RESPIRATORY ASSISTANCE APPARATUS
A head-mounted respiratory assistance apparatus configured to provide a respiratory gases stream to a user. The head-mounted respiratory assistance has a main body securable to the head of a user and a blower unit that is operable to generate a pressurised gases stream from a supply of gases from the surrounding atmosphere. A patient interface is provided on the main body that has a gases inlet which is fluidly connected to the blower unit and which is configured to deliver the pressurised gases to the user's nose and/or mouth.
This invention relates to a respiratory assistance apparatus that provides a stream of gases to a user for therapeutic purposes. In particular, although not exclusively, the respiratory assistance apparatus may provide respiratory assistance to patients or users who require a supply of gases for respiratory therapies such as Positive Airway Pressure (PAP) therapies, including but not limited to Continuous Positive Airway Pressure (CPAP) therapy, Bi-level Positive Airway Pressure (Bi-PAP) therapy, and Oral Positive Airway Pressure (OPAP) therapy, and which are typically used for the treatment of diseases such as Obstructive Sleep Apnea (OSA), snoring, or Chronic Obstructive Pulmonary Disease (COPD).
BACKGROUND OF THE INVENTIONRespiratory or breathing assistance devices or systems for providing a flow of humidified and heated gases to a patient for therapeutic purposes are well known in the art. Systems for providing therapy of this type (for example respiratory humidification) typically have a structure where gases are delivered to a humidifier chamber from a gases source, such as a blower (also known as a compressor, an assisted breathing unit, a fan unit, a flow generator or a pressure generator). As the gases pass over the hot water, or through the heated and humidified air in the humidifier chamber, they become saturated with water vapour. The heated and humidified gases are then delivered to a user or patient downstream from the humidifier chamber, via a patient interface comprising a flexible gases conduit and a patient interface.
In one form, such respiratory assistance systems can be modular systems that comprise a humidifier unit and a blower unit that are separate (modular) items. The modules are connected in series via connection conduits to allow gases to pass from the blower unit to the humidifier unit. For example,
In an alternative form, the respiratory assistance systems can be integrated systems in which the blower unit and the humidifier unit are contained within the same housing. A typical integrated system consists of, a main blower unit or assisted breathing unit which provides a pressurised gases flow, and a humidifier unit that mates with or is otherwise rigidly connected to the blower unit.
The patient interface 5 shown in
Impeller type fans or blowers are most commonly used in respiratory assistance systems of this type. An impeller blade unit is contained within an impeller housing. The impeller blade unit is connected to a drive of some form by a central spindle. A typical impeller housing is shown in
The respiratory assistance systems of the type described above typically present various problems or challenges to the manufacturer from a design viewpoint, some of which are briefly outlined below.
Effective respiratory therapy often requires a user to use respiratory assistance systems of the type described above on a daily basis for long periods of time. For the treatment of OSA, the user needs to use the respiratory assistance system at night when they are asleep. Patient comfort and convenience when using such respiratory assistance systems is paramount to compliant and effective treatment. Mask leaks are a common complaint of user's of the above type of respiratory assistance systems. Mask leaks are typically caused by the flexible gases conduit 3 tugging on the patient interface or mask 5 when the user moves in their sleep.
Most respiratory assistance systems of the type described above for treating OSA with PAP therapy provide a gas supply to the patient interface but have no return path for gases from the interface. To eliminate the build-up of carbon dioxide in the patient interface, the patient interface requires a gas washout vent for venting exhaled gases to atmosphere, and this is often referred to as the ‘bias flow’. The bias flow represents a loss in the gases supply circuit and the blower unit must have a motor that is powerful enough to maintain the bias flow while also generating the desired gas pressure at the patient interface. The gas washout vent can also become a source of noise and a source of discernable draughts. Excessive noise can be irritating for the patient and their bed partner. Depending on their location, draughts can also be annoying to the patient.
Humidification of the gases in the respiratory assistance systems also adds to the design complexity. For example, heating of the gases conduit 3 of the patient interface is often required to prevent condensation forming in the gases conduit.
In this specification where reference has been made to patent specifications, other external documents, or other sources of information, this is generally for the purpose of providing a context for discussing the features of the invention. Unless specifically stated otherwise, reference to such external documents is not to be construed as an admission that such documents, or such sources of information, in any jurisdiction, are prior art, or form part of the common general knowledge in the art.
It is an object of the present invention to provide an improved respiratory assistance apparatus, or to at least provide the public with a useful choice.
SUMMARY OF THE INVENTIONIn a first aspect, the invention broadly consists in a head-mounted respiratory assistance apparatus configured to provide a respiratory gases stream to a user, comprising: a main body securable to the head of a user; a blower unit provided on the main body having a gases inlet to receive a supply of gases from the surrounding atmosphere and which is operable to generate a pressurised gases stream at a gases outlet; and a patient interface provided on the main body having a gases inlet which is fluidly connected via a gases flow path to the gases outlet of the blower unit and which is configured to deliver the pressurised gases to the user's nose and/or mouth via one or more oases outlets, and wherein the gases flow path from the gases inlet of the blower unit to the gases outlet(s) of the patient interface is substantially sealed such that there is zero bias flow along the gases flow path, and wherein the blower unit comprises a lightweight impeller, and a motor with a rotatable drive shaft that is configured to rotate the impeller.
Preferably, the apparatus may be configured to passively humidify and warm the pressurised respiratory gases in the gases flow path via accumulated heat and moisture build up within at least a portion of the gases flow path. In one form, the gases flow path may be configured to accumulate heat and moisture build-up within at least a portion of the air flow path from exhaled gases from the user flowing back into the gases flow path from the patient interface.
Preferably, the apparatus may further comprise one or more heat and moisture exchangers (HMEs) in the gases flow path of the respiratory assistance apparatus.
Preferably, the gases or air flow path is provided through the respiratory-device between the gases inlet of the blower unit and an outlet or opening of the patient interface.
Preferably, excess exhaled gases from the user may vent back through the air flow path in the opposite direction of the pressurised gases stream and exit the respiratory assistance apparatus into the atmosphere from the gases inlet of the blower unit, Preferably, the gases flow path volume or ‘deadspace’ between the gases inlet of the blower unit and the gases outlet(s) of the patient interface may be less than approximately 200 mL, and more preferably in the range of approximately 50 mL to approximately 150 mL.
Preferably, the apparatus may be configured to be operatively connectable to a separate base station, the base station comprising: a power supply system that is operable to supply power to the respiratory assistance apparatus; a data transfer system that is operable to send and receive data to and from the respiratory assistance apparatus; and a control system that is operable to control the respiratory assistance apparatus via control signals.
Preferably, the apparatus may further comprise headgear that is-configured to secure or mount the main body to the head of a user, the headgear comprising one or more headstraps. In one form, the headgear may comprise an upper headstrap that is connected to an upper part of the respiratory assistance apparatus and is configured to extend around an upper part of the user's head; and a lower headstrap that is connected to a lower part of the respiratory assistance apparatus and is configured to extend around a lower part of the user's head, and wherein the headgear is configured to locate the main body of the respiratory assistance apparatus in the region of user's face.
In one form, the headgear may be fully flexible or formed substantially from flexible components. In another form, the headgear may be semi-rigid in that it may comprise one or more rigid components, such as but not limited to the various headgear embodiments described in published patent application WO2012/140514, the contents of which are herein incorporated by reference.
Preferably, the respiratory assistance apparatus may comprise one or more onboard power supply modules that are configured to supply power to the apparatus, and wherein the power supply modules are mounted to or integrated with the headgear. Alternatively, the power supply modules may be otherwise head-mounted with the respiratory assistance apparatus, such as mounted to or integrated with the main body or blower unit of the respiratory assistance apparatus. Preferably, the power supply modules are connected to the respiratory assistance apparatus by a power cable or cables. In one form, the power supply module(s) may be detachable or releasable from the respiratory assistance apparatus.
Alternatively or additionally, the power supply module(s) may be a separate non-head-mounted portable module that is connected to the respiratory device by a power cable. Alternatively or additionally, the respiratory assistance apparatus may be configured to connect to an AC power adaptor for a supply of power.
In one form, one or more pockets are provided within the headstrap(s) within which the one or more power supply module(s) are retained. Preferably, the pocket(s) may be openable to enable removal of the power supply module(s). In another form, the power supply module(s) may be releasably mounted to a part of the headgear such that they are detachable from the headgear. In another form, the power supply module(s) may be provided within a flexible package secured to the headgear and which is configured to extend at least partially over the top of the user's head. Preferably, the flexible package may be secured to one or more of the headstraps off the headgear by a base layer of flexible material.
Preferably, the headgear may further comprise one or more shielding plates located between the one or more power supply modules and the surface of the user's head when the headgear is worn by a user.
Preferably, the power supply module(s) comprise any one or more energy storage devices selected from the following: batteries or battery packs (rechargeable or disposable), fuel cells, and/or capacitors.
Preferably, the lightweight impeller of the blower unit may be shroudless or otherwise have reduced material.
In one embodiment, a distal end of the impeller blades curve in the direction of blade rotation. In another embodiment, the impeller blades curve in the opposite direction of blade rotation.
In some embodiments, the impeller is formed in one piece.
In some embodiments, the impeller comprises a radius of between 15 and 60 mm.
In some embodiments, the impeller has a mass of less than 2 grams and preferably between 0.8 and 1.8 grams.
In some embodiments, the impeller is configured to have a pressure to inertia to radius ratio greater than 50:1 Pa per gram*mm, and preferably greater than 80:1 Pa per gram*mm.
In some embodiments, the impeller is configured to have a moment of inertia to radius ratio less than 15 g*mm and preferably within the range of 8 to 12 g*mm.
In some embodiments, the impeller is configured to have a blade sweep volume to a blade volume ratio of 16:1 or greater.
Preferably, the blower unit may further comprise a casing having upper and lower internal surfaces that enclose the impeller, and wherein the impeller has a plurality of blades that are substantially open to the upper and lower internal surfaces of the casing by virtue of being shroudless or otherwise having reduced material. In one form, the casing forms part of or is integrated with the respiratory assistance apparatus.
Preferably, the blower unit may further comprise a partition to define first and second interior regions within the casing, the first region being defined by the casing and the partition and comprising the gases inlet and motor, the second region being defined by the casing and the partition and comprising the impeller, and wherein the first and second regions are fluidly connected by an opening formed in or by the partition.
Preferably, the impeller may have an axis of rotation, the partition extending radially from the axis of rotation.
Preferably, the casing of the blower unit may further comprise a volute that is fluidly connected to the second region by an air passage, and wherein the gases outlet of the blower unit is proximate the periphery of the volute.
In a first form, the blower unit may comprise a motor comprising: a stator, and at least one bearing structure to support the rotatable drive shaft within the stator, the bearing structure comprising one or more bearings that are supported by one or more bearing mounts about the axis of the rotatable drive shaft, Preferably the bearing mount(s) provide compliant support to the rotatable shaft.
Preferably, the stator may comprise a stator frame, and an outer portion of the one or more bearing mounts engages the stator and/or an inner surface of the stator frame. In one form, an outer portion of the one or more bearing mounts engages the stator and/or a stator frame and/or other structure.
Preferably, the blower unit may further comprise a motor mount that couples the stator and the casing to provide compliant support to the motor.
Preferably the bearing mount and/or motor mount are flexible and/or resilient.
Preferably the bearing mount is made from a material that provides resilience and/or flexibility to provide preload when in the engaged configuration.
Preferably the bearing mounts are made from a material that provides damping.
Preferably, the bearing mounts may be flexible and/or resilient, and wherein the bearing mounts may have a curved annular body and when engaged with the stator and/or stator frame the annular body is coerced into an engaged configuration that provides preload to the one or more bearings.
Preferably the motor is operated using field oriented control.
In one form, the rotatable drive shaft may be plastic. Preferably, the motor may further comprise a rotor within the stator, and wherein the plastic rotatable drive shaft is formed and coupled to the rotor by injection moulding. In one form, Preferably the motor comprises a plastic rotatable shaft extending through an opening in a magnet rotor and being coupled thereto.
Also described is a method of manufacturing a shaft and rotor assembly for a motor comprising: inserting a rotor with a central opening into a first mould part, supporting a shaft extended through the central opening, coupling a second mould part to the first mould part to create a mould cavity around the central opening, injection moulding a plastic insert between the plastic shaft and the central opening to couple the plastic shaft to the rotor.
Also described is a method of manufacturing a shaft and rotor assembly for a motor comprising: inserting a rotor with a central opening into a first mould part, coupling a second mould part to the first mould part to create a mould cavity around the central opening, injection moulding a plastic shaft that extends through and couples to the central opening of the rotor.
In a second form, the blower unit comprises: a motor comprising a rotatable shaft located within a stator, a bearing structure to support the rotatable shaft in the stator, the bearing structure having one or more bearing mounts.
In a third form, the blower unit may comprise: a centrifugal impeller driven by a motor within a casing, the casing having a gases inlet, a gases outlet and a partition (or divider) to define first and second interior regions wherein the first and second regions are fluidly connected by an opening in the partition.
In a fourth form, the blower unit may comprise: a motor with a rotatable shaft and at least one bearing structure to support the rotatable shaft within a stator, the bearing structure having one or more flexible and/or resilient bearing mounts to provide compliance and/or preload and/or damping for the rotatable shaft, a lightweight impeller coupled to the rotatable shaft, a flexible and/or resilient motor mount that couples the stator and the housing to provide compliance and/or damping for the motor a partition to define first and second interior regions within the housing, wherein the first and second regions are fluidly connected by opening formed in or by the partition.
In a fifth form, the blower unit comprises: a gases inset, a gases outlet, a motor with a shaft, and a lightweight impeller connected to the motor and rotatable to draw gases from the inlet and emit gases through the outlet, wherein the impeller is shroudless or otherwise has reduced material.
Each of the forms of the blower unit may additionally comprise any one or more features mentioned in respect to the other forms of the blower unit.
Preferably, the respiratory assistance apparatus comprises an operable control system having an onboard controller that is configured to control the blower unit to deliver the pressurised gases stream to the user at the desired pressure and/or flow rate during the user's breathing cycle. By way of example, the apparatus may comprise an onboard electronic controller that is mounted to or within the respiratory assistance apparatus and which is operable to control the pressure of respiratory gases delivered to the user by controlling the motor speed within the blower unit.
Preferably, the apparatus may further comprise one or more sensors mounted to or within the respiratory assistance apparatus that are configured to sense operational parameters and generate representative sensor signals for sending to the controller.
Preferably, the apparatus may further comprise an onboard wireless power transfer receiver that is configured to receive power from a wireless power transfer transmitter.
Preferably, the apparatus may further comprise an onboard power supply module.
In one form, the blower unit may be releasably mounted to the main body. In another form, the blower unit may be integrated with or fixed to the main body.
In one form, the main body may comprise: a forehead support member that is configured to engage with the user's forehead; a mask body for receiving a mask seal assembly of the patient interface; a connecting member extending between the forehead support member and mask body, and a gases inlet that is fluidly connected to the gases outlet of the blower unit. Preferably, the forehead support member of the main body may be horizontally oriented and the connecting member extends centrally from the forehead support member in a vertical orientation such that the members together form a T-shaped part (or T-piece), and wherein the blower unit is mounted to the T-shaped part. In one form, the blower unit may be provided on or may be mounted to the forehead support member of the main body such that it is located in the user's forehead region when in use.
In one form, the apparatus is configured as a positive airway pressure (PAP) device. For example, the apparatus may be configured to operate as a CPAP device, Bi-PAP device, or any other PAP device.
In one form, the patient interface is releasably mounted to the main body. In another form, the patient interface is integrated with or fixed to the main body.
In one form, the patient interface may comprise a nasal mask that is configured to sealingly engage with the user's face so as to cover their nose.
In another form, the patient interface may comprise any one of the following: a full face mask configured to sealingly engage with the user's face so as to cover their nose and mouth; a nasal pillows mask that sealingly engages the user's nostrils; an unsealed nasal cannula that is configured to be positioned inside the user's nostrils; or an oral interface that is configured to sealingly engage with or within the user's mouth.
Preferably, the main body may further comprise a gases passage or conduit that fluidly connects the gases outlet of the blower unit to the gases inlet of the patient interface, and wherein the gases passages forms part of the gases flow path.
In one form, the main body may be configured to mount or locate the blower unit in the forehead region of the user's face and patient interface in the nose and/or mouth region of the user's face, when the apparatus is worn in use. Alternatively, the blower unit may be fixedly or releasably mounted to the front of the patient interface (e.g. mask).
In a second aspect, the invention broadly consists in a base station that is operatively connectable to a head-mounted respiratory assistance apparatus configured to provide a respiratory gases stream to a user, the head-mounted respiratory assistance apparatus comprising: a main body securable to the head of a user; a blower unit provided on the main body having a gases inlet to receive a supply of oases from the surrounding atmosphere and which is operable to generate a pressurised gases stream at a gases outlet; and a patient interface provided on the main body having a gases inlet which is fluidly connected via a flow path to the gases outlet of the blower unit and which is configured to deliver the pressurised gases to the user's nose and/or mouth via one or more gases outlets, the base station comprising: a power supply system that is operable to supply power to the respiratory assistance apparatus; a data transfer system that is operable to send and receive data to and from the respiratory assistance apparatus; and a control system that is operable to control the respiratory assistance apparatus via control signals.
In one form, the power supply system may be configured to transfer power to the respiratory assistance apparatus via one or more power transfer cables.
In another form, the power supply system may comprise wireless power transfer circuitry that is configured to transfer power to the respiratory assistance apparatus wirelessly.
Preferably, the data transfer system may comprise a first communication module that is operable to transfer data between the base station and the respiratory assistance apparatus over a wired or wireless communication medium.
Preferably, the data transfer system may further comprise a second communication module that is operable to transfer data between the base station and an external server over a wired or wireless communication medium.
Preferably, the control system may be operable to send control signals to the respiratory assistance apparatus to control any one or more of the following operational modes: on/off mode, charging mode, drying mode, and/or data transfer mode.
In one form, the control system may be configured to automatically send control signals to the respiratory assistance apparatus to control one or more operational modes based on whether an operative connection between the base station and the respiratory assistance apparatus is detected.
In a third aspect, the invention broadly consists in a respiratory assistance system comprising: a head-mounted respiratory assistance apparatus configured to provide a respiratory gases stream to a user, the head-mounted respiratory assistance apparatus comprising: a main body securable to the head of a user; a blower unit provided on the main body having a gases inlet to receive a supply of gases from the surrounding atmosphere and which is operable to generate a pressurised gases stream at a gases outlet; and a patient interface provided on the main body having a gases inlet which is fluidly connected via a flow path to the gases outlet of the blower unit and which is configured to deliver the pressurised gases to the user's nose and/or mouth via one or more gases outlets; and a wireless power supply system that is configured to supply power wirelessly to the respiratory assistance apparatus.
Preferably, the wireless power supply may be configured to supply power to the respiratory assistance apparatus for powering of the blower unit.
Preferably, the respiratory assistance apparatus may comprise one or more sensors that are configured to sense various operational parameters and generate representative sensor signals, and wherein the wireless power supply is configured to supply power to the sensors.
In a fourth aspect, the invention broadly consists in a respiratory assistance system comprising: a head-mounted respiratory assistance apparatus configured to provide a respiratory gases stream to a user, the head-mounted respiratory assistance apparatus comprising: a main body securable to the head of a user; a blower unit provided on the main body having a gases inlet to receive a supply of gases from the surrounding atmosphere and which is operable to generate a pressurised gases stream at a gases outlet; and a patient interface provided on the main body having a gases inlet which is fluidly connected via a flow path to the gases outlet of the blower unit and which is configured to deliver the pressurised gases to the user's nose and/or mouth via one or more gases outlets; and one or more wireless sensors mounted to or within the respiratory assistance apparatus that are configured to sense operational parameters and generate representative sensor signals.
Preferably, the one or more wireless sensors may be configured to transmit, directly or indirectly, the generated sensor signals wirelessly to a separate external device or system.
Preferably, the one or more wireless sensors may be powered wirelessly by a wireless power transfer system that is wirelessly connected to the respiratory assistance apparatus
In a fifth aspect, the invention broadly consists in a respiratory assistance system comprising: a head-mounted respiratory assistance apparatus configured to provide a respiratory gases stream to a user, the head-mounted respiratory assistance apparatus comprising: a main body securable to the head of a user; a blower unit provided on the main body having a gases inlet to receive a supply of gases from the surrounding atmosphere and which is operable to generate a pressurised gases stream at a gases outlet; and a patient interface provided on the main body having a gases inlet which is fluidly connected via a flow path to the gases outlet of the blower unit and which is configured to deliver the pressurised gases to the user's nose and/or mouth via one or more gases outlets; and a wireless communication module onboard the respiratory assistance apparatus that is operable to receive and send data to external devices and/or systems.
Preferably, the respiratory assistance apparatus comprises one or more sensors that may be configured to sense operational parameters and generate representative sensor signals, and wherein the communication module is configured to send the generated sensor signals to a separate external device or system.
Preferably, the respiratory assistance apparatus may comprises an onboard electronic controller that is configured to store usage data indicative of the user's use of the respiratory assistance apparatus, and wherein the communication module is configured to transfer the usage data wirelessly to a separate external device or system.
In a sixth aspect, the invention broadly consists in a head-mounted respiratory assistance apparatus configured to provide a respiratory gases stream to a user, the head-mounted respiratory assistance apparatus comprising: a main body securable to the head of a user; a blower unit provided on the main body having a gases inlet to receive a supply of gases from the surrounding atmosphere and which is operable to generate a pressurised gases stream at a gases outlet; a patient interface provided on the main body having a gases inlet which is fluidly connected via a flow path to the gases outlet of the blower unit and which is configured to deliver the pressurised gases to the user's nose and/or mouth via one or more gases outlets; and a head-mounted power supply that is configured to supply power to the respiratory device.
In another aspect, also described is a head-mounted respiratory assistance apparatus configured to provide a respiratory gases stream to a user, comprising: a main body securable to the head of a user; a blower unit provided on the main body having a gases inlet to receive a supply of gases from the surrounding atmosphere and which is operable to generate a pressurised gases stream at a gases outlet; and a patient interface provided on the main body having a gases inlet which is fluidly connected to the gases outlet of the blower unit and which is configured to deliver the pressurised gases to the user's nose and/or mouth.
In some embodiments, the respiratory assistance apparatus may be configured to provide a bias flow and may comprise one or more gas washout vents in the vicinity of the patient interface through which a portion of exhaled gases may exit the respiratory assistance apparatus. In other embodiments, the respiratory assistance apparatus may be configured to have zero bias flow.
In another aspect, also described is a respiratory assistance system comprising: a head-mounted respiratory assistance apparatus according to any of the above aspects; and a base station that is configured to receive and retain the respiratory assistance apparatus when not in use.
Each aspect of the invention above may additionally have any one or more of the features mentioned in respect of the other aspects.
The phrase “bias flow” as used in this specification and claims is intended to mean, unless the context suggests otherwise, the deliberate or controlled leak or flow of gases from the respiratory assistance apparatus to the surrounding atmosphere from one or more gas flushing vents or gas washout vents provided on the respiratory assistance apparatus and which are fluidly connected with or provided at or along a portion of the air or gases flow path within the apparatus.
The phrases “zero bias flow” or “zero bias” as used in this specification and claims is intended to mean, unless the context suggests otherwise, nil bias flow or in some embodiments minimal bias flow of not greater than 5 litres per minute.
The term “comprising” as used in this specification and claims means “consisting at least in part of”. When interpreting each statement in this specification and claims that includes the term “comprising”, features other than that or those prefaced by the term may also be present. Related terms such as “comprise” and “comprises” are to be interpreted in the same manner.
It is intended that reference to a range of numbers disclosed herein (for example, 1 to 10) also incorporates reference to all rational numbers within that range (for example, 1, 1.1, 2, 3, 3.9, 4, 5, 6, 6.5, 7, 8, 9 and 10) and also any range of rational numbers within that range (for example, 2 to 8, 1.5 to 5.5 and 3.1 to 4.7) and, therefore, all sub-ranges of all ranges expressly disclosed herein are hereby expressly disclosed. These are only examples of what is specifically intended and all possible combinations of numerical values between the lowest value and the highest value enumerated are to be considered to be expressly stated in this application in a similar manner.
As used herein the term “and/or” means “and” or “or”, or both.
As used herein “(s)” following a noun means the plural and/or singular forms of the noun.
The invention consists in the foregoing and also envisages constructions of which the following gives examples only.
Preferred embodiments of the invention will be described by way of example only and with reference to the drawings, in which:
The invention relates to a respiratory assistance apparatus (respiratory device) that is capable of supplying a flow or stream of respiratory gases to a user or patient for respiratory therapies. An embodiment of the respiratory device that is configured as a CPAP respiratory device will be described by way of example, although it will be appreciated that the respiratory device may be adapted or configured for other PAP therapies, including but not limited to Bi-PAP therapy, or any other suitable respiratory therapy that employs the delivery of a flow of gases to a user.
WearableReferring to
The blower unit 24 comprises a rotatable impeller that is configured to draw or suck in surrounding atmospheric gases or air through a blower gases inlet 28 and then pressurise those gases into a supply or stream of pressurised gases. As will be appreciated by those skilled in CPAP devices and therapy, the blower unit 24 comprises a controllable variable speed fan unit that is controllable by one or more control signals to generate the desired level of flow and/or pressure of gases at the mask 26.
The blower unit 24 is fluidly connected or in fluid communication via an airway or gases passage with the mask 26 such that pressurised gases generated by the blower unit 24 can flow into the internal cavity 30 (see
Headgear (not shown in
The respiratory device 20 has an onboard electronic controller (such as a microcontroller, microprocessor or similar) or control system that is mounted to or within the blower unit 24, main body 22 or another part of the respiratory device. As well as other functionality, the electronic controller is primarily configured to control the pressure of respiratory gases delivered to the user by controlling the motor speed within the blower unit 24 as will be appreciated by those skilled in the art of CPAP respiratory devices. For example, the blower unit in use is set to a user-specified pressure level and/or the pressure level can be automatically controlled. The flow rate for the preferred embodiment will vary during use, depending on the users breathing. The power to blower unit can be altered, to change the speed at which the impeller is rotating, and therefore the pressure.
The electronic controller may be controlled by an onboard user interface or control panel comprising one or more switches, buttons, dials, touch screen control panels provided on the respiratory device. Additionally or alternatively, the onboard controller may be operable or controlled remotely by an external control device (e.g. a remote control, Personal Computer, portable communication device such as smart phone running a smart phone application, or any other programmable device, portable or otherwise) that communicates with the onboard controller via a wireless communication medium, such as RF communication, Bluetooth, Wi-Fi, infrared, or any other wireless communication standard or technique.
In some embodiments, the controller may be configured to employ sensorless vector control (also known as field-oriented control) of the motor in the blower unit.
The control system may comprise one or more sensors within the respiratory device that are configured to sense various operational parameters and generate representative sensor signals for the controller. For example, in some embodiments the respiratory system may comprise a flow rate sensor and/or a pressure sensor in the air flow path. The sensed signals are processed by the controller and used to control the motor in the blower unit to deliver the desired pressure and/or flow to the user as is known to those skilled in the art of CPAP respiratory devices.
The control system may also include additional sensors such as EEG, humidity, temperature, or accelerometers, to provide additional features or benefits as required.
The sensors may be hardwired or wireless, or a combination of these. In some embodiments, the sensors may be hardwired to the onboard power supply module or alternatively powered wirelessly by a wireless power transfer system in connectivity range. In some embodiments, the sensors are hardwired to the onboard controller such that the controller receives the sensor signals and/or sensor data generated. Additionally or alternatively, the sensors may be configured to transmit their sensor signals or sensor data wirelessly to the onboard controller or directly to an external system or device in connectivity range.
Power SupplyThe respiratory device 20 is preferably powered by an onboard power supply package or module that is head-mounted. The power supply module may be in the form of an energy storage device or devices such as, but not limited to, a battery package comprising one or more batteries, which are typically but not necessarily rechargeable, a fuel cell, capacitor, or any other suitable energy storage device. The power supply and associated power circuitry may be mounted to or within the respiratory device, such as to or within the blower unit 24 or main body 22, or may be mounted to or integrated with the headgear or any other part of the respiratory device. Additionally or alternatively, the power supply module may be non-head mounted but otherwise portable and wearable and which can be connected to the respiratory device by a power cable or other hardwiring. In such embodiments, the power supply module may be carried or worn e.g. carried in a pocket of the user's clothing or belt-mounted for example, if the user is moving. Otherwise, the power supply module may be placed down in a convenient location near the user if desired. Typically, the power supply module is a DC power supply. Additionally or alternatively, the respiratory device may also be configured for optional connection to an AC power adaptor that connects to an AC mains power supply and converts it to a DC power supply for the respiratory device. The power supplied by the AC power adaptor may also be configured to re-charge any battery power supply modules onboard the respiratory device.
If the power supply module is a rechargeable energy storage device, such as a rechargeable battery pack or comprises rechargeable batteries, it may be recharged by either a wired or a wireless charging system, including but not limited to inductive power transfer, some examples of which will be explained later with reference to
It will be appreciated that in some embodiments the respiratory device may be battery-less (i.e. not have an onboard power supply module) and may be powered directly be an AC power adaptor above or alternatively powered via a wireless power transfer system, as will be discussed later.
Passive HumidificationIn this embodiment, the respiratory device 20 is configured to provide passive humidification and warming or heating of the respiratory gases using accumulated moisture or humidity within the mask cavity and remaining volume of the air flow passage or path within the respiratory device that is created by the user's exhaled breath. This passive humidification may also heat the respiratory gases. This passive humidification method eliminates the requirement for active humidification, which is typically carried out by a conventional humidification unit comprising a humidification chamber after the blower unit as is known in conventional CPAP therapy respiratory devices. In some embodiments, one or more heat and moisture exchangers (HMEs) may also be provided in the air flow path to further enhance the passive humidification recycling effect.
In some embodiments, mask condensation control/reduction methods may be employed. This includes, but is not limited to, permeable mask materials, drip collection systems, and heating of the mask surface.
Zero Bias FlowIn this embodiment, the respiratory device 20 does not employ a bias flow to assist in expelling exhaled gases from the user as is known in conventional CPAP therapy respiratory devices as described with reference to
In other embodiments, the respiratory device may be configured to optionally provide a ‘reduced’ or small amount of bias flow, typically at a reduced level relative to that provided in conventional CPAP therapy respiratory devices of
In some embodiments, additional heating of the respiratory gases may be provided in the blower unit 24 where heat dissipated from the motor and control circuitry acts to heat the incoming respiratory gases above the ambient temperature by forced convection heat transfer.
Base StationIn this embodiment, the respiratory device is also optionally provided with a separate base station configured to supply power to the respiratory device for operation and/or charging of any onboard energy storage devices, such as battery packs or similar. The base station may additionally be configured to provide data communication for compliance data transfer and/or may be configured as a docking station or mounting stand upon which the respiratory device may be docked or mounted or otherwise stored when not in use. The base station may be a unit or assembly that is configured to either rest on a flat surface, such as a table, or alternatively may be wall-mounted or fixed to any other structure in a convenient location. The base station may be provided with or control an integrated or separate power module or system that is configured to connect to the respiratory device and power it during operation and/or recharge any onboard power supply, either when it is docked or otherwise in connectivity range. The power system may be via a hardwired cable connection to the respiratory device or a wireless energy transfer system (such as but not limited to electromagnetic induction power transfer, electromagnetic radiation power transfer, or the like). The base station may additionally or alternatively provide other optional features and functionality such as communication modules for compliance data transfer, memory stick interface, calibration, drying, cleaning, clock radio, music player. By way of example only, various base station embodiments are described later with reference to
In some embodiments, some or all of the elements or components of the respiratory assistance apparatus may be disposable or replaceable, including but not limited to the mask or mask assembly, blower unit, and main body, themselves or components thereof.
In some embodiments, either or both of the blower unit and patient interface may be modular components that are releasably or removably mounted or attached to the main body such that different patient interfaces or blower units of different type, specification, size or any other characteristic may be connected to the main body to vary or customize the operation, capability, specification, characteristics, and/or functionality of the respiratory device to suit a particular application or end user requirements.
In some embodiments, the respiratory assistance apparatus may be provided or configured as a snoring treatment device by operating in a limited pressure range, for example 1-4 cmH2O. In such embodiments, the size of the respiratory assistance apparatus would be smaller than a device configured for PAP therapy.
In some embodiments, the respiratory assistance apparatus may be configured to operate in a diagnostic mode, for use either in the home or a sleep clinic. In such embodiments, the respiratory assistance apparatus may have one or more additional sensors (EEG, accelerometer, SpO2 etc).
In some embodiments, the respiratory assistance apparatus may be switchable to a “zero pressure” or “low pressure” mode, on detection of the patient being awake, or by patient manual intervention, e.g. by pressing a button on the device, or by detection of head or body movements that indicate an awake state.
In some embodiments, multiple different models of the respiratory assistance apparatus may be provided, each configured to operate at a specific limited pressure range, to minimise weight and size of the apparatus for each pressure range, and each having a blower unit and power supply that is optimised for the model's target pressure range. For example, in one embodiment three separate models may be provided, covering pressure ranges of 4-10, 8-14, and 12-20 cmH2O respectively.
Main Body and Mask AssemblyReferring to
In this embodiment, the forehead support 32 is substantially elongate in the horizontal direction and extends between a first end 38a and second end 38b. At or toward each end is provided a connection aperture 40 to which respective ends of a headstrap may be releasably or fixedly connected or coupled. The forehead support 32 is also provided with one or more mounting apertures 42 to which one or more pads or cushions 44 may be releasably or fixedly mounted on the user-facing side of the main body 22. In this embodiment, a pair of mounting apertures 42 each located toward a respective side of the forehead support 32 relative to the centre are provided for receiving and retaining respective cushion members 44 (see
In this embodiment, the mask body 34 of the main body 22 forms an internal cavity 30 (see
In this embodiment, a mask 26 or mask seal assembly is configured to be releasably mounted to the mask body 34. Referring to
In this embodiment, the front side of the mask body 34 is provided with one or more dips 52 (see
In this embodiment, the blower unit 24 is mounted to the main body 22 such that it is located in the user's forehead region when in use. For example, the blower unit 24 is provided on or mounted to an upper part or portion of the main body, such as on or to the T-piece. In this embodiment, the blower unit 24 is mounted to the forehead support 32 or in the forehead support region of the T-piece, and is typically centrally located relative to the sides of the main body.
In this embodiment, the blower unit 24 is releasably mounted to the main body 22. The forehead support member 32 is provided with a central mounting aperture 54 (see
The bottom or underside of the blower unit 24 is provided with a gases outlet (see
Embodiments of the blower unit 24 of the respiratory device 20 will now be described in further detail with reference to
The front side or surface of the casing comprises one or more apertures or openings 64 that form a gases inlet. In this embodiment, the gases inlet 64 is a circular hole or aperture located in approximately the centre of the front side or surface of the casing 60 and passes from the outside of the casing to the inside. In use, the front face of the blower unit 24 faces away from the user and atmospheric air is drawn into the casing of blower unit via the gases inlet 64 where it is then pressurised by the rotating impeller to generate a pressurised gases stream at the gases outlet of the blower unit. While the predominant direction of flow of the respiratory gases is from the gases inlet 64 of the blower unit to the gases outlet 58 of the blower unit and into the mask body 22 for receiving by the user via the mask 26, a reverse flow also exists in the opposite direction during the user's respiratory cycle during expiration in which exhaled gases may flow back through the mask 26 and exit the respiratory device from the gases inlet 64 of the blower unit back into the atmosphere. Therefore, the gases inlets/outlets referred to are hi-directional in that they do not restrict flow in any particular direction. In this embodiment, the gases inlet 64 comprises a filter 66, which may be a foam material that has a dual purpose of filtering incoming air, and acting as a heat and moisture exchanger (HME). In alternative embodiments, the gases inlet need not necessarily comprise a filter. The rear side or surface of the casing which in use faces the user comprises a mounting protrusion or formation 56 (see
The blower unit casing 60 houses a motor that is configured to rotate or drive an impeller, also mounted in the casing. In this embodiment, the blower unit comprises a lightweight/low inertia impeller. The lightweight nature of the impeller provides the low inertia. In use, the blower unit 24 may be controlled or set to deliver respiratory gases at a user-specified flow rate and/or pressure level. The flow rate during use may vary depending on the user's breathing. The power delivered to the motor of the blower unit can be varied by control signals from the controller to change the speed at which the impeller is rotating and therefore the flow rate and/or pressure of the respiratory gases at the mask 26.
Referring to
The motor assembly 80 is mounted in the upper region 82 of the casing 60 which is defined between the front side of the casing, comprising the gases inlet 64 and filter 66, and the divider 84 as shown in
In an alternative embodiment, the aperture in the divider 84 through which gases flow through between the upper region and lower region may be an opening located at or close to the outer edge of the divider. For example, the opening may be a cut-away in the partition layer 84 or some other configuration/shape of the casing such that the combination/arrangement of the partition layer 84 and the casing creates an aperture/opening between the two. The cut-away could form a circumferential aperture between the casing and partition 84, for example. The curvature/centre of radius of the circumferential aperture is preferably offset from the centre of radius of the partition layer 84 or otherwise has a curvature that differs from that of the circumference of the partition 84 resulting in an eccentric or otherwise offset circumferential aperture around the circumference of the partition. This produces an aperture with a crescent (“smile”) opening that spans a leading edge to a trailing edge. However, the aperture may be of any shape with a gradual opening and closing relative to the plane of impeller rotation. The aperture allows for gradual supply of pressure and flow from the high static pressure source at the top of the blower. The angle of the aperture opening and closing is tuned to allow for reverse flow to return through the system in a stable fashion. It also contributes to the blade pass noise reduction by not having a sharp break in geometry.
The impeller 90 is mounted in the lower region 92 of the casing 60 which is defined between the rear side of the casing and the divider 84 as shown in
In this embodiment, the gases outlet of the blower unit 24 extends outwardly from the peripheral wall 72 of the casing. Referring to
Reverting to
It will be appreciated that the gases pathway from the gases inlet 64 of the casing 60 to the lower region 92 where the impeller 90 is situated may be provided in other ways and need not necessarily flow through the upper region 82 where the motor is located. For example, in an alternative embodiment the gases inlet may be provided on the rear side of the casing adjacent the impeller in the lower region 92.
OperationDuring operation of the blower unit 24, rotation of the impeller 90 by the motor 80 draws gases through the gases inlet 64 and into the upper region 82 of the casing and through the motor assembly 80 to the central aperture 86 of the divider 84. The air drawn through the motor assembly 80 can also act to cool the motor. The shroudless impeller enables air to be drawn through the motor in this manner to thus providing cooling. The gases flow through the aperture 86 into the lower region 92 and through the blades of the impeller toward the peripheral side wall 72 of the casing in the lower region. The impeller blades impart strong rotational forces to the gases circulating in the lower region 92 of the blower casing to thereby create high circulating gas speeds. Gases in the lower region 92 will naturally flow through the air passage 94 into the volute 96 due to pressure differential between regions. When the gases in the lower region 92, having a high velocity and low pressure, enter the volute 96, the gas velocity drops and the pressure increases. Typically, the volute 96 has a greater volume than the lower region 92 to help facilitate this gases pressure increase.
By dividing the blower internal space into separate regions a number of advantages can be realised. In a conventional blower, high velocity gases leaving the impeller are incident to an edge, or tongue, that defines a physical boundary where gases are split from the volute to enter the outlet passage. High velocity gas flow incident at the tongue is turbulent and inefficient to blower performance. The turbulence caused by the tongue also introduces a source of noise. In contrast, dividing the casing of the blower unit into separate but connected gases regions reduces the impact caused by the tongue. The lower region 92 allows the gases to circulate at a high speed. The gases path or passage 94 provides a fluid path to the volute 96 that is free from aerodynamically turbulent edges. When circulating gases have entered the volute region 96, the enlarged volume of the volute encourages the gases to slow and increase in pressure. The reduced gases velocity reduces the impact of turbulence normally caused by the tongue to a low or negligible level. The blower unit is therefore able to operate across a wide pressure and flow range with substantially reduced noise output when compared to other blowers, A wider passage 94 increases the flow rate of the volute relative to the lower region. Therefore, the size of the passage 94 is selected according to the desired flow rate and pressure range of the blower unit.
ImpellerA first embodiment of the impeller 90 is shown in
The blades 98 preferably provide a substantially flat surface, from the hub 100 to the blade tip, and incident the direction of rotation indicated by arrow R to thereby centrifuge gases. In this embodiment, the blades 98 are arcuate or curved from the hub 100 to the blade tips and the curve is preferably backward swept in the opposite direction of impeller rotation indicated by arrow R. The impeller is a backward facing impeller in that each blade 98 extends from the hub 100 in a direction backward of its associated radii extending from the hub, relative to the direction of the impeller rotation R. For example, blade 99 is shown extending backwardly relative to its associated radii X in
A second embodiment of the impeller 90a is shown in
It will be appreciated that the impeller of the blower unit may be implemented with any suitable blade profiles, whether forward, backward or radial blades, or any other suitable profile.
In either embodiment, the impeller 90, 90a is constructed to be lightweight. Preferably, this is by making the impeller shroudless, or at least partially shroudless, thereby removing weight. To achieve a lightweight impeller, as shown in
Alternatively, a shroud 101 with some of the material removed, such as shown in the third embodiment impeller 90b of
A lightweight impeller provides benefits such as manufacturing cost, low rotational inertia and is balanced or requires little effort to rotationally balance once manufactured. An impeller with low rotational inertia can be quickly accelerated and decelerated. A lightweight, shroudless impeller is therefore suited for quickly responding to fluctuating pressure requirements, such as the normal inhalation and exhalation cycle of a patient connected to the breathing assistance device in which the impeller operates. In other embodiments, the impeller need not necessarily be lightweight.
For example, a conventional shrouded impeller commonly used on a breathing assistance device, weighing approximately 17 grams and having inertia of 6 kg·mm2, can respond to pressure fluctuations of 10 cmH2O in approximately 2 seconds. By contrast, an impeller in accordance with either embodiment 90,90a, weighing approximately 1.7 grams and inertia of 0.5 kg·mm2, responds to pressure fluctuations of 10 cmH2O in approximately 100 ms.
As mentioned, the lightweight can be achieved by omitting a shroud. However, it is not necessary to omit the entire shroud—rather just sufficient shroud to bring the weight of the impeller to a suitable level such as shown in
The lightweight impeller can have a weight for example of less than 2 grams and preferably between 0.8 and 1.8 grams, or more preferably, between 1.2 and 1.7 grams, or even more preferably 1.7 grams. These are just examples of a preferred embodiment and the impeller need not be this weight, but some other weight that renders it lightweight.
Alternatively, a lightweight impeller can be designed to remove as much of the shroud as necessary to bring the moment of inertia to radius ratio down to preferably less than 15 gram*mm, and more preferably between 8-12 gram*mm and in one possible embodiment approximately 11 gram*mm. For example, in one possible embodiment, such an impeller can have a radius of 35 mm, a circumference of 219 mm, and at 15,000 rpm a moment of inertia of 344.22, a tip speed of 54.98 m/s, a pressure of 1,800 Pa and a tip speed to inertia to radius ratio of 3.5 or more and for example 5.59, More generally, a lightweight impeller could have dimensions/parameters within the following ranges (note these ranges are indicative—not limiting): Radius: 15 mm-60 mm; Weight: less than 2 grams; A pressure ratio to inertia to radius ratio of greater than 50:1 Pascals per gram*mm and preferably 80:1 Pa per gram*mm or more at 1,000 Pa.
S The lightweight nature of the impeller can be achieved through removing mass through any suitable means, such as removing the shroud and/or material from the impeller and/or using lighter materials. One possible manner in which to reduce impeller mass is to reduce the number of blades.
MotorReferring to
The drive shaft 110 is held within the motor by a bearing structure. Preferably the bearing structure has one or more bearings 116 and one or more bearing mounts 118. The bearing mounts 118 as shown engage with the bearings 116 on an inner surface and with the stator assembly on an outer surface. The preferred engagement of the bearing mounts to the bearings and the stator assembly is frictional. To promote a frictional engagement, the bearing mounts 118 are made of a soft, yet resilient and/or flexible material such as silicone rubber or other elastomeric material. The material can be low creep, temperature stable, low compression set with a high tan delta (highly viscous), highly damped. Examples comprise:
-
- Dough Moulding Rubbers like—NBR, Nitrile and Flouro silicone;
- Thermo Plastic Elastomers (TPE's) like Santoprene by Exxon;
- Thermo Plastic Urethanes like Dynaplast by GLS Corporation;
- Heat Cured Casting Urethanes like 10T90 by National Urethanes; and
- Multiple other cold cast rubbery compounds like RTV (Room Temperature curing Vulcanites) by Dow Corning, Whacker and others.
Such materials allow the bearing mounts 118 to compress when installed, then expand into their chosen location to be held in place by engagement expanded dimension with a restriction. The mounts 118 are optionally restrained by respective overhangs 119 provided on upper 120a and lower 120b stator mounts (bobbins) of the stator assembly or stator frame between which the stator 114 is sandwiched. The stator frame may be configured as an electrical insulator/isolator. Similarly, the bearings 116 may be restrained by an overhang 118a formed as part of the bearing mounts 118. Either or both of the overhangs may be discretely positioned about the inner and outer annulus of the bearing mounts, or alternatively, extends around the circumference of the mount to define a recess in which the mount is located.
The bearing mounts 118 provide compliance to the rotatable drive shaft 110. As rotatable objects, such as the rotor 112, shaft 110 and impeller 90 usually suffer from some degree of rotational imbalance, the bearing mounts are able to isolate inherent rotation induced vibration from the motor rotor. It has been found that the combination of the lightweight, shroudless impeller having a low rotational inertia, as described above, together with the given compliance of the bearing mounts enables the rotor 112, shaft 110 and impeller 90 to be manufactured and any post manufacture balancing process for the rotating components entirely omitted. These advantages benefit manufacturing costs and time. The lightweight nature of the impeller allows any imbalances to be compensated by the bearing mounts. A lightweight impeller also allows faster speed response of the impeller to changing conditions. Any unwanted fluctuations in pressure due the lack of shroud can be compensated for by quickly changing the impeller speed to return pressure to the desired level.
It should be noted that while
To provide further vibration damping of the rotational components of the blower, the motor and impeller, can optionally be mounted on a compliant mounting device.
A second embodiment of the motor and impeller assembly is shown in
Referring to the plan view of one of the laminations 240 in
The shaft 160 is held within the motor by a bearing structure. Preferably the bearing structure has one or more bearings 164 and one or more bearing mounts 260 (see
The bearing mounts 260 provide compliance to the rotatable shaft 160. As rotatable objects, such as the rotor 162, shaft 160 and impeller 90a usually suffer from some degree of rotational imbalance, the bearing mounts are able to isolate inherent rotation induced vibration from the motor rotor. It has been found that combination of the lightweight, shroudless impeller having a low rotational inertia, as described above, together with the given compliance of the bearing mounts enables the rotor 162, shaft 160 and impeller 90a to be manufactured and any post manufacture balancing process for the rotating components entirely omitted. These advantages benefit manufacturing costs and time. The lightweight nature of the impeller 90a allows any imbalances/misalignment to be compensated by the bearing mounts 260—the arrangement is self aligning due to the bearing mount compliance (due to resilience and/or flexibility, for example). The bearing mount construction, including the geometry and material, also provides axial preload on the bearings, e.g. of up to 7 Newtons. The annular nature of the bearing provides consistent/even preload around the bearing 164. The resilient/flexible curved annular body allows the bearing to be installed in place and provide the preload. The annular nature of the bearing mount 260 provides for even preload around the bearing, while the low creep construction material maintains preload. The material of the bearing mounts. 260 is also preferably a viscoelastic damping material that provides damping, which reduces the likelihood of resonance during operation of the motor. Such a viscoelastic material can also provide the required resilience/flexibility to provide the preload. An example of such a material is a Thermo Plastic Urethane like Dynaplast by GLS Corporation. Other materials resilient and/or flexible materials mentioned above for the bearing mount 260 could be adapted to provide the required damping by adding mica. A lightweight impeller also allows faster speed response of the impeller to changing conditions. Any unwanted fluctuations in pressure due the lack of shroud can be compensated for by quickly changing the impeller speed to return pressure to the desired level. The bearing mounts also provide vibration isolation.
To provide further vibration damping of the rotational components of the blower, the motor and impeller, can optionally be mounted an a compliant mounting device (motor mount) 280.
A plurality of projections 283 encircles the upper and lower surfaces of the mount 280. The end of projection extends past the upper and lower surfaces of the mount to provide supporting leverage to the mount and motor assembly. During operation of the motor, vibration caused by any imbalance of the rotational components is absorbed by each of the projections by allowing the body of the mount 280 to move relative to the surface on which the projections 283 are supported.
The description above describes embodiments of a blower unit comprising a lightweight impeller assembly.
Alternative shaft and magnet rotor assemblies are shown in
The assembly 420 also comprises a plastic shaft 421 that extends through the centre of the insert opening 410 and is overmoulded onto the magnet rotor 401 as will described below. When overmoulded, the shaft comprises an integral overmould magnet insert portion 423. The shaft 421 can be formed to comprise a hex 422 or other location profile for press fit coupling with the impeller. The plastic shaft 421 comprises any suitable plastic or combination thereof, such as acetyl or polypropylene, although any suitable injection moulding or other plastic could be used.
The assembly 420 can be used in the embodiments described above such as in
Previously, it has not been possible to use a plastic shaft/rotor assembly in the motor of a blower of a CPAP machine or similar. A plastic shaft is not sufficiently strong to withstand the forces involved in such motors. However, in the lightweight impeller embodiments described above, the forces are such that a plastic shaft rotor becomes a possibility. The lightweight and low inertia nature of the rotor along with the compliant bearing mount and other features that reduce unbalancing forces and other forces enable the use of a plastic shaft. Both the plastic rotor assembly and the method of manufacture provide advantages over existing metal shaft rotors.
The combination of various features of the motor and impeller provide advantages, which can be achieved using a single impeller. Using a lightweight/low inertia impeller (e.g. by removing some or all of the shroud and/or reducing blade material) reduces imbalance of the impeller due to manufacturing tolerances. Previously, after manufacture and during assembly of a blower, it has been necessary to remove/add material to the impeller to improve balancing. The lightweight nature of the impeller means that any small imbalance can be tolerated without requiring rectification. Coupled to this, where the imbalance is not small enough, the resilient/flexible bearing structure mounts 118 and/or stator mount 120 can compensate for any imbalance in the impeller. As the impeller is lightweight enough, any imbalance is of a small enough magnitude to be compensated for by the bearing structure mounts 118, without the need for altering the weight of the impeller during assembly. In addition to this, small magnets in the motor (combined with the bearing structure) remove the need for balancing during assembly, and improve dynamic performance.
The resilient/flexible bearing structure allows for self-alignment, compliance, damping and preload of the impeller and shaft assembly. This makes assembly easier, and in combination with the lightweight/low inertia impeller reduce or negates the need for balancing modifications during assembly, as mentioned previously. The bearing structure provides for relaxed tolerances during manufacture as it compensates for larger tolerances. The bearing structure also isolates and/or damps vibrations, also allowing high RPM speeds of the impeller where necessary. The stator frame/motor mount also provides vibration isolation.
The configuration of the casing that separates the blower into different interior regions separates out the high velocity region to reduce noise. This allows for and maintains a constant high velocity of flow while diffusing the velocity to pressure.
The use of a plastic shaft also provides a number of benefits over a metal (e.g. steel) shaft, including (but not limited to) the following:
The reliability risks associated with dissimilar materials are reduced.
The knurled interface between the cog/dog insert and the shaft does not have to be monitored for cracking, slipping, run out, shrinkage, fluid ingress/corrosion.
The impeller to shaft interface is improved and carries similar reduced reliability risks. It is less prone to cracking because of similar thermal expansion (due to plastic on plastic press fitting). There is reduced chance of slipping because of the opportunity to add some keying feature like a hex or grooves.
The plastic shaft assembly is a press fit rather than a sliding fit so is more stable with less chance of rattles.
The cost relative to a metal shaft is reduced. This is because of the following:
Manufacturing the shaft to the tolerance for a sliding fit is not required because the plasticity of the plastic shaft allows for much wider tolerance or inaccuracy to press fit the bearings.
The need for grinding of the shaft after knurling to re-establish straightness is not required.
The handling and inserting the shaft into the mould is not required.
It is possible to use materials with better vibration absorption properties than steel.
Ease of assembly can be improved by reducing the length of the bearing press fit engagement by reducing shaft diameter with a hex, undercutting the impeller side of the shaft.
In general, the following advantages of the motor and impeller in this embodiment are provided for by the combination of one or more features as follows:
Referring to
Referring to
In this embodiment, the lower headgear strap 205 is connected to the mask body 34 of the main body 22 of the respiratory device by an elongate glider member 207. In particular, the elongate glider member extends across the front of the mask body 34 and attaches to the mask body via at least one clip 52. In this embodiment, the elongate glider member 207 may slide or glide within the clips 52 so that the mask assembly may move laterally with respect to the headgear strap 205. The lower headgear strap 205 is coupled at either end to a respective end of elongate glider member 207. In this embodiment, each end of the lower strap 205 is coupled or looped about a hook formation 207a formed at each end of the elongate glider member 207. In alternative embodiments, it will be appreciated that a fixed or static arrangement for the connection of the lower strap to the mask body may be employed.
Integrated Battery HeadgearReferring to
The batteries may be integrated within the straps 213, 215 in various ways. In one embodiment, the straps may be formed of material comprising internal pouches, pockets or chambers within which the batteries are retained. The recesses or cavities in the head straps may be sealed or openable for the removal and replacement of batteries if desired. The battery packs need not necessarily be mounted within or inside the headgear. For example, the one or more battery pack or packages may be releasably Mounted to any part of the headgear such that they are detachable from the headgear.
Typically the type and configuration of the batteries will be selected based on parameters such as energy density per volume and mass, ie, Watt-hours per kilogram, and Watt-hours per cubic centimeter. Some embodiments may employ high density batteries such as Lithium-polymer and Lithium-Ion batteries. Alternatively, it will be appreciated that non-rechargeable or disposable batteries may alternatively be employed if desired.
Referring to
In these embodiments in which the battery packs are provided in or otherwise mounted to the headgear, the headgear may also comprise one or more shielding plates that are located between the batteries and the user's head when the headgear is being worn. The shielding plate or plates provide a physical and electromagnetic shield for the user. In some embodiments, the shielding plates may be formed from a metallic material. In some embodiments, the shielding plates may be embedded inside or integrated with the headgear material for user comfort. Alternatively, the shielding plates may be fixed or releasably mounted to the headgear in other suitable ways.
Further Alternative Headgear ConfigurationsWith reference to
In overview, in various embodiments, the base stations may comprise any one or more of the following modules or systems: a power supply system that is operable to supply power to the head-mounted respiratory device; a data transfer system that is operable to send and receive data to and from the head-mounted respiratory device; and a control system that is operable to control the head-mounted respiratory device via control signals. The control system may operate automatically and/or may comprise an operable user interface to enable a user to control the head-mounted respiratory device. Each of these systems may operatively connect to the head-mounted respiratory device via hardwiring, such as a connection cable, and/or wirelessly over a wireless medium.
In some embodiments, the base station is additionally configured as a physical docking station upon which the head-mounted respiratory device may be stored and/or mounted when not in use. However, in other embodiments the base station carries out the power supply, data transfer, and/or control aspects when connected via hardwiring or in wireless connectivity range.
First Embodiment Base Station—with Separate Wireless Power Transfer MatReferring to
The base station also comprises a second communication module 303a, which communicates, either wirelessly or via a hardwired connection, with a complementary communication module 303b onboard the respiratory device. The second communication module can be used to retrieve usage compliance data from the respiratory device for storage in the base station on an integrated data storage medium and/or further transmission to an external system as above. The second communication module 303a is also operable to send control signals to configure operating parameters or settings of the respiratory device. The base station comprises a control system for generating the control signals either automatically or in response to signals generated by a user interface that is operable by a user to control such operating parameters or settings via the second communication module 303a. By way of example, the control signals may be used to initiate various operational modes of the respiratory device including, but not limited to, on/off mode in which the device is switchable between on and off, charging mode in which the onboard power supply is charged, drying mode in which the blower unit is run for a predetermined time to dry the gases flow path after use, and data transfer mode when user usage data and/or sensor data is transferred to the base station.
In some embodiments, the control system may be configured to automatically send control signals to the respiratory device to control one or more of the operational modes based on whether an operative connection (wired or wireless) between the base station and respiratory device is detected, including initiating, halting or otherwise controlling the operational modes.
The second communication module 303a may optionally be configured to receive sensor signals and/or sensor data directly from any wireless sensors onboard the respiratory device.
Removable data storage media may also be provided on either or both of the respiratory device 301 and base station 300 to enable compliance data to be transferred.
The base station may be powered by a power supply such as a standalone AC power adaptor 304 that is coupled to a mains AC voltage supply 306. It will be appreciated that AC power adaptor circuitry may be integrated into the base station in alternative embodiments.
In this embodiment, the base station provides a power supply system in the form of a connected power supply mat 305 that is configured to transfer power to the un-tethered respiratory device 301 via wireless power transfer. In use, the power supply mat 305 is located under the user's pillow when they are wearing the respiratory device while sleeping for loose-coupled power transfer. The power received from the power supply mat may be used to power the respiratory device and/or charge any energy storage device onboard the respiratory device, such as battery packs, super-capacitors, or the like. In this embodiment, power is transmitted to the respiratory device 301 from the power supply mat 305 using magnetic resonance power transfer or similar methods.
The power supply system may also optionally be configured to directly power any wireless sensors onboard the respiratory device.
Second Embodiment Base Station—with Integrated Wireless Power TransferReferring to
Referring to
In this third embodiment configuration, a power supply 304, such as an AC adaptor connectable to the AC mains voltage 306, is connectable via a power cable 327 to the respiratory device components for powering or charging, ie the respiratory device is physically plugged into the power supply for operation and/or charging of any onboard energy storage devices. The intention is for the battery to be charged while the device is not in use, however the device can be used and charged simultaneously in a tethered mode of operation as shown at 325. Similarly the battery can be removed from the headgear/blower for charging as shown at 324 or the power supply may be directly plugged into the respiratory device for battery-less use as shown at 326. The power supply connection to the battery or respiratory device may contain a breakaway electrical connection to allow the cable to pull away from the battery or device if significant strain is applied.
Fourth Embodiment Base Station—with Battery DockReferring to
The base station is powered by an AC adaptor 304 connected to the AC mains voltage supply 306, although it will be appreciated that the AC adaptor circuitry could alternatively be integrated into the base station. The base station comprises a battery dock for receiving a removable energy storage device of the respiratory device such as a battery or battery pack 331 for recharging, ie the battery is physically removed from the headgear of the respiratory device and docked into the base station to charge. A power cable 332 extends from the base station and is optionally connectable to the respiratory device for powering operation and/or charging. For example, the power cable 332 may be connected to a respiratory device 333 with an onboard battery 334 to allow tethered use of the respiratory device and simultaneous charging of the battery. Alternatively or additionally, the power cable may be plugged into a battery-less respiratory device as shown at 335 to allow tethered use of such a device. Again, the power cable connection to the battery or respiratory device may contain a breakaway electrical connection to allow the cable to pull away from the device if significant strain is applied.
Fifth Embodiment Base Station—with Integrated Wireless Power Transfer MatReferring to
Referring to
Referring to
As shown, the power transfer at 305 is connected via a cable 367 to the base station 360. This connection 367 enables the base station 360 to power the wireless power transfer circuitry of the power supply mat 305 and in addition to transmit and receive data to and from the respiratory device. In particular, the base station may send control signals to configure operating parameters or settings for the respiratory device and may retrieve usage compliance data from the respiratory device as described with reference to the first embodiment of the base station in
The power received from the power supply mat may be used to power the respiratory device and/or charge any energy storage device on board the respiratory device, such as battery packs, super capacitors, or the like, as described in the first embodiment with reference to
In this seventh embodiment, the control board 362 on board the respiratory device is shown mounted to the headgear 363 and in particular to the top headstrap in the location of the top of the user's head. The control board 362 is then connected via a cable 364 to the blower unit of the respiratory device 301 and/or any additional control circuitry in the blower unit housing. However, it will be appreciated that in alternative embodiments the control board 362 may be integrated into the main respiratory device housing rather than being mounted to the headgear as shown.
The foregoing description of the invention includes preferred forms thereof. Modifications may be made thereto without departing from the scope of the invention as defined by the accompany claims.
Claims
1-57. (canceled)
58. A head-mountable respiratory assistance apparatus configured to provide a respiratory gases stream to a user, comprising:
- a patient interface; and
- a blower unit comprising a lightweight impeller, the blower unit being fixedly or releasably mounted to the front of the patient interface and having a gases inlet to receive a supply of gases from the surrounding atmosphere and being operable to generate a pressurised gases stream at a gases outlet,
- wherein the patient interface has a gases inlet which is fluidly connected to the gases outlet of the blower unit and which is configured to deliver the pressurised gases to the user's nose and/or mouth via one or more gases outlets,
- wherein a gases flow path from the gases inlet of the blower unit to the gases outlet(s) of the patient interface is substantially sealed such that there is zero bias flow along the gases flow path, and
- wherein the apparatus is configured so that excess exhaled gases from the user vent back through the gases flow path in the opposite direction of the pressurised gases stream and exit the head-mountable respiratory assistance apparatus into the atmosphere from the gases inlet of the blower unit.
59. The head-mountable respiratory assistance apparatus according to claim 58 wherein the gases flow path volume between the gases inlet of the blower unit and the gases outlet(s) of the patient interface is less than approximately 200 mL.
60. The head-mountable respiratory assistance apparatus according to claim 58 further comprising headgear that is configured to secure the apparatus to the head of a user, the headgear comprising one or more headstraps.
61. The head-mountable respiratory assistance apparatus according to claim 60 wherein the respiratory assistance apparatus further comprises one or more onboard power supply modules that are configured to supply power to the apparatus, and wherein the power supply modules are mounted to or integrated with the headgear.
62. The head-mountable respiratory assistance apparatus according to claim 61 wherein the power supply module(s) are releasably mounted to a part of the headgear such that they are detachable from the headgear.
63. The head-mountable respiratory assistance apparatus according to claim 58 wherein the lightweight impeller of the blower unit is shroudless.
64. The head-mountable respiratory assistance apparatus according to claim 58 further comprising an onboard electronic controller that is mounted to or within the respiratory assistance apparatus and which is operable to control the pressure of respiratory gases delivered to the user by controlling the blower unit.
65. The head-mountable respiratory assistance apparatus according to claim 64 further comprising one or more sensors mounted to or within the respiratory assistance apparatus that are configured to sense operational parameters and generate representative sensor signals.
66. The head-mountable respiratory assistance apparatus according to claim 65 wherein the one or more sensors are wireless sensors.
67. The head-mountable respiratory assistance apparatus according to claim 66 wherein the one or more wireless sensors are configured to send the generated sensor signals to the controller.
68. The head-mountable respiratory assistance apparatus according to claim 66 wherein the one or more wireless sensors are configured to transmit, directly or indirectly, the generated sensor signals wirelessly to a separate external device or system.
69. The head-mountable respiratory assistance apparatus according to claim 58 further comprising a wireless communication module that is operable to receive and send data to external devices and/or systems.
70. The head-mountable respiratory assistance apparatus according to claim 58 further comprising an onboard wireless power transfer receiver that is configured to receive power from a wireless power transfer transmitter.
71. A head-mountable respiratory assistance apparatus according to claim 58 wherein the apparatus is configured as a positive airway pressure (PAP) device.
72. The head-mountable respiratory assistance apparatus according to claim 58 wherein the patient interface comprises any one of the following: a full face mask configured to sealingly engage with the user's face so as to cover their nose and mouth; a nasal pillows mask that sealingly engages the user's nostrils; an unsealed nasal cannula that is configured to be positioned inside the user's nostrils; or an oral interface that is configured to sealingly engage with or within the user's mouth.
73. The head-mountable respiratory assistance apparatus according to claim 58 that is configured to be operatively connectable to a separate base station, the base station comprising:
- a power supply system that is operable to supply power to the respiratory assistance apparatus;
- a data transfer system that is operable to send and receive data to and from the respiratory assistance apparatus; and
- a control system that is operable to control the respiratory assistance apparatus via control signals.
74. The head-mountable respiratory assistance apparatus according to claim 73 wherein the power supply system of the base station is configured to transfer power to the respiratory assistance apparatus via one or more power transfer cables and/or comprises wireless power transfer circuitry that is configured to transfer power to the respiratory assistance apparatus wirelessly.
75. The head-mountable respiratory assistance apparatus according to claim 74 wherein the data transfer system of the base station comprises a first communication module that is operable to transfer data between the base station and the respiratory assistance apparatus over a wired or wireless communication medium.
76. The head-mountable respiratory assistance apparatus according to claim 75 wherein the data transfer system of the base station further comprises a second communication module that is operable to transfer data between the base station and an external server over a wired or wireless communication medium.
77. The head-mountable respiratory assistance apparatus according to claim 73 wherein the control system of the base station is operable to send control signals to the respiratory assistance apparatus to control any one or more of the following operational modes: on/off mode, charging mode, drying mode, and/or data transfer mode.
Type: Application
Filed: Nov 20, 2018
Publication Date: May 30, 2019
Inventors: Adam John Darby (Auckland), Donald Roy Kuriger (Auckland), Johannes Nicolaas Bothma (Otorohanga), Scott Bent (Auckland)
Application Number: 16/197,279
