Patent Description:
Many individuals suffer from disordered breathing during sleep. Sleep apnea is a common example of such sleep disordered breathing suffered by millions of people throughout the world. One type of sleep apnea is obstructive sleep apnea (OSA), which is a condition in which sleep is repeatedly interrupted by an inability to breathe due to an obstruction of the airway; typically the upper airway or pharyngeal area. Obstruction of the airway is generally believed to be due, at least in part, to a general relaxation of the muscles which stabilize the upper airway segment, thereby allowing the tissues to collapse the airway. Another type of sleep apnea syndrome is a central apnea, which is a cessation of respiration due to the absence of respiratory signals from the brain's respiratory center. An apnea condition, whether obstructive, central, or mixed, which is a combination of obstructive and central, is defined as the complete or near cessation of breathing, for example a <NUM>% or greater reduction in peak respiratory airflow.

Those afflicted with sleep apnea experience sleep fragmentation and complete or nearly complete cessation of ventilation intermittently during sleep with potentially severe degrees of oxyhemoglobin desaturation. These symptoms may be translated clinically into extreme daytime sleepiness, cardiac arrhythmias, pulmonary-artery hypertension, congestive heart failure and/or cognitive dysfunction. Other consequences of sleep apnea include right ventricular dysfunction, carbon dioxide retention during wakefulness, as well as during sleep, and continuous reduced arterial oxygen tension. Sleep apnea sufferers may be at risk for excessive mortality from these factors as well as by an elevated risk for accidents while driving and/or operating potentially dangerous equipment.

Even if a patient does not suffer from a complete or nearly complete obstruction of the airway, it is also known that adverse effects, such as arousals from sleep, can occur where there is only a partial obstruction of the airway. Partial obstruction of the airway typically results in shallow breathing referred to as a hypopnea. A hypopnea is typically defined as a <NUM>% or greater reduction in the peak respiratory airflow. Other types of sleep disordered breathing include, without limitation, upper airway resistance syndrome (UARS) and vibration of the airway, such as vibration of the pharyngeal wall, commonly referred to as snoring.

It is well known to treat sleep disordered breathing by applying a continuous positive air pressure (CPAP) to the patient's airway. This positive pressure effectively "splints" the airway, thereby maintaining an open passage to the lungs. It is also known to provide a positive pressure therapy in which the pressure of gas delivered to the patient varies with the patient's breathing cycle, or varies with the patient's breathing effort, to increase the comfort to the patient. This pressure support technique is referred to as bi-level pressure support, in which the inspiratory positive airway pressure (IPAP) delivered to the patient is higher than the expiratory positive airway pressure (EPAP). It is further known to provide a positive pressure therapy in which the pressure is automatically adjusted based on the detected conditions of the patient, such as whether the patient is experiencing an apnea and/or hypopnea. This pressure support technique is referred to as an auto-titration type of pressure support, because the pressure support device seeks to provide a pressure to the patient that is only as high as necessary to treat the disordered breathing.

Pressure support therapies as just described involve the placement of a patient interface device including a mask component having a soft, flexible sealing cushion on the face of the patient. The mask component may be, without limitation, a nasal mask that covers the patient's nose, a nasal/oral mask that covers the patient's nose and mouth, or a full face mask that covers the patient's face. Such patient interface devices may also employ other patient contacting components, such as forehead supports, cheek pads and chin pads. The patient interface device is typically secured to the patient's head by a headgear component. The patient interface device is connected to a gas delivery tube or conduit and interfaces the pressure support device with the airway of the patient, so that a flow of breathing gas can be delivered from the pressure/flow generating device to the airway of the patient.

Innovations are continuously being made to improve the comfort of patient interface devices, and thus improve patient compliance. Additionally, a need exists for improved pressure generating devices and blowers for use therein which can provide suitable supplies of treatment gas in as quiet and compact of manner as possible. US patent application <CIT> discloses an apparatus to deliver air to a patient through a mask. The apparatus includes an air blower having an impeller that is rotated by an electromotor. US patent application <CIT> discloses a blower that includes a housing having a proximal opening and a distal opening. An impeller is positioned between the openings and is driven by a motor. EP patent application <CIT> discloses a blower comprising an electric motor with a shaft. An impeller is attached to the shaft. US patent application <CIT> discloses a blower assembly comprising a blower housing having a stator assembly integrally formed therewith.

Accordingly, it is an object of the present invention to overcome shortcomings of conventional pressure generating devices and blowers for use therein.

As one aspect of the present invention a blower assembly for moving a fluid is provided. The blower assembly comprises: a housing having an inlet and an outlet defined therein; a first shaft member fixedly coupled to the housing, the first shaft member having a central axis, wherein the first shaft member includes a first end fixedly coupled to the housing, and a second end disposed opposite first end; and a stator assembly fixedly coupled to the housing, disposed around the central axis and spaced radially outward from the first shaft member. The blower assembly further comprises a driven assembly comprising: a second shaft member having a first end, a second end disposed opposite the first end, and a cylindrical cavity defined therein which extends inward from the first end; a magnetic ring fixedly coupled to the second shaft member at or about the first end; and an arrangement fixedly coupled to the second shaft member at or about the second end. The blower assembly also comprises a bearing system disposed between the first shaft member and the second shaft member such that the driven assembly is rotatably coupled to the first shaft member, wherein the bearing system is disposed in the cylindrical cavity and about the second end of the first shaft member. The driven assembly is structured to be rotated about the central axis via magnetic interactions between the stator assembly and the magnetic ring, and the arrangement is structured to cause movement of a fluid into the inlet of the housing and out from the outlet of the housing.

The arrangement may comprise an impeller structured to cause movement of a gas.

The housing may comprise a first housing portion and a second housing portion coupled to the first housing portion.

The first shaft member and the stator assembly may be fixedly coupled to the second housing portion.

The first shaft member may be fixedly coupled to the housing via an overmold.

The first shaft member may be fixedly coupled to the housing via a press-fit.

As another aspect of the present disclosure a driven assembly for use in a blower assembly for moving a fluid is provided, according to the previous aspect of the present invention.

As yet another aspect of the present invention a pressure support system for use in providing a flow of breathing gas to the airway of a patient is provided. The pressure support system comprises: a pressure support device having a blower assembly structured to generate the flow of breathing gas according to the previous aspect of the present invention; a patient interface structured to be attached to the patient; and a delivery conduit coupled between the pressure support device and the patient interface, the delivery conduit being structured to convey the flow of breathing gas from the pressure support device to the patient interface.

As used herein, the singular form of "a", "an", and "the" include plural references unless the context clearly dictates otherwise. As used herein, the statement that two or more parts or components are "coupled" shall mean that the parts are joined or operate together either directly or indirectly, i.e., through one or more intermediate parts or components, so long as a link occurs. As used herein, "directly coupled" means that two elements are directly in contact with each other. As used herein, "fixedly coupled" or "fixed" means that two components are coupled so as to maintain a constant, fixed orientation relative to each other. As used herein, "selectively coupled" means that two components are coupled in a manner which allows for the components to be readily coupled or uncoupled in a predictable, repeatable manner without damaging either of the components. Unless particularly described otherwise herein, any components which are described merely as being "coupled", may also be "fixedly" or "selectively" coupled without varying from the scope of the present invention.

As used herein, the word "unitary" means a component is created as a single piece or unit. That is, a component that includes pieces that are created separately and then coupled together as a unit is not a "unitary" component or body. As used herein, the statement that two or more parts or components "engage" one another shall mean that the parts exert a force against one another either directly or through one or more intermediate parts or components. As used herein, the term "number" shall mean one or an integer greater than one (i.e., a plurality).

Aspects of the present invention will be described herein in its application to non-invasive ventilation (NIVV) treatment apparatus (e.g., positive airway pressure (PAP) devices), such as CPAP, but it is to be understood that aspects of the invention may have application to other fields of application where blowers are used, e.g., in both positive pressure and negative pressure applications.

Also, although the example described below is a single stage design, it is ot be appreciated that examples of the present invention may be applied to multiple stage designs, e.g., two, three, four, or more stages.

An example airway pressure support system <NUM> according to one particular, non-limiting exemplary embodiment in which the present invention may be implemented is shown in <FIG>. Airway pressure support system <NUM> includes a pressure support device <NUM> which houses a blower assembly <NUM>, an example of which will be described in further detail below. Blower assembly <NUM> receives breathing gas, generally indicated by arrow C, from the ambient atmosphere through a filtered air inlet <NUM> provided as part of pressure support device <NUM>, and generates a flow of breathing gas therefrom for delivery to an airway of a patient <NUM> at relatively higher and lower pressures, i.e., generally equal to or above ambient atmospheric pressure, to generate pressure to provide pressure compensation to patient <NUM> via a patient circuit <NUM>,<NUM>. In the exemplary embodiment, blower assembly <NUM> is capable of providing a flow of breathing gas ranging in pressure from <NUM>-<NUM> cmH2O. The pressurized flow of breathing gas from blower assembly <NUM>, generally indicated by arrow D, is delivered via a delivery conduit <NUM> to a breathing mask or patient interface <NUM> of any known construction, which is typically worn by or otherwise attached to patient <NUM> to communicate the flow of breathing gas to the airway of patient <NUM>. Delivery conduit <NUM> and patient interface device <NUM> are typically collectively referred to as the patient circuit.

Pressure support system <NUM> shown in <FIG> is what is known as a single-limb system, meaning that the patient circuit includes only delivery conduit <NUM> connecting patient <NUM> to pressure support system <NUM>. As such, an exhaust vent <NUM> is provided in delivery conduit <NUM> for venting exhaled gases from the system as indicated by arrow E. It should be noted that exhaust vent <NUM> can be provided at other locations in addition to or instead of in delivery conduit <NUM>, such as in patient interface device <NUM>. It should also be understood that exhaust vent <NUM> can have a wide variety of configurations depending on the desired manner in which gas is to be vented from pressure support system <NUM>.

The present concept also contemplates that pressure support system <NUM> can be a two-limb system, having a delivery conduit and an exhaust conduit connected to patient <NUM>. In a two-limb system (also referred to as a dual-limb system), the exhaust conduit carries exhaust gas from patient <NUM> and includes an exhaust valve at the end distal from patient <NUM>. The exhaust valve in such an embodiment is typically actively controlled to maintain a desired level or pressure in the system, which is commonly known as positive end expiratory pressure (PEEP).

Furthermore, in the illustrated exemplary embodiment shown in <FIG>, patient interface <NUM> is a nasal/oral mask. It is to be understood, however, that patient interface <NUM> can include a nasal mask, nasal pillows, a tracheal tube, an endotracheal tube, or any other device that provides a suitable gas flow communicating function. Also, for purposes of the present invention, the phrase "patient interface" can include delivery conduit <NUM> and any other structures that couple the source of pressurized breathing gas to patient <NUM>.

In the illustrated embodiment, pressure support system <NUM> includes a pressure controller in the form of a valve <NUM> provided in internal delivery conduit <NUM> provided in a housing of pressure support device <NUM>. Valve <NUM> controls the pressure of the flow of breathing gas from blower assembly <NUM> that is delivered to patient <NUM>. For present purposes, blower assembly <NUM> and valve <NUM> are collectively referred to as a pressure generating system because they act in concert to generate and control the pressure and/or flow of gas delivered to patient <NUM>. However, it should be apparent that other techniques for controlling the pressure of the gas delivered to patient <NUM>, such as varying the speed of blower assembly <NUM>, either alone or in combination with a pressure control valve, are contemplated by the present invention. Thus, valve <NUM> is optional depending on the technique used to control the pressure of the flow of breathing gas delivered to patient <NUM>. If valve <NUM> is eliminated, the pressure generating system corresponds to blower assembly <NUM> alone, and the pressure of gas in the patient circuit is controlled, for example, by controlling the speed of blower assembly <NUM>.

Pressure support system <NUM> further includes a flow sensor <NUM> that measures the flow of the breathing gas within delivery conduit <NUM> and delivery conduit <NUM>. In the particular embodiment shown in <FIG>, flow sensor <NUM> is interposed in line with delivery conduits <NUM> and <NUM>, most preferably downstream of valve <NUM>. Pressure support system <NUM> additionally includes a pressure sensor <NUM> that detects the pressure of the pressurized fluid in delivery conduit <NUM>. While the point at which the flow is measured by flow sensor <NUM> and the pressure is measured by pressure sensor <NUM> are illustrated as being within pressure support device <NUM>, it is to be understood that the location at which the actual flow and pressure measurements are taken may be anywhere along delivery conduits <NUM> or <NUM>. The flow of breathing gas measured by flow sensor <NUM> and the pressure detected by pressure sensor <NUM> are provided to processing unit <NUM> to determine the flow of gas at patient <NUM> (QPATIENT).

An input/output device <NUM> is provided for setting various parameters used by pressure support system <NUM>, as well as for displaying and outputting information and data to a user, such as a clinician or caregiver.

<FIG> illustrate blower assembly <NUM> which is a single stage blower in accordance with an example embodiment of the present invention. As will be appreciated from the following description, blower assembly <NUM> provides an arrangement that is relatively compact and lightweight.

Referring first to <FIG>, blower assembly <NUM> includes a housing <NUM> (e.g., constructed of metal, plastic ( e.g., polycarbonate) or other suitable material) defining a space (not numbered) therein and having an inlet <NUM> and an outlet <NUM> defined therein. Blower assembly <NUM> is operable to draw a supply of gas into housing <NUM> through inlet <NUM> and provide a pressurized flow of gas at outlet <NUM>. Blower assembly <NUM> is of a generally cylindrical shape with inlet <NUM> aligned with a rotational axis of the assembly and outlet <NUM> structured to direct gas exiting blower assembly in a generally tangential direction. In the illustrated example, outlet <NUM> is in the form of an outlet tube that extends outwardly from housing <NUM>, however it is to be appreciated that one or more of the shape, size, and/or orientation of outlet <NUM> may be varied without varying from the scope of the present invention.

Housing <NUM> may be formed from a plurality of elements which are formed separately and then subsequently coupled together. In the example embodiment illustrated herein, housing <NUM> includes a first housing part <NUM> and a second housing part <NUM>, which are coupled together either selectively (e.g., via a snap-fit or removable fasters) or permanently (e.g., via adhesive, welding, etc.). In such example, inlet <NUM> is defined in first housing part <NUM> and outlet <NUM> is defined in-part by first housing part <NUM> and in-part by second housing part <NUM>.

Referring now to <FIG>, blower assembly further includes a cylindrical first shaft member <NUM> (e.g., without limitation, formed from steel or other suitable rigid material) and a wound stator assembly <NUM> having a generally toroidal shape which is disposed around (i.e., so as to encircle) a central axis A of first shaft member <NUM> and spaced radially outward from first shaft member <NUM>. First shaft member <NUM> includes a first end <NUM> fixedly coupled to housing <NUM> via any suitable arrangement (e.g., via press-fit, over-mold, or other suitable arrangement) and a second end <NUM>, disposed opposite first end <NUM>, which extends into the space within, and defined by housing <NUM>. Stator assembly <NUM> includes a stator core or electromagnetic core 42A (e.g., including a plurality of laminations stacked on top of one another) on which stator coils or windings 42B are wound. Stator assembly <NUM> is also fixedly coupled to housing <NUM> via any suitable arrangement. In the example illustrated embodiment, first shaft member <NUM> and stator assembly <NUM> are both fixedly coupled to second housing part <NUM>. More particularly, in the example embodiment illustrated, a portion (not numbered) of first shaft member <NUM> is disposed in, and coupled to (e.g., via press-fit, over-mold, or other suitable arrangement) a periphery of an aperture <NUM> defined in second housing part <NUM> and stator assembly <NUM> is fixedly coupled to a portion (not numbered) of second housing part <NUM> outward from aperture <NUM>. Although not shown, it is to be appreciated that stator assembly <NUM> is structured to be electrically coupled to any suitable source of power and/or control such as commonly provided in the art.

In addition to such components previously described, which may be generally considered as "fixed" components, blower assembly <NUM> further includes a rotatable or driven assembly <NUM>, which is driven about axis A of first shaft member <NUM> as discussed further below. Driven assembly <NUM> includes a second shaft member <NUM> (e.g., without limitation, formed from steel or other suitable rigid material) having a first end <NUM>, a second end <NUM> disposed opposite first end <NUM>, and a cylindrical cavity <NUM> defined therein which extends inward in first end <NUM>. Driven assembly <NUM> further includes a magnetic ring <NUM> (e.g., formed from any suitable permanent magnetic material) and an impeller <NUM> (e.g., formed from any suitable material) which are both fixedly coupled to second shaft member <NUM>. Impeller <NUM> may be of any suitable configuration for moving air without varying from the scope of the present invention. In the illustrated example embodiment, magnetic ring <NUM> is fixedly coupled (e.g., via an adhesive or other suitable arrangement) to an outer surface of second shaft member <NUM> at or about first end <NUM> such that magnetic ring <NUM> is disposed radially outward from cavity <NUM> and impeller <NUM> is fixedly coupled (e.g., via press-fit or other suitable arrangement) to second shaft member <NUM> at or about second end <NUM>.

Referring to the sectional view of <FIG>, driven assembly <NUM> is rotatably engaged with first shaft member <NUM> via a bearing system <NUM> which is disposed in cylindrical cavity <NUM> of second shaft member <NUM> and about second end <NUM> of first shaft member <NUM>. In the example arrangement illustrated in <FIG>, bearing system <NUM> includes a number of ball bearings <NUM> (two are shown in the illustrated embodiment separated by a spacer <NUM>). It is to be appreciated, however, that other types, quantities, and/or arrangements of bearings may be employed as bearing system <NUM> without varying from the scope of the present invention. It is to be appreciated that such arrangement provides for driven assembly to generally spin freely with respect to first shaft member <NUM> and housing <NUM>. It is also to be appreciated that such arrangement provides for a generally compact arrangement wherein, moving radially outward from axis A, second end <NUM> of first shaft member <NUM>, bearing system <NUM>, first end <NUM> of second shaft member <NUM>, magnetic ring <NUM> and stator assembly <NUM> are all disposed in a common plane P, as shown in <FIG>.

It is to be appreciated that in such arrangement, driven assembly <NUM> is caused to spin about axis A as a result of interactions between electromagnetic fields produced by stator assembly <NUM> interaction with magnetic ring <NUM> of driven assembly <NUM>. It is to be appreciated that the arrangement of driven assembly <NUM> generally minimizes mass and the distance such mass thereof is from axis A, thus generally minimizing the inertia of driven assembly <NUM>. As a result, driven assembly <NUM> provides for a faster response time than conventional designs.

Although exemplified as a blower assembly herein, it is to be appreciated that embodiment of the present invention may also be employed in other fluid moving devices, such as those used for moving liquids. <FIG> shows a sectional view of an assembly <NUM> for use in a fluid moving application in accordance with an example embodiment of the present invention. Assembly <NUM> is of a similar arrangement as blower assembly <NUM> and utilizes similar components with a few distinctions. One such distinction is that blower assembly includes a housing <NUM> which is formed from three different parts: first housing part <NUM> (similar to that of assembly <NUM>), a second housing part 138A, and a third housing part 138B. Second and third housing parts 138A and 138B function similarly as second housing part <NUM> of assembly <NUM>, while also providing a sealed housing in which stator assembly <NUM> is disposed. Such sealed housing is generally accomplished by sealing second housing part 138A about a second shaft member <NUM> (formed and positioned similarly as second shaft member <NUM> of assembly <NUM>) via a sealing mechanism <NUM>. An impeller <NUM>, which is structured to move a liquid, is rigidly coupled to second shaft member <NUM> outside of the sealed housing defined by second housing part 138A and third housing part 138B.

Although the invention has been described in detail for the purpose of illustration based on what is currently considered to be the most practical and preferred embodiments, it is to be understood that such detail is solely for that purpose and that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover modifications that are within the scope of the appended claims. For example, it is to be understood that the present invention contemplates that, to the extent possible, one or more features of any embodiment can be combined with one or more features of any other embodiment.

Claim 1:
A blower assembly (<NUM>) for moving a fluid, the assembly comprising:
a housing (<NUM>) having an inlet (<NUM>) and an outlet (<NUM>) defined therein;
a first shaft member (<NUM>) fixedly coupled to the housing, the first shaft member having a central axis (A), wherein the first shaft member (<NUM>) includes a first end (<NUM>) fixedly coupled to the housing (<NUM>), and a second end (<NUM>) disposed opposite first end (<NUM>);
a stator assembly (<NUM>) fixedly coupled to the housing, disposed around the central axis and spaced radially outward from the first shaft member;
characterized in that the blower assembly (<NUM>) comprises:
a driven assembly (<NUM>) comprising:
a second shaft member (<NUM>) having a first end (<NUM>), a second end (<NUM>) disposed opposite the first end, and a cylindrical cavity (<NUM>) defined therein which extends inward from the first end (<NUM>),
a magnetic ring (<NUM>) fixedly coupled to the second shaft member at or about the first end (<NUM>), and
an arrangement (<NUM>) fixedly coupled to the second shaft member (<NUM>) at or about the second end (<NUM>); and
a bearing system (<NUM>) disposed between the first shaft member and the second shaft member such that the driven assembly is rotatably coupled to the first shaft member, wherein the bearing system (<NUM>) is disposed in the cylindrical cavity (<NUM>) and about the second end (<NUM>) of the first shaft member (<NUM>),
wherein the driven assembly is structured to be rotated about the central axis via magnetic interactions between the stator assembly and the magnetic ring, and
wherein the arrangement is structured to cause movement of a fluid into the inlet of the housing and out from the outlet of the housing.