Obstructive Sleep
Apnea (OSA):
Introduction and Need
for Better Therapy Options
Obstructive Sleep Apnea (OSA)
is a sleep disorder that causes intermittent blockage of a person's airflow
while they sleep due to movement of their tongue, or other soft tissue,
into the airway. As a result, people with OSA are repeatedly
deprived of oxygen during their sleep. This oxygen deprivation can
cause serious short-term and long-term health problems. Health problems
caused by OSA include: heart attacks; congestive heart failure; disrupted
sleep; chronic fatigue; morning headaches; irritability; brain damage;
cognitive dysfunction; impotency; high blood pressure; motor vehicle crashes;
job-site accidents; and even death. For example, in patients with
heart failure, OSA is associated with an increased risk of death[1].
Despite these serious health hazards, it is estimated that only 5% to 8%
of the population with OSA are treated. Approximately 20 million
Americans, and 35 million people, worldwide have OSA. These numbers are
growing with the increased prevalence of obesity.
First-line therapy for most
people with Obstructive Sleep Apnea is CPAP (Continuous Positive Airway
Pressure) or other pressure-based therapies such as BIPAP (Bilevel Positive
Airway Pressure) or IPAP (Inspiratory Positive Airway Pressure).
All of these pressure-based therapies for OSA require a mask, or other
air-channeling device, that covers or inserts into the nose and/or mouth.
The mask is the weak link in pressure-based therapy. Such therapy
only works if a person tolerates wearing the mask and if the mask does
not leak too much air. If the mask fits too tightly in some places,
then this causes skin irritation, red marks, pain, and low patient compliance.
If the mask fits too loosely and there are gaps between the mask and the
person's face, then the mask leaks air. Air leaks erode clinical
effectiveness.
Mask problems such as annoying
air leaks, skin irritation and pain, red marks, and claustrophobic reactions
contribute to unsatisfactorily-low rates of compliance with pressure-based
therapy. Many people are not willing to wear a mask. Estimates of
the percentage of people who should wear a mask, but do not wear one, are
in the range of 46 to 83%.[2,3]. Medical research confirms a relationship
between reduction of mask leakage and better patient compliance[4].
Development of novel masks that are more comfortable, fit better, and leak
less can improve patient compliance with wearing a mask, thereby reducing
the oxygen deprivation and long-term adverse health events associated with
OSA.
Since rates of patient compliance
with pressure-based therapies are unsatisfactorily-low with currently-available
OSA masks, better mask designs are needed. A major challenge
is how to create masks that closely conform to the contours of an individual's
face while they sleep so that there are no places around the mask that
fit too tightly (causing irritation, skin marks, pain, and low compliance)
and no places that fit too loosely (causing air leaks and reducing clinical
efficacy). A second major challenge is how to create masks that are
not dislodged by torque forces if a person presses the side of their face
against a pillow while they sleep. Masks that satisfactorily
address these problems have the potential to increase patient compliance
and improve treatment of OSA.
Various approaches to address
these mask design challenges have been tried. These approaches include:
masks with adjustable straps; masks whose overall size can be manually
adjusted; masks with a cushion seal filled with a gas, liquid, or gel;
masks with an inflatable single-compartment cushion seal; masks that are
custom fitted for a person's face by pressing moldable material against
their face; and masks that are custom fitted for a person's face using
three-dimensional facial imaging and custom fabrication. However,
none of these approaches have been entirely successful. Skin irritation
from tight places around mask perimeters, air leaks from loose places around
mask perimeters, and mask dislodging from head-to-pillow interaction remain
ongoing problems for pressure-based OSA therapies. According,
there remains an unmet clinical need for development of innovative masks
to correct these problems.
Sleepnea's novel technologies
are targeting these problems. Sleepnea's long-term mission includes
development of masks that are more comfortable, fit better, leak less,
and are less prone to dislodging from head-to-pillow interaction than are
currently-available masks, thereby improving patient compliance and reducing
the adverse health effects of OSA.
There are alternative approaches
to treatment of Obstructive Sleep Apnea (OSA) that are not based on airway
pressure and masks. These approaches include: surgical removal or
shaping of soft tissue along the airway; surgical implantation of anchors,
sutures, stents, or fibrous members within soft tissue; neuroelectrical
stimulation of soft tissue muscles (such as to cause contraction of the
tongue); movement of soft tissue by the interaction of implants within
that tissue via a magnetic field; external positioning of the sleeper's
head and/or body by specially-shaped pillows or other body-positioning
members; devices that cause forward movement of the jaw; and devices that
hold the tongue in a forward position by means of suction or tissue piercing
members. All of these approaches have limitations.
Sleepnea's intellectual property
portfolio also includes innovative devices and methods for non-invasively
engaging the tongue to: prevent the tongue from moving backwards into the
airway during sleep; and/or move the tongue forwards out of the airway
if it does move backwards during sleep.
________
1. H. Wang et al.,
"Influence of Obstructive Sleep Apnea on Mortality in Patients with Heart
Failure," Journal of the American College of Cardiology, 2007, Vol.
49(15), 1625-1631.
2. Wolkove et al.,
"Long-Term Compliance with Continuous Positive Airway Pressure in Patients
with Obstructive Sleep Apnea," Canadian Respiratory Journal: Journal
of the Canadian Thoracic Society, 2008, October; 15(7), 365–369.
3. Weaver et al., "Adherence
to Continuous Positive Airway Pressure Therapy: The Challenge to Effective
Treatment,"
The Proceedings of the American Thoracic Society, 2008,
5, 173-178.
4. Sopkova et al.,
"Predictors of Compliance with Continuous Positive Airway Pressure Treatment
in Patients with Obstructive Sleep Apnea and Metabolic Syndrome,"
Wiener
Klinische Wochenschrift, Vol.121, No. 11-12, June, 2009, 398-404 |