary as shown, the “motor means” continues to include some type of mechanical motor, e.g. a solenoid. Shown with continued reference to  FIGS. 9-15  is an embodiment using a wire  72  and shaft  73  to move the rotational butterfly valve  71 . 
     Specifically, shown is a valve assembly  16  including a valve seal formed as a butterfly valve  71 . Since the function is equivalent to that disclosed herein, butterfly valve  71  conforms to inside of interior feed tube  7  and partially opens during inhalation and then returns to its original resting for exhalation. The process would then repeat itself as described previously. The herein disclosed controller circuits  12  ( FIG. 1 ) and switches  18  ( FIG. 1 ) are similarly used for this embodiment, the connections and other differences as follows. 
     Butterfly valve  71  is disposed proximate to one proximal end  16   c  of a single feed tube  7  within a valve assembly  16  adapted to attach to an airflow generator  9  ( FIG. 1 ). Proximal end  16   c  is end of tube  7  which is most opposite the point of entry of exhaled patient breath. Therefore, distal end  16   d  is the end of tube  7  nearest the mouthpiece, hence, farthest from source of generated airflow. 
     Butterfly valve  71  is attached a pivot shaft  73 . Shaft  73  is a perpendicular rod relative to feed tube disposed through the butterfly valve  71  along the center axis of rotation having a top shaft end  73   a  and bottom shaft end  73   b . Top shaft end  73   a  terminates exterior to the top  74  of the tube  7  and bottom shaft end  73   b  terminates exterior to the bottom  75  of the tube  7  to anchor and maintain the butterfly valve  71  in a rotationally fixed position within the tube  7  (top and bottom used for differentiation only as the orientation of the tube may vary). 
     In one embodiment, attached to bottom shaft end  73   b  is a clutch  82 . The exact structural form of the clutch  82  can vary, such as by using a clutch  82  of the wrap spring type or cam type. The clutch  82  can be as simple as a single wrap of the wire around the bottom shaft end  73   b  or in alternative is a direct drive through the use of a lever/tension spring combination or a cam, idler roller or floating gear train on a lever perpendicular to the shaft  73 . The clutch  82  may also include an elastic band  80  ( FIG. 13 ) or clutch spring  81  at the top shaft end  73   a  ( FIG. 12 ) or secondary torsion spring  82   a  ( FIG. 14 ) as a means for urging the butterfly valve  71  to its originally closed position depending on the type of clutch  82  used, the elastic band  80  or valve return spring  81  having one end connected to the top shaft end  73   a  as shown or being wrapped thereon. 
     In this continued embodiment, instead of an actual solenoid, butterfly valve  71  opens and closes using the combination of the clutch  82  and one or more nickel titanium wires  72 , i.e. the metal alloy of nickel and titanium commonly known as Nitinol  72 . Due to its shape-memory characteristics, the Nitinol  72  acts as a “motor” by contracting with voltage, and it can then relax or be stretched using a return spring  86  or other means. As before, the electric current to operate the apparatus is supplied through wires (only one shown) to conductors  24  and  26 , which also supplies current to the Nitinol  72  and switch  18  ( FIG. 1  also). Recall the airflow generator  9  is intended to operate continuously whereby a constant head of pressurized air is maintained. When the Nitinol  72  is in an un-contracted, resting state, air passage through the tube  7  is halted or restricted, and state change occurs only when the Nitinol  72  is charged by switch  18  and contracts, as follows. 
     Bottom shaft end  73   b  of shaft  73  forms a segment around which is disposed a torsion spring  82 , also known as a wrap spring clutch. It should be understood that the bottom shaft end  73   b  may or may not include the torsion spring  82  depending on the type of clutch used, so the Nitinol in “conductive communication” with the shaft means with or without a clutch. The Nitinol may be wedged between two cams, one attached to the main shaft and one attached a side arm. Other possible clutch types include Idler rollers or floating gears with sway arms. In the preferred embodiment, however, a torsion spring  82  is present. Torsion spring  82  can vary in cross-section to be a normal round wire or a square wire, which makes more contact with the bottom shaft to increase grip thereon. Further included on bottom shaft or bottom shaft end  73   b  is a mounting plate  83 , on which an electrical contact  84  is connected. One end of the Nitinol  72  is connected to the electrical contact  84 . The other end of the Nitinol  72  is connected to the other electrical contact at the other end of the feed tube  7 , for instance at post  85  which acts as both an anchor for the Nitinol  72  and the positive or negative terminal since electrical polarity is required (pair of terminal posts mounted to the valve assembly are a means for anchoring and polarizing the Nitinol  72 ). Upon voltage being applied, the Nitinol  72  contracts, thereby pulling on torsion spring  82 , as a result rotating butterfly valve  71 . Because Nitinol  72  takes time to relax from its contracted state, the Nitinol  72 , as a means for being urged from its contracted state, can be urged by being stretched using a return spring  86  which is preferably mounted with one end to an anchor  87 , the other end attached to the Nitinol  72 . As an alternative means, the return spring  86  for the Nitinol  72  can be connected to the wrap spring slip clutch or in alternate, directly to a Butterfly shaft side lever or directly to the Nitinol, if a slip clutch is not used. For instance, referencing  FIG. 15 , the Nitinol can be wrapped directly around the Butterfly valve shaft  73  instead of using a standard type wrap spring clutch. The Nitinol is wrapped around the shaft  73 , forms a loop, which is closed off and connected to a solder ring  82   b  for instance. One end of the return spring  82  is then connected to the solder ring  82   b  and the other end of the return spring  82  is connected to the anchor  87 . 
     The type of exhalation valve  88  covering outlet  4  may vary according to but not limited to the embodiments of  FIGS. 10 ,  11 , and  16  and is critical only by its capability to release exhaled breath from the feed tube  7  through outlet  4  defined through top  74  of feed tube  7 . Any type of mechanical valve can be used.  FIG. 10  shows the exhalation valve  88  in an open-position, attached within interior of feed tube  7 . In this embodiment the exhalation valve  88  is a flapper valve hingedly attached to top  74  of feed tube  7 .  FIG. 11  shows an embodiment of the exhalation valve  88  which takes the form a thin tube section within a larger tube, the larger tube connected to a rigid or flexible member such as a connector band  91  which closes when the butterfly valve  71  opens and which opens for exhalation when the air flow is shut-off. With reference to  FIG. 16 , one or more funnels  89  disposed across outlet  4  can also be used. Here, the butterfly valve  71 , when open, seals off the funnels  89  and thus allows the air to flow thru the tube  7  and switch (valve and air flow shown in dotted line). When the butterfly valve  71  is closed (valve and air flow shown in solid line) air from the CPAP unit is sealed off and the patient exhales thru the funnels  89  (funnel shaped vents), the exact number of which may vary. 
     In use therefore, upon inhalation, switch  18  ( FIG. 1 ) programmed by controller circuit  12  ( FIG. 1 ) charges the Nitinol  72 . The Nitinol  72  immediately contracts to open butterfly valve  71 . An exhalation valve  88  at the top of the feed tube  7  closes until the Nitinol  72  stops contracting. The Nitinol then expands and releases and releases the shaft  73  attached to the butterfly valve  71 . This shuts off the airflow and opens the exhalation valve  88 . The cycle then repeats with each breath.