U.S. patent application number 12/955633 was filed with the patent office on 2011-03-24 for nasal respiratory devices.
Invention is credited to Rajiv Doshi, Bryan Loomas, Ryan Kendall Pierce.
Application Number | 20110067709 12/955633 |
Document ID | / |
Family ID | 38779217 |
Filed Date | 2011-03-24 |
United States Patent
Application |
20110067709 |
Kind Code |
A1 |
Doshi; Rajiv ; et
al. |
March 24, 2011 |
NASAL RESPIRATORY DEVICES
Abstract
Described herein are nasal respiratory devices and methods for
treating a variety of medical diseases including snoring and steep
apnea through the use of such devices. In general, these devices
include an airflow resistor, such as a flap valve and a holdfast
for securing the device in communication with the subject's nasal
cavity. The devices may be configured to include leak paths to
regulate the expiratory pressure when worn by a subject. Methods
for using these devices may include securing a device over or at
least partially within (or both of) a subject's nasal cavities.
Inventors: |
Doshi; Rajiv; (Los Altos,
CA) ; Pierce; Ryan Kendall; (San Francisco, CA)
; Loomas; Bryan; (Los Gatos, CA) |
Family ID: |
38779217 |
Appl. No.: |
12/955633 |
Filed: |
November 29, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11805496 |
May 22, 2007 |
7856979 |
|
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12955633 |
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60808034 |
May 23, 2006 |
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Current U.S.
Class: |
128/848 |
Current CPC
Class: |
A61M 16/1055 20130101;
A61M 2016/0027 20130101; A61M 16/0683 20130101; A61M 2016/003
20130101; A62B 23/06 20130101; A61M 2205/583 20130101; A61M 16/1065
20140204; A61M 15/085 20140204; A61F 5/56 20130101; A61F 5/08
20130101; A61M 16/208 20130101; A61M 16/0688 20140204; A61M 15/08
20130101; A61M 16/06 20130101; A61M 15/002 20140204; A61M 16/106
20140204; A61M 16/20 20130101; A61M 16/107 20140204; A61M 2205/75
20130101; A61M 2210/0618 20130101 |
Class at
Publication: |
128/848 |
International
Class: |
A61F 5/56 20060101
A61F005/56 |
Claims
1. A nasal respiratory device comprising: an opening configured to
communicate with a subject's nasal cavity, a flap valve configured
to regulate airflow through the opening to inhibit exhalation more
than inhalation; at least one leak path that is not formed through
a flap of the flap valve; a flap valve support adjacent to the flap
valve, wherein the flap valve support is configured to keep the
flap valve closed during exhalation.
2. The device of claim 1, wherein the flap valve support is
configured to contact a central portion of the flap.
3. The device of claim 1, wherein the flap valve support comprises
a mesh.
4. The device of claim 1, wherein the flap valve support is
flexible.
5. The device of claim 1, wherein the flap valve support comprises
a crossbar.
6. The device of claim 1 further comprising a holdfast.
7. The device of claim 1 further comprising an adhesive
holdfast.
8. The device of claim 1 further comprising a plurality of
flaps.
9. The device of claim 1 further comprising a rim at least
partially surrounding the opening.
10. The device of claim 1, wherein the at least one leak path
comprises a leak path formed at the periphery of the flap valve
where the flap valve does not mate with a valve seal, allowing air
to flow past the flap valve even when the valve is closed during
exhalation.
11. The device of claim 1, wherein the leak path is configured to
maintain a predetermined pressure across the flap valve of between
about 0.5 and about 20 cm of H.sub.2O when the flap valve is closed
and exposed to a constant flow rate of about 100 ml/sec.
12. A nasal respiratory device comprising: an opening configured to
communicate with a subject's nasal cavity, a flap valve configured
to regulate airflow through the opening to inhibit exhalation more
than inhalation, wherein the flap does not completely seal the
opening during exhalation so that expiratory airflow passes around
a portion of the flap valve during exhalation; a flap valve support
adjacent to the flap valve, wherein the flap valve support is
configured to keep the flap valve dosed during exhalation.
13. The device of claim 12, wherein the flap valve support is
configured to contact a central portion of the flap.
14. The device of claim 12, wherein the flap valve support
comprises a mesh.
15. The device of claim 12, wherein the flap valve support is
flexible.
16. The device of claim 12, wherein the flap valve support
comprises a crossbar.
17. The device of claim 12 further comprising a holdfast.
18. The device of claim 12 further comprising an adhesive
holdfast.
19. The device of claim 12 further comprising a plurality of
flaps.
20. The device of claim 12 further comprising a rim at least
partially surrounding the opening.
21. The device of claim 12 further comprising a leak path formed at
the periphery of the flap valve where the flap valve does not mate
with a valve seal during exhalation, allowing expiratory airflow to
pass around the flap valve during exhalation.
22. The device of claim 12, wherein the flap valve is configured to
maintain a predetermined pressure across the flap valve of between
about 0.5 and about 20 cm of H.sub.2O when the flap valve is closed
and exposed to a constant flow rate of about 100 ml/sec.
23. A nasal respiratory device configured to be worn while sleeping
and to be secured in communication with a subject's nasal cavity,
the device comprising: an opening configured to communicate with a
subjects nasal cavity, an airflow resistor configured to regulate
airflow through the opening to inhibit exhalation more than
inhalation, wherein the airflow resistor comprises a plurality of
flaps; a flap valve support adjacent to the airflow resistor,
wherein the flip valve support is configured to keep the airflow
resistor closed during exhalation.
24. The device of claim 23, wherein the flap valve support is
configured to span the opening.
25. The device of claim 23, wherein the flap valve support
comprises a mesh.
26. The device of claim 23, wherein the flap valve support
comprises a crossbar.
27. The device of claim 23, wherein the flap valve support is
flexible.
28. The device of claim 23 further comprising a holdfast.
29. The device of claim 23 further comprising an adhesive
holdfast.
30. The device of claim 23 further comprising a rim at least
partially surrounding the opening.
31. The device of claim 23 further comprising a leak path at is not
formed through any of the flaps.
32. The device of claim 23 further comprising at least one teak
path formed at the periphery of the flaps where the flaps do not
mate with a valve seal, allowing air to flow past the flaps even
when the airflow resistor is closed during exhalation.
33. The device of claim 23 further comprising a leak pathway
configured to maintain a predetermined pressure of between about
0.5 and about 20 cm of H.sub.2O when the airflow resistor is closed
and exposed to a constant flow rate of about 100 ml/sec.
34. A valved nasal device configured to be secured to a subject's
nose, the device comprising: a body having a passageway configured
to communicate with a subject's nasal cavity, a valve configured to
regulate airflow through the passageway to inhibit exhalation more
than inhalation; a valve lock configured to secure a movable
portion of the valve within the passageway and prevent the moveable
portion from separating from the device and being inhaled by the
patient; and a holdfast configured to secure the nasal device in
communication with the subject's nasal cavity.
35. The device of claim 34, wherein the valve lock comprises a
restraining member.
36. The device of claim 34, wherein the valve lock comprises a pin
or cord.
37. The device of claim 34, wherein the valve lock is not connected
directly to the movable portion of the valve but prevents the
movable portion of the valve from separating from the respiratory
device.
38. The device of claim 34, wherein the movable portion of the
valve comprises at least one flap.
39. The device of claim 34 further comprising a flap valve support
adjacent to the valve configured to span the passageway to keep the
valve closed during exhalation.
40. The device of claim 39, wherein the flap valve support
comprises a mesh.
41. The device of claim 39, wherein the flap valve support
comprises a crossbar.
42. The device of claim 34, wherein the holdfast comprises an
adhesive holdfast.
43. The device of claim 34 further comprising a leak path that is
not formed through any of the movable portions of the valve.
44. The device of claim 34 further comprising at least one leak
path formed at the periphery of the moveable portion of the valve,
where the moveable portion does not mate with a valve seal,
allowing air to flow through the valve even when the valve is
closed during exhalation.
45. The device of claim 34 further comprising a leak pathway
configured to maintain a predetermined pressure across the valve of
between about 0.5 and about 20 cm of H.sub.2O when the valve is
closed and exposed to a constant flow rate of about 100 ml/sec.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 11/805,496, filed May 22, 2007, entitled
"Nasal Respiratory Devices", which claims priority to U.S.
Provisional Patent Application No. 60/808,034, filed May 23, 2006,
entitled "Nasal Respiratory Devices", each of which are
incorporated by reference in their entirety.
BACKGROUND
[0002] Numerous disease states could benefit from the modification
of subject respiration, including heart failure, sleep disordered
breathing (e.g., sleep apnea, etc.) and other sleep disorders
(e.g., snoring), hypertension, chronic Obstructive pulmonary
disease (COPD), bronchitis, asthma, and many others.
[0003] Heart failure, or congestive heart failure (CHF), is a
common clinical syndrome that represents the end-stage of a number
of pulmonary and cardiac disease states. Heart failure is a
degenerative condition that occurs when the heart muscle weakens
and the ventricle no longer contracts normally. The heart can then
no longer adequately pump blood to the body including the lungs.
This may lead to exercise intolerance, or may cause fluid retention
with subsequent shortness of breath or swelling of the feet. Over
four million people are diagnosed with heart failure in the United
States atone. Morbidity and mortality in subjects with heart
failure is high.
[0004] Sleep apnea is one form of sleep disordered breathing. Sleep
apnea is defined as the temporary absence or cessation of breathing
during sleep. Airflow must be absent for some period of time longer
than the usual inter-breath interval, typically defined as ten
seconds for adults and eight seconds (or more than two times the
normal respiratory cycle time) for infants. There are several
general varieties of sleep apnea: central, obstructive, complex,
and mixed. In central sleep apnea, the subject makes no effort to
breathe. In obstructive apnea, ventilatory effort is present, but
no airflow results, because of upper airway closure, in mixed
apnea, there is initially no ventilatory effort (suggestive of
central sleep apnea), but an obstructive sleep apnea pattern
becomes evident when ventilatory effort resumes. Finally, hypopnea
is a temporary decrease in inspiratory airflow relative to the
previous several inspirations. The terms sleep apnea and/or sleep
disordered breathing may refer to hypopnea.
[0005] Hypertension refers to elevated blood pressure, and is a
very common disease. Hypertension is characterized by elevated
systolic and/or diastolic blood pressures. Despite the prevalence
of hypertension and its associated complications, control of the
disease is far from adequate. Only a third of people with
hypertension control their blood pressure adequately. This failure
reflects the inherent problem of maintaining long-term therapy for
a usually asymptomatic condition, particularly when the therapy may
interfere with the subject's quality of life, and when the
immediate benefits of the therapy are not obvious to the
subject.
[0006] Chronic obstructive pulmonary disease (COPD) includes
chronic bronchitis, emphysema and asthma. In both chronic
bronchitis and emphysema, airflow obstruction limits the subject's
airflow during exhalation. COPD is a progressive disease
characterized by a worsening baseline respiratory status over a
period of many years with sporadic exacerbations often requiring
hospitalization. Early symptoms include increased sputum production
and sporadic acute exacerbations characterized by increased cough,
purulent sputum, wheezing, dyspnea, and fever. As the disease
progresses, the acute exacerbations become more frequent. Late in
the course of the disease, the subject may develop hypercapnia,
hypoxemia, erythrocytosis, cor pulmonale with right-sided heart
failure, and edema.
[0007] Chronic bronchitis is characterized by a chronic cough with
sputum production leading to obstructed expiration. Pathologically,
there may be mucosal and submucosal edema and inflammation and an
increase in the number and size of mucus glands. Emphysema is
characterized by destruction of the lung parenchyma leading to loss
of elastic recoil, reduced tethering of airways, and obstruction to
expiration. Pathologically, the distal airspaces are enlarged.
[0008] Asthma is another chronic lung condition, characterized by
difficulty in breathing. People with asthma have extra-sensitive or
hyper-responsive airways. The airways react by obstructing or
narrowing when they become inflamed or irritated. This makes it
difficult for the air to move in and out of the airways, leading to
respiratory distress. This narrowing or obstruction can lead to
coughing, wheezing, shortness of breath, and/or chest tightness. In
some cases, asthma may be life threatening.
[0009] In all of these diseases, current medical and surgical
therapies are not completely effective, and there is considerable
room for improvement. Two therapies that are used to treat these
diseases are pulmonary rehabilitation (including pursed-lip
breathing) and non-invasive mechanical ventilation.
[0010] Pulmonary rehabilitation is frequently used to treat
subjects suffering from a variety of medical ailments such as those
mentioned. For example, COPD subjects are taught new breathing
techniques that reduce hyperinflation of the lungs and relieve
expiratory airflow obstruction. One of the goals of this training
is to reduce the level of dyspnea. Typically, these new breathing
techniques include diaphragmatic and pursed-lip breathing.
Pursed-lip breathing involves inhaling slowly through the nose and
exhaling through pursed-lips (as if one were whistling), taking two
or three times as long to exhale as to inhale. Most COPD subjects
instinctively learn how to perform pursed-lip breathing in order to
relieve their dyspnea. Moreover, subjects with asthma and other
respiratory ailments, and even normal people during exercise, have
been shown to use pursed-lip breathing, especially during times of
exertion.
[0011] It is widely believed that producing a proximal obstruction
(e.g., pursing the lips) splints open the distal airways that have
lost their tethering in certain disease states. In other words,
airways that would normally collapse during respiration remain open
when the subject breathes through pursed-lips. Moreover, by
increasing exhalation time, respiratory rate can be reduced and, in
some cases, made more regular.
[0012] The medical literature has confirmed the utility of
pursed-lip breathing in COPD subjects. Specifically, it has been
found that pursed-lip breathing by COPD subjects results in a
reduction in respiratory rate, an increase in tidal volumes, and an
improvement of oxygen saturation. All of these effects contribute
to a reduction in subject dyspnea. However, pursed-lip breathing
requires conscious effort. Thus, the subject cannot breathe through
pursed-lips while sleeping. As a result, the subject can still
become hypoxic at night and may develop pulmonary hypertension and
other sequelae as a result. Furthermore, the subject has to
constantly regulate his own breathing. This interferes with his
performing of other activities because the subject must pay
attention to maintaining pursed-lip breathing.
[0013] Non-invasive positive pressure ventilation (NPPV) is another
method of treating diseases that benefit from regulation of the
subject's respiration. NPPV refers to ventilation delivered by a
nasal mask, nasal prongs/pillows or face mask. NPPV eliminates the
need for intubation or tracheostomy. Outpatient methods of
delivering NPPV include bilevel positive airway pressure (BIPAP
bilevel) ventilator devices, or continuous positive airway pressure
(CPAP) devices.
[0014] NPPV can deliver a set pressure during each respiratory
cycle, with the possibility of additional inspiratory pressure
support in the case of hi-level devices. NPPV has been shown to be
very efficacious in such diseases as sleep apnea, heart failure,
and COPD, and has become increasingly used in recent years. Many
subjects use CPAP or BIPAP at night while they are steeping.
[0015] However, most subjects experience difficulty adapting to
nocturnal NPPV, leading to poor compliance. Mask discomfort is a
very common problem for subjects new to NPPV, because of the high
pressures on the nose, mouth, and face, and because of
uncomfortably tight straps. Nasal congestion and dryness are also
common complaints that may vary by season. The nasal bridge can
become red or ulcerated due to excessive mask tension. Eye
irritation and acne can also result. Still other subjects
experience abdominal distention and flatulence. Finally, air
leakage through the mouth is also very common in nasal NPPV
subjects, potentially leading to sleep arousals.
[0016] Both pursed-lip breathing and the use of NPPV have been
shown to offer significant clinical benefits to subjects with a
variety of medical illnesses, including but not limited to COPD,
heart failure, pulmonary edema, sleep apnea (both central and
Obstructive) and other sleep disordered breathing, cystic fibrosis,
asthma, cardiac valve disease, arrhythmias, anxiety, and snoring.
Expiratory resistance is believed to provide the bulk of clinical
improvements when using pursed-lip breathing and NPPV, through a
variety of physiologic mechanisms. In contrast, inspiratory support
is not believed to offer clinical benefits in many subjects. For
example, in COPD, expiratory resistance facilitates expiration,
increases tidal volume, decreases respiratory rate, and improves
gas exchange. In the case of heart failure, it is felt that
positive pressure in the airways (due to expiratory resistance)
reduces pulmonary edema and improves lung compliance, decreases
preload and afterload, increases pO.sub.2, and decreases pCO.sub.2.
In many disease states, expiratory resistance helps maintain a more
stable respiratory rate that can have profound clinical effects to
the subject.
[0017] It would therefore be desirable to have a medical device
and/or procedure that mimics the effect of pursed-lip breathing
and/or the benefits of non-invasive ventilation without suffering
from the drawbacks described above.
[0018] General respiratory devices addressing many of these
problems may be found in U.S. patent application Ser. No.
11/298,640, filed Dec. 8, 2005, herein incorporated by reference in
its entirety. Described herein are respiratory devices and methods
of using them that include many features not previously developed
or described.
BRIEF SUMMARY
[0019] Described herein are nasal respiratory devices and methods
for treating a variety of medical diseases through the use of such
devices. In general, these devices include a rim configured as a
substantially tubular body enclosing a passageway, an airflow
resistor within the passageway (where the airflow resistor is
typically a flap valve), and a holdfast for securing the
respiratory device within a nasal cavity.
[0020] The respiratory devices described herein may include a
passageway, a flap valve in communication with the passageway, a
flap valve support located adjacent to the flap valve (wherein the
flap valve support is configured to prevent the flap valve from
opening in more than one direction), and a holdfast. The holdfast
is configured to secure the passageway of the device respiratory
device in communication with the nasal cavity without covering the
subject's mouth. Any of the devices described herein may be
removably secured in communication with a nasal cavity (e.g., over
and/or at least partially within the subject's nasal cavity). Thus,
the nasal devices described herein typically interact with the
subject's nose but do not cover the subject's mouth.
[0021] The nasal devices described herein may also include at least
one leak path. As described in greater detail below, a leak path
allows air to flow through or past the respiratory device even when
the airflow resistor is closed. In some variations, the devices
includes one or more leak paths through the device that are not
formed though a flap of the flap valve (for example, a leak path
may be formed through a body or holdfast portions of the
device).
[0022] In some variations, the device includes a flap valve that is
a continuously flexible flap valve. A continuously flexible flap
valve is flexible along the majority (or entirety) of the flap. For
example, the flap of the flap valve may be made of silicone.
Furthermore, the flap of the flap valve may have a thickness that
is sufficient to allow the flap to bend or flex along the movable
length of the flap.
[0023] The devices may be secured over, across, and/or within a
subject's nose. For example, the holdfast may be configured to
secure the respiratory device over the subject's nasal cavity. In
some variations, the holdfast is configured to secure the
respiratory device at least partially within the subject's nasal
cavity. In some variations, the holdfast is configured to secure
the respiratory device in communication with one of the subject's
nostrils, or both of the subject's nostrils. A holdfast may be made
of a foam (or foamed) material. For example, the holdfast may be
made of foamed polyurethane.
[0024] Further, the devices described herein may also include a
substantially tubular body forming the passageway. The
substantially tubular body may have an elliptical cross-section.
Thus, the devices may include a rim (or rim body) forming the
tubular body.
[0025] A nasal respiratory device may also include a valve seal
surface within the passageway configured to seat the edge of the
flap valve when the flap valve is closed. The valve seal surface
may be, for example a lip protruding into the circumference of the
passageway.
[0026] A flap valve support may be a mesh, crossbeam, pin, or the
like, that can abut the flap of a flap valve to prevent it from
bending in an undesirable direction (e.g., preventing the valve
from opening in any direction but the appropriate direction). For
example, a flap valve support may include at least one crossbeam
spanning the passageway. In some variations, the flap valve support
includes a pair of intersecting crossbeams.
[0027] Some variations of the devices described herein include a
flap valve aligner that is configured to keep a flap (or flaps) of
the flap valve oriented within the opening of a passage through the
device. For example, a flap valve aligner may be a post or posts
projecting from a crossbeam spanning the passageway, wherein the
flap valve aligner orients the flap valve within the passageway by
securing the hinge (or central region) of the flap on the post(s).
In this example, the post(s) may pass through an opening (or
openings) on the flap of the flap valve.
[0028] Also described herein are nasal respiratory devices
configured to be secured in communication with a subject's nasal
cavity that include an airflow resistor configured to inhibit
expiration more than inspiration and a holdfast configured to
secure the device in communication with the subject's nasal cavity
without covering the subject's mouth, wherein device has a
resistance to expiration that is between about 0.001 and about 0.25
cm H.sub.2O/ml/sec, and a resistance to inhalation that is between
about 0.0001 and about 0.05 cm H.sub.2O/ml/sec, when resistance is
measured at 100 ml/sec. In some variations the nasal respiratory
device has a resistance to expiration that is between about 0.03 cm
H.sub.2O/ml/sec and about 0.2 cm H.sub.2O/ml/sec, or between about
0.03 and about 0.15 cm H.sub.2O/ml/sec. In some variations, the
nasal respiratory device has a resistance to inhalation that is
between about 0.001 and about 0.02 cm H.sub.2O/ml/sec, or between
about 0.001 and about 0.01 cm H.sub.2O/ml/sec. In some variations,
the devices include one or more leak paths. The resistance to
inspiration and the resistance to expiration may be determined by
the airflow resistor and the total leak path.
[0029] Any of these nasal respiration devices may include an
airflow resistor that is a flap valve, as described above. Further,
the devices may include at least one leak path that is not formed
though a movable portion of the airflow resistor (e.g., a flap of a
flap valve).
[0030] Any of the holdfasts or configurations of holdfasts
described above may be used as well. For example, the nasal
respiratory device may include a holdfast configured to secure the
device in communication with the subject's nasal cavity.
[0031] Also described herein are nasal respiratory device including
a passageway having an opening, a flap valve in communication with
the opening, a flap valve aligner aligning a flap of the flap valve
in communication with the opening, and a holdfast configured to
secure the respiratory device in communication with a subject's
nasal cavity. As described above, these nasal respiratory devices
may include one or more leak paths, include leak paths that are not
formed though the flap of the flap valve. The flap valve may have a
continuously flexible flap.
[0032] The nasal respiratory devices may be secured over, at least
partially over, across, and/or at least partially within a
subject's nose (e.g., via the holdfast). The holdfast may be
configured to secure the respiratory device in communication with
one of the subject's nostrils, or both of the subject's nostrils.
In some variations, the nasal respiratory device also includes a
flap valve support. The nasal respiratory devices described herein
are typically secured over, at least partially over, across, or at
least partially within a subject's nose, but not over (e.g.,
covering) the subject's mouth. Thus, in many variations, these
devices are in communication with the subject's nose (e.g., over or
at least partially within the subject's nose) without covering or
obscuring the subject's mouth and the subject may breathe through
the mouth even while breathing through the nose is regulated.
[0033] Also described herein are methods of treating a disorder
including the steps of allowing the subject to breathe through the
mouth without additional resistance while inhibiting nasal
expiration more than nasal inhalation, and inhibiting nasal
expiration more than nasal inspiration by providing a resistance to
nasal expiration that is between about 0.04 and about 0.5 cm
H.sub.2O/ml/sec, and a resistance to nasal inhalation that is
between about 0.0002 and about 0.1 cm H.sub.2O/ml/sec measured at a
flow rate of 50 ml/sec. The method may also include the steps of
securing a respiratory device in communication with the subject's
nasal cavity, wherein the respiratory device comprises an airflow
resistor that inhibits expiration more then inhalation. The
disorder treated may be selected from the group consisting of:
sleep disordered breathing or snoring.
[0034] Also described herein are methods of treating a disorder
comprising the steps of securing a nasal respiratory device in
communication with a subject's nasal cavity, wherein the
respiratory device comprises a flap valve and a flap valve support
adjacent to the flap valve, and the flap valve support is
configured to prevent the flap valve from opening in more than one
direction. The disorder treated is selected from the group
consisting of: sleep disordered breathing or snoring.
[0035] Also described herein are methods of treating a disorder
including the steps of securing a nasal respiratory device in
communication with a subject's nasal cavity, wherein the
respiratory device comprises a flap valve and a flap valve aligner
aligning a flap of the flap valve in communication with an opening
through the nasal respiratory device. The disorder treated is
selected from the group consisting of: sleep disordered breathing
or snoring.
[0036] General respiratory devices addressing many of these
problems may be found in U.S. patent application Ser. No.
11/298,640, filed Dec. 8, 2005, herein incorporated by reference in
its entirety. Described herein are respiratory devices and methods
of using them that include many features not previously developed
or described.
INCORPORATION BY REFERENCE
[0037] All publications and patent applications mentioned in this
specification are herein incorporated by reference in their
entirety to the same extent as if each individual publication or
patent application was specifically and individually indicated to
be incorporated by reference.
BRIEF DESCRIPTION OF THE DRAWINGS
[0038] FIG. 1 is a perspective view of a respiratory device adapted
for an oral cavity.
[0039] FIG. 2 is a perspective view of another respiratory device
adapted for the oral cavity.
[0040] FIG. 3 is a perspective view of the device shown in FIG. 2,
where the device is positioned in a subject's oral cavity.
[0041] FIG. 4 shows a respiratory device adapted for the nasal
cavity.
[0042] FIG. 5 shows a respiratory device adapted to fit
substantially within the nasal cavity.
[0043] FIG. 6 shows a cross-sectional view of the device shown in
FIG. 4, where an airflow resistor is shown within the device.
[0044] FIGS. 7a and 7b show cross-sectional views of the device
shown in FIG. 4; FIG. 7a shows the device during inhalation, and
FIG. 7b shows the device during exhalation.
[0045] FIGS. 8a and 8b are perspective views of a respiratory
device showing an airflow resistor during exhalation (FIG. 8a) and
inhalation (FIG. 8b), respectively.
[0046] FIGS. 9a and 9b are perspective views of a respiratory
device having an airflow resistor where the airflow resistor is
shown during exhalation (FIG. 9a) and inhalation (FIG. 9b),
respectively.
[0047] FIG. 10 is a perspective view of a respiratory device having
an airflow resistor where the airflow resistor is shown during
exhalation.
[0048] FIG. 11 is a perspective view of a respiratory device having
an airflow resistor where the airflow resistor is shown during
exhalation.
[0049] FIGS. 12a and 12b show cross-sectional views of the
respiratory devices shown in FIGS. 9a, 9b, 10, and 11 during
exhalation (FIG. 12a) and inhalation (FIG. 12b), respectively.
[0050] FIG. 12c shows a cross-sectional view of a variation of the
respiratory device during exhalation.
[0051] FIGS. 13a and 13b are perspective views of a respiratory
device having an airflow resistor where the airflow resistor is
shown during exhalation (FIG. 13a) and inhalation (FIG. 13b),
respectively.
[0052] FIG. 14 is a perspective view of a respiratory device having
an airflow resistor where the airflow resistor is shown during
exhalation.
[0053] FIGS. 15a, 15b, and 15c are perspective views of a
respiratory device having an airflow resistor. FIG. 15a shows the
airflow resistor during higher levels of exhalation airflow and/or
pressure. FIG. 15b shows the airflow resistor during lower levels
of exhalation airflow and/or pressure. FIG. 15c shows the airflow
resistor during inhalation.
[0054] FIG. 16 is a perspective view of a respiratory device where
the device is removable and adapted for the nasal cavity.
[0055] FIG. 17 is a perspective view of a respiratory device where
the device is removable and adapted for the nasal cavity.
[0056] FIG. 18 is a cross-sectional view of a respiratory device
where the device is removable and adapted for the nasal cavity.
[0057] FIG. 19 is a cross-sectional view of a respiratory device
where the device is removable and adapted for the nasal cavity.
[0058] FIG. 20 is a cross-sectional view of a respiratory device
where the device is removable and adapted for the nasal cavity.
[0059] FIG. 21 is a cross-sectional view of a respiratory device
where the device is removable and adapted for the nasal cavity.
[0060] FIGS. 22a and 22b are perspective views of a respiratory
device having a moveable air filter where the moveable air filter
is shown during inhalation (FIG. 22a) and exhalation (FIG. 22b),
respectively.
[0061] FIG. 23 is a perspective view of another respiratory device
where the device is removable and adapted for the nasal cavity.
[0062] FIG. 24 shows a cross-sectional view of another respiratory
device where the device is removable and adapted for the nasal
cavity.
[0063] FIG. 25 shows a perspective view of the rim portion of one
example of a respiratory device as described herein.
[0064] FIGS. 26, 27, and 28 show side, top, and cross-sectional
views of the rim portion shown in FIG. 25.
[0065] FIG. 29 shows a perspective view of one variation of a
respiratory device as described herein.
[0066] FIGS. 30a and 30b show cross-sectional views of the
respiratory device of FIG. 29.
[0067] FIG. 31a shows one example of a flap valve seated in a
respiratory device.
[0068] FIG. 31b shows another example of a flap valve.
[0069] FIGS. 32a and 32b illustrate the operation of one example of
a respiratory device, as described herein.
[0070] FIG. 33 is a cross-sectional view of one variation of a
nasal respiratory device, and
[0071] FIG. 34 is a top view of the same device shown in FIG.
33.
DETAILED DESCRIPTION
[0072] Respiratory devices, kits, and methods for their use in
improving respiratory and cardiovascular function are described
herein. In general, these respiratory devices are referred to as
respiratory devices or simply as "devices." The devices and methods
described herein may be useful to treat a variety of medical
disease states, and may also be useful for non-therapeutic
purposes. The devices and methods described herein are not limited
to the particular embodiments described. Variations of the
particular embodiments may be made and still fall within the scope
of the appended claims. It is also to be understood that the
examples and particular embodiments described are not intended to
be limiting. Instead, the scope of the present invention will be
established by the appended claims.
[0073] As used in this specification, the singular forms "a" "an,"
and "the" include plural reference unless the context clearly
dictates otherwise. Unless defined otherwise, all technical and
scientific terms used herein have the same meaning as commonly
understood by one of ordinary skill in the art.
Devices
[0074] The respiratory devices described herein alter airflow into
and out of the lungs through a respiratory cavity such as the mouth
and/or the nostrils of the nose. The respiratory devices typically
include an airflow resistor capable of at least partially
obstructing airflow, particularly airflow in one direction (e.g.,
expiration) more than the opposite direction (e.g., inhalation). In
particular, the respiratory devices include an airflow resistor
exemplified by a flap valve. Additional examples of airflow
resistors are also described herein. These respiratory devices may
be used to increase the resistance to expiration during the
expiratory phase of the respiratory cycle. Many of the respiratory
devices described herein may prevent collapse of airways and
airflow conduits. Flap valves are described in greater detail
below.
[0075] The respiratory devices described herein generally include
an airflow passageway and an airflow resistor. The airflow
passageway (or "passageway") generally defines a channel allowing
the passage of air. The passageway may be of any suitable size or
shape; however it is configured so that when the respiratory device
is worn by a subject, the passageway provides an opening leading
toward the subject's lungs in fluid connection with an opening that
leads away from the subject's lungs. The terms "patient" and
"subject" are used to describe any user of the respiratory device,
including users who are not using the respiratory device for
therapeutic purposes. The airflow passageway may be any suitable
length. For example, the passageway may be as short as the airflow
resistor will allow (e.g., substantially just an opening that is
regulated by the airflow resistor). Similarly, the airflow
passageway may be longer than the space required to support the
airflow resistor. For example, in versions of the respiratory
device adapted for at least partial insertion into a nasal cavity,
the airflow passageway may be approximately as long as the length
of an average nares. In some versions, the passageway extends the
length of an average nasal chamber.
[0076] The neutral cross-sectional area of the passageway may be of
any appropriate size. Neutral cross-sectional area may refer to the
cross-sectional area of the passageway when the device allows air
to flow through the passageway without additional resistance (e.g.,
due to an airflow resistor). In particular, the size (e.g.,
diameter) or shape of the passageway may depend upon configuration
of the respiratory device. For example, respiratory devices
configured to be inserted within the nasal cavity (e.g., a nasal
chamber) may have an area that is approximately the area of a
narrow portion of the nasal cavity, or slightly narrower.
Respiratory devices configured to be secured over an oral cavity or
a nasal cavity may have passageways of larger diameters.
Furthermore, the cross-sectional area of a passageway may vary
along the length of the device.
[0077] The airflow passageway may comprise a dedicated structure
defining the inner wall of the airflow passageway, or it may be a
structural component of the device. For example, the passageway may
comprise a passage wall defined by a rim. A rim may be a tube (or
tunnel) of material of any appropriate thickness. The rim may also
be a frame, rather than a complete tube. The rim may comprise a
sufficiently rigid material so that it can support the passageway,
and prevent the passageway from collapsing during use and during
respiration. In some versions, at least a portion of the rim is
made of a compressible material that may be compressed to
facilitate insertion and removal, while maintaining the ability to
support the passageway and prevent complete collapse of the
passageway during respiration. The rim may also be somewhat
compressible during respiratory flow, or alternatively, it may be
rigid. The airflow passageway (including a rim portion) may also
serve as an attachment site for other components such as airflow
resistors, filters, anchors, holdfast etc.
[0078] A rim may be any suitable shape or size. For example, a rim
may comprise a ring shape or an oval shape. As mentioned above, a
rim may define the inner diameter of the passageway. In some
versions, the rim comprises a material having strength sufficient
to prevent the collapse of a respiratory device that has been
inserted into a nasal cavity. For example, the rim may comprise a
metal, a polymer (particularly stiff polymers), etc. In some
versions, the rim may comprise softer or "weaker" materials which
are formed or arranged so that the final shape of the rim has
sufficient strength to prevent the collapse of the respiratory
device during use.
[0079] As mentioned above, a respiratory device may include a rim
that is a tube or tubular body having a distal end and a proximal
end, through which the airflow passageway extends. In variations of
the device that are adapted to be secured in a subject's nasal
cavity, the distal end of the respiratory device is inserted first
into the subject's nose, so that the device is worn so that during
inhalation air flows from the proximal to the distal end of the
passageway, and during expiration air flows from the distal to
proximal end of the passageway. In some variations, the proximal
end of the tubular body has different properties from the distal
end. For example, the thickness of the tubular body from distal end
to proximal end may vary.
[0080] In some variations, the respiratory device has a tubular
body in which the distal end is more compliant than the proximal
end. Thus, the distal end may be more readily compressed for
insertion into the nasal cavity, while the proximal end is somewhat
more rigid, allowing for easier removal/insertion of the device. A
more compliant distal end may also help the device better tit a
subject wearing the device, and may enhance comfort. As described
more fully below, the distal region of the device may conform to
fit the nasal cavity.
[0081] In some variations, the distal end is more compliant than
the proximal end because different regions of the tubular body are
made from different materials or have different structures. For
example, a distal portion of the tubular body may have a wall
thickness that is less than the wall thickness of the more proximal
portion of the tubular body, as described in more detail below when
discussing FIGS. 25-28. The rim (e.g., tubular body) may have two
or more regions of different wall thickness, or it may have regions
of continuously varying thickness. The wall thickness may be
uniform for a given distal-to-proximal position (e.g., along the
length of a respiratory device's tubular body). As mentioned above,
the wall thickness of the tubular body (rim) may be zero in some
regions, meaning that the tubular body includes holes or windows,
or comprises a frame.
[0082] Regions of different wall thickness may result in different
regions of the airflow passageway having different diameters or
cross-sectional shapes. For example, in some variations the device
has a tubular body forming a passageway, and the inner wall of the
passageway includes a step or ledge along the inner wall of the
passageway. In one example, the outer diameter (OD) of the tubular
body is uniform while the inner diameter (ID) has at least two
different measures. As described in more detail below, this ledge
or step within the passageway may form a valve seal surface by
providing a surface on which a valve (e.g., a flap valve) may abut
or lie against when in the closed position.
[0083] In variations having a tubular body (i.e., rim), the tubular
body may have any appropriate cross-sectional area. For example, a
rim configured as a tubular body may have an elliptical
cross-section through its length that is shaped similarly to that
of most subjects' nares. This shape may help maximize the
cross-sectional size of the passage white maintaining comfort. In
any of the variations described herein, the passageway may comprise
any appropriate cross-sectional shape or shapes, such as circular,
polygonal, teardrop, or other asymmetric shapes.
[0084] In some versions, the respiratory device does not include a
separate rim forming the passageway. For example, the airflow
passageway of the respiratory device may be a passageway through a
holdfast.
[0085] The devices described herein typically include an airflow
resistor configured as a flap valve. An airflow resistor is
typically positioned in communication with the airflow passageway,
so that at least some of the air flowing through the passageway
passes the airflow resistor. Thus, an airflow resistor modulates,
alters, varies, or keeps constant the amount of resistance, the
degree of airflow, or the pressure differential across the device
or through a passageway in the device. In some versions, the
airflow resistor inhibits airflow more greatly in one direction
than the opposite direction. Thus, the airflow resistor may
regulate airflow to and from the lungs. Some versions of the device
have a greater resistance to exhalation than to inhalation during
use.
[0086] In some versions of the respiratory device, the airflow
resistor comprises a valve that does not appreciably impede airflow
in a certain direction (e.g., inspiration), and that partially or
completely impedes airflow in the other direction (e.g.,
expiration). In some embodiments, the valve allows for an
expiratory obstruction to be relieved if a certain degree of
airflow or pressure differential across the device is achieved, as
might be the case with coughing or nose blowing. For example, in
some embodiments, the valve comprises a flap made of a shape memory
or deformable material (e.g., an elastic material); when the
pressure differential across the valve (the expiratory airflow
pressure) is large enough, the flap bends upon itself, thereby
relieving the obstruction. This may be important during coughing
and may also facilitate the clearance of mucous and other
substances during coughing. After the cough, the flap returns to
its original, non-bent conformation. Alternatively, embodiments
that allow for relief of expiratory obstruction if a certain
airflow or pressure differential across the device is achieved may
act as a PEEP valve where PEEP refers to positive end expiratory
pressure.
[0087] Examples of different types of airflow resistors have been
previously described (e.g., in U.S. patent application Ser. No.
11/298,640), and may be shown in some of the figures below.
However, valve type airflow resistors, and particularly "flap
valve" resistors are of particularly interest. In general the
airflow resistor is capable of altering the resistance of air
passing through an air passageway during expiration and/or
inspiration, for example by selectively increasing the resistance
of air flow in one direction more than in the opposite direction.
Multiple airflow resistors may also be used, which may include
combinations of different types of airflow resistors (including
multiple flap valves).
[0088] A flap valve is an airflow resistor having one or more flaps
or leaves that may move to block or open a passageway. The flap may
be made of a stiff or flexible material, or some combination
thereof. In some variations, the flap valve includes a stiff region
of the valve, which may help give the flap support. In some
variations, the flap comprises a polymeric material, as described
below. The flap valve may be biased (e.g., in an open or a closed
position) or it may be unbiased. A bias element such as a spring
may be used, or the flap may be made of a material that has
elastomeric properties that bias the valve in a particular
position. A biased valve is a valve that tends to remain in a
particular position (e.g., flat, bent, open, closed, etc.) when at
rest. In some variations, the flap valve includes a flap made of an
elastomeric material such as silicone. In this variation, the flap
comprises a sheet of silicone that is cut (e.g., laser cut, dye
cut, etc.) so that the flap (or flaps) can cover the opening of the
device passageway when the valve is closed, and may bend to expose
the passageway to airflow when the valve is opened. The flaps may
be secured to the wall of the passageway (e.g., to the tubular
body). The flap valve (or other variations of the airflow resistor)
may also be used with additional components. For example,
respiratory devices may include an airflow resistor seal surface
(valve seal surface), an airflow resistor support (valve support),
and/or an airflow resistor aligner (valve aligner).
[0089] A flap of a flap valve may be continuously flexible. For
example, a flap may be made of a relatively flexible material such
as silicone (or other rubbers). Although these flaps may be
relatively stiff (e.g., depending on the shape, thickness, etc.),
they are typically bendable over the majority of the movable
portion of the flap. In using a continuously flexible flap as part
of the flap it may also be useful to include a support for the flap
(e.g., a flap valve support), as described in greater detail below.
In addition, nasal respiratory devices may be configured so that
the flap is protected within at least a portion of the device
during operation of the device (e.g., both when the flap is open
and when it is closed), preventing interfering contact with the
subject's nose.
[0090] The flap valve may be any appropriate shape, particularly
shapes in which the passageway may be blocked or at least partially
occluded. The flap is typically flat, though it may be any
appropriate thickness, and the valve may have any appropriate
surface area and surface shape. As described further below, the
passageway may have an elliptical or irregular cross-sectional
shape (e.g., when looking into the passageway from one end of the
valve). For example, when the device is inserted into the nose, the
passageway may have a substantially cross-sectional profile. Thus,
the flap valve may be substantially elliptical in shape (e.g., en
face shape) so that it may fit within the passageway. The flap may
therefore be substantially flat, but include an elliptical
(including oval), polygonal, or asymmetric (including tear-drop
shaped) cross-section.
[0091] A flap may be thin enough to allow the entire flap to flex
or bend, curving all along its length. In this variation, the flap
may move to provide a large opening even when only a very small
differential pressure is applied across the face of the valve.
Thin, highly flexible flap valves may be particularly useful when
used in conjunction with a support member, as described further
below.
[0092] A flap valve may also have any appropriate dimensions,
(e.g., thickness and surface area), so that it may block the
passageway of a respiratory device sufficiently to provide a
desired resistance to exhalation and/or inhalation during use. For
example, the flap valve may be anon-circular flap valve (e.g., an
elliptical flap valve), in which the ratio of the long axis of the
flap valve profile to the short axis of the flap valve profile is
between about 1.2:1 and about 3:1. In one variation, the long axis
of the non-circular profile is between about 8 mm and about 20 mm
long.
[0093] The respiratory devices described herein may also include
airflow resistor seals, airflow resistor supports, valve aligners,
and/or valve locks. For example, these devices may include a valve
seal surface that seats the airflow resistor when it is in the
closed position, permitting it to "seal." As used herein, a valve
seal surface does not have to provide a tight seal. A valve seal
surface may be provided so that the airflow resistor (e.g., flap
valve) operates in a predictable manner, for example, obstructing
the airflow through the passage to approximately consistent levels
when in the closed configuration. A valve seal surface may be a
seat or surface against which the valve portion of the airflow
resistor contacts when closed. When the airflow resistor is a flap
valve, the valve seal typically comprises a valve seal surface that
is a flat surface against which the flap valve, and particularly
the periphery of the flap valve, rests when the flap valve is
closed. As described in the examples below, and shown in FIGS.
30a-30b, the valve seal surface for a flap valve may comprise a lip
or ridge around the inner diameter of the passageway (e.g., the rim
or tubular body forming the passageway).
[0094] A valve seal surface may comprise any appropriate surface
for seating the valve. For example, the valve seal surface may
comprise a hard surface. In some variations, the valve seal surface
comprises a cushioned or compliant material which may help prevent
damage to the valve. The valve seal surface is typically smooth.
The valve seal surface may extend within the passageway. The
surface of the valve seal surface may be adapted to seat the edge
of the flap valve. For example, the valve seal surface may include
a flap seating surface that is parallel with the flap (when it is
in the closed position). The valve seal surface may also support
the valve, particularly around the perimeter of the flap. A valve
seal surface may be used as (or in addition to) a flap valve
support.
[0095] In some variations, the valve seal surface is not flat. For
example, the valve seal surface may be ridged, notched, or sinuous.
Such surfaces may help control the seating of a flap valve in order
to delay the complete closure of the flap valve. For example, a
flexible flap valve may seal with a non-flat surface more gradually
than it would with a flat surface when exposed to the same
differential pressure across the flap. Delaying closure and seal of
the flap valve to later in the exhalation cycle may be beneficial.
For example, it may make inhalation initially easier. Also, as
described further below, the valve seal surface may comprise a leak
path. For example, the valve seal surface may include one or more
passageways (e.g., missing regions) which do not permit sealing
with the flap valve.
[0096] A respiratory device may include a valve support. This
airflow resistor valve support (specifically referred to as a flap
support or a flap valve support) prevents the flap of the flap
valve from improper operation. For example, a valve support
appropriate for a flap valve may prevent the flap(s) of the flap
valve from collapsing when in the closed position or extending past
the closed position. For example, when a flap valve is configured
to open by moving the flap (or flaps) distally, a valve support may
be located adjacent to the flap valve proximally to restrict
proximal motion of the flaps. The flap valve support may be
configured to contact (or support) any region of the flap, but
particularly the more central portions of the flap. For example, a
flap support may support the appropriate center of the region of
the flap that moves.
[0097] A flap valve support may be a bar, post, notch, mesh, web,
cable, or the like, and typically projects into the passageway
behind a portion of the valve (e.g., the flap) to provide support.
The flap valve support may be stiff or flexible. A flap valve
support typically supports the moving member of the flap or flaps
in one or more positions. Flap valve supports may be used with any
airflow resistor. When used with a flap valve, the flap valve
support may prevent the flap from opening during one half of the
respiratory cycle, despite large pressures. For example, in one
variation of a device including a thin flap valve, the valve is
configured so that the flap bends easily in the distal direction to
"open" the valve and expose the device passageway during
inhalation. The flap may then return to the unbent position to
close over the passageway during exhalation. Pressure from the
subject's lungs during exhalation pushes against the flap. A flap
valve support located adjacent and proximally to the flap may
prevent this pressure from bending or buckling the flap proximally
and thereby opening the valve during exhalation.
[0098] In some variations, a valve support includes one or more
crossbars. As described further below, FIG. 27 illustrates a valve
support having two crossbars. In general a valve support is located
within the passageway, and presents a profile that only minimally
affects the airflow through the passageway. A valve support may
span the entire diameter of the passageway, or only a portion of
the passageway. In some variations, the valve support is a beam or
crosspiece that spans the passageway of the respiratory device.
[0099] A respiratory device may also include a valve aligner. A
valve aligner may be used to align the airflow resistor within the
passageway, particularly the movable portion of the airflow
resistor. Aligning the airflow resistor may make the movement of
the airflow resistor predictable. A valve aligner may also secure
the valve within the passageway. For example, a flap valve may be
used with one or more valve aligners so that the flaps open and
close without contacting the sides of the passageway, or otherwise
interfering with portions of the respiratory device. The valve
aligner may be used to hold the valve in place in conjunction with
a fulcrum support, as described further below. A valve aligner may
comprise a post, a notch, a knob, a socket, etc. In general, the
valve aligner mates with a portion of the valve. For example, a
flap of a flap valve may be positioned within the passageway by
mating with a post (valve aligner). The post may pass through a
hole in the flap valve that holds the valve in the passageway in
the correct position. Two posts, offset from each other, or a non
circular cross-section post may be used to orient the flap valve
within the passageway. An example of a valve aligner is shown in
FIG. 30a.
[0100] A respiratory device may also include a valve lock (e.g., a
flap valve lock) for securing the movable portion of a valve (e.g.,
the flap portion of a flap valve) within the passageway of the
device. A flap valve lock may enhance the safety of the respiratory
devices by preventing the flap from detaching from the device
during operation. A flap valve lock may be configured to prevent
the flap portion of a flap valve from separating from the device
even when the flap valve is exposed to large (e.g., physiologically
large) pressures applied to the device. In most applications the
flap valve lock prevents the flap valve from separating in the
distal direction within the passageway, since the valve support
typically restrains the flap valve in the proximal direction. Of
course, the distal and proximal orientations of the device may be
reversed, as described herein.
[0101] A flap valve lock typically comprises a restraining member
such as a pin, a cord (e.g., a fiber, thread, strap, etc.), a
button, or the like, that prevents the flap from separating from
the device. In some variations, the flap valve lock contacts the
flap. For example, the flap valve lock may be a cord or pin that
passes through a region of the flap. In some variations, the flap
valve lock is not connected directly to the flap, but prevents the
flap from separating from the device only when the flap moves into
contact with the flap valve lock. In variations of the device in
which a valve aligner is used, a valve lock may be used in
conjunction with the valve aligner to prevent the flap from
disengaging from the valve aligner. For example, if the valve
aligner is a post passing through the flap, a valve lock may be a
blocking element (e.g., a knob, button, cap, etc.) at the end of
the valve aligner preventing the flap from disengaging from the
respiratory device. If the flap moves down the valve aligner too
far in the distal direction, the valve lock prevents it from
separating from the valve aligner, and keeps the flap substantially
within the passageway.
[0102] The respiratory devices described herein may also include
one or more leak paths. A leak path allows air to flow through or
past the respiratory device even when the airflow resistor is
closed. A leak path may be included as part of any portion of the
device, including the holdfast, the rim (e.g., the tubular body),
or the airflow resistor. The sizes, locations and distributions of
the leak path(s) may be chosen to permit a desired amount of
airflow through the device at a known pressure and/or flow rate. In
particular, the leak path may be incorporated as part of an airflow
resistor. For example, the leak path may be one or more holes or
channels through a flap. A teak path may also be included as a
notch or region of the flap 3121 as shown in FIG. 31a. In FIG. 31a,
the airflow resistors are shown as portions of the periphery of the
flap valves which do not mate with a valve seal, allowing air to
flow past the flap valve even when the valve is in the closed
position. In some variations, the leak path is not included as part
of the valve.
[0103] As mentioned above, a flap valve may include one or more
passages or holes through which air can pass even when the flap
valve is closed. These leak paths may be chosen so that they
maintain a predetermined pressure across the closed airflow
resistor when air is flowing through or around the device at a
known flow rate. For example, in a flap valve, leak paths (e.g.,
holes) may be sized so that when the device is exposed to a
constant flow rate of 100 ml/sec, and the valve is in the closed
position, the pressure across the flap valve is between about 0.5
and 20 cm H.sub.2O, or between 3 and 15 cm of H.sub.2O. In one
variation the flap valve includes four holes having a diameter of
approximately 0.03 inches (.+-.0.01), resulting in a pressure of
approximately 8 cm H.sub.2O when exposed to 100 ml/sec airflow. Any
appropriate number and size leak paths may be included so that the
differential pressure between inhalation and exhalation may be
controlled. This is described in more detail below.
[0104] In general, the respiratory devices described herein affect
both the inspiratory and expiratory resistances in subjects wearing
the devices. In some variations, resistance during inspiration is
affected as little as possible, and resistance on expiration is
controlled to allow a leak of a specified amount of airflow. The
resistance to airflow in either inspiration or expiration may be
understood in terms of back-pressures at a given flow rate. Back
pressure can be defined as the differential pressure across the
valve, and is positive on the side of the valve from which the air
is flowing. For example, the back pressure during inspiration may
be <1 cmH.sub.2O, or more preferably, less than 0.3 cmH.sub.2O,
and most preferably less than 0.2 cm H.sub.2O, when measured at a
flow rate of 100 ml/sec. On expiration, it may be desirable to have
a back pressure of between about 0.1 to about 20 cmH.sub.2O (or
more preferably between 3 and 15 cm H.sub.2O) when measured at a
flow rate of 100 ml/sec (when the device is configured for both
nostrils). Both the back pressure on inspiration and back pressure
on exhalation are present in the same device. The flow rates
provided here are in reference to a nasal device having one or more
airflow resistors, and typically refer to a pair of airflow
resistors (e.g., one airflow resistor per nostril). When referring
to a single nostril device, the differential pressure (back
pressure) is measured at a flow rate that is typically 50 ml/sec.
Oral devices may use a corresponding flow rate.
[0105] The total leak path is the sum of the teak paths through the
device (e.g., the sum of all of the unregulated flow past the
device when properly worn by a subject). The devices described
herein may have a back pressure to inspiration that is between
about 0.01 and about 5 cm H.sub.2O, or between about 0.01 and about
2 cm H.sub.2O, or between about 0.1 and about 2 cm H.sub.2O, or
less than about 1 cm H.sub.2O. This gives a resistance to
inspiration (in cm H.sub.2O/ml/sec), when measured at a flow rate
of 100 ml/sec, of between about 0.0001 cm H.sub.2O/ml/sec to about
0.05 cm H.sub.2O/ml/sec, or between about 0.0001 cm H.sub.2O/ml/sec
to about 0.02 cm H.sub.2O/ml/sec, or between about 0.001 cm
H.sub.2O/ml/sec to about 0.02 cm H.sub.2O/ml/sec, or less than
about 0.01 cm H.sub.2O/ml/sec. The devices described herein may
have a back pressure during exhalation that is between about 0.1 cm
H.sub.2O and about 25 cm H.sub.2O, between about 1 cm H.sub.2O and
about 25 cm H.sub.2O, between about 2 cm H.sub.2O and about 20 cm
H.sub.2O, between about 3 cm H.sub.2O and about 20 cm H.sub.2O, and
between about 3 cmH.sub.2O and about 15 cm H.sub.2O. This gives a
resistance to expiration (in cm H.sub.2O/ml/sec), when measured at
a flow rate of 100 ml/sec, of between about 0.001 cm
H.sub.2O/ml/sec and about 0.25 cm H.sub.2O/ml/sec, or between about
0.01 cm H.sub.2O/ml/sec and about 0.25 cm H.sub.2O/ml/sec, or
between about 0.02 cm H.sub.2O/ml/sec and about 0.2 cm
H.sub.2O/ml/sec, or between about 0.03 cm H.sub.2O/ml/sec and about
0.2 cm H.sub.2O/ml/sec, or between about 0.03 cm H.sub.2O/ml/sec
and about 0.15 cm H.sub.2O/ml/sec.
[0106] The back pressure for inspiration and for expiration is
typically determined by the configuration of the leak paths and
airflow resistor. For example, in a device having a flap valve,
when the flap valve is closed during expiration, the back pressure
for expiration is typically a function of the leak paths through or
around the device, which may include leak paths through the flap as
well as leak paths through other portions of the device, such as
the body (e.g., rim) and the holdfast. In the same example, when
the flap valve is open during inhalation, the back pressure for
inspiration may be a function of the open passageway through the
device (regulated by the flap valve) plus any leak paths located on
non-flap regions of the device. Any leak paths on the flap
typically do not contribute to the back pressure for inspiration,
since (in this example) the passageway through the device that is
controlled by the flap valve is open. Flow through the leak path is
typically determined by the size, shape and location of the leak
paths (as well as the number of leak paths).
[0107] As described above, a leak path may be located anywhere on
the device, including the movable portion of the airflow resistor
(e.g., the flap of a flap valve), and on portions of the device
that are not the airflow resistor (e.g., the holdfast or the body).
Leak paths formed through non-airflow resistor (e.g., non-flap)
portions of the device may also be particularly beneficial because
they may be quieter and/or more predictable than leak paths through
movable portions of the airflow resistor. For example, a leak path
through a thin flap (particularly a silicone flap) may vibrate when
air flows through it.
[0108] A respiratory device may further comprise a holdfast for
releasably securing the device in communication with a nasal anchor
oral cavity. The holdfast may facilitate the positioning and
securing of the device in a desired location, such as over or
within, or both over and within, or at least partially within a
respiratory orifice. In particular, the holdfast may allow the
device to be anchored, positioned, and/or stabilized in any
location that is subject to respiratory airflow such as a
respiratory cavity.
[0109] Examples of respiratory cavities include nasal and oral
cavities. Nasal cavities may comprise the nostrils, nares or nasal
chambers, limen, vestibule, greater alar cartilage, alar fibrofatty
tissue, lateral nasal cartilage, agger nasi, floor of the nasal
cavity, turbinates, sinuses (frontal, ethmoid, sphenoid, and
maxillary), and nasal septum. The term "nasal cavity" may refer to
any sub-region of the Nasal Fossa (e.g., a single nostril, nare, or
nasal chamber).
[0110] In some versions, the holdfast may also secure a seal
between the respiratory device and the respiratory airway, so that
at least some of the air exchanged between the outside of the
subject and the respiratory airway must pass through the
respiratory device. In some versions, the holdfast seals the device
in communication with a respiratory cavity completely, so that all
air through that respiratory opening must be exchanged through the
device. In some versions, the holdfast seal is incomplete, so that
only some of the air exchanged between the subject and the external
environment passes through the device. As used herein, "air" may be
air from the environment external to the subject, or it may be any
respiratory gas (e.g., pure or mixed oxygen, CO.sub.2, heliox, or
other gas mixtures provided to the user). In some versions, the
holdfast may comprise an anchor or anchor region.
[0111] In some variations, the device is to be placed by the
subject or the healthcare provider in or around (or both) the nasal
cavity. Holdfasts appropriate for nasal cavities may secure the
device in position within a nasal cavity (e.g., through one or both
nostrils) or against surrounding structures. The holdfast may
comprise a shape, surface or material that secures the device in
communication with a nasal cavity. For example, the holdfast may
comprise a cylindrical shape that allows the device to fit securely
or snugly within a nostril. The outer surface of the device may be
formed by a holdfast including an adhesive material. In addition to
holding the device in place, the holdfast may also partially or
completely seal the device in communication with the nasal cavity.
The holdfast may comprise insertive and/or non-insertive
mechanisms. In some versions, the holdfast comprises a mechanical
connection between the device and the user, such as clips, straps,
and the like.
[0112] The holdfast may be formed from a soft or compliant material
that provides a seal, and may enhance subject comfort. Furthermore,
compliant materials may reduce the likelihood that the device cuts
off blood flow to the part of the respiratory cavity and
surrounding regions (mouth or nose) to which the device is
anchored. This compliant material may be one of a variety of
materials including, but not limited to, plastic, polymers, cloth,
foamed, spongy, or shape memory materials. Shape materials include
any that have a preferred conformation, and after being deformed or
otherwise deflected or altered in shape, have tendency to return to
a preferred conformation. Soft shape memory materials may include,
but are not limited to, urethane, polyurethane, sponge, and others
(including "foamed" versions of these or other materials).
Alternatively, the holdfast may not be soft or compliant and may
instead be a rigid structure that interfaces directly with the
respiratory orifice. For example, in versions of the respiratory
device configured to be used at least partially within a nasal
cavity, it is understood that the device may fit completely within
a nostril (or both nostrils), or may project out of the nostril,
depending on the particular embodiment. In some cases, the device
may be placed high enough within the nasal cavity so that it cannot
be seen within the nostril. In some embodiments the device may be
located completely outside of the nose, for example, in some
versions the holdfast has a shape that conforms to the outside
surface of the nose. Thus, the holdfast may comprise one or more
straps, bands, or the like to ensure an adequate fit and/or seal
maintaining the device in communication with the nasal cavity. In
another embodiment the holdfast may comprise one or more
projections that are inserted within the nostrils. In some
versions, a device may be placed at least partially in both
nostrils, and may comprise a bifurcated passageway or two
passageways that the holdfast places in communication with the
nasal cavity through each nostril. In this case, the inspiratory
and/or expiratory airflow to and from the lungs may be regulated
through each nostril separately or together. In some versions,
separate devices may be placed at least partially in each nostril,
and may be connected to each other and/or to the subject using a
clip, tether, strap, band, chain, string, or the like. Such a
system would facilitate subsequent removal of the device and make
migration of the devices deeper into the nasal cavity less likely.
Finally, in some devices, an adhesive flap may be present to help
attach the device to the inside or outside of the nose (including
the nostrils), to the oral cavity, to the neck, or to the face. The
use of an adhesive or any other means may prevent the inadvertent
or otherwise undesired removal of the devices during sleep.
[0113] The holdfast portion of a respiratory device may also be
shaped to fit within the subject's anatomy to secure the device in
place and/or to prevent leakage of airflow around the device. For
example, the holdfast may be shaped to fit within the widening of
the nasal cavity immediately inside the nares (opening of the
nostril). As mentioned above, the holdfast may conform to the walls
of a portion of the nasal cavity both to hold the device within the
nose, and also to prevent substantial leak of air around the device
when worn in the nose. Materials such as foams (e.g., foamed
polyurethane) may be particularly useful for this purpose, since
these materials may be readily compressed for insertion and rapidly
expand within the nasal cavity to secure the device in place.
[0114] A holdfast may be attached to a respiratory device. For
example, a holdfast may be attached to a rim. In one variation, the
holdfast is connected to the outer surface of the tubular body. A
holdfast may be glued, taped, stitched, welded, or otherwise
connected to the rim of a respiration device. In some variations
the holdfast circumferentially surrounds at least a portion of a
rim. For example, in one variation the distal end of the tubular
body (e.g., rim) of the device is ensheathed by a holdfast of
foamed material. In some variations, the holdfast thickness is
substantially uniform along most or the entire periphery of the
device. In some variations, it may have variable thickness, for
example it may be thicker or thinner at the long ends of the
device. In other cases, the holdfast thickness may be either
symmetrically or asymmetrically distributed. Similarly, the height
and length of the foam forming a holdfast may also be uniform or
non-uniform, symmetrically or asymmetrically distributed.
[0115] A holdfast may be thicker in some regions than in other
regions. For example, the cross-sectional profile of the holdfast
(e.g., the profile though the long axis of a respiratory device
including a holdfast) may be thicker in some places than in others.
In some variations, e.g., when the tubular body or passageway of
the device has an elliptical profile (cross-sectional profile) as
shown in FIG. 29, the holdfast in communication with the tubular
body is thicker near the long axis of the elliptical profile of the
tubular body than at the short axis of the tubular body. In some
variations, the thickness of the holdfast around the profile of the
tubular body cross-section is related to the diameter of the
passageway through the device. For example, the thickness of the
holdfast at any point outside of the passageway may be between
about 0.2 times and about 2 times the distance from the center of
the passageway to the outer edge of the tubular body around the
radius of the passageway. On an exemplary device having a tubular
body with an elliptical profile, the holdfast may be between about
0.8 mm and about 8 mm thick at the long axis of the elliptical
cross-section of the tubular body, and between about 0.4 mm and
about 4 mm thick at the short axis of the elliptical cross-section
of the tubular body.
[0116] The device may be removably secured by a holdfast, meaning
that the device may be inserted into the subject's nasal cavity for
some amount of time, and then removed. For example, a removable
holdfast exerts sufficient pressure on the nostril walls (e.g.,
within the nasal cavity) to hold the device in position without
harming the subject, or producing too much discomfort. The device
may be used continuously for an appropriate time period (e.g.,
overnight, such as 6-8 hours). Thus, the holdfast does not
generally need to be secured more permanently. The holdfast
material properties and shape typically lend themselves to easy,
fast, and pain-free insertion and removal. Thus, as described
herein, the holdfast may be a compressible/expandable foam
material. The shape and size of the holdfast may also be chosen to
appropriately secure the device within a subject's nasal cavity
comfortably. For example, the foam may have compression properties
that allow it to be readily compressed (for insertion into the
nasal cavity), but expand to fit the cavity quickly once inserted.
The holdfast may also have a thickness and width sufficient to fit
snugly but comfortably within the subject's (including an `average`
subject or range of different subject sizes) nasal cavity. In some
variations, the foam thickness is not uniform. For example, in some
variations, the ends of the holdfast region comprise a foam that is
thicker at the ends than in the middle, which may allow the device
to fit noses which are longer and narrower.
[0117] Respiratory devices may be made from any appropriate
material or materials. In certain embodiments, the devices include
a shape memory element or elements, as part of the holdfast, in the
airflow resistor, or in giving form to the passageway. Any
convenient shape memory material that provides for flexibility and
resumption of configuration following removal of applied force may
be employed in these embodiments. For example, shape memory alloys
may be used. A variety of shape memory alloys are known, including
those described in U.S. Pat. Nos. 5,876,434; 5,797,920; 5,782,896;
5,763,979; 5,562,641; 5,459,544; 5,415,660; 5,092,781; 4,984,581;
the disclosures of which are herein incorporated by reference in
their entirety. The shape memory alloy that is employed should
generally be a biocompatible alloy. Biocompatible alloys may
include nickel-titanium (NiTi) shape memory alloys sold under the
Nitinol.TM. name by Memry Corporation (Brookfield, Conn.). Also of
interest are spring steel and shape memory polymeric or plastic
materials, such as polypropylene, polyethylene, etc.
[0118] Rubber and polymeric materials may also be used,
particularly for the holdfast, rim, or airflow resistor. Injection
moldable materials such as polyether block amide (e.g.,
PEBAX.RTM.), and the like may be used. Materials which may be used
include: latex, polyethylene, polypropylene, polystyrene, polyvinyl
chloride, polyvinylidene chloride, polyvinyl acetate, polyacrylate,
styrene-butadiene copolymer, chlorinated polyethylene,
polyvinylidene fluoride, ethylene-vinyl acetate copolymer,
ethylene-vinyl acetate-vinyl chloride-acrylate copolymer,
ethylene-vinyl acetate-acrylate copolymer, ethylene-vinyl
acetate-vinyl chloride copolymer, acrylonitrile-butadiene
copolymer, polyacrylonitrile, polyvinyl chloride, polychloroprene,
polybutadiene, thermoplastic polyimide, polyacetal, polyphenylene
sulfide, polycarbonate, thermoplastic polyurethane, thermoplastic
resins, thermosetting resins, natural rubbers, synthetic rubbers
(such as a chloroprene rubber, styrene butadiene rubber,
nitrile-butadiene rubber, and ethylene-propylene-diene terpolymer
copolymer, silicone rubbers, fluoride rubbers, and acrylic
rubbers), elastomers (such as a soft urethane, water-blown
polyurethane), and thermosetting resins (such as a hard urethane,
phenolic resins, and a melamine resins).
[0119] Biocompatible materials may be used, particularly for those
portions of the device (e.g., the holdfast) which may contact a
user. In addition to some of the materials described above, the
biocompatible materials may also include a biocompatible polymer
and/or elastomer. Suitable biocompatible polymers may include
materials such as: a homopolymer and copolymers of vinyl acetate
(such as ethylene vinyl acetate copolymer and polyvinylchloride
copolymers), a homopolymer and copolymers of acrylates (such as
polypropylene, polymethylmethacrylate, polyethylmethacrylate,
polymethacrylate, ethylene dimethacrylate, ethylene dimethacrylate
and hydroxymethyl methacrylate, and the like),
polyvinylpyrrolidone, 2-pyrrolidone, polyacrylonitrile butadiene,
polyamides, fluoropolymers (such as polytetrafluoroethylene and
polyvinyl fluoride), a homopolymer and copolymers of styrene
acrylonitrile, cellulose acetate, a homopolymer and copolymers of
acrylonitrile butadiene styrene, polymethylpentene, polysulfones
polyimides, polyisobutylene, polymethylstyrene and other similar
compounds known to those skilled in the art.
[0120] A respiratory device may be oriented in any direction. For
example, in some embodiments, the airflow resistor comprises a flap
valve that is oriented such that the flap(s) are in a closed
position during expiration and in an open position during
inspiration, so that the airflow resistor increases resistance to
expiration, and has a relatively lower or negligible resistance to
inspiration. However, these devices can be oriented in the opposite
direction as well, so that the device offers increased resistance
to inspiration and decreased resistance to expiration. Such
orientation may be used for a variety of pulmonary, cardiac,
inflammatory, neurologic, or other disorders that might benefit
from such changes in resistance and its subsequent changes to
intra-thoracic and airway pressures. This version of the device may
be structurally identical to other embodiments described elsewhere
in this application. In some versions, the respiratory device is
reversible, so that it may be used in either orientation by the
user (e.g., to increase the resistance of inspiration relative to
expiration in one orientation, or to increase the resistance of
expiration relative to inspiration in another orientation). In one
variation, a respiratory device may be used in one nostril in an
opposite orientation to a respiratory device in the other nostril,
which may alternate through which nostril resistive inspiration or
expiration occurs.
[0121] In some versions, the respiratory device is shaped so that
the direction of the airflow resistor is immediately evident. For
example, the respiratory device may be of a different shape or size
on one end, or may include a visual indication. In one version, the
respiratory device may be shaped so that it fits securely into a
respiratory orifice only in one orientation (e.g., so that the
airflow resistor inhibits the expiration more than it inhibits
inhalation). For example, a flange or other mechanical stop may be
used to insure proper orientation, while simultaneously preventing
migration of the device further into the respiratory orifice.
[0122] In many embodiments, the device provides some level of
resistance to expiration. It may be preferable to have little if
any effect on resistance to inspiration, though in some cases, some
degree of inspiratory restriction may be beneficial. In some
versions of the device, both inspiration and expiration may be
inhibited by the airflow resistor.
[0123] The device may also be adapted for comfort. Any device
placed either in or around the oral cavity or in or around the nose
should not cause undue pain or discomfort, and if possible, should
not be noticeable by the subject. Thus, the holdfast may be shaped
to conform to the attachment site in or around the respiratory
orifice. In some versions, the holdfast comprises a flexible or
shapeable material (e.g., a foam or other soft shape-memory
material). In some versions, the entire respiratory device
comprises a soft material.
[0124] When using devices that feature a foam on the portion of the
device that fits within or otherwise communicates with the inside
of a nostril, the device may be inserted by the subject or
healthcare provider foam end first. It may be helpful to insert a
corner of the device into the nostril and then rotate the device
into place. The device may then be gently pulled outward (without
removing the device from the nostril) so that it rests in the
correct position and provides a seal between the periphery of the
device and the nasal cavity or nostril.
[0125] The user may be instructed to breathe through his/her/its
mouth or nose, whichever is more comfortable. If the device is
going to be worn by a subject during sleep, the user may be
instructed to breathe primarily or relatively primarily through his
mouth while he is still awake. This may make the sensation of
expiratory resistance and pressure easier to tolerate, it is
expected that when the subject goes to sleep, he will revert
primarily or at least partially to nose breathing, thus promoting
the beneficial effects of the device. The subject devices may also
be used with any commercially available device that promotes
closure of the mouth during sleep, including but not limited to
straps, mouthguards, tape and the like.
[0126] In some cases, a nasal cannula or other means of monitoring
nasal airflow (such as a thermistor) may be attached, fixed, or
non-fixably positioned within or near the device to allow various
diagnostic parameters to be measured. In some cases, the nasal
cannula or other diagnostic device may be held in place with tape
(on the face for example, near the chin or cheek). By attaching the
diagnostic device to the device, it is less likely that inadvertent
or undesired motion will shift or displace the device while
sleeping or otherwise during use. In some cases, the subject device
may be extended or otherwise altered or changed to allow the
placement of the nasal cannula.
[0127] In other cases, an intranasal pressure probe or sensor may
be placed beyond the device (deeper within the nasal cavity or
nostril) to provide a pressure reading for the airways, nose, and
other respiratory pathways.
[0128] Furthermore, the device may be adapted so that it is more or
less visible to others. In some cases, the device may be configured
to be placed high enough within the nostrils to make it difficult
for others to see. Furthermore, the device may be of any color
and/or pattern that help to camouflage it. In other versions, it
may be useful to include colors and patterns that stand out,
including ones that are fluorescent or otherwise offer increased
visibility during the night or other setting where ambient light is
reduced.
[0129] In some versions, the respiratory device may be "one size
fits all", so that it may be used with any subject (or any subject
of approximately the same size), despite differences in shapes and
sizes of their nose/nostrils, oral cavity, teeth and other relevant
anatomic features. In one version, the devices may conform to a
range of sizes, for example "small," "medium," and "large" (or any
other appropriate range, such as, e.g., a numerical range).
Alternatively, the devices may involve a custom fit of the device
or devices to the subject.
[0130] Custom fitting may improve subject comfort and potentially
improve performance by improving the seal between the device and
the subject's oral cavity, mouth, nasal cavity and nostrils, for
example. In some versions, custom fitting may involve the placement
of a device in warm or cold liquid or air with subsequent placement
in the subject's nose or mouth. This process is meant to "prime"
the materials in the device (e.g., particularly the materials of
the holdfast), so that when the holdfast is secured to the subject,
the device permanently assumes a shape or configuration
corresponding to a portion of the subjects anatomy.
[0131] In some cases, the device may be over the counter (OTC) and
in other cases, it may require a prescription. Some possible
indications for the device will include but not be limited to steep
apnea, snoring and upper airway resistance syndrome. In other
cases, the device may be used to improve athletic performance,
heart or lung function, or improve oxygenation. In some cases, the
devices will be reusable. In some cases, the devices will be
disposable after one or more uses. The devices may be modular; for
example, at least one component or subassembly of the device may be
reusable and at least one component or subassembly may be
disposable.
[0132] As described above, the device may include one or more holes
or air leak paths even in the closed position, so that some air may
pass through the device even if the holdfast forms a relatively
tight seal with the nasal cavity. For example, the airflow resistor
(e.g., flap valve) may include one or more holes providing an air
leak path. The size of the holes may be configured to allow a
predetermined rate of airflow through the holes when a certain
pressure is applied (e.g., by the user's breathing). For example
holes may be small (e.g., having diameters of 0.030 inches.+-.0.010
inches). In some variations, multiple holes are used. The total
leak through the leak path may be the sum of the leak through all
of the leak paths (e.g., holes). The size and number of leak paths
may be chosen based on the desired I:E ratio, as described
below.
[0133] A leak path (e.g., a hole) may be on any appropriate region
of the device, on the holdfast, on the rim, or on some combination
of these. In some variations, the leak path may be provided by
removing a portion of the airflow resistor, as illustrated in FIG.
31b. For example, a portion of the edge of a flap valve may be
missing, providing a leak path, or the flap valve may include one
or more holes. In variations in which the holdfast comprises a
foamed material, the foam itself may provide a leak path.
[0134] One example of a respiratory device in operation is
illustrated in FIGS. 32a and 32b. The illustrated device 3200 is
adapted to be removably secured in communication with a nasal
cavity, and is shown inserted into a schematically-illustrated
nasal cavity so that the holdfast region (shown here as foam 3205)
is in communication with the nostril walls 3207. The respiratory
device includes a flapper valve 3209 and a tubular body 3211. The
device is oriented so that it provides a significant resistance to
airflow during exhalation. FIG. 32a shows the device during
inhalation, in which air is drawn into the lungs through the
proximal opening in the device and out of the distal end of the
tubular body. The airflow is shown by the grey arrows 3215.
Pressure exerted by the subject during inhalation opens the flap
valve 3209, permitting air to pass through the passageway. During
exhalation, pressure pushes air from the lungs into the distal end
of the device towards the proximal end, through the tubular body,
causing the flap valve 3209 to close, as shown in 32b. The valve
includes a leak path, holes 3220 in the valve and non-valve region
(not shown). Because the combined leak path (the opening provided
by the holes) is smaller than the unobstructed nasal passage, and
smaller than the passage through the open device illustrated in
FIG. 32a, the pressure on the distal side of the valve will be
greater than it would be during the unobstructed situation, or if
the valve were opened. Thus, exhalation is limited by the valve to
the leak path. This may prolong expiration, and may also result in
a positive end expiratory pressure (PEEP) effect.
[0135] In general, the devices described herein may create a PEEP
effect by differentially changing the resistance to airflow in one
direction based on the pressure applied against the device. For
example, in some designs, expiratory airflow is subjected to
resistance by the airflow resistor (or valve) until a certain
threshold pressure differential or level of airflow is achieved;
below that threshold, a more complete closure of the airflow
resistor occurs (potentially completely occluding airflow through
the device). The desired levels of PEEP are on the order of about
0.1 to about 30 cm H.sub.2O and more preferably about 1 to about 15
cm H.sub.2O pressure. Similarly, the differential resistance may
also be triggered in the opposite direction; for example, above a
certain threshold of pressure or level of airflow, the airflow
resistor (e.g., valve) may open to decrease the resistance due to
the airflow resistor, as when a subject coughs, sneezes, or blows
his or her nose.
[0136] In some cases, the device may offer a variable resistance
that is lower during the start of expiration (to promote comfort
and tolerance) and that continues to increase (in a stepwise or
more gradual fashion) for the remainder of expiration. In many
cases, at the end of expiration, PEEP will be maintained. In still
other cases, there will not be PEEP at the end of exhalation.
[0137] The use of an airflow resistor may also alter the
inspiratory time:expiratory time ratio (I:E ratio), which is
defined as the ratio of inspiratory time to expiratory time. The
desired I:E ratio will be between about 3:1 and about 1:10 and more
preferably about 1:1 to about 1:4 depending on the needs of the
individual subject. In some versions, the desired ratio is
approximately about 1:2.
[0138] In some versions, the device comprises an insertion,
adjustment, or removal mechanism. In some cases, this mechanism
involves any appropriate rigid or non-rigid positioner that
facilitates removal or positioning of the device. Non-rigid
positioners include but are not limited to cables, chains, wires,
strings, chains, sutures, or the like. Rigid positioners include
knobs, handles, projections, tabs, or the like. A user may grasp or
otherwise manipulate the positioner to facilitate insertion,
re-adjustment, or removal of the device. Furthermore, various
applicators or other insertion devices may be used. For example, a
tubular applicator holding a respiratory device adapted for
insertion into a nasal cavity may be advanced into the nasal
respiratory orifice (e.g., nostril) to insert the respiratory
device.
[0139] In some cases, devices that insert into the respiratory
orifice are oversized, or larger than the cavity (orifice) that
they are to be inserted into. Oversizing the device may reduce
resistance in one or more direction of airflow. In some versions,
the passageway through the device is oversized. In some versions,
an outer portion of the device that contacts the respiratory
orifice is oversized. Thus, the respiratory device may exert
pressure against the nasal cavity of a user. In subjects with
obstructive sleep apnea or snoring, for example, increasing the
size of a respiratory device configured to be inserted into one or
more nostrils may prevent the more distal tissues of the airway,
tongue, and nasopharynx from being sucked in or closed during
inspiration. Moreover, airflow through an oversized passageway may
assume a less turbulent flow profile, resulting in a decreased
propensity for noise production in the case of snoring, for
example. Similarly, the respiratory device passageway may be shaped
so as to decrease turbulence of airflow. Likewise, the shape and
activity of the airflow resistor may be chosen to minimize
turbulence and, therefore, sound or vibration.
[0140] In some versions, devices comprise a passageway and a
holdfast and may or may not include additional support such as a
rim. In some cases, the holdfast may be of adequate strength to
support and prevent migration or movement of the device, and to
provide adequate radial support to prevent reduction of the
passageway of the device during the various phases of the
respiratory cycle.
[0141] In operation, the user may be asked to clean his or her
nose, trim or clip his or her nose hairs, and remove all or
substantially all nasal mucus or boogers. The device, especially if
it is at least partially composed of foam or other deformable
material, may be squeezed to reduce its size prior to insertion
into the nasal cavity or nostril. In some cases, the deformable
material may expand or swell over time, providing a comfortable fit
and/or seal. In some cases, water or water vapor may facilitate or
expedite said swelling or increase in size. In some cases, water or
other liquids may fill in holes within open cell foam, therefore
improving seal.
[0142] The respiratory devices may be manufactured and assembled
using any appropriate method. Representative manufacturing methods
that may be employed include machining, extruding, stamping, and
the like. Assembling methods may include press-fitting, gluing,
welding, heat-forming, and the like.
[0143] Any of the features described herein may be used with
respiratory devices. Certain of the figures show features described
herein, particularly FIGS. 25 through 34. FIGS. 1-24 help
illustrate general principles of respiratory devices. Turning now
to the figures, FIG. 1 provides a perspective view of one version
of a respiratory device 1 in which the device can lit into the oral
cavity of a user. The holdfast 5 comprises grooves 2 and 3 in which
the user's teeth and/or gums may preferentially sit, thus securing
the device in the oral cavity. Airflow resistor 4 represents any
airflow resistor capable of modulating inspiratory and/or
expiratory resistance during any or all portions of the respiratory
cycle, as described above. The airflow resistor 4 sits within a
passageway 6.
[0144] FIG. 2 is a perspective view of another embodiment of the
respiratory device 1 that may be fitted in an oral cavity. In this
embodiment, the subject's teeth and/or gums help to secure the
device in place by contacting the holdfast. The holdfast comprises
an inner frame 10, and outer frame 12, and a positioner 14. The
inner frame 10 is located on the internal portions of the subject's
teeth or gums. The outer frame 12 is positioned outside the
subject's teeth/gums or outside the subject's lips. The positioner
14 is located between the upper and lower jaws, teeth, and/or gums.
An airflow resistor 4 modulates inspiratory and/or expiratory
resistance during any or all portions of the respiratory cycle.
[0145] FIG. 3 is a view of the device 1 shown in FIG. 2, where the
device is depicted within and protruding from the subject's oral
cavity. The outer frame 12 of the holdfast is shown outside of the
subject's teeth and gums. The airflow modulator 4 within the
passageway 6, modulates inspiratory and/or expiratory resistance
during any or all portions of the respiratory cycle through the
oral respiratory passageway. One or more airflow resistors 4 and/or
passageways 6 may be used in this (or any, e.g., oral or nasal)
respiratory device.
[0146] FIG. 4 is a perspective view of another embodiment of the
respiratory device 1 in which the device is removable and may be
secured within a subject's nasal cavity 16. In this embodiment, the
device protrudes from the nasal opening. The sides of the device
comprise a holdfast which is shown fitting snugly within the nasal
passage, as well as projecting out from the nasal passage.
[0147] FIG. 5 is a perspective view of another version of the
respiratory device 1 in which the device is placed completely
within the nasal passage 16. The entire respiratory device fits
snugly within the nasal passage.
[0148] FIG. 6 is a cross-sectional view of a respiratory device 1
similar to those shown in FIGS. 4 and 5. A holdfast 28 comprises
the outer surface of the device that contacts the inner portions of
the nasal cavity, thus serving to secure the device in place while
ideally creating a partial or complete seal. The passageway 6
through which air may flow is surrounded by a rim 30 that provides
additional structural support to the device. A rim 30 is not
required, particularly if the walls of the passageway (which may be
defined by the holdfast 28, for example) provide sufficient
support. An airflow resistor 24 is included within the passageway
which may modify inspiratory and/or expiratory resistance during
any or all portions of the respiratory cycle.
[0149] FIGS. 7a and 7b show more detailed views of the operation of
airflow resistors shown in FIGS. 4 and 5. These cross-sectional
views illustrate the holdfast 28, the optional rim 30, the
passageway 6, and the airflow resistor, shown as a valve 32. The
rim 30 separates the holdfast 28 and the valve 32, frames the valve
32, and provides overall structural support to the entire device.
In FIG. 7a, the valve 32 is shown in the open position, providing
less resistance to airflow. In FIG. 7b, valve 32 is shown in the
closed position, providing more resistance to airflow, because the
cross-sectional area of the passageway 6 has been constricted by
the closing of the valve.
[0150] FIGS. 8a and 8b show perspective views of an airflow
resistor that could be used, for example with any of the devices
described in FIGS. 1-5. In these figures, a rim 30 is shown. The
rim may be part of the holdfast which positions and secures the
device within a respiratory passageway; alternatively, additional
material (e.g., compliant material) may be attached to the rim to
form the holdfast. In FIGS. 8a and 8b, the rim provides support to
the airflow resistor 24. The airflow resistor is shown here as a
flap valve mechanism that comprises a flap 36 that pivots around a
joint 38 and is connected to a fixed element 40. Fixed element 40
is attached to the inner region of the passageway 6, which is
defined in this figure by the rim 30. In some versions, the flap
valve and the inner surface of the passageway 6 (e.g., the rim 30)
may constitute a single piece. Alternatively, the flap 36, joint
38, and fixed element 40 may be fabricated as a single piece, in
which case joint 38 may be a hinge. Thus, joint 38 may be a pinned
hinge or a non-pinned hinge joint. Alternatively, rim 30, flap 36,
joint 38, and fixed element 40 may all be created as a single piece
or material. Thus, flap 36 is able to pivot in relation to fixed
element 40 depending on the direction of the subject's airflow and
the desired level of resistance to airflow. FIG. 8a shows the
airflow resistor with flap 36 in a closed position during
expiration, thus providing increased resistance. In some versions,
the flap portion of the airflow resistor closes completely, as
shown. In these versions, the edges of the flap 36 may close off
the entire passageway (as shown), or may only occlude a portion of
the passageway. FIG. 8b shows the airflow resistor with flap 36 in
the open position (e.g., during inspiration), thus providing
decreased resistance. Flap 36 may define a hole, or may have other
openings (which may stay open during all or part of the respiratory
cycle) to help modulate the degree of inspiratory and expiratory
resistance. The flap 36 may return to a preferred opened or closed
position. For example, a bias such as a shape memory material, a
spring (such as a torsion spring), or the holdfast may apply force
to flap 36 to return it to a closed position. For example, the use
of foam or urethane surrounding the airflow resistor may provide
such force as to close flap 36 in the absence of adequate airflow.
Bi-leaflet versions of the airflow resistor are also contemplated
and wilt have similar function. These bi-leaflet versions may
involve multiple sets of flaps 36, joints 38, and fixed elements
40, etc.
[0151] FIGS. 9a and 9b show a perspective view of another
embodiment of an airflow resistor that could be used in any of the
respiratory devices described herein. The inner surface of the
passageway shown includes a rim 30 that supports the airflow
resistor. This airflow resistor 24 is also shown as a valve
mechanism. Moveable elements 42a and/or 42b (flaps) are attached to
one another or are constructed from a single piece. Moveable
elements 42a and 42b are attached to the inner surface of the
passageway (shown as a rim 30) at attachment points 44a and 44b,
and these attachment points may allow the valve to pivot around a
hinge 43 in response to direction and amplitude of airflow. In one
version, attachment points 44a and 44b are formed directly into the
rim 30 or holdfast 28 during the manufacturing (e.g., casting)
process. In one version, the hinge is statically attached to an
inner region of the passageway, and the flaps 42a and 42b are
movably (or flexibly) attached to the hinge. FIG. 9a shows this
airflow resistor when the resistance is high (e.g., the flap valve
is mostly closed), as during expiration, and FIG. 9b shows the
airflow resistor when the resistance is low (e.g., the flap valve
is mostly open), as during inspiration.
[0152] FIG. 10 shows a perspective view of another embodiment of an
airflow resistor that is similar in structure and function to the
device shown in FIGS. 9a and 9b. However, the airflow resistor
shown has an internal opening 45 that is located approximately
where moveable elements 42a and 42b pivot relative to one another.
The addition of internal opening 45 modulates airflow (e.g.,
inspiratory or expiratory airflow) by altering the level of
resistance. Addition of this opening reduces the resistance in one
direction (e.g., expiratory resistance, when the flap valve is
"closed") more than resistance in the opposite direction (e.g.,
inspiratory resistance, when the flap valve is "open").
[0153] FIG. 11 shows a perspective view of another embodiment of an
airflow resistor that is similar in structure and function to the
device shown in FIGS. 9a and 9b. Peripheral openings 46a and 46b
are placed completely within, or on the periphery of the moveable
elements 42a and 42b. These peripheral openings 46a and 46b also
modulate inspiratory and/or expiratory resistance. The addition of
peripheral openings 46a and 46b helps modulate inspiratory and
expiratory airflow by altering the level of resistance. Addition of
these peripheral openings also reduce the resistance in one
direction (e.g., expiratory resistance, when the flap valve is
"closed") more than resistance in the opposite direction (e.g.,
inspiratory resistance, when the flap valve is "open").
[0154] FIGS. 12a and 12b show more detailed views of the operation
of the valve mechanisms as described in FIGS. 9a, 9b, 10, and 11.
In this figure, we assume that the airflow resistor is oriented so
that the airflow resistor increases resistance during expiration
relative to inhalation (e.g., the lungs are located to the right in
FIGS. 12a, 12b and 12c). Moveable elements 42a and 42b are coupled
to each other via hinge 43. FIG. 12a demonstrates the valve
mechanism during expiration, in which moveable elements 42a and 42b
are in a closed position due to the expiratory airflow in the
direction from the lungs to the external environment. FIG. 12b
demonstrates the valve mechanism during inspiration, in which
moveable elements 42a and 42b are in an open position due to the
inspiratory airflow in the direction from the external environment
to the lungs. FIG. 12c demonstrates a modification of the valve
mechanism shown in FIGS. 12a and 12b in which there are one or more
apertures within or on the periphery of the moveable elements that
reduce resistance to expiratory airflow, further increasing the
rate of expiratory airflow. All of these valve mechanisms and
configurations can be placed in the opposite orientation so that
inspiratory airflow leads to valve closure and expiration leads to
valve opening.
[0155] Moveable elements (flaps) 42a and 42b of the airflow
resistor may be made of any appropriate material. In particular,
materials which have sufficient stiffness to withstand the forces
applied by the respiratory process. Furthermore, durable materials
(e.g., which may withstand the moisture, etc. of the respiratory
passage) may also be desirable. In some versions, the devices are
disposable, and thus durability may be less critical. Furthermore,
the moveable elements 42a and 42b may also be made from porous
materials or filters, etc. that do not overly restrict or resist
airflow but at the same time can remove debris, pollen, allergens,
and infectious agents for example.
[0156] FIGS. 13a and 13b show perspective views of another airflow
resistor that could be used in any of the devices described herein.
FIG. 13a shows the airflow resistor (a flap valve) in a closed
position, as might be seen during expiration, resulting in
increased resistance to airflow. FIG. 13b shows the airflow
resistor in an open position, as might be seen during inspiration,
resulting in a decreased resistance to airflow relative to the
closed position. Because of the small profile of the retracted flap
valves, the resistance added by the airflow resistor when the
airflow resistor is "open" may be negligible. Moveable elements 42a
and 42b are attached to each other or are a single piece. Moveable
elements 42a and 42b are attached to the walls of the passageway
(in this example, defined by a rim 30), to the rim 30, or to the
holdfast 28 by a securing element 54a and 54b which uses a tab,
adhesives, press fit, external pressure (as from a holdfast 28) or
any way known to those skilled in the art. Internal opening 45 is
located centrally, decreasing the resistance to expiratory airflow
(in the "closed" state), although peripheral locations are also
contemplated. In some versions, the size and number of openings
(e.g., the leak paths) in the valves may determine the resistance
of the airflow resistor during expiration and inspiration.
[0157] FIG. 14 provides a perspective view of another embodiment of
an airflow resistor that is similar in structure and function to
the airflow resistor shown in FIGS. 13a and b. In FIG. 14, the
movable elements further comprise a flap reinforcement 60a and 60b
that is located partially or completely covering the moveable
elements 42a and 42b. The flap reinforcement provides additional
structure and/or stiffness to these moveable elements. Furthermore,
flap reinforcement 60a and 60b may also promote a more reliable
seal and may standardize the movements of moveable elements 42a and
42b while reducing the likelihood that moveable elements will
invert, buckle in the direction of airflow, or otherwise fail,
especially when exposed to high pressures and airflow as might be
seen during coughing, although an additional flap valve support
(not shown) may also be used. The addition of flap reinforcements
60a and 60b also dampens any whistling or other sounds during
inspiration or expiration. Moveable element 42a and flap
reinforcement 60a and moveable element 42b and flap reinforcement
60b may be a single unit (or each "flap" may be a single unit).
Alternatively, both moveable elements 42a and 42b and both flap
reinforcements 60a and 60b may be a single unit. A central leak
path opening 45 is also shown in the figure.
[0158] FIGS. 15a-15c show perspective views of another embodiment
of an airflow resistor that may be used in any of the devices
described herein. The airflow resistor is similar to that shown in
FIGS. 13a and 13b with the exception that internal opening 45 is
replaced by another airflow resistor 64 (a "nested airflow
resistor"). This nested airflow resistor 64 automatically closes
when the flow through the valve (or the pressure differential
across the valve) falls below a predetermined level. This allows
the airflow resistor (with the nested airflow resistor region) to
provide positive end expiratory pressure (PEEP). In FIG. 15a, the
airflow resistor is shown during exhalation, and the moveable
elements 42a and 42b of the airflow resistor are in the closed
position. The nested portion of the airflow resistor 64 is open no
long as the pressure differential across the airflow resistor
and/or airflow is above a certain level. Thus, this figure
demonstrates the beginning of expiration, when airflow in the
passageway and pressure differential are largest. In FIG. 15b, the
same airflow resistor is again shown during expiration, and
moveable elements 42a and 42b of the airflow resistor are still in
the closed position. However, the nested airflow resistor region 64
now assumes a closed position, since the pressure differential
across the airflow resistor and airflow through the passageway is
no longer above the threshold value. This scenario may correspond
to the later stages of exhalation, when airflow and pressure
differential are decreasing or are lower. Thus, at the end of
exhalation, PEEP has been created. For example, the nested airflow
resistor 64 may be set to close whenever air pressure in the
respiratory orifice coming from the lungs is less than 10 cm
H.sub.2O, or less than 5.0 cm H.sub.2O, or any value from 1 to 25
cm H.sub.2O. FIG. 15c shows the device during inhalation, in which
moveable elements 42a and 42b of the airflow resistor are in the
open positions, allowing inhalatory airflow with minimal resistance
to said airflow.
[0159] FIG. 16 is a perspective view of another embodiment of the
respiratory device where the device is removable and may be placed
in communication with the nasal cavity. In FIG. 16, a holdfast 28
is located between the subject's nose and the airflow resistor in
the device 1, providing a partial or complete seal, anchoring the
device, and providing comfort for the subject. The holdfast 28 has
a cross section that is roughly circular and capable of fitting
within a subject's nostrils.
[0160] FIG. 17 is a perspective view of another embodiment of a
respiratory device where the device is removable and may be placed
within the nasal opening. This device shows a holdfast 28 having an
approximately oval cross-section. Many such cross-sectional shapes
are possible to optimize placement, anchoring, sealing, and
comfort, including a variety of conical or asymmetric shapes
designed to fit within a subject's nasal openings. In some cases,
the rim 30 and/or any air flow resistor 4 may also assume any
desired cross sectional shape, including that of an oval or any
other non-circular orientation. In some embodiments, the holdfast
28 will be shapeable, deformable, or adjustable by the subject
either before, after, or during placement of the device.
Alternatively, the device can be customizable to fit individual
subjects through the use of imaging modalities including MRI, CT,
x-ray, or direct vision, or through the use of molding techniques
that are common in dentistry and other fields.
[0161] FIG. 18 is a cross-sectional view of an embodiment of a
respiratory device where the device is removable and may be secured
in fluid communication with a nasal cavity. The device comprises a
holdfast 28 and rim 30 that lends the device support. The device
may be oversized to decrease resistance and increase airflow in one
or more directions. In some cases, a drug (with either an active or
inactive ingredient) may be embedded in or located on any of the
device's components, for example, the rim 30. It is appreciated
that in some cases, there may be no rim 30, so long as structural
support is provided by another component of the device, e.g., the
holdfast. In this case, the drug may be loaded or coated on the
holdfast or within the passageway.
[0162] FIG. 19 shows a cross-sectional view of another embodiment
of a respiratory device where the device is removable and may be
secured in communication with a nasal cavity. In this figure, there
are two airflow passageways. Each passageway is shown with an
airflow resistor 24 therein. The holdfast 28 surrounds both
passageways, and each passageway includes an (optional) rim 30.
Each of the flow resistors 24 may increase or decrease resistance
to airflow independently and may work simultaneously or at
different times during the respiratory cycle. For example, in some
cases, during inhalation, one of the airflow resistors 24 may
decrease resistance to airflow while the second airflow resistor 24
increases resistance to airflow. On exhalation, the first airflow
resistor 24 may increase resistance to airflow white the second
airflow resistor 24 decreases resistance to airflow. In other
words, inspiratory airflow may proceed through one location, and
expiratory airflow may proceed through a second location within the
same device.
[0163] FIG. 20 is a cross-sectional view of another embodiment of
the respiratory device where the device is removable and may be
secured in communication with a nasal cavity. The device is shown
with a fixed filter 98 that is located in the path of the airflow
as it traverses the device. The fixed filter 98 may help clear the
airflow of any solid or liquid particles, debris, odors, allergens,
pollen, and/or infectious agents. This filter 98 may remain roughly
fixed in place during all parts of the respiratory cycle though
some degree of movement may be permitted. A drug may be placed
within or on the surface of one or more components of the device to
provide additional benefit to the subject. The addition of fixed
fitter 98 may not lead to increased resistance in either direction,
unless such a design is desired. The fixed filter 98 can be created
from any number of filter materials that are known to those skilled
in the art. This fixed filter 98 may be used in any of the
respiratory devices herein, in addition to, or as an alternative
to, an airflow resistor 4.
[0164] FIG. 21 is a cross-sectional view of another embodiment of
the respiratory device, where the device is removable and may be
secured in communication with a nasal cavity. The respiratory
device of FIG. 21 comprises a moveable cleansing filter 100 that is
shown located within the device, and which may help to clear the
airflow of solid or liquid particles, debris, odors, allergens,
pollen, and/or infectious agents. In some versions, the filter may
be configured to move so that it filters only during inhalation (or
exhalation), or may move out of the way during periods of extremely
large airflow (or air pressure) in the airflow passageway (e.g.,
during coughing, nose blowing, sneezing).
[0165] FIGS. 22a and 22b are perspective views of one version of a
moveable cleansing filter where the moveable cleansing filter is
shown during inhalation and exhalation respectively. A movable
cleansing filter may be a movable filter, scrubber, or any other
device capable of removing (particularly selectively removing) any
solid or liquid particles, debris, odors, allergens, pollen, and/or
infectious agents. This moveable cleansing filter may be used in
any of the respiratory devices herein, in addition to, or as an
alternative to, an airflow resistor 4. FIG. 22a shows the moveable
cleansing filter (shown as movable filters) during inspiration
(during which airflow travels from right to left in the figure)
leading to displacement of moveable filter elements 102a and 102b
away from one another. FIG. 22b shows the moveable cleansing filter
during expiration (during which airflow travels from left to right
in the figure) leading to displacement of moveable filter elements
102a and 102b towards one another. Thus, on inspiration, airflow
passes through the moveable filter elements 102a and 102b and the
air may be cleansed of the relevant substances. On expiration,
airflow passes both through and around moveable filter elements
102a and 102b. The addition of moveable filter elements 102a and
102b ideally does not lead to increased resistance in either
direction, unless such a design is desired. The moveable filter
elements 102a and 102b can be created from any number of filter
materials that are known to those skilled in the art. One or more
openings or apertures may be placed within the moveable filter
elements 102a and 102b to alter inspiratory or expiratory
resistances.
[0166] FIG. 23 is a perspective view of another embodiment of the
subject devices where the device is removable and secured in
communication with both nasal cavities. Nasal mask 108 is
positioned securely against the nose and face in order to minimize
or eliminate the possibility of air leak around the periphery of
the device. The device includes a holdfast comprising straps 110a
and 110b (that facilitate the secure positioning) and a nasal mask
108 that is secured against the face by the straps. The mask's
airflow resistor 116 modulates inspiratory and/or expiratory
resistance during any or all portions of the respiratory cycle.
There is at least one airflow resistor 116 located on the device,
though two or more airflow resistors 116 may be used (e.g., one
placed in proximity to each nostril). An adhesive may find use with
this embodiment, to help promote a seal or anchoring of the
device.
[0167] FIG. 24 is a cross-sectional view of another embodiment of a
respiratory device, where the device is removable and may be
secured in communication with a nasal cavity. In FIG. 24, a
respiratory device further comprises a respiratory gas supply. A
respiratory gas inlet 120 is shown attached to the respiratory
device, providing gas, such as pure oxygen or mixed oxygen to the
passageway. An airflow resistor 24 is included within the
passageway which may modify inspiratory and/or expiratory
resistance during any or all portions of the respiratory cycle. In
some versions of the device, the airflow resistor 24 during
exhalation may feature a flap mechanism in which the flap partially
or completely occludes respiratory gas inlet 120, thereby only
providing release of gas when the subject is inhaling and the flow
resistor 24 is therefore open to some degree. The device that
provides the respiratory gas may be permanently or non-permanently
fixed, attached, or otherwise coupled to the holdfast, rim, or
airflow resistor via a press fit, adhesive, or in some other
fashion. In some cases, the respiratory gas supply may be an
off-the-shelf device that that provides respiratory gas, as is
currently available from multiple manufacturers.
[0168] FIGS. 25 to 28 illustrate components of respiratory devices
configured for use in a subject's nasal cavity, similar to the
device illustrated in FIG. 29. FIG. 25 shows a perspective view of
a rim portion of a respiratory device. The rim is configured as a
tubular body 2501. FIG. 26 shows a side view of this tubular body
2501. The tubular body 2501 has openings at the distal and proximal
ends to allow air to flow through the internal passageway formed by
the rim. This passageway can be seen in FIG. 27, looking down
through one end of the rim. In this variation, two flap valve
supports 2507, 2507' are shown spanning the passageway. The flap
valve is not shown. Two valve aligners 2511, 2511' project off of
one of bars of one of the valve supports 2507'. In this variation,
these valve aligners are posts which can pass through the flap
valve (not shown) and orient and secure the flap. In FIGS. 27 and
28, measurements (given in inches) are shown merely to illustrate
one example of dimension that may be used. Other variations may
include other dimensions).
[0169] FIG. 28 shows a cut-away side view of half of this rim
showing part of a valve support (crossbar 2507). As described
above, the rim includes a proximal region 2513 and a distal region
2515. The distal region may be inserted into the subject's nasal
cavity first, so that air leaving the subject's lungs during
exhalation passes from the distal end towards the proximal end. The
distal portion of the rim corresponds to the distal end of the
device. As mentioned above, a flap valve (not shown) may contact
the flap valve support 2507. In embodiments such as the one shown
here, the device includes a distal region that is configured so
that the flap valve cannot extend past the opening at the
distal-most end of the device (e.g., the distal-most edge of the
rim), even when the flap valve is completely opened. Thus, the rim
may protect the flap valve and allow its full range of motion. Also
as described above, the wall thickness of the distal region 2515 is
thinner than the wall thickness of the proximal region 2513. This
discrepancy in wall thickness may form a lip or ledge within the
passageway at the interface between the proximal and distal region
of the device. A lip is not visible in the device shown in FIG. 27
or 28 because it is blocked from view by the crossbar spanning the
central portion of the passageway. FIGS. 30a and 30b illustrate
another example of a respiratory device in which this lip (which
forms a valve seal surface) is visible.
[0170] FIG. 29 shows a perspective view of a respiratory device
incorporating the rim shown in FIGS. 25-28. This device includes a
tubular body 3001, a passageway 3003, and a holdfast 3005 connected
to the distal region of the tubular body. The holdfast shown is a
foam ring that ensheathes the elliptical tubular body. A
cross-sectional view of this device (taken through line A-A' along
the midline of the flap valve) is shown in FIG. 30a, and FIG. 30b
shows detail of the indicated region (B''). In FIGS. 30a and 30b
the flap valve 3009 is shown in the closed position, and a valve
seal surface is located between the flap valve 3009 by the lip 3015
formed on the inner wall of the tubular body 3001. The edge of the
flap 3009 rests against this valve seal surface (lip 3015). In this
variation, the lip 3015 is formed from the different wall
thicknesses of the distal region 3011 and the proximal region 3013
of the rim. These regions have the same outer diameter (OD), but
different inner diameters (IDs).
[0171] The flap valve shown in FIGS. 30a and 30b is aligned within
the passageway of the device by valve aligners 3021, and the flap
can be secured in position by including a flap valve lock around
which the valve can move. In the variation shown in FIGS. 30a and
30b, the flap valve lock is configured as a fulcrum support 3025
and is formed from a flexible material such as a suture. In
general, the flap valve lock secures the flap of the flap valve (in
this example, the flexible flap) so that it cannot separate from
the device. The flap valve lock in FIGS. 30a and 30b is connected
to the valve aligners 3021. The flap valve lock (suture) passes
through the wall of the passageway, over the flap valve, and
through the posts of the valve aligner. Thus, the suture `locks`
the flap in place. A flap valve lock may prevent the flap valve
from disengaging from the valve aligner. For example, a flap valve
lock may comprise a cap or projection that communicates with the
valve aligner to prevent the flap valve from disengaging from the
valve aligners.
[0172] In some variations, the flap valve lock may also act as a
fulcrum support. A fulcrum support is typically a point, line or
surface about which the flap valve moves. Any appropriate fulcrum
support may be used, including a pin (e.g., comprising a metal,
plastic or other polymer, etc.), or fibrous material (e.g., thread,
suture, etc.) that acts as a fulcrum, supporting the flap valve so
that it can move. In some variations, a flap valve does not use a
fulcrum support. As shown in FIG. 30a, the fulcrum support 3025
extends across the width of the flap valve, passing through the
valve aligners 3021, and into the sides of the rim. As mentioned
above, this suture is also a flap valve lock that secures the flap
in place (shown in detail in FIG. 30b). In general, however, a
fulcrum support does not have to be a flap valve lock. Likewise, a
flap valve lock does not have to be a fulcrum support. For example,
a flap valve lock may comprise a cage structure (e.g., a wire cage)
that surrounds the flap valve, preventing it from leaving the
device, but does not provide a point, line, or surface about which
the valve moves. Thus, a respiratory device may include a flap
valve lock but not a fulcrum support. A respiratory device may also
include a fulcrum support but not a flap valve lock.
[0173] FIG. 31a shows a view looking into a respiratory device
(similar to the one shown in FIG. 30) from the distal end. The flap
valve 3009 is shown in outline only, so that two valve supports
3105, 3105' can be seen. A valve seal is not shown in FIG. 31a. The
two valve supports form a cross-shape within the passageway of the
device. When the flap valve is closed (as illustrated), the flap
may rest against the valve supports. The flap valve also includes
four leak paths 3109 through the flap valve through which air may
pass. These leak paths are shown as small holes, though any
appropriate shape (e.g., round, square, oval, polygonal, etc.) may
be used. Two additional holes are shown through which valve
aligners 3111 pass to align and/or secure the flap valve. These
exemplary valve aligners comprise two posts projecting from the
valve support.
[0174] As described above, the flap valve 3009 may be a thin and
flexible piece of silicone. This flap may be any appropriate
thickness that allow it to be flexible (e.g., to bend from the open
and closed positions). For example, the flap may comprise silicone
that is approximately 0.002 inches thick. In this example, the flap
valve is matched to the cross-sectional shape of the passageway, so
that it may close off passage through the passageway when in the
closed position. The exemplary respiratory devices shown above may
be manufactured by any appropriate method. For example, the tubular
body, flap valve supports, and valve positioners may be injection
molded as a single component from a material such as polyether
block amide (e.g., PEBAX.RTM.), which is somewhat flexible and
biocompatible. The flap valve may be die cut from a sheet of
silicone (e.g., medical grade silicone), including any leak paths.
These components may be manually or automatically assembled, and
the flap valve may be secured in place by a fulcrum support (e.g.,
a suture, as described above), an adhesive, or the like. A holdfast
may be attached to the outer portion of the tubular body,
particularly the distal region of the tubular body.
[0175] As mentioned, the holdfast may be polyurethane foam. The
foam may be pre-molded into the appropriate shape, or it may be cut
(e.g., die cut, water jet cut, laser cut, etc.) into a ring or
other appropriate shape and attached to the tubular body. For
example, the foam may be attached via an adhesive (e.g., tape,
glue, etc.). In one variation, the foam is cut from a strip of foam
that is attached around the tubular body. The foam may be any
appropriate size so that the device is secured within a subject's
nasal cavity. In some variations, the foam is between about 1/4 and
1/8 of an inch thick. The thickness of the foam holdfast may vary
around the diameter of the device. For example, the foam holdfast
may be thicker at the ends of an elliptical cross-section so that
it conforms better to the shape of a subject's nasal cavity,
particularly in the region immediately within the subject's nose,
past the nares.
[0176] The aforementioned devices and methods of using them may
provide a first airflow resistance to airflow from proximal airways
to distal airways (inhalation) and a second flow resistance to
airflow from distal airways to proximal airways (expiration). In
some of the respiratory devices described herein, the resistance to
expiration is sufficient to cause the subject to inhale prior to
reaching a complete expiration, causing PEEP during the expiration
cycle. In some respiratory devices described herein, when
expiratory airflow and/or expiratory airway pressures fall below a
threshold (one that is too low to keep an airflow resistor
mechanism open), expiration airflow will be stopped, leading to
PEEP. As a result, normal inspiration, normal expiration, and PEEP
are accommodated while offering potential benefits to the subject,
including clinical benefits.
[0177] FIG. 33 is a cross-sectional view though one variations of a
nasal respiratory device having a flap valve, similar to the view
shown in FIG. 30a. In this example, a leak pathway through a
non-flap portion of the device 3405. The flap 3412 is attached to
the rim (or body) 3410 of the device by two posts 3407, and each
post has a flap lock 3408, which is a cap-like stop on the end of
the posts in this variation. These posts 3407 act as flap valve
aligners. The body 3410 is surrounded by a tapered, foamed holdfast
3414 that may be used to secure the device at least partially
within a subject's nostril. The flexible flap may bend to open
during inhalation (while staying secured by the flap valve aligners
3407) but is prevented from opening during exhalation because of a
flap valve support (not apparent in this section). Air may pass
through the leak path through the body of the device 3405 either
when the flap is closed, or when it is open, as indicated by the
double arrows. In addition, leak paths on the flap 3403 are visible
in the top view of FIG. 34.
[0178] FIG. 34 is a top view of the same valve shown in FIG. 33. In
FIG. 34, the rim body is an oval shape, as described above, and the
foam holdfast 3414 is substantially circular. The flap 3012
includes leak paths 3403 in addition to the leak paths through the
rim 3405. Three non-flap leak paths are shown.
Uses of the Respiratory Devices
[0179] The respiratory devices and methods described herein my be
used for a variety of therapeutic and non-therapeutic purposes. A
description of some of these uses is given below. The respiratory
devices and methods described herein may be used in other ways as
well, and these examples are not to be considered exhaustive.
[0180] Generally, the respiratory devices described herein may
improve the respiratory and cardiovascular function of a person in
need thereof (e.g., a patient or subject). Thus, these respiratory
devices may be used therapeutically, for example, to cure, treat or
ameliorate the symptoms of a variety of medical disease states.
Furthermore, the respiratory devices may be useful in generally
improving the health and well being of any person.
[0181] Disease states which may be treated by the devices and
methods described herein include but are not limited to: heart
failure (right-sided and/or left-sided), COPD, pulmonary edema,
steep apnea (including obstructive and/or central),
sleep-disordered breathing, Cheyne-Stokes respiration, insomnia,
snoring and other sleep disorders, asthma, bronchomalacia, acute
lung injury, ARDS, sinusitis, allergies, hey fever, nasal
congestion, cystic fibrosis, hypoxemic respiratory failure,
gastroesophageal reflux disease, hiatal hernia, heartburn,
hypertension, myocardial infarction, arrhythmia, cardiomyopathy,
cardiac valve disease (either stenosis or regurgitation of the
mitral, aortic, tricuspid, or pulmonic valves), stroke, transient
ischemic attack, increased cerebral pressure, a variety of
inflammatory diseases, and degenerative neurologic conditions.
Moreover, the devices may be beneficial for subjects being weaned
off mechanical ventilation, as well as post-operative patients.
[0182] The increased pressure within the airways may reduce the
amount and frequency of pulmonary edema, a common consequence of
heart failure. Afterload and preload on the heart may also be
affected; for example, afterload and preload may be decreased in
subjects with heart failure. Filling pressures may be increased or,
more likely, decreased. Decreasing filling pressure may potentially
benefit subjects with failing hearts. Gas exchange may improve in
many cases, leading to increases in pO.sub.2 and decreases in
pCO.sub.2. In some cases, the level of pCO.sub.2 may actually
increase or become more stable and less likely to fluctuate. This
increase in the stability of pCO.sub.2 levels may lead to profound
benefits in subjects with central sleep apnea and in subjects with
Cheyne-Stokes breathing, for example. Oxygen saturation levels may
improve. Oxygen desaturations which may result from apneas or
hypopneas may no longer drop as far. For example there may be fewer
oxygen desaturations to the 80-89% range. Fewer oxygen
desaturations may drop below 90%. Duration of desaturations may
also be reduced. The use of the device to reduce oxygen
desaturations (perhaps leading to performance enhancement) while
awake or asleep may represent a viable market opportunity for the
device.
[0183] In some cases, the use of an expiratory resistor will
interfere with loop gain, and will thus promote more stable
breathing. In other cases, the device will reduce the amplitude,
duration, and frequency of snoring.
[0184] Any location within the body that is exposed to respiratory
airflow (including but not limited to the upper airway, trachea,
bronchi, nasopharynx, oropharynx, nasal cavity, oral cavity, vocal
cords, larynx, tonsils and related structures, back of the tongue,
sinuses, and turbinates) may benefit from the increased airway
pressure and increased duration of expiratory airflow. In some
cases, there will be a reduction in swelling and edema in these
locations, leading to increased diameters of the airways and
conduits in which the airflow passes. This leads to less of a
tendency for these structures to collapse upon inhalation.
Moreover, these structures may be less prone to create noise on
inspiration or expiration, thereby reducing the quantity and/or
quality of snoring. Put another way, the reduction of edema in the
airways may make it less likely that these structures will collapse
and may reduce the volume and frequency of snoring, apnea, or
hypopnea. Furthermore, reduction in swelling and edema and improved
lymphatic flow due to these positive pressures may reduce nasal
congestion, inflammation, and sinusitis for example.
[0185] The respiratory device may also increase lung compliance.
For example, lung compliance may increase partially if fluid which
might otherwise be in the lung and alveoli is driven away by the
increased airway pressure. This increased lung compliance may make
it easier to breathe and may require less effort and force on the
part of the subject to displace the diaphragm a certain distance to
achieve a certain tidal volume. Moreover, increased lung compliance
may decrease the pressure differential between the alveoli and
mouth. As this pressure differential decreases, it becomes less
likely that an inhalation attempt will induce a collapse of the
upper airway. Thus, an increase in lung compliance may herald a
reduction in the frequency or severity of obstructive sleep apnea
or hypopnea episodes. Similarly, snoring frequency and severity
(volume) may be reduced for similar reasons.
[0186] The respiratory device may also improve ejection fraction.
This effect may be mediated via increases in intra-thoracic
pressure and alterations in transmural pressures and the beneficial
effects on preload and afterload on the failing heart. In addition
to left-sided benefits to the heart, there may also be benefits
afforded to the right side of the heart. Improving ejection
fraction with the respiratory devices described herein may result
in positive short- and long-term changes to the energetics and
biologic properties of the heart tissue. Some of these positive
changes may mimic the positive remodeling changes seen in hearts
treated with various complicated cardiac support devices such as
those developed by Acorn Cardiovascular (St. Paul, Minn.) and
Paracor Medical (Sunnyvale, Calif.). These expiratory resistors use
the subject's own intra-thoracic pressure to "support" the
subject's heart. Moreover, because the support potentially provided
by the respiratory devices described herein is not limited to just
the ventricle, it may support the atria, which can also be severely
affected by heart failure and other cardiac or pulmonary diseases.
There may be reductions in left ventricular and left atrial sizes,
both in the shorter and longer term. Furthermore, cardiac
sympathetic activation may be reduced, and cardiac output may be
increased or decreased depending on the nature of the resistance
provided.
[0187] There are a variety of other beneficial effects of enhanced
expiratory resistance and increases in intra-thoracic pressure that
may be achieved with the respiratory devices described herein.
Examples include decreased heart rate and blood pressure. There may
be a reduction in the number of arrhythmias, including but not
limited to atrial/supraventricular and ventricular
atrial/supraventricular and ventricular tachycardias, heart block,
and other common arrhythmias. Thus, the respiratory devices
described herein may also reduce the incidence of sudden cardiac
death and other cardiac disorders. Furthermore, coronary perfusion
may be expected to increase. Further, expiratory resistance and
increased intra-thoracic pressures may lead to improvements in
gastroesophageal reflux disease (i.e., heartburn), gastritis.
Barrett's esophagus, esophageal cancer, hiatal hernia, and other
causes of diaphragmatic hernia. This effect may be mediated by the
compression of the esophagus located within the thorax due to the
increased intra-thoracic pressures. As a result, food and other
stomach contents may no longer be able to reflux superiorly into
the esophagus, which is otherwise common when subjects are lying
down. Furthermore, hernias (primarily hiatal) may be reduced and
pushed back into the abdomen by the increased intra-thoracic
pressure. The use of these respiratory devices may have beneficial
effects on other gastroenterologic conditions beyond those already
described.
[0188] Cardiac valve disease, including but not limited to mitral,
tricuspid, pulmonic and aortic regurgitation, and mitral,
tricuspid, pulmonic and aortic stenosis may also benefit from the
respiratory devices described herein. In particular, the
respiratory device may effect mitral regurgitation and may help
prevent further annular dilatation (a byproduct of heart failure
and generalized heart dilation).
[0189] Use of the respiratory devices described herein will result
in a reduction in respiratory rate, which may be very helpful in
diseases such as COPD, asthma, hyperventilation, and anxiety
disorders including panic attacks, among others. The ratio of
inspiratory time to expiratory time (I:E ratio) may be decreased
with the device. Tidal volumes may increase as well. For example,
in COPD, the increased resistance may facilitate improved
expiratory function. This may also allow the subject to benefit
from larger tidal volumes and increased minute ventilation. In
embodiments in which the respiratory device creates PEEP (positive
end expiratory pressure), the amount of PEEP (or resistance
generated by the device) may overcome some, or all, of the
intrinsic PEEP that is common in subjects with COPD. In subjects
with COPD or other pulmonary disorders, gas exchange may improve.
In this case, gas exchange refers to the removal of CO.sub.2 from
the body and addition of O.sub.2 into the blood stream from
inspired air. Thus, pO.sub.2 may increase and pCO.sub.2 may
decrease, particularly in subjects with COPD, but more generally in
all subjects treated with the device. Moreover, oxygen saturation
may increase, reflecting an increase of oxygen binding to
hemoglobin.
[0190] Other benefits offered by the respiratory device may include
a reduction in diaphragm fatigue and improved efficiency of the
accessory muscles of inspiration. This may make breathing
significantly easier in subjects with pulmonary disease, and more
specifically COPD and cystic fibrosis.
[0191] As previously mentioned, the respiratory devices described
herein may decrease respiratory rate. It has been shown that slowed
breathing techniques can lead to a reduction in blood pressure.
Thus, the device may reduce blood pressure in a subject, including
subjects with hypertension (systemic and pulmonary). The reduction
in blood pressure may be systolic and/or diastolic. Reductions in
blood pressure may be on the order of 1-70 mm Hg systolic or
diastolic. This may bring the subject to normal (<140/80 mm Hg)
or near normal (<160/100 mm Hg) levels. In subjects who are
being treated for hypertension, the device could be used as an
adjunctive therapy to drugs or as a stand-alone therapy in some
subjects. In some versions, a respiratory device as described
herein may be used for short periods (minutes, hours, or longer)
over a span of days to weeks to months to offer longer term
benefits for weeks or months after the cessation of therapy.
Treatments may last 15 seconds to 24 hours and may be repeated over
a regular or irregular interval, for example, on the order of hours
to days. The devices may be worn at night or day, while awake or
during sleep, to slow respiratory rate. A reduction in blood
pressure and/or heart rate may be seen while the device is in
place, or after the device has been removed. This may be due to
hormonal influences whose effects last longer than the period in
which the device is in place. More specifically, the device may
work though either a sympathetic or parasympathetic pathway.
[0192] Expiratory resistance may also prolong expiratory time,
which may reduce the respiratory rate. Thus, the devices described
herein may be used to reduce respiratory rate. This may have
benefits in treating insomnia, since it may promote a sense of
relaxation in the user, through increased parasympathetic
stimulation, decreased sympathetic simulation, and/other hormonal
and non-hormonal effects. This may also promote a sense of well
being or relaxation that may allow the user to fall asleep easier
and quicker and improve sleep quality and quantity. Thus, the
respiratory devices described herein represent a novel
non-pharmacologic method of treating insomnia and promoting
relaxation. The device may be used throughout the day and/or night
to promote said relaxation and well being.
[0193] The respiratory devices described herein may also be used to
treat or ameliorate disorders characterized by ineffective,
non-productive, or otherwise disturbed inspiration (including but
not limited to obstructive sleep apnea or restrictive pulmonary
disease). For example, with the device in place, a subject may be
more likely to have slightly elevated lung volumes after
exhalation. Put another way, more air than normal may be present in
the lungs after exhalation when using some versions of the device.
Fewer alveoli may be collapsed; thus inhalation may be easier
because it will require less effort to re-open the alveoli during
the subsequent breath. Moreover, pulmonary congestion and pulmonary
edema may also be reduced, so compliance may be improved. As a
result, it may require less effort for subjects to inhale. It
follows that a smaller pressure differential (between the alveoli
and the mouth) will be required. The smaller the pressure
differential, the less likely that the subject's conducting airways
(including the upper airways and pharyngeal tissues) will collapse,
thus reducing the likelihood of obstructive sleep apnea, hypopnea,
and snoring.
[0194] Infectious diseases may also benefit from the respiratory
devices described herein. These diseases include but are not
limited to pneumonia (community and hospital acquired),
tuberculosis, bronchitis, HIV, and SAPS.
[0195] The respiratory devices may also be useful in pulmonary or
cardiac rehabilitation. For example, the device may find use in
subjects with chronic pulmonary disease including but not limited
to chronic bronchitis, emphysema, asthma, pulmonary fibrosis,
cystic fibrosis, and pulmonary hypertension. Alternatively, the
devices may benefit subjects with cardiac disease, including but
not limited to: angina, myocardial infarction, right or left sided
heart failure, cardiomyopathy, hypertension, valve disease,
pulmonary embolus, and arrhythmia.
[0196] Subjects with obesity may also benefit from the use of the
respiratory devices described herein. Obesity can contribute to
exercise intolerance partially because it increases the metabolic
requirement during activity and alters ventilatory mechanics by
reducing functional residual capacity (FRC) and promoting
atelectasis. Obesity may also reduce cardiac reserve, since a
higher than normal cardiac output response is required during
physical activity. This in turn may cause systemic hypertension,
which increases left ventricular afterload. Thus, the device,
through its potential reduction in atelectasis and beneficial
effects on FRC, cardiac output, and blood pressure may be useful in
subjects with obesity.
[0197] It has been suggested that expiratory positive airway
pressure (as induced by the subject devices) may increase neural
drive to the muscles that serve to maintain upper airway patency.
Furthermore, FRC increases may improve length-tension relationships
of the inspiratory muscles, allowing inspiratory pressures to
decrease. This reduction of inspiratory pressure would thus make it
less likely for the upper airway to obstruct, presumably due to a
reduction in the transmural pressure gradient. As previously
suggested, expiratory positive airway pressure may improve
ventilation-perfusion relationships which may improve oxygen
saturation.
[0198] Furthermore, it is known that the upper airway partially or
completely occludes during the expiratory phase of the breaths
preceding an occlusive apnea. It is this narrowing of the upper
airway at end-expiration that sets the stage for total occlusion
during the next inspiration as subatmospheric pressures are
generated within the airway. Expiratory positive airway pressure
may therefore prevent airway narrowing during expiration, thus
reducing the propensity toward total occlusion during inspiration.
The phenomena of lung hysteresis may also provide therapeutic
benefit.
[0199] The subject devices are also expected to improve sleep
quality, duration and architecture.
[0200] The respiratory devices may also be used by athletes, for
example, during both aerobic and non-aerobic activities, partially
because of the potentially beneficial direct effects on the heart
and on gas exchange. In some versions, the respiratory device may
be oversized, to increase the amount of inspiratory airflow,
potentially increasing the amount of oxygen transmitted to the
lungs for gas exchange.
[0201] The respiratory devices described herein may also be used
for therapeutic and non-therapeutic effects on sleep. Sleep quality
may be improved, with more slow-wave sleep, fewer arousals, and
improved REM sleep. The user may have more productive sleep and may
be less tired during the day. Furthermore, the beneficial effects
of the device may extend beyond the period of use, and into the
daytime as well, even when the device's use is limited to the night
(e.g., when the user is sleeping). In some cases, sympathetic
discharge may be reduced and/or parasympathetic discharge may be
increased. Thus, the device may have positive benefits on the
autonomic nervous system. This may offer beneficial systemic
effects as well as local effects, some of which have already been
described.
[0202] The respiratory devices described herein may also be used in
other locations besides the nasal and oral cavities. Indeed, any
location in the body that serves as an entry or exit location for
respiratory airflow or serves as a conducting airway or conduit for
airflow may benefit from the use of the devices described herein.
For example, a device may be used within, on the external surface
of or near a stoma site (e.g., for use in a subject after a
tracheostomy).
[0203] Inflammation (which is present in a variety of disease
states) may also be reduced using the respiratory device, possibly
via the aforementioned parasympathetic or sympathetic mediated
effects and/or effects of the vagus nerve and its stimulation. The
treatment of any condition mediated by an inflammatory cytokine
cascade is within the scope of the devices and methods described
herein. In some embodiments, the respiratory device is used to
treat a condition where the inflammatory cytokine cascade is
affected through release of pro-inflammatory cytokines from a
macrophage. The condition may be one where the inflammatory
cytokine cascade causes a systemic reaction, such as with septic
shock. Alternatively, the condition may be mediated by a localized
inflammatory cytokine cascade, as in rheumatoid arthritis. Examples
of conditions which may be usefully treated using the respiratory
devices described herein include, but are not limited to:
appendicitis, peptic, gastric or duodenal ulcers, peritonitis,
pancreatitis, ulcerative, pseudomembranous, acute or ischemic
colitis, diverticulitis, epiglottis, achalasia, cholangitis,
cholecystitis, hepatitis, Crohn's disease, enteritis, Whipple's
disease, asthma, allergy, anaphylactic shock, immune complex
disease, organ ischemia, reperfusion injury, organ necrosis, hay
fever, sepsis, septicemia, endotoxic shock, cachexia, hyperpyrexia,
eosinophilic granuloma, granulomatosis, sarcoidosis, septic
abortion, epididymitis, vaginitis, prostatitis, urethritis,
bronchitis, emphysema, rhinitis, cystic fibrosis, pneumonitis,
pneumoultramicroscopicsilicovolcanoconiosis, alvealitis,
bronchiolitis, pharyngitis, pleurisy, sinusitis, influenza,
respiratory syncytial virus, herpes, disseminated bacteremia,
Dengue fever, candidiasis, malaria, filariasis, amebiasis, hydatid
cysts, burns, dermatitis, dermatomyositis, sunburn, urticaria,
warts, wheals, vasulitis, angiitis, endocarditis, arteritis,
atherosclerosis, thrombophlebitis, pericarditis, myocarditis,
myocardial ischemia, periarteritis nodosa, rheumatic fever,
Alzheimer's disease, coeliac disease, congestive heart failure,
adult respiratory distress syndrome, meningitis, encephalitis,
multiple sclerosis, cerebral infarction, cerebral embolism.
Guillame-Barre syndrome, neuritis, neuralgia, spinal cord injury,
paralysis, uveitis, arthritides, arthralgias, osteomyelitis,
fasciitis, Paget's disease, gout, periodontal disease, rheumatoid
arthritis, synovitis, myasthenia gravis, thryoiditis, systemic
lupus erythematosus, Goodpasture's syndrome, Behcets's syndrome,
allograft rejection, graft-versus-host disease, diabetes,
ankylosing spondylitis, Berger's disease, Retier's syndrome, or
Hodgkins disease.
[0204] Furthermore, the respiratory devices and methods of using
them may be used by or applied to a variety of different types of
animals. Representative animals with which the methods and devices
find use include, but are not limited to: canines; felines;
equines; bovines; ovines; etc. and primates, particularly humans.
The respiratory devices described herein may also be packaged for
use. For example, the respiratory devices may be packaged
individually or as a set (e.g., in sets of pairs, particularly in
variations in which an individual device is used with each
nostril). Furthermore, the packaging may be sterile, sterilizable,
or clean.
[0205] The respiratory devices described herein may also be
provided as part of a kit that includes at least one of the
devices. Examples of kits may include a respiratory device and
instructions for how to use the device. The instructions are
generally recorded on a suitable recording medium. For example, the
instructions may be printed on a substrate, such as paper or
plastic, etc. As such, the instructions may be present in the kits
as a package insert, in the labeling of the container of the kit or
components thereof (i.e., associated with the packaging or
sub-packaging) etc. In other embodiments, the instructions are
present as an electronic storage data file present on a suitable
computer readable storage medium, e.g., CD-ROM, diskette, etc. The
instructions may take any form, including complete instructions on
how to use the device, or references, directing a user to using
additional sources for instructions (e.g., a website address with
which instructions posted on the world wide web).
[0206] The device may be used in a clinical study, wherein said
clinical study involves comparing sleep data from a subject with
the device in place to sleep data from the same subject without the
device in place. Any duration of the sleep study shall suffice,
from minutes to hours.
[0207] The device may be used in subjects who have already
undergone ENT surgery to help their sleep apnea and/or snoring.
This combination of surgery and use of the device may thus reduce
AHI, snoring and other relevant parameters. Similarly, the use of
weight reduction or sleep position therapy may find use in
conjunction this device.
[0208] As mentioned above, a respiratory device adapted for use in
the nasal cavity may be placed into one or both of a subject's
nostrils by medical personnel or by the subject himself. The
respiratory device may be secured in place in the subject's
nostrils by the interaction between the nostril cavity and the
holdfast of the device. The device may be worn during the night or
day, while the subject is awake or sleeping. In some cases, the
device may be worn around the clock. For example, the device may be
worn at night to prevent snoring.
[0209] All publications and patent applications cited in this
specification are herein incorporated by reference in their
entirety, as if each individual publication or patent application
were specifically and individually indicated to be incorporated by
reference. The citation of any publication is for its disclosure
prior to the filing date and should not be construed as an
admission that the present invention is not entitled to antedate
such publication by virtue of prior invention.
[0210] Although the foregoing invention has been described in some
detail by way of illustration and example for purposes of clarity
of understanding, it is readily apparent to those of ordinary skill
in the art in light of the teachings of this invention that certain
changes and modifications may be made thereto without departing
from the spirit or scope of the appended claims.
* * * * *