Abstract:
An oscillating positive expiratory pressure apparatus having a housing defining a chamber, a chamber inlet, a chamber outlet, a deformable restrictor member positioned in an exhalation flow path between the chamber inlet and the chamber outlet, and an oscillation member disposed within the chamber. The deformable restrictor member and the oscillation member are moveable between an engaged position, where the oscillation member is in contact with the deformable restrictor member and an disengaged position, where the oscillation member is not in contact with the deformable restrictor member. The deformable restrictor member and the oscillation member move from the engaged position to the disengaged position in response to a first exhalation pressure at the chamber inlet, and move from the disengaged position to an engaged position in response to a second exhalation pressure at the chamber inlet.

Description:
RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Application No. 61/109,075, filed on Oct. 28, 2008, pending, which is incorporated herein by reference. 
     
    
     TECHNICAL FIELD 
       [0002]    The present disclosure relates to an expiratory treatment device, and in particular, to an oscillating positive expiratory pressure (“OPEP”) device. 
       BACKGROUND 
       [0003]    Each day, humans may produce upwards of 30 milliliters of sputum, which is a type of bronchial secretion. Normally, an effective cough is sufficient to loosen secretions and clear them from the body&#39;s airways. However, for individuals suffering from more significant bronchial obstructions, such as collapsed airways, a single cough may be insufficient to clear the obstructions. 
         [0004]    OPEP therapy represents an effective bronchial hygiene technique for the removal of bronchial secretions in the human body and is an important aspect in the treatment and continuing care of patients with bronchial obstructions, such as those suffering from chronic obstructive lung disease. It is believed that OPEP therapy, or the oscillation of exhalation pressure at the mouth during exhalation, effectively transmits an oscillating back pressure to the lungs, thereby splitting open obstructed airways and loosening the secretions contributing to bronchial obstructions. 
         [0005]    OPEP therapy is an attractive form of treatment because it can be easily taught to most hospitalized patients, and such patients can assume responsibility for the administration of OPEP therapy throughout their hospitalization and also once they have returned home. To that end, a number of portable OPEP devices have been developed. 
       BRIEF SUMMARY 
       [0006]    A portable OPEP device and a method of performing OPEP therapy is described herein. In one aspect, a portable OPEP device includes a housing defining a chamber, a chamber inlet configured to receive exhaled air into the chamber, a chamber outlet configured to permit exhaled air to exit the chamber, a deformable restrictor member positioned in an exhalation flow path between the chamber inlet and the chamber outlet, and an oscillation member disposed within the chamber. The deformable restrictor member and the oscillation member are moveable relative to one another between an engaged position, where the oscillation member is in contact with the deformable restrictor member and a disengaged position, where the oscillation member is not in contact with the deformable restrictor member. The deformable restrictor member and the oscillation member are also configured to move from the engaged position to the disengaged position in response to a first exhalation pressure at the chamber inlet, and move from the disengaged position to an engaged position in response to a second exhalation pressure at the chamber inlet. The first exhalation pressure is greater than the second exhalation pressure. 
         [0007]    In another aspect, the deformable restrictor member deforms in response to an intermediate exhalation pressure at the chamber inlet, and returns to a natural shape in response to the first exhalation pressure at the chamber inlet. 
         [0008]    In another aspect, the OPEP device has a biasing member positioned to bias the deformable restrictor member and the oscillation member to the engaged position. The biasing member maybe a spring. Alternatively, the biasing member may have at least one pair of magnets, wherein a first magnet of the at least one pair of magnets is connected to the oscillation member and a second magnet of the at least one pair of magnets is connected to the housing. The position of the biasing member may also be selectively moveable to adjust the amount of bias 
         [0009]    In yet another aspect, the OPEP device includes a glide surface extending from the housing into the chamber, such that the glide surface is in sliding contact about the oscillation member, and movement of the oscillation member is substantially limited to reciprocal movement about an axis of the oscillation member. 
         [0010]    In another aspect, the oscillation member includes at least one channel adapted so that the exhalation flow path is not completely restricted when the deformable restrictor member and the oscillation member are in the engaged positioned. 
         [0011]    In another aspect, the OPEP device includes a mouthpiece connected to the housing that is in fluid communication with the chamber inlet. The mouthpiece may have a cross-sectional area greater than a cross-sectional area of the chamber inlet. 
         [0012]    In yet another aspect, the housing has a first portion and a second portion, with the second portion being removably connected to the first portion. 
         [0013]    In another aspect, the OPEP device includes a respiratory portal for receiving an aerosol medicament. Additionally, the oscillation member may comprise a one-way valve configured to permit the aerosol medicament to enter the chamber through the respiratory portal, the respiratory portal being in fluid communication with the chamber inlet when the one-way valve is open. 
         [0014]    In another aspect, a method of performing oscillating positive expiratory pressure therapy is provided. The method includes passing a flow of exhaled air along an exhalation flow path defined between an inlet and an outlet of a chamber in an oscillating positive expiratory pressure device. The method also includes restricting the flow of exhaled air by maintaining a deformable restrictor member and an oscillation member disposed within the chamber in an engaged position, where the oscillation member is in contact with the deformable restrictor member, until a first exhalation pressure is reached at a chamber inlet. The method further includes unrestricting the flow of exhaled air by moving the deformable restrictor member and the oscillation member to a disengaged position, where the oscillation member is not in contact with the deformable restrictor member, until a second exhalation pressure is reached at the chamber inlet. The method also includes returning the deformable restrictor member and the oscillation member to the engaged position with a biasing force when the second exhalation pressure is reached at the chamber inlet. The first exhalation pressure may be greater than the second exhalation pressure. Finally, the method may also include deforming the deformable restrictor member in response to an intermediate exhalation pressure at the chamber inlet, and returning the deformable restrictor member to a natural shape in response to the first exhalation pressure at the chamber inlet. 
         [0015]    In another embodiment, a system for providing oscillating positive expiratory pressure therapy in combination with aerosol therapy is provided. The system includes an oscillating positive expiratory pressure apparatus having a housing defining a chamber, a chamber inlet configured to receive exhaled air into the chamber, and a chamber outlet configured to permit exhaled air to exit the chamber. The oscillating positive expiratory pressure apparatus also has an exhalation flow path defined between the chamber inlet and the chamber outlet, and an oscillation member disposed within the chamber and configured to operatively restrict a flow of exhaled air along the exhalation flow path. The oscillation member is moveable relative to the flow path between a restrictive position, where the flow of exhaled air is substantially restricted and an unrestrictive position, where the flow of exhaled air is substantially unrestricted. The oscillating positive expiratory pressure apparatus may also have a respiratory portal for receiving an aerosol medicament. The respiratory portal maybe in fluid communication with the chamber inlet. The system also includes an aerosol therapy apparatus removably connected to the respiratory portal of the oscillating positive expiratory pressure apparatus. The aerosol therapy apparatus includes an aerosol housing having an aerosol chamber for holding an aerosol medicament, and an aerosol outlet communicating with the aerosol chamber for permitting the aerosol medicament to be withdrawn from the aerosol chamber. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]      FIG. 1  is a front perspective view of a first embodiment of an OPEP device; 
           [0017]      FIG. 2  is a side perspective view of the embodiment of  FIG. 1 ; 
           [0018]      FIG. 3  is a cross-sectional side view of the embodiment of  FIG. 1 , showing a deformable restrictor member and an oscillation member in an engaged position; 
           [0019]      FIG. 4  is a cross-sectional perspective view of an inlet insert shown in the embodiment of  FIG. 1 ; 
           [0020]      FIG. 5  is a cross-sectional perspective view of a deformable restrictor member shown in the embodiment of  FIG. 1 ; 
           [0021]      FIG. 6  is a front perspective view of an oscillation member shown in the embodiment of  FIG. 3 ; 
           [0022]      FIG. 7  is a rear perspective view of the oscillation member shown in the embodiment of  FIG. 3 ; 
           [0023]      FIG. 8  is a cross-sectional side view of a second embodiment of an OPEP device, showing a deformable restrictor member and an oscillation member in an engaged position; 
           [0024]      FIG. 9  is a cross-sectional side view of the embodiment of  FIG. 8 , showing the flow of air upon a user&#39;s inhalation; 
           [0025]      FIG. 10  is a cross-sectional side view of the embodiment of  FIG. 8 , showing the flow of air upon a user&#39;s exhalation; 
           [0026]      FIG. 11  is a cross-sectional side view of an OPEP device connected to a nebulizer, showing the flow of an aerosol medicament upon a user&#39;s inhalation; 
           [0027]      FIG. 12  is a cross-sectional side view of the OPEP device and nebulizer of  FIG. 11 , showing the flow of air upon a user&#39;s exhalation; and, 
           [0028]      FIG. 13  is a cross-sectional rear perspective view of a third embodiment of an OPEP device having a biasing member comprised of at least one pair of opposing magnets. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0029]    OPEP therapy is very effective within a specific range of operating conditions. For example, an adult human may have an exhalation flow rate ranging from 10 to 60 liters per minute, and may maintain a static exhalation pressure in the range of 10 to 20 cm H 2 O. Within these parameters, OPEP therapy is believed to be most effective when changes in the exhalation pressure range from 5 to 20 cm H 2 O oscillating at a frequency of 10 to 40 Hz. In contrast, an infant may have a much lower exhalation flow rate, and may maintain a lower static exhalation pressure, thereby altering the operating conditions most effective for OPEP therapy. As described below, the present invention is configurable so that ideal operating conditions may be selected and maintained. 
         [0030]    Referring to  FIG. 1 , a first embodiment of an assembled OPEP device  100  is shown. The OPEP device  100  comprises a housing  102  having a front portion  104  and a rear portion  106  which together defines a chamber  108  (see  FIG. 3 ). The housing  102  may be constructed of any durable material, such as a plastic or a metal. The OPEP device  100  shown in  FIG. 1  is substantially spherical in shape, which provides for an easy grasp of the OPEP device  100  in the hands of a user, as well as portability. It should be appreciated, however, that the OPEP device  100  could be any shape, so long as it defines a chamber  108  capable of housing the necessary components, as described herein. Preferably, the housing  102  is openable so the chamber  108  may be accessed for cleaning and replacing components contained therein. As shown, the front portion  104  and the rear portion  106  of the housing  102  are removably connected along a joint  110 , such as by a snap fit or a threaded screw connection. 
         [0031]    The OPEP device  112  also includes a mouthpiece  112  which may either be formed as an integral part of the housing  102  or removably attached to the housing  102 . Although the mouthpiece  112  is shown as being cylindrical in shape, the mouthpiece  112  could be any number of alternative sizes or shapes to accommodate various users of the OPEP device  100 , such as children or adults. A chamber inlet  114  positioned within the mouthpiece  112  is configured to receive exhaled air into the chamber  108 . In view of the description below, it should be apparent that the cross sectional area of the chamber inlet  114  is an important variable affecting the exhalation pressure generated at the mouth of a user, and maybe modified or selectively replaced according to the desired operating conditions. 
         [0032]    A side perspective view of the OPEP device  100  is shown in  FIG. 2 . The OPEP device  100  further comprises at least one chamber outlet  116  configured to permit exhaled air to exit the chamber  108 . The at least one chamber outlet  116  may comprise any number of apertures, having any shape or size. Furthermore, the at least one chamber outlet  116  maybe located elsewhere on the housing  102 . The OPEP device  100  may also include a grate  117  to prevent unwanted objects from entering housing  102 . 
         [0033]    Referring to  FIG. 3 , a cross-sectional side view of the OPEP device  100  shows the internal components of the OPEP device  100 . The minimal number of components contained in the OPEP device  100 , and its relatively simple operation, make the OPEP device  100  particularly suitable for single patient use. In general, the housing  102  of the OPEP device  100  encloses an inlet insert  118 , a deformable restrictor member  120 , an oscillation member  122 , a coil spring  124 , and a glide surface  126 . As explained below, the various alternatives for each of the inlet insert  118 , the deformable restrictor member  120 , the oscillation member  122 , and the coil spring  124  provide of a highly configurable OPEP device  100 . 
         [0034]    A cross-sectional perspective view of the inlet insert  118  is shown in  FIG. 4 . The inlet insert  118  is removably connectable to the housing  102  and/or mouthpiece  112  of the OPEP device  100 , and includes the chamber inlet  114 . The chamber inlet  114  may be a single narrow aperture, or alternatively, may comprise any number of apertures having any size or shape. Because the inlet insert  118  is removably connectable to the OPEP device  100 , a user may select an inlet insert  118  having the appropriate sized chamber inlet  114  for the prescribed OPEP therapy. It is important, however, that the mouthpiece  112  have a cross-sectional area greater than the cross-sectional area of the chamber inlet  114 . 
         [0035]    The inlet insert  118  is configured to be snap or compression fit within the front portion  104  of the housing  102 , which maybe accomplished while the front portion  104  and the rear portion  106  are detached. The inlet insert  118  includes an annular recess  128  for receiving a corresponding annular protrusion  130 , which may be located on a rim  131  connected to either the mouthpiece  112  or the housing  102 , as shown in  FIG. 4 . Furthermore, the inlet insert  118  is shaped to fit within the spherically shaped OPEP device  100 ; however, the inlet insert  118  could be modified to fit within any other shaped OPEP device. Alternatively, the inlet insert  118  and the chamber inlet  114  may be formed as an integral part of the housing  102  or the mouthpiece  112 . The inlet insert  118  further includes an annular mounting surface  132  for supporting the deformable restrictor member  120 , as described below. 
         [0036]    Referring to  FIG. 5 , a cross-sectional perspective view of the deformable restrictor member  120  is shown. The deformable restrictor member  120  operates as a regulator of the exhalation pressure at the chamber inlet  114 . The deformable restrictor member  120  maybe constructed of an elastic material, preferably having an elasticity of at least 40 durometers (A scale). Like the inlet insert  118 , the deformable restrictor member  120  maybe any number of shapes, but is shown in  FIG. 5  as being circular to fit within the spherically shaped OPEP device  100 . 
         [0037]    The deformable restrictor member  120  generally includes an upper portion  134 , a lower portion  136 , and a reinforcing band  138  of elastic material. As shown in  FIG. 3 , the upper portion  134  is configured for mounting the deformable restrictor member  120  on the mounting surface  132  and about the rim  131 , as explained above. When the front portion  104  and the rear portion  106  of the housing  102  are detached, the upper portion  134  of the deformable restrictor member  120  is mountable about the rim  131  of the inlet insert  118 , and the inlet insert  118  maybe snapped into place within the housing  102 . Once the inlet insert  118  is connected to the housing  102 , the deformable restrictor member  120  is retained by the rim  131 , the mounting surface  132 , and the front portion  104  of the housing  102 . Alternatively, the housing  102  or the mouthpiece  112  may be configured to provide the rim  131  and the mounting surface  132  for mounting and retaining the deformable restrictor member  120 . 
         [0038]    The deformable restrictor member  120 , and in particular, the lower portion  136 , is configured to deform as the exhalation pressure at the chamber inlet  114  increases. Preferably, the lower portion  136  of the deformable restrictor member  120  should be curved inward so that, as the deformable restrictor member  120  deforms, the lower portion  136  expands in a direction away from the upper portion  134 . To improve the elasticity and rigidness of the deformable restrictor member  120 , a reinforcing band  138  of elastic material maybe added to the deformable restrictor member  120 . Depending on the shape of the deformable restrictor member  120  and the desired elasticity, the reinforcing band  138  maybe omitted or located elsewhere on the deformable restrictor member  120 . 
         [0039]    Referring to  FIG. 6 , a front perspective view of an oscillation member  122  is shown. In general, the oscillation member  122  includes a contact surface  140  connected to the end of a post  142 . The contact surface  140  is configured to engage the lower portion  136  of the deformable restrictor member  120 . As shown in  FIGS. 3 and 6 , the contact surface  140  maybe hemispherically shaped to fit within a correspondingly shaped portion of the inlet insert  118 , or a correspondingly shaped portion of the housing  102  or mouthpiece  112  if the inlet insert  118  is omitted. Alternatively, the contact surface  140  maybe substantially flat. 
         [0040]    The contact surface  140  shown in  FIG. 6  includes at least one channel  143  which traverses a portion of the contact surface  140  where the deformable restrictor member  120  and the oscillation member  122  engage one another. In this embodiment, the channels  143  are sized such that an air passage from the chamber inlet  114  to the chamber outlet  116  is maintained during both inhalation and exhalation via the space defined by the restrictor member  120  and the channels  143 . This air passage, or collection of air passages, is sized to prevent complete restriction of air flow but selected to allow sufficient build-up of pressure to provide oscillating pressure upon patient exhalation. 
         [0041]    Although the contact surface  140  is shown in  FIG. 6  as having seven separate channels  143 , the contact surface  140  could include any number of channels  143 . Furthermore, the one or more channels  143  may have a variety of sizes, depending upon the desired restriction of exhaled air received from the user. Alternatively, the contact surface  140  may be fabricated without any channels  140 . 
         [0042]    Because the oscillation member  120  is removably enclosed within the housing  102  of the OPEP device  100 , a user may select an oscillation member  120  having the appropriate shape, size, or number of channels for the prescribed OPEP therapy. 
         [0043]    A rear perspective view of the oscillation member  122  is shown in  FIG. 7 . The post  142  is configured for positioning about the glide surface  126 , as shown in  FIG. 3 , so that the post  142  is in sliding contact with the glide surface  126 . When the post  142  is positioned about the glide surface  126 , the oscillation member  122  is substantially limited to reciprocal movement about the central axis of the oscillation member  122 . As shown in  FIGS. 3 and 7 , the glide surface  126  and the post  142  are shaped as hollow cylinders, and the post  142  is sized to fit within the glide surface  126 . However, the glide surface  126  and the post  142  may have any shape, and the glide surface  126  maybe alternatively sized to fit within the post  142 . The oscillation member  122  also includes a skirt  144  for aligning a biasing member, such as the coil spring  124 , about the oscillation member  122  when the OPEP device  100  is assembled. 
         [0044]    Referring to  FIG. 3 , the coil spring  124  is positioned to extend from the housing  102  and contact a lower surface  146  of the oscillation member  122 . The coil spring  124  is positioned to bias the oscillation member  122  into engagement with the deformable restrictor member  120 . Similar to the deformable restrictor member  120  and the oscillation member  122 , the coil spring  124  maybe selectively replaced with other springs have a different rigidity or number of coils to achieve the desired operating conditions for the prescribed OPEP treatment. 
         [0045]    To administer OPEP therapy using the OPEP device  100  descried above, a user begins by exhaling into the mouthpiece  112 . In doing so, an exhalation flow path  148  is defined between the chamber inlet  114  and the at least one chamber outlet  116 . The exhalation pressure at the chamber inlet  114  represents a function of the flow of exhaled air permitted to traverse the exhalation flow path  148  and exit the OPEP device  100  through the chamber outlet  116 . As the exhalation pressure at the chamber inlet  114  changes, an equal back pressure is effectively transmitted to the respiratory system of the user. 
         [0046]    As shown in  FIG. 3 , prior to using the OPEP device  100 , the oscillation member  122  is biased to an engaged position, where the deformable restrictor member  120  is in contact with the oscillation member  122 . In the engaged position, the exhalation flow path  148  is substantially restricted by the deformable restrictor member  120  and the oscillation member  122 . As a user exhales into the OPEP device  100 , an initial exhalation pressure at the chamber inlet  114  begins to increase, as only a fraction of the exhaled air is permitted to flow along the exhalation flow path  148  through the at least one channel  142  on the oscillation member  122 . As the exhalation pressure increases at the chamber inlet  114  to an intermediate pressure, the deformable restrictor member  120  begins to expand under the force of the increased pressure. As the deformable restrictor member  120  expands, the lower portion  136  moves in an outward direction, toward the oscillation member  122 . In the engaged position, however, the outward movement of the lower portion  136  is resisted by the oscillation member  122 , which is biased against the deformable restrictor member  120  by the coil spring  124 . As the exhalation pressure continues to increase, the deformable restrictor member  120  continues to deform until a maximum point of expansion is obtained. When the deformable restrictor member  120  obtains its maximum expansion, the exhalation pressure is also at a maximum pressure. 
         [0047]    At the maximum point of expansion, the increasing exhalation pressure causes the deformable restrictor member  120  to quickly retract, ultimately returning to its natural shape. As the deformable restrictor member  120  retracts, the deformable restrictor member  120  and the oscillation member  122  move to a disengaged position, where the deformable restrictor member  120  is not in contact with the oscillation member  122 . At that time, exhaled air is permitted to flow substantially unrestricted along the exhalation flow path  148  from the chamber inlet  114  to the chamber outlet  116 . Because the retraction of the deformable restrictor member  120  is quicker than the movement of the oscillation member  122  under the biasing force of the coil spring  124 , the deformable restrictor member  120  and the oscillation member  122  remain in the disengaged position for a short period of time, during which the exhalation pressure at the chamber inlet  114  decreases. Depending on multiple variables, including the elasticity of the deformable restrictor member  120 , the biasing force of the coil spring  124 , and the exhalation flow rate, the deformable restrictor member  120  and the oscillation member  122  may remain in the disengaged position for only a fraction of a second. 
         [0048]    After the deformable restrictor member  120  returns to its natural shape, the oscillation member  122 , under the biasing force of the coil spring  124 , moves back into an engaged position with the deformable restrictor member  120 . Then, as a user continues to exhale, the exhalation pressure at the chamber inlet  114  begins to increase, and the cycle described above is repeated. In this way, the exhalation pressure at the chamber inlet  114  oscillates between a minimum and a maximum so long as a user continues to exhale into the OPEP device  100 . This oscillating pressure is effectively transmitted back to the respiratory system of the user to provide OPEP therapy. 
         [0049]    A cross-sectional side view of a second embodiment of an OPEP device  200  is shown in  FIG. 8 . Like the OPEP device  100 , a housing  202  of the OPEP device  200  encloses a deformable restrictor member  220 , an oscillation member  222 , a coil spring  224 , and a glide surface  226 . The OPEP device  200  also includes a mouthpiece  212 , a chamber inlet  214 , a chamber outlet  216 , and has an exhalation flow path  248  defined therebetween. 
         [0050]    The OPEP device  200  further comprises an adjustment plate  254  for selectively moving an end of a biasing member, such as the coil spring  224 , to adjust the amount of bias. The adjustment plate  254  is connected to at least one thumb screw  256  extending from the adjustment plate  254  to a location outside the housing  202 . In this way, a user may rotate the at least one thumb screw  256  in one direction to move both the adjustment plate  254  and an end of the coil spring  224  toward the oscillation member  222 , thereby increasing the bias. A user may rotate the at least one thumb screw  256  the opposite direction to decrease the bias. By changing the amount of bias, a user may selectively increase or decrease the resistance the oscillation member  222  applies against the deformable restrictor member  222  while in the engaged position. A change in the bias also changes the rate at which the oscillation member  222  moves from the engaged position to the disengaged position, and back to the engaged position, during the administration of OPEP therapy. 
         [0051]    The OPEP device  200  shown in  FIG. 8  further comprises a respiratory portal  250  and a one-way valve  252  positioned on the oscillation member  222 . The oscillation member  222  shown in  FIG. 8  omits the at least one channel and has a substantially flat contact surface  240  to accommodate the one-way valve  252 . The one-way valve  252  is configured to open as a user inhales, and permit air to enter the chamber  208  from the respiratory portal  250 , as shown in  FIG. 9 . In contrast, the one-way valve  252  is closed during exhalation, as seen at one point during the administration of OPEP therapy in  FIG. 10 , when the deformable restrictor member  220  and the oscillation member  222  are in the disengaged position. 
         [0052]    Referring to  FIG. 11 , the respiratory portal  250  of the OPEP device  200  is also configured to receive an aerosol outlet  260  of a nebulizer  258 . The nebulizer  258  maybe removably connected to the OPEP device  200  by any suitable means for the combined administration of OPEP and aerosol therapies. Any of a number of commercially available nebulizers may be used with the OPEP device  200 . One suitable nebulizer is the AeroEclipse® II breath actuated nebulizer available from Trudell Medical International of London, Canada. Descriptions of suitable nebulizers may be found in U.S. Pat. No. 5,823,179, the entirety of which is hereby incorporated by reference herein. 
         [0053]    In this configuration, a user receives aerosol therapy upon inhalation. As seen in  FIG. 11 , when a user inhales, the one-way valve  252  opens, and an aerosol medicament is drawn from the aerosol output  260 , through the respiratory 250 portal and the chamber  208 , and into the respiratory system of the user. In contrast, OPEP therapy is delivered upon exhalation. As seen in  FIG. 12 , when a user exhales, the one-way valve  252  closes, the aerosol medicament is contained within the respiratory portal  250 , and the OPEP device  200  is able to deliver OPEP therapy in accordance with the method described above. 
         [0054]    A cross-sectional perspective view of a third embodiment of an OPEP device  300  is shown in  FIG. 13 . In general, a housing  302  of the OPEP device  300  encloses a deformable restrictor member  320 , an oscillation member  322  having a one-way valve  352 , a glide surface  326 , and an adjustment plate  354 . The OPEP device  300  also includes a mouthpiece  312 , a chamber inlet  314 , a chamber outlet  316 , and a respiratory portal  350 . 
         [0055]    The OPEP device  300  is different from the OPEP device  200  in that it includes a biasing member comprised of at least one pair of magnets  362 . For each pair of the at least one pair of magnets  362 , one magnet is positioned on the oscillation member  322  and another magnet is positioned on the adjustment plate  354 . The magnets in each pair have opposing polarities. As such, the oscillation member  322  is biased by the at least one pair of magnets  362  into the engaged position with the deformable restrictor member  320 . 
         [0056]    During the administration of OPEP therapy, the at least one pair of magnets  362  functions in the same manner as the coil spring, as discussed above. Specifically, as a user exhales into the OPEP device  300  and the deformable restrictor member  320  expands, the at least one pair of magnets  362  resist the movement of oscillation member  322 . After the deformable restrictor member  320  has reached its maximum point of expansion and quickly returned to its natural shape, the at least one pair of magnets  362  bias the oscillation member  322  from the disengaged position back to the engaged position. Furthermore, like the OPEP device  200 , the amount of bias supplied by the at least one pair of magnets  362  may be adjusted by rotating the at least one thumb screw  356 , thereby moving the adjustment plate  354  and the magnets positioned thereon closer to the magnets positioned on the oscillation member  322 . 
         [0057]    The foregoing description of the inventions has been presented for purposes of illustration and description, and is not intended to be exhaustive or to limit the inventions to the precise forms disclosed. It will be apparent to those skilled in the art that the present inventions are susceptible of many variations and modifications coming within the scope of the following claims.