Aerosol high flow therapy apparatus

Abstract

A patient interface (1) for aerosol therapy has a base (2) for surrounding the mouth and nose of a patient and engaging in a resilient seal with the skin and a strap (8) for attaching to the head of the patient. The base has a cradle (3) on and across the base for supporting an aerosol delivery head with cannulae (4, 5). An enclosed volume is formed in the interface by attachment of a housing (10) having a draw port (11) for attachment of a draw system (20) to draw gas from the volume. The HFNT system comprises a patient interface around the nose and mouth and an aerosol delivery device (4, 6), a draw device (20) and a controller (100) for controlling delivery of aerosol and / or gas to the interface and for drawing gas from the volume enclosed by the interface. Because of the fully sealed volume within the interface, various control schemes are possible with the use of pressure sensing devices within the volume, bypass valves (201), dynamically controllable nebulizers (203).

Description

Technical Field

[0001] This invention relates to aerosol therapy, particularly high-flow aerosol therapy. Background Technology

[0002] High-flow nasal therapy (HFNT) typically delivers an air / oxygen / aerosol mixture to the patient at a rate exceeding the patient's peak inspiratory rate. An example is a treatment control of 50 LPM with an average inspiratory rate of approximately 20 LPM (averaged over one inspiratory cycle), having a peak inspiratory rate of approximately 35 LPM. The aerosol delivered in the high-flow stream will be evenly distributed. Therefore, excess airflow contains aerosolized drug that the patient cannot absorb, leading to reduced efficiency. Furthermore, this excess can be dispersed into the surrounding room air. This is escape emission, which can potentially expose clinicians, patients, and visitors to aerosolized drug and patient-generated pathogens.

[0003] Additionally, during exhalation (usually through the mouth), high-flow therapy may continue to be delivered into the nasal cavity. A portion of this flow will enter the cavity and flow out of the patient's mouth, increasing the expiratory airflow rate and potentially collecting pathogens from the patient. The remaining flow will exit the cavity through the nostrils, but it may also collect pathogens before that.

[0004] WO2015 / 155342A (Stamford Devices Ltd) and WO2019 / 007950A (Stamford Devices Ltd) describe an HFNT system in which aerosol is primarily delivered during periods of reduced gas flow to improve efficiency and reduce losses. US2012 / 285455 (Varga et al.) describes a mask for patient ventilation. US2004 / 244799 (Landis) describes a tube-sealing adapter for a mask. WO2018 / 204969 (P&M Hebbard PTY) describes a sealing pad for a respiratory mask. WO2019 / 159063 (Fisher & Paykel) describes a mask mounted on a nasal cannula interface.

[0005] This invention solves the problem of achieving effective aerosol therapy with reduced or eliminated gas loss, especially for high-flow therapy. Summary of the Invention

[0006] We describe a patient interface for aerosol therapy, comprising a base configured to surround at least a portion of a patient's mouth and nose and engaging with the skin in a resilient, sealing manner. The base preferably has a support for supporting the aerosol or gas delivery head. Additionally, it preferably has a housing configured to form an enclosure together with the base. An extraction port may be provided for attaching an extraction system to extract gas from the volume during use.

[0007] In some examples, the base is annular and is constructed to completely surround the patient's mouth and nose. In some examples, the base includes a spine with an inner soft layer for attaching to the patient's face. In some examples, a support is attached to the spine.

[0008] In some examples, the support extends across the base at or near its center to divide the base in two. In some examples, the support includes an opening for receiving a nasal cannula for the aerosol delivery head. In some examples, the housing has at least one opening for the aerosol delivery tube. In some examples, the housing includes a pair of openings to allow connection of the aerosol head to either side. In some examples, the housing includes a sealing element to close any unused openings. In some examples, the housing is configured to engage with the base.

[0009] Preferably, the extraction port is located approximately at the center of the base for alignment with the patient's mouth during use. Preferably, the interface further includes a pressure sensor. In some examples, the pressure sensor is mounted on the housing. In some examples, the housing includes at least one vent.

[0010] We also describe an aerosol therapy system comprising a patient interface for covering a patient's mouth and nose, and a high-flow therapy system connected to a mask. In some examples, the system further includes an aerosol delivery device, an extraction device, and a controller configured to control the delivery of aerosol and / or gas to the interface and to extract gas from a volume surrounded by the interface. In some examples, the high-flow therapy system is a high-flow nasal therapy system (HFNT).

[0011] In some examples, the system includes sensors for detecting patient breathing, and a controller is configured to provide a delivery of synchronized breathing. In some examples, the system includes a heater and a humidifier, used separately or in combination, to provide a heated and humidified air / O2 mixture delivered to the interface.

[0012] Preferably, the system includes a valve configured to split the delivery flow into an aerosol branch with an atomizer and a parallel bypass branch, and these branches merge into a common duct leading to an interface.

[0013] Preferably, the controller is configured to dynamically control the system to provide solutions including some or all of the following:

[0014] Complete bypass;

[0015] No bypass, continuous aerosol delivery;

[0016] No bypass, respiratory-synchronized aerosol delivery based on signals from pressure sensors within the volume enclosed by the interface; and / or

[0017] A synchroscopic bypass shunts airway during expiration; continuous aerosol generation allows aerosols to accumulate in the lumen and shunt airway flow during inspiration to increase aerosol concentration.

[0018] Preferably, the aerosol generator includes a cavity with increased volume to slow the delivery flow rate. Preferably, the controller is configured to provide slowed aerosol delivery. Preferably, the controller is configured to reduce the gas flow rate and increase aerosol delivery during inhalation to improve dosing efficiency.

[0019] Preferably, the controller is configured to provide a sufficiently short period of reduced flow rate to prevent a de-recruitment effect. Preferably, the controller is configured to provide dynamic extraction based on monitoring of the pressure within the interface volume.

[0020] Preferably, the controller is configured to adapt to baseline aspiration to match high-flow treatment settings and dynamically change the aspiration rate to match the patient's breathing pattern.

[0021] Preferably, the suction device includes a filter. Preferably, the filter is adapted to capture pathogens or drugs before they are released into the environment.

[0022] Preferably, the controller is configured to increase the power supplied to the extraction source to maintain a consistent extraction flow rate as the filter approaches saturation.

[0023] Preferably, the suction device includes a condenser for removing vapor from the extracted gas, preferably before it reaches a filter. Preferably, the condenser is included in a heat pump, wherein the collected heat is used to heat the flow rate delivered to the patient.

[0024] Aerosol therapy systems may include interfaces for any of the examples described above. Attached Figure Description

[0025] The invention will be more clearly understood from the following description of some embodiments of the invention, given by way of example only with reference to the accompanying drawings, wherein:

[0026] Figures 1 to 4These are perspective views of a high-flow aerosol mask being applied in four steps;

[0027] Figure 5 This is a diagram showing the position of the mask on a model patient's head used for testing;

[0028] Figure 6 It shows the use of Figure 5 The device and the stage test results of particle number versus time determined by an aerodynamic particle analyzer for 50 LPM high-flow-rate treatment, and, Figure 7 This is a curve showing the particle measurement values ​​versus time in a staged test, applicable to various high flow rates, and also used for... Figure 5 The apparatus, and in this case, the curves for higher-level extractions from 70 to 135 LPM are shown in more detail;

[0029] Figure 8 The curve used for this device shows the relationship between the percentage of captured particles and the extraction flow rate.

[0030] Figure 9 The fluid flow rate detected by the imaging sensor is shown, and the volumetric velocity within the mask is illustrated by encoding for nominal mask fit, low-mask fit, and closed mask fit.

[0031] Figure 10 It is used for Figure 5 The device shown also includes a set of curves showing the extraction flow rate of the nasal pressure sensor changing over time.

[0032] Figure 11 It is a bar chart showing the peak nasal pressure during opening and closing of the suction, and Figure 12 It is a bar chart showing the minimum nasal pressure when opening and closing the suction.

[0033] Figure 13 It is shown Figures 1 to 4 A diagram showing the mask and controller in place together;

[0034] Figure 14 This is a flow diagram illustrating how flow rate reduction is achieved during inhalation and how the flow rate bypasses the edge of the aerosol chamber during inhalation.

[0035] Figure 15 These are a pair of curves illustrating dynamic extraction and pressure monitoring, showing the relationship between extraction and respiratory flow, where extraction is matched to aerosol flow; and

[0036] Figure 16It is a schematic diagram showing the flow of humidified and heated air and O2 toward the mask and the dried, drawn-out humid air, which is dried along the extraction direction by means of a heat recovery condenser and a heat exchanger that recovers heat for humidification. Detailed Implementation

[0037] Reference Figure 1 The patient interface 1 includes an annular, flexible, sealing base 2, configured for fitment around the patient's mouth and nose, and having a large contact surface of an elastic material suitable for skin contact. The base 2 has a relatively rigid core, which is surrounded at least on the patient side by a flexible material for contact with the patient's face. A spinal support cannula receiver 3 extends across the base 2 and is made of a robust, strong plastic material to support the attachment of a nasal cannula tip 4 with a cannula 4 at the end of a tube 6 for delivering high-flow-rate gas and aerosol into the nostrils.

[0038] Figure 2 The interface also includes a housing 10, which engages with the base 2 and the bracket 3 in a sealing manner to form a closed volume around the patient's mouth and nose area. Figure 3 The extraction head 20 is shown, which has an L-shaped tube 21 with a flange 22 configured to fit into a cylindrical port 11 of the housing.

[0039] Figure 4 The complete interface 1 is shown, with all these components in place, along with the lead 25 of the pressure sensor from within the volume formed by the base 2 and the housing 10. The pressure sensor is attached to the inner surface of the housing 10.

[0040] The patient interface is modular, with a flexible, sealing base 2 attached to the patient's head using a headband 8. A support 3 supports the cannula tip 4 to ensure proper alignment of the cannula 5. It is conceivable that in other embodiments, the cannula support would be self-supporting via the headband, rather than being attached to the flexible, sealing base, particularly for use without removal.

[0041] First, the soft sealing base 2 is placed on the face, creating a comfortable sealing surface. This establishes an airtight seal and provides support for the high-flow treatment tubing, allowing clinicians to easily and accurately insert the nasal cannula 3, which is secured to the soft sealing base 2. The fit of the cannula 5 can be checked and adjusted.

[0042] The housing 10 can now be assembled. The periphery of the housing 10 abuts against the base, allowing it to self-position and form a seal. The flexible sealing base 2 provides a means of securing the housing 10 in place via, for example, elastic bands, hook-and-loop fasteners, or clips. Preferably, the housing engages via a snap-fit ​​connection with resilient edges. The contours of the housing 10, the nasal cannula 4 / 5, and the flexible sealing base 2 are designed to allow the high-flow treatment tube and head 4 to enter from either the left or right side, while still establishing a seal without requiring additional components. In another embodiment, an additional cover feature may be provided.

[0043] The housing 10 preferably includes one or more vents to prevent excessive negative pressure drop due to suction within the volume formed by the base 2 and the housing 10. These vents are located away from the mouth and nostrils in the expiratory / exhaustive airflow. The housing 10 has a port 11 for attaching a suction device, in this case, a suction head 20. The suction port 11 is positioned such that, during use, it is opposite the mouth and nostrils for optimal collection of exhaled / exhausted gases and particles. One or more vents may not be within the mask itself and may be, for example, part of the exhalation tubing. The advantage of the vents is that, because the mask seals the space around the nose and mouth very effectively, the operation of high-flow and forced-exhaust systems does not make the system too disruptive by effectively functioning like a ventilator, where all inhalation and exhalation are controlled. For example, very soft openings may be present on inhalation valves that do not affect breathing, and / or on pressure relief valves that ensure safety in the event of reduced suction. The vent can be equipped with a suitable filter to prevent unwanted droplets from flowing out, thus avoiding environmental pollution.

[0044] The housing also has a retainer for attaching a sensor that measures the pressure inside the mask.

[0045] Figures 6 to 8 It shows the use of Figure 5 The mask and system shown are tested for environmental aerosol particles in the environment surrounding the patient's head. This mask is conventional in how it is configured for contact with the face; it is simply a flexible, transparent polymer with openings to accommodate the delivery and extraction tubing for the HFNT. It does not have… Figures 1 to 4 The advantages of face masks.

[0046] Figure 6 This indicates that an extraction flow rate in the range of 80 LPM to 100 LPM is required to capture almost all aerosol particles; in these examples, the treatment used 50 LPM. Figure 6 The main differences between the ranges of 7-135 LPM, 40 LPM, and no extraction are shown. In the latter, there is essentially no difference in the presence or absence of a mask due to loss around the edge of the mask. Figure 7 More details are shown for the higher extraction rate range, displayed on the vertical axis in terms of percentage per cm. 3 Several dozen particles. Figure 9 The bar chart provides a general overview, showing a linear relationship between the extraction flow rate and the percentage of particles captured, with complete capture achieved at an extraction rate of approximately 90 LPM.

[0047] For a given aspiration rate, the position of the aspiration port opposite the patient's mouth affects the excrement capture rate. Figure 9 In the medium, the "low blend" was superior to the "nominal blend" in capturing emissions (94.8% vs. 88.7%). For a given extraction rate, the degree of seal between the mask and face affects the emission capture rate. Figure 9 In the comparison, the "closed fit" is the same as the "low fit," except that there is a seal at the cheek. At the same extraction level (60 LPM) and the same emission flow rate (50 LPM, no breathing in this example), the "closed fit" is superior to the "low fit" in terms of emission capture (97.7% vs. 94.8%).

[0048] The effects of sampling on the nasal cavity have been investigated. The experimental setup is as follows: Figure 5 As shown, but with the addition of a nasal pressure sensor, involving:

[0049] High flow rate for humidification at 50 LPM

[0050] Insert the pressure tube into the nasal cavity

[0051] Extraction flow rate off or at 100 LPM

[0052] The flow meter is consistent with the extraction source.

[0053] The results are shown in Figures 10 to 12 The figure shows the distribution of peak nasal pressures during exhalation with and without suction. With suction, the average difference decreased by 0.3 mBar; the maximum difference was 0.53 mBar.

[0054] Figure 12 The distribution of nasal pressure troughs (which occur during inspiration) is shown with and without suction. The mean difference decreased by 0.68 mBar when suction was applied; the minimum difference was also 0.68 mBar.

[0055] These results demonstrate the advantages of reducing suction during exhalation and eliminating suction during inhalation.

[0056] The main advantages of this invention include:

[0057] The flexible patient-contact side of base 2 provides a consistent seal, which in particular allows for successful aspiration at lower flow rates.

[0058] Predictable sealing allows for a smaller safety margin buffer on the application's extraction rate.

[0059] Less extraction allows for less pressure drop, less noise, more extraction source options, and controlled vents.

[0060] Maximize suction at a given suction flow rate.

[0061] Avoid biting the patient's face.

[0062] Reduced wind noise / wind feel

[0063] The dimensions can be determined to mitigate the pressure drop in a predictable manner.

[0064] Modular design allows the base to be mounted to the head without compromising the treatment's ability to adjust for a secure seal and comfort.

[0065] Allows for clinical intervention to set / inspect / change cannulas.

[0066] Pressure port.

[0067] A device for measuring the pressure inside a face mask.

[0068] It can be used as a security measure.

[0069] It can be used to detect respiration and dynamically control the suction rate.

[0070] This allows for more efficient extraction while minimizing the impact on pressure drop.

[0071] like Figure 13 As shown, patient interface 1 can be connected to a separate aerosol / high-flow therapy device 100 via tubing 101. This allows for slowed aerosol delivery with synchronized breathing. Figure 14 As shown, a heated and humidified air / O2 mixture is supplied to pipe 200, and the flow rate is split by valve 201 into an aerosol branch 202 with atomizer 203 and a parallel bypass branch 204. These branches merge into a common pipe 205, which leads to interface 1.

[0072] In some examples, the aerosol delivery path may include an aerosol chamber with an increased volume to slow the flow rate at the aerosol delivery point.

[0073] Bypass scheme

[0074] Valve 201 can dynamically throttle the flow rate and dynamically split the flow rate to provide the following solutions:

[0075] Complete bypass, normal high-flow therapy, no aerosols.

[0076] No bypass, open throttling, continuous aerosol delivery.

[0077] No bypass, open throttling, respiratory-synchronized aerosol delivery (pressure sensor used to detect breathing pattern).

[0078] Synchronized Breathing Bypass: During expiration, flow is shunted through the bypass. The nebulizer remains on to allow aerosol buildup within the chamber. During inhalation, flow is shunted through the chamber to increase aerosol concentration.

[0079] Slow down delivery

[0080] Slowing down aerosol delivery: When switching to aerosol path 202 during inhalation, the average flow rate decreases. This effectively increases the dose. The time period for reducing the flow rate is short to prevent de-recruitment effect. The reduced flow rate has a gradient / rise, and these gradients can be controlled / adjusted to minimize de-recruitment and discomfort.

[0081] Dynamic extraction / stress monitoring

[0082] The system controller can adjust the baseline extraction to accommodate high-flow treatment settings. For example... Figure 15 As shown, the controller can be programmed to dynamically change the extraction rate to match the breathing pattern. This maximizes the effectiveness of the extraction, thereby reducing the required extraction rate. The benefit of this is reduced stress on the treatment process and also reduced requirements on the extraction source.

[0083] filter

[0084] An advantageous component of the extraction system is a filter that is synchronized with the extracted airflow to capture any pathogens or drugs before they are released into the ambient room. This can be a standard commercial filter that can be replaced by a clinician. Due to the high humidity levels in the exhaust gas, the filter will become saturated, and its operating conditions will adjust accordingly. The system can determine the actual flow rate based on pressure readings from the mask. Alternatively, additional flow and pressure sensors can be incorporated into the system side of the filter. As the filter approaches saturation, the system can increase the power supplied to the extraction source to maintain a consistent extraction flow rate.

[0085] Condenser

[0086] A condenser can be used to remove vapor from the extracted gas before it reaches the filter. This can extend the filter's lifespan. The condensation mechanism is preferably such that the surfaces in contact with the extracted gas are part of a single-use loop. Figure 16As shown, a heat pump (e.g., using a Peltier heat exchanger) can be used to increase the condensation rate. The heat collected in this exchange can be used to heat the high-flow-rate treatment delivered to the patient. This will have energy-saving benefits.

[0087] Escape emissions of no treatment drugs

[0088] Do not spread the patient's pathogens

[0089] Improve drug efficiency

[0090] Increase drug rate

[0091] This invention is not limited to the described embodiments, but can be varied in structure and details. For example, it is envisioned that the mask be provided as a pre-assembled component, perhaps using a size chart, to allow clinicians to pre-configure and position the nasal cannula. If the mask does not have a removable housing, it can have an inlet baffle to allow adjustment of the nasal cannula. The performance features and advantages described for interfaces with conventional characteristics are applicable to... Figures 1 to 4 The interface, and due to the reference Figures 1 to 4 The enhanced sealing and other advantages described are expected to result in better performance. Regardless of the interface used, any interface that supports HFNT delivery and extraction and provides a closed or near-closed environment around the mouth and nose is advantageous, as referenced above. Figures 5 to 12 As described in 14 to 16, and in use Figures 1 to 4 With the interface of 13, it enhances the sealing of this volume around the nose and mouth.

Claims

1. An aerosol therapy system, comprising: A patient interface for covering a patient's mouth and nose, a high-flow treatment system connected to the patient interface, and a controller, characterized in that the aerosol treatment system further includes: A heater and a humidifier, which are used independently or in combination to provide a heated and humidified air / O2 mixture (200) supplied to the interface (1). A valve (201) is configured to split the delivery flow into an aerosol branch (202) with an atomizer (203) and a parallel bypass branch (204), and these branches merge into a common pipe (205) leading to the interface (1). Sensors are used to detect a patient's breathing, and the controller is configured to provide a breath-synchronized delivery. It includes an aerosol generator with a cavity that increases volume, an aerosol delivery device (4, 6), an extraction device (20), and a controller (100). The controller is configured to control the delivery of aerosols and / or gases to the interface and to extract gases from the volume surrounded by the interface, in order to dynamically control the system to provide one or more of the following: Complete bypass; No bypass, enabling continuous aerosol delivery; No bypass, aerosol delivery for respiratory synchronization based on signals from a pressure sensor within the volume surrounded by the interface; and / or A breathing-synchronized bypass through which flow is shunted during exhalation; continuous aerosol generation allows aerosol accumulation in the cavity, and during inhalation, a flow rate is shunted through the cavity to slow the delivery flow rate and increase the aerosol concentration.

2. The aerosol therapy system according to claim 1, characterized in that, The high-flow treatment system is a high-flow nasal treatment system (HFNT).

3. The aerosol therapy system according to claim 1 or 2, characterized in that, The controller is configured to provide slowed aerosol delivery.

4. The aerosol therapy system according to claim 3, characterized in that, The controller is configured to reduce gas flow rate and increase aerosol delivery during inhalation to improve dosage efficiency.

5. The aerosol therapy system according to claim 4, characterized in that, The controller is configured to provide a period of reduced flow rate that is short enough to prevent a reduction effect.

6. The aerosol therapy system according to claim 1 or 2, characterized in that, The controller is configured to provide dynamic extraction based on monitoring of the pressure within the interface volume.

7. The aerosol therapy system according to claim 6, characterized in that, The controller is configured to adapt to baseline extraction to match high-flow treatment settings and dynamically change the extraction rate to match the patient's breathing pattern.

8. The aerosol therapy system according to claim 1 or 2, characterized in that, The extraction device includes a filter.

9. The aerosol therapy system according to claim 8, characterized in that, The filter is adapted to capture pathogens or drugs before they are released into the environment.

10. The aerosol therapy system according to claim 1 or 2, characterized in that, The controller is configured to increase the power supplied to the extraction source to maintain a consistent extraction flow rate as the filter approaches saturation.

11. The aerosol therapy system according to claim 1 or 2, characterized in that, The extraction device includes a condenser to remove vapor from the extracted gas before it reaches the filter.

12. The aerosol therapy system according to claim 11, characterized in that, The condenser is included in a heat pump, and the heat collected in the heat pump is used to heat the airflow delivered to the patient.

13. The aerosol therapy system according to claim 1 or 2, characterized in that, The patient interface includes: A base (2) is constructed to at least surround the patient's mouth and nose and to be joined to the skin in an elastic seal. The bracket (3) on the base is used to support the aerosol or gas delivery head. Construct a housing (10) for forming an enclosure together with the base, and An extraction port (11) is used for attaching to the extraction system to extract gas from the volume during use.

Images