NZ744240B2 - Adjustable headgear tubing for a patient interface - Google Patents
Adjustable headgear tubing for a patient interface Download PDFInfo
- Publication number
- NZ744240B2 NZ744240B2 NZ744240A NZ74424017A NZ744240B2 NZ 744240 B2 NZ744240 B2 NZ 744240B2 NZ 744240 A NZ744240 A NZ 744240A NZ 74424017 A NZ74424017 A NZ 74424017A NZ 744240 B2 NZ744240 B2 NZ 744240B2
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- New Zealand
- Prior art keywords
- patient
- positioning
- tube
- seal
- gas delivery
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Abstract
Aspects of the present technology comprise a positioning and stabilising structure to hold a seal-forming structure in a therapeutically effective position on a head of a patient. The positioning and stabilising structure may comprise at least one gas delivery tube to deliver the flow of air to the entrance of a patient's airways via the seal-forming structure. The at least one gas delivery tube may be constructed and arranged to contact, in use, at least a region of the patient's head superior to an otobasion superior of the patient's head. The positioning and stabilising structure may comprise an adjustment mechanism for adjustment of a length of the at least one gas delivery tube to enable the positioning and stabilising structure to fit different size heads. The positioning and stabilising structure may comprise a bias mechanism to impart a biasing force along at least a part of a length of the at least one gas delivery tube to urge the seal-forming structure towards the entrance of the patient's airways in use. entrance of a patient's airways via the seal-forming structure. The at least one gas delivery tube may be constructed and arranged to contact, in use, at least a region of the patient's head superior to an otobasion superior of the patient's head. The positioning and stabilising structure may comprise an adjustment mechanism for adjustment of a length of the at least one gas delivery tube to enable the positioning and stabilising structure to fit different size heads. The positioning and stabilising structure may comprise a bias mechanism to impart a biasing force along at least a part of a length of the at least one gas delivery tube to urge the seal-forming structure towards the entrance of the patient's airways in use.
Description
James & Wells Ref: 506131NZ
ADJUSTABLE HEADGEAR TUBING FOR A PATIENT
INTERFACE
1 CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of US Provisional Patent Application
No. 62/281,322 and US Provisional Patent Application No. 62/330,371, which are
incorporated herein by reference in their entirety.
2 STATEMENT REGARDING FEDERALLY SPONSORED
RESEARCH OR DEVELOPMENT
Not Applicable
3 THE NAMES OF PARTIES TO A JOINT RESEARCH
DEVELOPMENT
Not Applicable
4 SEQUENCE LISTING
Not Applicable
BACKGROUND OF THE TECHNOLOGY
.1 FIELD OF THE TECHNOLOGY
The present technology relates to one or more of the detection, diagnosis,
treatment, prevention and amelioration of respiratory-related disorders. The present
technology also relates to medical devices or apparatus, and their use.
Certain forms of the present technology relate to patient interfaces used in
the treatment of respiratory, prevention and amelioration of respiratory-related
disorders.
.2 DESCRIPTION OF THE RELATED ART
.2.1 Human Respiratory System and its Disorders
The respiratory system of the body facilitates gas exchange. The nose and
mouth form the entrance to the airways of a patient.
James & Wells Ref: 506131NZ
The airways include a series of branching tubes, which become narrower,
shorter and more numerous as they penetrate deeper into the lung. The prime function
of the lung is gas exchange, allowing oxygen to move from the air into the venous
blood and carbon dioxide to move out. The trachea divides into right and left main
bronchi, which further divide eventually into terminal bronchioles. The bronchi make
up the conducting airways, and do not take part in gas exchange. Further divisions of
the airways lead to the respiratory bronchioles, and eventually to the alveoli. The
alveolated region of the lung is where the gas exchange takes place, and is referred to
as the respiratory zone. See “Respiratory Physiology”, by John B. West, Lippincott
Williams & Wilkins, 9th edition published 2011.
A range of respiratory disorders exist. Certain disorders may be
characterised by particular events, e.g. apneas, hypopneas, and hyperpneas.
Obstructive Sleep Apnea (OSA), a form of Sleep Disordered Breathing
(SDB), is characterized by events including occlusion or obstruction of the upper air
passage during sleep. It results from a combination of an abnormally small upper
airway and the normal loss of muscle tone in the region of the tongue, soft palate and
posterior oropharyngeal wall during sleep. The condition causes the affected patient to
stop breathing for periods typically of 30 to 120 seconds in duration, sometimes 200
to 300 times per night. It often causes excessive daytime somnolence, and it may
cause cardiovascular disease and brain damage. The syndrome is a common disorder,
particularly in middle aged overweight males, although a person affected may have no
awareness of the problem. See US Patent No. 4,944,310 (Sullivan).
Cheyne-Stokes Respiration (CSR) is another form of sleep disordered
breathing. CSR is a disorder of a patient's respiratory controller in which there are
rhythmic alternating periods of waxing and waning ventilation known as CSR cycles.
CSR is characterised by repetitive de-oxygenation and re-oxygenation of the arterial
blood. It is possible that CSR is harmful because of the repetitive hypoxia. In some
patients CSR is associated with repetitive arousal from sleep, which causes severe
sleep disruption, increased sympathetic activity, and increased afterload. See US
Patent No. 6,532,959 (Berthon-Jones).
James & Wells Ref: 506131NZ
Respiratory failure is an umbrella term for respiratory disorders in which
the lungs are unable to inspire sufficient oxygen or exhale sufficient CO to meet the
patient’s needs. Respiratory failure may encompass some or all of the following
disorders.
A patient with respiratory insufficiency (a form of respiratory failure) may
experience abnormal shortness of breath on exercise.
Obesity Hyperventilation Syndrome (OHS) is defined as the combination
of severe obesity and awake chronic hypercapnia, in the absence of other known
causes for hypoventilation. Symptoms include dyspnea, morning headache and
excessive daytime sleepiness.
Chronic Obstructive Pulmonary Disease (COPD) encompasses any of a
group of lower airway diseases that have certain characteristics in common. These
include increased resistance to air movement, extended expiratory phase of
respiration, and loss of the normal elasticity of the lung. Examples of COPD are
emphysema and chronic bronchitis. COPD is caused by chronic tobacco smoking
(primary risk factor), occupational exposures, air pollution and genetic factors.
Symptoms include: dyspnea on exertion, chronic cough and sputum production.
Neuromuscular Disease (NMD) is a broad term that encompasses many
diseases and ailments that impair the functioning of the muscles either directly via
intrinsic muscle pathology, or indirectly via nerve pathology. Some NMD patients are
characterised by progressive muscular impairment leading to loss of ambulation,
being wheelchair-bound, swallowing difficulties, respiratory muscle weakness and,
eventually, death from respiratory failure. Neuromuscular disorders can be divided
into rapidly progressive and slowly progressive: (i) Rapidly progressive disorders:
Characterised by muscle impairment that worsens over months and results in death
within a few years (e.g. Amyotrophic lateral sclerosis (ALS) and Duchenne muscular
dystrophy (DMD) in teenagers); (ii) Variable or slowly progressive disorders:
Characterised by muscle impairment that worsens over years and only mildly reduces
life expectancy (e.g. Limb girdle, Facioscapulohumeral and Myotonic muscular
dystrophy). Symptoms of respiratory failure in NMD include: increasing generalised
James & Wells Ref: 506131NZ
weakness, dysphagia, dyspnea on exertion and at rest, fatigue, sleepiness, morning
headache, and difficulties with concentration and mood changes.
Chest wall disorders are a group of thoracic deformities that result in
inefficient coupling between the respiratory muscles and the thoracic cage. The
disorders are usually characterised by a restrictive defect and share the potential of
long term hypercapnic respiratory failure. Scoliosis and/or kyphoscoliosis may cause
severe respiratory failure. Symptoms of respiratory failure include: dyspnea on
exertion, peripheral oedema, orthopnea, repeated chest infections, morning headaches,
fatigue, poor sleep quality and loss of appetite.
A range of therapies have been used to treat or ameliorate such conditions.
Furthermore, otherwise healthy individuals may take advantage of such therapies to
prevent respiratory disorders from arising. However, these have a number of
shortcomings.
.2.2 Therapy
Continuous Positive Airway Pressure (CPAP) therapy has been used to
treat Obstructive Sleep Apnea (OSA). The mechanism of action is that continuous
positive airway pressure acts as a pneumatic splint and may prevent upper airway
occlusion, such as by pushing the soft palate and tongue forward and away from the
posterior oropharyngeal wall. Treatment of OSA by CPAP therapy may be voluntary,
and hence patients may elect not to comply with therapy if they find devices used to
provide such therapy one or more of: uncomfortable, difficult to use, expensive and
aesthetically unappealing.
Non-invasive ventilation (NIV) provides ventilatory support to a patient
through the upper airways to assist the patient breathing and/or maintain adequate
oxygen levels in the body by doing some or all of the work of breathing. The
ventilatory support is provided via a non-invasive patient interface. NIV has been
used to treat CSR and respiratory failure, in forms such as OHS, COPD, NMD and
Chest Wall disorders. In some forms, the comfort and effectiveness of these therapies
may be improved.
James & Wells Ref: 506131NZ
Invasive ventilation (IV) provides ventilatory support to patients that are
no longer able to effectively breathe themselves and may be provided using a
tracheostomy tube. In some forms, the comfort and effectiveness of these therapies
may be improved.
.2.3 Treatment Systems
These therapies may be provided by a treatment system or device. Such
systems and devices may also be used to diagnose a condition without treating it.
A treatment system may comprise a Respiratory Pressure Therapy Device
(RPT device), an air circuit, a humidifier and a patient interface.
.2.3.1 Patient Interface
A patient interface may be used to interface respiratory equipment to its
wearer, for example by providing a flow of air to an entrance to the airways. The flow
of air may be provided via a mask to the nose and/or mouth, a tube to the mouth or a
tracheostomy tube to the trachea of a patient. Depending upon the therapy to be
applied, the patient interface may form a seal, e.g., with a region of the patient's face,
to facilitate the delivery of gas at a pressure at sufficient variance with ambient
pressure to effect therapy, e.g., at a positive pressure of about 10 cmH O relative to
ambient pressure. For other forms of therapy, such as the delivery of oxygen, the
patient interface may not include a seal sufficient to facilitate delivery to the airways
of a supply of gas at a positive pressure of about 10 cmH O.
Certain other mask systems may be functionally unsuitable for the present
field. For example, purely ornamental masks may be unable to maintain a suitable
pressure. Mask systems used for underwater swimming or diving may be configured
to guard against ingress of water from an external higher pressure, but not to maintain
air internally at a higher pressure than ambient.
Certain masks may be clinically unfavourable for the present technology
e.g. if they block airflow via the nose and only allow it via the mouth.
Certain masks may be uncomfortable or impractical for the present
technology if they require a patient to insert a portion of a mask structure in their
mouth to create and maintain a seal via their lips.
James & Wells Ref: 506131NZ
Certain masks may be impractical for use while sleeping, e.g. for sleeping
while lying on one’s side in bed with a head on a pillow.
The design of a patient interface presents a number of challenges. The
face has a complex three-dimensional shape. The size and shape of noses and heads
varies considerably between individuals. Since the head includes bone, cartilage and
soft tissue, different regions of the face respond differently to mechanical forces. The
jaw or mandible may move relative to other bones of the skull. The whole head may
move during the course of a period of respiratory therapy.
As a consequence of these challenges, some masks suffer from being one
or more of obtrusive, aesthetically undesirable, costly, poorly fitting, difficult to use,
and uncomfortable especially when worn for long periods of time or when a patient is
unfamiliar with a system. Wrongly sized masks can give rise to reduced compliance,
reduced comfort and poorer patient outcomes. Masks designed solely for aviators,
masks designed as part of personal protection equipment (e.g. filter masks), SCUBA
masks, or for the administration of anaesthetics may be tolerable for their original
application, but nevertheless such masks may be undesirably uncomfortable to be
worn for extended periods of time, e.g., several hours. This discomfort may lead to a
reduction in patient compliance with therapy. This is even more so if the mask is to
be worn during sleep.
CPAP therapy is highly effective to treat certain respiratory disorders,
provided patients comply with therapy. If a mask is uncomfortable, or difficult to use
a patient may not comply with therapy. Since it is often recommended that a patient
regularly wash their mask, if a mask is difficult to clean (e.g., difficult to assemble or
disassemble), patients may not clean their mask and this may impact on patient
compliance.
While a mask for other applications (e.g. aviators) may not be suitable for
use in treating sleep disordered breathing, a mask designed for use in treating sleep
disordered breathing may be suitable for other applications.
For these reasons, patient interfaces for delivery of CPAP during sleep
form a distinct field.
James & Wells Ref: 506131NZ
.2.3.1.1 Seal-forming portion
Patient interfaces may include a seal-forming portion. Since it is in direct
contact with the patient’s face, the shape and configuration of the seal-forming
portion can have a direct impact the effectiveness and comfort of the patient interface.
A patient interface may be partly characterised according to the design
intent of where the seal-forming portion is to engage with the face in use. In one form
of patient interface, a seal-forming portion may comprise two sub-portions to engage
with respective left and right nares. In one form of patient interface, a seal-forming
portion may comprise a single element that surrounds both nares in use. Such single
element may be designed to for example overlay an upper lip region and a nasal
bridge region of a face. In one form of patient interface a seal-forming portion may
comprise an element that surrounds a mouth region in use, e.g. by forming a seal on a
lower lip region of a face. In one form of patient interface, a seal-forming portion may
comprise a single element that surrounds both nares and a mouth region in use. These
different types of patient interfaces may be known by a variety of names by their
manufacturer including nasal masks, full-face masks, nasal pillows, nasal puffs and
oro-nasal masks. An oro-nasal mask may include a compact full-face mask without a
forehead support. Alternatively an oro-nasal mask may include a full-face mask that
seals around the entrance of the mouth and nose, wherein the nose seal includes a
cradle that seals below the lateral cartilage.
A seal-forming portion that may be effective in one region of a patient’s
face may be inappropriate in another region, e.g. because of the different shape,
structure, variability and sensitivity regions of the patient’s face. For example, a seal
on swimming goggles that overlays a patient’s forehead may not be appropriate to use
on a patient’s nose.
Certain seal-forming portions may be designed for mass manufacture such
that one design fit and be comfortable and effective for a wide range of different face
shapes and sizes. To the extent to which there is a mismatch between the shape of the
patient’s face, and the seal-forming portion of the mass-manufactured patient
interface, one or both must adapt in order for a seal to form.
James & Wells Ref: 506131NZ
One type of seal-forming portion extends around the periphery of the
patient interface, and is intended to seal against the patient's face when force is
applied to the patient interface with the seal-forming portion in confronting
engagement with the patient's face. The seal-forming portion may include an air or
fluid filled cushion, or a moulded or formed surface of a resilient seal element made
of an elastomer such as a rubber. With this type of seal-forming portion, if the fit is
not adequate, there will be gaps between the seal-forming portion and the face, and
additional force will be required to force the patient interface against the face in order
to achieve a seal.
Another type of seal-forming portion incorporates a flap seal of thin
material positioned about the periphery of the mask so as to provide a self-sealing
action against the face of the patient when positive pressure is applied within the
mask. Like the previous style of seal forming portion, if the match between the face
and the mask is not good, additional force may be required to achieve a seal, or the
mask may leak. Furthermore, if the shape of the seal-forming portion does not match
that of the patient, it may crease or buckle in use, giving rise to leaks.
Another type of seal-forming portion may comprise a friction-fit element,
e.g. for insertion into a naris, however some patients find these uncomfortable.
Another form of seal-forming portion may use adhesive to achieve a seal.
Some patients may find it inconvenient to constantly apply and remove an adhesive to
their face.
A range of patient interface seal-forming portion technologies are
disclosed in the following patent applications, assigned to ResMed Limited: WO
1998/004,310; ,513; ,785.
One form of nasal pillow is found in the Adam Circuit manufactured by
Puritan Bennett. Another nasal pillow, or nasal puff is the subject of US Patent
4,782,832 (Trimble et al.), assigned to Puritan-Bennett Corporation.
ResMed Limited has manufactured the following products that
TM TM
incorporate nasal pillows: SWIFT nasal pillows mask, SWIFT II nasal pillows
TM TM
mask, SWIFT LT nasal pillows mask, SWIFT FX nasal pillows mask and
James & Wells Ref: 506131NZ
MIRAGE LIBERTY full-face mask. The following patent applications, assigned to
ResMed Limited, describe examples of nasal pillows masks: International Patent
Application ,778 (describing amongst other things aspects of the
ResMed Limited SWIFT nasal pillows), US Patent Application 2009/0044808
(describing amongst other things aspects of the ResMed Limited SWIFT LT nasal
pillows); International Patent Applications ,328 and ,903
(describing amongst other things aspects of the ResMed Limited MIRAGE
LIBERTY full-face mask); International Patent Application ,560
(describing amongst other things aspects of the ResMed Limited SWIFT FX nasal
pillows).
.2.3.1.2 Positioning and stabilising
A seal-forming portion of a patient interface used for positive air pressure
therapy is subject to the corresponding force of the air pressure to disrupt a seal. Thus
a variety of techniques have been used to position the seal-forming portion, and to
maintain it in sealing relation with the appropriate portion of the face.
One technique is the use of adhesives. See for example US Patent
Application Publication No. US 2010/0000534. However, the use of adhesives may
be uncomfortable for some.
Another technique is the use of one or more straps and/or stabilising
harnesses. Many such harnesses suffer from being one or more of ill-fitting, bulky,
uncomfortable and awkward to use. When designed to be worn on the patient’s head,
such harnesses may be referred to as headgear.
.2.3.1.3 Pressurised Air Conduit
In one type of treatment system, a flow of pressurised air is provided to a
patient interface through a conduit in an air circuit that fluidly connects to the patient
interface so that, when the patient interface is positioned on the patient’s face during
use, the conduit extends out of the patient interface forwards away from the patient’s
face. This may sometimes be referred to as an “elephant trunk” style of interface.
Some patients find such interfaces to be unsightly and are consequently
deterred from wearing them, reducing patient compliance. Additionally, conduits
James & Wells Ref: 506131NZ
connecting to an interface at the front of a patient’s face may sometimes be vulnerable
to becoming tangled up in bed clothes.
.2.3.1.4 Pressurised Air Conduit used for Positioning / Stabilising the Seal-
Forming Structure
An alternative type of treatment system which seeks to address these
problems comprises a patient interface in which a tube that delivers pressurised air to
the patient’s airways also functions as part of the headgear to position and stabilise the
seal-forming portion of the patient interface to the appropriate part of the patient’s
face. This type of patient interface may be referred to as incorporating ‘headgear
tubing’ or ‘conduit headgear’. Such patient interfaces allow the conduit in the air
circuit providing the flow of pressurised air from a respiratory pressure therapy device
to connect to the patient interface in a position other than in front of the patient’s face.
One example of such a treatment system is disclosed in US Patent Publication No. US
2007/0246043, the contents of which are incorporated herein by reference, in which
the conduit connects to a tube in the patient interface through a port positioned in use
on top of the patient’s head.
The Philips DreamWear™ nasal mask includes such headgear tubing. One
problem with this mask is that the length of the headgear tubes cannot be adjusted.
Consequently the DreamWear™ mask is supplied in different sizes to cater for
different sized patient faces. However, this creates complexity and cost to
manufacture the DreamWear™ mask and larger packaging. Additionally, the supply
of discretely sized masks limits the extent to which differently sized patient heads can
be accommodated, for example, if the patient’s head size falls between or outside the
mask sizes provided.
Patient interfaces incorporating headgear tubing may provide some
advantages, for example avoiding a conduit connecting to the patient interface at the
front of a patient’s face, which may be unsightly and obtrusive. However, it is
desirable for patient interfaces incorporating headgear tubing to be comfortable for a
patient to wear over a prolonged duration when the patient is asleep while forming an
effective seal with the patient’s face.
James & Wells Ref: 506131NZ
.2.3.2 Respiratory Pressure Therapy (RPT) Device
Air pressure generators are known in a range of applications, e.g.
industrial-scale ventilation systems. However, air pressure generators for medical
applications have particular requirements not fulfilled by more generalised air
pressure generators, such as the reliability, size and weight requirements of medical
devices. In addition, even devices designed for medical treatment may suffer from
shortcomings, pertaining to one or more of: comfort, noise, ease of use, efficacy, size,
weight, manufacturability, cost, and reliability.
One known RPT device used for treating sleep disordered breathing is the
S9 Sleep Therapy System, manufactured by ResMed Limited. Another example of an
RPT device is a ventilator. Ventilators such as the ResMed Stellar™ Series of Adult
and Paediatric Ventilators may provide support for invasive and non-invasive non-
dependent ventilation for a range of patients for treating a number of conditions such
as but not limited to NMD, OHS and COPD.
.2.3.3 Humidifier
Delivery of a flow of air without humidification may cause drying of
airways. The use of a humidifier with an RPT device and the patient interface
produces humidified gas that minimizes drying of the nasal mucosa and increases
patient airway comfort. In addition in cooler climates, warm air applied generally to
the face area in and about the patient interface is more comfortable than cold air.
6 BRIEF SUMMARY OF THE TECHNOLOGY
The present technology is directed towards providing medical devices
used in the diagnosis, amelioration, treatment, or prevention of respiratory disorders
having one or more of improved comfort, cost, efficacy, ease of use and
manufacturability.
A first aspect of the present technology relates to apparatus used in the
diagnosis, amelioration, treatment or prevention of a respiratory disorder.
An aspect of certain forms of the present technology is to provide methods
and/or apparatus that improve the compliance of patients with respiratory therapy.
James & Wells Ref: 506131NZ
One form of the present technology comprises a patient interface for
delivery of a supply of pressurised breathable gas to an entrance of a patient’s
airways.
Another aspect of one form of the present technology comprises a
positioning and stabilising structure to hold a seal-forming structure in a
therapeutically effective position on a head of a patient. The seal-forming structure
may be constructed and arranged to form a seal with a region of the patient’s face
surrounding an entrance to the patient’s airways for sealed delivery of a flow of air at
a therapeutic pressure of at least 4 cmH O with respect to ambient air pressure
throughout the patient’s respiratory cycle in use. The positioning and stabilising
structure may comprise at least one gas delivery tube to deliver the flow of air to the
entrance of a patient's airways via the seal-forming structure. The at least one gas
delivery tube may be constructed and arranged to contact, in use, at least a region of
the patient’s head superior to an otobasion superior of the patient’s head. The
positioning and stabilising structure may comprise an adjustment mechanism for
adjustment of a length of the at least one gas delivery tube to enable the positioning
and stabilising structure to fit different size heads. The positioning and stabilising
structure may comprise a bias mechanism to impart a biasing force along at least a
part of a length of the at least one gas delivery tube to urge the seal-forming structure
towards the entrance of the patient’s airways in use.
Another aspect of one form of the present technology comprises a patient
interface comprising a plenum chamber pressurisable to a therapeutic pressure of at
least 4 cmH O above ambient air pressure. The plenum chamber may include a
plenum chamber inlet port sized and structured to receive a flow of air at the
therapeutic pressure for breathing by a patient. The patient interface may comprise a
seal-forming structure constructed and arranged to form a seal with a region of the
patient’s face surrounding an entrance to the patient’s airways such that the flow of air
at said therapeutic pressure is delivered to at least an entrance to the patient’s nares.
The seal-forming structure may be constructed and arranged to maintain said
therapeutic pressure in the plenum chamber throughout the patient’s respiratory cycle
in use. The patient interface may comprise a connection port to fluidly connect, in
use, with an air circuit connected to the flow of air. The connection port may be
James & Wells Ref: 506131NZ
located, in use, proximal a top, side or rear portion of a patient’s head. The patient
interface may comprise a positioning and stabilising structure to hold the seal-forming
structure in a therapeutically effective position on the patient’s head. The positioning
and stabilising structure may comprise at least one gas delivery tube to deliver a flow
of air to the entrance of a patient's airways via the seal-forming structure. The at least
one gas delivery tube may be constructed and arranged to contact, in use, at least a
region of the patient’s head superior to an otobasion superior of the patient’s head.
The positioning and stabilising structure may comprise an adjustment mechanism for
adjustment of a length of the at least one gas delivery tube to enable the positioning
and stabilising structure to fit different size heads. The positioning and stabilising
structure may comprise a bias mechanism to impart a biasing force along at least a
part of a length of the at least one gas delivery tube to urge the seal-forming structure
towards the entrance of the patient’s airways in use.
Another aspect of one form of the present technology comprises a
positioning and stabilising structure to hold a seal-forming structure in a
therapeutically effective position on a head of a patient. The seal-forming structure
may be constructed and arranged to form a seal with a region of the patient’s face
surrounding an entrance to the patient’s airways for sealed delivery of a flow of air at
a therapeutic pressure of at least 4 cmH O with respect to ambient air pressure
throughout the patient’s respiratory cycle in use. The positioning and stabilising
structure may comprise at least one tie. The at least one tie may be configured to
contact the patient’s head in use. The at least one tie may comprise at least one gas
delivery tube to deliver the flow of air to the entrance of a patient’s airways via the
seal-forming structure. The at least one gas delivery tube may be constructed and
arranged to overlie, in use, at least a region of the patient’s head superior to an
otobasion superior of the patient’s head. The positioning and stabilising structure may
comprise an adjustment mechanism for adjustment of the at least one tie to enable the
positioning and stabilising structure to fit different size heads. The positioning and
stabilising structure may be configured such that, in use, the adjustment mechanism is
positioned out of contact with a patient’s face.
Another aspect of one form of the present technology comprises a patient
interface comprising a plenum chamber pressurisable to a therapeutic pressure of at
James & Wells Ref: 506131NZ
least 4 cmH O above ambient air pressure. The plenum chamber may include a
plenum chamber inlet port sized and structured to receive a flow of air at the
therapeutic pressure for breathing by a patient. The patient interface may comprise a
seal-forming structure constructed and arranged to form a seal with a region of the
patient’s face surrounding an entrance to the patient’s airways such that the flow of air
at said therapeutic pressure is delivered to at least an entrance to the patient’s nares.
The seal-forming structure may be constructed and arranged to maintain said
therapeutic pressure in the plenum chamber throughout the patient’s respiratory cycle
in use. The patient interface may comprise a connection port to fluidly connect, in
use, with an air circuit connected to the flow of air. The connection port may be
located, in use, proximal a top, side or rear portion of a patient’s head. The patient
interface may comprise a positioning and stabilising structure to hold the seal-forming
structure in a therapeutically effective position on the patient’s head. The positioning
and stabilising structure may comprise at least one tie. The at least one tie may be
configured to contact the patient’s head in use. The at least one tie may comprise at
least one gas delivery tube to deliver the flow of air to the entrance of a patient’s
airways via the seal-forming structure. The at least one gas delivery tube may be
constructed and arranged to overlie, in use, at least a region of the patient’s head
superior to an otobasion superior of the patient’s head. The positioning and stabilising
structure may comprise an adjustment mechanism for adjustment of the at least one
tie to enable the positioning and stabilising structure to fit different size heads. The
positioning and stabilising structure may be configured such that, in use, the
adjustment mechanism is positioned out of contact with a patient’s face.
Another aspect of one form of the present technology comprises a patient
interface comprising a plenum chamber pressurisable to a therapeutic pressure of at
least 4 cmH O above ambient air pressure. The plenum chamber may include a
plenum chamber inlet port sized and structured to receive a flow of air at the
therapeutic pressure for breathing by a patient. The patient interface may comprise a
seal-forming structure constructed and arranged to form a seal with a region of the
patient’s face surrounding an entrance to the patient’s airways such that the flow of air
at said therapeutic pressure is delivered to at least an entrance to the patient’s nares.
The seal-forming structure may be constructed and arranged to maintain said
therapeutic pressure in the plenum chamber throughout the patient’s respiratory cycle
James & Wells Ref: 506131NZ
in use. The patient interface may comprise a positioning and stabilising structure to
hold the seal-forming structure in a therapeutically effective position on the patient’s
head. The positioning and stabilising structure may comprise a first tube portion
constructed and arranged to overlay a region of the patient’s head superior to an
otobasion superior of the patient’s head in use. The positioning and stabilising
structure may comprise a tie portion to overlay or lie inferior to the occipital bone of
the patient’s head in use. The patient interface may comprise a vent structure to allow
a continuous flow of gases exhaled by the patient from an interior of the plenum
chamber to ambient, said vent structure being sized and shaped to maintain the
therapeutic pressure in the plenum chamber in use. The first tube portion may be
configured to conduct at least a portion of the flow of air for breathing by the patient.
The first tube portion may be configured to be in tension in use. The first tube portion
may include a lengthwise adjustment mechanism.
Another aspect of one form of the present technology comprises a
positioning and stabilising structure to hold a seal-forming structure in a
therapeutically effective position on a head of a patient. The seal-forming structure
may be constructed and arranged to form a seal with a region of the patient’s face
surrounding an entrance to the patient’s airways for sealed delivery of a flow of air at
a therapeutic pressure of at least 4 cmH O with respect to ambient air pressure
throughout the patient’s respiratory cycle in use. The positioning and stabilising
structure may comprise a first conduit portion constructed and arranged to overlay a
region of the patient’s head superior to an otobasion superior of the patient’s head in
use. The positioning and stabilising structure may comprise a tie portion to overlay or
lie inferior to the occipital bone of the patient’s head in use. The first conduit portion
may be configured to conduct at least a portion of the flow of air for breathing by the
patient. The first conduit portion may be configured to be in tension in use. The first
conduit portion may include a lengthwise adjustment mechanism.
Another aspect of one form of the present technology comprises a patient
interface comprising a plenum chamber pressurisable to a therapeutic pressure of at
least 4 cmH O above ambient air pressure. The plenum chamber may include a
plenum chamber inlet port sized and structured to receive a flow of air at the
therapeutic pressure for breathing by a patient. The patient interface may comprise a
James & Wells Ref: 506131NZ
seal-forming structure constructed and arranged to form a seal with a region of the
patient’s face surrounding an entrance to the patient’s airways such that the flow of air
at said therapeutic pressure is delivered to at least an entrance to the patient’s nares.
The seal-forming structure may be constructed and arranged to maintain said
therapeutic pressure in the plenum chamber throughout the patient’s respiratory cycle
in use. The patient interface may comprise a positioning and stabilising structure to
provide an elastic force to hold a seal-forming structure in a therapeutically effective
position on a patient’s head for sealed delivery of the flow of air at the therapeutic
pressure. The positioning and stabilising structure may comprise a tie. The tie may be
constructed and arranged so that at least a portion of the tie overlies a region of the
patient’s head superior to an otobasion superior of the patient’s head in use. The tie
may comprise a length-adjustable gas delivery tube to deliver the flow of air to the
entrance of a patient's airways via the seal-forming structure. The gas delivery tube
may be configured to contact a portion of the patient’s head in use. The positioning
and stabilising structure may comprise a bias mechanism to impart a biasing force
upon the length-adjustable gas delivery tube to urge the seal forming structure
towards the entrance of the patient’s airways in use.
Another aspect of one form of the present technology comprises a
positioning and stabilising structure to hold a seal-forming structure in a
therapeutically effective position on a head of a patient. The seal-forming structure
may be constructed and arranged to form a seal with a region of the patient’s face
surrounding an entrance to the patient’s airways for sealed delivery of a flow of air at
a therapeutic pressure of at least 4 cmH O with respect to ambient air pressure
throughout the patient’s respiratory cycle in use. The positioning and stabilising
structure may comprise a tie. The tie may be constructed and arranged so that at least
a portion of the tie overlies a region of the patient’s head superior to an otobasion
superior of the patient’s head in use. The tie may comprise a length-adjustable gas
delivery tube to deliver the flow of air to the entrance of a patient's airways via the
seal-forming structure. The gas delivery tube may be configured to contact a portion
of the patient’s head in use. The positioning and stabilising structure may comprise a
bias mechanism to impart a biasing force upon the length-adjustable gas delivery tube
to urge the seal forming structure towards the entrance of the patient’s airways in use.
James & Wells Ref: 506131NZ
Another aspect of one form of the present technology comprises an
inflatable positioning and stabilising structure to maintain a seal at an entrance of the
patient’s airways formed by a seal-forming structure of a patient interface for sealed
delivery of a flow of air at a continuously positive pressure with respect to ambient air
pressure and configured to maintain a therapy pressure in a range of about 4 cmH O
to about 30 cmH O above ambient air pressure in use, throughout the patient’s
respiratory cycle, while the patient is sleeping, to ameliorate sleep disordered
breathing. The positioning and stabilising structure may comprise at least one gas
delivery tube to deliver the flow of air to the entrance of a patient's airways via the
seal-forming structure. The positioning and stabilising structure may also comprise an
adjustment mechanism to enable dimensional adjustment of the positioning and
stabilising structure. The positioning and stabilising structure may also comprise a
bias mechanism to impart a biasing force upon the adjustment mechanism and urge
the seal-forming structure towards the entrance of the patient’s airways.
Another aspect of one form of the present technology comprises a patient
interface for delivery of a supply of pressurised air at a continuously positive pressure
with respect to ambient air pressure to an entrance of a patient’s airways , the patient
interface being configured to maintain a therapy pressure in a range of about 4 cmH O
to about 30 cmH O above ambient air pressure in use, throughout the patient’s
respiratory cycle, while the patient is sleeping, to ameliorate sleep disordered
breathing. The patient interface may comprise a connection port to fluidly connect, in
use, with an air circuit connected to the supply of pressurised air, the connection port
being located, in use, proximal a top, side or rear portion of a patient’s head. The
patient interface may also comprise a seal-forming structure to seal with an area
surrounding the entrance to the patient’s airways. The patient interface may also
comprise an inflatable positioning and stabilising structure to maintain the seal
formed by the seal-forming structure. The positioning and stabilising structure may
comprise at least one gas delivery tube to deliver the flow of air to the entrance of a
patient's airways via the seal-forming structure.
Another aspect of a related form of the present technology comprises a
patient interface comprising a positioning and stabilising structure comprising an
James & Wells Ref: 506131NZ
adjustment mechanism to enable dimensional adjustment of the positioning and
stabilising structure.
Another aspect of a related form of the present technology comprises a
patient interface comprising a bias mechanism to impart a biasing force upon the
adjustment mechanism and urge the seal-forming structure towards the entrance of the
patient’s airways.
Another aspect of one form of the present technology comprises an
inflatable positioning and stabilising structure to maintain a seal at an entrance of the
patient’s airways formed by a seal-forming structure of a patient interface for sealed
delivery of a flow of air at a continuously positive pressure with respect to ambient air
pressure and configured to maintain a therapy pressure in a range of about 4 cmH O
to about 30 cmH O above ambient air pressure in use, throughout the patient’s
respiratory cycle, while the patient is sleeping, to ameliorate sleep disordered
breathing. The positioning and stabilising structure may comprise at least one gas
delivery tube to deliver the flow of air to the entrance of a patient's airways via the
seal-forming structure. The positioning and stabilising structure may also comprise an
adjustment mechanism to enable dimensional adjustment of the positioning and
stabilising structure. The positioning and stabilising structure may be configured such
that, in use, the adjustment mechanism is positioned out of contact with a patient’s
cheek region.
Another aspect of one form of the present technology comprises a patient
interface for delivery of a supply of pressurised air at a continuously positive pressure
with respect to ambient air pressure to an entrance of a patient’s airways , the patient
interface being configured to maintain a therapy pressure in a range of about 4 cmH O
to about 30 cmH O above ambient air pressure in use, throughout the patient’s
respiratory cycle, while the patient is sleeping, to ameliorate sleep disordered
breathing. The patient interface may comprise a positioning and stabilising structure.
The positioning and stabilising structure may comprise at least one gas delivery tube
to deliver the flow of air to the entrance of a patient's airways via the seal-forming
structure. The positioning and stabilising structure may also comprise an adjustment
mechanism to enable dimensional adjustment of the positioning and stabilising
structure. The positioning and stabilising structure may be configured such that, in
James & Wells Ref: 506131NZ
use, the adjustment mechanism is positioned out of contact with a patient’s cheek
region.
Another aspect of certain forms of the present technology is a system for
treating a respiratory disorder comprising a patient interface according to any one or
more of the other aspects of the present technology, an air circuit and a source of air at
positive pressure.
Another aspect of one form of the present technology is a patient interface
that is moulded or otherwise constructed with a perimeter shape which is
complementary to that of an intended wearer.
Another aspect of certain forms of the present technology is a patient
interface comprising a seal-forming structure configured to leave the patient’s mouth
uncovered in use.
Another aspect of certain forms of the present technology is a patient
interface comprising a seal-forming structure configured so that no part of the seal-
forming structure enters the mouth in use.
Another aspect of certain forms of the present technology is a patient
interface comprising a seal-forming structure configured so that the seal-forming
structure does not extend internally of the patient’s airways.
Another aspect of certain forms of the present technology is a patient
interface comprising a seal-forming structure configured so that the seal-forming
structure does not extend below a mental protuberance region in use.
Another aspect of certain forms of the present technology is a patient
interface constructed and arranged to leave a patient’s eyes uncovered in use.
Another aspect of certain forms of the present technology is a patient
interface constructed and arranged to allow a patient to breathe ambient air in the
event of a power failure.
Another aspect of certain forms of the present technology is a patient
interface comprising a seal forming structure configured to form a seal on an
James & Wells Ref: 506131NZ
underside of a patient’s nose without contacting a nasal bridge region of the patient’s
nose.
Another aspect of certain forms of the present technology is a patient
interface comprising a vent and a plenum chamber, wherein the patient interface is
constructed and arranged so that gases from an interior of the plenum chamber may
pass to ambient via the vent.
Another aspect of certain forms of the present technology is a patient
interface constructed and arranged so that a patient may lie comfortably in a side or
lateral sleeping position, in use of the patient interface.
Another aspect of certain forms of the present technology is a patient
interface constructed and arranged so that a patient may lie comfortably in a supine
sleeping position, in use of the patient interface.
Another aspect of certain forms of the present technology is a patient
interface constructed and arranged so that a patient may lie comfortably in a prone
sleeping position, in use of the patient interface.
An aspect of certain forms of the present technology is a medical device
that is easy to use, e.g. by a person who does not have medical training, by a person
who has limited dexterity, vision or by a person with limited experience in using this
type of medical device.
An aspect of one form of the present technology is a patient interface that
may be washed in a home of a patient, e.g., in soapy water, without requiring
specialised cleaning equipment. An aspect of one form of the present technology is a
humidifier tank that may be washed in a home of a patient, e.g., in soapy water,
without requiring specialised cleaning equipment.
Of course, portions of the aspects may form sub-aspects of the present
technology. Also, various ones of the sub-aspects and/or aspects may be combined in
various manners and also constitute additional aspects or sub-aspects of the present
technology.
James & Wells Ref: 506131NZ
Other features of the technology will be apparent from consideration of
the information contained in the following detailed description, abstract, drawings and
claims.
7 BRIEF DESCRIPTION OF THE DRAWINGS
The present technology is illustrated by way of example, and not by way
of limitation, in the figures of the accompanying drawings, in which like reference
numerals refer to similar elements including:
7.1 TREATMENT SYSTEMS
Figs. 1A shows a system including a patient 1000 wearing a patient
interface 3000, in the form of a nasal pillows, receiving a supply of air at positive
pressure from an RPT device 4000. Air from the RPT device 4000 is humidified in a
humidifier 5000, and passes along an air circuit 4170 to the patient 1000. A bed
partner 1100 is also shown.
Fig. 1B shows a system including a patient 1000 wearing a patient
interface 3000, in the form of a nasal mask, receiving a supply of air at positive
pressure from an RPT device 4000. Air from the RPT device is humidified in a
humidifier 5000, and passes along an air circuit 4170 to the patient 1000.
Fig. 1C shows a system including a patient 1000 wearing a patient
interface 3000, in the form of a full-face mask, receiving a supply of air at positive
pressure from an RPT device 4000. Air from the RPT device is humidified in a
humidifier 5000, and passes along an air circuit 4170 to the patient 1000.
7.2 RESPIRATORY SYSTEM AND FACIAL ANATOMY
Fig. 2A shows an overview of a human respiratory system including the
nasal and oral cavities, the larynx, vocal folds, oesophagus, trachea, bronchus, lung,
alveolar sacs, heart and diaphragm.
Fig. 2B shows a view of a human upper airway including the nasal cavity,
nasal bone, lateral nasal cartilage, greater alar cartilage, nostril, lip superior, lip
inferior, larynx, hard palate, soft palate, oropharynx, tongue, epiglottis, vocal folds,
oesophagus and trachea.
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Fig. 2C is a front view of a face with several features of surface anatomy
identified including the lip superior, upper vermilion, lower vermilion, lip inferior,
mouth width, endocanthion, a nasal ala, nasolabial sulcus and cheilion. Also indicated
are the directions superior, inferior, radially inward and radially outward.
Fig. 2D is a side view of a head with several features of surface anatomy
identified including glabella, sellion, pronasale, subnasale, lip superior, lip inferior,
supramenton, nasal ridge, alar crest point, otobasion superior and otobasion inferior.
Also indicated are the directions superior & inferior, and anterior & posterior.
Fig. 2E is a further side view of a head. The approximate locations of the
Frankfort horizontal and nasolabial angle are indicated. The coronal plane is also
indicated.
Fig. 2F shows a base view of a nose with several features identified
including naso-labial sulcus, lip inferior, upper Vermilion, naris, subnasale,
columella, pronasale, the major axis of a naris and the sagittal plane.
7.3 PATIENT INTERFACE
Figs. 3A, 3B, 3C, 3D and 3E show patient interfaces 3000 comprising
positioning and stabilising structures 3300 in accordance with certain forms of the
present technology.
Fig. 3F shows a plan view of the patient interface 3000 shown in Figs. 3C,
3D and 3E.
Fig. 3G shows in cross-section a portion of the patient interface 3000
shown in Fig. 3F.
Fig. 3H shows a longitudinal section of a headgear tube 3350 of a patient
interface 3000.
Fig. 3I shows a plot of an exemplary force-extension characteristic of a
headgear tube 3350 of a patient interface 3000.
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Fig. 3J shows a side view of the patient interface shown in Figs. 3C, 3D
and 3E worn by a patient with a connection port 3600 in a central position and, in
phantom, in forward and rearward positions.
Fig. 3K shows a side view of the patient interface shown in Figs. 3C, 3D
and 3E worn by a patient with one head size and, in phantom, a patient with a larger
head size.
Fig. 3L shows a side view of the patient interface shown in Figs. 3C, 3D
and 3E worn by a patient with an adjustment mechanism 3360 positioned centrally
and, in phantom, forwardly and rearwardly.
Figs. 4A, 4B, 4C, 4D and 4E show cushion assemblies 3150 of a patient
interface 3000 according to certain forms of the present technology.
Fig. 5 shows a patient interface 3000 comprising a positioning and
stabilising structure 3300 having a fold portion 3364 and a strap 3390 in accordance
with one form of the present technology.
Figs. 5A and 5B show in cross-section the fold portion 3364 of the patient
interface 3000 of Fig. 5 with rolling fold portion 3366 folded over adjacent tube
portion 3368 to varying degrees.
Fig. 6 shows a patient interface 3000 comprising a positioning and
stabilising structure 3300 comprising flexible tubes 3350 in accordance with one form
of the present technology.
Figs. 7A, 7B and 7C show patient interfaces 3000 comprising a
positioning and stabilising structure 3300 having first and second tube portions 3370
and 3372 in accordance with certain forms of the present technology.
Fig. 8 shows part of a patient interface 3000 comprising a positioning and
stabilising structure 3300 having discretely adjustable first and second tube portions
3370 and 3372 in accordance with one form of the present technology.
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Fig. 9 shows part of a patient interface comprising a positioning and
stabilising structure 3300 having first and second tube portions 3370 and 3372 in
accordance with one form of the present technology.
Fig. 10A shows a patient interface 3000 comprising a positioning and
stabilising structure 3300 having an adjustment mechanism 3360 in accordance with
one form of the present technology.
Fig. 10B shows a patient interface 3000 comprising a positioning and
stabilising structure 3300 having threaded tube sections 3380 and 3382 in accordance
with one form of the present technology
Fig. 11 shows a patient interface 3000 comprising a positioning and
stabilising structure 3300 having replaceable tube portions 3385 and 3386 in
accordance with one form of the present technology.
Fig. 12 shows a patient interface 3000 comprising a positioning and
stabilising structure 3300 having insertable tube portions 3387 in accordance with one
form of the present technology.
Fig. 13 shows part of a tube 3350 for a patient interface comprising a
stretchable tube section 3355 in accordance with one form of the present technology.
Fig. 14 shows a patient interface 3000 comprising a positioning and
stabilising structure 3300 having band 3395 in accordance with one form of the
present technology.
Fig. 15 shows a part of a patient interface comprising replaceable loop
insert members 3410 and 3411 in accordance with one form of the present
technology.
Fig. 16 shows a part of a patient interface comprising an inflatable loop
insert member 3420 in accordance with one form of the present technology.
Fig. 17 shows a patient interface 3000 comprising a positioning and
stabilising structure 3300 having concertina tube sections 3362 and an elastic sleeve
3340 in accordance with one form of the present technology.
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7.4 RPT DEVICE
Fig. 18 shows an RPT device in accordance with one form of the present
technology.
7.5 HUMIDIFIER
Fig. 19A shows an isometric view of a humidifier in accordance with one
form of the present technology.
Fig. 19B shows an isometric view of a humidifier in accordance with one
form of the present technology, showing a humidifier reservoir 5110 removed from
the humidifier reservoir dock 5130.
8 DETAILED DESCRIPTION OF EXAMPLES OF THE
TECHNOLOGY
Before the present technology is described in further detail, it is to be
understood that the technology is not limited to the particular examples described
herein, which may vary. It is also to be understood that the terminology used in this
disclosure is for the purpose of describing only the particular examples discussed
herein, and is not intended to be limiting.
The following description is provided in relation to various examples
which may share one or more common characteristics and/or features. It is to be
understood that one or more features of any one example may be combinable with one
or more features of another example or other examples. In addition, any single
feature or combination of features in any of the examples may constitute a further
example.
8.1 THERAPY
In one form as shown in Fig. 1A, the present technology comprises a
method for treating a respiratory disorder comprising the step of applying positive
pressure to the entrance of the airways of a patient 1000.
8.2 TREATMENT SYSTEMS
In one form, the present technology comprises an apparatus or device for
treating a respiratory disorder. The apparatus or device may comprise an RPT device
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4000 for supplying pressurised air to the patient 1000 via an air circuit 4170 to a
patient interface 3000. Figs. 1A, 1B and 1C illustrate treatment systems which utilise
different forms of patient interface 3000
8.3 PATIENT INTERFACE
With reference to Fig. 3A, a non-invasive patient interface 3000 in
accordance with one aspect of the present technology comprises the following
functional aspects: a cushion assembly 3150, a positioning and stabilising structure
3300 and a connection port 3600 for connection to air circuit 4170. In some forms a
functional aspect may be provided by one or more physical components. In some
forms, one physical component may provide one or more functional aspects.
The cushion assembly 3150 comprises a seal-forming structure 3100 and a
plenum chamber 3200. In use the plenum chamber 3200 receives the supply of air at
positive pressure from the air circuit 4170 and the seal-forming structure 3100 is
arranged to seal with an area surrounding an entrance to the airways of the patient so
as to facilitate the supply of air at positive pressure to the airways.
8.3.1 Seal-forming structure
In one form of the present technology, a seal-forming structure 3100
provides a seal-forming surface, and may additionally provide a cushioning function.
A seal-forming structure 3100 in accordance with the present technology
may be constructed from a soft, flexible, resilient material such as silicone.
The seal-forming structure 3100 may be non-invasive, i.e. does not extend
internally of the patient’s airways. In some forms of the technology, no part of the
seal-forming structure 3100 enters the patient’s mouth in use. In some forms of the
technology, the seal-forming structure 3100 is configured to leave the patient’s mouth
uncovered in use. In some forms of the technology, the seal-forming structure 3100
does not cover the patient’s eyes in use.
In one form, the seal-forming structure 3100 comprises a sealing flange
and a support flange. The sealing flange comprises a relatively thin member with a
thickness of less than about 1mm, for example about 0.25mm to about 0.45mm that
extends around the perimeter of the plenum chamber 3200. Support flange may be
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relatively thicker than the sealing flange. The support flange is disposed between the
sealing flange and the marginal edge of the plenum chamber 3200, and extends at
least part of the way around the perimeter. The support flange is or includes a spring-
like element and functions to support the sealing flange from buckling in use. In use
the sealing flange can readily respond to system pressure in the plenum chamber 3200
acting on its underside to urge it into tight sealing engagement with the face.
In one form as shown in Fig. 1A, the seal-forming portion of the non-
invasive patient interface 3000 comprises a pair of nasal puffs, or nasal pillows, each
nasal puff or nasal pillow being constructed and arranged to form a seal with a
respective naris of the nose of a patient. A nasal pillows patient interface 3000 is also
shown in Fig. 3A.
Nasal pillows in accordance with an aspect of the present technology
include: a frusto-cone, at least a portion of which forms a seal on an underside of the
patient's nose, a stalk, a flexible region on the underside of the frusto-cone and
connecting the frusto-cone to the stalk. In addition, the structure to which the nasal
pillow of the present technology is connected includes a flexible region adjacent the
base of the stalk. The flexible regions can act in concert to facilitate a universal joint
structure that is accommodating of relative movement both displacement and angular
of the frusto-cone and the structure to which the nasal pillow is connected. For
example, the frusto-cone may be axially displaced towards the structure to which the
stalk is connected.
In one form, the non-invasive patient interface 3000 comprises a seal-
forming portion that forms a seal in use on an upper lip region (that is, the lip
superior), a nasal bridge region and a cheek region of the patient's face. This is the
case, for example, with the patient interface 3000 shown in Fig. 1B. This seal-forming
portion delivers a supply of air or breathable gas to both nares of patient 1000 through
a single orifice. This type of seal-forming structure may be referred to as a “nasal
cushion” or “nasal mask”.
In another form, the seal-forming structure is configured to form a seal in
use with the underside of the nose around the nares and optionally with the lip
superior. This type of seal-forming structure may be referred to as a “nasal cradle
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cushion” or “sub-nasal mask”. The shape of the seal-forming structure may be
configured to match or closely follow the underside of the patient’s nose, i.e. the
profile and angel of the seal-forming structure may be substantially parallel to the
patient’s naso-labial angle. In one form of nasal cradle cushion, the seal-forming
structure comprises a septum member defining two orifices, each of which, in use,
supply air or breathable gas to a different one of the patient’s nares. The septum
member may be configured to contact or seal against the patient’s columella in use. In
some forms of the technology, the seal-forming structure 3100 is configured to form a
seal on an underside of the patient’s nose without contacting a nasal bridge region of
the patient’s nose.
In one form the non-invasive patient interface 3000 comprises a seal-
forming portion that forms a seal in use on a chin-region, a nasal bridge region and a
cheek region of the patient's face. This is the case, for example, with the patient
interface 3000 shown in Fig. 1C. This seal-forming portion delivers a supply of air or
breathable gas to both nares and mouth of patient 1000 through a single orifice. This
type of seal-forming structure may be referred to as a “full-face mask”.
In another form the non-invasive patient interface 3000 comprises a nasal
seal-forming structure 3170 in the manner of a nasal cushion or nasal cradle cushion
and an oral seal-forming structure 3180 that is configured to form a seal in use around
the mouth of a patient (which may be referred to as a “mouth cushion” or “oral
mask”). In such a mask air or breathable is supplied in use through separate orifices to
the patient’s nares and the patient’s mouth. This type of seal-forming structure 3100
may be referred to as an “oro-nasal mask”. In one form, the nasal seal-forming
structure 3170 and oral seal-forming structure 3180 are integrally formed as a single
component. This is the case, for example, with the cushion assembly 3150 shown in
Figs. 4A, 4B and 4C. Alternatively, the nasal seal-forming structure 3170 and oral
seal-forming structure 3180 may be formed separately and are configured to be
attached together, either directly or indirectly, for example by connecting together
frames attached to each cushion. For example, the nasal seal-forming structure 3170
and the oral seal-forming structure 3180 may be configured to be detached and re-
attached in modular fashion. This enables the patient interface to be converted from
an oro-nasal mask to a nasal mask or sub-nasal mask and vice versa, as desired by the
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patient and/or physician. This is the case, for example, with the cushion assembly
3150 shown in Figs. 4D and 4E.
In some forms of the technology, the seal-forming structure 3100 is
configured so that the seal-forming structure does not extend below a mental
protuberance region of the patient’s head in use.
Unless clearly specified otherwise, embodiments of patient interface
according to the present technology may comprise any of the above types of seal-
forming structure.
In certain forms of the present technology, a seal-forming structure 3100
is configured to correspond to a particular size of head and/or shape of face. For
example one form of a seal-forming structure 3100 is suitable for a large sized head,
but not a small sized head. In another example, a form of seal-forming structure 3100
is suitable for a small sized head, but not a large sized head.
8.3.2 Plenum chamber
The plenum chamber 3200 receives, in use, pressurised breathable gas and
is pressurised at a pressure above ambient pressure. In some forms of the present
technology, the plenum chamber 3200 has a perimeter 3210 that is shaped to be
complementary to the surface contour of the face of an average person in the region
where a seal will form in use. In use, a marginal edge of the plenum chamber 3200 is
positioned in close proximity to an adjacent surface of the face. Actual contact with
the face is provided by the seal-forming structure 3100. The seal-forming structure
3100 may extend in use about the entire perimeter of the plenum chamber 3200.
The plenum chamber 3200 may receive the pressurised breathable gas
through a plenum chamber inlet port that is sized and structured to receive the gas
from another part of the patient interface 3000.
8.3.3 Positioning and stabilising structure
The seal-forming structure 3100 of the patient interface 3000 of the
present technology may be held in sealing position in use by the positioning and
stabilising structure 3300. Positioning and stabilising structure 3300 may be referred
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to as “headgear” since it engages the patient’s head in order to hold the patient
interface 3000 in a sealing position.
In one form of the present technology, a positioning and stabilising
structure 3300 is provided that is configured in a manner consistent with being worn
by a patient while sleeping. In one example the positioning and stabilising structure
3300 has a low profile, or cross-sectional thickness, to reduce the perceived or actual
bulk of the apparatus.
The positioning and stabilising structure 3300 may comprise at least one
tie. A tie will be understood to be a structure designed to resist tension. In use, a tie is
part of the positioning and stabilising structure 3300 that is under tension. Some ties
will impart an elastic force as a result of this tension, as will be described. A tie may
act to maintain the seal-forming structure 3100 in a therapeutically effective position
on the patient’s head. In certain forms of the present technology, the positioning and
stabilising structure 3300 may comprise ties in the form of headgear tubes 3350
and/or headgear straps, as will now be described.
8.3.3.1 Headgear tubing
In the form of the present technology illustrated in Fig. 3A, the
positioning and stabilising structure 3300 comprises at least one tube 3350 that
delivers pressurised air received from a conduit forming part of the air circuit 4170
from the RPT device to the patient’s airways, for example through the plenum
chamber 3200 and seal-forming structure 3100. The tubes 3350 are an integral part of
the headgear 3300 of patient interface 3000 to position and stabilise the seal-forming
structure 3100 of the patient interface to the appropriate part of the patient’s face (for
example, the nose and/or mouth). This allows the conduit of air circuit 4170 providing
the flow of pressurised air to connect to a connection port 3600 of the patient interface
in a position other than in front of the patient’s face which may be unsightly to some
people.
Since air can be contained and passed through tubes 3350 in order to
deliver pressurised air from the air circuit 4170 to the patient’s airways, the
positioning and stabilising structure 3300 may be described as being inflatable. It will
be understood that an inflatable positioning and stabilising structure 3300 does not
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require all components of the positioning and stabilising structure 3300 to be
inflatable.
In certain forms of the present technology, the patient interface 3000 may
comprise a connection port 3600 located proximal a top, side or rear portion of a
patient’s head. For example, in the form of the present technology illustrated in Fig.
3A, the connection port 3600 is located on top of the patient’s head. Patient interfaces
in which the connection port is not positioned in front of the patient’s face may be
advantageous as some patients find a conduit that connects to a patient interface in
front of the face to be unsightly and obtrusive. For example, a conduit connecting to a
patient interface in front of the face may be prone to being tangled up in bedclothes or
bed linen, particularly if the conduit extends downwardly from the patient interface in
use. Forms of the technology with a patient interface with a connection port
positioned proximate the top of the patient’s head in use may make it easier or more
comfortable for a patient to lie or sleep in one or more of the following positions: in a
side or lateral position; in a supine position (i.e. on their back, facing generally
upwards); and in a prone position (i.e. on their front, facing generally downwards).
Moreover, connecting a conduit to the front of a patient interface may also cause a
problem known as tube drag, wherein the conduit may provide an undesired drag
force upon the patient interface thereby causing dislodgement away from the face.
In the example of Fig. 3A, the at least one tube 3350 extends between the
cushion assembly 3150 from the connection port 3600 across the patient’s cheek
region and above the patient’s ear, i.e. a portion of tube 3350 that connects to cushion
assembly 3150 overlays a maxilla region of the patient’s head in use and a portion of
tube 3350 overlays a region of the patient’s head superior to the otobasion superior on
the patient’s head.
In the form of the present technology illustrated in Fig. 3A, the
positioning and stabilising structure 3300 comprises two tubes 3350, each tube being
positioned in use on different sides of the patient’s head and extending across the
respective cheek region, above the respective ear (superior to the otobasion superior
on the patient’s head) to the connection port 3600 on top of the patient’s head. This
form of technology may be advantageous because, if a patient sleeps on the side of
their head and one of the tubes in compressed to block or partially block the flow of
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gas along the tube, the other tube remains open to supply pressurised gas to the
patient. In other embodiments of the technology, the patient interface may comprise a
different number of tubes, for example one tube, or three or more tubes. In one
example in which the patient interface has one tube 3350, the single tube 3350 is
positioned on one side of the patient’s head in use (e.g. across one cheek region) and a
strap forms part of the positioning and stabilising structure 3300 and is positioned on
the other side of the patient’s head in use (e.g. across the other region) to assist in
securing the patient interface 3000 on the patient’s head.
In the form of the technology shown in Fig. 3A the two tubes 3350 are
fluidly connected at their upper end to each other and to connection port 3600. In one
embodiment, the two tubes are integrally formed while in other embodiments the
tubes are separate components that are connected together in use and may be
disconnected, for example for cleaning or storage. Where separate tubes are used they
may be indirectly connected together, for example each may be connected to a T-
shaped conduit having two conduit arms each fluidly connectable to the tubes 3350
and a third conduit arm or opening acting as the connection port 3600 and connectable
in use to the air circuit 4170.
The tubes 3350 may be formed of a semi-rigid material such as an
elastomeric material, e.g. silicone. The tubes may have a natural, preformed shape and
be able to be bent or moved into another shape if a force is applied to the tubes. For
example, the tubes may be generally arcuate or curved in a shape approximating the
contours of a patient’s head between the top of the head and the nasal or oral region.
The exemplary form of the technology illustrated in Fig. 3A has tubes
3350 which curve around the upper part of the patient’s head from the upper end of
the tubes 3350 that connect to connection port 3600 on top of the head to the point at
which the rear headgear strap 3310 connects to the tubes 3350 substantially without
any curvature in the sagittal plane. In between the point at which the rear headgear
strap 3310 connects to the tubes 3350 and the lower ends of the tubes 3350 where
they connect with the cushion assembly 3150 in front of the patient’s airways under
the nose, the tubes 3350 curve forwards between the patient’s ears and eyes and
across the cheek region. The radius of curvature of this section of the tubes 3350 may
be in the range 60-100mm, for example 70-90mm, for example 80mm. The lower end
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of the tubes 3350 and the section of the tubes 3350 at which the rear headgear strap
3310 connects to the tubes 3350 may subtend an angle in the range 65-90°, for
example 75-80°.
In certain forms of the technology, one or more portions of the tubes 3350
may be rigidised by one or more rigidising or stiffening elements. Examples of
rigidising elements include: sections of the tubes 3350 that are comparatively thicker
than other sections; sections of the tubes 3350 that are formed from a material that is
comparatively more rigid that the material forming other sections; and a rigid member
attached to the inside, outside or embedded in a section of tube. The use of such
rigidising elements helps to control how the positioning and stabilising structure 3300
will function in use, for example where the tubes 3350 is more likely to deform if
forces are applied to them and where the shape of the tubes 3350 is more likely to be
maintained if forces are applied. The selection of where such rigidising elements are
positioned in the tubes 3350 can therefore help to promote comfort when the patient
interface 3000 is worn and can help to maintain a good seal at the seal-forming
structure during use. Rigidising or stiffening elements may be in positioning and
stabilising structures 3300 which are configured to support relatively heavy seal-
forming structures such as full face or oro-nasal cushion assemblies.
The tubes 3350 in the form of the technology shown in Fig. 3A have a
length of between 15 and 30cm, for example between 20 and 27cm. In one
embodiment the tubes are 25cm long. The length of the tubes is selected to be
appropriate to the dimensions of the heads of typical patients, for example the
distance between the region proximate the top of the head where the upper end of the
tubes 3350 are situated to the region proximate the openings to the patient’s airways
at which the lower end of the tubes 3350 connect to the cushion assembly 3150 when
following a generally arcuate path down the sides of the heads and across the patient’s
cheek region such as is shown in Fig. 3A. As described in more detail below, the
patient interface 3000 is configured so that the length of the tubes 3350 can be varied
in some forms of the technology and the above lengths may apply to the tube in a
contracted, stretched or neutral state. It will be appreciated that the length of the tubes
3350 will depend on the length of other components in the patient interface 3000, for
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example the length of arms of a T-shaped conduit to which the upper ends of tubes
3350 connect.
The level to which the patient interface 3000 fits an individual patient can
be altered by varying the length of the tubes 3350 and, alternatively or additionally,
by altering the position of the patient interface 3000 on the patient’s head. For
example, a patient interface 3000 having tubes 3350 of a certain length can be
adjusted to better fit a patient by moving the positioning and stabilising structure 3300
in the posterior or anterior direction on the patient’s head. Positioning the connection
port 3600 further forward (i.e. in the anterior direction) enables a patient interface
3000 having tubes 3350 of a certain length to fit a larger head than if the connection
port 3600 is positioned further backward (i.e. in the posterior direction).
In certain forms of the present technology the patient interface 3000 is
configured such that the connection port 3600 can be positioned in a range of
positions across the top of the patient’s head so that the patient interface 3000 can be
positioned as appropriate for the comfort or fit of an individual patient. One way this
can be achieved so that the cushion assembly 3150 forms an effective seal with the
patient’s face irrespective of the position of the connection port 3600 on the patient’s
head is to de-couple movement of the upper portion of the patient interface 3000 from
the lower portion of the patient interface 3000. Such de-coupling can be achieved
using, for example, mechanisms that allow parts of the headgear tubes 3350 to easily
move or flex relative to other parts of the patient interface 3000. Such mechanisms
will be described below.
In a certain form of the present technology, the patient interface 3000 is
configured such that the connection port 3600 is positioned approximately at a top
point of the patient’s head. The connection port 3600 may be positioned in the sagittal
plane and aligned with the otobasion superior points in a plane parallel to the coronal
plane. The otobasion superior points are identified in Fig. 2D. As will be described
below, in some forms of the technology, the headgear 3300 is configured to be worn
in different positions, with the effect that the connection port 3600 may be positioned
proximate the top of the patient’s head in the sagittal plane up to around 20mm
forward or 20mm rearward of the otobasion superior points.
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The cross-sectional shape of the tubes 3350 may be circular, elliptical,
oval, D-shaped or a rounded rectangle, for example as described in US Patent No.
6,044,844, the contents of which are incorporated herein. A cross-sectional shape that
presents a flattened surface of tube on the side that faces and contacts the patient’s
face or other part of the head may be more comfortable to wear than, for example a
tube with a circular cross-section.
The cross-sectional width and/or height of the tubes 3350 may be in the
range 8-25mm, for example 10-20mm. In some forms in which the tubes have a D-
shaped cross-section, for example in the case of the longitudinal section of headgear
tubing 3350 shown in Fig. 3H, the tubes have a width in the range 15-25mm, for
example 20mm, and a height in the range 8-15mm, for example 10mm. The height
may be considered to be the dimension of the tube away from the patient’s face, i.e.
the distance between the patient contacting side 3348 and the outermost part of the
non-patient contacting side 3349, while the width may be considered to be the
dimension across the surface of the patient’s head. The cross-sectional thickness of
the material forming the tubes 3350 may be in the range 0.8-1.6mm, for example 1.0-
1.5mm, for example 1.3mm.
The D-shaped cross-sectional tube 3350 shown in Fig. 3H has rounded
edges 3347 flanking the patient contacting side 3348. Rounded edges in contact with,
or proximate to, the patient’s skin help the patient interface 3000 to be more
comfortable to wear and to avoid leaving marks on, or irritating, the patient’s skin. A
tube with a D-shaped cross-sectional profile is also more resistant to buckling than
other shaped profiles.
Also as described in US Patent no. 6,044,844, the tubes 3350 may be
crush resistant to avoid the flow of breathable gas through the tubes if either is
crushed during use, for example if it is squashed between a patient’s face and pillow.
Crush resistant tubes may not be necessary in all cases as the pressurised gas in the
tubes may act as a splint to prevent or at least restrict crushing of the tubes 3350
during use. A crush resistant tube may be advantageous where only a single tube 3350
is present as if the single tube becomes blocked during use the flow of gas would be
restricted and therapy will stop or reduce in efficacy.
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The two tubes 3350 are fluidly connected at their lower ends to the
cushion assembly 3150. In certain forms of the technology, the connection between
the tubes 3350 and the cushion assembly 3150 is achieved by connection of two rigid
components so that the patient can easily connect the two components together in a
reliable manner. The tactile feedback of a ‘re-assuring click’ or like sound may be
easy for a patient to use or for a patient to know that the tube has been correctly
connected to the cushion assembly 3150. In one form, the tubes 3350 are formed from
silicone and the lower ends of the silicone tubes 3350 are overmolded to a rigid
connector made, for example, from polypropylene. The rigid connector may comprise
a male mating feature configured to connect to a female mating feature on the cushion
assembly 3150, although the male / female features may be arranged the other way
around.
In another embodiment a compression seal is used to connect the tube
3350 to the cushion assembly 3150. For example, a resiliently flexible (e.g. silicone)
tube 3350 without the rigid connector may need to be squeezed slightly to reduce its
diameter so that it can be jammed into a port in the plenum chamber 3200 and the
inherent resilience of the silicone pushes the tube 3350 outwards to seal the tube 3350
in the port in an air-tight manner. In a hard-to-hard type engagement between the tube
3350 and port, a pressure activated seal such as a peripheral sealing flange may be
used. When pressurised gas is supplied through the tubes 3350 the sealing flange is
urged against the join between the tubes and the inner circumferential surface of the
port of the plenum chamber 3200 to enhance the seal between them. If the port is soft
and a rigid connector is provided to the tube 3350, the pressure activated seal as
described earlier may also be used to ensure the connection is air-tight.
Similar connection mechanisms may be used to fluidly connect the tubes
3350 with a T-shaped top member defining the connection port 3600 or connectable
to the connection port 3600 in some forms of the technology. In one embodiment, a
swivel elbow connected at the connection port 3600 is rotatable in order to drive a
port size adjustment mechanism that decreases or increases the size of the ports into
which tubes 3350 are inserted in order to improve the fit of the tubes through an
increase or decrease of compressive forces and to reduce unintended leakage.
James & Wells Ref: 506131NZ
8.3.3.2 Headgear straps
In certain forms of the present technology, the positioning and stabilising
structure 3300 comprises at least one headgear strap acting in addition to the tubes
3350 to position and stabilise the seal-forming structure 3100 to the entrance to the
patient’s airways.
8.3.3.2.1 Position of headgear straps
In one example, for example as shown in Fig. 3A, the positioning and
stabilising structure 3300 comprises a rear headgear strap 3310 connected between the
two tubes 3350 positioned on each side of the patient’s head and passing around the
back of the patient’s head, for example overlaying or lying inferior to the occipital
bone of the patient’s head in use. The rear strap 3310 connects to each tube above the
patient’s ears. In other embodiments, for example for an oro-nasal mask, the
positioning and stabilising structure 3300 additionally comprises one or more lower
side headgear straps that connect between the tubes and pass below the patient’s ears
and around the back of the patient’s head.
In one form of the present technology, the positioning and stabilising
structure 3300 comprises a chin strap 3320 that, in use, extends under the patient’s
chin, for example as shown in Figs. 10A and 10B. The chin strap 3320 may be
connected to the headgear tubes 3350 or, in another embodiment, to the cushion
assembly 3150 or a frame assembly operatively connected to the cushion assembly.
Certain forms of the present technology may comprise multiple headgear
straps to increase stability as described above, for example a rear strap, side headgear
straps and a chin strap.
In certain forms of the technology, the positioning and stabilising
structure 3300 comprises a mechanism for connecting a headgear strap to the seal-
forming structure 3100. The headgear strap may be connected directly or indirectly to
the seal-forming structure 3100. In the case of the patient interface 3000 shown in Fig.
3A, for example, a tab 3345 configured to connect to rear strap 3310 projects
outwardly from each headgear tube 3350 in a generally posterior direction. The tabs
3345 have holes in them to receive the ends of rear strap 3310.
James & Wells Ref: 506131NZ
In some forms of the present technology, the rear strap 3310 is adjustable.
For example, in the case of the patient interface shown in Fig. 3C the rear strap 3310
is, in use, threaded through a hole in each tab 3345. The length of the rear strap 3310
between the tabs 3345 may be adjusted by pulling more or less of the rear strap 3310
through one or both of the tabs 3345. The rear strap 3310 may be secured to itself
after passing through the holes in the tabs 3345, for example, with hook-and-loop
fastening means. The rear strap 3310 therefore is able to be adjusted to fit around
different head sizes. In some forms of the technology the angle of the rear strap 3310
relative to the headgear tubes 3350 or patient’s head is able to be adjusted to fit
around the patient’s head at a different locations. This adjustability assists the
headgear 3300 to accommodate different head shapes and sizes.
In some forms of the technology, the rear strap 3345 exerts a force on the
headgear tubes 3350 to pull them in an at least partially posterior (e.g. rearwards)
direction at the locations of the tabs 3345. The rear strap 3310 may also exert a force
on the headgear tubes 3350 to pull them in an at least partially inferior (e.g.
downwards) direction. The magnitude of this force may be adjusted by altering the
length of the rear strap 3310 between the tabs 3345.
In some forms of the technology, such as the form shown in Fig. 3C, the
direction of the force applied to the headgear tubes 3350 by the rear strap 3310 may
also be altered. This direction may be altered by adjusting the angle of the rear strap
3310 relative to the headgear tubes 3350 or patient’s head. In some forms of the
technology the location at which the rear strap 3310 exerts a force on the headgear
tubes 3350 may be altered by adjusting the location at which the rear strap 3310 is
secured to the headgear tubes 3350.
The adjustability of the magnitude and direction of the force applied to the
headgear tubes 3350 by the rear strap 3310 may advantageously enable the headgear
3300 to accommodate a range of head sizes and head shapes. The rear strap 3310 may
balance forces in the headgear tubes 3350 which may assist the headgear to maintain
its shape and an effective seal to the patient’s face, while remaining comfortable.
In some forms of the technology, when worn by a patient, a point on the
headgear tubes 3350 near the tab 3345 will receive a generally upward (e.g. superior)
James & Wells Ref: 506131NZ
force from the upper portion of the headgear tubes 3350 due to a biasing mechanism
(described in further detail below) acting to keep the headgear secured to the patient’s
head. Additionally, the point on the headgear tubes 3350 near the tab 3345 may
receive a generally forward (e.g. anterior) and downward (e.g. inferior) force caused
by a biasing mechanism acting to urge the seal forming structure 3150 upwards and
into the patient’s nose. The directions and magnitudes of the forces required for a
secure fit and effective seal may vary between patients based on the position of the
positioning and stabilising structure 3300 on the head, which may vary due to, for
example, differences in head shapes and sizes. In some forms of the technology, the
adjustability of the rear strap 3310 enables the forces to be balanced for a range of
head shapes and sizes to hold the headgear 3300 in a comfortable position while
maintaining an effective seal.
For example, to balance a large force acting in the anterior (e.g. forward)
direction on the portions of the headgear tubes 3350 proximate the tabs 3345, the rear
strap 3310 may be adjusted by pulling more of the rear strap 3310 through the slots in
the tabs 3345, thereby causing the rear strap 3310 to shorten in length and, if the rear
strap 3310 is elastic, to apply a larger force on the headgear tubes 3350 in the
posterior (e.g. rearward) direction. Similarly, the angle of the rear strap 3310 may be
adjusted as required to balance both the vertical and horizontal components of the
forces acting on the portions of the headgear tubes 3350 proximate the tabs 3345,
across a range of head shapes and sizes.
8.3.3.2.2 Form of headgear straps
In one example, the positioning and stabilising structure 3300 comprises
at least one strap 3310 having a rectangular cross-section. In one example the
positioning and stabilising structure 3300 comprises at least one flat strap. In another
example the positioning and stabilising structure 3300 comprises at least one strap
3310 having a profile with one or more rounded edges to provide greater comfort and
to reduce the risk of headgear straps marking or irritating the patient.
In one form of the present technology, a positioning and stabilising
structure 3300 comprises a strap 3310 constructed from a laminate of a fabric patient-
contacting layer, a foam inner layer and a fabric outer layer. In one form, the foam is
porous to allow moisture, (e.g., sweat), to pass through the strap 3310. In one form,
James & Wells Ref: 506131NZ
the fabric outer layer comprises loop material to engage with a hook material portion.
The hook material portion may be positioned at a distal portion of the strap 3310.
In certain forms of the present technology, a positioning and stabilising
structure 3300 comprises a strap 3310 that is extensible, e.g. resiliently extensible. For
example the strap 3310 may be configured in use to be in tension, and to direct a force
to draw the seal-forming structure 3100 into sealing contact with a portion of a
patient’s face. In an example the strap may be configured as a tie. In other forms of
the technology, the positioning and stabilising structure 3300 comprises a strap 3310
that is adjustable in order to alter the length of the strap. For example, the strap 3310
may connect to tubes 3350 by a strap adjustment mechanism, e.g. hook-and-loop
fasteners. An adjustable strap 3310 may add further adjustment capability to other
adjustment features of the patient interface 3000 to enable a patient to improve
comfort and fit. In some forms of the present technology the degree of adjustability
provided by other parts of the positioning and stabilising structure may mean the
patient interface 3000 is sufficiently adjustable without strap 3310 also being
adjustable.
In certain forms of the present technology, a positioning and stabilising
structure 3300 comprises a strap 3310 that is bendable and e.g. non-rigid. An
advantage of this aspect is that the strap 3310 is more comfortable for a patient to lie
upon while the patient is sleeping.
In certain forms of the present technology, a positioning and stabilising
structure 3300 comprises a strap 3310 that comprises two or more strap bands
separate by a split. A split strap 3310 may anchor the patient interface 3000 on the
patient’s head in a particularly stable fashion in the case of some patient interface
designs.
In certain forms of the present technology, a positioning and stabilizing
structure 3300 provides a retaining force configured to correspond to a particular size
of head and/or shape of face. For example one form of positioning and stabilizing
structure 3300 provides a retaining force suitable for a large sized head, but not a
small sized head. In another example, a form of positioning and stabilizing structure
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3300 provides a retaining force suitable for a small sized head, but not a large sized
head.
8.3.3.3 Headgear tubing adjustment mechanism
In certain forms of the present technology, the positioning and stabilising
structure 3300 comprises an adjustment mechanism 3360. Adjustment mechanism
3360 is configured to allow the positioning and stabilising structure 3300 to be
dimensionally adjusted. In at least one embodiment, the adjustment mechanism 3360
may particularly allow length adjustment of the positioning and stabilising structure
3300 between the connection port 3600 and seal-forming structure 3100, for example
length adjustment of a tie, for example the headgear tubing 3350. Additionally or
alternatively, the adjustment mechanism 3360 is configured to enable the positioning
and stabilising structure 3300 to be bendably adjusted, for example bending of the
headgear tubing 3350. The adjustment mechanism 3360 allows the patient interface
3000 to be adjusted to improve the fit of the patient interface 3000 to the patient’s
head, and thereby to enable the patient interface 3000 to fit different size heads. A
patient interface that fits a patient well is comfortable to wear, is likely to be more
stable and thus reduces the likelihood of seal disruption and maintains the sealing
structure against the entrance of the patient’s airways with a comfortable level of
headgear tension. These factors improve patient compliance with therapy, improving
therapeutic results. It will be understood that the adjustment mechanism may
comprise a plurality of mechanisms for adjustment. For example, combinations of
adjustment mechanisms described below may be provided to headgear in some forms
of the present technology.
For example, the adjustment mechanism 3360 may allow the size and/or
shape of the patient interface 3000 to be adjusted. In one form of the technology, the
length of tubes 3350 between the connection port 3600 and the seal-forming structure
3100 may be adjusted.
In some forms of the technology, the adjustment mechanism 3360 allows
the size of the patient interface 3000 to be adjusted by a total of up to 100mm to allow
the patient interface 3000 to fit a broad range of patients. For example, the adjustment
mechanism 3360 may allow the total length of the tubes 3350 to be adjusted by a total
of up to 100mm. In one form of the technology, the total length of the tubes 3350 can
James & Wells Ref: 506131NZ
be adjusted by a total of up to 80mm. For example, the length of the tube 3350
positioned on each side of the patient’s face in use may be adjusted by up to 40mm.
The patient interface 3000 may be configured and structured so that, if the
positioning and stabilising structure 3300 exerts a force on the patient’s face to retain
the cushion assembly 3150 in sealing relationship with the patient’s face against the
force exerted by the gas at positive pressure inside the plenum chamber 3200, that
force is approximately constant or within predetermined limits over the range of sizes
the patient interface 3000 is able to adopt. This is described in more detail below.
Different forms of adjustment mechanisms 3360 will be described in the
ensuing description. In some forms the adjustment mechanism 3360 is comprised as
part of the headgear tubing 3350 while in other forms the adjustment mechanism 3360
is distinct from the headgear tubing 3350. Certain forms of the technology may
comprise multiple adjustment mechanisms 3360 as described below.
In some forms of the technology the adjustment mechanism 3360 is
configured to be manually adjusted to enable the patient interface 3000 to fit the
patient comfortably and with therapeutic effectiveness, i.e. adjusted by the patient or
other person. In other forms the adjustment mechanism 3360 is configured to
automatically adjust to fit the patient. An automatic adjustment mechanism may
provide an advantage in that it reduces the chances of a patient fitting the patient
interface 3000 incorrectly or uncomfortably. On the other hand, some patients may
prefer the ability to alter the fit of the patient interface themselves.
In some forms of the technology, the patient interface 3000 is configured
such that different forms of seal-forming structure 3100 can be interchangeably
connected to the positioning and stabilising structure 3300. The different forms of
seal-forming structure 3100 may include seal-forming structures of different size and
weight. For example, an oro-nasal cushion may be heavier than a nasal cushion. In
such forms of the technology a manual adjustment mechanism may provide an
advantage in that the mechanism can be initially set to suit the type of seal-forming
structure being used. For example, the manual adjustment mechanism may be set to
provide a tighter fit if a relatively heavy seal-forming structure is used to counteract
the tendency of a relatively heavy seal-forming structure to pull on the positioning
James & Wells Ref: 506131NZ
and stabilising structure 3100 in an inferior direction. Similar considerations may
apply to seal-forming structures that are subject to movement by a patient’s mouth
(e.g. jaw drop).
8.3.3.3.1 Folding / concertina headgear tubes
In certain forms of the technology, the adjustment mechanism 3360
comprises tubes 3350 having one or more folding portions, pleats, corrugations or
bellows, i.e. the folding portions pleats, corrugations or bellows comprise the
adjustment mechanism 3360. When each folding portion is in a first, folded
configuration, the length of the respective tube 3350 is different to its length when the
folding portion is in a second, unfolded configuration.
The patient interface 3000 shown in Fig. 3A comprises tubes 3350
comprising a concertina tube section 3362 between lengths of the tubes 3350 without
concertinas. Concertina tube section 3362 comprises a plurality of folds or bellows
able to fold and unfold independently or in concert to shorten or lengthen the
concertina tube section 3362 and hence the respective tube 3350. The folds in
concertina tube section 3362 may be able to be expanded (stretched) or contracted by
differing degrees on different sides of the tube 3350. For example, the concertina
folds on the side of the tube 3350 nearest the patient’s head may be contracted more
than those furthest from the patient’s head, which increases the curvature of the tubes
3350. This allows the shape of the tubes 3350 to be altered as well as their length,
which also helps the patient interface be adjusted to fit the patient’s specific head size
and head shape.
In certain forms of the technology the concertina tube sections 3362
provide for adjustment of the length of the tubes 3350 of the patient interface 3000
continuously through a range of different lengths. In some embodiments the length of
each concertina tube section may be continuously adjustable. An adjustment
mechanism, such as a concertina section, which provides for continuous adjustment
may fit comfortably to a wide range of head sizes. In contrast, an adjustment
mechanism which provides of adjustment between discrete lengths may fit less
comfortably on a patient for whom the most comfortable fit would require a length
between two of the discrete length options.
James & Wells Ref: 506131NZ
In some forms of the technology the tubes 3350 comprise a plurality of
concertina tube sections 3362 at predetermined locations, each separated by lengths of
the tubes 3350 without concertinas.
In some forms of the technology, concertina tube sections 3350 are
situated in relatively straight portions of the tubes 3350. This avoids the tendency for
concertina sections 3350 to straighten when pressurised gas is passed through the
tubes 3350, which may alter the position of the patient interface on the patient’s head
and adversely affect the stability of the seal and/or flow impedance.
In the form of the technology shown in Fig. 3B, patient interface 3000
comprises tubes 3350 comprising concertina tube sections 3362 that are longer than
the concertina tube sections 3362 shown in Fig. 3A. In the form of the technology
shown in Fig. 3B the concertina tube sections 3362 span the majority of the length of
the respective tube 3350 in between the point at which headgear strap 3310 connects
to the tube 3350 and the upper end of the tube 3350 that connects to connection port
3600. For example, the concertina tube sections 3362 may have a lower end at a point
just above the point at which headgear strap 3310 connects to the tube 3350 and may
have an upper end at the point where tube 3350 connects to connection port 3600. A
longer concertina tube section may provide a greater extensibility to the tube 3350. A
high extensibility may alternatively be provided by increasing the number of
concertina folds in the concertina tube section 3362. A greater extensibility may be
advantageous in enabling the patient interface 3000 to fit many patients with a large
range of head sizes while exerting a desired level of retaining force on a patient’s face
to ensure a good seal across this range of head sizes.
In the form of the technology shown in Figs. 3C, 3D and 3E the patient
interface 3000 is similar to the patient interface 3000 shown in Fig. 3B. One
difference is the configuration of the concertina tube sections 3362. In the form of the
technology shown in Figs. 3C, 3D and 3E, the concertina tube sections 3362 have a
width and diameter that vary along the length of each concertina tube section 3362.
More particularly, the concertina tube sections 3362 taper so that the width and
diameter of the tube at one end of each concertina tube section 3362 is smaller than
the width and diameter of the tube at the other end of each concertina tube section
3362. More particularly still, the upper end of each concertina tube section 3362
James & Wells Ref: 506131NZ
(where the concertina tube section 3362 connects to connection port 3600) has a
larger width and diameter than the lower end of each concertina tube section 3362
(where the concertina tube section 3362 connects to a section of tube 3350 without
concertinas), with the width and diameter of the concertina tube section 3362
increasing gradually and approximately linearly in between the upper and lower ends.
The tapering of the concertina tube section 3362 is also shown in Fig. 3F, which
shows in plan view the patient interface 3000 of Figs. 3C, 3D and 3E, and Fig. 3G,
which shows the patient interface 3000 of Fig. 3F in cross-section along the line 3G-
3G. The tapering of the concertina tube section 3362 fluidly connects the connection
port 3600 to the lower lengths of tubes 3350 without concertinas in a manner that
reduces discontinuities in the cross-sectional profile of the air path, providing a
smooth transition to reduce added impedance and promote fluid flow along the tubes
3350.
One advantage of concertina tube sections 3362 for the adjustment
mechanism 3360 is that concertina tube sections may be more readily able to curve or
bend as well as extend longitudinally, in comparison to other adjustment mechanisms.
Fig. 3J shows headgear 3300 worn in three different positions on a patient’s head
indicated by reference numerals with suffixes “a”, “b” and “c”. As shown in Fig. 3J,
the concertina tube sections 3362a, b and c are curved to different extents with
concertina tube section 3362a curving forwardly on the patient’s head, concertina tube
section 3362b having less curvature in the posterior/anterior direction and concertina
tube section 3362c having substantially no curvature on the patient’s head.
In some forms of the technology, the concertina tube sections 3362 are
able to extend by different amounts on the front and rear (e.g. anterior and posterior)
sides of the headgear tubes 3350. That is, the walls forming the concertina tube
sections 3362 may be relatively more contracted (e.g. more folded) on one side of the
tube, and relatively more extended (e.g. unfolded) on the opposite side of the tube, to
facilitate a bend or curve in the tube. This effect is visible in Fig. 3L. As shown, the
walls of the concertina tube section 3362 are less extended (e.g. more collapsed) on
the anterior side than on the posterior side in the case of concertina tube section
3362a, i.e. when the headgear is worn on the patient’s head forwardly of the coronal
plane. The ability for the concertina tube sections 3362 to curve in the anterior
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direction helps enable the headgear 3300 to be worn in a forward position without
causing the cushion assembly 3150 to roll forward and out of sealing contact with the
patient’s face, which may occur if the headgear tubes were rigid. The ability for the
headgear tubes 3350 to curve in anterior or posterior directions assists in decoupling
the connection port 3600 from the cushion assembly 3150. There is less difference in
the amount of extension of the concertina tube section 3362c between the front and
rear sides of the concertina tube section 3362c (i.e. when the headgear 3300 is worn in
a rearward position on the patient’s head) compared to the difference in the amount of
extension of the concertina tube section 3362a between the front and rear sides of the
concertina tube section 3362a (i.e. when the headgear 3300 is worn in a forward
position on the patient’s head). The concertina enables the headgear tubes 3350 to
straighten (or curve) less in order to be worn rearwardly.
In one form, the concertina tube sections 3362 on each side of the patient
interface 3000 are approximately 40mm longer in a fully expanded configuration
compared to a fully contracted configuration.
In other forms of the technology, the concertina tube sections 3362 may
be situated at a different portion of the length of tubes 3350. One advantage of the
patient interfaces 3000 shown in Figs. 3A and 3B, in which the concertina tube
sections 3362 are located at a position along the length of the tubes 3350 so that the
concertina tube sections 3362 are in contact with the top and/or upper sides of the
patient’s head, i.e. a region of the patient’s head superior to the otobasion superior of
the patient’s head, is that the concertina tube sections 3362 are not in contact with the
patient’s cheek region. This avoids the discomfort that might arise if a concertina tube
section contacted a patient’s cheek region in use.
The concertina tube sections 3362 may be vulnerable to collapsing,
particularly when they are heavily stretched. This presents a risk that the concertina
tube sections 3362 cause a blockage in tubes 3350 which restricts or prevents the
delivery of breathable gas to the patient. In some forms of the technology, the patient
interface 3000 comprises one or more structures configured to prevent or at least
hinder collapsing of the concertina tube sections 3362. In one embodiment, the patient
interface 3000 comprises one or more rigid or semi-rigid rings provided to the
concertina tube sections 3362 and positioned circumferentially around the tubes 3350.
James & Wells Ref: 506131NZ
For example, the rings may be placed inside the concertina tube sections 3362 or they
may be moulded (for example co-moulded or overmoulded) with the concertina tube
sections 3362. In another embodiment a helical element is provided along the
concertina tube sections 3362 to hinder collapse. In such an embodiment, the sections
of material between the pitch of each helix turn, known as the tape, may provide
resiliency to the tube. The tape may be formed of a resilient material or otherwise be
structured to provide the appropriate level of elasticity to exert sufficient tension
forces on the tube for contraction. In other embodiments, the concertina tube sections
3362 are formed with concertina tube sub-sections having a higher thickness or being
made of a stiffer material than other concertina tube sub-sections such that collapse is
hindered.
In another form of the technology, the patient interface comprises an
adjustment mechanism 3360 comprising tubes 3350 having one or more
circumferential folds enabling adjacent sections of the tubes 3350 to fold
longitudinally. When the circumferential folds are in a folded configuration, a length
of the tube overlays an adjacent length of tube. The rigidity of the material from
which the tubes are formed may be configured so that the tubes tend to stay in the
folded configuration unless pulled apart by a substantial force (greater than, for
example, a force exerted on the tubes during typical use of the patient interface).
Alternatively, the patient interface may comprise means to maintain the tubes in a
folded configuration, for example clips. In another embodiment, magnets are
embedded in the tube that align between overlaying folding portions when the tube is
folded to maintain the tube in a folded configuration unless the magnets are pulled
apart.
The patient interface 3000 shown in Fig. 5 comprises an adjustment
mechanism 3360 comprising a fold portion 3364. Fold portion 3364 comprises a first
tube wall portion 3366 able to fold over an adjacent tube portion 3368 by a varying
degree by rolling over the adjacent tube portion. Figs. 5A and 5B are cross-sectional
views of the fold portion 3364 of the patient interface 3000 shown in Fig. 5. In Fig.
5A the rolling fold portion 3366 is folded over adjacent tube portion 3368 to a greater
degree than how much it is folded over in Fig. 5B and therefore the length of the tube
3350 when the fold portion 3364 is in the configuration shown in Fig. 5B is longer
James & Wells Ref: 506131NZ
than the length of the tube 3350 when the fold portion 3364 is in the configuration
shown in Fig. 5A. It can be seen from Figs. 5A and 5B that, at the location of the fold
portion 3364, three layers of tube 3350 overlap each other, although the length of the
overlapping tube sections differs between the configuration of Fig. 5A compared to
the configuration of Fig. 5B. The rolling fold portion 3366 may comprise a localised
section of tube wall that is thinner than other sections of the tube 3350.
Another form of folding adjustment mechanism 3360 for a positioning
and stabilising structure 3300 of a patient interface 3000 is shown in Fig. 6. In this
embodiment of the present technology, tubes 3350 extend from a connection port
3600 to tube ends 3352 which are configured to connect to a cushion assembly 3150
of the patient interface 3000. Tubes 3350 have a generally wavy shape along their
length and comprises at least one curved portion, for example curved portions 3353A,
3353B. The tubes 3350 are formed of a material that has sufficient flexibility for the
curved portions to increase in curvature or decrease in curvature to allow each tube to
fit a smaller or larger head respectively. For example, the tubes may be formed of
meta-silicon having a hardness of 40 durometer on the Shore hardness scale.
In the form of the technology shown in Fig. 6, a tube 3350 on one side of
the patient’s head extends, at an upper end, in a generally anterior-inferior direction
away from the connection port 3600 and a generally inferior direction at the side of
the patient’s head proximate the point that headgear strap 3310 attaches to the tube
3350 such that there is an upper curved portion 3353A positioned generally over an
upper side portion of the patient’s head and having the outer part of the curved portion
on the anterior side and the inner part of the curved portion on the posterior side.
Below the point that headgear strap 3310 attaches to the tube 3350, the tube 3350
extends generally in the inferior direction and curves slightly forwards in the anterior
direction. A lower curved portion 3353B is positioned in use generally above the
patient’s cheek region. A lower end of tube 3350 extends across the patient’s cheek
generally horizontally in the anterior direction towards tube ends 3352 which connect
to cushion assembly 3150. The lower end of tube 3350 may be oriented slightly
downwards, i.e. extending slightly in the inferior direction, when worn by some
patients. The lower curved portion 3353B positioned generally over the patient’s
James & Wells Ref: 506131NZ
cheek region has the outer part of the curved portion on the posterior side and the
inner part of the curved portion on the anterior side.
The lower portion of tube 3350 in Fig. 6 is structured and configured so
that the tube 3350 is generally positioned, in use, away from the patient’s eyes so that
the tube 3350 does not enter into the patient’s field of view, or at least does so
minimally. This may be achieved by structuring the lower portion of tube 3350 so that
the apex or the point of maximum curvature of lower curved portion 3353B is
positioned in use over a rear region of the patient’s cheek region.
Although not shown in Fig. 6, the tube 3350 positioned over the left side
of the patient’s face is structured symmetrically to the tube 3350 over the right side of
the patient’s face. In other forms, the tubes 3350 may have different structures on
each side of the patient’s face.
8.3.3.3.2 Telescopic headgear tubes
In certain forms of the technology, the adjustment mechanism 3360
comprises tubes 3350 having a first tube portion 3370 that is telescopically moveable
relative to a second tube portion 3372.
The patient interface 3000 shown in Fig. 7A comprises an adjustment
mechanism 3360 comprising first and second tube portions 3370 and 3372 that slide
telescopically relative to each other. In the embodiment of Fig. 7A, first tube portion
3370 is connected to the connection port 3600 and is therefore positioned higher on
the patient’s head than the first tube portion when the patient interface is worn. The
second tube portion 3372 has a smaller diameter than, i.e. fits inside, first tube portion
3370 and is fixedly connected to a part of the tube 3350 positioned lower on the
patient’s head when the patient interface is worn. First tube portion 3370 may be
described as enveloping second tube portion 3372 through the telescopic movement
between the two tube portions.
In certain forms of the present technology, the patient interface comprises
a tube securing mechanism that secures the first and second tube portions 3370 and
3372 in a plurality of discrete positions relative to one another. For example, in the
form of the technology shown in Fig. 7A, second tube portion 3372 comprises a
plurality of raised ribs 3374 on an outer surface and first tube portion 3370 comprises
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one or more protrusions or detents (not shown) that interlock with the ribs 3374 to
hold the first and second tube portions 3370 and 3372 in a plurality of relative
longitudinal positions, enabling the length of the tubes 3350 to be adjusted. In other
forms of the technology, the tube sections may be secured in a plurality of discrete
positions using other interlocking mechanisms, for example one or more grooves or
holes that interlock with one or more protrusions or detents. It will be appreciated that
the grooves may be provided on a surface of either the first or second tube portions
with the protrusions provided on a surface of the other of the first or second tube
portion in a position to interlock with the grooves in use.
In one form, the patient interface 3000 of Fig. 7B comprises an adjustment
mechanism 3360 comprising first and second tube portions 3370 and 3372 that slide
telescopically relative to each other. The first tube portion 3370 may slide over the
outer surface of the second tube portion 3372. The second tube portion 3372 is
positioned lower on the patient’s head when patient interface 3000 is worn than first
tube portion 3370, i.e. second tube portion 3372 is downstream of first tube portion
3370. The patient interface 3000 has two similar such adjustment mechanisms 3360,
one positioned on each side of the patient’s head in use.
Patient interface 3000 comprises an upper tube member 3351 which is
positioned over the top portion of the patient’s head in use. First tube portions 3370
on each side of the patient’s head are integrally formed as part of upper tube member
3351. A connection port 3600 is provided to upper tube member 3351, for example
the upper tube member 3351 has an opening in an upper side of the central portion
thereof.
The first tube section 3370 on each side of the patient’s head may
comprise a first or upper tab 3371 and the second tube portion 3372 may comprise a
second or lower tab 3373. The second tab 3373 may be pushed towards the first tab
3371. For example, the user may place their thumb on the second tab 3373 and their
index finger on the first tab 3371 and pinch the two tabs together such that the second
tab 3373 moves towards the first tab 3371. Moving the second tab 3373 towards the
first tab 3371 telescopically slides the first and second tube portions 3370 and 3372 to
shorten the headgear tubes 3350. Moving the second tab 3373 away from the first tab
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3371 telescopically slides the first and second tube portions 3370 and 3372 to
lengthen the headgear tubes 3350.
The second tab 3373 may slide towards a peripheral edge of the first tube
3370 such that when the second tab 3373 contacts the peripheral edge it acts as a stop
to prevent further shortening of the tube 3350.
The second tube portions 3372 of the patient interface 3000 shown in Fig.
7B are integrally formed with the lengths of tube 3350 that, in use, are positioned in
contact with the side of the patient’s head and across the patient’s cheek region. So
that the patient interface 3000 is comfortable to wear and able to adapt to the shape of
a range of patients’ heads, the lower parts of tubes 3350 (of which second tube
portions 3370 are an integral part) may be formed of a semi-rigid material such as an
elastomeric material, e.g. silicone. In contrast, upper tube member 3351 (and
consequently first tube portions 3370) may be formed from a relatively rigid material.
One possible consequence of a patient interface in which a tube portion
formed from a relatively flexible material telescopically moves relative to a tube
portion formed from a relatively rigid material is that, when the inner tube portion is
pushed towards the outer tube portion, the tube portion made of the relatively flexible
material may buckle. This may affect the ease with which the length of tubes 3350
can be adjusted. The patient interface 3000 shown in Fig. 7B comprises rigidising
members 3379 to address this problem. Rigidising members 3379 act to increase the
rigidity of the section of second tube portion 3372 that moves, in use, in and out of
first tube portion 3370. In the embodiment shown, rigidising members 3379 are
lengths of relatively rigid material provided to the upper side of each of second tube
portions 3372. The rigidising members 3379 may be mounted on the outer side of the
second tube portions 3372 or they may be moulded (for example co-moulded or
overmoulded) as part of second tube portions 3372. In certain forms of the
technology, each rigidising member 3379 may be integrally formed with the tab 3373
on an upper side of the tab 3373 on the respective second tube portion 3372.
The patient interface of Fig. 7B comprises a padded member 3330 on a
patient contacting side of the upper tube member 3351 to improve comfort when the
patient interface 3000 is worn. One or more padded members 3330 may be provided
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to any part of the positioning and stabilising structure 3300 of any of the forms of
patient interface 3000 described in this specification unless otherwise stated. For
example, padded members 3330 may be provided to a part of the tubes 3350 to make
wearing the patient interface more comfortable. Padded members 3330 may be
permanently attached to a part of tubes 3350, for example by being moulded (e.g. co-
moulded or overmoulded) or adhered thereto. Alternatively, padded members 3330
may be removably attached to tubes 3350, for example using hook-and-loop fastening
material or fasteners. Since padded members 3330 will, in use, be in contact with the
patient’s head, they may become dirty and the ability to remove them for cleaning
and/or replacement may be advantageous.
Another form the present technology is illustrated in Fig. 7C. In this form,
patient interface 3000 comprises a second tube portion 3372 that telescopically slides
over the outer surface of the first tube portion 3370. That is, the tube portion
telescopically fitting inside the other tube portion is positioned higher than the other
tube portion on the patient’s head in use.
In the embodiment of Fig. 7C, first tube portion 3370 is relatively rigid.
Second tube portion 3372 comprises a relatively rigid ring member 3384 at its upper
end. Ring member 3384 encircles the opening in the upper end of the second tube
portion 3372. Second tab 3373 may be provided to, for example integrally formed
with, ring member 3384. Since first and second tube portions 3370 and 3372 are both
formed of relatively rigid materials, they are able to telescopically move relative to
each other without buckling. The patient interface 3000 shown in Fig. 7C may
therefore avoid the need for a rigidising member such as is described in relation to
Fig. 7B while still allowing the same length of extension of the tubes 3350.
Another form of telescopic adjustment of tubes 3350 is shown in Fig. 8. In
this embodiment, a second tube portion 3372 of tubes 3350 telescopically slides
relative to a first tube portion 3370 with a ratchet mechanism 3376. Ratchet
mechanism prevents or hinders movement of the telescopically moveable first and
second tube portions relative to each other in one or both directions unless the ratchet
mechanism is released, for example by pushing buttons 3378. Buttons 3378 are each
operatively connected to a locking member (not shown) that interlocks with grooves
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or protrusions (e.g. ribs 3374) on second tube portion 3372 unless button 3378 is
pushed down.
Another form of ratchet mechanism 3376 is shown in the form of the
technology shown in Fig. 7C. In this form, ratchet mechanism 3376 comprises a
tongue 3397 provided to the head contacting side of second tube portion 3372.
Tongue 3397 is connected to second tube portion 3372 at a lower end and extends
generally along the length of second tube portion 3372. Tongue 3397 is free at its
upper end and has a protrusion on its upper side. First tube portion 3370 comprises a
plurality of grooves 3398 on its head contacting side. The protrusion on the end of
tongue 3397 is configured to selectively mate with each of grooves 3398 in order to
hold the first and second tube portions 3370, 3372 in relative position. Tubes 3350
may have a generally D-shaped cross-section with the flat part of the ‘D’ contacting
the patient. Ratchet mechanism 3376 may be advantageously located on the head
contacting side of the patient interface 3000 (such as is the case in Fig. 7C) as tongue-
and-groove ratchet mechanism 3376 may be more effective if provided on a relatively
flat region of tube 3350 to provide a larger contact area than that which would result if
more curved surfaces mated in the ratchet mechanism.
In an alternative form of the technology, button 3378 comprises tabs
positioned on the sides of tube 3350 that are squeezed inwardly to release an interlock
mechanism and allow the telescoping tube sections to be moved relative to each other.
The tabs may comprise a gap or window in the first tube section 3370, which
envelopes the second tube section 3372, enabling a patient or clinician to squeeze
together a section of the second tube section 3372 to release the interlock.
Alternatively, the gap may be covered by one or more overmoulded buttons which are
pressed to squeeze on the second tube section 3372 to release the interlock. Covering
the gap with overmoulded buttons or otherwise avoiding gaps in the adjustment
mechanism 3360 reduces the prospect of the patient’s hairs being caught in the
adjustment mechanism 3360, which may reduce comfort. In one exemplary
embodiment, the adjustment mechanism 3360 is configured such that, when the sides
of ring members 3384 at the upper end of the second tube portions 3372 are pressed
inwardly, interlocking features between the second tube portions 3372 and first tube
portions 3370 are released and telescopic movement between the tube portions is
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possible. For example, the ring member 3384 may comprise a silicone overmoulded
hard plastic pinch button and one or more protrusions on its inner top surface to
interlock with grooves on the top surface of the first tube portion 3370 so that, when
the ring member 3384 is squeezed inwardly at the sides, the protrusions and grooves
are pushed out of interlocking engagement.
The patient interface of Fig. 8 comprises padded members 3330 on a
patient contacting side of the positioning and stabilising structure 3300 to improve
comfort when the patient interface 3000 is worn.
Another form of telescopic adjustment of tubes 3350 is shown in Fig. 9. In
this embodiment the tube 3350 comprises a plurality of nested concentric tube
sections 3375a, 3375b and 3375c that slide relative to each other. Each nested
concentric tube section 3375 can be fully exposed or fully covered by telescopically
extending or retracting an adjacent nested concentric tube section 3375 relative to it
with the nested concentric tube sections interlocking with one another in fully
extended or contracted positioned to hold their position, for example via a snap-fit
mechanism. In some embodiments, the nested concentric tube sections 3375 can be
held in intermediate positions, i.e. not fully extended or retracted.
In the embodiment shown in Fig. 9, each nested concentric tube section is
marked with a visual indicator 3377 representative of the length of the tube 3350 if
that tube section is exposed, for example ‘S’ for small 3377a, ‘M’ for medium 3377b
and ‘L’ for large 3377c. Other forms of indicator may also be used, for example
numerical indicators or coloured indicators. Physical indicators may also be used such
as embossment which may be advantageous in dimly lit rooms prior to the patient
sleeping. The nested concentric tube sections 3375a-c may be configured to extend or
retract in a predetermined order.
Other forms of the technology comprise tubes 3350 formed from multiple
telescoping tube sections that are coupled together in other ways. For example, each
tube 3350 may comprise a central inner tube section flanked by two outer tube
sections, the central inner tube section telescopically sliding in and out of each of the
two outer tube sections in use. Alternatively, the central tube section may be outside
the two outer tube sections.
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In other forms of telescopically adjustable headgear tubes forms of other
size indicators may be provided. In certain forms, a first tube section 3370 of a tube
3350 that envelopes a second tube section 3372 during telescopic movement between
the two tube sections may comprise a window or gap through which a visual indicator
3377 on the second tube section 3372 can be seen to indicate the size of tube 3350
thus provided.
Another telescopic adjustment mechanism 3360 for headgear tubes 3350
is shown in Fig. 10A. In this embodiment the length of the headgear tubes 3350 is
able to be adjusted by an adjustment mechanism 3360 comprising a cog or pinion
3383 that, when rotated, causes ribbed or racked portions of adjacent first and second
tube sections 3370 and 3372 of tube 3350 to move telescopically, thus altering the
length of the tube 3350. The first tube section 3370 may be integrally, permanently or
removably connected to cushion assembly 3150. In the embodiment shown in Fig.
10A the adjustment mechanism 3360 is positioned at a lower end of the headgear
tubes 3350. For example, adjustment mechanism 3360 may be provided in or adjacent
to the cushion assembly 3150. In the embodiment shown in Fig. 10A, rotation of the
cog or pinion 3383 causes the lower end of tube 3350 to move telescopically in
relation to the cushion assembly 3150.
In another form of the technology the adjustment mechanism 3360 is
located at the connection port 3600 and a swivel elbow is provided to the cog or
pinion so that rotation of the elbow causes movement of headgear tube sections
relative to each other or relative to a T-shaped connection port member. A lock may
be provided to prevent or limit rotation of the elbow when the desired arrangement is
achieved.
Where a discrete number of relative positions of first and second tube
sections is provided for by the telescopic adjustment mechanism it will be appreciated
that a higher number of positions allows for more adjustment positions and promotes
a better fit for patients. In some embodiments, 3, 4, 5, 6 or more adjustment positions
are provided.
In certain forms of the technology, telescoping tube sections are
configured to move relative to each other and be adjusted in a continuous fashion, i.e.
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the relative position of the tube sections is not constrained to discrete positions. This
enables a greater degree of customisation in the length of the tubes 3350.
One example of a tube 3350 having a continuously adjustable length is
shown in Fig. 10B in which tube section 3372 comprises a first threaded portion 3382
on first tube section 3370 which is in screwed engagement with a second threaded
portion 3380 on second tube section 3372. Rotation of one of the threaded portions
relative to the other adjusts the length of tube 3350 by translating the rotational
movement into relative longitudinal movement of the associated tube sections. One or
both of the threaded portions are connected in rotational engagement to the other parts
of their respective tube portions so that rotation of the threaded portions does not twist
the rest of the tube 3350. The enveloped or smaller diameter first threaded portion
3372 may be provided on the lower end of the tube 3350, i.e. the part of tube 3350
connected to cushion assembly 3150 (as shown in Fig. 10B) or to the upper end of the
tube 3350, i.e. the part of tube 3350 connected to the connection port 3600. An
abutment or screw-limiting member (not shown) may be provided at one end of one
of the threaded sections to prevent the threaded sections being screwed apart and
detached accidently during use.
In one form of the technology, a screw mechanism is provided as a fine
adjustment mechanism in addition to a coarser adjustment mechanism, which may be
any of the other adjustment mechanisms described herein, for example. In general any
of the adjustment mechanisms described herein may be used in combination, with a
first adjustment mechanism providing a finer adjustment than a second adjustment
mechanism.
In another embodiment of the present technology, telescoping sliding
sections of tube 3350 are held in frictional contact through ribs on the sliding surface
of one or both sliding sections. Alternatively, one or more O-rings may be provided
between the telescopically sliding tube sections. The ribs or O-rings hold the tube
sections together with sufficient frictional force to keep them in the desired position
during normal use of the patient interface but enable their relative position to be
adjusted on application or a sufficient longitudinal adjustment force.
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In another form of the technology, telescopic tube sections may be
secured in position using other securing mechanisms. In one example, a length of a
strap is attached to one of the telescopic tube sections with a portion of hook-and-loop
fastener material provided to the strap. The strap may be secured to a complimentary
portion of hook-and-loop fastener material provided to the other telescopic tube
section to secure the sections in the desired position and thereby effect adjustment of
the length of tube 3350.
In the above-described embodiments of the present technology in which
one or more tube sections are telescopically movable relative to other tube sections it
will be appreciated that the tube sections are telescopically engaged in a substantially
sealed manner to reduce the amount of breathable gas leaking from the patient
interface. The manner in which this is achieved will differ depending on the nature of
the telescopic engagement but one or more O-rings or other sealing members may
typically be provided.
In the case of the patient interface 3000 shown in Fig. 7B, for example, an
O-ring is provided on an inner surface of the lower end of first tube portion 3370. For
example, the O-ring may be provided in a slot on the inner surface of the lower end of
first tube portion 3370. The O-ring is in sealing contact with the outer surface of the
upper end of second tube portion 3372. In other forms of the technology, the O-ring
may be provided on the outer surface of the upper end of second tube portion 3372. In
one example, the O-ring is provided to, or is integrally formed with, the rigidising
member 3379.
The configuration and structure of the sealing contact between the first
and second tube sections that move telescopically may be selected to provide the
appropriate level of friction to achieve a balance between the quality of the seal and
the ease of adjusting the first and second tube sections. In some forms of the
technology, for example the patient interface 3000 shown in Fig. 7B, it has been
found that a minimum retaining force between the first and second tube sections 3370,
3372 may be approximately 10N and a maximum retaining force may be
approximately 20N. If the retaining force is less than the predetermined minimum
amount the first and second tube sections may move apart too easily and the length of
tubes 3350 may be accidentally adjusted during normal use of the patient interface
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3000, for example by being jogged by the patient or the patient’s bedding, or as a
result of the flow of gas at positive pressure through the tubes 3350. If the retaining
force is more than the predetermined maximum amount the first and second tube
sections may be too difficult for a patient to move to adjust the length of the tubes
3350.
In an alternative form of the technology, the inner or outer surface of the
first or second tube portions 3370, 3372 may comprise one or more moveable flap
seals, lip seals or a compressible gasket seal. In another form, there may be a
controlled leak between the first and second tube portions 3370 and 3372, such that
the leak does not interfere with respiratory pressure therapy. In one form, the
controlled leak may act as an additional washout vent.
In the above-described forms of the technology in which one or more tube
sections are telescopically movable relative to other tube sections, the patient interface
3000 may comprise one or more end stops to prevent the first tube section 3370 and
the second tube section 3372 from coming apart. In one form, the inner tube section
comprises a flange at its end, and the outer tube section comprises an end stop on an
inner surface against which the flange abuts at the maximum extension of the tube
sections.
Although a swivel elbow has been described, it is possible a ball and
socket elbow may be used instead to provide six degrees of freedom for providing
greater decoupling of tube drag forces.
8.3.3.3.3 Modular tube portions
Fig. 11 shows a patient interface 3000 in which the adjustment mechanism
3360 takes the form of a replaceable tube portion 3385 which can be removed from
the patient interface 3000 and replaced with a replacement tube portion 3386 having a
different length to the first tube portion or module 3385. The replaceable and
replacement tube portions 3385 and 3386 may be described as tube modules.
In the example of Fig. 11, the replaceable tube portion 3385 comprises a
T-shaped tube member that has three ports so that the replaceable tube portion 3385,
in use, fluidly connects to each of tubes 3350 and the air circuit 4170. For example, a
central port in the upper side of replaceable tube portion 3385 is configured to connect
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to connection port 3600 or comprise connection port 3600. For example, replaceable
tube portion 3385 may be positioned in use on top of the patient’s head.
Tube portion 3385 is able to be disconnected from the other parts of
patient interface 3000 and replaced with replacement tube portions 3386a and 3386b.
Replacement tube portions 3386a and 3386b have tube sections extending outwards
from connection port 3600 by a differing amount to replaceable tube portion 3385.
Any number of replacement tube portions may be provided but in the embodiment of
Fig. 11, patient interface 3000 comprises ‘small’, ‘medium’ and ‘large’ replaceable
portions.
In the form of the present technology shown in Fig. 12, patient interface
3000 comprises one or more tube insert members 3387a and 3387b configured to be
selectively fluidly connected to the tub 3350 to alter the length of the tube. For
example, tube insert members 3387a and 3387b are configured to be fluidly
connected between tubes 3350 and cushion assembly 3150 to alter the effective length
of tubes 3350. In alternative embodiments, the tube insert members may be connected
to other parts of the patient interface, for example at an upper end of the tubes 3350
between the tubes 3350 and the connection port 3600. Each tube insert member 3387
may be marked with a size indication, for example ‘M’ for medium and ‘L’ for large
and the like. One size of patient interface may be achieved with no tube insert
members connected.
8.3.3.3.4 Cuttable tubes
In another embodiment of the present technology, the tubes 3350 may be
cut to the desired length. To assist the patient or clinician to determine where to cut
the tubes 3350, the tubes may comprise one or more indicators indicating where to cut
the tube for fitting the patient interface to different sizes heads. For example, lines or
perforations may be provided around the diameter of the tubes 3350 to indicate where
they may be cut. Each line or perforation may be marked with a size marking, for
example ‘small’, ‘medium’ or ‘large’. The cut markings on tubes 3350 may be
provided on the lower ends of the tubes configured to connect to the cushion assembly
3150 or on the upper ends of the tubes configured to connect to the connection port
3600.
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In one embodiment, a patient interface is supplied with a cutting tool
configured to cut tubes 3350.
One disadvantage of cutting tubes 3350 to tailor the size of the patient
interface is that, if the tubes are mistakenly cut too short, the cut off sections of tube
may be difficult to replace.
8.3.3.3.5 Stretchable tubes
In certain forms of the present technology the adjustment mechanism
comprises one or more stretchable sections 3355 of headgear tubes 3350 formed of a
stretchable material. Stretchable sections allow the length of tubes 3350 to be adjusted
continuously to fit different sizes of patient heads. It will be appreciated that a section
of tube may be stretchable by virtue of the material it is made from (e.g. if it is made
from stretchable material), its configuration (e.g. the concertina tube section 3362
shown in Fig. 3A is stretchable by virtue of its configuration), or both.
Fig. 13 illustrates a headgear tube 3350 having a relatively stretchable
section of tube 3355 connected to one or more non- or less stretchable sections of tube
3354. A securing mechanism 3356 may be provided to hold the tube 3350 in position
when the desired length is attained. Securing mechanism 3356 may comprise a first
securing member 3357 mounted on a length of tube 3350 on one side of the
stretchable section 3355 and a second securing member 3358 mounted to a length of
tube 3350 on the other side of the stretchable section 3355. First and second securing
members 3357 and 3358 are configured to connect together by any appropriate
mechanism, for example an interlocking clip, magnet connection, hook-and-loop
fasteners. One of the securing members 3358 may comprise a plurality of sites at
which the other securing member 3357 may connect to it to allow the tube 3350 to be
secured at the desired length.
In another embodiment no securing mechanism is provided and the length
of the tube 3350 is achieved automatically by the elastic contraction of the stretchable
section 3355.
The stretchable section of tube 3355 may comprise a section that is
thinner than the less stretchable sections 3354. Alternatively or additionally the
stretchable section of tube 3355 may comprise a section that is formed from a material
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that is softer and/or has a lower durometer rating than the less stretchable sections
3354.
In one embodiment a stretchable section of tube 3355 has a cross-
sectional thickness that reduces along its length. For example, the cross-sectional
thickness may reduce in stepped longitudinal sections. Alternatively, the cross-
sectional thickness of the tube section 3355 may alternate between thicker and thinner
longitudinal sections. The surface transition between sections of differing cross-
sectional thickness may be smooth or abrupt. The regions of differing cross-sectional
thickness may have different rigidities and/or durometer ratings. The regions of
differing cross-sectional thickness may be formed from the same or different
materials. By selecting the structure of the stretchable section of tube 3355 using
different materials and different cross-section thicknesses, specific sections of tube
3350 may be designed to stretch more than others. This may help the patient interface
to fit differing patients by enabling parts of the tube 3350 that, in use, are positioned
over parts of patients’ anatomy that have particularly differing sizes between
individuals to be made to stretch more than other parts. In addition, or alternatively,
the stretchable section of tube 3355 may be designed to, in use, substantially maintain
a pre-determined minimum aperture area so that the impedance of the patient interface
to the flow of breathable gas can be configured to suit the respiratory treatment
system, for example the desired rate of flow of gas.
8.3.3.3.6 Different tube connection positions
In certain forms of the present technology, the tubes 3350 are able to be
connected in a plurality of ways which enables the effective length of the fluid path
between the connection port 3600 and the seal-forming structure 3100 to be adjusted.
In certain forms, each tube 3350 comprises two or more separate tube
members able to be fluidly connected together at multiple positions to alter the length
of the fluid path formed by the tube members. In one form, a first tube member
comprises a plurality of ports along a side and a second tube member comprises one
or more tubes protruding from a side of the second tube member and able to mate
with selected ports in the first tube member to fluidly connect the first and second
tube members. The length of the tube 3350 formed by the first and second tube
members may be adjusted by selection of which ports the protruding tubes on the
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second tube member is connected to. The ends of the first and second tubes members
adjacent to the connecting ports and protruding tubes are sealed so breathable gas
passes only through each tube member and does not intentionally leak. Also the ports
on the side of the first tube member may be provided with automatically closing
valves to avoid leakage of gas if those ports are not connected to the second tube
member.
In some forms of the technology, multiple tube connections are provided
at the connection port and/or at the cushion assembly 3150. For example, the plenum
chamber 3200 may comprise two or more ports on each side to which the tubes 3350
may selectively be fluidly connected. The ports may be arranged such that adjustment
of which port the tubes are connected to alters the size of patient the patient interface
fits. For example one port may be positioned so that, in use, it is closer to the patient’s
face than another port. Connection of the tube 3350 to a port closer the patient’s face
will accommodate a larger patient head than connection of the tube 3350 to a port
further from the patient’s face.
8.3.3.3.7 Alteration of patient interface loop
Certain forms of the present technology comprise a patient interface 3000
in which the positioning and stabilising structure 3300 defines a loop configured to, in
use, encircle a part of the patient’s head. For example one or more ties may define a
loop that encircles part of the patient’s head in some forms of the technology. For
example, in the embodiment shown in Fig. 3A, the loop is defined by the tubes 3350
and the cushion assembly 3150. These components create a loop within which the
patient’s head is positioned when the patient interface 3000 is being worn.
In some forms of the present technology the positioning and stabilising
structure between the connection port 3600 and the seal-forming structure 3100 of
cushion assembly 3150 is adjusted by an adjustment in the size of this loop.
Adjustment of this loop enables the patient interface to be tailored to fit different sized
patients. Previously described embodiments show how the size of the loop may be
adjusted by alteration of the length of the tubes 3350. There will now be described
embodiments in which other mechanisms for adjusting the size of the loop are
provided.
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8.3.3.3.8 Loop adjustment mechanisms
In certain forms of the present technology, the patient interface 3000
comprises a loop adjustment mechanism that is operable to adjust the position at
which two regions of the positioning and stabilising structure 3300 are held together
to adjust the size of the loop.
In Fig. 5, the patient interface 3000 comprises a strap 3390 connected
between the tubes 3350. The strap 3390 is positioned towards an upper end of the
patient interface 3000 below connection port 3600 such that, in use, it passes over the
top of the patient’s head, or proximate thereto. The strap 3390 may be upwardly
curving to accommodate the top of the patient’s head. The strap 3390 may be formed
of a flexible, rigid or semi-rigid material.
In this embodiment, a loop of the patient interface 3000 that encircles a
part of the patient’s head when the patient interface 3000 is worn is defined by the
strap 3390, the cushion assembly 3150 and the parts of tubes 3350 connected between
strap 3390 and cushion assembly 3150. The size of this loop may be adjusted by
adjusting the strap. The patient interface comprises a strap adjustment mechanism
3391 by which the length of the strap 3390 may be adjusted. Strap adjustment
mechanism 3391 may comprise an adjustable fastening attachment between two
sections of the strap 3390. For example, one section of the strap 3390 may pass
through a loop attached to the end of the other section of the strap 3390 and attach to
itself using a hook-and-loop material. Alternatively, the two strap sections may be
able to be connected together using poppers or interlocking members that can connect
in a plurality of different positions. In another embodiment, two sections of strap 3390
each comprise rack portions which engage with a pinion or cog and the length of the
strap 3390 can be adjusted by rotation of the cog. In another embodiment, the two
sections of the strap 3390 are telescopically slideable relative to each other and may
be secured in place via an interlocking mechanism, magnets or frictional engagement.
In further alternative embodiments, one or both ends of the strap 3390
may connect to the tubes 3350 by an adjustable strap connection mechanism such that
the position at which the strap 3390 connects to one or both tubes 3350 can be varied.
James & Wells Ref: 506131NZ
Another form of the technology is shown in Fig. 14. In this form, patient
interface 3000 comprises a band 3395 positioned around the upper ends of the tubes
3350, i.e. the ends of the tubes closest to the connection port 3600. Band 3395 holds
the tubes 3350 together at their upper end and its position determines the size of the
loop defined in part by the tubes 3350 which encircles a part of the patient’s head
when the patient interface 3000 is worn. During use the band 3395 may be moved
along the tubes 3395 to alter where the tubes 3350 are held together and thus alter the
size of the loop defined by the patient interface 3000. Moving band 3395 along the
tubes 3350 towards the connection port 3600 makes the size of the loop larger so the
patient interface can fit a larger head.
Band 3395 may be secured tightly around tubes 3350 with a high level of
friction between the band and the tubes so that it cannot easily slide upwards and
loosen during use. For example, the band 3395 may be formed from rubber or other
high friction material. Alternatively, the patient interface may comprise a mechanism
to secure the band in position. For example, a plurality of ridges and/or protrusions
may be provided on the outer edges of tubes 3350 and one or more detents may be
provided on the inner surface of band 3395 to interlock with the ridges / protrusions
of the tubes 3350 and secure the band in position. The detents may be disengaged
from the ridges / protrusions by an appropriate mechanism to enable the band to be
moved along the tubes 3350 when desired.
In another embodiment upper sections of the two tubes 3350 are secured
together by a clasp locker or zip. For example, one row of teeth of the clasp locker
may be mounted on one tube 3350 and another row of teeth of the clasp locker may
be mounted on the other tube 3350. The slider is moveable between the rows of teeth
to adjust the position at which the two tubes 3350 are held together to alter the size of
the loop formed by the patient interface 3000 are thereby accommodate different
patient head sizes.
8.3.3.3.9 Loop inserts
In certain forms of the present technology, the positioning and stabilising
structure 3300 comprises one or more loop insert members configured to be secured
to another part of the patient interface 3000, for example directly or indirectly secured
to the tubes 3350. The loop insert member(s) is configured to be secured so that it
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defines, at least in part, the loop which, in use, encircles part of the patient’s head. By
adjusting the size of the loop insert member, or by replacing the loop insert member
with a loop insert member of a differing size, the size of the loop can be adjusted to
accommodate different sizes of patient heads.
One form of the present technology is shown in Fig. 15. In this form,
patient interface 3000 comprises a loop insert member 3410 that is connected to the
underside of tubes 3350 and connection port 3600 and, in use, is positioned between
the patient’s head and the tubes 3350 and connection port 3600. Loop insert member
3410 acts to change the size of the loop that encircles a part of the patient’s head
compared to the size of the loop formed by the tubes 3350 if the loop insert member is
not present.
Loop insert member 3410 is removably attached to tubes 3350. Loop
insert member 3410 may therefore be removed and replaced by one or more
replacement loop insert members 3411a, 3411b or 3411c. Replacement loop insert
members 3411a, 3411b or 3411c differ in size from loop insert member 3410 and by
selection of the loop insert members the size of the loop for encircling a part of the
patient’s head can be adjusted and consequently the patient interface can be adapted
to fit the patient more comfortably and more securely. The ability to remove the loop
insert members 3410 and 3411 is also beneficial so that they can be cleaned.
Loop insert members may be formed from a rigid or semi-rigid material
able to space the tubes 3350 from the patient’s head in use and thereby alter the shape
of the loop encircling the patient’s head. A material that has some resilience and give
may provide more comfort when worn, for example a foam or gel material. Since the
loop insert members are in contact with the patient’s hair or skin when worn they are
preferably made from a material that is easily cleaned.
The loop insert members 3410 and 3411 shown in Fig. 15 are generally U-
shaped with the apex of the ‘U’ positioned in use at the top of the patient’s head
below the connection port 3600. This helps the patient interface to conform to the
shape of the top of the patient’s head. In other embodiments, different shaped insert
members are used, for example an insert member may comprise a short straight pad
configured to contact a small part of the patient’s head. Different sized replacement
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insert members 3411 may have different thicknesses, different lengths, and/or
different degrees of curvature. The patient contacting surface of each insert member
may be the same or similar to conform to the patient’s head shape irrespective of
which insert member is used.
The loop insert members 3410 and 3411 are attached to the tubes 3350 by
a fastening mechanism. In one embodiment the fastening mechanism comprises hook-
and-loop material attached to the underside of tubes 3350 and the upper side of loop
insert members 3410 and 3411. In other embodiments, poppers, domes, clasp lockers
or magnets are used to connect loop insert members 3410 and 3411 to the tubes 3350.
In the embodiment of Fig. 15 the patient interface 3000 comprises a single
loop insert member 3410 and the replacement loop insert members 3411 are single or
monolithic components. In other embodiments, multiple loop insert members are able
to be attached to the tubes 3350 at any one time. For example, multiple loop insert
members may be able to be attached along the length of tubes 3350 to act as a
plurality of spacers spacing different parts of the patient’s head from the tubes 3350.
In another embodiment, multiple of the loop insert members 3410 and the
replacement loop insert members 3411 may be mounted on the tubes 3350 at any one
time. For example, different sized loop insert members may be able to be nested. To
achieve this, the loop insert members 3410 and 3411 may be able to connect to each
other, for example using any of the loop insert member connection mechanisms
mentioned above.
In the form of the present technology illustrated in Fig. 16 the patient
interface 3000 comprises an inflatable loop insert member 3420. Inflatable loop insert
member 3420 may comprise a bladder provided on an inner surface of tubes 3350.
The bladder has a sealable opening into which air can be introduced or released to
alter the size of the bladder and consequently adjust the size of the loop defined by the
patient interface 3000 which encircles part of the patient’s head in use. In one
embodiment, the patient interface comprises a pump button which can be repeatedly
depressed to introduce air into the bladder through a valve.
In the form shown in Fig. 16 the patient interface comprises a single U-
shaped bladder 3420 that is connected to each tube 3350 on either side of and on top
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of the patient’s head. The thickness of the bladder 3420 may be largest at the top of
the patient’s head to accommodate a symmetrical movement of the tubes 3350 away
from the surface of the patient’s head as the bladder is inflated. In other embodiments,
multiple inflatable bladders are mounted on the tubes 3350. These inflatable bladders
may be inflatable together or separately. Separately inflatable bladders allows a
patient to alter the fit of the patient interface as desired, for example by inflating a
bladder on one side of the head more than the other side.
8.3.3.3.10 Magnitude of dimensional adjustment of headgear tubing
As discussed previously, the positioning and stabilising structure 3300
may be configured to be worn with the upper portion of the headgear tubing 3350
positioned differently for different patients. For example, the position of the
connection port 3600 on the patient’s head during use may vary within a range of
forward/rearward positions in the sagittal plane. The circumference of a patient’s head
around which the headgear tubing 3350 fits may be smaller if the upper portion of the
headgear tubing 3350 is worn further forward compared to if the headgear tubing
3350 was worn further back. In some forms, the positioning and stabilising structure
3300 allows a patient with a large head size to wear the upper portion of the headgear
in a more forward (e.g. anterior) position on their head, reducing the magnitude of
length adjustment that is needed from the adjustment mechanism 3360 to
accommodate the large head size.
Fig. 3J shows three depictions of a patient interface 3000a, b, c according
to one form of the technology, each depiction of the patient interface 3000 being
shown in a different position on the patient’s head, for comparison. The patient
interface 3000b is shown in solid lines in a central position, while the patient
interfaces 3000a and 3000c are shown in phantom and are worn forwardly and
rearwardly, respectively. In each of the depictions in Fig. 3J, the adjustment
mechanism 3360 has substantially the same length. That is, the adjustment
mechanism 3360 is not extended or contracted between the depictions labelled “a”,
“b” and “c”. While there is no change in length of the adjustment mechanism 3360,
the patient interface 3000a (the forward position) can fit over a larger head (shown in
phantom) since it is worn forward. Similarly, the patient interface 3000c (rearward
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position) can fit properly to a smaller head (shown in phantom) with the same length
of adjustment mechanism 3360.
In one depiction in Fig. 3J, identified by reference numerals labelled “b”,
the patient is wearing the headgear in a central position, in which the adjustment
mechanism 3360b and connection port 3600b are approximately aligned vertically.
The connection port 3600b is located centrally in the anterior-posterior axis. That is,
the connection port 3600b is located in a central position rather than in a generally
forward (e.g. anterior) position or a generally backward (e.g. posterior) position. The
connection port 3600b is located approximately at a top point of the patient’s head.
The connection port 3600b may be positioned in the sagittal plane and aligned with
the otobasion superior points in a plane parallel to the coronal plane. The otobasion
superior points are identified in Fig. 2D.
In another depiction in Fig. 3J, identified by reference numerals labelled
“a”, the patient is wearing the headgear tubing 3350a in a relatively forward (e.g.
anterior) position compared to the position of headgear tubing 3350b. In this
configuration, the connection port 3600a is positioned generally forward of the
adjustment mechanism 3360a. In this position, the connection port 3600a is anterior to
the otobasion superior points. In another depiction in Fig. J, identified by reference
numerals labelled “c”, the patient is wearing the headgear tubing 3350c in a relatively
rearward (e.g. posterior) position compared to the position of headgear tubing 3350b.
In this configuration, the connection port 3600c is positioned generally rearward of
adjustment mechanism 3360c. In this position, the connection port 3600c is posterior
to the otobasion superior points.
When worn in the position depicted by headgear 3300a in Fig. 3J, the
headgear tubing 3350a will generally fit around a smaller circumference of the
patient’s head, enabling the positioning and stabilising structure 3300 to be worn in a
relatively forward position to accommodate a patient with a larger head (shown in
phantom). Similarly, when worn in the position depicted by positioning and
stabilising structure 3300c in Fig. 3J, the headgear tubing 3350c will generally fit
around a larger circumference of the patient’s head, enabling the positioning and
stabilising structure 3300 to be worn in a relatively rearward position to accommodate
a patient with a smaller head (shown in phantom). The positioning and stabilising
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structure 3300 may be worn in a continuous range of positions between a generally
forward position and generally rearward position depending on the patient’s head size,
head shape, personal preference, among other factors. In some forms the present
technology the positioning and stabilising structure 3300 is configured to be worn
such that the connection port 3600 is positioned in use up to approximately 20mm
forward (e.g. anterior) of a central position at a top point of the head, and up to
approximately 20mm rearward (e.g. posterior) of the central position. In some forms
of the technology the upper portion (e.g. the portion above the rear strap 3310) of the
headgear tubes 3350 are configured to flex, bend and move in forward or rearward
directions substantially without corresponding movement in the lower portion or non-
adjustable tube section 3363 (e.g. the portion below the rear strap 3310). In other
forms of the technology, the upper portion and lower portion may move together
(although not necessarily to the same extent). The rear strap 3310 may be configured
to prevent or resist movement of the non-adjustable tube section 3363. For example,
by moving the upper portion of the headgear tubes 3350 forward on a patient’s head
without loosening the rear strap 3310, more movement of the upper portion of the
headgear tubes 3350 may be required in comparison to the non-adjustable tube
portion 3363.
Separately to the ability of the positioning and stabilising structure 3300
to be worn in different forward/rearward positions, in some forms of the technology
the headgear tubing adjustment mechanism 3360 enables the positioning and
stabilising structure 3300 to fit to different sized heads. The headgear tubing
adjustment mechanism 3360 may be configured to provide a predetermined amount of
length adjustment to the headgear tubing 3350. An amount of adjustment to the length
of the headgear tubing 3350 may be determined based at least partly on a range of
head sizes for which the positioning and stabilising structure 3300 is configured to
accommodate. In some forms of the present technology the adjustment mechanism
3360 may be enable the headgear tubes 3350 to increase in length by an amount
between approximately 10mm and 50mm, inclusive, on either side of the positioning
and stabilising structure 3300. In some forms of the present technology the increase in
length may be an amount between 20mm and 40mm, inclusive, on either side. In
some forms of the present technology the increase in length provided may be any one
of substantially 25mm, 30mm, 35mm, or 40mm on either side.
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Fig. 3K shows a patient interface 3000 with positioning and stabilising
structure 3300 having headgear tubes 3350 and a headgear tube adjustment
mechanism in a first configuration identified with the reference numeral 3360. The
adjustment mechanism 3360 is also shown in phantom in a second configuration and
identified with the reference numeral 3360’. In the first configuration of the
adjustment mechanism 3360 the headgear 3300 fits around a patient with one size
head and in the second configuration of the adjustment mechanism 3360’ the
headgear 3300 fits around a patient with a larger head. In this form of the technology,
the adjustment mechanism 3360’ enables an extension of the length of the headgear
tubes 3350 in order to fit around the larger head. As shown in Fig. 3K, the adjustment
mechanism 3360/3360’ enables the headgear to adjust (or be adjusted) to
accommodate different head sizes while worn in a central position (e.g. with the
connection port 3600/3600’ positioned centrally at a top point on the head rather than
forward or backwards).
In some forms of the present technology the adjustment mechanism 3360
is also able to enable length adjustment of the headgear tubes 3350 when the headgear
3300 is worn in forward, central and/or rearward positions. Fig. 3L shows a patient
interface 3000 with headgear 3300 worn in three positions on a patient’s head, as
identified by reference numerals suffixed with “a”, “b” and “c”. The positioning and
stabilising structure 3300a is worn in a forward position, positioning and stabilising
structure 3300b is worn in a central position and positioning and stabilising structure
3300c is worn in a rearward position. That is, the connection port 3600a is in a
forward position on the patient’s head, while the connection port 3600b is in a central
position and connection port 3600c is in a rearward position. In the forward position,
the headgear tubes 3350a fit around a smaller circumference of the patient’s head in
comparison to the circumference that the headgear tubes 3350b fit around in the
central position. To accommodate this smaller circumference the adjustment
mechanism 3360a in the forward position provides a reduction in the length of the
headgear tubes 3350 (or less of an extension). In the rearward position the
circumference of the patient’s head around which the headgear tubes 3350c fit is
larger than the circumference in the central position. To accommodate this larger
circumference, the adjustment mechanism 3360c provides an increase in length of the
headgear tubes 3350 in comparison to their length in the central position.
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The combination of the different positions in which the positioning and
stabilising structure 3300 can be worn, and the different amounts of length adjustment
provided by the adjustment mechanism 3360, provides versatility in the adjustment
options available to patients. This versatility may result in a wide range of head
shapes and sizes being accommodated by the positioning and stabilising structure
3300 without excessive discomfort and while enabling a sufficient seal of the seal
forming structure 3150 to the patient’s face. In some embodiments, the adjustment
mechanism 3360 provides for a lower magnitude of length adjustment, as patients
with larger head sizes are able to wear the upper portion of the headgear tubing 3350
in a forward position, rather than relying solely on the adjustment mechanism 3360 to
accommodate their large head size. In other embodiments the adjustment mechanism
3360 provides for a large magnitude of length adjustment, and the ability for patients
with larger head sizes to wear the upper portion of the headgear tubing 3350 further
forward means that the patient interface 3000 may be suitable for a large range of
head sizes.
8.3.3.4 Position of headgear tubing adjustment mechanism
It is generally desirable to avoid features of patient interfaces causing a
patient discomfort. Therefore patient interfaces may be designed with few
components contacting the patient’s skin and those that do contact the patient’s skin
may be soft and/or smooth. The cheek region is known to be a source of patient
discomfort when wearing patient interfaces.
Mechanisms allowing the positioning and stabilising structure to be
adjusted, such as those described above, may comprise features that cause discomfort
to a patient if contacting a patient’s face or head, particularly the cheek region.
Therefore certain forms of the present technology comprise positioning and stabilising
structures configured such that, when the patient interface is worn, the adjustment
mechanism or parts thereof are positioned out of contact with areas of the patient’s
skin or hair, for example out of contact with the patient’s face or out of contact with
the patient’s cheek regions. In some forms of the technology the adjustment
mechanism is positioned higher than a patient’s ears, i.e. superior to the otobasion
superior of the patient’s head or proximate a top portion of the patient’s head. In these
forms of the technology, the headgear tubes comprise a non-adjustable headgear tube
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section that is positioned adjacent to the patient’s face in use, i.e. in a position where
the non-adjustable headgear tube section might come into contact with the patient’s
face during use of the patient interface. For example, in some forms, the non-
adjustable headgear tube section is positioned adjacent to the patient’s cheek regions
when worn and only non-adjustable headgear tube sections are adjacent to the
patient’s cheek regions, inferior to the otobasion superior of the patient’s head or
overlaying a maxilla region of the patient’s head in some forms of the technology.
It will be understood that a non-adjustable headgear tube section is a
section that is not specifically configured to be dimensionally adjusted during use, i.e.
the adjustment mechanism does not form part of the non-adjustable headgear tube
section. This does not preclude, however, the non-adjustable headgear tube section
being able to be dimensionally adjusted if, for example, excessive force is imparted
on it. The position of the non-adjustable headgear tube section may, however, be
adjusted during use. In some forms of the present technology, non-adjustable
headgear tube sections may be substantially non-adjustable in axial length, but may be
adjustable in other ways such as by flexing, curving, straightening, and the like. For
example, as shown in Fig. 3L, the non-adjustable headgear tube sections 3363a, b and
c are configured to bend or curve to different extents in order to facilitate the different
positions in which the positioning and stabilising structure 3300 is worn on the head,
with different amounts of extension provided by the adjustment mechanism 3360a, b
and c.
Locating the adjustment mechanism out of the patient’s field of view may
also be beneficial to avoid a feeling of claustrophobia or an interrupted view.
In the case of the form of patient interface 3000 shown in Figs. 3A, 3B,
3C, 3D, 3E and 3F, for example, the concertina sections 3362 are positioned on either
side of the patient’s head between the ears or ear level and the crown or top of the
head and non-adjustable headgear tube sections 3363, which form the lower ends of
the headgear tubes (i.e. the inferior ends when worn by a patient) are positioned
adjacent to (or over) the patient’s cheek region when worn. Other examples of non-
adjustable headgear tube sections 3363 are shown in Figs. 5, 7A, 7B, 7C and 17.
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In certain forms of the present technology the non-adjustable headgear
tube sections 3363 are configured such that they assist in maintaining an adequate seal
between the cushion assembly 3150 and the patient’s face during use of the patient
interface 3000. This may require the flexibility (or stiffness) of the non-adjustable
headgear tube sections 3363 to be selected so that they are sufficiently stiff so as not
to deform too easily during use while being sufficiently flexible to accommodate
some movement during use and some variation in the position in which individual
patients wear the patient interface 3000.
Rear headgear strap 3310 stabilises the headgear tubes 3350 on the
patient’s head but the lower ends of the headgear tubes 3350 are more freely able to
move, particularly at points relatively far from the point at which rear headgear strap
3310 connects to the headgear tube 3350. An overly flexible lower end of a headgear
tube 3350 tends to allow the cushion assembly 3150 to roll forward away from the
patient’s face, which disrupts the seal. This rolling forward effect can be mitigated by
increasing the stiffness of the lower end of the headgear tubes 3350, i.e. the non-
adjustable headgear tube section 3363 in the forms of the technology shown in Figs.
3A, 3B, 3C, 3D, 3E, 3F, 5, 7A, 7B, 7C and 17. For the purposes of this discussion, the
lower end of the headgear tubes 3350 may be considered to be the part of the
headgear tubes 3350 positioned below (i.e. inferior to, when the patient interface 300
is worn by a patient) the point at which rear headgear strap 3310 connects to each
headgear tube 3350 as this point is stabilised on the patient’s head and therefore may
tend to act as a pivot point to any movement of the headgear tubes 3350 below that
point. It will be understood that other arrangements of headgear straps may lead to a
different positioning of an effective pivot point.
For a similar reason it may be advantageous for the lower end of the
headgear tubes 3350 to be free of any adjustment mechanisms in some forms of the
technology. Locating a concertina section, for example, on the headgear tubes 3350 at
a point below where the rear headgear strap 3310 connects to the headgear tubes 3350
means that the concertina section tends to buckle and distort if movement occurs and
acts as a natural pivot, allowing movement of the cushion assembly, which could
disrupt the seal with the patient’s face.
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Furthermore, an adjustment mechanism 3360 on the upper portion of
headgear tube 3350 (which is considered, for the purposes of this discussion, to be the
part of the headgear tubes 3350 positioned above, i.e. superior to, the point at which
the rear headgear strap 3310 connects to each headgear tube 3350) helps to de-couple
the upper and lower portions of the headgear tube 3350 so that movement of the upper
portion (either during use or by virtue of variations in positioning of the patient
interface 3000 on the patient’s head) do not exert excessive forces on the cushion
assembly 3150 that may tend to disrupt the seal with the patient’s face. In particular,
an adjustment mechanism 3360 in which the length of the headgear tube 3350 can be
extended helps avoid straightening of non-adjustable headgear tube sections 3363 in
the lower end of headgear tube 3350 as this kind of adjustment mechanism 3360
enables the lower end of the patient interface 3000 to move up and down relative to
the patient’s head (i.e. in the inferior and superior directions). Excessive straightening
and/or stretching of the non-adjustable headgear tube sections 3363 may also cause
the cushion assembly 3150 to roll forward, disrupting the seal to the patient’s face.
In some forms of the technology, the radius of curvature of a non-
adjustable headgear tube section 3363 (or lower end of the headgear tube 3350) also
affects the degree of movement of the upper end of the headgear tubes 3350. The
larger the radius of curvature the greater the de-coupling effect between the upper and
lower ends of the headgear tubes 3350 so that the upper end of the headgear tubes
3350 can move without causing significant rolling forward to the cushion assembly
3150 and consequent loss of seal.
In some forms of the present technology, the provision of the adjustment
mechanism 3360 on the upper portion of the headgear tube 3350, proximate the
connection port 3600 may help to alleviate tube drag on the head as it allows the
connection to decouple through stretch and flex provided by the adjustment
mechanism.
In some forms of the present technology, providing the adjustment
mechanisms 3360 on the upper portions of the headgear tubes 3350, spaced far from
the cushion assembly 3150, may reduce effects on the cushion assembly 3150 caused
by differences in the extension of the headgear tubes 3350. For example, effects of
imbalances in the extension of, and/or any forces exerted by, the adjustment
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mechanism 3360 on either side of the patient’s head may be less pronounced. Such
effects may compromise the seal formed by the cushion assembly 3150 to the
patient’s face.
In other forms of the present technology the adjustment mechanism may
be positioned close to the cushion assembly 3150 of the patient interface and be
spaced from the patient’s face by virtue of the size of the plenum chamber and the
location of the port to which the tube 3350 connects to the plenum chamber distancing
the lower end of the tube 3350 (and consequently the adjustment mechanism) from
the patient’s skin. The form of the present technology shown in Fig. 10B is one such
example of a patient interface 3000 where the adjustment mechanism is spaced from
the patient’s face in use.
8.3.3.5 Headgear tubing bias mechanism
In certain forms of the present technology, the positioning and stabilising
structure 3300 comprises a bias mechanism which acts in use to urge the seal-forming
structure 3100 towards the patient’s face, i.e. towards the area surrounding the
entrance to the patient’s airways to which the seal-forming structure 3100 seals. The
bias mechanism therefore acts to help the seal-forming structure 3100 provide a good
seal with the patient’s face during the use of the patient interface 3000 and to promote
the retention of the seal when the patient interface supplies gas under positive
pressure to the patient. In some forms of the technology, the bias mechanism acts (i.e.
imparts a biasing force) on the adjustment mechanism 3360. When the plenum
chamber 3200 is pressurised the tendency is for the cushion assembly 3150 of the
patient interface 3000 to move away from the patient’s face. A bias mechanism acting
to bias or urge the cushion assembly 3150 towards the patient’s face counters this
tendency in order to maintain a seal.
In some forms of the technology, the bias mechanism acts to impart a
biasing force along at least a part of a length of the headgear tube 3350 to urge the
seal-forming structure towards the entrance of the patient’s airways in use. In such
forms the headgear tube 3350, or parts thereof, are in tension when in use. In some
forms the bias mechanism is comprised as part of the headgear tubing 3350 while in
other forms the bias mechanism is distinct from the headgear tubing 3350.
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A bias mechanism may also assist in automatically adjusting the patient
interface to fit a particular patient’s head.
8.3.3.5.1 Magnitude of force exerted by bias mechanism
The bias mechanism is preferably configured to apply sufficient inwards
(i.e. towards the patient’s airway openings) force to maintain a good seal during use
while avoiding applying an excessive force. An excessive force may cause the seal-
forming structure 3100 to compress and its geometry change so that some parts of the
structure move away from the patient’s face and gas leaks out of the seal-forming
structure. Furthermore, avoiding excessive forces on the patient’s face from the
patient interface promote comfort and avoid red marks, abrasion or sweating on the
patient’s face.
In some forms of the present technology, an acceptable force provided by
the bias mechanism may be in the region of 0.5-4N on each side of the positioning
and stabilising structure 3300. In some forms an acceptable force may be in the region
of 1-3.5N. Forces around 2N may be considered acceptable. In some forms of the
present technology the positioning and stabilising structure 3300 is configured to
support a seal-forming structure 3100 in the form of a full face or oro-nasal cushion
assembly (e.g. such as the seal-forming structures 3100 shown in Figs. 4A-4E). In
some forms of the technology a full face or oro-nasal seal-forming structure 3100 is
heavier than other forms of seal-forming structure (e.g. nasal cradle or nasal pillows)
due to its larger size and the positioning and stabilising structure 3300 is configured to
provide a larger biasing force accordingly to take up the weight or counteract the drag
of the heavier seal-forming structure 3100 while still urging the cushion assembly
3150 into the patient’s face with a sufficiently large force to maintain an effective
seal, without causing excessive discomfort. Additionally, a full face or oro-nasal seal-
forming structure 3100 may be subject to a downward (e.g. inferior) force when the
patient relaxes or moves their lower jaw (which may be known as “jaw drop”). The
positioning and stabilising structure 3100 may also be configured to account for the
effects of jaw drop by counteracting the downwards forces received during jaw drop.
In some forms of the present technology, the positioning and stabilising
structure 3300 is configured to interchangeably receive seal-forming structures of
different sizes, including relatively small or light seal-forming structures such as a
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nasal cradle cushion assembly and relatively large or heavy seal-forming structures
such as an oro-nasal cushion assembly. The positioning and stabilising structure may
comprise a bias mechanism configured to support both types of seal-forming
structure, by imparting a biasing force sufficiently strong for either type of seal-
forming structure, but not excessive so as to cause discomfort.
In some forms of the technology, the positioning and stabilising structure
3300 is configured to provide a sufficient range of force magnitudes in a plurality of
adjustment configurations to maintain an effective seal of either a nasal cradle or a
full face mask, without being excessively large so as to cause discomfort.
In some forms of the present technology, the bias mechanism is
configured to impart a force on the headgear tubes 3350 or portions thereof that urges
the headgear tubing to fit around a patient’s head. The bias mechanism may be
configured to provide forces with magnitudes within a predetermined range. Such a
predetermined range may be limited to magnitudes in which the headgear 3300 is
both comfortable and able to maintain a sufficient seal of the seal-forming structure
3100 to the patient’s face. The bias mechanism may be configured to urge the seal-
forming structure 3100 into sealing contact with the patient’s face with a force that is
not less than a minimum force required for a sufficient seal. That is, the force may be
equal to or greater than a minimum sealing force. The bias mechanism may be
configured to urge the headgear tubing 3350 to fit to the patient’s head with a force
that is not larger than a maximum force considered comfortable by the patient. That
is, the force may be less than or equal to a maximum comfort force.
In some forms of the present technology, each headgear tube 3350
comprises a force-extension characteristic which results from a relationship between
the extension of the headgear tube 3350 and a force imparted to the headgear tube
3350 by the bias mechanism. Alternatively, or additionally, the force-extension
characteristic may result from a relationship between the force imparted to the
headgear tube 3350 by the bias mechanism and the extension of the headgear tube
3350. It will be understood that an “extension” refers to a change in overall length of
the headgear tubes and does not imply any particular manner in which the change in
overall length of the headgear tubes 3350 occurs or the physical structure of the
adjustment mechanism.
James & Wells Ref: 506131NZ
In certain forms of the present technology, the bias mechanism may
provide a biasing force on the headgear tube 3350 which tends to return the headgear
tube 3350 or portions thereof to a predetermined length, such as a length prior to
adjustment with the adjustment mechanism. In some forms of the technology the bias
mechanism imparts a restoring force on the headgear tube 3350.
As described above, the adjustment mechanism 3360 of a patient interface
3000 according to some forms of the present technology allows an adjustment in
length of a headgear tube 3350. In some embodiments, such as when there is a
relationship between biasing force and the extension of a headgear tube 3350, a first
amount of extension of the headgear tube 3350 (e.g. to a first extended length) results
in a force provided by the bias mechanism which is equal to or greater than the
minimum sealing force. Additionally, a second amount of extension of the headgear
tube 3350 (e.g. to a second extended length) may result in a force provided by the bias
mechanism which is less than or equal to the maximum comfort force. Furthermore,
amounts of extension between the first and second amounts of extension may result in
a force imparted by the biasing mechanism that is between the minimum sealing force
and the maximum comfort force.
In some forms of the present technology the headgear tubes 3350 may
comprise a force-extension characteristic in which, when the headgear tubes 3350 are
adjusted to a first amount of extension (e.g. to the extension at which the bias
mechanism provides at least the minimum sealing force), the positioning and
stabilising structure 3300 accommodates a predetermined minimum head size.
Similarly, when the headgear tubes 3350 are adjusted to a second amount of extension
(e.g. to the extension at which no more than the maximum comfort force is exerted by
the bias mechanism), the positioning and stabilising structure 3300 may accommodate
a predetermined maximum head size. At extensions between the first and second
amounts of extension the positioning and stabilising structure 3300 may accommodate
head sizes between the minimum and maximum predetermined head sizes. The
predetermined minimum head size may be, for example, a 5 percentile head size and
the predetermined maximum head size may be, for example, a 95 percentile head
size of the particular category of person. It will be understood that other
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measures/ranges may be used to determine minimum and maximum head sizes
accommodated by the positioning and stabilising structure 3300.
Fig. 3I shows a force-extension plot 6000 illustrating a force-extension
characteristic 6300 of a headgear tube 3350 of a patient interface 3000 according to
one form of the present technology. The force-extension plot 6000 includes a
horizontal extension axis 6100 and a vertical force axis 6200 to illustrate the
relationship between the length of the headgear tube 3350 and the resulting force
imparted by the bias mechanism.
Three extensions of the headgear tube 3350 are indicated on the extension
axis 6100: zero extension 6105, a first amount of extension 6110 corresponding to an
extension required to accommodate a 5 percentile head size (e.g. a predetermined
minimum head size), and a second amount of extension 6120 corresponding to an
extension required to accommodate a 95 percentile head size (e.g. a predetermined
maximum head size). Two force magnitudes are indicated on the force axis 6200: a
minimum sealing force 6210 and a maximum comfort force 6220.
In this exemplary form of the technology, the headgear tube 3350
comprises a force-extension characteristic 6300 in which the force imparted by the
biasing means is greater than the minimum sealing force 6210 and less than the
maximum comfort force 6220 throughout the range of extensions between the first
amount of extension 6110 and the second amount of extension 6120. That is, across
the full range of head sizes that are accommodated, a sufficient seal is able to be
maintained without discomfort caused by an excessive biasing force.
It will be understood that in some forms of the technology the relationship
between extension and biasing force may not be directly proportional. For example, in
some forms of the technology there may be a relatively large increase in force during
an initial stage of extension, but only minor or no variation in force in the range of
extension required to accommodate minimum and maximum predetermined head
sizes. The results of an effective seal without discomfort may be achieved if the
magnitude of the force remains between the minimum seal force and the maximum
comfort force throughout the range of extension between the minimum head size and
maximum head size, regardless of the how force varies within the limits.
James & Wells Ref: 506131NZ
8.3.3.5.2 Position of bias mechanism
In some forms of the present technology, the bias mechanism acts
between seal-forming structure 3100 and connection port 3600. For example, the bias
mechanism is comprised of components of the patient interface connected between
the seal-forming structure 3100 and connection port 3600 and may urge the seal-
forming structure 3100 generally in the direction of the connection port 3600 and/or
longitudinally along the length of tubes 3350.
8.3.3.5.3 Form of bias mechanism
The bias mechanism may take a number of forms. In some forms of the
technology, the bias mechanism is a separate mechanism to the adjustment
mechanism that enables adjustment of the positioning and stabilising structure such as
those described above. In such forms the adjustment mechanism enables the patient
interface to be adjusted to fit a patient’s head while the bias mechanism acts to urge
the seal against the patient’s face. In other forms, the bias mechanism and adjustment
mechanism are provided at least in part by the same features of the patient interface
and the adjustment and bias described above are different functions performed by said
same features.
In some forms of the technology the bias mechanism comprises an elastic
or resilient member or assembly. In some forms the elastic or resilient member or
assembly is connected between the seal-forming structure 3100 and the connection
port 3600, for example it is comprised as part of, or is connected to, the tubes 3350 or
the connection assembly between the tubes 3350 and the plenum chamber 3200
and/or the connection assembly between the tubes 3350 and the connection port 3600.
For example, in the form of the technology shown in Figs. 3A, 3B, 3C, 3D
and 3E, the bias mechanism comprises the concertina tube portions 3362. The
concertina tube portions 3362 are configured such that they are biased to compressed
positions. Consequently the concertina tube portions 3362 act to pull the seal-forming
structure 3100 into the patient’s face in use.
In some forms of the present technology, there is a relationship between
the extension of the concertina tube portions 3362 and a restoring force imparted to
the headgear tubes 3350. The restoring force may be tension in the concertina tube
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portions 3362. The concertina tube portions 3362 may have a force-extension
characteristic with similarities to the force-extension characteristic discussed in
relation to Fig. 3I.
The concertina tube portions 3362 may be designed to extend to a first
amount of extension in which the positioning and stabilising structure 3300 can
accommodate a predetermined minimum head size (such as a 5 percentile head size)
and also to a second amount of extension in which the positioning and stabilising
structure 3300 can accommodate a predetermined maximum head size (such as a 95
percentile head size). The concertina tube portions 3362 may be designed so that, at a
first amount of extension, the tension is greater than a minimum force required to
create a suitable seal of the seal-forming structure 3100 to the patient’s face. At a
second amount of extension, the concertina tube portions 3362 may be designed so
that the tension does not exceed a maximum force considered comfortable by the
patient. In this way, the positioning and stabilising structure 3300 can accommodate a
range of head sizes, creating a sufficient seal across the full range without discomfort
caused by excessive force.
In certain forms of the present technology, the concertina tube portions
3362 may comprise a concertina profile which provides the concertina tube portions
3362 with a force-extension characteristic such as discussed above. As shown in Fig.
3G, the concertina tube portions 3362 may comprise walls having a concertina profile
having a repeating wave-like pattern with rounded inside troughs and flat outside
peaks. The flattened outside peaks provide a smooth flat surface which may
comfortably rest against the patient’s head. The concertina tube portions 3362 may
comprise a plurality of ribs formed in the walls of the headgear tubes 3350 to form the
concertina. The ribs may be inwardly extending as shown in Fig 3G. Alternatively, or
additionally, the concertina tube portions 3362 may comprise a plurality of grooves.
The profile of the concertina tube portions 3362 may be varied to achieve
a desired force-extension characteristic. For example, the pitch of the ribs (e.g.
peaks/troughs of the concertina waveform) may be reduced to provide a more
extendible concertina tube portion 3362 (e.g. generally more extension for a given
amount of force). Furthermore, the height of the ribs (e.g. the amplitude of the
concertina waveform) may be increased to provide a more extendible concertina tube
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portion 3362. Alternatively, a less extendible concertina tube portion 3362 may be
produced by increasing the rib pitch, or by reducing the rib height.
Additionally, or alternatively, a longer concertina tube portion 3362 may
be provided to increase extendibility. This may be provided by, for example,
increasing the number of ribs formed in the wall of the concertina tube portion 3362.
Additionally, or alternatively, the wall thickness of the concertina tube
portion 3362 may be reduced to provide a more extendible concertina tube portion
3362, or increased to provide a stiffer concertina tube portion 3362.
Additionally, or alternatively, the material forming the concertina tube
portions 3362 may be selected to assist in providing a predetermined force-extension
characteristic. In one form of the technology, the material is 50 durometer silicone.
Other materials and/or durometer values may also be selected, such as 40 durometer
silicone, for example.
Additionally, or alternatively, a different concertina profile shape may be
provided to the concertina tube portion 3362, to achieve a different amount of
extension. For example, a concertina tube portion 3362 in which the walls defining
the profile are generally more folded together may result in a more extendible
concertina tube portion 3362.
The configuration of the concertina tube portion 3362 may vary along its
length. In some forms of the present technology, such as the form shown in Fig. 3G,
the rib height decreases along the length of the concertina tube portion 3362 in the
direction away from the connection port 3600 (e.g. the direction towards the non-
adjustable headgear tube section 3363). The rib height may vary between, for
example, a range of 0-6mm, 0-5mm, 0-4mm, 1-5mm and the like. Alternatively the
rib height may be constant and may be, for example, 2mm, 3mm, 4mm and the like.
The wall thickness may be substantially constant along the length of the concertina
tube portion 3362, or may vary. In some forms of the technology the wall thickness
may be between 0.5mm-1.2mm, such as 0.6mm-1mm, or 0.8mm and the like. The rib
pitch may be between 3.5-5mm, such as 3.8-4.5mm, or 4.2mm and the like.
James & Wells Ref: 506131NZ
In other forms of the present technology, the shape and configuration of
the concertina tube portion 3362 differs from those parameters mentioned above by
way of example.
In the form of the technology shown in Fig. 13 the relatively stretchable
section of tube 3355 is resiliently or elastically deformable and has a tendency to
return to its non-stretched state. Therefore in use the relatively stretchable section of
tube 3355 acts to pull the seal-forming structure 3100 into the patient’s face.
Alternatively tubes 3350 may be completely formed from a resilient material that
tends to return to its non-stretched state when stretched.
Another form of the present technology is shown in Fig. 17. In this form,
patient interface 3000 comprises one or more elastic sleeves 3340 that cover the tubes
3350. It will be understood that the elastic sleeves 3340 may partly cover the tubes
3350, for example there may be holes in the sleeves 3340 such as will be described
below. Alternatively, the headgear tubes may be considered to comprise both the
elastic sleeves and inner gas delivery conduits with the elastic sleeves covering the
inner gas delivery conduits. Elastic sleeves 3340 may be formed from any elastic,
resilient or stretchable material, for example an elastic fabric such as elastane, that has
a tendency to return to its natural size and shape when stretched.
Elastic sleeves 3340 cover tubes 3350 that each comprise a concertina
tube section 3362. The concertina tube section 3362 may or may not be biased to a
compressed position. The concertina tube section 3362 allows the length of tubes
3350 to be adjusted so that the patient interface 3000 fits an individual patient while
the elastic sleeves 3340 act to pull the seal-forming structure 3100 of cushion
assembly 3150 into the patient’s face to enhance the seal.
Elastic sleeves 3340 may comprise a single sheet of elastic material or
may be formed from multiple sheets of elastic material connected together, for
example sewn or glued together. Alternatively, patient interface 3000 may comprise a
plurality of separate elastic sleeves, for example one sleeve may cover each of tubes
3350.
Elastic sleeves 3340 may comprise openings to allow parts of the patient
interface to pass through the sleeves. For example, the elastic sleeves may comprise
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rear or side openings 3342 through which rear headgear straps 3310 connect to tubes
3350. Additionally or alternatively, the sleeves may comprise a top opening 3343
through which the air circuit 4170 connects to connection port 3600, or through which
connection port 3600 may protrude. The headgear tubes 3350 may contact the
patient’s head through the openings 3342.
A concertina tube section 3362 of tube 3350 may be uncomfortable to a
patient if it contacts their skin or hair during use. Patients may also find concertina
sections unsightly or present the prospect of being uncomfortable to wear even if the
concertina does not actually create extra discomfort, either of which may be
undesirable. Covering the concertina section 3362 with an elastic sleeve 3340 avoids
these problems. An inelastic sleeve may be used in some embodiments to provide the
advantage of comfort. The sleeve may be advantageously formed of a soft material
that is not uncomfortable if it contacts the patient.
As the elastic sleeve 3340 may be in contact with the patient’s hair or skin
during use it may easily become dirty from the patient’s natural oils. Therefore the
elastic sleeve 3340 may be advantageously formed from a material that is easily
washed, e.g. fabric. To make it easy for the patient to wash the elastic sleeve 3340 it
may be removable from the rest of the patient interface 3000. For example, the sleeve
may comprise a mechanism for securing the sleeve on the tubes 3350 that can be
disengaged for the sleeve to be removed. For example the elastic sleeve 3340 may
wrap around the tubes 3350 and connect to itself by clips, poppers, hook-and-loop
material or other suitable fasteners.
In some forms of the technology the elastic sleeve 3340 is formed from a
material or textile that helps wick moisture away from the patient’s face. This may
help to maintain comfort if the patient sweats while wearing the patient interface.
In other forms of the technology, elastic sleeves may cover tubes or other
parts of the positioning and stabilising mechanism having other adjustment
mechanisms such as those described above. Sleeves may be beneficial in covering
mechanisms or components that appear complicated or medical which may deter the
patient from wearing the patient interface.
James & Wells Ref: 506131NZ
In other forms of the technology, telescopically adjustable headgear tubes
may comprise a bias mechanism acting to contract the telescopically movable
headgear tube sections, for example a spring.
An advantage of manually adjustable adjustment mechanisms which may
also provide a biasing force, such as the adjustment mechanism 3360 shown in Fig.
7C, is the ability to support both relatively heavy and relatively light seal-forming
structures in a modular design, i.e. where different types of seal-forming structures
can be interchanged. For example, if the cushion assembly 3150 of the embodiment
shown in Fig. 7C is replaced with a heavier oro-nasal cushion assembly the patient is
able to manually adjust the length of the headgear tubes 3350 to a shorter
configuration to counteract the weight of the oro-nasal cushion and prevent the
cushion from sagging downwards or being pushed downwards by movement of the
patient’s lower jaw.
8.3.4 Vent
In one form, the patient interface 3000 includes a vent constructed and
arranged to allow for the continuous flow or washout of exhaled gases, e.g. carbon
dioxide (CO ) from an interior of the plenum chamber to ambient to reduce the risk of
the patient rebreathing such gases. That is, the vent allows the flow of patient exhaled
CO to an exterior of the patient interface. The vent is sized and shaped to maintain
the therapeutic pressure in the plenum chamber.
One form of vent in accordance with the present technology comprises a
plurality of holes, for example, about 20 to about 80 holes, or about 40 to about 60
holes, or about 45 to about 55 holes.
The vent may be located in the plenum chamber 3200. Alternatively, the
vent may be located in another part of the patient interface, e.g., a tube 3350 fluidly
connecting connection port 3600 with the plenum chamber 3200.
8.3.5 Decoupling structure(s)
In one form the patient interface 3000 includes at least one decoupling
structure, for example, a swivel or a ball and socket. The decoupling structure may be
arranged at or proximate the connection port 3600 to permit the conduit of the air
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circuit 4170 to move relative to patient interface 3000 and reduce the risk of de-
stabilising the seal of the seal-forming structure 3100 against the patient’s face.
8.3.6 Connection port
Connection port 3600 allows for connection to the air circuit 4170. In the
embodiments of the technology shown in Figs. 3 and 5-17, for example, the
connection port is positioned on top of the patient’s head when the patient interface
3000 is being worn. In other embodiments, the connection port is configured to be
positioned, in use, proximal a top, side or rear portion of the patient’s head. Patient
interfaces in which the connection port is not positioned in front of the patient’s face
may be advantageous as some patient’s find a conduit that connects to a patient
interface in front of the face to be unsightly and obtrusive. For example, a conduit
connecting to a patient interface front of the face may be prone to being tangled up in
bedclothes, particularly, if the conduit extends downwardly from the patient interface
in use.
8.3.7 Forehead support
In one form, the patient interface 3000 includes a forehead support for
contacting the patient’s forehead region to support the patient interface on the
patient’s head during use and helping to maintain the sealing structure in sealed
contact with the patient’s face.
8.3.8 Anti-asphyxia valve
In some forms of the technology the patient interface 3000 is constructed
and arranged to allow a patient to breathe ambient air in the event of a power failure.
In one form, the patient interface 3000 includes an anti-asphyxia valve.
8.3.9 Ports
In one form of the present technology, a patient interface 3000 includes
one or more ports that allow access to the volume within the plenum chamber 3200.
In one form this allows a clinician to supply supplemental oxygen. In one form, this
allows for the direct measurement of a property of gases within the plenum chamber
3200, such as the pressure.
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8.4 RPT DEVICE
An RPT device 4000 in accordance with one aspect of the present
technology (as shown in Fig. 4A) comprises mechanical and pneumatic components
4100, electrical components 4200 and is configured to execute one or more
algorithms 4300. The RPT device may have an external housing 4010, formed in two
parts, an upper portion 4012 and a lower portion 4014. Furthermore, the external
housing 4010 may include one or more panel(s) 4015. The RPT device 4000
comprises a chassis 4016 that supports one or more internal components of the RPT
device 4000. The RPT device 4000 may include a handle 4018.
The pneumatic path of the RPT device 4000 may comprise one or more
air path items, e.g., an inlet air filter 4112, an inlet muffler 4122, a pressure generator
4140 capable of supplying air at positive pressure (e.g., a blower 4142), an outlet
muffler 4124 and one or more transducers 4270, such as pressure sensors 4272 and
flow rate sensors 4274.
One or more of the air path items may be located within a removable
unitary structure which will be referred to as a pneumatic block 4020. The pneumatic
block 4020 may be located within the external housing 4010. In one form a pneumatic
block 4020 is supported by, or formed as part of the chassis 4016.
The RPT device 4000 may have an electrical power supply 4210, one or
more input devices 4220, a central controller 4230, a therapy device controller 4240, a
pressure generator 4140, one or more protection circuits 4250, memory 4260,
transducers 4270, data communication interface 4280 and one or more output devices
4290. Electrical components 4200 may be mounted on a single Printed Circuit Board
Assembly (PCBA) 4202. In an alternative form, the RPT device 4000 may include
more than one PCBA 4202.
8.4.1 RPT device mechanical & pneumatic components
An RPT device may comprise one or more of the following components
in an integral unit. In an alternative form, one or more of the following components
may be located as respective separate units.
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8.4.1.1 Air filter(s)
An RPT device in accordance with one form of the present technology
may include an air filter 4110, or a plurality of air filters 4110.
In one form, an inlet air filter 4112 is located at the beginning of the
pneumatic path upstream of a pressure generator 4140.
In one form, an outlet air filter 4114, for example an antibacterial filter, is
located between an outlet of the pneumatic block 4020 and a patient interface 3000.
8.4.1.2 Pressure generator
In one form of the present technology, a pressure generator 4140 for
producing a flow, or a supply, of air at positive pressure is a controllable blower 4142.
For example the blower 4142 may include a brushless DC motor 4144 with one or
more impellers housed in a volute. The blower may be capable of delivering a supply
of air, for example at a rate of up to about 120 litres/minute, at a positive pressure in a
range from about 4 cmH O to about 20 cmH O, or in other forms up to about 30
cmH O. The blower may be as described in any one of the following patents or patent
applications the contents of which are incorporated herein by reference in their
entirety: U.S. Patent No. 7,866,944; U.S. Patent No. 8,638,014; U.S. Patent No.
8,636,479; and PCT Patent Application Publication No. .
The pressure generator 4140 is under the control of the therapy device
controller 4240.
In other forms, a pressure generator 4140 may be a piston-driven pump, a
pressure regulator connected to a high pressure source (e.g. compressed air reservoir),
or a bellows.
8.4.1.3 Air circuit
An air circuit 4170 in accordance with an aspect of the present technology
is a conduit or a tube constructed and arranged to allow, in use, a flow of air to travel
between two components such as the RPT device 4000 and the patient interface 3000.
In particular, the air circuit 4170 may be in fluid connection with the
outlet of the RPT device 4000 and the patient interface 3000. The air circuit may be
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referred to as an air delivery tube or conduit. In some cases there may be separate
limbs of the circuit for inhalation and exhalation. In other cases a single limb is used.
In some forms, the air circuit 4170 may comprise one or more heating
elements configured to heat air in the air circuit, for example to maintain or raise the
temperature of the air. The heating element may be in a form of a heated wire circuit,
and may comprise one or more transducers, such as temperature sensors. In one form,
the heated wire circuit may be helically wound around the axis of the air circuit 4170.
The heating element may be in communication with a controller such as a central
controller 4230. One example of an air circuit 4170 comprising a heated wire circuit
is described in United States Patent 8,733,349, which is incorporated herewithin in its
entirety by reference.
8.5 HUMIDIFIER
8.5.1 Humidifier overview
In one form of the present technology there is provided a humidifier 5000
(e.g. as shown in Fig. 5A) to change the absolute humidity of air or gas for delivery to
a patient relative to ambient air. Typically, the humidifier 5000 is used to increase the
absolute humidity and increase the temperature of the flow of air (relative to ambient
air) before delivery to the patient’s airways.
The humidifier 5000 may comprise a humidifier reservoir 5110, a
humidifier inlet 5002 to receive a flow of air, and a humidifier outlet 5004 to deliver a
humidified flow of air. In some forms, as shown in Fig. 5A and Fig. 5B, an inlet and
an outlet of the humidifier reservoir 5110 may be the humidifier inlet 5002 and the
humidifier outlet 5004 respectively. The humidifier 5000 may further comprise a
humidifier base 5006, which may be adapted to receive the humidifier reservoir 5110
and comprise a heating element 5240.
8.6 GLOSSARY
For the purposes of the present technology disclosure, in certain forms of
the present technology, one or more of the following definitions may apply. In other
forms of the present technology, alternative definitions may apply.
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8.6.1 General
Air: In certain forms of the present technology, air may be taken to mean
atmospheric air, and in other forms of the present technology air may be taken to
mean some other combination of breathable gases, e.g. atmospheric air enriched with
oxygen.
Ambient: In certain forms of the present technology, the term ambient will
be taken to mean (i) external of the treatment system or patient, and (ii) immediately
surrounding the treatment system or patient.
For example, ambient humidity with respect to a humidifier may be the
humidity of air immediately surrounding the humidifier, e.g. the humidity in the room
where a patient is sleeping. Such ambient humidity may be different to the humidity
outside the room where a patient is sleeping.
In another example, ambient pressure may be the pressure immediately
surrounding or external to the body.
In certain forms, ambient (e.g., acoustic) noise may be considered to be
the background noise level in the room where a patient is located, other than for
example, noise generated by an RPT device or emanating from a mask or patient
interface. Ambient noise may be generated by sources outside the room.
Automatic Positive Airway Pressure (APAP) therapy: CPAP therapy in
which the treatment pressure is automatically adjustable, e.g. from breath to breath,
between minimum and maximum limits, depending on the presence or absence of
indications of SDB events.
Continuous Positive Airway Pressure (CPAP) therapy: Respiratory
pressure therapy in which the treatment pressure is approximately constant through a
respiratory cycle of a patient. In some forms, the pressure at the entrance to the
airways will be slightly higher during exhalation, and slightly lower during inhalation.
In some forms, the pressure will vary between different respiratory cycles of the
patient, for example, being increased in response to detection of indications of partial
upper airway obstruction, and decreased in the absence of indications of partial upper
airway obstruction.
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Flow rate: The volume (or mass) of air delivered per unit time. Flow rate
may refer to an instantaneous quantity. In some cases, a reference to flow rate will be
a reference to a scalar quantity, namely a quantity having magnitude only. In other
cases, a reference to flow rate will be a reference to a vector quantity, namely a
quantity having both magnitude and direction. Flow rate may be given the symbol Q.
‘Flow rate’ is sometimes shortened to simply ‘flow’.
In the example of patient respiration, a flow rate may be nominally
positive for the inspiratory portion of a breathing cycle of a patient, and hence
negative for the expiratory portion of the breathing cycle of a patient. Total flow rate,
Qt, is the flow rate of air leaving the RPT device. Vent flow rate, Qv, is the flow rate
of air leaving a vent to allow washout of exhaled gases. Leak flow rate, Ql, is the flow
rate of leak from a patient interface system or elsewhere. Respiratory flow rate, Qr, is
the flow rate of air that is received into the patient's respiratory system.
Leak: The word leak will be taken to be an unintended flow of air. In one
example, leak may occur as the result of an incomplete seal between a mask and a
patient's face. In another example leak may occur in a swivel elbow to the ambient.
Noise, conducted (acoustic): Conducted noise in the present document
refers to noise which is carried to the patient by the pneumatic path, such as the air
circuit and the patient interface as well as the air therein. In one form, conducted noise
may be quantified by measuring sound pressure levels at the end of an air circuit.
Noise, radiated (acoustic): Radiated noise in the present document refers
to noise which is carried to the patient by the ambient air. In one form, radiated noise
may be quantified by measuring sound power/pressure levels of the object in question
according to ISO 3744.
Noise, vent (acoustic): Vent noise in the present document refers to noise
which is generated by the flow of air through any vents such as vent holes of the
patient interface.
Patient: A person, whether or not they are suffering from a respiratory
disease.
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Pressure: Force per unit area. Pressure may be expressed in a range of
units, including cmH O, g-f/cm and hectopascal. 1 cmH O is equal to 1 g-f/cm and
is approximately 0.98 hectopascal. In this specification, unless otherwise stated,
pressure is given in units of cmH O.
The pressure in the patient interface is given the symbol Pm, while the
treatment pressure, which represents a target value to be achieved by the mask
pressure Pm at the current instant of time, is given the symbol Pt.
Respiratory Pressure Therapy (RPT): The application of a supply of air to
an entrance to the airways at a treatment pressure that is typically positive with
respect to atmosphere.
Ventilator: A mechanical device that provides pressure support to a
patient to perform some or all of the work of breathing.
8.6.1.1 Materials
Silicone or Silicone Elastomer: A synthetic rubber. In this specification, a
reference to silicone is a reference to liquid silicone rubber (LSR) or a compression
moulded silicone rubber (CMSR). One form of commercially available LSR is
SILASTIC (included in the range of products sold under this trademark),
manufactured by Dow Corning. Another manufacturer of LSR is Wacker. Unless
otherwise specified to the contrary, an exemplary form of LSR has a Shore A (or
Type A) indentation hardness in the range of about 35 to about 45 as measured using
ASTM D2240.
Polycarbonate: a typically transparent thermoplastic polymer of
Bisphenol-A Carbonate.
8.6.1.2 Mechanical properties
Resilience: Ability of a material to absorb energy when deformed
elastically and to release the energy upon unloading.
• ‘Resilient’: Will release substantially all of the energy when unloaded.
Includes e.g. certain silicones, and thermoplastic elastomers.
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Hardness: The ability of a material per se to resist deformation (e.g.
described by a Young’s Modulus, or an indentation hardness scale measured on a
standardised sample size).
• ‘Soft’ materials may include silicone or thermo-plastic elastomer
(TPE), and may, e.g. readily deform under finger pressure.
• ‘Hard’ materials may include polycarbonate, polypropylene, steel or
aluminium, and may not e.g. readily deform under finger pressure.
Stiffness (or rigidity) of a structure or component: The ability of the
structure or component to resist deformation in response to an applied load. The load
may be a force or a moment, e.g. compression, tension, bending or torsion. The
structure or component may offer different resistances in different directions.
• ‘Floppy’ structure or component: A structure or component that will
change shape, e.g. bend, when caused to support its own weight, within
a relatively short period of time such as 1 second.
• ‘Rigid’ structure or component: A structure or component that will not
substantially change shape when subject to the loads typically
encountered in use. An example of such a use may be setting up and
maintaining a patient interface in sealing relationship with an entrance
to a patient's airways, e.g. at a load of approximately 20 to 30 cmH O
pressure.
As an example, an I-beam may comprise a different bending stiffness
(resistance to a bending load) in a first direction in comparison to a second,
orthogonal direction. In another example, a structure or component may be floppy in a
first direction and rigid in a second direction.
8.6.2 Respiratory cycle
Apnea: According to some definitions, an apnea is said to have occurred
when flow falls below a predetermined threshold for a duration, e.g. 10 seconds. An
obstructive apnea will be said to have occurred when, despite patient effort, some
obstruction of the airway does not allow air to flow. A central apnea will be said to
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have occurred when an apnea is detected that is due to a reduction in breathing effort,
or the absence of breathing effort, despite the airway being patent. A mixed apnea
occurs when a reduction or absence of breathing effort coincides with an obstructed
airway.
Breathing rate: The rate of spontaneous respiration of a patient, usually
measured in breaths per minute.
Duty cycle: The ratio of inhalation time, Ti to total breath time, Ttot.
Effort (breathing): The work done by a spontaneously breathing person
attempting to breathe.
Expiratory portion of a breathing cycle: The period from the start of
expiratory flow to the start of inspiratory flow.
Flow limitation: Flow limitation will be taken to be the state of affairs in a
patient's respiration where an increase in effort by the patient does not give rise to a
corresponding increase in flow. Where flow limitation occurs during an inspiratory
portion of the breathing cycle it may be described as inspiratory flow limitation.
Where flow limitation occurs during an expiratory portion of the breathing cycle it
may be described as expiratory flow limitation.
Types of flow limited inspiratory waveforms:
(i) Flattened: Having a rise followed by a relatively flat portion, followed
by a fall.
(ii) M-shaped: Having two local peaks, one at the leading edge, and one at
the trailing edge, and a relatively flat portion between the two peaks.
(iii) Chair-shaped: Having a single local peak, the peak being at the
leading edge, followed by a relatively flat portion.
(iv) Reverse-chair shaped: Having a relatively flat portion followed by
single local peak, the peak being at the trailing edge.
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Hypopnea: According to some definitions,, a hypopnea is taken to be a
reduction in flow, but not a cessation of flow. In one form, a hypopnea may be said to
have occurred when there is a reduction in flow below a threshold rate for a duration.
A central hypopnea will be said to have occurred when a hypopnea is detected that is
due to a reduction in breathing effort. In one form in adults, either of the following
may be regarded as being hypopneas:
(i) a 30% reduction in patient breathing for at least 10 seconds plus an
associated 4% desaturation; or
(ii) a reduction in patient breathing (but less than 50%) for at least 10 seconds,
with an associated desaturation of at least 3% or an arousal.
Hyperpnea: An increase in flow to a level higher than normal.
Inspiratory portion of a breathing cycle: The period from the start of
inspiratory flow to the start of expiratory flow will be taken to be the inspiratory
portion of a breathing cycle.
Patency (airway): The degree of the airway being open, or the extent to
which the airway is open. A patent airway is open. Airway patency may be
quantified, for example with a value of one (1) being patent, and a value of zero (0),
being closed (obstructed).
Positive End-Expiratory Pressure (PEEP): The pressure above
atmosphere in the lungs that exists at the end of expiration.
Peak flow rate (Qpeak): The maximum value of flow rate during the
inspiratory portion of the respiratory flow waveform.
Respiratory flow rate, patient airflow rate, respiratory airflow rate (Qr):
These terms may be understood to refer to the RPT device’s estimate of respiratory
airflow rate, as opposed to “true respiratory flow rate” or “true respiratory airflow
rate”, which is the actual respiratory flow rate experienced by the patient, usually
expressed in litres per minute.
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Tidal volume (Vt): The volume of air inhaled or exhaled during normal
breathing, when extra effort is not applied.
(inhalation) Time (Ti): The duration of the inspiratory portion of the
respiratory flow rate waveform.
(exhalation) Time (Te): The duration of the expiratory portion of the
respiratory flow rate waveform.
(total) Time (Ttot): The total duration between the start of one inspiratory
portion of a respiratory flow rate waveform and the start of the following inspiratory
portion of the respiratory flow rate waveform.
Typical recent ventilation: The value of ventilation around which recent
values of ventilation Vent over some predetermined timescale tend to cluster, that is, a
measure of the central tendency of the recent values of ventilation.
Upper airway obstruction (UAO): includes both partial and total upper
airway obstruction. This may be associated with a state of flow limitation, in which
the flow rate increases only slightly or may even decrease as the pressure difference
across the upper airway increases (Starling resistor behaviour).
Ventilation (Vent): A measure of a rate of gas being exchanged by the
patient’s respiratory system. Measures of ventilation may include one or both of
inspiratory and expiratory flow, per unit time. When expressed as a volume per
minute, this quantity is often referred to as “minute ventilation”. Minute ventilation is
sometimes given simply as a volume, understood to be the volume per minute.
8.6.3 Ventilation
Adaptive Servo-Ventilator (ASV): A servo-ventilator that has a
changeable, rather than fixed target ventilation. The changeable target ventilation may
be learned from some characteristic of the patient, for example, a respiratory
characteristic of the patient.
Backup rate: A parameter of a ventilator that establishes the minimum
breathing rate (typically in number of breaths per minute) that the ventilator will
deliver to the patient, if not triggered by spontaneous respiratory effort.
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Cycled: The termination of a ventilator's inspiratory phase. When a
ventilator delivers a breath to a spontaneously breathing patient, at the end of the
inspiratory portion of the breathing cycle, the ventilator is said to be cycled to stop
delivering the breath.
Expiratory positive airway pressure (EPAP): a base pressure, to which a
pressure varying within the breath is added to produce the desired mask pressure
which the ventilator will attempt to achieve at a given time.
End expiratory pressure (EEP): Desired mask pressure which the
ventilator will attempt to achieve at the end of the expiratory portion of the breath. If
the pressure waveform template ( ) is zero-valued at the end of expiration, i.e.
( ) = 0 when = 1, the EEP is equal to the EPAP.
Inspiratory positive airway pressure (IPAP): Maximum desired mask
pressure which the ventilator will attempt to achieve during the inspiratory portion of
the breath.
Pressure support: A number that is indicative of the increase in pressure
during ventilator inspiration over that during ventilator expiration, and generally
means the difference in pressure between the maximum value during inspiration and
the base pressure (e.g., PS = IPAP – EPAP). In some contexts pressure support
means the difference which the ventilator aims to achieve, rather than what it actually
achieves.
Servo-ventilator: A ventilator that measures patient ventilation, has a
target ventilation, and which adjusts the level of pressure support to bring the patient
ventilation towards the target ventilation.
Spontaneous/Timed (S/T): A mode of a ventilator or other device that
attempts to detect the initiation of a breath of a spontaneously breathing patient. If
however, the device is unable to detect a breath within a predetermined period of
time, the device will automatically initiate delivery of the breath.
Swing: Equivalent term to pressure support.
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Triggered: When a ventilator delivers a breath of air to a spontaneously
breathing patient, it is said to be triggered to do so at the initiation of the respiratory
portion of the breathing cycle by the patient's efforts.
Typical recent ventilation: The typical recent ventilation Vtyp is the value
around which recent measures of ventilation over some predetermined timescale tend
to cluster. For example, a measure of the central tendency of the measures of
ventilation over recent history may be a suitable value of a typical recent ventilation.
8.6.4 Anatomy
8.6.4.1 Anatomy of the face
Ala: the external outer wall or "wing" of each nostril (plural: alar)
Alare: The most lateral point on the nasal ala.
Alar curvature (or alar crest) point: The most posterior point in the
curved base line of each ala, found in the crease formed by the union of the ala with
the cheek.
Auricle: The whole external visible part of the ear.
(nose) Bony framework: The bony framework of the nose comprises the
nasal bones, the frontal process of the maxillae and the nasal part of the frontal bone.
(nose) Cartilaginous framework: The cartilaginous framework of the nose
comprises the septal, lateral, major and minor cartilages.
Columella: the strip of skin that separates the nares and which runs from
the pronasale to the upper lip.
Columella angle: The angle between the line drawn through the midpoint
of the nostril aperture and a line drawn perpendicular to the Frankfurt horizontal while
intersecting subnasale.
Frankfort horizontal plane: A line extending from the most inferior point
of the orbital margin to the left tragion. The tragion is the deepest point in the notch
superior to the tragus of the auricle.
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Glabella: Located on the soft tissue, the most prominent point in the
midsagittal plane of the forehead.
Lateral nasal cartilage: A generally triangular plate of cartilage. Its
superior margin is attached to the nasal bone and frontal process of the maxilla, and
its inferior margin is connected to the greater alar cartilage.
Lip, lower (labrale inferius):
Lip, upper (labrale superius):
Greater alar cartilage: A plate of cartilage lying below the lateral nasal
cartilage. It is curved around the anterior part of the naris. Its posterior end is
connected to the frontal process of the maxilla by a tough fibrous membrane
containing three or four minor cartilages of the ala.
Nares (Nostrils): Approximately ellipsoidal apertures forming the
entrance to the nasal cavity. The singular form of nares is naris (nostril). The nares are
separated by the nasal septum.
Naso-labial sulcus or Naso-labial fold: The skin fold or groove that runs
from each side of the nose to the corners of the mouth, separating the cheeks from the
upper lip.
Naso-labial angle: The angle between the columella and the upper lip,
while intersecting subnasale.
Otobasion inferior: The lowest point of attachment of the auricle to the
skin of the face.
Otobasion superior: The highest point of attachment of the auricle to the
skin of the face.
Pronasale: the most protruded point or tip of the nose, which can be
identified in lateral view of the rest of the portion of the head.
Philtrum: the midline groove that runs from lower border of the nasal
septum to the top of the lip in the upper lip region.
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Pogonion: Located on the soft tissue, the most anterior midpoint of the
chin.
Ridge (nasal): The nasal ridge is the midline prominence of the nose,
extending from the Sellion to the Pronasale.
Sagittal plane: A vertical plane that passes from anterior (front) to
posterior (rear) dividing the body into right and left halves.
Sellion: Located on the soft tissue, the most concave point overlying the
area of the frontonasal suture.
Septal cartilage (nasal): The nasal septal cartilage forms part of the
septum and divides the front part of the nasal cavity.
Subalare: The point at the lower margin of the alar base, where the alar
base joins with the skin of the superior (upper) lip.
Subnasal point: Located on the soft tissue, the point at which the
columella merges with the upper lip in the midsagittal plane.
Supramentale: The point of greatest concavity in the midline of the lower
lip between labrale inferius and soft tissue pogonion
8.6.4.2 Anatomy of the skull
Frontal bone: The frontal bone includes a large vertical portion, the
squama frontalis, corresponding to the region known as the forehead.
Mandible: The mandible forms the lower jaw. The mental protuberance is
the bony protuberance of the jaw that forms the chin.
Maxilla: The maxilla forms the upper jaw and is located above the
mandible and below the orbits. The frontal process of the maxilla projects upwards by
the side of the nose, and forms part of its lateral boundary.
Nasal bones: The nasal bones are two small oblong bones, varying in size
and form in different individuals; they are placed side by side at the middle and upper
part of the face, and form, by their junction, the "bridge" of the nose.
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Nasion: The intersection of the frontal bone and the two nasal bones, a
depressed area directly between the eyes and superior to the bridge of the nose.
Occipital bone: The occipital bone is situated at the back and lower part of
the cranium. It includes an oval aperture, the foramen magnum, through which the
cranial cavity communicates with the vertebral canal. The curved plate behind the
foramen magnum is the squama occipitalis.
Orbit: The bony cavity in the skull to contain the eyeball.
Parietal bones: The parietal bones are the bones that, when joined
together, form the roof and sides of the cranium.
Temporal bones: The temporal bones are situated on the bases and sides
of the skull, and support that part of the face known as the temple.
Zygomatic bones: The face includes two zygomatic bones, located in the
upper and lateral parts of the face and forming the prominence of the cheek.
8.6.4.3 Anatomy of the respiratory system
Diaphragm: A sheet of muscle that extends across the bottom of the rib
cage. The diaphragm separates the thoracic cavity, containing the heart, lungs and
ribs, from the abdominal cavity. As the diaphragm contracts the volume of the
thoracic cavity increases and air is drawn into the lungs.
Larynx: The larynx, or voice box houses the vocal folds and connects the
inferior part of the pharynx (hypopharynx) with the trachea.
Lungs: The organs of respiration in humans. The conducting zone of the
lungs contains the trachea, the bronchi, the bronchioles, and the terminal bronchioles.
The respiratory zone contains the respiratory bronchioles, the alveolar ducts, and the
alveoli.
Nasal cavity: The nasal cavity (or nasal fossa) is a large air filled space
above and behind the nose in the middle of the face. The nasal cavity is divided in two
by a vertical fin called the nasal septum. On the sides of the nasal cavity are three
horizontal outgrowths called nasal conchae (singular "concha") or turbinates. To the
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front of the nasal cavity is the nose, while the back blends, via the choanae, into the
nasopharynx.
Pharynx: The part of the throat situated immediately inferior to (below)
the nasal cavity, and superior to the oesophagus and larynx. The pharynx is
conventionally divided into three sections: the nasopharynx (epipharynx) (the nasal
part of the pharynx), the oropharynx (mesopharynx) (the oral part of the pharynx),
and the laryngopharynx (hypopharynx).
8.6.5 Patient interface
Anti-asphyxia valve (AAV): The component or sub-assembly of a mask
system that, by opening to atmosphere in a failsafe manner, reduces the risk of
excessive CO rebreathing by a patient.
Elbow: An elbow is an example of a structure that directs an axis of flow
of air travelling therethrough to change direction through an angle. In one form, the
angle may be approximately 90 degrees. In another form, the angle may be more, or
less than 90 degrees. The elbow may have an approximately circular cross-section. In
another form the elbow may have an oval or a rectangular cross-section. In certain
forms an elbow may be rotatable with respect to a mating component, e.g. about 360
degrees. In certain forms an elbow may be removable from a mating component, e.g.
via a snap connection. In certain forms, an elbow may be assembled to a mating
component via a one-time snap during manufacture, but not removable by a patient.
Frame: Frame will be taken to mean a mask structure that bears the load
of tension between two or more points of connection with a headgear. A mask frame
may be a non-airtight load bearing structure in the mask. However, some forms of
mask frame may also be air-tight.
Headgear: Headgear will be taken to mean a form of positioning and
stabilizing structure designed for use on a head. For example the headgear may
comprise a collection of one or more struts, ties and stiffeners configured to locate
and retain a patient interface in position on a patient’s face for delivery of respiratory
therapy. Some ties are formed of a soft, flexible, elastic material such as a laminated
composite of foam and fabric.
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Membrane: Membrane will be taken to mean a typically thin element that
has, preferably, substantially no resistance to bending, but has resistance to being
stretched.
Plenum chamber: a mask plenum chamber will be taken to mean a portion
of a patient interface having walls at least partially enclosing a volume of space, the
volume having air therein pressurised above atmospheric pressure in use. A shell may
form part of the walls of a mask plenum chamber.
Seal: May be a noun form ("a seal") which refers to a structure, or a verb
form (“to seal”) which refers to the effect. Two elements may be constructed and/or
arranged to ‘seal’ or to effect ‘sealing’ therebetween without requiring a separate
‘seal’ element per se.
Shell: A shell will be taken to mean a curved, relatively thin structure
having bending, tensile and compressive stiffness. For example, a curved structural
wall of a mask may be a shell. In some forms, a shell may be faceted. In some forms a
shell may be airtight. In some forms a shell may not be airtight.
Stiffener: A stiffener will be taken to mean a structural component
designed to increase the bending resistance of another component in at least one
direction.
Strut: A strut will be taken to be a structural component designed to
increase the compression resistance of another component in at least one direction.
Swivel (noun): A subassembly of components configured to rotate about a
common axis, preferably independently, preferably under low torque. In one form, the
swivel may be constructed to rotate through an angle of at least 360 degrees. In
another form, the swivel may be constructed to rotate through an angle less than 360
degrees. When used in the context of an air delivery conduit, the sub-assembly of
components preferably comprises a matched pair of cylindrical conduits. There may
be little or no leak flow of air from the swivel in use.
Tie (noun): A structure designed to resist tension.
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Vent: (noun): A structure that allows a flow of air from an interior of the
mask, or conduit, to ambient air for clinically effective washout of exhaled gases. For
example, a clinically effective washout may involve a flow rate of about 10 litres per
minute to about 100 litres per minute, depending on the mask design and treatment
pressure.
8.7 OTHER REMARKS
A portion of the disclosure of this patent document contains material
which is subject to copyright protection. The copyright owner has no objection to the
facsimile reproduction by anyone of the patent document or the patent disclosure, as it
appears in Patent Office patent files or records, but otherwise reserves all copyright
rights whatsoever.
Unless the context clearly dictates otherwise and where a range of values
is provided, it is understood that each intervening value, to the tenth of the unit of the
lower limit, between the upper and lower limit of that range, and any other stated or
intervening value in that stated range is encompassed within the technology. The
upper and lower limits of these intervening ranges, which may be independently
included in the intervening ranges, are also encompassed within the technology,
subject to any specifically excluded limit in the stated range. Where the stated range
includes one or both of the limits, ranges excluding either or both of those included
limits are also included in the technology.
Furthermore, where a value or values are stated herein as being
implemented as part of the technology, it is understood that such values may be
approximated, unless otherwise stated, and such values may be utilized to any suitable
significant digit to the extent that a practical technical implementation may permit or
require it.
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 to
which this technology belongs. Although any methods and materials similar or
equivalent to those described herein can also be used in the practice or testing of the
present technology, a limited number of the exemplary methods and materials are
described herein.
James & Wells Ref: 506131NZ
When a particular material is identified as being used to construct a
component, obvious alternative materials with similar properties may be used as a
substitute. Furthermore, unless specified to the contrary, any and all components
herein described are understood to be capable of being manufactured and, as such,
may be manufactured together or separately.
It must be noted that as used herein and in the appended claims, the
singular forms "a", "an", and "the" include their plural equivalents, unless the context
clearly dictates otherwise.
All publications mentioned herein are incorporated herein by reference in
their entirety to disclose and describe the methods and/or materials which are the
subject of those publications. The publications discussed herein are provided solely
for their disclosure prior to the filing date of the present application. Nothing herein is
to be construed as an admission that the present technology is not entitled to antedate
such publication by virtue of prior invention. Further, the dates of publication
provided may be different from the actual publication dates, which may need to be
independently confirmed.
The terms "comprises" and "comprising" should be interpreted as
referring to elements, components, or steps in a non-exclusive manner, indicating that
the referenced elements, components, or steps may be present, or utilized, or
combined with other elements, components, or steps that are not expressly referenced.
The subject headings used in the detailed description are included only for
the ease of reference of the reader and should not be used to limit the subject matter
found throughout the disclosure or the claims. The subject headings should not be
used in construing the scope of the claims or the claim limitations.
Although the technology herein has been described with reference to
particular examples, it is to be understood that these examples are merely illustrative
of the principles and applications of the technology. In some instances, the
terminology and symbols may imply specific details that are not required to practice
the technology. For example, although the terms "first" and "second" may be used,
unless otherwise specified, they are not intended to indicate any order but may be
utilised to distinguish between distinct elements. Furthermore, although process steps
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in the methodologies may be described or illustrated in an order, such an ordering is
not required. Those skilled in the art will recognize that such ordering may be
modified and/or aspects thereof may be conducted concurrently or even
synchronously.
It is therefore to be understood that numerous modifications may be made
to the illustrative examples and that other arrangements may be devised without
departing from the spirit and scope of the technology.
James & Wells Ref: 506131NZ
8.8 REFERENCE SIGNS LIST
1000 Patient
1100 Bed partner
3000 Patient interface
3100 Sealing or seal-forming structure
3150 Cushion assembly
3170 Nasal seal-forming structure
3180 Oral seal-forming structure
3200 Plenum chamber
3210 Plenum chamber perimeter
3300 Positing and stabilising structure / headgear
3310 Headgear strap
3320 Chin strap
3330 Padded members
3340 Elastic sleeves
3342 Side opening
3343 Top opening
3345 Tab
3347 Rounded edges
3348 Patient contacting side
3349 Non-patient contacting side
3350 Headgear tube
3351 Upper tube member
3352 Tube ends
3353A Upper curved portion
3353B Lower curved portion
3354 Less stretchable tube section
3355 More stretchable tube section
3356 Securing mechanism
3357 First securing member
3358 Second securing member
3360 Adjustment mechanism
3362 Concertina tube section
3363 Non-adjustable headgear tube section
3364 Fold portion
3366 Tube wall fold / rolling fold portion
3368 Adjacent tube portion
3370 First tube portion
3371 First tab
3372 Second tube portion
3373 Second tab
3374 Ribs
3375 Nested concentric tube sections
3376 Ratchet mechanism
3377 Visual indicator
3378 Button
3379 Rigidising members
3380 First threaded portion
3382 Second threaded portion
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3383 Pinion
3384 Ring member
3385 Replaceable tube portion
3386 Replacement tube portions
3387 Tube insert member
3390 Strap
3391 Strap adjustment mechanism
3395 Band
3397 Tongue
3398 Grooves
3410 Loop insert member
3411 Replacement loop insert members
3420 Inflatable loop insert member
3600 Connection port
3744 ISO
4000 RPT device
4010 External housing
4012 Upper portion
4014 Portion
4015 Panel
4016 Chassis
4018 Handle
4020 Pneumatic block
4100 Pneumatic components
4110 Air filter
4112 Inlet air filter
4114 Outlet air filter
4122 Inlet muffler
4124 Outlet muffler
4140 Pressure generator
4142 Controllable blower
4144 Brushless DC motor
4170 Air circuit
4200 Electrical components
4202 Printed Circuit Board Assembly (PCBA)
4210 Electrical power supply
4220 Input devices
4230 Central controller
4240 Therapy device controller
4250 Protection circuits
4260 Memory
4270 Transducers
4272 Pressure sensors
4274 Flow rate sensors
4280 Data communication interface
4290 Output devices
4300 Algorithms
5000 Humidifier
5002 Humidifier inlet
5004 Humidifier outlet
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5006 Humidifier base
5110 Humidifier reservoir
5130 Humidifier reservoir dock
5240 Heating element
6000 Force-extension plot
6100 Extension axis
6105 Zero extension
6110 First amount of extension
6120 Second amount of extension
6200 Force axis
6210 Minimum sealing force
6220 Maximum comfort force
6300 Force-extension characteristic
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Claims (28)
1. A positioning and stabilising structure configured to hold a seal-forming structure in a therapeutically effective position on a head of a patient, the seal-forming structure being constructed and arranged to form a seal with a region of the patient’s face surrounding an entrance to the patient’s airways for sealed delivery of a flow of air at a therapeutic pressure of at least 4 cmH O with respect to ambient air pressure throughout the patient’s respiratory cycle in use, the positioning and stabilising structure comprising: two gas delivery tubes, each of the two gas delivery tubes being configured to deliver the flow of air to the entrance of a patient's airways via the seal-forming structure, each of the two gas delivery tubes being constructed and arranged to contact, in use, at least a region of the patient’s head superior to an otobasion superior of the patient’s head; a bias and adjustment mechanism configured to allow adjustment of a length of each of the two gas delivery tubes to enable the positioning and stabilising structure to fit different size heads and configured to impart a biasing force along at least a part of a length of each of the two gas delivery tubes to urge the seal-forming structure towards the entrance of the patient’s airways in use; a rear strap connected between the two gas delivery tubes and configured, in use, to pass around the posterior portion of the patient’s head; and a connection port configured to fluidly connect, in use, with an air circuit connected to a supply of pressurised air, the connection port configured to be located, in use, superior to the patient’s head, wherein each of the two gas delivery tubes comprises a first end configured to be connected to the seal-forming structure, wherein the bias and adjustment mechanism comprises an elastic member provided between the seal-forming structure and the connection port, wherein the elastic member comprises a portion of the gas delivery tube having a concertina structure configured to impart the biasing force to allow adjustment of the length of each of the two gas delivery tubes, James & Wells Ref: 506131NZ wherein the portion of the gas delivery tube having the concertina structure is, in use, positioned in contact with a region of the patient’s head superior to the patient’s otobasion superior, and wherein the rear strap is connected to each of the two gas delivery tubes between the portion of the gas delivery tube having the concertina structure and the first end.
2. A positioning and stabilising structure as claimed in claim 1, wherein each of the two gas delivery tubes comprises the bias and adjustment mechanism.
3. A positioning and stabilising structure as claimed in one of claim 1 or claim 2, wherein the elastic member comprises an elastic sleeve, wherein each of the two gas delivery tubes comprises the elastic sleeve and an inner gas delivery conduit, the elastic sleeve covering the inner gas delivery conduit.
4. A positioning and stabilising structure as claimed in any one of claims 1 to 3, wherein the elastic member comprises a portion of each of the two gas delivery tubes formed from an elastic material.
5. A positioning and stabilising structure as claimed in any one of claims 1 to 4, wherein the bias and adjustment mechanism enables the length of each of the two gas delivery tubes to be adjusted through a continuous range of lengths.
6. A positioning and stabilising structure as claimed in any one of claims 1 to 5, wherein each of the two gas delivery tubes comprises a first tube portion and a second tube portion, the first tube portion being telescopically moveable relative to the second tube portion to adjust the length of each of the two gas delivery tubes.
7. A positioning and stabilising structure as claimed in claim 6, further comprising one or more tabs to facilitate telescopic relative movement between first tube portion and second tube portion. James & Wells Ref: 506131NZ
8. A positioning and stabilising structure as claimed in one of claim 6 or claim 7, further comprising a tube portion securing mechanism configured to secure the first and second tube portions at a plurality of discrete positions relative to one another.
9. A positioning and stabilising structure as claimed in any one of claims 1 to 8, wherein each of the two gas delivery tubes comprises a fold portion such that, the length of each of the two gas delivery tubes when the fold portion is in a folded configuration is different to the length of each of the two gas delivery tubes when the fold portion is in an unfolded configuration.
10. A positioning and stabilising structure as claimed in claim 9, wherein each of the two gas delivery tubes comprises a plurality of fold portions in a portion of each of the two gas delivery tubes having a concertina structure.
11. A positioning and stabilising structure as claimed in any one of claims 1 to 10, wherein the bias and adjustment mechanism comprises a stretchable section of each of the two gas delivery tubes.
12. A positioning and stabilising structure as claimed in any one of claims 1 to 11, wherein the bias and adjustment mechanism comprises a first tube portion that is removable and replaceable by a second tube portion having a different length to the first tube portion.
13. A positioning and stabilising structure as claimed in any one of claims 1 to 12, wherein the bias and adjustment mechanism comprises one or more tube insert members configured to be selectably fluidly connected to each of the two gas delivery tubes to alter the length of each of the two gas delivery tubes.
14. A positioning and stabilising structure as claimed in any one of claims 1 to 13, wherein each of the two gas delivery tubes comprises a plurality of indicators indicating where to cut each of the two gas delivery tubes for fitting different sized patient heads. James & Wells Ref: 506131NZ
15. A positioning and stabilising structure as claimed in any one of claims 1 to 14, wherein the bias and adjustment mechanism is configured to enable each of the two gas delivery tubes to be bendably adjusted to enable the positioning and stabilising structure to fit different size heads.
16. A positioning and stabilising structure as claimed in any one of claims 1 to 15, wherein the positioning and stabilising structure is configured such that, in use, the bias and adjustment mechanism is positioned out of contact with a patient’s face.
17. A positioning and stabilising structure as claimed in claim 16, wherein the positioning and stabilising structure is configured such that, in use, the bias and adjustment mechanism is positioned out of contact with a patient’s cheek region.
18. A positioning and stabilising structure as claimed in any one of claims 1 to 17, wherein the positioning and stabilising structure extends, in use, across a patient’s cheek region.
19. A positioning and stabilising structure as claimed in any one of claims 1 to 18, wherein the positioning and stabilising structure is free of any mechanisms for enabling length adjustment of each of the two gas delivery tubes inferior to the otobasion superior of the patient’s head.
20. A positioning and stabilising structure as claimed in claim 19, wherein the positioning and stabilising structure is free of any mechanisms for enabling length adjustment of each of the two gas delivery tubes extending, in use, across a patient’s cheek region.
21. A positioning and stabilising structure as claimed in any one of claims 18 to 20, wherein the two gas delivery tubes are fluidly connected between the connection port and the seal- forming structure, each gas delivery tube extending, in use, across one of the patient’s cheek regions, the two gas delivery tubes being on different sides of the patient’s head. James & Wells Ref: 506131NZ
22. A positioning and stabilising structure as claimed in any one of claims 1 to 21, wherein the connection port is located, in use, on top of the patient’s head.
23. A positioning and stabilising structure as claimed in claim 22, wherein the positioning and stabilising structure extends, in use, between the patient’s eye and patient’s ear.
24. A positioning and stabilising structure as claimed in claim 23, wherein a length of the rear strap between the two gas delivery tubes is adjustable.
25. A positioning and stabilising structure as claimed in one of claim 23 or claim 24, wherein an angle of the rear strap to each gas delivery tube is adjustable.
26. A positioning and stabilising structure as claimed in any one of claims 1 to 25, wherein the positioning and stabilising structure comprises the bias and adjustment mechanism positioned, in use, above a point of connection of the rear strap to each of the two gas delivery tubes and the positioning and stabilising structure is free of any mechanisms for enabling length adjustment of each of the two gas delivery tubes positioned, in use, below the point of connection of the rear strap to one of the gas delivery tubes.
27. A patient interface comprising: a plenum chamber pressurisable to a therapeutic pressure of at least 4 cmH O above ambient air pressure, said plenum chamber including a plenum chamber inlet port sized and structured to receive a flow of air at the therapeutic pressure for breathing by a patient; a seal-forming structure constructed and arranged to form a seal with a region of the patient’s face surrounding an entrance to the patient’s airways such that the flow of air at said therapeutic pressure is delivered to at least an entrance to the patient’s nares, the seal-forming structure constructed and arranged to maintain said therapeutic pressure in the plenum chamber throughout the patient’s respiratory cycle in use; James & Wells Ref: 506131NZ a connection port to fluidly connect, in use, with an air circuit connected to the flow of air, the connection port being located, in use, proximal a top, side or rear portion of a patient’s head; and the positioning and stabilising structure of any one of claims 1 to 26.
28. A system for treating a respiratory disorder, the system comprising: a patient interface as claimed in claim 27; an air circuit; and a source of air at positive pressure with respect to ambient air pressure.
Applications Claiming Priority (9)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US201662281322P | 2016-01-21 | 2016-01-21 | |
US62/281,322 | 2016-01-21 | ||
AU2016901163A AU2016901163A0 (en) | 2016-03-30 | Adjustable Headgear for a Patient Interface | |
AU2016901163 | 2016-03-30 | ||
US201662330371P | 2016-05-02 | 2016-05-02 | |
US62/330,371 | 2016-05-02 | ||
AUPCT/AU2017/050044 | 2017-01-20 | ||
PCT/AU2017/050044 WO2017124152A1 (en) | 2016-01-21 | 2017-01-20 | Adjustable headgear tubing for a patient interface |
PCT/AU2017/050050 WO2017124155A1 (en) | 2016-01-21 | 2017-01-23 | Adjustable headgear tubing for a patient interface |
Publications (2)
Publication Number | Publication Date |
---|---|
NZ744240A NZ744240A (en) | 2021-03-26 |
NZ744240B2 true NZ744240B2 (en) | 2021-06-29 |
Family
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