NZ759926B2

NZ759926B2 - Treatment of respiratory conditions

Info

Publication number: NZ759926B2
Application number: NZ759926A
Authority: NZ
Inventors: Adam Vivian Benjafield; Steven Paul Farrugia; Dieter Heidmann; Paul Jan Klasek; Glenn Richards; Peter John Sweeney
Original assignee: ResMed Pty Ltd
Priority date: 2008-06-05
Filing date: 2009-05-28
Publication date: 2022-01-06

Abstract

patient interface device for respiratory treatment of a patient has a coupling for breathable gas delivery hose, a gas directing outlet portion to deliver gas to nares of the patient, and a nasal dilator (882L, 882R) which may be mounted for dilating nares internally as shown, or for dilating nares externally such as by nasal bridge adhered to the nose (not shown). s externally such as by nasal bridge adhered to the nose (not shown).

Description

TREATMENT OF RESPIRATORY CONDITIONS CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the beneﬁt of the ﬁling dates of United States Provisional Patent Application No. ,084 ﬁled June 5, 2008 and United States Provisional Patent Application No. 61/117,375 ﬁled November 24, 2008, the disclosures of which are hereby incorporated herein by reference. 1. FIELD OF THE TECHNOLOGY [00 02] The present technology relates to methods and apparatus for treatment of respiratory ions such as the conditions related to sleep disordered breathing (SDB) (including mild obstructive sleep apnea (OSA)), y induced upper airway obstruction or early viral infection of the upper airway. 2. BACKGROUND OF THE TECHNOLOGY Sleep is important for good health. Frequent disturbances during sleep or sleep fragmentation can have severe consequences including me sleepiness (with the attendant possibility of motor-vehicle accidents), poor mentation, memory problems, depression and hypertension. For example, a person with nasal tion may snore to a point that it disturbs that person's ability to sleep. Similarly, people with SDB are also likely to disturb their partner’s sleep. One known ive form of treatment for patients with SDB is nasal continuous positive airway pressure (nasal CPAP) applied by a blower (air pump or compressor) via a connecting hose and patient interface. In some forms the supply of air at positive re is delivered to both the nose and mouth. The positive pressure can prevent a collapse of the patient’s airway during inspiration, thus preventing events such as snoring, s or hypopnoeas and their sequelae.

Such positive airway pressure may be red in many forms. For example, a positive re level may be maintained across the inspiratory and expiratory levels of the patient's breathing cycle at an approximately constant level. Alternatively, pressure levels may be adjusted to change synchronously with the patient's breathing cycle. For example, pressure may be set at one level during inspiration and another lower level during expiration for patient comfort. Such a re treatment system may be referred to as bi—level. Alternatively, the pressure levels may be continuously adjusted to smoothly change with the patient's breathing cycle. A pressure setting during expiration lower than inspiration may generally be referred to as expiratory pressure relief. An automatically adjusting device may increase the treatment pressure in response to indicatiOns of partial or complete upper airway obstruction. See US.

W0 2009/146484 Patent Nos. 5,245,995; 6,398,739; 6,635,021; 6,770,037; 7,004,908; 7,141,021; 6,363,933 and ,704,345. .

Other devices are known for providing atory tract therapy. For example, Schroeder et a1. describes an apparatus for delivering heated and humidiﬁed air to the respiratory tract of a human patient in US. Patent No. 7,314,046, which was ﬁled on 8 Dec. 2000 and assigned to Vapotherm Inc. rly, Genger et a1. discloses an anti-snoring device with a compressor and a nasal air cannula in US. Patent No. 7,080,645, ﬁled 21 July 2003 and assigned to Seleon GmbH.

It may be desirable to develop further s and devices for treating upper respiratory conditions. 3. SUMMARY OF THE TECHNOLOGY A ﬁrst aspect of the some embodiments of the technology is to provide s and apparatus for treatment of respiratory conditions.

Another aspect of some embodiments of the technology is to provide methods and apparatus for treating sleep disordered breathing.

In one embodiment of the technology, air at a high ﬂow rate is delivered to the nasal es, preferably in the range of about 10 to about 35 litres/minute.

In another embodiment, air is provided with a temperature in the range of about 30°C to about 37°C.

In another embodiment, air with a high humidity is provided to the nasal passages, preferably with an absolute humidity in the range of about 27 to about 44 mg/litre.

In another embodiment, methods and apparatus are provided for servo-controlling sleep disordered ing by varying one or more of ﬂow, temperature and level of ﬁcation.

Another aspect of the logy is to provide a device for treating respiratory conditions having one or more start-up and/or shut-down protocols that vary any of ﬂow, temperature and level of humidiﬁcation. For example, the device may provide for ramping any one or more of ﬂow, temperature and level diﬁcation.

Another aspect of the technology is to vary any of ﬂow, temperature and level of humidiﬁcation within, or as a function of detection of, a respiratory cycle of a t. For example, a device may provide ﬁrst levels of ﬂow, ature and/or humidiﬁcation during inhalation and second or different levels of ﬂow, temperature and/or humidiﬁcation during exhalation.

W0 2009/146484 Another aspect of the technology is to provide different levels of ﬂow, temperature and/or humidiﬁcation to each naris. For example, in one form of device, levels of ﬂow, temperature and/or humidiﬁcation are cycled between the nares.

In accordance with the technology, methods and apparatus are provided for varying the levels of ﬂow, temperature and/ or humidiﬁcation.

In accordance with the technology, levels of ﬂow, temperature and/or humidiﬁcation may be varied either manually or automatically.

In accordance with the technology, levels of one or more of ﬂow, temperature and humidiﬁcation may be varied over a period having a duration less than, equal to or greater than the duration of a respiratory cycle. For example, ﬂow, temperature and humidiﬁcation may be increased over several breaths, or decreased over several breaths.

Another aspect of the technology is to provide an air delivery conduit having a diameter that changes along its length.

Another aspect of the technology is to provide each naris with individually controlled levels ofﬂow, temperature and/or humidity. onal .features of the present respiratory technology will be apparent from a review of the following detailed discussion, drawings and claims. 4. BRIEF DESCRIPTION OF DRAWINGS The t technology is illustrated by way of example, and not by way of limitation, in the ﬁgures of the anying drawings, in which like nce numerals refer to similar elements including: shows example ents of an tus for treatment of the upper airway of a patient; FIGS. 2A and 23 illustrate embodiments of a gate valve for adjusting temperature and/or humidity ofthe treatment provided by an apparatus of the present technology; shows a rechargeable embodiment of an apparatus for treatment according to an embodiment of the t technology; [0026 ] shows an example sing airﬂow channel er of a delivery conduit for a ﬂow source of the present technology; is an example ﬂowchart bing the l of the apparatus in warm-up mode; is another example ﬂowchart describing the control of the apparatus in warm- up mode; [ 0029] shows a ﬂowchart describing the control of the apparatus in cool-down mode; W0 2009/146484 is an illustration of an ment of a patient interface with internal nasal dilators for insertion within a patient's nares; is a side view illustration of another example embodiment of a patient interface with external nasal dilators for contact with an external surface ofthe patient‘s nose; is a top View illustration of the example patient interface of is a front cross-sectional view illustration of the example patient ace of Fig. 9; is an illustration of an example diffuser clip conﬁgured with an example agement sensor; is a further clip with another example disengagement sensor; [003 6] illustrates an example er for a prong of a nasal cannula; and is an ration of a bafﬂe for a prong of a nasal cannula.

. DETAILED DESCRIPTION The embodiments of the present logy may be implemented with an airway treatment device 102 that may include some or all of the components illustrated in FIG. ‘1. For example, the airway treatment delivery device'will typically include a ﬂow generator such as a controlled blower 104. The blower 104 will typically e an air inlet and impeller driven by a motor (not shown). ally, the air inlet may be coupled with a gas supply, such as for oxygen as shown in to mix with or supplement the breathable gas supplied by the impeller to the airway of a user. Optionally, the supplementary gas supply may be introduced through a port, 133, upstream of the humidiﬁer, and/or downstream of the humidiﬁer, through a port 134. er, an air ﬁlter may be provided, such as a HEPA ﬁlter, to remove dust or other allergens from the air drawn into the air inlet. The blower may optionally be conﬁgured for generating varied ﬂows or pressures.

The delivered breathable gas flow rate may be in the range of about —250 to about +250 liters/min, more preferably between about -100 and about 100 liters/min, more preferably, between about 0 to 100 liters/min, more preferably between about 0 and 75 liters/min, yet further more preferably between about 0 to about 50 liters/min with the preferred range being between about 10 to about 35 liters/min, to provide for comfort and efﬁcacy. [004 0] The delivered breathable gas temperature may be in the range of about -10°C to about 50°C, more preferably about +4°C to about +45°C, yet more preferably room temperature up to 40°C with the most preferred range being 30°C to 37°C, to provide for comfort and efﬁcacy.

The delivered breathable gas relative humidity may be in the range of room humidity up to 100%, for e in the range of about 50% to about 100%, or about 70% to about 100%, or about 80% to about 95%, with the preferred range being 90% to 100%, to e for comfort W0 46484 and efﬁcacy. An absolute ty range will be about 0 to about 82 mg/liter, or" more preferably about 27 to about 44 mg/liter. .1 PATIENT INTERFACE The airway treatment device 102 will also typically include a patient interface such as an air ry conduit 106 and nasal prongs or nasal cannula 108 to carry the ﬂow of air or breathable gas to the upper airway of a user of the device or patient. The blower 104 can be coupled with the air delivery conduit 106 and the nasal cannula 108 so as to provide the breathable gas from the blower 104. In one form of patientinterface, as will be disCussed in more detail with respect to the particular interface embodiments herein, exhaust gas of the blower and/0r expiratory gas from the patient's airway can be vented away from the patient interface from a location proximate to the patient's airway or the nares themselves. Signiﬁcant gaps or venting between the patient interface and the nares of the patient can permit a ﬂow from the ﬂow generator to escape or leak ﬁ'om the patient's nares without being inspired. A patient interface that permits such venting can provide a comfortable interface for the treatment described herein. Thus, a patient interface that provides a leak—free seal with the nares of the t is not required. r, a sealed patient interface may be used as an alternative.

The patient interface will lly be held in place proximate or inside the nares of the patient. A harness 110 may be optionally provided for this purpose. In addition, a nasal or septum clip and/or adhesive (not shown) may also be provided to maintain the nasal cannula in a desired position for use. Examples of suitable ments ofthe patient interface are disclosed in US. Patent Provisional Patent Application No. 61/058,659, entitled "Unobtrusive Interface Systems," ﬁled on June 4, 2008, the disclosure of which is hereby incorporated herein by cross- reference. In some embodiments, the nasal cannula may also or alternatively include ear attachment portions connected with the nasal cannula to ensure oning of nasal cannula by or in the nares during treatment. For example, cannula arms extending over and/or around the ears from the nasal cannula may be utilized. Optionally, the ry conduit may be incorporated with such cannula arms, which may alternatively be designed to run under the ears rather than over the ears to reduce noise that might otherwise be heard by the user from the ﬂow of gas through the delivery conduit.

In some embodiments, the patient interface or cannula may be implemented with a nasal r, such as an internal or al nasal dilator. Illustrations of example ments are shown in FIGS. 8 to 11. In the embodiment of dilator extension members 882R, 882L t from a patient interface such as a portion of a cannula 808 body. For example, the ion members may project from prongs 880R, 880L of the cannula 808 as illustrated in In such a case, the prongs serve as dilator mount portion of the cannula or patient W0 2009/146484 interface. The extension members in are sized to project inside nares of a patient's nose even if the prongs 880L, 880R also do not extend within the nares. Such extension members may then be formed or shaped to ply an expansion force against an internal e of each nare.

This expansion force, which is illustrated by the arrows in Fig. 8, permits the extension members to assist with keeping the nasal passages dilated from inside the nares. Thus, the extension members may be formed of a material that is ﬂexible and resilient to e a dilation force.

However, these extensions may otherwise be conﬁgured with one or more spring elements (not shown) to provide a suitable expansion force with more rigid extension members.

In some embodiments, the extension members of the patient interface may be formed to ply an expansion force from an exterior surface of a patient’s nares. An example of such an, embodiment is illustrated in FIGS. 9-11. In such an embodiment, the extension members 982 may comprise a dilator strip or strips. For example, a portion of the patient interface or cannula 908 may e a bridge t 990. The bridge support may be ﬂexible for adjustment so that, it may conform to the nose shapes of ent patients. When the a is in place to provide gas ﬂow to the nares of a patient, the bridge support may extend from the cannula so that the ' bridge t is proximate to a ridge area of a patient's nose. The support may then serve as a dilator mount portion to permit the dilator ion members to be mounted thereto and positioned proximate to the exterior surface ofthe patient’s nose.

For example, the bridge support 990 may optionally include a gap or clip so that a disposable dilator strip may be releasably retained by the bridge support 990. In such an embodiment, a disposable r strip may be inserted or coupled to the bridge support for use.

Such a dilator strip may then be a ﬂexible and resilient material so as to permit ent at opposing external es of the nose of the patient and yet still be able to ply the expansion force at those surfaces to assist with dilation of the nares by pulling at the exterior surfaces of the nose. Thus, these strips may also typically include an adhesive so that a surface of the dilator strip may adhere to opposing exterior surfaces of the nose. Thus, a left side dilator strip 982L and a right side dilator strip 982R may then be adhered to the left and right sides of the patient's nose respectively. With such embodiments, the ion members may serve the purpose of securing the cannula or patient interface in a suitable position for providing a ﬂow to the nares of the patient with prongs 980, 980R, 9080L as well as ing a dilation force to assist with - keeping the patients nasal passages open during a use of the patient interface. Moreover, although not shown in FiGS. 8-11, onal components of the patient interface may be provided for further securing of the cannula in the desired position for use, such as the cannula arms previously discussed.

W0 2009/146484 In some embodiments, the extension members 982L, 982R may be more permanently constructed with the bridge support by, for example, forming the r strip as an orated portion of the t interface or bridge support of the cannula 908. Thus, rather than replacing disposable exterior dilator strips as previously discussed, for each use a suitable ve may be re-applied to the nasal surface sides of the attached or incorporated dilator strip.

In some embodiments, an optional spring element 996 may also be provided with the dilator strip. For example, where extension members themselves are not formed to have a sufﬁcient resilience to e the expansion force, the spring element, when coupled with the extension members, may serve to provide the expansion force with the extension members 992R, 992L. In the example of a wire or other resilient component may serve as the spring element.

As ﬁirther illustrated in the t interface may also include one or more swivels. A swivel 994 can permit the patient interface or carmula 908 to remain in a desirable position for directing the ﬂow to the nares ofthe patient if a patient moves during sleep. Thus, a swivel provides relative movement between an air delivery portion of the patient interface and a delivery tube portion of the patient interface. For example, one or more swivels may permit relative rotation between a cannula 908 and delivery tube 906 about one or more different axes (illustrated as perpendicular axes X, Y, Z). As illustrated in the embodiment of a swivel may permit a rotation of the cannula 908 with respect to the delivery tube 906 along arrows 81 or about an ary X axis. Such nt can permit an air delivery n of the cannula (e.g., prongs 980) to vertically rotate with respect to the delivery tube 906.

Similarly, as illustrated in the ment of , a swivel 994 may permit a rotation of the a 908 with respect to the delivery tube 906 along arrows 82 or about an imaginary Y axis. Such movement can permit an air ry portion of the cannula (e.g., prongs 980L, 980R) to horizontally rotate with respect to the delivery tube 906.

Finally, as illustrated in the embodiment of FIG. V 1 1, a swivel may permit a rotation of the cannula 908 with respect to the delivery tube 906 along arrows S3 or about an imaginary Z axis. Such movement can permit an air delivery portion of the cannula (e.g., prongs 980L, 980R) to tilt rotation with respect to the delivery tube 906. .2 HUMIDIFIER, HEATER AND TUBE Breathable gas is supplied to the patient by a blower (104 of , which may be integrated with other elements of the apparatus, or from a reticulated source, or from bottled gas, or otherwise. The air may be ﬁltered at the input to the blower (104) or at some other point in the gas ﬂow path. ally, the apparatus may also e a humidiﬁer and/or heater (112, 111) and a delivery tube heater (135) (or apparatus to regulate heat loss from the delivery tube W0 2009/146484 106). In the case of a heated delivery tube, insulation material may be provided on the tube to prevent the heat from the tube from bothering the patient or otherwise being transferred to the skin of the patient. Such a tube may be d with an insulating material or the tube al may be selected for is insulation properties. For example, the delivery tube may be increased in thickness to provide or increase its insulating effect. The heater device 111 may be exposed to a water mass and/or to the breathable gas ﬂow. For example, the humidiﬁer device may e a reservoir or ﬂuid circuit for passing the breathable gas through or proximate with a ﬂuid or vapor ofthe reservoir or ﬂuid circuit. One or more heating elements (not shown separately from heater 1 11) may be provided to warm the ﬂuid to create the vapor and/or to warm the breathable gas by convection. The warming device may further include a pump for circulating ﬂuid within the oir or a ﬂuid circuit of the t interface or blower. For purposes of regulating the temperature and/or humidity of the warming element, the apparatus may also include humidity sensors (117, 121, 134), and/or temperature sensors, and/or a ﬂow rate sensor, and/or pressure sensors. The sensor(s) generate temperature and/or humidity signals and/or a ﬂow rate signal, and/or pressure signals (illustrated, in for controlling the humidiﬁer and/or heater and/or tube heater using l logic (120) to maintain the ature and/or humidity of the breathable gas delivered to the patient. In some applications, this device can be controlled to alter the ature and humidity of the breathable gas such that the delivery conditions are within the acceptable or preferred ranges as stated above.

Generally, it has been found that some available devices are slow when changing the level or degree of humidiﬁcation due to the need to heat a relatively large mass or water.

However, in embodiments ofthe present technology, two air streams may be provided, namely a ﬁrst relatively dry air stream in one ﬂow channel, and a second relatively moist air stream in another ﬂow channel. By mixing the streams to a third ﬂow channel, the level diﬁcation of the air delivered to the patient may be rapidly changed as necessitated by the settings of the apparatus.

One means of achieving this is to employ an active ﬂow gate 299 as illustrated in the examples of FIGS. 2A and 2B. For example, if, when the ﬂow gate is in one position, it directs ﬂow from the blower to a path that provides for one desired level of temperature and humidiﬁcation of the breathable gas, and in an alternate on directs ﬂow ﬁom the blower another path that provides a signiﬁcantly different level of ature and humidiﬁcation ofthe breathable gas, optionally with no ﬁcation. The ﬂow gate may be controlled to switch ﬂow direction in response to breathing cycle phase, or otherwise under control of the controller 120. Optionally, the ﬂow gate may be controlled to activate to a position that allows the splitting or mixing of the ﬂow between the two paths. For e, based on the desired humidity and/or W0 2009/146484 temperature settings measured by one set of sensors in a combined tube, the controller may adjust the ﬂow gate to mix variable s of gas of two distinct ﬂow paths at two different humidity and/or temperature settings, which may be separately controlled by readings from two additional and different sets of sensors. Another version of the ﬂow gate that allows for mixing of ﬂows is illustrated in with a controllable iris valve. Other mechanisms of generating and mixing ﬂows of different temperatures and humidities, such as dual blower supply, may be used.

By way of further e, by controlling the ﬂow gate in conjunction with detected changes in the patient's atory cycle, a lower humidity and/or temperature gas may be delivered during patient expiration and a higher humidity and/or temperature gas may be delivered during patient inhalation. Alternatively, a higher humidity and/or ature gas may be delivered during exhalation. Thus, such ﬂow control of the humidity of the breathable gas delivered to the patient can generate high temperature and/or humidity delivery only when the t requires such for eutic reasons, for example during an inhalation phase of a breathing cycle. This controlled delivery in turn may allow for a reduction in the power and/or water requirements of the apparatus over the duration of a therapy session. ion of the phases of the respiratory cycle of the t may be based on an analysis of data from an appropriate sensor such as the sensors discussed in more detail herein.

In one embodiment, shown in the delivery conduit 406A, 406B, 406C from the airway ent device may be formed with a gas delivery channel that has a decreasing cross section or diameter. A ion in the cross section diameter can reduce the impedance of the delivery tube and may also reduce heat loss. For e, as illustrated in the embodiment of the delivery conduit of the open airway treatment device 402 of an internal airﬂow channel GC ofthe delivery conduit decreases from at least one larger cross nal area portion shown as delivery conduit 406A to at least one smaller cross sectional area n shown as conduit 406B to a yet smaller cross sectional area portion shown as delivery conduit 406C proximate to the nasal cannula 408. In this way, for a given ﬂow resistance, the tube diameter proximal to the patient can be smaller than with a constant diameter tube. Further, the tube section 406A, and optionally 406B, may be heated (not shown) to control the breathable temperature and/or humidity to a level that allows for the change in temperature of the breathable gas through 406C such that the delivered gas to the patient is within the desired range. The small tube section of 406C reduces the heat transfer between the breathable gas and the environment compared with the larger sections of 406B or 406C.

The cross sectional area of any portion of the airﬂow channel would typically be r than the cross sectional area of the airﬂow channel of the upstream portion of the W0 2009/146484 delivery conduit. To avoid undesired ﬂow restriction and/or noise, transitions between these different cross sectional portions of the delivery conduit may be made by gradual blending at or near their intersections. Additional tube portions may be interposed n 406A and 406B to provide for more gentle transitions in diameter.

In one embodiment, the end portion of the delivery conduit near the ﬂow generator may have an internal airﬂow l cross n diameter of about 8-15 mm. Such an embodiment may also end with an airﬂow channel having a cross sectional area er of about 3-6 mm proximate to the nasal cannula. Such a delivery conduit may optionally be formed as a foam silicone tube to provide improved thermal tion properties. .3 SENSORS In some embodiments, the airway treatment delivery device may optionally include one or more ﬂow sensors 116. For example, ﬂow through the nasal cannula 108 may be measured using a pneumotachograph and differential pressure transducer or similar device such as one employing a bundle of tubes or ducts to derive a ﬂow signal. Although the ﬂow sensor is rated in in a on proximate to the blower, the ﬂow sensor may optionally be located closer to the patient, such as in the patient interface or nasal cannula 108; The airway treatment device may also ally include one or more pressure sensors 114, 131, such as a pressure transducer. The pressure sensor(s) 114, 131 can be conﬁgured to e the pressure generated by the blower 104 and/or supplied at the nasal cannula or patient . In the illustrated embodiment, the pressure sensors 114, 131 are proximate to the blower and located downstream of the blower proximate to the patient interface.

For example, one or more pressure sensors may be located in the prongs or body of the nasal cannula. The pressure sensor(s) 114, 131 generates a pressure signa1(s) indicative. of the measurement(s) ofpressure at its particular location. Such a signal(s) can be utilized in settings or ations of the device. The pressure sensor 114 has only been shown symbolically in since it is understood that other conﬁgurations and other components may be implemented to measure the pressure associated with the blower 104. For example, the pressure may be deduced from dge of the blower performance characteristics and the operating blower current and/or voltage and/or rotational speed and/or ﬂow rate. Optionally, different groups of sensors may be provided for a delivery tube associated with each nare of the nasal a. For example, a delivery tube for each nare may e a pressure sensor and/or ﬂow sensor so that independent measurements ofﬂow and/or pressure may be measured for each nare.

The airway ent device may also include one or more temperature sensors as previously mentioned. For example, such sensors may be located to e the heater(s) 111, 135, and/or the treatment gas at various locations in the delivery tube such as near the blower W0 2009/146484 (e.g., before or after), after the humidiﬁer and near the patient. Similarly, the treatment device may also e one or more humidity sensors as described above. Thus, humidity may be measured before and/or after the humidiﬁer and near the patient. Additional such sensors may be employed when multiple ﬂow channels are utilized such as in the embodiments of FIGS. 2A and 2B for more measuring of the conditions of the distinct portions of the tubes. Still further sensors may also be conﬁgured to measure ambient humidity and ature. .4 CONTROLLER The signals from the various sensors (when present) may be sent to a ller or processor 120. Optional analog-to-digital (A/D) converters/samplers (not shown separately) may be utilized in the event that supplied signals from the sensors are not in digital form and the controller is a digital controller. Based on input signals from these sensors and/or other optional sensors, the controller may in turn generate blower control signals. For example, the controller may generate an RPM request signal to l the speed of the blower 104 by setting a desired frequency or rotational velocity set point and comparing it with the measured condition of a ﬁequency or velocity sensor. atively, such changes may be based on ining a desired ﬂow set point and comparing it with the measured condition of the ﬂow sensor. lly, such changes to the motor speed are accomplished by sing or decreasing supplied motor current with the servo based on determined differences between set and measured conditions such as in a closed loop feedback n and ating the difference to current.

Thus, the processor 120 or controller may make controlled s to the ﬂow delivered to the patient interface by the blower 104. Optionally, such changes to ﬂow may be implemented by controlling an t with a mechanical release valve (not shown) to increase or decrease the t while maintaining a relatively constant blower speed.

The controller or processor 120 is typically conﬁgured and adapted to implement particular l methodology such as the methods described in‘more detail herein. Thus, the controller may include integrated chips, a memory and/or other control instruction, data or information storage medium. For example, prograrmned instructions encompassing such a control methodology may be coded on integrated chips in the ts or memory of the device or such instructions may be loaded as soﬁware or ﬁrmware using an riate medium. With such a controller or processor, the apparatus can be used for many different open airway treatment therapies, such as the ﬂow treatments previously mentioned, by adjusting a ﬂow delivery equation that is used to set the speed of the blower or the exhaust venting by an optional release valve (not shown). Thus, ﬂow may be set to desired levels as set by the es of the device and optionally increased in response to detected respiratory conditions such as an apnea, hypopnea, or airway resistance. The ﬂow rate may be kept substantially constant over the phases W0 2009/146484 of respiration. In some embodiments, the generated ﬂow may be kept generally constant over the respiratory cycle and provide some end expiratory relief. Altemately, in some ments the ﬂow may be varied smoothly to replicate the patient's detected respiration cycle.

In another example embodiment of the device, indications of upper airway obstruction determined by the controller are servo-controlled by varying the ﬂow rate and/or level of humidiﬁcation and/or temperature. For example, a device in accordance with the technology rs the patient for signs of partial or complete upper airway obstruction. Upon detection of partial upper airway obstruction, and according to the severity and frequency of such events, the level of ﬁcation is increased. In some embodiments, if the partial airway obstruction is eliminated, or not detected, the level of humidiﬁcation may be reduced. rly, ifpartial airway obstruction is detected, ﬂow may be further increased.

In one embodiment of the technology, indications of the need to vary treatment are derived from a pressure signal that is in turn used to infer patient ﬂow in the controller 120. The inferred ﬂow estimate is applied to automatic pressure control algorithms such as those described in US. Patent No. 5,704,345, the entire contents of which are hereby expressly incorporated by reference. The output of the automatic pressure algorithms is however, in one ment, used to control the ﬂow rate and/or level ofhumidiﬁcation and/or temperature.

In other forms, pressure is used directly by the controller to determine the presence of partial or complete airway obstruction. In other forms, other non-pressure, non-ﬂow based diagnostic techniques are used, such as movement of the suprasternal notch, patient movement, sympathetic nervous system activation (e.g. sweating, skin ance, heart rate), pulse try, EEG and ECG. Such additional diagnostic devices may be conﬁgured with the apparatus to provide measurement data to the controller.

In one ment, the controller may determine a tidal volume or inspired volume of air or gas by the patient during treatment. Such a determination may be used for setting the pressure or ﬂow and/or analyzing conditions of the patient‘s airway or ation. In view of the venting or unsealed nature of the patient interface that permits the external ﬂow, the tidal volume (Vp) may be determined by measuring the volume of air delivered by the blower 0/0) and measuring or determining the volume of leak air (VL) ated with the nasal a and subtracting the latter from the former (e.g., V0 — VL é Vp). In some embodiments, the patient interface may seal with the t nares but have a pre-determined venting characteristic, or one that may change as a function of the pressure or ﬂow rate setting of the ﬂow generator. Thus, the volume of leak may be determined by a p table or calculation by the controller 120 based on the gs of the ﬂow generator.

W0 2009/146484 .5 OTHER ASPECTS OF THE APPARATUS In other embodiments of the technology, the apparatus can be combined with additional components like accessories, which may be attached to pre-deﬁned interfaces or using the shape of the ment, gs, screw holes, or other ng methods or prominent areas of the apparatus to attach. These accessories can be for example additional ﬁlters, or sound dampening mechanisms, or data g electronics, which may have for example either a mechanical, pneumatic, magnetic and/or electrical connection to the apparatus. The connection and interaction may also be wired so that the accessories work together with the tus from a distance.

One example is a able battery pack as illustrated in The airway treatment device of this embodiment may be implemented with a DC battery sufﬁcient to permit at least a use for a single sleep session without connection to an AC power outlet. A dock 333, such as a cradle with a docking port charger that may be releasably coupled with a charging port of the respiratory treatment device 302, provides a ient way to charge the battery of the respiratory ent device 302.

Other accessories can add additional features to the devices or modify the existing feature set, for example by using a new method for motor control to reduce noise. For example, a noise sensor or microphone may be provided to detect levels of noise generated by the blower or the patient interface. Noise measurements may be made and an increase in ambient noise (e.g., a level of sound aﬁer ﬁltering out frequencies such as the ﬁequencies that may be associated with snoring) may be responded to by the controller 120 changing a motor speed in attempt to reduce the noise. However, the controller may further reject such s to the extent that any change would prevent a minimum desired level of treatment from being generated by the ﬂow generator for the patient. .6 WARM-UP METHODOLOGY One practical consideration in the design and ion of the apparatus described herein is that the humidiﬁcation apparatus may comprise an arrangement whereby a mass of water is required to be increased or decreased in temperature. This, in turn, may result in some delay between the change in the heater state and the humidity and/or temperature of the breathable gas delivered. When such a delay prevents the desired combination of ﬂow, temperature and humidity to be met in the delivered gas, it may be desirable to prioritize the ties that are to be met for therapeutic, comfort or functional reasons. For example, it may be desirable to ensure that humidity is within the preferred range as the ﬁrst ty, temperature is within the red range as the second priority, and ﬂow is within the preferred range as the third priority.

W0 2009/146484 Such prioritizing can be accomplished by the logic sequence described in The ﬂow rate Fmin is a small ﬂow of about 5% - 35% of the desired therapy ﬂow — sufﬁciently large to transport the breathable gas to allow sensing and control, but sufﬁciently small to ensure that the patient does not suffer any fort as a consequence of the delivered sub-Optimal breathable gas.

Optionally, this sequence may be initiated conditionally upon, and/or triggered by, detection of a patient connected to the apparatus. Such detection may be by observation or detection of ﬂuctuations in pressure and/or ﬂow signal(s) and other techniques such as those described in US. Patent No. 6,240,921 (ResMed Limited), the contents of which are hereby expressly incorporated herein by cross-reference.

In addition to control of the ﬂow to meet the desired delivered breathable gas property ranges, it may also be ble for the t to l the ﬂow of the apparatus in a manner that allows the ﬂow rate to increase in accordance with a selected rate. Such l may offer ages in acceptance and compliance of such therapy because the patient is able to become accustomed to the therapy over a longer time than would be the case without such rate control.

This start-up strategy may be applied for a cold-start or a warm-startiAs shown in an example algorithm monitors the temperature and humidity delivered at the patient interface r directly or calculated from other inputs), for example by means of temperature and humidity sensors 132 and 134, and ramps up the temperature as quickly as le to the desired range (while maintaining relative humidity (RH) within the desired range). Then the ﬂow rate is increased from the initial value to the desired value in accordance with the user ramp g such that the red temperature and humidity are maintained within the desired ranges.

The algorithm of may be further described as follows. At 502 of FIGS, the start-up procedure determines if the apparatus is in a cool-down mode. If the result is afﬁrmative, the ﬂow rate is ined in 504. Otherwise, a minimum ﬂow rate will be set in 506. Process moves to 510 where the ﬂow of the apparatus is controlled to meet the target or set point. The method then proceeds to 512 where the relative ty (RH) is measured and compared to a d range or deviation of the target or set point for relative humidity, If the result in 512 is negative then the process proceeds to 514 to control the humidity related ts of the apparatus to the set point or target for relative humidity. The process then advances to 510 to l the breathable gas ﬂow rate. If the result is afﬁrmative in 512 then process advances to 516. In 516, the breathable gas temperature is checked to see if it is within a desired range or deviation from the target or set point value. If the result in 516 is negative then W0 2009/146484 2009/000671 the process proceeds to 518 to control the temperature related elements of the tus to the set point or target for temperature. The process then advances to 510 to control the breathable gas ﬂow rate.

If the result in 516 is afﬁrmative, then the process proceeds to 520. In 520, the ﬂow rate is checked to see if it is below a desired range or acceptable deviation from the therapy target ﬂow rate. If, in 520, the result is negative then the s is complete. If, in 520, the result is afﬁrmative then the process advances to 522. In 522, the ﬂow rate is measured or calculated to determine if a step increase in the rate is appropriate for g up of the ﬂow rate. If the step increase would raise the ﬂow rate above the therapy target, then process ﬂows to 524 and 510 without an increase in the target set point of the ﬂow rate for the warm-up process.

If in 522 a step increase would not raise the ﬂow rate above the therapy target, the target set point is incremented to increase or ramp up the ﬂow rate in 526 and then controlled in 510 at the new stepped~up ﬂow rate. In this way, the ramping of ﬂow rate may be governed without allowing the humidity or temperature to deviate from their desired or target set—points.

Another example start-up procedure algorithm is illustrated in At 602 the start up procedure begins. In 604, the temperature (and/or ty) of one or more g elements (e.g., ﬁer heating element) is set and allowed to raise to the desired set point as determined by a temperature and/or ve humidity sensor. Once the set temperature and/or humidity setting has been reached, at 606, a ramp-up procedure for the ﬂow generator begins in which an incremental increase in the ﬂow rate will be set over toward a maximum, such as by setting an incremental increase in the RPM set point of the blower every several minutes. At 608, the temperature and/or humidity levels are checked with the appropriate sensors to determineif the temperature and humidity is within an acceptable deviation margin of the set point after an increase in the blower ﬂow rate. If the margins are acceptable (e.g., a margin of +/- 1, 2, 3, 4 or 5 degrees of the temperature setting or +/— l, 2, 3, 4 or 5% ve humidity of the humidity setting) the process will ﬂow to 609 to check if the ramp-up of ﬂow has reached the target therapy level for the treatment session. If not, then the process returns to 606 to again increment the ﬂow generator according to the p procedure and its time ment period.

If, in 609, the therapy level has been reached, the warm-up process is te and the y session protocol may begin. [007 9] However, in 608, if the levels are not within a predetermined margin ofthe set points, the measurement/comparison process ﬂows to .610 to wait a period of time. Process then returns to the comparison process of 608 to again check the temperature and/or humidity sensors compliance with the deviation margin. In this way, the ﬂow rate of the apparatus may ramp up W0 46484 2009/000671 in a comfortable fashion to the therapy ﬂow rate g while maintaining the desired set points for the humidity and/or temperature of the gas delivered by the apparatus. .6.1 RE-RAMP METHODOLOGY In some situations, during the course of therapy with the apparatus a patient may desire a temporary decrease in the ﬂow rate to permit the patient to more comfortably fall asleep with a lower ﬂow rate before the ﬂow rate would then return to a higher prescription or therapeutic level during sleep. Thus, in some embodiments of the apparatus, a re—ramp methodology may be implemented by the controller. The apparatus may permit the user to activate the re-ramp procedure by a switch, button, knob or other user interface of the apparatus.

Thus, upon activation of the procedure, the tus would lower the ﬂow rate for a predetermined period of time. The period of time may optionally be adjustable by the user with an input device of the tus. At the conclusion of the period of time the ﬂow rate may then return to the therapeutic level. Alternatively, it may gradually return to the therapeutic level over the period of time or after a period of time. However, in the event that humidiﬁcation ,is also provided during the particular therapy session, additional elements of the control of the re—ramp procedure may be implemented as a on of the presence of humidiﬁcation and/or heating so as to assist with avoiding rainout or condensation.

For example, in a typical embodiment, the re-ramp algorithm or methodology of the apparatus may only permit the re-ramp feature to be activated after the apparatus has achieved a warmed—up state, such as if the apparatus has already ted the warm-up procedure previously described. Similarly, in an embodiment, the re-ramp feature may be ed if the apparatus has achieved a cool down state such as at a time after completing a cool-down methodology or when the apparatus is performing a cool-down methodology as bed in more detail herein. Thus, the methodology of the re-ramp feature may be implemented as a function of humidiﬁcation and/or temperature or a humidiﬁcation state and/or temperature state of the apparatus. In the event that a cool-down state has been achieved, such as with the ing described cool-down methodology, and/or the re—ramp feature is disabled, the apparatus may then be re-activated by execution of the warm-up methodology previously described rather than the re-ramp ure.

In some embodiments, the selection of the rate for the reduced ﬂow duringthe ramp ure may be user adjusted or selected with an input device or user ace of the apparatus. onally, in some embodiments the reduced ﬂow rate may be a ﬁmction of humidity and/or temperature such that the reduced ﬂow rate selection is at least partially set in a manner that prevents condensation from forming in the patient interface and/or delivery tube.

For example, the thm may monitor the temperature and humidity internal and/or external to W0 2009/146484 the apparatus, for example by means of ature and ty sensors, and then automatically select a reduced ﬂow rate, such as from a look-up table based on the ature and/or humidity information. [0 083] In some embodiments, the reduced ﬂow may be implemented without a blower speed change by the ﬂow generator. In such an embodiment, an exhaust vent or release valve, which may be a mechanical valve that is controlled by a processor or controller of the apparatus, may be opened to vent part of a humidiﬁed gas supply from the blower so that only a n of the ﬁed ﬂow generated by the ﬂow generator is directed to the patient interface. In this way, a lower humidiﬁed ﬂow rate may be red to the patient for the re-ramp procedure. The vent or e valve may then close, such as gradually over a period of time that is typically longer than several breaths, to return the humidiﬁed ﬂow to the therapeutic rate. Although not shown in such a release valve or exhaust vent may, for e, be positioned to exhaust gas ﬂow generated by the blower 104 at a position in the air deliver circuit after the humidiﬁer 112. .7 COOL-DOWN METHODOLOGY Another consequence of the practical eration described above is that the immediate power-down of the tus may lead to condensation in the apparatus — particularly the tube — because the heated water mass will continue to emit vapor and so the regions where the breathable gas path is in thermal contact with the environment, for example the tube walls, may cool rapidly. The presence of condensation in the apparatus will adversely affect the comfort and/or'function ofthe apparatus at a subsequent start-up, because droplets may be blown down the tube to the patient interface causing patient discomfort, and/or the presence of water in the heated tube may lead to additional humidiﬁcation in the breathable gas delivered to the patient or otherwise affect the ability of the system to control the breathable gas delivery at the patient interface within the desired ranges.

An aspect of the current technology is a control methodology that may be optionally used with the apparatus to control the rate of cooling of the apparatus — especially the tube — to diminish the likelihood of signiﬁcant condensation forming during apparatus power—down.

Such a strategy es enting a sequence ofapparatus states or tions to promote the maintenance of the temperature of the breathable gas in the system above the local dew-point temperature. Optionally, this sequence may be initiated ionally upon, and/or tn'ggered by, detection of the absence of a patient connected to the apparatus. Such detection may be by detection of ﬂuctuations in pressure and/or ﬂow signa1(s). The initiation of this sequence may be delayed by a predetermined period, which may be t-selectable, following such triggering, to allow for temporary disconnection and reconnection of the apparatus. The predetermined period may be about 1 - 30 minutes.

W0 2009/146484 This strategy can be accomplished by the example logic described in The ﬂow rate Fminl may be about 50% - 150% of the typical therapy ﬂow. The ﬂow rate needs to be sufﬁciently high to promote cooling of the water mass but not so high so as to te obtrusive noise. This ﬂow rate may be a ﬁxed value, a value that is directly or indirectly selected by the user, for example should a rapid cool-down be desired, and/or a le value that follows a proﬁle with time, or with a sensed breathable gas property value such as humidity.

The ﬂow rate Fmin2 is a small ﬂow of about 5% - 35% of the typical therapy ﬂow — sufﬁciently large to transport the breathable gas to allow sensing and control, but sufﬁciently small that the humidiﬁcation of the breathable gas is low and does not cause condensation when the apparatus is uently powered-down. The transition in ﬂow rate from Fminl to Fmin2 may be controlled to a predetermined proﬁle. Fmin2 may be a ﬁxed value, a value that is directly or indirectly selected by the user, for example should a rapid cool-down be desired, and/or a variable value that follows a proﬁle with time, or with a sensed breathable gas property value such as humidity.

This cool-down strategy applies to any mode or phase of operation of the apparatus.

Optionally, a pause to therapy may be requested by the user such that the breathable gas conditions are maintained for a short , for example 1 — 30 minutes, and if therapy is not restarted within this period, either-manually or by the detection method above, then the cool- down strategy will be initiated. As shown in the algorithm monitors the temperature and humidity delivered at the patient interface (either directly or calculated from other inputs), for example by means of temperature and ty sensors 132 and 134, and ramps down the humidity as quickly as le until such time as the system humidity is stable, whilst maintaining an acceptable int margin, for e about a 2-5°C . The margin can be determined from the Saturation Vapour Pressure at the ﬂow temperature, for example using the formulas in ISO Standard 8185 2007. The ﬂow rate is decreased from the initial value to the Fmin2 in a manner that allows the maintenance of the dew-point . The apparatus may then be powered-down.

The algorithm of may be summarized as follows. In 702, after the ent therapy controlled by the apparatus is stopped, humidity generation with the humidiﬁer is d. In 704, the ﬂow rate generated by the ﬂow generator is controlled to the Fminl target value. In 706, one or more of the g elements are controlled to in a target temperature in the delivery tube of the patient interface. In 708, a dew-point temperature is checked to assess if it has stabilized. If it has not, process ﬂow returns to 704. If it has, process ﬂows to 710. In 710, the ﬂow rate of the ﬂow generator is then controlled to the target Fmin2 value. In 712, one or more of the heating elements are controlled to maintain a target W0 2009/146484 temperature in the delivery tube of the patient ace. In 714, a dew-point ature is checked to assess if it has ized. If it has not, process ﬂow returns to 710. If it has, process ﬂow ofthe cool-down procedure is complete. .8 ATIONS OF METHOD AND APPARATUS A user will be titrated to determine the optimal ﬂow rate and temperature for treating the user’s sleep disordered breathing (SDB). The l settings for ﬂow rate and temperature are those that maximize efﬁcacy of the therapy as well as user comfort. For example, the temperature will be set to the highest value within the range capable by the device that is deemed comfortable by the user. The temperature may also be changed to compensate for any droplets of water that may form in the air ry tube or user interface, for example nasal cannula. The temperature may also be changed to maximize the efﬁcacy of the therapy. For ﬂow, an example would be for the rate of ﬂow to start at the lowest le by the device. When the user is asleep and SDB events are detected, such as by the controller of the device, the ﬂow rate would be incrementally increased in response to the SDB events (for example, apneas, hypopneas, ﬂow limitation and snoring) to prevent them from repeating and hence maximizing the efﬁcacy of the therapy. Another method would be to set the ﬂow rate to the highest rate that is table for the user when awake. When the user is asleep, the necessary s in ﬂow rate may be made in response to the SDB events, again to maximize the efﬁcacy of the therapy.

Changes to ﬂow rates and temperature may be done manually, by an observer of the user when they are asleep. For example, by a sleep technologist observing the user using polysomnography (PSG). I Changes to ﬂow rate, gas temperature and/or humidity levels may also occur automatically in response to the SDB events detected by the apparatus. This would be based on an algorithm that incrementally increases the ﬂow rate, gas temperature and/or humidity levels in response to the SDB events. The magnitude of the increase would be governed by the type of the SDB event. For example, the increase in ﬂow rate, gas ature and/or humidity levels would be greater for an apnea compared to ﬂow limitation which in turn would be greater than the response to snore. Alternatively, incremental decreases in the ﬂow rate, gas temperature and/or humidity levels would occur in response to an absence of detected SDB events after a certain period of time. [0 094] The gs of ﬂow rate, ty and/or ature may be increased or decreased by the device with some step value by simply detecting whether any one or more of these SDB events occur. er, such adjustments may be a ﬁmction of the measure of the detected SDB event. For example, a measure of partial obstruction may be a varying index from 0 to 1 where 1 is fully obstructed, 0 is not obstructed and 0.5 if half obstructed. The change in any of W0 2009/146484 the ﬂow rate, humidity and/or temperature may then be a ﬁmction of the degree of partial obstruction, such as, a function that generates a greater ment when there is a larger degree of obstruction and a lesser adjustment when there is a smaller degree of obstruction. In some embodiments, a degree of partial obstruction may be assessed by a ﬂattening analysis of a respiratory ﬂow , a roundness analysis of a respiratory ﬂow signal and/or other partial obstruction methodology for assessing of the patient's upper airway.

To assist in the treatment of SDB, in some embodiments the ratio of the outer diameter of the nasal prongs of the patient interface to the surface area of user’s nares may be increased or decreased. These changes would be to increase the efﬁcacy and comfort of the therapy. [009 6] Once titration has been effected, optionally, the patient may alter the therapy settings manually within a restricted range to improve comfort according to personal choice. .9 CYCLING In some embodiments of the logy, the ﬂow and or humidiﬁcation of air delivered to each nare is individually controlled. For example, a higher ﬂow and/or more humidiﬁcation may be delivered on one side compared to the other. In one form, each of the air ﬂow & ﬁcation may be individually cycled in a nare. For example, a ﬂow rate may be adjusted in one nare while maintaining a fairly constant ﬂow rate or ty in the other nare.

By way of further example, a high ﬂow rate may alternate between the leﬁ nare and a right nare such that when a high rate is directed at one nare, a low rate is directed at the other. In another form changes in ﬂow and/or humidiﬁcation of air red to one nare are synchronized with changes in ﬂow and or humidiﬁcation of air delivered to the other nare.

The delivery of a higher ﬂow to one nare compared to the other may be to compensate for a user with unilateral nasal obstruction. In one embodiment, the higher ﬂow rate would be delivered to the nare that was not obstructed. This would maximize the efﬁcacy of the therapy. Alternatively, a higher rate may be delivered to the obstructed mate as an t to decrease the obstruction. Obstruction may be ined by automatic method of ing partial obstruction, for example, by analysis of a respiratory ﬂow signal. Such an analysis may be independent for the respiratory ﬂow signal associated with each nare. Alternatively, unilateral l obstruction may be detected by an increase in a measure of re from a re sensor associated with one nare with respect to a measure of pressure of another pressure sensor ated with the other nare.

The delivery of more humidiﬁcation to one nare compared to the other might be to compensate for the higher ﬂow being delivered to one nare because it is less obstructed.

Alternatively, more humidiﬁcation may be delivered to the nare with higher nasal resistance to W0 2009/146484 reduce this resistance. Optionally, while this is occurring, 3 higher ﬂow may be delivered to the other nare. After the higher nasal resistance is reduced, by more humidiﬁcation and/era higher ﬂow rate, and the resistance is equal between the two nares, the humidiﬁcation and air ﬂow may then be returned to equal delivery to each of the nares. This may be tested by analysis of the ve pressures of the sensors associated with each nare. For example, the ﬂows directed at each nare may be set to be equal and the two pressures associated with the nares may then be d and compared for substantial equality, which may indicate that there is no unilateral obstruction.

This delivery of different ﬂow can be achieved, for example, by the use of two motors within the device. One motor for each of the two nares with a controller linking both motors. Alternatively, a single motor blower might be used with lled venting valves in the ﬂow paths for each nare. In such a case, the blower may be set to a desired rate for the highest ﬂow desired for either nare. The ﬂow at the high rate may be delivered to one nare without substantial venting while the blower ﬂow rate to the other nare may be reduced by venting some of the ﬂow of the ﬂow path of the other nare without delivering all of it to that nare. This may be achieved by separately lling the diameter of an re associated with a venting valve of each delivery tube associated with each nare by the controller. Alternatively, one or more variably controlled gate valves may split a single supply tube from a blower into a y-junction.

For example, mechanical gate valves, near a y-junction, may then be set to position(s) to. gate a portion of the ﬂow to one delivery tube directed at one nare and a portion of ﬂow into another delivery tube directed at the other nare. For example, 60% of the ﬂow may be directed to one mare and 40% ofthe ﬂow may be directed at the other nare. The gate valve may be controlled to divide the supply rate by other tages (e.g., 50%/50%, O%/100% etc.) Essentially, the controller can set the gate valve to divide the ﬂow between the nares by any desired on or aperture g. An example of suitable gate valves may be comparable to the gate valves illustrated in Figs. 2A or 2B but with the ﬂows traveling in the opposite ion from that illustrated in those ﬁgures. Optionally, additional tubes and gate valves may also be added to then adjust the humidity levels directed to each nare tube as previously described with regard and 2B. [ 0 101] Still ﬁirther, the delivery of different levels of humidiﬁcation can be achieved, for example, by altering the proportion of air being delivered that comes ﬁom the humidiﬁer compared to that from the environment. By increasing the proportion of air ﬁ'om the environment the lower the amount of ﬁcation being red to the patient. In such a case, ambient humidiﬁcation and ature sensors may be utilized to provide the controller W0 2009/146484 with data concerning these ambient conditions. Alternatively, there may be two humidiﬁcation systems. One for each nare of the user with a ller linking both humidiﬁers. .10 DUAL RATE OPERATION In one embodiment of the technology, a dual rate mode of operation may be employed. In this mode, the device is triggered by the inspirational ﬂow of a user, in particular by the ﬂow rate provided at the beginning of inspiration. This ﬂow rate may be detected by nce from the pressure signal, or otherwise, and compared to a predetermined threshold. The threshold may be set to different sensitivities, e.g. high, medium and low. Once a trigger event is detected, a ﬁrst ﬂow rate is provided. When the inspirational ﬂow of a user, in particular by the ﬂow rate provided at the end of inspiration, falls below another threshold, the device cycles to a second ﬂow rate. The ﬂow rate may be ed as described above. Again, the thresholds for cycling may be set to different sensitivities, e.g. high, medium and low.

In one form of this dual rate operation, the inspiration ﬂow rate is higher than the ’ expiration ﬂow rate. This is a form of expiration ﬂow relief that may improve the comfort of the therapy.

In another form of this dual rate operation, the tion ﬂow rate is higher than the inspiration ﬂow rate. This may assist in further increasing the end expiratory pressure (EEP) in the upper airway of the user. By increasing the EEP, the efficacy of the therapy may be improved.

As previously mentioned, such triggering may also be utilized to implement ﬁrst and second ct humidiﬁcation levels or ﬁrst and second distinct breathable gas temperatures according to the detected phases of the patient's respiratory cycle. Thus, the controller may set different gas temperatures and/or different humidiﬁcation levels depending on the phase of respiration. .11 ALTERNATIVE THERAPY The therapeutic mode described herein, may be implemented in a device also capable of delivering CPAP or APAP therapy. In this case, the mode apy delivered by the device may be changed through a button, dial, menu or other control. A change of therapeutic mode might also be associated with changing the air-delivery circuit to that appropriate to the therapeutic mode.

The device may have an indicator, for example an LED, which will illuminate when the device believes it is not satisfactorily treating the SDB of the user based on data g. For example, the LED would be nated when the device recorded SDB events were above a ermined threshold at the end of a session. This threshold could be set based on the requirements of the ng physician. An e of a threshold would be an apnea and W0 2009/146484 hypopnea index (AHI) r than 5 per hour of use. The illumination of this indicator based on SDB events would indicate a change to an ative y from that described in this patent to conventional continuous positive airway pressure (CPAP) or automatic positive airway pressure (APAP).

The indicator described above in one case may result in the device of the user being changed to a PAP device. In another case, it may indicate that the mode of therapy being delivered by the device he switched, manually, to CPAP/APAP mode. For this the device would be capable of delivering both types of y (i.e., that described in this document and CPAP/APAP). In another case, the indicator may lead to an automatic change of therapy mode and the device which is e of delivering both types of therapy automatically makes the change. The indicator in this instance would be to notify the user that the change had .12 DISLODGEMENT AVOIDANCE AND DETECTION The relatively high ﬂow rates of the devices and systems may give rise to additional ms relating to patients experiencing problems wherein the nasal cannula accidently dislodged during operation. These problems may include potential damage to' the eyes or face of the patient n the high ﬂow rates of air are accidently directed to sensitive parts of the face.

The preferred system and device may also detect accidental dislodgement, wherein the dislodgement is ed by at least one of the aforementioned preferred sensors.

When the dislodgement is detected, the system or device may be automatically shut off to prevent or limit potential damage from the high ﬂow rates being accidentally directed to sensitive parts of the patient’s face. Alternatively or in on to the shut off, the dislodgment detection may automatically open a mechanical vent valve controlled by the ller to vent the air at or near the controller or ﬂow tor in a manner that more immediately depressurizes the supply tube to the cannula. One example dislodgement sensor may be a pressure transducer that detects a change in pressure as an indication of dislodgement. In another example, a clip with electrical contacts 1210A, 1210B, such as that illustrated in or 13, may serve as a dislodgment sensor by sending an electrical switch signal to the controller.

During use, the clip may be attached to a portion of the nares, such as at the base of the nose. A light spring force used to hold the clip in place may also be utilized to te the sensor upon dislodgment. Upon removal or dislodgment, the clip may be conﬁgured to spring closed (or open depending on its desired conﬁguration). The closing of the contacts (or opening thereof depending on the conﬁguration of the switch and the spring action) may then be detected electrically by the controller as a dislodgment. The clip may even be combined with the other W0 2009/146484 components of the patient interface such as the nasal dilators previously discussed (e.g., the dilator of FIGS. 8 or 11), and may even also serve to maintain the cannula in place as described further herein.

In this regard, the chance or likelihood of accidental dislodgement may also be zed by attaching a specialized clip 1310 onto the nasal cannula. The clip may be constructed of ﬂexible and resilient material ding polyermic materials) and may attach and secure the nares of the patient to the nasal a with a retaining force, and may still maintain a non-sealed relationship between the nose and nasal cannula.

Also in some embodiments, the end of the nasal a that may be ed into the nose during operation may include an air diffuser such as the example diffuser with radial ﬁns 1440 on the prong 880 illustrated in . Preferably, the air er may prevent or limit the ﬂow of air in a single direction but increases the dispersion of air g the nasal cannula. This may serve as an additional safety feature, wherein the nasal cannula are accidentally dislodged from their position in nares. If the dislodgement occurs, the air diffuser reduces the risk that relatively high ﬂow air will directed into a sensitive region of the patient’s face such as the eyes. Even if the air is accidentally ed into the eyes of the patient, the attachment of the air diffuser may signiﬁcantly reduce the overall ﬂow of air directed into the eyes and thereby increase safety ofthe device and reduce the overall risks.

In situations where the nasal cannala is dislodged while in operation, and this is detected by sensors attached to the system, the system or device may include a controller that sounds and/or displays an alarm to alert a patient or clinician to the dislodgement. .13 A DESIGN MODIFICATION [ 0114] The nasal a previously described for use with any of the aforementioned embodiments may further include noise limiting features. These noise ng features may reduce the l noise heard by the patient and people around the patient, wherein the system or device is operational.

In some embodiments, these noise limiting features may include specialized bafﬂes mounted on or in the nasal cannula or prongs to disperse or diffuse any noise emitted by the nasal cannala. This may be particularly true when the nasal cannula are ring relatively high ﬂow rates when compared to standard closed CPAP devices.

The noise bafﬂe may be ucted of a foam insert, a maze-like structure mounted on or proximal to the end of nasal cannula engaging the nares of the patient. An e, bafﬂe 1550 about a prong 880 is illustrated in .

In the foregoing description and in the accompanying drawings, speciﬁc terminology, equations and drawing symbols are set forth to provide a thorough understanding of W0 2009/146484 the present technology. In some instances, the terminology and symbols may imply c details that are not required to practice the technology. Moreover, although the technology herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative ofthe principles and applications of the logy. It is therefore to be understood that numerous modiﬁcations may be made to the illustrative embodiments and that other arrangements may be d without departing from the spirit and scope of the technology. For example, a device in accordance with the present technology could provide nasal CPAP. In one form ofthe technology, drug delivery is provided with the supply of breathable gas, for e in the form of a nebulised drug. For example, the present system may be used for ent of COPD or Cystic Fibrosis and accompanied with appropriate drugs for the respective diseases.

Claims

1. A patient interface device for a respiratory treatment apparatus to direct a flow of breathable gas to the respiratory system of a patient comprising: a coupling for a breathable gas delivery hose, a gas directing outlet portion to direct a flow of breathable gas to nares of a patient; and a nasal dilator mount portion configured for supporting a nasal dilator ion member that plies an expansion force for dilation of at least one of the nares, wherein the patient interface device is configured to permit the flow of breathable gas to escape at gaps n the patient interface device and the nares of the patient when, in use, the flow of breathable gas is provided to the nares, and while dilator extension members, ing the nasal dilator extension member, are able to ply the expansion force for dilation of the nares.

2. The patient interface device of claim 1 n the nasal dilator mount portion comprises a gap ured to receive a removable nasal dilator strip.

3. The pat ient interface device of either claim 1 or claim 2 wherein the nasal dilator mount portion comprises a bridge support configured to, in use, conform to a nose shape of a patient.

4. The pat ient interface device of claim 3 wherein the bridge support is configured to, in use, be proximate to a ridge area of the patient’s nose.

5. The patient interface device of claim 1, further comprising another nasal dilator extension member of the dilator extension s.

6. Th e patient interface device of claim 5 wherein the nasal dilator mount portion comprises a set of nasal dilator ion members coupled to the nasal dilator mount portion, the set sing the nasal dilator ion member and the another nasal dilator extension member.

7. The patient interface device of claim 6 wherein the set of nasal dilator extension s is configured to secure the patient interface device in a suitable on for providing the flow of breathable gas to the nares of the patient.

8. The patient interface device of any one of claims 1 to 7 wherein the nasal dilator extension member is configured to provide, in use, the expansion force at an external surface of a nose to dilate a nare of the nose.

9. The patient interface device of any one of claims 5 to 7 wherein the nasal dilator extension member is configured to e, in use, the ion force against an al surface of a nare to dilate the nare.

10. The patient ace device of claim 9 wherein the nasal dilator extension member extends from a nasal prong of the patient interface device.

11. The patient interface device of any one of claims 1 to 10, wherein the nasal dilator extension member is formed of a flexible and resilient material to provide a dilation force.

12. The patient interface device of any one of claims 1 to 11, wherein the nasal dilator extension member is configured with one or more spring elements for providing the expansion force.

13. The pati ent interface device of any one of claims 1 to 12 wherein the patient interface device comprises a cannula and the gas directing outlet portion comprises a set of nasal prongs.

14. The patient interface device of any one of claims 1 to 13 wherein the ng comprises a swivel configured for relative rotation between the breathable gas delivery hose and the gas directing outlet portion.

15. The patient interface device of claim 14 wherein the swivel is configured for relative rotation between the breathable gas delivery hose and the gas ing outlet n about a plurality of perpendicular axes.

16. The patient interface device of any one of claims 1 to 15 wherein the t interface device is adapted to, in use, engage the nares of the patient, and n the patient ace device includes a baffle on, or proximal to, an end of the patient interface device that, in use, s a nare of the patient.

17. The patient interface device of claim 16 wherein the flow of breathable gas is directed from the respiratory treatment tus, wherein the respiratory treatment apparatus is a high flow rate respiratory treatment apparatus.

18. A respiratory treatment apparatus to direct a flow of breathable gas to the respiratory system of a patient comprising: the patient interface device of any one of claims 1 to 17, one or more sensors, a flow generator, and a controller coupled with the flow generator and the one or more sensors and configured to control the flow generator to control flow rate of the flow of able gas, wherein the respiratory treatment apparatus comprises a high flow rate respiratory treatment apparatus.

19. The respiratory treatment apparatus of claim 18 wherein the controller is configured to control the flow generator to vary the flow rate of the flow of breathable gas.