Respiratory support apparatus

Abstract

An apparatus for providing respiratory support for a patient includes a first gas flow path, a second gas flow path, and a first gas port configured to receive gas from the first gas flow path and the second gas flow path. The apparatus includes a switching mechanism operable to switch flow to the first gas port between the first gas flow path and the second gas flow path. Gas from the first gas port is provided to the patient for respiratory support.

Description

Technical Field

[0001] The present disclosure relates to providing respiratory support to a patient, and to apparatus and systems for providing switching between modes of respiratory support provided to a patient. The present invention particularly, but not exclusively, relates to apparatus for switching between modes of respiratory support providing ease of use in a clinical setting. Background Art

[0002] Patients may lose respiratory function during anesthesia or sedation, or more generally during certain medical procedures. Prior to a medical procedure, a medical professional may pre-oxygenate the patient to provide a reserve of oxygen saturation. Pre-oxygenation and CO2 flushing / washout may be performed using high-flow respiratory support via a nasal cannula or other patient interface.

[0003] High flow systems may be present in operating rooms and used during anesthesia or sedation procedures or other medical procedures. High flow respiratory support has been shown to effectively meet or exceed the patient's normal inspiratory needs, increase the patient's oxygenation, reduce the work of breathing, or perform transnasal humidified rapid inflation ventilatory exchange (THRIVE). Pre-oxygenation using a high flow system before administering anesthesia or sedation provides an oxygen reserve and prolongs the safe apnea time. In addition, high gas flow can generate a flushing effect in the nasopharynx, so that the anatomical dead space of the upper airway is flushed by the high inflow gas flow. This creates a reserve of available fresh gas for each breath while minimizing the rebreathing of carbon dioxide, nitrogen, etc. THRIVE is the provision of high flow respiratory gas to the patient when the patient is apneic, which occurs after the anesthetic takes effect and before the patient is successfully intubated and mechanically ventilated. High flow respiratory support refers to the delivery of heated and humidified respiratory gas to the patient at a high flow rate via a non-sealed patient interface (e.g., a nasal cannula), generally intended to meet or exceed the patient's inspiratory needs when the patient breathes spontaneously.

[0004] Once pre-oxygenated, an anesthetic is delivered to the patient to sedate the patient prior to intubation. After intubation, an anesthetic is also delivered to maintain the patient's state of anesthesia during the medical procedure. This delivery of the anesthetic can be performed intravenously or via inhaled aerosol / vapor - the latter can be achieved by using an anesthesia machine. Systems configured for anesthesia procedures typically include an anesthesia machine that includes a rebreathing system in which the patient's exhaled gases are returned to the machine. The anesthesia machine provides anesthetics to sedate the patient and / or keeps the patient sedated via a sealed mask placed on the patient. Once sedated, the patient is intubated and then mechanically ventilated (anesthesia ventilation) by the anesthesia machine to assist or replace spontaneous breathing.

[0005] The provision of various respiratory support modes rarely occurs in a simple sequential manner. In a clinical setting, it is often necessary to switch between support modes, for example, to ensure adequate oxygenation during anesthesia induction and intubation. Because each different respiratory support mode may require the use of a different patient interface, e.g., non-sealed, sealed, mask, endotracheal tube, etc., this may require multiple inspiratory gas flow conduits to provide gas flows from multiple gas sources or respiratory support systems. It may be desirable to simplify the clinical setup by reducing the number of tubes and / or connections (and / or connect / disconnect actions) while still enabling the clinician to switch between different respiratory support modes as needed to achieve the desired clinical outcome for the patient.

[0006] The reference herein to a patent document or any other matter identified as prior art should not be taken as an admission that the document or other matter is already known or that the information it contains is part of the common knowledge. Summary of the invention

[0007] From one aspect, the present disclosure provides an apparatus for providing respiratory support to a patient, the apparatus comprising: (a) a first gas flow path; (b) a second gas flow path; (c) a first gas port configured to receive gas from either the first gas flow path and the second gas flow path; and (d) a switching mechanism operable to switch a flow to the first gas port between the first gas flow path and the second gas flow path; wherein the gas from the first gas port is provided to the patient for respiratory support.

[0008] In some embodiments, operation of the switching mechanism to allow flow from one of the gas flow paths to the first gas port prevents flow from another of the gas flow paths to the first gas port.

[0009] In some embodiments, the first gas port can be coupled to a first conduit that provides gas to a patient through a second patient interface.

[0010] In some embodiments, the device includes a second gas port that can be coupled to a second conduit configured to receive exhaled gas from the patient. The device can include a first patient interface, such as, for example, a mask configured to receive exhaled gas from the patient to return to the device through the second conduit.

[0011] In some embodiments, applying the first patient interface to the patient causes the switching mechanism to allow flow from the first gas flow path to the first gas port. In some embodiments, whether the first patient interface is applied to the patient can be determined by detecting an increase in one or more parameters of gas in the expiratory gas flow path between the second patient interface and the device, the parameters selected from gas pressure, CO2, O2, flow rate, temperature, and humidity. In some embodiments, the first patient interface is a mask including a sealing cuff having a sensor for determining pressure within the cuff, and wherein application of the mask to the patient is determined by an increase in cuff pressure.

[0012] In some embodiments, the first patient interface includes one or more sensors configured to determine when the second patient interface is applied to the patient. In some embodiments, the one or more sensors of the first patient interface include one or more of an optical sensor, a proximity sensor, and a thermal sensor.

[0013] In some embodiments, the device includes an endotracheal tube (ETT) or a laryngeal mask airway (LMA) that can be coupled to the first and second conduits via a Y-connector and used as both a first patient interface and a second patient interface. In some such embodiments, the device can be configured to function as a ventilator.

[0014] In some embodiments, removing the first patient interface from the patient causes the switching mechanism to allow flow from the second gas flow path to the first gas port.

[0015] In some embodiments, when gas flows from the second gas flow path to the first gas port, the device is operable to provide gas to the patient through a second patient interface, which is a non-sealing patient interface, such as, for example, a nasal cannula.

[0016] In some embodiments, the switching mechanism includes a switching element configured to prevent flow from the flow source to the other gas flow path when the switching mechanism operates to allow flow from one of the gas flow paths to the first gas port.

[0017] In some embodiments, the switching mechanism includes one or more valves located upstream of a joint between the first gas flow path and the second gas flow path, and when the switching mechanism is operated to allow flow from one of the gas flow paths to the first gas port, the valves are configured to prevent backflow in the other gas flow path.

[0018] In some embodiments, the switching mechanism may be operably coupled to one or more flow meters configured to stop gas flow to a gas flow path that does not provide flow of gas to the first gas port based on operation of the switching mechanism.

[0019] In some embodiments, the switching mechanism is operably coupled to one or more flow meters operable to control the flow of gas to the gas flow path to provide a flow of gas to the first gas port in accordance with operation of the switching mechanism.

[0020] In some embodiments, the switching mechanism is operably coupled to one or more flow meters, the flow meters being operable to control a gas flow to a gas flow path, the gas flow path providing a flow of gas to a first gas port in accordance with operation of the switching mechanism, wherein one or more fixed flow meters control the gas flow at one or more preset gas flow rates.

[0021] In some embodiments, the device includes a controller that is operatively in communication with the switching mechanism and is operative to cause the device to provide respiratory support to the patient. In some embodiments, the controller may receive input from one or more sensors to determine whether the first patient interface has been applied to the patient.

[0022] In some embodiments, after determining that the first patient interface has been applied to the patient, the controller automatically controls the device to provide respiratory support in a first mode; and after determining that the first patient interface has been removed from the patient, the controller automatically controls the device to provide respiratory support in a second mode.

[0023] In some embodiments, the controller may receive input from one or more sensors located at one or more locations selected from: in the inspiratory flow path that provides gas to the patient; in the device between a first gas port and a connector where return gas in the device meets a fresh gas supply; in the expiratory flow path that returns gas from the patient to the device; in the device between a second gas port that receives return gas from the patient and a connector; and in the gas flow downstream of a flow generator or flow mixer of the device. The one or more sensors may be a sensor type selected from the following, including but not limited to a pressure sensor, a flow rate sensor, and an O2 sensor.

[0024] In some embodiments, the controller may receive input from one or more CO2 sensors located at one or more locations selected from: an expiratory flow path that returns gas from the patient to the device; and in a device having a rebreathing circuit and a CO2 absorber, between a second gas port in the device that receives return gas from the patient and the CO2 absorber. In some embodiments, the controller determines that one or more locations containing a CO2 concentration greater than ambient air are associated with a patient interface applied to the patient.

[0025] In some embodiments, the controller may receive input from a plurality of sensors to determine whether the first patient interface has been applied to the patient to mitigate erroneous switching between the first mode and the second mode.

[0026] In some embodiments, the controller may control the device to provide respiratory support with a signature flow element, and wherein the controller looks for the signature flow element in the returned gas to determine that the first patient interface has been applied to the patient. The signature flow element may include, for example, oscillations of one or more of the frequency, amplitude, and curve of one or more of the pressure, flow rate, and O2 concentration of the gas provided to the patient.

[0027] In some embodiments, the controller may receive sensor signals from one or more sensors, including one or more pressure and / or flow rate and / or gas concentration sensors in the inspiratory flow path and / or expiratory flow path, to control the switch from the second mode to the first mode, and optionally, wherein the same or different one or more sensor signals may be received by the controller to control the switch from the first mode to the second mode. The controller may be configured to require that more sensor conditions are met before switching from the first mode to the second mode, and vice versa. This may be configured according to user preferences.

[0028] In some embodiments, the controller can control the device to provide a residual flow of gas in one or both of the first gas flow path and the second gas flow path for continuous or periodic monitoring of the gas. In some embodiments, the residual flow can be, for example, from about 0.5 L / min to about 5 L / min.

[0029] In some embodiments, the device may include one or more sensors for sensing one or more characteristics of the gas selected from the group consisting of: pressure, flow rate, and concentration of gas species.

[0030] In some embodiments, the controller may apply a timing control in which, upon detecting a condition that should trigger a mode switch, the controller applies a delay before controlling a switching element to cause the mode switch. In some embodiments, the controller may control a user interface to provide one or more of an audible and visual countdown indicator of when the controller switches control of the device between a first mode and a second mode. In some embodiments, the controller may be configured to abandon automatic switching between modes upon receiving a canceling user input during the delay period.

[0031] In some embodiments, the controller may control the user interface to provide one or both of an audible and visual mode indication indicating the current operating mode of the device. In some embodiments, the controller may control the user interface to include one or more audible and / or visual output elements located on, at, or near the gas conduit or patient interface and provide the mode indication.

[0032] In some embodiments, the device may include a user interface that is in operative communication with the controller and is configured to receive input from a user corresponding to one or more parameters of the respiratory support to be provided to the patient. The parameters may include one or more parameters for a rebreathing mode of respiratory support and / or a high flow mode of respiratory support. Alternatively or additionally, the parameters may include one or more of the flow rate, composition, pressure, temperature, and humidity of the gas to be provided to the patient.

[0033] In some embodiments, the controller can be configured to receive a user input that causes the switching mechanism to switch the flow to the first gas port between the first gas flow path and the second gas flow path. The user input can be received from one or more of: (a) a touch screen display; (b) a wired or wirelessly coupled remote unit; (c) a foot-operated pedal or switch; and (d) a physical switch provided on the device.

[0034] In some embodiments, the first gas flow path includes a rebreathing gas flow path that receives and processes exhaled gas returned from the patient. Processing the exhaled gas returned from the patient may include recirculating the exhaled gas in the first gas flow path. In some embodiments, the apparatus may be operable to provide one or both of anesthesia and ventilation breathing support via the rebreathing gas flow path.

[0035] In some embodiments, the second gas flow path comprises a high flow gas flow path. In some embodiments, the apparatus comprises a flow source configured to generate a flow of gas in the second gas flow path.

[0036] In some embodiments, the first gas port is a common gas outlet port that can be coupled to the first conduit for delivering gas from either the first gas flow path or the second gas flow path to the patient.

[0037] In some embodiments, wherein a housing is provided for a first gas flow path and a second gas flow path, the housing provides a first gas coupling defining a first gas port to which a first conduit may be coupled.

[0038] In some embodiments, the apparatus includes a humidifier configured to condition gas to a predetermined temperature and / or humidity prior to delivery to the patient via one or both of the first and second gas flow paths.

[0039] In some embodiments, the apparatus may be operable to provide a flow of gas in the second gas flow path at a flow rate selectable from a usable range of about 20 L / min to about 100 L / min. Alternatively, the apparatus may be operable to provide a flow of gas in the second flow path at a flow rate selectable from a plurality of usable fixed flow rates including at least 0 L / min, 40 L / min, and 70 L / min.

[0040] In some embodiments having a second gas port configured to receive exhaled gas from a patient, the device may include a CO2 absorber configured to process exhaled gas returning from the patient in the first gas flow path. This may be provided before the gas is recirculated to the patient in the first gas flow path.

[0041] In some embodiments, the device includes one or more of the following features in the first gas flow path: (a) a pressure limiting valve configured to maintain a substantially constant pressure in the first gas flow path; (b) a variable volume for displacing gas in the first gas flow path; (c) a supplemental gas flow for supplementing anesthetic gas delivered to the patient in the first gas flow path; (d) a gas mixer; (e) a vaporizer for vaporizing a volatile anesthetic into the gas in the first gas flow path; and (f) a flow rate limiter configured to limit the flow in the first gas flow path to approximately 15 L / min.

[0042] In some embodiments, the device may include one or more gas supply ports configured to receive a supply of one or both of: (a) breathing gas for delivery to the patient via the first or second gas flow path; and (b) anesthetic gas for delivery to the patient via the first gas flow path.

[0043] In some embodiments, the device may be configured to couple to a power source including a common power outlet or batteries.

[0044] In some embodiments, the device has a second gas port configured to receive exhaled gas from the patient, and the device can be configured to operate in the following modes: (a) in a rebreathing mode, wherein gas flows from the first gas flow path to the first gas port and is provided to the patient, and exhaled patient gas is returned to the device via the second gas port; and (b) in a high flow mode, wherein gas flows from the second gas flow path to the first gas port and is provided to the patient, and exhaled patient gas is not returned to the device. In some embodiments, the rebreathing mode may include an anesthesia rebreathing mode for providing anesthesia to the patient. Alternatively or additionally, the device may be configurable for a ventilation rebreathing mode, wherein gas flows from the first gas flow path to the first gas port and is provided to the patient through an ETT or LMA, and exhaled patient gas is returned to the device from the ETT or LMA via the second gas port. The device may be operable to provide automatic rebreathing, for example, by using a bellows in the device, or by providing manual rebreathing using a manually operated bag ventilator.

[0045] From another aspect, the present disclosure provides a device for providing respiratory support to a patient, the device comprising: a first gas flow path; a second gas flow path; a first gas port configured to receive gas from either the first gas flow path and the second gas flow path; and a switching mechanism operable to switch a flow to the first gas port between the first gas flow path and the second gas flow path; wherein the gas from the first gas port is provided to the patient for respiratory support; and wherein the device comprises a controller configured to receive input from one or more sensors for determining whether conditions exist that trigger switching of the flow to the first gas port between the first gas flow path and the second gas flow path, wherein the one or more sensors are provided at one or more locations selected from the following: in an inspiratory flow path for providing gas to the patient; in the device between a first gas port and a connector where return gas in the device meets a fresh gas supply; in an expiratory flow path for returning gas from the patient to the device; in the device between a second gas port and a connector for receiving return gas from the patient; and in a gas flow downstream of a flow generator or flow mixer of the device.

[0046] In some embodiments, the apparatus includes a second gas port configured to receive gas returning from the patient, and the condition includes the controller determining whether a sealed patient interface in fluid communication with the second gas port is applied to the patient.

[0047] From another aspect, the present disclosure provides a device for providing respiratory support to a patient, the device comprising: a first gas flow path; a second gas flow path; a first gas port configured to receive gas from either the first gas flow path and the second gas flow path; and a switching mechanism operable to switch the flow to the first gas port between the first gas flow path and the second gas flow path; wherein the gas from the first gas port is provided to the patient for respiratory support; and wherein the device comprises a controller configured to control the device to provide respiratory support with a signature flow element, and wherein the controller searches for the signature flow element in the gas returned from the patient to the device to determine whether a patient interface has been applied to the patient.

[0048] In some embodiments, the signature flow elements may include oscillations of one or more of the frequency, amplitude, and curve of one or more of the pressure, flow rate, and O2 concentration of the gas provided to the patient.

[0049] It should be understood that each of the various aspects described herein may be combined with one or more features, modifications and alternatives described in the context of one or more other aspects, and may appropriately include one or more features, modifications and alternatives of any embodiment described below. For efficiency, these features, modifications and alternatives are not disclosed repeatedly for each aspect, but those skilled in the art will recognize that such combinations of features, modifications and alternatives disclosed for some aspects and embodiments are similarly applicable to other aspects and belong to the scope of this disclosure and constitute part of its subject matter. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] The present invention will now be described in more detail with reference to the accompanying drawings, wherein like features are indicated by like reference numerals. It should be understood that the illustrated embodiments are examples only and should not be taken as limiting the scope of the invention as defined in the provisional claims appended hereto.

[0051] Figure 1 is a schematic diagram showing components of a prior art anesthesia machine.

[0052] Figure 2 It is a schematic diagram of a prior art ventilator.

[0053] Figure 3 is a schematic diagram of components of a prior art high flow system.

[0054] Figure 4 is a schematic diagram illustrating components in an apparatus for providing respiratory support to a patient according to an embodiment of the present disclosure.

[0055] Figure 5 It is shown Figure 4 Schematic diagram of a modification of the device in which a switching element is present.

[0056] Figure 6 is a schematic diagram of an apparatus for providing respiratory support according to an embodiment of the present disclosure, the apparatus having a switching mechanism including a switching element located between a gas source and first and second flow paths.

[0057] Figure 7 yes Figure 6 A modified example of the device in which the humidifier is a separate component provided outside the device.

[0058] Figure 8 yes Figure 6 Another modified example of the device in, wherein the humidifier is a separate component provided outside the device.

[0059] Fig. 9 is a schematic diagram of an apparatus for providing respiratory support according to another embodiment of the present disclosure, the apparatus having a switching mechanism including a flow rate selector for a second gas flow path.

[0060] Fig.10 is a schematic diagram of an apparatus for providing respiratory support according to another embodiment of the present disclosure, the apparatus having a switching mechanism including a set of flow rate selectors common to a first gas flow path and a second gas flow path.

[0061] Fig.11 is a schematic diagram of an apparatus for providing respiratory support having a switching mechanism including a separate set of flow rate selectors for each gas flow path according to another embodiment of the present disclosure.

[0062] Fig.12 is a schematic diagram of an apparatus for providing respiratory support showing possible locations of sensors for sensing characteristics of gases in the inspiratory and expiratory flow paths.

[0063] Fig.13 is a schematic diagram of an apparatus for providing respiratory support showing possible locations of sensors for sensing characteristics of the gas when providing a residual flow.

[0064] Figures 14 to 16 The use of multiple patient interfaces in delivering different modes of respiratory support in accordance with an embodiment of the present disclosure is illustrated.

[0065] Fig.17 is a schematic diagram of a connector according to an embodiment of the present disclosure that can be used to facilitate replacement of components to deliver different modes of respiratory support.

[0066] Fig.18 is a schematic diagram of another connector according to an embodiment of the present disclosure.

[0067] Fig.19 is a schematic diagram of another connector according to an embodiment of the present disclosure, which is used with a nasal cannula to deliver different modes of respiratory support.

[0068] Fig. 20 As Fig.19 A schematic diagram of the connector with changes to the connector.

[0069] Fig.21 As Fig.19 A schematic diagram of a connector showing another variation of the connector. DETAILED DESCRIPTION

[0070] Embodiments of the invention are discussed herein with reference to the accompanying drawings, which are not drawn to scale and are merely used to aid in explaining the invention.

[0071] Parts of anesthesia machine

[0072] Figure 1 1 is a schematic diagram showing components of an anesthesia machine 10, which may be configured to receive a gas supply 1060 for delivering respiratory support to a patient 300 via a pipeline connection known in the art. The gas supply 1060 may include one or more of an anesthetic gas (e.g., nitrous oxide (NO)), oxygen (O2), and an air supply. The air supply may be ambient air. A flow meter may be incorporated into the gas supply 1060, or placed upstream of the anesthesia machine 10, or incorporated therein, to control the flow of gas through the machine. The flow meter may be manually controlled and / or precisely controlled by a controller of the anesthesia machine.

[0073] The breathing circuit delivers gas to the patient 300 and returns exhaled gas to the rebreathing component 140. The breathing circuit may include bellows, valves, and one or more patient interfaces for directing gas into the patient's airway and removing exhaled gas. Figure 1 In the schematic diagram of FIG, the breathing circuit is simplified and represented as including (but not limited to) an inspiratory conduit 110 and a first patient interface 120 that directs gas into the airway 310 of the patient 300, and an expiratory conduit 130 that collects exhaled gas. Therefore, the first patient interface 120 can be a sealing interface, such as a sealing mask or an endotracheal tube, and can be configured to direct exhaled gas from the patient 300 to the expiratory flow path 130, which returns the exhaled gas to the rebreathing component 140 of the anesthesia machine 10. The inspiratory and expiratory conduits can be connected to the patient interface by a Y-shaped connector.

[0074] One or more vaporizers 150 convert volatile anesthetics (such as isoflurane and sevoflurane) from liquid to vapor and control these agents into the breathing circuit at accurately controlled concentrations and doses based on the needs of the user (such as an anesthesiologist). The vaporizer 150 can be manually controlled and / or precisely controlled by a controller of the respiratory device. In some embodiments, the vaporizer 150 feeds into the rebreathing component 140.

[0075] Integrated into the anesthesia machine 10 is a ventilation system that ventilates the patient 300 during induction and after the administration of anesthetics to achieve continuous anesthesia. The clinician can use a manual ventilation bag 142, for example, during induction (dotted line within the rebreathing component 140), when volatiles are delivered, and before the patient is intubated. The flexibility of the ventilation bag 142 enables the patient to inhale and exhale a fixed amount of gas through a sealed first patient interface 120 in the form of a mask. Once intubated, the ventilation mode changes from manual to mechanical, effectively isolating the manual ventilation bag 142 and the associated pressure relief valve 143 from the rebreathing component 140 so that ventilation is performed via a mechanical system (dashed line within the rebreathing component 140). This can involve a foldable bellows 145 and / or an electronically actuated valve (under the control of a controller of the anesthesia machine 10) that controls the tidal volume and breathing time delivered to the patient through a sealed first patient interface 120 in the form of an endotracheal tube or a sealed mask. The gas provided to the patient can be controlled by a mechanical system for pressure and / or volume, and / or flow. Pressure relief valves 143, 146 provide for the release of excess gas (fresh gas flow from vaporizer 150 and returned patient exhaled gas) from the rebreathing component 140 while preventing ambient air from entering the breathing circuit. Manual ventilation through the ventilation bag 142 can also be used after intubation if desired.

[0076] The rebreathing component 140 provides a gas recirculation system in which the patient's exhaled gases are processed as they flow in the circuit and then re-inhaled. This provides advantages by reusing oxygen and volatiles in the patient's exhaled gas stream, reducing costs, and reducing the presence of anesthetic agents in the atmosphere. The exhaled gases in the rebreathing component 140 pass through a CO2 absorber 141, which may include a tank filled with soda lime (or another CO2 absorbing substance). Soda lime (a mixture of NaOH and Ca(OH)2) acts as a CO2 scrubber to remove CO2 before the gases in the rebreathing component 140 re-enter the inspiratory duct 110. In addition, the gases from the pressure relief valves 143, 146 are directed via an exhaust device (not shown) to an external scavenging system 144 that filters and collects anesthetic gases in the gas stream.

[0077] It should be understood that other features may also be provided as part of the anesthesia machine 10, such as, for example, patient monitoring, suction, pressure gauges, regulators, and "pop-up" valves to protect the patient and components of the machine from high pressure gases, as is known in the art. For simplicity, these features are not included in the illustrated example.

[0078] Figure 2 is a schematic diagram of a ventilator 20 that may be used in an intensive care unit (ICU). The ventilator 20 ventilates a patient with gas from a gas supply 1060 and is often actively humidified by a humidifier 420 that is configured to heat and humidify the gas delivered to the patient's airway 310. Although the humidifier 420 is Figure 2 120. The mechanical ventilator 184 is shown as part of the ventilator 20, but this need not be the case. The gas from the ventilator 20 can be humidified by a humidifier provided separately from the ventilator, humidifying the gas from the ventilator before reaching the first and second patient interfaces 120. The ventilator 20 can support the patient's own breathing or replace the patient's breathing by delivering respiratory gases to the patient, and these respiratory gases are controlled to replicate the "normal" inhalation and exhalation breathing phases. The mechanical ventilator 184 may include a flow modulator and / or a blower, and control the pressure, volume and breathing rate of the respiratory gas delivered through the inspiratory conduit 110, and the respiratory gas is delivered to the patient through the sealed first patient interface 120. The sealed first patient interface can be invasive (e.g., endotracheal tube or laryngeal mask airway (LMA)) or non-invasive (e.g., a sealed mask). The exhaled gases leave the patient via the first patient interface and the expiratory conduit 130, where they are processed by, for example, a filter 182 and released into the atmosphere. In some non-invasive ventilation systems, exhaled gases are exhausted through a vent or exhaust port in patient interface 120 or an exhalation conduit, which allows the exhaled gases to be exhausted to the atmosphere without returning to ventilator device 20 .

[0079] Components for high flow systems

[0080] Figure 3is a schematic diagram of components of a high flow system 30 that can be configured to receive gas from a gas supply 1060 to provide high flow respiratory support to a patient 300. The gas supply 1060 can be one or more of an anesthetic gas (e.g., nitrous oxide (NO)), oxygen (O2), or an air supply, preferably O2 and / or an air supply. The air supply can be ambient air. The high flow system 30 has a flow modulator 250 that is configured to generate a gas flow through a humidifier 420 that is configured to heat and humidify the gas flow generated by the flow modulator 250. In some embodiments, the flow modulator 250 can include a gas supply 1060 as described below or a flow source such as a fan or blower. The humidified high gas flow is delivered to the patient 300 through a second inspiratory conduit 210 and a non-sealed second patient interface 220. This can include a nasal cannula that directs a high flow of respiratory gas into the patient's airway 310 through one or both nostrils. An optional filter 230 may be provided between the inspiratory conduit 210 and the second patient interface 220 so that components of the breathing circuit upstream of the filter may be reused without risk of contamination by any exhaled gases inadvertently captured by the second patient interface 220. Relatedly, the filter 230 may be provided elsewhere in the flow path, such as, for example, between the humidifier 420 and the inspiratory conduit 210. In some examples, the filter may be associated with the cannula of the non-sealing second patient interface 220 and / or the exhalation flow path 130.

[0081] In some configurations, the flow modulator 250 is configured to provide gas to the patient through the high flow system 30. In some embodiments, the flow modulator includes a gas generating means, such as a blower adapted to receive gases from an environment external to the high flow system 30 and propel them through the high flow system 30. In some configurations, the flow modulator 250 may include a source (e.g., oxygen or air) available from a hospital gas outlet or wall supply, or one or more containers of compressed air and / or another gas and one or more valve arrangements adapted to control the rate at which the gas leaves the one or more containers. In some configurations, the flow modulator 250 may include an oxygen concentrator.

[0082] In this specification, "high flow" refers to (but is not limited to) any flow rate higher than the usual / normal gas flow, such as higher than the normal inspiratory flow rate of a healthy patient, or higher than some other threshold flow rate related to the context. It can be provided by a non-sealed respiratory system with a large amount of leakage, such as occurs at the patient's airway entrance. It can also be provided together with humidification to improve the patient's comfort, compliance and safety. "High flow" can refer to any gas flow with a flow rate higher than some other threshold flow rate related to the context-for example, when a gas flow is provided to a patient at a flow rate to meet the inspiratory demand, the flow rate may be regarded as "high flow" because it is higher than the nominal flow rate that may have been provided. Therefore, "high flow" is context-related, and the factors that constitute "high flow" depend on many factors, such as the patient's health status, the type of protocol / therapy / support provided, the nature of the patient (large, small, adult, child), etc. Those skilled in the art will recognize what constitutes "high flow" in a specific context. However, without limitation, some indicative values ​​of high flow can be as follows.

[0083] In some configurations, delivering gas to a patient at a high flow rate at a therapeutic flow rate can include a flow rate greater than or equal to about 5 or 10 liters per minute (5 or 10 LPM or L / min). The therapeutic flow rate can vary (e.g., oscillate) over time. That is, the therapeutic flow can have a flow rate component that varies (e.g., oscillates) over time. Such a time-varying flow rate can help support breathing and / or reduce the risk of atelectasis by providing improved oxygenation and / or CO2 clearance, which can in turn result in a more evenly distributed patient pressure throughout the lungs.

[0084] In some configurations, the flow rate of high-flow gas delivered to the patient is about 5 or 10 LPM to about 150 LPM, or about 10 LPM to about 120 LPM, or about 15 LPM to about 95 LPM, or about 20 LPM to about 90 LPM, or about 20 LPM to about 70 LPM, or about 25 LPM to about 85 LPM, or about 30 LPM to about 80 LPM, or about 35 LPM to about 75 LPM, or about 40 LPM to about 70 LPM, or about 45 LPM to about 65 LPM, or about 50 LPM to about 60 LPM. For example, in accordance with the various embodiments and configurations described herein, the flow rate of gas supplied by embodiments of the disclosed system may include, but is not limited to, a flow rate of at least about 5, 10, 15, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150 LPM, or more, and a useful range may be selected to be any of these values ​​(e.g., about 20 LPM to about 90 LPM, about 15 LPM to about 70 LPM, about 20 LPM to about 70 LPM, about 40 LPM to about 70 LPM, about 40 LPM to about 80 LPM, about 50 LPM to about 80 LPM, about 60 LPM to about 80 LPM, about 70 LPM to about 100 LPM, about 70 LPM to about 80 LPM). Thus, "high flow" or "high flow respiratory support" can refer to the delivery of gas to a patient at a flow rate of between about 5 or 10 LPM to about 100 LPM, between about 15 LPM to about 95 LPM, between about 20 LPM to about 90 LPM, between about 25 LPM to about 85 LPM, between about 30 LPM to about 80 LPM, between about 35 LPM to about 75 LPM, between about 40 LPM to about 70 LPM, between about 45 LPM to about 65 LPM, or between about 50 LPM to about 60 LPM.

[0085] In "high flow", the delivered gas will be selected based on the intended use, such as therapy or support. The delivered gas may include a percentage of oxygen. In some configurations, the percentage of oxygen in the delivered gas may be about 15% to about 100%, 20% to about 100%, or about 30% to about 100%, or about 40% to about 100%, or about 50% to about 100%, or about 60% to about 100%, or about 70% to about 100%, or about 80% to about 100%, or about 90% to about 100%, or about 100%, or 100%.

[0086] The flow rate for "high flow" for premature babies / infants / pediatrics (weight range of about 1 to about 30 kg) can be different. The flow rate can be set to about 0.4 LPM / kg to about 8 LPM / kg, with a minimum of about 0.5 LPM and a maximum of about 70 LPM. For patients weighing less than 2 kg, the maximum flow can be set to 8 LPM. The oscillating flow can be set to 0.05-2 L / min / kg, with a preferred range of 0.1-1 L / min / kg and another preferred range of 0.2-0.8 L / min / kg.

[0087] High flow can be used as a means of promoting gas exchange and / or respiratory support by delivering oxygen and / or other gases and by removing CO2 from the patient's airway. High flow can be particularly useful before, during or after a medical procedure. Further advantages of high gas flow can include that high gas flow increases the pressure in the patient's airway, thereby providing unobstructed support for opening the airway, trachea, lungs / alveoli and bronchioles. The opening of these structures enhances oxygenation and helps to remove CO2 to a certain extent.

[0088] The increased pressure can also prevent structures such as the larynx from blocking the view of the vocal cords during intubation. When humidified, high gas flow can also prevent the airway from drying out, reduce mucociliary damage, and reduce the risk of laryngospasm and the risks associated with airway dryness, such as epistaxis, aspiration (due to epistaxis), and airway obstruction, swelling, and bleeding.

[0089] In this specification, the terms subject and patient are used interchangeably. A subject or patient may refer to a human or animal subject or patient.

[0090] In this specification, reference to the numerical ranges disclosed herein (e.g., 1 to 10) also incorporates reference to all rational numbers within that range (e.g., 1, 1.1, 2, 3, 3.9, 4, 5, 6, 6.5, 7, 8, 9, and 10) and any rational number range within that range (e.g., 2 to 8, 1.5 to 5.5, and 3.1 to 4.7), and thus, all subranges of all ranges explicitly disclosed herein are explicitly disclosed herein. These are only examples of specific intent, and all possible numerical combinations between the lowest and highest values ​​recited should be considered to be explicitly stated in this application in a similar manner.

[0091] Overview

[0092] Embodiments of the present disclosure relate to an apparatus for providing respiratory support to a patient that provides switching between different forms or modes of respiratory support provided by a single device. Such an apparatus may be desirable and / or useful for a clinician user who may desire to switch between different forms of respiratory support delivered to a patient.

[0093] Figure 4 1 is a schematic diagram showing components of an apparatus 1000 for providing respiratory support to a patient. The apparatus includes a first gas flow path 1100, a second gas flow path 1200, and a first gas port 1300, the first gas port 1300 being configured to receive gas from either of the first gas flow path and the second gas flow path. The apparatus also includes a switching mechanism 1370 operable to switch between the first gas flow path 1100 and the second gas flow path 1200 to the flow of the first gas port 1300. In the use where the first gas port 1300 is a port for providing inhalation gas to the patient, the first gas port can be considered a common gas port for delivering inhalation gas to the patient.

[0094] In some embodiments, the device 1000 includes a controller 1010, and the operation of the switching mechanism 1370 can be triggered by the controller detecting one or more conditions of the operation of the device and / or receiving user input through the controller, as will be described below. Therefore, in some embodiments, the device 1000 includes a user interface 1094, which can include, for example, a touch screen and / or a display device and / or a monitor with a keyboard and / or other input actuators (buttons, knobs, dials, etc.) that are operatively communicated with the controller 1010.

[0095] The operation of the switching mechanism 1370 to allow flow 1300 from one of the gas flow paths to the first gas port may be referred to herein as "enabling" the flow path because the switching causes flow to occur between the enabled flow path and the first gas port 1300. In some embodiments, the operation of the switching mechanism 1370 to allow flow 1300 from one of the gas flow paths to the first gas port while also preventing flow from another of the gas flow paths to the first gas port. Preventing a gas flow path from flowing to the first gas port 1300 may be referred to herein as "disabling" because the switching does not enable or allow flow to occur between the disabled flow path and the first gas port 1300.

[0096] Figure 4 Also shown is a gas supply 1060 for supplying gas to the first gas flow path 1100 and / or the second gas flow path 1200, although it should be understood that in many embodiments more than one gas supply may be provided. Figure 4 The gas supply 1060 shown in FIG. 1 is merely exemplary and is provided merely for context to illustrate that at least one gas is provided to the device to provide respiratory support to the patient 300 .

[0097] In some embodiments, the first gas port 1300 can be considered a gas outlet port to which a first conduit (such as an inspiratory conduit) can be coupled to provide gas to the patient via a second patient interface, as will be described below. Figure 4 Also shown is a second gas port 1400 configured to be coupled to a second conduit, such as an exhalation conduit, which is configured to receive exhaled gas from the patient 300 via the first patient interface. The exhaled gas received at the second gas port 1400 is returned to the first gas flow path 1100, as will be described below.

[0098] However, in some uses, the direction of flow through the first gas port 1300 can change when switching occurs. For example, consider that the second gas flow path 1200 initially enables a flow of gas provided to the patient via a non-sealed second patient interface (e.g., a cannula) to provide high flow respiratory support. When the flow path to the first gas port 1300 is switched to enable the first gas flow path 1100, the non-sealed second patient interface can receive exhaled gas from the patient, and the inspiratory flow is provided from the second gas port 1400 and delivered through the sealed first patient interface (e.g., a mask). In this arrangement, the flow direction outside the device 1000 is reversed, with the non-sealed second patient interface and conduit 210 providing an expiratory flow path, while the sealed first patient interface and conduit 130 provide an inspiratory flow path.

[0099] The switching mechanism 1370 may be provided by one or more components or a combination of components of the device for switching between flow paths for providing a flow of gas to the first gas port 1300. Figure 4 In the embodiment shown in , the switching mechanism 1370 includes a switching element that has been operated to provide flow between the first gas flow path 1100 and the first gas port 1300. The broken lines show an alternative "switching" operation, in which the switching element provides flow between the second flow path 1200 and the first gas port 1300. The switching mechanism 1370 may include a switching element, such as a mechanical or pneumatic actuator, a flow diverter, a valve, etc., and may be operated by a user of the device 1000, thereby directly triggering the switching mechanism.

[0100] Although the switching mechanism 1370 Figure 4 is shown as a single switch, but it should be understood that the switching mechanism may include Figure 51370A and 1370B. Here, a first switching element 1370A is provided for the first flow path 1100 and a second switching element 1370B is provided for the second flow path 1200. The switching elements may include shutoff valves or other valves that may be operated under the control of a controller 1010 (such as an electronic controller, which may be a sensor-driven automatic controller). In some embodiments, the switching elements 1370A, B may include user-operable actuators, such as described herein in the context of actuators for the switching mechanism 1370.

[0101] Figure 4 and Figure 5 The location of the switching mechanism 1370 is merely representative, and as will become clear by reference to other examples provided herein, the switching mechanism may include one or more switching elements that are provided anywhere upstream of the joint between the first and second flow paths 1100, 1200 supplying the first gas port 1300, such as upstream of components of the first and second gas flow paths 1100, 1200, and / or downstream of elements of the first and second gas flow paths 1100, 1200.

[0102] The switching mechanism (and associated switching elements) may be operated directly by a user or indirectly, for example, via a controller 1010 (such as an electronic controller). Thus, the switching mechanism 1370 may include a user-operable actuator that enables a user to manually select an operating mode and thereby cause operation of the switching mechanism to enable or disable a gas flow path to the first gas port 1300, and / or a sensor-driven automatic controller that operates the switching mechanism 1370 (and other components of the device), as will be discussed below. The various switching elements may be operably coupled to actuate substantially simultaneously, or in response to other switching elements or actuators, or under the control of the controller 1010, as will become clear by reference to the non-limiting examples provided.

[0103] In some embodiments, the first gas flow path 1100 may be configurable to deliver a breathing gas including one or more anesthetic agents to a patient, and the second gas flow path 1200 may be configurable to deliver a breathing gas to a patient at a desired flow rate. Figure 1 ) and / or ventilation system 20( Figure 2 ) and the second gas flow path 1200 can be combined with the high flow system 30 ( Figure 3 ). For simplicity, the same reference numerals are used throughout this disclosure to represent these components.

[0104] In some embodiments, operation of the switching mechanism 1370 is employed to configure the device 1000 for different operating modes in order to provide different forms of respiratory support to the patient. For example, when the switching mechanism 1370 is operated to enable the first gas flow path 1100, the device 1000 can be configured to operate in a first operating mode, which first operating mode includes a rebreathing mode in which exhaled gas from the patient is returned to the first gas flow path; and when the switching mechanism 1370 is operated to enable the second gas flow path 1200, the device can be configured to operate in a second operating mode, which second operating mode can be a flow-controlled mode without rebreathing. The second operating mode can include a high flow mode. In some embodiments, when the switching mechanism 1370 is operated to enable the first gas flow path 1100, the device 1000 can be configured to operate in a first mode (i.e., an anesthesia rebreathing mode) or a third mode (i.e., a ventilation rebreathing mode), as previously described with respect to Figure 1 As described herein. References to operation in the first mode should therefore be considered to also refer to the third mode (i.e., rebreathing mode). The gas provided to the patient in this mode of operation may be pressure and / or volume controlled, and / or flow controlled. Ventilation may be triggered by the patient's effort, or by a ventilation device (e.g., an anesthesia machine) at a set breathing rate.

[0105] Although various embodiments of preventing the delivery of anesthetic to a patient when the second flow path is enabled are disclosed herein, it should be understood that other methods may be used as an alternative or supplement to the examples provided. For example, to avoid injury caused by the release of anesthetic when the second gas flow path is enabled, the device 1000 may stop releasing anesthetic to the patient by shutting down the vaporizer or reducing its function to an ineffective level. Alternatively or additionally, the device 1000 may deactivate the delivery of anesthetic. For example, the device may shut down the vaporizer or reduce its function to an ineffective level in the first gas flow path 1100. Alternatively or additionally, the device may inactivate the anesthetic in the gas flow delivered from the first gas flow path 1100 by using a neutralizer in the first gas flow path, which is activated when the device is operated with the gas flow path 1200 enabled, so that any anesthetic that may flow through the device is inactivated. Although wasteful, this can be an important safety measure.

[0106] When the first gas flow path 1100 is enabled, the device 1000 allows gas to flow from the first gas flow path to the first gas port 1300 so that the device operates in a first mode. From here, the first conduit 210 provides gas from the first gas port 1300 to the second patient interface 220 (which is an inspiratory patient interface), which directs the gas into the airway of the patient 300. In this arrangement, the second patient interface 220 that provides gas to the patient can be a non-sealed interface, such as a nasal cannula. The first patient interface (such as a mask), which is a sealed interface, is configured to direct the patient's exhaled gas to the second conduit 130, which returns the exhaled gas to the first gas flow path 1100 via the second gas port 1400. The returned exhaled gas can be processed by the rebreathing component 140 in the first gas flow path 1100, as described with respect to Figure 1 When the first gas flow path 1100 is enabled, the device 1000 also blocks flow from the second gas flow path 1200 to the first gas port 1300, thereby rendering the second gas flow path "disabled."

[0107] When the second gas flow path 1200 is enabled, the device 1000 allows gas to flow from the second gas flow path to the first gas port 1300. In addition, the device 1000 blocks gas from the first gas flow path 1100 to the first gas port 1300. Therefore, the first gas flow path 1100 is "disabled", thereby preventing the delivery of anesthetic gas, which may include NO and vaporized anesthetic agents, to the patient 300. The first conduit 210 provides gas from the first gas port 1300 to the second patient interface 220 (which is an inspiratory patient interface), which directs the gas into the airway of the patient 300. In this arrangement, the second patient interface 120 is a non-sealed interface, such as a nasal cannula with one or more nasal prongs, for directing gas into one or both nostrils of the patient. When the second gas flow path is enabled and the device is configured to operate in the second mode, the first patient interface or the second conduit does not need to return the exhaled gas to the device.

[0108] The device 1000 can be configured to receive a gas supply including NO, O2, and / or air from a gas supply 1060. One or more flow meters can be provided to control the flow rate of the gas in the device 1000 to achieve the desired respiratory support. One or more gas mixing elements can also be provided to combine the gases. Control of the flow meter can be achieved by direct control performed by a user (e.g., actuating an actuator such as a rotary or linear switch to directly change the flow through the flow meter), or by a user providing input to a controller 1010, which is configured to provide precise control of, for example, an electronically controlled flow meter within the device 1000.

[0109] A flow meter may be incorporated into the gas supply 1060, or placed downstream of the gas supply to control the ratio of gas entering the first gas flow path 1100 and the second gas flow path 1200. Alternatively, a flow meter may be provided within the device 1000 (see Figure 6 and Figure 7 ). Such a flow meter may be controlled manually, for example, by a proportional valve with a rotary actuator, or by the controller 1010 of the apparatus 1000. Safety features may be built in to limit the flow rate and ratio of the gas to safe limits, for example ensuring that the flow rate of the gas leaving the first gas flow path 1100 does not exceed 15 L / min in some embodiments and / or that the FiO2 does not drop below 0.21.

[0110] In some embodiments, the device 1000 may include a humidifier 420 ( 420.RTM. ) configured to condition the gas to a predetermined temperature and / or humidity prior to delivery to the patient. Figure 4 A-7). Preferably, such conditioned gas is provided in the second gas flow path 1200, but it is contemplated that when used in a ventilation rebreathing mode, the humidifier 420 may be configured to condition the gas to a predetermined temperature and / or humidity prior to delivery to the patient via the first gas flow path 1100. An advantage of providing the humidifier 420 within the device 1000 is that the setup of the humidifier is simplified by integrating the humidifier into the routine of setting up the device 1000 to provide respiratory support to a patient. However, the humidifier 420 need not be provided within the device 1000. In some embodiments, the device 1000 may be configured to operate with the humidifier 420, such as Figure 7 and Figure 8 The individual components or devices shown in the figure can be Figure 5-7 The embodiments in are similarly modified to provide a humidifier 420 external to the device, but for the sake of simplicity these are not illustrated separately in the figures.

[0111] exist Figure 7 and Figure 8 , the device 1000 includes a housing represented by solid line 1050, which includes Figure 6 1100 and the second gas flow path 1200 are shown as elements of the first gas flow path 1100 and the second gas flow path 1200, but the humidifier 420 is shown outside the device housing to represent a separate component or device. The third gas port 1210 is provided downstream of the flow source 250 and is configured to enable fluid coupling between the first segment 1200A of the second gas flow path and the third conduit 240 supplying gas to the humidifier 420.

[0112] exist Figure 7In the arrangement of , the humidified gas returns to the device 1000 via the fourth gas port 1220, which is configured to enable fluid coupling between the fourth conduit 260 containing the humidified gas from the humidifier 420 and the second portion 1200B of the second gas flow path. Figure 8 In the arrangement of FIG. 1 , the fourth conduit 260 is not coupled to a gas port in the apparatus 1000. Instead, the humidified gas in the fourth conduit 260 flows into the first conduit 210 via a joint or connector 600 (such as a tee joint connector). The connector 600 may form part of or be incorporated into the first gas port 1300, or may be as Figure 8 is provided downstream of the first gas port as shown in FIG. Figure 8 In an arrangement of, check valve 149A may be located upstream of humidifier 420, within device housing 1050. Figure 7 In embodiments where the humidifier is located within the device housing 1050, it is also possible that the check valve 149A is located upstream relative to the humidifier 420. As described below, check valves 149A, 149B may be provided to prevent backflow in the disabled flow path.

[0113] The humidifier 420 may be directly controlled by a user providing manual input to a control interface provided with or on the humidifier when the humidifier is provided separately from the device 1000. Alternatively / additionally, the external humidifier may be operatively coupled to the controller 1010 of the device such that operation of the device 1000 controls the performance of the humidifier 420 when the humidifier 420 is provided as part of the device or when the humidifier 420 is provided as a separate component external to the device. Thus, when the switching mechanism is operated to enable the second gas flow path, the controller 1010 may cause the humidifier 420 to increase the temperature and humidity of the gas flowing in the second gas flow path 1200 to a preset target. The target temperature and humidity may be programmed into the controller or selected by the user via the user interface 1094. In this sense, the controller 1010 may be viewed as a master controller that is operable to control all elements of the respiratory support provided to the patient.

[0114] When the switching mechanism is operated to switch the flow to the first gas port 1300 from the second gas flow path 1200 to the first gas flow path 1100, the controller can cause the humidifier 420 to enter a standby mode in which the temperature is reduced below the target temperature, but the humidifier is not completely deactivated. When control is switched back to enable the second gas flow path, this can improve performance by allowing the humidified gas to reach the target temperature and humidity more quickly. However, it should be understood that deactivation is also considered a feasible control during device operation when the first gas flow path is enabled (and the second gas flow path is disabled).

[0115] Figures 6 to 8 is a schematic diagram of the apparatus 1000, wherein a switching mechanism is located between a gas source 1060 and first and second gas flow paths 1100, 1200. The switching mechanism includes a first switching element 710 operable to direct a flow of O2 to the first gas flow path 1100 (which also receives a supply of air and NO) to operate the apparatus in a first mode, and to the second gas flow path 1200 to operate the apparatus in a second mode. Figures 6 to 8 A schematic diagram depicting the operation of such a switching mechanism is provided to enable the first gas flow path 1100 to operate the device 1000 in a first mode. It is noted that in a preferred embodiment, in the first mode of operation, the second switching element 720 is also operable to allow the first gas flow path 1100 to operate in either a manual (147) or automatic / mechanical (148) ventilation / rebreathing mode. Figures 6 to 8 In the embodiment shown in , the manual first mode has been selected. In some embodiments, the switching mechanism may further include one or more switching elements (not shown) operable to control the flow of air and / or NO to the first gas flow path 1100 .

[0116] The second switching element 720 can be responsive to the first switching element 710. Thus, when the first switching element 710 is switched to enable the second gas flow path 1200 to operate the device in the second mode, O2 is directed to the second gas flow path 1200 (represented by the flow modulator 250 and the humidifier 420), and the second switching element 720 can be moved to the lowest position 722, thereby shutting off manual and automatic ventilation / rebreathing and preventing exhaled gas returning from the patient to the second gas port 1400 from entering the rebreathing component 140 of the first gas flow path 1100 and then flowing to the first gas port 1300. When the first switching element 710 is switched to enable the second gas flow path, O2 is directed to the second gas flow path 1200. In Figure 8 In the example of FIG. 1 , gas from the second flow path 1200 enters the inspiratory conduit 210 downstream of the first gas port 1300. Therefore, the first switching element 710 enables operation of the second gas flow path 1200 to block O2 from flowing into the gas mixing element 1042 of the first gas flow path 1100, while also blocking fresh gas from flowing to the patient 300 through the first gas outlet 1300.

[0117] In addition to the switching mechanism (the switching mechanism may include, for example Figures 6 to 9 In addition to the switching elements 710 / 730 and 720 in the apparatus 1000, the apparatus 1000 may also include one or more check valves or other one-way valves to prevent or control backflow in the system, such as backflow from a "disabled" gas flow path to the first gas port 1300. Figures 6 to 9In the example shown in , when the switching mechanism is operated to switch the gas flow to the first gas port 1400 from the first gas flow path 1100 to the second gas flow path 1200, the check valve 149B prevents backflow from the first gas port to the first gas flow path. Conversely, when the switching mechanism is operated to switch the gas flow to the first gas port 1300 from the second gas flow path 1200 to the first gas flow path 1100, the check valve 149A prevents backflow from the first gas port 1400 to the second gas flow path 1200. Additional check valves may be implemented elsewhere in the flow path of the device 1000, which is a common situation in gas flow systems, particularly in rebreathing circuits.

[0118] In some embodiments, including in the context of the examples already described, the desired flow rate of gas delivered from the second gas flow path 1200 to the first gas port 1300 may be selected from a range of about 20 LPM to about 100 LPM by a user selecting through the user interface 1094 of the controller 1010, or by manually operating a flow controller of a component or device of a switching mechanism. However, in some cases, such as pediatric or neonatal patients, a lower range may be desired. In some embodiments, the desired flow rate may be selectable by the user from a plurality of available flow rates, such as, for example, 0 LPM, 40 LPM, and 70 LPM, but it should be understood that additional and / or different flow rates may be selected within the high flow range disclosed herein.

[0119] Selection of the desired flow rate can be achieved through operation of a switching element, which in some embodiments includes a rate selector in the form of, for example, a knob, sliding switch, touch screen or other actuator that provides the user with selection of the desired flow rate from a plurality or a range of available flow rates.

[0120] In some embodiments, the rate selector may include a rate switching element 730, such as Fig. 9 Schematically shown in . In some examples, the rate switching element 730 can replace the first switching element 710, but in some embodiments, it may be desirable to provide the rate switching element 730 in addition to the first switching element 710 to avoid the problem of delayed gas flow rate termination when the second gas flow path 1200 is enabled. Preferably, the rate switching element 730 is operably coupled to the second switching element 720 so that the operation of the rate selector 730 to enable flow in the second gas flow path 1200 to the first gas port 1300 (including through the humidifier 420 as shown) also prevents exhaled gas returning from the patient to the second gas port 1400 from entering the rebreathing component 140 of the first gas flow path 1100 and then flowing to the first gas port 1300.

[0121] exist Fig. 9In the arrangement of , the switching element 730 controls the flow of O2 to the first and second gas flow paths 1100, 1200. Therefore, when the rate switching element 730 is operated to select one of the two predetermined flow rates associated with the flow rate controller 250A (corresponding to, for example, 40 LPM) or the flow rate controller 250B (corresponding to, for example, 70 LPM), O2 flows in the second gas flow path 1200, and the device 1000 is configured to operate in the second mode; when the rate switching element 730 is operated to select the top position shown in the figure, the flow from the O2 supply is directed to the first gas flow path 1100, and the device is configured to operate in the first mode. The rate switch element 730 and the second switch element 720 can be operably coupled such that operation of the rate selector 730 to enable the second gas flow path 1200 can activate switching of the switch element 720 to the lowest position 722, thereby preventing exhaled gas returning from the patient to the second gas port 1400 from entering the rebreathing component 140 of the first gas flow path 1100 and then flowing to the first gas port 1300. Since the operation of the rate switch element 730 to enable the second gas flow path 1200 prevents O2 from flowing into the gas mixing element 1042 of the first gas flow path 1100, no fresh gas will flow from the first gas flow path 1100 to the patient through the first gas port 1300. In some embodiments, operation of the switch element 730 can also shut off the NO / air supply to the second gas flow path 1200. For example, this can be achieved by one or more operably coupled shut-off valves provided in the NO and / or air gas flow paths. In some embodiments, the switching mechanism may further include one or more switching elements (not shown) operable to control the flow of air and / or NO to the first and / or second gas flow paths 1100 , 1200 .

[0122] In some embodiments, the switching mechanism may include one or more flow rate selectors / flow meters 190A, 190B, 190C, such as Fig.10 As shown in the schematic diagram of . In this example, a single set of flow meters 190A, 190B, 190C is provided to control the flow of each of O2, air and NO to a common gas mixing element 1042, from which the first gas flow path 1100 and the second gas flow path 1200 both receive gas. In this arrangement, there is an operational coupling between the flow meters 190A, 190B, 190C and a switching mechanism including a switching element 710, as shown by the broken lines. As previously described, the switching element 710 is operable to switch the flow of gas to the first gas outlet 1300 between the first gas flow path 1100 and the second gas flow path 1200. In Fig.10In the arrangement of, when the switching element 710 is operated to enable the first gas flow path 1100 (configured as shown), the operational coupling between the switching element 710 and the flow meters 190A, 190B, 190C causes the flow meters to operate to deliver gas at a flow rate suitable for achieving respiratory support in the first operating mode. Conversely, when the switching element 710 is operated to enable the second gas flow path 1200, the operational coupling between the switching element 710 and the flow meters 190A, 190B, 190C causes the flow meters to operate to deliver gas at a flow rate suitable for achieving respiratory support in the second operating mode. The flow rate required for each flow meter 190A, 190B, 190C can be preset for operation in a particular operating mode. For example, when the first gas flow path 1100 is enabled, the flow meters 190A, 190B, 190C can be configured to deliver a mixed gas flow rate suitable for providing respiratory support in the first operating mode (e.g., 15 L / min at the first gas outlet 1300). When the second gas flow path 1200 is enabled, the flow meters 190A, 190B, 190C can be configured to deliver a mixed gas flow rate suitable for providing respiratory support in the second operating mode (e.g., 40 L / min or 70 L / min at the first gas outlet 1300). The flow rate provided by the flow meters 190A, 190B, 190C can be determined based on, for example, the desired O2 and / or NO concentrations. For example: in order to achieve a 100% O2 concentration at a flow rate of 15 L / min, the flow meter 190A can be set to 15 L / min, and the flow through the flow meters 190B, 190C is zero. Alternatively or additionally, when the NO flow is required to be zero, the NO source can be disabled as an additional safety mechanism, for example, when providing respiratory support in the second operating mode. In order to achieve a 50:50 ratio of O2:air in the mixed gas at 15 L / min, each of the flow meters 190A and 190B can be set to provide 7.5 L / min. The flow rate from flow meter 190C can be adjusted based on the desired NO fraction in the mixed gas flow to the patient as determined by the clinician, and the flow rate of one or both of flow meters 190A, B can be adjusted accordingly based on clinical requirements. Alternatively or additionally, flow meters 190A, 190B, 1900 can be adjustable by manual operation or via user interface 1094 in an arrangement where the flow meters are in operable communication with controller 1010.

[0123] Fig.11 Provided Fig.10A variation of the embodiment in which separate groups of flow meters 190A, 190B, 190C and 190D, 190E, 190F and separate gas mixing elements 1042A, 1042B are provided. The first group of flow meters 190A, 190B, 190C controls each of O2, air and NO flowing into the first gas mixing element 1042A, and the first gas flow path 1100 receives gas from the first gas mixing element. The second group of flow meters 190D, 190E, 190F controls each of O2, air and NO flowing into the second gas mixing element 1042B, and the second gas flow path 1200 receives gas from the second gas mixing element. Although Fig.11 Separate gas sources 1060A and 1060B are shown, but this is for ease of representing the flows in the figure. It should be understood that in the illustrated embodiment, it is not necessary for separate gas sources 1060A and 1060B to supply gas to each of the first and second gas flow paths 1100 and 1200. It is contemplated and expressly noted that each of the first and second gas flow paths 1100 and 1200 can receive gas from a single source for each of the one or more gases provided to the patient and feed it into a respective set of flow meters. When the first and second gas flow paths 1100 and 1200 receive gas from a single source, it should be understood that in some embodiments, NO may not be supplied to the second gas flow path 1200. In addition, while the vaporizer 150 is shown as being located downstream of the gas mixing element 1042A, it should be understood that the positions of these elements can be reversed, including arrangements where the first and second gas flow paths 1100 and 1200 receive gas from a single source.

[0124] exist Fig.11 In FIG. 1 , each of the first set of flow meters 190A, 190B, 190C is operably coupled to the second set of flow meters 190D, 190E, 190F, and a switching mechanism including a switching element 710 is present, as shown by the broken lines. As previously described, the switching element 710 is operable to switch the flow of gas to the first gas outlet 1300 between the first gas flow path 1100 and the second gas flow path 1200. Fig.11In the arrangement of, when the switching element 710 is operated to enable the first gas flow path 1100 (as in the configuration shown), the operational coupling between the switching element 710 and the flow meters causes the first group of flow meters 190A, 190B, 190C to operate to deliver gas at a flow rate suitable for achieving respiratory support in the first operating mode, and to cut off the flow from the second group of flow meters 190D, 190E, 190F. Conversely, when the switching element 710 is operated to enable the second gas flow path 1200, the operational coupling between the switching element 710 and the flow meters causes the second group of flow meters 190D, 190E, 190F to operate to deliver gas at a flow rate suitable for achieving respiratory support in the second operating mode, and to cut off the flow from the first group of flow meters 190A, 190B, 190C. The flow rate required for each flow meter can be pre-set for operation to supply a specified gas flow path, similar to Fig.10 Description of. For example: When the first gas flow path 1100 is enabled, the flow meters 190A, 190B, 190C can be configured to deliver a flow rate of a mixed gas suitable for providing respiratory support in the first operating mode (e.g., 15 L / min at the first gas outlet 1300). When the second gas flow path 1200 is enabled, the flow meters 190D, 190E, 190F can be configured to deliver a flow rate of a mixed gas suitable for providing respiratory support in the second operating mode (e.g., 40 L / min or 70 L / min at the first gas outlet 1300). In some embodiments, when the second gas flow path 1200 is enabled, the gas flow meters can be configured so that only the O2 gas flow meter 190D provides a flow of gas to the gas mixing element 1042B, while the air and NO flow meters 190E, 190F are disabled or provide zero flow. In other cases, it may be desirable that one or both of the gas flow meters 190DE, 190E provide a flow to the gas mixing element 1042B. Alternatively / additionally, the flow meters 190A, 190B, 190C, 190D, 190E, 190F may be adjustable by manual operation or via the user interface 1094 in an arrangement where the flow meters are in operable communication with the controller 1010 .

[0125] Figure 6 and Figure 7 The example in provides a switching element 710 as part of a switching mechanism of the device 1000. The switching element 710 may include an actuator, a knob switch, or an input interface 1094 operable by a user to select an operating mode. Alternatively / additionally, the switching mechanism may include operation of a controller 1010 of the device 1000 to switch operating modes in response to a change in an operating condition determined by a sensor providing input to the controller (such as applying a sealing patient interface to or removing a sealing patient interface from a patient).

[0126] Advantageously, Figure 4-7 The embodiment of the invention eliminates the need to provide an additional oxygen supply because both the first gas flow path 1100 that enables the device to operate in the first operating mode and the second gas flow path 1200 that enables the device to operate in the second operating mode can receive oxygen from the common gas supply 1060. In addition, this arrangement facilitates switching the first gas flow path 1100 and the second gas flow path 1200 at the same time, so that when the second mode is selected, the first gas flow path 1100 stops delivering gas to the patient 300. This provides greater safety by preventing the delivery of anesthetic agents including NO and volatile anesthetic agents evaporated in the first gas flow path 1100 in the flow of gas to the first gas port 1300. In addition, it does not allow anesthetic agents to enter the environment, thereby avoiding inhalation of these agents by caregivers who are caring for the patient, while also reducing waste.

[0127] In some embodiments including the controller 1010 and the user interface 1094, when a switch is made to enable the second gas flow path 1200, the device can provide a prompt (such as an audible, visual, or tactile prompt) to the user to continue using the first patient interface 120 on the patient until the amount of anesthetic agent in the exhaled gas returned to the device at the second gas port 1400 is very low or empty. Such an alarm provides a safety feature to reduce or eliminate the risk of anesthetic agent leaking into the care environment. Alternatively / additionally, the controller 1010 can be configured to provide a prompt (e.g., a second prompt) prompting the user to remove the first patient interface 120 from the patient. The controller 1010 can be configured with a timer and the second prompt is given when sufficient time has passed after the switch so that the amount of anesthetic agent in the exhaled gas returned to the patient is very low or empty. In some examples, the user interface 1094 can provide a visible and / or audible countdown timer to provide guidance to the user as to when the elapsed time has expired, indicating that the amount of anesthetic agent in the exhaled gas is very low or no anesthetic agent, and that the first patient interface 120 can be removed. Alternatively or additionally, the device 1000 can include one or more sensors in the exhaled gas flow path to detect the presence of anesthetic gas, and the controller 1010 can be configured to provide the second prompt only when the sensor indicates that no anesthetic gas is detected or the amount of anesthetic gas detected is below a predetermined safety threshold.

[0128] The electronically enabled switching element 710 can be physically attachable to one or both of the first or second patient interfaces 120, 220 to enable rapid switching between gas flow paths when swapping patient interfaces (e.g., when moving from cannula to cannula, or when taking a patient out of sedation) to enable the device 1000 to operate in different modes. For example, the switching element 710 can include a button or electronic switch located on the patient interface that can be actuated to cause the device 1000 to switch to an operating mode in which gas will be safely delivered to the patient through the interface. Alternatively, a foot pedal or foot switch or voice control can be used. Each of these has the potential to improve the accessibility of gas flow path / mode selection when the user is physically away from the controls located on the device itself.

[0129] While some embodiments of the present disclosure provide for switching between enabled gas flow paths (and operating modes) of the device 1000 based on user input manually provided to a switching element or provided through a user interface, in some embodiments, the device 1000 includes a controller 1010 that receives input from one or more sensors that are configured to detect operating conditions of the device, such as whether the first patient interface 120 is applied to the patient to receive exhaled gas, as this is only suitable for use when the first gas flow path 1100 is enabled. Therefore, when the sensor(s) detect that the first patient interface 120 is applied to the patient, the controller 1010 ensures that the first gas flow path 1100 is enabled, so that the device is configured for operation in the first mode (anesthesia rebreathing) or the third mode (ventilation rebreathing), which can be considered a specific example of the first mode, and which collectively or individually can be considered as a "rebreathing" mode. Conversely, when the sensor(s) detect that the first patient interface 120 is not applied to a patient, the controller 1010 ensures that the second gas flow path 1200 is enabled such that the device is configured to operate in the second mode, delivering nasal high flow (NHF) respiratory support.

[0130] A range of different methods and combinations of methods for sensing may be used as a means of providing gas flow paths and / or mode switching in the device 1000 for delivering gas to a patient. In one example, the pressure within the mask cavity may be monitored by a pressure sensor and used to detect when the mask is placed on the patient. Detection of the mask on the patient may be achieved by detecting an increase in mask pressure relative to the pressure expected during high flow respiratory support delivery (consistent with the mask being placed on the cannula), and causing a switching mechanism to disable the second gas flow path 1200 and enable the first flow path 1100, such that the configuration of the device switches from the second (high flow) mode of operation to the first (rebreathing) mode. Additionally or alternatively, an optical sensor may be provided in the mask that is configured to monitor changes in emitted / detected light that occur in the presence of the patient's skin and may be used to detect the position of the mask on the patient. In some embodiments, this can be used in conjunction with a pressure sensor (e.g., to sense pressure in the cuff of the mask or in the mask cavity) that detects an increase in pressure when the mask is applied to the patient, which causes a switching mechanism to disable the second flow path and enable the first flow path, such that there is a switch from the second mode of operation to the first mode of operation. In some embodiments, a pressure sensor in the cuff of the mask can be used independently of the optical sensor. Likewise, if an opposite change in these measurements is detected, this can coincide with the removal of the mask from the patient, which can cause the switching mechanism to disable the first flow path and enable the second flow path, such that there is a switch from the first mode of operation to the second mode of operation. Additionally or alternatively, one or more pressure sensors can be provided on the outer surface of the nasal cannula. For example, a pressure sensor can be provided in an area of ​​the cannula on which a portion of the mask cuff is applied to operate the device in the first mode, and / or a pressure sensor can be provided in an area of ​​the cannula that is located within the sealing mask when the mask is applied to the patient. The increase in cannula pressure indicates that the mask is applied to the cannula and causes the switching mechanism to disable the second flow path 1200 and enable the first flow path 1100 to operate in the first (rebreathing) mode.

[0131] Alternatively or additionally, the sensor may include a pressure sensor arranged to measure pressure in one or both of the first gas flow path 1100 and the second gas flow path 12000. The device 1000 may provide a continuous or intermittent flow of gas through the first gas flow path 1100 and / or the second gas flow path 1200 to enable measurement of pressure in the device. In some embodiments, such a continuous or intermittent flow of gas includes a flow rate, pressure and / or volume that is less than the flow of gas provided to the patient in the first and / or second modes. When each of the first (sealed) patient interface 120 and the second (non-sealed) patient interface 220 is coupled to the patient 300 for use in the first and second modes, respectively, different flow resistance values ​​are associated with each of the first (sealed) patient interface 120 and the second (non-sealed) patient interface 220. When the measured pressure indicates that exhaled gas is returned from the patient through a sealed patient interface that is substantially sealed with the patient, the controller 1010 causes the switching mechanism to enable the first gas flow path 1100 and operate the device 1000 in a first mode, wherein gas that may include an anesthetic agent is delivered to the patient 300 and exhaled gas is returned to the rebreathing component 140 of the first gas flow path 1100. Alternatively, when the measured pressure indicates that breathing gas is delivered to the patient through a non-sealed patient interface (i.e., there is no mask that returns exhaled gas), the controller 1010 causes the switching mechanism to enable the second gas flow path and operate the device 1000 in a second mode, wherein gas that does not include an anesthetic agent is delivered to the patient at a desired (high flow) flow rate. In some embodiments, the pressure sensor can be located at or downstream of the flow modulator 250 of the device 1000, or at any convenient location in the gas flow path between the patient's airway and the flow modulator 250.

[0132] Alternatively or additionally, the one or more sensors may include a CO2 sensor associated with an inspiratory gas flow path (such as in one or more of the first gas port 1300, the first conduit 210, the first patient interface 120, and / or the second patient interface 220, depending on the interface configuration) and / or an expiratory gas flow path (e.g., in one or more of the second gas port 1400, the second conduit 130, and the first patient interface 120). In such an embodiment, the controller 1010 determines that the gas flow path containing a higher concentration of CO2 than ambient air is associated with a patient interface coupled to the patient's airway. If the CO2 concentration in both flow paths is higher than ambient air, the controller determines that the flow path with the higher CO2 concentration is associated with the patient interface receiving the expiratory gas, and is therefore coupled to the patient's airway, and causes the device 1000 to enable the first gas flow path 1100, so that the device operates in the first (or third) mode, while the second gas flow path 1200 is disabled.

[0133] Alternatively or additionally, the one or more sensors may include an O2 sensor that measures a characteristic (e.g., gas concentration) of O2 in the expiratory flow path. Upon understanding the characteristic of O2 supplied to the patient during respiratory support, the controller 1010 may compare the sensed O2 characteristic with the supplied O2 characteristic and determine that the first patient interface 120 has been applied to the patient when it is equal to or close to or within the range of the supplied value. Alternatively, if the sensed O2 characteristic (e.g., concentration) is greater than the atmospheric O2 concentration (e.g., greater than 22% or greater than 25%), then the controller 1010 may determine that the first patient interface has been applied to the patient. Alternatively / additionally, a trace gas (e.g., nitrous oxide or another inert gas) or a trace gas flow pattern (e.g., a flow rate or pressure oscillation containing a known frequency or behavior) may be provided in addition to respiratory support in the first conduit 210. If the controller determines that a trace gas or a trace gas flow pattern is present in the expiratory gas, then it may be determined that the first patient interface has been applied to the patient.

[0134] Alternatively or additionally, sensing in the expiratory flow path may be utilized to determine when the first patient interface 120 (e.g., a sealing mask) is in place on the patient to trigger a switch to the first (rebreathing) mode. Suitable sensors may be used to determine one or more parameters in the expiratory flow path, such as flow rate, pressure, temperature, or humidity. An increase in one or more of these parameters (e.g., if the sensor determines that the temperature in the expiratory flow path has increased or is above ambient temperature) will indicate that a mask has been placed on the patient and trigger a switch to enable the first gas flow path, thereby configuring the device 1000 to operate in the first (or third) mode.

[0135] Fig.12is a schematic diagram showing two example locations S1 and S2 of sensors for detecting characteristics of gases in the inspiratory flow path 210 and the expiratory flow path 130, respectively. Sensors may be provided at one or both locations S1, S2 for determining, for example, whether the first patient interface 120 is applied to a patient (or not applied to a patient). The sensors at S1 and / or S2 may sense characteristics of the gas, such as, but not limited to, pressure, flow rate, and gas type concentration (e.g., O2, CO2 concentration). These sensors may be mainstream sensors (sensing components are located in the inspiratory or expiratory gas flow path) or sidestream sensors that receive sampled gas extracted from the inspiratory or expiratory gas flow path. Each location S1, S2 may include zero, one, or more than one sensor, and the sensor type may be selected based on one or more characteristics of the gas to be sensed. Position S1 in the inspiratory flow path 210 and / or position S1 between the connector 145 of the flow path connecting the rebreathing component 140 and the gas outlet port 1300 in the device 1000 can facilitate sensor-driven determination of the enabled flow path because a single sensor at S1 can be used to measure the flow in the first gas flow path 1100 and the second gas flow path 1200. The gas pressure sensor at S1 can be used to determine whether the first patient interface is applied to the patient because the pressure measured at S1 can be compared to an expected pressure value corresponding to the respiratory support mode provided. In an example, the first mode can be a rebreathing mode in which the first (sealed) patient interface is applied to the patient, and the second mode can be a high flow mode in which the first patient interface is not applied to the patient.

[0136] Alternatively or additionally, a sensor may be provided at S2 to determine the characteristics of the exhaled gases in the exhalation conduit 130. The sensor provided at S2 may be used to determine whether the first (sealed) patient interface 120 has been applied to the patient. In one example, when the device is operating in the second mode, the detection of gas flow at S2 may be used to trigger a switch to the first (rebreathing) operating mode. Conversely, when the device is operating in the first mode, the detection of no gas flow at S2 may be used to trigger a switch to the second operating mode. The use of more than one sensor (optionally at both sensor locations S1 and S2) provides redundancy in the sensor-driven automatic switching between the operating modes of the device. This may mitigate false triggering of mode switching, which may be caused by, for example, unexpected flow from room ventilation or other sources. In addition, when multiple sensors are provided to provide input to the controller 1010 for determining when to perform a mode switch, inaccurate performance or failure of only one sensor will not compromise the safe operation of the device.

[0137] It should be understood that Fig.12The sensor positions S1 and S2 in are merely examples. The flow rate sensor sensing the flow in the second gas flow path 1200 may be located anywhere downstream of the flow modulator 250 or the flow meter 190. To sense the flow in the first mode of operation, the flow rate sensor may be located anywhere downstream of the gas mixer 1042. To sense the flow in either mode of operation, the flow rate sensor may be located anywhere downstream of the check valves 149A, B, and / or anywhere downstream of the first gas port 1300. Alternatively or additionally, the flow rate sensor sensing the flow in the expiratory flow path 130 may be located anywhere in the flow path between the patient 300 and the connector 145. This may include a location between the patient 300 and the second gas port 1400 and / or a location inside the device 1000 between the second gas port 1400 and the connector 145 and / or between the second gas port 1400 and the check valve 149C. The pressure sensor may be positioned at the same location as the flow rate sensor, in addition to or in lieu of the flow sensor.

[0138] The O2 sensor sensing the O2 concentration in the inspiratory flow path 210 may be located anywhere downstream of the flow source 1060 in either operating mode, including downstream of the check valves 149A, B and / or downstream of the first gas port 1300. Alternatively or additionally, the O2 sensor sensing the O2 concentration in the expiratory flow path 130 may be located anywhere in the flow path between the patient 300 and the connector 145. This may include a location between the patient 300 and the second gas port 1400 and / or a location inside the device 1000 between the second gas port 1400 and the connector 145 and / or between the second gas port 1400 and the check valve 149C. A CO2 sensor sensing the flow in the expiratory flow path 130 may be provided at any location in the flow path between the patient 300 and the CO2 absorber 141 (if provided). This may include a location between the patient 300 and the second gas port 1400 and / or a location inside the device 1000 between the second gas port 1400 and the check valve 149C and / or between the check valve 149C and the CO 2 absorber 141 .

[0139] In some examples, it may be beneficial to position the sensor on the device side of the first and / or second gas ports 1300, 1400 to avoid incorporating the sensor into a consumable / disposable component of the system, thereby reducing cost. However, in some examples, it may be beneficial to sense the characteristics of the gas closer to the patient (e.g., within a patient interface or within a conduit coupled to the patient interface) for accuracy and to mitigate false readings (and potential mode switching) caused by accidental squeezing of the conduit or other movement that may affect the sensor measurement.

[0140] Sensor-driven automatic switching between gas flow paths may be achieved by the controller 1010 receiving sensor inputs and controlling the operation of the switching elements of the device based on these inputs when certain predefined conditions are met, so that the device 1000 operates in different modes. In an example, one or more sensors that can sense one or more of pressure, flow rate, and gas concentration in the expiratory flow path 130 provide input to the controller 1010. If the flow rate or pressure or gas concentration meets a predetermined condition, such as being greater than a predetermined threshold, such as a flow rate greater than 0 or about 0.5 to about 2 L / min, and / or a pressure greater than ambient air, and / or a CO2 concentration greater than ambient air (if the patient is breathing) and / or an O2 concentration greater than ambient air (if the O2 provided to the patient is greater than 21%), then the controller determines that a sealing mask has been applied to the patient and the system can operate in the first (rebreathing) mode.

[0141] Conversely, if the sensed parameter satisfies a predetermined condition, e.g., is below a predetermined threshold, the controller determines that the sealing mask is not applied to the patient, and the system can operate in a second (high flow) mode. In some examples of sensing gas concentration parameters, if the threshold corresponds to a gas concentration value corresponding to ambient air, the predetermined condition can include that the sensed gas concentration is at or near a predetermined threshold. If the device 100 is not already operating in an appropriate mode, the controller operates a switching element of the device to provide respiratory support in an appropriate mode. Thus, if the device is providing respiratory support in a first mode and the controller determines that (one or more) sensor inputs are below a threshold, control is switched to provide respiratory support in a second mode. Conversely, if the device is providing respiratory support in a second mode and the controller determines that the sensor input is above a threshold, control is switched to provide respiratory support in a first mode. It may be desirable to set the thresholds for CO2 and O2 concentrations slightly above ambient values ​​to mitigate false threshold detections due to ambient flow (e.g., from room ventilation or other sources). The thresholds used by the controller 1010 in sensor-driven automatic switching may be adjustable, for example, by a user or service technician. In some examples, the threshold for triggering a switch from the first mode to the second mode may be the same as the threshold for triggering a switch from the second mode to the first mode. Alternatively, these switching conditions may be triggered by different threshold values ​​to allow tolerance and certainty of switching and / or mitigate undesirable oscillations between modes when, for example, a single threshold is used.

[0142] In another example, one or more sensors may sense pressure in the inspiratory flow path 210. When the device is operating in the second mode, the controller 1010 may receive continuous or regular inputs from (one or more) pressure sensors and compare these inputs with a threshold or range of high flow pressure values ​​known to be consistent with providing respiratory support in the second (high flow) mode. When the controller detects an increase in pressure above the threshold or range of high flow pressure values, the controller determines that a sealing mask has been applied to the patient and controls the switch element of the device to provide respiratory support in the first mode. Similarly, when the device is operating in the first mode, the controller 1010 may receive continuous or regular inputs from (one or more) pressure sensors and compare these inputs with a threshold or range of re-breathing pressure values ​​known to be consistent with providing respiratory support in the first mode. When the controller detects a drop in pressure below the threshold or range of re-breathing pressure values, the controller determines that a sealing mask is not applied to the patient and controls the switch element of the device to provide respiratory support in the second mode.

[0143] In another example, one or more sensors may sense pressure and / or flow rate and / or gas concentration in the expiratory path 130 and provide input to the controller 1010. If the controller 1010 determines that the time-averaged flow rate or O2 concentration of the gas in the expiratory flow path 130 is approximately equal to, close to, or within a percentage of the flow rate or O2 concentration provided as part of the respiratory support (e.g., within 90+%), then the controller determines that a mask has been applied to the patient, and if the respiratory support is in the second mode, then the switching element of the control device switches the respiratory support to the first mode. Conversely, if the controller 1010 determines that the time-averaged flow rate or O2 concentration of the gas in the expiratory flow path 130 is not equal to, close to, or within a percentage of the flow rate or O2 concentration provided as part of the respiratory support (e.g., within 90%), then the controller determines that a mask is not applied to the patient, and if the respiratory support is in the first mode, then the switching element of the control device switches the respiratory support to the second mode. In some examples, one or more sensors may also sense pressure and / or flow rate and / or gas concentration in the inspiratory path 210 to determine the characteristics of the respiratory support provided to the patient. It is to be noted that the characteristics provided as part of the respiratory support (such as flow rate, O2 concentration and gas flow pressure) will differ depending on the mode of respiratory support provided. The values ​​of pressure and / or flow rate and / or gas concentration are preferably time-averaged over at least one respiratory cycle (if the patient is breathing spontaneously) to allow for measurement delays.

[0144] Alternatively or additionally, the respiratory support provided to the patient may include a controlled component that provides a "signature" in the gas flow that the controller can use to determine whether a mask is applied to the patient. The signature may include, for example, oscillations in a characteristic such as the frequency, amplitude, or curve of the pressure and / or flow rate and / or O2 concentration of the gas provided to the patient. The oscillations may be achieved, for example, by a valve in the flow path, such as a proportional valve. During the provision of respiratory support, if the controller determines that there is a signature in the gas received in the expiratory flow path 130, the controller determines that the mask is applied to the patient, and if the respiratory support is in the second mode, the switching element of the control device switches the respiratory support to the first mode. Conversely, if the controller determines that there is no signature in the gas received in the expiratory flow path 130, the controller determines that the mask is not applied to the patient, and if the respiratory support is in the first mode, the switching element of the control device switches the respiratory support to the second mode. In some embodiments, a signature may be provided in only one mode, or different signatures may be provided for different modes of respiratory support.

[0145] In an example where the controller 1010 compares the sensed flow rate value to a reference value or threshold value, the controller may calculate the difference as an absolute value and / or percentage of the threshold or respiratory support provided. The controller 1010 may also be configured to display the calculated difference on the user interface 1094. In the event that the controller determines a difference between the provided value and the sensed value, the display of the difference may provide useful data that may indicate the presence of a leak in the system. When a sealing mask is used in the first mode, such a display may indicate that the mask is not sealing adequately on the patient's face.

[0146] It should be understood that the controller 1010 can utilize and / or combine one or more of the aforementioned sensing examples to provide greater certainty that the switching condition is met, thereby reducing the possibility of false detection leading to false switching. By way of example only, one such combination can include flow rate plus CO2 detection in the expiratory flow path 130, or flow rate detection in the inspiratory flow path 210 plus gas concentration sensing in the expiratory flow path 130. Another combination can include pressure sensing in the inspiratory gas flow path 210 plus pressure sensing in the expiratory gas flow path 130, and optionally also adding CO2 sensing in the expiratory flow path 130.

[0147] The controller may use, for example, pressure, flow rate, or gas concentration sensing in the expiratory flow path 130; pressure sensing in the inspiratory flow path 210 and any one or more of pressure, flow rate, and / or gas concentration sensing in the inspiratory or expiratory flow paths 210, 130 to control the switch from the second mode to the first mode, and the controller may use the same or different one or more sensor inputs to control the switch from the first mode to the second mode. In some cases, it may be desirable to have greater redundancy or certainty (thereby requiring more conditions to be met before switching) when the controller switches from the second mode to the first mode due to the release of volatiles. However, in some cases, it may be desirable to have greater certainty when switching from the first mode to the second mode to ensure that it is safe and / or appropriate before stopping ventilation or providing volatiles in the inspiratory gas flow path.

[0148] exist Fig.13 In another example schematically shown in , even when the first and / or second flow paths 1100, 1200 are inactive (not enabled), a small amount of residual flow can be provided in the first and / or second flow paths 1100, 1200, and one or more sensors can be provided in positions S3 and / or S4 upstream of the check valve 149. The residual flow can be, for example, on the order of about 0.5 L / min to about 5 L / min to ensure that the sensors at positions S3 and / or S4 are in fluid communication with the first gas port 1300 (e.g., if there are check valves 149A, 149B in the flow paths, the residual flow will keep these valves open). The residual flow can include air instead of O2 to reduce O2 consumption and / or waste.

[0149] In an example, if the device is providing respiratory support in the second mode, the residual flow may be maintained beyond S3 by the rebreathing component 140 to keep the flow path open. The pressure at S3 may be periodically / continuously sensed, and the controller 1010 receives inputs from the pressure sensor(s) and compares these inputs to a threshold or range of values ​​known to be consistent with providing respiratory support at a particular flow rate in the second mode. When an increase in pressure is detected at S3, the controller determines that a mask is to be applied to the patient and controls the switching element of the device to provide respiratory support in the first mode.

[0150] When operating in the first mode, a residual flow maintained in the second gas flow path 1200 keeps the flow path open. The pressure at S4 can be sensed periodically / continuously, and the controller 1010 receives inputs from the pressure sensor(s) and compares those inputs to a threshold or range of values ​​known to be consistent with providing respiratory support in the first mode. When a pressure drop is detected at S4, the controller determines that the mask is not applied to the patient and controls a switching element of the device to provide respiratory support in the second mode at a flow rate greater than the residual flow rate. The controller can determine an increase or decrease in pressure at S3 and / or S4 by reference to a threshold value or range or value, which can be an absolute value (e.g., 1 cmH2) or a percentage of an expected pressure for a particular operating mode (e.g., 20+% difference from an expected value).

[0151] In the figure, the check valves 149A, B are shown as separate valves located upstream of the joint between the inspiratory flow of the first gas flow path 1100 and the second gas flow path 1200. However, the functionality of these valves can be combined into a single check valve provided downstream of the joint between the inspiratory flow from the first gas flow path 1100 and the second gas flow path 1200. Alternatively, a valve to prevent backflow can be placed additionally at this position downstream of the joint. In this arrangement, it may be desirable to place a valve to prevent backflow, for example, downstream or upstream of the humidifier 420 and / or at the switching element 710 to prevent backflow out to the atmosphere in the first (rebreathing) mode.

[0152] Alternatively or additionally, the sensor may include one or more proximity sensors, such as, for example, acoustic (including audible and / or ultrasonic), optical (including infrared), radio frequency, pressure (in the inspiratory / expiratory conduit and / or mask cuff), flow, conductivity, resistance, temperature or other sensors to determine which breathing circuit is coupled to the patient's airway via the first or second patient interface. Such proximity sensors are explained in more detail in WO2016157105A1, the contents of which are incorporated herein by reference.

[0153] In some examples of automatic (sensor-driven) switching between respiratory support modes, the controller 1010 may apply timing control to the switching control, wherein after detecting a condition that should trigger a mode switch, the controller applies a delay before controlling the switching element to cause the mode switch. This can avoid erroneous switching due to sensing errors or transient conditions that are resolved after a few seconds, such as those caused by accidental squeezing of the catheter or other movements. The user interface 1094 may provide a visible and / or audible countdown timer that provides the user with an indication of when the switch between modes occurs. The user interface 1094 may also be expected to provide the user with an option to cancel the mode switch proposed by the controller within a predetermined time, for example, if the user realizes that an erroneous switching condition has been met (erroneous triggering). For example, when switching from a first mode to a second mode, the controller may control the operation of one or more of the gas sources 1060, 1600A, 1060B and the flow meters 190C, 190F to stop supplying and / or reduce the flow rate of the volatiles provided in the first gas flow path 1100, but the treatment through the first gas flow path can continue until the predetermined time has passed. If the user cancels the proposed switch during the predetermined time period, the controller will resume the supply of volatiles and will not stop the flow from the first gas flow path 1100 to the patient.

[0154] The switching mechanism 1370 may include one or more actuators operable by a user, such as, but not limited to, one or more of a button, a switch, a knob, a foot switch, or a pedal. Alternatively or additionally, the switching mechanism 1370 may include or be in operative communication with one or more of an electronic input device, a touch screen, a voice activated sensor, etc., which may operate in conjunction with the electronic controller 1010 of the device 1000. The one or more actuators of the switching mechanism 1370 may be located at or near the first or second patient interface 120, 220 through which exhaled gas is removed or respiratory gas is delivered to the patient. Positioning one or more of the actuators at or near the patient end of the breathing circuit that delivers gas to the patient's airway provides convenience for clinicians operating on patients during anesthesia, because during anesthesia, clinicians often have to switch between the operating mode of the device 1000 and the form of respiratory support delivered. Positioning the actuator that enables mode selection at the patient end may be more convenient and time-saving for clinicians and others nearby. In other arrangements, the device 1000 may be configurable to detect whether a first patient interface (an expiratory patient interface configured to receive exhaled gases from the patient to return to the device) is attached to the patient and modify the operating mode and flow path selection accordingly.

[0155] In some embodiments, the user interface 1094 may provide an audible and / or visual output (such as an indication on a display screen and / or an audible sound or message) to indicate to the user the operating mode in which the device 1000 is operating. Alternatively or additionally, another component of the respiratory support system (such as a gas conduit or a patient interface of a breathing circuit) may include an audible or visual output element (such as a speaker and / or an LED or other lighting element) operable by the controller 1010 to provide an output to indicate to the user the operating mode in which the device 1000 is operating. In an example, a predetermined color and / or sound and / or symbol on the output element may be associated with the operation of the device 1000 in a first mode, while a different predetermined color and / or sound and / or symbol may be associated with the operation in a second mode. One or more predetermined colors and / or sounds and / or symbols may be user-selectable and / or user-defined. Positioning one or more of the output elements at or near the patient end of the breathing circuit that delivers gas to the patient's airway provides a convenience for the clinician operating the patient, enabling him to understand at any time throughout the anesthesia phase the mode in which the device is operating.

[0156] It should be understood that the switching mechanism 1370 may include one or more switching elements, such as mechanical, electronic, electromechanical, electromagnetic, pneumatic, or any other suitable switching mechanism, to achieve the functionality disclosed herein. In addition, one or more switching elements may be coupled to the switching mechanism 1370 via a wired and / or wireless coupling using techniques that are readily understood and determinable by those skilled in the art. The switching element may include an actuator that can be operated by a user of the device 1000 to select a desired operating mode (and a flow path to be enabled), and may include or consist of any of the switching elements described. In some embodiments, the switching element may include an electronic input device that wirelessly communicates with the controller 1010 of the device 1000 and can be movably positioned to different positions relative to the patient 300 and / or the device 1000 and / or the patient interface 120 / 220.

[0157] In some embodiments, one or more switching elements of switching mechanism 1370 may be operable to control one or more characteristics of the gas delivered to the subject, such as, but not limited to, the presence of volatiles, flow rate, gas composition, gas concentration, temperature, and / or humidity.

[0158] For the sake of simplicity, certain features of the first gas flow path 1100 are not always shown in the figures. However, it should be understood that in a preferred embodiment, the first gas flow path 1100 performs the functions of the anesthesia machine 10 and / or the ventilator 20 and includes one or more of the following: a CO2 absorber 141, configured to process the returned exhaled gas before recirculating it to the patient in the first mode; a pressure limiting valve 146, configured to maintain a substantially constant pressure in the device in the first mode; a variable volume 145, for replacing gas in the first mode (e.g., using a bellows or bag ventilator); a supplemental gas flow, for supplementing the anesthetic gas delivered to the patient in the first mode; and a vaporizer 150, for vaporizing a volatile anesthetic into a gas delivered to the patient in the first mode.

[0159] Similarly, for the sake of brevity, certain features of the second gas flow path 1200 are not always shown in the figures. However, it should be understood that in a preferred embodiment, the second gas flow path 1200 delivers high flow respiratory support as described herein and includes one or more of a flow source 250 or a modulator configured to generate a flow of gas through the second gas flow path 1200 in the second mode. A humidifier 420 may also be provided, which is configured to condition the gas to a predetermined temperature and / or humidity before delivering the gas to the first gas port 1300, but it may be omitted in some cases.

[0160] In some embodiments, a switching mechanism can be provided by using the first and second patient interfaces 120, 220 simultaneously. Thus, when the first (expiratory) and second (inspiratory) patient interfaces are applied to the patient simultaneously, the first gas flow path 1100 is enabled and the configuration device 1000 operates in the first mode, and when only the second (inspiratory) patient interface is applied to the patient, the second gas flow path 1200 is enabled and the configuration device 1000 operates in the second mode. In one arrangement, the first patient interface 120 is a mask that is capable of sealing the second patient interface 220 (nasal cannula) without blocking the gas flow through the cannula. The inspiratory gas flow is delivered via the cannula and the expiratory gas returns via the mask. This arrangement can be used to deliver anesthetics in a closed system, delivering the anesthetic to the patient using the cannula and returning the exhaled gas using the mask. The pressure sensor can be used to determine when the mask is applied to the patient and sealed on the cannula, so that when a target pressure is detected at the mask (e.g., within the mask or within the mask cuff, or using a pressure sensor on the cannula body), the switching mechanism 1370 is triggered, thereby enabling the first gas flow path 1100 to provide anesthetic through the nasal cannula. Commonly owned patent publication WO2015145390 discloses a mask suitable for this context and is hereby incorporated by reference herein.

[0161] Figures 14 to 16 An example of how to switch between flow paths within the device 1000 disclosed herein to configure the device for different respiratory support modes by using the first and second patient interfaces 120, 220 simultaneously or separately is illustrated. The device 1000 provides a first gas port 1300 configured to be coupled to a first (inspiratory) conduit 210. A second gas port 1400 is provided for coupling with a second (expiratory) conduit 130 to return exhaled gas from the patient via the first patient interface 120. When either flow path of the device 1000 is enabled, gas is provided to the patient's airway via the conduit 210 and the second patient interface 220. When the first flow path 1100 is enabled, the device 1000 can operate in a first mode to provide gas to the patient using a first flow parameter and return exhaled gas from the patient to the second gas port 1400 via the first patient interface 120 and the second conduit 130. When the second gas flow path 1200 is enabled, the device 1000 can operate in a second mode to provide gas to the patient using a second flow parameter. The first and second flow parameters include or correspond to the first and second flow rates, respectively. In some embodiments, the first flow rate is less than 15 L / min, and the second flow rate is greater than 15 L / min. In some embodiments, the second flow rate is in the range between about 20 L / min and about 90 L / min, optionally between about 40 L / min and about 70 L / min. However, it should be understood that the first flow parameter may alternatively or additionally include pressure and / or volume parameters.

[0162] like Fig.14 As shown in , the second patient interface 220 is a non-sealed patient interface, shown as a nasal cannula 224 in fluid communication with the first conduit 210, while the first patient interface is a sealed patient interface, shown as a mask 124. Fig.15 In the embodiment, the nasal cannula 224 and the mask 124 are simultaneously applied to the patient, so that the device 1000 can be operated in a first mode to provide anesthetic ventilation, wherein the mask 124 is configured to seal on the nasal cannula 224 and the patient is 300. In this arrangement, gas is delivered to the patient via the first conduit 210, and exhaled gas from the patient is returned from the patient to the device 1000 via the mask 124 and the second conduit 130. Fig.14 In the second mode, only a non-sealed patient interface (e.g., nasal cannula 224) is applied to the patient to deliver gas to the patient's airway in the second mode, thereby providing high-flow respiratory support. In some embodiments, the second conduit 130 is not necessary or inoperable in the second mode.

[0163] In an alternative embodiment, gas may be delivered to the patient via the second conduit 130 and mask 124, and exhaled gas from the patient returned from the patient to the apparatus 1000 via the nasal cannula 224 and the first conduit 210. In such an embodiment, the second conduit 130 is an inspiratory conduit and the first conduit 210 is an expiratory conduit.

[0164] Advantageously, if Fig.14 As illustrated in , physically applying a sealing mask 124 to a non-sealing cannula 224 provides a gas flow path between the cannula and the mask using the patient's own airway. This enables breathing gases to be provided via an inspiratory conduit, and exhaled gases to be removed via an expiratory conduit, without the use of a Y-connector typically used to re-breath a patient circuit to couple the inspiratory and expiratory limbs. Moreover, removal of the mask 124 leaves the cannula 224 in place, ready to provide respiratory support in a second mode of operation without the need to apply another patient interface to the patient. The reduction in components due to the elimination of the Y-connector and the simplification of components and patient intervention steps can save costs and time and simplify aspects of the anesthesia protocol.

[0165] Fig.16 An arrangement for operation of the device 1000 in a third mode is provided. In the third mode, ventilation rebreathing is delivered by the endotracheal tube 126. Here, the first conduit 210 has been separated from the nasal cannula 224 and coupled to the inlet of the coupling 620. Similarly, the second conduit 130 has been separated from the mask 124 and coupled to the outlet of the coupling 620. The patient end of the coupling 620 has been connected to the endotracheal tube 126, thereby providing the functions of both the first and second patient interfaces in the third mode. In some embodiments, the endotracheal tube 126 can be another type of patient interface, such as a laryngeal mask airway or a tracheostomy interface or a mask. In the third mode, gas can be delivered to the patient, including a third flow parameter, which can include one or more of a flow rate, a pressure or a volume parameter. Although not shown in the figure, it should be understood that during the operation of the device in the third mode using an endotracheal tube, a laryngeal mask airway or a tracheostomy interface, the second patient interface 220 including the nasal cannula 224 can remain in place on the patient, but disconnected from the first conduit 210. This may be beneficial as it enables the user to easily switch between the third and first breathing support modes and / or the third and second breathing support modes.

[0166] According to about Figures 14 to 16 An advantage of the mode switching of the described example is that several modes of breathing support can be provided to a patient using a single inspiratory conduit and a single expiratory conduit. This reduces the cost and complexity of the breathing circuit used to treat the patient.

[0167] Fig.17is a schematic diagram of a novel connector 1700 that can be used to facilitate interchange of components for delivering respiratory support in first and second modes, as shown in FIG. Figures 14 to 16 The connector 1700 is configured to couple with a standard Y-connector 1750. In normal use, the Y-connector 1750 is configured to couple with a catheter at port 1755, thereby providing a Fig.14 and Fig.15 A mask 124 of the type shown in FIG. 1 provides a flow of breathing gas. A Y-connector 1750 receives the flow of gas from the first conduit 210 and provides an outflow path for exhaled gas from the patient via the second conduit 130. Fig.15 In use, the mask 124 forms a sealed interface with the patient's airway to deliver gases, which may include anesthetic agents, via the nasal cannula 224 while returning exhaled gases to the device 1000 via the mask 124 and the second conduit 130.

[0168] To facilitate interoperability between different patient interfaces, a novel connector 1700 may be used that provides a wall 1720 that is configured to protrude into a Y-shaped connector 1750. When connected, the wall 1720 separates the flow in the inspiratory and expiratory flows into separate branches 1710 and 1730. In use, the connector 1700 is configured to couple the first branch 1710 with a conduit attached to the nasal cannula 224, and is configured to couple the second branch 1730 with a conduit attached to the mask 124. Due to the dividing wall 1720, the inspiratory flow (see Fig.14 , Fig.15 ) and from the mask 124 (when in Fig.15 In order to quickly switch to the patient interface required for delivery support in the third mode, connector 1700 can be removed from Y-connector 1750, which is coupled to endotracheal tube 126. Advantageously, connector 1700 can be used to simultaneously couple and disconnect Y-connector 1750 to nasal cannula 224 and mask 124, and quickly connect endotracheal tube 126 with fewer disconnections / reconnections of parts and reduced potential for error. When switching back to the first support mode, mask 124 is configured to seal on nasal cannula 224 (such as Fig.15 ), the endotracheal tube 126 is decoupled from the Y-connector 1750 and the connector 1700 is reconnected, while the first and second conduits 210 , 130 are connected to the cannula 224 and the mask 124 .

[0169] Fig.18 It is for Fig.151800, which replaces the standard Y-connector 1750. Using the connector 1800, the mask 124 can be used to remove exhaled gas via the second conduit 130. For operation in the first mode ( Fig.15 ), connector 1800 can remain in position connected between mask 124 and second conduit 130, but separated from first conduit 210, which is coupled to nasal cannula 224. For inspiratory flow in first conduit 210, one-way valve 1810 is biased toward mask 124, operating to prevent exhaled gas in the mask from being discharged to the atmosphere, because no inspiratory conduit is attached to connector 1800 in this operating mode. To operate in the third mode ( Fig.16 ), the first conduit 210 can be reconnected to the connector 1800, and the mask 124 can be decoupled and replaced with a connection to the endotracheal tube 126. An advantage of this arrangement is that the connector 1800 can be used to deliver Fig. 9 and Fig.10 The two respiratory support modes shown in , while avoiding the need to disconnect and reconnect the second conduit 130 required to remove the gas, as is required with a standard Y-connector.

[0170] Fig.19 1 is a schematic diagram of another novel connector 1900 used in an embodiment configured as a nasal cannula 224 for delivering different respiratory support modes. The connector 1900 can be coupled with three conduits to provide fluid communication with each of the first inspiratory gas flow path 210A, the second inspiratory gas flow path 210B, and the expiratory gas flow path 130, the first inspiratory gas flow path 210A being configured to provide a gas flow for delivering nasal high-flow respiratory support; the second inspiratory gas flow path 210B being configured to provide a gas flow for delivering anesthetic ventilation; and the expiratory gas flow path 130 being used to discharge exhaled gas from the patient. When a different support mode is selected, a switch 1910 (e.g., a switching valve, a solenoid, etc.) is provided to change the internal flow path of the connector 1900. When the nasal cannula 224 is used to deliver anesthetic rebreathing, the switch 1910 is in the position shown in solid lines, thereby allowing the delivery of respiratory gas (including anesthetic agent) from the second inspiratory gas flow path 210B and providing access to the expiratory gas 130. During manual rebreathing, a bag mask may be applied to the nasal cannula 124 and sufficient pressure applied (e.g., by a clinical caregiver) so that the cannula can provide both inspiratory and expiratory flow paths. In high flow respiratory support, the switch 1910 is in the position shown in broken lines (diagonal position). The switch 1910 may be operably linked with other switch elements in the device 1000 operated by a user (or a device controller 1010 having a user interface 1094) to configure the device to operate in different support modes.

[0171] Fig. 20 and Fig.21 As Fig.19 Schematic diagram of connectors 1950A, 1950B of a variation of connector 1900 in FIG. 1 , wherein connections are provided to both the nasal cannula 224 and the mask 124. When switch 1910 is in the broken (diagonal) position, this connector 1950A, 1950B provides for nasal high flow delivery. When switch 1910 is in the solid (vertical) position, anesthesia rebreathing can be provided through the cannula 224, and exhaled gases can be removed by applying the mask 124, and the device is arranged as shown in FIG. Fig.15 as shown in . Fig. 20 Connector 1950A is shown with all flow paths located in one integral connector block. Fig.21 Connector 1950B is shown, which includes an inspiratory flow path with connection for the nasal cannula 124, and a separate conduit for providing a second (expiratory) conduit 130 attached to the mask 124.

[0172] Can be used with Figures 14 to 16 The device 1000 for use with the patient interface shown in can include a controller 1010 in communication with the flow source / modulator 250, and one or more sensors and / or user interfaces in communication with the controller to provide input to the controller to control the flow source / modulator to provide a flow of gas in the first or second mode. The sensors and / or user interface can also be configured to provide input to the controller to control the flow source / modulator to provide a flow of gas in a third mode.

[0173] It should be understood that the terms "first", "second", and "third" are used merely as labels to designate features of the present disclosure and should not be considered descriptive. Thus, reference to a "second" feature does not necessarily require the provision of such a "first" feature, and reference to a "third" feature does not necessarily require the provision of such features as "first" and "second". For example, providing a second patient interface (which may be a high flow patient interface) in the present disclosure does not require the provision of a first patient interface (which may be a rebreathing patient interface).

[0174] advantage

[0175] Embodiments of the present disclosure provide a device that can deliver high-flow respiratory support and rebreathing respiratory support for delivery of anesthesia and / or ventilation, and enables easy switching between these respiratory support modes. That is, embodiments of the present disclosure allow clinicians to easily switch between the deployment of high-flow respiratory support and rebreathing respiratory support to induce / ventilate patients. This reduces the total number of components, simplifies the work environment, and makes it easier for anesthesiologists to perform required tasks during procedures involving high-flow therapy or respiratory support in addition to administering anesthesia. This can be beneficial, for example, when preparing to intubate a patient or when weaning a patient from sedation. This arrangement can conveniently place user-controlled features for delivering high-flow respiratory support together with user-controlled features for delivering sedation or deep anesthesia. The embodiments disclosed herein can also simplify and reduce the instruments and catheters that take up valuable space in a clinical environment.

[0176] When switching from rebreathing mode to high flow mode, it is desirable to transition to stop the delivery of anesthetic gas for safety reasons. Uncontrolled delivery of O2 outside of the first gas flow path (e.g., when the mask is removed from the patient) may pose a fire risk and may waste anesthetic gas, as well as accidental release of anesthetic gas into the surgical environment, which may not only contaminate the high flow respiratory support gas, but also affect the performance of individuals in the surgical environment. Embodiments of the present invention may address one or more of these issues.

[0177] Also described herein are various embodiments, devices, connectors, assemblies, accessories, equipment, etc., for implementing switching between respiratory support modes. Some of these provide the convenience of controlling mode selection and / or displaying the operating mode when the user is not at the "machine". Some embodiments automatically select the operating mode by monitoring gas characteristics (such as gas pressure, O2 and CO2 concentrations in exhaled gas). These features not only improve the convenience and operability of the equipment providing these respiratory support modes, but also have the ability to improve patient safety.

[0178] It should be understood that various modifications, additions and / or substitutions may be made to the parts previously described, without departing from the scope of the invention as defined in the accompanying provisional claims.

[0179] The invention may also be broadly said to consist of the parts, elements and features mentioned or indicated, individually or collectively, in the specification of the present application, and of any or all combinations of two or more of the parts, elements or features. In the foregoing description, reference has been made to integers or components having known equivalents, which integers are incorporated herein as if individually set forth.

[0180] When any or all terms "including" or "comprising" are used in this specification (including the provisional claims), they should be interpreted as specifying the presence of stated features, integers, steps or components, but not excluding the presence of one or more other features, integers, steps or components, or groups thereof.

[0181] Future patent applications may be filed based on or claim priority from this application. It should be understood that the following claims are provided by way of example only and are not intended to limit the scope of what may be claimed in future applications. Features may be added to or deleted from the provisional claims at a later time to further define or redefine one or more inventions.

Claims

1. A device for providing respiratory support to a patient, the device comprising: (a) a first gas flow path; (b) a second gas flow path; (c) a first gas port configured to receive gas from any one of the first gas flow path and the second gas flow path; as well as (d) a switching mechanism operable to switch flow to the first gas port between a first gas flow path and a second gas flow path; The gas from the first gas port is provided to the patient for respiratory support.

2. The apparatus of claim 1, wherein operation of the switching mechanism to allow flow from one of the gas flow paths to the first gas port prevents flow from another of the gas flow paths to the first gas port.

3. An apparatus according to claim 1 or claim 2, wherein the first gas port is coupleable to a first conduit for providing gas to a patient through a second patient interface.

4. The apparatus of any preceding claim, comprising a second gas port coupleable to a second conduit configured to receive exhaled gas from the patient.

5. The device of claim 4, further comprising a first patient interface configured to receive exhaled gas from the patient for return to the device via the second conduit.

6. The apparatus of claim 5, wherein applying the first patient interface to the patient causes the switching mechanism to allow flow from the first gas flow path to the first gas port.

7. An apparatus according to claim 5 or claim 6, wherein application of the first patient interface to the patient is determined by detecting an increase in one or more parameters of gas in an expiratory gas flow path between the first patient interface and the apparatus, the parameters being selected from gas pressure, CO2, O2, flow rate, temperature and humidity.

8. The apparatus of claim 7, wherein the first patient interface comprises one or more sensors configured to determine when the first patient interface has been applied to the patient.

9. The apparatus of claim 8, wherein the one or more sensors of the first patient interface include one or more of an optical sensor, a proximity sensor, and a thermal sensor.

10. Apparatus according to any one of claims 5 to 9, wherein the first patient interface is a mask.

11. The apparatus of claim 10, wherein the mask comprises a sealing cuff having a sensor for determining pressure within the cuff, and wherein application of the mask to the patient is determined by an increase in cuff pressure.

12. The apparatus according to any one of claims 5 to 11, comprising an endotracheal tube (ETT) or a laryngeal mask airway (LMA), which can be coupled to the first conduit and the second conduit via a Y-connector and used as both the first patient interface and the second patient interface.

13. The device of claim 12, wherein the device is configurable for use as a ventilator.

14. The apparatus of any one of claims 5 to 13, wherein removal of the first patient interface from the patient causes the switching mechanism to allow flow from the second gas flow path to the first gas port.

15. Apparatus according to any one of the preceding claims, wherein When gas flows from the second gas flow path to the first gas port, the device is operable to provide gas to the patient through the second patient interface, which is a non-sealing patient interface.

16. The apparatus of claim 15, wherein the non-sealing patient interface is a nasal cannula.

17. The apparatus of any preceding claim, wherein the switching mechanism comprises a switching element configured to prevent flow from the flow source to the other gas flow path when the switching mechanism operates to allow flow from one of the gas flow paths to the first gas port.

18. An apparatus according to any of the preceding claims, wherein the switching mechanism includes one or more valves located upstream of the joint between the first gas flow path and the second gas flow path, and when the switching mechanism is operated to allow flow from one of the gas flow paths to the first gas port, the valve prevents backflow in the other gas flow path.

19. An apparatus according to any of the preceding claims, wherein the switching mechanism is operably coupled to one or more flow meters, the flow meters being configured to stop the flow of gas to a gas flow path that does not provide a flow of gas to the first gas port based on operation of the switching mechanism.

20. The apparatus of any preceding claim, wherein the switching mechanism is operably coupled to one or more flow meters operable to control a flow of gas to a gas flow path that provides a flow of gas to the first gas port in accordance with operation of the switching mechanism.

21. An apparatus according to any of the preceding claims, wherein the switching mechanism is operably coupled to one or more flow meters, the flow meters being operable to control a gas flow to a gas flow path, the gas flow path providing a flow of gas to a first gas port in accordance with operation of the switching mechanism, wherein the one or more fixed flow meters control the gas flow at one or more preset gas flow rates.

22. Apparatus according to any preceding claim, comprising a controller in operable communication with the switching mechanism and operable to control the apparatus to deliver respiratory support to the patient.

23. The apparatus of claim 22, wherein the controller receives input from one or more sensors for determining whether the first patient interface has been applied to the patient.

24. The apparatus of claim 23, wherein: After determining that the first patient interface has been applied to the patient, the controller automatically controls the device to provide respiratory support in a first mode; as well as After determining that the first patient interface has been removed from the patient, the controller automatically controls the device to provide respiratory support in the second mode.

25. An apparatus according to claim 23 or claim 24, wherein the controller receives input from one or more sensors located at one or more locations selected from: In the inspiratory flow path that delivers gas to the patient; in the device between the first gas port and a junction in the device where return gas meets a fresh gas supply; in the expiratory flow path that returns gas from the patient to the device; in the device between a second gas port for receiving return gas from the patient and the connector; and In the gas flow downstream of the flow generator or flow mixer of the device.

26. The apparatus of claim 25, wherein the one or more sensors are of a sensor type selected from a pressure sensor, a flow rate sensor, and an O2 sensor.

27. The apparatus of any one of claims 23 to 26, wherein the controller receives input from one or more CO2 sensors located at one or more locations selected from: an expiratory flow path that returns gas from the patient to the device; and In an apparatus having a rebreathing circuit and a CO2 absorber, in the apparatus between a second gas port receiving return gas from the patient and the CO2 absorber.

28. The apparatus of claim 26, wherein the controller determines that the one or more locations containing a CO2 concentration greater than ambient air are associated with a patient interface applied to the patient.

29. The apparatus of any one of claims 24 to 25, wherein the controller receives input from a plurality of sensors to determine whether the first patient interface has been applied to the patient to mitigate erroneous switching between the first mode and the second mode.

30. An apparatus according to any one of claims 23 to 26, wherein a controller controls the apparatus to provide respiratory support with a signature flow element, and wherein the controller looks for the signature flow element in the returning gas to determine that the first patient interface has been applied to the patient, and optionally wherein the signature flow element includes oscillations of one or more of the frequency, amplitude and curve of one or more of the pressure, flow rate and O2 concentration of the gas provided to the patient.

31. An apparatus according to any one of claims 24 to 29, wherein the controller receives sensor signals from one or more sensors, the one or more sensors comprising one or more pressure and / or flow rate and / or gas concentration sensors in the inspiratory flow path and / or the expiratory flow path to control the switch from the second mode to the first mode, and optionally wherein the same or different one or more sensor signals can be received by the controller to control the switch from the first mode to the second mode.

32. The apparatus of claim 30, wherein the controller is configurable to require that more sensor conditions be met before switching from the first mode to the second mode, or vice versa.

33. An apparatus according to any one of claims 23 to 32, wherein a controller controls the apparatus to provide a residual flow of gas in one or both of the first gas flow path and the second gas flow path for continuous or periodic monitoring of the gas, and optionally wherein the residual flow is from about 0.5 L / min to about 5 L / min.

34. Apparatus according to any preceding claim, comprising one or more sensors for sensing one or more characteristics of the gas selected from the group consisting of: pressure, flow rate and gas species concentration.

35. An apparatus as claimed in any one of claims 24 to 34, wherein the controller applies a timing control, wherein after detecting a condition that should trigger a mode switch, the controller applies a delay before controlling the switching element to cause the mode switch.

36. A device according to claim 35, wherein the controller controls the user interface to provide one or more of an audible and visual countdown indicator of when the controller will switch control of the device between the first mode and the second mode, and optionally wherein the controller is configured to abandon automatic switching between modes after receiving user input for cancellation during a delay period.

37. An apparatus according to any of the preceding claims, wherein a controller controls a user interface to provide one or both of an audible and a visual mode indication representing a current operating mode of the apparatus, and optionally wherein the user interface includes one or more audible and / or visual output elements located on, at or near the gas conduit or patient interface and providing the mode indication.

38. Apparatus according to any one of claims 22 to 37, comprising a user interface in operable communication with the controller and configured to receive input from a user corresponding to one or more parameters of respiratory support to be provided to the patient.

39. The apparatus of claim 38, wherein the parameters include one or more parameters for a rebreathing mode of respiratory support and / or a high flow mode of respiratory support.

40. Apparatus according to claim 38 or claim 39, wherein the parameters include one or more of the flow rate, composition, pressure, temperature and humidity of the gas to be provided to the patient.

41. The apparatus of any one of claims 22 to 40, wherein the controller is configured to receive a user input causing the switching mechanism to switch flow to the first gas port between the first gas flow path and the second gas flow path.

42. The apparatus of claim 41, wherein the user input is received from one or more of: (a) Touch screen display; (b) a remote unit coupled by wire or wirelessly; (c) a foot-operated pedal or switch; and (d) A physical switch provided on the equipment.

43. The apparatus of any one of claims 5 to 42 when appended to claim 4, wherein the first gas flow path comprises a rebreathing gas flow path that receives and processes exhaled gas returned from the patient.

44. Apparatus according to claim 43, wherein the apparatus is operable to provide one or both of anaesthesia and ventilation breathing support via a rebreathing gas flow pathway.

45. The apparatus of any preceding claim, wherein the second gas flow path comprises a high flow gas flow path.

46. ​​The apparatus of any of the preceding claims, wherein the first gas port is a common gas outlet port coupleable to a first conduit for delivering gas from either the first gas flow path or the second gas flow path to the patient.

47. Apparatus according to any preceding claim, comprising a housing in which a first gas flow path and a second gas flow path are provided, the housing providing a first gas coupling defining a first gas port to which the first conduit is coupleable.

48. The apparatus of any preceding claim, comprising a humidifier configured to condition gas to a predetermined temperature and / or humidity prior to delivery to the patient via one or both of the first gas flow path and the second gas flow path.

49. Apparatus according to any preceding claim, operable to provide a flow of gas in the second gas flow path at a flow rate selectable from a usable range of about 20 L / min to about 100 L / min.

50. Apparatus according to any one of claims 1 to 48 operable to provide a flow of gas in the second flow path at a flow rate selectable from a plurality of available fixed flow rates including at least 0 L / min, 40 L / min and 70 L / min.

51. Apparatus as claimed in claim 49 or claim 50 comprising a flow source configured to generate a flow of gas in the second gas flow path.

52. Apparatus according to any one of claims 5 to 51 when appended to claim 4, comprising a CO2 absorber configured to process exhaled gas returning from the patient in the first gas flow path.

53. The apparatus of any preceding claim, comprising one or more of the following features in the first gas flow path: (a) a pressure limiting valve configured to maintain a substantially constant pressure in a first gas flow path; (b) a variable volume for displacing gas in the first gas flow path; (c) a supplemental gas flow for supplementing anesthetic gas delivered to the patient in the first gas flow path; (d) Gas mixers; (e) a vaporizer for vaporizing a volatile anesthetic into the gas in the first gas flow path; and (f) a flow rate limiter configured to limit flow in the first gas flow path to approximately 15 L / min.

54. Apparatus according to any preceding claim, comprising one or more gas supply ports configured to receive a supply of one or both of: (a) a breathing gas for delivery to a patient via a first gas flow path or a second gas flow path; and (b) An anesthetic gas for delivery to a patient via a first gas flow path.

55. The apparatus of any one of claims 5 to 54 when appended to claim 4, configured to operate in the following modes: (a) a rebreathing mode, in which gas flows from a first gas flow path to a first gas port and is provided to a patient, and exhaled patient gas is returned to the device via a second gas port; and (b) High flow mode, in which gas flows from the second gas flow path to the first gas port and is provided to the patient, and exhaled patient gas is not returned to the device.

56. The apparatus of claim 55, wherein the rebreathing mode comprises an anesthesia rebreathing mode for providing anesthesia to the patient.

57. An apparatus according to claim 55 or claim 56, configured for a ventilation rebreathing mode, wherein gas flows from a first gas flow path to a first gas port and is provided to a patient through an ETT or LMA, and exhaled patient gas returns to the apparatus from the ETT or LMA via a second gas port.

58. An apparatus for providing respiratory support to a patient, the apparatus comprising: - a first gas flow path; - a second gas flow path; - a first gas port configured to receive gas from any one of the first gas flow path and the second gas flow path; as well as - a switching mechanism operable to switch flow to the first gas port between a first gas flow path and a second gas flow path; wherein gas from the first gas port is provided to the patient for respiratory support; and wherein the apparatus comprises a controller configured to receive input from one or more sensors for determining whether a condition exists to trigger switching of flow to the first gas port between the first gas flow path and the second gas flow path, wherein the one or more sensors are provided in one or more locations selected from the group consisting of: - in the inspiratory flow path for supplying gas to a patient; - between the first gas port in the device and the junction where the return gas in the device meets the fresh gas supply; - in the expiratory flow path returning gas from the patient to the device; - in the device between a second gas port receiving return gas from the patient and the connector; and - In the gas flow downstream of a flow generator or flow mixer of the device.

59. The apparatus of claim 58, wherein the apparatus comprises a second gas port configured to receive gas returned from the patient, and the condition comprises the controller determining whether a sealed patient interface in fluid communication with the second gas port is applied to the patient.

60. An apparatus for providing respiratory support to a patient, the apparatus comprising: - a first gas flow path; - a second gas flow path; - a first gas port configured to receive gas from any one of the first gas flow path and the second gas flow path; as well as - a switching mechanism operable to switch flow to the first gas port between a first gas flow path and a second gas flow path; wherein gas from the first gas port is provided to the patient for respiratory support; and Wherein the device includes a controller configured to control the device to provide respiratory support having a signature flow element, and wherein the controller looks for the signature flow element in gas returning to the device from the patient to determine whether a patient interface has been applied to the patient.

61. The apparatus of claim 60, wherein the signature flow elements include oscillations of one or more of frequency, amplitude, and curve of one or more of pressure, flow rate, and O2 concentration of the gas provided to the patient.

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