Respiratory Support Systems

Abstract

The device for providing breathing gas includes a blower configured to receive a first gas from a first gas flow path to generate a first gas flow that is provided through a first gas outlet of the blower; a second gas flow path configured to receive a second gas flow to provide a second gas flow through the second gas outlet; and a mixing chamber configured to receive the first gas flow from the first gas outlet and the second gas flow from the second gas outlet. The received gases are configured to mix in the mixing chamber to form a mixed gas. The received gases are configured to move in the mixing chamber in a mixed flow direction toward the mixed gas inlet, and the mixed gas exits the mixing chamber via the mixed gas inlet to provide flow into the mixed gas flow path.

Description

[Technical field]

[0001] This application claims priority to U.S. Provisional Patent Application No. 63 / 265,954, filed December 23, 2021, the contents of which are incorporated herein by reference.

[0002] The present disclosure relates to devices and systems for providing respiratory assistance to a patient, and in particular, but not exclusively, to a system for providing high-flow respiratory assistance that provides a flow of mixed gas to a patient, and devices for use with the system in providing respiratory assistance. [Background technology]

[0003] Patients with or at risk of respiratory decline may benefit from high-flow respiratory support. Patients may lose respiratory function during anesthesia or sedation, or more generally during some medical procedures. Prior to a medical procedure, the patient may be pre-oxygenated by a medical professional to create a reserve of oxygen saturation, and this pre-oxygenation is typically performed with a bag and face mask. Once under general anesthesia, the patient must be intubated to ventilate the patient. In some cases, intubation is often completed in less than 60 seconds, but in other cases, especially if the patient's airway is difficult to cross (e.g., due to cancer, severe injury, obesity, or spasms of the neck muscles), it may take significantly longer. Pre-oxygenation mitigates the loss of oxygen saturation, but longer intubation procedures require the intubation process to be interrupted and the patient's oxygen saturation to be increased to an appropriate level with the face mask again. Interruptions to the intubation process may occur several times during a difficult intubation process, which can be time-consuming and potentially endanger the patient. After approximately three attempts at intubation, medical treatment is abandoned.

[0004] Other situations in which patients may experience reduced respiratory function that may benefit from the administration of high-flow respiratory support include those in which the patient suffers from respiratory disease, such as those frequently encountered in intensive care units (ICUs).

[0005] The present disclosure relates to systems and devices for providing respiratory assistance, and in particular high flow respiratory assistance.

[0006] The reference herein to a patent document or any other matter identified as prior art is not to be considered an admission that the document or other matter was publicly known or that the information it contains was part of the common general knowledge at the priority date of any of the provisional claims. Summary of the Invention [Means for solving the problem]

[0007] Viewed from one aspect, the present disclosure provides an apparatus for providing a breathing gas, the apparatus including: (a) a blower configured to receive a first gas from a first gas flow path to generate a first flow of gas that is provided through a first gas outlet of the blower; (b) a second gas flow path configured to receive a second flow of gas to provide a second flow of gas through the second gas outlet; and (c) a mixing chamber configured to receive the first flow of gas from the first gas outlet and the second flow of gas from the second gas outlet, the received gases configured to mix in the mixing chamber to form a mixed gas, the received gases configured to move within the mixing chamber in a mixed flow direction toward the mixed gas inlet, and the mixed gas exits the mixing chamber via the mixed gas inlet to provide flow into the mixed gas flow path.

[0008] In some embodiments, the mixing chamber receives a flow of gas from a second gas outlet upstream of the first gas outlet in the mixed flow direction.

[0009] In some embodiments, one or both of the first gas outlet and the second gas outlet are positioned to achieve a flow of the first gas and / or the second gas substantially tangentially along a wall of the mixing chamber.

[0010] In some embodiments, the first gas flow path is an oxygen flow path.

[0011] In some embodiments, the first gas outlet and the second gas outlet are positioned relative to the mixing chamber such that the first gas outlet is positioned to direct a first gas entering the mixing chamber away from the second gas outlet.

[0012] In some embodiments, the first gas flow outlet and the second gas flow outlet are arranged such that the first gas in the first gas flow outlet is directed in a first flow direction between a direction that is substantially parallel to a second flow direction of the second gas in the second gas flow outlet and a direction that is substantially perpendicular to the second flow direction. For example, the first flow direction relative to the second flow direction can be at an angle of about 0° to less than about 90°.

[0013] In some embodiments, the first flow direction and the second flow direction are in a common plane. Alternatively / additionally, the mixed flow direction, the first flow direction and the second flow direction may be in a common plane.

[0014] In some embodiments, the mixed gas inlet is positioned such that the mixed gas flow in the mixed gas flow passage is directed in a mixed flow direction between a direction substantially perpendicular to one or both of the first and second flow directions and a direction anti-parallel to one or both of the first and second flow directions.

[0015] In some embodiments, the mixed flow direction is substantially anti-parallel to the second flow direction, where anti-parallel has its conventional meaning of parallel but opposite moving directions.

[0016] In some embodiments, the cross-section of the mixing chamber is substantially circular. For example, the mixing chamber can be substantially cylindrical.

[0017] In some embodiments, the mixed flow direction within the mixing chamber is about a central shaft. The central shaft may include a portion of a blower, such as a blower motor assembly, where the mixed flow direction is about the axis of the blower motor assembly.

[0018] In some embodiments, the mixing chamber is configured such that the gas moves in a spiral manner within the mixing chamber. This may include a spiral movement of the gas as it exits the first gas outlet into the mixing chamber. Alternatively / additionally, this may include a spiral movement about the axis of the blower motor assembly.

[0019] In some embodiments, the mixing chamber is configured with a plurality of adjacent sectors, and the first gas outlet and the second gas outlet are disposed within adjacent sectors of the mixing chamber. The plurality of sectors may include four quadrants. In some embodiments, the mixed gas inlet may be disposed within a non-adjacent sector of the first gas outlet. The mixed gas inlet may be disposed in a sector that optimizes flow uniformity within the mixed gas flow path.

[0020] In some embodiments, the second gas outlet arrangement allows for the flow of gas from the mixing chamber into the second gas flow passage. The second gas outlet may include a guide portion. The guide portion may include a taper configured to direct the flow of the second gas into the mixing chamber.

[0021] In some embodiments, the second gas flow path includes a flow conditioner at the second gas outlet configured to increase resistance to gas flow from the mixing chamber. The flow conditioner may include a plurality of substantially parallel flow channels. In some embodiments, the flow conditioner may have an outlet end shaped to be continuous with an inner wall of the mixing chamber. In some embodiments, the flow conditioner is integrally formed with the device. The term "second gas outlet" refers to an oxygen outlet that introduces O2 into the mixing chamber.

[0022] In some embodiments, the second gas flow passage includes one or more nozzles configured to provide a flow of the second gas to the mixing chamber through a nozzle diameter that is smaller than a diameter of the second gas flow passage.

[0023] In some embodiments, the second gas flow path includes a check valve.

[0024] In some embodiments, the second gas flow path includes a proportional valve.

[0025] In some embodiments, the instrument includes a first flow sensor for sensing a flow rate of gas in the first gas flow path.

[0026] In some embodiments, the instrument includes a second flow sensor for sensing a flow rate of the gas in the second gas flow path. The second flow sensor, when provided, may sense a flow rate of the gas downstream of the proportional valve.

[0027] In some embodiments, the instrument includes a third flow sensor for sensing a flow rate of the mixed gas in the mixed gas flow path.

[0028] In some embodiments, the mixed gas flow path includes a mixed flow regulator upstream of the third flow sensor. The mixed flow regulator can be located at or proximate to the mixed gas inlet. The mixed flow regulator can be integral to the mixed gas inlet.

[0029] In some embodiments, the mixed flow regulator has an inlet end configured to be contiguous with an interior wall of the mixing chamber. The mixed flow regulator can include a plurality of substantially parallel flow channels.

[0030] In some embodiments, one or more of the first gas, the second gas, and the mixed gas flow include a flow rate of 0 L / min or more, optionally, the mixed gas flow includes a flow rate of about 20 L / min to about 90 L / min, optionally, the mixed gas flow includes a flow rate of about 40 L / min to about 70 L / min.

[0031] In some embodiments, the device includes a plurality of cooperating components having bores formed therethrough that cooperate to define a plurality of gas flow paths and cooperating cavities formed therein that define cavities for receiving a blower and a mixing chamber.

[0032] In some embodiments, the instrument includes a pneumatic block having three or more cooperating components: (a) a first component includes a first opening defining a first gas inlet, a second opening defining a second gas inlet, and a first cavity for receiving a first portion of a blower; (b) a second component includes three parallel through bores defining respective portions of the first gas flow path, the second gas flow path, and the mixed gas flow path, and a third opening defining an instrument outlet; (c) a third component includes three parallel through bores defining respective portions of the first gas flow path, the second gas flow path, and the mixed gas flow path, and a second cavity for receiving a second portion of the blower and defining a mixing chamber; the bores in the second component align with the bores in the third component to define collinear portions of the first gas flow path, the second gas flow path, and the mixed gas flow path. In some embodiments, the instrument includes a housing.

[0033] Viewed from another aspect, the present disclosure provides an apparatus for providing a breathing gas, the apparatus including: (a) a blower configured to generate a first flow of gas provided through a first gas outlet; (b) a second gas flow path configured to receive a second flow of gas and provide the second flow of gas through the second gas outlet; (c) a mixing chamber configured to receive the first flow of gas from the first gas outlet and the second flow of gas from the second gas outlet, the received gases configured to mix in the mixing chamber to form a mixed gas, the received gases configured to move within the mixing chamber in a mixed flow direction toward the mixed gas inlet; the mixed gas exits the mixing chamber via the mixed gas inlet and provides flow to the mixed gas flow path; and the mixed gas inlet is positioned within the mixing chamber relative to one or both of the first gas outlet and the second gas outlet to optimize flow uniformity within the mixed gas flow path.

[0034] In some embodiments, the first gas outlet is positioned such that flow from the first gas outlet is directed away from the mixed gas inlet within the mixing chamber.

[0035] In some embodiments, the second gas outlet is positioned such that flow from the second gas outlet is directed away from the mixed gas inlet within the mixing chamber.

[0036] In some embodiments, the first gas flow outlet and the second gas flow outlet are arranged such that the first gas in the first gas flow outlet is directed in a first flow direction between a direction that is substantially parallel to a second flow direction of the second gas in the second gas flow outlet and a direction that is substantially perpendicular to the second flow direction. The first flow direction relative to the second flow direction can be at an angle of about 0° to less than about 90°. In some embodiments, the first flow direction and the second flow direction are in a common plane.

[0037] In some embodiments, the mixed gas inlets are positioned such that the mixed gas flow in the mixed gas flow passage is directed in a mixed flow direction between a direction substantially perpendicular to one or both of the first and second flow directions and a direction anti-parallel to one or both of the first and second flow directions, and the first and second directions may be in a common plane.

[0038] In some embodiments, the instrument includes a mixed gas flow sensor for sensing a flow rate of the mixed gas in the mixed gas flow path. In some embodiments, the mixed gas flow path includes a mixed flow regulator upstream of the mixed gas flow sensor. In some embodiments, the mixed flow regulator is located at the mixed gas inlet. In some embodiments, the mixed flow regulator has an inlet end that is shaped to be continuous with an interior wall of the mixing chamber. The mixed flow regulator may include a plurality of substantially parallel flow channels. In some embodiments, the mixed flow regulator may be integral with the mixed gas inlet.

[0039] In some embodiments, the cross-section of the mixing chamber is substantially circular. The mixing chamber may be substantially cylindrical.

[0040] In some embodiments, the mixed flow direction within the mixing chamber is about a central shaft. The central shaft may include a portion of a blower, such as a blower motor assembly, where the mixed flow direction is about the axis of the blower motor assembly.

[0041] In some embodiments, the mixing chamber is configured such that the gas travels in a spiral manner within the mixing chamber.

[0042] In some embodiments, the mixing chamber is configured with a plurality of adjacent sectors, and the first gas outlet and the second gas outlet are disposed within adjacent sectors of the mixing chamber. The plurality of sectors may include four quadrants. In some embodiments, the mixed gas inlets are disposed within non-adjacent sectors of the first gas outlet. The mixed gas inlets may be disposed in sectors that optimize flow uniformity within the mixed gas flow path. In some embodiments, the arrangement of the second gas outlet allows gas to flow from the mixing chamber into the second gas flow path.

[0043] In some embodiments, one or more of the first gas, the second gas, and the mixed gas flow include a flow rate of 0 L / min or more, optionally, the mixed gas flow includes a flow rate of about 20 L / min to about 90 L / min, optionally, the mixed gas flow includes a flow rate of about 40 L / min to about 70 L / min.

[0044] In view of another aspect of the present disclosure, there is provided an apparatus for providing a flow of breathing gas, the apparatus comprising a pneumatic block assembly including a plurality of cooperating block components configured, when assembled, to provide: (a) a first through bore defining a first gas flow path; (b) a second through bore defining a second gas flow path; (c) a cavity defining a mixing chamber; and (d) a third through bore defining a mixed gas flow path; the pneumatic block assembly including a material having an unoccupied volume comprised of the through bore and the cavity, wherein a proportion of the unoccupied volume attributable to the through bore is greater than a proportion of the unoccupied volume attributable to the cavity.

[0045] In some embodiments, the cavity is configured to accommodate a blower.

[0046] In some embodiments, the unoccupied volume attributable to the through bore is greater than about 50%, preferably greater than about 60%, optionally greater than about 64% of the unoccupied volume.

[0047] In some embodiments, the unoccupied volume attributable to cavities is about 20%, optionally about 18% of the unoccupied volume.

[0048] In some embodiments, the pneumatic block assembly further comprises one or more sensor cavities, wherein the unoccupied volume attributable to the sensor cavities is about 20%, optionally about 18% of the unoccupied volume.

[0049] In some embodiments, the pneumatic block assembly comprises a metal or metal alloy with through bores and cavities machined or milled therein.

[0050] In another embodiment, the pneumatic block assembly includes a metal or metal alloy having through bores and cavities formed therein using a mold.

[0051] In some embodiments, the pneumatic block assembly includes one or more thermally conductive materials, hi some embodiments, the pneumatic block assembly includes one or more materials selected from the group including metals, metal alloys, ceramics, and polymers.

[0052] In some embodiments, the arrangement of the cavity housing the first gas flow path, the second gas flow path, the mixed gas flow path, and the blower and defining the mixing chamber within the pneumatic block assembly provides a compact form factor.

[0053] In some embodiments, a pneumatic block assembly includes a plurality of block components, a first block component providing a mounting surface to which the other block component is configured to be mounted.

[0054] In some embodiments, the pneumatic block assembly includes a mounting element configured to cooperate with a mounting structure to which the instrument can be attached during use.

[0055] In some embodiments, the device includes a housing. The attachment element may be provided through the housing.

[0056] In some embodiments, the housing includes a ventilation blower configured to ventilate within the housing. The housing may include a baffle configured to direct flow from the ventilation blower over an upper side of the pneumatic block within the housing. In some embodiments, the flow from the ventilation blower is separated from the flow of breathing gas.

[0057] In some embodiments, the baffle includes one or more slots for accommodating electrical components within the housing. Alternatively / in addition, the baffle may include one or more structures to guide airflow from the ventilation blower to the power supply connector of the equipment. Alternatively / in addition, the baffle may include one or more features that provide structural strength to mitigate one or more of sagging, compression, or bending of the baffle or portions thereof.

[0058] In some embodiments, the baffle divides the airflow from the ventilation blower and optionally includes one or more features that direct the flow over different components of the equipment, such as, but not limited to, the topsides of the power distribution components of the equipment.

[0059] In some embodiments, the baffle includes one or more hollow portions positioned to engage one or more protrusions on the interior surface of the housing. The one or more hollow portions may include a conical section configured to engage a protrusion including a threaded boss within the housing.

[0060] In some embodiments, the baffle includes one or more slots configured to cooperate with protrusions on the inner surface of the housing.

[0061] In some embodiments, the baffle is disposed between opposing walls of the housing.

[0062] In view of another aspect of the present disclosure, there is provided an apparatus for providing a flow of breathing gas, the apparatus including: (a) a flow modulator having an inlet and an outlet, the flow modulator configured to effect a flow of gas through the outlet; and (b) a flow regulator configured to regulate the flow of gas from the outlet; the flow regulator configured to disperse the flow of gas entering the flow regulator and to regulate gas exiting the flow regulator.

[0063] The flow modulator may include a proportional valve.

[0064] In some embodiments, the flow conditioner includes a first portion configured to receive and distribute a flow of gas. The first portion may include a sintered metal filter, preferably a bronze sintered filter. In some embodiments, the first portion includes a cavity configured to fill with the flow of gas that is distributed through an opening in the filter when pressure within the filter exceeds a filter threshold.

[0065] In some embodiments, the flow conditioner includes a second portion configured to straighten the dispersed gas.

[0066] In some embodiments, the first portion includes a conical exterior shape having a tip configured to be received in a corresponding recess in the second portion. In some embodiments, the recess includes a through hole. The tip may be shaped to key or cooperate with the recess in the second portion.

[0067] In some embodiments, the second portion includes a plurality of openings. The cross-section of the openings may be substantially circular. In some embodiments, the openings in the second portion provide a honeycomb structure. In some embodiments, the second portion includes a plurality of parallel flow channels. In some embodiments, the length of the plurality of flow channels may be non-uniform among the plurality of flow channels. The diameter of the plurality of flow channels may be uniform or non-uniform. The cross-sectional shape of the plurality of flow channels may be uniform or non-uniform. In some embodiments, the plurality of flow channels are radially arranged within the second portion.

[0068] In some embodiments, the plurality of flow channels are disposed in the second portion such that they are entirely within the flow channel downstream of the flow conditioner.

[0069] In some embodiments, the gas flow exits the outlet at a high velocity and / or the cross-sectional area of ​​the gas flow exiting the outlet is smaller than the cross-sectional area of ​​the passageway it entered.

[0070] In view of another aspect of the present disclosure, there is provided an apparatus for providing a flow of respiratory gas, the apparatus including: an inlet; and an outlet for providing a flow of respiratory gas to a patient, the outlet including an outlet connector configured to be coupled with a delivery connector to provide the flow of respiratory gas to the patient; the outlet connector including an outlet end configured to releasably receive the delivery connector, the outlet end including a plurality of apertures having an opening size smaller than the delivery connector to prevent over-insertion of the delivery connector into the apparatus.

[0071] In some embodiments, the apertures are positioned towards a central portion of the outlet connector, and therefore may be located closer to the central axis of the outlet connector than to the periphery of the outlet connector.

[0072] In some embodiments, the outlet connector includes an inlet end configured to receive a flow of breathing gas into the outlet connector.

[0073] In some embodiments, the outflow end includes a central opening and a plurality of apertures.

[0074] In some embodiments, the outlet connector, when mated with the feed connector, is configured to provide a plurality of flow paths including at least a central flow path between the inlet end and the central opening, and a plurality of outer flow paths between the inlet end and the plurality of apertures. The plurality of outer flow paths may be substantially parallel to the central flow path.

[0075] In some embodiments, the central opening is configured to align with the central opening of the feed connector.

[0076] In some embodiments, the outflow end includes an internal taper configured to guide insertion of the delivery connector.

[0077] In some embodiments, the outflow end is configured to form a sealing engagement with the delivery connector.

[0078] In some embodiments, the outflow end has a smaller internal cross-section at or near the apertures or at or near a central portion of the outlet connector compared to the internal cross-section at or near the terminal end.

[0079] In some embodiments, the device includes a check valve between the mixed gas outlet of the device and the inlet end of the outlet connector.

[0080] In some embodiments, the apparatus includes a pneumatic block defining a first gas flow path, a second gas flow path, a mixed gas flow path, and a mixing chamber, and the check valve is downstream of a mixed gas outlet of the pneumatic block, In some embodiments, the outlet connector includes a connector gasket configured to provide a substantially sealed coupling with the pneumatic block.

[0081] In some embodiments, the check valve is positioned at an angle such that gravity biases the check valve to a closed position when the device is upright.

[0082] In some embodiments, the outlet connector is oriented to receive the inlet connector at an angle that requires the application of a connection force having both vertical and horizontal force vectors. For example, the outlet connector may be oriented at an angle of approximately 60 degrees to the vertical that requires the application of a lateral and upward connection force simultaneously.

[0083] The present invention will now be described in detail with reference to the accompanying drawings, in which like features are represented by like numerals, and in which it should be understood that the illustrated embodiments are examples only and are not to be taken as limitations on the scope of the invention as defined in the provisional claims appended hereto. [Brief description of the drawings]

[0084] [Figure 1] FIG. 1 is a schematic diagram of an example of a breathing system for providing breathing gas to a patient. [Diagram 2] FIG. 1 is a schematic diagram illustrating components of a system for delivering respiratory gas according to an embodiment of the present disclosure. [Figure 3A] 1 is a flow diagram based on a computational fluid dynamics model showing the flow of gas within the mixing chamber and flow paths of the device, according to various embodiments of the present disclosure. [Figure 3B] 1 is a flow diagram based on a computational fluid dynamics model showing the flow of gas within the mixing chamber and flow paths of the device, according to various embodiments of the present disclosure. [Figure 3C] 1 is a flow diagram based on a computational fluid dynamics model showing the flow of gas within the mixing chamber and flow paths of the device, according to various embodiments of the present disclosure. [Figure 4A] FIG. 13 is a computational fluid dynamics (CFD) diagram showing the undesirable flow of gas within the mixing chamber and flow passages when the blower outlet is located in an unfavorable sector of the mixing chamber. [Figure 4B] FIG. 13 is a computational fluid dynamics (CFD) diagram showing the undesirable flow of gas within the mixing chamber and flow passages when the blower outlet is located in an unfavorable sector of the mixing chamber. [Figure 4C] FIG. 13 is a computational fluid dynamics (CFD) diagram showing the undesirable flow of gas within the mixing chamber and flow passages when the blower outlet is located in an unfavorable sector of the mixing chamber. [Figure 4D] FIG. 13 is a computational fluid dynamics (CFD) diagram showing the undesirable flow of gas within the mixing chamber and flow passages when the blower outlet is located in an unfavorable sector of the mixing chamber. [Figure 5A] FIG. 2 is an end view of a flow conditioner for use in some embodiments of the present disclosure. [Figure 5B] FIG. 2 is a perspective view of a flow conditioner for use in some embodiments of the present disclosure. [Figure 5C] FIG. 2 is a side view of a flow conditioner for use in some embodiments of the present disclosure. [Figure 6A] FIG. 1 is a front perspective view of a pneumatic block constructed from multiple block components and assembled in accordance with an embodiment of the present disclosure. [Figure 6B] FIG. 1 is a front perspective view of a pneumatic block constructed from multiple block components and assembled in accordance with an embodiment of the present disclosure. [Figure 7A] FIG. 7 is a front perspective view of the pneumatic block 700 of FIGS. 6A and 6B with a mixed gas straightener formed integrally with the device. [Figure 7B]FIG. 7B is a front perspective view of the pneumatic block of FIGS. 6A, 6B and 7A modified such that the mixed gas straightener is not integrally formed with the device. [Figure 8] FIG. 7C is a perspective view of the rear of the pneumatic block in FIGS. 6A-7B, particularly showing the first component features on the rear surface of the pneumatic block. [Figure 9] FIG. 3 shows a representation of the flow lines of air being received into an air inlet of a pneumatic block first component, traveling through a bore in a third component, to a cavity within the first component, and delivering the air to the inlet of a blower 310. [Figure 10A] 1 is a schematic diagram of an airflow conditioner that may be provided in an air flow path according to an embodiment of the present disclosure. [Figure 10B] 13 is a schematic diagram of another airflow conditioner that may be provided in the air flow path according to an embodiment of the present disclosure. FIG. [Figure 11A] FIG. 2 is an end view of a mixed gas flow regulator not integrally formed with the instrument. [Figure 11B] FIG. 2 is a side view of a mixed gas flow regulator not integrally formed with the equipment. [Figure 12A] FIG. 1 illustrates a side view of an outlet connector according to an embodiment of the present disclosure. [Figure 12B] FIG. 13 illustrates an end view of an outlet connector according to an embodiment of the present disclosure. [Figure 12C] FIG. 1 illustrates a cross-sectional view of an outlet connector according to an embodiment of the present disclosure. [Figure 13A] 1 illustrates an air inlet of an appliance with a removable filter and a removable cover according to an embodiment of the present disclosure. [Figure 13B] 1 illustrates an air inlet of an appliance with a removable filter and a removable cover according to an embodiment of the present disclosure. [Figure 13C] 1 illustrates an air inlet of an appliance with a removable filter and a removable cover according to an embodiment of the present disclosure. [Figure 14A] 1 illustrates a second air inlet of a device with a removable filter and a removable cover according to an embodiment of the present disclosure. [Figure 14B] 1 illustrates a second air inlet of a device with a removable filter and a removable cover according to an embodiment of the present disclosure. [Figure 14C] 1 illustrates a second air inlet of a device with a removable filter and a removable cover according to an embodiment of the present disclosure. [Figure 15A] 1 shows the flow path within the housing of the device, illustrating the path of least resistance. [Figure 15B] 1 shows the flow paths within the housing of the device, illustrating the guided flow paths. [Figure 16A] FIG. 2 is a front perspective view of a baffle for directing flow within an equipment housing. [Figure 16B] FIG. 2 is a rear perspective view of a baffle for directing flow within an equipment housing. [Figure 17A] 16A and 16B are shown positioned to direct flow across the pneumatic block and IEC connector. [Figure 17B] 17B illustrates the arrangement of FIG. 17A, further showing the display screen. [Figure 18A] 1 illustrates an oxygen flow regulator having a first portion and a second portion according to an embodiment of the present disclosure. [Figure 18B] 18D shows a first portion of an oxygen flow regulator separated from the second portion shown in FIG. 18C. [Figure 18C] 1 shows a second portion of the oxygen flow regulator. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0085] Embodiments of the present disclosure are described herein with reference to the drawings, which are not to scale and are intended solely to aid in illustrating the invention.

[0086] In anesthesia procedures where high-flow respiratory support is provided, the oxygen (O2) level of the high-flow gas may be higher than ambient air (21%). In general anesthesia procedures, 100% O2 is delivered to the patient during pre-oxygenation to store O2 in the patient's lungs and blood (acting as a buffer) before induction of anesthesia, and before intubation (during which the patient may be apneic) to maintain blood oxygen levels or prevent / reduce a drop in blood oxygen levels.

[0087] Flow rates during general anesthesia procedures can reach 70 L / min, or in some cases, 90 L / min during apneic oxygenation. In this context, the combination of high O2 concentrations and high flow rates required to provide respiratory assistance requires a system that can reliably, accurately, and safely control the delivery of high gas flows and / or high O2 concentrations to a patient. Embodiments of the present disclosure may improve one or more of sensor performance, gas mixing, and flow regulation, which in turn may result in improved system and device performance in providing high-flow respiratory assistance. It may be desirable to provide gas with a flow profile that is linear, uniform, and / or parallel with respect to the sensors and their measurements, for example, to improve sensing accuracy and / or consistency. In some embodiments, a flow regulator may be used to adjust the gas flow to approximate a desired flow profile. Alternatively and / or in addition, flow sensors may be used to determine the actual flow within the device, so that improved gas flow control and delivery may be achieved.

[0088] 1 is a schematic diagram of an example of a respiratory system 1 for providing respiratory gas to a patient. System 1 includes a flow source 3, such as an in-wall source of O, an O tank, a blower, a flow therapy device, or any other source of O or other gas, or a combination thereof. In some embodiments, flow source 3 includes a flow modulator, which in some embodiments includes a flow generator, such as a blower, that provides a gas flow including a mixture of air and O at a high flow rate as controlled by controller 4. From flow source 3, respiratory gas travels via first conduit 17 and inlet 9 to humidification chamber 6 of humidifier 7, where the gas may be conditioned to a predetermined temperature and / or humidity as determined by controller 4.

[0089] The humidifier 7 is configured to condition the gas to a predetermined temperature and / or humidity before delivery to the patient. The flow of respiratory gas provided by the patient may be humidified or, in some implementations, non-humidified. The humidifier 7 may also include a humidification base unit. In one example, the humidification base unit includes a heating element operable to heat a humidification fluid in the humidification chamber 6, for example, via a conductive base in the chamber 6. The first conduit 17 may provide a conduit for delivering the dry gas flow to the humidifier 7. The first conduit 7 may be coupled to the humidification chamber 6 of the humidifier 7 as shown. Alternatively, the humidifier 7 may be a single component (not shown), eliminating a separate humidification chamber 6 and / or base unit. The humidifier 7 may be configured to condition the gas provided by the flow source 3 to a required temperature and / or humidity. The required temperature and / or humidity may be determined according to the respiratory assistance being provided and may be selected by a user or operator as appropriate for the respiratory assistance being provided.

[0090] The humidified and / or warmed breathing gas exits the humidifier 7 via an outlet 11 to which an inhalation conduit 101 is coupled for delivering conditioned breathing gas to the patient 16 via the patient interface 5. Typically, for high flow delivery using the system 1, the patient interface is a non-sealing interface, such as a non-sealing nasal cannula. In other embodiments, the patient interface 5 may be a sealing interface, such as a nasal mask, a full face mask, or a nasal pillow. In some embodiments, the humidified gas in the inhalation conduit 101 may be heated by a heating element 119 provided in the inhalation conduit or in the inhalation conduit. In some embodiments, an optional filter 13 may be provided to filter the gas delivered to the patient 16. The optional filter 13 may also be provided to prevent contamination of the humidification chamber and inhalation conduit in the event of backflow from the patient. The optional filter 13 includes an inlet end 19 configured to couple with the inhalation conduit 101 at a coupling 105. Gas entering inlet end 19 is passed through filter 15 and exits filter outlet end 21 for delivery to patient interface 5 via filtered gas conduit 22 .

[0091] The controller 4 includes an input-output interface (I / O interface) 20 configured to receive user input according to the respiratory assistance provided to the patient and then communicate to the user by audible means such as a screen or speaker when one or more alarm conditions are met. The controller 4 includes or is in operative communication with one or more memory components configured to cause the processor to execute instructions for controlling the flow of respiratory gas according to one or more protocols stored in the memory.

[0092] In some embodiments, a user provides the I / O interface 20 with respiratory support conditions, such as the composition (e.g., O2 concentration), flow rate, and / or pressure of the gas to be delivered to the patient's airway. The controller 4 then computes the control signals necessary for operation of the components of the system to deliver the flow rate, pressure, and / or O2 concentration by controlling the flow source 3 and / or various components in the system (e.g., proportional valve 212 - see FIG. 2) to regulate the flow of gas. The controller 4 may receive multiple sensor inputs that are used by the controller to determine the control signals as described herein. In some embodiments, the I / O interface 20 may display one or more parameters of the system, such as gas flow rate, pressure (e.g., patient, system, etc.), temperature, gas concentration, e.g., O2 concentration, etc., which may be received from one or more inputs, such as the controller 4 and sensors.

[0093] In some embodiments, the present disclosure provides a device comprised of mechanical, electrical and electronic components arranged to provide a flow of gas that safely and / or efficiently provides the necessary respiratory support. FIG. 2 is a schematic diagram showing components of a device 100 for providing respiratory gas according to an embodiment of the present disclosure. The device 100 includes an O2 flow path 200, an air flow path 300 and a mixed gas flow path 400. The O2 flow path 200 is in fluid communication with an O2 supply 210, which may be a high pressure O2 supply. The device 100 represents the flow source 3 of FIG. 1. In one example, the flow source 3 may also include the O2 supply 210. The flow rate of gas in the O2 flow path 200 is controlled by a proportional valve 212 operably coupled to the controller 4. The air flow path 300 has a blower 310 that draws in ambient air from an air intake 314. The flow rate of gas in the air flow path 300 is controlled by the blower 310 operably coupled to the controller 4. Air from the air intake 314 may be filtered by an air filter 316 to remove particulates. Similarly, a filter 216 may be provided to filter small particles (e.g., <100 um) from the O2 supply 210. The filter may be located in an O2 connector that is coupled to the inlet of the O2 supply 210. The O2 mixes with air downstream of the blower 310 to form a mixed gas flow in the mixed gas flow path 400, which is delivered to the patient as a flow of respiratory gas. A flow regulator, such as the flow regulator 250 shown in Figures 7A and 18A-C, may be provided downstream of the proportional valve 212 and upstream of the O2 flow sensor 218.

[0094] Various sensors may also be provided, such as an O2 pressure sensor 214 configured to sense an O2 pressure in the O2 flow path (e.g., to determine that there is a flow of O2 entering the O2 flow path), an O2 flow sensor 218 configured to sense a flow rate in the O2 flow path 200, an air flow sensor 318 configured to sense a flow rate in the air flow path 300, and a mixed gas flow sensor 418 configured to sense a flow rate in the mixed gas flow path 400 delivered to the patient. Additionally, one or more gauge pressure sensors 414 may be provided in the mixed gas flow path 400, and one or more ambient pressure sensors 114 may be provided to sense ambient air pressure. The one or more gauge pressure sensors 414 may take a reference from the one or more ambient pressure sensors 114 to measure the pressure in the mixed gas flow path 400. The flow rate and pressure of the mixed gas in the mixed gas flow path 400 may be controlled by operation of the blower 310 and / or the proportional valve 212.

[0095] Mixing of gases from the O2 flow path 200 and the air flow path 300 occurs in the mixing chamber 500 shown in dashed lines in FIG. 2, where gases from the O2 flow path 200 enter the mixing chamber through the O2 outlet 220, and gases from the air flow path 300 enter the mixing chamber through the air outlet 320. Due to the physical arrangement of the blower 310 in the air flow path 300 in some preferred embodiments, as will become apparent below, the air outlet 320 may be referred to as the blower outlet 320 in some embodiments. The mixing chamber 500 may have a circular cross-section, e.g., cylindrical or spheroidal, or an oval or elliptical cross-section, such that interruptions or obstructions to the flow of gases within the mixing chamber due to corners or other internal features of the mixing chamber are minimized. The mixing chamber 500 has a mixed gas inlet 510, through which the mixed gases from the mixing chamber flow into the mixed gas flow path 400.

[0096] The device 100 may be mounted within a housing 900, which may further include a ventilation blower 650 to improve safe operation of the device, as described in more detail below. Not shown in the schematic layout of Figure 2 are the electrical inputs to the device 100 which supply each of the electrically powered components. The electrical input to the device 100 is by way of an IEC connector. The IEC connector may be connected to an IEC retainer 960 (see Figures 17A and 17B). Both the IEC connector and the IEC retainer are of a type known to those skilled in the art.

[0097] Components of the device 100 that direct the flow of gases within the device are provided in a substantially sealed pneumatic block 700 (e.g., as shown in Figures 6A & 6B), as described in more detail below. As shown in the schematic diagram of Figure 2, the O2 flow path 200 and the air flow path 300 are depicted as parallel flow paths. Relatedly, when the schematic diagram of the device 100 in Figure 2 is depicted in a mechanical device 100, in some embodiments, it may also be desirable to arrange the O2 flow path 200 and the mixed gas flow path 400 within the device such that at least a portion of the flow paths are arranged in a parallel configuration, as described below.

[0098] In some embodiments, the O2 flow path 200 and the air flow path 300, and in particular the O2 outlet 220 and the air outlet 320, are positioned relative to one another to reduce or prevent flow into the O2 path in a counterflow direction (i.e., against the direction of the bulk flow of O2 from the O2 source 210 into the O2 flow path). It is desirable to reduce or prevent backflow into the O2 path because this can affect the accuracy of sensing by the O2 flow sensor 218. Inaccurate sensing of O2 flow can affect the control signal provided to the proportional valve 212, which in turn can have negative consequences on the accuracy and safety of the respiratory gas delivered to the patient.

[0099] 2, where the O2 concentration in the flow delivered to the patient is calculated based on flow sensors 218, 318 and the concentration of O2 in the O2 flow path (e.g., 100% O2) and the concentration of O2 in the air flow path (21%), when a user provides input to I / O interface 20 to provide the delivered gas flow to the patient with a percentage of 21% O2, the flow in the O2 flow path should be zero or low because 21% O2 represents primarily ambient air. However, if undesirable flow occurs in O2 flow path 200, flow sensor 218 may record a negative or positive flow reading, which may cause controller 4 to record that there is less or more than 21% O2 in the delivered gas flow. This may cause the controller to open the proportional valve 212 to allow more O2 to flow to the patient if there is less than 21% O2 in the delivered flow, or to close the proportional valve 212 further if there is more than 21% O2 in the delivered flow, or to log an error if the proportional valve 212 cannot close further. In some applications, for example when the O2 supply is limited, additional O2 may be undesirable. An embodiment of the present disclosure seeks to mitigate such problems by carefully positioning the blower outlet 320 relative to the O2 outlet 220, and may use multiple flow sensors, for example flow sensors 218, 318, 418, to accurately monitor and control the percentage of O2 in the mixed gas flow path 400. The risk of this error occurring may also be reduced by adding an O2 concentration sensor to one or more flow paths, for example the O2 flow path 200 or the mixed gas flow path 300.

[0100] In some embodiments, it may be desirable to deliver breathing gas containing 100% O2. In such a scenario, the user inputs this O2 concentration set point into the I / O interface 20. The controller 4 then controls the proportional valve 212 to open sufficiently (e.g., by increasing the supply current) to allow enough O2 to enter the flow of breathing gas to meet the O2 concentration set point. This may create pressure downstream of the blower 310 so that only O2 is delivered to the patient; the blower 310 still operates to control flow and pressure, but the proportional valve 212 acts to prevent dilution of O2 with air from the air delivery circuit. In other words, in an embodiment where the device is set to output 100% FiO2 (where FiO2 is the percentage of oxygen delivered to the patient), the controller 4 adjusts both the opening of the proportional valve 212 and the speed of the blower 310 to meet the flow requirements set by the user. The blower 310 maintains pressure to limit the O2 coming out of the air inlet. For example, if the set point is 70 LPM and 100% FiO2, and the O2 flow sensor registers 72 LPM, the blower 310 speed can be slowed down and the opening size of the proportional valve 212 reduced. Therefore, the blower 310 still controls the flow to the patient.

[0101] In some embodiments, the mixing chamber 500 receives a flow of gas from the O2 outlet 220, upstream of the blower outlet 320, in a mixed flow direction within the mixing chamber 500. In some embodiments, the flow direction within the mixing chamber 500 may be represented by direction A in FIG. 3A. In some embodiments, one or both of the blower outlet 320 and the O2 outlet 220 are positioned to achieve a substantially tangential flow of air and O2 along the wall of the mixing chamber 500, to avoid air flow or backflow from the air flow passage 300 directly into the O2 flow passage 200. Alternatively / additionally, the blower outlet 320 and the O2 outlet 220 may be positioned relative to the mixing chamber such that the blower outlet 320 is positioned to direct air entering the mixing chamber 500 away from the O2 outlet 220. This means that air entering the mixing chamber 500 will join the gas flow in the mixing chamber and move tangentially within the mixing chamber, away from the O2 outlet 220, when the O2 outlet and air outlet 320 are in a common plane with the gas flow of the mixing chamber 500. However, it is also contemplated that in some embodiments, these outlets may not be provided in a common plane, and in such embodiments, the blower outlet 320 and O2 outlet 220 may be positioned such that the air flow into the mixing chamber 500 flows in a direction away from the O2 outlet 220 in three dimensions.

[0102] In some embodiments, the blower outlet 320 and the O2 outlet 220 are positioned such that air from the blower outlet is directed in a first flow direction and O2 from the O2 outlet 220 is directed in a second flow direction, where the first flow direction is between a direction substantially parallel to the second flow direction and a direction substantially perpendicular to the second flow direction. Ideally, the first and second flow directions are in a common plane, but this need not be the case. These flow directions may be described with reference to FIGS. 3A-3C, which are flow diagrams simulating gas flow within the device 100 with various relative placements of the blower outlet 320 and the O2 outlet 220. In some embodiments, the blower outlet 320 is positioned downstream of the O2 outlet 220. For ease of explanation of the various positions of the blower outlet 320 and O2 outlet 220 relative to the mixing chamber 500, the chamber is divided into a number of sectors called quadrants, with the first quadrant designated Q1, the second quadrant designated Q2, the third quadrant designated Q3, and the fourth quadrant designated Q4. It should be understood that there may be more than four sectors, but for ease of explanation, the sectors are represented in this disclosure as four quadrants.

[0103] In the flow diagram of Figure 3A, the blower outlet 320 is positioned such that the flow exiting the blower outlet enters Q1 and the first flow direction relative to the second flow direction is at an angle of 0° where the first and second flow directions are substantially parallel. The flow diagram generally shows that the flow from the blower outlet 320 enters the mixing chamber 500 and travels in a circular fashion through Q1, Q2 and Q3 before most of the flow exits the mixing chamber through the mixed gas inlet 510. The flow that remains in the mixing chamber 500 may be recirculated and preferably does not enter the O2 outlet 220.

[0104] In the flow diagram of Figure 3B, the blower outlet 320 is positioned such that the flow exiting the blower outlet enters Q1 and the first flow direction is at an angle of approximately 60° relative to the second flow direction. In the flow diagram of Figure 3C, the blower outlet 320 is positioned such that the first flow direction is at an angle of approximately 90° relative to the second flow direction at Q1. In both Figures 3B and 3C, the flow diagrams show that the flow from the blower outlet 320 enters the mixing chamber 500 and travels circularly through the remainder Q1, Q2, and Q3, and the remainder Q2 and Q3, respectively, before exiting the mixing chamber through the mixed gas inlet 510.

[0105] Flow uniformity within the mixed gas flow path 400 is also important for accurate flow measurement. The placement of the blower outlet 320 relative to the mixed gas inlet 510 can affect the flow behavior within the mixed gas flow path 400, as will be explained.

[0106] 3A-3C, with the blower outlet 320 positioned such that the flow enters the circular mixing chamber Q1, the flow entering the mixed gas flow passage 400 through the mixed gas inlet 510 has a level of uniformity that allows the flow sensor 418 to produce a value that is more representative of the actual flow in the mixed gas flow passage than if the flow in the mixed gas flow passage were less uniform. Ideally, the mixed gas flow passage 400 is positioned such that the mixed gas flow is directed in a mixed flow direction, where the mixed flow direction is between (and includes) a direction substantially perpendicular to one or both of the first and second flow directions and a direction anti-parallel to one or both of the first and second flow directions. Preferably, the mixed flow direction, the first flow direction and the second flow direction are in a common plane, but this need not be the case.

[0107] In the flow diagrams of Figures 3A-3C, the mixed flow direction is substantially anti-parallel to the second flow direction, where anti-parallel has its conventional meaning of parallel but opposite moving directions.

[0108] 4A-4D show flow diagrams simulating gas flow in the device 100 with various arrangements of the blower outlet 320 relative to the mixed gas inlet 510 simulating undesirable characteristics. In FIG. 4A, the blower outlet 320 is arranged such that the flow exiting the blower outlet enters Q2 resulting in a first flow direction at an angle of approximately 120° to the second flow direction. A portion of the flow from the blower outlet 320 exits the mixing chamber 500 via the mixed gas inlet 510 while a portion of the flow recirculates within the mixing chamber. The recirculating flow may travel at a higher velocity compared to the flow velocity simulated in FIG. 3A-3C and may swirl and spread when the recirculating flow hits the wall of the mixing chamber 500, causing a portion of the swirl and spread to enter the O2 flow path 200 creating an undesirable flow in the oxygen flow path. This may cause errors in the detection of the bulk gas flow in the O2 flow path 200.

[0109] In FIG. 4B, the blower outlet 320 is positioned such that the flow exiting the blower outlet enters Q3 resulting in a first flow direction at an angle of approximately 180° to the second flow direction. Most of the air flow from the blower outlet 320 exits the mixing chamber 500 via the mixed gas inlet 510. However, the flow uniformity in the mixed gas flow path 400 is compromised because the flow exiting the blower 310 is at a high velocity and the flow path length is insufficient for the flow to develop into a desired flow profile for accurate flow sensing. This may have a negative impact on the accuracy of the flow sensor 418. In some embodiments, a flow conditioner in the mixed gas flow path 400, for example at the mixed gas inlet 510, may be provided as described with respect to FIG. 11A and FIG. 11B, but this may be ineffective to achieve a desired flow profile, and in some cases, the gas flowing from the blower outlet 320 is at a high velocity. Therefore, the blower outlet 320 can be positioned relative to the mixed gas inlet 510 to improve the flow profile within the mixed gas flow passage 400 and reduce the risk of flow errors generated by the mixed gas flow sensor 418.

[0110] In Fig. 4C, the blower outlet 320 is located at Q3, which creates significant undesirable flow in the O2 flow path 200. This may be due to the undesirable flow profile of high velocity gas from the blower entering the mixing chamber 500, causing some of the flow, including the recirculating flow, to strike the edge of the O2 flow outlet 320, thereby inducing a spin motion in the flow and causing the flow to exit the mixing chamber and enter the O2 flow path 200. The uniformity of the flow in the mixed gas flow path 400 is also adversely affected, which may affect the accuracy of the operation of the mixed gas flow sensor 418. Both of these effects are undesirable.

[0111] In Figure 4D, the blower outlet 320 is positioned such that the flow exiting the blower outlet enters Q4. Due to the high energy of the gases exiting the blower, the flow from the blower outlet 320 interferes with the gases in the mixing chamber 500, including those in close proximity to the O2 outlet 200. This also creates undesirable flow in the O2 flow path 200. The uniformity of the flow in the mixed gas flow path 400 is also negatively affected.

[0112] In some embodiments, such as those depicted in the flow diagrams of FIGS. 3A-3C, the flow direction in the mixing chamber 500 may be about a central shaft that may include a portion of the blower 310, such as a blower motor assembly (which may include a motor and may include a motor housing), where the flow direction in the mixing chamber 500 may be about the axis of the blower motor assembly. The axis of the blower motor assembly may be an axis that runs through the length of the blower motor assembly. The axis of the blower motor assembly may also be an axis that runs through the length of the blower. Ideally, the mixing chamber 500 that receives the flow of gas from the blower 310 is configured such that the gas received in the mixing chamber travels in a spiral manner, which may aid in mixing of the gas in the mixing chamber in some embodiments.

[0113] As is evident from the characteristics of undesired flows in the flow diagrams of Figures 3A-3C and 4A-4D, it may be desirable to provide the mixed gas inlet in a sector that optimizes flow uniformity within the mixed gas flow path. This may include, in some embodiments, locating the mixed gas inlet 510 in a non-adjacent sector of the mixing chamber 500 with the sector that includes the blower outlet 320. In some embodiments, the O2 outlet 220 may be located such that undesired gas flow from the mixing chamber 500 into the O2 flow path 200 is not precluded. That is, there is no one-way valve or other flow control feature within the O2 flow path that would prevent flow from the flow chamber 500 into the O2 flow path 200. Rather, the likelihood of such undesired flows occurring is minimized by appropriately positioning the blower outlet 320 relative to the O2 outlet 220 as described above, thereby avoiding undesired flows within the O2 flow path 200. Alternatively / in addition, one or more baffles may be provided to guide the flow from the blower outlet 320 away from the O2 outlet 220. This may have the added benefit of directing the O2 around the curvature of the mixing chamber 500 to improve mixing and minimize the possibility of short-circuiting the O2 from the O2 outlet 220 to the mixed gas inlet 420. However, in some embodiments, it may be desirable to provide a check valve in the O2 flow path 200 to eliminate the risk of phantom flow. In some embodiments, the check valve may be located near the O2 outlet 220. It is therefore beneficial that one or both of the first gas outlet and the second gas outlet may be positioned to achieve a flow of the first gas and / or the second gas substantially tangentially along the wall of the mixing chamber. In some embodiments, the blower outlet 320 and the O2 outlet 220 are substantially in the same plane. In some embodiments, the blower and / or oxygen outlets 320, 220 are substantially in the same plane as the mixing chamber. In some embodiments, the mixed gas inlet 510 is substantially in the same plane as the mixing chamber.

[0114] Benchtop testing has shown that when the blower outlet 320 is positioned such that the first flow direction is at an angle between 0° and 90° relative to the second flow direction, there is negligible undesired flow in the O2 flow path, and the gas flow measured by the flow sensor 418 in the mixed gas flow path and the flow sensor 318 in the air flow path is substantially accurate and represents the true gas flow. For this benchtop testing, the true gas flow is the flow measured by the more accurate reference flow sensor compared to the flow sensors 218, 318, and 418 positioned in fluid communication with the instrument outlet 744. Testing has also shown that blower outlets 320 positioned at 135°, 180°, and 270° create undesired flow in the O2 flow path, which can affect the accuracy of the O2 flow sensor. The sensing accuracy of the flow sensor 418 in the mixed gas flow path or the flow sensor 318 in the air flow path or both was poor at angles of 135°, 180° and 270° compared to the 0° to 90° position.

[0115] In some embodiments, the O2 outlet 220 includes a guide portion. The guide portion may include a taper configured to direct flow from the O2 flow path 200 into the mixing chamber 500. The taper may be provided on a portion of the interior wall of the bore or conduit defining the O2 flow path 200, or the entire interior wall may be tapered to form a nozzle. In other embodiments, the O2 flow path 200 may include a number of nozzles configured to provide a nozzle diameter that is less than the diameter of the O2 passage. In some embodiments, the guide portion or nozzle may provide a resistance to flow from the mixing chamber 500, minimizing the possibility of phantom flow entering the O2 flow path 200 in a counterflow direction.

[0116] In some embodiments, the O2 flow path 200 includes a flow conditioner at the O2 outlet 220 configured to increase resistance to the flow of gas from the mixing chamber. An example of a suitable flow conditioner 230 is described in connection with Figures 5A and 5B. The flow conditioner may be integrally formed with devices such as conduits and bores that form the O2 flow path 200, however, in embodiments in which the flow conditioner 230 is provided as a separate component, the flow conditioner 230 may form a sealed joint with the bore or conduit through the use of an O-ring, as described in further detail in connection with the pneumatic block of Figures 6A-8.

[0117] In some embodiments, the flow conditioner 230 includes a plurality of substantially parallel flow channels that may be circular, oval, elliptical, hexagonal, or other cross-sectional shapes, or combinations thereof. Figures 5A-5C show an example of a flow conditioner 230 including a plurality of flow channels 232 having circular cross-sections. Note that the flow channels need not share a common cross-sectional dimension of diameter (for a round flow channel), as shown in Figure 5A. In some embodiments, the flow conditioner 230 has an outlet end shaped to be continuous with the inner wall of the mixing chamber 500 to avoid or minimize disruption of flow within the mixing chamber.

[0118] In some embodiments, the device 100 is created from multiple cooperating components, thereby forming bores and cavities. The multiple bores cooperate to form multiple gas flow paths, and the multiple cavities cooperate to define a space in which a blower can be received while forming a mixing chamber. In some embodiments, the cooperating components include a pneumatic block having multiple cooperating components.

[0119] In some embodiments, the flow path schematic of FIG. 2 may be realized in a pneumatic block 700 comprised of three pneumatic block components as shown in FIGS. 6A-8.

[0120] When assembled, the pneumatic block 700 provides a substantially sealed system in which a cavity is formed for housing the blower 310. The cavity also defines the mixing chamber 500. The assembled pneumatic block 700 includes flow paths for O2, air and mixed gases. Ideally, the block is designed with specific fluid inlets and outlets to control the flow of gases within the block, but it should be understood that the flow paths described herein need not be realized within the pneumatic block; in some embodiments, the flow paths or parts thereof may be realized by conduits and connectors arranged to provide the functionality of the respiratory device as described herein, as will be understood by those skilled in the art. However, the provision of aspects of a respiratory system using a pneumatic block composed of cooperating block components as described herein may provide several advantages, which may include a compact form factor in addition to the control of gas flow. By maintaining good control of gas flow within the device, the safety of the device may be improved.

[0121] In some embodiments, the pneumatic block includes three (or more) cooperating components, as shown in Figures 6-8 as a first block 710, a second block 720, and a third block 730. Ideally, the block components are machined, such as milled, drilled, or using other machining techniques, to form one or more cavities for housing the blower and defining the mixing chamber 500, and to form bores that cooperate to define the O2 flow path 200, the air flow path 300, and the mixed gas flow path 400. In some embodiments, the block components are also fabricated to house one or more sensors and flow regulators, as described herein. Although the pneumatic block components 710, 720, and 730 are described as being milled to form the necessary cavities and bores, it should be understood that if these block components are metal, other metal fabrication techniques may be employed. However, it should be understood that the material construction of the components need not be metallic, and one or more of the block components may include polymeric, ceramic or other materials or combinations of materials, which may be manufactured using injection molding or other fabrication techniques to perform the functions required for the pneumatic block components.

[0122] In some embodiments, the cavities include open channels or recesses that may be configured to cooperate with corresponding cavities in opposing block components (e.g., first block component 710 and third block component 730) to define a space to receive a blower and may also define a mixing chamber 500. In contrast, a through bore may be considered a closed tunnel extending through a block component with a single inlet and outlet, where the tunnel defines a flow path for gas within the device. Because a through bore is a tunnel formed within a block component, there is no place within the tunnel where gas can leak. In some embodiments, it may be desirable for the unoccupied volume of the block due to the through bore to be greater than about 50%, preferably greater than about 60%, optionally about 64% of the unoccupied volume. In some embodiments, the unoccupied volume due to the cavities may be greater than about 20%, optionally about 18% of the unoccupied volume. Because interfaces between block components that include cooperating cavities provide an opportunity for gas leakage, in some embodiments it may be desirable to provide a greater proportion of tunnels than cavities in the pneumatic block to reduce the likelihood of gas leakage occurring. In some embodiments, the pneumatic block assembly 700 further includes one or more sensor cavities, and the unoccupied volume attributable to the sensor cavities may be about 20%, optionally about 18%, of the unoccupied volume.

[0123] In some embodiments, it may be desirable for one or more of the block components 710, 720, 730 to be fabricated from a metal or metal alloy into which the through bores and cavities may be machined or milled or formed using a molding process. In some embodiments, it may be desirable for one or more of the block components 710, 720, 730 to be fabricated from a heat absorbing or conducting material. In some embodiments, the first component 710 provides a mounting surface to which the other block component may be configured to be mounted or attached. Thus, the first component 710 may be considered to provide a substantially rigid backplate.

[0124] Since the first component 710 serves as a mounting plate for the other components, it may be desirable for the first component to be manufactured from a high strength material, such as aluminum, stainless steel, or high strength polymer. In some embodiments, the material of one or more of the pneumatic block components may be selected to reduce the risk of fire and / or minimize the effects of fire during operation. Thus, one or more components of the pneumatic block may be manufactured, either in whole or in part, from, for example, brass and / or stainless steel and / or aluminum alloy and / or anodized aluminum alloy (Al alloy). It should be understood that other materials with similar properties to the above examples may also be used.

[0125] 6A is a perspective view of a pneumatic block 700 according to an embodiment of the present disclosure, comprised of three block components 710, 720, 730. Through bores 722, 723, 724 formed in the second component 720 define portions of the oxygen, air, and mixed gas flow paths, respectively. These bores extend vertically in the illustrated embodiment and may be substantially parallel. The second component 720 also provides a mixed gas outlet 744. The third block component 730 provides an opening 738 for receiving a portion of the blower 310, the blower being contained within a space defined by cooperating cavities in the third component 730 and the first component 710.

[0126] FIG. 6B shows the pneumatic block of FIG. 6A showing additional components including O2 flow sensor 218, air flow sensor 318, and mixed gas flow sensor 418, in addition to a portion of the blower motor assembly 315 of the blower 310 protruding through the opening 738. The fluid flow sensor may perform mass flow measurements using thermal measurement principles or using other techniques. Due to the compact arrangement of the pneumatic block and its various features, the fluid entering the flow sensor may have a flow profile (e.g., non-uniform, non-linear, etc.) that is undesirable for flow sensing because the flow cannot develop into a desired profile over such a short distance. This may negatively impact the performance of the sensor or the accuracy of their measurements. Therefore, it may be desirable to reduce this non-uniformity or turbulence to mitigate erroneous readings. To help reduce turbulence upstream of the flow sensor, one or more flow conditioners may be provided as disclosed herein. One or more flow conditioners may be provided to condition the flow by making the flow more uniform across the cross-sectional area of ​​the individual conduits leading to the flow sensor. They may also help straighten the flow. A more uniform flow ensures that the flow sensors are more likely to provide readings that are representative of the behavior of the bulk flow moving through the individual conduits.

[0127] 6B shows an outlet connector 800 coupled to an outlet 744 on the second component 720, and an O2 connector coupled to an O2 inlet 712 on the first component 710. Also shown in FIG. 7A is a printed circuit board (PCB) 760 that may be screwed or press-fitted or otherwise attached to the pneumatic block 700 (specifically the second block component 720) and includes a processor and circuitry configured to control the operation of one or more pressure sensors 114, 214, 414, as well as housing the pressure sensor itself. The PCB 760 may also include a processor and circuitry configured to control the operation of other electronic components of the instrument, such as the blower 310, the sensors 218, 318, 418, and the proportional valve 212, although in some embodiments this functionality may be provided by a processor and circuitry provided on a separate, larger PCB that may potentially house the ambient pressure sensor 114. In some cases, one or more pressure sensors (e.g., one or more O2 pressure sensors 214, one or more mixed gas pressure sensors 414) or one or more temperature sensors may be mounted on the PCB 760 and through holes may be provided in the second component 720 to sense the pressure in the associated flow path. It should be understood that other similar sensors may be housed on the PCB if there is sufficient available space on the PCB. One or more gaskets, seals or O-rings 755 may be provided between the pressure sensor and / or flow sensor and the second component 720 to reduce the risk of gas leakage. In some embodiments, one or more O2 pressure sensors 214 and / or one or more flow sensors may be provided to determine whether the oxygen supply 210 is connected to the oxygen inlet 712. In some embodiments, there may be two pressure sensors in the mixed gas flow path 400, one of which may be a spare and serve as a back-up sensor in case the first mixed gas pressure sensor 414 fails. In some embodiments where there is more than one pressure sensor, one pressure sensor may operate at a different pressure range than another pressure sensor, for example, one sensor providing accurate sensing at high pressure and another sensor providing accurate sensing at low pressure.

[0128] Figure 7A is a front perspective view of the pneumatic block 700 of Figures 6A and 6B showing the second block component 720 and the third block component 730 and various features of the equipment disposed between them. The second block component 720 includes three through bores 722, 723, 724, which may be vertically and adjacent to one another and define portions of the O2 flow path 200, the air flow path 300, and the mixed gas flow path 400, respectively. The arrangement of the through bores 722, 723, 724 allows the pneumatic block 700 to be provided in a compact form factor.

[0129] The third component 730 also includes three through bores 732, 733, 734, ideally also vertically adjacent to one another and positioned to align with the three corresponding through bores 722, 723, 724 in the second component 720 to define a portion of the O2 flow path 200, the air flow path 300, and the mixed gas flow path 400. The third component 730 also provides a cavity 736 configured to define a space to receive a portion of the blower 310 (ideally the motor side of the blower) and also to define the mixing chamber 500. The space to receive the blower 310 and define the mixing chamber 500 is formed by the cooperation of the cavity 736 formed in the third component 730 and the cavity 715 formed in the first component 710, and a seal or gasket 752 may be provided to reduce the risk of gas leakage. In some embodiments, the cavity 715 in the first component 710 may be configured to house the impeller portion of the blower 310, or a portion thereof, and the cavity 736 in the third component 730 may be configured to house the motor portion of the blower, or a portion thereof. Because the third component may be configured to house the motor component of the blower 310, it may be desirable for the third component 730 to provide a structure that can ensure the stability of the equipment when the blower 310 is operated at high speeds, i.e., high revolutions per minute (RPM). It may therefore be desirable for the material of the third component to be able to withstand the cyclic loads applied by the blower 310 and not prone to failure due to fatigue. Examples of suitable materials that may include or form a portion of the third component 730 may include, but are not limited to, brass and / or stainless steel and / or aluminum alloy and / or anodized Al alloy and stainless steel. In some embodiments, the third component 730 may include a mixed gas flow regulator 750, as described below.

[0130] 7A also shows the blower outlet 320, illustrating the location of the exit of air from the blower 310 into the mixing chamber 500, according to some embodiments of the present disclosure. As previously mentioned, it should be understood that the location of the blower outlet 320 relative to the O2 outlet 220 and the mixed gas inlet 510 can be important in improving the performance of the device in terms of reducing or eliminating undesirable flows in the mixed gas flow path 400 and the O2 flow path 200.

[0131] Figure 7B is a perspective front view of the pneumatic block 700 of Figures 6A, 6B and 7A. This view is provided to show that the through bores 722, 732 together define an O2 flow path 200 to the O2 outlet 220 that provides O2 to the mixing chamber 500; the through bores 723, 733 together define an air flow path 300 to the air outlet 320 that provides air to the blower 310, and the bores 724, 734 together define a mixed gas flow path 300 between the mixed gas inlet 510 and the mixed gas outlet 744 of the mixing chamber 500 (see Figure 6A). Figure 7B also shows an outlet connector 800 on the second component 720 and an O2 coupling 980 on the rear of the block 700 in the first component 710 for coupling the O2 inlet 712 to the O2 supply 210. The O2 inlet 712 may be positioned to receive the O2 coupling 980 in an orientation that is perpendicular to the orientation of the through bore 722 that defines a portion of the O2 flow path 200.

[0132] In some embodiments, the O2 inlet 712 is configured to provide an O2 conduit coupling, such as a standard CGA V-5:2019 Diameter Index Safety System (DISS) type of connection, although other connection types may be used depending on system requirements. The O2 inlet 712 is provided at the rear of the block 700 and receives O2 from the O2 supply 210. In some embodiments, the O2 inlet 712 may be positioned to receive a coupling for an O2 supply conduit when inserted with a force perpendicular to the rear face of the first component 710 of the block 700. This arrangement may allow a user to easily insert an O2 supply coupling into the O2 inlet 712. An O2 pressure sensor 214 may be provided to sense the pressure of gas from the O2 source 210. In some embodiments, the O2 pressure sensor 214 may be mounted to the PCB 760 to sense the pressure of oxygen entering the inlet (upstream of the proportional valve). A seal, gasket or O-ring 755 may be provided to reduce the risk of gas leakage where the pressure sensor 214 is located in the O2 flow path 200. A flow sensor or other similar sensor may be positioned in the same or substantially similar location as the pressure sensor(s) 214 described above.

[0133] FIG. 7B also shows the proportional valve 212 disposed in front of the second component 720. O2 received in the O2 inlet 712 passes through the proportional valve 212, which releases gas in the direction of the flow sensor 218. The proportional valve is used to control the flow rate of O2 in the O2 flow path 200, allowing a high velocity and / or uneven flow to enter the flow sensor 218 depending on the degree of opening of the valve. In the sense that the proportional valve 212 regulates the flow of O2 in the O2 flow path 200, the proportional valve may be considered a flow modulator. Therefore, in some embodiments, a flow regulator may be provided to enhance the uniformity of gas entering the O2 flow sensor 218 from the flow modulator provided by the proportional valve 212.

[0134] In some embodiments, the O2 flow conditioner may be described as a hybrid or two-stage flow conditioner 250 configured to condition the flow of O2 gas, as shown in FIGS. 18A-18C. In some embodiments, the O2 flow conditioner 250 includes a first portion 250A configured to receive and disperse the flow of gas, and a second portion 250B configured to improve the characteristics (e.g., directionality, e.g., straightness, spread across a cross-section of the flow path, velocity uniformity, etc.) of the dispersed gas received from the first portion. The first portion 250A includes a porous component. The porous component may be a rigid component. The first portion 250A may be a filter. In some embodiments, the first portion 250A includes a sintered metal filter, preferably a bronze sintered filter. The second portion 250B may include a flow conditioner having a plurality of openings 252. The first portion 250A and the second portion 250B may be configured to cooperate, for example, the first portion may include a conical outer shape made of a porous material with a tip 255 shaped to key or cooperate with a correspondingly shaped recess 253 (which may be a blind bore or a through hole) in the second portion 250B. This type of coupling saves space within the device, but it should be understood that in other embodiments, the second portion 250B may be integrally formed with the second component 720 of the pneumatic block by machining, milling, drilling, etc. In some embodiments, the first and second portions 250A, 250B may be spaced apart and may not key or cooperate together. In some embodiments, a hybrid or two-stage flow conditioner 250 as disclosed herein may be beneficial by facilitating conditioning of the flow toward a desired flow profile in a shorter flow path than a single-stage flow conditioner providing a single conditioning function, such as straightening the flow.In some embodiments including a convergent stream of gas, a longer inlet flow path may be required to allow the gas flow to develop before straightening in the flow conditioner corresponding to the second portion 250B to avoid a majority of the convergent gas flow flowing through the center portion of the second portion 250B. A two-stage flow conditioner 250 as disclosed herein may benefit from dispersing the convergent flow before entering the second portion 250B and providing a shorter gas flow path upstream of the second portion 250B to straighten the flow. This in turn benefits from aiding in the design of flow systems with smaller form factors. The hybrid or two-stage flow conditioner 250 may be positioned to receive high velocity gas, for example downstream of the proportional valve 212. In some embodiments, the flow straightener 250 may be positioned downstream of the blower outlet 320.

[0135] In some embodiments, the first portion includes a sintered filter having an outer and inner profile, for example, constructed of sintered bronze. As O2 fills the inner cavity of the filter, pressure inside increases. When the pressure exceeds a given threshold, O2 exits the filter through the porous sintered wall, distributing the O2 throughout the filter. A second element of the flow conditioner improves the characteristics of the dispersed flow, for example, straightening the flow and / or increasing uniformity across the cross-sectional area of ​​the inlet to the O2 flow sensor 218.

[0136] The plurality of openings in the second portion 230 of the O2 flow conditioner may include a circular, oval, elliptical, hexagonal, or other cross-sectional shape, or combinations thereof, as shown in FIGS. 5A-5C. In some embodiments, the second portion 230 of the O2 flow conditioner includes a plurality of parallel flow channels 232. In some embodiments, the cross-section of the honeycomb cross-sectional profile with the plurality of flow channels is hexagonal. The lengths of the flow channels may be equal or different. In some embodiments, the plurality of flow channels may be non-uniform in diameter as shown and radially arranged in the second portion. Ideally, the plurality of flow channels are arranged in the second portion such that they are entirely within the range of the downstream flow channel of the flow conditioner, for example, the flow channel that flows into the O2 flow sensor 218. In some embodiments, the second portion 230 may be a separate portion that is inserted into the O2 flow path 200. A groove 234 may be provided in the outer wall of the second portion 230 for receiving a seal, gasket or O-ring configured to minimize leakage of O2 between the second portion and the through bore 722 that defines the O2 flow path.

[0137] FIG. 8 is a perspective view of the rear of the pneumatic block 700 of FIGS. 6A-7B, particularly showing features of the first component 710. An air inlet 713 receives ambient air into the rear of the first component 710. The ambient air may first pass through a filter, which may be positioned over the air inlet 713, and / or a housing in which the pneumatic block 700 is contained. The air inlet 713 receives air into a cavity 714 formed in the first component 710, which may have a generally square, rectangular, oval, oval, circular, or other cross-sectional shape. The air inlet 713 is positioned to receive air in a direction perpendicular (i.e., 90°) to the direction of a through bore 733 that defines a portion of the air flow path 300 and includes an air flow sensor 318. As the air flow passes from the inlet 713 into the bore 733, a change in flow direction may cause the flow to separate from the walls that define the flow path.

[0138] 9 is a flow diagram showing the flow lines of air received in the air inlet 713 and air cavity 714 of the first component 710, passing through the through bore 723 in the second component 720 and the through bore 733 in the third component 730, and into the cavity 716 in the first component 710 that supplies the air to the inlet of the blower 310. Most of the turning flow uses a larger turning radius at the outer edge of the 90° corner 735. This may cause the flow to move faster at the top of the flow path as it enters the mass airflow sensor 318. There is little or no flow toward the bottom of the flow path, especially toward the inside of the 90° corner 735, which may be due to the air having too much energy to turn at a small radius. Thus, the corner 735 allows the air flow path to be incorporated into the pneumatic block 700 in a compact form factor, but may create non-uniform flow near the flow sensor 318, which may result in inaccurate readings. In some embodiments, this can be mitigated by providing a flow conditioner 740 in the air flow path 300.

[0139] 10A is a schematic diagram of an airflow conditioner 740 that may be provided in the air flow path 300. As in the illustrated embodiment, the airflow conditioner 740 may include a 90° flow conditioner configured to be provided in a 90° turn in the flow path 300 at the corner 735. Ideally, the internal structure of the airflow conditioner 740 includes multiple flow channels 742 that are configured to receive air from the airflow inlet 713 and provide a parallel flow path through the corner 735 so that the airflow exiting the flow conditioner 740 into the throughbore 733 is substantially uniform. Thus, the airflow conditioner 740 may receive and maintain a uniform flow of air entering the airflow inlet 713, or may increase the uniformity of air exiting the airflow inlet 713 that may not have good uniformity upon entry. The flow channels 742 in the airflow conditioner 740 may include a circular, oval, elliptical, hexagonal (as shown), or other cross-sectional shape, or combinations thereof. For example, a honeycomb cross-sectional profile in which the flow channels 742 are hexagonal may provide a beneficial pressure profile across the airflow conditioner 740 because it provides a larger cross-sectional area for air to move through. In some embodiments, the flow channels 742 are disposed within the airflow conditioner 740 so that the flow exiting the flow channels 742 is unobstructed as it enters the through bore 733. The provision of the airflow conditioner 742 may increase the uniformity of the flow into the airflow sensor 318, which may improve the overall performance of the system. It should be understood that the airflow conditioner 740 may be provided as a separate component of the pneumatic block 700 or may be integrally formed with the second component 720 of the block 700, for example, by machining, milling, additive manufacturing, 3D printing, etc.

[0140] 10B is a schematic diagram of another airflow conditioner 746 that may be provided in the airflow flow path 300. As in the illustrated embodiment, the airflow conditioner 746 is integral with the second block component 720. The airflow flow path 300 includes a corner 748 that may be radiused to minimize pressure drop as the flow moves around the corner 748. The corner 748 may be positioned downstream of the flow conditioner 746. The airflow conditioner 746 conditions the flow moving from the cavity 714 to the mass airflow sensor 318 (e.g., spreads the flow across a cross-sectional area of ​​the flow path). The provision of the airflow conditioner 746 may increase the uniformity of the flow moving through the mass airflow sensor 318, which may increase the accuracy of the flow sensed by the mass airflow sensor 318. It should be understood that the airflow conditioning device 746 may also be provided as a separate component of the pneumatic block 700 (not shown) or may be integrally formed with the second component 720 of the block 700 (as shown), e.g., by machining, milling, additive manufacturing, 3D printing, etc., as shown in FIG. 10B.

[0141] In some embodiments, the blower 310 includes a centrifugal blower configured to draw air from the airflow inlet 713 through a central inlet on one side of the blower positioned in a cavity 716 in the first component 710. The blower 310 may tangentially move gas into the spiral-shaped cavity of the blower toward the blower outlet 320 as described above. In some embodiments, the air exits the blower outlet 320 tangentially. The blower 310 moves air primarily within the pneumatic block 710 by drawing air from the airflow inlet 713. O2 may be introduced into the gas flow generated by the blower 310 downstream of the blower. Due to the downstream introduction of O2, the blower does not impart energy to the O2 in the mixed gas flow because the O2 gas is not moved by the blower blades. Therefore, the blower 310 moves a smaller volume of gas than a system that mixes air with O2 upstream of the blower, which may require less power and generate less heat. Additionally, the compressed O2 at a lower temperature than the ambient air absorbs heat from the blower 310 motor. Alternatively / in addition, in some embodiments, due to the conductive nature of the pneumatic block components, heat may be dissipated by heat transfer through one or more block components. Both of these may provide a cooling effect to the equipment. This may increase the efficiency of operation and / or reduce the risk of overheating the blower motor. Additionally, mixing of O2 and air downstream of the blower 310 may provide a lower temperature mixed gas stream than a system that provides a mix of these gases upstream of the blower. A lower temperature mixed gas stream may be beneficial in embodiments where the mixed gas stream is humidified and / or warmed before being provided to the patient, since the heating and humidification of the gas can be more precisely controlled by the downstream humidifier. In some embodiments, turbulence in the air stream exiting the blower 310 at the blower outlet 320 and / or turbulence in the O2 flow path 200 at the O2 outlet 220 causes mixing of gases within the mixing chamber 500 defined by the cooperating cavities 715 and 736.

[0142] When the blower 310 is mounted between the first component 710 and the third component 730 of the pneumatic block 700, it may be desirable to provide at least three seals. A first seal or gasket 752 may be provided between the first component 710 and the third component 730 to reduce the risk of gas leakage. This seal may also isolate vibrations generated by the blower 310 during operation, minimizing the possibility of vibrations transferring through the pneumatic block 700 to the mounting element 701 and the equipment to which the equipment is mounted. This seal may be configured to limit leakage of air and / or O2 from one or both of the cooperating cavities 715 and 736. Leaking of O2 and air from the mixing chamber (and / or joints within the pneumatic block 700) may pose a fire risk and also present a pressure loss risk, which is undesirable. This seal may function to limit the ingress of air or other gases that may be present in the housing into the mixing chamber. Additionally, the seal may beneficially prevent gas from escaping from the mixing chamber to the surroundings. A second seal 753 may be provided around the outer periphery of the blower 310. The second seal 753 may mount the blower 310 to one or both of the first component 710 and the third component 730. The second seal 753 may be clamped between a portion of the first component 710 and a portion of the third component 730 to secure the blower 310 within the cavity formed by the first and third components 710, 730. The seal 753 may also isolate vibrations resulting from operation of the blower 310. A third seal 756 may be provided around the blower motor assembly. The third seal 756 may also serve to isolate vibrations and reduce the transfer of vibrations from the blower motor assembly to the third component 730. The third seal 756 may prevent gas from escaping or entering the mixing chamber 500.

[0143] In some embodiments, the first component 710 is configured to perform significant load-bearing functions of the device. In some embodiments, the first component 710 may include a mounting element 701 that may be configured to cooperate with a mounting structure, such as a mounting bracket, a pole mount, or a monitor mount. Alternatively or in addition, the mounting element may be attached to a rear enclosure of the device. The mounting element 701 may be formed of one or more pieces. In some embodiments, the mounting element 701 or a portion thereof may be directly coupled to the first component 710. In some embodiments, the mounting element 701 or a portion thereof (best shown in FIGS. 17A and 17B) may be replaceable and replaced by a user according to specific needs. In some embodiments, the mounting element 701, including the monitor mount, may allow the device to be mounted, for example, to anesthesia or other machines configured to provide some type of respiratory assistance or other therapy to a patient. Ideally, the various attachment methods that can be achieved by the attachment element 701 would allow the device to be customized to the environment in which the patient is being treated, ideally ensuring visibility while also providing a stable, secure and effective platform for providing respiratory assistance. In some embodiments, the attachment element 701 can be provided through a housing in which a pneumatic block is provided.

[0144] In some embodiments, the blower 310 emits a flow such that the gases in the mixing chamber 500 (which may include one or both of O2 and air) are moved by the flow generated by the blower 310 and / or by the flow through the O2 flow path. In some embodiments, the flow exiting (i.e. emitted) the blower 310 includes a high velocity flow and / or is turbulent. In embodiments where O2 from the O2 flow path and air from the blower 310 enter the mixing chamber 500, the O2 and air move through the mixing chamber 500 such that they mix to form a mixed gas. Although the high velocity and / or turbulent flow generated by the blower 310 may be effective in mixing the gases, these flow characteristics may cause inaccurate sensing of the mixed gas flow rate by the mixed gas flow sensor 418 located in the mixed gas flow path 400. This is in part because the mixed gas flow may not include a desired flow profile across the cross-section of the mixed gas flow 400 that would allow accurate sensing by the mixed gas flow sensor 418. The desired flow profile is application dependent. The desired flow profile may be parabolic. A parabolic flow profile is characteristic of laminar flow through a circular pipe, while a profile with a flat or flatter leading edge is characteristic of turbulent flow. To mitigate undesirable flow, in some embodiments, the present disclosure may provide a mixed gas flow conditioner 750 to improve the uniformity of the mixed gas before entering the mixed gas flow sensor 418. The mixed gas flow conditioner 750 may be provided at or near the mixed gas inlet 510 and may straighten the flow, spread the flow across the mixing flow passage 400, and / or break up large scale vortices that may develop in the mixed gas flow. In some embodiments, this is accomplished by providing the mixed gas flow conditioner 750 with multiple flow channels 751. As the mixed gas flow exits the mixing chamber 500 through the mixed gas inlet 510, it is forced through the smaller channels 751 to increase the uniformity of the flow.

[0145] The flow channels 751 in the mixed gas flow conditioner 750 may include circular, oval, elliptical, hexagonal, or other cross-sectional shapes, or combinations thereof. The cross-sectional shapes need not be the same or of the same dimensions for all flow channels 751. Although circular flow channels 751 are shown in FIG. 11A, a honeycomb cross-sectional profile in which the flow channels 751 are hexagonal may provide a larger cross-sectional area for air to move through, resulting in a smaller pressure drop across the air flow conditioner 750. In some embodiments, the flow channels 751 are disposed within the air flow conditioner 750 such that air exiting the flow channels 751 is unobstructed as it enters the mixed gas flow sensor 418. Thus, the flow channels 751 may be disposed within the flow conditioner 750 such that they are also disposed within the interior range of the inlet to the mixed gas flow sensor 418. Providing an unobstructed flow from the flow channels 751 to the mixed gas flow sensor 418 may avoid gas recirculation and / or loss of uniformity, which may have negative consequences on the accuracy of the flow measurement. Providing a mixed gas flow conditioner 750 may increase the uniformity of flow into the mixed gas flow sensor 418, thereby improving the overall performance of the system. Although the flow conditioner 750 is described with respect to increasing the uniformity of flow in the mixed gas flow path, it should be understood that such a flow conditioner may also be used in the air and oxygen gas flow paths.

[0146] The mixed gas flow regulator 750 may be provided as a separate component of the pneumatic block 700, as shown in Figures 7B and 11A and 11B, or may be integrally formed with the third component 730 of the block 700, for example by machining, milling, drilling, etc., as shown in Figure 7A. If the mixed gas flow regulator 750 is a separate component, a groove 754 may be provided to receive a seal, gasket, or O-ring configured to minimize leakage of the mixed gas between the mixed gas inlet 510 and the mixed gas flow sensor 418.

[0147] In embodiments where the mixed gas flow conditioner 750 is integrally formed with the third component 730 of the block 700 (see FIG. 7A), the flow channel 751 may be drilled or otherwise formed to form a length of the flow conditioner that terminates at the mixed gas inlet 510 of the mixing chamber 500. In some arrangements, the mixed gas inlet 510 is positioned to be continuous with the wall of the mixing chamber, e.g., aligned with an arc of the side wall of the mixing chamber. This allows the inlet end of the channel 751 to match the arc-shaped interior contour of the mixing chamber. This may reduce or eliminate undesirable flows that may occur when gas in the mixing chamber impinges on the edge of the flow conditioner, which may occur if the flow conditioner 750 is formed as a separate component that includes a portion that protrudes into the mixing chamber when assembled with the block 730. Therefore, integral formation of the flow conditioner 750 with the block 730 is advantageous.

[0148] In preferred embodiments, the mixed gas flow regulator 750 has a length sufficient to generate a flow that is sufficiently uniform to reduce or eliminate erroneous flow rate readings by the mixed gas flow sensor 418. In some embodiments, as shown in 7A, the mixed gas flow regulator 750 can have a length that spans the distance between the mixed gas inlet 510 and the inlet to the mixed gas flow sensor 418.

[0149] FIG. 12A is a side view of an outlet connector 800 according to an embodiment of the present disclosure. The outlet connector 800 may be oriented to receive a feed connector at an angle that requires simultaneous application of a connection force vertically (upward) and horizontally (sideways). For example, the outlet connector may be oriented at an angle of approximately 60 degrees relative to the vertical. FIG. 12B is an end view of the connector 800 from the inlet end 810. FIG. 12C is a cross-sectional view of the outlet connector 800 showing internal features according to some embodiments. In FIG. 12A, the connector 800 is shown mated (e.g., by an interference fit) with a feed connector 850, which provides a fluid flow path via a feed conduit 852 that allows gas to be delivered to the patient by the patient interface. In some embodiments, the fluid flow path may also include a humidifier. The outlet connector 800 has a larger central opening 802 that may be aligned with a corresponding central opening in the feed connector 850. The outlet connector 800 has a number of smaller apertures, such as apertures 804 as shown in FIG. 12B. The apertures 804 may be located toward the center of the length of the outlet connector 800 as shown. In some embodiments, the multiple apertures may be located closer to the central axis of the outlet connector than the periphery of the outlet connector. These smaller apertures 804 increase the total cross-sectional area of ​​the openings between the inlet end 810 and the outlet end 820 of the outlet connector 800 through which gas from the mixed gas flow path 400 may flow to enter the feed connector 850 and the feed conduit 852. This maximizes the amount of flow from the outlet connector 800 to the feed connector 850 and the feed conduit 852. In some embodiments, the smaller apertures 804 are configured to cooperate with corresponding openings in a specially designed feed connector 850 that also has smaller apertures (not shown) located around the periphery of the main flow path in the feed connector. An example of a feed connector 850 may be a connector having the features described in International Publication No. WO2020157707, the entirety of which is incorporated herein by reference.

[0150] In some embodiments, the central opening 802 and the multiple apertures 804 provide multiple flow paths when coupled with a feed connector 850 that includes at least a central flow path through the main opening 802 and multiple outer flow paths through the smaller outer apertures 804. The outer flow paths may be substantially parallel to the central flow path, which may allow for more efficient operation since the larger total opening area provided by the combination of the larger central opening 802 and the smaller apertures 804 (which may be matched by corresponding openings in the feed connector 850) may reduce the pressure drop across the connection. Additionally, the arrangement of the central opening 802 with the smaller apertures 804 reduces the risk of over-inserting the feed connector 850 into the outlet connector 800 because the tip of any such feed connector will first impinge on the flange or web portion 805 that surrounds the central opening 802 and the smaller apertures 804. The obstruction provided by the web portion 805 may protect against over-insertion of the feed connector into components upstream of the connector. Such upstream components may include a check valve 770 that may be provided to limit or prevent backflow of gas into the instrument as described below. The outlet connector 800 may have an internal taper 807 that guides the feed connector 850 into place and provides a first sealing surface with the feed connector 850. A further taper 806 provides a second sealing surface with the feed connector 850 and may also provide some protection against over-insertion of the feed connector 850.

[0151] In some embodiments, a seal, gasket or O-ring 808 may be provided to form a substantially sealed joint when the outlet connector 800 is fastened to the pneumatic block 700. The seal 808 may mitigate leakage and unwanted pressure loss in the flow of gas provided to the patient, thereby further enhancing operational efficiency.

[0152] The portion of the outlet connector 800 between the apertures 804 and the outlet end 820 may present a smaller internal cross-section at or near the apertures 804 compared to the inner diameter of the outlet connector at the terminal outlet end 820. That is, the outlet end 820 may have a smaller internal cross-section at or near the apertures 804 at or near a central portion of the outlet connector 800 compared to the internal cross-section at or near the terminal outlet end.

[0153] In some embodiments, the check valve 770 may prevent gas flow from the outlet connector 800 back into the instrument, and particularly into the mixed gas flow path 400. The check valve 770 may include a weighted flap portion. The check valve 770 may be positioned at an angle, such as 10° from vertical, such that gravity acts on the weighted flap portion to bias the check valve to a closed position when the instrument is oriented upright (normal operating position) and there is no or substantially low flow. The direction of flow of the outlet connector A moving from the instrument toward the outlet connector 800 with sufficient force to overcome the weight of the flap portion will actuate the check valve 770 to open. Backflow moving from the outlet connector 800 in a direction toward the instrument, and particularly toward the mixed gas flow path 400, will bias the check valve 770 to close.

[0154] In some embodiments, the device may include a pneumatic block 700 as described elsewhere herein, and the outlet connector 800 may be fastened or coupled to the pneumatic block. In some arrangements, the mixed gas from the mixed gas flow path 400 turns a corner, such as a 90° corner, before traveling to the outlet connector 800. The outlet connector 800 may be fastened to the pneumatic block 700 such that it is oriented at an angle, such as 60° relative to the vertical, to receive the feed connector 850 at an angle necessary to apply both lateral and upward connection forces to form a substantially sealed joint when the feed connector is received within the outlet connector 800. The check valve 770 includes a mounting portion that is held between a rib or protrusion of the outlet connector 800 and a portion of the block 700. As described above, the check valve 770 may be opened by a flow of gas from the mixed gas flow path 400 moving towards the outlet connector 800, while a flow in the opposite direction (i.e., away from the outlet connector 800) will actuate the check valve to close. This may prevent the entry of contaminants or water or water vapor (from a downstream humidifier) ​​that may cause degradation of the pneumatic block, compromise the sterile environment, and / or damage equipment components.

[0155] The device may include a housing forming an outer box. The housing may be molded from a polymer (e.g., polycarbonate) and / or formed from another material. The housing material may provide fire retardancy so that in the event of a fire, the housing may self-extinguish the fire. Ambient air is drawn into the housing through an air inlet 913 and continues along the air flow path 300 toward the blower 310. The air inlet may include a removable filter 916 with a removable filter cover 917, as shown in FIGS. 13A-13C. The filter 916 may cover a recess 918 in the housing 900 that includes a number of ribs 920 that act as spacers to maintain the filter 916 in the recess and at a distance from the surface of the housing. A trough between the ribs 920 and the filter 196 creates a channel allowing air to flow freely into the air inlet 913.

[0156] In some cases, the device contained within the housing 900 may be operable to supply 100% O2 to the patient via the outlet connector 800. However, leakage from any flow path within the device may allow O2 to leak or build up within the housing, which may pose a fire risk. Therefore, in some embodiments, it is desirable to prevent the build-up of O2 within the housing. This may be accomplished in some embodiments by using a blower 650 that is different from the ventilation fan or blower 310.

[0157] Ambient air may be drawn into the housing through the second air inlet 923 to the ventilation blower 650. The second air inlet 923 may include a separate removable filter 926 with a removable filter cover 927 as shown in FIGS. 14A-14C. The filter 926 may cover a recess 928 in the housing 900 that receives the filter 926. The filter cover 927 may be snap-fit ​​or press-fit, screwed or otherwise fastened (e.g., by levering a flat head screw or other tool) into a removable position to provide access to the filter 926 for cleaning, replacement, etc. Ideally, the air drawn through the second air inlet 923 may be drawn into the housing 900 by the ventilation blower 650 and distributed within the housing to minimize dead space. This may reduce or prevent O2 buildup within the housing.

[0158] Generally, the flow within the housing will take the path of least resistance, as illustrated by the arrows in Figure 15A. However, the flow within the housing is preferably directed to minimize O2 buildup. Figure 15B shows a more preferred flow path for air to enter the inlet 923, where the flow is directed substantially across the width of the appliance before traveling downstream to the air outlet 930. The flow closer to the ventilation blower 650 may move at a higher speed, with the air flow slowing down as it moves toward the air outlet 930.

[0159] In some embodiments, one or more baffles 940 may be provided to direct the flow within the housing, examples of which are provided in Figures 16A-16B and 17A-17B. The baffles may be manufactured from elastomeric materials, including silicone and / or other materials that may be compression molded, or other suitable materials, such as injection molded thermoplastic elastomers, that may provide rigidity, if necessary. The baffles 940 may be positioned in compression between the front and rear covers that comprise the housing 900. Due to the flexibility of the baffle material, the structure of the baffles 940 may compress and conform to the internal contours of the front and rear covers. Advantageously, the compliant baffle material may also act as a damper of vibrations and / or noise generated by the ventilation blower 650 and / or the flow blower 310.

[0160] The baffle 940 may be configured with one or more cutouts 942 to provide a clear passageway for the connectors and wiring required within the housing 900 to power the ventilation blower 650 and flow generator blower 310 and PCB 760 from the appliance distribution board (not shown). The contours or cutouts 944 allow air from the ventilation blower 650 to enter the portion of the housing 900 that contains the IEC connectors. The ribs 951 provide structural integrity and may prevent the baffle 940 from sagging (due to gravity and / or material degradation). Additionally, the ribs 951 may help separate and / or guide the airflow within the housing, for example over the top side of the distribution board.

[0161] Not only may ventilation within the housing 900 reduce O2 build-up, but it may also have the beneficial effect of providing a mechanism for thermal regulation by removing heat from within the housing, which may further increase efficiency of operation and reduce the risk of overheating of components within the device.

[0162] The baffle 940 may include one or more hollow conical sections 946 that may be configured to each receive a threaded boss in the housing to position the baffle in place. Various features may be provided on the baffle 940 to cooperate with components in the housing 900 to limit movement, including one or more of sliding and twisting, when the baffle is compressed between the front and rear covers of the housing. These may include, for example, slots in the base of the baffle 940 that mate with ribs on the rear housing. In some embodiments, it may be desirable to avoid using screws or other fasteners that are used through the baffle 940, as these may create areas of localized stress that may lead to material failure, for example, by cracking or splitting during assembly or over time. Figures 17A and 17B show an example of a baffle 940 positioned to direct air flow from the ventilation blower 650, across the pneumatic block 700, and over the top of the IEC connector. FIG. 17B shows the arrangement of FIG. 17A and further illustrates the display screen 20 providing some of the equipment and I / O equipment used to receive user input to determine the operating parameters of the distribution board 970.

[0163] The embodiments of the present disclosure provide an apparatus for delivering breathing gas at a higher O2 concentration than ambient air, so that it may be safer and more efficient than existing apparatus. Thanks to the arrangement of the flow paths within the apparatus and their inlets and outlets relative to the blower, undesired flows may be reduced or avoided, thereby enhancing sensor accuracy, while also achieving gas mixing when a mixture of O2 and air needs to be delivered. In some embodiments, the apparatus is provided by a pneumatic block composed of a plurality of block components including cooperating bores and cavities that define flow paths. In some embodiments, the block components are arranged with one or more flow sensors and one or more pressure sensors that may be configured to safely and reliably deliver the required flow of breathing gas. At the same time, the arrangement of the bores and cavities within the block components may provide a compact apparatus with a form factor that may be beneficial, especially in medical environments where space for additional equipment may be limited.

[0164] Additionally, various features, such as flow conditioners, filters, outlet connectors and baffles, may be provided to improve the overall operation of the instrument and provide the potential for increased operational efficiency and / or accuracy and / or safety.

[0165] A device for generating a flow of respiratory gas as disclosed herein may be useful for delivering a high flow of respiratory gas to a patient. In particular, the device may be useful during anesthesia procedures, although the use of the device is not limited to such procedures and may be used to deliver respiratory gas including air, 100% O2, or a mixture of air and O2 in other environments such as ICUs or other medical environments where a patient requires high flow respiratory support. The operating parameters of the device may be controlled to meet the patient's respiratory support requirements (e.g., gas composition, flow rate, and / or pressure, etc.) by using one or more sensors, controller 4, blower 310, and other features of the device as disclosed herein.

[0166] It should be understood that various modifications, additions and / or substitutions may be made to the foregoing without departing from the scope of the present disclosure as defined in the provisional claims appended hereto.

[0167] The present disclosure may also be broadly described as consisting in any or all combinations of two or more of the parts, elements and features mentioned or shown in the specification of this application, individually or collectively. Where components having wholes or their equivalents are mentioned in the above description, those wholes are incorporated herein as if they were individually described. Similarly, where features or elements of specific aspects or embodiments are mentioned in the above description, it should be understood that those features or elements are incorporated herein as if they were expressly disclosed in combination with other aspects or embodiments, such that the skilled addressee understands that those features or elements are interchangeable.

[0168] When any or all of the terms "comprise", "comprises", "comprised of" or "comprising" are used in this specification (including the provisional claims), they shall be construed as specifying the presence of a stated feature, integer, step or component but not excluding the presence of one or more other features, integers, steps or components or groups thereof.

[0169] Future patent applications may be filed based on or claiming priority from this application. It should be understood that the following provisional claims are provided by way of example only and are not intended to limit the scope of what may be claimed in any such future applications. Features may be added to or omitted from the provisional claims at a later date to further define or redefine one or more inventions.

Claims

1. 1. Apparatus for providing a breathing gas comprising: (a) a blower configured to receive a first gas from a first gas flow path and generate a flow of the first gas that is provided through a first gas outlet of the blower; (b) a second gas flow passage configured to receive a flow of a second gas and effect said flow of said second gas through a second gas outlet; (c) a mixing chamber configured to receive the first gas flow from the first gas outlet and the second gas flow from the second gas outlet, the received gases configured to mix within the mixing chamber to form a mixed gas, the received gases configured to travel within the mixing chamber in a mixed flow direction toward a mixed gas inlet, and the mixed gas exiting the mixing chamber via the mixed gas inlet for flow into a mixed gas flow path; and Including, equipment.

2. The apparatus of claim 1 , wherein the mixing chamber receives the flow of gas from the second gas outlet upstream of the first gas outlet in the mixed flow direction.

3. 3. The apparatus of claim 1, wherein one or both of the first gas outlet and the second gas outlet are arranged to achieve a flow of the first gas and / or the second gas in a substantially tangential direction along a wall of the mixing chamber.

4. 2. The apparatus of claim 1, wherein the first gas outlet and the second gas outlet are positioned relative to the mixing chamber such that the first gas outlet is positioned to direct the first gas entering the mixing chamber away from the second gas outlet.

5. 2. The apparatus of claim 1, wherein the first gas flow outlet and the second gas flow outlet are arranged such that the first gas in the first gas flow outlet is directed in a first flow direction between a direction that is substantially parallel to a second flow direction of the second gas in the second gas flow outlet and a direction that is substantially perpendicular to the second flow direction.

6. The device of claim 5 , wherein the first flow direction is at an angle of about 0° to less than about 90° relative to the second flow direction.

7. 7. The device of claim 5 or 6, wherein the first flow direction and the second flow direction are in a common plane.

8. 6. The apparatus of claim 5, wherein the mixed gas inlet is positioned such that the mixed gas flow in the mixed gas flow path is oriented in a mixed flow direction between a direction substantially perpendicular to one or both of the first and second flow directions and a direction anti-parallel to one or both of the first and second flow directions.

9. The device of claim 8 , wherein the mixed flow direction, the first flow direction, and the second flow direction are in a common plane.

10. 10. The apparatus of claim 8 or 9, wherein the mixed flow direction is substantially anti-parallel to the second flow direction.

11. The device of claim 1 , wherein the cross section of the mixing chamber is substantially circular.

12. The device of claim 1 , wherein the mixing chamber is substantially cylindrical.

13. The device of claim 1 , wherein the mixing flow direction within the mixing chamber is around a central shaft.

14. The device of claim 13 , wherein the central shaft comprises a portion of the blower.

15. The device of claim 1 , wherein the mixing chamber is configured such that gas travels in a spiral pattern within the mixing chamber.

16. 10. The apparatus of claim 1, wherein the mixing chamber is configured into a plurality of adjacent sectors, and the first gas outlet and the second gas outlet are disposed within adjacent sectors of the mixing chamber.

17. 17. The apparatus of claim 16, wherein the mixed gas inlets are disposed in non-adjacent sectors of the first gas outlet.

18. 18. An apparatus according to claim 16 or 17, wherein the mixed gas inlets are provided in sectors that optimise flow uniformity within the mixed gas flow path.

19. 18. The apparatus of claim 16 or 17, wherein the plurality of sectors comprises four quadrants.

20. The apparatus of claim 1 , wherein the second gas outlet arrangement allows gas to flow from the mixing chamber into the second gas flow path.

21. The apparatus of claim 1 , wherein the second gas outlet comprises a guide portion.

22. 22. The apparatus of claim 21, wherein the guide portion includes a taper configured to direct the flow of the second gas into the mixing chamber.

23. The apparatus of claim 1 , wherein the second gas flow path includes a flow conditioner at the second gas outlet configured to increase resistance to gas flow from the mixing chamber.

24. 24. The device of claim 23, wherein the flow conditioner comprises a plurality of substantially parallel flow channels.

25. 25. The apparatus of claim 23 or 24, wherein the flow conditioner has an outlet end shaped to be continuous with an interior wall of the mixing chamber.

26. 25. The device of claim 23 or 24, wherein the flow regulator is integrally formed with the device.

27. 10. The apparatus of claim 1, wherein the second gas flow path includes one or more nozzles configured to direct the flow of the second gas into the mixing chamber through a nozzle diameter that is smaller than a diameter of the second gas flow path.

28. The apparatus of claim 1 , wherein the second gas flow path includes a check valve.

29. The instrument of claim 1 , wherein the instrument includes a first flow sensor for sensing a flow rate of gas in the first gas flow path.

30. The instrument of claim 1 , wherein the instrument includes a second flow sensor for sensing a flow rate of gas in the second gas flow path.

31. The apparatus of claim 1 , wherein the second gas flow path includes a proportional valve.

32. 32. The apparatus of claim 31, wherein the second flow sensor senses a flow rate of gas downstream of the proportional valve.

33. The instrument of claim 1 , wherein the instrument includes a third flow sensor for sensing a flow rate of the mixed gas in the mixed gas flow path.

34. 34. The apparatus of claim 33, wherein the mixed gas flow path includes a mixed flow regulator upstream of the third flow sensor.

35. 35. The apparatus of claim 34, wherein the mixed flow regulator is located at or proximate to the mixed gas inlet.

36. 36. The apparatus of claim 34 or 35, wherein the mixed flow conditioner has an inlet end configured to be continuous with an interior wall of the mixing chamber.

37. 36. The apparatus of claim 34 or 35, wherein the mixed flow regulator comprises a plurality of substantially parallel flow channels.

38. 36. The apparatus of claim 34 or 35, wherein the mixed flow regulator is integral with the mixed gas inlet.

39. 10. The apparatus of claim 1, wherein one or more of the first gas, second gas, and mixed gas flow comprise a flow rate of 0 L / min or greater, optionally the mixed gas flow comprises a flow rate of between about 20 L / min and about 90 L / min, optionally the mixed gas flow comprises a flow rate of between about 40 L / min and about 70 L / min.

40. 10. The apparatus of claim 1, including a plurality of cooperating components having bores formed therethrough to cooperatively define a plurality of gas flow paths, and cooperating cavities formed therein to define a cavity for receiving the blower and mixing chamber.

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